[From the U.S. Government Printing Office, www.gpo.gov]






            4
              Integrated Measures of Biological and Habitat Integrity
            r.



                                   Final Report

                                        to

                     Maryland Department of Natural Resources
                             Tidewater Administration -
                     Coastal and Watershed Resources Division
                            Tawes State Office Building
                                Annapolis, MD 21401

                               Grant   NA 3702 0359








                                        by

                                  S. Ian Hartwell


                                  Celia E. Dawson

                                  Eric Q. Durell

                                 David H. Jordahl




10


                               Grant No. NA370ZO359


                                      Task 2






                     Maryland Department of Natural Resources
                          -   Tidewater Administration
                  Chesapeake Bay Research and Monitoring Division
                         Toxic Aquatic Contaminants Program












                                   ACKNOWLEDGKIWS

          Most of the sediment bioassays were conducted by Dr. Ray Alden
          and Pete Adolphson at the Old Dominion University, Applied Marine
          Research Xnstitute. Copepod bloassays were conducted by Dr. David
          Wright, Gena Coelho and John McGee at the University of Maryland,
          Chesapeake Biological Laboratory. Xnvaluable field sampling
          assistance was provided by Margaret McGinty, Sandy Xves, Doug
          Randle and Bill Rodney of the CBRM Habitat Xmpacts Program, under-
          the direction of Dr. Stephen Jordan. Additional field assistance
          was provided by Dr. Randy Kerhin of the DNR, Maryland Geological
          Survey. This project was partially funded by NOAA through the
          Maryland Department of Natural Resources, Coastal and Watershed
          Resources Division (Grant # NA 370 Z.0359).





                                       FOREWORD


               This report represents the second year of a program to
          integrate an ambient toxicity testing approach with fish
          community population--iev'el ir@dtjrics. It describes the results of
          tributary specific toxicity testing and the assessment of a
          toxicity risk ranking model developed specifically for ambient
          toxicity testing. It also summarizes results from a parallel
          study on fish community.-Index of Biotic Integrity (IBI)
          investigations and the correlations between the two. The project
          was undertaken to further our understanding of how toxic
          contaminants are affecting habitat quality and resource
          populations in Chesapeake Bay.












                                         A33STRACT

            The goal of this study was to evaluate ambient toxicity
            conditions in tidal tributaries of Chesapeake Bay, whose
            watersheds are impacted by existing urban areas and urban
            development, and assess the results in the framework of a
            toxicological risk ranking model and a fish community health
            index. A battery of standardi*zed, directly modified or recently
            developed water column and sediment toxicity tests were employed
            with fish, grass shrimp, copepods, amphipods, polychaetes and
            vascular plants. The study was conducted in coordination with a
            fish community sampling program. Tests were conducted monthly
            from April through August 1994 in four tidal tributaries: South
            River, Severn River, Patuxent River and the Wicomico River
            (tributary of the Potomac River), which was a nominal reference
            site. Mortality, reproduction and growth rates in the water
            column assays did not indicate consistent chemical contamination
            in any river. These results varied from month to month and from
            species to species. Water column chemical analyses did not
            indicate elevated levels of contaminants. The sediment bioassays
            demonstrated greater responses than water column assays. Sediment
            in the upper reaches of the South River demonstrated significant
            toxicity. Peaks of toxiE61ty-i-were also observed at the upper-most
            Severn River station and the middle Patuxent River station.
            Sediment chemistry indicated elevated metals levels in the South
            River. Some metals were above threshold values in the Patuxent
            and Wicomico Rivers also. The AVS/SEM ratios in pore water were
            below I in all cases. organic analyses on bulk composite samples
            demonstrated low level PAH contamination in all four systems.
            Pore water ammonia was relatively high (> 7mg/1) in all samples.
                A toxicity risk ranking model, developed previously, was
            applied to the laboratory data. The model ranked the South River
            as the most toxicologically impacted site. The Patuxent and South
            Rivers were ranked far below the-South River, however some
            specific locations in the Severn and Patuxent Rivers showed
            indications of sediment contamination. The wicomico River had the
            lowest overall risk score. The Patuxent River may require more
            intense sampling due to it's relatively larger size. The model is
            tolerant of variable amounts of data between stations. A factor
            for consistency of results dampens the effect of individual
            spikes in the data base without.masking them altogether. The
            model can identify trends within and between sampling stations.
            It can reliably reduce an array of ambient toxicity data into a
            site-specific metric which is appropriate for comparisons with
            other metrics, such as IBI or community diversity indices. It
            does not generate probability limits. The model can document
            where chemical contamination is contributing to community impacts
            and also where toxicological impacts are not likely to be
            contributing to observed population level impairment. The
            Margalef species diversity index for fish communities sampled by
            bottom trawl was significantly correlated with toxicological risk
            scores for sediment.















                                     INTRODUCTION




               It is unknown if toxic contaminants directly or indirectly
          affect fish population levels' in Chesapeake Bay. What is*known is-

          that many species which depend on the Chesapeake Bay habitat for

          reproduction are in a more advanced state of decline than those

          that spawn outside the Bay (Richkus et al. 1991). Clearly, this

          is due to over-harvest and/or loss of habitat or access to

          spawning grounds in some cases. It is also clear that some areas

          (e.g. Baltimore Harbor, Back River) are severely contaminated and

          others demonstrate localized ambient toxicity (Hall et al. 1994).

          It is unknown if localized toxic contamination effects influence

          populations in the Bayas a whole, or if low level, but

          -widespread contamination is a greater problem, or if a

          combination of the two affect living resource populations. Wise

          management policy for resource use, including aquatic habitats,

          wetlands and the watershed requires a simple, yet meaningful

          method of habitat assessment to gauge the impact of resource

          utilization in coastal areas. Utilization results in by-products

          which include not only direct discharges, but also non-point

          runoff and changes in the hydrologic cycle. Resource use also

          requires a strategy that applies to management decisions

          concerning the location of preserves and buffers, development,

          agricultural use and provisions for public access.

               An expanding development in the effort to quantify

          environmental impacts of toxic contaminants on specific sites and












                                                                          2

           regions is to employ biological indicators of toxic stress from

           theambient environment. An ambient toxicity approach was

           developed in pilot programs sponsored by the Maryland Department

           of Natural Resources (DNR) and the EPA Chesapeake Bay Program

           (Wright et al. 1989; Hall et al. 1991). The objective was to

           provide a picture of biologically significant environmental

           contamination. The ambient toxicity pilot program field-validated

           a suite of sensitive lethal and sublethal bioassays for resident

           aquatic organisrus. It has been demonstrated that the bioassays

           have the ability to detect the presence of toxic effects in

           contaminated areas, in areas of unknown quality and in areas

           previously thought to be pristine (Hartwell et al. 1991; Hartwell

           et al. 1993; Hall et al.. 1994).

               Measurements of changes in the biodiversity of communities

           at specific locations are also useful in appraising the

           ecological effects of toxic contaminants and other habitat

           alterations. A pilot project to assess the effects of urban

           development on fish assemblages and water quality in tidal

           tributaries of Chesapeake Bay was initiated in 1988 by Maryland

           DNR (Carmichael et al. 1992a; 1992b).

                It is possible to combine the two approaches to relate

           quantifiable changes in fish communities to quantifiable

           toxicological impacts of contamination and begin to address the

           question of the impact of toxic contamination on populations and

           communities in specific regions (Jordan et al. 1994; May et al.

           1992). This information may aid natural resource habitat












                                                                          3

          protection or restoration efforts by providing additional focus

          for prioritization of areas for implementation of regulatory

          programs and growth management plans.

               In addition to the regulatory need for site specific

          estuarine biological measurements, it is.useful to be able to

          represent the condition of complex ecosystems concisely by means
          of composite indices or simple graphics, so that managers and

          non-specialists can readily evaluate and compare information,

          establish goals, and set priorities for remediation. This

          requires the use of concise, understandable statistics that also

          are meaningful, representative, reproducible, and can be

          generated routinely without massive investments in data

          collection. Indicators are essential for (1) determining priority

          areas for management, (2) measuring the effectiveness of

          management actions and progress towards restoration goals, and

              developing the capability to predict the ecological

          consequences of management scenarios.

               This project is also a component of a larger effort underway

          in coordination with the Chesapeake Bay Program. The Ambient

          Toxicity Assessment Pilot Project was initiated in 1990 to

          address specific commitments in the Chesapeake Bay Toxics

          Reduction Strategy. Specifically, the commitment states that the

          signatories will:


               Develop and begin to implement a plan for Baywide assessment
               and monitoring of the effects of toxic substances, vithin
               natural habitats, on selected commercially, recreationally
               and ecologically important species of living resources.












                                                                           4

               In addition, the program addresses specific recommendations

          of the Living Resources Monitoring Plan which calls for;

               Identification of indicator species, biomonitoring
               techniques and specific assays suitable for long-term
               monitoring of ambient habitat toxicity to Chesapeake Bay
               living resources; recommend specific geographic areas, media
               and monitoring frequency.

               implement ambient habitat biomonitoring based on pilot
               program recommendations.


               The objectiVes of this project were to assess ambient

          toxicity in water and sediment from Chesapeake Bay tributaries

          whose watersheds are undergoing urbanization and to compare the

          results with fish community health indices from the same areas.

















                                      METHODS


          Site Selection

              To relate changes in fish assemblages to land use, eight

          tidal tributaries were categorized according to the dominant land

          use within each watershed, with special attention paid to areas

          immediately adjacent to the tributary itself. Evenly-spaced

          stations were established along the axis of each tributary from

          its mouth to near the head of tide. These stations were sampled

          three times each summer in 1989-1992 (July, August, September)

          with beach seine-s--and bottom trawls deployed near mid-channel.

          All fish captured were identified and counted. Data from each

          station were sum-med over the summer sampling period and an IBI

          metric was calculated. Salinity, temperature, dissolved oxygen,

          pH, Secchi depth, and physical habitat characteristics were

          recorded. Detailed habitat assessments were also conducted at

          each site. The metric was primarily designed to assess non-point

          pollution and nutrient enrichment impacts on a system-wide basis.

               An association was found between dissolved oxygen and the

          number of species captured by the bottom trawls (Fig. 1)

          (Carmichael, et al., 1992a). However, some stations with

          acceptable dissolved oxygen demonstrated a completely depauperate

          bottom fauna. Also, fish assemblages in tributaries whose

          watersheds were dominated by urban development were less diverse

          than tributaries whose watersheds were dominated by forest and

          wetlands. The sample stations were located in critical habitats












                                                                         6

         for living resources, beyond the direct influence of point

         sources. Information on ambient toxicity and fish community

         health in these areas provides quantification of the impacts of

         nonpoint source pollution and.sediment contamination on resident

         populations. Specifically, where low dissolved oxygen or other

         habitat measures do not predict the observed impaired fish

         communities, ambient toxicity may provide an explanation for

         depressed fish populations.

              A preliminary study was conducted in four tributaries in

         1993. The goal of this study was to test the suite of sediment

         and water column bioassays and assess the results in the

         framework of the toxicological risk ranking model. The study was

         conducted in coordination with the fish community sampling

        -program. Tests were conducted in four tidal tributaries: Curtis

         Creek, Rock Creek (tributaries of the Patapsco River), Fishing

         Bay (north of Tangier Sound), and the Wicomico River (tributary

         of the Potomac River). Mortality, reproduction and growth rates

         of test organisms in the water column bioassays indicated

         chemical contamination in Curtis Creek and Rock Creek. These

         results varied from month to month and from species to species.

