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              1992)





                                  NOAA STATUS AND TRENDS
                                               Mussel Watch Project
                                           Year 6 Technical Report


                                                                The Geochemical and
                                                                Environmental Research Group
                                                                Texas A&M Research Foundation







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                                                                December 1992






              NOAA
              STATUS AND TRENDS

              Mussel Watch Project

              Year 6 Technical Report

                                              r
                                                Property of CSC Library

              Prepared by

              The Geochemical and Environmental Research
              Group
              Texas A&M University
              833 Graham Road
              College Station, Texas 77845



              Submitted to

            jiU.S. Department of Commerce
              National Oceanic & Atmospheric Administration
              Ocean Assessment Division
              6001 Executive Blvd., Rin 323
              Rockville, Maryland 20852

              December 1992                              U . S . DEPARTMENT 01F COMMERCE NOAA
                                                         COASTAL SERVICES CENTER
                                                         2234 SOUTH HOBSON AVENUE
                                                         CHARLESTON , SC 29405-2413










                                                                                     TABLE oF CoNTENTs



                         1.0 EXECUTIVE SUMMARY                                           ............................................................................    1-1

                                      REPRINT 1: Processes Controlling Temporal Trends in
                                             Gutf of Mexico Oyster Health and Contaminant
                                             Concentrations                  ........................................................................................    1-9


                                      REPRINT 2: International Mussel Watch: the Initial
                                             Implementation Phase                            ......................................................................   1-17

                         2.0          INTRODUCMON                    ...........................................................................................         2-1

                                      2.1 Project Relevance and Direction                                               ...............................................  2-1
                                      2.2 Study Objectives                             ...............................................................................   2-4

                         3.0          POLYNUCLEAR AROMATIC HYDROCARBON RESULTS                                                                           ............... 3-1

                                      REPRINT 3: Trace Organic Contamination in Galveston
                                             Bay: Results from the NOAA National Status and Trends
                                             Mussel Watch Program                             .....................................................................   3-33

                                      REPRINT 4: Toxic Contamination of Aquatic Organisms in
                                             Galveston Bay               .....................................................   . .................................  3-37

                                      REPRINT 5: Transplanted Oysters as Sentinel Organisms
                                             in Monitoring Studies                          .......................................................................   3-41

                                      REPRINT 6: The Effects of the Apex Barge Oil Spill on the
                                             F1.sh ofGah@esbn Bay                   .........................................................................         3-43

                                      PREPRINT 1:                          Polynuclear Aromatic Hydrocarbon
                                             Contaminants in Oysters from the Gutf of Mexico (1986-
                                             1990)         .......................................................................................................    3-47

                                      PREPRINT 2: Sources of Local Variation in Polynuclear
                                             Aromatic Hydrocarbon and Pesticide Body Burden                                                             .............. 3-85

                         4.0 CBLOR1XATED 11YDROCARBONS                                                  ..........................................................       4-1

                                      REPRINT 5: Chlorinated Hydrocarbons in Gu!f of Mexico
                                             Oysters: Overview of the FIrst Four Years of the NOAA's
                                             National Status and Trends Mussel Watch Program
                                             (1986-1989)                  .........................................................................................   4-21

                                      PREPRINT 3: National Status and Trends Mussel Watch
                                             Program: Chlordane-Related Compounds in Gutf of
                                             Mexico Oysters, 1986-1989                                   ...........................................................  4-39











                                PREPRINT 4: Concurrent Chemical and Historical
                                     Analyses: Are They Compatible?                          .................................................. 4-61

                                PREPRINT 5: Environmental Significance of the Uptake
                                     and Depuration of Planar PCB Congeners by the
                                     American Oyster (Crassostrea virginica)                      .................................... 4-61

                      5.0       TRACE METALS RESULTS                           ...................................................................... 5-1

                                5. 1 Laboratory Intercalibration Results                     .............................................. 5-1
                                5.2 Muce Metals in Year 6 Oysters                     ...................................................... 5-1
                                5.3 Summary and Conclusions from Six Years of Trace
                                       Metals in Oysters Data             ....................................I ................................. 5-6

                                REPRINT 8: T@-ace Metals in Galveston Bay Oysters                                   .................. 5-21

                     6.0        BUTYLTIN RESULTS                .................................................................................. 6-1

                                PREPRINT 6:, Butyltin Concentrations on Oysters from the
                                     Gulf of Mexko during 1989-1991                   ................................................... 6-5

                      7.0       BIOLOGICAL RESULTS                      .............................................................................. 7-1

                                7.1         Condition Index/Shell Length                        ................................................. 7-1
                                7.2         Gonadal/Somatic Index                    .............................................................. 7-1
                                7.3         Long-Term Changes                  ..................................................................... 7-3

                                PREPRINT 7: Spatial and Temporal Distributions of
                                     Contaminant Body Burden and Disease in Guff of Mexico
                                     Oyster Populations: The Role of Local and Large-Scale
                                     Climatic Conbuls         ................................................................................ 7-21









                                         1.0 Executive Summary


                       The purpose of the Mussel Watch Project is to determine the
                 long-term temporal and spatial trends of selected environmental
                 contaminant concentrations in bays and estuaries. The key questions
                 in this regard are: (1) What is the current condition of the nation's
                 coastal zone?; and (2) Are these conditions getting better or worse?
                 This report contains the first six years of data from a multi-year
                 project. The first question has been addressed in detail as evidenced
                 by the scientific papers and reports (Table 1.1) that have resulted
                 from the Geochemical and Environmental Research Group's (GERG)
                 interpretations of the Gulf Coast data. Publications not included in
                 GERG's Year 4 or 5 Technical Report are appended to the appropriate
                 sections.

                       This report is an estimate of the current condition of the Gulf of
                 Mexico coastal zone, based on results from Years I thru 6 of the NOAA
                 Mussel Watch Project. Following is a brief sampling survey of these
                 years:

                        Year I  - 51 sites (153 stations) - sediments and oysters
                        Year 2  - 49 sites (147 stations) - sediments and oysters
                        Year 3  - 65 sites - oysters. Sediments at new sites only.
                        Year 4  - 67 sites - oysters. Sediments at new sites only.
                                  (the 67 sites.were sampled in 26 days.)
                        Year 5  - 71 sites - oysters. Sediments at new sites only.
                        Year 6  - 64 sites - oysters. Sediments at new sites only.

                       Year 6 sites included the original list of sites sampled in Years 1
                 and 2, some sites first sampled in Year 3, seven new sites'sampled for
                 the first time in Year 4, four new sites sampled in Year 5 and two new
                 sites in year 6. Sediments and oysters were collected from all but one
                 of the new sites for Years 4, 5 and 6 sites. Eleven sites were deleted
                 from those sampled in previous years. Three of the Texas sites, which
                 had no oysters in Year 3 due to the freshwater-induced die-off, again
                 had no oysters for collection in Year 4. These sites were in San
                 Antonio and Espiritu Santo Bays (SAPP, SAMP, ESSP). Extensive effort
                 was made to sample the sites but only a few spat, too small and too few
                 for collection, were found.

                       Although a new site for Year 4 was designated in the lower
                 Laguna Madre at Arroyo Colorado, no oysters were found. Further
                 surveys around Port Mansfield also yielded no oysters. Thus, no
                 samples were collected at the new site designated in the lower Laguna
                 Madre.









                         Oysters from three stations were collected at all sites where
                   there were oysters except at the Pass A Loutre site on the Mississippi
                   River (MRPL). Two and a half hours of dredging did not provide
                   sufficient samples for three replicate sites of twenty individuals per
                   site. This low productivity, adverse and worsening weather, and one
                   total engine failure combined to result in a short site (not enough
                   replicates for all analyses). In Year 5, twelve sites were eliminated
                   from and five sites were added to the sampling project. In year 6, two
                   new sites were sampled. Details of the sample collection and location
                   of field sampling sites are contained in a separate report titled "Fleld
                   Sampling and Logistics".

                         The oyster and sediment samples were analyzed for contaminant
                   concentrations [trace metals, polynuclear aromatic hydrocarbons
                   (PAH), pesticides and PCBsJ, disease incidence and other parameters
                   that aid in the interpretation of contaminant distributions (grain size,
                   oyster size, lipid content, etc.). The analytical procedures used and
                   the QA/QC Project Plan are detailed in a separate report titled
                   "Analytical Methods". The data that was produced from the sample
                   analyses for Year 6 is found in a separate report titled "Analytical Data".

                         A complete and comprehensive interpretation of the data from
                   the Status and Trends Project for oyster data coupled. with the
                   sediment data is an ongoing process. We have begun and are
                   continuing that process as evidenced by this report and the scientific
                   manuscripts that we have published or submitted for publication
                   (Table 1.1). As part of the data interpretation and dissemination, over
                   forty presentations of the NOAA NS&T Gulf Coast Mussel Watch
                   Project were given at national as well as international meetings. With
                   six years of data, the question of temporal trends of contaminant
                   concentrations can be addressed. Detailed examinations of this
                   question are presented in individual sections of this report. A general
                   conclusion that is found for most contaminants measured is that the
                   concentrations have remained relatively constant over the six-year
                   sampling period (Reprint 1). This general trend, however, is not
                   observed at all sites. Some sites show significant changes (both
                   increases and decreases) between years (Reprint 1).              Continued
                   sampling will be required to determine the frequency and rates of
                   these changes.

                         Exceptions to this general trend are found for DDTs and TBT.
                   When historical data for DDT in bivalves is compared to current NS&T
                   data, a decrease in concentration is apparent. Also based on TBT data
                   collected as part of the NOAA NS&T Mussel Watch Project, a decline
                   in TBT concentration in oysters is apparent. Both declines may be in
                   response to regulatory actions.



                                                       1-2









                       During Year 3 of this project, sixteen additional sites were
                 sampled. These sites were chosen to be closer to urban areas, and
                 therefore to the sources of contaminant inputs. These sixteen new
                 sites were not, however. located near any known point sources of
                 contaminant input. These sites were added to better represent the
                 current status of contaminant concentrations in the Gulf of Mexico.
                 Generally the mean contaminant concentration at these new sites was
                 higher than the other 48 or 49 Gulf of Mexico sites.

                       While sampling sites for this project were specifically chosen to
                 avoid known point sources of contaminant input, the detection of
                 coprostanol in sediment from all sites indicates that the products of
                 man's activities have reached all of the sites sampled. However, when
                 compared to known point sources of contamination, all of the
                 contaminant concentrations reported are, in most cases, many orders
                 of magnitude lower than obviously contaminated areas. The lower
                 concentrations in Gulf of Mexico samples most -likely reflect the fact
                 that the sites are far removed from point sources of inputs, a condition
                 which is harder to achieve in East and West Coast estuaries. In fact,
                 new sites added in Years 3. 4, 5 and 6 to be closer to urban areas
                 generally had higher contaminant concentrations. An important
                 conclusion derived from the extensive NS&T data set is that
                 contamination levels in Gulf Coast Near Shore areas remain the same
                 or are getting better, and most areas removed from point sources are
                 not severely contaminated.

                       In addition to analyzing and synthesizing data from the Status
                 and Trends portion of the "International Mussel Watch," GERG was
                 also involved in its initiation. The objectives of that program, funded
                 by NOAA through UNEP/IOC, have been summarized in Reprint 2.

                       This document represents one of four report products as part of
                 Year 6 of the NS&T Gulf of Mexico projects. The other three reports
                 are entitled:

                       ï¿½ Analytical Methods
                       9 Analytical Data
                       ï¿½ Field Sampling and Logistics










                                                   1-3









                                                                                              t


                      Table 1.1 GERG/NOAA NS&T PUBLICATIONS                                       Included in
                                                                                                 Year Report

                      Wade, T.L., B. Garcia-Romero and J.M. Brooks (1988)
                             Tributyltin Contamination of Bivalves from U.S.
                             Coastal Estuaries. Environmental Science and                                                     01
                             Technology, 22:1488-1493.                                                   IV

                      Wade, T.L., E.L. Atlas, J.M. Brooks, M.C. Kennicutt H, R.G.
                             Fox, J. Sericano, B. Garcia-Romero and D. DeFreitas
                             (1988) NOAA Gulf of Mexico Status and Trends
                             Program: Trace Organic Contaminant Distribution
                             in Sediments and Oysters. Estuaries 11:171-179.                             IV                   01

                      Wade, T.L., B. Garcia-Romero and J.M. Brooks (1988)
                             Tributyltin analyses in association with NOAA's                                                  r
                             National Status and Trends Mussel Watch
                             Program. OCEANS '88 Conference Proceedings,
                             Baltimore, MD, 31 Oct. - 2 Nov. 1988, pp 1198-1201.                         IV

                      Wade, T.L., M.C. Kennicutt, H and J.M. Brooks (1989) Gulf of
                             Mexico Hydrocarbon Seep Communities:                     III:
                             Aromatic Hydrocarbon Burdens of Organisms
                             from Oil Seep Ecosystems. Marine Environmental
                             Research, 27:19-30.                                                         IV

                      Wade, T.L. and J.L. Sericano (1989) Trends in Organic                                                   01
                             Contaminant Distributions in Oysters from the
                             Gulf of Mexico. Proceedings, Oceans '89 Conference,
                             Seattle, WA, 585-589.                                                       IV                   -

                      Wade, T.L. and B. Garcia-Romero (1989) Status and Trends
                             of Tributyltin Contamination of Oysters and
                             Sediments from the Gulf of Mexico. Proceedings,
                             Oceans '89 Conference, Seattle, WA, 550-553.                                IV

                      Wade, T.L. and C.S. Giam (1989) Organic contaminants in
                             the Gulf of Mexico. In: Proceedings, 22nd Water for
                             Texas Conference, Oct. 19-21, 1988, South Shore Harbour
                             Resort and Conference Center, Uague City, TX (R. Jensen
                             and C. Dunagan, Eds.), pp. 25-30.                                             V

                      Craig, A., E.N. Powell, R.R. Fay and J.M. Brooks (1989)
                             Distribution of Perkinsus marinus in Gulf coast
                             oyster populations. Estuaries, 12:82-91.                                    IV

                      Presley, B.J., R.J. Taylor and P.N. Boothe (1990) Trace
                             Metals in Gulf of Mexico Oysters. The Science of the
                             Total Environment, 97/98, pp. 551-553.                                      IV






                                                                 1-4









                   Sericano, J.L., E.L. Atlas, T.L. Wade and J_M. Brooks.(1990)
                           NOAA's Status and Trends Mussel Watch
                           Program:     Chlorinated Pesticides and PCBs in
                           Oysters (Crassostrea virginica) and Sediments
                           from the Gulf of Mexico, 1986-1987Marine
                           Environmental Research 29:161-203.                                       IV

                   Wade, T.L., B. Garcia-Romero, and J.M. Brooks (1990)
                           Butyltins in Sediments and Bivalves from U.S.
                           CoastalAreas. Chemosphere 20:647-662.                                    IV

                   Brooks, J.M., M.C. Kennicutt II, T.L. Wade, A.D. Hart, G.J.
                           Denoux and T.J. McDonald (1990) Hydrocarbon
                           Distributions Around a Shallow Water Multimell
                           Platform. Environmental Science and Technology,
                           24:1079-1085.                                                            IV

                   Sericano, J.L., T.L. Wade, E.L. Atlas and J.M. Brooks (1990).
                           Historical Perspective on the Environmental
                           Bioavailability of DDT and Its Derivatives to Gulf
                           of Mexico Oysters. Environmental Science and
                           Technology, 24:1541-1548.                                                IV

                   Wade, T.L., J.L. Sericano, B. Garcia-Romero, J.M. Brooks, and
                           B.J. Presley (1990) Gulf Coast NOAA National
                           Status & Trends Mussel Watch: The First Four
                           Years, MTS'90 Conference Proceedings, Washington,
                           D.C., 26-28 September 1990, pp. 274-280.                              IV, V

                   Brooks, J.M., T.L. Wade, B.J. Presley, J.L. Sericano, T.J.
                           McDonald, T.J. Jackson, D.L. Wilkinson and T.F. Davis
                           (1991) Toxic Contamination of Aquatic Organisms
                           in Galveston Bay, Proceedings Galveston Bay
                           Characterization Workshop, February 21-23, 1991, pp. 65-
                           67.                                                                      VI

                   Wade,   T.L. J.M. Brooks, J.L. Sericano, T.J. McDonald, B.
                           Garcia-Romero, R.R. Fay, and D.L. Wilkinson (1991)
                           Trace Organic Contamination in Galveston Bay:
                           Results from the NOAA National Status and
                           Trends Mussel Watch Program, Proceedings
                           Galveston Bay Characterization Workshop, February 21-23,
                           1991, pp. 68-70.                                                         VI

                   Presley, B.J., R.J. Taylor and P.N. Boothe (1991) Trace
                           Metals in Galveston Bay Oysters, Proceedings
                           Galveston Bay Characterization Workshop, February 21-23,
                           1991, pp- 71-73.                                                         VI








                     Sericano, J.L., T.L. Wade and J.M. Brooks                  (1991)
                             Transplanted Oysters as Sentinel Organisms in
                             Monitoring Studies, Proceedings Galveston Bay
                             Characterization Workshop, February 21-23, 1991, pp. 74-
                             75.                                                                      VI

                     McDonald, S.J., J.M. Brooks, D. Wilkinson, T.L. Wade, and T.J.
                             McDonald (1991) The Effects of the Apex Barge Oil
                             Spill on the Fish of Galveston Bay, Proceedings
                             Galveston Bay Characterization Workshop, February 21-23,
                             1991, pp. 85-86.                                                         VI

                     Wade,   T.L., J.M. Brooks, M.C. Kennicutt 11, T.J. McDonald,
                             G.J. Denoux and T.J. Jackson (1991) Oysters as
                             Biomonitors of Oil in the Ocean. Proceedings 23rd
                             Annual Offshore Technology Conference (6529) (Houston,
                             TX, May 6-9, 199 1), p. 275-280.                                           V

                     Brooks, J.M., M.A. Champ, T.L. Wade, and S.J. McDonald
                             (1991) GEARS: Response Strategy for Oil and
                             Hazardous Spills. Sea Technology, April 1991, pp. 25-
                             32.                                                                        V

                     Sericano, J.L., T. L. Wade and J.M. Brooks (1991) Chlorinated
                             hydrocarbons in Gulf of Mexico oysters:
                             Overview of the first four years of the NOAA's
                             National Status and Trends Mussel Watch
                             Program (1986-1989) In: Water Pollution: Modelling,
                             Measuring and Pre&ction. Wrobel, L.C. and Brebbia, C.A_
                             (Eds.)    Computational Mechanics Publications,
                             Southampton, and Elsevier Applied Science, London. pp.
                             665-681.                                                               V'VI

                     Wade, T.L., B. Garcia-Romero, and J.M. Brooks (1991)
                             Bioavailability of butyltins. In: Organic Geochemistry
                             - Advances and applications in the natural environment.
                             Manning, D.A.C. (Ed.). Manchester University Press,
                             Manchester. pp. 571-573.                                                   V

                     Wilson, E.A., EX Powell, M.A. Craig, T.L. Wade and J.M.
                             Brooks (1991) The distribution of Perkinsus
                             marinus in Gulf coast oysters:         Its relationship
                             with temperature, reproduction and pollutant body
                             burden. Int. Reuve der Gesantan Hydrobioligie, 75:533-
                             550.                                                                     IV

                     Sericano, J.L., A.M. El-Husseini, and T.L. Wade (1991)
                             Isolation of planar polychlorinated biphenyls by
                             carbon column chromatography. Chemosphere,
                             23(7):915-924.                                                        V, VI

                     Wade, T.L., B. Garcia-Romero, and J.M. Brooks (1991)
                             Oysters as Biomonitors of Butyltins in the Gulf of
                             Mexico. Marine Environmental Research, 32:233-24 1.                      IV


                                                               1-6










                      Powell, W.N., J.D. Gauthier, E.A. Wilson, A. Nelson, R.R. Fay,
                             and J.M. Brooks (1992) Oyster disease and climate
                             change. Are yearly changes in Perkinsus marinus
                             parasitism in oysters (Crassostrea virginica)
                             controlled by climatic cycles in              the Gulf of
                             Mexico? PSZNI: Mar. EcoL (In Press).                                             IV

                      Sericano, J.L., T.L.'Wade, and J.M. Brooks            (1993) The
                             Usefulness        of Transplanted             Oysters        in
                             Biomonitoring Studies. Proceedings           of The Coastal
                             Society Twelfth International Conference, Oct. 21-24, 1990,
                             San Antonio, TX (In Press).                                                      V

                      Wade, T.L., J.L. Sericano, J_M. Brooks, and B.J. Presley (1993)
                             Overview of the First Four Years of the NOAA
                             National Status and Trends Mussel Watch
                             Program. Proceedings of The Coastal Society Twelfth
                             International Conference, Oct. 21-24, 1990 (San Antonio,
                             TX) (In Press).                                                                  V

                      Sericano, J.L., T.L. Wade, B. Garcia-Romero, and J.M. Brooks,
                             Environmental Accumulation and Depuration of
                             Tributyltin by the American Oyster, Crassostrea
                             virginica. Marine Biology (Submitted).                                           IV

                      Sedcano, J.L., T.L. Wade, E.N. Powell and J.M. Brooks,
                             Concurrent Chemical and Histological Analyses:
                             Are They Compatible? Chemistry and Ecology (in
                             press).                                                                       V'V1

                      Wilson, E.A., E.N. Powell, T.L. Wade, R.J. Taylor, B.J. Presley,
                             and J.M. Brooks, Spatial and Temporal Distributions
                             of Contaminant Body Burden and Disease in Gulf
                             of Mexico Oyster Populations: The Role of Local
                             and Large-Scale Climatic Controls. Helgol.
                             Meeresunters (in press).                                                         V

                      Sericano, J.L., T.L. Wade, J.M. Brooks, E.L. Atlas, R.R. Fay and
                             D.L. Wilkinson. National Status and Trends Mussel
                             Watch Program: Chlordane-related compounds in
                             Gulf of Mexico oysters: 1986-1990. Environmental
                             Pollution (in press).                                                         V'V1

                      Hofmann, E.E., J.M. Klinck, E.N. Powell, S. Boyles, M. Ellis.
                             Modeling oyster populations 11. Adult size and
                             reproductive effort. (in preparation).                                           V

                      Hofmann, E.E., E.N. Powell, J.M. Klinck, E.A. Wilson.
                             Modeling oyster populations 111. Critical feeding
                             periods, growth and reproduction. (in preparation).                              V





                                                                  1-7









                       Jackson, T.J., T.L. Wade, T.J. McDonald, D.L. Wilkinson and
                              J.M. Brooks. Polynuclear Aromatic Hydrocarbon                                                   OF
                              Contaminants in Oysters from the Gulf of Mexico
                              (1986-1990) Environmental Pollution (in press).                              vi

                                                                                                                              01
                       Sericano, J.L., T.L. Wade, A.M. El-Husseini and J.M. Brooks.
                              Environmental significance of the uptake and
                              depuration, of planar PCB congeners by the
                              American oyster (Crassostrea virginica). Marine
                              Pollution Bulletin (inpress).                                                VI

                       Wade, T.L., E.N. Powell, T.J. Jackson and J.M. Brooks (1992)
                              Processes Controlling Temporal Trends in Gulf of
                              Mexico Oyster Health and Contaminant
                              Concentrations. Proceedings MTS '92, Marine
                              Technology Society, Oct. 19-21, 1992, Washington, D.C.
                              223-229.                                                                     VI

                       Ellis, M.S., K.-S. Choi, T.L. Wade, E-N. Powell, T.J. Jackson
                              and D.H. Lewis. Sources of local variation in
                              polynuclear aromatic hydrocarbon and pesticide
                              body burden in oysters (Crassostrea virginica)
                              from Galveston Bay, Texas. Estuaries (Submitted).                            V1

                       Tripp, B.W., J.W. Farrington, E-D. Goldberg, and J.L. Sericano
                              (1992) International Mussel Watch: the initial
                              implementation phase. Marine Pollution Bulletin,
                              24:371-373.                                                                  VI

                       Garcia-Romero, B., T.L. Wade, G.G. Salata, and J.M. Brooks.
                              Butyltin concentrations in oysters from the Gulf
                              of Mexico during 1989-1991. Environmental Pollution
                              (in press).                                                                  VI





















                                                                  1-8






















                                      Reprint 1


           Processes Controlling Temporal Trends in Gulf of Mexico Oyster
                       Health and Contaminant Concentrations


             Terry L. Wade, Eric N. Powell, Thomas J. Jackson, and James M. Brooks





                 PROCESSES CONTROLLING TEMPORAL TRENDS IN GULF OF
             ME)GCO OYSTER HEALTH AND CONTAMINANT CONCENTRATioNs

                 Terry L. Wade. Eric N. Powell, Thomas J_ Jackson and James M. Brooks
                             Geochemical and Environmental Research Group
                                           Texas A&M University
                                             833 Graham Road
                                     College Station, TX 77845 USA


                                                        recently summarized in a worldwide
                        ABSTRACT                        mussel watch literature survey (1). The
                                                        NS&T program has already provided a
           The concentrations of PAIL DDT, PCB,         good description of the current status
           dieldrin and chlordane in Gulf of            of selected contaminants in bivalves
           Mexico oysters as cumulative % for five      and sediments (2.3,4,5,6) from U. S.
           consecutive years are discussed. Gulf-       coastal areas.
           wide changes in contaminant                  The continued collection of data will
           concentrations are observed. PAH and         allow for the resolution of possible
           DDT co-vary while PCB has a different        temporal trends in the contaminant
           distribution. The body burden of PAH         concentrations. The objective of this
           and pesticides in oysters is correlated      paper is to examine polynuclear
           with latitude.     Available evidence-
           suggest a linkage between oyster             aromatic hydrocarbon (PAH), selected
           health     '(infection      intensity),      pesticides, and polychlorinated
           reproductive effort and contaminant          biphenyl (PCB) data for the first five
           body burden. Analyses of oyster              years of the NS&T Gulf of Mexico
           gonadal material confirms the                program for temporal trends and to
           reproductive process can purge               summarize correlations between oyster
           contaminants from oysters, which             health and contaminant concentra-
           confounds        interpretation       o f    tions. These trends will continue to be
           contaminant body burden data.                reassessed as additionial years of data
                     INTRODUCTION                       become available.
                                                                      METHODS
           The National Status and Trends
           (NS&T) Mussel Watch Program was              The collection and analytical
           instituted in 1986/87 by the                 techniques used have been described
           National Oceanic and Atmospheric             elsewhere (3,6) and will only be briefly
           Administration (NOAA). The purpose           described here. Homogenized oyster
           of this program is to determine the          tissue is extracted with CH2C12 in the
           current status and long-term trends of       presence     of NA2SO4 (to remove
           selected contaminants in U.S. coastal        water). The pesticide/ PCB/ PAH are
           waters using bivalves as sentinel            isolated from other organic materials
           organisms. This approach has been            using silica gel/alumina column
           used successfully in the past as             chromatography and high performance







                                                     1-10





           liquid chromatography with phenogel           The distributions of the PAH/PCB and
           columns. The purified samples are             pesticide concentrati6ns are described
           then. analyzed by gas chromatography          by a lognormal distribution, Le. the
           with a mass selective detection for PAH       distribution of data is skewed to low
           and an electron capture detector for          concentrations and has a fraction
           pesticides/ PCBs. The accuracy and            which extends to high concentrations.
           precision of these methods have been          The lognormal distribution. typical of
           established by several intercalibration       environmental data. has been used (2)
           exercises overseen by the U.S. National       to define "high" concentrations as
           Institute of Standards and Technology.        those with logarithmic values more
           These intercalibrations document the          than the mean plus one standard
           comparability of the data between             deviation of the logarithms for all
           sampling years and between partici-           concentrations.
           pating analytical laboratories.               Distribution functions are useful
                                                         measures of environmental quality
             RESULTS AND DISCUSSION                      data in that changes with time can be
                                                         determined without being influenced
           The geographical distributions 'of            by "outliers". For the cumulative
           PAH/ PCB /pesticides for the most             distribution plot, the data -are -sorted
           southern Texas site and continuing to         from lowest value to highest value.
           the most southern Florida site have           similar to rank transformation (10).
           been reported (3,4,5,6). . In general,        Each observation is 1/n fraction of the
           no consistent temporal trends in              data set, where n ds the number of
           concentration have been observed for          samples in the data set.. Te sum of
           most contaminants measured as part            the fraction of samples less than the
           of the NS&T program (4). with the             concentration is plotted against-    -the
           exception of tributyltin which has            concentration. From this plot the
           decreased from 1989 to the present            median can be determined, since it is
           (7).                                          defined as the 50th percentile. The
                                                         interquatrile range (IQR) is usedas a
           Bar graphs (5) or crossplots (4) of data      measure of variability@ The IQR is the
           comparing one year's data versus              75th percentile minus the 25th
           another have been used to display the         percentile and equals 1.35 times the
           general trend for PAH/PCB and-                standard deviation for a -normal
           pesticide data (4,5,8). The variations        distribution (11).
           in concentration for a particular site
           are easily visualized using these data        The cumulative % distribution for
           presentations. However, a cumulative          DDTs is shown in Figure 1. Similar
           frequency function can be used                distribution plots were made for all the
           to examine the heterogeneous                  contaminants measured, but their
           distribution of contaminants in Gulf of       distributions will only be summarized
           Mexico oysters (9). This approach has         here. All of the DDT plots are smooth
           the advantage of examining the Gulf of        "S" shaped curves, indicating the log
           Mexico as a single environmental              data is a normal distribution. There is
           system, determining the percentage of         a slight decrease in DDT in Year 2 at
           sites exposed to a particular threshold       lower concentrations compared to Year
           concentration, and providing informa-         1. but almost identical distributions
           tion for environmental evaluation.            at higher concentrations.            The







                                            YFAR I                                                          YEAR2
                          120---                                                          120-


                          100---                                                          100-


                          so-                   ----------------                          80-


                          60-                                                             60

                                           - - ---------------
                          40-                                                             40           FE

                          20                                                              20


                          0                                                               0
                           1         10        100      1000       10000                  1         10       100       1000     10000
                                      TOTAL DDrS (ng/gl                                              TOTAL DDrS (Wgo,


                                             MAR 3                                                         YEAR 4

                          120-                                                            120-


                          100-                                                            100-


                          80-                                                             so--
                          60-                                                                              ff

                                          IF              I
                          40-                                                             40--


                          20                                                              20--


                                                                                          0
                          0
                          .1        10        100       1000      10000                   1         10       100       1000      10000
                                      TOTAL DDrS (ndgi                                               TOTAL DDrS (W&J




                                            YEAR 5                                                     YEAR 4 AND 5
                          120-                                                            120


                          100-                                                            100
                10                                                             .40
                          so-                                                             so-


                          60-                                                             60-
                                         Ae
                          40--                                                 :D         40-


                                                                                          20



                                     10        100       1000      10000
                                                                                          1        10       100       1000      10000
                                      TOTAL DDTS (ag/gI                                            TOTAL DDrS (agl&j


                                         Figure 1. Cumulative percent of total DDT (ng/g).
                                                                                                              row





































































                                                                           1-12





         distribution for Years 3 and 4 indicates                          YEAR
         increased concentrations throughout                 0.0    1.0  2.0 13.0    4@O
         the entire Gulf of Menxico. In Year 5 a          10001:_
         return to a similar distribution to that
         seen in Years I and 2 was observed. It       _t@b
         I easier to see changes between years
         when the plots can be superimposed.                    13   PAH
                                                            100
         The last graph in Figure 1 shows DDTs        0
         for Years 4 and 5 on the same plot- It                      PCB
         is easy to see that both are normal
                                                                     DDT
         distributions, but Year 4 (farthest from     Z
                                                      W
         the right) had higher concentrations         0      10
                                                      :;_1           CHLO .LNE
         throughout the entire Gulf.                  0
                                                                     DIE@@RIN
         Because of space limitations. not all of
         the distributions are presented here.               1
         However, the geometric median of the
         distributions for PAH, PCB. DDT,             Figure 2.   Median vs. year.
         chlordane and dieldrin are plotted vs.
         sampling year in Figure 2. This figure
         summarizes the distributions as seen
         from comparison of the DDT
         distribution in Figure I to the DDT
         plot in Figure 2. In Figure 2 the            The NS&T program was designed to
         geometric mean concentration for DDT         address the question of temporal
         decreases slightly between Years I and       trends in the contaminant loadings of
         2, increases in Years 3 and 4 and is         U. S. coastal waters. Examination of
         back to concentrations similar to Years      the first five years of data indicates
         I and 2 in Year 5. This was expected.        that for the entire Gulf of Mexico
         based on Figure 1. The distribution          contaminant concentrations appear to
         for the total of the 18 PAHs measured        be remaining relatively constant.
         as part of the NS&T program shows            However, there are yearly fluctuations
         the same distribution as the DDT             above      and below this "normal
         (Figure 2). The PAH distribution has         concentration". These concordant
         been described in detail (12).. The          Gulf-wide fluctuations suggest that
         other contaminant classes displayed          climatic factors exert a strong
         different distributions. Total PCBs          influence on contaminant body
         distribution for the Gulf of Mexico had      burdens and on biological attributes of
         a slight decrease between Year I and         oysters (13).
         Year 2, then a steady increase from
         Year 2 to Year 5. It therefore appears       The NS&T program was not designed
         that the PCBs have different source          to answer the question of what effect
         functions than the DDTs and PAHs.            the contaminant loading has on the
         The dieldrin and chlordane concen-           health of oysters. The program does,
         trations change little between the           however, measure several indicators of
         years, except for the possibility of a       oyster health, including condition
         slight decrease over the five years of       index.     disease incidence and
         sampling.                                    reproductive stage.     Since the NS&T








                                                     1-13





            study was not designed to answer              reduce reproductive    'effort (24). In
            these. questions. they can not be             oysters, both reproductive rate and
            answered rigorously with the data             disease are significantly effected by
            available, but can be partially               temperature and salinity (25) and
            answered.                                     thus could serve as important
                                                          intermediaries between climate change
            Biological and   environmental factors        and contaminant body burden.
            may effect the rate and extent of
            bioaccumulation. These biological             Recently, newly developed techniques
            factors include differential growth rate      have enabled us to determine t        "he
            (14,15). reproductive stage (14,16,17),       concentration of organic contaminants
            stress and disease (18,19.20). These          in oyster gonadal tissues (26). These
            biological factors make spatial and           analyses revealed that eggs and sperm
            temporal comparisons designed to              are enriched in PAH and PCB
            evaluate the status and trends of             compared to somatic tissue. Eggs. but
            contaminant loading more difficult.           not sperm, were enriched in DI)Ts and
                                                          chlordane. Dieldrin was not detected
            Analysis of the first four years of NS&T      in these oyster samples. This evidence
            data has shown that the body burden           indicates that the frequency of
            of polynticlear aromatic hydrocarbons         spawning and timing of oyster
            (PAHs) and pesticides in oysters is           collection during their spawning cycle
            correlated with latitude in the Gulf of       may effect body burden of
            Mexico. Wilson et al. (21) suggested          contaminants. These processes may
            that the latitudinal temperature              explain the latitudinal gradient in PAH
            gradient in the Gulf produced variation       and pesticide body burdens observed
            in reproductive effort and that this          for the Gulf -of Mexico (2 1) and the
            variation in reproductive effort effected     relationship of PAH body burden and.
            PAH body. burden sufficiently to              climate change.
            override the effect of local variation in
            contaminant loading in many cases.            These complexities as oysters . makes
            Wilson et al. (13). in a more thorough        interpretation of NS&T data - a
            analysis, showed that PAH body                challenge. The more we can learn
            burden responds to climate change             about the NS&T sentinel organisms,
            and that biological factors. climate's        C.virginim the more likely we will be
            effect on temperature, and freshwater         able to meet that challenge..
            inflow may effect the final body burden
            of PAHs.
            Likely biological factors are                         ACKNOWLEDGMENTS
            reproduction and disease (Perkinsus           This research was supported       by the
            marinus) infection intensity.                 National Oceanic and Atmospheric
            Reproduction has frequently been              Administration         (NOAA),       U.S.
            suggested as an important route of            Department of Commerce, Grants
            depuration (22) because lipid loss            50-DGNC-5-00262 and 50-DGNC-0-
            peaks at this time.       Parasites and       00047 from the Office of Ocean
            pathogens are less frequently                 Resources       Conservation         and
            implicated (23). but parasites and            Assessment.
            pathogens should have an effect: if for
            no other reason, they frequently







                                                       1-14





                        REFERENCES                             Gulf of Me-xico. t Marine Envtron.
                                                               Res., 32.1991. pp. 233-241.
           1.   Cantillo, A. Y.     Mussel Watch
                worldwide literature survey.              8-   Wade. T. L_ Brooks. J. M..
                NOAA Technical Memorandum                      Kennicutt 11. M. C.. Denoux, G.J.
                NOS ORCA 63, 1991, 136 p.                      and Jackson. T. J. Oysters as
                                                               Biomonitors of Oil in the Ocean.
           2.   O'Connor, T. P.             Coastal            Proceedings of the 23rd Annual
                Environmental Quality in the                   Offshore Technology Conference,
                United States. 1990. Chemical                  OTC 6529. 199 1. pp. 275-280.
                Contamination in Sediment and
                Tissues. A Special NOAA 20th              9.   Mackay, D. and Paterson. S.
                Anniversary Report, 1990. 34 p.                Spatial concentration distri-
                                                               butions. Environ. Sci. TechnoL,
           3.   Wade, T. L., Atlas, E. L.. Brooks.             18, 1984, pp. 207A-214A_
                J. M., Kennicutt 11, M. C.. Fox, R.
                G., Sericano. J., Garcia-Romero.          10.  Conover. W. J. and Iman. R_ L.
                B. and Defreitas, D. A. NOAA Gulf              Rank Transformations as a Bridge
                of Mexico Status and Trends                    between Parametric and Non-
                Program: Trace organic contam-                 parametric Statistics. Arneri.
                inant distribution in sediments                Statistic@ 35, 1981.pp. 124-129.
                and oysters. Estuaries, 11. 1988.
                pp. 171-179.                              11.  Hensel, D. R_ Less than obvious.
                                                               Statistical treatment of data below
           4.   Wade, T.L. @   and Sericano. J_                the detection limit. Environ. ScL
                Trends in Organic Contaminant                  TechnoL.24,1990, pp. 1766-1774.
                Distributions in Oysters from the
                Gulf of Mexico. Oceans '89                12.  Jackson. T.J., Wade. T. L..
                Proceedings, 1989. pp. 585-589.                McDonald. T.J., Wilkinson, D. L.
                                                               and Brooks. J. M. Polynuclear
           5.   Wade, T. L., -Sericano, J. L.,                 Aromatic           Hydrocarbon
                Garcia-Romero, B., Brooks, J. M.               Contaminants in Oysters from the
                and Presley, B. J. Gulf Coast                  Gulf of Mexico (1986-1990).
                NOAA National Status & Trends                  Environmental Pollution (in press).
                Mussel Watch: The, First Four
                Years. Proc. Mar. TeclL Soc., 1990,       13.  Wilson, E.A.. Powell, E.N., Wade.
                pp. 274-280.                                   T. L_ Taylor, R. J., Presley, B.J.
                                                               and Brooks, J.M. Spatial and
           6.   Sericano, J. L., Wade, T. L., Atlas.           temporal      distributions        of
                E. L. and Brooks, J. M. Historical             contaminant body burden          and
                Perspective on the Environmental               disease in Gulf of Mexico oyster
                Bioavailability of DDT and Its                 populations: The role of local and
                Derivatives to Gulf of Mexico                  large-scale climatic controls.
                Oysters. EnvLron. ScL Technol..                Helgot. Meeresunters. (submitted).
                77,1990. pp. 1541-1548.                   14.  Cunningham, P.A. and Tripp,
           7.   Wade, T. L., Garcia-Romero. B.,                M.R.      Factors affecting the
                and Brooks, J. M. Oysters as                   accumulation and removal of
                Biomonitors of Butyltins in the                mercury from tissues of the





                 American oyster Crassostrea                   marinus in Gulf Coast oysters: its
                 qirginica. Mar. Biol. (Berl.). 3 1.           relationship with temperature.
                 1.975, pp. 311-319.                           reproduction, and pollutant body
                                                               burden. Int. Rev. Gesamten
            15.  Boyden. C.R- Effect of size upon              Hydrobiol.. 75. 1990, pp. 533-550.
                 metal content of shellfish. J. Mar.
                 Biol. Assoc. U.K. 57. 1977, pp.          22.  Cossa. D. A review of the use of
                 675-714.                                      Mytilus spp. as quantitative
                                                               indicators of cadmium and
            16.  Frazier, J.M. The dynamics of                 mercury contamination in coastal
                 metals in the American oyster,                waters. Oceanol. Acta, 12. 1989.
                 Crassostrea virginica. 1. Seasonal            pp. 417-432.
                 effects. Chesapeake Sci.. 16.
                 1975, pp. 162-171.                       23.  Khan. R-A. Effects of chronic
                                                               exposure       t o     petroleum
            17.  Martinicic.- D., Ndrnberg. H.W.,              hydrocarbons on two species of
                 Stoeppler, M., and Branica, M.                marine fish    infected with a
                 Bioaccumulation of heavy metals               hernoprotozoan. Trypanosoma
                 by bivalves from Lim ]Fjord (North            munnanensis. Cam J. - Zool.. 65,
                 Adriatic Sea). Mar. Biol. (Berl.),            1987, pp. 2703-2709.
                 81, 1984, pp. 177-188.                   24.  Barber. B-J.. Ford, S.E. and
            18.  Shuster, Jr., C.N. and Pringle,               Haskin, H.H.      Effects of the
                 B.H. Trace metal accumulation                 parasite MSX (Haplosporidium
                 by the American eastern oyster,               nelsoni) on oyster (Crassostrea
                 Crassostrea 6irginica. Rroc. NatL             virginica) energy metabolism. 1.
                 Shell IL Assoc., 59, 1969, pp. 9 1 -          Condition index.. and relative
                     Yls
                 103.                                          fecundity. J. Sheltftsh Res., 7.
                                                               1988, pp. 25-3 1.
            19.  Sindermann, C.J. An examination
                 of some relationships between            25.  Soniat, T.M. and Gauthier. J.D.
                 pollution and disease. Rapp. P-V.             The prevalence and intensity of
                 R6un. Cons. Int. Explor. Mer., 182,           Perkinsus marinus from the mid
                 1983, pp. 37-43.                              northern Gulf of Mexico. with
                                                               comments or! the relationship of
            20.  Moore, M.N., Livingstone, D.R.                the oyster parasite to temperature
                 and Widdows, J. Hydrocarbons in               and salinity@ Tulane Stu& Zool.
                 marine mollusks:         Biological           Bot., 27. 1989. pp. 21-27.
                 effects      and       ecological
                 consequences. In: U. Varanasi            26.  Ellis, M.S., Choi, MS.. Wade, T.L.,
                 (ed.). Metabolism of polycyclic               Powell, E. N.. Jackson, T.J. and
                 aromatic hydrocarbons . in the                Lewis. D. H.    Sources of local
                 aquatic environment. CRC Press,               variation in.polynuclear aromatic
                 Boca Raton, FL, 1989, pp. 291-                hydrocarbon and pesticide body
                 329.                                          burden in oysters (Crassostrea
                                                               virginica) from Galveston Bay.
            21. Wilson, E.A., Powell, E.N., Craig,             Texas. Estuaries (submitted).
                 M.A., Wade, T.L. and Brooks, J.M.
                 The distribution of Perkinsus








                                                       1-16























                                             Reprint 2


              International Mussel Watch: the Initial Implementation Phase


              Bruce W. Tripp, John W. Farrington, Edward D. Goldberg, and- Jos6 Sericano



















                                   International Mussel Watch: the                                                                               TABLE I
                                                                                                                        Members of the Intemational Mussel Watch Committee.
                                   initial implementation phase                                                              Members                  EX Officio
                                   As a consequence of increasing population and inten-                          Edward D. Goldberg, Chairman         Bruce NV. Tripp,
                                   sifying industrial development on a global scale, the                         Scripps Institution of               Executive Officer
                                                                                                                 Oceanography, USA                    CRC/Woods Hole Oceanographic
                                   world's coastal waters will continue to receive societal                                                           Institution, USA
                                                                                                                 John W Farrington,
                                   waste. The goals of the International Mussel Watch                            vice Chairman                        Josi Sericano,
                                   Project are to assess the extent and severity of contarm-                     Woods Hole Oceanographic             Field Scientific Officer
                                   nation of the coastal waters of the world with respect to                     Institution, USA                     GERG/Tcxas A&M University,
                                   selected chemicals, and to develop an international                           Roger Dawson                         USA
                                                                                                                 Chesapeake Biological                Anthony H. Knap,
                                   infrastructure of cooperating scientists and laboratories                     Laboratory, USA                      UNESCO-GEMS[ Liaison
                                   for research and monitoring of contaminants in coastal                        Arne 13. jlmelo,                     Bermuda Biological Station for
                                   waters worldwide in the future.                                               Water & Air Pollution Research       Research, Bermuda
                                      The International Oceanographic Commission of                              Laboratory, Sweden
                                   UNESCO (IOC), in collaboration with the United                                Laurence D_ Mee
                                                                                                                 Intemational Atomic Energy
                                   Nations Environment Program (UNEP) and the US                                 Aeency, Monaco
                                   National Oceanographic and Atmospheric Administra-                            Eric Schneider
                                   tion (NOAA) are jointly funding -the International                            Nationil Oceanic and
                                   Mussel Watch Program and have initiated a monitoring                          Atmospheric Administration,
                                   programme in Central and South America in 1991-92.                            USA
                                   The programme is being directed by the International
                                   Mussel Watch Committee (Table 1) and administered by                          , The need for an International Mussel Watch project
                                   the Project Secretariat office based at the Woods Hole                        was recognized in 1975, when Professor Edward Gold-
                                   Oceanographic Institution, Woods Hole, Massachusetts,                         berg in his Marine Pollution Bulletin editorial, called for
                                   02543, USA-                                                                   a global marine monitoring programme to serve as a





















                                                                                                     1-18






                                                                                                                                                        Marine Pollution Bulletin


                                   -springboard for actiore. He outlined a fiscally reason-                     meeting. Communication'at the international level was
                                          Z,
                                   able, global scale monitoring programme based on the                         continued at a second meeting held in Hawaii in
                                   sentinel organisms concept--Mis monitoring programme                         November of 1983. Participants at the Hawaii meeting
                                   must be capable of detecting spatial and temporal trends                     examined the conceptual approaches used by the Mussel
                                   in concentrations of several important chemical con-                         Watch programmes and assessed the potential for
                                   taminants. Since the late 1960s, scientists have been                        expansion of this approach to a global scale and
                                   usinQ bivalve filter-feeding molluscs to monitor for                         especially to the southern hemisphere- The need for the
                                   selected chemical contaminants in coastal marine waters                      International Mussel Watch Project was reaffirmed at
                                   and an extensive'mussel watch' literature has developed                      the Hawaii meeting. Planning momentum was main-
                                   from that work. Such contamination of coastal waters                         tained by the International Mussel Watch Committee
                                   mi ht result in changes that are deleterious, over the tong                  during the next few years.
                                     9                                                                  C,
                                   tenn. to both the integrity of the coastal environment                       The International Mussel Watch Project is being
                                   and to human health. Because of their sedentary habits                       implemented initially in the Central-South America and
                                   and their ability to bioconcentrate the pollutants of                        Caribbean region and will focus on organochlorine
                                   interest, mussels and other bivalve species appear to be                     biocide contaminants and PCBs (Table 2). Plans are
                                   appropriate sentinel organisms even considering com-
                                   plexities such as age, season, organism health and inter-                                               TABLE2
                                   species differences. The mussel watch approach has                           Chlorinated hydrocarbons to be analysed in collected tissue samples.
                                   been adopted as one of several coastal environmental                         We envisage that about 70-80 sites will be sampled for indigenous
                                   quality monitoring strategies by several national pro-                       bivalves and tissue samples will be analysed for a variety of chlorinated
                                   grammes and by UN programmes. The International                              pesticides and -,elected chlorinated biphenyls- -
                                   Mussel Watch Project will build on this cumulative                           Aldrin       Heptachlor
                                                                                                                Fmdrin       Reptachlor epoxide
                                   experience. A world-wide literature search has recently                      Dieldrin     Rex;ichlorobemene (HCB)
                                   been completed by the US NOAA Status and Trends                              chlodane,    m-Hexachlorocycloherane (cc-HCH)
                                   Program and is available as a special reporL                                              fl-Hexachlorocyclohexane (fl-HCH)
                                      Particulaily important among the monitoring
                                                                                                ., pro-         op@-DDD      undarte (rHCH)
                                   grammes that were established during the 1970s were                          pV-DDD       Trans-nonachlor
                                                                                                                p%DDE        Methoxychlor
                                   those of the International Council for the Exploration of                    o' '
                                                                                                                pp -DDE
                                   the Sea (ICES@ The United Nations Environment                                o,p'-DDrr
                                   Program has also created its Regional Seas Program                           p4)'-DDT
                                   which has placed a major emphasis on the development                         NOTES: I-firex and Kelthane may       be added to the suite of
                                   of host country capabilities for measuring the levels of                     contaminants analysed if funding for analysis becomes available-
                                   contaminants in coastal and marine environments. The                         A common set of individual chlorobiphenyls (PCEks) %%ill be chosen
                                                                                                                for analysis followirig the assessment of the results of the first round of
                                   IOC sponsored the formation of a Task Team on Marine                         intercalibration exercises Qf lOC/lCES/JMG. TOW PCBs will be
                                   Pollution Research and Monitoring in the West Pacific                        estimated from these dam
                                   region- National governments in many countries have
                                   initiated their own coastal monitoring, progg                                                                                  th         tami
                                                                                          .,rammes to           being made to expand the programme to o er con
                                   provide technica    *I information that can be used to protect               nants and to other regions so that all countries that wish
                                   coastal resources from the deleterious effects of                            to participate, may do so. We invite anyone interested in
                                   chemical contamination. In the United States, the                            participating in subsequent phases. of International
                                   'Mussel Watch' Program was begun by the US EPA in                            Mussel Watch to contact the Project Secretariat in
                                   the mid 1970s and involved academic scientists from                          Woods Hole. Currently available funding does not
                                   several academic research institutions. This programme                       permit a global-scale programme or a Western Hemi-
                                   used mussels and oysters as indicators of the local levels                   sphere program that includes all types of chemical
                                   of four classes of pollutants in US coastal waters, includ-                  contaminants. This initial implementation phase will
                                   ing synthetic organics, fossil fuel compounds and their                      focus on organochlorine biocides because of their
                                   derivatives, several metals, and the transuranic radio-                      continued used in agricultural and public health applica-
                                   active elements produced in the nuclear fuel cycle and                       tions in several tropical and sub-tropical areas and
                                   by fallout from nuclear weapons tests. Mussel Watch                          because we know very little about production and use or
                                   became an operational contaminant monitorin
                                                                                                g pro-          about the resulting coastal contamination. The experi-
                                   gramme in the United States in 1986 and is presently                         enced gained from this initial phase vill be useful in
                                   directed by US NOAA as a component of the Status and                         implementing an expansion of the programme.
                                   Trends Program-                                                              In May, 1991 members of the International Mussel
                                      In a 1978 workshop in Barcelona, the members of the                       Watch Committee and representatives of three regional
                                   US Mussel Watch Program joined with scientists of                            monitoring programmes met at the University of Costa
                                   other countries to assess the methodologies employed                         Rica to finalize the initial implementation phase of Inter-
                                   for the detection and measurement of pollutants in                           national Mussel Watch. At that meeting, sampling sites
                                   coastal zones throu-h the sentinel organism approach.                        and participating national scienti@ts were selected. The
                                   The participants at the Barcelona workshop decided                           Project Secretariat coordinates the work of two central
                                   that continuing international collaboration and com-                         analytical facilities. International Laboratory for Marine
                                   munication would be worthwhile, and elected a com-                           Radioactivity (ILMR) in Monaco and Geochemical and
                                   mittee charged uith the task of planning for A f                             Environmental Research Group (GERG) at Texas









                              Volume 24/NumbLr7/July 1992

                              A&M University, will anaIN    se the collected samples for     country scientists is being organized for early 1993. For
                              ori!anochlorine contaminants. Tissue samples and               those scientists with analytical expertise, tissue samples
                              extracts will be archived for later analysis of other          will be available for in-country analysis and inter-
                              contaminants if funding is available. ILMR will also           laboratory comparison. Host-country scientists will be
                              supervise the Field Scientist responsible for sample           asked to assemble production and use data as well, from
                              collection. The International Mussel Watch Project vill        available sources in their respective countries.
                              complement, regional monitoring programmes where                  This initial implementation phase will: L generate
                              they are established, thus linking the existing pro-           high quality data on chlorinated pesticides and estimate
                              grammes and increasing their effectiveness. These exist-       PCB concentrations in the Central-South America-
                              ino regional programmes provide a base on which to             Caribbean coastal region, 2 serve as a 'field-test' of a
                              build an international prop
                                                          ,ramme and their support and       large-scale international marine monitoring programme
                              collaboration is critical to the success of the inter-         for chemical contaminants, 3 create an international
                              national programme. In the initial implementation              network of coastal environmental scientists, 4. provide a
                                            0
                              phase, samples will be collected throughout the region         forum for training and for discussion of analytical
                              with the assistance of host-country scientists. These          results, and 5. create the institutional structure for a
                              scientists will form the nucleus of an internationar           global scale coastal monitorina . programme.
                              marine monitoring network, through which the results of           Continuation (and expansi    on) of this project will be
                              the project will be disseminated.                              considered when the programme is assessed at the
                                 Host-country scientists and IMW sampling sites will         conclusion of the initial implementation phase. Host-
                              be coordinated by the Woods Hole-based Project                 countries and the entire UN family will benefit from the
                              Secretariat, working with the Field Scientific Officer. AU     scientific results generated during this initial phase and
                              sampling and sample logistics will be supervised by the        will have an opportunity to expand local monitoring
                              Field Scientific Officer and the host-country scientists       activities with technical support from the Project as well
                              will work directly. with him. The field sampling is            as to integrate these activities into regional and global-
                              currently underway, and collection have already been           scale programmes.
                              completed in much of Central America and South
                              America. The Project Secretariat and the Field Scien-          BRUCE W. TRIPP
                                                                                             Woods Hole Oceanographic Instifution, Woods Hole,
                              tific Officer will provide technical support to host-              02543 SA
                                                                                             MA         U _                                                     I
                              country scientists as resources permit. The International      JOHN W. FARRINGTON
                              Mussel Watch Committee, in concert with the Project            Woods Hole Oceanographic Institution, Woods Hole,
                              Secretariat, the Field Scientific Officer, and the contract    MA 02-543, USA.
                                                                                             EDWARD D. GOLDBERG
                              laboratories will provide data interpretation, taking into     Scripps Instilwion of0ceanography, La Jolla, C4 92093, USA.
                              account comments from host-country scientists..'An             JOSE SERICANO
                              international meeting, involving participating host-           internationai Laboratotyfor Marine Radioac&4, Monaco.


























                                                                                   1-20









                                           2.0 Introduction


                      This document is    one volume of the Sixth Annual Report
                prepared by the Geochemical and Environmental Research Group
                (GERG), in the College of Geosciences and Maritime Studies at Texas
                A&M University, for the U.S. Department of Commerce National
                Oceanic and Atmospheric Administration's Mussel Watch Project for
                the Gulf of Mexico. This section discusses the background and
                relevance of the proposed project and reviews the study objectives.

                      The overall goal of the national Mussel Watch Project is to assess
                and document the status and long-term changes in the environmental
                quality of coastal and estuarine environments along the East and West
                coasts of the United States and the Gulf of Mexico coast. In order to
                meet this goal, a series of systematic observations of selected chemical
                contaminants (e.g., trace metals, PAHs, PCBs, and pesticides) in
                representative samples of bivalves and sediments has been
                undertaken. GERG's portion of the project deals with U.S. Gulf of
                Mexico coastal sites. This document presents the results obtained
                during the first six years of the project. Three other documents as
                part of the sixth year study include:

                      0 Analytical Methods
                      0 Analytical Data
                      0 Field Sampling and Logistics


                2.1   Project Relevance and Direction

                      Over the last several decades, problems associated with
                chemical contamination of the marine environment have received
                increasing attention. Numerous studies have been undertaken to
                identify the inputs, transport, and effects of a variety of elements and
                compounds. Among the major contaminants studied are petroleum
                hydrocarbons, halogenated organic compounds, and a suite of trace
                metals including cadmium (Cd), lead (Pb), zinc (Zn), mercury (Hg),
                and others. Particular attention has focused on the coastal zone and
                estuaries near large population centers. These areas potentially
                experience the largest impact from chemical contamination and may
                be most sensitive to the accumulation of toxic compounds.

                      One approach for monitoring the status of coastal and estuarine
                pollution on a national scale has been the concept of "sentinel
                organisms" or "bioindicators". The National Mussel Watch Project
                initially sponsored by the Environmental Protection Agency was an
                application of this concept. The project used bivalves to monitor the
                "health" of marine ecosystems and identify "hot spots" of chemical
                contamination along the nation's coastline. Some of the results of this

                                                  2-1







                 project have been summarized (Farrington et al., 1983; NAS, 1980)
                 and are discussed later in this report.

                       Farrington et al. (1983) summarized the rationale for using
                 common mussels (Mytilus sp.), various oyster species (Crassostrea and
                 Ostrea) and other bivalves as "sentinel" organisms:

                       1.   Bivalves are cosmopolitan             (widely distributed
                            geographically).     This characteristic minimizes the
                            problems inherent in comparing data for markedly different
                            species with different life histories and relationships within
                            their habitat.

                       2.   They are sedentary and are thus better than mobile species
                            as integrators of chemical pollution at a given area.

                       3.   They concentrate many chemicals by factors of 102 to 105
                            compared to seawater concentrations in their habitat.
                            Trace constituent measurements are easier to accomplish in
                            tissues than in seawater.

                       4.   Inasmuch as the chemicals are measured in the bivalves, an
                            assessment of biological availability of chemicals is obtained.

                       5.   In comparison to fish and crustacea, bivalves exhibit low or
                            undetectable activity of those enzyme systems that
                            metabolize many xenobiotics such as aromatic hydrocarbons
                            and polychlorinated biphenyls (PCBs).         Thus, a more
                            accurate assessment of the magnitude of xenobiotic
                            contamination in the habitat of the bivalves can be made.

                       6.   They have many relatively stable local populations extensive
                            enough to be sampled repeatedly, providing data on short-
                            and long-term temporal changes in concentrations of
                            pollutant chemicals.

                       7.   They survive under conditions of pollution that often
                            severely reduce or eliminate other species.

                       8.   They can be successfully transplanted and maintained on
                            subtidal moorings or on intertidal shore areas where normal
                            populations do not grow due to a lack of suitable substrate.

                       9.   They are a commercially valuable seafood species on a
                            worldwide basis. Therefore, measurement of chemical
                            contamination is of interest for public health considerations.




                                                    2-2








                      An international workshop. "Mussel Watch 11", convened to
                reassess the "Mussel Watch" concept and to evaluate the
                accomplishments and deficiencies of the EPA Mussel Watch Project
                that was implemented. Some of the conclusions are summarized
                below:



                      Accomplishments:

                      ï¿½   An extensive data base of radionuclides in mussels and oysters
                          was obtained. These data allowed the detection of several
                          minor leakages from nuclear reactors.

                      0   The Mussel Watch data base of trace metals has permitted an
                          assessment of the perturbations in the biogeochemical cycles
                          of metals in coastal waters induced by their mobilization by
                          man and by waste discharges.

                      ï¿½   Measurements of PCB and DDT compounds established a data
                          base against which future changes -can be measured.

                      ï¿½ Data from the Mussel Watch Project provided conclusive
                          evidence that' polynuclear aromatic hydrocarbons produced
                          from combustion products are not generally accumulated in
                          food webs.

                      Deficiencies:

                      ï¿½   Analytical limitations in trace  organic analysis prevented a
                          wider spectrum of organic compounds from being measured.
                          Subsequent analyses have revealed other compounds such as
                          hexachlorobenzene, mirex, and others.

                      ï¿½   Data management was inadequate, and consequently data was
                          not promptly available.

                      ï¿½   Some samples from the Gulf Coast were never analyzed.

                      0   Statistical design was not established prior to the sampling
                          and analytical project.

                      ï¿½   Mussels (or oysters) are unsatisfactory for the identification of
                          new pollutant compounds, and they do not readily accumulate
                          potentially important compounds or compound groups.

                      The consensus opinion was that a modified, more specifically
                defined approach to using marine organisms as environmental
                indicators would be a valuable tool in assessing estuarine and coastal
                contamination.


                                                   2-3









                2.2 Study Objectives

                      Reliable and continuous information regarding the status and
                trends of environmental quality in the nation's coastal and estuarine
                regions is necessary to make informed decisions involving the use and
                allocation of resources. The National Status and Trends Project for
                Marine Environmental Quality was initiated in 1984 by the Ocean
                Assessment Division of NOAA to provide this environmental quality
                information. Based on the experience gained during the EPA Mussel
                Watch Project and on recommendations from a workshop report, the
                chemical measurements segment of the National Status and Trends
                Project was developed.       During the workshop on chemical
                measurements, the working hypothesis of the project was worded as
                follows:

                    "Chemical measurements of t@xic contaminant levels in
                    environmental samples serve as leading indicators of trends
                    in environmental quality and can reflect trends in inputs of
                    these chemicals into marine systems.               Significant
                    correlations have been demonstrated between contaminant
                    levels in marine samples and the health of marine biological
                    components."

                Implicit in such a statement is that the chemical measurements are of
                the highest quality obtainable, are directly comparable between all
                sites and samples, and have a known statistical variability. Simply
                stated, the objective of this project is to provide such measurements
                in sediments and bivalves and to provide sufficient ancillary data to
                allow meaningful interpretation of the measurements.

                      There are four stated objectives for the National Status and
                Trends Project:

                      1.  The primary objective is to establish a national data base
                          using state-of-the-art sampling, preservation, and analysis
                          methodologies which are consistently applied and subject to
                          rigorous quality control and assurance.

                      2.  Use the information in the data base to estimate
                          environmental quality, to establish a statistical basis for
                          detecting spatial and temporal change, and to identify areas
                          of the nation that might benefit from more intensive study.

                      3.  Seek and validate additional measurement techniques,
                          especially those that describe a biological response to the
                          presence of contaminants.



                                                 2-4








                      4. Create a cryogenic, archival specimen bank containing
                         environmental samples collected and preserved through
                         techniques that will permit reliable analysis over a period of
                         decades.

                      In a general sense, scientific objectives relating to the goals of
               our Mussel Watch portion of the National Status and Trends Project
               include:

                      ï¿½ What is the geographic distribution of contaminant
                        concentration in oysters and sediments at selected sites
                        along the Gulf of Me2dco coast?

                      ï¿½ Are there "problem" areas?

                      ï¿½ Are particular compounds or classes of compounds significant
                        contaminants in broad regions of the Gulf.?

                      ï¿½ What is the relationship between contaminant concentration
                        in sediments and in oysters?

                      ï¿½ What is the relationship between the concentration of
                        specific metals and organic compounds?

                      ï¿½ What is the variability in contaminant concentrations VAthin
                        sites and between sites?

                      ï¿½ What portion of that variability can be removed by normalizing
                        chemical measurements to other parameters (e.-g. to TOC,
                        lipid weight, etc.)?

                      ï¿½ Are there unidentified contaminants present in significant
                        quantities in the samples?

                      ï¿½ What is the relationship between the "health" of oysters and
                        the concentration of contaminants9

                      ï¿½ Are contaminant concentrations increasing or decreasing
                        with time?

                      The long-term project is designed to examine the above
               problems in a rigorous manner. Some of these objectives are being
               pursued as is evidenced by publications that have resulted from this
               program (Table 1.1). It can be expected, too, that other problems and
               questions will arise during the course of the project.

                      Researchers at GERG are pursuing the answers to some of the
               above questions through our association with this NOAA NS&T Project
               as well as other programs (i.e. EPA Galveston Bay National Estuary

                                                 2-5








                Program, EPA - EA4AP-NQ and through unfunded student thesis and
                dissertation research. Some of the ongoing research at GERG involves
                oyster transplant studies in an attempt to better calibrate oysters as
                detectors of environmental contaminants. GERG has developed
                techniques to analyze alkylated PAH, PAH metabolites and planer
                PCBs,    and is currently developing methods for dioxins and
                dibenzofurans. All of these research projects may be of value to the
                NS&T Project in the future.







































                                                2-6








                            3.0 Polynuclear Aromatic Hydrocarbon Results


                       Polynuclear Aromatic Hydrocarbon (PAH) concentrations are of
                 concern because many of these compounds are known or suspected
                 carcinogens and/or mutagens. The sources of PAH in the environment
                 are petroleum, petroleum products, and combustion of fossil fuels and
                 organic materials (i.e. forest fires). /,@n@estuarine systems PAH inputs
                 may come from natural seepage,/oil production, oil transportation,
                 atmospheric deposition, combustion products (i.e. creosote),
                 municipal waste, industrial wastq and runoff. Although large spills get
                 most of the publicity in the popular press, they account for less than
                 15% of the total PAH entering the marine environment.
                       The concentration of 24 POI y1nuclear Aromatic Hydrocarbons
                 (PAH) are measured as part of the NS&T project in oyster and
                 sediment samples from the Gulf of Me@dco. The NS&T data can           ' be
                 used to provide some indication of the relative importance of
                 petroleum verses combustion sources, but analyses of additional
                 alkylated PAH is even more definitive (Preprint 1).

                       One purpose of the NS&T project is             to determine the
                 environmental quality of the nation's coastal zone. This has been fairly
                 well addressed, as described in the recent publications and reports
                 that have resulted from this project (Tablel.1 and reprints 3.4.5. and
                 6). Another purpose of the NS&T project is to determine if the
                 environmental conditions of the U.S. coastal zone are getting better or
                 worse. The continued collection of data is necessary in order to
                 address this last question.

                       The NS&T sites are chosen to avoid "hot spots" or known point
                 sources of contaminant inputs. The sites are sampled once a year in
                 the winter in an attempt to eliminate seasonal variability. Samples are
                 collected from three stations at each site and analyzed individually.
                 The geographical distribution of Gulf Coast oyster PAHs are shown in
                 Figures 3.1 to 3.29. The total of the PAH measured in all years (Figure
                 3. 1) indicates concentration ranges from below the detection limit
                 (-20 ng/g) to concentration of over 12 mg/g. Based on the total of
                 measured PAH, little change is obvious for the first six years in
                 geographic PAH distribution, when within-site variability is
                 considered. Most sites have lower total measured PAH concentration
                 in Year 6 when- compared to the mean of Years I to 5. Only three sites
                 had higher concentrations in Year 6. The 2 and 3 ring lower
                 molecular weight PAHs (Figure 3.25) show a similar distribution with
                 only three sites higher in year 6. The high molecular weight 4 and 5
                 ring PAHs (Figure 3.26) had higher concentrations at only eight sites
                 in Year 6 compared with the mean of the first five years. The 4 and 5
                 ring PAHs represent the major percentage of PAH present in these
                 samples (Figures 3.27 and 3.28). The total of all 24 PAHs measured



                                                    3-1









                  since year 2 (Figure 3.29) shows the same trend as the total of the 18
                  PAHs.

                       The concentrations of PAH at most sites did not change when
                  the concentrations for Year 6 are compared to the mean
                  concentrations for Years I to 5. The predominant PAHs detected
                  were pyrene, fluoranthene, chrysene and napthalenes. In general, the
                  4 and 5 member rings predominated, however, there were
                  considerable amounts of 2 and 3 ring aromatics at some sites. -The                 01
                  decrease at some sites in total aromatics for Years 1-4 vs. Year 5 was
                  due to a decrease in the 2 and 3 ring aromatics (i.e., BBSD, CBJB and
                  SAV%TB, Figure 3.25). The presence of the 4 and 5 ring aromatics is
                  indicative of PAH from combustion sources. However, as discussed
                  above, alkylated PAH provide additional resolution of sources (Preprint
                  U.

                       There are generally higher PAH concentrations in bay systems
                  that are adjacent to large urban areas with the associated high levels of
                  industrial activities. An example of this is Galveston Bay, Texas. The
                  closer the site is to the urban area, the higher the PAH concentration
                  (Reprint 4).

                       The general overall conclusion from the PAH data is there is no
                  significant change in PAH concentrations at most of the sites sampled
                  over the six year period. The PAHs found in higher concentrations
                  (pyrene, fluoranthene) are mainly derived from combustion sources.
                  This input should be relatively constant with time and reflect the
                  consistency in PAH concentrations between sampling years. The sites
                  that show large increases in a given sampling year usually show
                  decreases in subsequent years. This indicates that episodic inputs of
                  PAH, possibly from oil spills, account for these increases. Then when
                  the input stops, the ecosystem starts to recover.

                       We are continuing to look for temporal trends in the PAH data.
                  The data set for the six years of NS&T program is large. Therefore,
                  trends analyses require the use of various techniques including
                  statistical ones. Other complications with data interpretation are
                  caused by the nature of oysters. They can accumulate and depurate
                  contaminants.     There is currently only limited data on these
                  processes.     GERG is developing more data through several
                  independant resarch projects (Preprint 2 and Reprint 5). We are
                  currently looking at the data in an attempt to detect any gulf-wide
                  temporal trends.








                                                    3-2



















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                               cn      zi         GBYC                                                                                        MBCP                                                                                       RBHC
                                       0          GBSC                                                                                        MBM                                                                AL                      EVFU
                                                  GBHR                                                            483.30
                                                  SLBB                                                                                        MBDR                                                                                       BHKP
                                       (D






















                                                                                                                                                                      LA
                                                                         .0    .........                   0    .....
                                                  LMSB                                                                                        CLSJ                                                                                       PBPH
                                                  LMPI                                                                                        CLLC                                                                                       PBIB
                          LO 0        >           LMAC                                                                                                                                                                                   PBSP
                               '@@    <           CCBH                                                                                        jHJH                                                                                       CBM
                                   cf)M
                                   r-t,"          CCNB                                                                                        VBSP
                                   (D                                                                                                                                                                                                    CBSR
                                   I  P           ccic                                                                                        A130B
                                   cl) M                                                                                                                                                                                                 CBSP
                                      (D
                                                  ABLR                                                                                        CLCL                                                                                       PCLO
                                                  ABIU                                                                                        TB12                                                                                       PCMP
                                                  CBCR
                                                                                                                                              TBLF                                                                                       SAWB
                                   CD             MBAR
                                                                                                                                              B 97MB                                                                                     APDB
                                                  SAPP
                                                  SAMP                                                                                        BBSD                                                                                       APCP
                                                                                                                                                                                                                                         AE P
                          p        z              L.SSP                                                                                       BBNM
                                   Po             ESBD                                                                                        MRT?                                                                                       SRWP
                                                  MBGP                                                                                        MRPL                                                                                       CKBP
                                      w           MBLR                                                                                                                                                                                   TBNP
                                   910
                                                                                                                                              BSSI
                                                  M13CB                                                                                                                                                                                  TBMK
                                                  MBI?                                                                                        BSBG                                                                                       TBPB
                                   cn p                                                                                                                                                                           LA
                                   n  (D          WIN                                                                                         I'llml,                                                                                    1130T
                          p                       IMBIN                                                                                       LBNO                                                                                       MA
                                                  BRCL                                                                                                                                                       1096.03                     TBHB
                                                                                                                                              LPGO              N     "A        N.                          \ \ \
                                   0  0           BRFS                                                                                                       ..................... .... .............. ..............................    IBCB
                                      @3          GBCR                                                                                        MSPC
                                      n                                                                                                                                                                                                  CBBI
                                      m           GBOB                                                                                        MSBB                          x 7,777=                              ms                     CBFM
                                      :n          GBID                                                                                        MSPB
                                                  GBYC                                                                                        MBCP           .......................................................................     NBNB
                                                                                                                                                                                                                                         RBHC
                                                  GBSC
                                                                                                                                                                                                                  AL
                                                  GBHR                                                          2111.07                                                                                                                  EVFU
                                                                                                                                              MBDR                                                                                       BHKF
                                      U)          SLBB


                                   o
                                                                m





                                                                m
                                                                                                                                                             m





                                              Acenaphthylene- (ppb)
                                              0 Mem Yews 1-5 0 Kew @Y= 6
                        100                  C4


                        80-




                        60-




                        40

                                                          LILL                 ILLILIL    -4
                              M ei- F-0 040      M c- - a- - @! @ = 8 5 T 6 M :@  2  0  R"
                                        CQ                                              >
                                 CO       U
                            M                  <      <                0        CO   C4 w




                        100-








                        60




                        40




                        20




                          0

                            U U                     CO                      -V 5EA



                        100




                        80-




                        60-




                        40-




                        20
                          0'    . . . . .        a.   a.  LIU
                            w
                            Vj
                                                               (5 ;-11 E ILd 6 - R I
                                  IU=        CQ ;5 a- -@E w0 .                 0
                                                      V2                       CO
                                                           CO
                                  U  U

               Figure 3.7       Average acenaphthylene concentrations in oysters from
                                each NS&T Mussel Watch Gulf of Mexico sampling site
                                for Years 1-5 and Year 6.
                                                        3-9






















                                                                                                 00                                                                               06


                                           LMSB                                                                              CLSI                                                                             PBPH
                                           LMPI                                                                              CLLC                                                                             PBIB
                           (D >            LLM A C                                                                                                                                                            PBSP
                                           CCHH                                                                                                                                                               CBM
                                                                                                                             VBSP
                                           CCNB
                                                                                                                                                                                                              CRSR
                                m          CCIC                                                                              A130B
                                M                                                                                                                                                                             CBSP
                                           ABLR                                                                              CLCL
                                p                                                                                                                                                                             PCLO
                                0          ABFR                                                                              IMB                                                                              PCMP
                                n          CBCR'oo
                      w    @@ @l                                                                                             1T*BLF                                                                           SAWB
                                P)         MBAR      21
                           @;@o                                                                                                                                                                               APDR
                                ::;,       SAPPY                                                                             Bffm                                                                             APCP
                           (D              SAMP                                                                              BBSD
                                                                                                                                                                                                              AESP
                                           ESSP                                                                              BBNM
                           :@                                                                                                                                                                                 SRWP
                           w               ESBD                                                                              MRTP
                                           MBGP                                                                                                                                                               CK13P
                                0          MBI.R                                                                             MRPL                                                                             TBNP
                                @:s                                                                                          lissi
                           on              MICH                                                                                                                                                               'IIIMK
                                                                                                                             13slio                                                                           ITIM
                                           mIB3DI                                                                            LBMP                                                                             TBOT
                                                                                                                             LBNO                                                                             7BI3KA
                                           BRCL
                                                                                                                             LPGO                                                       LA                    T B13 HOB
                                cn         BRFS                                                                                             ......... ........... ...... ................ ..................  TsJ3CB
                                ".         GBCR                                                                              MSPC
                           0 :z            GBOB                                                                              MSBB                                                       ms                    CBOI
                           Ct)  o                                                                                                                                                                             CBFM
                                t,<        GBTD                                                                              ms?         .... .......                           ....... .......               NBNB
                                           GBYC                                                                              MBC?
                                                                                                                                                                                                              RBHC
                                           GBSC
                                                                                                                             NMIR                                                       AL                    sVFU
                                cn         GBHR                                                     9@@7]
                                ;@,,       Sim                                                                               MBDR                                                                             BHKF
                           cn.  0
                                                                                                                                                                                                                           MOM





                                                                                                                                                                                                                           mom
















































                                                                                                                        @lk            i












                                      L.MSB     . . . CLSI                                                                                                                     PBPH
                                      LNTI                                                                 CLLC                                                                PBM
                                      I@NAC                                                                IRIH                                                                PBSP
                                                                                                                                                                               CWB
                                      CCBH                                                                 VBSP
                                      CCNB                                                                                                                                     CBSR
                                                                                                           ABOB
                                      ccic                                                                                                                                     CBSP
                                      ABLR                                                                 CLCL                                                                PCLO
                   (70, @;l
                              t)      ABM                                                                  Tml3LI3                                                             PCMP
                              -W      CBCR                                                                    LF
                                                                                                           TBLF                                                                SAWB
                              Ul      MBAR                                                                                                                                     APDB
                                                                                                           BMB
                                      SAPP                                                                                                              m                      APCP
                                                                                                           BBSD
                                      SAMP
                                      ESSP                                                                 RRNM                                                                AESP
                    p z @,                                                                                                                                                     SRWP
                        0             ESBD                                                                 MRTP
                w                                                                                                                                                              CKBP
                                      MBGP                                                                 MRPL
                                                                                                                                                                               TBNP
                              z       MBLR
                                      mlicli                                                               lissf                                                               'IBMK
                                                                                                           BSBG                                                                113PB
                                                                                                                                                              LA               TBOT
                              P       MBDI                                                                 LBMP                                                                IMKA
                                      M B EAM                                                              12NO
                              :zz                                                                                                                         1510.53              TBO
                              m       BRCL                                                                 U>GO                                          x @ x N
                                                                                                                    ........................ ..................................................
                              0       BRFS                                                                 MSPC                                                                TBCB
                              0       GBCR                                                                                                                                     CBBI
                              z                                                                            MSBB                                              ms
                              C)      GBOB                                                                                                                                     CBFM
                                      GBTMD                                                                MSPB                                                                NBNB
                         +) r+        GBYC                                                                 MBCP
                                                                                                                                                                               RBHC
                              e-+     GBSC                                                                 M131                                               AL               EVFU
                                                                                    1725.97                                                                                    EVFU
                              0       GB14R
                              I                                                                            MBD                                                                 BHKF
                              11      SLBB

                        C)




















                            CD


                                                      LA                 LA


                                      ILMSB                                                                CLSJ                                                                PBPH
                                      LMPI                                                                 CLLC                                                                PBIB
                            >         LMAC                                                                                                                                     PBSP
                        cn            CCBH                                                                 JHJH
                        5                                                                                                                                                      C=BMJB
                   C/)                CCNB                                                                 VBSP
                                                                                                                                                                               C13SR
                                      CCIC                                                                 A130B                                                               CBSP
                                      ABLR                                                                 CLCL                                                                PCLO
                                      AB IMH                                                               7BLJ3                                                               PCMP
                        M             CBCR
                            CD                                                                             TBLF                                                                SAWR
                            :n        MBAR                                                                 BMB                                                                 APDB
                            CnD       SAPP
                                                                                                                                                                               APCP
                                      SAMP                                                                 BHSD
                            0                                                                                                                                                  AESP
                            :z        ESSP                                                                 BB
                                      ESBD                                                                                                                                     SRWP
                                                                                                           MRTP
                        z @3          MBGP                                                                                                                                     CKBP
                        @ r-@.                                                                             MRPL
                            +1 @j     MUR                                                                                                                                      TBNP
                            pp)
                        0 r"t,                                                                             IISSI
                            _.        MBCII                                                                                                                                    TBMK
                            0         MB7?                                                                 BSB                                                                 7MPB
                                      NMDI                                                                 LBMP                                                                'MOT
                        X.            MBEM                                                                 111NO                                                               T13KA
                        0             BRCL                                                                 LPGO                                             LA                 TBHB
                        C/)           BRFS                                                                           ........................................................................
                        p cr)                                                                              MSPC                                                                TBCB
                                      GBCR
                                                                                                                                                                               CBBI
                        ,-o           GBOR                                                                 MSBB                                             ms
                            cn                                                                                                                                                 CBFM
                                      GBTD                                                                 MSPB      ........................................................................ NBNB
                                      GBYC                                                                 MBCP
                            0                                                                                                                                                  RBHC
                                      GBSC !      . . . . . . . .                                          MBM                                              AL                 EVFU
                                      GBHR
                                                                                                           MBDR
                                      SLBB                                                                                                                                     BHKF









                                                                                       iMi           ilMi       loll         I      I    I      I




















                                   LMSB                                                          CLSJ                                                          pBPH
                                   LMPI                                                          CLLC                                                          PBM
                                   LMAC                                                          JFIJH                                                         PBSP
                                   CCBH                                                                                                                        CRIB
                                                                                                 VBSP,
                                   CCNB                                                                                                                        CBSR
                             (D    ccic                                                          ABOB
                                                                                                                                                               CBSP
                             -0    ABLR                                                          CLCL                                                          PCLO
                             @3-   ABIR                                                                                                                        PCMP
                  Cn         n
                             :3    CBCR
                             W     MBAR                                                          TBLF                                                          SAWB
                       cn    @$                                                                  BM13                                                          APDB
                       co          SAPP
                       n                                                                                                                                       APCP
                  rD               SAMP                                                          BBSD
                  p ,A                                                                                                                                         AESP
                       -',   :z    rssp                                                          1IRMB
                       p     CD                                                                                                                                SRWP
                  m                I:SBD                                                         MRTP
                             0     MBGP                                                                                                                        CKBP
                             o                                                                   MRPL
                             @l    MBLR                                                                                                                        TBNP
                       C) n                                                                      Bssl
                             (D    WWII
                                   M11,11,                                                       listio                                                        TBPB
                                                                                                                                               LA
                                   MBDI                                                          1.11ml,                                                       1MMOT
                                   MBEM                                                          LBN6                                                          TBKA
                             0
                             @3    BRCL                                                                                                      782.13
                             cn    BRFS                                                          LPGO                                   .... ..                TBHB
                                                                                                 MSPC                                                          ncB
                             :n    GBCR                                                                                                                        CBBI
                       U)    0     GBOB                                                          MSBB                                          ms              CBFM
                                   GBTD                                                          MSPB
                             cn                                                                           ......................................................................... NBNB
                             e-q,  GBYC                                                          MBCP                                                          RBHC
                                   GBSC
                       @3    cn.                    . . .                                        MBIU                                          AL              EVFU
                       m     ;I    GBUR                                      1512.47             MIJDR                                                         BHKF
                       U).   c)    SLBB













                         Oil






                                  LMSB                                                         CLSJ                                                        PHPH
                                  LMPI                                      328.07             CLLC                                                        PBM
                                  LMAC                                                                                                                     PBSP
                 C D                                                                           JHJH
                                  CCBH                                                                                                                     CBM
                                  e@                                                           VBSP
                                  CCNB                                                                                                                     CBSR
                                  ccic                                                         ABOB
                                  AB'LR                                                        CLCL                                                        CESP
                                                                                                                                                           PCLO
                                  AM                                                           IIMB L B
                                                                            429.47                                                                         PCMP
                                  CIBCR
                                                                                               TBLF                                                        SAWB
                                  MBAR
                                                                                               BBM                                                         APDR
                                  SAPP
                                  SAMP                                                         BBSD                                                        APCP
                                  ESSP                                                         BBNM                                                        AESP
              w          0        ESBD                                                                                                                     SRWP
                                                                                               MRTP
                                                                                                                                                           CKBP
                         n        MBGP
                         M                                                                     MRPL
                                  MBLR                                                                                                                     THNP
                                                                                               lissi
                                  mlicil                                                                                                                   113MK
                       +) A)
                         cl,      M13,11,                                                      IISBG                                                       TBPB
                         0        NIBDI                                                        LBMP                                                        7130T
                      X1. cn      MBEM                                                         LJ3NO Ml                                                    TBKA
                                  BRCL
                         ::5                                                                   LPGO                                        LA              TBHB
                         0        BRFS                                                                                       ......                        TBC13
                      p '--<      GBCR                                                         MSPC                                                        CBBI
                         r+                                                                    ms
                         '        GBOB                                                            BB                                       ms
                         CMD                                                                                                                               CBFM
                                  GBTD                                                         MSPB
                                                                                                                                                           NBNB
                                  GBYC
                      oq @;,              ..l.                                                 MBCP                                                        RBHC
                         0        GBSC                                                                                                     AL              EVFU
                                  GBHR
                                  SLBB                                                         MBDR  FM                                                    BHKF
                                                                                                                                                                   "M








                                                                                                                                                                   mm























                                                                                                                                                                                                               PBPH
                                   w        LMSB                                                                              CLSJ                                                                             PBIMB
                                            LMPI                                                                              CLLC                                                                             PBSP
                     cp 0          >        LMAC                                                                              JHJH                                                                             CRJB
                         -<@                CCBH
                          Cl)      6                                                                                          VBSP                                                                             CBSR
                                            CCNB                                                                              ABOB                                                                             CBSP
                                            ccic
                                            ABLRR                                                                             CLCL                                                                             PCLO
                                            AB
                     cf)  0                      IME                                                                          TBIB                                                                             PCMP
                                            CBC-p                                                                                                                                                              SAVWM]3
                                            WAR                                                                               T13LF                                                                            APDB
                                   n                                                                                          BB113
                          r)                SAPP                                                                                                                                                               APCP
                                   @l                                                                                         BBSD
                                            SAMP                                                                                                                                       670.60                  AESP
                                                                                                                              BBMJ3
                      p   Z -o              ESSP                                                                                                                                                               SRWP
                      p'           :7'      ES13D                                                                             MRTP                                                                             CKBP
                                   n
                      )-I-         @l       MBGP                                                                              MRPII                                                                            TBNP
                 Ul cn             p        M13LR
                                                                                                                              lissi                                                                            113MK
                                            MIIC13
                                                                                                                              BSBG                                                                             TBPB
                                            MBIII                                                                                                                                                              7130T
                                            MBDI                                                                              LBNIP                                                        LA
                                                                                                                                                                                                               TBKA
                                            IMBEM                                                                             u3NO
                      4)                                                                                                                                                               727.57                  71314B
                                            BRCL                                                                              LPGO
                            e4              BRFS                                                                                                              ..............................                   7BCB
                                                                                                                              MSPC
                                   :n       GBCR                                                                                                                                                               C13BI
                                   n                                                                                          MSBB                                                        ms
                                            GBOB                                                                                                                                                               C13FM
                                                                                                                              MSPB
                                            GBTD                                                                                            .......................................................... ........... NBNB
                                            GBYC                                                                              MBCP                                                                             RBHC
                                                                                                                                        ...........
                                            GBSC                                                                              MBHI                                                         AL                  EVFU
                                   0        G B IHMR                                                                                                                                                           BHKF
                                   @3-                                                                                        MBDR
                                   C/)      SLBB























                                                                                                                                                                                                                       LA


                                                   LMSB                                                                                        CLSI                                                                                       PBPH           x N
                                                   LMPI                                                                                        CLLC                                                                                       PBM
                                                   LMAC                                                                                                                                                                                   PBSP
                                                   CCBH                                                                                        JHIH
                                                                                                                                                                                                                                          CBJB
                                         w         CCNB                                                                                        VBSP
                                 zm                                                                                                                                                                                                       CBSR
                                 cn                ccic                                                                                        ABOB
                                                                                                                                                                                                                                          CBSP
                                                   ABLR                                                                                        CLCL                                                                                       PCLO
                                         Z:        ABIU                                                                                        TBILE                                                                                      PCMp
                           Ul            0
                           w                       CBCR                                                                                        TBLF                                                                                       SAWB
                           @j                      MBAR
                           0. cr)        :@
                                 cn                SAPP                                                                                        BMTI                                                                                       APDB
                           -- n                                                                                                                                                                                                           APCP
                           @@ - CD                 SAMP                                                                                        BBSD
                           p                       -CSSP                                                                                       BBMB                                                                                       AESP
                                                   ESBD                                                                                                                                                                                   SRWP
                                                                                                                                               MRTP
                                                                                                                                                                                                                                          CK13P
                                         0         MBGP                                                                                        MRPL
                                                   MBLR                                                                                                                                                                                   TBNP
                                                                                                                                               BSSI
                                                   MBCB                                                                                                                                                                                   IBMK
                                                   MBI`P                                                                                       BsBG                                                                                       TBP8
                                         p         WDI                                                                                         LBMF                                                                                       7130T
                                                   MBEM                                                                                        UINO                                                                                       'MKA
                                                   13RCL
                                                                                                                                               LPGO          IZ                                                    LA                     TnB HMB
                                                   IARFS                                                                                                                .......                            ................               7BCB
                                                                                                                                               MSPC                                                                                       7BCB
                                         .0        GBCR                                                                                                                                                                                   CBBI
                                         0         GBOR                                                                                        MSBB                                                               ms                      CBFM
                                 P) "<             GBTD                                                                                        MSPB
                                         cn                                                                                                                  .......................................................................      NBNB
                                         r-t,      GBYC
                                 10      (D                                                                                                    MBCP                                                                                       RBHC
                                 @:- -1            GBSC
                                 @:3     Ch                                                                                                    Milli]                                                              AL                     EVM
                                                   G 131 IR
                                                   SLBB                                                                                        MBDR                                                                                       BHK









                                                                                                                                                                        11111-1          loll             1 11 1



                                                                          M                       @on On -so M 'm M On





                                                                                                                                                                            P
                                                                                                                                                                               PH
                                                                                                                                                                            BPH
                                      LMSB                                                               CLSJ                                                               PBIB
                                      LMPI                                         1230.37               CLLC                                                               PBSP
                                      LMAC                                                               1111H                                                              ClWB
                   rD                 CCBH
                   @1)                                                                                   VBSP                                                               C13SR
                      19,0            CCNB
                   CD  H                                                                                 ABOB                                                               CBSP
                                      ccic
                      -n              ABLR                                                               CLCL                                                               PCLO
                                                                                                         TBLB                                                               PCMP
                   p cn               ABHI                                                                      M                                                           SAM
                       cn             CBCR                                                               TBLF
                            (-D                                                                                                                                             APDB
                            :I        MBAR                                                                                                                                  APCP
                                      SAPP'
                            0                                                                            BBSD
                                      SAMP                                                                                                                                  AESP
                            0                                                                            13BMB
                            ::3       rssp                                                                                                                                  SRWP
                            0
                w           (D        E-SBD                                                              MRTP                                                               CKBP
                            n         MBGP                                                               MRPL M                                                             TBNP
                            w         IMBLR                                                              BSSI                                              LA               TBMK
                            =         MBCB                                                                                                                                  TBPB
                                                                                                         BSBG
                                      MBTp                                                               LBNT                                                               TBOT
                                      N,93DI                                                                                                                                7183 KA
                                      m B Em                                                             LIBNO                                         1524.80              TBHB
                                      BRCL                                                               LPGO                                                               TBCB
                            0                                                                                                --------
                                      BRFS                                                               MsIlIc                                                             CBBI
                                      GBCR                                                                                                                 ms
                                                                                                         MSBB                                                               CRFM
                                      GBOB
                        Zj  cn                                                                           MSPB                                                               NBNB
                                      GBTID)                                                                       ....... . ........................ ......................................
                                      GBYC                                          1614.23              MBCP                                                               RBHC
                            C)
                        Cf)           GBSC                                                                                                                 AL               EVFU
                                      GBHR                                                               MBDR                                                               BHKF
                                      SLBB




















                             CD

                                                        LA
                                                                          LA                                                                                                                                    tA


                                         ILAM S B                                                                    CLSI                                                                        PBPH
                                         L.MPI                                               674.13                  CLLC                                                                        PBM
                    cn       >           LMAC                          mm                                            JHJH                                                                        PBSP,
                         o   -,          CCBH
                             (D                                                                                                                                                                  CBJB
                             "I          CCNB                                                                        VBSP
                             ;o                                                                                                                                                                  CBSR
                                         ccic                                                                        ABOB
                                                                                                                                                                                                 CBSP
                                         ABLR                                                                        CLCL
                    (-D      cr                                                                                                                                                                  PCLO
                    w                    A13M
                    11   z   (D                                                                                      TmBL2                                                                       PCMP
                                         CBCR
                                         MBAR                                                                        TBLF                                                                        SA
                    Ul                   SAPP                                                                        BB*M                                                                        APDB
                    w                    S A MPP                                                                     BBSD                                                                        APCP
                    Z                                                                                                                                                                            AESP
                         cn              ESSP                                                                        BBMB
                                         ESBD                                                                                                                                                    SRWP
                       <                                                                                             MRI?
                    n                    MBGP                                                                                                                                                    CKBP
               co   2L)                                                                                              MRPL
                                         MBL.R                                                                                                                                                   TBNP
                             0           milcil                                                                      lissi                                                                       lIB3 WK
                             0           MBIII                                                                       BSBG
                         :7  0                                                                                                                                                                   TBPB
                                         MBDI                                                                        LBMP                                                     L.A                TBOT
                                         I'M B EM                                                                    UINO                                                                        T13KA
                                         BRCL                                                                                                                             432.47
                         0   r1l,                                                                                    LPGO                                                                        TBHMB
                                         BRFS
                                                                                                                                                                                                 TBCB
                                         GBCR                                                                        MSPC
                             0                                                                                                                                                                   CBBI
                                         GBOB                                                                        MSBB                                                    ms
                             :@
                             (n          GBTD                                                                        MSPB                                                                        CBFM
                                                                                                                                   ................................... ................................ NBNB
                         0               GBYC                                                                        MBCP                                                                        RBHC
                         V)  0           GBSC                                                                        NIBIU                                                    AL                 EVFU
                                         GBHR                                                360.63
                         mo (n           SLBB                                                                        MBDR                                                                        BHKF




















                                            LMSB                                                                              CLSI                                                                             PBPH
                                            LMPI                                                                              CLLC                                                                             PBE3
                            7-   >          L.MAC                                                                                                                                                              PBSP
                            cn                                                                                                114111
                      p          CD         CCBH                                                                                                                                                               CBM
                                 11                                                                                           VBSP
                      C/)        w          CCNB                                                                                                                                                               CBSR
                                 m          ccic                                                                              ABOB
                                 (D                                                                                                                                                                            CBSP
                                 r)         ABLR                                                                              CLCL                                                                             PCLO
                      p     co   @7         ABM                                                                               TBLZ
                            w                                                                                                                                                                                  PCMP
                            CD              CBCR
                                 cn                                                                                           TBLr                                                                             SAWB
                                 (D         MBAR
                                                                                                                              BBM                                                                              APDB
                                            SAPP
                                                                                                                                                                                                               APCP
                                            SAMP                                                                              BBSD                                                                             AESP
                                 0          ESSP                                                                              13BMB
                                 @3                                                                                                                                                                            SRWp
                                 n          r-Sl3D                                                                            MRTP
                                 n                                                                                                                                                                             CKBP
                  Q0                        MBGP                                                                              MRPI,
                                                                                                                                                                                                               TBNP
                                            INIBLR
                                                                                                                              Bssl                                                                             '111MK
                                            MIIC13
                                            N411,11,                                                                          INIG                                                                             TBIIB
                                            MBDI                                                                              I'M,                                                                             IBOT
                                                                                                                                                                                          LA
                                            1\4 13 Elm                                                                        LBNO                                                                             MA
                                                                                                                                                                                       677.10
                            0               BRCL                                                                                                                                                               'MHB
                                 0                                                                                            IJIGO
                                            BRFS                                                                              MSPC           .......                                                           TBCB
                                                                                                                                                                                                               CBBI
                                            G13CR
                                            GBOB                                                                              MSBB                                                        ms
                                                                                                                                                                                                               CBFM
                                                                                                                                                                                                                           123




























                                            GBITDD                                                                            MSPB
                                                                                                                                                                                          .........            NBNMB
                                            G13YC                                                                             mila,                                                                            RBIAC
                                 0
                                            GBSC                                                                              IM13141                                                     AL                   EVFU
                                            GBHR                                                     917.77
                                 (D                                                                                           MBDR                                                                             B14KF
                                 w          SLBB














                               171






                                                                                LA
                               CK)
                                                                                                                                                                           I .... I....
                                           LMSB                                                                              CLS]                                                                             PBPH
                               >           LMPI
                                                                                                                             CLLC                                                                             PBIB
                                           L.MAC                                                                             JHJH                                                                             PBSP
                                           CCBH                                                                                                                                                               CWB
                                                                                                                             VBSP
                                           CCNB                                                                                                                                                               CBSR
                                           ccic                                                                              ABOB
                                           A B LLAR                                                                          CLCL                                                                             CBSP
                               (D                                                                                                                                                                             PCLO
                               ;n          ABM                                                                               TBLI3
                           CD N                                                                                                                                                                               PCMP
                               0           CBCR                                                                              TBLF                                                                             SAWB
                                           MBAR
                                                                                                                             BWMB                                                                             APDB
                               0           SAPP
                           C                        a                                                                                                                                                         APCP
                                           SAMP                                                                              131ISD
                           0                                                                                                                                                                                  AESP
                           cn              ESSP                                                                              B13MB
                           2. r-tl
                     w                     r-.S B D                                                                          MRTp                                                                             SRWP
                 a                         MBGP                                                                                                                                                               CKBP
                                                                                                                             RPL
                           P (D            MBLR     3'                                                                       MRPL                                                                             T13NP
                                           MBCB     m                                                                        BSSI                                                                             TBMK
                           :7 0

                                           MBDI
                           Z: n                                                                                              LBMV                                                        LA                   IIBOT
                               :n          w3rm
                               r1t,                                                                                          1,11NO                                                                           TIB3KA
                           0               IIRCL                                                                                                                                      344.97
                                                                                                                             LPGO                                                    NN                       TBHB
                                           BRFS                                                                                                  ........... .................  ........................      Imca
                               0           GBCR                                                                              MSPC
                               @3                                                                                                                                                                             CBBI
                               W           GBOB                                                                              MSBB                                                        ms
                                                                                                                                                                                                              CBFM
                           0               GBTID)                                                                            MSPB
                                                                                                                                          ..................... ................................................. NBNB
                                           GBYC                                                     371.57                   MBCP                                                                             RBHC
                               0           Gasc
                                                                                                                             MB141                                                       AL                   EVFU M
                               cn          GB14R
                               ril                                                                                           MBDR                                                                             BHKF
                               CD          SLBB
                                                                                                                                                                                                                          mm





















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                                                             LA                 z;;                                                           t.A                                             L4
                                            LMSB,3''                                                                          CLSJ                                                                             PBPH
                                            LMPI                                                                              CLLC                                                                             PBIUB
                                            LMAC.                                                                                                                                                              Pasp
                                                     =95=                                                                     JHWJH
                                            CCBH,                                                                                                                                                              cam
                                            CCNB                                                                              VBSP
                                                                                                                                                                                                               CBSR
                            (j) n           ccic                                                                              ABOB
                                   cr       ABLR                                                                              CLCL                                                                             CBSP
                                   n                                                                                                                                                                           PCLO
                                            A13IR                                                                             TBIA                                                                             PCMP
                                            CBCOO
                                                                                                                              TBLF                                                                             SAWB
                                            MBAR'S
                            cn
                            CP                                                                                                BKM                                                                              APDB
                                            SAPPF
                      (T                    SAMP                                                                              BBSD                                                                             APCP
                                            ESSP                                                                              BBMB                                                                             AESP
                                                                                                                                                                                                               SRWP
                      M r4                  ES13D
                                                                                                                              MRTP
                                            MBGP                                                                                                                                                               CKBP
                                   0                                                                                          MRPL
                                   :n       M[31,R                                                                                                                                                             T13NP
                                                                                                                              BSSI
                                            WWII                                                                                                                                                               '113MK
                                                                                                                              13SBG                                                                            TBPB
                            0               MBDI                                                                              LBMP                                                                             TnBOT
                                                                                                                                                                                           LA
                                            MBEM
                                   0                                                                                          U3NO                                                                             TnB KA
                                   :n       BRCL
                                   cn       BRFS                                                                              LPGO                                                                             TBHB
                                                                                                                              MS11C                                    ..............                          TBCB
                                   :3       GBCR                                                                                                                                                               CBBI
                            cn              GBOIB3                                                                            MS1311                                                      ms
                            p      0                                                                                                                                                                           CBFM
                                   1-1@     GBTD                                                                              MSPB
                                   cn                                                                                                    .......................................................................... NBNB
                                   r-t-     GBYC                                                                              MBCP
                                   n                                      ...                                                                                                                                  RBHC
                                   "        GBSC       I I I I I I - z ; @ @ @ @ @ F
                            (tck            GBHR                                                     407.43                   M13M                                                         AL                  EVFU
                            cn                                                                                                MBDR                                                                             BHKF
                                                                                                                                                                                                                          Room

































                                                                                                                                                                                                                          m


                                                                                                                                         FM

                                              LBB
                                   0        SLBB











                               ITI




                                                                                                                                                  LA
                                                                                                                                                                              CD

                                            LMSB                                                                              CLSJ                                                                            PBPH
                                            LMI-I                                                                             CLLC                                                                            PBIEB3
                                            LMAC'                                                                                                                                                             PBSP
                                                                                                                              JHJH
                                            c
                                               ntr
                                            c.H                                                                                                                                                               CBJB
                                            CCNB                                                                              VBSP                                                                            CBSR
                                            CICIC                                                                             ABO13
                                                                                                                                                                                                              CBSP
                          940 C 7'          ABLR                                                                              CLCL                                                                            PCLO
                            3 (D            ABM                                                                               IBLI3                                                                           PCMP
                                            CJB3CR
                                                                                                                              TBLF                                                                            SAWB
                     Z    C:                MBAR
                          cn                                                                                                  13LT113                                                                         APD9
                                            SAPP
                                            SAMP                                                                              BBSD                                                                            APCP
                                                                                                                                                                                                              AESP
                                            ESSP                                                                              BBMB
                                                                                                                                                                                                              SRWP
                                            SSBD                                                                              MRTP   m
                                                                                                                                                                                                              CKBP
                                            MBGP
                               0            MBLR                                                                              MRPL                                                                            TBNP
                                            milcil                                                                            MST                                                                             'IIIMK
                                                                                                                              BSBG                                                                            TBPB
                                            MBDI                                                                              LIMP                                                                            TBOT
                                            M B EM                                                                            LBNO                                                                            TBKA
                          CD   0            13RCL
                               z                                                                                              I.PGO                                                     LA                    TBHB
                               cn           BRFS
                                                                                                                              MSPC                   ......                                                   IMB Cal 3
                                            GBCR                                                                                                                                                              CBBI
                                            GBOB                                                                              MSB13  FM                                                 ms
                                                                                                                                                                                                              CBFM
                                                                                                                              MSPB
                                            GBID
                                                                                                                                                                                                              NBNB
                          @O                GBYC                                                    230.64                    MBCP
                                                                                                                                                                                                              RBHC
                                            OBSC
                                                                                                                              MB                                                        AL                    EVFU
                                            GBHR
                                                                                                                                DR                                                                            BIAKF
                                            SLBB                                                                              MB
                               0







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                                                                                                                                                                             LA
                                                                       tA                        LA                       LA                                                 0            '.A

                                                   LMSB                                                                                     CLSJ                                                                                     PBPH
                                                   LMPI                                                                                     CLLC                                                                                     PBM
                                                   LMAC                                                                                                                                                                              PBSP
                                C/)                                                                                                         JHJH
                                                   CCBH                                                                                     VBSP                                                                                     CBM
                                                   CCNB
                                      pp)                                                                                                                                                                                            CBSR
                                     olc@          ccic                                                                                     ABOB                                                                                     CBSP
                                      (D
                                                   ABLR                                                                                     CLCL                                                                                     PCLO
                          w     Cn                 ABM                                                                                      IBLB                                                                                     PCMP
                                                   CBCR
                                                                                                                                            TBLF                                                                                     SAWB
                                                   MBAR                                                                                     B RTMB                                                                                   APDB
                                                   SAPP
                                      CD
                                                   SAMP                                                                                     BBSD                                                                                     APCP
                                                   rssp                                                                                     BBMB                                                                                     AESP
                                                                                                                                                                                                                                     SRWp
                                                   ESBD
                                      (D           MBGP                                                                                                                                                                              CKBP
                                                                                                                                            MRPL
                                                                                                                                                                                                                                     TBNP
                                                   MBLR
                                0 p                                                                                                         BSSI
                                      f-t-         MBCB                                                                                     BSBG                                                                                     T13MK
                                      0            IMBI?                                                                                                                                                                             TBPB
                                                   MBDI                                                                                     LBMP                                                                                     TBOT
                                                           Fo                                                                               LBNO                                                                                     TBKA
                                                   BRCL
                                0                                                                                                           LPGO                                                              LA                     TBHB
                                                   BRFS                                                                                                      .......... .........  .................. .... .................
                                                                                                                                                                                                                                     TnBCB
                                                                                                                                            msfIc                                                                                    CBBI
                                      n            GBOB                                                                                     MS1111                                                           ms
                                                                                                                                                                                                                                     CBFM
                                                   GBID                                                                                     MS1 11           ................................... ................................    NBNB
                                                   (;Iiyc                                                                                   M13cl,
                                                                                                                                                                                                                                     RBHC
                                      0
                                                   GBSC          A X                                                                        MBIR                                                              AL                     EVFU
                                                   GBHR                                                          195.77
                                                   SLBB                                                                                     MBDR                                                                                     BHKF
                                      pp)
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                                                                                                                                                                                                                                                   m
                                                           bm























                                                                                                          LA


                                                    LMSB                                                                                        CLSJ                                                                                       PBPH
                                  0       >         LMPI                                                                                        CLLC                                                                                       PBE3
                                  '4.!@   <         LMAC                                                                                                                                                                                   PBSP
                                  cn      0                                                                                                     JHIH
                                                    CCBH                                                                                                                                                                                   CRIB
                                          w         CCNB                                                                                        VBSP
                                  Ct) m                                                                                                                                                                                                    CBSR
                                          (D        ccic                                                                                        ABOB
                           orc@   ::@                                                                                                                                                                                                      CBSP
                                  0                 ABLR                                                                                        CLCL                                                                                       PCLO
                                                    AM                                                                                          -mb      mom                                                                               PCMP
                                                    CBCR                                                                                        TBLF                                                                                       SAWB
                                                    MBAR'MM
                                          0                                                                                                     BITI13                                                                                     APDB
                                  z-                SAPP
                            p                       SAMP                                                                                        111ISD                                                                                     APCP
                            'l    cn                                                                                                                                                                                                       AESP
                       W                            ESSP                                                                                        BBMR
                                                                                                                                                                                                                                           SRWP
                                                    LSBD                                                                                        MRTP
                            cn                      MBOP                                                                                                                                                                                   CKBP
                            w     E:                MBLR                                                                                        MRPL                                                                                       TBNP
                            @3                                                                                                                  BSSI
                                                    MBCB                                                                                                                                                                                   TBMK
                                  (D 0              MBIP                                                                                        BSBG                                                                                       TBPB
                                                    MBDI                                                                                        I,BMP                                                                                      TnBOT
                                  4)                                                                                                            IJINO                                                                                      '113KA
                                  r-, 0             JJRCL
                                  n       0                                                                                                     LPGO                                \NN\l                          LA                      7BHB
                                          @5        13RrS                                                                                                       .....................................................................
                                          0                                                                                                     mSPc                                                                                       TBCH
                                          (D        (313CR                                                                                                                                                                                 CBBI
                                  a                 GBOB                                                                                        MSBB                                                              ms
                                                    G13,11),                                                                                    MS1,11                                                                                     CBFM
                                                                                                                                                                .....................................................................      NBNB
                                                    GBYC                           ......... .           ......                                 MBCP                                                                                       RBHC
                                          0         GBSC                            . . . . ..
                                          @3                                                                                                    IIABM                                                              AL                      EVFU
                                  CD      Cn        G B HMR
                                                    SLBB                                                                                        MBDR                                                                                       BHKF
                                  o                                                                                                                               .....................
                                                                                                                                                                 ..................






















                                                         LA                                                                                                            tA

                                          LMSB                                                                 CLSJ                                                                   PBPH
                                          LMPI                                                                 CLLC                                                                   PBM
                      Ct) 0    >          LMAC                                                                                                                                        PBSP
                      w '--<   <                                                                               JHJH
                      :Z   CO  ('D        CCBH                                                                                                                                        CBjB
                                                                                                               VBSP
                                          CCNB
                                                                                                               ABOB
                           C/) m          ccic
                     dc,                  ABLR                                                                 CLCL                                                                   PCLO
                                          ABIE                                                                 TBLB                                                                   PCMP
                                          CBCR                                                                    LF                                                                  SAWB
                                          MIIAR
                           p                                                                                                                                                          APDII
                                              p
                                            pp                                                                 BM13
                                          SA                                                                                                                                            Cp
                                                                                                                                                                                      AP
                                          SAMP                                                                 BBSD
                                                                                                                                                                                      AESP
                                          ESSP                                                                 BBMB                                                                   SRWP
                                          ESBD
                                                                                                               MRTP                                                                   CKBP
                                          'M B CG; P
                      C-n      rt@                                                                             MRPL                                                                   TBNP
                                          MBLR
                                                                                                               BSSI                                                                   TBMK
                           C:             %VCB
                           C/)            MBI?                                                                 lislic) I                                                              TBPB
                           CD             MBDI                                                                 LIM,
                      CD
                                          M 13 EM                                                              LBNO                                                LA                 TMB KA
                                          BRCL                                                                                                                                        TIB31HMB
                                                                                                               LPGO
                                                                                                                                          ..............................................
                           n   0          BRIS                                                                                                                                        nCB
                               :'         13CR                                                                 MS1,C
                               n          G                                                                                                                                           CBBI p
                                                                                                               MSBB                                               ms
                                          GBOB
                                          GBTD ...                                                             MSPB
                                                                                                                                         ................................ ................
                                          GBYC                                                                 M13cl,
                           0   r-l-                                                                                                                                                   BH
                               0          GBSC                                      745.10                     MB14I                                               AL                 EVFU
                                          GBRR
                                                                                                               MBDR                                                                   HKF
                                          SLBB


                           o






















                                                                                                            LA                                                                                LA


                                           Lmsa                                                                              CLSI                                                                             PBPH
                                           Lmpi                                                                              CLLC                                                                             PRIB
                      cn.                  LMAC
                      rl@                                                                                                                                                                                     PBSP
                           @j              CCBH                                                                              J14JH                                                                            CBJB
                                W          CCNB                                                                              VBSP
                                m                                                                                                                                                                             CHSR
                           p CD            ccic                                                                              ABOIB3
                           0                                                                                                                                                                                  CBSP
                           @3' cr          A B LLAR                                                                          CLCL
                                                                                                                                                                                                              PCLO
                                           All U
                      C/)                                                                                                    1131,13                                                                          PCmp
                           (/) t."         CBCR
                                                                                                                             TBLF                                                                             SAWB
                                           MRAR
                                )aq                                                                                          BMB                                                                              APDB
                                           SAPP
                                           SAMP                                                                              B13SD                                                                            APCP
                           CD   %:)                                                                                                                                                                           AESP
                                           ESSP                                                                              BBNO
                                           r,-SBD                                                                            MRTP                                                                             SRWP
                 C-,                       IMBGP                                                                                                                                                              CKBP
                           :@   @3                                                                                           MRPL
                      0) p                 m B LLAR                                                                                                                                                           TBNP
                                                                                                                             BS I
                                                                                                                                                                                                              T13MK
                                                                                                                             BsHG
                                           M11DI                                                                             1.11ml,
                                           MBEM                                                                              LLJ3NO                                                      LA                   TBKA
                                           13RCL                                                                                                                                       57.83
                                                                                                                                                                                                              TBHB
                                           BRFS                                                                              LPGO                                           ..........................
                                                                                                                             MSPC    FM*"****'*         .........  ... .. ..                                  TBCB
                                0          GBCR                                                                                                                                                               CBBI
                                           GBOB                                                                              MSB13   TqM                                                 ms
                                           GBTMD                                                                             MSPB                                                                             CBFM
                           0    -                                                                                                              .................................................................. N13NB
                           C/)  :n         GBYC                                                                              MBCP                                                                             RBHC
                                0          GBSC                                                                              Nmtfl                                                       AL                   EVFU
                                "<         GBHR                                                      85.17
                                           SLBB                                                                              MBDR                                                                             814KF
                                (D









                                                                                                                                    NOR            111101111      00111          1 NMI          I       I






















                                                                 LA


                                            LMSB                                                                              CLSI                                                                             PBPH
                           0    >           LMPI                                                                              CLLC                                                                             PBD3
                                            LMAC                                                                              JHJH                                                                             PBSP
                                            CCBH                                                                                                                                                               CWB
                                                                                                                              VBSP
                                            CCNB                                                                                                                                                               CBSR
                           C/) 010.
                      11:3      CD          ccic                                                                              A130B
                     010,                   ABLR                                                                              CLCL                                                                             CBSP
                                                                                                                                                                                                               PCLO
                                            ABM                                                                               InB LB                                                                           PCMP
                                            CJB3CR
                           CD                                                                                                 TBLF                                                                             SAWB
                                            MBAR
                                N)                                                                                            1311113                                                                          APDB
                                +           SAPP
                                CO          SAMP                                                                              13BSD                                                                            APCP
                      po   Z
                      11                                                                                                                                                                                       AESP
                           cn   -1.         ESSI,                                                                             1313MB                                                                           SRWP
                           Ro   :n          ESBD                                                                              MRI?
                 N)             cfo.                                                                                                                                                                           CKBP
                  -j                        MBGP                                                                              MRPL    mm
                                            M B LUR                                                                                                                                                            TBNP
                           Z:               IMBCB                                                                             BSSI                                                                             TBNIK
                           cr,  0
                           cn               MB'I`P                                                                            BSBG                                                                             TBPB
                                w           MBDI                                                                              1,13m),                                                                          TBOT
                                r-tl                                                                                                                                                     LA
                                            M IB3 LM                                                                          LBNO                                                                             TBKA
                      m 1+                  BRCL                                                                                                                                    3564.13                    TBHB
                      .    0    0                                                                                             LPGO @\\\77"Z7
                           ::5, 0           BRFS                                                                              MSPC                         A  .............................................    nCB
                                            GBCR                                                                                                                                                               CBBI
                           0 0
                                rD          GBOB                                                                              MSBB.@@                                                    ms                    CBFM
                                z
                                            GBID                                                                              MSPB
                                                                                                                                           ....................................................................... NBNB
                           0                GBYC                                                                              MBCP                                                                             RBHC
                                r--t-       GBSC
                                0                                                                  7962.70                    MB141                                                      AL                    EVFU
                                p           GBHR
                                                                                                                                                                                                                           Em







                                cn          SLBB                                                   @@710                      MBDR                                                                             BHKF
                           o




















                           (D


                                                                                                                              LA


                                      LMSB                                                                  CLSJ                                                                  PBP14
                   cn 0    >          LMPI                                           2380,67                CLLC                                                                  PBIB
                       -<  e,         LMAC                                                                                                                                        PBSP
                       CD  q                                                                                JHJH
                                      CCBH                                                                                                                                        CBJH
                                                                                                            VBSP
                                      CCNB                                                                                                                                        CBSR
                                      ccic                                                                  ABOB
                                                                                                                                                                                  casp
                                      ABLR                                                                  CLCL                                                                  PCLO
                                      ABIU
                                      CBCR                                                                  713LB                                                                 PCMp
                                                                                                            TBLF                                                                  SAWB
                                      IMBAR                                                                                                                                       APDB
                           +          SAPP
                                                                                                            BITIM
                                                                                                                                                                                  APCP
                   @L) z              SAMP                                                                  BBSD
                   "   0-1.           ESSP                                                                                                                                        AESP
                   cn  @o  -                                                                                BB&M                                                                  SRWp
                   )-_     z          ESBD                                                                  MRTP
                       H Oro,
              00                      MBCjP                                                                                                                                       CKBP
                                      mill R                                                                                                                                      TIM'
                                                                                                            lissi
                       w   0          mliclj                                                                                                                                      '173MK
                       (/) 9          MBTP                                                                  BS13G,
                   CD  2. @')                                                                                                                                                     TBPB
                                      MBDI                                                                  LBMII                                               LA                Imm
                       w              mBEM                                                                  LBNO'm                                                                TBKA
                                      BRCL                                                                                                                  3541.70
                                                                                                            LPOO                                    "N                            TBHB
                                      BRFS                                                                                                               :@AAA.N                  TBCB
                                                                                                            mspc
                                      GBCR
                                                                                                                                                                                  CBBI
                                      GBOB                                                                  MsBB                                                ms                CBFM
                                      GBTD                                                                  MSPB
                       0                                                                                                  .....I.................... ........................................ Nl3NI3
                                      GBYC                                                                  MBCP                                                                  RBHC
                                      GBSC                                               X-N                MBI-H                                                AL               EVRJ
                       CD             GBHR                                           4441.57
                           U)
                                      SLBB                                                                  MBDR                                                                  BHKF
                       0   @3
                                                                                                                                                                                              9

                                                                                                                                                                                              am






















                                                                      bi                                     00                                                                                         C*
                                    tlD
                                                  LMSB                                                                                      CLSJ                                              3                                         P'BPH
                                                  LMPI                                                                                      CLLC                                                                                        P13IB
                                                  LMAC                                                                                                                                                                                  PBSP
                              p                                                                                                             3141H
                                                  CCBH
                                                                                                                                                                                                                                        CBJB
                         CD                       CNB                                                                                       VBSP
                                    O'c'                                                                                                                                                                                                CBSR
                                                  ccic                                                                                      A130B
                                                                                                                                                                                                                                        CBSP
                                                  ABLR                                                                                      CLCL                                                                                        PCLO
                                    +             A.BM
                         u          w                                                                                                       IBLB                                                                                        PCMP
                                                  CBCR
                                                  MBAR                                                                                      TBLF                                                                                        SAWB
                                                                    ....... ...
                                    70.           SAPP                                                                                      BR"M                                           FF IF                                        APDR
                                    P             SAMP                                                                                      BBSD                                                                                        APCP
                         p          0             ESSP                                                                                      BBMB                                                                                        AESP
                                                  ESBD                                                                                                                                                                                  sRWp
                         C)                                                              Mm                                                 MRTP
                              r
                                                  MBGP                                                                                                                                                                                  CKBP
                    (-0        :7                                                                                                           MRPL
                                    cp            IM 13 LR                                                                                    BSSI                                                                                      TBNP
                                    ;Z@           IMBCB                                                                                                                                                                                 'M
                                                  MBT?                                                                                      BSBG                                                                                        T:pB
                                                  MBDI                                                                                      LB
                                                                                                                                                NV                                                                                      TBOT
                                                  B
                                                     'M                                                                                     113NO                                                                                       IBKA
                                                  BRCL
                                                                                                                                            LPGO            K     K x       Ix N N q                            LA
                                                  13RFS
                                                  GBCR                                                                                      mspc
                                cn                GBOB                                                                                      MSBB                    K       K                                  ms                       CBFM
                                                  GBTD                                                                                      MSPB
                                                     YC
                                                  GB   C                                                                                                                               ......................................           NBNB
                                                                                                                                            MBCP                                                                                        RBHC
                                                  GBSC
                                                                                                                                            MBIH                                                                AL                      EVFU
                                    cn            G B 14MR                                                                                  MBDR
                                cn                SLBB     .... ......                                                                                                                                                                  BHKF INN x
                                                                                                                                                     W7

















                                                                                                          8       8
                       00
                                 LMSB                                                        CLSI                                                            PBPH
                                 LMPI                                                        CLLC                                                            IIB
                                                                                                                                                             PB

                                                                                                                                                             Sp
                       >         LMAC                                                                                                                        P BP
                                                                                             JHJH
                                 CCBH
                       n                                                                     VBSP                                                            CBJB
                       w         CCNB                                                                                                                        CBSR
                                 ccic                                                        ABOB
                                                                                                                                                             CBSP
                       4         ABLR                                                        CLCL                                                            PCLO
                       +         ABM                                                         TBLIB3
                Ul     Ul                                                                                                                                    PCMP
                                 CBCR
                                                                                             BLF                                                             SAWB
                                 BAR
                   cn            SAPP                                                        Bam                                                             APDB
                                 SAMP                                                        BBSD                                                            APCP
                                                                                                                  \RMR                                       AESP
                       0         ESSP                                                        13BMB
                       -                                                                                                     \N1
                       @s        LSBD                                                                                                                        SRWP
                C))    w                                                                     MRTp
            C)                   IMBGP                                                                                                                       KBP
                                                                                             MRPL
                                 l%4BLR                                                      BSSI                         q
                       0         MBCB
                                 MBTP                                                        BSHG
                    0  a         WIN                                                         1.11mil
                                 MMM                                                         LBNO                                                            TBKA
                                 BRCL       . . . . . . . S=)                                LPGO                                        LA                    ----------
                                 BRFS                                                                                   .......... .......................
                                                                                                                                                             713CB
                                                                                             MSPC                 x x
                    0            GBCR                                                                                                                        I M,
                                                                                                                                                             CBBI xqll "Ill I
                       :3        GBOB                                                        MSBB                                       ms
                       0                                                                                  11 \ x                                             CB
                                 GBlD                                                        MSP13 RkRl@ -,-.
                                                                                                                              .. ........................    NB
                                 GBYC
                                                                                             MBCp                                                            RBH
                                 GBSC
                                                                                             NMIR                                        AL                  EVFU
                                 GBHR
                                                                                             MBDR                                                            BRKF
                                 SLBB




















                                                LMSB                                                                                        CLSJ                                                                                       PBP
                                                LMPI                                                                                        CLLC     F!FM                                                                              PBIB
                                                LMAC                                                                                        mm                                                                                         PBSP
                                                CCBH                                                                                                                                                                                   CBJB
                                                                                                                                            VBSP
                                                CCNB
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                                       Reprint 3


                   Trace Organic Contamination in Galveston Bay:
                  Results from the NOAA National Status and Trends
                                 Mussel Watch Program


             Terry L. Wade, James M. Brooks, Josil, L. Sericano, Thomas J. McDonald,
                  Bernardo Garcia-Romero, Roger R. Fay, and Dan L. Wilkinson







                                Trace Organic Contamination in Galveston Bay:
                              Results &onx the NOAA National Status and Trends
                                             Mussel Watch Program

                      Terry L. Wade, James M. Brooks, Josd L. Sericano, Thomas J. McDonald,
                            Bernardo Garcia-Romero, Roger R. Fay, and Dan L. Wilkinson
                      Geochemical and Environmental Research Group, Texas A&M University


                   In order to determine the current status and long-     term trends for selected
                   environmental contaminants in U.S. coastal areas, the National Oceanic and
                   Atmospheric Administration (NOAA) established the National Status and Trends
                   (NS&T) Mussel Watch Program. As part of the NS&T Program, sediment and
                   oyster samples have been collected and analyzed from over 70 estuarine sites in
                   the Gulf of Mexico representing all major Gulf Coast estuaries. Sampling sites
                   were located in areas not influenced by known point sources of inputs.

                   Oysters have been employed as sentinel organisms because they are
                   cosmopolitan, sedentary, known to bioaccumulate contaminants of interest, able
                   to provide an assessment of bioavailability, not readily capable of metabolizing
                   contaminants, able to survive pollution loading, readily found as locally stable
                   populations, transplantable, and commercially valuable. Oysters are, therefore,
                   excellent biomonitors for contamination in estuarine areas.

                   The Galveston Bay system is one of the largest and most economically important
                   estuaries along the Texas Gulf Coast. This area has been the recipient of various
                   contaminant inputs because of an aggressively growing urban. and industrial
                   region. Houston, Deer Park, Baytown, Texas City and Galveston, surrounding
                   Galveston Bay  to the north and west, are some of the most heavily industrialized
                   areas in Texas. Hundreds of industrial plants bordering the Galveston Bay
                   estuarine system, including petrochemical complexes and refineries, as well as
                   runoff, are--likely to introduce significant amounts of organic contaminants into
                   the bay. In general, ecological studies have suggested that the waters of
                   Galveston Bay contained contaminants in sublethal amounts which caused stress
                   to organisms resulting in significant changes in the, estuarine community
                   structure.

                   Samples were collected at six locations in Galveston Bay (Fig. 1). Sampling was
                   conducted each winter and began January of 1986 at four sites (15-18), and in
                   December of 1987 at two other sites (58-59). Additional samples were collected at
                   some of these sites to provide information on seasonal trends in contaminant
                   concentrations. Sediments (top 1 cm) and oysters (20) were collected at three
                   stations at each site and analyzed for polynuclear aromatic hydrocarbons (PAHs),
                   polychlorinated biphenyls (PCBs), chlorinated pesticides (e.g DDT, chlordane) and
                   tributyltin. All sample analyses were performed using Standard Operating
                   Procedures to provide high quality, precise, accurate and reproducible data. Data
                   quality was further assured by participation in NOAA/NIST intercalibration
                   exercises. This allows for direct comparison of NS&T Gulf Coast data with NS&T
                   data for the East and West Coasts.




                                                      3-33

































                                                                                                               rRINlry BAY




                                                                                     15



                                                                                                 16                                     CASf
                                                                                                                                          *17
                                                                                                        GALVESTON 8AY




















                                                                                                       too
                                                                                             Of






                                                                     -SAN LUIS                      01    11 1.   1 1 1 '"i"
                                                                        -AS$









                             Figure 1. Galveston Bay sampling sites included the Ship Channel (59), Yacht Club (15), Todd's
                             Dump (16), Hanna Reef (17), Offatt's Bayou (58) and Confiederate Reef (18).




                                                                                               3-34







                    Total PAH average concentrations ranged from 54 to'2400 ng/g. Th highe
                                                                                                C        r
                    concentrations were measured in oysters from the upper portion of Galveston Bay
                    (i.e., stations 15 and 59) and near the City of Galveston (i.e., stations 18 and 58).
                    Oyster samples from areas farther away from urban centers (i.e., stations 16 and
                    171) had average concentrations one to two orders of magnitude lower. In general,
                    these concentrations are in good agreement with those previously encountered
                    during temporal studies in Galveston Bay. Two PAHs, pyrene and fluoranthene,
                    generally accounted for >25% of the total PAHs measured. The predominance of
                    these compounds would suggest that the major source of PAHs in the Galveston
                    Bay area is combustion products.

                    Average total PCB and DDT concentrations in Galveston Bay oysters were in the
                    48-1100 and 12-240 ng(g ranges, respectively. Most of the DDT residue is present
                    as metabolites, DDE and DDD. hi general, less than 10% of the total contaminant
                    load in oysters is the parent compound, DDT. Samples from stations 15 and 59
                    were the most contaminated, while oysters from Station 17 had the lowest residue
                    concentrations. These concentrations agree with the ranges reported earlier for
                    Galveston Bay bivalves.

                    Contaminant concentration patterns were similar for most contaminants. The
                    upper bay sites (15; 59) had higher concentrations than the mid-bay sites (16, 17)
                    for DDT, PAH, PCB and butyltins. Sites from the lower bay (18, 58) had
                    intermediate concentrations. This most likely results from proximity to large
                    urban areas and runoff inputs. The lower contaminant loading in the mid-bay
                    region probably results from dilution effects. The concentrations found in
                    Galveston Bay are similarto the range found throughout the Gulf of Mexico for
                    the NS&T Program. The concentrations in the upper bay are above average for
                    the Gulf of Mexico, mid-bay concentrations are below, and lower bay
                    concentrations are close to the average Gulf of Mexico concentrations. Most of the
                    sites show no consistent temporal trend for the organic contaminants. However,
                    there is a general decrease in concentrations over time at Station 15 for PAH, PCB
                    and DDT.    '" Sample collections at other times of the year indicate some seasonal
                    variability of contamination concentrations.




















                                                         3-35






















                                           Reprint 4


              Toxic Contamination of Aquatic Organisms in Galveston Bay


             James M. Brooks, Terry L. Wade, Bobby J. Presley, Jos6 L. Sericano, Thomas
               J. McDonald, Thomas J. Jackson, Dan L. Wilkinson, and Tamara F. Davis







                       Toidc Contamination ofAquatic Organisnis in "veston B:4y

                  James M. Brooks, Terry L_ Wade, Bobby J. Presley, Jos,,5 L. Sericano, Thomas J.            r
                     McDonald, Thomas J. Jackson, Dan L_ Wilkinson and Tamara F. Davis
                    Geochemical and Environmental Research Group, Texas A&M University
                                                                                                             01

                  Little information regarding historical trends and concentrations of heavy
                  metals, hydrocarbons, pesticides and PCBs in aquatic organisms in Galveston
                  Bay has been available to guide decision makers and regulators. Each year
                  millions of pounds of fish and shellfish are caught by commercial and sport
                  fishermen in Galveston Bay and consumed as nutritional seafood. However, little
                  or no testing of edible tissues for toxic contamination by heavy metals,
                  hydrocarbons, pesticides and PCBs has been conducted to assure public health
                  and safety.' For this reason, the Galveston Bay National Estuary Program
                  (GBNEP), funded by.the U.S. Environmental Protection Agency (EPA) and the
                  State of Texas, undertook this study to characterize cont.-iminatibn in selected
                  aquatic organisms in Galveston Bay.

                  The 'Sampling design called for the analysis of trace contamin a*nts in five species
                  from four sites in Galveston Bay. Five species of marine organisms were targeted
                  for collection and analyzed as follows: two macroinvertebrates, Crassostrea
                  virginica, the oyster, and Callinectes sapidus, the blue crabl' ind three vertebrate
                  marine fishes, Cynoscion nebulosus, the spotted sea trout, Pogonias cromis, the
                  black drum, and Paralichthys lethostigma, the southern flounder. The goal of the
                  program was to collect. ten specimens of each target organism of legal market size
                  from each collection site.     Standard fisheries data were recorrded for all
                  collections. The collection sites for these target species (Fig. 1) were Morgan's
                  Point, at the mouth of the Galveston Ship Channel, Eagle Point off San Leon,
                  Carancahua Reef in West Bay, and Hanna Reef in East Bay.

                  Four samplings of aquatic organisms have been undertaken for: the GBNEP. The
                  first sampling May 23-25 collected oyster and crab samples; however, trawling for
                  fish was not very successful as a result of low salinity water due to Trinity River
                  flooding. A second sampling was undertaken June 6-8 that involved gill netting
                  at the four sites. This sampling had some success in collecting black drum, sea
                  catfish (Arius felis), spotted sea trout and southern flounder from some of the
                  sites, although not in sufficient quantities for most analyses. Most fish samples
                  were collected from a sampling from July 30 to August 3 after the bay had
                  returned to a somewhat normal salinity regime. However, late July sampling
                  was complicated by the-Apex Barge oil spill that occurred on July 28. Because of
                  this spill, few fish were collected near Eagle Point (close to the oit spill site). A
                  final sampling trip on September 4-6 completed the remaining sampling at Eagle
                  Point.

                  The analytical program called for the analyses of ten individual specimens of the
                  five target organisms from each site (200 edible muscle tissue samples). Fifty
                  liver samples were composited for analyses from the approximately 120 fishes-
                  Trace contaminants measured included heavy metals, polynuclear aromatic
                  hydrocarbons (PAHs), pesticides and PCBs and a GC-MS scan for'other EPA


                                                        3-37


































                                                                                                                   TRINI r Y BA Y
                                                                                        R N'S
                                                                                        IN




                          . .....                                                                  EAGLE                                             OAy
                                                                                                        NT
                                                                                                                                             EAS HANN
                                                                                                            GALVESMV BAY                                       ROUOVER PASS)





                                                                                   A

                                                                                                 of
                                                                                             kf





                                                                                                        0  1  2  5     5 6     OWWS
                                                                         S4A1 LUIS
                                                                           PASS












                            Figure 1. Collection sites for tissue samples.




                                                                                                3-38









                organic priority pollutants. Trace elements of interest in this study were those on
                the EPA Priority Pollutant List (PPL) which included: arsenic (As), cadmium
                (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium
                (Se), silver (Ag), and zinc (Zn). PAHs determined by GC/MS/SIMs included 39
                two- to five-ring aromatics and selected alkylated homologs. Pesticides and PCBs
                were determined by gas chromatography with election capture detection (ECD).
                Selected chlorinated pesticides (aldrin, chlordane, dieldrin, endrin, heptachlor,
                BHC, heptachlor epoxide, hexachlorobenzene, lindane, mirex, trans-nonachlor,
                toxaphene, DDTs, DDDs and DDEs) and individual PCB congeners were
                quantitated. Analytical methods for trace organic analyses. followed those of the
                NOAA National Status and Trends Mussel Watch Program.

                None of the average concentrations of trace metals or trace organic contaminants
                in fish tissue, oysters, or crabs collected in this study pose a risk to human health
                associated with consumption of seafood based'on the U.S. EPA (,1989) guidance
                manual for assessing human health risks for chemically contaminated fish and
                shellfish. In general, trace contaminants were higher in oyster and crab tissues
                than fish tissue. This was especially true for trace organics and certain trace
                metals such as zinc, lead, nickel, copper, cadmium and silver. Mercury showed
                the opposite trend with higher concentrations in fish tissue.         Most PAHs in
                Galveston Bay seem to originate from combustion sources (atmospheric
                deposition or runoff) and not from petroleum inputs based -on the distribution of
                PAHs and their alkylated homologs. The chlorinated hydrocarbons were
                represented by low levels of DDT and its metabolites (DDD and DDE). As expected,
                higher contaminant levels were generally found in the upper portion of Galveston
                Bay.(Morgan's Point) near the Houston Ship Channel.



























                                                     3-39





















                                              Reprint 5


                  Transplanted Oysters as Sentinel Organisms in Monitoring
                                                Studies



                          Jos6 L. Scricano, Terry L. Wade, and James M. Brooks







                    Tranvlanted Oysters as Sentinel Organisms in Monitonng Stuches

                               Jos4 L_ Sericano, Terry L. Wade and Jarnes M. Brooks
                   Geochemical and Environmental Research Group, Texas A&M University

                                                                                                              01
                   Coastal marine environment contamination by a number of organic compounds
                   of synthetic or natural origin has received increasing attention over the last
                   several years. Biomonitoring of these compounds in the aquatic environment is
                   well established and bivalves are generally preferred for this purpose. The
                   rationale for the "Mussel Watch" approach using different bivalves, e.g., mussel,
                   oysters and/or clams, has been summarized by different authors and its concept
                   has been applied to many monitoring programs during the last decade.

                   The National Oceanic and Atmospheric Administration (NOAA). National Status
                   and Trends (NS&T) Program, for example, is designed to monitor the current
                   status and long-term effects of selected organic and inorganic contaminants of
                   environmental concern, i.e., polynuclear aromatic hydrocarbons (PAHs),
                   chlorinated pesticides, polychlorinated biphenyls (PCBs), and trace metals.
                   Concentrations of these contaminants in bivalves are measured along the coasts
                   of the U.S.A. over several years. During the first five years of this program (1986-
                   1990) the objective was to sample all the locations prescribed by NOAA; however,
                   this goal was compromised by locations depleted of living oysters because of
                   diseases, predators, excessive freshwater runoff, harvesting or dredge material
                   burying entire reefs. Therefore, in some instances, it was not possible to obtain
                   samples. At the end of the first five years of the NS&T program, nearly 20% of the
                   original locations presented some of the above mentioned sampling problems that
                   left the data base withmissing values. Transplantation of bivalves to areas where
                   indigenous individuals were not originally present or have been lost because of
                   natural or man-induced actions could be a potentially useful tool in monitoring
                   environmental pollution.

                   The present study was designed to examine the uptake and depuration of selected
                   organic contaminants, PAHs and PCBs in oysters (Crassostrea virginica)
                   through transplantation experiments in two -locations in Galveston Bay, Texas.

                   Approximately 250 oysters of similar dimensions (e.g., 6-8 cm) were collected
                   from a relatively uncontaminated area in Galveston Bay, Hanna Reef, and
                   transplanted in 24x7O cm net bags, containing 25-30 individuals per bag, to a new
                   location near the Houston Ship Channel (HSC) in the upper part of the bay.
                   Composite samples of 20 transplanted and 15 indigenous oysters were collected at
                   zero, three, seven, 17, 30, and 48 days during the first phase of the transplantation
                   experiment. The remaining Hanna Reef oysters were then back- transplanted to
                   their original location in Galveston Bay. At the same time, approximately 150
                   indigenous oysters from the HSC site were also transplanted to the Hanna Reef
                   area. Composite samples of 20 oysters from each population were collected at
                   three, six, 18, 30, and 50 days after transplantation.

                   The concentrations of most organic contaminants in oysters transplanted from
                   Hanna Reef to the HSC increased dramatically during the seven-week exposure


                                                        3-41







                period.  Comparatively, concentrations of individual PAHs and PCBs in
                indigenous oysters during the first phase of this experiment were fairly constant.
                The analyte concentrations in native oysters represent the time-integrated
                contaminant concentrations available to the oysters in solution,    adsorbed onto
                particles and incorporated into food.

                Initial concentrations of total PAHs in transplanted oysters increased from 290
                ng/g to a final value of 4360 ng/g. Two- and three-ring PAHs were detected in low
                concentrations in transplanted and indigenous oysters. Four- and five-ring
                compounds were accumulated to the highest concentrations in Hanna Reef
                oysters. By the end of the first 48 days, transplanted oysters accumulated these
                PAHs to levels that were not statistically differentiable from the concentrations
                measured in native individuals.       The PAHs accumulated to the highest
                concentrations were: pyrene > fluoranthene > chrysene > benzo(e)pyrene >
                benzo(b)anthraceni;

                Hanna Reef and HSC oysters showed statistically significant depluration (p < 0.05)
                of four- and five-ring PAHs after relocation to the Hanna Reef area. Depurations
                of these aromatic compounds by both groups of oysters were approximately
                exponential. The half-lives ranged from 10.4 and 12.4 days for pyrene to 25.6 and
                38.5 days for fluoranthene in Hanna Reef and HSC oysters, respectively. Most of
                the values were, however, between ten and 16 days.

                PCB concentrations in transplanted oysters increased from 30 ng/g to 850 ng/g
                after the 48-days exposure period. Pentachlorobiphenyls were the compounds
                accumulated to the highest concentrations in transplanted and native oysters. In
                comparison, practically no octa-, nona- or decachlorobiphenyls were detected in
                either oyster group. Unlike the PAHs, not all the PCB homologs, measured in
                transplanted oysters reached the concentration encountered in indigenous
                individuals by the end of the first phase of this experiment. While there were no
                statistically significant differences in the tri- and tetra chlorobiphenyl
                concentrations measured in transplanted and native oysters, significant
                differences were observed in the total concentrations of penta- and
                hexachlorobiphenyls. It is evident that a longer exposure period is needed for the
                higher molecular weight PCB to reach a steady state concentration.

                Hanna Reef and HSC oysters showed statistically significant depuration (p < 0.05)
                of low molecular weight PCBs when relocated to the Hanna Reef area. Originally
                uncontaminated oysters depurated PCBs at a faster rate than chronically
                contaminated oysters. The clearance rates of high molecular weight PCBs were
                significantly slower in both oyster populations Biological half-lives for these PCBs
                in Hanna Reef and HSC oysters ranged from 21 to 129 days and from 20 days to >
                year, respectively-

                Transplanted oysters can be considered valuable bioindicators of environmental
                contamination by PAHs and PCBs in areas lacking indigenous oysters. However,
                in order to avoid misleading interpretations of environmental data collected using
                transplanted bivalves, it is imperative to understand that some trace organic
                compounds need extremely long time, i.e., several months, to reach equilibrium
                concentrations.