         Survival, reproduction and growth of test organisms in the

         Wicomico River and Fishing Bay was generally good, but some

         borderline effects were seen. The sediment bioassays demonstrated

         greater toxicological impacts than water column assays. The

         results demonstrated toxic impact in Curtis Creek and to a lesser

         extent in Rock Creek. Consistent with the biological data,











                                                                           7

         sediment chemistry clearly showed the that the  Curtis Creek and

         Rock Creek sites were contaminated with heavy metals and PAHs.

         All four systems had detectable petroleum hydrocarbons present in

         the sediment.

              The toxicity risk ranking model was.valida ted with the

         laboratory data. The model correctly ranked Curtis Creek as the

         most chemically impacted site, followed  by Rock Creek, and

         Fishing Bay and Wicomico River, which were essentially equal. The

         model also identified spatial trends between sampling stations in

         Curtis Creek. The risk ranking scores were significantly

         correlated with the diversity index of fish captured in bottom

         trawls. In addition, the toxicological risk scores correlated

     -----:with bottom fish community metrics derived from a five year fish

         sampling data base. The model not only documented where chemical

         contamination was contributing to community impacts, it also

         indicates that observed population level impairment in Fishing

         Bay was not likely to be due to chemical contamination. Based on

         these studies, four tidal tributaries were selected for paired

         ambient toxicity/fish IBI sampling to aBBeBS the impact of

         urbanizing watersheds on receiving stream habitat quality (Fig.

         2-6).



         Severn River




              The Severn River watershed is located in Anne Arundel County

         and covers approximately 51,688 acres. With 36% of this area











                                                                         8

         developed, it was the most urbanized watershed studied.

         Residential and forested areas dominate the shoreline, and major

         highway crossings include Routes 50 and 450 near Annapolis, and

         Interstate 97 near its headwaters. The.river is subject.to

         intense boating pressure, as both the United States Naval Academy

         and several marina facilities are located at or near its mouth.




         South River




              The South River watershed is located in Anne Arundel County

         and covers approximately 43,452 acres. Roughly 25% of the

         watershed is developed, and about 17% is agricultural.

         Residential and forested areas compose much of the shoreline,

         with many public and private marinas and their resultant boating

         traffic. Major highway crossings include Routes 2, 301, and 50.

         Land use ratios are nearly identical to those of the Severn River

         watershed.




         Patuxent River



              The Patuxent River is bordere d on the west by St. Mary's,

         Charles, Prince George's, and Montgomery Counties, and on the

         east by Charles, Anne Arundel, and Howard Counties. The

         watershed is covers approximately 480,660 acres, of which about

         11% is developed. The dominant land types are agricultural and

         forested. Two large reservoirs have been constructed an the












                                                                          9

           mainstem near Laurel, and United States Naval Testing Centers are

           located on Solomon's Island and Cedar Point at the river's mouth.

           The Patuxent River was chosen for this study in part because of

           its great potential for further urbanization. Fast-growing areas-

           within the watershed include Bowie, Columbia, Crofton, Laurel,

           and Upper Marlboro among others.




           Wicomico River



               The Wicomico River is located between Charles and St. Mary's

           Counties, and drains approximately 61,062 acres. Agriculture and

           forest make up the dominant land uses at about 30% and 40%

           respectively. Less than 6% of this watershed is developed. The

           Wicomico River served as the saltwater reference tributary in

           Carmichael, et al. (1992b), and consistently demonstrated healthy

           fish -community metrics. It was selected to represent a

           relatively clean field reference tributary with little direct

           point source pollution. The Wicomico River was retained from

           last year's study to serve as an established field reference site

           and to lend continuity to the Ambient Toxicity project from one

           year to the next.





           water Column Bioassays

                Fish community sampling methods were designed to assess the

           fish community at its' peak diversity in summer. Ambient toxicity












                                                                          10

           testing was initiated before the fish community IBI sampling was

           begun to assess the potential impact of toxic contamination as

           the fish communities matured and to assess any short term spikes
           in toxic effects which may be detectable during the late'spring

           and summer.

                The following water column.tests were conducted on a monthly

           basis from April through August 1994: 7-d sheepshead minnow

           (cyprinodon varie'gatus) survival and growth test; 7-day grass

           shrimp (Palaemonetes puglo) survival and growth test; a copepod

           (Eu.rytemox,a affinis) life-cycle survival and reproduction test;

           and a bacterial luminosity bioassay (MicrotoxR) . Water column

           tests were also conducted in July and August with the submerged

           aquatic plant species,.sago pondweed (Potamogeton pectinatus)

           which measured growth and reproduction. These bioassays go far

           beyond the original scope of the proposed project, but the data

           are included here since they represent a more thorough data base.

           Fish and grass shrimp bioassays were conducted at DNR's Aquatic

           Toxicology Laboratory (Glen Burnie, MD). The copepod bioassays

           were conducted at the University of Maryland, Chesapeake

           Biological Laboratory (CBL). The vascular plant bioassays were

           conducted at the Anne Arundel Community College, Environmental

           Center.

                Depth integrated water samples were collected by boat from

           the four rivers. Standard water quality parameters were measured

           at the time of collection (Table 1). Samples were taken twice

           from each site during the course of each 7-day test to provide











           fresh renewal water for the bioassays. The sampling interval was

           four days. Water samples were filtered through 37Am mesh and

           adjusted to a salinity of 15 ppt. All water was stored in amber

           bottles at VC until use. When the sample salinity exceeded 15

           ppt, no adjustment was made. Water for the copepod assays was not

           s'alinity adjusted until delivery to CBL for testing.

                Heavy metals, acid and base/neu tral extractable semi-

           volatile organic compounds and chlorinated pesticides were

           analyzed on August samples only. The semi-volatile organic

           compounds were analyzed by GC/MS, EPA method 625. Chlorinated

           pesticides and PCBs were analyzed by GC/MS EPA method 608.

           Arsenic, selenium, silver and thallium were analyzed by furnace

           or flame AA (EPA method 206.2, 270.2, 272.1 and 279.2

           respectively. Mercury was analyzed by cold vapor AA (EPA method

           245.1). The other metals (Sb, Be, Cd, Cr, Cu, Pb, Ni, Zn) were

           analyzed by inductively coupled plasma atomic emission

           spectroscopy (ICP) (EPA method 200.7).



           Fish and Grass Shrimp

                Culture and maintenance procedures for grass shrimp and

           sheepshead minnow used methods contained in APHA 8720 and EPA-

           600/4-90-027 respectively. Adult sheepshead minnows were fed with

           Tetramin' and Artemia nauplii. Spawning was induced by

           temperature shift and was timed so the larvae were between 24-48

           hrs old when bioassay testing started. The eggs were deposited on

           spawning mats which were then incubated in high salinity water












                                                                          12

           (30-40 ppt) to minimize fungal growth and aerated vigorously.

           Salinity was adjusted to 15 ppt 24-48 hours before hatching.

                Grass shrimp larvae wereeither purchased from commercial

           suppliers or brooding grass shrimp were collected from A clean

           site at Ship Point near Calvert Cliffs State Park. They were fed

           ad libitum with Artemia nauplii prior to spawning. They were

           then transferred to Carolina bowls to spawn. Larvae were

           separated from adults and incubated between 4-7 days prior to

           testing.

                For both fish and grass shrimp,ten larvae were placed in a

           600 ml beaker with 400 ml of ambient water. Four replicates were

           conducted for all tests. Temperature and photoperiod were.
           maintained constant within an incubator at -200C and 16: 8 L:D.

           Eighty percent of the test water in each beaker was renewed daily

           with water from storage. Survival was monitored daily. Dissolved

           oxygen, temperature, salinity and pH were measured daily. The

           tests organisms were fed Artemia nauplii in the morning before

           water change and after the water change. The water was aerated -

           if DO levels fell below.60% saturation. At the completion of the

           7-day experiments, all larvae were preserved in 8% formalin and

           stored for no more than four weeks. Following a deionized water

           rinse, they were dried f or up to 24 hr at 1000C and weighed.

                Percent survival of the larvae was compared to controls

           using the t-test following arc sine transformation, or a Wilcoxon

           rank sum test if the data were not normal. Growth parameters were

           compared using ANOVA and the Wilcoxon rank sum test. Differences












                                                                             13

            between means were considered significant at the a=0.05 level.

                A 48-h static potassium chloride reference toxicant test was

            conducted for each species to establish the relative health and

            sensitivity of test organisms.



            Eurytemora affinis

                Copepod bioassays were conducted during April through

            August. Ambient water from each site was filtered through 5um.

            mesh and its salinity adjusted to 10ppt. Reference water was

            taken from Wachepreague Bay on the Atlantic coast of Virginia

            each month. It was autoclaved, filtered to Igm and diluted from

            its original salinity (33Yoo) to match the salinity of the test

            water. Dilutions were made with CBL well water. All media were

            adjusted to laboratory temperature (240C) prior to the test.

                Animals were obtained from a culture of E. affinis which has

            been maintained at Chesapeake Biological Laboratory for >10

            years. The culture is normally maintained at 210C and 107boand is

            fed every second day on a 1:1 mixture of Thallasiosira pgeudonana

            and Isochrysis galbana. To segregate young nauplii from the

            culture, adults were separated using a 200pm, Nitex filter and

            placed in a tank with a 64gm Nitex screen at its base. This tank

            was placed inside a second container such that eggs passed

            through the screen into the second tank. Twenty four hour old

            nauplii from the second tank were concentrated using a 64Am

            screen and pipetted into plastic weighing dishes. Four replicates

            with fifteen nauplii were tested in water from each river.












                                                                          14

           Individual vessels were 400ml beakers with rectangular 63AM Nitex

           windows 1cm from the bottom. The beakers were   ersed in test

           water in polycarbonate containers. Each beaker contained 200ml of

           test water. Close scrutiny of the containers was maintained

           throughout the assay and periodic gentle brushing of algae from

           the outside of the Nitex window.ensured good water exchange.

                Water was renewed every second day, at which time the algal

           feeding mixture (1:1 T. pseudonana/l. ga@bana) was added to
           achieve a cell density of 4 x 105 cells/ml. Algal cell densities

           were monitored at each feeding and adjustments made such that

           each system had the same cell density.

                Copepod development was followed through one life cycle,

           e.g. 10-14 days. Numbers of surviving adults were counted and

           eggs and nauplii and subadults from the F1 generation were also

           counted at the end of the test.

                Percent survival of the larvae was compared to controls

           using the t-test following arc sine transformation, or a Wilcoxon

           rank sum test if the data were not normal. Reproduction was

           compared using ANOVA and the Wilcoxon rank sum test. Differences

           between means were considered significant at the a=0.05 level.



           Potamogeton R@ctinatus

                The techniques used in this study were developed by the U.S

           Fish and Wildlife Service, Patuxent Wildlife Research Center and

           the Environmental Center of Anne Arundel Community College

           (Fleming et al. 1988; Ailstock et al. 1991). Laboratory












                                                                           15

            propagated stocks of sago pondweed, originally collected from

            Chesapeake Bay, were weighed and rooted in anutrient agar

            medium. Eight replicates were submersed in 750ml of ambient water

            from each river. Light levels were maintained at 70mol/m@/s PAR

            on a 12L:12D cycle. Temperature was held constant at 22 OC.

            Filtered air supplemented with C02 to approximately 3% was

            continuously pumped into each test chamber. After four weeks, the

            plants were removed and weighed. The number of rhizome tips on

            each plant were counted as a measure of reproduction. The plants

            were then dried and weighed again.



            Microtoxp

                The MicrotoxR assay was performed on water samples from

            April through August. Each of the two water samples taken each

            month was tested (except April). The bioassay method exposes a

            luminescent bacteria (Photobacterium phosphoreum) to ambient

            water samples and measures changes in light output following

            incubation. Changes in light output are proportional to toxicity

            (Microbics, 1993). Tests were run as dilution series bioassays

            for each sample. Samples were filtered through 37gm mesh,

            adjusted to 15 ppt salinity, and tested at concentrations of 0

            (control), 60, 70, 80, 90, and 100 %. Four replicates were

            conducted at each concentration. Reference water supplied by

            Microbics Corporation was used as the diluent for the samples and

            as the control. Incubation time was 15 minutes at 150C. Light

            output was then measured with a photometer. Response was measured












                                                                            16

           as inhibition (or stimulation) of luminosity over time as

           compared to the control. Luminosity of the bacteria in ambient

           water was compared to controls using the t-test or a Wilcoxon

           rank sum test if the data were not normal. Differences between

           means were considered significant at the a=0.05 level. Lowest

           Observed Effect Concentrations (LOEC) were determined by

           Dunnetts' procedure (Microbics, 1993) on inhibitory samples.



           Sediment Bioassays

                Sediment toxicity tests were  conducted using the following

           tests: 10-d sheepshead minfi-64-(C. variegatus) embryo-larval

           survival and teratogenicity test;  10-d amphipod (Lepidactylus

           dytiscus) survival and.growth test; 10-d amphipod (Leptocheirus

           plumulosus) survival and growth test; 10-d polychaete worm,

           (Stx-eblospio benedicti) survival and growth test; and a lettuce

           and Spartina alternaflora seed germination test. The Leptocheirus

           plumulosus bioassays were conducted at the DNR Toxic Aquatic

           Contaminants Laboratory. The seed tests were conducted at the

           Anne Arundel Community College. All the other sediment bioassays

           were conducted by Old Dominion University, Applied Marine

           Research Laboratory (AMRL).

                Sediment samples were collected with a petit ponar grab

           sampler in April, 1994 from each station for initial grain size

           analysis. The top two centimeters were retained for testing. In

           August, 1994, five discreet field samples were collected from

           each river system (Figs 3-6). The sampling stations were selected












                                                                          17

           to coincide with fish community assessment trawl sampling

           stations. The sampling plan does not provide for true field

           replication for statistical purposes, but does allow a contrast

           of upstream vs downstream locations. The decision to sample

           discrete locations throughout each river was based on the intent

           to assess the condition of the entire system, relative to the

           fish community indices. This was unnecessary in the water samples

           since all the systems were tidal. Samples were segregated

           throughout the collection and toxicological tests. Samples were

           held out of direct sunlight at 41C and used within two weeks.

                Control sediments for each animal species consisted of

           native sediments from the area in which the test organisms were

           collected or naturally.occur. Control and/or reference sediments

           (see below) were tested with each set of test samples. The fine

           grained reference sediment was obtained from a small tidal creek

           within the Poropotank River, Virginia. The sand reference

           sediment was collected from Lynnhaven Inlet, Virginia Beach,

           Virginia. The control sediment for the L. plumulosus bioassays

           was their laboratory culture sediment.

                 Particle size analysis of test sites ranged from less than

           1 to 99% sand (Table 2). Because of the large range in particle

           size between test sites, two reference sediments were used with

           the L. dytiscus, C. variegatus and S. benedicti bioassays. The

           purpose of these reference sediments was to assess what effect

           "normal" physicochemical parameters (primarily particle size)

           would have on the survival of the organism being exposed in the












                                                                          18

           absence of toxicants. The reference  sediments which were used

           bracketed the sediment particle sizes found at the selected test

           sites. Reference and control sediments were from the designated

           sites and are indicated throughout the'text as follows:



                          1) Lynnhaven Sand

                          2) Lynnhaven Mud

                          3) Poropotank Mud



                Lynnhaven mud was used as the control sediment for S.

           benedict! and C. variegatus eggs. Lynnhaven sand was used as the

           control for L. dytiscus. L. plumulosus survives well in a.wide

           range of sediment grain sizes. Mud from Fishing Bay on the

           eastern shore of Maryland was used as the control for this

           species.

                inorganic contaminants were evaluated concurrently with

           toxicity tests on a composite sample from each river system.

           Sediments were analyzed for acid volatile sulfides (AVS) and

           total organic carbon (TOC). Samples were frozen until analysis,

           at which time they were thawed,.and then homogenized by gently

           stirring. Samples were analyzed for AVS using the method of

           DiToro et al. (1990). Simultaneously extractable metals (SEM)

           analysis was conducted on all samples to use with the AVS data in

           order to determine the potential toxicity of the sediment due to

           metals. The sample for the SEM analysis was obtained from a step

           in the AVS procedure. The concentrations of the SEM were












                                                                           19

           determined by EPA-600/4-79-020 (1979). Cadmium, lead, copper,

           nickel, and zinc were determined by ICP following USEPA method

           number 200.7. Mercury was determined by cold vapor generation

           following USEPA method number 245.1. The concentrations'were

           then converted to micromoles per gram dry sediment and were added

           together to provide the total SEM value. Pore water samples were

           extracted by squeezing with a nitrogen press. All pore water

           samples were filtered then frozen until analyses of ammonia,

           nitrite and sulfides were conducted. Bulk metals were analyzed by

           ICP using EPA method 200.1, 200.2 or 200.7. Acid and base/neutral

           extractable semi-volatile compounds were analyzed on samples

           composited by river using GC-MS by US EPA method 8270 (SW846).



                C. variegatus

                Sheepshead adults were maintained in accordance with

           standard methods and guidance from general literature and U.S.

           EPA (1991). Animals were cultured at 20ppt salinity at ambient
           laboratory light and approximately 200C. Adult breeders were

           -maintained in an 800 liter tank in an elevated "breeder" basket

           at 20ppt salinity, 250C, and a 16L:8D photoperiod. Breeders were

           fed a commercial marine blend flake food 10 times per day and

           supplemented with newly hatched Artemia nauplii twice daily.

           Eggs were collected daily below the baskets and transferred to

           clean 4 liter aquaria. These aquaria were then placed into 250C

           incubators and aerated. Daily water changes of approximately 90%

           were performed until the eggs were 48 hours old, when they were












                                                                           20

           ready for placement into test chambers.

               A series of test containers was set up ac cording to ASTM

           methods (1990). Two centimeters of sediment were placed into each

           of f ive replicate, 2-liter test containers with 750 ml of 15 ppt

           overlying water. Ten embryos were placed into a cylindrical mesh

           egg chamber. The chamber was then gently placed into the

           sediment such that the sediment passed through the bottom mesh

           and was allowed to contact the eggs. Control sediment consisted

           of Lynnhaven mud. Test containers were monitored daily for

           oxygen, temperature, and pH. The number of animals, i. e.,

           live/dead eggs, live/dead larvae, and the number hatched was also

           recorded. Deformed larvae were treated as dead. The larvae were

           not fed. The test was performed a total of ten days from test

           initiation or two days post-hatch for all controls, whichever

           occurred first.




                L. plumulosus

                Amphipods were maintained in accordance with laboratory

           methods and guidance from DeWitt et al (1992). Animals were

           cultured at 15ppt salinity in 10 liter tanks maintained at
           ambient laboratory light and approximately 200C. One to two

           centimeters of native sediment was placed on the bottom of the

           culture tanks and enriched with a food supplement weekly. The

           food supplement consisted of approximately 50:50 mixture of

           ground commercial marine flake food and powdered alfalfa. Fifty

           percent water changes were performed weekly. Animals were












                                                                          21

           harvested on a monthly basis and were either used for testing,

           culture expansion, or simply culled. Culture tanks were aerated

           gently. Test animals were collected for testing by siphoning the
           culture sediment from the tanks and passing it through a'series

           of stacked sieves. Those animals which passed through a 1000 Am

           sic-.:-, but were retained on a 500 Am sieve, were used for the

           tests. A subset of the test animal population was selected for

           initial weight measurements.



                L. dytiscus

                These amphipods were collected from an estuarine site in

           Virginia Beach and transported to the AMRL for acclimation to

           laboratory conditions. Salinity was slowly adjusted to 15ppt.

           Animals were held in their native sandy sediment at least one

           week prior to initiation of the bioassays.



                S. benedicti

                Worms were collected in the field, brought to the laboratory

           and held for at least one week prior to testing. Animals were

           sieved out of the holding tank and placed into culture dishes 24-

           hr prior to addition to the test containers.




           Procedure

                For the polychaete and both amphipod species, a series of

           test containers was set up according to the methods outlined in

           ASTM (1990). Two centimeters of sediment were placed into each of












                                                                          22

           five replicate 1 liter test containers with 700 ml of overlying

           water. Twenty animals were added to each test vessel and

           monitored for 10 days at 250C.. Test containers were monitored

           daily for dissolved oxygen, temperature, and Ph. In the L.

           dytiscus bioassays, the animals were fed 25 mg of ground
           alf alf a/TetraminTu cichlid f lake. f ood in a 1: 1 ratio per test

           container every three days throughout the duration of the test.

           At the end of 10*days, animals were sieved from test containers

           and mortality was recorded. Animals were then preserved for

           weight measurements. Static, acute, hon-renewal, water-only
           reference toxicant tests 4-ei@_performed for C. variegatus, L.

           dytiscus and S. benedicti using cadmium chloride. Seasonal

           changes in sensitivity @iave been observed previously in L.

           dytiscus Deaver and Adolphson, 1990). Static, acute, non-renewal,

           water-only reference toxicant tests were performed for L.

           plumulosus using potassium chloride.






           Lettuce seed

                One hundred seeds were placed in porous bags which were then

           buried in sediment samples from each sample site. Ten replicates

           per test were employed. Control tests were done in a sand

           sediment adjusted to salinities of 0 to 9 ppt. Parallel tests

           with Spartina alternaflora seeds were conducted to assess

           potential effects of salinity on the lettuce seed bioassay. Seeds

           were incubated in the sediment for 3 days at 20C. Percent












                                                                          23

           germination was recorded at intervals of 2, 7 and 14 days.



           Statistical Analysis

                Statistical evaluations 'relative to particle size effects.

           were made based on the response to the reference sediments.

           Sheepshead egg data were evaluated using analysis of variance

           ANOVA) contrasts and compared to the controls. Evaluation of

           total mortality was assessed by combining egg mortality, larval

           mortality, and unhatched eggs remaining at the termination of the

           test. Unhatched eggs were included as mortality based upon

           previous observations and the assumption that probability of

           hatching and thus survival decreases essentially to zero by test

           termination i.e. eggs are ecologically dead).

                For all other tests, the analyses consisted ofIANOVA models

           with a. priori tests of each treatment contrasted to the

           controls. Arcsine transformations were used for the percent

           mortality data. Mortality was corrected for particle  size effects

           using the regression equation previously established  for L.

           dytiscus % survival = 98.41 - 0.35066 X % Silt/Clay)  Hall et. al.

           1991). Weight was expressed as,percentage of change   from the

           initial weight measurements.