                                                    3-42






















                                        Reprint 6

                          The Effects of the Apex Barge Oil Spill
                               on the Fish of Galveston Bay

                      Susanne J. McDonald, James M. Brooks, Dan Wilkinson,
                             Terry L. Wade, and Thomas J. McDonald







                      The Effects of ffie Apex Bmge OR SpiR on ffie Msh of Galveston Bay

                                Susanne J. McDonald, James M. Brooks, Dan Wilkinson,
                                        Terry L. Wade, and Thomas J. McDonald
                       Geochemical and Environin    .ental Research Group, Texas A&M University


                    On July 28, 1990 the Greek tanker, Shinoussa, collided with three barges in the
                    Houston Ship Channel in Galveston Bay, Texas. Over 700,000 gallons of
                    petroleum product.were released into the bay from one of the Apex barges. The
                    spilled petroleum was a processed product known as a vacuum reformate that
                    contained unusually high concentrations of the toxic polynuclear aromatic
                    hydrocarbon (PAH), benzo(alpyrene (BaP). The purpose of this study was to
                    assess the effects of the spilled petroleum on the fish of Galveston Bay and to
                    compare results obtained from more typical monitoring methods (i.e., PAH tissue
                    residue concentrations) *and a recently developed technique for detecting PAH
                    metabolites in fish bile. Measuring the concentrations of biliary PAH metabolites
                    in fish is a sensitive method that can provide an improved estimation of PAH
                    exposure, early indications of habitat deterioration, and a clear association
                    between pollutant source and resultant exposure. Data of this nature is beneficial
                    for informed management and regulatory decisions.

                    Field crews were on Galveston Bay collecting fish as part o    f the Galveston Bay
                    National Estuary Program (GBNEP) monitoring study the week following the oil
                    spill. One of the designated stations in this study, Todd's Dump (or Eagle Point),
                    is located within two miles of the Apex barge oil spill and was sampled on August
                    3, 1990, one week after the spill. Fish were collected using gill nets at the
                    north/northwest end of Redfish Island and over the oyster reef at Todds Dump. A
                    prominent oil slick was observed in waters surrounding Redfish Island; whereas,
                    no obvious slick was evident in waters over the oyster reef. Additionally,. follow up
                    studies resampled the Todd's Dump area for fish approximately four and sixteen
                    weeks after the spill. The fish captured were analyzed for PAH metabolites in bile
                    and PAH residue in liver and muscle tissues. The PAH metabolites analyzed
                    were naphthalenes, phenanthrenes, and BaPs.

                    Fish rapidly metabolize lipophillic PAH to more polar and excretable metabolites.
                    A number of polar metabolites formed by the enzymatic transformation of PAH in
                    fish livers are excreted into bile and urine. Biliary PAH metabolites were
                    analyzed using a non-radiometric technique employing HPLC and fluorescence
                    detection. The advantages of this techniq  .ue include the ease with which samples
                    are collected and stored, the minimal sample preparation required, its sensitivity,
                    its low cost, and that it is an in vivo measurement.           Field studies have
                    documented elevated concentrations of PAH metabolites in the bile of fish collected
                    near hydrocarbon contaminated sediments and downstream from an oil spill. An
                    increased incidence of idiopathic hepatic lesions and reduced ovarian maturation
                    has been correlated with high concentrations of biliary PAH metabolites in fish.

                    The analysis of fish collected near Redfish Island, one week after the spill,
                    revealed the highest biliary concentrations of PAH metabolites ever reported for
                    fish. The. mean concentration of naphthalene, phenanthrene and benzo[alpyrene


                                                       3-44








               metabolites was 4,200,000, 1,900,000, and 11,000 ng/g wet weight, respectively.
               Fish captured over the oyster reef, in waters that were not obviously oiled, had
               metabolite concentrations of 1,100,000 (naphthalene), 540,000 (phenanthrene), and
               3,900 (BaP) ng/g. The. high concentration of BaP metabolites is of particular
               concern since many of these compounds are highly carcinogenic and reflect the
               high concentration of BaP in the spilled petroleum.            The mean biliary
               concentrations of PAH metabolites in fish captured four weeks after the spill were
               lower than those observed one week after the spill, but were still elevated
               (naphthalene = 900,000, phenanthrene = 290,000, and BaP = 2400 ng/g); whereas,
               fish collected sixteen weeks after the spill had significantly lower concentrations
               of PAH metabolites in their bile (naphthalene = 240,000, phenanthiene = 70,000,
               and BaP = 630 ng/g).

               In contrast to results of the bilary- analysis, the concentration of PAH residues in
               the tissues of fish captured one week after the spill are low to nondetected.
               Significant concentrations of PAH are seldom detected in fish, even when the
               adjacent environment contains high concentrations of PAH, because fish rapidly
               metabolize PAH to derivatives not detected by routine analytical techniques for
               monitoring hydrocarbon exposure. Evaluating the effects of the Apex oil spill only
               on the concentration of PAH residue in fish tissues would suggest no significant
               evidence of -exposure.    However, metabolite data indicates that the fish near
               Todd's Dump were exposed to high concentrations of PAH.





































                                                       -A r.






















                                       Preprint I


             Polynuclear Aromatic Hydrocarbon Contaminants in Oysters
                          from the Gulf of Mexico (1986-1990)


            Thomas J. Jackson, Terry L. Wade, Thosmas J. McDonald, Dan L. Wilkinson.
                                    and James M. Brooks






                 manuscript 00646


                         Polynuclear Aromatic Hydrocarbon Contaminants
                        in Oysters from the Gulf of Mexico (1986-1990)

                    Thomas J. Jackson, Terry L. Wade, Thomas J. McDonald,
                             Dan L. Wilkinson and James M. Brooks

                         Geochemical and Environmental Research Group,
                         College of Geosciences and Maritime Studies,
                                    Texas A & M University,
                             College Station, Texas, U.S.A. 77845




                                            ABSTRACT



                      Polynuclear aromatic hydrocarbon (PAH) contaminant

                 concentrations in 870 composite oyster samples from coastal

                 and estuarine areas of the Gulf of Mexico analyzed as part

                 of National Oceanic and Atmospheric Administration's

                 (NOAA's). National Status-and Trends-(NS&T) Mussel Watch

                 Program exhibit a lognormal distribution. There are two

                 major populations in the data. The cumulative frequency

                 function was used to deconvolute the data distribution into

                 two probability density functions and calculate summary

                 statistics for each population. The   first population

                 consists of sites with lower PAH concentration probably due

                 to background contamination (i.e., stormwater runoff,
                 atmospheric deposition). The secoi@d population are sites

                 with higher concentrations of PAHs associated with local
                 point sources of PAH input (i.e., small oil-- spills, etc-.).

                 The temporal pattern for the mean concentration of the
                 populations from the Gulf of Mexico is consistent with
                 large-scale climatic factors such as the El Nii@o cycles

                 which affect the precipitation regime.



                                            3-47







                                                                           2
                Manuscript 00646

                                        INTRODUCTION



                     Oysters and other bivalve molluscs have been used for

                monitoring contaminants in the environment (Farrington, et

                al., 1983). Oysters are sentinel organisms which

                concentrate contaminants from the marine environment, yet do

                not readily metabolize contaminants such as polynuclear

                aromatic hydrocarbons (PAHs) (Farrington and Quinn, 1973).

                PAHs enter the near-coastal environment through a number of.

                mechanisms (e.g. runoff, discharge of industrial waste or

                sewage, natural or industrial combustion processes, natural

                oil seepages, and spills of petroleum or petroleum

                products).


                     The contaminants found in oysters reflect the current

                contaminant burden of an ecosystem. The concentration of a

                contaminant in an oyster is the difference between uptake

                and excretion of that contaminant. Galveston Bay oysters

                transplanted from a "high" level site to a "low." level site

                and vice versa come to a new equilibrium concentration, for

                trace organic contaminants such as PAHs, within,
                approximately one month (Sericano qnd Wade, unpublished

                data).


                     To assess the spatial and temporal va'r`iation of

                contaminant levels of coastal and estuarine environments,

                the National Oceanic and Atmospheric Administration (NOAA)

                instituted the National Status and Trends (NS&T) Mussel

                Watch Program under its Program for Marine Environmental



                                          3-48







                                                                          3
                Manuscript 00646


                Quality (O'Connor, 1990). The sample sites were selected to

                characterize the overall concentration of contaminants in

                coastal and estuarine ecosystems away from known point-

                sources of contamination.


                     The focus of this paper is to examine the distribution

                of the PAH contaminant concentrations in oysters collected

                from the Gulf-of Mexico as part of NOAA's NS&T Mussel Watch

                Program, and determine the environmental factors controlling

                tile concentration of PAHs.




                                          METHODS



                Sample Collection


                     Oysters (Crassostrea virginica) were collected from

                three stations at each site, during the winter of each year

                (1986 - 1990). The number of sites per year varied from 48

                to 68. In some years not all sites had three stations due

                to the low abundance of oysters at a specific site

                (Table 1). Sample sites give coverage of the Gulf of Mexico

                coastal and estuarine areas from southern-most Texas to

                southern-most Florida (Figure 1).. Individual stations at

                each site are generally from 100 to 1,000 meters apart. An

                analysis at each station represents a composite of twenty

                individual oysters. Each year, the field sampling returned

                to as many sites as possible. In some instances it was

                necessary to relocate or abandon an established oyster site




                                          3-49






                                                                         4
                Manuscript 00646


                due to lack of suitable size bivalves (Wilkinson, et al.,

                1991). The locations and designators for the oyster sites

                are found in Wilkinson, et al. (1991), Sericano et al.

                (1990) and Wade et al. (1990).


                Tissue Extraction



                    The tissue extraction used was adapted from a method

                developed by MacLeod, et al. (1985). Approximately 15 grams

                of wet tissue were used.for the PAH analysis. After the

                addition of internal standards (surrogates) and 50 grams of

                anhydrous Na2SO4, the tissue was extracted three times with

                dichloromethane using 4 tissuemizer. A 20 ml sample was

                removed from the total solvent volume and concentrated to

                one ml for lipid percentage determination. The 280 ml of

                remaining solvent was concentrated to approximately 20 ml in

                a flat-bottomed flask equipped with a three-ball Synder

                column condenser. The tissue extract was then transferred

                to a Kuderna-Danish tubes heated in a water bath (600C) to

                concentrate the extracts to a final volume of two

                milliliters. During concentration, the dichIoromethane was

                exchanged for hexane.


                    The tissue extracts were fractionated--,-by alumina:silica
                (80-100 mesh) open column chromatography. The silica gel

                was activated at 1700C for 12 hours and partially

                deactivated with 3% distilled water (v/w). Twenty grams of

                silica gel were slurry-packed in dichloromethane over ten




                                         3-50







                                                                          5
                manuscript 00646


                grams of alumina. Alumina was activated at 4000C for four

                hours and partially deactivated with 1% distilled water

                (V/W). The dichloromethane was replaced with pentane by
                elution. The extract was then applied to the top of the

                column. The extract was sequentially eluted from the column

                with 50 ml of pentane (aliphatic fraction) and 200 ml of 1:1

                pentane:dichloronethane (aromatic fraction). The aromatic

                fraction was further purified by HPLC to remove the lipids.

                The lipids were removed by size exclusion using

                dichloromethane as an isocratic mobile phase (7 ml/min) and

                two 22.5 x 250 mm Phenogel 100 columns (Krahn, et al.,

                1988). The purified aromatic fraction was collected from

                1.5 minutes prior to the elution of 4,41-dibromofluoro-

                biphenyl to 2 minutes after the elution of perylene. The

                retention times of the two marker peaks were checked prior

                to the beginning and at the end of a set of ten samples.

                The purified aromatic fraction was concentrated to 1 ml

                using Kuderna-Danish tubes heated in a water bath at 600C.


                     Quality assurance for each set of ten samples included

                a procedural blank, matrix spike, duplicate, and tissue

                standard reference material (NIST-SRM 1974) which were

                carried through the entire analytical scheme. Internal

                standards (surrogates) were added to the samples prior to

                extraction and were used for quantitation. The surrogates

                were d8-naphthalene, djo-acenaphthene, djo-phenanthrene,

                d12-chrysene, and d12-perylene. Surrogates were added at a




                                           3-51







                Manuscript 00646


                concentration similar to that expected for the analytes of

                interest. To monitor the recovery of the surrogates,

                chromatography internal standards djo-fluorene and

                dl2-benzo(a)pyrene were added just prior to GC-MS analysis.


                Gas Chromatography-Mass Spectrometry (GC-MS)


                    PAHs were separated and quantified by GC-XS (HP5980-GC

                interfaced to a HP5970-MSD). The samples were injected in

                the splitless mode on to a 30 m X 0.25 mm (0.32 um film

                thickness) DB-5 fused silica capillary column (J&W

                Scientific Inc.) at an initial temperature of 600C and

                temperature programmed at 120C/min to .3000C and held at the

                final temperature for 6 minutes. The mass spectral data

                were acquired using selected ions for each of the PAH

                analytes. The GC-MS was calibrated and linearity determined

                by injection of a standard containing all analytes at five

                concentrations ranging from 0.01 ng/ul to 1 ng/ul. Sample

                component concentrations were calculated from the average

                response factor for each analyte. Analyte identifications

                were based on correct retention time of the quantitation ion

                (molecular ion) for the specific analyte and confirmed by

                the ratio of quantitation ion to confirmation ion.


                    Calibration check samples were run with each set of

                samples (beginning, middle, and end), with no more than six

                hours between calibration checks. The calibration check

                must maintain an average response factor within 10% for all




                                         3-52







                                                                          7
                 Manuscript 00646


                 analytes, with no one analyte greater than +25% of the known

                 concentration. A laboratory reference sample (oil spiked

                 solution) was also analyzed with each set of samples to

                 confirm GC-MS system performance and calibration.



                                    RESULTS and DISCUSSION


                 oyster site variations


                     During the first five years of this study a total of

                 870 composited-oyster samples have been analyzed for PAHs.

                 The tPAH (total NS&T PAHs) is the sum of the eighteen

                 aromatic hydrocarbon analytes, as measured in Year.I, with

                 concentrations greater than 20 ng/g dry weight (Table 2);

                 this was the reporting limit for Year I data (Wade, et al.,

                 1988). The median PAH concentration at a site is used as a

                 measure of the best indicator of the concentration. The

                 median is a more stable (or "resistant") estimator of the

                 typical value than the mean for data which may contain

                 outliers (Hensel, 1990).


                     The data in Table 3 presents t
                                                   .@ie spatial and temporal

                 variation for the median tPAH concentration in the coastal
                 and estuarine areas of the Gulf of Mexico., The sites are
                 separated into Bay groups (Wilson, et al., 1992) for data
                 comparison. The variability for each Bay group is the
                 standard deviation as computed from the interquatrile range

                 (IQR) for the five years of data (Hensel, 1990). In Texas,




                                           3-53








                                                                        8
               Manuscript 00646


               Corpus Christi (CCBH, CCNB, CCIC & ABHI) and Galveston Bays

               (GBCR, GBOB, GBTD, GBYC, GBSC & GBHR) are near industrial

               and population centers and exhibit high median

               concentrations of tPAH and large variability in

               concentration compared to Matagorda (ESBD, MBGP, MBLR, MBCB,

               MBTP & MBDI) and Aransas Bays (ABLR, CBCR & MBAR) which

               exhibit low median concentrations of tPAH and small

               variability in concentration. The highest median tPAH

               concentration for a Bay Group in Texas is the Brazos River.

               (BRCL & BRFS), which carries the runoff from agriculture and

               wastewater discharge from industrial point-sources (NOAA,

               1985). For the entire coastal and estuarine area of the

               Gulf of Mexico (Table 3), the highest median tPAH

               concentration for a Bay Group is near Panama 4City, Florida

               (PCLO' PCMP & SAWB), which is close to-a paper mill (NOAA,

               1985; Wilkinson et al., .1991).


                    There are fifteen sites (LMSB, ABLR, CBCR, MBAR, SAPP,

               ESSP, ESBD, MBGP, MBCB, MBTP, CLCL, LBMP, TBCB, CBBI & RBHC)

               with low concentration of tPAH ( < 100 ng/g) and little

               variation in the observed values (e.g., Figure 2). There

               are also six sites (GBSC, BBMB, MSBB, CBJB, PCMP & SAWB), of
               the seventy-eight different sites, where high concentrations

               of tPAH ( > 1000 ng/g) are observed. Four sites (CCIC,

               PBPH, PBIB & PCMP) exhibited a decrease in the tPAH each
               year during the first five years of this study. Many sites
               exhibited a cyclic variation with time. At Choctawhatchee




                                          3-54







                                                                          9
                Manuscript 00646


                Bay off Santa Rosa (CBSR, Figure 3), the order of magnitude

                increase in concentration of tPAH in Years II and III is

                probably due to relocation of the collection site to an area

                containing wood pilings, which if treated with creosote are

                a source of PARs. The decrease in Years IV and V probably

                reflects relocation of the collection stations to an oyster

                reef away from wood pilings. Due to prolohged freshwater

                conditions in San Antonio Bay during 1988 and 1989 (Years

                III and IV), the oyster..reefs experienced a die-off

                resulting in no oysters being taken from SAPP, SAMP and             01

                ESSP.



                cumulative Frequency Model


                     Bar Graphs (Wade, et al., 1990), or crossplots (Wade

                and Sericano, 1989) of data comparing one year's data versus

                another have been used to display the general trend for tPAH

                data (Wade and Sericano, 1989; Wade, et al., 1990; Wade, et

                al., 1991). These data presentations easily visualize the

                variation in concentration for a particular site. In this

                report the cumulative frequency function is used to examine
                the heterogeneous distribution of PAHs in Gulf of Mexico

                oysters (Mackay and Paterson, 1984). This approach has the

                advantage of examining the Gulf of Mexico ds a single
                environmental system, determining the percentage of sites
                exposed to a particular threshold concentration, and
                providing information for environmental evaluation.





                                          3-55







                                                                           10
               Manuscript 00646


                    The distribution of the PAH data in Table 3 is best

               described by a lognormal distribution; i.e. the distribution

               of data is skewed to low concentrations and has a fraction

               which extends to high concentrations (Figure 4). O'Connor

               (1990) used the lognormal distribution, typical of

               environmental data, to def ine "high" concentrations as those

               whose logarithmic value is more than the mean plus one

               standard deviation of the logarithms for all concentrations.

               The tPAH data in Figure 4 is further skewed in that analytes

               with concentrations less than 20 ng/g are not included in

               the sum of eighteen 2 - 5 ring aromatic hydrocarbon analytes

               in Table 2, i.e., the data has been censored. For Years I -

               III, only censored data was available, whereas for Years IV

               and V both censored and uncensored data was available. A

               regression analysis of the censored (tPAH) data versus

               uncensored data for the sum of all analytes (T-PAH) in Table

               2 from Years IV and V yields the best fit line as y = 153.0
               + 0.9834 x (r2=0.9989) ; where y   uncensored data, and x

               censored data. Using the best fit line from the Year IV and

               V data, the censored data for the cumulative -fr .equency data
               was corrected to,be the same as theN uncensored cumulative

               frequency data.


                    Distribution functions are useful measures of

               environmental quality data in that changes with time   can be

               ascertained without being influenced by "outliers". For the

               cumulative distribution plot, the data is sorted from the




                                          3-56







                 Manuscript 00646


                 lowest value to the highest, similar to rank transformation

                 (Conover and Iman, 1981). Each observation is 1/n fraction

                 of the data set, where n is the number of samples in the

                 data set. The sum of the fraction of samples less than the

                 concentration is plotted against the concentration. From

                 this plot the median can be determined, since it is defined

                 as the 50th percentile. The interquatrile range (IQR) is

                 used as a measure of variability. The IQR is the 75th

                 percentile minus the 25th percentile and equals 1.35 times

                 the standard deviation for a normal distribution (Hensel,

                 1990).


                      To begin the examination of the distribution of the PAH

                 concentration data, the logarithm of the sum of all PAH

                 analytes (T-PAH) for Year V data was plotted as a cumulative

                 frequency distribution. The 50th percentile was 250 ppb and

                 the standard deviation as determined from the IRQ was 218.

                 The log of the data versus fraction of the samples was

                 plotted and compared with a lognormal distribution

                 (Figure 5). The shape of the cumulative frequency     curve
                 (i.e., the positive deviation from :% the lognormal model) for
                 the T-PAH data suggests two overlapping lognormal
                 distributions. Making the assumption that--there is a 2.5%
                 overlap for the two distributions, the mean and standard

                 deviation were computed for each data set, or population
                 (Table 4). The cumulative frequency distribution from the
                 two population model data compare well with the actual T-PAH




                                            3-57







                                                                          12
               Manuscript 00646


               data (Figure 6). Other increments of overlap were computed,

               but did not compare as well with the actual data for Year V.


                    The implication of the two populations in the data is

               that there are two primary mechanisms accounting for the

               distribution of T-PAH concentration in the Year V data. The

               sites with lower concentration PAHs are probably due to low

               level background inputs from stormwater runoff, atmospheric

               deposition and sewage effluents, etc. (NOAA, 1985). The

               sites with higher concentration PAHs are probably due to

               local point-sources of PAH contamination (i.e., small

               spills). From the lognormal cumulative frequency function

               two probability density functions were derived, the relative

               proportion of the two populations were estimated to be 0.9

               for population one and 0.25 for population two. Comparison

               of the cumulative frequency distribution derived from the

               sum of the two probability density functions, in the above

               proportions, with the actual data for the cumulative

               frequency distribution (Figure 7) indicates a good

               correlation.


                    since historical NS&T data (TAble 3) is censored data

               (Wade, et al., 1988; Wade and Sericano, 1989; Wade, et al.,

               1990), the cumulative frequency distribution of this

               censored (tPAH) data was corrected using the best-fit-line

               from the data for Years IV and V. Data below the reporting

               limit were extrapolated (Hensel, 1990; Mackay and Paterson,
               1984). The summary statistics for the corrected data using



                                         3-58







                                                                            13
                 Manuscript 00646


                 the two population model for Years I to Year V data

                 (Table 5) were calculated using the data from 0-80% for the

                 original cumulative frequency distribution for Population 1

                 and from 77.5-100% of the original cumulative frequency

                 distribution for population 2 (Table 6).


                      The summary statistics for the first five years of

                 measuring PAH contaminants in the Gulf of Mexico for NOAA's

                 NS&T Mussel Watch Program (Table 5) show variation in the

                 means for both populations, indicating temporal change in

                 the total Gulf of Mexico data, with the highest values found

                 in Years III and IV. The higher mean  concentrations of PAHs

                 in Years III and IV and the lower abundance in Years 1, 11

                 and V pattern is probably related to large-scale climatic
                 factors such as the El Kino cycles (Philander, 1989) which

                 affects the precipitation regime (Wilson, et al., 1992).

                 Examination of the PAH data for individual sites, as

                 discussed above,. does not show this pattern.


                      The cumulative frequency data for Years I to V gives

                 the percentage of sites whose PAH concentration is less than
                 a particular'concentration (Table @). As an example, using

                 1,000 ppb as an arbitrary concentration, 89% of the sites

                 for Years I and II are less than this conc6ntration, while

                 Year III had 80%, Year IV 83% and Year V had 87%.

                 Alternatively, the cumulative frequency data can be used to
                 calculate the percentage of sites exposed to a concentration

                 in excess of a particular threshold.



                                           3-59







                                                                        14
               Manuscript 00646


                    The cumulative frequency distribution was used in this

               study.as an environmental evaluation tool to examine the

               heterogeneous distribution of total PAH contaminants in Gulf

               of Mexico oysters from coastal and estuarine areas collected

               during the winters of 1986 - 1990. The PAH concentration

               exhibits a lognormal distribution with two major populations

               in the data for each year. The two populations were

               deconvoluted into probability density functions and summary

               statistics for each population were calculated. The lower

               PAH concentrations are probably related to chronic inputs.

               Many of these low PAH concentration sites show little

               variability from year to year, supporting the contention

               that the PAH contamination is on a continual basis. The

               higher concentration PAHs are probably associated with local

               point-sources of PAH contamination or spills. Most of the

               high concentration sites ( > 1000 ng/g dry tissue) show

               large variability from year to year, supporting the

               contention that PAH contamination for these sites is on an

               episodic basis. In additiont 20% of Gulf of Mexico sites in

               Year III were exposed to a PAH threshold concentration of
               greater than 1000 ng/g of dry oyste-r tissue. whereas, in

               Years I and II only 11% of the Gulf of Mexico sites had

               concentrations greater than 1000 ng/g of t6tal NS&T PAHs.

               The changes in the mean concentration of the two populations

               between years display a cyclic pattern which is probably due
               to large-scale climatic factors such as the El Ni@o cycles

               which affects the precipitation regime (Wilson, et al.,



                                          3-60







                                                                          15
                Manuscript 00646


                1992). The cyclic pattern  was obtained by examining the

                Gulf of Mexico as a single heterogeneous system, since the

                PAH concentration data for individual sites does not clearly

                show this pattern.




                                       ACKNOWLEGEMENTS



                     Funding for this research was supported by the National

                Oceanic and Atmospheric Administration, contract number

                50-DGNC-5-00262 (National Status and Trends Mussel Watch

                Program)., through the Texas A & M Research Foundati on,

                Texas A & M University.




































                                          3-61




                manuscript 00646                                          16

                                         REFERENCES



                Conover, W.J. & Iman, R.L. (1981). Rank Transformations as

                     a Bridge between Parametric and Nonparametric

                     Statistics. The American Statistician, 35, 124-129.


                Farrington, J.W. & Quinn, J.G., (1973). Petroleum

                     hydrocarbons in Narragansett Bay. 1. Survey of

                     hydrocarbons in sediments and clams (Mercenaria

                     mercenaria). Estuarine and Coastal Mar. Scl., 1, 71-79.


                Farrington, J.W., Goldberg, E.D., Risebrough, R.W., Martin,

                     J.H. & Bowen, V.T. (1983). US 'Mussel Watch' 1976-1978:

                     An overview of the trace metal, DDE, PCB, hydrocarbon

                     and artificial radionuclide data. Environ. Sci.

                     Technol., 17  490-6.


                Hensel, D.R. (1990). Less than obvious. Statistical

                     treatment of data below the detection limit. Env.lron.

                     Sci. Technol., 24, 1766-1774.


                Krahn, M.M., Moore, L.K., Bogar, R.G., Wigren, C.A., Chan,

                     S-L. & Brown, D.W. (1988). High-performance liquid.
                     chromatography method for isofating organic

                     contaminants from tissue and sediment extracts.


                     J. Chromatogr., 437, 161-175.


                Mackay, D. & Paterson, S. (1984).   Spatial concentration

                     distributions. Environ. Sci.   Technol., IS, 207A-214A.







                                           3-62







                                                                                  17
                  Manuscript 00646


                  MacLeod, W.D., Brown, D.W., Friedman, A.J., Burrows,       D.G.1

                        Maynes, 0., Pearce, R.W., Wigren, C.A. & Bogar,       R.W.

                        (1985). Standard analytical procedures of the NOAA

                        National Analytical Facility 1985-1986. Extractable

                        Toxic Organic Compounds, 2nd Ed. U.S. Department of

                        Commerce, NOAA/NMFS. NOAA Tech. Memo NMFS F/NWC-92.


                  NOAA (1985). Gulf of Mexico Coastal and Ocean Zones

                        Strategic Assessment: Data Atlas, United States

                        Department of Commerce, National Oceanic and

                        Atmospheric Administration. pp. 4.0-5.32.


                  O'Connor, T.P. (1990). Coastal Environmental Quality in the               V

                        United States, 1990. Chemical Contamination in

                        Sediment and  Tissues. A Special NOAA 20th Anniversary

                        Report. 34 pp.


                  Philander, G. (1980). El Nin'o and La Nin,4a. American

                        Scientist, 77, 451-459.


                  Sericano, J.L., Wade, T.L., Atlas, E.L. & Brooks, J.M.

                        (1990). Historical Perspective on the Environmental
                        Bioavailability of DDT and Its' Derivatives to Gulf of

                        Mexico Oysters. Environ. Sci. Technol., 77, 1541-1548.














                                               3-63







               Manuscript 00646


               Wade, T.L., Atlas, E.L., Brooks, J.M., Kennicutt II, M.C.,

                    Fox, R.G., Sericano, J.L., Garcia-Romero, B. &

                    Defreitas, D.A. (1988). NOAA Gulf of Mexico Status and

                    Trends Program: Trace organic contaminant distribution

                    in sediments and oysters. Estuaries, 11, 171-179.


               Wade, T.L. & Sericano, J.L. (1989). Trends in organic

                    Contaminant Distribution in oysters form the Gulf Of

                    Mexico. Oceansf89 Proceedings, pp. 585-589.


               Wade, T.L., Sericano, J.L., Garcia-Romero, B., Brooks, J.M.

                    & Presley, B.J. (1990). Gulf Coast NOAA National

                    Status & Trends Mussel Watch: The-First Four Years.

                    Proc. Mar. Tech. Soc., 274-280.


               Wade, T.L., Brooks, J.M., Kennicutt II, M.C., Denoux, G.J. &

                    Jackson, T.J. (1991). Oysters as Biomonitors of Oil in

                    the Ocean. Proceedings of the 23rd Annual Offshore

                    Technology Conference, OTC 6529, pp. 275-280.


               Wilkinson, D.L., Brooks, J.M. & Fay, R.R. (1991). NOAA

                    Status and Trends: Mussel Watch Program- Field
                    Sampling and Logistics Report'- Year VI. GERG

                    Technical Report 91-046, U.S. Department of Commerce,

                    National Oceanic & Atmospheric Administration, Ocean

                    Assessment Division.










                                          3-64







                                                                         19
               Manuscript 00646


               Wilson, E.A., Powell, E.N., Wade, T.L., Taylor, R.J.

                     Presley, B.J., and Brooks, J.M. (1992). Spatial and

                     temporal distributions of body burden and disease in

                     Gulf of Mexico oyster populations: The role of local

                     and large-scale climatic controls. Helgol.

                     Meeresunters. (in press).
















































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                                                                                 20
                  Manuscript 00646


                           Table 1:  National Status and   Trends oysters
                     Gulf of Mexico Sampling Program -     Summary of Sampling
                   Year                   1986    1987    1988   1989    1990
                                             I      II    III       IV      V


                   Number of Sites          49      48      65      62     68

                   Number of Samples       142     144    195     186     203


















































                                               3-66







                                                                           21
                Manuscript 00646


                         Table 2: National Status and Trends Oysters
                          Polynuclear Aromatic Hydrocarbon Analytes                  OF

                       Analytes used in tPAH summation

                         Low Molecular Weight Aromatic Hydrocarbons

                     Biphenyl                       * Acenaphthene
                     Naphthalene                      Acenaphthylene
                     1-methylnaphthalene            * Fluorene
                     2-methylnaphthalene            * Phenanthrene
                     2,6-dimethylnaphthalene        * Anthracene,
                     1,6,7-trimethylnaphthalene     * 1-methylphenanthrene

                        High Molecular Weight Aromatic Hydrocarbons

                     Fluoranthene                   * Benzo(a)pyrene
                     Pyrene                         * Benzo(e)pyrene
                     Benz(a)anthracene              * Perylene
                     Chrysene                       * Dibenz(a,h]anthracene
                     Indeno[1,2,3-cd]pyrene           Benzo(g,h,i)perylene








                                                                                     F&






























                                            3-67




                Manuscript   00 646                                             22

                      Table  3a:  Total NS&T PAH concentration in oysters
                                               (Texas)
                              Median concentration in ng/g of tPAH

                      Site       V     IV      III    II        I      Bay Group
                      Code   1990    1989   1988     1987   1986           Median



                   1  LMSB     22      20      30     20      25
                  52  LMPI                  3380                         30 + 58
                  78  LMAC    120


                  53  CCBH   1530           1600
                   2  CCNB    161     264      598    434     45       565 + 725
                   3  CCIC    137     430      848          1140
                  54  ABHI                  1870


                   4  ABLR     20      20      20     21      20
                   5  CBCR     88              20     20      22          20 + I
                   6  MBAR     20      20      2-0    20      21


                   7  SAPP     26                     51      45
                   8  SAMP                            49      93         25 + 23
                   9  ESSP     20                     21      20


                  10  ESBD     21      70      21
                  12  MBGP             20      86     56      20
                  11  MBLR     96     348             59      90         45 + 48
                  56  MBCB     20              56
                  13  MBTP     20      20      56     20      20
                  55  MBDI                     53


                  14  MBEM    201     200      23     22      78       138 + 119


                  72  BRCL    761      60
                  57  BRFS    955    1670      682                     792 + 792


                  18  GBCR    370    1170      525    478    1070
                  58  GBOB    315     593      543
                  16  GBTD     25      44      20     112     149      259 + 606
                  15  GBYC    247     132      207    56-8   1030
                  59  GBSC   1290    1350   3100
                  17  GBHR     20     119      34     20      31


















                                               3-68







                                                                                23
                 Manuscript 00646


                      Table 3b:    Total NS&T PAH concentration in Oysters
                                (Louisiana, Mississippi, Alabama)
                              Median concentration in ng/g of tPAH

                       site      V     IV     III     II        I      Bay Group
                       Code  1990     1989  1988     1987    1986         Median



                  Louisiana


                  19 SLBB     108     154     169     26     247        154 + 72


                  20   CLSJ   180     228     102     57     :376      220 + 218
                  60   CLLC   404     726      20


                  21   JHJH    88      72      20     84      43         44 + 50


                  22   VBSP   189      31      20    118      79        79 + 108


                  24   ABOB    20      28     192    115      32         22 + 42
                  25   CLCL    20      54      20     20      20


                  26   TBLB    20      49     306     37      20        40 + 162
                  27   TBLF   101      50      83     20      25


                  61   BBTB                    20
                  28   BBSD   963     5480     44     25      57     963 + 1020
                  29   BBMB  1080    @1380  1460     1150    822


                  65   MRTP   212     310   1410                       391 + 582
                  64   MRPL   403     330     695


                  31   BSSI   185      71     484     68     177       181 + 134
                  30   BSBG    45     202     213    118     265


                  32   LBMP    20      84      89     26      20         39 + 59
                  62   LBNO                    81

                  Mississippi

                  33 MSPC     103     300     175    31-9     99
                  34 MSBB    1210     893   1500     4310    1600      322 + 654
                  35 MSPB      59     306     776    300     246


                  Alabama


                  36 MBCP      20      90     288    137      31
                  66 MBHI     767     554   1110                       295 + 740
                  79 MBDR    1520









                                              3-69







                                                                                 24
                 Manuscript  00646


                       Table  3c:  Total NS&T PAH concentration in Oysters
                                              (Florida)
                               Median concentration in ng/g of tPAH

                       Site       V     IV    III      II        I     Bay Group
                       Code  1990    1989    1988    1987     1986          Median



                  67   PBPH    168     369    842
                  37   PBIB             21    204      250    406       197 + 198
                  80   PBSP    130


                  73   CBJB  1680    8590.
                  39   CBSP    225     355    703      543    428      429 + 1140
                  38   CBSR     69      21   2540    2470     208


                  74   PCLO     98     229
                  68   PCMP  1210    2690    4750                     1800 + 1590
                  40   SAWB  1150    2090    1990    1970    11800


                  41   APDB     20      24   2800      20      20        57 + 530
                  42   APCP    269   1110     740      20     109


                  75   AESP     33      74                               64 + 103


                  69   SRWP                   119
                  43   CKBP     20      74     24      68      22        46 + 103


                  76   TBNP    269     394
                  47   TB14K   101     170     20      49     372
                  44   TBPB     20     217    286      68      95
                  70   TBOT    112     357    212                       126 + 165
                  77   TBKA    252     834
                  45   TBHB                   552    2150     460
                  46   TBCB     20      65     94      22      20


                  48   CBBI     20      83     31      43      20        51 + 180
                  71   CBFM     69     546    272


                  49   NBNB     87     203    253      108    228        72 + 129
                  50   RBHC     20      77     67      20      47


                  51   EVFU     47      68    257      20     112        68 + 125

















                                              3-70








                                                                           25
                Manuscript 00646


                      Table 4: Two Population Lognormal Distribution Model

                                Year V - T-PAH data (2.5% overlap)

                             Percentile            STD=                 STD of
                 Set    25%     50%       75%    IRQ/1.35    Log-mean Log-data

                   1     135    214       320         137      2.3308    0.2783


                   2     801   1210      1530         544      3.0810    0.2093



























































                                           3-71








                                                                                           26
                  manuscript 00646


                          Table 5: Two Population Lognormal Distribution Model

                                    Corrected tPAH data - ng/g dry weight

                             Median            Population 1                   Population 2
                     Year      Total          Mean          STD              Mean           STD
                                Data         (LOG)        (LOG)              (LOG)         (LOG)

                        1       229           197           108              1075           714
                                        (2.2945)      (0.2298)          (3.0314)      (0.2772)

                       11       208           186             87             1150          1100
                                        (2.2695)      (0.1967)          (3.0599)      (0.3811)

                      111       345           259           216              1910           1190
                                        (2.4133)      (0.3435)          (3.2808)      (0.2618)

                       IV       352           269           174              1350           1190
                                        (2.4298)      (0.2500)          (3.1316)      (0.3039)

                        V       270           212           131              1170           637
                                        (2.3263)      (0.2639)          (3.0689)      (0.2435)






































                                                    3-72







                                                                                       27
                   Manuscript 00646


                              Table 6: NS&T Concentration Distribution Data
                                             (Cumulative Frequency)

                                   Corrected tPAH data - ng/g dry weight

                                 1990         1989         1988         1987         1986
                               Year V      Year IV     Year III      Year II       Year I


                     10%          110          171          110          110           110
                     20%          140          200          153          140           140
                     30-9a        164          226          206          162           169
                     40%          212          269          259          186           197
                     50%          270          352          345          208*          229
                     60-0o        318          435          445          258           286
                     70%          397          519          832          370           378
                     80%          597         .869         1030          480           557
                     9016        1290         1440         2090         1300         1180
                     95%         1670         2840         3020         2300         1750
                     98%         1920         5630         4550         3740         2450













































                                                   3-73







                                                                          28
                Manuscript 00646


                Figure Captions

                Figure 1: Location of NS&T Mussel Watch Sites in the Gulf

                of Mexico (Sericano, et al., 1990).


                Figure 2: Total NS&T PAH concentration distribution during

                the first five years for all three stations; Caillou Lake in

                Louisiana (Site 25 - clcl).


                Figure 3: Total NS&T PAH concentration distribution during

                the first five years for all three stations; Choctawatchee

                Bay off Santa Rosa (Site 38 - CBSR).


                Figure 4: Frequency distribution of the median total NS&T

                PAH (tPAH) concentration in the Gulf of Mexico during the

                first five years of the program.


                Figure 5: Plot of the cumulative frequency distribution for

                Year V total NS&T PAH (tPAH) concentration, compared to the

                gaussian curve and its cumulative frequency distribution

                generated from a lognormal model with a mean of 250 ppb and

                standard deviation of 218.


                Figure 6: Plot of the cumulative frequency distribution for

                Year V NS&T PAH (tPAH) concentration, compared to the

                gaussian curves and their cumulative frequency distributions

                generated from a two population lognormal model with a mean

                of 214 ppb for Population 1 and a mean of 1205 ppb for

                Population 2.







                                           3-74






                                                                         29
               Manuscript 00646


               Figure 7: Comparison of the cumulative frequency

               distributions for the actual Year V total NS&T PAH (tPAH)

               concentration data and the cumulative frequency distribution

               generated from the two population model.















































                                           3-75



                                                                        Mao m MM M m










                                                                           MISSISSIPPI            ALABAMA



                                 TEXAS                  LOUISIANA
                                                                                    Gulf                                 0
                                                                                                                          T
                                                        0    Baton Rbuge 0                             39      Panam&Clty
                                                                                                  67
                                                                               62 140, 313 34 35 16      36
                                    Houston
                  300-                  0  59                           Now Orleans
                                                                                32  30
                                                        20  0               6  2.4   31                              42
                                                            2`1 22 23               0                            41
                  29*-         1? V)3, @@ 57  Alveston               24  26 2  26   0 -64
                                     14
                              1
                          5-     910
                  280-  2-6%47416(46
                          .1 #1 @4
                         51  3


                  270-

                                                                 GIF OF hJDW
                             52
                        IV. S. 0-1
                  260---,                         1
                        MEX



                  250-
                                                                           MSSSS
                                                                    A
                                                                        N @n.
                                                                           a.
                                                                        -w Or'  32

                                                                   23   2@
                                                                            27 26


























                  240-




                             970    960    950    940    930    920     910    900   890    880    870    860     850    84










                                         NS&T PAH Data - Years I to V
                       500

                                                                                              V
                                                                                              m
                                                                                              IV

                       400-





                       300-

                   U)
                   'r
                   <


                       200-
                   C-5
                   C/)
                   z



                       100-




                                           I I WMA  W
                          0-
                                      CLCL-1             CLCL-2            CLCL-3
                                                    Site and Station
                                 ML










                                        MINI              11111111011 mile 101 1 1 1











                                         NS&T PAH Data - Years I to V
                       4500-

                                                                                             V
                                                                                             m
                       4000-                                                                 IV


                       3500


                  -0   3000-


                   u) 2500-


                  CL
      00               2000-
                  06
                  U)   1500-
                  z


                       1000-



                         500-


                           01              ------
                                      CBSR-l            CBSR-2            CBSR-3
                                                    Site and Station










                                          NS&T PAH Data - Years I to V

                      70-




                      60-




                      50-




                   U) 40-
                   4-
                   0

                   (D
                   E  30-
                   =3
                   z


                      20-




                      10-




                        0-
                                <20     30     100    300   1000   3000 10000    30000
                                            Median of Site - NS&T PAH (ppb)
                                       IIM.

                            Sim








                                                      Year V             lognormal MODEL
                                                               Mean      250 STD =218


                                0.9-                                                                             -0.9             Model
                                                                                                                                 --i-
                                0.8-                                                                             -0.8            Actual

                           0
                                0.7-                                                                             -0.7

                                                                                                                          '0
                           22   0.6-                                                                                0.6    r-
                           4-                                                                                              =3
                           a)
                           >    0.5-                                                          Gaussian           -0.5
                                                                                                                           Cz
                                                                                              Function
                                0.4-                                                                                0.4
                           E                                                                                     -0.3
                                0.3-
                           L)
                                0.2-                                                                                0.2

                                                                                                                 -0.1

                                    01                                                                        Ili 0
                                    10                       100                     1000                    10000
                                                          Total NS&T PAHs (ppb)








                                             Year V              lognormal MODEL-2 populations
                                                              Mean 1         2 14 Mean 2             12 0 5

                                       1 -                                                                                   0.9

                                                                                                                                            Model
                                    0.9-                                                                                  -0.8
                                    0.8-                                                                                  -0.7             Actual
                               'C'  0.7-
                                                                                                                          -0.6      Cz
                               c"   0.6-
                                                                                                                          -0.5      5
                               0    0.5-                                                                                            .0
                                                                                                                                    Cz
                                                                                                                          -0.4      (D
                                    0.4-                                                                 Gaussian                   >
                                                                                                         Function                   +-A
                               E                                                                                          -0.3      Cz
                                    0.3-                                                                                            a)
                               C)   0.2-                                                                                  -0.2      cc
                                    OAT                                                                                   -0.1

                                        0-                                                 1 T-r-r-                       10
                                        10                        100                       1000,                    10000
                                                               Total NS&T PAHs (ppb)
                                                                                                               ian

                                                                                                              0
                                                                                                      _@Fua@nucstsin








                                            Year V-lognormal MODEL                               2 populations
                                                            Mean 1 =214 Mean2= 1205


                                   0.9-                                                                                       Actual
                                                                                                                               Model
                                   0.8-
                              C:
                              0    0.7-
                              T    0.6-

                              >    0.5-

                                   0.4-
                              E                                                                  Model is
                                   0.3-                                              Sum    0.90 x Popl + 0.25 x Pop2

                                   0,2-

                                   0.11

                                       0-
                                        10                        100                        1000                       10000
                                                                Total NS&T PAHs (ppb)




























                                       Pre rint 2



                   Sources of Local Variation in Polynuclear Aromatic
                        Hydrocarbon and Pesticide Body Burden


             Matthew S. Ellis, Kwang-Sik Choi, Terry L. Wade, Eric N. Powell, Thomas J.
                                   Jackson, Donald H. Lewis










                                                                                          Ellis 2




                                                    ABSTRACT


                     The sources of local (intrapopulation) variation in PAH body burden

               among adjacent oysters on a reef in Galveston Bay were examined. Both eggs

               and sperm contain significantly more PAH than somatic tissue. The quantity of

               gonadal material was the most important correlate of PAH body burden. Sex was

               an important secondary determinant. Body burden of males was correlated with

               general indicators of health such as digestive gland atrophy; body burden of

               females was not. The evidence suggests that the most important factor

               determining variation in PAH body burden within an oyster population during

               any single sampling period is the frequency of spawning and how soon

               collection occurred after the most recent spawn. Analysis of eggs and sperm

               for PAHs and pesticides revealed that eggs and sperm were enriched in all PAHs

               relative to somatic tissue. Eggs, but not sperm, were enriched in chlorinated

               compounds (e.g. chlordane, DDE, DDD). Both eggs and sperm were enriched in

               total PCBs relative to somatic tissue. oysters may lose 50% or more of their

               total body burden of certain PAHs and pesticides in a single spawn.




























                                                      3-85








                                                                                     Ellis 3



                                              INTRODUCTION


                   Bivalve molluscs have frequently been used as indicator organisms in

             studies monitoring levels of contaminants in the environment. These organisms

             are utilized because of their ability to accumulate and concentrate both metal

             and organic contaminants enabling them to serve as long-term integrators of

             their environment (Phillips, 1977). One such program is the NOAA Status and

             Trends (NS&T) Program ("Mussel Watch") designed to monitor changes in

             environmental quality along the Atlantic, Pacific, and Gulf coasts of the

             United States by measuring levels of chemical contaminants in fish, bivalves,

             and sediments and identifying biological responses to those contaminants (e.g.

             Wilson et al., in press, 1990; Sericano et al., 1990; Presley et al., 1990).

                   Unfortunately, many biological and environmental fact6rs affect the rate

             and extent of bioaccumulation besides contaminant availability. Biological

             factors include differential growth rate (Cunningham and Tripp, 1975; Boyden,

             1977), reproductive stage (Cunningham and Tripp, 1975; Frazier, 1975;

             Martinci6 et al., 1984), stress and disease (Shuster and Pringle, 1969;

             Sindermann, 1983; Moore et al., 1989). These biological factors make spatial

             and temporal comparisons designed to evaluate the status and trends of

             contaminant loading more difficult. The NOAA Status and Trends Program has

             proven to be no exception.

                   In the Gulf of Mexico, the mollusc used for monitoring by NOAA is the

             oyster Crassostreg virginic .   Analysis of the first 4 yr of NS&T data has

             shown that the body burden of polynuclear aromatic hydrocarbons (PAHs) and

             pesticides in oysters is correlated with latitude in the Gulf of Mexico.

             Contaminant body burdens average higher at higher latitudes. Wilson et al.

             (1990) suggested that the latitudinal temperature gradient in the Gulf

             produced variation in reproductive effort and that this variation in


                                                  3-86









                                                                                     Ellis 4



              reproductive effort affected PAH body burden sufficiently to override the

              effect of local variation in contaminant loading. Wilson et al. (in press),

              in a more thorough analysis, showed that PAH body burden responds to climate

              change and that biological factors are the likely intemediaries between

              climate's effect on temperature and freshwater inflow and the final body


              burden of PAHs.


                    Two likely intermediaries are spawning and disease. Spawning has

              frequently been forwarded as an important route of depuration Marcus and

              Stokes, 1985; Jovanovich and Marion, 1987; Cossa, 1989) because lipid loss

              peaks at this time (Chu et al., 1990). Parasites and pathogens are less

              frequently implicated (Khan, 1987), but parasites and pathogens should have an

             .effect; if for no other reason, they frequently reduce spawning frequency or

              the numbenof gametes per spawn (Akberali and Trueman, 1985; Ford and

              Figueras, 1988; Barber et al., 1988). In oysters, both spawning frequency and

              disease are significantly affected by temperature and salinity (Hofmann et

              al., in press, submitted; Soniat and Gauthier, 1989) and thus could serve as

              important intermediaries by which variation in climate might affect

              contaminant body burden.

                    Climate exerts its influence over large geographic scales. Biological

              parameters capable of responding to climate change and, thus, affecting

              contaminant body burden on a large geographic scale should certainly do so as

              well on a local scale. Accordingly, spawning frequency and disease should be

              important sources of local (within population) variability in contaminant body

              burden. Monitoring programs typically sample infrequently (NS&T samples once

              per year) so that the basis for within-sample variability is an important

              consideration. Accordingly, the primary purpose of this study was to examine

              sources of local variability in PAH body burden at any sampling period. Some

              analyses of pesticides were also conducted.
                                                   3-87










                                                                                        Ellis 5


                    Unfortunately, the variables likely of most importance in determining

              local variability in body burden, spawning frequency and the time since the

              last spawn, are variables that cannot be readily measured even in a

              temporally-intensive sampling program because continuous (or dribble) spawning

              is a frequent condition at latitudes south of Chesapeake Bay, including the

              entire Gulf of 118xico (Hofmann et al., in press). Consequently, more readily
              measured variables must be used as surrogates for the more desirable   @/
              variables. Thus, we examined a series of indices related to reproductive

              state, including stage of reproduction and the quantity of gonadal material

              present, and a series of indices related to health, namely    digestive gland

              atrophy, condition and P marinu infection intensity. P-,.     marinu , an

              endoparasitic protozoan, is responsible for high mortality    (typically > 50%)

              in market-sized oysters in the Gulf each year (Hofstetter,    1977; Osburn et

              al., 1985; Ray, 1987) and is known to delay reproduction (White et al., 1988;

              Wilson et al., 1988). Digestive gland atrophy is a putatively pathogenic

              condition (e.g. Marig6mez et al., 1990; Moore et al., 1989) common in Gulf

              coast oysters (Gauthier et al., 1990).



                                                   METHODS


              Within-population differences in body burden,


                    Oysters were collected in September from Confederate Reef in the West

              Bay extension of Galveston Bay. Confederate Reef oysters normally have a

              relatively high PAH body burden in comparison to the Gulf-wide mean (Sericano

              et al., 1990; Wade et al., 1988). September is near the end of the spawning

              season; most individuals should have spawned at least twice over the 4

              previous months. The oysters were placed on ice and returned to the

              laboratory. Maximum length and wet weight were determined. The condition of

              each meat was rated on a semiquantitative scale from 1, very good, to 9, very

                                                    3-88








                                                                                      Ellis 6



               poor, according to Quick and Mackin (1971). A small section of gonadal tissue

               was taken and fixed in Davidson's fixative (Fig. 28 in NOAA, 1983). A small

               section of mantle tissue was removed for determination of P. marinus infection

               following Ray (1966). The remaining tissue was placed in a precombusted mason

               jar with a teflon-lined screw cap and frozen for PAH analyses.

                    P
                     , marinus infection intensity was rated on the 0 (uninfected) to 5

               (highly infected) point scale of Mackin (1962) as modified by Craig et al.

               (1989). Tissue samples were embedded in paraffin, sectioned at 6 Pm and

               stained in Harris' hematoxylin and picro/Navy eosin (Preece, 1972).

               Reproductive stage was rated on a scale of 1 (sexually undifferentiated) to 8

               (spawned out) slightly expanded from Ford and Figueras (1988) by GERG (1990)

               (Table 1). Digestive gland atrophy was rated semiquantitatively from 0 (no

               atrophy) to 4 (extreme atrophy) as described by Gauthier et al.., (1990) (Table

               2).

                     The analytical procedures used for PAHs and pesticides were based on the

               NOAA's NS&T techniques for organic compounds (MacLeod et al. 1985) with some

               modification by Wade et al. (1988). These methods have been detailed

               elsewhere (Wade et al., 1988; Wade and Sericano, 1989; Sericano et al., 1990;

               GERG, 1990) and only a brief overview will be given here.

                     Samples were extracted with methylene chloride after drying with Na  2so  4*

               The samples were then purified by silica/alumina column chromatography. In

               order to remove lipids, a high-performance liquid chromatography separation

               was performed. Purified extracts were then analyzed by gas chromatography

               with a mass spectrometry detector, GC/MS/SIM for PAHs and GC-ECD for

               pesticides. All concentrations are reported as ng of analyte per gram dry

               weigh t of sample, or ppb. Concentrations in the procedural blanks were, in

               all cases, below reporting levels for each individual analyte. The accuracy


                                                    3-89








                                                                                    Ellis 7



              and precision of these methods have been established by several

              intercalibration exercises overseen by the U.S. National Institute of

              Standards and Technology.

                   Oyster gonadal tissue surrounds much of the body mass and, thus, is

              difficult to excise cleanly and weigh (Kennedy and Battle, 1964; Morales-Alamo

              and Mann, 1989). Thus, a quantitative gonadal index based on gonad weight, as

              is frequently used in invertebrates and fish, is not available. Accordingly,

              a polyclonal rabbit anti-oyster egg antibody was used to quantify the amount

              of egg protein present (Choi et al., in press). A single radial

              immunodiffusion assay (14ancini et al., 1965; Garvey et al., 1977) was

              performed to quantitate egg protein using 1.5% agarose in barbitone buffer

              (0.01 M sodium barbital, 0.0022 M barbital, 0.01% sodium azide as

              preservative, pH 8.6). Two ml of the rabbit serum containing anti-oyster

              antibody was mixed in 18 ml of the agarose gel and cast on a 10 X 10 cm glass

              plate. Four mm diameter wells were made on the plate using a gel puncher and

              20 pl of oyster egg standard (0.05 mg ml- to 3.2 mg ml-    or the sample were

              placed in the wells and incubated in a humid chamber for 48 hr at room

              temoeriture. After incubation, the plate was pr essed, dried, stained with

              0.5% (w/v) Coomassie Brilliant Blue, and destained with 50% EtOH and 10%


              acetic acid. Diameters of the precipitation rings were measured to the

              nearest 0.1 mm. A standard curve was constructed by plotting concentration of

              the egg standard against the diameter squared of the precipitation rings and

              the concentration of each sample Was read from the curve.

                    Removal of the body section for histological analysis biases both the

              total PAH concentration and the gonadal quantity as measured by us. Sericano

              et al. (in pre33 b) showed that the effect of this bias on PAH content is an

              exoected 10 to 201. reduction in measured body burden. For gonadal quantity,



                                                  3-90








                                                                                       Ellis 8


               the percent reduction can be expected to be considerably higher.   Readers are          OF
               cautioned not to accept the reported measures of gonadal quantity as true

               measures of completely intact oysters. However, as most oysters were similar

               in size, the bias introduced in both measures would be equivalent over all

               samples and thus not compromise the data analysis.


               Bpdy_burden of elz s and SDerM.'

                    In July, 1991 additional  oysters were obtained from Galveston Bay for

               examining the relative PAH and pesticide content.of eggs, sperm and the

               remaining body tissues.  Most oysters were. 7 to 12 cm long and exhibited

               fully-developed gonads. Oysters were shucked and their sex determined by

               microscoDe slide smear.


                    The contaminant content of the gametes, which, is the only tissue

               com,Donen.t lost during spawning, *may be dissimilar from the remaining gonadal

               tissue. Therefore, the eggs and sperm were isolated from the remaining

               gonadal and somatic mass.  The body of each oyster was separated from other

               somatic tissues. The remainder including gill, mantle, adductor muscle, and

               labial palps were stored at -20*C for PAH and Desticide analysis.    Gonads

               containing eggs or sperm were excised from the visceral mass using scissors

               and forceps. Gonads were placed on a petri dish and phosphate buffered saline

               (0.15 M NaCl, 0.003 M KCI, 0.01 M phosphate buffer, pH 7.4) (PBS) was added.

               Eggs or sperm were extracted by squeezing the gonads with a rubber-headed

               syringe piston. The egg extract was then filtered through a 100 PM nylon mesh

               screen; the sperm extract was filtered through a 30 pm nylon mesh screen.

                    Oyster egg filtrates were washed 4 times by resuspending the filtrates

               into 30 ml of PBS and centrifuging at 700 xg for 10 min.   During each washing,

               tissue debris and other impurities sedimented on the egg pellets were removed

               by pasteur pipette. After the final washing, the egg pellets were    resuspended

                                                    3-91









                                                                                   Ellis 9



            into an equal volume of PBS. Five m.1 of the resuspension was transferred to a

            15-ml. centrifuge tube, 7 ml PBS added to resuspend the eggs, and the

            suspension centrifuged at 500 xg for 15 min. Any remaining tissue debris

            layered on the egg pellet was removed using a pasteur pipette. Egg pellets

            from 10 to 20 oysters were pooled in a 50-ml centrifuge tube and sedimented by

            centrifugation (700 xg for 15 min). Oyster egg pellets were then resuspended

            into an equal volume of PBS. A 60% Percoll solution (4:6 PBS/100% Percoll)

            (100% Percoll is 9:1 Percoll stock: 1OX PBS) was prepared. Five ml egg

            suspension was mixed with 35 mi 60 % Percoll. and centrifuged at 900 xg for 20

            min. Oyster eggs formed an aggregate at the top of the centrifuge tube after

            centrifugation, Purified eggs were harvested from the tube and washed twice

            by centrifuging at 700 xg for 10 min.

                  Oyster sperm filtrates were washed 4 times with PBS by centrifuging 700

            xg for 15 min. Tissue debris found at the top of the oyster sperm pellet was

            removed using a pasteur pipette during each washing step. After the final

            washing, the sperm extracts were resuspended into an equal volume of PBS. 70%

            Percoll. was prepared and 35 ml. 70% Percoll was mixed with 5 ml. sperm

            suspension and centrifuged at 900 xg for 20 min. Oyster sperm was found at

            the bottom of the centrifuge tube and other impurities found at the top of the

            Percoll as a float. Purified oyster sperm was pooled from 20 to 30 oysters

            and washed twice with PBS by centrifuging at 800 xg for 15 min.

                  Because an involved procedure of this sort could lend to significant

            contamination, each solution was subjected to PAH analysis. No solutions were

            found to be significantly contaminated.









                                                 3-92








                                                                                           Ellis 10



                                                      RESULTS


                Within-population differences in PAH body burden.

                      Forty oysters were analyzed, 30 females and 10 males. We present the

                means and ranges of the variables measured in Table 3. The mean length for

                the group was 8.0 cm, wet weight 9.61 g, condition code 4.3 (fair plus), F,

                marinus infection intensity 1.33 (light plus), and digestive gland atrophy 2.1

                (about half atrophied). The sample contained individuals covering nearly the

                entire range of condition codes, two-thirds of the range of possible P'_

                marinus infection intensities, six of eight possible gonadal states and all

                stages of digestive gland atrophy. The variability in this data set is

                typical of single collections of oysters in the Gulf of Mexico region (Wilson

                et al., 1990).

                      By sex, the lengths of females and males were fairly close (7.9 cm vs.

                8.1 cm), however females were heavier than males (9.9 vs. 8.6 g). The weight

                difference is considerable since females are actually 0.2 am shorter on

                average. Condition code for both sexes was also fairly close, 4.6 for males

                vs. 4.2 for females, as was digestive gland.atrophy, 1.9 for males and 2.2 for

                females. P. marinus infection intensity differed substantially with males at

                0.77 and females at 1.67. Most animals were nearly ready to spawn or

                spawning. Reproductive stage was-similar: 5.3 and 5.6 for males and females,

                respectively. When measured quantitatively, the 30 females averaged 6.29 mg
                eggs per female (equivalent to about 4   .8 x 105 fully.-developed eggs per

                female). As a section of gonad was removed for histology, these values

                underestimate female fecundity.

                      Although we explored the entire suite of PAHs per NOAA's Status and

                Trends protocol (GERG, 1990), we only report data for the 5 most important

                PAHs: fluoranthene, phenanthrene, pyrene, naphthalene, and chrysene. Males


                                                       3-93








                                                                                    Ellis 11



              and females had similar body burdens except for rluorantheno where females had
              about one-third more. Means for both sexes ranged from 12.0 ng g-dry wt -1 for
              phenanthrene to 49.0 ng g dry wt-1 for fluoranthene.

                    A Spearman's rank analysis showed that many of the biological variables

              were correlated as might be expected. Accordingly, prior to considering their

              relationship with the PAHs, the relationships among the biological variables

              themselves must be understood. Because of the many significant correlations

              among them, we chose to identify the best 3-variable model explaining

              variation for each of the important biological variables, as detailed in

              Tables 4 to 6. Because gonadal quantity was measured in only 30 of the 40

              individuals and only in females, we examined the data with and without this

              variable included. The variables examined were length, wet weight, F,, marinus

              infection intensity, digestive gland atrophy, sex, condition code, gonadal

              stage and gonadal quantity.

                    The important correlations were ones (a) between sex and T,_ marinus

              infection intensity, males had lighter infections, and (b) between gonadal

              stage, condition code and digestive gland atrophy. Among the females, only

              the relationship between gonadal-stage and condition code remained

              significant. Among the males, digestive gland atrophy was correlated with L.-

              marinus infection intensity. Inasmuch as the two sexes were distinctive in

              the relationships among biological attributes, we will consider the sexes

              separately in most of the remaining analyzes.

                    Considering both sexes together, condition code and sex were the most

              important variables correlating with the PAHs (Table 7). Among the females,

              gonadal quantity had a significant effect in 3 of 5 cases (Table 8):

              fluoranthene, pyrene and chrysene. Each of the contaminant's concentrations

              was higher in females having more eggs. Digestive gland atrophy was also a


                                                   3-94









                                                                                    Ellis 12



               significant correlate of chrysene. Female oysters having a higher degree of

               atrophy had more chrysene. If gonadal quantity was removed, few significant

               correlations remained. Among the males, digestive gland atrophy was

               significantly correlated in 3 of 5 cases (Table 9). PAH concentration was

               lower in male oysters characterized by a greater degree of digestive gland

               atrophy. Condition code was significant in 2 of 5 cases; higher condition

               code (less healthy) occurred with higher PAH concentration.


               Body burden of eggs and sperm.

                    Samples of pure eggs and sperm, collected from oysters taken earlier in

               the spawning season than those supporting the previous data$' had significantly

               higher PAH levels than somatic tissue for all 5 PAHs (Table 10). A factor of

               5 difference was typical. Total PCBs were concentrated in eggs and sperm by a

               factor of about 5 over the somatic tissue. The chlorinated compounds like

               lindane, chlordane, dieldrin and DDT (plus breakdown products) were

               concentrated in eggs by about 4 times, but tended to be equivalent to or lower

               than the somatic tissue in sperm.



                                                DISCUSSION


               Spawning as a route of devuration.

                    Our data suggest that reproduction is an important depuration route for

               oysters; the frequency of reproduction is the most important determinant of

               body burden, under equivalent exposure levels. Sex and health are important

               secondary determinants of body burden because both affect reproductive state

               and the frequency of reproduction. The three following observations support

               these two conclusions.

                     (1) Both eggs and sperm contain significantly more PAH and pesticide

               than somatic tissue. The concentration factor is sufficient to conclude that


                                                   3-95








                                                                                   Ellis 13


             over half of the PAH body burden, and somewhat less of the pesticide body

             burden, could be in gonadal tissue prior to spawning. Eggs and sperm had PAH

             concentrations 5 times higher than somatic tissue, 3 to 4 times higher for

             pesticides, and the gonadal tissue can account for 25% of animal dry weight

             prior to spawning (Choi et al.9 in press; Klinck et al., 1992).

                   (2) The quantity of gonadal material was the most important correlate of
             PAH body burden and much more important than, for example, gonadal stage.

             Less gonadal material indicates recent spawning since these oysters were

             collected well into the spawning season; all had certainly spawned at least

             once prior to collection.

                   (3) Sex was an important determinant of body burden. Not only did PAH

             concentrations differ in some casess and dramatically so for some pesticides,

             but the factors correlating with body burden also differed among the sexes.

             Health-related factors were much more important in males. Factors decreasing

             health probably also decrease spawning frequency. The most important

             correlate occurred with digestive gland atrophy; however in males, digestive

             gland atrophy was highly inversely correlated with E.,_ marinus infection

             intensity, so the two parameters behaved similarly in explaining the variation

             in PAH body burden among oysters taken from the same site. PAHs were lower

             with lower L, marinus infection intensity and E, marinus is known to slow

             reproduction in oysters (Wilson et al., 1988; White et al., 1988).


             Reproduction, he;alth-and body burden.

                   The importance of reproduction in molluscs in controlling or affecting

             body burden is open to disagreement. Mix et al. (1982) and DiSalvo et al.

             (1975) found PAHs no more concentrated in Mytilus edulis gonadal material than

             somatic tissue (purified eggs were not measured), but noticed a significant

             drop in body burden during the spawnJ*,ng,,,season. Sericano et al. (i n press)









                                                                                    Ellis 14



              found that the central body region including the gonad contained

              proportionately more PAH in oysters. Lee et al. (1972), Fortner  and Sick

              (1985) and Solbakken et al. (1982), as examples, found the hepatopancreas to

              be an important depot for PAHs in bivalves, however gonadal material, and in

              particular, gametes, were not separately measured. In scallops where gonads

              can be separated from the somatic tissue by dissection, Friocourt et al.

              (1985) found gonadal material enriched in PAHs over muscle but not digestive

              gland tissue. Rossi and Anderson (1977) observed spawning to be an important

              depuration route in a polychaete Neanthe arenaceodentata.

                    If spawning is an important route of depuration, then factors affecting

              spawning frequency and how recently the last spawn occurred prior to

              collection will affect body burden. The biological variables measured as

              surrogates of spawning frequency Are gonadal quantity and gonadal stage,

              marinus infection intensity, and some general indicators of health. Few of

              these were correlated among themselves, so that most serve as separate,

              somewhat unique, indicators of the many factors that might affect spawning

              frequency and how recently the last spawn occurred prior to collection. Each

              has its own history, in some cases not necessarily related to spawning

              frequency, so that each is only a poor surrogate for the desired variable, but

              we emphasize that these are variables that can normally be easily measured in

              oyster individuals whereas spawning time and frequency cannot. Nevertheless,

              under these conditions, only the strongest relationships might be expected to

              generate a signal of sufficient intensity to be observed as a significant

              correlation.

                    Correlations were found, indicating the importance of reproductive state

              and health on body burden. The amount of variation explained among

              individuals in their PAR body burdens was generally low; however, this

                                                  3-97








                                                                                    Ellis 15



             probably emphasizes the previous point, that each of the measured variables

             are themselves relatively poor indictors of how recently and how frequently

             each animal had spawned. Stegeman and Teal (1973) emphasized the importance

             of the total exposure history of any individual organism in determining body

             burden. One aspect of this exposure history is the time since the last

             significant depuration event due to spawning.

                   Hydrocarbons can be taken up by feeding as well as in the dissolved

             phase (e.g. McElroy et al., 1989) and can affect filtration rate (Axiak et

             al., 1988; Barszcz et al., 1978). PAHs can also affect the digestive gland

             (Nott and Moore, 1987). Theoretically, digestive gland atrophy should be

             related to nutritional state. Digestive gland atrophy was correlated weakly

             with higher PAHs in females and more strongly with lower PAHs in males. One

             possible explanation for these divergent results is the strong correlation of

             digestive gland atrophy and T-, marinu infection intensity in males. In any

             case, no unambiguous effect of  digestive gland atrophy could be discerned.

                   Our data clearly support  the importance of reproduction, at least in

             oysters, during the summer and  fall. We suggest that the weak evidence for

             the importance of reproduction  in most time series of contaminant body burden

             generally stems from 3 factors: collect  ion of animals out of spawning season

             when little gonadal material is present, failure to analyze purified gametes

             which are the primary vehicle of depuration during spawning, and the poor

             understanding of the dynamics of uptake after spawning. We suggest that the

             timing of the last spawning event prior to             animals recover their

             body burden within a month or less after a depuration event (Sericano et al.,

             in press a) - and the degree of gonadal development (e.g. Hofmann et al., in

             press) are important variables affecting PAR body burden in oysters.



                                                  3-98








                                                                                        Ellis 16


                     Lowe and Pipe (1987) and Moore et al. (1989) observed gonadal resorption

               at high PAH concentrations. We observed no such effect in our analyses,

               however body burdens were lower.



               Variation between COMRounds.

                     Fluoranthene, pyrene and chrysene were very similar in their response to

               the biological variables; naphthalene and phenanthrene formed a second group

               quite different from the other three. Certainly, uptake, storage and

               depuration must be relatively similar within these two groups but different

               between them. Phenanthrene and naphthalene are lower molecular weight, more

               water soluble compounds and equilibrate faster with the environment (Pruell et

               al., 1986, Sericano et al.,  in prep.). They might lose the signal imposed by

               spawning events faster than  the larger three  PAHs examined. Phenanthrene and

               naphthalene,supported fewer  significant correlations, none with reproduction,

               despite their enriahment in  eggs-and sperm, but were correlated with general            MN

               measures of health, like condition. Possibly such general measures include

               factors controlling the equilibrium state of these PAHs. These analyses again

               suggest that an important variable controlling PAH body burden is the time

               between the most recent spawning and collection.

                     Nasci and Fossato (1982) noted that female gonadal material was enriched

               in total DDTs but male gonadal material was not in Mytilus galloprovincialis.