           Ranking Model

                At the inception of the ambient toxicity program, a ranking

           scheme was proposed to evaluate the toxicological results on a

           site by site basis (Hartwell 1989). This scheme has five












                                                                          24

           components: 1) severity of effect; 2) degree of response; 3) test

           variability 4) site consistency; and.5) number of measured

           endpoints. Consistency and the number of endpoints measured are

           site specific attributes, while severity, response and

           variability are characteristics of the individual bioassays

           conducted at all sites. The rational of the ranking system is to

           quantify environmental risk, not merely to rank presence or

           absence of toxic'effects. Thus, high uncertainty or variability

           will result in increased risk scores to a similar extent as

           positive toxic responses.

                Severity refers to the degree of effect which the bioassay

           endpoints measure. Mortality is considered the most severe

           response followed by impaired reproduction and impaired growth.

           Other endpoints could be included in the list. The severity

           factors were arbitrarily set at mortality = 3, reduced fecundity

             2 and reduced growth

                Degree of response is the measure of the proportion of

           organisms responding in each bioassay regardless of statistical

           significance e.g. 10% mortality, 15% growth inhibition, etc.).

           In this regard, it is as important to know what percentage of the

           organisms responded as it is to know whether it was

           'statistically significant'. In the statistical contrasts,

           mortality was not corrected for control mortality e.g. Abbott's

           formula) because of inherent uncertainties of the effects of

           laboratory manipulations on 'non-standard' species in some cases,

           and no such corrections exist for other bioassay endpoints e.g.












                                                                          25

          growth). The response values are adjusted for control values in

          their calculation formulas. Negative values were assigned a value

          of zero in the model data base. The following equations were used

          to calculate degree of response values:



                        Ambient Toxicity Scoring Calculations



                                    growth response=

                       Jeontrol wt   test wt)/control wtJ X 100



                               % reproduction response=

                 (control reprod   test reprod)/control reprod) X 100



                                  luminosity response=

                  Icontrol lumin.- test lumin.)/oontrol lumin.1 X 100



                                 % mortality response=

                 Itest # dead - control # dead)/initial total #1 X 100





                Variability was expressed as the coefficient of variation of

           response for each set of laboratory replicates. This parameter

           reflects the internal variability for each endpoint and sample

           period. Data were pooled by river or sample date for this

           purpose.

                consistency refers to the agreement between the various












                                                                           26

           bioassay endpoints measured at a site. If the results from all

           tests and/or species agree, consistency is high, and confidence

           in predicting toxic impacts is high. Ifhalf of the results are

           positive and half are negative, consistency and certainty of

           toxic impacts is lower. Consistency was calculated as the cube of

           the difference between 1/2 the number of endpoints and the number

           of statistically non-significant responses at each site.

           Statistical significance in this instance refers to typical

           'sample site vs control' comparison tests, not a statistical test

           of the calculated response values.



                                _X) 3,
              Consistency = N/2)     where N= total number of endpoints and
           X= number of statistically non-sign7ificant endpoints.



                When bioassay endpoint values tend to be non-significant N/2

             X), the function is negative. When half of the endpoints are

           significant and half are non-significant N/2 = X) the function is

           zero. When endpoint values are statistically different than

           control values the function is positive (Fig. 7). The absolute

           value is dependent on the amount of data available. Large data

           sets high N) will have higher extremes. This polynomial function

           was devised as an additive factor in the equation. It reduces the

           risk score of a station when most of the test results were not

           significantly different than controls but increases the risk

           score when more than half the tests are significant.

                The number of endpoints measured at each site refers to the











                                                                         27

          number of bioassays species) and measured parameters survival,

          growth, etc.) which are monitored. For statistical and

          experimental reasons, the number of tests run at each site should

          ideally be the same. However,.given the uncertainties of

          experimental work, this is not always possible. For example, if

          mortality is very high, it may not be possible to measure growth.

               Each site was ranked by the following scheme; endpoint

          severity was multiplied by the percent response of the test

          organisms for each bioassay endpoint, and the coefficient of

          variation for that test endpoint. The products from all tests

          were summed for each test site. The sum was adjusted by the site

          consistency factor and divided by the square root of the number

          of test endpoints for each site to equalize scores from different

          sites where different amounts of data may be present.



                                    Site Score =

             [JE severity) % Response) Coeff.Var.)J + (ConsistencyJ]/'/N




               There are three possible risk ranking scores which may be

          calculated; water only, sediment only or water and sediment

          combined. since water column bioassays are replicated in the

          laboratory, a risk score can be calculated for each sampling

          month or the response scores can be averaged by river over

          months. This approach allows for an assessment of water column

          contamination effects on pelagic communities or possibly specific












                                                                           28

          species. Sediment samples were collected and te.sted as discrete

          samples without laboratory replication. Therefore, calculation of

          a risk score can only be done by pooling the data together by

          river to calculate the C.V. and consistency factors. The-

          rationale for sampling sediment in this way was the assumption of

          low temporal variation in sediment relative to the water column

          and for the purpose of examining sediment contamination effects

          on a system-wide basis, which is consistent with the IBI

          community approach. This approach allows for an assessment of

          sediment contamination impacts on bottom communities.and could be

          contrasted with benthic community metrics as well as bottom trawl

          survey data.

               Sediment-and water data may be'pooled together by river

          system to calculate a toxicity risk factor  for the whole system.

          This calculation allows an assessment of toxic contamination on

          the entire river system with equal weight given to sediment and

          water column assuming equal data availability). It also has the

          advantage of combining the data into larger subsets which tends

          to dampen out individual spikes in the data set. To pool the

          data, the calculated response results are averaged over months

          for water and over locations for sediment. The C.V. of the mean

          responses is used in the risk calculation, rather than the mean@

          C.V. value. consistency is calculated as before.

               A simple toxicity score can also be calculated for each

          sample. This is the sum of the products of endpoint severity and
          percent response divided by/N. This score is a useful technique












                                                                         29

          for comparing individual sites and for examining spatial or

          temporal trends in sediment 'and water samples. These calculations

          are also instructive in examining the response of the risk

          rankinq model and its' response to inclusion of the interrelated

          factors of consistency, coefficient of variability and the number

          of data points.



                   Toxicity Score = (E Severity) % Response)j/ VN




               The risk scores were contrasted to diversity indices

          (Margalef 1968).and the IBI data. Pearson correlation

          coefficients were calculated for every combination of

          toxicological risk score (water, sediment and combined) and fish

          community index for the 1994 sampling year. Three categories of

          community index were used, including bottom trawl species

          diversity, resident (estuarine spawners) species diversity and

          the overall IBI (Table 3). The resident species data included

          both bottom trawl and beach seine data. The IBI score effectively

          incorporates all resident and migratory species in both the trawl

          and beach seine data. Calculation of an IBI score with only the

          trawl data would not be effective because it would incorporate an

          incomplete set of species, relative to the number of metrics in

          the IBI derivation. The IBI is designed to reflect the diversity

          and trophic structure of the entire fish community. This also

          means the IBI score should respond to a variety of factors in the











                                                                        30

         habitat, including but by no means limited to, toxic impacts.

              Briefly, the IBI derivation method includes measures of

         species richness, dominance, abundance, trophic structure and

         life history traits. All metrics have been evaluated for-

         correlation with salinity, sampling frequency, consistency and

         effectiveness of sampling. Nine metrics are used to calculate the

         IBI (Jordan et al. 1991; Vaas and Jordan 1991) including number

         of species in trawls, total species, number of species comprising

         90% of individuals, total individuals (excluding menhaden),

         number of anadromous species, number of resident species, %

         carnivores, % benthivores and % planktivores. Following

         transformations and salinity calibrations, the individual metric

         values are ranked between stations and divided into three groups;

         low, medium and high. A ranking-value of 1, 3 or 5 is then

         assigned to each metric at each station. The ranking values of

         all nine metrics at each station are then summed to compute the

         IBI score, which can range from 9 (lowest integrity) to 45

         (highest integrity). The Margalef diversity index is calculated

         as



                                 I = (S - 1)/ logN



                   where      S = number of species

                             N = number of individuals











                                                                        31





                                      -RESULTS




              Statistically significant mortality did not occur in water,

          column bioassays with fish or grass shrimp (Table 4). Grass

          shrimp survival values were lower than normal in the August tests

          in the South and Severn River bloassays, but were not

          statistically significant. Growth rates in fish were slightly,
          but significantly reduced in 4rii in the Severn River water

          sample (Table 5). The difference was small, but variability was

          very low. All of the August fish bioassays resulted in poor

          growth. It is unclear if this is a real effect or a sample

          handling artifact. Control growth was very good, and all tissue

        --samples were handled and weighed with exactly the same methods

          and all at the same time. Significant inhibition of grass shrimp

          growth was not observed (Table 5). The reference toxicant data

          for sheapshead minnows and grass shrimp are shown in Table 6. The

          1994 experiments used Kcl as a reference toxicant for the first

          time so no historical data base exists for comparison. Results

          were reasonably consistent from month to month, where comparisons

          are possible. In the copepod assays, survival to adult stage was

          significantly reduced in the July tests in the Patuxent River

          (Table 7). The South River had the lowest overall average

          survival, but no river was consistently lower than others in all

          months. Survival was significantly lower than controls in the May

          Wicomico River test. However, survival and reproduction in may











                                                                           32

          was reduced in all tests, including the controls. Reproduction,

          as measured by the number of-eggs, nauplii and subadults present,

          was highly variable between stations and months. Significantly

          reduced reproduction was observed in June and July samples from.

          the South and Patuxent Rivers, and the Severn River in June.

          Reproduction in the Wicomico River in May was completely absent

          (Table 7). Again, the significance of-results from May are

          questionable for all stations. No mortality, growth or

          reproduct ive effects were seen in the plant bioassays in July or

          August (Table 8) . The MicrotoxR assays. demonstrated statistically

          significant inhibition in April, May and August (Table 9a). None

          of the samples were inhibitory in June or July. The bioassays

          often showed significant stimulatory results (Table 9a). This may
          be due to eutrophic conditions in the tributaries. The LOECs for

          the inhibitory tests are shown in Table 9b. Only one instance of

          effects below 70 % river water was observed. Due to the

          experimental design, the true LOEC for the Severn River #2 run is

          unknown. The water chemistry analyses from the August samples are

          shown in Table 10. Some metals were above detection limits, but

          all values were relatively low, and all were below marine ambient

          water quality criteria.

               Survival results from-the sediment bioassays with amphipods,

          worms and sheepshead minnow eggs are included in Tables 11 and

          12. High levels of mortality were observed in the amphipod tests.

          After adjustment for grain size however, only the South River

          demonstrated elevated mortality levels. Results were not











                                                                        33

         statistically significant due to high variability. Mortality in

         the polychaete tests was also highly variable, and statistically

         significant differences were not observed. Higher levels of

         polychaete mortality were observed in the Patuxent River relative

         to controls. Mortality in the South and Wicomico Rivers was

         marginally elevated. Again, results were not statistically

         significant. Mortality in the fish bioassays was also highly

         variable (Table 12). The highest mortality level was observed in

         the South River. Fish mortality was also elevated above the

         controls in the Wicomico and Patuxent Rivers. Mortality in the

         South and Patuxent Rivers was primarily due to hatching failure

         as opposed to larval mortality. Very distinct patterns of site

         specific mortality in the amphipod, worm and fish tests are seen

         when the data are viewed on a site by site basis Figs B-14.