               Total PCBs were enriched in both female and male gonadal tissue. We observed

               the same phenomenon in oysters. Unlike PAHs and PCBs, sperm do not

               concentrate DDTs. The biochemical basis for this observation remains unclear.



               Reproduction and the latitudinal gradient in body burden,

                     The data suggest one explanation for the latitudinal gradient in PAH and

               pesticide body burden observed in the Gulf of Mexico (Wilson et al., 1990) and

                                                    3-99









                                                                                   Ellis 17



             the relationship of PAH body burden and climate change (Wilson et al., in

             press). Slight variations in temperature, as affected by climate change, or

             varying average temperature across latitudes will vary the reproductive

             season, the annual reproductive effort, and the frequency of spawning in

             oysters (Hofmann et al., in press, submitted). Small changes in temperature

             produce large changes in reproductive effort. As a result, body burdens will

             vary even under similar exposure levels and this variability may be

             considerable if a substantial fraction of the body burden is lost in spawning.

                  Wilsqn et al. (1990) found the latitudinal gradient in PAH body burden

             to be stronger than the latitudinal iradient in pesticide body burden. We

             found gonadal material concentrated much more highly in PA113 than pesticides

             and some pesticides are not concentrated in male gonadal material at all. Our

             data would suggest that temperature, and therefore latitude, should have a

             much grlaater impact on PAHs through reproduction than on pesticides, in

             agreement with the findings of Wilson et al. (1990). Taken together, our data

             and those of Wilson et al. (1990, in press) suggest that interpretation of the

             results of monitoring studies such as the Status and Trends program using

             bivalves requires that close attention be paid to the reproductive state and

             health of the sampled populations.



                                             ACKNOWLEDGMENTS

                  This research was supported by a grant from the Center for Energy and

             Minerals Resources, Texas A&M University (TAMU), an institutional grant NA89-

             AA-D-SG139 to TAMU bythe National Sea Grant College Program, National Oceanic

             and Atmospheric Administration (NOAA), U.S. Department of Commerce, grant 50-

             DGNC-5-00262 from the U.S. Department of Commerce, NOAA, Ocean Assessments

             Division, and computer funds from the TAMU College of Geosciences and Maritime

             Studies Research Development Fund. We appreciate this support.
                                                 3-100




                                                                                                     01



                                                                                    Ellis 18         OF



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                                                                                 Ellis 25



           WILSONt E.A., E.N. POWELL, T.L. WADE, R.J. TAYLOR, B.J. PRESLEY, AND J.M.

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                                                                                         Ellis 26


                                              LEGENDS TO TABLES                                            01
              Table 1                   The scale used for the analysis of gonadal stage

                                        (after GERG, 1990).

              Table 2                   The scale used for digestive gland atrophy.

              Table 3                   Means and ranges of PAH concentration and the

                                        biological parameters measured. ND, not determined.

              Table 4                   Best 3-variable model for each biological variable for

                                        all oysters combined (i.e. both sexes combined) and
                                        the amount of variation explained . (R 2).    Significant

                                        partial correlations are shown by asterisks: *, 0.05 <

                                        P < 0.1; **, 0.025 < P < 0.05; ***, 0.01 < P < 0.025;

                                              0.001 < P < 0.01;         0.0001 < P < 0.001.

              Table 5                   Best 3-variable model for each biological variable for

                                        female oysters and the amount of variation. explained
                                        (R2      Analyses were conducted with and without

                                        gonadal quantity included.         Signif icant partial

                                        correlations are shown by asterisks, as defined in

                                        Table 4.


              Table 6                   Best 3-variable model for each biological variable for

                                        male oysters and the amount of variation explained
                                        (R2    Significant partial correlations are shown by

                                        asterisks, as defined in Table 4.

              Table 7                   Best 3-variable model for each PAH for all oysters
                                        combined and the amount of variation explained (R     2 ).

                                        Significant   partial    correlations   are    shown    by

                                        asterisks, as defined in Table 4.




                                                     3-109









                                                                                              Ellis 27


              Tabl e 8                   Best 3-variable model for each PAH for female oysters
                                         and the amount of variation explained (W). Analyses

                                         were conducted with and without gonadal quantity

                                         included.    Significant partial correlations are shown

                                         by asterisks, as defined in Table 4.

              Table 9                    Best 3-variable model for each- PAH for male oysters
                                         and    the    amount    of   variation     explained     (R2

                                         Significant     partial    correlations     are    shown     by

                                         asterisks, as defined in Table 4.


              Table 10                   PAH concentrations in pooled samples of purified

                                         oyster eggs, purified sperm and somatic tissue (in

                                         ppb).

              Table 11                   Pesticide concentrations in pooled samples of purified

                                         oyster eggs, purified sperm and somatic tissue (in

                                         ppb).



























                                                        3-110









                                                                                     Ellis 28



                                                  Tabl e 1


                                       Assigned


                                       Numerical


             Developmental St"g          Valur,              Description

             Sexually

               Undifferentiated            1      Little or no gonadal tissue visible

             Early Development             2      Follicles beginning to expand

             Mid-Development               3      Follicles expanded and beginning to

                                                  coalesce; no mature gametes present
             Late Development              4      Follicles greatly expanded, coalesced, but          01

                                                  considerable connective tissue remaining;

                                                  some mature gametes present

             Fully Developed               5      Mc>st gametes mature; little connective

                                                  tissue remaining

             Spawning                      6      Gametes visible in gonoducts

             Spawned                       7      Reduced number of gametes; some mature

                                                  gametes still remaining; evidence of

                                                  renewed reproductive activity

             Spawned                       8      Few or no gametes visible, gonadal tissue

                                                  atrophying

















                                                  3-111







                                                                                  Ellis 29



                                               Table 2



                        Assigned



                       Numerical



                         Val ue                 Description



                            0           normal


                            1           less than one-half atrophied

                            2           about one-half atrophied

                            3           greater than one-half atrophied

                            4           completely atrophied.





































                                                3-112










                                                                                                                                                 Ellis 30



                                                                              Tabl e 3


                              Condi- -L maring       Wet                Digestive Gonad        Fluor- Phenan-         Napth-

                    Length      tion   Infection Weight Gonadal           Gland    Quantity anethene threne           alene     Pyrene Chrysene

                       (cm)     Code   Intensity      (g)      Stage     Atrophy(mg dry wt.)(ppb)         (ppb)       (ppb)      (ppb)     (ppb)

          Mean          8.0      4.3       1.45       9.6        5.5         2.1        ND      48.95     11.98       24.60      26.01     21.70

          Range    4.8-10.5     2-6     0.-3.33   5.9-20.9      2-7         o-4         ND  13.-104.85.2-52.0 14.1-83.8 B.-56.35.7-41.1

          Mean
           Yale         8.1      4.6       0.77       8.6        5.3         1.8        ND      38.47     14.08       28.84      21.34     21.59


          Mean
           Femalb       7.9      4.2       1.67       9.9        5.6         2.2      6.29      52.44     11.28       23.19      27.57     21-74









                                                                                           Ellis 31



                                                     Table 4

            Variable                                 B2     Explanatory Variable (N=39)          

               Perkinsus marinus infection           .18    Condition code                             

               intensity                                    Wet weight

                                                            Sex***

               Digestive gland atrophy               .14    Length

                                                            Condition code

                                                            Gonadal stage **

               Sex                                   .21    Length

                                                            Condition code
 
                                                            P. marinus infection intensty ***

               Gonadal stage                         .34    Condition code *

                                                            Wet weight ****

                                                            Digestive gland atrophy *

               Condition code                        .15    Gonadal stage *

                                                            Wet weight **

                                                            Digestive gland atrophy

























                                                  3-114










                                                                                                                                Ellis 32



                                                                       Tabl. e 5

                                                With Gonadal Quantity (N=23)                Without Gonadal Quantity (N=29)

         Variabl                                12    Explanatory Variabl                   32    Explanatory Variabl

            Gonadal stage                       .54   Length                                .47   Condition code

                                                      Condition code**                            Wet weight

                                                      Wet weight***                               Digestive gland atrophy

            Condition code                      .23   Length                                .11   Gonadal stage

                                                      Gonadal state                               Wet weight

                                                      Wet weight                                  Digestive gland atrophy

            Perkinsus marinu infection          .22   Length                                  o6  Condition code

            intensity                                 Gonadal stage                               Gonadal stage

                                                      Digestive gland atrophy                     Digestive gland atrophy
            Digestive gland atrophy             .16   Per@insus marinu infection            .11   Condition code

                                                      intensity                                   Wet weight

                                                      Length                                      Gonadal stage

                                                      Wet weight

            Gonadal quantity                                                                .07   Perkinsu   marinu infection

                                                                                                  intensity

                                                                                                  Wet weight

                                                                                                  Digestive gland atrophy



                                                                             I=     Ism     I   I








                                                                                             Ellis 33


                                                       Table 6


               Variable                                B2     Explanatory Variable (N=10)
                  
			Gonadal stage                        .70    Length

                                                              Wet weight

                                                              Perkinsus marinus infection

                                                              intensity***
                  
                  Condition code                       .20    Length

                                                              Wet weight
                                                              
                                                              Perkinsus marinus infection intensity

                  Perkinsus marinus infection          .74    Length*

                  intensity                                   Wet weight**

                                                              Digestive gland atrophy****
                  
                  Digestive gland atrophy              .80    Perkinsus marinus infection

                                                              intensity****

                                                              Length**

                                                              Wet weight***


























                                                 3-116








                                                                                      Ellis 34



                                                  Table 7


             Variable                             _B2    Explanatory Variabl

                Fluoranthene                       .20   Length

                                                         Perkinsu marinu infection


                                                         intensity

                Phenanthrene                       .11   Sex**


                                                         Condition code


                                                         Gonadal stage

                Naphthalene                        .20   Sex


                                                         Condition code***


                                                         Gonadal stage

                Pyrene                             .19   Sex


                                                         Length


                                                         Perkinsu marinu infection


                Chrysene                           .14.  intensity

                                                         Sex**


                                                        -Perkinsu marinu infection

                                                         intensity

                                                         Wet Weight

                                                         Sex



















                                                   3-117







                                                                                                   Ellis 35



                                                          Tabl e 8


                                          With Gonadal Quantity            Without Gonadal Quantity

             Variabl                      12 Explanatory Variable          B2   Explanatory Variable

                 Fluoranthene             .37 Condition code               .18 Length

                                               Wet Weight                       Condition code

                                               Gonadal quantity***              Perkinsu.  marinu.

                                                                                infection  intensity

                 Phenanthrene             .18 Perkinsu marinu              .16  Condition  code


                                               infection intensity              Perkinsu   marinu

                                               Digestive gland atrophy          infection  intensity

                                               Gonadal quantity                 Digestive  gland atroohy

                 Naphthalene              .21  Length                      .27  Length***

                                               Digestive gland atrophy          Perkinsu   marinu

                                               Gonadal quantity                 infection  intensity

                                                                                Digestive  gland atrophy*

                 Pyrene                   .31  Gonadal quantity**          .20  Length

                                               Digestive glandatrophy           Condition  code

                                               Gonadal stage                    Perkinsu   marinu

                                                                                infection  intensity

                 Chrysene                 .51 Length***                    .25  Perkinsu   marinu

                                               Digestive gland atrophy**        infection  intensity*

                                               Gonadal quantity*****            Wet weight*

                                                                                Digestive gland atrophy











                                                      3-118








                                                                                      Ellis 36
             Mariabl                              Tabl e 9
                                                   B2    Explanatory Variabl

                 Fluoranthene                      .49   Length

                                                         Gonadal stage

                                                         Digestive gland atrophy*

                 Phenanthrene                      .67   Condition code**


                                                         Gonadal stage

                                                         Digestive gland atrophy

                 Naphthalene                       .73   Condition code***

                                                         Gonadal stage*

                                                         Digestive gland atrophy

                 Pyrene                            .68   Length

                                                         Gonadal stage

                                                         Digestive gland atrophy***

                 Chrysene                          .59   Condition code

                                                         Gonadal stage

                                                         Digestive gland atrophy*
























                                                    3-119








                                                                                                     Ellis 37



                                                          Table 10


                              Group A       Group B       Group C        Group D        Group E

                              Eggs Tissue Eggs Tissue     Eggs Tissue Sperm Tissue Sperm Tissue


             Naphthalene      45.1   9.0    51.9  8.9     42.5  5.9      64.8 12.3      70.5 12.3

             Phenanthrene     23.5   2.9    26.9  4.1     29.0  3.4      26.1    5.6    29.9    5.6

             Fluoranthene     16.1   2.9    15.8  3.0     17.7  3.2      11.6    3.3    17.6    3.3

             Pyrene           20.7   3.7    18.4  3.7     18.2  3.8      13.1    4.0    18.1    4.0

             Chrysene         11.5   2.4    12.5  2.0     10.9  2.2        7.2   2.4    16.6    2.4










































                                                         3-120








                                                                                                   Ellis 38



                                                         Table 11


                               Group A      Group B      Group C        Group D       Group E

                               Eggs Tissue Eggs Tissue   Eggs Tissue Sperm Tissue Sperm Tissue


               Lindane         9.4 2.06      5.5 2.2      8.2 1.8       <1.0   2.2     0.0    2.2

               Total BHCs      14.7 5.0      9.5 5.2     14.0 3.9       0.0    5.2     2.4    5.2

               a-chlordane     6.5 3.8       5.0 3.8      5.1 2.4       0.0    4.5     [email protected]   4.5

               Dieldrin        6.3 2.2       6.1 1.9      5.8 1.7       0.0    1.8     1.7    1.8

               4,41 DDE        32.1 9.1     26.o 8.2     26.7 7.5        4.1   11.9    6.6   11.9

               4,4T DDD        12.3 3.7     11.7 3.2     12.5 3.1       <1.0   3.6     3.5    3.6

               Total PCBs    132.6 36.5    147.8 33.5   113.0 29.6     114.2   53.8   102.3  53.8







































                                                        3-121








                                   4.0 Chlorinated Hydrocarbons


                     The concentration of selected chlorinated hydrocarbons has
               been measured for six years (1986-1991) in oyster samples from 50 to
               71 Gulf of Mexico sites as part of the NOAA National Status and Trends
               (NS&T) Mussel Watch project. The results for pesticides and PCBs as
               the mean of years I to 5 verses year 6 are plotted in Figures 4.1 to
               4.19.    Oysters are valuable sentinel organisms that reflect
               contamination of an ecosystem on time scale of months. These sites,
               removed from known point-sources of contamination, give coverage of
               U.S. Gulf of Mexico coastal areas from southern-most Texas to
               southern-most Florida. General overviews of the results of the NOAA!s
               NS&T Program pesticide and PCB data have already been reported
               (Table 1. 1 and Reprint 7).

                     Total DDT (sum of o-p'DDE + p-p'DDE + o-p'DDD + p-p'DDD + o-
               p'DDT + p-p'DDT) data for oysters collected along the U.S. Gulf of
               Mexico coast between 1986 and 1989 is shown in Figure 4.10. Total
               DDT is the most abundant chlorinated pesticide found in Gulf of
               Mexico oysters. Most of the DDT is present as metabolites, DDE and
               DDD. Less than 10% of the total contaminant load in oysters is the
               parent compound, DDT. The highest total DDT concentrations were
               encountered in samples near the Brazos River mouth (BRFS) and
               Galveston Bay (GBSC) in Texas, Mississippi River (MRPL and LPGO) in
               Louisiana, Mobile Bay (MBHI) in Alabama, and Choctawhatchee (CBSP.
               and PCLO) and St. Andrews Bays (SAWB) in Florida. With few
               exceptions, total DDT concentrations were consistently low in samples
               from southern Texas, Louisiana sites to the west of the Mississippi
               River, and southernmost Florida. The general distribution of total DDT
               concentrations encountered during 1991 in the Gulf of Mexico was
               very similar to the distribution for the 1986-1990  'sampling period.
               Total DDT concentrations measured during Year 6 were lower or the
               same as those encountered in the average of the previous five years of
               this study at all except five sites. The incorporation of new sampling
               sites, located closer to supposed contaminating centers, during 1989,
               1990, and 1991 added more details to the overall DDT distribution in
               the northern Gulf of Mexico, but did not greatly affect the regional
               distribution. In general, the average concentrations measured at those
               sites were in good agreement with the concentrations previously
               reported for the surrounding geographical area. A greater fraction of
               DDT is found as DDE in the general region south of Galveston Bay along
               the Texas coast. This may be related to an "older" source of DDTs in
               the South Texas area, but additional data is required to examine this
               hypothesis.

                     The concentrations of hexachlorobenzene (HCB, Figure 4.1)
               were generally low (maximum was 2.10 ng/g). These values are very
               close to the method detection limit and analytical difficulties make



                                                 4-1








                  interpretation of this data problematic. This same problem is found
                  when attempting to interpret the data for lindane, heptachlor, aldrin,
                  heptachlor epoxide and mirex (Figures 4.2, 4.3, 4.4. 4.5 and 4.9).

                        Chlordane and its breakdown products are represented by a-
                  chlordane (Figure 4.6) and trans-nonachlor (Figure 4.7).              The
                  chlordane distribution is similar to the DDT distribution with low
                  concentrations in Southern Texas, highs in Galveston Bay, near the
                  Mississippi River, and in Florida Bays. Details of the chlodane
                  distribution have been reported (Preprint 3). Dieldrin (Figure 4.8) has
                  a distribution similar to chlodane, with the exception that the Florida
                  sites are not as high relative to the Galveston Bay and Mississippi River
                  sites.

                        Endrin was measured in NS&T oysters for the first time in Year
                  5. The concentrations ranged from below detection (-I ng/g) to 30.6
                  ng/g. The concentrations are lower in southernmost Texas and
                  Florida, with higher concentrations in the northern regions of the Gulf
                  Coast.   Endrin concentrations were in general lower in year 6
                  compared to year 5. Endrin does not appear to have a simlar
                  distribution to other chlorinated hydrocarbons.

                        The general trend of chlorinated hydrocarbon concentrations is
                  relatively constant at most sites with episodic increases and decreases
                  at selected sites. These episodic changes are probably due to site
                  specific input events. However, Gulf-wide -temporal changes have been
                  reported (Reprint I ).                                                             I
                        PCBs proved to   be ubiquitous contaminants in Gulf of Mexico
                  oysters. PCB congeners were detected in all NS&T samples analyzed
                  (Figure 4.18). PCB concentrations were higher at 18 sites in year 6
                  compared to the mean of years 1 to 5. As in the case of DDTs, the
                  addition of new locations to the sampling project did not greatly
                  modify the general distribution of average PCB concentrations in Gulf
                  of Mexico oysters described for the first three years of the NS&T
                  project. A possible exception could be Tampa Bay (TBKA), which had
                  average PCB concentrations clearly higher than the surrounding sites.
                  The new site for year 6 (LPGO) has the highest concentration
                  reported.

                        GERG has recently taken a closer look at the consequence of
                  removing part of the oyster sample that was collected for organic
                  analyses to use in biological testing (Preprint 4). While it would not
                  affect the overall interpretation of NS&T data, it does add a bias into
                  the data. More details are available in the attached Preprint 3. GERG
                  has also recently developed methods for analyses of the most toxic
                  planar PCB congeners and applied these techniques to selected NS&T
                  samples (Preprint 5).



                                                    4-2
























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                  Ch 0                                                                BRSD                                                     AESP
                  CD '0                                                               BBNM
                             FSsp                                                                                                              SRWP
                             F-SBD                                                    MRI?
                             MBGP                                                                                                              CKBP
                                                                                      MRPL                                                     TBNP
                             MBLR
                                                                                      BSSI                                                     TBMK
                     0       )@MCB
                                                                                      BSBG                                                     TBPH
                             mB7p
                                                                                                                                               TBOT
                             NSDI                                                     LBUWP
                  0          MBEM                                                     LJ3NO                                                    TBKA
                             BRCL                                                                                               LA             TBHB
                                                                                      LPGO
                       t
                                                                                                 .................................... ...............................
                             BRFS                                                     MSPC                                                     TBCB
                             GBCR                                                                                               ms             CBBI
                  0  cwo                                                              MSBB
                  0          GBOB                                                                                                              cnpm
                             GB11)                                                    MSI'B         ........ ... . ................................................ NBNB
                             G13YC                                                    MBCP                                                     RBIIC
                             GBSC
                  plz@ cp                                                             wimn                                      AL;            EVFU
                             GBHR                                     41.07
                             SUR                                                      MBDR                                                     BHKF
                                                                                                 :s
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                                                                                                                                                        sm



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                                                                                                                                                     L













                      >    LMSB                                                  CLSJ                                                 I'Bl'll
              n  cn        LMPi                                                  CLLC                                                 PBIB
                 940       L.MAC                                                                                                      PBSP
              U) -@                                                              JHJH
                      m    CCBH                                                                                                       CMBM
                      (D   CCNB                                                  VBSP,                                                CBSR
                 r, P                                                            ABOB
                      I    ccic                                                                                                       CBSP
                 ucn,      ABIR                                                  CLCL                                                 PCLO
                      0    ABIU                                                  TBt2                                                 PCMP
                           CBCR                                                  TBLF                                                 SAWB
                           MBARR
                 r+                                                              BMB                                                  APDB
              a) n    n    SAPP
                      0    SANT                                                  BBSD                                                 APCP
                      0                                                                                                               AESP
                      :5   Essp                                                  BBIVM
           Go    @: o                                                                                                                 SRW
                           ESBD                                                  MRI?
                           MBGP                                                                                                       CKBP
                 0 q                                                             MRPL                                                 T13NP
                           MBLR                                                  RSSI                                                 7 B NMMX
                           MBCB
                      0
                      @$   MBTP                                                  BSBG                                  LA             TBpB
                           NSDI                                                                                                       7ROT
                 C)        MBEM                                                  LBNO                                                 7BKA        X
                      0    BRCL                                                                                                       THHB
                      g    BRFS                                                  L.PGO                                                IBCB
                 PC        GBCR                                                  MSPC                                                 CBBI
                      cp   GBOB                                                  MSBB                                  ms             CBFM
                 m         GBTD                                                  MSPB                                                 NBNB
                 cf)  0    CIRYC
                                                                                                                                      RBIlC
                           OBSC
                 (D   (D                                                                                                AL            RVFU
                      P    G B IHMR                              68.851
                 slo                                                             MBDR                                                 BHKP
                           SLBB
                                                                                                                                                Ell
























                                                                                                                                                W                 LA


                                     LMSB                                                                       CLSJ                                                                      PBPH
                                     LM-Pl                                                                      CLLC                                                                      PEM
                  Cl)  @r            LMAC                                                                       JHJH                                                                      PBSP
                       ZA            CCBH                                                                                                                                                 CBJB
                       cn (D         CCNB                                                                       VBSP
                  r_n                                                                                                                                                                     CBSR
                                     ccic                                                                       A130H                                                                     CBSP
                                     ABLR                                                                       CLCL                                                                      PCLO
                                     AB IME                                                                     TBLB                                                                      PCMP
                                     C B CMR                                                                    TBLF                                                                      SAWB
                           @3        MBAR
                                     SAPP                                                                       BBIB                                                                      APDB
                                     SAMP                                                                       BBSD                                                                      APCP
                                     ESSP                                                                       BBNIB                                                                     AESP
                                                                                                                                                                                          SRWP
                                     ESBD                                                                       MRT?
                           0         MBGP                                                                                                                                                 CKBP
                           @3.                                                                                  MRPL
                           0         MBLR                                                                                                                                                 TBNP
                       o (D                                                                                     BSSI
                       -,) Z         NMCB
                                     MBTP                                                                       BSBG                                                  LA                  'rpB
                                     NMDI                                                                       LBNT                                                                      7BOT
                       0'  0         MBEM                                                                       lLJ23 N 0                                                                 TBKA
                       0   z
                           (n        BRCL                                                                                                                          104.18
                                     BRFS                                                                       L.PGO                                               ...........           TBHB
                                     GBCR                                                                       MSPC                                                                      IBCB
                           0                                                                                                                                                              CBBI
                                     GBOB                                                                       MSBB                                                  ms                  CBFM
                                     G131D                                                                      MSPB
                                                                                                                               ................................................................... NBNB
                                     GBYC
                           cn                                                                                   MBCP
                                                                                                                                                                                          RBHC
                                     GBSC
                                                                                                                                                                      AL'                 EVFU
                                     GBHR                                                                       MBDR                                                                      BHKF
                                     SLBJ3

























                                                                           U3


                                  LMSB                                                               CLSJ                                                             PBPH
                     (J)          LIVIPI                                                             CLLC                                                             PBIB
                     k*           LLMAC                                                                                                                               PBSP
                 co               CCBH                                                               Immm                                                             CBJB
                 ).@                                                                                 VBSP
                  i               CCNB                                                                                                                                CBSR
                 ul               ccic                                                               A130B
                                                                                                                                                                      CBSP
                                  ABLR                                                               CLCL                                                             PCLO
                                  AU131n                                                             TBLE                                                             PCMP
                                  CBCR                                                               TBLF                                                             SAWB
                                  MAR
                                                                                                     BHM                                                              APDB
                 O)o     0        SAPP
                     V 0          SAMP                                                               BBSD                                                             APCP
              4          0                                                                                                                                            AESP
                                  Essp                                                               BBNMM
                                                                                                                                                                      SRWP
                                  ESBD                                                               MRT?
                                  NMMB G P                                                           MRPL                                                             CKBP
                     0" Pr        MBLR                                                                                                                                713NP
                         0                                                                           assl                                                             TBMK
                                  MBCB                                                               BSBG                                             LA              TBPB
                                  =1                                                                 LBNWP                                                            IBOT
                         0        MBEM                                                               LBNO                                                             TBKA
                                  BRCL                                                                                                              62.44             ME
                                                                                                     LPGO                                          -\,\ -,
                                  BRFS                                                               MSPC         .................................................................. T13CB
                                  GBCR                                                                                                                                CBBI
                         cr)
                                  GBOB                                                               MSBB                                            ms               CBFM
                                  GBM                                                                MSPB
                                                                                                                     ..... . .................... . ................................. N13N]3
                                  GB                                                                 MBCP                                                             RBHC
                                  GBSC                                                               NIBIff                                           AL              EVFU
                                  GBHR                                           57.92                     1
                                  SLBB                                                               MBDR                                                             BHKF
                                                                                                                                                                                  m




















                               CD


                               >      LMSB                                                                      CLS]                                                                      PBPH
                                      I.MPI,                                                                    CLILC                                                                     PBIB
                                      LMAC'
                                                                                                                                                                                          PBSP
                               cp                                                                               JHJH
                               (D M   CCHH                                                                                                                                                CBM
                               CD     CCNB                                                                      VBSP                                                                      CBSR
                                      ccic                                                                      ABOB                                                                      CBSP
                               rl'    ABLR                                                                      CLCL                                                                      PCLO
                               '@3    A131MU                                                                    7M'B I B                                                                  PCMP
                                      CBCR
                               0                                                                                TBLF                                                                      SAWB
                                      MBAR
                                                                                                                BSn                                                                       APDB
                               0      SAPP                                                                                                                                                APCP
                               I      SAMP                                                                      BBSD
                                      ESSP                                                                      BBMB                                                                      AESP
                               Ct     ESBD                                                                                                                                                SRWp
                               0                                                                                MR7?
                                      MBGP                                                                                                                                                CKBP
                                      MBLR                                                                      MRPL                                                                      TBNP
                                                                                                                BSSI                                                                      TBMK
                                      MBCB                                                                      BSBG
                               0      MBIP                                                                                                                                                TBPB
                               .<                                                                                       mm
                               (p     NMDI                                                                      LBNT                                                                      TBOT
                               Z      MBFM                                                                      LJ3NO                                                                     7BKA
                               cn cn  BRCL                                                                      L.PGO                                                  LA                 TBH13
                               @;'    BRFS                                                                                         ............................................................ TBclB3
                               0      GBCR                                                                      MSPC
                                      GBOR                                                                      MSBB                                                  ms                  CBBI
                                                                                                                                                                                          CBFM
                               .,A P  GBTD                                                                      MSPB
                               ,in                                                                                                  ............................................................ NBNH
                                      GBYC                                                                      MBCP                                                                      RBHC
                               z.     GBSC
                               cn (-n GBHR                                                                                                                             AL                 EVFU
                                      SLBB                                                                      MBDR                                                                      BHKF



























                                                                                    I
                                      L.MSB                                                                   CLS1                                                                    PHPH
                        Z >           LmPl                                                                                                                                            P81B
                        CP            LMAC                                                                    CLLC                                                                    PBSP
                        9@-                                                                                   nuH
                                      CCBH                                                                    VBSP                                                                    CBM
                                      CCNB                                                                                                                                            CBSR
                                      ccic                                                                    AIB30B
                            0                                                                                                                                                         CBSP
                                      ABLR                                                                    CLCL                                                                    PCLO
                   0. CD              ABIR                                                                    7BLMJ3
                                      CBCR                                                                                                                                            PCMP
                                      MBAR                                                                    TBLF                                                                    SA  DR
                                                                                                              BOM                                                                     APDR
                                      SAPP
                        n                                                                                                                                                             APCP
                                      SAMP                                                                    B13SD
                                                                                                                                                                                      ABSP
                            @l        ESSP                                                                    BBMB
                            0                                                                                                                                                         SRWP
                                      ESED                                                                    MRT?                                                                    CKBP
                                      MBGP                                                                    MRPL
                        o q                                                                                                                                                           TBNP
                                      MBLR                                                                    BSSI                                                                    7BMWK
                                      NMC13
                                      Ma7p                                                                    BSEIG                                                                   77BPB
                                      M13DI                                                                   LBMP                                                                    TBOT
                        0 Z           MHEM                                                                    lJ3NO                                                                   713KA
                            0         BRCL                                                                                                                         LA                 T13HB
                            1,4                                                                               LPGO
                            Cf)       BRFS                                                                    MSPC        .................. ......                                   TBC8
                                      G,13CR                                                                                                                                          CBBI
                                                                                                              MSBH                                                ms
                                      GBOB                                                                                                                                            CBFM
                                      GBTMD                                                                   MSPB
                                                                                                                                    ..... ................................................. NBNB
                                      GBYC                                                                    MBCP                                                                    RBHC
                                      GBSC
                                      GBITR                                                                   MBIU                                                 AL.                Evr-u
                                      SLBB                                                                    MBDR                                                                    BHKF
























                                                                                                                                                         00


                                     L.MSB                                                                  CLSJ                                                                  PBPH
                                     LMPI'                                                                                                                                        PBIB
                       rj)                                                                                  CLLC
                       @o            LMAC                                                                   im                                                                    PBSP
                   CP                CCBH'                                                                                                                                        CBM
                          m                                                                                 VBSP
                           n         CCND                                                                                                                                         CBSR
                           ND        CCIC'                                                                  A130B                                                                 CBSP
                                     ABLR'                                                                  CLCL                                                                  PCLO
                                     ABM                                                                    TBLJ3                                                                 PCMP
                                     CBCR                                                                   T13LF                                                                 SAWB
                                     MBAR                                                                   B9m                                                                   APDH
                                     SAPP.                                                                                                                                        APCP
                       :7 0          SAMP                                                                   BBSD
               4           @s                                                                                                                                                     AESP
                           0         ESSP                                                                   BBNM
                           CD                                                                                                                                                     SRWP
                           0         FSBD                                                                   MRI?
                           r+                                                                                                                                                     CXBP
                                     MBGP.                                                                  MRPL
                                     MBLR 3                                                                                                                                       TBNP
                                                                                                            BSSI                                                                  T13MK
                           0         NMCB
                           @s                                                                               BSBG                                                                  TBPB
                       n             MBI?
                                     NIBDI                                                                  LBNT                                                                  7BOT
                       0                                                                                                                                                          TBKA
                       0   0         MBEM                                                                   LBNO                                                LA                T13HB
                       Cl) Q@        BRCL                                                                   LPGO
                                     BRFS'                                                                                  ......                                                TBCB
                                                                                                            MSPC
                                     OB                                                                     MSBR                                               ms                 CBBI
                                     GBOB                                                                                                                                         CBFM
                       Z                                                                                    MSPB
                                     GB7D                                                                                               . ........................................ NBNB
                                     GBYC.                                                                  MBCP                                    AL 208.141                    R13HC
                                     GBSC                                                                                                                                         EVFIUJ
                                     GBHR'                                                                  MBDR                                                                  BHKF
                                     SLBB                                     -------------                                                                  166.65






















                                                LmSB                                                                                        CLS1                                                                                       PBPH
                                                LM?l                                                                                        CLLC                                                                                       PBM
                                                L@MAC                                                                                                                                                                                  PBSP
                                                                                                                                            JHJH
                                    OA          CCBH                                                                                        VHSP                                                                                       C=mBm
                                                CCN]3                                                                                                                                                                                  CBSR
                                    4           ccic                                                                                        ABOR                                                                                       CBSP
                                    '4-         A13LR                                                                                       CLCL                                                                                       PCLO
                                                ABW                                                                                         TBL13                                                                                      PCmP
                                                CBCR                                                                                        TBLF                                                                                       SAWB
                                                MBAR
                                                                                                                                            Bom                                                                                        APDB
                                    0           SAPP
                                    0           SAMP                                                                                        BBSD                                                                                       APCP
                                                ESSP                                                                                        BBNM                                                                                       AESP
                                                                                                                                                                                                                                       SRWP
                                                ESBD                                                                                        MRTP
                                                MBGP                                                                                                                                                                                   CKBP
                               0 P                                                                                                          MRPL
                                    ;7t.        MBLR                                                                                        BSSl                                                                                       TBNP
                               40               NMC13                                                                                                                                                                                  T13MK
                                    0
                                                MBT?                                                                                        BSBG                                                                                       T13PB
                                                NSDI                                                                                        LBMP                                                                                       7BOT
                               0    0           MBEM                                                                                        LBNO                                                                                       MA
                                    (.-,        BRCL                         .305sm                                                         Lpoo                                                                LA                     7BHB
                                                BRFS                                                                                                      ........................................................................     7BCIB
                                                                                                                                            MSPC
                                                GBCR                                                                                                                                                                                   CBBI
                                    cun)
                                                GBOB                                                                                        MSBB                                                               ms
                               :z                                                                                                                                                                                                      CBFM
                               010@             GBTD                                                                                        MSPB                ................................................................       NOR
                               cn.              GBYC                                                                                        MBCP
                                                                                                                                                                                                                                       RBHC
                                                GBSC
                                    (mD         GBHR                                                                                                                                                            AL                     EVFU
                                                                                                                                            @ODR                                                                                       BHKF'l
                                                SLBB










                                                NNIM             NINE             MINI             1=1             I         I      I



















                                  CD




                                  CAD                                             t.A
                                                                                                                                                                                    LA
                                  >          LMSB                                                                                CLSJ                                                                               PBPH
                                             LIM                                                                                 CLLC'                                                                              PBIB
                                             LMAC                                                                                                                                                                   PBSP
                                             CCBH                                                                                                                                                                   CBJMB
                                                                                                                                 VBSP
                                             CCNB                                                                                                                                                                   CBSR
                                  N-)        ccic                                                                                ABOR                                                                               CBSP
                                  *4-        ABLR                                                                                CLCL                                                                               PCLO
                       CL    n
                                             ARM                                                                                 7BLI3                                                                              PCMp
                                             C13CR                                                                               TMB L F                                                                            S A VWMB
                                             MBAR
                                                                                                                                 BBM                                                                                APDB
                                             SAPP
                             :r b                                                                                                BBSD                                                                               APCP
                                  5          SAW                                                                                                                                                                    AESP
                                             ESSP                                                                                BBMB
                                                                                                                                                                                                                    SRWP
                                  Z          ESBD                                                                                MRTP
                                  r+.                                                                                                                                                                               CKBP
                             0               MBGP                                                                                MRPL
                                             MBLR                                                                                                                                                                   TBNP
                                  pt                                                                                             BSSI                                                                               TBMK
                                  0          NMCB
                                             MBTP                                                                                BSBG                                                                               TBPR
                                                                                                                                 LBNIP'l                                                                            IBOT
                                             NIBDI
                             0               MBENM4                                                                              L13NO                                                                              TBKA
                                  0
                                  k-114      BRCL                                                                                12GO                                                        LA                     7SHB
                                  cn         HRFS                                                                                            .. .................................... ...................... ..........
                                                                                                                                 mspc                                                                               7SCB
                                                                                                                                 MSPC
                                             GBCR
                                                                                                                                                                                                                    CBHI
                                             GROB                                                                                MSBB                                                        ms
                             :z                                                                                                                                                                                     CBFM
                                             GB7D                                                                                MSPB
                                  0          GBYC                                                                                                            ...........................................            NBNB
                                                                                                                                 MBCP                                                                               RBHC
                                             GBSC
                             (D   0                                                                                                                                                                                 EVFU
                                  p          G B HMR
                             510             SLBB                                                                                MBDR                                                                               BHKP
                                                                                                                                                                                                                             mm



                                                                                                                                                                                                                             m













                       Oil






                                            LA

                               LMSB                                                         CLSI                                                       PBPH
                       >       I.W,                                                                                                                    PBIR
               CD              LMAC                                                         CLLC'                                                      PBSP
                                                                                            JHJH
                               CC13H                                                                                                                   CBJB
                                                                                            VBSP
                       M       CCNB                                                                                                                    CBSR
                       P,      ccic                                                         A130B                                                      CBSP
                               AHLR'                                                        CLCL                                                       PCLO
                   CD          ABW                                                          7BlJ3                                                      PCMp
                       tz@     C13CR ''
                       t@                                                                   713LF                                                      SAWB
                               NMAR.                                                                                                                   APDB
                                                                                            BBrM
                               SAPP,
                   @r 0        SAMP                                                         BBSD                                                       APCP
                       0                                                                                                                               AESP
                               ESSP                                                         BBNM
                                                                                                                                                       SRWP
                               MD.                                                          MR7?
                               MBGP   m                                                                                                                CKBP
                                                                                            MRPL
                   0 A)                                                                                                                                TBNP
                       @:r     MBLR
                       0       NIBCB                                                        BSSI                                                       TBMK
                       0       M13TP                                                        BSBG                                                       TRPB
                               NMDI                                                         LBNT                                                       7130T
                   0           M13FM                                                        LBNO                                                       TBKA
                               BRCL                                                         LPGO                                       LA              nHB
                               BRFS                                                                 .................     ........                     ncB
                                                                                            MSPC
                               GBCR
                                                                                                                                                       CBBI
                                                                                            MSBB                                       ms
                               GBOB                                                                                                                    CBFM
                               GBTD                                                         MSPB
                                                                                                        ................................................................. NBNB
                       0       GBYC                                                         MBCP                                                       RBHC
                               GBSC                                                                                                    ALi:            RVFU
                   CD  (D      GBHR                                                         M13DR                                                      BHKF
                               SUR




















                                      C'D



                                                                                                               tA                                 LA                     LA
                          .,A Z >             LMSB                              ...............                                 CLSI                                                                            PBPH
                                      @<      I-wi                                                                              CLLC'                                                                           PBM
                                      1. 11   LMAC                                                                                                                                                              PBSP
                         cn '-3 p                                                                                               IHJH                                                                            CBM
                                              cc
                                              CCN13                                                                             VBSP                                                                            CBSR
                         Ul           ND      ccic                                                                              ABOD                                                                            CBSP
                         @ cun)               ABLR                                                                              CLCL                                                                            PCLO
                                              A1319.                                                                            TBLJ3                                                                           PCMP
                                                                                                                                TBLF
                                              C13CR                                                                                                                                                             SAWH
                                      w       MBAR                                                                                                                                                              APDB
                                      C-tl
                         9)           00      SAPP                                                                                                                                                              APCP
                                      @7. 0                                                                                     BBSD
                                      @Z      SAMP                                                                                                                                                              AESP
                                              ESSP                                                                              B B INVM                                                                        SRWP
                                              ESBD                                                                              MRI?
                                                                                                                                                                                                                CKBP
                                              MBGP
                                      0 p                                                                                       MRPL                                                                            TBNP
                                              MBLR
                                                                                                                                BSSI                                                                            TBNT
                                      0       NMCB
                                      0                                                                                         13SBG                                                                           TBPB
                                      cn      MB7?
                                      *..                                                                                                                                                                       TBOT
                                      :z      @MDI                                                                                                                                                              MA
                                      0       MBEM                                                                              L13NO
                                      r                                                                                                                                                    LA                   TBHB
                                      4..@    BRCL                                                                              LPGO            .................................................................... TnBCB
                                      C'n,    BRFS
                                      tv                                                                                        MSPC
                                              GBCR                                                                                                                                                              CBBI
                                                                                                                                MSBR
                                                                                                                                                                                           ms
                                              GBOB                                                                                                                                                              CBFM
                                      0       GBID                                                                              MSP9                          ................................................. NBNB
                                      Co.     GBYC                                                                              MBCP                                                        AL'                 RB14C
                                              Gasc                                                                              NMM
                                                                                                                                                                                                                RVFU
                                                                                                                                         m













                                                                                                                                         EM






                                                                                                                                         m
                                                                                                                                                                                                                          IM


















                                                                                                                                                                                                                          m




                                      'N'     GBHR                                                                              MBDR                                            =Room=                          BHKF
                                              SLBB                                                                                                                                        44,98-

























                                                                                                                  LJ                                                                tj                  W
                                                                tA                                                                                   %A                  t.A                 LA                                            -.A

                                             LMSB                                                                                   CLS1                                                                                 PBPH
                                             LMPI                                                                                                                                                                        PBM
                        (D   CO                                                                                                     CLLC
                             9
                                             LWMMAC                                                                                                                                                                      PBSP
                                             CCBH                                                                                                                                                                        CBJB
                                                                                                                                    VBSP
                                             CCNH
                                                                                                                                    ABOB
                                             ccic
                                             A B LLUR                                                                               CLCL                                                                                 PCLO
                                             A1B IMU                                                                                7BLJB3                                                                               PCMP
                                             CBCR
                                                                                                                                    7TILF                                                                                SAWB
                                             MBAR                                                                                   Bffm                                                                                 APD3
                                             SAPP
                             :7. 0           SAMP                                                                                   BBSD                                                                                 APCP
                                   z                                                                                                                                                                                     AESP
                                             ESSP                                                                                   BRNM
                                                                                                                                                                                                                         SRWP
                   00                        ESBD                                                                                   MRTP                                                                                 CKBP
                                             MBGP
                             0 PO                                                                                                   MRPL
                                   a         MBLR                                                                                                                                                                        TBNP
                                   0         MBCB                                                                                   BSSI                                                                                 TRUK
                             0               MJB3Tp                                                                                 BSBG                                                                                 TBPH
                                             NMDl                                                                                   LBMP                                                                                 TBOT
                             0     0         MEEM                                                                                   L33NO                                                                                TTIKA
                             Cl)             BRCL                                                                                   LPGO                           V1                              LA                    T13BB
                                             BRFS                                                                                   mspc                  ............            .............................          TBCB
                                             GBCR                                                                                                                                                                        CBBI
                                                                                                                                    MSBR                                                          ms
                                             GBOB                                                                                                                                                                        CBFM
                                             GEM                                                                                    MSPB
                                                                                                                                                      .................................................................  NBNB
                                             Gayc                                                                                   MBCP                                                                                 RBHC
                                             GBSC
                                             GBHR                                                                                   MBIT                                                           AL                    EVFU
                                             SLIBB                                                                                  MHDR                                                                                 HHKF
                                                                                                                                                         .................



















                                                                             In III

























                                                            tA                         kA                                              tA                        tA
                                         I-MSB   m .                                                                CLSI                                                                      PBPH
                                         LMPI'                                                                      CLLC                                                                      PBIMB
                                         LMAC                                                                                                                                                 PBSP
                                                                                                                    jHJH
                                         CCBH                                                                                                                                                 CBM
                                         CCNB                                                                       VBSP                                                30.60                 CBSR
                                         ccic                                                                       ABOB                                                                      CBSP
                          CL             ABLR                                                                       CLCL                                                                      PCLO
                      0                  ABM                                                                        7BLB                                                                      PCMp
                      cn                 CBCR                                                                                                                                                 SAWB
                                                                                                                    7TIB3 L F
                                         MBAR                                                                       B IMMI 3                                                                  APDB
                                         SAPP                                                                                                                                                 APCP
                          cr)            SAMP                                                                       BBSD                                                                      AESP
                                         Essp                                                                       BBMB
                                                                                                                                                                                              S WP
                      cn. cn             FSBD'Wo                                                                    MRTP
                                                                                                                                                                                              CKBP
                                         MBGP                                                                       MRPL                                                                      ITMB NTP
                          0
                                         MBLR
                                         NMCB                                                                       BSSI                                                                      TBMX
                                                                                                                    BSBG                                                                      IBPB
                                         MBTP
                          :5-            NMDI                                                                       LHNT                                                                      TBOT
                          z              MBEM                                                                       L2NO                                                                      TBKA
                          cn             BRC                                                                        LPGO                                                  LA                  TBHB
                      vi Ro                                                                                                                  ...................................................
                          @-i            BRFS                                                                       MSPC                                                                      T13CB
                                         GBCR                                                                                                                                                 CBBI
                      0.4                                                                                           MSHB                                                 ms
                                         GBOB                                                                                                                                                 CHFM
                                                                                                                    MSPB
                          cn             GBM                                                                                             ......................................................... NBNB
                                         GBYC                                                                       MBCP                                                                      111111C
                      9)                 GBSC                                                                       NMIR                                                                      EVFU
                                         MR                                                                         MBDR                                                                      BffKF
                                         SLBB























                    00


                                LMSB                                                        CLSI                                                        PBPH
                                LMPI                                                                                                                    MIS
                                                                                            CLLC'
                                L.MAC                                                                                                                   PBSP
                                CCBH                                                                                                                    CBJB
                 z All I                                                                    VBsp
                 cn 0           cm                                                                                                                      CBSR
                 Ro e+          ccic                                                        ABOB
                 HO                                                                                                                                     CBSP
                     e-+
                                ABLR                                                        CLCL                                                        PCLO
                                ABIMR                                                       IBLE                                                        PCMP
                     0
                                CBCR                                                        TBLF                                                        SAWB
                                MBAR
                     Go         SAPP                                                        BBTB                                                        APDB
                                SAMP                                                        13BSD                                                       APCP
             4 r+.                                                                                                                                      AESP
                 0              F-SSP                                                       BBNIB
                                ESBD                                                        MRTP                                                        SRWP
                                MBGP                                                                                                                    CKBP
                                                                                            MRPL
                                MBLR                                                                                                                    TBNP
                                                                                            OSSI                                                        TBMK
                 0              baCB
                                                                                            BSBG
                                MBIP                                                                                                     LA             TBPB
                                MBDI                                                        LBNV                                                        TBOT
                     r+
                     0          MBEM                                                                                                                    TBKA
                                                                                            LBNO
                                                                                                                                      1212.40
                                BRCL                                                        LPGO                                                        T13HB
                                BRFS                                                                                  ...........................
                                GBCR                                                        MSPC        .... TBCB
                                                                                                                                                        CBS
                                GBOR                                                        MSBB                                         ms             CBFM
                                GBM                                                         MSPB
                 otk  (D                                                                                . .................................... ............................ NBNB
                                GBYC                                                        MBCP                                                        RBHC
                                GESC                                                        wtu                                          AIL            EVFU
                                GBRR                                     1115.00
                                SL.BB                                                       MBDR                                                        BHKF
                                                                                                     113






                                                                                                     :s


























                                                      "M k        1 11 1 1   1






















                                     Reprint 7


                Chlorinated Hydrocarbons in Gulf of Mexico Oysters:
            Overview of the First Four Years of the NOAA!s National Status
                   and Trends Mussel Watch Program (1986-1989)


                          J.L. Sericano, T.L. Wade, and J.M. Brooks













                                   Chlorinated Hydrocarbons in Gulf of
                                   Mexico Oysters: Overview of the First Four
                                   Years of the NOAA's National Status and
                                   Trends Mussel Watch Program (1986-1989)
                                   J.L. Sericano, T.L. Wade, J.M. Brooks
                                   Geochemical and Environmental Research Group,
                                   College of Geosciences., Texas A&M University,
                                   833 Graham Road, College Station, Texas 77845,
                                   U.S.A.


                                   ABSTRACT

                                   During the first four years of the NOAA's National Status and
                                   Trends Mussel Watch program selected chlorinated hydrocarbons
                                   were analyzed in more than 660 oyster samples from the northern
                                   coast of the Gulf of Mexico. Chlordane-related compounds, DDT
                                   and its metabolites and PCB congeners were detected at all the
                                   locations monitored.- Concentrations ranged over two to three
                                   orders of magnitude. Alpha-chlordane and trans-nonachlor
                                   comprised more than 90% of the total load of chlordane-related
                                   compound in the samples. The bulk of the total DW burden in
                                   oysters corresponded to the degradation products, DDE and DDD.
                                   while DDT isomers only accounted for a small fraction of the total
                                   load. PCB congeners corresponded mainly to the four-, five- and
                                   six-chlorine homologs. After the first four yean of this progTam,
                                   the concentration distributions in oysters from the northem Gulf
                                   of Mexico is well defined. Temporal trends are not apparent at
                                   most sites.

                                   INTRODUCTION

                                   The National Oceanic and Atmospheric Administration's
                                   National Status and Trends Mussel Watch (NS&T) Program has
                                   been designed to monitor the current status and long-term trends
                                   of selected organic and inorganic environmental contaminant@;
                                   e.g. chlorinated pesticides, polychlorinated biphenyls (PCBs),
                                   polynuclear aromatic hydrocarbons (PAHs) and trace metals,
                                   along the coasts of the U.S.A. by measuring the concentrations of
                                   these contaminants in bivalves and sediments over several years-
                                   The rationale for the "Mussel Watch" approach using bivalves;
                                   e.g. mussels, oysters and clams, has been summarized by









                                                                4-22


















                                      666 Watcr Pollution


                                      different authors [1-4), and -its concept has been applied to several
                                      monitoring programs during the last decade (5-10).

                                          An over-view of the concentrations of the selected chlorinated
                                      hydrocarbons analyzed in oyster samples collected during the first
                                      four yearis of the NOAA's NS&T program in the Guif of Mexico
                                      are presented here. The ultimate goals of this program are to
                                      define the geographical distributions of contaminants and
                                      determine trends in their concentrations.



                                      MATERIALS AND METHODS


                                      Sampling
                                      Originally, the NS&T sampling program contemplated tile
                                      collection of bivalve samples from three stations at 51 sites from
                                      Gulf of Mexico coastal areas. Distances between stations within
                                      each site varied from 100 to 1000 meters- Oyster samples were
                                      collected over two- to three-month periods starting in late
                                      December or early January. Depending on the water depth,
                                      oysters were collected by hand, tongs or dredge. Twenty oysters
                                      per site were pooled in precombusted jars and frozen until
                                      analysis. During 1986 and 1987, oyster samplings were completed
                                      at 49 and 48 sites with totals of 147 and 143 samples, respectively.
                                      These sites provided a good coverage of the northem Gulf of
                                      Mexico coast from the U.S.A_-Mex:ico border to southernmost
                                      Florida, with an ample variety of different environmental
                                      conditions- The sites were selected to avoid known-point source of
                                      contaminants. Starting in 1988, new sites were added to the
                                      sampling program to obtain more information in areas located-
                                      closer to suspected sources of contaminants. During 1988 and*
                                      1989, oyster samples were collected from 63 and 62 different
                                      locations with totals of 189 and 186 samples, respectively. By the
                                      end of the fourth sampling period, 76 sites have been visited, 41.of
                                      them in all four years (Figure 1 and Table 1).
                                      Table  1. Sampling site locations in the Gulf of Mexico for the:
                                      NOA_A7s Status and Trends Mussel Watch Program, 1986-1989.

                                      -----------------------------------------------
                                             Site          General                   Specific             state

                                        1    LMSB       Laguna Madre               South Bay               TX
                                        2    CCNB       Corpus Christi             Nueces Bay              Tx
                                        52   LMPI       Laguna Madre               Port Isabel             TX
                                        53   CCBH       Corpus Christi             Boat Harbor             Tx
                                        3    CCIC       Corpus Christi             Ingleside Cove          TX
                                        54   ABHI       Aransas Bay                Harbor Island           TX
                                        4    ABLR       Aransas Bay                Long Reef               T*X

                                      -----------------------------------------------









                                                                       4-23































                                                                                                                              miss
                                                                                                                                     ISSIPPI             ALABAMA                           GEORGIA
                                                                                                                                                               ...........

                                                                                                         LOUISIANA                                                                                ......
                                                                                                               I'll, 14.60
                                                            Jo@                                                            No.               32333433  36
                                                                      TEXAS                                                   2 21          -30                                                     FLORIDA
                                                                                                                    22                        -31                                     42       43"
                                                                                                                                                 -14
                                                            29,              11,1356
                                                                        12       1                                           24  21   29

                                                                                10                                                                                                                    10
                                                                                                                     G U L F          OF          ME XICO                                          Pa -
                                                                                                                                                                                                      A4     -4S
                                                                                                                                                                                                     41-     41



                                                                                                                                                                                                        41@
                                                                        31
                                                                U, S. A.
                                                                                                                                                                                                            49'
                                                                MIXIC0                                                                                                                                       so
                                                                                                                                                                                                                31






                                                                        t".                        9%      a).                *1-     9,0-                       toy.                       1,4.              1r


                                                      Fig. I Gulf of Mexico sampling site locations. Shown are the original sites (0) and the sites add
                                                                   sampling program (N)since 1988. See Table 1 for a complete site identification.





















                                         66.1; Walcj-


                                         Table 1. (Continued)

                                          -------------------------------------                               : -----------
                                                   Site             General                       Specific                 State

                                             6     CBCR         Copano Bay                      Copano Reef                  Tx
                                             6     MBAR         Mesquite Bay                    Ayres Reef                   Tx
                                             7     SAPP         San Antonio Bay                 Panther Pt- Reef             Tx
                                             8     SAMP         San Antonio Bay                 Mosquito Point               Tx
                                             9     ESSP         Espiritu Santo                  South Past Reef              Tx
                                            10     ESBD         Espiritu Santo                  Bill Days Reef               TX
                                            11     MBLR         Matagorda Bay                   Layaca. River                Tx
                                            12     MBGP         Matagorda Bay                   Galliniper Point             Tx
                                            56     MBCB         Matagorda Bay                   Carancahua Bay               TX,
                                            13     MBTP         Matagorda Bay                   Tres Palacios Bay            Tx
                                            55     MBDI         Matagorda Bay                   Dog Island                   TX
                                            14     MBEM         Matagorda Bay                   East Matagorda               TX
                                            57     BRFS         Brazos River                    Freeport Surfside            TX
                                            72     BRCL         Brazos River                    Cedar Lakes                  Tx
                                            15     GBYC         Galveston Bay                   Yacht Club                   TX
                                            59     GBSC         Galveston Bay                   Ship Channel                 TX
                                            58     GBOB         Galveston Bay                   Offats; Bayou                TX
                                            16     GBTD         Galveston Bay                   Todd's Dump                  TX
                                            17     GBHR         Galveston Bay                   Hanna Reef                   TX
                                            18     GBCR         Galveston Bay                   Confederate Reef             TX
                                            19     SLBB         Sabine Lake                     Blue Buck Point              TX
                                            20     CLSJ         Calcasieu Lake                  St. John!s Island            La
                                            60     CLLC         Calcasieu Lake                  Lake Charles                 La..
                                            21     JHJH         Joseph Harbor Bayou             Joseph Harbor Bay            La.
                                            22     VBSP         Vermillion Bay                  Southwest Pass               La%
                                            23     ECSP         East Cote Blanche               South Point                  La.'
                                            24     ABOB         Atchafalaya Bay                 OysterBayou                  La
                                            25     CLCL         Caillou Lake                    Caillou Lake                 La
                                            26     TBLB         Terreborme Bay                  Lake Barre                   La
                                            Z7     TBLF         Terreborme Bay                  Lake Felicity                La.:
                                            61     BBTB         Barataria Bay                   Turtle Bay                   La
                                            2B     BBSD         Barataria Bay                   Bayou SL Denis               La:
                                            29     BBMB         Barataria Bay                   Middle Bank                  LA.
                                            65     MRTP         Mississippi River               Tiger Pass                   La
                                            64     MRPL         Mississippi River               Pass a Loutre                La
                                            30     BSBG         Breton Sound                    Bay Gardeme                  La:'
                                            31     BSSI         Breton Sound                    Sable Island                 La
                                            32     LBMP         Lake Borgne                     Malheureux Point             La
                                            62     LBNO         Lake Borgne                     New Orleans                  La"
                                            33     MSPC         Mississippi Sound               Pass Christian               MS
                                            34     MSBB         Mississippi Sound               Bilo3d Bay                   Ms  ,
                                            35     MSPB         Mississippi Sound               Pascagoula Bay               Ms
                                            36     MBCP         Mobile Bay                      Cedar Point Reef             Al
                                            66     MBHI         Mobile Bay                      Hollingers Is. Ch- A!
                                           ------------------------------------------------






                                                                                  4-25















                                                                                           XV;itcr PoIlLition


                                        Table L (Continued)

                                        -----------------------------------------------
                                              Site          General                  Specific             State

                                        67    PBPH      Pensacola Bay              Public Harbor           F1
                                        37    PRIB      Pensacola Bay              Indian Bayou            F1
                                        38    CBSR      Choctawhatchee Bay         Off Santa Rosa          F1
                                        39    CBSP      Choctawhatchee Bay         Shirk Point             F1
                                        73    CBJB      Choctawhatchee Bay         Joe7s Bayou             F1
                                        68    PCMP      Panama City                Municipal Pier          F1
                                        74    PCLO      Panama City                Little Oyster Bay       F1
                                        40    SAVVB     St. Andrew Bay             Watson Bayou            F1
                                        41    APDB      Apalachicola Bay           Dry Bar                 F1
                                        42    A_PCP     Apalachicola Bay           Cat Point Bar           F1
                                        75    AESP.     Apalachee Bay              Spring Creek            -F1
                                        69    SRWP      Suwannee River             West Pass               Fl
                                        43    CKBP      Cedar Key                  Black Point             F1
                                        44    TBFB      Tampa Bay                  Papys Bayou             F1
                                        70    TBOT      Tampa Bay                  Old Tampa Bay           F1
                                        45    TBBB      Tampa Bay                  Hillsborough Bay        Fl
                                        46    TBCB      Tampa Bay                  Cockroach Bay           F1
                                        76    TBNP      Tampa Bay                  Narvaez Park            F1
                                        77    TBKA      Tampa Bay                  P. O'Knight Airport.    Fl
                                        47    TBAM      Tampallay                  Mullet Key Bayou        F1
                                        48    CBBI      Charlotte Harbor           Bird Island             Fl
                                        71    CBFM      Charlotte Harbor           Fort Meyers             F1
                                        49    NBNB      Naples Bay                 Naples Bay              F1
                                        50    RBHC      Rookery Bay                Henderson Creek         Fl
                                        51    EVFU      Everglades                 Faka Union Bay          F1

                                        -------  - --------------------------------------

                                        Analytical -Procedure
                                        The analytical procedure was adapted from a method developed by
                                        MacLeod et al. (111 and has been described in more details
                                        elsewhere (9,101. Briefly, approximately 15 g of wet tissue were
                                        extracted 3 times with methylehe chloride using a homogenizer
                                        (Tekmar Tissumizer). Before extraction 4:4 dibromooctafluoro-
                                        biphenyl (DBOFB) and two PCBs, 1UPAC numbers 103 and 198,
                                        were added to all samples, blanks and reference materials as
                                        internal standards. Tissue extracts were fractionated into two
                                        fractions by silica-alumina column chromatography. Pentane
                                        and pentane:methylene chloride (50:50) were used as elutants for
                                        the first (aliphatic hydrocarbons) and second (chlorinated and
                                        polynuclear aromatic hydrocarbons) fractions, respectively. A
                                        further clean-up of the second fraction was performed by either
                                        Sephadex LH-20 column chromatography (121 (years I, II and IM
                                        or high performance liquid chromatography (HPLQ (year IV).
                                        Both techniques have produced comparable results. Sample
                                        extracts were finally concentrated to a volume of 0.5 nil, in







                                                                      4-26


















                                       670 \Vticr Polltition


                                       hexane, for gas chromatographic analysis- Each set of eight to
                                       ten samples was accompanied by a complete system blank and
                                       spiked blank or,reference material, carried through the entire
                                       analytical procedure-

                                       Gas chromatography
                                       Chlorinated hydrocarbon concentrations were determined by gas
                                       chromatography with an electron capture detector (GC-ECD,
                                       63Ni) using a 30 in DB-5 fused silica capillary column (0-25 um
                                       film thickness, 0.25 min i.d.) as previously described (9,1o].
                                       Chlorinated hydrocarbon were quantitated against authentic
                                       standards injected at four different concentrations.

                                           Quality control/Quality assurance activities, that included
                                       several laboratory inter-calibration exercises with repeated,
                                       routine analyses of homogenated samples supplied by the
                                       National Institute of Standards and Technology (NIST), formerly
                                       National Bureau of Standards (NBS), have been undertaken to
                                       ensure that the data produced during the NS&T program is
                                       reproducible, accurate and analyst independent.           Interim
                                       reference materials as well as spiked blanks are also part of our
                                       ongoing laboratory QA/QC activity.

                                       RESULTS AND DISCUSSION

                                       Over 660 oyster samples from 76 different sites on the riorthern
                                       Gulf of Mexico coast have been analyzed for selected chlorinated
                                       hydrocarbons during the first four years of the NS&T program-
                                       In the following sections, the average concentrations of total
                                       chlordane-related compounds, i.e., sum of alpha- chlo rdane,
                                       trans-nonachlor, heptachlor and heptachlor epoxide, total DDT,
                                       i.e. the sum of o-p@-DDE, p-p'@-DDE, o-p-DDD, p-p@--DDD, o-p-DDT
                                       and p-p-DDT, and total PCBs will be discussed- During 1986 and
                                       1987, total PCB, concentrations represented the sum of all the
                                       measurable PCB congeners in the samples. Starting in 1988, total
                                       PCB concentrations in oyster samples were calculated by a
                                       regression equation relating the sum of 18 selected PCB congener
                                       data, generally the major components of commercial PCB
                                       mixtures and among the most commonly observed congeners in
                                       environmental samples, and total PCB congener data from the
                                       previous years.    Analyte mean concentrations for each site
                                       represent the average of the mean concentrations encountered
                                       during each sampling period-

                                       Chlordane-related cQmyounds
                                       Technical chlordane is a complex mixture formed by more than
                                       140 different components. Recently, 120 of these compounds have
                                       been identified (131. The most abundant constituents of technical
                                       chlordane are alpha-chlordane, gamma-chlordane, heptachlor







                                                               4-27



















                                                                                             Water Pollution  671  


                                            and tran-nonachlor.  Because of the toxicity, potential
                                            carcinogenicity and environmental persistence of ist components,
                                            technical chlordane sales and/or applications in the U.S.A. were  
                                            suspended after April 15, 1988.  The NS&T program included
                                            three chlordane-related compounds: alpha-chlordane, heptachlor 
                                            and trans-nonachlor.  Heptachlor epoxide, a metabloite of          
                                            heptachlor, was also monitored.  

                                                 Chlordane-related compounds were gernerally present in low
                                            ng g-1 concentrations.  Average concentrations, plus 1 standard  
                                            deviation, ranged from 3.5+0.44 to 120+70 ng g-1 (Figure 2).          

                                                       
















                                            Fig. 2. Average concentrations, in ng g-1, of total chlordane-
                                                    related compounds in oysters from the Gulf of Mexico.







                                                                           4-28




















                                         672  Water Pollution


                                         The highest average concentrations in oyster samples were
                                         encountered in samples from sites in Galveston Bay (GBYC, 852qï¿½54
                                         ng g-1; GBSC, 87ï¿½73 ng g-1; GBOB, 93ï¿½7-1 ng g-1), near the mouth
                                         of the Mississippi River (MRPL, 64ï¿½4-0 ng g-1), Biloxi Bay (MSBB.
                                         82ï¿½13 ng g-1), and Choctawhatchee (CBSP, 114ï¿½120 ng g-1), Tarapa
                                         (TBPB, 75ï¿½19 ng g-1; TBCB, 88ï¿½36 ng g-1; TBNP, 120ï¿½66 ng g-1;
                                         TBKA, 110ï¿½51 ng g-1) and Charlotte Bays (CBFM, 120ï¿½70 ng g-1).
                                         With the exception of the sites in the Galveston Bay area, average
                                         concentrations were lower to the west of the Mississippi River-

                                              Approximately 90% of the total load of chlordane-related
                                         compounds encountered in oysters corresponded to the sum Of
                                         alpha chlordane (45ï¿½2.5%) and trans-nonachlor (43ï¿½4.2%), two of
                                         the most important constituents of technical chlordane (131
                                         (Figure 3). The fact that beptachlor epoxide is dominant over its
                                         parent compound indicates environmental degradation of
                                         heptachlor.



                                                 

                                         Fig. 3. Average composition of total chlordane-related compoun6q6i
                                                 in oyster samples from the Gulf of Mexico.


                                              A comparison of average concentrations measured in 1989
                                         with the concentrations encountered during the first year of the
                                         N32qS32q&T program, i.e. 1986, is presented in Figure 4. On this scatter
                                         plot, sites with the same concentrations during both sampling
                                         years fall on the center line of the graph (intercept = 0; slope = 1).:
                                         Sites that plot above or below the center line show an increase or a
                                         decrease in concentration, respectively, between 1986 and 1989.
                                         Also shown are lines that represent a 2-fold increase or decrease
















                                         



                                                                   4-29


















                                                                                      Water Pollution  673




                                            10000
                                                  Chlordane-related compounds


                                            l000




                                              100




                                               10


								1

                                                         1    10          100         IODO        10000

                                                         1986 Average Concentrations (ng/g)


                                     Fig. 4 Oyster total chlordane-related compound concentrations in
                                            1986 versus 1989.



                                     average concentrations encountered in 1986 when compared to
                                     data collected four years later. Over 80% of the sites showed a
                                     decrease in average concentrations; nearly 30% of the sites had a
                                     decrease larger than a 2-fold change. Only 15% of these locations
                                     revealed slight increases in their average concentrations.

                                     DDT and metabolites
                                     In spite of its ban in 1972, DDT and its metabolites, DDE and DDD,
                                     are still present, in significant concentrations, in the near-shore
                                     environments of the U.S.A. DDT and/or its derivatives were
                                     detected in every oyster sample analyzed. Figure 5 summarizes
                                     the average total DDT concentrations, plus 1 standard deviation,
                                     encountered in oyster samples from the Gulf of Mexico. Total
                                     DDT concentrations ranged from 6.92ï¿½1.9 to 890ï¿½440 ng g-1. With
                                     the exception of some samples collected from sites in Galveston
                                     Bay (GBSC, 170ï¿½81 ng g-1) and near the mouth of the Brazos River
                                     (BRFS, 220ï¿½47 ng g-1), in Texas, and from locations in Tampa
                                     (TBKA, 160ï¿½32 ng g-1) and Charlotte (CBFK 170ï¿½85 ng g-1) Bays,
                                     in Florida, the highest concentrations were encountered in
                                     samples collected to the east of the Mississippi River between its
                                     mouth and St Andrew Bay, Florida, e.g., MRPL, 280ï¿½54 ng g-1;
                                     MBCP. 200ï¿½64 ng g-1; MBHI, 830ï¿½270 ng g-1; CBSP, 890ï¿½440 ng g-1,
                                     and PCLO, 520ï¿½730 ng g-1. With the exceptions mentioned above,
                                     the lowest concentrations were generally found along the Texas
                                     a0nd southern Florida coasts.







                                                                   4-30




















                                                  6-74 Waizr Pollution




                                                                                               2S-URSO
                                                            2-CCNB                             29-BBIAM
                                                                 IN
                                                            52AA                               65-AIRTP
                                                            53-CCBH                            64-bUWL
                                                            3-CCIC                             30-BSBG
                                                            54-ABHI                            31-BSSI
                                                            4-AID31LAR                         32-LBNIIP
                                                            5-CBCR                             62-LENO
                                                            6-AIBAR                            33-MSPC
                                                            7-SAPP                             34-MSBB
                                                            S-SAMP                             35-MSPB
                                                            *-MP                               36-1kf8CP
                                                            10-ESSD                            6G@MBM
                                                            U-MBLR                             67-PEPH
                                                            MZ*IBGP                            37-PBM
                                                            56-DIBCB                           38-CBSR
                                                            1341IMP                            33k'BSP
                                                            55-NMZDI                           73-(MJB
                                                            14-TUBEA1                          68-PCCWMP
                                                            57-BRFS                            74-FPICLWO
                                                            72,BRCL                            40-SAWB
                                                            15-GRYC                            41-APDR
                                                            5%GBSC                             4@2-APCP
                                                            58-GBOR                            75AESP
                                                            1S-GBTD                            G9-SRW
                                                            17-GBEIR                           43-CEMP
                                                            18-GBCR                            44-TEPR
                                                            O-SLBB                             70-TBOT
                                                            20-(X.SJ                           45-TEUB
                                                            60-CLLC                            4G@TBCB
                                                            21-JHJH                            76-TBNTP
                                                            2Z-VBSP                            77-TBEA
                                                            23-ECSP                            47-TBbIK
                                                            24-ABOB                            48-03BI
                                                            25-CLCL
                                                                                               49
                                                                                               50-=
                                                            27-TBLIF                                  C
                                                            61-BBTB                            51-EVIFU

                                                                   0 200 400 600 800                    0 200 400 6W 80



                                                  Fig. 5 Average concentrations, in ng g-1, of total DDT in oyster
                                                            samples &om the Gulf of Meidco.


                                                        Isomers of the DDT accounted for a small fraction (5.2+-3.0%)
                                                  of the total DDT burden in oysters during this study (Figure 6).
                                                  Isomers of the DDD and DDE'contributed with 50ï¿½2.1 and 44+-2-3%
                                                  of the total amount, respectively. Technical DDT contained
                                                  appro)dmately 75% p-p-DDT, 15% a-p-DDT, 5% p-p'-DDE, <05%
                                                  o-p'-DDE, <0.5%. p-p'-DDD, <0.5% o-p-DDD and <5% unidentified
                                                  compounds. It is generally accepted that increasing percentages
                                                  of DDE and/or DDD, which were found as impurities in the





                                                                                  4-31



















                                                                                        Water Polluilon 675


                                    commercial DDT mixture, indicate a decreasing exposure to new
                                    inputs of DDT-



                                          DDE





                                          DDD





                                          DDT




                                                0       10      2()      39      4D       5D       6)

                                                                   Percentages

                                    Fig. 6  Average composition of the DDT burden i     n oysters from the
                                            Gulf of Mexico


                                        t4  10000-
                                                   DDT and Metabolites
                                        b



                                        0    10W 7




                                              Wo




                                                                     AN
                                               10
                                        4W



                                        00

                                                                           100         1"          10"
                                                          1286 Average Concenft-altions (ng/g)

                                    Fig. 7  Oyster total DDT concentrations in 1986 versus 1989.


                                          The average total DDT concentrations encountered          at the
                                    different sites during 1986 and 1989 are compared on Pigure 7. In






                                                                   4-32



















                                                                670 W.QCr P01111,1011


                                                                general, concentrations were very similar at most of the sites.
                                                                Only a few sites showed differences in concentrations greater
                                                                than a 2-fold change. Although it is not possible to visualize a
                                                                trend in average total DDT concentrations with a four-year data
                                                                base, mainly due to the long environmental persistency of these
                                                                compounds, it has been shown that the total DDT concentrations
                                                                in Gulf of Mexico oysters have decreased since 1969 [101-

                                                                Polyclilorinated Biphenyls
                                                                PCBs have proven to be ubiquitous contaminants in.the Gulf of
                                                                Me)dco coastal environment. Average total PCB concentrations,
                                                                plus 1 standard deviation, are presented in Figure S.

                                                                              I-LMS13                               28-BBSD
                                                                              2,-CXCNt.B                            2:9-laMM
                                                                              52-LMPI                               GS-NUUP
                                                                              S3-(=H                                &I-NaIPL
                                                                              3-(=C                                 30-USBG
                                                                              54-AMM                                31-BSSI
                                                                              4-A)MR                                32-LWIP
                                                                              54CBM                                 62-LENO
                                                                              C-DIMB"AR                             33-MSM
                                                                              7-qAM                                 34-WSBB
                                                                              B-SAW                                 35-WISPB
                                                                              S-ESSP                                S&NMCP
                                                                              10-ESSD                               er@BIBM
                                                                              MAZUR                                 V-P13PH
                                                                              M?4WP                                 37-PBM
                                                                              5&xas=                                38-CBM
                                                                              13-Itfln?                             39-CWP
                                                                              55-MDI                                73-CBJB
                                                                              14-INMEM                              6s-PCbI:P
                                                                              57-BIPJS                              74-PC7WO
                                                                              72-BRCL                               40--SAWR
                                                                              IS4WC                                 41-A.PDB
                                                                              59-GBSC                               42-APCP
                                                                              584MOB-                               75-AESP
                                                                              16-CBM                                69-SRWP
                                                                              17-GBIEIR                             43-CKSP
                                                                              18-GUM                                44-TBPB
                                                                              194SLBB                               70-TBOT
                                                                              20-CLSJ                               45-TREEB
                                                                              60-CLLC                               46@T13M
                                                                              21-JELJH                              76-TBNP
                                                                              22-NVFBSP                             77-TBKA
                                                                              23-ECSP                               47-TBAIK
                                                                              24-ABOB                               48-CBBI
                                                                              25-CLCL                               71-CBF"NI
                                                                              2&TBLB                                49-NBrM
                                                                              27-TBLF                               50-RBHC
                                                                              61-BBTE                  -4           51-EVFU
                                                                                      0 300 600 900 1200                     0 300 600 900 1200

                                                                Fig. 8 Average total PCB concentrations in oyster samples from
                                                                              the Gulf of Mexico








                                                                                            4-33

















                                                                                   XV.itcr Pollulioti 077


                                       PCB congeners were detected in all the oyster samples
                                   collected between 1986 and 1989 with average concentrations
                                 --ranging from 26ï¿½17 to 1000ï¿½730 ng g-1.              The highest
                                   concentrations were encountered in samples collected from sites
                                   in Galveston Bay (GBYC, 1000ï¿½730 ng g-1; GBSC, 910ï¿½81 ng g-1),
                                   near the mouth of the Mississippi River (MRPL, 620ï¿½210 ng g-1),
                                   Mobile Bay (MBHI, 520ï¿½150 ng g-1) and Pensacola (PBIB, 590ï¿½130
                                   ng g-1), St Andrew (SAWB, 620ï¿½190 ng g-1) and Tampa (TBKA,
                                   490ï¿½110 ng g-1) Bays. Similar to total DDT concentrations, the
                                   high. concentrations measured in samples from Galveston Bay
                                   were the exception to the west of the Mississippi river.

                                       The average composition of PCBs in oysters collected during
                                   1986 and 1987 was largely dominated by pentachlorobiphenyls
                                   (46.8%), with some hexa- (22.3%) and tetrachlorobiphenyls
                                   (21.0%), and were almost depleted in di- (0.6%), octa- (0.5%) and
                                   nonachlorobiphenyls (0.2%) (Figure 9). The same general
                                   distribution is found in organisms from different PCB-
                                   contaminated locations (14-16]. In general, differential partition
                                   of PCB congeners between aqueous and lipids phases as well as
                                   stereochemistry appear to significantly affect bioaccumulation
                                   (14,17-19]. Maximum PCB uptake by organisms is observed with
                                   isomers having four to six chlorine atoms. Congeners with a
                                   lower number of chlorines have higher water solubilities and, as
                                   a consequence less favorable partition coefficients, while
                                   congeners with more than six chlorines-have unfavorable steric
                                   configurations.


                                          Di-CB

                                         Tri-CB

                                      Tetra-CB

                                      Penta-CB

                                      Hexa-CE

                                      Hepta-CB

                                        Octa-CB

                                      Nona-CB;

                                                0         10       20        30       40        50

                                                                   Permnta@

                                   Fig. 9 Fractional composition of PCB homologs in oyster samples
                                          from the Gulf of Mexico.









                                                                4-34




















                                       67S Walcr Politit


                                           Total PCB concentrations measured in oyster samples in 1989
                                       did not differ significantly from the levels encountered four years
                                       earlier (Figure 10). With few exceptions, most of the sites had
                                       PCB concentrations in 1986-1989 that fell within the factor-of-two
                                       lines.


                                                    Polychlorinated Biphenyls


                                          0   Iwo 7


                                          U    100                     Ole*   19.0-'



                                          Cz    10



                                          00

                                                              1                                   100W

                                                          1986 Average Concentrations (XW9)

                                       Fig. 10 Oyster total PCB concentrations in 1986 versus 1989.


                                       CONCLUSIONS

                                       After the first four years, the objectives of the NS&T program in
                                       the Gulf of Mexico have been partially accomplished.
                                       Distributions of chlordane-related compounds, DDT and its
                                       metabolites, and PCBs in oysters are weU established- Oysters
                                       from some locations have consistently had high concentrations of
                                       these analytes, e.g. sites located in Galveston and Tampa Bays,
                                       near the mouth of the Mississippi River and in different sites
                                       along the Florida coastline between the Mississippi River and St
                                       Andrew Bay. Temporal trends are not readily apparent for all the
                                       contaminants. Continued sampling will help to further establish
                                       temporal trends for various analytes at the different sites.

                                       ACKNOWLEDGEMENTS

                                       This work was supported by the National Oceanic and
                                       Atmospheric Administration, contract No. 50-DGNC-5-00262,
                                       through the Texas A&M Research Foundation, Texas A&M
                                       University.







                                                               4-35


















                                                                                     Waier Pollutioti 679


                                     REFERENCES

                                     1.  Goldberg, E.D.. Bowen, V.T., Farrington, J.W., Harvey, G.,
                                         Martin, J.H., Parker. P.L., Risebrough, W., Schneider, E. and
                                         Gamble, E. The Mussel Watch, Environmental Conservation,
                                         Vol 5,101-125,1978.

                                     2.  Farrington, J.W-, Albaiges, J, Burns, K.A., Dunn, B.P.,
                                         Eaton, P., Laseter, J.L., Parker, P.L. and Wise, S- The
                                         International Mussel Watch: Report of a Workshop Sponsored
                                         by the Environmental Studies Board Commission on Natural
                                         Resources, pp 7-77, National Research Council, Washington
                                         DC, 1980.

                                     3.  Phillips, D.J.H. Quantitative Biological Indicator, Their Use
                                         to Monitor Trace Metals and Organochlorine Pollution,
                                         Applied Science, London, 1980.

                                     4-  Risebrough, R.W., DeLappe, B.W., Walker II, W., Simoneit,
                                         B.T., Grimalt, J., Albaijes, J. and Regueiro, J.A.G.
                                         Application of the Mussel Watch Concept in Studies of the
                                         Distribution of Hydrocarbons in the Coastal Zone of the Ebro
                                         Delta. Marine Pollution Bulletin, Vol. 14, pp. 181-187,1983.

                                     5.  F@@gton, J.W., Goldberg, E.D-, Risebrough, R-W., Martin,
                                         J.H. and Bowen, V.T. U.S- 'Mussel Watch' 1976-1978: An
                                         Overview of the Trace Metal, DDE, PCB, Hydrocarbons and
                                         Artificial Radionuclide Data. Environmental Science and
                                         Technology, Vol. 17, pp. 490-496,1983.

                                     6.  Martin, M. State Mussel Watch: Toxic Surveillance in
                                         California, Marine Pollution Bulletin, Vol. 16, pp.140-146,
                                         1985.

                                     7.  Tavares, T.M., Rocha, V.C., Porte, C., Barceld, D. and
                                         Albaig6s, J. Application of the Mussel Watch Concept in
                                         Studies of Hydrocarbons, PCBs and DDT in the Brazilian Bay
                                         of Todos os Santos (Bahia), Marine Pollution Bulletin, Vol. 19,
                                         pp. 575-578,1988.

                                     8.  Wade, T.L-, Atlas, E.L., Brooks, J.M., Kennicutt II, M.C.,
                                         Fox, R-G., Sericano, J.L., Garcia-Romeroj B., DeFreitas, D.
                                         NOAA Gulf of Mexico Status and Trends Program: Trace
                                         Organic Contaminant Distribution in Sediments and Oysters,
                                         Estuaries, Vol. 11, pp. 171-179,1988.

                                     9. Sericano, J.L, Atlas, E-L., Wade, T.L and Brooks, J.M.
                                         NOAA*s Status and Trends Mussel Watch Program:
                                         Chlorinated Pesticides and PCBs in Oysters (Crassostrea







                                                                 4-36


















                                          6SO walet- Pollutioll

                                              virginica) and Sediments from the Gulf of Mexico, 19,96-1987.
                                              Marine Environmental Research, Vol- 29, pp- 161-203, 1990.

                                          10. Sericano, J.L., Wade, T-L., Atlas. E.L. and Brooks, J_14.
                                              Historical Perspective on the Environmental Bioavailability of
                                              DDT and its Derivatives to Gulf of Mexico Oysters.
                                              Environmental Science and Technology, Vol. 24, pp. 1541-1548,
                                              1990.

                                          11- MacLeod, W.D., Brown, D-W., Friedman, A.J., Burrows,
                                              D.G., Maynes, 0., Pearce, R-W-, Wigren, C-A- and Bogar,
                                              R.G- Standard Analytical Procedures of the NOAA National
                                              Analytical Facility, 1985-1986.. Extractable Toxic Organic
                                              Compounds (2nd Edition), U.S- Department of Commerce,
                                              NOAA Technical Memorandum, NMFS F/NWC-92,1985-

                                          12. Ramos, L and Prohaska, P- Sephadex LH-20 Chromatography
                                              of Extracts of Marine Sediments and Biological Samples for
                                              the Isolation of Polynuclear Aromatic Hydrocarbons. Journal
                                              of Chromatography, Vol- 211, pp- 284-289,1981-

                                          13. Dearth, ACA- and Hites, R-A. Complete Analysis of Technical
                                              Chlordane Using Negative Ionization Mass Spectrometry
                                              Environmental Science and Technology, Vol. 25, pp. 245-254,
                                              1991.

                                          14. Shaw, G.R. and Connell, D.W. Relationships Between Stearic
                                              Factors and Bioaccumulation of Polychlorinated Biphenyls
                                              (PCBs) by the Sea Mullet (Mugil cephalus Linnaeus),
                                              Chemosphere, Vol. 9, pp. 731-743, 1980.

                                          15- Duinker, J.C., Hillebrand, M-T.J. and Boon, J-P., Organo-
                                              chlorines in Benthic Invertebrates and Sediments from the
                                              Dutch Wadden Sea; Identification of Individual PCB
                                              Components, Netherlands Journal of Sea Research, Vol 17,
                                              pp. 19-38,1983.

                                          16. Boon, J.P., Van Zantvoort, NLB-, Govaert, M.J.M.A. and
                                              Duinker, J.C. Organochlorines in Benthic Polychaetes
                                              (Nephtys spp.) and Sediments from the Southern North Sea.
                                              Identification of Individual PCB Components, Netherlands
                                              Journal of Sea Research, Vol 19, pp. 93-109, 1985.

                                          17. Matsuo, M-         A Thermodynamic Interpretation of
                                              bioaccumulation of Aroclor 1254 (PCB) in Fish, Chemosphere,
                                              Vol. 9, pp. 671-675,1980.

                                          18. Shaw, G-R. and Connell, D-W. Physicochemical Properties
                                              Controlling Polychlorinated Biphenyls (PCB) Concentrations'
                                              in Aquatic Organisms. Environmental Science and
                                              Technology, Vol- 8, pp.18-23,1984-

                                          19. Samuel  Ian, J. and O*Connor, J.M-            Structure-a   ctivity
                                              Relationship and Accumulation of PCB Congeners in
                                              Estuarine Fishes: A Field Study (Abstract only), Estuaries,
                                              Vol. 8. p- 83A. 19854 _37





















                                       Preprint 3


                   National Status and Trends Mussel Watch Program:
               Chlordane-Related Compounds in Gulf of Mexico Oysters,
                                        1986-1990



                        Josd L. Sericano, Terry L. Wade, James M. Brooks,
                        Elliot L. Atlas. Roger R. Fay, and Dan L. WiUdnson









                                 National Status and Trends Mussel Watch Program:

                      Chlordane-Related Compounds in Gulf of Mexico Oysters, 1986-1990



                             Jos6 L. Sericano+*. Terry L. Wade+. James M. Brooks+. Elliot L AtlasA.

                                             Roger RL Fay' and Dan L Wffldmon+



                                      + Geochemical and Environmental Research Group,

                                     Department of Oceanography. Texas A&M University.

                                     833 Graham Road. College Station. Texas 77845. U.SA-



                                          ANational Center for Atrnospheric Research
                                         P.O. Box 3000, Boulder@ Colorado 80307, U.S-k                                or


                                                                                                                      e
                      Abstract


                          The National Oceanic and Atmospheric Administration's National Status and

                      Trends (NS&T) Program has been monitoring the chemical contamination in bivalve

                      tissues from the U.S. coastal waters since 1986. Alpha-chlordane, trans-nonachlor,

                      heptachlor and heptachlor epoxide. components of technical chlordane. are among the
                      chloriiiiied- pesticides measured. The geographical distribution of these chlordane

                      compounds in the.oyster samples from the U.S. Gulf of Mexico is well established. For.

                      example, highest residue levels, predominantly alpha-chlordane and trans-nonachlor,

                      were encountered in samples. collected near heavily populated areas in contrast with

                      the concentrations measured in predominantly agricultural areas. Data collected

                      during five years of bivalve sampling are used to evaluate temporal trends in residue

                      concentrations at most NS&T sites. Minor decreases can be observed in the


                      concentrations of alpha-chlordane and trans-nonachlor. Heptachlor and its epoxide

                      concentratIons. in contrast, have been increasing since 1987.




                                                              4-39





                                                                                                                 2





                       Introduction


                            In 1986. the National Oceanic and Atmospheric Administration (NOAA) initiated

                       the National Status and Trends (NS" Mussel Watch Program to assess the extent of

                       coastal marine contamination in the U.S. by measuring selected organic and inorganic

                       contaminants, e.g.. chlorinated pesticides, polychlorinated biphenyls (PCBs).

                       polynuclear aromatic hydrocarbons (PAHs) and trace metals, and to identify trends in

                       their concentratioiis with time. The NS&-T Program is an ongoing project which has

                       been collecting bivalve samples, on an annual basis. from over 150 sites along the East.

                       Gulf and West coasts. including the Hawaiian islands. Overviews of the initial NS&T

                       results have been published (1-7).

                            This report focuses on the chlordane-related compounds. i.e.. alpha-chlordane.

                       trans-nonachlor, heptachlor and heptachlor epoxide. included in the suite of
                       chlorinated pesticides measured for the NS&r program- Technical grade chlordane is a

                       complex mixture of more than 140 different components. ReceAtly, 120 of these

                       compounds have been resolved and identified by high-resolution. gas chromatography

                       combined. with negative ionization mass spectrometry. Alpha-chlordane, gamma-

                       chlordane, heptachlor and b-ans-nonachlor are the dominant constituents (8). Since

                       1946, the total production of chlordane by Velsicol Chern.. Co.. the major producer in the

                       U.S..1;'estimated to   .be over 70,000 tons (8). Because of the toxicity. potential

                       carcinogenecity @Lnd environmental persistence of their components and/or

                       metabolites, e.g.. heptachlor hepoxide and oxychlordane, the use of chlordane is under

                       federal regulations (9). In 1974, the EPA proposed the cancellation of all uses of

                       chlordane. Ayear later, the EPA suspended the production of heptachlor and@chlordane

                       and limited their uses on most food crops. Its use was pennitted only where no other

                       alternative existed and in all home and garden application with the exception of

                       underground termite control. In 1987. Velsicol Chem. Co.. in an agreement with the






                                                                  4-40





                                                                                                               3


                      EPA, voluntarily reduced the sales and distribution of chlordane and all sales and/or

                      uses in the U.S. were suspended after April 15. 1988.

                           The. extensive use of technical chlordane during the last decades. together with

                      their natural persistence. caused a worldwide environmental. This paper examines the

                      geographical distribution and trends in concentrations of chlordane in oyster samples

                      collected from the northern coast of the Gulf of Mejdco between 1986 and 1990.




                      Methods


                           Sampling. Oyster samples were collected each year over a two- to three-month

                      period starting In late December or early January. Depending on water depth. oysters

                      (twenty per station) were collected by hand, tongs or dredge, pooled in precombusted jars

                      and frozen until analysis.

                           Bivalve samples were collected from three stations at approximately 50 sites

                      located on the U.S: Gulf of Meidco. Distances between stations within each site varied

                      from 100 to 1000 meters. During 1986 and 1987, oysters *collection was completed at 49

                      and 48 sites with a total of 147 and 143 samples. rvespectively. - Although these sites

                      provided a good coverage of a broad range of different environmental conditions from

                      the U.S.A_-Mexico border. to southern Florida, they were specifically selected to avoid

                      known sources of contaminant Inputs. Starting in 1988      .. new sites were added to the
                      sampfirl@:prograrri in order to obtain more information from areas located closer to but

                      not at suspected sources of contaminants. During 1988. 1989 and 1990. oyster samples

                      were collected from 63. 62 and 68 sites with totals of 189. 186 and 203 samples.

                      respectively.

                           Thus. by the end of the fifth year of the NS&T program in the Gulf of Mexico.

                      eighty different sites had been sampled (Figure 1); thirty nine of them in all five years.

                      Sites numbered I through 51 are the original locations, sites numbered 52 through 80

                      are the new sites added to the sampling program since 1988.






                                                                 4-41





                                                                                                              4


                       Extraction and separation. The analytical procedure used was adapted from a

                   method developed by MacLeod et aL(10). Briefly, approximately 15 g of wet tissue were

                   extracted with methylene chloride using a homogenizer (Tekmar Tissurnizer). Each set

                   of eight to ten samples was accompanied by a complete system blank and spiked blank

                   or reference material that were carried through the entire analytical procedure. Before

                   extraction. 4:4 dibromooetafluorobiphenyl (DBOFB) and two polychlorinated

                   biphenyls UUPAC No 103 and 198) were added to all samples. blanks and reference

                   material as interrial standards. Tissue extracts were fractionated by silica:alumina

                   column chromatography. The sample extracts were eluted from the column using

                   pentane    (fl=aliphatic hydrocarbons) and pentane:methylene chloride (1:1)

                   (f2=chlorinated hydrocarbons and PAHs). The second fractions were further purified to

                   remove lipids by either Sephadex LH-20 column chromatography eluted with a mixture

                   of cyclohexane:raethanol:methylene chloride (6:4:3) (11) or high-performance liquid

                   chromatography (112). Finally. the samples extracts were concentrated to a volume of

                   0.5 to 1 mL, in hexane, for gas chromatographic analysis.



                       Gas chromatography. Alpha-chlordane, trans-nonachlor. heptachlor and its

                   epwdde were determined by gas chromatography with an electron capture detector (GC-
                   ECD. 63Ni) using a 30 m DB-5 fused silica capillary column (0.25 mm film thickness.

                   0.25 nii m--' @d.. J&W Scientific). as previously described (6.7). Quantitation was achieved

                   using authentic standards injected at four different concentrations. The detection limit

                   for each of these compounds, calculated on the basis of 2 g dry weight of oyster tissue
                   sample sizes and 0.2% by volurne'of the extract injected into the GC-ECD, is 0.25 ng g- 1.



                       guality Control/guality Assurance (!gA/gC). These activities included several

                   laboratory intercalibration exercises with repeated. routine analysis of homogenated

                   natural samples. supplied by the National Institute of Standards and Technology

                   (NIST), to ensure that the data produced during this program is reproducible, accurate,




                                                                4-42





                                                                                                              5


                     and analyst independent. Interim reference material and spiked blanks. analyzed

                     along with each set of samples, are also part of an ongoing laboratory QA/QC program.



                        Data analysis. For summaxy and statistical purposes, the reported mean total

                     analyte concentrations include contributions equal to the analytical detection limits

                     for those analytes that were below the limit of detection. Trends In concentrations with

                     time at those locations that were sampled at least four of the five years were

                     statistically evaluated. at alpha=0.05. by linear regression.




                     Results and discussion


                          For the last five years. alpha-chlordane. trans-nonachlor. heptachlor and Its

                     metabolite heptachlor epoxide were analyzed in more than 860 oyster samples collected

                     from 80 different sites along the northern coast of the Gulf of Mexico as part of the
                     NS&T Program (Fijure 1). A summary of the median and average concentrations as

                     well as ranges and distribution frequencies for each compound and t6tal chlordane, i.e.

                     summed individual analytes. corresponding to the original locations are given in Table

                     1. Table H summarizes the complete data set. Le. all sites included. from 1988 to .1990.

                          Except for a few samples collected in .1990, these analytes were detected in every

                     sample analyzed since 1986. Concentrations varied over I to 3 orders of magnitude
                     (Table--I).:: In 1986, concentrations for total chlordane ranged from 2.00 to 175 ng g- 1
                     with a mean value. of 24.1ï¿½30.3 ng g- 1. During 1987, the overall average concentration
                     for the Gulf of Mexico (29.5ï¿½58.5 ng g- 1. range 2.12-590 ng g- 1) was higher than the

                     average concentration encountered in 1986. As previously discussed for DDT and Its

                     metabolites (7), this increase was a consequence of high residue concentrations
                     encountered at site 39 (Choctawhatchee Bay; 288ï¿½256 ng g-1). In 1988, the total

                     chlordane average concentration was sirnflar to the concentration measured during the
                     first sampling year (21.7ï¿½22.8 ng g- 1. range 1.29-132 ng g- 1). Further decreases in mean





                                                                4-43






                                                                                                             6

                   concentrations were observed in 1989 (16_3ï¿½25.0 ng g- 1. range 1.37-159 ng g- 1) and in
                   1990 (15.3ï¿½14.0 ng g-1, range <1.00-69.4 ng g-1)_

                        The addition of sites closer to suspected sources of contaminants to the sampling

                   program resulted In higher average concentrations and larger ranges (Table 11).

                   However, these changes were not as dramatic as expected for sites located near suspected

                   sources of contaminants. In general. the concentrations encountered at the new sites

                   compared well with the existing information obtained from the original 51 sites.



                         Geographical distribution. At this point of the NS&T program, the distribution of

                   chlordane concentrations in oysters from the U.S. Gulf of Mexico is well established.

                   Overall average concentration in the entire area for the five-year period was 24.1ï¿½25.2
                   ng g- 1. The highest residue concentrattons were encountered in oysters collected near

                   highly populated urban areas. For example, mean concentrations higher than three

                   times the overall -average for the Gulf of Mexico were measured in samples from

                   Galveston Bay. Texas, Mississippi Sound. Mississippi and Chocta*h@tchee. Tampa and

                   Charlotte Bays. Florida (Figure 2). The c3dstence of higher residue concentrations in

                   these areas. compared to predominantly agricultural coastal areas, is in good

                   agreement with the regulations that have ruled chlordane usage for the last 15 years.

                   After 1975, most of the chlordane use In the U.S. was limited to structural underground

                   termite .- control. therefore., the higher the population. e.g. more houses, the higher the

                   chlordane concentrations. With the exception of sites in Galveston Bay, the lowest

                   concentrations of total chlordane were encountered in samples collected to the west of

                   the Mississippi River. The addition of the new sites after 1987 (Figure 1). adds to the

                   definition of the distribution of pesticide concentrations for the first two years of this

                   program (6).



                         Residue composition. Alpha-chlordane and trans-nonachlor comprised from 38

                   to 48% and 36 to 49% of the total chlordane load. respectively. in oyster samples




                                                               4-44






                                                                                                              7


                     collected between 1986 and 1990. The contribution of heptachlor and Its epoxide to the

                     total oyster burden were between 2-9% and 6-17%, respectively. Relative ratios of

                     alpha-chlordane, trans-nonachlor and heptachlor in Gulf of Mexico oysters.were

                     1.00-0.92:0.05, in 1986. 1.00.0.82:0.04, in 1987; 1.00:0.92:0.05. In 1988; 1.00.1.11:0.09.

                     in 1989; and 1.00:0.98:0.21. In 1990. Ratios for the last three years correspond to the

                     average values between both oyster data sets. Puri et aL (13) reported the percent

                     composition of chIordane constituents in four different technical chlordane

                     formulations. Thd average percent contribution of alpha-chlordane. &ans-nonachIor

                     and heptachlor to the total technical mixtures are 16.5ï¿½2.79. 13.4ï¿½4.34 and

                     12.5ï¿½2.190/o, respectively. Heptachlor epoxide is reported to be present as tracc levels.

                     Relative ratios among alpha-chlordane. trans-nonachlor and heptachlor in the

                     average technical chlordane mixture are 1.00:0.81:0.75. The NS&T data clearly show

                     that alpha-chIordane:trans-nonachlor ratios for the average technical chlordane

                     mixture and Gulf 6f Mexico oysters are similar. There is. however, a marked depletion

                     in the relative concentration of heptachlor in oyster, samples. -This decrease in the

                     relative concentration of heptachlor is commonly reported for biota tissues (13-15).. In

                     1990, however. the higher relative alpha-chlordane:heptachlor ratio in oyster tissues

                     Indicate a somewhat reduced chemical/blochemical epoxidation of heptachlor, which

                     is confirmed by an increase in the heptachlor- heptachlor epo-xide ratio from 1:6. in
                     1986@@;9.; *6 1:2. in 1990. This suggests fresh inputs of technical chlordane mixtures or

                     the related pesticide heptachlor into the coastal marine environment- The Increase in

                     the concentrations of heptachlor and its metabolite heptachlor epoxide in oyster

                     tissues during 1990, which are not accompanied by a proportional increase in the

                     concentration of alpha-chlordane and trans- nonachlor. might point to the second

                     source as the most proVable. However, this possibility must be taken with caution until

                     more data. from this or other studies, becomes available.









                                                               4-45



  It
 Z                                                                                                          8

                        Temporal trends. A five years database is available to look for trends in

                   chlordanc concentrations with time. Although with overlapping standard deviations,

                   the annual average concentrations of total chlordane have been decreasing in oyster

                   samples from the Gulf of Me)dco. This tendency is supported by a shift in the percent

                   distribution of concentrations to lower values (Table I and 11). For example. in 1986, the

                   total chlordane concentration in oysters from the original sites were largely dominated
                   by concentrations between 10.0 and <100 ng g-1 with some values over 100 ng g-1 trable
                   1). . In 1990. the t6tal residue concentrations were ahnost equally distributed between
                   the 1.00-<10.0 and 10.0-<100 ng g-I ranges with 4% of the samples below the

                   quantitation limit. The same analysis can be made for the individual analytes except

                   heptachlor. Heptachlor concentrations have been shifting in the opposite direction

                   since 1987. Agairi. this suggests that fresh heptachlor has been or is entering the

                   coastal marine environment. The analysis of the samples already collected for the

                   sixth sampling period (199 1). and those of the following years. will probably assist in

                   this matter.


                        Table III indicates the average total chlordane concentrations at each site between

                   1986 and 1990. Sites listed in this table are shown in geographical order from the U.S.-

                   Me:xico border to the southernmost Florida site. In general, the total chlordane

                   concentrations seem to be oscillating around a certain value without showing any trend

                   with time. Statistical analysis of the slopes of the regression lines of concentrations

                   versus time at those sites with at least four years of collected data identified only a

                   thirteen sites with significant decreases. These sites are marked with an asterisk in

                   Table 111. . Most of these sites are located along the southern Texas coast from Corpus

                   Christi to Matagorda Bays. Paradoxically, the only site that showed a statistically

                   significant increase in concentration with time. Copano Bay, is located within this


                   area.










                                                               4-46







                                                                                                             9


                     Aknowledgement

                          This research was supported by the National Oceanic and Atmospheric

                     Administration. Contract 50-DGNC-5-00262, through the Texas A&M Research

                     Foundation, Texas A&M University.




                     Literature Cited




                     (1)     Robertson, A. Monitoring coastal water environmental quality: The U.S.

                             National Status and Trends Program. In G.E. Schweitzer and  A.S. Phillips

                             (eds.), Monitoring and Managing Environmental Impact: American and Soviet

                             Perspecttves. National Academy Press. 281 pp.                                                   qr

                     (2)     Wade, T.L., Garcia-Romero, B. and Brooks. J.M. Erwtron. Sci. Technol. 1988,

                             22,1488-1493.

                     (3)     MacDonald, D.A. Oceans '89 Conf. Proc., 1989, 2,647-651.

                     (4)     O'Connor. T.P., Price. J.E. and Parker. C.A. Oceans '89 Conf. Proc., 1989. 2 569-

                             572.


                     (5)     Presley. B.J., Taylor, R.J. and Boothe, P.N. Sci. Total Environ.    1990.97/98,

                             551-593..


                     (6)     Sericano, J.L., Atlas, E.L., Wade, T.L. and Brooks. T.L. Mar. Environ. Res., 1


                             990a. 29.161-203.


                     (7)     Sericano. J.L., Wade. T.L., Atlas, E.L.: Brooks, J.M. Environ. Sci. Technol.,


                             1990b, 24,1541-1548.

                     (8)     Dearth, M. A. and Hites, R. A. Environ. Sci Technol. 1991, 25. 245-254.

                     (9)     Shigenaka, G. Chlordane in the Marine Environment of the United States:

                             Review and Results from the National Status and Trends Program. NOAA

                             Tech. Memo. NOS OMA 55,Seattle, Washington. 1990. 230 pp..

                     (10)    MacLeod, W. D.; Brown. D. W.; Friedman, A. J.: Burrows. D.G.: Maynes, O.;

                             Pearce, R. W.; Wigren. C. A. and Bogar, R.G. Standard analytical procedures of




                                                                4-47






                                                                                                                       10


                             the NOAA National Analytical Facility. 1985-1986. Extractable toxic organic

                             compounds. 2nd. Edition. U. S. Department of Commerce, NOAA,/NMFS. NOAA

                             Tech. Memo. NMFS F/NWC-92. 1985. 121 pp.

                     (11)    Ramos, L.: Prohaska. P. G. J. Chromatogr., 1981, 211, 284-289.

                     (12)    Krahn, M.M.; Wigren, C.A.: Pearce. R.W.; Moore. L.K.; Bogar, R.G.: MacLeod.

                             W.D.; Chan. S-L. and Brown. D.W. Standard analytical procedures of the NOAA

                             National Analytical Facility. 1988. New HPLC cleanup and revised extraction
                             procedures for organic contaminants. NOAA Tecn. Memo. 1988. 52,pp.

                     (13)    Puri, R.K., Orazio. C.E., Kapila, S., Clevenger, T.E., Yanders, A.F., McGrath, K.E.,

                             Buchanan. A.C., Czarnezki, J. and Bush, J. Studies on the Transport and Fate of

                             Chlordane in the Environment. In: D.A. Kurtz (ed.), Long Range Transport of

                             Pesticides. Lewis Publishers. 1990. pp 271-289.

                     (14)    Muir. D.C.G.; Norstrom, R.J.; Simon. M. Environ. Sci. Technol., 1988,22.1071-


                             1079.


                     (15)    Kawano. M.; Inoue, T.; Wada, T.,; Hidaka, H.: Tatsukawa, R Environ. Sci.

                             Technol., 1988, 22.792-797.


































                                                                      4-48

















                                                                 M1     JO      1 0              ISO    I                                                          ALABAMA
                                                                                                                                    MISSISSIP
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                                                                                                                                                    401  oil
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                                                                                                                           G U L F            0





                                                                          52





                                                       F -ig, I Gulf of Mexico sampling site locations. Shown are the original                                                                 sites (0)
                                                                      sampling program (N)since 1988.






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                                                                                           CIMDRDANE (nflg. dry wt)





                                   Fig. 2           Average total Chlordane concentrations in oyster samples
                                                     from the Gulf of Mexic4-50












                  Table 1: Chlordane-related Compound Concentrationsa. and Distribution Frequencies in Gulf of Mexico Oysters

                             (original Sites), 1986-1.990

                                                   concn, ng/g                                      distribution


                                        median meanï¿½1 STD       range       P.00-0.25 0.25-<1.00 1.00-<10.0 10.0-<100 100+, (ng/g)



                  1986 (n-147)


                  Heptachlor                  25  0.51ï¿½0.69 <0.25-4.62            63         29            8

                  Heptachlor Epoxide       1.87   2.71ï¿½3.31    <0.25-24.5         14         12          70              4

                  Alpha-chlordane          5.23   10.9ï¿½14.4     0.91-96.3                     1          72            27

                  Trans-nonachlor          4.58   10.0ï¿½13.8     0.60-71.9                     1          76            23


                  ZChlordane               13.1   24.1ï¿½30.3     2.00-175                                 36            61           3




                  1987 (n=143)


                  Heptachlor               <0.25  0.54ï¿½0.99    <0.25-7.04         77         14            9

                  Heptachlor Epoxide       2.45   3.30ï¿½3.93    <0.25-27.3          2         11          82              5

                  Alpha-chlordane          6.42   14.1ï¿½29.0     0.65-292                      1          71            27           1


                  Trans-nonachlor          4.78   11.6ï¿½27.7     <0.25-289          1          5          73            20           1


                  7,Chlordane              14.4   29.5ï¿½58.5     2.12-590                                 28            66           6



                                                                                                                                        M.IRA


                  Table I (continuation)









                                                  concn, ng/g                                        distribution-


                                         median   meanï¿½1 STD    range        0.00-<0.25 0.25-<1.00 1.00-<10.0       10.0-<100 100+, (ng/g)




                  1988 (n-132)

                  Heptachlor              <0.25   0.49ï¿½0.66 <0.25-5.81            73          16         11

                  Heptachlor Epoxide       1.69   2.44ï¿½2.33   <0.25"14.3          3           15         80              2

                  Alpha-chlordane          5.80   9.76ï¿½10.7     0.40-60.2                       2        72            26
        @n
                  Tran's-nonachlor         5.02   8.98ï¿½11.5   <0.25-81.6          1             4        70            25

                  7-Chlordane              13.9   21.7ï¿½22.8      1.29-132                                35            64            1




                  1989 (n=135)

                  Reptachlor               0.33   0.78ï¿½1.03   <0.25-8.23          40          40         20

                  Heptachlor Epoxide       0.60   1.25ï¿½1.41   <0.25-9.33          20          41         39

                  Alpha-chlordane          3.14   7.00ï¿½9.84   <0.25-48.3          1             7        76            16

                  Trans-nonachlor          2.33   7.29ï¿½14.5   <0.25-99.1          1           16         69            14


                  7,Chlordane              7.68   16.3ï¿½25.0      1.37-159                                61            37            2









                   Table I (continuation)








                                                     conen, ng/g                                         distribution-


                                           median   mean:tl STD    range        10. 00-<O. 25 0.25-<I. 00 1. 00-<10. 0 10, 0-<100 100+, (ng/g)



                   1990 (n=138)

                   Heptachlor                .0.72  1.34ï¿½1.81     <0.25-15.2          30           28          41              1

                   Reptachlor Epoxide        1.20 .2.63ï¿½4.53 <0.25-29.9               27           19          50              4
                   Alpha-chlordane           4.16   5.81ï¿½5.66 <0.25-36.3               5            6          72             17

                   Trans-nonachlor           3.13   5.55ï¿½6.49     <0.25-29.8           4           17          62             17

                   IChlordane                10.7   15.3ï¿½14.0     <1.00-69.4                        4          42             54



                   a Concentrations on a dry weight basis











                  Table II: Chlordane-related Compound Concentrationsa and Distribution Frequencies in Gulf of Mexico oysters

                              (Complete Data Set), 19'88-1990

                                                   conch, ng/g                                       distribution'


                                          median  meanï¿½l STD    range        .0.00-<0.25 0.25-<1.00 1.00-<,10.0     10.0-<100 100+, (ng/g)



                  1988 (n-189)


                  Heptachlor               <0.25  0.58ï¿½0.81 <0.25-5.81             68         18          14

                  Heptachlor Epoxide       1.73   2.95ï¿½3.63    <0.25-21.5          5          is          75              5

                  Alpha-chlordane          6.31   11.4ï¿½13.3     0.40-88.4                       2         66            32

                  Trans-nonachlor          5.46   10.5ï¿½12.8    <0.25-81.6          1            3         65            31


                  7-Chlordane              14.3   25.4ï¿½27.7       1.29-182                                34            64           2




                  1989 (n=186)


                  Heptachlor               0.32 0.74ï¿½0.98 <0.25-8.23               43         38          18              1

                  Heptachlor Epoxide       0.88 1.50ï¿½1.65 <0.25-10.7              16          37          46              1

                  ,Alpha-chlordane         4.01 10.2ï¿½15.3       <0.25-116          1            5         69            24           1

                  Trans-nonachlor          3.02 11.8ï¿½22.7       <0.25-183          1          13          64            21           1


                  7,Chlordane              9.63   24.2ï¿½38.4       1.37-302                                52            43           5









                  Table II (continuation)







                                                 concn, ng/q                                     distribution'

                                        median  meanil STD    range       10.00-0.25 0.25-<1,00 1.00-<10.0 10.0-<100 100+, @ng/q)



                  1990 (n-203)
                  Heptachlor              -0.84 1.36ï¿½1.63 <0.25-15.2           24          30         45             1
                  Heptachlor Epoxide      1.24  2.51ï¿½4.10 <0.25-29.9           26          19         51             4
                  Alpha-chlordane         4.97  7,74ï¿½8.37 <0.25-59.0             4           6        65            25
                  Trans-nonachlor         4.37  7.72ï¿½9.85    <0.25-73.6         3          12         59            26

                                              6 19.4ï¿½19.3     <1.00-139                     1         36            62          1
                  7,Chlordane            12.

                  a Concentrations on a  dry weight basis























                                           dooms  @k      I   k



                     M Mae M M1 M M,                                                M M M M M M M IM.M



                      Table III.   Total Chlordane Concentrations in oyster Samples from NS&T Program Sites, 1986-1991a.
                          Site     Location            State                                   mean:@l SD
                                                                  1986           1987           1988           1989          1990
                          I  LMSB  Laguna Madre             TX   3.77ï¿½0.60    2.83ï¿½0.71        3.68ï¿½3.92    3.63ï¿½1.06       1,771:0.87
                          2  CCNB  Corpus Christi           TX   19.1ï¿½12.3     13.9ï¿½4.37       13.8ï¿½10.5    8.1@ï¿½2.52       13.2ï¿½2.48
                          52 LMPI  Laguna Madre             TX                                 8.78ï¿½2.81
                          78 LKAa  Laguna Madre             TX                                                              8.8W.43
                                                                                               14.9ï¿½7.50                    7.76ï¿½1@35
                          53 CCBH  Corpus Christi           TX
                          3  CCIC* Corpus Christi           TX   23.8ï¿½1.61                     4.62ï¿½1.70     3.46ï¿½1.07      3. 7 O:k2. 9 0

                          54 ABHI  Aransas Bay              TX
                          4  ABLR* Aransas Bay              TX   8.82ï¿½3.12      9.76ï¿½2.22      4.86ï¿½1.15     3.57ï¿½1.05      4.49ï¿½2.48
                          5  CBCR' Copano Bay               TX    8.84ï¿½2.41     12Aï¿½0.21       9.70ï¿½5.48                    19.4ï¿½11.8
                          6  14BAR* Mesquite Bay            TX    8.56ï¿½2.95     11.0ï¿½3.13      8.22ï¿½2.33     5.09ï¿½2-01      6.17ï¿½5.40
                             sAP?  San Antonio Bay          TX    9.61ï¿½3.61     9.20ï¿½2.38                                   4.96ï¿½2.82
                          6  SANP  San Antonio Bay          TX    11.9ï¿½2.42     i"4. 8ï¿½3. 52
                          9  E s s P, Espiritu Santo        TX    5.08ï¿½1.81     8.97ï¿½0.59                                   3.81ï¿½1.59
                          10 SSBD  Espiritu Santo           TX                                 1.97ï¿½1.65     3.19ï¿½0.82      2.76ï¿½3.12
                          11 MBLR* Matagorda Say            TX    16.5ï¿½6.08     16.4ï¿½2.31                     4.71ï¿½1.40     i.76ï¿½i.26
                                                                  8.21ï¿½0.22     1818ï¿½17.2      9.36ï¿½3.33      3.69ï¿½1.04
                          12 MBG?  Matagorda Bay            TX
                                                                                               9.04ï¿½4.58                    3.65ï¿½1.98
                          56 MBCB  Matagorda Bay            TX








                     Table III (continuation)

                                  site              Location                             state    mean:tl SD


                                                               1986         1987          1988          1989          1990

                                                                                                                            26
                     13   MBTP* Matagorda Bay        tx     14.8ï¿½10.3     19.7ï¿½4.40     8. 79ï¿½2.. 95  4.50ï¿½1.23    6.66ï¿½5.

                                                                                        8.41ï¿½0.21
                     55   MBDI Matagorda Bay         TX
                     14   MBEM* Matagorda Bay        TX     16.3ï¿½9.52     19.5ï¿½iO.9     8.49ï¿½3.19     6.96ï¿½1.17    7.51ï¿½4.29
                                                                                        10.1ï¿½1.76     7:25ï¿½3.04    5.85ï¿½4.86
                     57   BRFS  Brazos River         TX
                     72   BRCL  Brazos  River        TX                                               7.31ï¿½6.90    19.3ï¿½5.69
                     15   GBYC* Galveston Bay        TX     124ï¿½24.9      136ï¿½30.3      60.8ï¿½8.95     20.4ï¿½3.57    42.li9.63
                     59   GBSC  Galveston Bay        TX         -             -          139ï¿½38.5     35.2ï¿½M6      51.7ï¿½13.6
                     58   GBOB  Galveston Bay        TX                                 88.2ï¿½15.2     98.2ï¿½11.7    111ï¿½35.9
                     16   GBTD  Galveston Bay        TX     25.5ï¿½4.68     55-218-13     14.2ï¿½2.93     11.4ï¿½1.25    27.7ï¿½6.03
                     13   GBHR  Galveston Bay        TX     10.7ï¿½2.14     15.6ï¿½7.89     8.06ï¿½2.42     7.36ï¿½0.48    21.0ï¿½13.4
                     18   GBCR  Galveston Bay        TX     9.92tl.78     14.8ï¿½2.78     14.2ï¿½7.33     7.93ï¿½2.37    11.0ï¿½1.20
                     19   SLBB  Sabine Lake          TX     11@9ï¿½4:31     9.23ï¿½1.36     20.4ï¿½11.4     6.99ï¿½1.18    12.4ï¿½6.63
                     20   CLSJ* Calcasieu Lake       LA     14.0ï¿½1.35     1*6.2ï¿½3.71    14.5ï¿½3.19     7.94ï¿½7.19    6.65ï¿½4.28
                     60   CLLQ- Calcasieu Lake       LA                                 45.1ï¿½3.88     6.63ï¿½1.56    20.2ï¿½4.51
                     21   JHJH  Joseph Harbor        LA     11.2ï¿½3.03     11.1ï¿½1.22     5.26ï¿½0.78     7.24ï¿½3.16    14.0ï¿½9.92
                     22   VBSP  Vermilion Bay        LA     15.2ï¿½2.36     21.4ï¿½6.25     15.2ï¿½1.19     12,0ï¿½1.60    32.7ï¿½14.9

                     23   ZCSP  East Cote Blanche    LA
                     24   ABOB* Atchafalaya Bay      LA     13.8ï¿½1.34     20.3ï¿½6.84     15.1ï¿½3.00     9.11ï¿½1  '..48 8.32ï¿½2.78


                                                                                           Ilk







                       Table III (continuation)


                                    site                 Location                                state    meardl SD


                                                                    1986           1987           1988           1989           1990

                       25  CLCL   Caillou Lake           LA      8.30ï¿½0.91      10.2ï¿½4.35      5. 2 8ï¿½1,. 11  4.77ï¿½2.56,     9.02ï¿½3.44

                       26  TBLB   Terrebone Bay          LA      6.77ï¿½3.25      8.88ï¿½2.34      11.8ï¿½9.95      5.38ï¿½1.05      9.97ï¿½4.51
                       27  TBLF   Terrebone Bay          LA      6.69ï¿½2.01      .5.67ï¿½2.23     5.55ï¿½1.78      3.9@ï¿½1.31      10.1ï¿½4.40

                       61  BBTB   Barataria   Bay        LA                                    7.86ï¿½4.62

                       28  BBSD   Barataria   Bay        LA      10.7ï¿½1.86      12.0ï¿½7.60      20.0ï¿½7.25      7.21ï¿½2.51      8.20ï¿½1.92

                       29  BBMB*  Barataria   Bay        LA      35.3ï¿½21.6      16.2ï¿½3.98      14.3ï¿½1.53      7.86ï¿½3.69      7.60ï¿½0.86

                       65  MRTP   Mississippi River      LA                                    27.1ï¿½11.0      17.3ï¿½2.39      13.3ï¿½2.04

                       64  MRPL   Mississippi River      LA                                    61.3ï¿½17.1      66.9ï¿½1.37      39.0ï¿½15.4
         00
                       30  BSBG   Breton Sound           LA      10.5ï¿½7.14      10.8ï¿½3.51      12.5ï¿½4.60      5.71ï¿½1.75      8.03ï¿½3.33

                       31  BSSI*  Breton Sound           LA      45.4ï¿½18.0      12.8ï¿½1,39      28.8ï¿½10.2      13.1ï¿½6.14      12.6ï¿½3.35

                       32  LBMP   Lake Borgne            LA      12.6ï¿½5.75      10.4ï¿½4.57      11.0ï¿½9.94      7.11ï¿½2.22      17.4ï¿½2.16

                       62  LBNO   Lake Borgne            LA                                    8.82ï¿½3.25
                       33  MSPC   Mississippi    Sound   MS      21.5ï¿½3.13      6:9.0ï¿½41.2     15.9ï¿½4.63      22.7ï¿½7.70      14.8ï¿½2.03

                       34  MSBB   Mississippi    Sound   MS      98.0ï¿½67.8      86.0ï¿½55.6      71.4ï¿½22.3      71.2ï¿½18.7      49.8ï¿½16.2

                       35  MSPB   Mississippi    Sound   MS      12.0ï¿½4.25      18.9ï¿½1.34      28.0ï¿½7.81      18.5ï¿½7.60      28.6ï¿½32.7

                       36  MBCP   Mobile Bay             AL      14.8ï¿½7.07      24,1ï¿½16.3      14.7ï¿½3.36      25.3ï¿½10.9      17.1ï¿½3.54

                       66  MBH1   Mobile Bay             AL                                    34.3ï¿½7.12      40.3ï¿½3.22      34.3ï¿½2.98

                       79  MBDR   Mobile Bay             AL                                                                  31.6ï¿½2.09








                       Table III (continuation)


                                   site               Location                                State    meanï¿½1 SD


                                                                  1986          1987           1988          1989           1990
                                                        A
                       67  PBPH Pensacola Bay           FL                                  35.6ï¿½@.67      17.0ï¿½0.80      28.6ï¿½8.36

                       37  PBIB Pensacola Bay           FL      15.0ï¿½0.88     24.'5ï¿½4.55    17.4ï¿½2.31      13.7ï¿½1.13
                       80  PBSP   Pensacola Bay         FL                                                                14.9ï¿½1.84

                       38  CBSR   Choctawhatchee Bay    FL      10.5ï¿½3.63     8.37ï¿½1.43     14.5ï¿½5.66      5.92ï¿½1.25      8.92ï¿½3.39
                       39  CBSP   Choctawhatchee Bay    FL      57.5ï¿½20.5     288ï¿½256       45.4ï¿½20.8      65.8ï¿½36.8      39.3ï¿½26.6
                       73  CBJB   Choctawhatchee Bay    FL                                                 17.4ï¿½13.9      20.2ï¿½8.25
                       68  PCMP   Panama City           FL                                  25.8ï¿½9.48      17.0ï¿½1.29      16.9ï¿½7.55
                       74  PCLO   Panama City           FL                                                 8.42ï¿½1.00      12.1ï¿½1.46
                       40  SAWB*  St. Andrew Bay        FL      79.8ï¿½26.7     57.8ï¿½7.39     37.5ï¿½22.4      38.5ï¿½8.33      26.1ï¿½10.3
                       41  APDB   Apalachicola Bay      FL      8.28ï¿½1.49     13.2ï¿½0.44     53.9ï¿½34.1      2.95ï¿½0.86      22.7ï¿½7.62
                       42  APCP   Apalachicola Bay      FL      12.1ï¿½1.*92    11.6ï¿½2.14     14.9ï¿½4.72      13.5ï¿½2.61      11.4ï¿½3.51
                       75  AESP   Apalachee Bay         FL                                                 5.11ï¿½2.31      13.7ï¿½12.7

                       69  SRWP   Suwannee River        FL                                  11.2ï¿½1.91
                       43  CKBP   Cedar Key             FL      8.90ï¿½3.15     14.4ï¿½3.16     25.6ï¿½31.2      8.18ï¿½5.33      6.71ï¿½2.33
                       44  TBPB   Tampa Bay             FL      58.0ï¿½13.2     98.9ï¿½66.7     60.1ï¿½20.1      81.4ï¿½3.90      24.0ï¿½10.9
                       70  TBOT   Tampa Bay             FL                                  34.8ï¿½5.85      28.1ï¿½11.8      12.2ï¿½6.96'

                       45  TBHB   Tampa Bay             FL      21.8ï¿½4.46     17.6ï¿½1.04
                       46  T5CB   Tampa Bay             FL      73.8ï¿½16.6     45.1ï¿½8.58     107ï¿½47.2       127ï¿½27.3       41.3ï¿½3.42







                       Table III (continuation)


                                     site                Location                               State     meanï¿½1 SD



                                                                    1986          1987           1988           1989           1990

                       76   TBNP Tampa Bay               FL                                                  117ï¿½66.3.      47.1ï¿½5.99

                       77   TBKA Tampa Bay               FL                                                  113ï¿½50.8       62.0ï¿½1.07

                       47   TBMK Tampa Bay               FL      23.7ï¿½4.20      '21.0ï¿½3.63    21.4ï¿½13.4      18.2ï¿½8.05      23.0ï¿½17.9
                       48   CBBI 'Charlotte   Harbor     FL      9.56ï¿½2.98      23.8ï¿½15.9                    8'. 69ï¿½1.17    8.3@ï¿½3.31

                       71   CBFM Charlotte    Harbor     FL          -                        73.3ï¿½4.81       172ï¿½114       36.8ï¿½11.0

                       49   NBNB* Naples Bay             FL      114ï¿½27.4       40.0ï¿½17.2     31.3ï¿½9.16      17.0ï¿½2.58      11.5ï¿½3.08

                       50   RBHC Rookery Bay             FL      4.26ï¿½2.;52     3.87ï¿½2.13     19.4ï¿½15.8      3.51ï¿½0.23      3.00ï¿½1.07

                       51   EVFU Everglades              FL      2.51ï¿½0.46      5.70ï¿½2.31     22.7ï¿½12.0      1.91ï¿½0.72      25.3ï¿½20.8

                       a Concentration (ng g-1 on a dry     weight basis);       no sample      or    indicate sites that have shown

                       statistically concentration increases or decreases, iespectively, with time (see text)






















                                              Preprint 4


                        Concurrent Chemical and Histological Analyses:
                                        Are They Compatible?


                          J.L. Sericano, T.L. Wade, E.N. Powell, and J.M. Brooks











                          CONCURRENT Cj1EAHCAL AND HISrOLOGICAL ANALYSES:

                                                  ARE THEY COMPATUBLE?



                          J. L. Sericano(l); T. L. Wade(l); E. N. powell(2) and J. M. Brooks(l)



                                Geo chemical and Environmental Research Group, College of

                                  Geosciences, Texas A&M University, 833 Graham Rd,

                                                  College Station, Texas 77845.



                                    Department of Oceanography, Texas A&M University,

                                                  College Station, Texas 77840.




                         Bivalves are often*' used as sentinel organisms in monitoring programs for trace
                         organic contaminants. The animal's physiological state may be important in
                         interpreting trends in contaminant body burden- Simultaneous evaluation of
                         physiological state and organic contaminant concentration in bivalves typically
                         involves removal of a lipid-rich cross-section of the body mass for
                         histopathological and/or gonadal analysis.
                              In this study, the bias introduced by this technique in the final trace organic,
                         e.g. polynucl.ear aromatic hydrocarbons, chlorinated pesticides and
                         polychlorinated biphenyls, toncentrations are evaluated on five different size
                         groups of oysters. As a test case, we evaluated the use of this method in the NOAA:s
                         Status & Trends Mussel Watch (NS&T) program. The average biases introduced
                         by this technique in the final trace organic concentrations in Gulf of Mexico
                         oysters have been increasing since 1986 as a consequence of a continuous decrease
                         in the sizes of the individuals sampled.










                                                                   4-62







                                                                                                 2





                     INTRODUCTION



                     Seasonal variations in organic contaminant concentrations in

                     bivalves have been attributed to a number of Aifferent factors

                     including the stage of the reproductive cycle, nutritional Status and

                     ambient temperature (Wormell, 1979; Neff & Anderson, 1981;

                     Jovanovich & Marion, 1987). Several studies have indicated the

                     importance of considering the bivalve's physiological state when
                     measuring contaminant loads (Fossato & Canzonier, 1976; Boe_hi@-&

                     Quinn, 1977; Mix & Schaffer, 1979; Lunsford & Blem, 1982; Widdows

                     et at., 1982; Jovanovich & Marion, 1987). Monitoring programs that

                     use bivalves as sentinel organisms typically try to assess some of

                     these problems. In NOAA's National Status and Trends Mussel

                     Watch (NS&T) Program, for example, reproductive state, condition
                     index and disease incidence in oyster samples from        .the Gulf of

                     Mexico have been monitored since 1986 (e.g. Craig et al., 1989; Wilson

                     et al., in preparation).

                          One aspect of the problem involves the determination of the

                     reproductive state, which typically requires a histological analysis in

                     most bivalves (e.g. Morales-Alamo & Mann, 1989). In some cases,

                     where the seasonal variability in contaminant concentrations in

                     bivalves was followed in relation to their reproductive cycle, the

                     chemical and biological analyses were performed on t       wo different

                     groups of individuals collected at the same site (e.g. Jovanovich &

                     Marion, 1987). Since the reproductive state of bivalves may vary
                     considerably among individuals at certain times of the year -,(e.g.



                                                        4-63






                                                                                                  3




                    Wilson et al., in preparation), adequate comparison requires a large

                    sample size and the approach necessarily restricts statistical

                    analysis.

                         An alternative approach is to take a cross-section of tissue from

                    the same individual that is used for trace organic analyses. Bivalves

                    where the gonadal material is in the mantle, such as mussels

                    (Bullogh, 1970), present only a minor problem; but oysters, where the

                    gonadal tissue surrounds the visceral mass (Morales-Alamo &

                    Mann, 1989), require removal of a tissue cross-section that maybe

                    rich in trace organic contaminants.                   Any additional

                    histopathological analysis would, of course, require removal of a

                    larger tissue cross-section in either species.

                        'The objecti ve of this study was to evaluate the bias in the final
                    organic conf,4@nant concentrations introduced by the selective

                    removal of a tissue cross section for histopathological or gonadal

                    analysis. Five groups of oysters, Crassostrea virginica, of different

                    average sizes were dissected and the portions normally used for

                    his to pathological and trace organic analysis were separately

                    analyzed for selected polynuclear aromatic and chlorinated

                    hydrocarbons to evaluate this bias.





                    MATERIALS AND METHODS



                    Oysters were collected from Galveston Bay, Texas, near the Houston

                    Ship Channel in December 1988. This area is one of the 71 sites that




                                                        4-64







                                                                                                     4




                     was sampled during the NS&T program in the Gulf of Mexico
                     (Sericano et al., 1990). The site, Galveston Bay Ship Channel (GBSC),

                     is located at the mouth of Goose Creek in Tabbs Bay. Immediately

                     after collection, the oysters were transported to the laboratory and

                     sorted into five different size groups. A cross-section of the body of the
                     oysters was separated by first making a transverse cut where the
                     palps..and gills meet. A second parallel cut was made about 5 mm

                     from the first cut toward the center of the organism. This cross-

                     section contained portions of gonad-, stomach, intestine, dig-esti@ve

                     diverticula. and connective tissue as well as mantle.and gill. In

                     standard practice, 3 to 5 mm. sections are cut for histological

                     analysis; consequently, the 5 mm cross-section would represent a
                     maximum estimate of any bias incurred. The cross-section and
                     remaining b6d@ tissues from oysters within each size group were
                     pooled into two separated samples and analyzed' for PAHs,

                     chlorinated pesticides and PCBs. The methods used to measure the

                     analyte concentrations were fully described elsewhere (e.g. Sericano

                     et al., 1990).





                     RESULTS AND DISCUSSION



                     Average lengths of the five different groups of oysters used in this

                     study ranged from 6.1 to 9.5 cm (Table 1). Also shown are the mean

                     percent contribution on a dry weight basis of the cross-section and






                                                          4-65






                                                                                                5




                   remaining body tissues to the total body mass, and the percentage of

                   extractable lipids corresponding to each of these fractions.
                        In.,general, the concentrations of PAHs, pesticides and PCBS
                   measured in oysters are similar in each of the five'size groups when

                   the same subsamples, cross-section (A) or remaining body tissues
                   (B), are compared (Table 2j.         In contrast, the trace organic

                   concentrations of the two subsamples differ substantially in all five
                   size classes. The cross-section (A) is the portion _ffiat normally would
                   have been used for histological analysis.. Since aromatib: and
                   chlorinated hydrocarbons* are hydrophobic, they tend to be associated

                   with lipid-rich tissues. This could in part explain the higher

                   concentrations measured in the cross-section tissues which contain

                   between 35 t  o 50% more extractable lipid than the. remaining body

                   tissues (Table 1).

                        The removal of the tissue cross-sections from* the sample

                   analyzed for trace organic compounds will introduce a bias towards

                   lower total concentrations in the sample. The magnitude of this bias

                   will largely depend on the sizes of the oysters sampled. In this study,

                   the tissue cross-sections accounted for about 15% of the tissue dry

                   weight in a 9 cm oyster, but for nearly 23% in a 6 cm oyster (Table 1).

                   Accordingly, in large oysters, a proportionally smaller fraction is

                   used for biological assays whereas, in smaller oysters, a 5 mm cross-

                   section represents the removal of a comparatively large fraction of
                   the total body mass. In the extreme, the cross-section of a very small

                   specimen may include all of the tissues from where the palps and






                                                       4-66






                                                                                                  6




                     gills meet to the adductor muscle which removes most of the lipid-

                     rich internal organs.

                          The concentrations of PAHs, chlorinated pesticides and PCBs

                     can be corrected for the contribution to the total b6dy burden of the

                     cross-section removed for histology. The differences between the

                     uncorrected, which represent the values that would normally be

                     reported, and corrected concentrations for each of the oyster groups

                     are shown in Figure 1. As expected, the biases in the individual
                     concentration of trace organic compounds increase as the dysiier

                     sizes decrease. Average biases are 6.1ï¿½2.0, 8.8ï¿½2.4, 10.5ï¿½2.7, 14.0ï¿½2.6,

                     and 14.3ï¿½2.4%, for PAHs, 10.5ï¿½2.1, 11.7-+0.7, 13.3ï¿½1.0, 13.9ï¿½0.8 and

                     16.8ï¿½1.5, for pesticides, and 6.3ï¿½0.9, 8.9ï¿½1.7, 10.9-+1.2, 13.3ï¿½1.4 and

                     13.9-+0.9, for PCBs, in oysters groups I to V, respectively.

                         As an example for this study, we consider the NS&T program in

                     the Gulf of Mexico. In this program, oysters are used as sentinel

                     organisms to monitor the current status and long-term trends of

                     selected organic and inorganic environmental contaminants along

                     the Atlantic, Pacific and Gulf coasts of the United States. In 1986, the

                     overall average oyster size collected for the Gulf of Mexico portion of

                     the NOAA's S&T Program was 8.5ï¿½1.4 cm, (Brooks et al., 1987)

                     (Figure 2). During the following sampling years there was a
                     continuous decrease in the sizes of the oysters that were sampled. In

                     1987, the average oyster size for the Gulf of Mexico was 7.6ï¿½1.8 cm

                     (Brooks et al, 1988); in 1988, the average oyster size was 7.2ï¿½1.4 cm

                     (Brooks et al., 1989); and in 1989, the average oyster size was 7.0ï¿½1.3

                     cm (Brooks et al., 1990).




                                                         4-67






                                                                                                 7




                         Wilson et al. (in preparation) discuss the possible reasons for

                    this decline in the sizes of the sampled oysters and concluded that the

                    trend toward smaller sizes was probably a manifestation of decreased

                    population health. For our purposes, this downward trend could

                    introduce a bias in the trace organic values.

                         The bias imposed by the continuous decrease in oyster sizes with

                    the successive sampling years in the observed PAH concentrations in

                    the Gulf of Mexico can be estimated from the regression lines in

                    Figure 1. Assuming that the cross-section was 5 mm in each case,

                    the average percent biases in PAH concentrations that were reported

                    for 1986, 1987, 1988 and 1989 can be estimated as 9.7, 11.7, 12.5 and

                    13.0%, respectively. Similarly, average percent biases for chlorinated

                    pesticides and  PCBs can be estimated as 12.6, 13.8, 14.4 and 14.7%
                    and 9.7, 11.4,'12.2 and 12.6%, respectively. However, under the
                    protocol used for the NS&T program, a cross-section' of tissue is

                    removed from only 10 of the 20 oysters collected per sampling station.

                    Thus, the estimated bias for each group of analytes would be about

                    half of these values.

                         In order to avoid misleading interpretations of comparative

                    spatial and temporal data, it is imperative to understand how the

                    methodology affects the trace organic concentration measurements

                    in bivalves. This understanding is of particular importance if tissue

                    cross sections are removed for histological analysis and it is

                    especially important in sites where considerable variability exists in

                    the sizes of the individuals sampled over the years and in cases

                    where smaller organisms must be used. The development of -non-




                                                       4-68






                                                                                            8




                    histologically based gonadal indices (e.g. Choi et al-, 1989; 1990) offers

                    one way to avoid this problem.





                    ACKNOV,TLEDGEMENTS



                    This research was supported by the National Oceanic and

                    Atmospheric Administration, - contract No. 50-DGNC-5-00262,

                    through the Texas A&M Research Foundation, Texas - A&M

                    University.



                    References

                    Boehm, P.D. and Quinn, J.G. (1977). The persistence of chronically

                        accumulated hydrocarbons in the hard shell      clam, Rangia

                        cuneata. Marine Biology, 44, 227-233.

                    Brooks, J.M., Wade, T.L., Atlas, E.L., Kennicutt II, M.C., Presley,

                        B.J., Fay, R.R., Powell, E.N. and Wolff, G. (1987). Analyses of

                        bivalves and sediments for organic chemical and trace elements

                        from Gulf of Mexico estuaries. Annual Report, Geochemical

                        and Environmental Research Group, College of Geosciences,

                        Texas A&M University, TX, 618 pp.

                    Brooks, J.M., Wade, T.L., Atlas, E.L., Kennicutt II, M.C., Presley,

                        B.J., Fay, R.R., Powell, E.N. and Wolff, G. (1988). Analyses of

                        bivalves and sediments for organic chemical and trace elements

                        from Gulf of Mexico estuaries. Annual Report, Geochemical





                                                     4-69






                                                                                            9




                        and Environmental Research Group, College of Geosciences,
                        Texas A&M University, TX, 644 pp.

                   Brooks, J.M., Wade, T.L., Atlas, E.L., Kennicutt 11, M.C., Presley,

                        B.J., Fay, R.R., Powell, E.N. and Wolff, G. (1989). Analyses of

                        bivalves and sediments for organic chemical and trace elements

                        from Gulf of Mexico estuaries. Annual Report, Geochemical

                        and Environmental Research Group, College of Geosciences,

                        Texas A&M University, TX, 678 pp.

                   Brooks, J.M., Wade, T.L., Atlas, E.L., Kennicutt II, M.C., Presldy,

                        B.J., Fay, R.R., Powell, E.N. and Wolff, G. (1990). Analyses of

                        bivalves and sediments for organic chemical and trace elements

                        from Gulf of Mexico estuaries. Annual Report, Geochemical

                        and Environmental Research Group, College of Geosciences,

                        Texas A&M University, TX

                   Bullogh, W.S. (1970). Practical invertebrate anatomy.' Macmillian

                        and Co. Ltd., London, 483 pp.

                   Choi, K-S, Wilson, E.A., Lewis, D.H, Powell, E.N. and Ray, S.M.

                        (1989). The energetic cost of Perkinsus marinus parasitism in

                        oysters: quantification of the thioglycollate method. Journdl of

                        Shellfisheries Research, 8, 125-131

                   Choi, K-S, Lewis, D.H. and Powell, E.N. (1990). Quantitative

                        evaluation of gonadal proteins in male and female oysters
                        (Crassostrea virgrinica) using an immunological technique.

                        Journal of Shellfisheries Research, 8, 431 (abstract).








                                                     4-70






                                                                                              10




                     Craig, A., Powell, E.N., Fay, R.R. and Brooks, J.M. (1989)_
                         Distribution of Perkinsus marinus in Gulf coast oyster

                         populations. Estuaries, 12, 82-91.

                     Fossato, V.U. and Canzonier, W.J. (1976). Hydrocarbon uptake and

                         loss by the mussel Mytilus edulis. Marine Biology, 36, 243-250.

                     Jovanovich@ M.C. and Marion, MR. (1987). Seasonal variation in

                         uptake and depuration of anthracene by the brackish water clam

                         Rangia cuneata. Marine Biology, 95, 395-403.

                     Lunsford, C.A. and Blem, C.R. (1982). Annual cycle of Kepdhe

                         residue and lipid content of the estuarine clam, Rangia cuneata.

                         Estuaries, 5, 121-130.

                     Mix, M.C. and Schaffer, R.L. (1979). Benzo(a)pyrene concentrations

                         in mussels (Mytilus edulis) from Yaquina Bay, Oregon, during

                         June 1976-May 1978. Bulletin of Environmental Contamination
                         and Toxicology, 23, 667-684.

                     Morales-Alamo, R. and Mann, R. (1989). Anatomical features in

                         histological sections of Crassostrea virginica (Gmelin, 1971) as

                         an aid in measurement of gonad area for reprodu.ctive

                         assessment. Journal of Shellfisheries Research, 8, 71-82.

                     Neff, J.M. and Anderson, J.W. (1981). Response of marine animals

                         to petroleum and specific petroleum hydrocarbons, Applied

                         Science Publishers Ltd, London, 177 pp.

                     Sericano, J.L., Atlas, E.L., Wade, T.L. and Brooks, J.M. (1990).

                         NOAA's Status and Trends Mussel Watch Program:

                         Chlorinated pesticides and PCBs in oysters (Crassostrea






                                                       4-71










                         virginica) and sediments from the Gulf of Mexico, 1986-1987.