         Mortality in the South River is primarily at the upstream sites

         as opposed to the Patuxent River where peak mortality occurred

         at the middle site. The most substantial mortality in the

         Wicomico River was at the downstream station. In this case,

         mortality was observed in the larval (post-hatch) stage as

         opposed to the embryos (egg stage). No significant mortality was

         observed in the L. plumulosus bioassays (Table 13). Mortality

         levels were lower than in the other benthic species, with the

         exception of the South River. Growth was poor in the Patuxent and

         South River bioassays (Table 14) however, control growth was also

         poor. Growth of controls in the L. dytiscus and S. benedicti

         tests was also lower than ambient results (Table 15). The results











                                                                        34

         of reference toxicant tests conducted with L. dytiscus,

         polychaetes and sheepshead minnows are shown in Table 16. Values

         were below historical levels. No significant effects on

         germination were observed in sediment bioassays with either the

         lettuce or S. alternaflora seeds (Table 17).

              Bulk sediment chemistry results for sediments are shown in

         Tables 18 and 19. Lead and zinc were ab ove NOAA ER-L levels in

         the Patuxent, South and Wicomico Rivers long and Morgan 1990).

         The South River also had chromium levels near the ER-L value.

         contamination with routine organic contaminants was relatively

         low in all systems (Table 19). Data for SEM and SEM/AVS ratios

         for metals in sediment pore water are shown in Tables 20 and 21.

         The Patuxent River sediments had the,highest-SEM levels,
         primarily due to zinc values, but no SEK/AVS ratios were above

         1.0. The South River had the highest ratio of 0.384. Ammonia

         levels in pore water were relatively high in all samples,

         including the reference sediments (Table 22). Total organic

         carbon values are shown in Table 23. The Severn River sample had

         less than it TOC.

              The water column risk scores for each sampling period are

         shown in Figure 15. Results were highly variable between months

         and stations, with no apparent pattern. Mean water toxicological

         risk values are shown in Figure 16. Toxicity risk scores in the

         four rivers are similar, and relatively low level. The toxicity

         scores for discrete sediment samples are shown in Figure 17.

         There appears to be a strong upstream to downstream gradient in











                                                                         35


         the South River. Data from the Severn River demonstrates a

         localized spike at the upstream station. The Patuxent River has a

         spike in the middle reach of the river. The Wicomico River scores

         are relatively uniform, with no extreme.peaks. The pooled

         sediment risk scores are shown in Figure 18. The pooled scores

         integrate variability and consistency into the scores. These

         valucs indicate that the South River has a high risk for sediment

         toxicity impacts. The risk scores for combined water and sediment

         data are shown in Figure 19. The South River clearly has the risk

         highest value. The Patuxent River has the next lowest risk score,

         which is three times below the South River value. The

         toxicological risk values for the Severn and Wicomico Rivers are

         low or negative.

              The correlation coefficients for the risk scores and the

         fish community metrics from 1994 are shown in Table 24. The

         bottom trawl diversity index was strongly correlated with the

         sediment toxicological risk score. The combined score, which was

         dominated by the sediment score also tracks the bottom diversity

         score, but was not statistically correlated due to increased

         variability. The resident species diversity index and the overall

         IBI did not have strong correlations with the toxicological risk

         scores. The relationships between the toxicological risk scores

         and diversity indices can be seen in Figures 20-22.











                                                                        36




                                    DISCUSSION




              The South River bioassayp displayed greater toxicological

         responses than any other tributary. Statistically significant

         levels of mortality were not observed in the sediment bioassays,

         primarily due to high variability. However,.the South River

         bioassays generally exhibited the lowest survival rates in both

         water and sediment bioassays. Significant survival, growth and

         reproductive effects were seen in water column tests. Low levels

         of total organic carbon in the sediments, which can indicate

         potential food shortage stress on test organisms Adolphson and

         Alden, 1994) did not appear to be alcontributing factor. Pore

         water ammonia did not appear to be a contributing factor. There

         was a marked difference between the upstream and downstream

         portions of the river. Most of the observed sediment mortality

         effects were concentrated in the upper three stations (Figs 8-

         11). Sediment chemistry did not reveal any specific chemical or

         suite of chemicals which may be responsible for the observed

         effects. Metals levels in bulk sediment analyses were marginally

         higher than other stations, but this result was element specific.

         Levels of chromium, lead and zinc exceeded NOAA ER-L values. Pore

         water metals levels were not observed to be the highest of the

         four rivers. The AVS/SEM ratio was the highest, but was well

         below 1.0.

              The Severn river sediment bioassays demonstrated toxic











                                                                        37

         effects only at the upper-most station. As in the case of the

         South River, sediment results were not statistically significant

         in the pooled data due to high variability. Significant survival,

         growth and reproduction effects were observed in the water column

         bioassays. Chemical analyses of composite sediment and water

         samples were unremarkable.

              The Patuxent River results demonstrated both water column

         and sediment toxicity. Mortality of polychaetes and fish embryos

         was observed primarily at one station in the middle reach of the

         river. significant survival and reproduction effects were

         observed in the water column bioassays. The Patuxent River had

         the highest SEM metals levels. It also had the highest AVS level,

         resulting in a low SEM/AVS rat io. Patuxent River sediments were

         the only samples in which Cd was present at detectable levels.

         The levels of lead and zinc exceeded NOAA ER-L levels.

              The Wicomico River bioassays resulted in very few toxic

         responses. survival, growth and reproduction in the water column

         bioassays did not show any significant effects except in the May

         copepod bioassays. All the copepod bioassays, including the

         controls, had poor survival and reproduction in that particular

         month. one sediment sample yielded high mortality for fish

         larvae. Bulk sediment analyses demonstrated that lead and zinc

         concentrations were above NOAA ER-L levels.

              No specific chemical or suite of chemicals has been

         identified in these samples, which can explain the observed

         results. The standard suite of priority pollutant chemicals was











                                                                         38

         analyzed. However, a thousand chemical contaminants have been

         identified in the Bay USEPA CBLO 1992) and most of these are not

         analyzed for in standard surveys. In addition, many more organic

         chemicals are simply regarded.as unknowns in GC/MS analyses. Many

         chemicals can not be analyzed by GC at all. Finally, the chemical

         analyses are performed on composites of all stations within each

         river due to cost constraints. Thus, high level concentrations of

         chemicals from a specific location or locations could essentially

         be diluted by sediment from cleaner portions of the estuary.

              None of the sediment bioassays resulted in statistically

         significant results. Data from the polychaete, fish and L.

         dytiscus bioassays, which showed site specific responses, had

         high variability. This is due in part to the great differences,in

         response from different individual stations e.g. upstream vs

         downstream). Since data must be pooled by river to make

         statistical tests of river vs control, the mean level of response

         from a given station may be masked by lack of response at other

         stations. This is analogous to the analytical chemistry results,

         where concentration levels from specific stations are diluted by

         compositing with cleaner sediment from other stations. High

         variability was not observed in th e L. plumulosus or plant

         assays. These bioassays yielded few, if any positive responses in

         the first place.

              No mortality, growth or reproduction effects were observed

         in any of the vascular plant bioassays. Except for pesticides,

         the relative sensitivity of plants and animals to environmental











                                                                        39

         contaminants is largely an unknown factor. However, the sago

         pondweed has been tested with several individual chemicals and

         has been shown to be a reasonably sensitive species, especially

         to herbicides Flemming et al..1988, 1991, 1993). The potential

         for seasonal sensitivity of plants to low level contamination is

         also unknown. The impacts of herbicide runoff would be expected

         to be lower in late summer than in spring. This aspect of

         sampling design needs further investigation.

              The E. affinis data for the month of May are questionable.

         Survival to the adult stage was lower in May than in other

         months, including the controls. Reproductive values were

         drastically lower in-May than in any other month for all stations

         and the controls. The May copepod bioassay results are in large

         part responsible for the high-water risk score for the Wicomico

         River for that month.

              Interesting spatial patterns were observed in the sediment

         bioassays. Toxicological data from the upper half of the South

         River demonstrate severe impacts in three out of four of the

         animal bioassays. The downstream stations do not show above

         average toxicity values. A more intense evaluation of the South

         River west of Route 2 is indicated . Only the upper-most station

         of the Severn River demonstrated high toxicological responses.

         This is reflected in the fish and L. dytiscus survival and growth

         bioassays. In the Patuxent River, the middle sampling station

         demonstrated elevated toxicological effects. This was due to the

         fish embryo and polychaete survival bioassay results. It should











                                                                        40

         be noted that in spite of the high mortality rate for worms at

         this site, the highest rate of growth by the worms was achieved

         at this site also. The only area in the Wicomico River which

         demonstrated elevated response was at the mouth of the river.

         Only the fish bioassays demonstrated elevated responses in this

         region. In the South, Severn and Patuxent Rivers, the impact on

         fish was primarily on the embryonic (egg) stage. The eggs did not

         die, but up to 100% failed to hatch. In the downstream Wicomico

         River station the effect was on larval (post-hatch) survival. The

         eggs hatched, but the larvae did not survive.

                   overall, results indicate that the ambient toxicity

         bidassay approach is sensitive-enough to identify biologically

         significant contamination. The bioassays demonstrate that water

         column toxicity is not as severe as localized sediment toxicity

         but that water column effects are more wide spread and variable

         over time.

              The risk ranking procedure results in comparable risk scores

         between sites. The use of multiple species, multiple sampling

         times/locations and a correction for the number of significant

         data points on a tributary-by-trJbutary basis results in a robust

         scoring procedure. The combined toxicological risk scores do not

         respond strongly to small variations in data availability or

         isolated spikes. The consistency factor can drive the score

         negative if there are a large number of nonsignificant endpoints,

         if laboratory variability is high (as discussed above) or the

         response values are very low. Inclusion of factors for











                                                                        41

         variability and response consistency provide additional

         information on the risk of toxic impact. The consistency factor

         was designed to act as a counterweight to unusual response values

         for the purpose of damping out rare spikes-while not influencing

         scores from evenly divided results. It will tend to increase the

         score of highly polluted sites. Inclusion of the assay specific

         coefficients of variation in the calculation scheme tends to


         increase the cumulative score even in the absence of

         'statistically' significant results. The simple toxicity scoring

         method can demonstrate where the specific spatial and/or temporal

         differences between samples exist.

              The combined scores are not merely the sum of the sediment

         and water scores, due to the interplay between number of data

         points and the consistency factor. The combined score for the

         Wicomico River was strongly negative, while the sediment score

         was just below zero and the water score was over 40. The water

         and sediment scores for the Severn River were greater than 30 and

         10 respectively, but the combined score was less than 10. The

         South River had multiple high scores in the sediment and

         statistically significant water column results. The combined

         score is dramatically different than scores for the other rivers.

              Some information is lost in the process of pooling the data

         to calculate a risk score on a river-by-river basis. This has the

         advantage of smoothing out individual spikes in the whole data

         set, but it is instructive to look at the spikes on a sample by

         sample basis. This approach displays the existence of a











                                                                        42

         downstream gradient in the Severn River and site specific spikes

         in the Patuxent and Severn Rivers. Transient spikes, if present

         from spills or heavy runoff, may also be detectable in the water

         column bioassays. The ability.of the data set to identify
         isolated hot spots is dependent on the size of"the area relative

         to sampling intensity Gilbert 1987). The Patuxent River sampling

         stations were distributed over two to-threetimes the distance of

         stations in the other rivers. Thus the sensitivity of a 'river

         specific' combined score requires careful application of the

         data. Large areas of degraded habitat could be missed if the

         sampling stations are too far apart. The sheer size of the river

         will affect its' assimilative capacity for environmental

         degradation. Also, the relative size and complexity of the

         Patuxent River watershed is greater than that of the other

         rivers. A more intense examination of the upper South and Severn

         and the middle Patuxent Rivers may yield clearer pictures of the

         nature and extent of degraded habitats

              The correlation between the toxicological scores and the

         fish community metrics indicate that the sediment toxicological

         risk score is strongly correlated with the bottom community

         diversity index, as opposed to the resident diversity index and

         the IBI (Table 24). The resident species metrics and the IBI were

         not well correlated with the risk scores. Similar results were

         found in the 1993 sampling year (Hartwell et al. 1995). The

         definition of resident species as estuarine spawners is important

         in this regard. This metric is dominated by species taken in the











                                                                         43

         beach seines in terms of number of species and individuals. The

         'resident species' are thus not living in close contact with the

         sediment at the bottom of the channels where the sediment samples

         were taken. The toxicological.data clearly demonstrates that

         sediment toxicity is a dominant problem in the South River, but

         that the water column scores were marginal there, as well as the

         other systems. Consistent with results from 1993, results from

         the Wicomico River displayed good fish community indices and low

         toxicological risk scores.