                         Marine Environmental Research, 29, 161-203.
                    Widdows, J.' Bakke, T., Bayne, B.L., Donkin, P., Livingstone, D.R,

                         Lowe, D.M., Moore, M.N., Evans, S.V. and Moore, S.L. (1982).

                         Responses of Mytilus edulis on the exposure to the water-

                         accomodate fraction of north sea oil. Marine Biology, 67, 15-31.

                    Wilson, E.A., Powell, E.N., Wade, T.L., Taylor, R.J., Presley, B.J.

                         and Brooks, J.M. Spatial and temporal distributions of

                         contaminant body burden and disease in Gulf of Mexico -oyster

                         populations: The role of local and large-scale climatic controls

                         (in preparation).

                    Wormell, R.L. (1979). Petroleum hydrocarbon accumulation patterns

                         in Crassostrea virgainica: analyses and interpretations. Ph.D.

                         Dissertation, Rutgers University, The State University of New

                         Jersey (new Brunswick), 189 pp.


























                                                     4-72










               TABLE 1. Average shell length and percent contribution of the cross-section

                           and remaining-body tissues to the total body weight corresponding to

                           the five group of oysters analyzed. Lipid percentages for each

                           fraction are also indicated.




               Oyster    n     Shell        Cross-Section Tissues         Remaining Body Tissues


               Size             Length      Dry Weight.     Lipids        Dry Weight        Lipids

                                (CM)           M              (%)            M               M


                         8    9.5ï¿½0.8       15.6ï¿½2.7         14.2          84.4ï¿½2.7          9.6

                         8    9 . 3ï¿½0 . 9   17.0ï¿½1.9         13.3          83.0ï¿½1.9          9.0

                         8    8.5ï¿½1.4       18.5ï¿½3.0         12.7          81.5ï¿½3.0          8.9

               IV        14   6.7ï¿½0.9       22.2ï¿½3.4         14.9          77.8ï¿½3.4          10.2

               V         14   6.1ï¿½0.6       22.5ï¿½2.7         14.5          77.5ï¿½2.7          10.9



















                                                                11 A   I











                           TABLE 2. (cont.)




                           Analyte                                                                              Oyster size                                                               Average


                                                                                                                                           IV                 V



                                                                             A                  A         B        A         B         A        B         A                      A                  B              A%



                           Clorinated Pesticides


                           Gamma-chlordane                                20.0      11.2     21.1      12.1      21.3     12.2      23.1      13.8     23.7      13.2       21.8ï¿½1.52         12.5ï¿½1.01            74

                           Alpha-chlordane                                18.9      11.8     21.4      13.0      21.9     12.9      23.0      14.7     23.4      13.9       21.9ï¿½1.94         13.3ï¿½1.10            65

                           Trans-nonachlor                                17.2      10.0     18.7      10.9      19.2     10.8      20.0      12.1     20.8      11.6       19.2ï¿½1.36         11,1ï¿½0.80            73

                           p-p'DDE                                        42.2      28.5     48.1      28.6      43.5     26.5      50.2      31.7     47.8      28.6       4 6 . 4ï¿½3 . 3 7   28.8ï¿½1.86            61
                           p-p'DDD                                        45.2      25.2     48.0      28.8      49.1     28.3      51.6      31.9     53.8      30.2       4 9 . 5ï¿½3. 31     28.9ï¿½2.49            71





                           52                                             71.3      48.1     82.5      49.7      75.8     46.6      81.9      52.3     79.0      47.6       78.1ï¿½4.64         4 8. 9ï¿½2. 2 3        60

                           101                                               102    75.3        109    77.1        127    76.3         132    78.1        122    78.1         118ï¿½12.5        77.0ï¿½1.20            53

                           105                                            26.6      18.4     32.6      20.7      32.2     20.4      34.1      22.2     33.6      20.9       31 . 8ï¿½3 . 02     20 . 5ï¿½1. 37         55

                           118                                            74.0      54.2     82.6      56.3      82.9     55.6      93.3      57.7     92.2      55.6       85 . 0ï¿½7 . 9 4    55.9ï¿½1.23            52

                           138                                            52.5      38.5     64.6      42.8      67.5     42.8      66.0      42.1     68.0      42.1       63.7ï¿½6.41         41.7ï¿½1.80            53



                           A-  Cross-section Tissues


                           B-  Remaining-body Tissues








                   TABLE 2. Cross-section and remaining-body PAH, pesticide and PCB concentrations, ng g-1, measured

                                 in the five different groups of oysters. Average concentrations for each analyte in the

                                 subsamples and percent differences are also listed.




                   Analyte                                                       Oyster size                                           Average


                                                            I            II           III             IV           V



                                                       A       B      A      B      A      B      A      B      A      B         A            B           A%



                   Uhl

                   2,3,4 Trimethyl Naphthalene        95.2   64.6    106   64.5    98.4  57.2    101   59.6    124   68.2     105ï¿½11.3    62.8ï¿½4.38       67

          A,       I Methyl Phenanthrene               111   86.3    112   91.8    123   80.7    104   63.3    158   93.0     121ï¿½21.5    83.0ï¿½12.1       46

                   Fluoranthene                        615    462    676    446    626    392    686    402    766    474     674ï¿½60.0     435ï¿½36.0       55

                   Pyrene                             1300   1030    1430  1070    1470   970    i440   976    1750  1130     1480ï¿½165    1040ï¿½67.1       42

                   Benz(a)anthracene                   210    132    229    147    204    132    214    131    219    142     215ï¿½9. 4 7   137ï¿½7.26       57

                   Chrysene                            392    281    439    277    426    264    443    273    487    321     437ï¿½34.2     283ï¿½22.1       54

                   Benzo(b+k)fluoranthene              220    170    221    147    232    169    254    172    299    186     245ï¿½33.0     169ï¿½14.0       45

                   Benzo (e) pyrene                    253    201    282    172    267    290    298    204    352    226     290ï¿½38.3     201ï¿½19.2       44

                   Benzo(a)pyrene                     86.4   58.6   84.6   55.8    100   58.3    98.3  59.8    107   62.1    95.3ï¿½9.51    58.9ï¿½2.30       62

                   Perylene                            140   85.5    155   94.8    160   89.6    173   96.0    182    101     162ï¿½16.3    93.4ï¿½5.99       73









                                      FIGU RE CAPTIONS



              Figure 1.

              Percent differences between corrected and remaining-body PAH,

              chlorinated pesticide and PCB concentrations versus oyster size.



              Figure 2.
              Size distributions of oysters sampled in the Gulf of Mexico during the

              N0A.Xs S&T Program between 1986 and 1989.








































                                               4-76







                          25-
                              .A                        0 2,3.4 Trimethyl Naphth.       A  Pyrene
                                                        0 1-Methyl Phenanthrene         0  Chrysene
                                                        E3 Fluoranthene                 #  Benzo(e)vYrene
                          20                            0 Benzo(a)anthracene            +  Benzo(a)pyrene
                                      XO         x      A Benzo(b+k)fluoranthene        x  Perylene
                          15                      0                             x
                                      13,&                                     + a
                          10                    Ao@                                              x
                                                                               A              K+
                                                                                 A
                                                                                               A
                           5


                               y   28.156 - 2.1716x R,"-2  0.920
                           0   .........         .........       ......            ......     ......




                          25-
                              B                                                                0 52
                                                                                               0+ 103L
                                                                                               13 105
                          20-                                                                  N 138
                    Q                                                                          A 118

                          15-


                                                                                              0
                          ILO                                                   A             13
                    Q




                               y   26.031 - 1.9187x RA2   0.888
                           ol  .........                         .........      j ....
                                                                                                                    m



                          25
                              c                                                      0 Gamma-chlordane
                                                                                     * Alpha-chlordane
                          20-                                                        13 Trans-nonachlor
                                                                                     N p-p'DDD
                          15                                                         A p-p'DDE

                          10



                           5-

                              j y  24.776 7 1.4380x RA2   0.862

                              5.5            6.5              7.5               8.5              9.5

                                                           Oyster Size (cm)
                                                                                              0
                                                                                              13







































                                                          4-77
























                40-
                                                                                                1986

                                                                                                1987


          cn                                                                                    19as
                30'
                                                                                            Ea 19S9

          Cd
          U)


                20






                10
          PL4





                 0
                     3-<4     4-<5    5-<6    6-<7    7-<8    8-<9    9-<10 10-<Il   ll-<12 12-<13


                                                   Oyster Size (cm)
























                                                         4-78






















                                       In-.-Lveprint 5


              Environmental Significance of the Uptake and Depuration of
              Planar PCB Congeners by the American Oyster (Crassostrea
                                        virginica)


             Jos6 L. Sericano, Terry L. Wade, Amani M. El-Husseini, and James M. Brooks













                     Environmental Significance of the Uptake and Depuration
                           of Planar PCB congeners by the American Oyster
                                          (Crassostrea v&giniea)



                           Jos6 L. Sericano, Terry L Wade, Amani M. El-Husseini

                                            and James M. Brooks



                              Geochemical and Environmental Research Group

                                College of Geosciences, Texas A&M University

                                     College Station, Texas 77845, U.S.A.





                     Uptake and depuration of three highly to3ic PCB congeners, i.e.

                     PCBs 77, 126 and 169, by the American oysters (Crassostrea
                     virginica) were study under environmental conditions. Compared

                     with other PCB congeners, these compounds can be considerably

                     bioconcentrated, and retained, by bivalves and constitute a potential

                     health hazard for higher consumers. To evaluate the health risks

                     that these PCE congeners pose for human beings, concentrations in

                     oyster samples from two of the largest bays on the northern Gulf of

                     Mexico coast, Galveston and Tampa Bays, sampled as part of the

                     NOAA's National Status and Mrends'TAussel Watch!'Program, are

                     discussed.





                                                    4-80









                       Of -the 209 possible PCB congeners that can be produced by the

                       extensive chlorination of biphenyl, only 20 have non-ortho chlorine

                       substitutions in the biphenyl rings. These congeners can attain

                       planarity which makes their structure similar to the highly toxic

                       dibenzo-p-dioxins and dibenzofurans (McKinney et al., 1976, 1985;

                       Hansen, 1987). Particularly important within this group are the

                       PCBs having four, five or six chlorines in non-ortho positions, for

                       example, congeners 3,3,4,4' tetrachlorobiphenyl (IUPAC No 77),
                       3,3',4,4',5 pentachlorobiphenyl (IUPAC No 126), and 3,3',4,4%5,5'

                       hexachlorobiphenyl (IUPAC No 169) which are very potent mimics of

                       the 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8

                       tetrachlorodibenzofuran (TCDF) both in P-450 induction and toxic

                       effects, e.g. body weight loss, dermal disorders,     liver damage,

                       thymic atrophy, reproductive toxicity and immunotoxicity (Poland &

                       Knutson, 1982; Safe, 1984,1986,1990; Goldstein & Safe, 1989).

                         Although these planar PCB congeners represent a small portion

                       of the total technical PCB  mixtures (Duinker & Hillebrand, 1983;

                       Kannan et al., 1987; Schulz et al., 1989), a worldwide environmental

                       occurrence should be expected and monitoring of these compounds is

                       needed. Until recently, however, quantitation of individual non-ortho

                       substituted PCB congeners was very difficult because of their

                       extr emely low concentrations and routine high-resolution capillary

                       gas chromatography analyses failed to separate some of these planar

                       PCBs from other ortho-PCB congeners. Although, this separation

                       can now be achieved with, more expensive, techniques such as
                       multidimensional gas chromatography (Duinker et al., 1988),

                       simpler and less expensive methods, carbon chromatography for



                                                      4-81








                     example, are available for routine analysis of planar PCBs (Hong &
                     Bush, 1990; Kuehl et al-, 1991; Sericano et al., 1991)

                        This paper, which is part of a more comprehensive study, reports
                     the uptake'and depuration of three highly toxic PCB congeners, i.e.

                     PCBs 77, 126 and 169, by the American oysters (Crassostrea

                     virginica) under environmental conditions using a newly developed

                     carbon chromatographic method (Sericano et al., 1991) and evaluate

                     the health risks that these congeners pose in two of the largest bays

                     on the northern Gulf of Meidco coast, Galveston and Tampa Bays.

                     As part of the NOAA!s National Status and Trends "Mussel Watch"

                     Program, oyster samples from these, and other areas, have been

                     analyzed for selected organic pollutants since 1986. Although PCBs
                     are-6ne of the most commonly found contaminants in Gulf of Mexico

                     oysters (e.g., Sericano et al., 1990a), the occurrence of planar PCB,

                     congeners have not been previously reported.



                     Materials and Methods


                     Uptake and depuration experiments

                         Approximately 250 oysters were collected by dredge at Hanna

                     Reef, a relatively pristine area in Galveston Bay (Fig. 1). Collected

                     oysters were immediately transplanted live in nets to a site near the

                     Houston Ship Channel, an area where oysters have shown high PCB

                     concentrations. , Thereafter, oysters were sampled in groups of 20

                     individuals during the 3rd, 7th, 17th, 30th and 48th days after

                     transplantation, respectively. During the uptake period, native

                     oysters were collected from the Ship Channel area to compare their




                                                     4-82










                        concentrations of these trace organic contaminants with those

                        encountered in transplanted Hanna Reef oysters. The remaining
                        transplanted oysters, i.e. approximately 150 individuals, were re-                     F

                        located to the Hanna Reef area and sampled in groups of 20

                        individuals during the 3rd, 6th, 18th, 30th, and 50th days after

                        transplantation.



                        Extraction and initial sample fractionation

                           The analy@ical procedure used for the extraction, initial

                        fractionation and cleanup of oyster tissue samples for aliphatic and

                        aromatic (PAHs) hydrocarbons, polychlorinated biphenyls (PCBs),

                        including planar congeners, and chlorinated pesticides analyses is

                        based on a method developed by MacLeod et al. (1985) with a few

                        modifications that. proved to be equivalent or superior   to the original

                        technique. This method and its modifications. have been fully'

                        described elsewhere (Sericano et al., 1990a) and is not repeated here.



                        Isolation of planar PCB congeners

                           For the isolation and analysis of planar PCB congeners, 250 ul

                        fractions were withdrawn from the final 1 ml extract reserved for

                        PCB analyses (Sericano et al, 1990a). Before proceeding with the

                        isolation of planar congeners, PCB #81 was added to the extracts as

                        internal standard.

                           The methodology to analyze planar PCBs in tissue samples has

                        being published elsewhere (Sericano et al., 1991). Briefly, glass

                        chromatographic columns (10 mm i.d.) were packed in methyleine

                        chloride. Two grams of the adsorbent, a 1:20 mixture of activated



                                                         4-83









                      AX-21 charcoal (Super-A activated carbon) and LPS-2 silica gel (Low-
                      pressure silica gel, particle size 37-53 @tm, 450 m2  9-1), were packed

                      between two layers of anhydrous sodium sulfate. The adsorbent

                      mixture was carefully checked for interfering compounds by

                      running blanks with the solvent mixtures used to elute the columns

                      and concentrating them to a final volume of approximately 0.1 times

                      the working volume. Oyster tissue extracts were sequentially eluted

                      from the column with 50 ml of 1:4 methylene chloride and

                      cyclohexane, 30 ml of 9:1 methylene chloride and toluene, and 40 ml
                      of toluene. The flow rate through the column was 1.5 to 2.0 ml min-1.

                      The first two solvent mixtures were collected as one fraction M) and

                      contained the bulk of PCB congeners. The second -fraction (M),

                      containing the planar PCB congeners with four, five and six
                      chlorines in meta and para positions, was concentr       aited to a final

                      volume of 0.1 ml, in hexane, for GC-ECD analysis.



                      Instrumental analysis

                         Planar PCB congeners were analyzed by fused-silica capillary
                      column GC-ECD (Ni63) using a Hewlett Packard 5880A GC in

                      splitless mode. Capillary columns, 30 meters long x 0.25 mm, i.d.

                      with 0.25 mm DB-5 film thickness, were temperature-programmed
                      from 100 to 1500C at 100C min-1 and from 150 to 2700C at 60C min-1

                      with I min hold time at the beginning of the program and the

                      program rate change. A hold time of 3 min was used at, the final

                      temperature. Total run time was 30 min. Injector and detector

                      temperatures were set at 275 and 3250C, respectively. Helium Was
                      used as carrier gas at a flow velocity of 30.0 cm sec-1 at 1000C.


                                                       4-84










                       Argon:methane (95:5) was used as make-up gas at a flow rate of 20
                       ml min-1. The volume injected was 2 ul. Planar PCBs were

                       quantitated against a set of authentic standards which were injected                    r
                       at four different known concentrations, i.e., 1, 5, 20 and 50 pg ul-1, to
                       calibrate the instrument and to compensate for a non-linear response                    r

                       of the electron capture detector. PCB congeners 103 and 198 were

                       used as the GC internal standard to estimate the recovery of the

                       internal standard. The detection limits for individual planar PCB

                       congeners, calculated on the basis of 2 grams (dry weight) sample

                       size with 2% by volume of the extract injected into the G-C-ECD, was
                       50 pg g-1 dry weight.



                       Results and Discussion


                       Uptake and depuration of planar PCB congeners by             transplanted
                       oysters

                           The  concentrations of the three highly toxic planar congeners,

                       i.e., 3,3',4,4' (77), 3,3',4,4',5 (126) and 3,3',4,4',5,5' (169), in

                       tr-ansplanted and indigenous oysters are summarized in Table 1.

                       P lanar PCBs were found at low concentrations, e.g. part per trillion
                       (pg g-1) to part per billion (ng g-1). Congener 169 was present at

                       concentrations near or below the detection limits.

                           Congeners 77 and 126 have well defined uptake and depuration

                       curves as seen when the concentrations of these congeners versus
                       time are plotted during both stages of this study (Fig.-2). The

                       concentrations of these two planar PCB congeners in transplanted

                       Hanna Reef oysters increased over the seven week exposure peri          od.




                                                         4-85









                      PCB congener 77 reached a concentration similar to that encountered

                      in indigenous Ship Channel oysters within 30 days. The uptake of

                      congener 126 was slower and only approximated the concentration of

                      Ship Channel oysters by the end of the exposure period. Contrasting

                      with congeners 77 and 126, and because the extremely low

                      concentration, it was not possible to observe a clear trend for

                      congener 169.
                         The decreasing concentrations of accumulated planar PCBs with

                      the increasing number of chlorines substituted in the biphenyl rings

                      observed during this study in transplanted oysters were also reported

                      to occur in transplanted green-lipped mussels (Perna viridis) during

                      a 32 day exposure experiment-in Hong Kong waters (Kannan et al.,

                      1989). Kannan et al. (1987) reported the concentrations of these

                      planar congener in different commercial PCB mixtures. In general,

                      congener 77 is 1 to 2 and 3 to 5 orders of magnitude higher than

                      congeners 126 and 169, respectively. Comparing this relative

                      concentrations with those observed in transplanted oyster samples, it

                      appears that the high molecular weight congeners in oyster tissues

                      are enriched with respect to congener 77. The same observatio   n was
                      made by Kannan et al. (1989). This is not surprising since the Kow

                      (octanol-to-water partition coefficient) increases with the IUPAC
                      number of the PCB congener, e-g. 6.36, 6.89 and 7.42 for congeners 77,

                      126 and 169, respectively (Hawker & Connell, 1988).

                         When transplanted to the Hanna Reef area, exposed oysters

                      slowly depurated the concentrated planar congeners. These PCBs
                      were still present at relatively high concentrations by the end of the

                      50-days depuration period. Kannan et al. (1989) also observed that the



                                                      4-86









                         concentrations of these planar PCB congeners in transplanted green-
                         lipped mussels (Perna viridis), at the end of the exposure period (32
                         days), were substantially higher than those found in native

                         individuals.

                            Kinetics   parameters describing the uptake and depuration of

                         planar PCB     congeners by the oyster Crassostrea virginica can be

                         calculated according to the first-order equation:


                                                 dCt/dt = ku CW - kd Ct


                         where Ct is the concentration of the analyte in the tissue at time = t

                         and Cw is the concentration in water. If the concentration in the

                         depuration site is regarded as zero, i.e., Cw = 0, equation (1) can be

                         reduced to:


                                                     dCt/dt     kd Ct                           (2)


                            From this equation, the relationships to calculate Kd., biological

                         half-life and time to reach a concentration equal to 90% the

                         equilibrium concentration, i.e. concentration at time           infinity, can

                         be deduced. Respectively, these equations are:


                                               Log Ct = log GD - kd t / 2.303                   (3)


                                                     tj/2 = 0.693 / kd                          (4)


                                                     t90% = 2.303 / kd                          (5)


                         where Co is the initial concentration, i.e. time       zero, during

                         depuration.



                                                             4-87









                         Pepuration rate of congener 77 was higher than the rate observed

                      for congener 126. The estimated depuration constants for congeners
                      77 and 126  were 0.0079 and 0.0064 days-1, respectively. These values

                      were lower than the range of values observed for other PCB

                      congeners within the same homolog group (Sericano, unpublished

                      data). This would indicate longer biological half-lives for congeners

                      77 and 126 (88 and 107 days, respectively) and longer time to reach a

                      concentration within 10% the concentration at equilibrium (291 and

                      360 days, respectively-, Fig. 3).

                         The estimated biological half-lives for these toxic planar PCB

                      congeners during this study were significantly higher than those

                      reported by Kannan et al. (1989) for mussels (9 and 13 days,

                      respectively). However, it must be noted that all         the reported

                      biological half-lives for different PCB, congeners corresponding to that

                      transplantation study (i.e. Tanabe et al., 1987; Kannan et al., 1989)

                      were significantly lower than the estimated half-lives during this

                      study and previous reports involving different organisms (Table 2).

                      Despite this disagreement, both studies indicate that, compared to

                      other ortho-substituted congeners within the corresponding homolog

                      groups, planar PCBs take longer to equilibrate into and out of the

                      lipid pools of these organisms.



                      NOAA's National Status and Trends "Mussel Watch" Program

                         Details regarding site locations and oyster collection during this

                      program are given elsewhere (Sericano et al., 1990a, 1990b). The

                      concentrations of PCB congeners 77, 126 and 169, as well as the

                      concentrations of selected predominant mono- and di-ortho



                                                       4-88









                       substituted congeners and total PCBs in oyster samples from sites in

                       Galveston and Tampa Bays (Fig. 4) are summarized in Table 3.

                          In Galveston Bay, the highest concentration of these planar PCBs

                       was found   in samples collected near the area where the Houston

                       Ship Channel enters the upper Galveston Bay (GBSC) and decreases

                       seaward. The second highest total concentration was encountered in

                       samples from a site near the city of Galveston (GBOB). The general

                       distribution of planar congener concentrations in Galveston Bay.

                       clearly indicates high values near population centers. The same

                       correlation between urban, centers and concentrations of planar

                       PCBs can be observed in Tampa Bay. The highest concentrations

                       were measured in samples collected near Tampa (TBKA).

                          As expected from the small contributions of           these planar-

                       congeners to the total commercial PCB mixtures (Kannan et al.,

                       1987), these congeners were detected at much lower concentrations

                       than other mono- and di-ortho substituted PCB congeners. However,

                       as discussed previously, it appears that congeners 126 and 169 are

                       enriched with respect to congener 77. On average, the sum of these

                       three highly toxic congeners ranged from. 0.26 to 0.62% and from 0.31

                       to 1.40% of the total PCB load in Galveston and Tampa Bays,

                       respectively.

                          In a recent review, Safe (1990) discussed the environmental and

                       mechanistic considerations behind the development of the Toxic

                       Equivalent Factor (TEF) concept. He proposed provisional TEF values
                       of 0.01, 0.1 and 0.05 for planar congeners 77J26 and 169, respectively.

                       Calculated TEF in oysters tissues collected from Galveston and
                       Tampa Bay, as well as their averages, are listed in Table, 4. In



                                                       4-89









                      Tampa Bay, the total TEF values ranged from 14 to 52 whereas in

                      Ga Iveston Bay the TEP values were between 13 and 280. The data

                      show that, except for the sample collected near the Houston Ship

                      Channel, oysters from Tampa and Galveston Bays are similar in

                      terms of total toxicity. Oysters collected near the Houston Ship

                      Channel (GBSC), in Galveston Bay, were clearly the most toxic. This

                      area is closed to commercial or sport oystering.

                         In conclusion, two of the most toxic planar PCB congeners, i.e.

                      congeners 77 and 126, were bioconcentrated by transplanted oysters

                      during a seven-week exposure period. Congener 77 attained an

                      equilibrium concentration in a shorter period of time than congener

                      126. When contaminated oysters were back transplanted to the

                      Hanna Reef area, they significantly depurated both planar PCB

                      congeners; however, the estimated depuration half-lives were

                      significantly longer than those corresponding to different PCBs

                      within the same homolog groups. Because of their potential toxicity,

                      this persistency of highly toxic planar congeners is of significant

                      importance in environmental studies. These congeners can be

                      considerably bioconcentrated, and retained, by bivalves and constitute

                      a potential health hazard for higher consumers, including human

                      beings.





                      This research was supported by the National Oceanic and

                      Atmospheric Administration (NOAA), contract No 50-DGNC-5-00262,

                      through the Texas A&M Research Foundation, Texas A&M

                      University.



                                                      4-90










                       Duinker, J.C. & Hillebrand, M.T-J. (1983). Characterization of PCB

                          components in Clophen formulations by capillary GC-MS and GC-

                          ECD techniques. Environ. Sci Technol. 17, 449-456.

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                       Kannan, N., Tanabe, S., Tatsukawa, R. & Phillips, D.J.H. (1989).

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                         Standard analytical procedures of the NOAA National Analytical

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                         Tech. Memo. NMFS F/NWC-92.
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                      Pruell, R.J-, Lake, J.L., Davis, W-R. & Quinn, J. G. (1986). Uptake

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                         action. CRC Crit. Rev. Toxicol. 13, 319-393.

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                        and its derivatives to Gulf of Mexico oysters. Environ. ScL

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                        planar polychlorinated biphenyls by carbon column

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                                                    4-94












                                       TABLE I
            Planar PCB concentrations in oysters (Crassostrea virginica) during the
                       uptake and depuration. phases in Galveston Bay


            Sample    Sampling     Concentration of Planar PCBs Total PCBs
                                    77        126      169
                                   pg 9-1    Pg g- I  pg g- I     ng g-I

            HRSCM         3         330       110        ND        220
            HRSC          7         560       140        ND        380
            HRSC         17         630       140        ND        500
            HRSC         30         920       160        ND        650
            HRSC         48        1000       220        77        830


            HRHR(2)       3         900       170        106       850
            HRHR          6         800       250        ND        670
            HRHR         19         750       210        76        470
            HRHR         30         740       190        N D       400
            HRHR         50         630       150        N D       380


            SC(3)         3        1070       370        340       1500
            SC           17        1040       250        120       1200
            SC           30        1000       230        320       960
            SC           48         980       220        96        1100


            (1) Hanna Reef-to-Ship Channel oysters
            (2) Hanna Reef-back-to-Hanna Reef transplanted oysters
            (3) Ship Channel oysters
            ND = not detected















                                            4-95











                                                    TABLE 2
                       Biological half-lives of selected PCBs in different organisms

                 Congener                   Oystersa      Musselsb       Musselsc Wormsd



                 Planar PCBs


                 3,3', 4,4' (77)               88              9
                 3,3',4,4',5 (126)             107             13
                 3,3',4,4',5,51 (169)           -             26               -


                 Selected non-planar PCBs


                 2,4,4' (2@8)                  17              7            16
                 2,2', 5,5' (52)               55              6            28              -
                 2,2',4,5,5' (101) -           76              7            37             50
                 2.2'.3,3'.4,4' (128)          51              9            46             92
                 2,2',4,4',5,51 R53)           27              6                           36


                 a This study; b Tanabe et aL (1987) and Kannan et al. (1989); c Pruell
                 et aL (1986); d Oliver (1987)























                                                            4-96












                                      TABLE 3
              Planar- PCB concentrations in oysters (Crassostrea virginica) from
                              Galveston and Tampa Bays


            Sample                Concentration of Planar PCBs Total PCBs
                                   77        126     169
                                  Pg g-    p9 9-1    Pg g-I     ng g-1


            Galveston Bay


            GBSC                  2000      2200       790       1100
            GBYC                   330       210       190       210
            GBID                   140       120       54        110
            GBHR                    89       110       89         50
            GBCR                   100        94       51         77
            GBOB                   500       400       93        160


            Tampa Bay


            TBOT                   170       320       280        55
            TBKA                  1500       330       84        580
            TBPB                     85      100       51         75

            TBNP                   260       140       150       120

            TBCB                   200       290       100        49
            TBMK                    ND        ND       ND         38


            ND   not detected


















                                          4-97











                                    TABLE 4
            Toxic Equivalent Factors (TEF) in Crassostrea virginica Oysters from
                             Galveston and Tampa Bays.


           Sample               Twic Equivalent Factors   Total TEF
                                 77       126     169


           Galveston Bay


           GBSC                   20       220     40         280
           GBYC                   3.3      21      9.5        34
           GBTD                   1.4      12      2.7        16
           GBHR                   0.9      11      4.5        16
           GBCR                   1.0      9.4     2.6        13
           GBOB                   5.0      40      4.7        50


           Tampa Bay


           TBOT                   1.7      32        14       48
           TBKA                   15       33      4.2        52

           TBPB                   0.9      10      2.6        14
           TBNP                   2.6      14      7.5        24
           TBCB                     2      29      5.o        36

           TBMK                    -        -

























                                         4-98











                                                       F4--ure caT)tions



                         Fig. I        Galveston Bay transplantation sites



                         Fig. 2        Planar PCB concentrations in Hanna Reef oysters

                                       during the uptake and depuration phases of the

                                       transplantation experiments at Galveston Bay. Planar

                                       concentrations in Ship Channel oysters during the

                                       uptake phase are also indicated



                         Fig. 3        Depnmtion constants (kd) and biological half-lives (BHL)

                                       of planar PCB congeners compared to the ranges of

                                       values calculated for non-planar PCBs (Sericano,

                                       unpublished data).



                         Fig. 4        Location of Galveston and Tampa Bays sampling sites

                                       (NOANs National Status and Trends Mussel Watch

                                       Program)






















                                                            4-99



















                                                                                              0,


                                                                                   T E X A     S





                              Y.
                                                             A


                       LA PORTE






                                              Z-




                                                   0
                                                                     EAST

                                    SAN LEO








                                      TEXA.!@CITY






                                                             GALVESTON







                                                             Si-te 1: Hanna Reef

                                                             S-ite 2: Ship Channel














                                                           4-100














                                  3.3'4.4'TETRACHLOROBEPHENYL (rLYPAC No 77)
                            10000-
                                                                                Hanna Reef Oysters
                                                                                Ship Channel Oysters




                             1000-.0
                       0







                       0

                             100  ......... ..... ...
                                  0    10    .20    30    40     50     60     70    so     90    100
                                                             Time (days)

                                  3.T.4..V.5 PENTACHLOROBIPHENYL MWAC No 126)
                             10007
                                                                           0    Hanna Reef Oysters
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                                                       4-101











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                                                   4-102










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                                        5.0 Trace Metals Results


                 5.1   Laborato1y Intercalibration Results

                       As was discussed in the Laboratory Procedures section, standard
                 reference materials. U.S.G.S. standard rocks and other materials of
                 known trace metal concentrations were analyzed with almost every
                 batch of samples. In the case of INA& these materials were used to
                 quantify the amount of trace element in the sample, whereas in the
                 AAS analysis. working curves made from commercial standards were
                 used for quantification and the reference materials were used to verify
                 results and identify recovery problems.

                       In addition to the reference materials we had obtained from
                 NIST, USGS and other sources, we received interealibration materials
                 from the National Research Council of Canada (Dr. Shier Berman) again
                 this year as we have each year since the NS&T program began.


                 5.2. Trace Metal Concentrations in Year 6 Oysters

                       In an attempt to bring out geographic and temporal trends,
                 trace metal concentrations in oysters (the average of the three stations
                 for each site), were plotted as a function of site location from Lower
                 Laguna Madre, Texas, through the Everglades, Florida, in the annual
                 reports for the first five years of this project. Each plot showed the
                 geographic distribution of one of the trace metals determined. The
                 plots of averaged data for -the first five years are shown updated here
                 by addition of the Year 6 data (Figures 5.1 to 5.13). Some observations
                 based on these plots are given below, with emphasis on higher than
                 average values for a given element that persist for more than one year
                 and values that changed significantly in year 6 when compared to
                 average values for the first 5 years. The plots will continue to be
                 updated annually as the project proceeds, and both geographic and
                 temporal trends will be sought,

                       Silver concentration in oysters was very high at Copano Bay,
                 Texas, and at the nearby San Antonio and Matagorda bays during Year
                 I of the project. During Year 2, the Copano Bay site, which at 7ppm
                 was highest in Ag not only for the Gulf but for the entire U.S. in Year 1,
                 was about 50% lower in Ag. Four other Gulf sites had higher Ag
                 concentrations than it did. It was, however, still enriched relative to
                 most other sites along the Gulf Coast and remained enriched in Year 3
                 with a concentration very similar to the Year 2 value. Year 4 saw a
                 further decrease at this site to a near average Ag value. However, in
                 Year 5, two of the three stations at this site gave oysters which were
                 very enriched in Ag, even more so than in Year I of the project.. In
                 year 6 Ag was again down at this site.

                                                    5-1









                          The East Matagorda site was similar in Ag concentration in Years
                    I and 2 and was greatly enriched compared to most other sites. It
                    decreased to average values in Years 3 and 4 but was again enriched in
                    Year 5. The other three sites from Matagorda Bay were not enriched
                    in Ag in Years I and 2, but one site showed enrichment in Year 3. In
                    general during Years 4 and 5, slight enrichments were seen
                    throughout this part of Texas, but in year 6 Ag decreased to average
                    values at all but one of these sites. East Matagorda oysters increased in
                    year 6.

                          The south central Texas (Matagorda) areas where Ag is so
                    variable are generally areas of low population density and relatively
                    little commercial activity. There are, however, several large isolated
                    petrochemical plants in the area as well as a large aluminum refining
                    plant (ALCOA). It seems unlikely that human activity is involved in Ag
                    variability in this area, but it's not impossible.

                          The Galveston Bay area is much more industrialized than is the
                    Matagorda Bay area, but it produced oysters lower in Ag for the first 4
                    years. In Year 5, for some unknown reason, all stations at one site
                    (GBCR) in Galveston were highly enriched in Ag and this same site was
                    again greatly enriched in year 6. It seems that Ag input to this area of
                    Texas varies from year to year, but we can not explain why or why the
                    enrichments are so geographically localized.

                          Sabine Lake, Texas, just east of Galveston, was average in Ag in
                    Year 1, very high in Year 2, and moderately high in Years 5 and 6.
                    This area is heavily industrialized and was enriched in several metals
                    (Ag, Cd, Cu) in Year 2 compared to Year 1, but slightly depleted in
                    others (Cr, Fe, Zn). These large changes in Sabine Lake oysters might
                    be due to inputs of specific pollutants at specific times. (Cu, for
                    example, changed from a less than average value in. Year 1 to a value
                    more than three times greater than average in Year 2 to an average
                    value in Year 3 and 4, whereas Zn was very much above average in Year
                    1, decreased in Year 2, and decreased further in Years 3, 4, 5 and 6.)
                    However, we have no data on pollutants inputs that would confirm this
                    hypothesis.

                          In Louisiana, a high Ag value of about twice the Gulf average was
                    found at Vermilion Bay in central Louisiana in both Years I and 2.
                    There was a slight decrease at this site in Year 3 but in Year 4 it had
                    the highest Ag in the Gulf and it remained high in Years 5 and 6. As
                    with the Texas situation, a variable input of Ag from some unknown
                    source is suggested. Further east, the Ag concentration dropped
                    drastically (Figure 5. 1) through the next five sites and reached a
                    distinct minimum at Barataria Bay, just west of the Mississippi River
                    delta in Years 1 and 2. The pattern was similar in Years 3, 4, 5 and 6,
                    but the minimum at Barataria Bay was not as distinct because the

                                                        5-2








                  nearby Terrebonne Bay samples were also very low in Ag. Moving
                  eastward from Barataria Bay, scattered high values were found east of
                  the Southwest Pass of the Mississippi River delta, especially at the
                  Pass A Loutre site on the Mississippi River Delta, during Year 5, but
                  this site was not sampled for Year 6. Far-ther cast, site MBHI first
                  sampled in Year 3 almost doubled in Ag in Year 6 to become one of the
                  highest sites in the Gulf. Nearby site MBDR was high last year but was
                  not sampled this year.

                       Both high and low Ag values are found in Florida. Like the
                  Louisiana sites, the Florida sites were generally, but not always, very
                  similar for all 6 years, whether they were high, low, or average in
                  silver concentration. For example, Choctawhatchee Bay was much
                  above average all 6 years and Tampa Bay Mullet Key was much below
                  average. The CBSP site in Choctawhatchee Bay gave oysters averaging
                  6.4ppm in year 6, the highest in the Gulf. Oysters from this site were
                  also enriched in Pb and Se.

                       Barataria Bay, and the surrounding bays with low concentrations
                  of Ag in oysters, have probably been as physically disturbed by man as
                  any bays on the Gulf Coast based on the information we have at this
                  time. These are areas of extensive petroleum development and
                  widespread dredging and channel cutting. Almost every square foot
                  has been disturbed by man. Furthermore, these bays are directly
                  downstream of the Mississippi River outflow, which is usually
                  considered to be a major source of pollutants to the Gulf of Mexico.
                  Why, then, is Ag so low and does only Ag show this apparently
                  anomalous behavior? The second part of the question is easy. Several
                  other metals show distribution patterns almost identical to that of Ag
                  (e.g. Cd and Cu-, Figures 5.3 and 5.5); other metals (e.g. Fe, Cr, Se, and
                  Hg) show similar but not identical patterns. Something.about the
                  muddy, frequently stirred Louisiana bays may be keeping the
                  concentration of some trace metals in oysters low. Perhaps the large
                  amount of fine-grained clay from the Mississippi River effectively
                  competes with the oysters by adsorbing dissolved metals. The clay
                  itself would not become greatly enriched in trace metals due to
                  dilution by its large mass (- 3 x 1014g of sediment are transported by
                  the Mississippi River each year) and would not be a clear indicator of
                  pollution.

                       The idea that the amount and/or kind of suspended material in
                  the water might control the amounts of trace metals in oysters by
                  controlling the concentration of dissolved trace metal is one of several
                  possible explanations for the patterns seen. It is also possible that
                  local anthropogenic inputs influence trace metal concentration
                  patterns, even though such inputs have not yet been identified. As
                  noted above, it is interesting that oysters from Sabine Lake, Texas,
                  were greatly enriched in Cu in Year 2 compared to Year 1, and also in
                  Ag and Cd, but not in Fe, Hg, Pb or other metals. The extreme

                                                     5-3








                  enrichment in Ag of oysters taken at Confederate Reef in Galveston Bay
                  during Years 6 should also be noted, as well as the big increase in Cu at
                  a Lake Borgne site (LBMP) in Year 5 and the big increases in Cu. Pb
                  and Zn at Knight's Airport in Tampa Bay in Year 6. This shows that
                  oysters can change drastically in trace metal content in a one year
                  period under certain circumstances, even though the general pattern
                  in the Gulf of Mexico is to have similar concentrations of a given metal
                  at a site year after year. The implication is that the oysters do respond
                  to added pollutants.

                        Other anthropogenic-looking trace metal values include high Hg
                  in Lavaca Bay, Texas, and at some Florida sites, especially Old Tampa
                  Bay, very high Pb, increasing in concentration each year at one of the
                  two Choctawhatchee Bay sites: a two fold increase in Pb at the Houston
                  ship channel site in Year 5, very high Zn at the old Tampa Bay site;
                  and higher than average Ag, Cd and Cu at the Vermilion Bay site.
                  These abnormally high values may well be a result of anthropogenic
                  inputs of metals. It is also possible that some of the tissue metal
                  concentration variability is determined by the oysters themselves
                  through "natural" processes. As mentioned earlier, such parameters as
                  size and sexual stage of the oysters are being examined in this study
                  because trace metal levels in oysters are reported to vary with these               01
                  and other physiological parameters. In other work we have sampled
                  oysters in Mobile Bay four times over a year period and Galveston Bay
                  oysters in June and September (vs NS&T sampling in December). In
                  repeated sampling from the same reefs, we have found concentrations
                  of some metals as much as a factor of two lower in September than in
                  March-June. Thus, physiology may play a role in some metal variation.

                        We have not yet completed attempts to correlate oyster metal
                  data with the other information we have about the oysters, but this is
                  being done and preliminary work shows no simple relationships
                  applicable to the whole data set. One observation made in our earlier
                  reports is that the oysters around Barataria Bay, which were much
                  lower than average in trace metal content, were among the last oysters
                  collected in Year I of the project, and apparently were among the few
                  that had either just spawned, or were about to spawn, although
                  spawning state is not easy to determine for Gulf oysters. This
                  relationship obviously cannot explain all variability in the data,
                  however. Otherwise, all metals would correlate perfectly with each
                  other, which they do not. In fact, in some cases some metals are in
                  high concentration precisely where others are low. Likewise, the
                  sampling that occurred after Year I in Louisiana apparently did not
                  collect oysters at the same spawning state as the first year sampling,
                  yet trace metal levels were similar to those found in Year 1.

                        The Louisiana oysters for most years have been larger than
                  average, and trace metal content of all Gulf of Mexico oysters showed a
                  weak negative correlation with size, although there were exceptions to

                                                     5-4







                 this tendency- We have not seen any correlation between metals in
                 oysters and salinity, water depth, or such variables. In short, there is
                 no strong indication that physiological parameters have obscured
                 metal concentration variations which are due to environmental factors
                 such as variable input of pollutant metals. The strategy of sampling
                 during, the winter each year does seem to reduce "natural" variability
                 in oyster metals.

                       Some of the high metal levels in oysters from the clear waters of
                 western Florida are surprising. Arsenic especially is much higher in
                 some of the Florida oysters than it is elsewhere on the Gulf Coast, yet
                 some Florida oysters, for example those from most sites in Tampa Bay.
                 were very low in As all 6 years. Only the Tampa Bay site at Navarez
                 Park near the city of St. Petersburg was significantly enriched in As. It
                 was first sampled in Year 4, at which time it had the highest As
                 concentration in the Gulf. In Year 5 the As level was even higher and
                 in Year 6 the concentration more than doubled from the high Year 5
                 value. Arsenic at this site is now four times higher than that at any
                 other site. The new site at Knight Airport on the edge of the city of
                 Tampa was low in As in Years 4. 5. and 6. It is possible that the
                 extensive phosphate rock deposits in Florida are a source of arsenic,
                 but based on the limited data we have, there is no correlation between
                 phosphate rock occurrence, shipping, or mining, and As
                 concentration in oysters. For example, a phosphate plant is reportedly
                 adjacent to the TBHB site, yet oysters from it were low in As.

                       The As distribution in Florida does seem to call for some kind of
                 local environmental control, as do certain other metal distributions.
                 There seems to be no other explanation for high and low values of
                 trace metals to occur at adjacent sites, often in a given bay, and to have
                 these values repeat year after year. This suggestion is further
                 strengthened by the Year 5 and 6 results which show the As level at
                 CBBI, NBNB and RBHC dramatically lowered than was found through
                 the first four years. Some unknown environmental change, perhaps
                 rainfall and runoff or a change in pest control practices, must be
                 responsible for the As decrease.

                       The local patterns discussed above are imposed on regional
                 trends, for example, Hg is enriched in Florida sites where twelve of
                 the 25 sites are well above average. The oysters from Old Tampa Bay
                 are especially high in Hg, rivaling even those from Lavaca Bay, Texas,
                 which are known to be contaminated with Hg and to be a human
                 health threat. Se, Cd, and Ag, on the other hand, are generally lower
                 in Florida oysters than those collected elsewhere. Other metals show
                 no obvious regional trends, but subtle trends may exist.

                       Zn shows especially great variability from place to place, not only
                 in Florida but throughout the Gulf Coast, and can even vary widely
                 within a given bay. For example, Old Tampa Bay oysters averaged -8300

                                                     5-5








                  ppm Zn in Year 3 and 6700 ppm Zn in Years 4, 5, and 6, whereas
                  oysters from Mullet Key in Tampa Bay averaged only 240 ppm in Year
                  3 and only about 325 ppm in Years 4, 5, and 6. Apalachicola Bay
                  oysters were even lower in Zn than those from Mullet Key during the
                  six years of the project. Should the APD13 low Zn values be considered
                  background for all Florida oysters, or does the natural background
                  concentration vary by more than the observed factor of 20 from site to
                  site? It seems very unlikely that the background would vary so
                  drastically within a given bay. Human activity must somehow be
                  involved in these drastic differences in Zn content. This suggestion is
                  supported by the observation that Zn concentrations in oysters does
                  seem in a qualitative way to correlate with proximity to population and
                  industry.

                        St. Andrews Bay in north Florida provided oysters greatly
                  enriched in Zn and Cu in Yeax I but somewhat less enriched in later
                  years. These same oysters were depleted in Cd by almost a factor of
                  four during all six years and had less than average concentrations of
                  several other metals. This may be a case in which large amounts of
                  one or two metals inhibit the uptake of other metals, but again the
                  situation is ambiguous because high Cu- and Zn in Sabine Lake and
                  Vermillion Bay oysters are accompanied by high Ag, Cd, etc. It is
                  likely that the form (species) of metal in the environment is as
                  important as the amount where uptake by oysters is concerned.


                  5.3 Summ= and Conclusions from Six Years of Trace Metals in
                        Qysters Data

                        The trace metal concentrations found in the Gulf of Mexico,
                  oysters were generally less than or equal to literature values from
                  other parts of the world that are thought to be uncontaminated by
                  anthropogenic activity. A few sites, however, did show apparent trace
                  metal pollution, and other sites gave anomalous values that cannot be
                  readily explained by either known anthropogenic or niatural causes.

                        The range of values for the overall data set (maximum/minimum)
                  varied from 15-fold for Mn to more than 600-fold for Pb, whereas the
                  coefficient of variation (standard deviation/mean) was generally in the
                  50-60% range for most metals. Variations were much greater
                  between stations than between years at a given station. Enrichments
                  usually occurred in suites of 3-4 elements with Ag. Cd, Cu and Zn
                  being the most common suite: thus, several strong inter-element
                  correlations were found.     There was, however, little correlation
                  between metal levels in oysters and in sediments from the collection
                  sites even when sediment data were ratioed to Al. There was likewise
                  little correlation between oyster metal levels and size, sex, or
                  reproductive stage of the oysters.


                                                    5-6







                       Geographically, appreciably elevated (>3 x average) metal levels
                 were generally restricted to single sites within bays or estuaries which
                 implies local control (Reprint 8). On the other hand, Ag, Cd and Se
                 levels were somewhat higher in Texas oysters than in those from
                 Florida, whereas the reverse was true for As and Hg. Concentrations
                 were lower than average for several metals in oysters from central
                 Louisiana, especially Ag, Cd, and Cu. Thus, the Mississippi River
                 outflow and extensive offshore oil development do not seem to enrich
                 oysters in trace metals.






































                                                    5-7

























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    I
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    I                                             Reprint 8
    I                          Trace Metals in Galveston Bay Oysters
    I                             I B.J. Presley, R.J. Taylor, and P.N. Boothe
    I
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    I
    I
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                                      Trac e Metals in Galveston Bay Oysters

                                      B. J. Presley, R. J. Taylor and P. N. Boothe
                                  Oceanography Department, Texas A&M University



                   Oysters and other bivalves have been used as "sentinel" organisms for assessing
                   the pollution status of marinewater bodies for almost twenty years. For example,
                   Goldberg, et al., (1983) report data for a U.S. EPA funded "Mussel Watch"
                   program conducted in 1976-78 and the current NOAA funded "National Status
                   and Trends Program" (NS&T) is an outgrowth and extension of the "Mussel
                   Watch" concept. Bivalves are widely recognized as being responsive to changes in
                   pollutant levels in the environment, good accumulators of pollutants, widely
                   distributed along coasts, and easy to collect and analyze. They integrate pollutant
                   levels in the environment over weeks to months and therefore allow areas to be
                   compared even when sampling is done only once or twice per year.

                   Oysters (Crassostrea virginica) were collected at six different sites in Galveston
                   Bay during 1986-1989 as part of NS&T (see Fig. 1, page 69). Each site was on an
                   identifiable oyster reef and at each, twenty oysters were taken from each of three
                   stations, the stations being 100 to 500 m apart. Each site was sampled once each
                   year, except two of the sites (stations 58, 59) were not sampled the first two years.
                   The twenty oysters from each station were combined and analyzed as a single
                   sample each year. In most cases stations were located hundreds of meters to
                   many kilometers away from any obvious point sources of pollutant inputs in an
                   attempt to characterize large areas of Galveston Bay, rather than to identify
                   specific point sources of pollutant input.

                   Frozen oysters were returned to the lab where they were opened under clean room
                   conditions. The oyster tissue was put into teflon jars which were loaded into an
                   industrial paint shaker and shaken vigorously for 15-20 minutes to completely
                   homogenize the samples. An aliquot of the combined and homogenized sample
                   was freeze-dried, re-homogenized by ball milling in plastic, and weighed into a
                   digestion vessel. Digestion of the approximately 200 mg dry weight samples of
                   oyster tissue used three ml of a four to one mixture of ultra-pure nitric and
                   perchloric acids.

                   Two blanks and two reference materials were digeste       d with every set of 20-40
                   samples. Repeated analysis of these reference materials a Cd participation in
                   several intercalibration exercises give an estimate of ten perce@t or better for both
                   the precision and accuracy of the data reported here.

                   All data reported here were obtained by atomic absorption spectrophotometry
                   (AAS). The samples were analyzed for Ag, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb,
                   Se, Si, Sn, and Zn. Flame AAS was used for Cu, Fe, and Zn which exhibit high
                   concentrations in oysters, cold vapor AAS for mercury, andgraphite furnace
                   AAS for the remaining elements.

                   Trace metal concentrations found in oysters collected along the entire Gulf of



                                                         5-22








                   Mexico coastline during the first four years of NS&T were generally similar to
                   those reported in oysters, taken from non-contaminated water in other parts of the
                   world (Texas A&M Geochemical and Environmental Research Group, 1990).
                   Only a few sites showed obvious trace metal pollution       and these were restricted
                   geographically such that nearby sites were usually unaffected. Abnormally high
                   or low values at a site did, however, usually repeat year after year suggesting
                   local control. Abnormal sites for most metals were just as likely to be visibly
                   pristine as to be highly industrialized.    -

                   The oysters collected in Galv   'eston Bay for NS&T were similar in trace metal
                   content to those collected elsewhere along the Gulf coastline, i.e., there is no
                   indication of generalized trace metal pollution in Galveston Bay (Table 1). The
                   average Ag, Cd, Cr, Fe, Mn and Pb in Galveston Bay oysters differs by 10% or less'
                   from the Gulf-wide average. Copper is 13% higher in Galveston Bay, while Ni is
                   15% higher and Se is 16% higher. A "t-test" of the significance of those
                   differences shows that only the Se averages are significantly different at the 95%
                   confidence leveL Arsenic in Galveston Bay oysters is less than one-half the Gulf-
                   wide average, but the Gulf average is greatly influenced by several sites in
                   southern Florida that produce oysters greatly enriched in As. Oysters from other
                   Texas and Louisiana bays are similar in As content to those in Galveston Bay.
                   Tin seems to be about 20% lower than Gulf averages in Galveston Bay, but all Sn
                   values are near the detection limit of the method used and a 20% difference is not
                   significant. Finally, Zn is 43% higher in Galveston Bay oysters than in Gulf-wide
                   average oysters.


                   Table 1. Average trace metal concentrations in 1200 oysters from Galveston Bay and 14,000
                   oysters from the entire U.S. Gulfcoastline. All elements in ppm, pglg dry wt.

                              AP, As Cd -Cr Cu Fg@ HP, Mn Ni Pb                                  Sn Zn

                   GB avg.    2.35 4.74 4.29 0.53 166 Z79 .0815 16.2 2.01 0.66            3A6 0.26 3220
                   GOM avg. 2.13 9.94 4.06 0.57 148 309 0.135 15.1 1.75 0.68              2.96 0.33 2250
                   GB/GOM 1.10 0.48 1.06 0.93 1.12 0.90 0.60 1.07 1.15 0.97               1.17 0.79 1.43


                   Discussion of metals in Galveston Bay oysters averaged over all sites and all years
                   obviously cannot show possible geographic and temporal trends within the bay.
                   In the case of Zn, for example, three of the six Galveston Bay sites had oysters
                   with near Gulf average Zn, with relatively little year to year variation. The other
                   three sites had much higher Zn. Two of the high Zn sites, Ship Channel and
                   Yacht Club, are in extreme northwestern Galveston Bay near industrial waste
                   water inputs and boat basins where Zn contamination might be expected. The
                   other high Zn site was in Offatfs Bayou on Galveston Island and is surrounded by
                   residential development and private boat moorings. This apparent local control
                   on Zn, and in some cases on other metals, is seen not only in Galveston Bay but
                   also throughout the Gulf of Mexico. Large site to site and time to time changes in
                   trace metal concentration might be due to man, but the exact activity responsible
                   has not been identified.




                                                          5-23







                 Cadmium, Pb, Ag and Hg are often added to the environment by man in amounts
                 rivaling those added by nature but there is no evidence of anthropogenic inputs of
                 these metals in the Galveston Bay oyster data. Rather, except for Zn, trace metal
                 concentrations in oysters from Galveston Bay are similar to those in oysters from
                 pristine areas elsewhere and do not reflect the big differences in proximity to
                 population and industrialization of the different sites in the bay.


                                                 Uterature Cited

                 Texas A&M Geochemical and Environmental Research Group. 1990. NOAA
                    status and trends mussel watch program for the Gulf of Mexico. Technical
                    Report submitted to National Oceanic and Atmospheric Administration,
                    Rockville, MD.

                 Goldberg, E. D., M. Koide, V. Hodge, A. R. Flegal and J. Martin. 1983. U.S.
                    mussel watch: 1977-1978 results on trace metals and radionuclides.
                    Estuarine, Coastal and Shelf Science, 16: 69-93.








































                                                     5-24









                                              6.0 Butyltin Results


                         The analyses of butyltins as part of the National Status and
                   Trends (NS&T) Project for Marine Environmental Quality, Mussel
                   Watch Project was initiated in 1987 by GERG. Butyltin analyses was
                   added to the NS&T project because of the growing concern about the
                   effects of tributyltin from antifouling paints on non-target organisms.
                   This section serves as an overview of several papers that have resulted
                   from the butyltin studies performed by GERG (Table 1. 1).

                         Organotin compounds have a range of toxicity and as such have
                   found a broad spectrum of applications including use as fungicides,
                   bactericides, pesticides, anti-cancer agents, and biochemicals.
                   Tributyltins (TBTs) were a major component of many antifouling
                   paints because they are 10-100 times more effective than copper-
                   containing paints. . It is estimated that 140,000 kg of TBT-containing
                   antifouling paint was used each year prior to 1988 in the United States
                   on commercial and recreational boats and ships to retard fouling. The
                   U.S. Navy estimates that it could save $155 million annually by
                   repainting its fleet,of 550 ships with TBT-containing antifouling paint,
                   but has not begun this process because of the mounting evidence that
                   TBT compounds may have acute and chronic effects on non-target
                   organisms. However, the recreational and smaller commercial fleets
                   are potentially the most deleterious to estuarine resources because
                   these vessels spend most of their time in port and their antifouling
                   paints are formulated to give high static release rates.

                         Studies conducted in the United Kingdom and France have
                   determined that the short-term acute toxicity of TBT in water is at the
                   nanogram per liter level for oysters and other non-target molluscan
                   species. The re8ults of these studies and the finding that TBT water
                   column concentrations appear to be increasing in selected harbors
                   and marinas in the United States have prompted the U.S.
                   Environmental Protection Agency (EPA) to initiate a special review
                   study.

                         After review of the available data, the U.S. EPA concluded that
                   low concentrations (20 ppt) of TBT in the water can cause irreversible
                   chronic effects to a broad spectrum of aquatic organisms. This led to
                   the President signing the Organotin Paint Control Act of 1988
                   (OPACA). The act contained interim and permanent TBT use
                   restrictions as well as research and monitoring requirements. The
                   application of TBT antifoulant was prohibited from vessels under 25
                   meters (82 ft.) and the maximum average daily release rate was set at
                   4 Mg/CM2/day. These requirements of OPACA should reduce the total
                   amount of TBT entering the marine environment to about 10% of its
                   pre-OPACA levels. Furthermore, most of the reduction should come in



                                                       6-1










                  estuarine and fresh water areas where small vessels are used and
                  moored and where the risk from TBT input is greatest.

                        Bivalves (oysters and mussels) have been widely used as sentinel
                  organisms for monitoring the contamination burden of estuarine
                  ecosystem because they filter feed and bioaccumulate contaminants.
                  Oysters have been found to have bioconcentration factors for TBT that
                  range from 2300 to 11,400 times the water concentration, rapidly
                  reaching an equilibrium plateau and slowly depurating. Thus, analysis
                  of TBT concentrations in bivalves from coastal waters should provide
                  information by which to assess the extent of butyltin contamination.

                        In 1987, GERG analyzed bivalves (mussels and oysters) and
                  sediments from 36 coastal sites distributed on the Atlantic, Gulf, and.
                  Pacific Coasts, including one site in Hawaii. These selected S&T sites
                  were chosen as the NS&T sites closest to suspected sources of input
                  (for example-, near marinas, dry docks, etc.). It was anticipated that
                  no butyltins would be detected because the half-life of tributyltin in the
                  water column measured by C14 label techniques was estimated to be 2-
                  14 days. However, all but one of the 36 bivalve samples analyzed
                  contained TBT and its less toxic breakdown products (dibutyltin and
                  monobutyltin). The concentrations of TBTs ranged from <5 top 1560
                  (366 av) ng of Sn/g dry weight as tin and accounted on average for
                  74% of the tin present as butyltins. Replicate oyster samples from a
                  specific site concentrate TBT to the same level. Concentrations of
                  TBT found in oysters varied both spatially and temporally. Both
                  oysters and mussels concentrate TBT from their environment and are
                  therefore excellent sentinel organisms to monitor the environmental
                  levels of TBT available to marine organisms.

                        Butyltin concentrations in sediment samples.     from U.S. coastal
                  areas ranged from <5 to 282 ng Sn/g. - Butyltins were detected in 75%
                  of the sediment samples analyzed. The predominant butyltin was TBT,
                  which is also the most toxic. DBT and MBT were detected in 30% of
                  the sediment samples analyzed: the TBT degradation products were
                  only found when TBT was present, usually at high concentrations.
                  Mean bivalve butyltin concentrations were 18 times higher than mean
                  sediment concentrations. Based on bivalve analyses, bioavailable
                  butyltins were present at all the sites where butyltins were detected in
                  the sediment. The sediments are one possible source of these
                  bioavailable butyltins. However, the lack of correlation between
                  sediments and bivalve butyltin concentration indicates that other
                  sources may be predominant.

                        The purposes of the NS&T project is to determine the current
                  status and the long term trends of contamination in U.S. Coastal areas.
                  With the limitations imposed on the usage of TBT antifouling paint by
                  OPACA, a decrease in the concentration of TBT in the environment
                  would be expected. Studies done at GERG were designed to, examine



                                                     6-2








                 the uptake and depuration rates of TBT compounds in oysters
                 (Crassostrea virginica) through transplantation experiments at two
                 locations in Galveston Bay, Texas.          Oysters from a relatively
                 uncontaminated area (Hanna Reef) were transplanted to a new site
                 known to have indigenous oysters with higher TBT concentrations
                 (Houston Ship Channel). Total butyltin concentrations increased
                 rapidly from 62 to 380 ng Sn/g during the exposure period (48 days)
                 with TBT accounting for most of the increase. After the uptake
                 period, transplanted and indigenous oysters were relocated to the
                 relatively pristine location. During the depuration period (50 days),
                 oysters originally from the clean location depurated at a faster rate
                 than oysters from the chronically exposed population. This is
                 reflected in half-fives for TBT of 15 and 26 days for these oysters,
                 respectively.

                       These experiments indicate that we should see a decrease in
                 environmental levels of TBT in NS&T oyster samples from the Gulf of
                 Mexico. This was indeed found to be the case. The concentration of
                 total butyltins and tributyltin in oysters are decreasing at many Gulf of
                 Mexico sites (Reprint 6 and Preprint 6). The decrease is more than a
                 factor of two for 75% of these sites. The environmental half-life for
                 butyltins for some sites is less than 3 years. At several sites there was
                 no measurable decrease in butyltin concentration, but no site had an
                 increase in concentration between 1987 and 1990. The indications of
                 a decrease in TBT environmental levels appear to be reflected in the
                 1990 data. However, it is only one data point for these sites. The data
                 from the 1991 collection will determine if the trend of decreasing
                 concentrations continues.































                                                    6-3






















                                          Preprint 6


              Butyltin Concentrations on Oysters from the Gulf of Mexico
                                      during 1989-1991


                              Bemardo Garcia-Romero, Terry L. Wade,
                              Gregory G. Salata, and James M. Brooks








                            Butyltin Concentrations in Oysters
                         from the Gulf of Me@deo during 1989-1991

                    Bernardo Garcia-Romero, Terry L. Wade. Gregory G. Salata
                                       & James M. Brooks


                      Department of Oceanography, Texas A&M University,
                        Geochemical and Environmental Research Group,
                                       833 Graham Road @ - -
                               College Station, Texas 77845, USA


                                           ABSTRACT


              Oyster samples from 53 Gu!f of Mexico coastal sites were collected
              and analyzed for butyltins during 1989, 1990, and 1991. The

              geometric mean tributy[tLn concentrations were 85, 30, and 43 ng

              Snlg.for 1989,1990, and 1991, respectively.         The tributyltin
              concentrations are best represented by a log normal disiribution. A

              decline of the butyltin concentrations at sites with relatively low

              butyltin concentrations for 1989 compared to 1990 and 1991 was

              observed, while at relatively high butyltin concentrations (>400 ng

              Sn/g), there was almost no difference between 1989 and 1991 but

              lower concentrations were present in 1990. Continued monitoring

              is needed in order to determine if bubjltin contamination of the

              coastal marine environment is decreasing in response to use

              limitations.




                                        INTRODUCTION

                 The presence of tributyltin and its degradation products in the
           environment continues to be of environmental concern. Tributyltin (TBT)

           anti-fouling paints are a solution to the costly problem of fouling organisms


                                                 6-5









             which attach to the bottom of the hulls of boats and ships (Huggett et at.,
             1992). Although an effective antifouling agent@ tributyltin was found to
             adversely affect non-target organisms (Bushong et aL. 1987; Hall & Pinkney,

             1985: Minchin et al., 1987; Short & Thrower, 1986; Thain, 1986;

             Thompson et at., 1985: Alzieu, 1991). For example, commercially valuable

             species were adversely affected in France (Alzieu, 1991). The presence of

             TBT and its degradation products, dibutyltin (DBT) and monobutyltin (MBT),

             in samples removed from input sources (Wade et al., 1988; 1991b) suggest

             that environmental half-lives in the marine environment may be longer than

             reported values (Lee et al., 1987; Olson & Brinckman, 1986; Seligman et

             al.,1986a,b & 1988a). After the use of TBT-based paints was limited in

             countries such as France, England, and the United States, the concentration
             of organotins in water and oysters was shown to decline     (Shor-t & Sharp,
             1989: Wade et al., 1991b; Alzieu. 1991: Page & Widdows, 1991; VaMirs et

             al., 1991: Waite et al., 1991). In the United States, however     continuous          M

             monitoring is needed in order to provide information on the long term

             response of butyltin concentrations in the marine environment to these

             regulations.

                  OYS ters are excellent sentinels of TBT contamination. Bivalves have

             been used in uptake and depuration studies (Laughlin, et al., 1986: Langston

             & Burt, 1991; Sericano et al., in press; Alzieu et al., 1991; Ritsema et al.,

             1991: Salazar & Salazar, 1991) and to determine temporal and spatial
             variations of butyltin concentrations (Short & Sharp, 1989; Wade et al.,

             1988; Page & Widdows, 1991). These studies indicated that oysters
             integrate bioavailable TBT with equilibration rates on the order of weeks.
             This indicates that continuous and carefully planned sampling should be




                                                   6-6











            carried out. in order to determine trends in the variation of TBT

            concentrations in the environment.

                 Tributyltin and its degradation products have been determined in

            oysters from 53 sites in the Gulf of Mexico from 1989 to 1991. The overall

            butyltin concentrations showed a decline from 1989 to 1990 (Wade et aL,

            199 la,b).   If this decline resulted from the implementation of the

            Iimitations on the use of TBT in the United States by the       Organotin Anti-

            Fouling Paint Control Act of 1988 (OAPCA), a continuous decline would be
            expected. The results are now available for 1991. This report compares
            three years of data for the Gulf of Mexico to determine if there is a trend in

            butyltin concentrations.




                                              METHODS

                 Oyster (Crassostrea virginica) samples were collected       at 73 different

            sites along the Gulf of Mexico coast in the winter of 1989, 1990, and 1991.

            Table I shows the geographic location of the sites sampled and the symbols

            used to identify each site. Although known point sources of TBT such as
            marines of'dr-y docks were avoided, some locations are closer to such TBT

            sources. A complete description of field sampling and logistics has been

            reported (GERG, 1991).

                 The same sampling and analytical procedures were used for all oyster

            samples reported. A detailed description of these procedures has been
            previously reported (Arade et at., 1988; Wade & Garcia-Romero, 1989).

            Briefly, oyster tissues were homogenized, weighed, spiked with a surrogate

            standard, extracted with 0.2% tropolone in methylene chloride, hexylated,

            purified using Si/Al columns, and analyzed by gas chromatography w. ith a tin



                                                     6-7









             selective flame photometric detector. Quality control consisted of duplicate
             samples, procedural blanks, and spike blanks. Quadruplicate analysis of one
             sample yielded the following means and standard deviations 395 ï¿½ 14.5 ng
             Sn/g for TBT: 74.5 ï¿½ 5.80 for DBT: and 32.5 ï¿½ 6.5 for MBT. Method
             detection limit (MDL) on average for TBT and DBT was 5 ng Sn/g and for

             MBT was 10 ng Sn/g.




                                     RESULTS and DISCUSSION


               Annual Variation of Butyltins at Individual sites

                  Oyster butyltin concentrations determined in 1989, 1990, and 1991
             were compared. In order to simplify the presentation of 'data, the sites
             sampled have been divided into three geographical zones: Florida, Louisiana-
             Mississippi-Alabama (LA MS AL), and Texas. Only 730/6 of the sites reported

             were sampled during all three years. In some instances, some sites were

             not sampled because no oysters were available. Butyltin concentrations in
             oysters are reported in ng Sn/g dry weight (Maguire, 1991). Sites with an

             incomplete set of data are indicated with a star in Table I and Figures 1, 2,

             and 3.

                  The concentration of total butyltins. in 1989, 1990, and .1991 ranged
             from below the limit of detection (<5 ng Sn/g) to 1880 (TBKA), 850 (TBKA),

             and 1300 ng Sn/g (BBMB), for 1989, 1990, and 1991, respectively. In

             general the butyltin concentrations decreased from 1989 to 1990 and then

             increased slightly between 1990 and 1991.

                  Tributyltin, the most toxic butyltin, was the predominant butyltin

             found in oysters during the three-year sampling. Percentages of TBT




                                                     6-8







            determined .. were 85ï¿½15% for all years. Near the limit of detection the
            percentage of TBT is more variable- The high percentage of, TBT for C.
            virginica agrees with other reports (Wade et aL, 1988; Uhler et aL, 1989).

            Uhler et aL (1989) reported that bivalves have approximately constant ratios
            of TBT/DBT. The TBT percentages observed are the result of the uptake of

            TBT and DBT from the water column (Lee et aL, 1987; Olson & Brinckman.

            1986; Seligman et aL, 1986a: 1988)-, TBT degradation to DBT by oysters
            (Lee, 1985); and different rates of depuration for TBT, DBT, and MBT (Lee.

            1991). There is no evident relationship between the TBT concentration and
            the percentage of TBT present in the oysters for this study. Therefore. the
            fluctuation of percentage TBT around 85% is probably        the result of a
            dynamic equilibrium between uptake, metabolism, and depuration.