              The relatively high fish community scores and low

         toxicological risk score in the Patuxent River are consistent.

         However, as indicated above, this system is much larger than any

         other tributary tested to date, and localized problems may exist,

         as indicated by the data from the middle station. This station

         was approximately 1.5 km downstream of the Chalk Point power

         plant.

              The Severn River had a relatively high bottom diversity

         index but a low resident diversity index and IBI. The low IBI and

         resident indices in the Severn River system may be due to reasons

         other than ambient toxicity. This may not ba the case in the

         upper reaches however. Inclusion of this type of system in the

         correlation calculations affects the results. As illustrated in

         Figure 21, the low IBI and resident diversity index values from

         the Severn River (Table 3) introduce scatter in the relationship

         between those parameters and the sediment risk score. In

         contrast, the bottom diversity index for the Severn River is











                                                                        44

         relatively high, consistent with a low sediment-risk score. A

         similar situation in Fishing-Bay was observed in the 1993

         sampling year (Hartwell et al. 1995). Low IBI scores and

         relatively low numbers of resident individuals were taken in the

         Fishing Bay system, but the bottom diversity index was high. None

         of the toxicological indices in Fishing Bay indicated habitat

         degradation due to toxic contamination. Low.IBI scores in this

         area may be due to habitat deficiencies, such as the absence of

         SAV in shallow areas (Carmichael et al. 19 92b). A similar

         scenario appears to be the case for the lower Severn River. The

         value of the toxicological risk ranking approach is that it was

         equally able to indicate where toxic contamination is and is not

         a likely impact, in the face of indications of impaired community

         health. If this is true, three predictions can be made;



              1.   Areas with high IBI scores or diversity indices will

              always have,low toxicological risk scores, unless

              populations have adapted to contaminated conditions.



              2.   Areas with high toxicological risk scores will always

              have low IBI scores or divers ity indices, unless populations

              have adapted to contaminated conditions.



              3.   Areas with low IBI scores or diversity indices may or

              may not have high toxicological risk scores, depending on

              the nature of the reason for poor fish communities.











                                                                        45

             These hypotheses can be tested with a larger data base. As

         studies progress, more sites-will be included in the analyses.

         As the toxicological data base expands, correlations with a

         variety of community data bases will be.possible i.e. the

         juvenile seine survey). Additional work needs to be done to

         examine how well the toxicological risk ranking results from

         different years can be integrated. In-addition, an assessment is

         needed on the importance of sampling intensity, relative to the

         size of the river system, on risk score sensitivity.











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              DiToro, D.M., J.D. Mahony, D.J. Hansen, K.L. Scott, M.B.
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          J. Chaillou, P. Kazyak, C. DeLisle, R. Batiuk and D. Packer.
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          Washington, D.C. EPA 600/4-90/027.

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               Vaas, P.A. and S.J. Jordan. 1991. Long term trends in
          abundance indices for 19 species of fish of Chesapeake Bay:
          Reflections of trends in the Bay ecosystem. In: New Perspectives
          on the Chesapeake System: A Research and Management Partnership.
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          #137, Solomons, Md.








         Table   1.          Physicochemical parameters measured during water collections for ambient toxicity testing from four test stations, from April through
                             September, 1993. Means (SD) for each parameter are given. These values were derived by averaging over the depth of the water column
                             (i.e., bottom, middle, surface), and from two dates within each month on which the samples were collected.



                                               CURTIS CREEK                                                                                       ROCK CREEK


         Month        De2th         Temn.        Sal.          Do            pH          Tide                      PMth           eW.          Sal.         Do              -H        Tide
                        W           (OC)         (Ppt)        (PPM)                                                 (m)          (OC)          (Ppt)       (PPm)


         May            6.0         17.9           3.8         4.84                      Flood/Flood                2.7          20.1          2.2          5.86         7.10         Flood
                      (0-9)         (3-4)        (2.2)        (3.47)        (0.61)                                 (0)           (1-0)         (0.4)       (3.24)       (0.51)
         June           6.6         20.3           6.5         4.53          6.82        Ebb/Ebb                    3.3          22.1          5.6          6.51         7.10         Flood/Ebb
                      (0.2)         (2.5)        (1-0)        (2.94)        (0.32)                                 (0)           (1.2)         (0.2)       (1.9)        (0.35)
         July           6.2         27.6           6.9         4.42          7.52        Ebb/Ebb                    3.5          28.8          6.2          6.19         7.81         Flood/Ebb
                      (1.3)         (2.4)        (0.7)        (4.08)        (0.61)                                 (0.3)         (1.3)         (0-1)       (3.09)       (0.59)
         August         8.1         27.5         10.1            ND          7.99        Flood/Flood                3.6          28.5          9.7           ND          7.96         Flood/Ebb
                      (0)           (0-7)        (0-5)                      (0.52)                                 (0.7)         (1.4)         (1.5)                    (0.67)
         Sept           7.2         25.0         10.2            ND          7.73        Ebb/Flood                  4.2          24.2          9.5           ND          8.25         Flood/Flood
                      (0-5)         (1.4)        (1.4)                      (0.26)                                 (0.4)         (1. 1)        (0.7)                    (0-19)



         ND =no data








        Table l(cont.)     Physicoehemical parameters measured during water collections for ambient toxicity testing from four test stations, from April through
                           September, 1993. Means (SD) for each parameter we given. These values were derived by averaging over the depth of the water column
                           (i.e., bottom, middle, surface), and ftom. two dates within each month on which the samples were collected.



                                               FISHING BAY                                                                             WICOMICO RrVTR


        hLonth       Poth        Te            al.                        H         Tide                     Depth       LeW.          50all -     DO                      Tide
                                                           ROQ          p                                                                                         --
                                                                                                                                                                pH
                      (m)        (OP           (PPO        (PPM)                                              (in)       (Or-)         (PPO        (PPM)


        April         3.6        15.8          11.6        10.25        8.01        Ebb                        ND           ND          ND           ND         ND         ND
                     (0)         (0)           (0.1)       (0.05)      (0.12)
        May           4.0        23.1          8.7         7.63         7.35        Flood                     2.4        20.2          3.2         6.76         7.58       Flood
                     (0)         (0.4)         (0-1)       (0.31)      (0.23)                                (0.3)       (0.6)         (0.3)       .(1.06)     (0.12)
        June          3.0        24.2          9.3         9.60         7.74        Flood[Low                 3.3        24.2          5.4         7.00         7.71       High/High
                     (0)         (1.9)         (0-1)       (1.16)      (0.13)                                (0)         (0-9)         (0.7)       (1.42)      (0.33)
        July          4.2        30.8          10.9        7.05         7.08        Flood                     2.6        30.8          6.9         7.65         8.09       Flood
                     (0)         (0-5)         (0)         (0.81)      (0.10)                                (0)         (0.7)         (0.2)       (1.30)      (0.14)
        August        5.1        26.6          12.5        7.59         8.09        Flood                     3.3        27.2          9.9         5.67         7.78       HightFlood
                     (0)         (0.1)         (0.1)       (0.08)      (0.02)                                (0)         (1-0)         (0-1)       (0.29)      (0.04)
        Sept          3.4        24.8          14.0        8.08         8.11        Flood/Ebb                 3.2        25.3          10.3        7.29         7.80       Ebb/Flood
                     (0.2)       (1.6)         (0.2)       (0.17)      (0.13)                                (0.2)       (1.8)         (0.7)       (0.44)      (0.23)



        ND =no data








                Table 2.     Particle size analysis of sediments from test, reference, and control sites used in
                             toxicity tests. Sediments collected 8/8/94 - 8/15/94.     ("R" indicates replicates.)



              Station                        % Sand            % Silt            % Clay

              Set #l:


                Patuxent River R1            1.68              85.58            12.74
                Patuxent River R2            1.57              63.94            34.49
                Patuxent River R3            1.34              55.94            42.71
                Patuxent River R4          34.61               39.32            26.07
                Patuxent River R5          19.03               51.59            29.17
                Sevem River     Rl           6.02              57.50            36.48
                Sevem River     R2         99.19                 0.44            0.37
                Sevem River     R3         94.40                 3.89            1.71
                Sevem River     R4         84.36                 8.89            6.75
                Sevem River     R5           3.50              59.01            37.49
                South River     RI           3.96              57.70            38.34
                South River     R2         16.11               52.39            31.50
                South River     R3         12.46               50.94            36.60
                South River     R4           3.10              60.28.           36.62
                South River     R5         70.60               18.79            10.61
                Wicomico River Rl            1.83              57.68            40.49
                Wicomico River R2            1.55              57.79            40.66
                Wicomico River R3            3.38              56.24            40.38
                Wicomico River R4            0.68              59.32            40.00
                Wicomico River R5            0.37              58.49            41.14
                Poropotank Mud               0.63              60.96            38.41
                Lynnhaven Mud              37.23               50.03            12.74
                Lynnhaven Sand             97.63                 1.25            1.12









               Table 3.       Summary data of bottom fish diversity index, resident fish diversity index, and river LBI scores vs toxicological
                              risk scores for water, sediment, and water and sediment combined for four stations in the Chesapeake Bay
                              in 1994.






                                    Botto           Resident
                                   Diversity        Diversi1y                    Water       Sedim         CombLmd
               Stati                 Index           Index          IIBI         Risk          Risk           Risk


               Patuxent R.           1.991           1.478         34.6          25.15         20.84          42.33
               Severn R.             1.836           1.180         26.3          36.33          13.11         4.83
               South R.              1.400           1.402         28.0          .37.34       149.90         119.08
               Wicomico R.           2.037           1.409         31.4          42.85          -2.59        -20.91








              Table 4.      Summary of survival of fish, Qpfinodon variegatus,, and shrimp,
                            Palaemonetes pugio, after 7-day test, with water samples.from
                            four stations in the Chesapeake Bay versus the control in 1994.


              Month/                April          May           June           bly          August
              Station



              FISH


              Control                 98           100           95              93.3           90
              Patuxent               100           100           95             100             90
              Severn                 100           100           95              96.7           97
              South                  100           100           97.5           100             90
              Wicomico               100             98          97.5            90             100


              SHRIMP


              Control                100                                        100             95
              Patuxent                95                                        100             97.5
              Severn                  95                                        100             87.5
              South                  100                                        100             82.5
              Wicomico                92.5                                       97.5           90




                     Organisms not available.








                Table 5,      Summary of growth of fish, C@piinodon va?legatus,,and shrimp, Palaemonetes
                              pugio, during 7-day ambient toxicity bioassays with water from four stations in
                               the Chesapeake Bay in 1994. Values are calculated as mean terminal wt. - mean
                               initial wt. (mg).