                  The TBT concentrations determined for each site during 1989. 1990,

            and 1991 are shown in Figure 1. Sites are shown in         e
                                                                    . g ographical order
            from Texas to Florida. Tiibutyltin concentrations ranged from <5 ng Sn/g to
            1450 (TBKA), 770 (BBMB), and 1160 ng Sn/g (BBMB) in 1989, 1990, and

            199 1. respectively. TBT concentrations increased monotonically at some

            sites from 1989 to 1991, while at others sites concentrations decreased

            monotonically. For example. oyster TBT concentrations increased from
            1989 to 1991 at CLLC, BBMB and GBTD (Figure 1). Decreasing TBT

            concentrations from 1989 to 1991 were observed for oysters from PBPH,

            SAWB, TBCB, MBLR, and MBEM (Figure 1). Concentrations of TBT were the

            same at TBOT and GBCR during all three years. In general, higher

            concentrations of TBT were determined in Florida sites than in Texas,

            Louisiana, Mississippi, or Alabama sites. TBT was below the detection limit
            at I of 53 sites in 1989 and at 10 and I I sites during 1990 and 1991,




                                                  6-9










             respectively, Although the concentrations were low, butyltins were detected
             in oysters from every site sampled. in at least one sampling year.
                    Dibutyltin concentrations determined in oysters during 1989, 1990,
             and 1991 are shown in Figure 2. Dibutyltin concentrations ranged from <5
             ng Sn/g to 380 (TBKA), 160 (TBKA), and 200 ng Sn/g (TBKA), in 1989,

             .1990, and 1991, respectively. Sites sampled in Florida had the highest DBT

             concentrations. With the exception of five sites (CBJB, TBK& CBFM, BBMB,

             and BRFS), annual variation of DBT concentrations did not mimic the annual

             variation of TBT concentrations. Ship and boating activity have been cited as
             potential factors that may affect DBT fluctuations (Short & Sharp, 1989;

             Uhler et al., 1989). Also, the commercial usage of DBT as a stabilizer for

             plastics including PVC pipes may be another important source of input to
             the marine environment and may result in DBT fluctuations that do not
             mimic TBT fluctuations Went et aL, 1991; Maguire, 1991).           At this point it

             is not possible to estimate the influence of the factors discussed above on

             the DBT concentrations present in the oysters. Monotonic increases or
             decreases of DBT were observed at specific sites during the three year
             period. For example, Middle Bank (BBMB, @ Figure 1 and 2) showed not only
             increasing concentrations of TBT during the three year sampling period but

             also showed a steady increase of DBT in the same period. DBTwas detected
             in 39, 38, and 33 out of the 53 sites sampled each of the three years. In

             many instances DBT was not detected in any of the sampling years.

                    Regional MBT concentrations are shown in Figure 3. Since the MBT

             concentrations are low, annual variations in MBT concentrations for each

             site are large. The precision of MBT determination is also not as good as

             that of TBT and DBT (Wade et al.,1988). Monobutyltin concentrations

             ranged from <5 ng Sn/g to 145 (NBNB), 25 (CCIC), and 42 ng Sn/g (TBKA),



                                                      6-10









            in 1989, 1990, and 1991, respectively. Generally, sites with high TBT

            concentrations had high DABT concentrations- MBT was detected in 21, 4.
            and 19 of the 53. sites during 1989, 1990, and 1991, respectively. During

            all three years, A4BT was only detected at three sites in Florida (CBJB. TBEA,

            and CBFM) and at one site in Texas (CCIC). The fact that MBT was found in

            lower concentrations than DBT, and DBT was found in lower concentrations

            than TBT is consistent with the fact that TBT is the ma or constituent of

            antifouling paints while DBT and MBT are environmental breakdown
            products of TBT. This may indicate that only a limited degradation of TBT

            has occurred or that the more water soluble DBT and MBT are assimilated

            by the oysters at a slower rate than TBT.



                 Annual Variation of Butyltins in the Gulf of Mexico
                 A graphic representation of the TBT data for the 53 "sites sampled in
            1989, 1990, and 1991 is shown in Figure 4. The graph is a plot of 1989
            concentrations vs 1990 and 1991. The 'Y' and "Y' scales are identical. If no

            change occurs in the TBT concentration at a site, that data will be plotted

            on the center line. Sites that fall below the line show a decrease while

            points that rise above the line show an increase compared to 1989. Two

            other lines also appear in Figure 4. These are the lines that form the
            boundary of sites with a factor of 2 increase (top line) or decrease (bottom
            line). Only 6 sites for 1990 and 8 for 1991 of the 53 sites plotted for each

            year are above the center line.        Therefore, "over 85% of the TBT

            concentrations in 1990 and 1991 were less than the concentration

            measured in oysters at that site in 1989. There were 30 sites (570/6) in

            1990 and 20 sites (38%) in 1991 that had decreases of more than a factor of





                                                  6-11









             two. There was only one site that had an increase of TBT concentration of

             more than a factor of 2.

                   In order to detect temporal trends, the butyltin oyster concentrations
             for the entire Gulf of Mex:ico from 1989 to 1991 are compared. Annual
             variation of butyltins for the entire Gulf of Mex:ico are not readily apparent in

             Figures 1. 2. or 3 where only annual concentrations at individual sites are

             compared. Comparisons of arithmetic mean, geometric mean, and medians
             (Table 11) for butyltin concentrations determined during 1989, 1990, and
             1991 are based only on the 53 sites that were sampled all three years. All of
             these parameters were calculated by assigning 5 ng Sn/g to all of those
             samples with concentrations below the limit of detection. The percentage

             of samples below the detection limit is listed in Table 11. The median and

             geometric means are similar in, all cases, while the arithmetic mean is

             always higher. The median or the geometric means appear to be the better
             estimators of the central tendency of the data. Based on the median or the

             geometric means, there was a decrease in TBT oyster concentrations when

             1989 is compared to 1990 or 1991.
                    A complete view of butyltin concentrations for the whole Gulf of

             Mexico for a given year can be achieved using either cumulative percentage

             distribution or probability distribution curves (Mackay & Paterson, 1984;

             O'Connor & Ehler, 1990: Jackson.et al., in press). Although both types of

             curves may describe a distribution of butyltin concentration for each year.

             probability distribution curves were chosen because they are more easily

             compared.     Use of this type of curve assumes that the-log of the

             concentration produces a normal distribution. Log normal distributions have

             already been reported for environmental data obtained in the NOAA National





                                                     6-12









             Status and Trends Mussel Watch Program (O'Connor & Ehler, 1990;

             Jackson et aL, in press).

                  TBT log distribution curves are shown in Figure 5 for 1989, 1990, and
             1991. These curves were obtained by using the following equation (Milton

             & Arnold, 1986):
                  f(X) = IS [SQR(2n)])-1 EXp - [1/2 [Ix - M/S 12 1                     (1)

             where f(x) is the distribution probability of the log butyltin concentration, s
             is the standard deviation, SQR is the square root, x is the log of the butyltin
             concentration, and X is the geometrical mean. Then each Ax) was divided
             by the sum of the Ax) as shown by equation (2)
                  NX)i = f(X)i / E f(X)i                                               (2)

             in such a way that
                   E f wi                                                              (3)

                  TBT concentrations curves from 1989, 1990, and              (Figure 5) are
             Gaussian with some degree of skewness. DBT had a log normal distribution

             only in 1989 and 1990, while MBT does not follow a log normal distribution
             for any of the years. the geometric mean concentrations are indicated by
             solid lines for 1989, dotted for 1990, and dashed for 1991 (Figure 5) and

             are also reported in Table Ila. The TBT. DBT and MBT concentrations for

             plus and minus one standard deviation from the geometric mean are listed
             in Table IIb. Probability distribution curves of TBT in oysters from the Gulf

             of Mexico provide information about annual variations at low, medium, and

             high ranges of concentration. Although the standard deviations quantify the

             spread of a data set, they provide no information about how-low or high
             concentrations changed with time. TBT concentrations decreased from

             1989 to 1990 at all concentrations; while TBT concentration decreased

             from 1989 to 1991 at. low and medium concentrations, but were similar at



                                                    6-13









            high concentrations (Figure 5). This decrease may be the result of the TBT
            regulation of 1988 and/or development and use of lower release rate TBT
            paint formulations. Initial TBT regulations probably resulted in a marked
            reduction in private boat owners painting their own vessels. The fact that
            newer TBT containing paints are rated to be good for up to 5 years and '113T

            was not banned but its use limited probably leads to decreased TBT inputs.

            This may have resulted in the observed decreases in TBT concentrations in
            1990 and 1991. The decrease observed at high concentrations from 1989
            to 1990 but not in 1991 may be due to the naturally higher variation of TBT
            concentrations near input areas (Seligman et aL, 1988). Therefore, TBT
            lower concentrations ranges may have decreased as a consequence of TBT
            regulations or changes in TBT-based paint formulations, but the effect are

            not as apparent at sites with high TBT concentrations.. Distribution curves

            for DBT and MBT concentrations did not follow a log normal distribution but

            also show annual variations. This may be due to the high percentage of

            values below the MDL (Table 11).



                                            CONCLUSION



                  Oysters are valuable biomonitors for butyltins. The percentage of '!BT

            present with respect to the total butyltins oscillated around 85% during the
            three years sampled. There was a decrease of the butyltin concentration

            from 1989 to 1990 or 1991. However at high concentrations there was

            little difference between 1989 and 1991. Environmental response to the

            TBT regulation in 1988 is not yet apparent. The decline between 1989 and

            1990. 1991 may have resulted from previous changes in antifouling paint
            formulation with lower TBT release rates or suspension of painting activities



                                                   6-14









          by individual boat owners after 1988. Because the newer TBT paints were
          formulated to last 5 years or more, there are many boats still in use that
          were painted with TBT containing paints before the ban. Consequently,

          continuous monitoring is necessary to determine trends in butyltin

          contamination of the marine environment.






                                     ACKNOWLEDGMENTS

               This Research was supported by the National Oceanic and

          Atmospheric Administration Grant Number 50-DGNC-5-00262 (National

          Status and Trends Mussel Watch Program).


































                                              6-15










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                                                   6-16








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               linkages to effects. Mar. Environ. Res. 32, 29-35.

            Mackay D. & Paterson S. (1984) Spatial concentration distributions.
               Environ. ScL Technol. 18, 207A-214A.

            Maguire R. J. (1991) Aquatic environmental aspects of            non-pesticidal
               organotin compounds. WaterPoll. Res. J. Canada. 26,,243-360.

            Milton J.S. & Arnold J.C. (1986) Probability and statistics in the engineering
               and computing sciences. McGraw-Hill Book Company, New York-Toronto.
               643 pp.

            Minchin D., Duggan C.B. & King W. (1987) Possible effects of organotins on
               scallop recruitment. Man Poll. Bull. 18, 604-608.

            O'Connor T.P. & Ehler C.N. (1990) Results from the NOAA National Status
               and-Trends Program on distribution and effects of chemical contamination
               in the coastal and estuarine United States. Environ. Monitor. Assessment
               16, 1-17.
            Olson G.J. & Brinckman F.E. (1986) Biodegradation" of tributyltin by
               Chesapeake Bay microorganisms.           Proceedings of the Oceans '86
               Organotin SympositHm vol. 4. pp. 1196-1201.

            Page D.S. & Widdows J. (1991) Temporal and spatial variation in levels of
               alkyltins in mussel tissues: A toyicological interpretation of field data.
               Mar. EnvLron. Res. 32. 113-129.

            Ritsema..R, Laane R.W.P.M. & Donard O.F.X_ (1991) Butyltins in marine
               waters of the Netherlands in 1988 and 1989; concentrations and effects.
               Mar. Environ. Res. 32, 243-260.

            Salazar M.H. & Salazar S.M. (1991) Assessing site-specific effects of TBT
               contamination with mussel growth rates. Mar. EnvLrorL Res. 32, 131-150.

            Sericano J.L., Wade T-L., Garcia-Romero B. & Brooks, J.             (Submitted)
               Environmental Accumulation and Depuration of Tributyltin by the
               American Oyster, Crassostrea vLr9fnica_ Marine Biology.
            Seligman P.F., Valkirs A-0. & Lee R.F. (1986a) Degradation of fributyltin in
               San Diego Bay, California, waters. Environ. ScL Technol. 20, 1229-1235.







                                                   6-17








              Seligman P.F., Valkirs A.0. & Lee R.F. (1986b) Degradation of tributyltin in
                 marine and estuarine waters. Proceedings of the Oceans '86 Organotin
                 Symposftffn, vol. 4. pp. 1189-1195.

              Seligman P.F., Valkirs A-0., Stang.P.M. & Lee R-F. (1988a) Evidence for rapid
                 degradation of tributyltin in a marine. Mar. Poll. Bull. 19, 531-534.

              Short J.W. & Thrower F.P. (1986) Tri-n-butyltin caused mortality of chinook
                 salmon, Oncorhynchus tshawytcha, on transfer to TBT-treated marine net
                 pen. Proceedings of the Oceans '86 Organotin Symposium, vol. 4. pp.
                 1202-1205.

              Short J.W. & Sharp J.L. (1989) Tributyltin in bay mussels      (MyffLus edulis) of
                 the Pacific Coast of the United States. Environ. ScL Technol. 23, 7407743.

                                                                                                          01
              Thain J.E. (1986) Toxicity of TBT to bivalves: Effects on reproduction,
                 growth and survival. Proceedings of the Oceans '86 Organotin Symposium,
                 vol. 4. pp. 1306-1313.

              Thompson J.A.J... Sheffer M.G., Pierce R.C., Chau Y.K-, Cooney J.J.. Cullen
                 W.R. & Maguire R.J. (1985) Organotin Compounds in the Aquatic
                 Environment: Scientific Criteria for Assessing their Effects on
                 Environmental Quality. National Res. Council of Canada. NRCC. Associate
                 Committee on Scientific Criteria for Environmental Quality. 284 p.

              Uhler A.D., Coogan T.H., Davis YLS., Durell. G.S., Steinhauer W.G., Freitas S.Y.
                 & Boehm P.D. (1989) Findings of tributyltin in bivalves from selected U.S.
                 coastal waters. Environ. Toxic. Chem. 8, 971-979.

              Valkirs A-0., Davidson B., Kear L.L.., Fransham R.L., Grovhoug J.G. & Seligman
                 P.F. (1991) Long-term monitoring of tributyltin in San Diego Bay California.
                 Mar. Environ. Res. 32, 151-167.

              Wade T.L....Garcia-Romero B. & Brooks J.M. (1988) Tributyltin contamination
                 in bivalves from U.S. coastal estuaries. EnvLron. Sci. Technol. 22. 1488-
                 1492.

              Wade T.L. & Garcia-Romero B. (1989) Status and trends of tributyltin
                 contamination of oysters and sediments from the Gulf of Mexico.
                 Proceedings of the Oceans '89, vol. 2. pp. 550-553.

              Wade T.L., Garcia-Romero B. & Brooks J.M. (1991a) Bioavailability of
                 Butyltins. In Organic Geochemistry. Advances and Applications in the
                 natural environment. (Ed. D.A.C. MANNING). pp 571-573. ---Manchester
                 University Press.

              Wade T.L., Garcia-Romero B. & Brooks J.M. (1991b) Oysters as biomonitors
                 of butyltins in the Gulf of Mexico. Mar. Environ. Res. 32, 233-241.





                                                       6-18









          Waite M-E., Waldock M.J-, Thain J-E-, Smith D.J. & Milton S-M. (1991)
                Reductions in TBT concentrations in UK estuaries following legislation
                in 1986 and 1987. Mar. EnvirorL Res. 32, 89-111.

























































                                                 6-19









                   Table Ila.. Arithmetic, geometric means and medians (ng SnLgL
                   Numbers in parenthesis indicate percentage of samples below MDL.

                                      TBT          DBT        MBT
                   1989                                                                                  OF
                      Mean
                         Arith.       176           32           13
                         Geom.          85          14           8
                      Median            77(2%)       12(26%)      5(600/6)

                   1990
                      Mean
                         Arith.         96          17           6
                         Geom.          30           8           6
                      Median            24(17%)        5(72%)     5(900/0)


                   1991
                      Mean
                         Arith.       150           25           8
                         Geom.          43          13           6
                      Median            42(17%)        8(40%)     5(660/6)



                   TableIlb. Geometricmean. plus or minus one standard deviation of
                   the log butyltin. concentrations (ng Sn/g).

                                      TBT          DBT        MBT
                   1989
                      Plus            293          44            18
                      Minus             25          5            3

                   199-0;: .
                      Plus            141          21            8
                      Minus               6         3            4


                   1991
                      Plus            233          37            10
                      Minus               8         4            4
















                                                       6-20









                   Table 1. Sampling locations and site designators.
                   Desig.       Site                       Location     TEXAS                       Latitude         Longitude
                   LMSB         South Bay                  Lower Laguna Madre                       .260 02.58'      970  10.49'
                   LMAC*        Arroyo Colorado            Laguna Madre                             26   16.80       97   17.30
                   CCBH*        Boat Harbor                Corpus Christi                           27   50.00       97   23.00
                   CCNB*        Nueces Bay                 Corpus Christi                           27   51.70       97   21.00
                   CCIC         Ingleside Cove             Corpus Christi                           27   50.30       97   14.25
                   ABLR         Long Reef                  Aransas Bay                              28   03.30       96   57.50
                   CBCR*        Copano Reef                Copano Bay                               28   08.20       97   07.58
                   MBAR         Ayres Reef                 Mesquite Bay                             28   10.30       96   49.70
                   SAPP*        Panther Pt. Reef           San Antonio Bay                          28   13.20       96   43.00
                   SAMP*        Mosquito Point             San Antonio Bay                          28   19.00       96   42,20
                   ESSP*        South Pass Reef            Espiritu Santo Bay                       28   17.83       96   37.50
                   ESBD*        Bill Days Reef             Espiritu Santo Bay                       28   25.00       96   27.00
                   MBGP*        Gallinipper Pt.            Matagorda Bay                            28   35.00       96   34.00
                   MBLR         Lavac River Mouth          Matagorda Bay                            28   39.30       96   35.00
                   MBCB*        Carancahua Bay             Matagorda Bay                            28   40-00       96   23.20
                   MBTP         Tres Palacios Bay          Matagorda Bay                            28   39-00       96   15.50
                   MBEM         East Matagorda             Matagorda Bay                            28   42.30       95   53.00
                   BRCL*        Cedar Lakes                Brazos River                             28   51.50       95   27.90
                   BRFS         Freeport River             Brazos River                             28   55.00       95   20.50
                   GBCR         Confederate Reef           Galveston Bay                            29   15.75       94   50.50
                   GBOB         Offatts Bayou              Galveston Bay                            29   16.70       94   50.70
                   GBTD         Todd's Dump                Galveston Bay                            29   30.10       94   54.00
                   GBYC         Yacht Club                 Galveston Bay                            29   37.00       94   59.50
                   GBSC*        Ship Channel               Galveston Bay                            29   42.50       94   59.50
                   GBHR         Hanna Reef                 Galveston Bay                            29   29.50       94   42.50
                   SLBB         "Blue Buck Point           Sabine Lake                              29   48.00       93   54.42

                   *Sites that were not sampled consecutively from         1989   to 1991.











                 Table 1. Continuation.
                 Desig.       Site                      Location LOUISIANA                    Latitude         Longitude
                 CI,Sj        St. Johns Island          Qalcasieu Lake                        290  50.00'      930  32.00'
                 CLLC         Lake Charles              Calcasieu Lake                        30   03.50       93   17.50
                 JHJH         Joseph Harbor Bayou       Joseph Harbor Bayou                   29   37.75       92   45.75
                 VBSP         Southwest Pass            Vermillion Bay                        29   34.70       92   04.00
                 ABOB         Oyster Bayou              Atchafalaya Bay                       29   13.00       91   08.00
                 CLCL         Caillou Lake              Caillou Lake                          29   15.25       90   55.50
                 TBLB         Lake Barre                Terrebonne Bay                        29   15.00       90   36.00
                 TBLF         Lake Felicity             Terrebonne Bay                        29   16.00       90   24.50
                 BBSD         Bayou St. Denis           Barataria Bay                         29   24.10       89   59.80
                 BBMB         Middle Bank               Barataria Bay                         29   17.20       89   56.60
                 MRTP         Tiger Pass                Mississippi River                     29   08.69       89   25.67
                 MRPL*        Pass a Loutre             Mississippi River                     29   04.30       89   04.60
                 BSSI         Sable Island              Breton Sound                          29   24.70       89   28.70
                 BSBG         Bay Garderne              Breton Sound                          29   35.87       89   38.50
                 LBMP         Malheureux Point          Lake Borgne                           29   52.30       89   40.70
                 LPGO*        Gulf Outlet               Lake Ponchartrain                     30   02.20       89   03.00
                                                                MISSISSIPPI
                 MSPC         Pass Christian            Mississippi Sound                     30   19.75       89   19.58
                 MSBB         Bilo)d Bay                Mississippi Sound                     30   23.38       88   15.42
                 MSPB         Pascagoula Bay            Mississippi Sound                     30   21.05       88   37.00
                                                                  ALABAMA
                 MBCP         Cedar Point Reef          Mobile Bay                            30   19.40       88   07.30
                 MBHI         Harbor Island             Mobile Bay                            30   33.59       88   02.80
                 MBDR*        Dog River                 Mobile Bay                            30   35.50       88   02.72

                 *Sites that were not sampled consecutively from       1989  to 199 1.










                 Table 1. -Continuation.
                 Desig.       Site                     Location   FLORIDA                   Latitude        Longitude
                                                                                                                   .50'
                 PBPH         Public Harbor.           Pensacola Bay                        300 34.80'      870 11
                 PBIB*        Indian Bayou             Pensacola Bay                        .30 30.83       87  04.00
                 PBSP*        Sabine Point             Pensacola Bay                        30  20.80       87  08.10
                 CBJB         Joes Bayou               Choctawhatchee Bay                   30  24.70       86  29.55
                 CBSP         Shirk Point              Choctawhatchee Bay                   30  28.95       86  28,  60
                 CBSR         Off Santa Rosa           Choctawhatchee Bay                   30  23.50       86  10.60
                 PCLO         Little Oyster Bay        Panama City                          30  15.00       85  40.87
                 PCMP*        Municipal Pier           Panama City                          30  08.20       85  37.50
                 SAWB         Watson Bayou             St. Andrew Bay                       30  08.50       85  37.58
                 APDB         Dry Bar                  Apalachicola Bay                     29  41.50       85  05.00
                 APCP         Cat Point Bar            Apalachicola Bay                     29  43-00       84  52,50
                 AESP         Spring Creek             Apalachee Bay                        30  30.50       84  19.38
                 CKBP         Black Point              Cedar Key                            29  10.25       83  03.00
                 TBNP         Navarez Park             Tampa Bay                            27  48.30       82  45.28
                 TBMK         Mullet Key Bayou         Tampa Bay                            27  37.17       82  43.62
                 TBPB         Papys Bayou              Tampa Bay                            27  50.72       82  36.75
                 TBOT         Old Tampa Bay            Tampa Bay                            28  01.48       82  37.95
                 TBKA         K. Airport               Tampa Bay                            27  54.46       82  27.29
                 TBCB         Cockroach Bay            Tampa Bay                            28  40.55       82  30.56
                 CBBI         Bird Island              Charlotte Harbor                     26  31.00       82  02.60
                 CBFM         Fort Meyers              Charlotte Harbor                     26  38.64       81  52.48
                 NBNB         Naples Bay               Naples Bay                           26  00-00       81  32.00
                              Henderson Creek          Rookery Bay                          26  01.83       81  43.75
                 RBHC*                                                                      25  54.27       81  30.60
                 EVFU         Faka Union Bay           Everglades
                 BHKF*

                 *Sites that @vere not sampl  ed consecutively from 1989 t  o 1991.










                   Table Ila. Arithmetic, geometric means and medians (ng Sn/g).

                                      TBT          DBT        MBT
                   IL989
                      Mean
                         Arith.       176           32           13
                         Geom.          85          14           8
                      Median            77          12           5


                   1990
                      Mean
                         Arith.         96          17           6
                         Geom.          30            8          6
                      Median            24            5          5


                   1991
                      Mean
                         Arith.       150           25           8
                         Geom.          43          13           6
                      Median            42            8          5




                   Table Ilb. Geometric mean plus or minus one standard deviation of
                   the log butyltin concentrations (ng Sn/g).

                                      TBT          DBT        Mar
                   1989
                      Plus            293          44            18
                      Minus             25          5            3


                   1990
                      Plus            141          21            8
                      Minus               6         3            4


                   1991
                      Plus            233          37            10
                      Minus               8         4            4

















                                                      6-24
























                                                                                                                                                                                                                             0)          co
                                                                                                     0           0                                  AD


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                                                                                                                                                                                            ...........
















                                                                                            01
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                                                                                                                                   ..............






                                                                                                                                   .................









                                  10000--

                                               GULF COAST OYSTERS


                                                   19W
                                    1000            1991





                                     10011:

                                                                             El

       co                              10
                                                                0 91i ENS





                                           1              10             100            1000          10000

                                                          TBT (ng Sn/g) 1989

                      FIGURE 4. Tributyltin concentrations determined in 1989 versus the tributyltin concentrations
                                 determined in 1990 and 1991. Points falling along the center line have equal
                                 concentrations, colateral lines indicate a factor of two greater or lower than
                                 the concentrations determined in 1989.










                0.03
                                                                                    --Cl--  1989
                                                                                    11111111101111111 1990
                                              e@A
                                                                                    am*--   1991
                                              #A                  A
                                             A
                                           ASA
                0.02-





                                     A

                001







                0.00
                      1                   10                   100                  10 00               10000
                                                      TBT (ng Sn/g)



                         FIGURE 5. Log normal distribution of tributyltin concentrations determined in oysters
                                    in 1989, 1990, and 1991.
                                      A









                                          7.0 Biological Results


                 7.1 Condition Index/Shell Length /Condition Code

                       Condition code was rated as described in the Analytical Methods
                 volume. Higher numbers indicate oysters in better condition. Most
                 sites averaged 3 or 4. The highest median condition was 2 at five
                 sites, the lowest was 7 at three sites.

                       Condition index is an estimate of   the relative health of oysters.
                 Healthy oysters, generally have more tissue dry weight compared to
                 the cavity volume of their shells. Condition index is calculated by
                 dividing the tissue dry weight of oysters by their shell. volumes. The
                 higher the number, the healthier the oyster.

                       Condition index varied from 0.062 gm dry wt - mI-1 at Brazos
                 River, Freeport Surfside (BRFS) to 0. 197 gm dry wt * ml- 1 at. Aransas
                 Bay,. Long Reef (ABLIZ). Condition index usually varies with the
                 reproductive cycle being higher during the period of gonadal
                 development and decreasing after spawning. Lower condition indices
                 have also been associated with pollutant stress. Condition index varied
                 concordantly from year to year among the Gulf sites. Condition index
                 was relatively high in years 1987 and 1988 and was low in 1986 and
                 1989. P. marinus infection intensity followed the exact opposite
                 trend. In 1990, condition index fell between these two extremes, as
                 did P. marinus infection intensity. Length decreased steadily from
                 1986 to 1989 and declined at lower latitude sites. Length was
                 unusually low in the panhandle of Florida relative to that expected
                 from other sites in the equivalent latitude range.          Both trends
                 continued in 1990.



                 7.2 Gonadal/Somatic Index

                       Assessment of the physiological state of an oyster population
                 requires an analysis of the state of gonadal development. Typically,
                 oysters are undifferentiated in the winter, the gonads begin to develop
                 in early spring, and spawning occurs during late spring through early
                 fall. Most Gulf coast oysters spawn at least twice during that time
                 period.    The state of gonadal development is determined by
                 observation of histological sections after staining. Oysters are sexed
                 and assigned to a semiquantitative state of reproductive development
                 as detailed in the Analytical Methods volume. Four stages of gonadal
                 state were used as detailed below. This scale has been further refined
                 as described in the Analytical Methods volume last year.





                                                    7-1








                  Stage 1. Undifferentiated/Mid Development Gonad:

                              Little or no gonadal tissue visible.       Sex cannot be
                              determined.

                            Early Development: Follicles beginning to expand, no ripe
                              gametes visible. Primary and secondary gametocytes
                              present. Sex can be determined.

                            Mid-Development: Follicles expanded and beginning to
                              coalesce; no mature gametes present.

                  Stage 2. Undifferentiated /Mid -Development Gonad:

                            Late Development: Follicles greatly expanded, coalesced,                r
                              but considerable connective tissue remaining; gametocytes
                              and some mature gametes present.

                  Stage 3. Fully Developed Gonad:

                              Follicles packed with mature gametes. Most gametes
                              mature; little connective tissue remaining within the
                              gonadal tissue.

                  Stage 4. Spawning/Spent gonad:

                            Spawning: Gametes visible in gonoducts.

                            Spawned: Reduced number of gametes; some mature
                              gametes still remaining; evidence of renewed reproductive
                              activity.

                            Spent: Few or no gametes visible, gonadal tissue atrophying.


                        Gonadal index is calculated as the mean stage obtained from a
                  minimum of 15 individuals per site. This gonadal index in oysters is a
                  qualitative estimation of the state of reproductive development. It
                  does not allow direct comparison (or normalization) of other data (e.g.
                  hydrocarbon content) with reproductive development because a
                  histological determination of reproductive state does not measure the
                  total volume of gonadal material consistently present at all stages and
                  all individual sizes.

                        Most collected oysters that could be assigned to a sex were
                  female, as expected. Large oysters are usually female. and large oysters
                  were preferentially collected.      There has been no consistent
                  relationship among the years in sex ratio. Sites with more males in
                  any one year were not necessarily sites with more males in another


                                                    7-2








                 year. For example, the site (BBSD) which had the most males (6) in
                 1989 had few males in 1990.

                       In Year 1, except extreme south Texas, nearly all oysters
                 collected west and south of Joseph Harbor, Louisiana and east and
                 south of Lake Borgne were in the earliest stages of gonadal
                 development. Little gonadal tissue was present. Oysters from sites
                 between Joseph Harbor and Lake Borgne were collected later in the
                 season. Nearly all individuals were in late stages of development or
                 ready to spawn. A few individuals had already spawned and appeared
                 to be developing new gonadal material again. In Years 2 and 3,
                 collections were made earlier. Louisiana oysters were for the most
                 part in early development. Sites in Texas and South Florida, however,
                 provided some oysters in late development, full development or
                 spawning. Sites having the most oysters in late development or ready
                 to spawn were in the Laguna Madre and Corpus Christi Bay areas of
                 Texas (>20%), and in Tampa Bay and Charlotte Harbor, where 50% or
                 more of the oysters were ready to spawn at some sites. Elsewhere in
                 Texas and south Florida values averaged below 15%. In Year 4, the
                 majority of oysters in early development were in Florida, from the
                 Brazos River South in Texas, and in the Mississippi River Delta area.
                 Sites having >50% of the oysters in late development or ready to.
                 spawn occurred mostly in South Texas (Corpus Christi Bay, Matagorda
                 Bay, and Laguna Madre Bay). along with some isolated sites in the
                 Mississippi River Delta (Barataria Bay) and the Tampa Bay area. In Year
                 5, South Texas and South Florida again accounted for most of the sites.
                 In Year 6, sites were generally higher around the Gulf, particularly in
                 the northern Gulf- many more reproductive/advanced individuals
                 were collected.


                 7.3 Lona-Term Changes

                       We reported the Gulf-wide distributions of certain parameters in
                 Preprint 7. In the following figures (7.1-7.14), we have extended this
                 analysis to six years. The statistical approach is detailed in Preprint 7.
                 In the first set of figures (7.1-7.7), we asked the question "How far
                 apart must bays be before the similarity in yearly changes in certain
                 parameters no longer exists?" We expect nearby bays to behave
                 similarly. We expect bays far apart to behave differently. The evidence
                 present so far suggests that large-scale climatic shifts dictate year-to-
                 year changes so that bays within 500 to 10OOkm of each other may
                 behave similarly.

                       Figure 7.1 shows the situation for gonadal stage. The y-axis is a
                 plot of the log of the p value. Any value below -I indicates a significant
                 similarity. In this graph, nearby bays are very similar (PL .000001 at
                 200km).     Similarity disappears at about 10OOkm (IogP >-1 at
                 10OOkm). Accordingly, year-to-year changes in the frequency of
                 reproductive /active individuals were similar in bays up to 10OOkm


                                                    7-3








                 apart. On the average, bays within 1000kni rose or fell in unison in
                 the biological attribute from one year to the next. This would be
                 expected if climatic conditions, such as the average winter
                 temperature, controlled by climate cycles, like El Nifto, were
                 responsible for year to year shifts.

                       The following is clear from these graphs: P. marinus prevalence
                 and sex ratio were affected minimally by local conditions. Nearby bays
                 were as dissimilar as bays far apart. Like gonadal stage, condition
                 index, length, and P. marinus infection intensity all showed scales of
                 similarity in the range of 10OOkm. So, the primary indicators of
                 population health were impacted significantly by climate change on a
                 scale of 1000km over the six years of study.

                       In the second set of graphs (Fig. 7.8-7.14), we look at groups of
                 ten adjacent bays. This analysis searches. for the pattern of regional
                 similarity around the Gulf of Mexico. Preprint 7 has a detailed
                 description of the method. In this analysis, values above the. dark line
                 indicate significant similarity. The biological attributes show the
                 following pattern: Length, P. marinus prevalence, gonadal stage, and
                 sex show similarities in the southern Gulf, east or west or both. This
                 similarity suggests a subtropical climate control like El Nifto.
                 Condition index shows the opposite trend: similarity in the northern
                 Gulf of Mexico from approximately Galveston Bay to Tampa Bay. P.
                 marinus infection intensity reacts similar throughout the, Gulf. These
                 latter two indicate that temperate weather patterns are also
                 important. Overall, the data clearly show that weather patterns exert
                 control on oyster population health throughout the Gulf of Mexico and
                 can account for the assessed pattern of year-to-year changes in
                 population health over the six years of the study.




















                                                    7-4







                                                                                                                                                                                                                                                                                                                                              Bays
                                                                                                                Log                                   p               Values for Stage                                                                                                                           31


                                                                                                                                                                                                                                          I                A,                                                 I                    f          1  -
                                                                                                0


                                                                                                                                                                                                                                                                              A   ..... . .......                                                                 ........
                                                                                                                                                            it                                                                                                                                                                     ..................    ......
                                                                                                                                            .... ........   .......   .......  ........ ........   t........ .................   ........







                                                                                                                                                                                                                                                                                  .................   ........ ........
                                                                                                                             .................    ........  ........  .......  .......    ........ ..... . ......
                                                                                        - - --------
                                                                                                 2






                                                                                                                                                                                                                                                                                                                         ..............................
                                                                                                                                                                                                                                          ................. I ....                                                                                          ....
                                                                                                                                                                                                   ........ ...  . ........
                                                                                                             . ........ ........ ........ ......       . .....
                                                                                         -3






                                                                                                                                                                                                                                                                                            ........ ....      ........   ........ ......................      . . ........
                                                                                                                                                                               ....... ........ .................      .................                .... . ........      ... . .......
                                                                                                                                                            ................. .                                                           .......







                                                                                                                                                                                         ....... . ........  ........                     ........ ........    .......   .......            ........                                          . . .
                                                                                         -5



                                                                                                               0                                            500                                        1000                                             1,500                                            2000                                               2500
                                                                                                                                                                                                                   Distance,                                   KM






                                                     j@og p Values for Mean Infection Intensity
                                                                                                                                                                                                   31                          Bays

                                                                     >1
                                                                                                   0
                                                                     U)


                                                                                                                                                                                                                                                                                                  ........ ......
                                                                                                                                                              .......... .......   ....... . .......   .....     ........  ........  ..................                       ........ ........             . . ......          ..................   .......    ........  ........ -


                                                                    4-j



                                                                                                                                                                                                                                     ........ ............   ... .......      .......  4
                                                                                                                                                                                   ................     ........                                                                                  ........            ........            ........              ........


                                                                     C:


                                                                                                                                                                                                                                                                 4            4....... .......
                                                                                                                                                              ........     ....... .......   ........   ........           ........                                  .......                                ........  ........



                                                                                                                                                                                                                 ..... . .....       ........    .......                      .......  ........             ........  ........  ........  ........ . ....... . ....... . ........
                                                                                                               . .........                ........   .................   ........  ....... I      ..
                                                                                            -4




                                                                                                                                                                                                  .. ........    ........  ........  ........
                                                                                                                                                                                                                                                                    ................. ........    ........            ........            ........ . .......
                                                                                                                                                                       !........ . .......   1. .....
                                                                     CZ                     -5

                                                                                                                                               .............  ...... . .....       I. ............... . .................  ........  j.................   ....... . ........           ........             ........  ........  ........  ........ . .......     ........
                                                                                                   6



                                                                                                                                                                                                                                              . .......  .......                                                                          ........   ....... I .......     ........
                                                                                                                                                                                             ........ ........   ........  .....     ........                       .......   .......  ........                       ........ ........
                                                                                                   7

                                                                                                   8
                                                                                                                  0                                           500                                           10             00-                               1500                                              2000                                                2500
                                                                                                                                                                                                                         Distance,                                   KM






                                          6,iog p Values                                                                                      for                         Median                                               Infection                                                        Intensity
                                            (D                                                                                                                           31                    Bays
                                                              >1




                                                                                                                                                                                            ...............          . ...... . ................ ....... . ............... .......
                                                                                  0                                                                                                                                                                                                                       ......



                                                                                                                                                                                                            ........ . ........ ........ ........     ......  ........  ....
                                                                                                         . .........         ..... ........ ........   ... . ....... . ........ ....... ...







                                                                                                                                                           ....... ................         ......... .......  ....... ....... ....... .
                                                                                                                                                                                                                     T      T                 ........ ......                            ....... .......
                                                                                                                                  ........ ...... . .......
                                                                            -2
                                                                                                                                        +
                                                              Cz


                                                                                                          .................. ........             . .. . ....... .................   ........ ........  ...................
                                                                            -3






                                                                                                                                                                                                                                                               ................. ........ ....... .......
                                                                                                                           ...............
                                                               0-4






                                                                                                                                                                                     ----------


                                                                                              0                                  500                                   1000                                     1500                                     2000                                       2500
                                                                                                                                                                                 Distance,                           KM


















                                                 Olt%
                                                  z                                                  Log                                p                Values                                                for                           Length                                                  31 Bays
                                                  CD
                                                  -4
                                                  ;PI





                                                                                                                                                   ................  :. .......          ....... ........           .................. . ....... .......  ..... +              ...........               .................
                                                                                          0



                                                                                                                                                                                                                                       ...... . ..... I  *.......    ........I........ ........       4      ...... ........ ........ ....... ........
                                                                                                                                         ............................  ......              ...... ................. ..............
                                                                                                                                                        +



                                                                                                                                         ................. . ....... . ....... ....... :. ........        .....................           .......        . . .
                                                                                   -2







                                                                                                                                                                                                                    ................. . ....... . ....... . ....... ........ ........ ::.6
                                                                                                                                                                                                                                                                                                                         .. . ....... . ....... . ........
                                                                                   -3                                                             ........   .......



                                                                                                                                                                                                                                                                                                                                   7-7

                                                                                                         0                                      500                                         1000.                                          15 0 0                                         2000                                            2500
                                                                                                                                                                                                       Distance,                                 KM



                                                                                                        mm m






                                    Log p Values                                                for' Co,ndition Index                                                                 31             Bays

                                                   0


                                                                                                                                                                    +
                                                                                                                                                                      ............... . ....... .........
                                                         . ................................... .................  ....... ....... I ..... ........ ....... ........ .......



                           CP



                                                                                                . . . . . . . . . . .
                                                         . ........                                                        ........ ........ ........ ........ ....... ......
                                                                  ........ ........  ........ ........  ........ . ........ ........ ........
                                               -2

                                     0



                                                                                                                     ............                                               . ....... . ....... . ........
                                                                                                 ....... .. ....... ...... .....                   ....    ........ ........ ........ ........
                                                                                                                       I. . .............................
                                                                                       .....  .....
                                                                     ... ........   ... .. ..







                                                                                                                                             .... ................. ........ ........ ........ . ....... . ....... . ........
                                                                                 ........ . .... .. ....... ........  .......................... ........ ........ ........ .
                                               -4






                                                                             ........                         .... ....... ....... .... . ........ ..... ........ ........ ........ ........ ....... ........  ........-
                                                                                              ...... .......







                                               -6
                                                          0                      500                     1000                      1500                      2000                       2500
                                                                                                               Distance,              KM







                                                                                                                                    Log                                  p                  Values                                                         for                             Sex                                 31                         Bays

                                                                                             0.5




                                                                                                                                                                                                                                                                                                     ..........                                                     .......              ........
                                                                                                                             ........ .....                                                 ........                        ........            ... ............        ...... ....                  . ........            ........ ......... i.......... ........
                                                                                                                                                                  .....................
                                                                                                        0
                                                                                                                                                                                                  +
                                                                                                                                                                                                                                                                                                                           ........ . .....
                                                                                                                                                             ........ .......      .....  . .....                              ......  .....    . .........         ........ . ........    .....                                              ........              .......    ........  ........  -
                                                                                      -0.5

                                                                                                                                                     ......            ......        .....            It ....... 4........ ..... . .....                                                                              ...  .......  ......    . .....     ........  ....... . .......    4.......



                                                                                                                                                                                                                                                           . .........          .......       .... ...          .................   ........  .....     ......... .       ...  ....... . .... ...
                                                                                                                                                                                                                                           ... .......
                                                                                                                                       ........ ........     ......    ........ I. . .. .......                  ........ ........ .....        . .......                                            .....                                                          . ........ ....... .
                                                                                                     .5                                                                           ........ .....


                                                                                                                                                  ..............................                                                                           ................. ....... I     I.......                                                                                      . ........
                                                                                                                                                                                                                                                                                                     ..........       ............. ........  ........................... ........
                                                                                                                                                                                    ......                                             .......        ...
                                                                                                 -2




                                                                                                                                                             .................    ......              ..........................       ........            ........ ........    .......              ........   ........   ........
                                                                                                                                       ........ ........                                    .......
                                                                                      -2.5


                                                                                                                                                                                                                                                   ......                       ........   .......   ........   i........  I........i........ .....       ......... .......    .......   ........  -
                                                                                                                                                             ......       ..... ........              .......    ........   ........   ........



                                                                                      -3.5
                                                                                                                        0                                             500                                                                                                1500                                                2000                                                 2500
                                                                                                                                                                                                                                 Distance,                                      KM



                                                                                                                                                                  M Mao M MMM M M m                                                                                                                                                                                                                                                                            M



                                                                                          Log p Values                                                                                                         for Prevalence 31                                                                                                                                       Bays

                                                                                         0.5





                                                                                                                                                                          ........   ....... ........             .........                                   ......  L....... I.......   .................




                                                                                                                                                                                                               ................... . ......     ........   ........            .......   ........   ........ ........            ........   ........: .......             ........
                                                                                       0.5
                                                                                                                                                                                     .......                                                     .......                                 ........



                                                                                                                                                                                               .......   ..........................   ........ .                      .......                                                              ........ . .......   ........  ........
                                                                                                                                                                                                                                                            .......            .....       .....      ...... ........  ........ .....
                                                                                                                                                                                  . . ....... .




                                                               Cm                                                                                                                                                                                                     ......                        ........ .....                                  .................     ........
                                                                                                                                                                ......... ........   .... ........       ..................           ........   ........ .......                                                      ........  ......... .......
                                                                                                     2           . ........       ...... . .....



                                                                                                                                                                                                                                                         t ........   1@ .......4
                                                                                  -2.5


                                                                                             -3
                                                                                                                                                               500                                           1000                                              1500                                             2000                                                2500
                                                                                                                                                                                                                        Distance,. KM







                                                                                                                    Condition Index 31 Bays

                                                                         0.6



                                                                                                       ................... .....  ........................... ...... ....... .                  . . ...       +      ...                ; ..... ........... ..... . .....
                                                                         0.5                 . .....   I     I      I                                                                       ..........



                                                                                                                                                       ......            . .....           ..... ..... . .....   ...... ....
                                                                         0.4
                                                       C)




                                                                                                                                                                                                                                   ..... . .....
                                                                                                              ..... .....      ............. ..... ........... .... . ..... ..... ............ ...... ..... .          .....   .....
                                                                                                                                                                                                            .............                                                         ..... . ..... ..... . .....
                                                        4-a              0.3
                                                                                                                                              +


                                                                                                                                                                                                                 . ...... .....                                  ..... ...                    ..... . .....
                                                                                                                                      ...... ........................ . ............. .... A ..... ........... . ......            ..... I ..  ..... I
                                                                         0.2






                                                                                                                    ..... ..... ......      ............ ......    ......      .....      ..... ..               ......            ..... . .....
                                                                         0.1






                                                                                                                                                                                                I    I  A                   I I         I      I                      I

                                                                                               0                            5                          10                            15                          2      0                      2      5                     30                            35
                                                                                                                                                                         Steps Around Gulf                                                              -






                                                           P. marinus Median Infection Intensity

                                                           0.5








                                                                                                                                                      ..........                     .........                                               .......
                                                                                                                .................. ...... ...... .....             ..... . ........         . ..... ..... . ..... ........... ..... . .....           ...........
                                                           0.4


                                               Q)
                                                                                                         . .... ..... .... ..... ...... .....  ..... ..... ........... ....... ......................... ..... ..... .. ...... . .....
                                                                                                                                                                                                                                  ..... .  .. . .......................
                                                           0.3







                                                                                                                                                                                                                                            ........        .....
                                                                                                                                               ..... I ...... ............ ..................
                                                                                                      ........... . ......  ......I......                .....                                    ...... ........... ............ . ............  ..... .......
                                                                                                      lli!:j
                                                           0.2
                                               E

                                    Cn

                                                           0.1                                                  ..... .... ..... ..... ..... .....         ... ..... ..... .... ..... ......  ..... ..... ..... ...                               . .....



                                                                                                I    F-71
                                                                    0
                                                                              0                         5                       1    0                   1     5                  20                        25                          30                      35
                                                                                                                                               Steps              Around                   Gulf







                                                                                           P.                         marinus Mean                                                                                                                      Infect-ion                                                                       Intensity

                                                                                0.55


                                                                                                                                                                                                             ..... . ....                 ........................... . ....               . .....  ..... . ....
                                                                                                                                                         . ...........                                                                                                                                                     1. ..... ..... .. ..... ........... ...... ............
                                                                                       0.5
                                                                                                                                                                                              Hill


                                                                                                                                     ...........    .....  ..... .....  ......         ......                                                                                        ..... I .....                         .....         1. ..... .....
                                                                                                                                                                                                              .... .... ..         ..... ...        ... .....           ....... .....               .....   ..... .....
                                                                                o.45
                                                                                                                                                       +      +


                                                                                                                                            .....   .....                                                                                                                                                                          ......
                                                                                                                                                                                                                                                                                                ...         ..... .....
                                                                                       0.4                                                                                                                                                ...... ......


                                                                                                                                                                                                                                                                                                                                                ...........    ..... . .....
                                                                                                                                                                                       ......          ........... . ....  .....                               . .....  .....  .....                ..... . .....
                                                                                0.35                                          ..... ............

                                                       C'D
                                                                                                                                                                                                                                                        ..... .....            ..... .....   ..... .. .       ... .....
                                                       CO                                                                                                                                                                                                                                              4-
                                                                                       0.3                                                                                                                         1       :1:                  :       :      t


                                                                                                                                                                                                                                                 ..... .....                                                               ... . ..                     ...........          ......
                                                                                                                                                                                ...... .....                                       .. ....                                     ...           ..... .....    ........... .
                                                                                0.25                                   .....


                                                                                                                . ..... . .... . ...                                                   ......                ..... I ....  .....   .....                                       .....
                                                                                                                                                                        ........... .
                                                                                       0.2                                   . . .

                                                                                0.15
                                                                                                                   0                                  5                                10                                  15                                  20                                   25                                   30                                 35
                                                                                                                                                                                                             Steps                        Around                               Gulf






                                               Length 31              13 ays


                    0.45


                                                                       ..... ..... .....
                                                   ..... ..... ..... ...... .....
                                                                         T   T .....
                                ............. ..... ... ......
                      0.4




                                                                ....... .... ..... ..... ..... ...........
                              ... .....   ... ..... ...... ..... . ..... ..... . ....I
                    0.35


                                                                    ..... ......
                                                                               ..... ..... .....
                      0.3

      U1
                                     ............. .......... ........... .. .....  ..... .....
                                         .....+             .....  .....         .....
                            . .....          ...... ......             ..... I ..... .......... I ..... ..... I .....
                    0.25


                                    ...... ........ .......... . ..... . ..... . ............ ...... ..... ...... ........... ..... . ..... ...... ............ ...... ..... . .....
                      0.2


                                                     ... .... ............ ..... ..... ..... ..... ...I.... .... .... ....
                    0.15        1w  .......... 1;    1


                                            .............. ...... ..... .....  ..... ..... I ..... . ..... ..... ..... ..... . ...........
                      0.1
                                                             +
                    0.05
                             0        5        10        15      20         25      30        35
                                                     Steps Around     Gulf







                                                                             P. marinus Prevalence 31 Bays

                                                          0.4




                                                                                   ............ ......   ...... ............ ...... ..... ...... ................. .....                                                                 ......
                                                      0.35


                                                                                           ............ ............ .......... ...... ............ ..... . .....
                                                                                                                                                                                           ..... . ..... ..... . .....
                                                          0.3



                                                                                           i.....4   1           -S  .....I......I.....3..... 4. .1 .....             I  i.....i.....i
                                                                                   .....             ..... ... .....                                                                                               .....
                                   P's                0.25
                                                                                                                                                                                         +



                                                                                                                                                                                  ... . ... ...                                       .....
                                                                                                .....  . ..... .... ..... .... .. . ..... ...................... ..... .... .... .... .. I .. I . ....                          ..... .
                                                          0.2                                                                                                         7  V

                                                                                                                                         i   t    i         i            i


                                                                                           ..... .....   ..... . ............ .............  ............ ................ ..... .....I............ ............ . ..... ..... . ..... ..... . ..... ........... ..... ..... ......-



                                                                                                                                                       jilf:
                                                                                                                                                            :i.%
                                       U)                                                                                              *+
                                                                                                                                         ..................           ...... ..... I ... +..: . .....i. ..... ...........
                                                          0.1




                                                                                                                                                                                                          .........                   .....
                                                                                                                            ..... . ......   ..... ..... . .       ......... ..... ..... .....                     ..... ..... .... .....
                                                      0.05
                                                                                                                                                                   +


                                                                                                         I    I   i    I-T-T-r- I            I    I    I    I   F-r           I   I                  I        I   I        I   I    I I
                                                                  0
                                                                           0                       5               .10                       15                       20                   25                     30                     35
                                                                                                                                     Steps Around Gulf







                                                                                                                                                                                             stage 31                                                                        Bays


                                                                                                                                                                                                                                          I I f i
                                                                                             0.6                    -



                                                                                                                                                                                                                                                                ............   .....          ..... ..... .
                                                                                                                                                                ............. ............
                                                                                             0.5                    . .....                     ...... L* ... I                           ......          . ... . ........           ............. I .....


                                                                                             0                                                  ......                      ......        ......                       .....         .....                      ......         ........... ......                                                            ......
                                                                                                      64
                                                                       cz



                                                                                                                                                                                                                                                                                                                  ..... .....   .... . .....  ...... .....
                                                                                                                                                                                                                                                                                              ..... .....
                                                                                                                                                                                                                                                                       ..... I .....
                                                                                                                                                                                                               ...                     .........   .....
                                                                                                                                                ..... . .....   ..... .....         .................                         ..... . ..
                                                                                             0.3





                                                                                                                                                .............. .....  ........................... ..... I               ... . .....  ......... . .
                                                                                             0.2






                                                                                                                                                                                                                                                                       ............
                                                                                             0.1                    . .....      ......                         ......      ......  ..... ...... .....   .....                                                                           . ... ...


                                                                                                        0
                                                                                                                       0                                   5                              10                                 15                                 20                                 25                                  30                                 35
                                                                                                                                                                                                               steps Around Gulf







                                                   Sex 31 Bays
            CD




                                                                                        I tt
                       0.4
                                                                            t ii it



                                t............ ............. ...........  .................. ...........  ..... . ..... ............ ..... .....  ..... ......
            P@      0.35          1                1 t i


                                                                                       ..... . ........... . .....
                                        ..... ............  ...... ...... .....
                     .0.3    T i                 t


                                                              ..... ..... .....
                                                          .... ..... ..... ...
                                                     ..... .... ...          ........ ..... .....
               x    0.25                 ...... ....

       co
                                                 I...........:. ..... .... .....
                                  A..... . ..... .................. ..... . ..... ....... I ....... . .....  .......................i..... ......
                       0.2
                                                                                   +   i
                              .0077=77                  ..... ... .. .... .....   ....... ..... .... .....
                    0.15


                                         ..... .... ...  ...... ........... ..... . .. .. ..... ..... ..... ..... . ..... ..... . .....
                                                                                 ..... ..... ..... ..... .....
                                                       :11      it            1:::!!;I:



                                                                     ..... ..... .      1.
                                                                  ...... .....
                                      ............ ....... i ... .......  ..........I..... .A
                    0.05

                          0
                             0        5         10      15        20       25        30      35
                                                     Steps Around Gulf





















                                                 Preprint 7


                    Spatial and Temporal Distributions of Contaminant Body
                    Burden and disease in Gulf of Mexico Oyster Populations:
                        The Role of Local and Large-Scale Climatic Controls


                                      E.A. Wilson, E.N. Powell, T.L. Wade,
                                   R.J. Taylor, B.J. Presley, and J.M. Brooks
















							HELCOLANDER MEERESUNTERSUCHUNGEN
							Helgolander Meeresunters 46 (1992)

Spatial and temporal distributions of contaminant body
burden and disease in Gulf of Mexico oyster
populations:  The role of local and large-scale climatic
controls
E.A. Wilson, E.N. Powell, T.L. Wade, R.J. Taylor, B.J. Presley &
J.M. Brooks
Department of Oceanography. Texas A&M University:  College Station, TX  77843, USA

ABSTRACT:  As part of NOAA's Status and Trends Program.  oysters were sampled from 43 sites
throughtout the Gulf of Mexico from Brownsville, Texas, to the Florida Everglades from 1986 to 1989.
Oysters were analysed for body burden of a suite of metals and petroleum aromatic hydrocarbons
[PAIis].  the prevalence and intensity of the oyster pathogen, Perkinsus marinus, and condition
index.  The contaminants tell into two groups based on the spatial distrubution of body burden
throughout the Gulf Arsenic, selenium, mercury and cadmium were characterized by clinal
reduction in similarity with distance reminiscent of that followed by mean monthly temperature and
precipitation.  Zinc, copper, PAHs and silver showed no consistent georgraphic trend.  Within local
regions, industrial and agricultural land use and P. marinus prevalence and infection intensity
frequently correlated with body burden.
	Contaminants and biological attributes followed one of three temporal trends.  Zinc, copper and
PAHs showed concordant shifts over 4 years throughout the eastern and southern Gulf, Mercury and
cadmium showed concordant shifts in the northwestern Gulf, Selenium, arsenic, length, condition 
index and P. marinus prevalence and infection intensity showed concordant shifts throughout most
of or the entire Gulf.  Concordant shifts suggest that climatic factors, the El Nino/Southern Oscillation
being one example, exert a strong influence on biological attributes and contaminant body burdens
in the Gulf.  Correlative factors are those that probably affect or indicate the rate of tissue turnover
and the frequency of reproduction; namely, temperature, disease intensity, condition index and
length.

INTRODUCTION

Bivalve molluscs have frequently been used as indicator organisms in studies
monitoring levels of contaminants in the environment.  These organisms are preferred
because of their ability to accumulate and concentrate both metal and organic contamin-
ants enabling them to serve as long-term integrators of their environment (Phillips,
1977a).  However, many biological and environmental factors affect the rate and extent of
bioaccumulation.  Biological factors including differential growth rate (Cunningham & 
Tripp. 1975a; Boyden. 1977). reproductive stage (Cunningham & Tripp. 1975a; Frazier,
1975;     et al., 1984). and general physiological condition, stress and disease
(Shuster & Pringle, 1969; Sindermann, 1983) affect incorporation and depuration rates.
Similarly, changes in environmental parameters such as salinity (Denton & Burdon-

								7-21











                                                     
        James 1981; Wright & Zamuda, 1987), freshwater runoff (Windom & Smith, 1972; Phillips, 1976a; Zariugian & Cheer, 1976),
	  duration of exposure to contaminants (Shuster & Pringle, 1969, Scott & Lawerence. 1982). Temperature (Shuster & Pringle.1969; 
 	  Zaroogian & Cheer, 1976; Denton & Burden-Jones, 1981). resuspension of sediments (Uncles et al. 
	  1988) and proximity to point sources (Farrington & Quinn, 1973: Ratkowsky et al., 1974;
	  Phillips. 1976b) can affect the bioavailability of environmental contaminants.
		Although these local environmental and biological controls on variability in pollutant
	body burden are important; they, themselves, may be affected by long-term, large-scale
	phenomena such as climatic cycles.  Such phenomena may override local controls and
	impose large-scale, concordant oscillations in environmental and biological parameters.
	Seasonal, climatic and other longterm cycles have been used in predicting harvests of
	commercially important fish and shellfish, including oysters (Dow, 1977; Ulanowicz et al.,
	1980l Allen & Turner, 1989), and have been implicated in the distribution and intensity of
	oyster disease (Powell et al., in press).  By imprinting themselves on the local environ-
	ment, these long-term cycles may also alter the bioavailability of contaminants and
	therefore, contaminant body burden.  Accordingly, explaining spatial and temporal varia-
	bility in contaminant body burden may require understanding both local and large-scale
	environmental phenomena.
		The NOAA Status and Trends Program ("Mussel Watch") is an environmental moitoring program
	designed to monitor changes in environmental quality along the Atlantic,Pacific and Gulf coasts 
	of the United States by measuring levels of chemical contaminants in fish, bivalves, and sediments
	and identifying biological responses to those contaminants. As part of the program, pollutant body
	burdent of trace metals and polynuclear aromatic hydrocarbons (PAHs) were measured in oysters
	(Crassostrea virginica) collected from sites along the Gulf of Mexico coast from Brownsville, Texas
	to the Florida Everglades. The biological component of this study included determining the prevalence
	and intensity of infection by teh endoparasitic protozoan Perkinsus marinus in these oyster populations.
	Over four years (1986-1989), this program has produced the most extensive spatial and temporal data set
	on contaminant body buden and disease prevalence and intensity available for natural oyster populations in 
	the Gulf of Mexico and has implicated the El Nino/Southern Oscillation cycle as an important factor 
	controlling large-scale tempral variability in oyster disease. The goal of this paper is to integrate the 
	biological and chemical data to determine: (1) the spatial and temporal distributions of contaminent body 
	burden as they compare to P. marinus in oyster populations: (2) the biological and environmental factors 
	important in determining these distributions and (3) the role of local and long-term controls on contaminant
	body burdens.

							MATERIALS AND METHODS

							Sample collection

		Oysters were collected from natural populations along the coast of the Gulf of Mexico during December
	to February of each year from 1986 to 1989. In all, 75 sites were sampled; 43 sites were sampled in all 
	4 years. Forty oysters were collected at each three stations at each site: twenty for trace metal analysis and
	twenty for biological and trace organic analysis. Temperature and salinity were recorded at the time of collection.
	  	




                                                                                          


	(JN)1852  (KL)150  (SW)Wilson



		The maximum anterior-posterior length was measured for each oyster (Morales-Alama & Alama, 1989). 
	Displacement volume of the 20 oysters collected for the biological and trace organic analyses was determined
	before and ager shucking. Each oyster was sampled for the presence and intensity of infection by Perkinsus
	marinus (Ray, 1966). Prevalence of infection was calculated as: (the number of infected oysters/number of 
	oysters sampled). Infection intensity was ranked on the 0-to-5 point scale of Mackin (1962) as modified by 
	Craig et al. (1989). After the biological sample was removed, the remainder of the oyster tissue was placed
	in precombusted jars, sealed with Teflon lids, weighed and frozen for trace organic analysis. Tissue dry 
	weight and displacement volume were used to calculate condition index=dry weight of tissue/internal volume of 
	shell cavity (Lawrence & Scott, 1982). The twenty oysters collected for trace metal analysis were scrubbed,
	frozen in the shell and returned to the laboratory. Further sample preparation and the analytical techniques
	employed for both trace organic and trace metal analyses were described in Brooks et al. (1989).

								Statistical analysis

								Data reduction

		Within-site variability was typically low (Craig et al.,1989; Wilson et al.,1990), so the three stations
	were combined for the following statistical analyses. Statistical analysis of the data was limited to the 43
	sites sampled in each of the 4 years. Each site was assigned to one of the 26 bay systems as slightly modified
	from Broutman & Leonard (1988) (Table 1)[see Craig et al. (1989) or Presley et al. (1990) for site maps, and 
	Wilson et al. (1990) and Powell et al. (in press) for further information on the sites]. Salinity and temperature
	data for the sites are given in Brooks et al. (1989). Powell et al. ( in press) list mean P. marinus prevalences
	and infectioin intensities for the bay groups. Mean values of condition index and length for the bay groups are
	presented in Table 2.
		Seven of the 13 metals analysed as part of the Status and Trends protocol were chosen for further 
	consideration: arsenic, cadmium, copper, silver, mercury, zinc and selenium. These metals were selected because
	they generally were present in highest concentration among the metals measured and because they exhibited some of
	the most dramatic differences in body burdens in populations around the Gulf of Mexico and among the 4 years of 
	the study. Wade et al. (1988) and Brooks et al. (1989) list the individual PAHs analyzed, but, for this study,
	body burdens of the individual PAHs were summed and a total value was used for statistical analysis. Contaminant
	data are presented as the geometrc mean of all sites included in each bay group (Tables 3,4,and 5).
		Values for mean monthly precipitation and mean monthly temperature were obtained from NOAA (1985-1989). The
	values used were averages of several stations around each bay system. Average monthly stream flow from gauged 
	streams -Rio Grande (IBWC, 1985-1989), the Mississippi and atchafalaya Rivers (Army Corps of Engineers, personal
	communication) and the remaining gauged rivers and streams (USGS, 1985-1989)-and estimated freshwater runoff
	(from precipitation data) for areas downstream of gauges, estimated from the total watershed area (NOAA, 1987), 
	were summed to estimate total freshwater input to each bay system. Land use around the bay systems, classified 
	as either industrial, agricultural or residential, was compoled from NOAA (1987).




								7-23


















                                                                                 Nil-
                                                                  43         @md Ttvlid.-@ Nilv,                     ill 4 y,-tiN, 11 11w SIM1%,



                                                                 Silt- :1,111w                                                              Localilm
                                                                                                                                  I-alifilde         Lungittide


                                                                        T t, N
                                               I     Lagmic, Nladic. Sowh IMN-                               UNIS11               26   2.58          97     10.49
                                               'i    Corpus Chirisli Bay. Nueces Isay                        CCNB                 27   51.70         97     21-00
                                                     Aransas Day. Long R(:(-(                                A13LR                28   3.30          96     57.50
                                               wi             Day. Collano lzi,@O                            CIICR                28   8.20          97     7.58
                                                     NIt.squite Bay. Avres 14-0                              NIBAR                28   10.30         96     49.70
                                                     Nlaiagorda [lay. Gallinipper 13(fint                    J\.IBC;p             28   35.00         96     34.00
                                                     Matagorda Bav.Trei Palacios Bay                         NIRTP                28   39.00         96     15.50
                                                     East Matagorda Bay                                       113 E- M            28   42.30         95     :53.00
                                                     Galvesimi Bay. Yarlit Club R(tf.-[                      GBYC                 29   37.00         94     59.50
                                                     Galveslon flay. Twild's Dump R(:ef                      GBTD                 Z9   30.10         94     54.00
                                                     Galvesum Bay. Hanna                                     CAMIZ                29   27.50         94     42.50
                                                     Galveston Bay. Conlederat(! 11'(@ef
                                                                                                             C.RCR                '29  15.75         94     50.50

                                               9     Sabitie Lake. 111tic Buck Point                         SLI311               29   48.00         93     511.42


                                                                     Lo u i s i a n a
                                               10    Lake calrdsk-w. St. Johns Island                        CLSJ                 29   50.00         93     23.00

                                               11    Josepli I farbur Bayou                                                       2ii  37.75         92     45.75

                                               1*2   VC-1-million Bay.Soulhwesl Pass                         V13SIl               29   34.70         92     14.00
                                               I     Atchafalaya Ray. Ovstt-r Baymi                          AR013                29   13.00         91     8.00
                                                     Caillou Lak(-                                           CLCL                 29   15.25         90     55.50
                                               14    Lal,(! Barre                                            THLB                 29   15.00         90     36.00
                                                     La k(- N-1 ic-i I y                                     TIILF                129  16.00         90     24,5o
                                               1.5   laralaria Bav. flavtsit St. I`X-tiis                    1313sr.)             29   24.10         89     59.80
                                                     nara(aria flay. Middle saill,                           IIHNIB               29   17.20         89     56.50
                                               18    BrOon Sound. Bay Gardvrne                               IISBG                29   35.87         89     38.50
                                                     Br.@:umn S(sund. Salille Island                         Bssl                 19   24.70         89     28.70

                                               19    Lake                            flobit                  UNIP                 19   52.30         89     40.70


                                                                   IN'll i s s i s s i p I I i
                                                                            PJSSChJ-iSliIII                  N IS PC              :to  19.75         199    19.58
                                               ,2 0  Bilo.Ni Bay                                             NISIM                30   23.38         88     55. 4 2
                                                     I'd-waqutil'i flay                                      NISI'll              AO   21.05         88     17.0u


                                                                      A I d It it tit it
                                               I     N.I.-hile BJj-, Ct-dal Voilit lwel                      N 11WI,              30   19.40         118    "I.3o


                                                                       F I (I r i d a
                                               2*2   114-11sactila flay. Indian BaVIIII                      Illsill              3o   30.83         87     4.00

                                                                                                             CIIISR               :10  213.50        W;     I (I.(;()
                                                     CII.-clawlialchl-k- Bav. shirt, Poilif                                       341  '111-95       1*,(;

                                               2 4   St. Aitifirt-w Bay. %Vatm,is llavmt                     SAI'M                :10     11.50      85     3 7.5 11






                                                                                                7-24













                                                                              IN') I AG-201 0,L),50




                                                                                                                                                Tot 11@     I                         I








                                                                                                                  F I        i d
                                                                              1      Alial'Ichicola flay. Dly Bal                                                         APDB                             21! 1    4 LiU             M          5.00
                                                                                     Alwhichicola Bay. Cto hiiiii Bar                                                     A PC P                           29       4:1.00            84      52.50
                                                                              '!7                Kev. Mark Point                                                                                           9        10.25             83         3.00
                                                                                     T,jmpa flay, l1apys Baymi                                                            T131313                          27       50.72             82      36.75
                                                                              @i     [email protected] Bav. Cockroach Boy                                                         TBCH                             2 7      40.55             8*2     30.56
                                                                                     Tompt Bay. klullel Key Bay(m                                                         TBMK                             '27      37.28             82      43.61
                                                                                     Chadolle Hatb4ir. Bird I.-J'ald                                                      ("BlU                            26       31.00             82         IGO
                                                                              30     NUPIcs Bay                                                                           NBNR                             16       7.00             ..81     47.10
                                                                                     Rtwk4-ry flay. I Iendt!rscilt CJ'(!(-k-                                              Rill Ic                          '2 6     1.83              81      43.75
                                                   0
                                                   to                         J I    Everglades. Faka Union flay                                                          EVFU                             25       54.27             81      30.60


                                                                      Tifljl(@ 2. Arillinwlic ineans lor curidifion index (g cin ') and length (cm) for the 26 bay groups for
                                                                      each cii Ow 4 years of tlie sludy. Nittans are determined from all sit" within eacli designated bay
                                                                                                                                                               group


                                                Cl)
                                                0                             13dy                              conditicift iodex                                                                                   Length
                                                cri
                                                z                                           Nar,                IS187                 1988                1! 189                      1986                 1987              1988                1989
                                                -2
                                                                              1             0.086               0.076                    1 i2             0.115                       S. 163               6.95-3            6.035               6.028
                                                                              2             0.087               0.131                 0.110               0.065                       7.407                5.673             5.521               7.042
                                                                              3             0.092               0.141                 0.104               0.0118                      8.470                8.197             8.187               6.383
                                                                              3             0.0519              0.137                 0.11.4              0.075                       9.378                8.299             6.916               7.071
                                                                              (1            0.087               0.119                 o.100               0.099                       10.132               8.370             6.7 17              6.292
                                                                              8             0. 1 Mi             0. 119                o. I Off            omk                         9.032                a35(i             8.546               11.332
                                                                              @1            OA75                0. 130                o.088               0.043                       10.440               9.648             9.655               8.395
                                                                              111           0. 100              0.108                 o. 1:35             0.054                       11.477               8.265             7.9118              9.323
                                                                              1 1           0. 120              0. 126                0.081               0.112                       8.358                8@787             8.187               7.062
                                                                              12            0.108               0.097                 0.088               0.081                       8.715                9.658             9.908               9.057
                                                                              13            0.10.5              0.112                 0. 1,22             0.0.51                      9.731                lo.360            8.182               8.197
                                                                              1-1           0.096               0-106                 (1. 107             0.071                       8.116 1              $ 1.223           7.178               7.488
                                                                              13            (1.088              0.114                 0. 125              0.068                       it).w@i              9_566             7.040               6.861
                                                                              18            0. 146              0. 103                0. 1 13             0-058                       9.657                8.504             7.708               13.465
                                                                              1.1           ItMW                (1. 128               4 1. 125            0.0.53                      8.942                7.270             7-524               5-682
                                                                              1             0. 1 t 9            0. 11                 it. 144             0.093                       H.399                7. 153            7-104               7.204
                                                                              1             11.14.1             0.105                 41.11:1             0.096                       8.622                @1.003            (3.033              (1.663
                                                                                                 109            0. IA5                o. 14 4             O.Mi 1                      9.090                4.558             G.0 17              6.456
                                                                              i             OA 19               0. 122                ().fig[             0.063                       7.747                4.949             6.673               5.974
                                                                              'i-I          0.141               0. 130                0.140               0.08il                      6.008                4.1110            (71.5iii            6.347
                                                                                            0. 149              0. 109                OA 19               0. 102                      8.4.33               7.347             8.1286              6.637
                                                                                            o. I i@j            0.104                 o.100               Omg@l                       7.438                .5.515            6.714               5.390
                                                                              _211          0.087               0. 120                o.117               0_086                       6.578                                  6.373               6.443
                                                                                            (1.(181             0. 1 O@j              o,171,1             0.06 1                      fi.517               5.2 9 5           6.466               15.640
                                                                              'to           OA H;               (I. I (if,            0 @ 11,12           0.078                       6.702                         G2       -1-673              5_46o
                                                                              JI            o.1213              0. 125                                                                8.060                6.56io            6.558               5.11:15







                                                                                                                                                 7-25

















                                     (J(411.864 (KL,1150 ISVNW.Mio.'!