                Month/                      Apn                                                           August
                                                              May           June            July
                Station



                FISH


                Initial Weight              0.139           0.108           0.087           0.029           0.049

                Control                     0.399           0.271           0.024           0.377           0.434


                Patuxent River              0.419           0.324           0.039           0.220         -0.011**


                Severn River                0.390*          0.321*          0.066           0.197         -0.023**


                South River                 0.431           0.308           -0.018          0.236         -0.019*


                Wicomico River              0.444           0.309           0.037           0.208         -0.026**




                SHRIMP


                Initial Weight                +                                             0.183           0.070

                Control                       0.110                                         0.176           0.064


                Patuxent River                0.110                                         0.173           0.114*


                Severn River                  0.102                                         0.218           0.052


                South River                   0.090                                         0.183           0.040


                Wicomico River                0.106                                         0.151           0.077


                      organisms not available
                +      sample lost, reported vales are terminal weights
                       significant at p = 0.05
                       significant at p = 0.01








              Table 6.       Reference toxicant data results from 48-hr, water reference toxicant tests with
                             potassium chloride (KCI). All values are nominal.


              Date                 Species                    LC50          CIs (mg/L KCI)


              Apr 94            C. variegatus               .179.24           171.97-186.82
                                                                              107.05-145.96


                                P. Pugio                       52.52.          45.92-60.08


              May 94            C. variegatus                 124.97           101.79-153.43
                                                              176.78            nr



              Jun 94            C. vafiegatus                  50.73           43.65-58.97


              Jul 94            C vafiegatus                   71.78           61.73-83.46

                                P. Pugio                       85.18           72.07-100.67


              Aug 94            C variegatus                  176.78            nr

                                P. Pugio                       67.68             58.20-78.71


                                L. plumulosus              > 125.00

       nr    95 % confidence limits are not reliable by Trimmed Spearman-Karber Method.







               Table 7.       Summary of mortality and reproduction of copepod, Eurytemora affinis, from
                              ambient toxicity bioassays using water samples collected from four stations of the
                              Chesapeake Bay in 1994. Values are the mean of four replicates. Values in
                              parenthesis are standard deviations.


               Month/                  AW              May            June            MY              Augus
               Station
                                                              SURVIVAL

               Control                 2.25 / 5.2511   5.75           3.25            1.so            3.00
                                       (3.34)/(2.95)   (2.86)         (1.48)          (0.87)          (2.12)

               Patuxent                6.00            5.33           3.5             6.50*           1.50
                                       (4.74)          (2.49)         (2.69)          (1.5)           (1.5)

               Severn                  3.75            8.0            6.75            6.00            1.75
                                       (1.30)          (3.08)         (2.77)          (3.16)          (2.05)

               South                   6.00            7.5            5.25            7.50            2.00
                                       (2.12)          (3.91)         (2.17)          (4.09)          (1.22)

               Wicomico                4.5             10.5*          4.00            3.75            2.55
                                       (3.04)          (1.12)         (1.87)          (1.48)          (2.60)



                                                         REPRODUCTION



               Control             577.5/350.Oa        162.5          1188.75         1234.75         875.5
                                  (277.48)/(51.02)     (65.53)        (131.29)        (230.20)        (315.99)

               Patuxent              445.25            210.67         747.25*         738.5*          791.75
                                     (179.04)          (80.02)        (223.57)        (217.90)        (381.02)

               Severn                665.25            76.5*          239.25*         1293.0          778.0
                                     (113.23)          (81.56)        165.76)         (563.95)        (324.02)

               South                 547.0             310.75         320.0*          588.25*         1161.0
                                     (157.74)          (179.60)       (207.91)        (293.27)        (145.02)

               Wicomico              406.0             0.0**          804.75          855.5           982.0
                                     (211.93)          (0-0)          (274.32)        (170.37)        (212.67)

                    two controls were used during April due to wide differences in salinities of ambient test water.
                Salinity of all test water was adjusted to 10 ppt in other months.

                     significant at p = 0.05
                      significant at p = 0.01









               Table 8.     Growth and rhizome production of. Potamogeton pectinatus during 4-week
                             ambient toxicity bioassays with water from four stations in the Chesapeake Bay
                             in 1994. Weight values are the mean (SD) of 10 replicates in units of gm/plant.




               Station


                                  Initial wt.          Terminal wt.           Dry wt.     #Rhizome fips

               Control                1.28                 6.03               0.63              20.7
                                      (0.154)              (1.113)            (0.103)

               Patuxent               1.32                 6.72               0.69              20.6
                                      (0.149)              (1.508)            (0.125)

               Severn                 1.33                 6.32               0.70              23.0
                                      (0.124)              (6.317)            (0.154)

               South                  1.24                 6.53               0.71              19.2
                                      (0.099)              (1.272)            (0.176)

               Wicomico               1.21                 6.18               0.66              20.3
                                      (0.165)              (0.706)            (0.117)



                                                           August



               Control                1.33                 4.95               0.61              24.7
                                      (0.135)              (1.428)            (0.149)

               Patuxent               1.25                 4.41               0.51              26.2
                                      (0.149)              (1.508)            (0.125)

               Severn                 1.32                 5.26               0.59              24.3
                                      (0.116)              (5.262)            (0.123)

               South                  1.30                 4.54               0.50              25.0
                                      (0.099)              (1.272)            (0.176)

               Wicomico               1.23                 4.40               0.50              23.4
                                      (0.136)              (1.039)            (0.116)




                    Table 9a.             Summary of Microtox            R assay results, expressed as luminosity, for water samples collected from four stations in the
                                          Chesapeake Bay in 1994. Results are the mean of four replicates, with standard deviation in                                            Runs I and 2 refer to
                                          discrete water collections. Shading indicates inhibitory results.


                    Month/                                    April                              May                         June                             kily                       Augus
                    Station               Run           Ctrl          Amb                Ctrl          Amb             Ctrl          Amb              Ctri          Amb             Ctrl           Amb



                    Patuxent              1            92.50         115.25**            -50.."S                     102.75        120.25*            93.50         116.75
                                                        (2.50)         (6.94)                                          (9.12)        (4.15)           (2.06)        (4.60)
                                                                                                                                                                                               ...... ...........
                                                                                                                                                                                              . .. .... ..........


                    Patuxent              2                                              91.00         97.75           86.25       126.75*            90.00         99.75           73.75          88.00*
                                                                                         (6.82)        (2.95)          (7.50)      (11.84)            (1.22)        (6.02)          (1.48)         (4.74)

                                                                                                                                                                                   ......          6.63
                    Severn                1            7 - *-::::-:::-: -                    i-@$
                                                                                                                     108.25        152.00**           95.50         106.50**
                                                                                                                                                                                    . . . . . ... ....... ........ @.J 0
                                                       (2 .0.5.                                                        14.53)                                             7)
                                                                    . . ..... ..... ..                                               (6.28)           (2.96)        (2.8

                    Severn                2                                              97.50        104.75           71.75       135.75**           84.75         94.75**         .........  .................
                                                                                         (6.73)        (3.03)          (6.83)        (7.46)           (1.79)        (1.92)

                    South                 I           87.'*Oo@."'@@iiiiiiiiiiiiii@[email protected] ..S. 73.75 90.75** 109.00            123.75                                           6
                                                                                                                                                      95.00         105.50                         ..........

                                                                 ...........
                                                                   ...... .              (3.63)        (4.92)        (11.77)       (19.25)            (5.39)        (6.02)

                    South                 2                                              90.50      106.25**           89.50       119.00*            79.50         98.25*          64.75          87.75*
                                                                                         (2.69)        (5.17)        (13.86)         (9.14)           (9.10)        (3.27)          (0.43)         (7.08)

                    Wicomico,             I
                                                                                                                       79.75       103.00             80.25         91.00**         78.00          86.00*
                                                                   ........ .            ................  .......
                                                                   ...... ..
                                                                                                                     (15.75)       (20,94)            (1.79)        (3.24)          (2.74)         (2.92)
                                                                                         I ..........
                                                                                         . ... ....
                                                                  ...............        .............M

                    Wicomico              2                                              91.75       101.50*           75.75       113.75**           81.25         94.75**         76.25          82.25
                                                                                         (3.77)        (2.96)        (11.41)         (2.59)           (4.32)        (3.19)          (1.79)         (5.76)


                        Runs I and        2 combined for April assays.

                           significant at p = 0.05
                            significant at p = 0.01








              Table 9b.     Lowest Observed Effect Concentration (LOEC) for dilution series Microtox'
                            bioassays which - were inhibitory to bacterial luminosity, for water samples
                            collected from four stations in the Chesapeake Bay in .1994. Values are expressed
                            as % river water, diluted with control water.



              Month/                      A ril                Ma                    Aup-ust
                                                               W _y
              Station


              Patuxent                                           80                     70



              Severn. Run 1                   70                 70                      70


              Severn Run 2                                                            <60



              South                           70                                         90



              Wicomico                        '90                99








              Table 10.     Results of chemical analyses of water samples from four stations in the Chesapeake Bay
                            in 1994 for metals contamination. Units are ug/l.




              CHEMICA              Patuxen        South      Severn       Wicomico        EPA Marine Water
                                                                                            Qualily Criteria

                                                                                          Acute      Chronic

              Antimony                 2            3           2             4           1500*        500*
              Arsenic V              BDL            2           2             3           2319**       ---
              Chromium VI              6            6           9             4           1100          50
              Lead                     4          BDL           2            BDL            220           8.5
              Selenium                 1            2           3             8             300         71



              BDL = below detection limit
                   proposed criteria
                    based on LOEL






                           Table 11.     Mortality data for Lepidavylus dytiscus and Streblospio benedicti at the four stations. Tests were conducted
                                         from 08/30/94 to 09/9/94. "(R)" = Reference, "(C)" = Control. "SE" = Standard Error.

                                                                        % Mortality

        Specie                  Station
        L. dytiscus                                         Unad.itisted      SE                   AdJusted          SE

                                Patuxent River               34.00*         5.10                    5.39            4.14
                                Severn River                 17.00         12.30                    9.10            9.10
                                SOLIth River                 44.00*        11.79                    23.78          13.28
                                Wiconilco River              28.00*         2.55                    0.00            0.00
                                Lynnhaven Sand      (C)        3.00         2.00                    2.08             1.51
                                Poropotank Mud      (R)      33.00*         5.83                    5.38            4.13


        S. henedicti

                                Patuxent River               23.00        10.56
                                Severn River                 10.00         2.74
                                SOLIth River                 17.00         7.18
                                Wicomico River               14.00         3.32
                                Poropotank Mud      (R)      10.00         3.87
                                Lynnhaven MLid      (C)        5.00        3.16
                                Lynnhaven Sand      (R)      14.00         1.87

           Sigii1ficantly less than cowrols (1)<0.0.5).
         N OTI           Adjusted 1- (/Ytiu-tts and S. heitedicti survival is percent survival adjusted for predicted particle size effects.






         Table 12.     Mortality from qprinodon variegatus at the four stations. Tests were conducted from 08/30/94 to 09/9/94 "(R)"           Reference,
                       "(C)"= Control.