                                     Taljl(- :1. G(-orm-fric Incw-.- (d                        III-fly li,.:rcl(-Il lor Ow melals                 arsenic. cadmillill 1111clselellium                           I)zi\. (@Voup @1110 (-Zich vvc! e.,; ;I-,(-
                                                                                                              study. Values given are paris per million (Ppoll


                                                                                                                                Pollulaill body burclen
                                                                      Si:"...-r                                        Arsenic                                           cb(lillikull                                        Selenium
                                        group        ING        1987         S188       198s,            1 Si8r)    IS)87       1988        1989            1986         1987       1988         1 @189         1 98G       1 @167     1988         1 slb@l

                                          1          1.73       ).14         088        i 68             21.67      15.10       18.67       14.84           3.83         2.72       2.13         2. 64          2.87        21. 13     -66          2 4
                                          2          1.33       1 .80        1.9)       1 .4 P,          10.95      1 O.U       10.66       8. 210          6,30         11.88      4.74         4                    8     'j - 3.5                4
                                          3          4.05       2.08              9     1-0-63           7.47       6.36        G. 3 7      7.14            7.63         5.14       6.34         5.73           4.43        2.7@1      3.6 1
                                                     1. B-1     I . (Ili     3. i 0          5           8.24       5.88        7.914       9.37            4.37         3.90       4.84         3. 16          2.63        2. ' .5        82
                                          6          4 . 6 7    3.14         1-1.50                      8.33       5.77        5.93        6.84            7.33         6.61       4.70         5.38           4.07        3.50       4,57         1"', -
                                          8          1. 7 6     2,30         2. '-' 4   21 - 35          4.81       4A8         3.48        4.44            4.33         4.11       3.16         5.00           3.04        3.07       4.04         3. 3 4
                                                     -.6t,      7.13         4.60       3.-@)            5.50       4.10        5.50        5.80            4.17         7.16       4.3          .5.13          2.53        2.68          1) 7
                                        10           2.00       2. 11)       '2.4 3     1.74             10.33      6.60        4.37        5.91            4.33         5.08       3.49         3.88           2.30        2.25       3.00           31 1
                                        11           '2.3?      3.16         '2.S,O     2,. 21 @ 1       8.00       7.97        4.80        5.63            4.83         3.61       4.57         5.09           2.13        3.118      3.32         4 -^' 7
                                        1 1,         5.00       4.55         3.47       5.08             @1.67      8. iQ       4.67        6.13            9.67         9.25       6.43         10.39          2.23        4.37       5.43         4 A I
                                        13           1.04       1.61         2.01       1.67             10.09      7 * 14      7.20        5.69            3.34         5.28       4.84         3.53           1.78        2.61       3.27         'J. 17
                                        14           0.43       0.51         0.93       0.68             10.25      8.78        7.39        4.98            1.98         2.29       3.69         3.13           1.54        2.22       5. 1 r)      '21. 21 1
                                        15           0,3G       0.73         1.23       O@77             9,75       10.77       7.89        7.55            1.44         1.46       2.17         2.17           1.03        1.73       3.38         2. 24
                                        18           1.07       (P. 93       1. 4 @l    0. @' 1          6.83       9.28        10.22       6.34            2.99         6.76       7.04         5.10           1.85        2.15       3.8!?          :16
                                        19           1.83       0.78         1 - 4 9    1.47             6.33       4.27        4.90        4.46            3.43         3.26       5.68         6.13           2,57        2 @ 321    4 - 21 9
                                        20           3.29       2.03         2.12       2.79             14.96      9.66.       14.30       8.14            4.14         3.79       3.87         4.07           2.09        2. 6 1     3.41         21, , 3
                                        ,)I
                                                     2.20       1.84         1 -98      2.01             15.66      6.33        7.04        6.45            2.50         2.38       3.56         3.73           1.63        1.78       2.3.1          7.
                                        22           1,213      2.80         1.66       1.50             11.33      17.2 0      12.14       8.84            3.87         2.83       2.86         2.74           2.40        2.13       3.42           '-, 9
                                        23           3.99       2.49         2.79       1,69             6.71       8.01        6.21        9.35            3.57         2.51       4.29         3.09           3.27        3.62       5.87         4. 21 5
                                        24           1.70       1.67         1.64       1.85             13.67      12.97       17.48       12.412          1.13         1.16       1.06         1.35           1 .210      1.68       21. 7 t^)    2. ^14
                                        23           1.72       2.62         1.76       1.26             10.05      11.93       11.54       9.89            2V           2.59       2.55         2.12           1.61        1.99       3.2 7        2.03
                                        27           0.33       0,45         0.42       1. 12            39.00      23.70       18.86       18.90           2.10         1.72       2.44         3..1 *1        1.37        2.43       2@03         3.69
                                        28           0.90       1.15         0.85       1.08             7.32       6.66        8.66        7.26            2.29         M4         2.97         2.34           1.36        2.09       2.39           1 1
                                        29           1.53       3.38         1.27       2.13             38.67      31.13       11.67       106             3.90         4.06       3.01         2.86           1.70        2.63       1.77           9 1
                                        30           2.51       2.98         3.26       2.18             24.52      27,97       28-16       19.28           2.02         1.38       1.81         1.43           1.49        2.20       2.09         1.61
                                        31           0.70       1.39         0.7 7      1.29             8.83       7.63        7.47        7.97            3.20         1.83       2.21 0       2.27           1.87        1.97       2.37         2

















                                       ON)1865 iKL)150 (SV%I)\A'iIS@)n



                                                                            1@'                                      Iol' Ill(- ll)LIals C(lpper. zinc all(i 11"("'""Y 't)l' (,'Lldl IJOV (1111111) bl)d IULII VQcIl 01 llll,@ lu(!\
                                                                                                                          Ima           in parlst 1)('I- Illillion


                                                                                                                                   P0111118111 body )AIrden
                                          Say                                  Copp(f r                                                                Zinc                                                              Mercurv
                                          g 1-0 U 1)     1986            1087            j5i88           198.9                1986            1 q87           1988            1989                  1986            1987             988


                                             1           120.00         120.33          169,84         1,10.08              1633.33         1257.67         4 94 5.86       162 1.712             130-00          196.07             00.14           124.
                                             2           110-55         1 C, 2. 3 3     19 1. 6 1      111.18               3343.98         3260.00         4 3 4 G. 3 1    4137.87                 79.86           22.00         1 31 0. 25         1  -3 1;
                                             3           172.61          98.4 5         1 @, 7 - G 8   113.84,              1211.01           724.60        1304.14         1286.4 3              103.69            54.11         3 42. 0 0          1) 4 4
                                             5           11 G,O I       10 6. 2'21      182.32         233.00               1137.03           94 I.G9       1382.09         1700.61               173.69          10 6.2 7        14 8.38               7 '2
                                             6           1  0.00        12    6-1        14. @s b        3 B. 3@              983.33        312-1.00        10', 2. 67      1292.25                 V, . r)         -111.33          69. 00
                                             8           121.57         161.71          156.76         193.06               1186.77         2544.19         3 186.08        34 38.99                56.93           92.16            47.31                 1
                                             9           K.00           4 93.67         '279.33        220.52               8000.00         3989.00         4146.67         3370.@)g              143.3.1         14 6.67         108.33             I's 29
                                          10             1,83.33        180.00             6. 5 8      185.80               2600.00         1899.33         3093.52         234 3.64              111.67            89.33            9 R. 12 0       6a 1 @I
                                          11             173.33         182.67          170.00         192.22               1200.00         1324.33         1625.67         2129,86                 4 7.67          50.33            70.00              5 6
                                          12             353.33         509.33          248.67         611.67               2300.00         2896.67         1435.33         4089.20                 39.00      -    77.67            38.33           C) 6 i
                                          13             105.28         18().8.1        1'63.18        148.00               1264.9 1        2353.74         2143,93         17 83.13                32.44           46.47            45-34           33. '3
                                          14             63.89           75. i2         114.35           86.43              1568.44         1578.96         2104.39         2388.97                 43.72           77.81            87.49           7 7. C) 6
                                          15             39.28           86.93          134.88           71.44                9 16.67       2097.02         2593.78         2625.89                 413.72          77.81            87.49           7  -) 6
                                          18             921 . 4 9      1 u 5.32         95. 1 CI        67.39              1052.78         1491.33         1205M             03.89                 32.79         108.78             5 2.2 8         C. '3 '6
                                          19             2) 9 3.3 3     116.00          280 1.99       228.19               3400.00         1285.00         3433.13         3369.99                 33.33         153.33          124.37
                                                         128.52         146.79          i 72.63        208.14               3215,66         3229,64         2762.19         4555.68               130.52          136.36          1 13.7 G           111
                                          21             100.00          59.33          133.86         132.51                 916.67          956.00        1891.42         1957.27                 70.00           67.67            73.71           6!.09
                                          22             75.00           43.33           65.60           53.19              2133.33           470.00        1572.89         1356.49               243.33            84.33         119.58             1, 2.2 3
                                          '13            -7 -1. 12 8     54.89           99.86)        114.03               2178.69         1983.16         3331.22         2170.02               256.48          2 P G. 3 7      '233.33            '21 6.7 q
                                          24             4 )(3.67       '2 7 Sj. G 7    210.71         139.8G               i4 00.00        3316.00         3150.72         3657.02                 71.67           43.00            71.40           132.34
                                          25             34.21           41.16           49.67           71.32                530.72          333.13          336.36          529.04              117.36          100.43             74.09           113.64,
                                          27             14.67           20.33           18-07           38.64                300.00          483.00          916.73          488.36              :106.67         138.00          139.02             91.03
                                          28             68.06           52.83           67.33           74,37              1666.15         1211.38         1859.14         2026.37               230,97          1 C)GISP        23V.87             2 ! .1 ?1 -1
                                          29             85.00          153.00          103.30         163.71               1300,00         1679.67         1706.11         2695.68               313.33          296.67          188-30             1., @4.1 6 7
                                          30             149.40         237.02          202.52         189.0                1302.35         1827.04         2089.41         1963.47               187.08          164.92                             151.44
                                          31             44,67           40.33           48.33           69.88                933.33          664.67        1167.67         11133.40              246.67          190.00          153.00             181.52












                                                                      i,;Nj1C,,6G (KL)150 (StY)VJ!ir1o,,




                                                                                                                                         lwy@ll'.Jlll @llldvac!l v-;'l (d lilt-                                     ill peols I)k!j         11'.Mi"ll (ppil"


                                                                                                                                                                    PA I I I      -t 1   1. (11 dvi S

                                                                                                                                                                iM7


                                                                                                                                                                                                                                            4 8.00
                                                                                                                            5 7.                                .117.00                             9611.89                                 408.85
                                                                                                                            32. i 4                             -.!4. 1 ()                          1 (1(;. 1 t;                            29.67
                                                                                           5                                4 1 _'25                            711.4 R                               93.97                                 7.5.12
                                                                                                                            10_67                               64,67                                 '2! j. (; 7
                                                                                                                                                                2:13.97                             27.5.611                                3 1 j. 5,.4
                                                                                                                            I V.3 3                             511.33                              17 1.(17                                171(17
                                                                                                                                                                6A.33                               252. 44 G                               364.4 1
                                                                                           1                                -11.33                                                                    28.00                                 82.67
                                                                                       12                                   68-67                               ua.67                                 i 1.67                                -30.00
                                                                                       13                               15:1.33                                 61.65                                 57.04                                 81.99
                                                                                       14                               '213-ii2                                !Of J. 7 7                          354.18                                  204.29
                                                                                       15                               257.28                                  24 11.2 1                           14 7. 85                                16710.34
                                                                                       111                              '203.63                                 65.4 1                              263.38                                  131.48
                                                                                       19                                   7_00                                34.67                                 89.63                                 101.50
                                                                                                                        47 I.-W                                 687.311                             '1611.32                                453.26
                                                                                                                            7:!.-;7                             :133.33                             .535.73                                 214.97
                                                                                                                        4:15.67                                 187.67                              3 13.99                                 139.03
                                                                                       23                               298.80                                  940.56                             1121.29                                  398.74
                                                                                       .!4                           13277.67                               2709.0                                '2533.99                                  961.36
                                                                                       25                                   i1o'2                               22.33                            IT3 4. 12                                  1025.00
                                                                                       27                                   38.33                               44.33                               :480.11                                 72.50
                                                                                       '18                              144.93                                  71.73                               111.361                                 176.94
                                                                                                                            20.1;7                              20 1*.(;7                             84.85                                 509.35
                                                                                       :M                               100.18                                  51.77                                 68.90                                 134.98
                                                                                       Al                                   98-CIO                              20.00                               19G.G7                                  108.00



                                                                                                                                                Spatial Distribution
                                                                              The spalial distributk)ji .if (ta(-11 containinant WiIS CXalllillCd Using a spatial autocorre-
                                                                      Idlioll 11101110d (lCSCj-ibCd bV Cliff & Ord (1973). We used Moran's I as the test statistic,



                                                                                                                                                                              W" Z' Z'


                                                                                                                                                                   it
                                                                                                                                        I         (11/w)



                                                                      dild


                                                                                                                                        W                         wjj; 7.


                                                                      fl __ IMIllber of saniples. X,                                   Value (if each Samole and %\,,i                                          it welghling ni(_-asure tis
                                                                      dt*-Scrib'-d below.






                                                                                                                                                   7-28


		Moran's I is sensitive to the location of extreme departures from the mean [x1-x]. For example, in a 
	patchy distribution, adjacent samples would both tend to be much above or below the mean more frequently than
	would be expected by chance. Significance levels were calculated after Jumars et al. (1977) under the assumption
	of randomization. Cliff & Ord (1973) showed, for samples that are spatially randomly distributed, that the 
	expected value of I is -(a-1)'. Hence, values of I below -(n-1)-1 indicate negative spatial autocorrelation 
	(an even distribution) and values above -(n-1)-1 positieve spatial autocorrelation (a patchy distribution).
		The use of this technique depends upon the choice of a weighting system (wq) which is a mathematical
	expression of teh spatial relationship between the sampled sites. Factors involved in the choice of a weighting
	system were discussed by Jumars et al. (1977), Sokal & Oden (1978a) and Cliff & Ord (1973). We constructed a 
	Gabriel-connected graph (Gabriel & Sokal, 1969) for the bays sampled in all 4 years. In this case, two sites (AB)
	were connected between the other two (<ACB). Gabriel-connected pairs were given a weight (wq) of 1.0 and all other
	pairs wq=0 (Fig. 1)
		The change in spatial relationship among samples at varying distances can be used to identify the scale of 
	spatial variation. For example in a patchy population samples closer than patch size will be more similar than 
	expected by chance (e.g. Moran's I>-(n-1), whereas samples further apart than patch size will be less similar e.g.
	Moran's I <-(n-1)1). We examined the change in spatial relationship with distance using correlograms (plots of
	sample similarity versus distance between samples) calculated as discussed by Sokal & Oden (1978a,b). Distances
	were calculated along the Gabriel network by Marble's method (1967). Bays within a given distance from one another
	when joined along the Gabriel network were given wq =1.0; for all others wq=0. Therefore, our correlograms were
	distance-corrected using the terminology of Sokal & Oden (1978a).

							Temporal changes in spatial distribution

		To examine the spatial scale of yearly changes in the biological variables and contaminant body burdens 
	and to determine whether concerdant changes occurred among several variables, we used the analytical approach of
	Powell et al. (1984) as adapted by Powell et al. (in press). First, we ranked each of the 4 years for each bay
	group from 1 (highest) to 4 (lowest) for prevalence and mean infection intensity of P. marinus, lenght, condition
	index and each of the eigbht contaminants. Two bays or two parameters were compared by subtracting each year's
	rank for one from the corresponding rank for the other and summing the absolute value of the 4 differences. As
	an example, if the data for hay group 1 were ranked 1,2,3 and 4 years and the data for bay group 2 were ranked
	1,3,2 and 4, then the differences would be 0,-1,1,0 and the absolute value of teh sum would be 2. The values of 
	the sums obtained in this way can only take the values 0,2,4,6 and 8. The frequency spectrum of occurences of 
	possible sums between site pairs having randomly distributed ranks is 0 (.042).2 (.125),4(.292),6 (.375) and 8(.167).
	A frequency spectrum of sums calculated from the data in this way was compared to the frequency expected by chance
	combinations of the rankings using Kolmogerov-Smirnow (K-S) one-sample two-sided tests. Significance of the K-S
	statistic was judged using Conover's (1972) method for calculating exact P-values for discrete



									7-29




















                                                                                                                    MSPB    M13CP

                                                                                                            -LBMP
                                                              si
                                                                                      c CL
                                                                                      ' *..  .   :..:. .:.-   13S8G
                                                                   H  H V(3Sp
                                                                                  BOB         T8                 --BSSI

                                                                                                      86M
                                                                                          TSL



                                                                                                            msas msps
                                                                                                      MSPC

                                                                                                                           MBCP
                                                         CLSJ                ABOB                            L84MP
                                                                                      CLCL      138so        BS8G
                                                                                            TSLF                 Bssl
                                                        CL
                                                                 JHJH
                                                                         VBSIP


                                                                                         TBLB








                                                              Ps     cesp C 8 SR-t
                                                                                 -SAWS
                                                                                           APCP


                                                                                  APOB
                                                                                                  CKSP


                                                           rOsti
                                          P,1.8 CBSP
                                                              SAINS   APCP                                  -XSPS


                                                                                                     TBMK
                                                                  ADPS

                                                                              CKBP                     TlIce




                                                                                          TOPS                ceal
                                                                                                                 NSN13'k"-
                                                                                TStJK                            118HC
                                                                                   T3CO                               FU



                                                                                         COW
                                                                                           Nolu
                                                                                            AOHC
                                                                                                EVFu
                                                                                                                           MBCP
                                                                                                        L @8
                                                                                                              4M P
                                                                                        _CL 13       0       BS8G
                                                                                        1, TE3LF                 SSSI
                                                                                                     R
                                                                                                       R,
                                                                                                        "R
                                                         ,@_: Ips.-s-

                                                         1@@SA ZIS









                                                                                7-30


							

										*GBYC
													*SLBB
										 *GBTD    *GBHR
										*GBCR


								*MBTP
							*MBGP		*MBEM
												*GBYC			*SLBB
						*CBCR						 *GBTD		*GBHR
							      *MBAR				*GBCR
					*CCNB		   *ABLR				 	

										*MBTP
								    *MBGP			*MBEM
							*CBCR
										*MBAR
						   *CCNB		      *ABLR



				       *LMSB











								*LMSB


	Fig. 1. Distance-corrected Gabriel graphs for the sites sampled around the Gulf of Mexico in each of the 4 years
	of the Status and Trends Program. Four-letter site designations correspond with those in Table 1. Dots indicate
	site locations. Graph is drawn opposite for clarity. See Powell et al. ( in press) for more details


	data. In this analysis, if the year-to-year change in any variable between bay systems tended to co-vary, most 
	going down, then values of 0 or 2 in the previous example would occur more frequently than expected by chance. If
	the yearly changes tended to oppose one another (for example some bays going up, the others down) then values
	of 8 would be frequently obtained.
		We utilized the preceeding approach on two geographical scales, the entire Gulf of Mexico (all bay systems)
	and sets of ten contiguous bay systems, contiguous being defined along the Gabriel graph. In the latter case, 10 
	bay systems were chosen because the number of bay systems in Texas and extreme wester Louisiana, as defined here
	was




									7-31		






10. To determine hte extenl of regional sieilarity sels sets of nine hay system were examined step by step orounal the Gulf of Mexico in the following manner. Step one always comparel lays from the Liguna Aledre in South Texas through Vermillion Bay 
in western Louidiana. Step 2 was generated by deleting the most Southern Bay system (Laguma Medre) and adding the next bay system to the cast (Alvhafalaya Bay and Cailou Lake)
Consecutive  steps followed the same protocol with one exception. Step originaling on the Eastern  Gulf coast were alloud t wrap around the Gulf. For Example, Step 22
compard the five Southern most Florida Bay system (Cedar Key to the Everglades0 and the 5 southern most Bay system in Texas ( Laguna Madre through East Matagerda Bay). We exanmined all possible 
pair -wise combinations within the set of 10 Bay systemd. This gererated 45 sunis. The frequency of thesre sums was compared against the expected
frequency of sums using K-S tests as previously described. A non-signficant value for the K-S statistic among the 10 Bay systems making up one step indicates local control of the tempotal variation in the variable 
(E-G. pollutant simultaneously going up or down in value) from one year to the next did not occur among the 10 Bay systems more frequently than expected by chance over the spaliat scale encompassing the 10 Bay system.
This result would suggest no regional imprint on local control of variability. Similarly, a significant vale of the K-S statistic would suggest that regional influences overrode local controls so that
temporal variation, in contaminant body burden or disease for example was substantially affected by climatic, as well as local, factor. Plots of the K-S statistic as a function of steps around the Gulf give a graphical representation of the spatial extent of the similarity.

Within those geographic regions where yearly changes in pollutant body burden were concordant using the K-S test. R improvment test were conducted. Factors tested in most 
models included that might have produced the odserved concordancy. Factors tested in most models included length conition index, mean temperature, mean precipitation, P.
marinus prevalence and infection intensity. And agricultural and industrail land use. The parameters that produce the best R model were than used in regression analysis, again
only in regions of yearly concordancy as defined by consecutive significant results of the K-S test. Not knowing the response time for pollutant body burdens to shifts in environmental regimes in most casses analyses were
conducted using the average precipitation and tempuature values for the 5 months prior to sampling and the 2 months prior to sampling.
Prevalence and infection intensity of P. mainus were used in R improvement and regression analyses only with the average precipitation and temperature data for the 2 months prior to sampling because P. marinus responds do rapidly to changes in the Environmental Regime.


RESULTS

Spatial Distribution, Gulf-Wide

Correlograms calculated along the Gabriel network for the Distribution of contaminant body burden with distance around the Gulf Of Mexico are given in Figures 2 to 3. The 
contaminants can be divided into two distinct groups. For mercury, selenium, arsenic and casmium site-to-site similarty gradually declines with distance over the first approxi


7-32      

















                                             1,0-





                                             0.5-
                                                   L




                                       c

                                                                                                               %
                                                                                                                       A.
                                             -0.5 - -----     1986
                                                              1987
                                                              199S
                                                              19S9
                                             -1.0 i -            I                                                     .
                                               0      200      400     600      Boo     1000    1200    1400     1600    1800    2000
                                                                                   Distince (km)


                                                                                   Selenium




                                             0.5-

                                                                                   'A
                                             0.0            )K
                                                                                               %

                                             -0-5 -






                                                                 1987
                                             -1.5 -   ---- 1988                                                             41
                                                                 1989

                                             -2.0f
                                                 0     '200    4@O     6@O      8@O   10'00    1200   1400    16,00 ieDO 2000
                                                                                 Dist:incc (km)


                                          2. Corlolotirallis ol-lalinq dislance (kiii) Us Nhirail*s I (ditaitieJ ti-sing licidy litirden of inercurN and
                                     st-k-Ilitful jor all sil(@.-; sallipled in ea(-h year. Di.-.1imccts were calculakid along the Gabriel
                                     wiwiv slations separdled Ily. lor             10 1 alld 200 1,111 werc. It-,4:ILI to slew.-rate. the 200-1,111 J)'Jilll.
                                                         I'lle itik-al rolid(lill v,tltt(! Im- P Itirais's I i-@ approximately -0.04



                                     incitc-ly IGOO kill in (:cich of flie 4         The C.-0rl-V.I(I(jralllS I)iISS tlll-OLI(jll I = -(]I - ])-@ Zit
                                     (11101.11 -100 kill. I'll'a is. Ijay groups k-ss than 400 kin iparl are more similar in b(gly Ijuv(ien
                                     (01 llltl*@C 11101cif" 111(ill Vxjwclod hy Cluilict. alld Sit4L-.-, become. less and less similar at larger
                                     xMd larq(tr spitial sc,fles. Anollwr characteri,,tic of [lie (listribitticin of groUl) I C011taillin-
                                     aills 'is Ihe closic. association between the fir-st '! years ( 19116 and MR71 and the last 2 y@!ars
                                     (PIN'l 'Illd P1,191 <11 dw It'll(lost spali'll scalos.. Body 13111-dell 411 --y-ilers Iroill IIIC east 'Ind
                                             co'ININ of Ow. Gtflt variod similarly alliollig tht. bays within both pairs of years and







                                                                                  7-33














                                                                                                              Arsenic




                                                           0.5-



                                                           0.0-


                                                           -0.5 -                                                                                           'A



                                                           -1-0-


                                                                                   x987
                                                           -1.5-                   1988
                                                                                   1989

                                                           .2.0                      4         4         4     .    .      I  I.                         -    .         I
                                                                 0      200        400       coo       800        1000      1200       1400      1600      1.8.00     2000
                                                                                                         DLst2nce (km)


                                                                                                           Cadmium

                                                           1.0



                                                           05-

                                                                                                                                                       -A@
                                                                                                              A,.




                                                           -0.5-
                                                                                                                              *A'
                                                     2     -1.0-
                                                                                   1986
                                                                                   1987
                                                                                   1988
                                                                                   1989

                                                           -2.0-                                                                                    4
                                                                 0      200        400      6@O        6@O        1000      1200       1400      1600      1800       2c;00

                                                                                                          Dislaticc (kill)


                                                                          III, w1atill(I dist.111ce (kill] Ill               141litailled 41iiII(I 111)(IN. Istil-doll (Ifarsellicand

                                                     lw!.- -lall-11, -'1411011"d 131'. 11W.'XIIIIIIIIv, 101 and 200 kill wt-we tis4-.(I to gencrik! III(-, '200-kin 1)(4111.
                                                                            The idv'd I'alldt'Ill valm- I(Ov MocaWs I i%                                -0.04



                                                        I. cl I Ict 14 .0 sI Ill I I it Ov h Y s(l I I It.! I -(I(. I(! ev(!111 %v I, icli occorred Ix.-tween 1987 a I I (I

                                                           Ill c(IIIII-cls-I 14) (11-oup I c(JI11,1111itliIIIIS, Ille diitribtilicin of gamp 1 C011till1lillaillS. Copper.
                                                  Z1111'. N'Ilvor '111d I(,'U(1 PAI Is. ShOwS, Ito coverall                                   (11(@ piit(erli tell(Is to ().sCiliate
                                                            ill(.. ldcal rawl(IIII valw. ill ntos( spallill scilics for all 4 years. This pjdj(-rn itl%o (10(!S
                                                   11-1 @.Iv'lrly sIval, Ow dis(inct bi-cal,                            19416-1987 and 19811-19119.






                                                                                                         7-34












                                                                                              Copper





                                                  0.5-





                                                 0.0-                                                                 _Ak



                                                                                                        )IL
                                                                                                                'A
                                                                                                                            %
                                                                      1987
                                                                      1983
                                                                      1989
                                                -1.0  i
                                                      0      200      4@O      6@O       600      1000     1200     1400      1600     1800     2000
                                                                                          DiSt2rKV (kM)


                                                                                               Zinc







                                                                         A


                                                  0.0-

                                                                                                                        ,It



                                                   -0-5                 19M
                                                                        1967
                                                                        Im
                                                                        1989

                                                   -1.0
                                                       0       200      4@0      6@O      8@0      1000     1200      1400     1600     1800     2000
                                                                                            Di:auncc (km)


                                         Fig. 4. Correlograms rt--lating diNutru-41 (luill to Morall's I Obldillt.-d using body burdeve of copper all([
                                         zillc i4jr all     Sampled ill (-ach yt:ar. Distanc-c!s xvcre rzdculai(--(t alunq dic Gabriel network. where
                                                               11jr. 101' ('XdIlljJI(-. 101 md '100 kill         mcd to cl(itwr@alt-. Itie 100-kin point. The
                                                                  idt-,it random           tor Mor,m*s I is                      -0.04




                                               perk-ills(IS marillus is all impOl'UtIlt J)dtlLO(J(211 ill                    I)OI)LIlatiOlIS ill the GUlf Of
                                         NlexiCO. and is responsible lor high mortality ill most years (I lofstetter. 1977). Correlo-
                                         grCillis lot, ttleall prevaterice wid meim itifection ititeresity (if 1@ mariijus for each of Ific 4
                                         yoars are clivell ill Powell (.-( at. (in press). Overall, the spattal distributioti of A marinus
                                         prevalviiCk! all([ infection inteitsi(y. while not identical, retaires many of the spatial
                                         (I k(I 1-@rl Cl erest Ics of grollp I cuntaminatits- Correlograms for P. mariijus prevaterece aged






                                                                                           7-35













                                                                                       Silver




                                                                   1 1-8
                                               0.5-                1939]
                                                                                                                                   A@
                                               0.0-



                                                                                                         ILI
                                                                                                             'XI







                                                   0     200       400    600      Boo     1000    1200     1400    1600    1800     2000

                                                                                    Distanct (km)



                                                                                   Total PAH

                                               1.0





                                               0.5-



                                                                                                                         A

                                                                           A
                                               0-0-
                                                                                                           --A


                                                                               Ik
                                               -0.5-               1986
                                                                   1987
                                                                   1988
                                                            ---    1989


                                               -1.0
                                                   0     200       400   600      800     1000    1200     1-100   1600     1800    2000
                                                                                   Distance (km)


                                       Fiq. 5. Corm-locirams r0ating clislan(:c (kill) to N-loran's I ubtained using budy burden (of silver and
                                       I-I.d PAI I for all siles sampit-d in vach yvar. Dislallc(-., vvd-rc cal4rulaied alung (lie Gabriel network.
                                       X-divit- .'Idliolls separdled by. for         R, I and '100 kill werit Used to (Itnierate Ow 2004,111 julint.
                                                           'mi.. itit!.l racidmn valuca I(jr        I is isppruximatOy -0.04
                                       - '. .- .                                                                                                                   I
                                       Ilifecliull ilitensily (lei'. lolls( 1-41 le it VC1,11 strong relationship between year pairs 1.986/87
                                       and 1988/89. Again. the I)reak- between. 1987 and 1988 I-CSIARS in two very different
                                       di@,Irihtltiolwl patterns Cit C@-rl(titi sp,diiii scales. Similarity dedines over (lie first approxi-
                                       m,itt-lv 1-100 kill. allhoti(th mork. rallidly Illall It does for Ille conlaininants. and relurns
                                       citizilit <if Imi(Icr spatial scak-s.







                                                                                    7-36


                          Temporal changes in spatial distribution

Utilizing test the spatial scale of the Gulf of Mexico (2000 km along the Gabriel
network), few contaminents had significantly concordant shifts (Table 6). For selenium.
and to a lesser extent zinc,copper and arsenic,however,many more bay systems in the
Gulf tended to vary simularly year-to-year than would be expected by chance. That is the
tissue concentration of these contaminants tended to increase or decrease uniformly from

Table G. Results of analyses to detect concordent temporal shifts among all 26 bay systems in the
Gulf of Mexico. A significant result indicates that temporal shifts of the measured variable were of
the same sign (values increasing or decreasing) in most of the bay systems around the Gulf

Patameter                            KS Statistic                         P Value
Silver                               0.11218                              0.3833
Arsenic                              0.17949                              0.0640
Cadmium                              0.11859                              0.3744
Copper                               0.19551                              0.0601
Mercury                              0.11859                              0.3744
Selenium                             0.50321                           6.0x 10-m
Zinc                                 0.21795                              0.0313
Total PAH                            0.05128                              1.00
Condition index                      0.38782                           5.9x10-5
Length                               0.34936                           3.4x10-4
P.marinus mean infection             0.48718                           6.0x10-8
P.marinus mean prevalence            0.21795                             0.0313

one year to the next in all or a significant portion of the bay systems. Such coincident
shifts in body burden would indicate some regional or Gulf-wide control on body burden.
Among the biological indices,condition index,length. Perkinsus marinus prevalence and
P.marinus infection intensity all were characterized by nearly Gulf-wide coincident
oscillations in yearly values.
   Meteorological data (Trenberth et al. 1988; Ropelewski & Halpert, 1986; Douglas &
Englehart. 1981) suggest that the eastern and southern Gulf are dissimilar from the
western Gulf. Powell et al. (in press) found that P.marinus prevalence followed this trend.
Consequently, substantial geographic areas of similarity might go unrecognized at a
spatial scal encompassing the entire Gulf of Mexico. Accordingly, we also looked at
groups of  10 bay systems covering approximately 600 km of coastline (range
500-900 km,excepting those that "wrap around" the Gulf,thereby including the eastern
and western portions of the southern Gulfs.
    Average length of the oysters sampled tended to decrease in each year throughout
the study. The largest oysters were always preferentially sampled at each site. The
decrease in length could represent teh depletion of the largest individuals over time due
to this sampling strategy: however, the decrease occurred in fished and unfished
populations and in many areas most collected oysters were no more than 2 years old.
Accordingly collections the previos year would not have sampled the same cohort.
Trends in size then are probably a natural phenomenum. Yearly trends in length are
coincident over most of the Gulf,except the Galveston Bay/Sabine Lake area of Texas.

                                     7-37















                                                                       Cadmium                                                                          Arsenic
                                                0.20                                                                         0.40-



                                                                                                                             0.30-


                                                                                                                       .2    0.20
                                                                                                                       LOI)                                  -------         3, A,
                                                0.10-                                                                                                                         4@
                                                                                                                                   ------------                              - -----


                                                                                                                             0.10-



                                                0.05-                                                                        0.00-1
                                                     0         5         10         15        20          25                       1         6          1 1        16         21         26
            ---I                                                  Steps Around Gulf                                                             Steps Around Gulf
            C@
            00                                                            Mercury                                                                       Silyer
                                                0,2                                                                        0.20-



                                                0,151-                - - - - - - - - - - - - - - - - - - - -              0.15  -- - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                                                                                                      U



                                                O.io-                                                                      .0.10-



                                         x      0.05                                                                       0,05-



                                                0.00                                                                       0.00
                                                     1          6         1 1         1 G       21          2 G                  I          G          I i        I G        2 1        2 G
                                                                   Stens Around Gulf                                                           Steps Around Gulf
                               Fig. 6. Graphical representation of results of the       Kolmogorov-Smirnov test for arsenic, silver, cadmium, and mercury using              all bay pairs  in ea
                               group of 10 bay systems (one step), The two lines indicate the a             0.05 (solid) and 0.10 (dashed) significance levels for an n of 45 (number of SI(C.-
                                                                                                            pairs used)






                                                      MEMO&                    Wt



                     =ago MIMM









                                                                                  Zinc                                                                      Total PAH
                                                    0.507                                                                         0.4


                                                    0.40-
                                                                                                                                  0.30-


                                                    0.30

                                                                                                                                  0.20-

                                                    0.20
                                                                                                                                         -- - - - - - - - - - - - - - - - - - -      - - - - - -
                                                          - - - - - - - - - - - - - - -                    - - - -          too)
                                                                                                                                  0.10-
                                                    0.10         Id


                                                    0. DO                                . . . . . . . . .                        0.00
                                                          1         6          1 1        1 G        21          26                                           1 1         16         2 1         2 G
                                                                       Steps Around      GuirI                                                        Steps Around Gu)t

                                                                             Copper                                                                        Selenium
                                                  0.25                                                                           0.70
                                                  0.20                                                                           0.60
                                                                                                                                 0.50

                                                  0.15    - - - - - - - - - - - -          - - - - - - - - - -                   0.40-

                                                                                                                           V)
                                                  0,10                                                                           0.30-,
                                            V)
                                                                                                                           X     0.20
                                                  0.05                                                                                   -------- --------
                                                                                                                                 0.10-,


                                                  0.                                                                             0.00
                                                        1         6          It          iG         21          26                       1        8          11          16         21          26
                                                                     Steps Around Guir                                                               Steps Around Guir
                                 Fig. 7. GraphiW representation of results of the Kolmogorov-SmImov test for seleni=, copper, zinc, and PAH using all bay pairs in each goup
                                 of 10 bay systems (one step), The two lines indicate the cc - 0,05 (solid) and 0.10 (dashed) significance levels for an n of 45 (number of sitepairs
                                                                                                                   used)



length increasing or decreasing from one year to the next coincidentally in most bays
within a contiguous group of 10(Figure B). Of particular note are the highly significant 
concordancies in the eastern and southern Gulf of Mexico. Yearly trends in length in
southern Texas and southern Florida were nearly identical,small oysters being collected
in certain years and large oysters in other years.
    Low values of condition index typically indicate a stressed or unhealthy population.
Condition index also varies with the reproductive cycle in 1989, 3 of the 26 bay systems
had condition indices greater than 0.1. while 1986 had 1.5, 1987 24 and 1988 21. The two
years with lower mean prevalences of P.marinus had higher average condition indices,
as might be expected. Similar year-to-year variations in condition index occurred
throughout the Gulf of Mexico(Figure 8). As the time of sampling of the populations was
similar in all cases, except the Louisiana bays in 7986(Craig et at., 7989; Wilson et al.,
1990), this trend indicates that a Gulf-wide variation in climatic conditions probably
controls condition index in Gulf oysters.
    Similar year-to-year variations in prevalence of P. marinus occurred throughout the
Gulf with the exception of the central-northern region represented by bays on both sides
of the Mississippi River(Figure 8). Powell et al.(in press) noted that the Mississippi River
represents an important boundary in P. marinus infection. The only uninfected popula-
tions in the Gulf of Mexico are regularly found on the Mississippi delta. Concordant year-
to-year variations in mean infection intensity of P. marinus occurred throughout the Gulf
of Mexico, as was the case for condition index and nearly so for length, suggesting a
similar relationship with climatic variables, if not a causal process. P. marinus infection
intensity could be a controlling factor in both length and condition index. Again, in both
prevalence and infection intensity, the similarity in yearly trends on both sides of the
southern Gulf is noteworthy.
    The pollutants divide into 3 groups based on their temporal variations (1) Like
condition index, length and P. marinus infection intensity, year-to-year variations in
selenium coincided throughout the Gulf. The similarity between selenium and condition
index is particulary noteworthy. Year-to-year variations in arsenic were only slightly
lower than selenium in their regional scale of concordancy; concordancy occurred over
much of the eastern and western Gulf,only failing to encompass the Louisiana region.
   (2)Mercury and cadmium varied similarly in the western Gulf,but not in the eastern
Gulf. The degree of concordancy was low, large-scale control of body burden occurred
only in the Texas region. This pattern,then,is different from all biological parameters.
   (3)Year-to-year variations in copper,zinc and PAH body burden were concordant in
the eastern and southern Gulf,particularly Florida and southern Texas, but not in the
northern and western Gulf, a trend exactly opposite of that noted for cadmium and
mercury.  The concordance of yearly variations in body burden on both sides of the
southern Gulf similar to that noted previously for P. marinum prevalence and infection
intensity and condition index.  Again the region of concordancy begins in the Mississippi/
Alabama area of the Gulf at a similar location as it does for P. marinus, suggesting a
similar climatic control.
    (4)Silver failed to show regional concordancy anywhere in the Gulf.

                                7-40









                                                                     Condition Index                                                           Mean Infection Intensity
                                                 0.60                                                                            0.00

                                                 0.50- .                                                                         o.7o-

                                                                                                                                 0.60-
                                                 O.AO
                                                                                                                                 0.50-
                                           V)                                                                                                             . . . . . .
                                                 0.30                                                                            01.40-

                                           X                                                                                     0.30.
                                                 0.20'
                                                       -- - - - - - - - - - - - - - - - - - - - - - - - - - - -                  0.20.
                                                                                                                                       ----------------------
                                                 OJ 0                                                                            O.j 0
                                                       1          6                                 21         26                                                           a       21          26
                                                                     Stcps Around Gulf                                                               Steps Around Gulf


                                                                              Length                                                                      Prevalence
                                                 0.60                                                                            0.60-


                                                                                                                                 0.50
                                                 0.50-

                                                                                                                                 0,40-,
                                                 0.40
                                                                                                                                 0.30
                                           i7                                                                              GO
                                                 0.30                                                                            0.20
                                                                                                                                          - - - - - - - - - - - - - --
                                                 o.20-                                                                           0.10.


                                                                                                                                 0.00
                                                 0.10                                                . . . . . .                                                                     21         26
                                                       1          6          1 1        1 G         21         26                      1           6                      16
                                                                     Steps Around Gulf                                                               Steps   Arour\d Gulf
                                 Fig, 8, Graphical     representation of resWts of'the Kolmogorov-Synimov test for condition index, length and t@e inean infection inkcns:ty and.
                                 prevalence of infection of Perkinsus rnarinus for all pairs in each group of 10. The two lines indicate Lhe oc - 0.05 (solid) and 0.10 (': ' '
                                                                                                                                                                                                    'as.'Iocl
                                                                                   significance levels for an n of 45 (number of site pairs used)


							DISCUSSION

	Explaining the temporal and spatial variation in contaminant body burdens is complicated because body burden may be
affected by so many environmental and biological factors (Farrington et al. 1983). Oysters can incorporate metal and 
organic contaminants either through direct absorption from water or ingestion with food particles (Ehrhardt, 1972;
Stegeman & Teal, 1973). Therefore, any factor which affects the bioavailability of pollutants such as changes in 
environmental condition, physiological condition or food supply may ultimately affect contaminant body burden 
(Farrington et al.,1983). Factors controlling these conditions are, in teh extreme, of two kinds: local an large-scale.
These, in the extreme, offer two opposing expectations. In the local case, temporal varioations in body burden should
never occur simultaneaously in adjacent bays more frequently than expected by chance. In the large-scale case, we 
should expect coincidental variations within some large geographic region. It may be true that local variations outweigh
large-scale factors in some regions and not in others, depending upon the strength of the two signals. El Nino, for
example, affects the southern and eastern Gulf. A contaminant significantly affected by environmental conditions associ-
ated with El Nino might show coincidental changes in the eastern and southern Gulf while local variables controlled 
its temporal variability in the northwestern Gulf. Understanding the variation in contaminant body burden, then, requires
investigating the effects of biological and environmental factors on both the local and larger geographic scales.


								Temporal distribution and climatic control on variability

	The biological attributes and contaminants can be placed into three groups based on the regional scale of their
concordant temporal changes in the Gulf. For selenium and arsenic body burden, condition index, length, and prevalence
and mean infection intesity of Perkinsus marinus, year-to-year variations are similar in nearly every bay around the
Gulf. This implies controlling factors Gulf-wide of nearly Gulf-wide in scope. The geographic scale is largest for
selenium. P. marinus infection intensity, condition index and length, but encompasses all save the Louisiana bays for
arsenic and P. marinus prevalence. The second group, including mercury and cadmium, varies concordantly from southern
Texas to approximately the Mississippi delta, suggestive of some large-scale phenomenon in the northwestern Gulf 
producting similar changes in body burden for these contaminants. The last group, including copper, zinc, and total
PAHs, varies concordantly in southern Texas and southern Florida, suggesting a subtropical control on body burden for
these contaminants. 
	Of particular note are the geographic boundaries of these three groups. The boundaries between the northwestern
and the southern/eastern Gulf are clear; the vicinity of the Mississippi River delta and the Matagorda/Aransas Bay 
area of Texas. The break in similarity for arsenic and P. marinus prevalence in the Mississippi River region also marks
the eastern extent of similarity for mercury and cadmium and the western extent for copper, zinc, and PAHs. The western
extent of similarity for mercury and cadmium, Matagorda Bay, approximates the northern extent of similarity for PAHs,
zinc and copper. 
	These groupings of contaminants and biological attributes require three levels of

explanation. First, if only climatic factors are of sufficient scale to explain the concord-
ances observed. what climatic factors are ultimately responsible? Second, why certain
grops of pollutants climatically controlled only in one part of the Gulf; do geochemical
similarities for example, explain these groupings? Third, what factors mediate the
climatic control on body burden?
	Climatic controls. Large-scale concordances in temporal change can only be
explained by climatic factors; only these operate on an appropriate geographic scali.
Choices for the climatic factors ultimately responsible are relatively limited. (Of course,
our data do not permit us to cerify what the ultimate caosative factors are. A 4-year time
series is inadequate for statistical treatment.) The concordant shifts in the easetern and 
southern Gulf suggest a tropical or subtropical control. The El Nino/Southern Oscillation
phenomena is of appropriate scale and location. El Nino occurs in the Pacific, but affects
temperature and rainfall in the Gulf of Mexico region by altering dominant weather
patterns (Trenberth et al., 1988: Philander, 1989) and has been implicated in temporal 
variations in P. matinus prevalence and infection intensity. El Nino/La Nina events
typically affect the Gulf from the panhandle of Florida through southern Florida and 
southern Texas, where concordancy for selenium, arsenic, copper, zin, PAHs and most
biological cariables occur. A strong El Nino/La Nina shift occured between 1987 and 
1988 and contributed to the Noth American drought that summer (Philander, 1989). We
noted that the year that the groups 1986/87 tended to be statistically similar in many
analyses, as did Powell et al. (in press). A second large-scale meteorological phenome-
non, the Pacific North American Teleconnection (PAMT), control the number and 
severity of winter storms in the northwest Gulf region (Wallace & Gutzer, 1981) where
concordancy for mercury and cadmium, as well as selenium, aresenic, and most biological 
cariables occurs. Combined, these two weather patterns could explain the geographic
scale of concordancy observed in each of the contaminants and biological variables.
	Why groupings exist. Any of the contaminants of biological attributes might 
respond to two scales of environmental change. Local changes, originating for example
from the nearness of urbanized areas, the presence of certain contaminants in particular 
drainage basins and the extent of agricultural development, should produce discordance
between adjacent bay systems. Galveston bay, for example, might drain a large geo-
graphic area wheras an adjacent bay, East Matagorda Bay, may receive only local
precipitation. Contrasting wtih this ate large-scale climatic trends which affect weather
patterns at least regionally. Changes in the precipitation regime during El Nino cycles are
a good example. All watershesds in regional areas may be affected in the same way.
Depending upon the conpeting strengths of local and climatic variability, biological
attributes or contaminants might respond most strongly to one or the other. In our case,
the body burdens of copper, zinc, and PAHs would apear to be predominantly under 
local control in the northwestern Gulf and under climatic control in the eastern/
southern Gulf. Mercury and cadmium have the opposite distinction. Selenium, arsenic
and many of the biological attributes respond regionally in both areas. Silver seems 
generally to be under local control.
	For the first two groups, the reason why local controls are relatively more important
in one region than another is unclear, nor is it clear why cadmium and mercury behave 
similarly, as do copper, zinc, and PAHs. To the extent that copper and zinc often behave
similarly in bivalves (Phillips, 197Ga, b; Phelps et al., 1985; Roesijadi & Klerks, 1989) and





					7-43      

quite diffierently from Cadanae: tBrooks & Rumsby. 1965; Boyden, 1974; Cheng, 1988a,b:
bet see Roesquda et al.,1989 these data fit an expected scenario.
	Mediating factors We used R2 improvement and regression anayses on the
yearly rankings for those locations in the Gulf demonstrating concordant yearly shifts to
examine what biological and climatic parameters might contribute most to the observed
concoidancy. Inasmuch as the biological parameters certainly were also influenced by
climatic parameters, the set of independent variables were not in themselves completely
independent: thus the analyses serve as a guide to the mediating factors responsible only
in this context. Moreover, we expected factors to differ between the northwestern and the
eastern and southern Gulf regions.
      In detemining which variables might affect P. marinus, we considered condition
index, monthly mean temperature, monthyly mean precipitation, length, cadmium, 
selenium, zinc, copper, PAHs, silver and mercury (Table 7). P. marinus prevalence was
positively correlated with mercury body burden and negatively correlated with tempera-
ture and condition index in the western Gulf. Negative correlations existed for zinc,
selenium, copper and cadmium and positive correlations for PAHs and arsenic in the
eastern and southern Gulf (Table7). P. marinus infection intensity responded negatively
to selenium, condition index, and length and positively to copper in the western Gulf;
condition index and selenium demonstrated negative correclations in the eastern and
souther Gulf. These correlations demonstrate serveral important trends. (1) Biological
variables were the most important correlates of the distribution of P. marinus in the
western Gulf where concordance in contaminant body burdne was least well developed;

Table 7. Results of regression analyses within regions of concordancy of yearly changes for
Perkinsus marinus prevalence and infection intensity. Possible significant results represent the
number of steps or groups of 10 bay systems tested individually.Number given indicates the number
out of that possible number significant at a =0.10.N, a negative correclation; P, a positive correlation

                                        P. marinus prevalence
              Western Gulf                                     Eastern/southern Gulf

             (10 possible)                                       (11 possible)
         Temperature            9 N                            Arsenic           6 N
         Condition index        9 N                            Copper            4 P
         Mercury                7 P                            Cadmium           5 N
                                                               PAH               4 P
                                                               Zinc              6 N
                                                               Selenium          8 N
                    
                                        P. marinus infection intensity


              Western Gulf                                      Eastern/southern Gulf

             (15 possible)                                          (10 possible)
 
         Copper                 7 P                              Condition index    10 N    
         Length                12`N                              Selenium            5 N
         Condition index       15 N
         Selenium               8 N



                                                7-44
  

contaminants were most important in the eastern and southern Gulf where the El Nino
signal was strongest (2) Most correlations were negative for biological and environ-
mental variables and contaminants. Mercury, copper and PAHs were important excep-
tions. (3) The negative relationships with condition index and length are, perhaps,
expected; that with temperature is a surprise as is the absence of an effect of precipita-
tion. (4) The most consistent Gulf-wide signals were negative correlations with selenium
body burden and condition index. Both of these responded concordantly throughout the
Gulf as did P. marinus prevalence and infection intensity.
   The parameters used for the analyses of the contaminants were length, condition
index, P. marinus prevalence and mean infection intensity, and mean monthly tempera-
ture and mean monthly precipitation for the two months prior to sampling. Cadmium,
mercury and arsenic varied concordantly in the northwestern Gulf (Table 8). Tempera-
ture (negative), length and condition index (positive) generally explained about 35% of
the variation for arsenic; temperature, length (negative) and mean infection intensity
(positive) explained 25-35% of the variation for cadmium. Mercury responded positively
with temperature and P. marinus prevalence.
   Copper, zinc, arsenic and PAHs generally varied concordantly in the eastern and
southern Gulf. Temperature (negative), mean infection intensity (positive) and preva-

Table 8. Results of regression analyses with regions of concordancy of yearly changes in contami-
nant body burden. Possible significant results represent the number of steps or groups o 10 bay
systems tested individually. Number given indicates the number out of that possible number
     significant at a -0.10.N, a negative correclation; P, a positive correlation.

                Arsenic (Western Gulf)                    Arsenic (Eastern/southern Gulf)
                    (8 possible)                                  (7 possible)
           Temperature               6 N                   Precipitation              4 N
           Condition index           5 P                   Temperature                3 N

                Mercury (Western Gulf)                       PAH (Eastern/southern Gulf)
                      (3 possible)                                   (6 possible)
           Temperature               3 P                    Temperature               3 N
           Precipitation             3 P                    Length                    3 N

                Cadmium (Western Gulf)                        Copper (Eastern/southern Gulf)
                     (9 possible)                                   (6 possible)
           Perkinsus Marinus intensity  4 N                 Perkinsus marinus prevalence  3 N
           Length                       3 N                 Length                        6 N
                                                            Condition index               2 N
    
                Selenium (Entire Gulf)                         Zinc (Eastern/southern Gulf)
                   (26 possible)                                      (10 possible)
           Length                      24 N                  Perkinsus marinus prevalance   9 N
           Condition index             15 N                  Temperature                    6 N
           Temperature                  7 N                  Perkinsus marinus intensity    6 P
           (only southern sites)
           Precipitation               11 N
           (only northern sites)





                                                  7-45
   
      


     (negative) explained 30 to 50 of the yearly variation in zinc. Prevalence {nega-
tive). condition index (negative ) and length (negative)explained 35 to 55% of the
variation in copper. For PAHs. temperature (negative) and length (negative) were most
important. Temperature and precipitation were most important for arsenic.
	Selenium body burden varied concordantly over most of the Gulf. In the northwest-
ern Gulf, precipitation (negative). lenght (negative) and condition index (negative)
explained 35 to 75% of the variation. In the eastern and southern gulf, condition index
(negative), length (negative) and temperature (negative) explained 25 to 45% of the 
variation.
	Overall, then, a few trends were evident. (1) Regressions with condition index and
length were generally negative, higher body burdens occurred in smaller oysters, which
is a general phenomenon (Boyden, 1977; and others referenced previously). Lower
condition index suggests that small size was not just indicative of young oysters, but in
fact indicates oysters in poorer health (less biomass per length or mantle cavity volume).
The relationship between P. marinus infectin intensity and condition index corroborates
this view. (2) Temperature was usually negatively correlated. the exception was mer-
cury, where temperature was a positive factor. Although temperature might directly
affect body burden, we would suggest that temperature probably controls the frequency
of fall spawning and spawning generally results in lower pollutant body burdens ie.g.
Frazier, 1975, 1976; Boyden & Phillips, 1981; Wilson el al. 1990), hence the higherbody
burdens at lower temperatures. (3) Precipitation was generally negatively correlated,
suggesting higher salinities corresponded to higher body burdens, but precipitation was
only important in selenium and arsenic. For the most part, temperature and precipitation
were not themselves correlated, the exception being the north-central Gulf. (4) Arsenic is
taken up primarily from food (Sanders, 1980. Sanders et al. 1989): accordingly, it is likely
that the response of body burden to climatic factors was biologically mediated in at least
thist case. (5) P. marinus prevalence and mean infectin intensity were important in 
copper, zinc, mercury and cadmium. Correlations were generally negative with preva-
lence but positive with infectin intensity. Again, mercury was the exception. Lower
prevalence would correspond with lower temperatures (Sonial & Gauthier, 1989). Preva-
lence includes many light infectins which probably are meaningless with respect to
body burden. High infection intensities, on the other hand, probably slow reproduction
(White el al. 1988; Wilson el al. 1988; Wilson el al. 1990) and are likely responsible for 
the observed reductions in condition index and length.
	Again, we emphasize the intimate relationship between P. marinus and the other
biological and environmental variables; consequently, the analyses can only provide a
rough estimate of the relative importance of these variables without the actual processes
being more completely understood. Overall, the factors affecting the rate of tissue
turnover, particularly the ganietogenic cycle and general health, determined in part by
the temperature reginie and disease intensity, would seem to be of the primary importance in
determining yearly trends in contaminant body burden (see also Wilson el al., 1990).
Generally, higher contaminant body burdens were found in populations characterized by
lower health.



                                 7-46 


























                                                                          7-46
 

              Spatial distribution and climatic control on variability	   
        Gulf-wide trends. As with P matinas, most characteristics of the spatial
distribution of the pollutants were conservative features; they were repeated in each of
the 4 years.  A general clinal relationship might be expected to dominate the spatial
distribution of contaminants; bays farther and farther apart being less and less similar in
body burden.  Temperature and precipitation show this clinal relationship (Fig. 9).  The
farther sites are apart, the less similar the local weather regines are likely to be. Many
geographical variables related to contaminant source availability probably do so as well.
River inflow does not (Fig. 9).

                                Total inflow and prevalence
05

03

01

01

03

05
      Total inflow:April-September 1985
      Total inflow:April-September 1988
07    Prevalence:Bay average 1986
      Prevalence:Bay average 1989
09

    0  200  400  600  800  1000  1200  1400  1600  1800  2000

                          Distance
Fig. 9. Correlograms relating distance (km) to Moran's I obtained using temperature precipitation
and total freshwater inflow for all sites sampled in each year. Distances were calculated along the
Gabriel network, where stations separated by, for example, 101 and 200 km were used to generate
                 the 200-km point. See Powell et al (in press) for more details

    Arsenic,selenium,mercury and cadmium show gradually declining similarities with
distance; the clinal variation predicted from the precipitation and temperature regime.
The correlograms of copper,zinc,silver and PAHs do not; the spatial extent of regional
similarity is of varying size throughout the Gulf so that no consistently significant spartial
scale exists. Why these two groups differ can be related to the temporal trends previously
discribed. From one year to the next, the body burden of selenium and arsenic varied 
concordantly throughout the Gulf; the body burden of cadmium and mercury was
predominately affected by local factors throughout the Gulf. In both cases, the Gulf-wide
 
                                      7-47

trends were suficiently uniform that local factors of a clinal nature might successfully
generate a strong spatial signal throughout the Gulf in any given year. In constrast, for
those contaminants having a strong regional response in the year-to-year variability in
the eastern Gulf, but which were locally controlled in the western Gulf (copper,zinc and
PAHs), fundamental differences in the controlling factors between the two regions
probably prevented a general clinal relationship from being observed throughout the
entire Gulf.
     None of the correlograms mimic those of local argricultural or urban land use(Craig et
al. 1989) or P. marinus prevalence and infection intensity (Powell et at.,in press). It is
tempting, therefore, to suggest that the precipitation and temperature regimes are
important in controlling site-to-site trends in contaminant body burden over large
geographic areas, whereas organism health modifies these bay-to-bay relationships on
smaller regional scales.  A correlation with latitude and body burden of some
contaminants does exist in Gulf coast oysters (Wilson et al., 1990). Temperature and
feshwater inflow can change the supply of contaninants and therefore their biovail-
ability (Shuster & Pringle, 1969;Zaroogian & Cheer, 1976;Denton & Burdon-Jones 1981).
Cunningham & Tripp (1973, 1975b), Zaroogian & Cheer (1976). Zaroogian (1980), and
Zaroogian & Hofmann (1982), for example, comment on the temperature dependence of
body burdens in cadmium,mercury and arsenic either linked directly to temperature or a
seasonal biological cycle, such as reproduction that correlates directly with temperature
(Wilson et al., 1990),and Parizek et al. (1974) describe a relationship between selenium,
cadmium and mercury. Several sources cite the co-occurrence of zinc,copper and silver,
and that a common source for these metals in freshwater runoff (Windom & Smith, 1972:
Frazier, 1975: Phillips, 1977b. c), as is also likely for PAHs (Wade et al., 1988). Body
burdens of copper and zinc may also be related to salinity (Wright & Zamuda, 1987).
Nevertheless, sufficient data is not now available to identify the primary controlling
factors behind the large-scale distribution of contaminants in the Gulf.
     Regional correlations. We examined the correlations between various
environmental and biological variables and contaminant body burdens within the re-
gions observed to have concordant yearly shifts in body burden; the reason being the
expectation that the significant variables controlling body burden may be different in
different areas of the Gulf and that the areas providing concordant temporal trends might
offer some guidance in dividing the Gulf into regional areas.
    Using the 5-month average for precipitation and temperature (no measures of P.
marinus infection included)(Table 9) shows that precipitation and temperature are only
significantly correlated with some contaminants and are only significant in 1986 and
1988.  Whereas precipitation is always positively correlated, temperature is negatively
correlated,indicating that high precipitation and low temperatures over long periods of
time before sampling may influence body burden. Agricultural and industrial land use
are also important for some contaminants. Including P. marinus and necessarily using a
shorter time scale (2 month) (Table 10). shows the P. marinus prevalence and mean
infection intensity are often significantly corelated with contaminant body burdens
within regions showing similar temporal responses to climatic variation.
    Despite the seeming likelihood that large-scale trends in the Gulf must ultimately
originate in Gulf-wide trends in temperature and freshwater inflow, few of the contamin-
ants show consistent correlations with either temperature or precipitation on the regional


                                      7-48

























                                    (JN)1870 (KL)150 (SW)WilsOn



                                    Table 9. q(:'sults Of @(-grc!ss'on 6nal" s \N,it,lin regions of SillI)arily in pollutant body bUrden as cic@ttrminvd using the K-S tc-si. Tht-@(,
                                    tile average of the 5 months prior to s6nipling for precipitation and temperature. ' @ignifies a significant negative ceinc-latior, C! = Co:-.('@iiun
                                                                  ind(m Industn! refers to indusuial land use; Agriculture refers to agricOurb) land use


                                      Pollutant                       1@8G                             15,67                            1 @188                           1


                                      A t s e 1) i c                    ....                             ....                Length P     0.0099'
                                      C     III i LI III    prvcipilalion 11  0. o -I i 7   Indti-on- 11 n 0.0473            Length 1)    0,0057
                                                            'rempt..'raturc, 1) = 0.0)67,
                                      C     p                          . . . .                          . . . .                          . . . .                          . . . .
                                      N1 e r c u r 1,       Industry P - 0.0441                                                        P @ 0.0)30'            Indkistry P = 0 0,27
                                                                                                                                                              AgriCUNUIle P = 0,0446
                                      S  I c- n im          Agriculluit? P   0.0054                     . . . .              Agriculture P     0.0021         A cri c t,,:,"e P = 0 0 46

                                      5  1 v e r
                                         n c                Precipitation P   0.0074                                         Pr(,cipifntion P   0.01-15
                                                            C) 11  0,0035

                                      P    H                           . . . . . . .                                                     . . . .                          . . . .



















                                              ij,40871 iKI-050



                                              T@i!@!-' , 10. Rf-su)!@ ol                                    ...!?hm                (11 similarily ill pollulaw body hurden as ds?l(-rmini@d using 0-,(, I\*-S ie@@. T"w'-i.
                                              u I i I i z v i I-) (. u vr i i q f., cIt I i v 21 111 r, i hr ir ii s b i i iI I n gIm, pRCil)ilbli0ll and                              Meall and Medilin                           bn (I
                                                                                                Perkinw.s metrinus. 011it-r obbrevialions and svjiflluls iis dem,ib(-d in Tabic. @i



                                                 Pullutall;
                                                                                              19 8 r,                                         1987                                          1988


                                                 A r s (- 1) i C          Indusirv P =        0.0002'                                                                  Length P = 0.0061
                                                                                                                         Pl-(.6pilalion      P = 0.0111                                                                 prec;p@!1i lion p
                                                                          Prevalence 1) = 0.0472                                                                                                                        C) P = 0,0098
                                                                                                                                                                                                                        Median Inlection 1)              0.(11,35'
                                                 C a d ill I u ill        C: 1 1) = 0. L, 1152,                          Industry P = 0,0483                           Precipitation P            0.0087'                                 . . . .
                                                                          Pr(-vaionce P =          0.0.'J)O                                                            Length P = 0,0037
                                                                             (t 6 n I n f c, c, I on P = 0.004 4                                                       Mean Infection P = 0.0132'
                                                 C 0 p 1) C. r            Temperature P            = 0.03,311)           Mean Infection P =             0.0062         Temperature P = 0.0230                           Industry 11 = 0.040'2'
                                                                                                                         Median Infection P            = 0.0033'                                                        Median Infection P = 0 029C,
                                                                                                                                                                                                                        Prevalence P = 0 0308.
                                                 NI e r c u r y           I n d L; s try 1) - 0. 04 10'                  InduFtry P = 0.0199,                                              . . . .                      Temperature P = 003c.@."'
                                                                          Prevalence 11            0.0116                Njebll Infection P = 0.0187                                                                    Agriculture P - 0.01C.
                                                                                                                                                                                                                        Industry P = 0.0204'
                                                         11 1 u ill       .-\(Iriculture P         0.0023                Agricullure P @ 0.0283                        Agriculture P = 0.0037                           Agriculture P = 0.0'-,-*)4
                                                                          Mc-an Infection P = 0.0159'                    Nlean Infection P = 0.0159
                                                                                                                         Median Infection P               0.0173'
                                                 S i I v e r              Precipitation P = 0.0082'                                         . . . .                                        . . . .                      Length P = 0.0168
                                                                          P.evalence P = 0.0429                                                                                                                         Cl P = 0.0073
                                                                          Mean Infection P = 0.0042'                                                                                                                    Prevalence p
                                                                          Median Infection P = 0.0177                                                                                                                   Mr-dian Infection P              0.',)010
                                                 Z i 11                   Ill 1.-Opll al ion 1,      Om(OP2,                                . . . .                    Median h-Ilt-ction P              0.02167'       L(-nclih 11        0.02,@)7

                                                                          Cl P        0.0039,
                                                 P A H                                                                                      . . . .                    Prevalence P = 0.0247                            Length P           0.0101
                                                                                                                                                                       Mean Inlection P               0.024 1


level, and these regions typically cover a substantial range in latitudes (Tables 9, 10). In
fact from these analyses local imput from industrial and agricultural land use and levels
of P. marinus infection appear to be more important.  Most pollutants show a significant
correlation with some measure of P. marinus infection in at least one instance.  The
relationship between P. marinus and temperature and salinity (again, related to precipi-
tation) is well documented in the literature (Mackin, 1962; Soniat, 1985; Soniat &
Gauthier, 1989). correlations are more frequent using the average of the climatic date for
the 2 months before sampling rather than for the 5 months before sampling, suggesting
that response times to variations in environmental varibles might be more nearly 2 than
5 months, and this is the response time expected if P. marinus was an important factor in
body burden (Choi et al., 1989). The infrequent correlations with length, condition index
or P. marinus prevalence (as opposed to infection intensity) are also noteworthy, particu-
larly considering the frequent importance of these biological indices generally (Cossa et
al., 1980;Scott & Larence, 1982;Lytle & Lytle, 1990; Paez-Osuna & Marmolejo-Rivas,
1990; and others referenced previously) and in the temporal trends we observed. Recall,
however, that P. marinus infection intensity condition index and length are correlated on
most spatial scales.
     Whether a cause and effect relationship exists between disease and contaminant
body burden has not been demonstrated. P. marinus can produce physiologic abnor-
malities in its oyster host that in turn can affect the oyster's ability of feed (Mackin & Ray,
1955). Since feeding is one method of uptake for certain contaminants, such as arsenic
(Sanders et al., 1989). boyd burden could be reduced with increased infection of P.
marinus. Contaminant exposure and disease may also affect the health of the digestive
gland (Bayne et al., 1979; Axiak et al., 1988). Cadmium has been shown to stimulate
phagocytosis (Cheng, 1988a) which is one means of defense against disease (Fisher &
Nowell, 1986; Fisher & Tamplin, 1988).  The negative correlation between cadmium body
burden and P. marinus may be a reflection of this stimulatory action.

                                    CONCLUSIONS

     The results of environmental monitoring studies have long been looked upon with
suspicion when the results have been compared over varied environmental conditions
(Phillips, 1977a). Our results stress the variability of pollutant body burdens as they relate
to variations in environmental and physiological conditions. Consideration of local
controls are important, but so are large-scale geographic and climatic controls which can
override the local controls. All biological variabls responded regionally on a Gulf-wide
scale. Local controls were relatively unimportant throughout the Gulf in explaining
temporal trends,albeit of more importance in explaining the spatial relationships within
any one year. Among the contaminants, local and regional controls were important in
discrete geographic areas in most cases. Some contaminants responded primarily region-
ally (e.g. selenium), some primarily locally (e.g. silver). These regional differences
affected not only the temporal trends, but also the spatial distribution of body burden
within any one year.  Accordingly, consideration of the spatial distribution of body
burden, and particularly, consideration of the temportal trends in body burden must take
into account that climatic factors may be more important in some regions than others and
that the health of the population may contribute markedly to body burden;consequently,

                                      7-51







about controlling the health of populations may moderatly affect temporal trends by
medtating the climatic response.
     Variations in source content have not been included in the analysis. Inasmuch as
arguably the most important parameter controlling body burden has not explicitly been
included in the analysis, the fact that several environmental and biological parameters
nevertheless demonstrated significant correlations with body burden is noteworthy.
Among the biological parameters, factors related to disease, and among the environ-
mental parameters,factors related to land use and meterological conditions are likely to
play an important role in determining pollutant body burden at least regionally. It is
particularly important to recognize that regional factors of importance may go unrecog-
nized at larger geographic scales because statistical analyses may be compromised by
varying responses to selected variables in different regions. We should not expect
selected variables to be consistently of paramount importance everywhere.
    Both P. marinum prevelence and intensity, as well as the other biological variables,
and contaminant body burdens must ultimately respond to temperature and rainfall.
These latter two parameters should be the initial factors mediating the effect of climate on
pollutant body burden. Whether they are the proximate causes of whether biological
parameters intercede, remains unclear. Certainly, however, factors like disease intensity
and the gametogenic cycle play an important role in determining the health and
condition of Gulf oyster populations. That the contaminant body burdens in the Gulf are
almost uniformly relatively low suggests that the correlations observed between body
burden and biology originate either in biological control of contaminant body burden or
coincident control of both directly by climatic cycles rather than the impact of pollution on
organism health (e.g. Khan, 1990) which might result at higher exposure levels.

Acknowledgements. The authors wish to thank the Status and Trends field and laboratory crews at
Texas A & M University who collect and analyse the trace metal and PAH samples. This research was
conducted under grants from the U.S.Department of Commerce,National Oceanic and Atmospheric
Administration Ocean Assessments Division #50-DGNC-5-00262 and #46-DGNC-0-00047, the Sea
Grant College Program #NA89AA-D-SG139 and the Center for Energy and Minerals Resources and
a Sea Grant Marine Fellowship to E.W.Funds for computer analysis were provided by the TAMU
College of Geosciences. We appreciate this support.

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