       Species--       Station
                                                   % Mortality SE         % Hatched SE        %Dead eggs SE          %Dead fish SE
       C vaiiegatuv
                       Patuxent River                    58.00   13.19        46.00   15.68        32.00    11.58        5.56    5.56
                       Severn River                      40.00    -16.43      62.00   16.55        20.00    3.16         3.57    3.57
                       South River                       72.00   15.30        ..30.00 16.43        10.00    8.37         4.76    4.76
                       Wicomico River                    66.00.  15.01        52.00   10.68        20.00    10.20        42.50   17.50
                       Poropotank Mud (R)                46.00   14.00        62.00   16.85        22.00    10.68        11.07   7.15
                       Lynnliaven Sand  (R)                2.00    2.00       100.00    0.00         0.00   0.00         2.00    2.00
                       Lynnhaven Mud (C)                 42.00   12.81        66.00   13.64        28.00    9.70         10.67   6.86
       Note:           % Mortality     (Dead fish + dead eggs at test  termination)/(# eggs exposed)*100.
                       % Dead fish     (Dead fish)/(# hatched)*100
                       % Dead eggs      (Dead eggs)/(# exposed)*100
                       % Hatched        hatched)/(# eggs exposed)*100












                Table 13.      Summary of mortality of amphipod, Leptocheirus plumulosus, after 10-day
                               test, with sediment samples from four tributaries of the Chesapeake Bay versus
                               the control in August 1994. Units are percent (standard deviation).


                Station                             % Mortalijy




                Control                                 12.0
                                                        (10.30)

                Patuxent                                  6.0
                                                        (7.35)

                Severn                                    8.0
                                                        (5.10)

                South                                   22.0
                                                        (20.15)

                Wicomico                                10.0
                                                        (7.07)












               Table 14.      Summary of growth of amphipods Leptocheinis         plwnulosus during 10-day
                              ambient toxicity bioassays with sediment from four tributaries of the Chesapeake
                              Bay in 1994. Values are calculated as mean terminal wt. - mean initial wt. (mg).


                                                                      Weight (mg)


               Initial Weight                                           0.029

               Control                                                 -0.015


               Patuxent River                                           0.004*


               Severn River                                             0.034**


               South River                                              0.004


               Wicomico River                                           0.011**



                      significant at p   0.05.
                       significant at p  0.01.









             Table 15.      Summary of growth data for Lepidactylus dytiscus and Streblospio benedicti
                            after 10-day ambient toxicity bioassays with sediment from four tributaries
                            of the Chesapeake Bay in 1994. Values are mean terminal dry weight.
                            '4(R)"  Reference, "(C)"    Control.

                                      Number of
     Site                           True Replicates    Weight(mg) S.E.

     L. dytiscu-s

     Initial                             5               0.518      0.016
     Patuxent River                      5               0.806      0.150
     Severn River                        5               0.735      0.419
     South River                         5               1.201      0.808
     Wicomico River                      5               0.724      0.055
     Poropotank Mud    (R)               5               0.799      0. 161
     Lynnhaven Sand   (C)                5               0.531      0.031

     S. benedicti


     Initial                             5               0.103      0.007
     Patuxent River                      5               0.771      0.394
     Sevem River                         5               0.578      0.037
     South River                         5               0.650      0.165
     Wicomico River                      5               0.607      0.054
     Poropotank Mud    (R)               5               0.581      0.063
     Lynnhaven Mud     (C)               5               0.529      0.060


                Sianificantly less than controls (p < 0.05).








              Table 16.       Reference toxicant data results from 96-hr, water only, reference toxicant
                              tests. Cadmium chloride (CdC12) was used for all organisms.




                                                            Historical
               Orp-anism      LC50 & Cls (=/L Cd)              Mean                       SE




               L. dytiscus         1.75 1.47-2.08               4.18                    0.510




               S. benedicti        2.91, 2.30-3.70              4.80                     0.703




               C. variegatus       0.64 0.53-0.71               0.58                     0.056









                Table 17.      Summary of percent germination (SD) of lettuce and,Spartina altemafl-ora seeds
                               following 3-days exposure to ambient sediments from four stations in the
                               Chesapeake Bay, versus the control, in 1994.




                Station                       Lettuce              S. alternaflora




                Control                       94.52                      11.29
                                              (5.12)                     (3.34)

                Patuxent                      94.31                        6.75
                                              (2.01)                     (3.69)

                Severn                        93.87                        7.34
                                              (3.39)                     (2.09)

                South                         96.68                      10.27
                                              (1.34)                     (2.92)

                Wicomico                      92.20                        9.55
                                              (8.04)                     (4.37)







               Table 18.      Results of chemical analyses for metals in composite sediment samples from four* tributaries of the
                              Chesapeake Bay in 1994. Units are mg/kg.


               CHEMICAL               Patuxen         Sot              Severn      Wicomico NOAA ER-L NOAA ER-M

               Antimony                 ND              ND             ND              1.08            2             25
               Arsenic                  7.96            11.9           5.91            7.65          33              85
               Beryllium                1.31            1.45           0.66            1.69          ---             ---
               Cadmium                  1.69            ND             ND              ND              5               9
               Chromium                40.0            78.7            33.6           46.2           80              145
               Copper                  17.2            30.8            12.8           19.7           70              390
               Lead                    50.8            60.*6           23.4           72.3           35            110
               Nickel                 17.7              15.3           6.69           20.4           30              50
               Selenium                2.54             2.19           0.52            4.31          ---             ---
               Zinc                   155            219               77.8          141             120            270



               ND      not detected'








               Table 19.     Results of chemical analyses for semi-volatile acid/base neutral compounds in composite
                             sediment samples from four tributaries of the Chesapeake Bay in 1994. Units are ug/kg.



               CHEMICAL               Patuxent      South        Severn     Wicqmico NOAA ER-L NOAA ER-M



               Fluoranthene            ND             30           70          ND           600            3600
               Pyrene                  ND            ND            60          ND           350            2200
               Butylbenzylphthalene    ND            110          230'         560          ---            ---
               Chrysene                ND            ND            60          ND           400            2800
               Benzo(a)anthracene'     ND            ND            30          ND           230            1600

               ND     not detected.





                      Table 20.         Me  an SEM metals values for Sediments collected 8/8/94 - 8/15/94.





                                    Cadmium                Lead               Coppe                Nickel                Zinc                sum
                                      umol/g             umol/g               umol/g               umol/g               umol/g              umol/g

          Site

          Patuxent River                  0.036              0.202                 0.298               0.155                 2.176              2.868

          Severn River                    0.036              0.069                 0.149               0.160                 0.912              1.326

          South River                     0.012              0.064                 0.167               0.078                 0.814              1.140

          Wicomico River                  0.172              0.169                 0.432               0.445                 1.155              1.301
          Lynnhaven Sand                  0.000              0.000                 0.000               0.000                 0.013              .0.013
          Lynnhaven Mud                   0.000              0.021                 0.036               0.029                 0.441              0.527
          Poropotank Mud                  0.000              0.021                 0.000               0.054                 0.539              0.613
                    Detection Limits     0.001               0.004                 6.003               0.007                 0.005

           NOTE: Mercury     values for all site were < 0.0001 uniol/g w/DL of 0.0001 umol/g.









         Table 21.       Average SEM and AVS values and the SEMAVS ratio for sediment samples tested in
                         1994.


                                           Mean AVS              Mean SEM              Ratio



              Patuxent River                31.09                2.868                 0.092
              Severn River                  9.96                 1.326                 0.133
              South River                   2.98                 1.140                 0.384
              Wicomico River                11.54                1.301                 0.113
              Lynnhaven Sand                0.63                 0.013                 0.021
              Lynnhaven Mud                 3.17                 0.527                 0.166
              Poropotank Mud                5.46                 0.613                 0.112








               Table 22.         Chernical data for pore water samples from the six stations and the references and
                                 controls.





                                                                                            Unionized
                 Site                        Ammonia         Nitrite.        Sulfide        Ammonia
                                             (mp
                                                  ,/L)       (mg/L)          finsUL)        Ou/L)


                 Patuxent River              15.621          0.0165          0.009          0.2493
                 Severen River               13.496          0.0064       < 0.006           0.2152
                 South River                 10.2 9 4        0.0059          0.011          0.2580
                 Wicomico River              25.499          0.0078          0.007          .0.4069
                 Lynnhaven Sand              18. '114        2.7851          0.007          0.3644
                 Lynnhaven Mud               44.009          0.0075          0.495          0.5597
                 Poropotank Mud                2.545         0.0090          0.006          0.0509








     Table 23. Chemical data (TOC) for sediment samples from the four stations and the controls. All data is on
                a dry weight basis. 8/8/94 - 8/15/94.

      Station                Total Orp-anic Carbon-L%jo



      Patuxent River                  3.04
      Severn River                    0.99
      South River                     2.17
      Wicomico River                  2.58
      Lynnhaven Sand                  <0.37
      Lynnhaven Mud                   1.07
      Poropotank Mud                  4.26










                Table 24.      Pearson correlation coefficients and p values        for
                               toxicological risk s'cores and fish community metrics
                               for four stations in the Che*sapeake Bay in 1994.


                                                                 Bottom             Residen
                                                                DiverNily            Diversijy
                Risks                     IBI score               Index               Index


                Water Risk                  -0.5366              -0.1444             -0.3245
                                            (0.4634)             (0.855ï¿½)            (0.6755)

                Sediment Risk               -0.3463              -0.9626              0.1816
                                            (0.6537)             (0.0374)            (0.8184)

                Combined Risk               -0.1505              -0.8787              0.2985
                                            (0.8495)             (0.1213)            (0.7015)













                                                                           ............
                                                                             : X ::;:.:
                                                                .. ........ ....... ....


                        ..........           ......
                                                                                                           IN
                                                                                                           -- --------------
                                                                                     ............

                                                                                                         ------ - - - - - - - - - - - -
                                                      ... ........ ...............
                                                                                      A
                                                                                                                    XX-:

                     :4:

                                   URBAN
                                   IMPACTED
                                                         V
                                V  SALTWATER
                 X..               REFERENCE

                                   RURAL

                                   FRESHWATER
                                   REFERENCE                                                                        ....


                                                    V
                                            V

                                                            V

                                             V

                                                                            0

                                                    V



                                                             EM

                                             Ej
                               *> M1 M1



                                                                                                        ..............
                                                    .......                                                        .......
                                                              .M*0
                                                                                                        ..................
                                                                 QONT-Efff
                                                                                                    ......................
                                                                           ........................ ......
                                                                 ARM

                          Figure 1 Bottom water dissolved oxygen concentration vs, number of species in bottom trawls
                          from Chesapeake Bav tributaries (from Carmichael et al. 1992).















                                                                                                                                        .......... . .
                                                                                                                                        .......... .




                                                                                                                                     ....... ...
                                                                                                                                      X  X
                                                                                                                                        ............

                                                                                                                     . . . . . . . . . . .


                                                      BALTIMORE








                                                       SEVERN RIVER
                                                      ANNAPOLIS


                                                          Sou                                                      ......
                                                                  TH       RNER


                                                                                             ........ . ...


                                                                                                       .... .....       ...
                                                                                               . . .. ..... .








                                                                              RIVER
                                                                                                    7C,


                                             W/Com/co
                                                     RIVER











                                                                                                                                              ..........



                                                                                            ...............
                                                                                            ................



                                                                                       . . . . . . .......
                                                                                            ......   .......
                                                                                                     ....................
                                                                                                  .. ...    ....
                                                                                                      .. ...........



                                                                                                                                                          . . ..........-.....
                                                                                                                           .. . . . .....
                                                                                                                                            . ..... . . ..
                                                                                                                       ... ...  ... . . ....
                                                                                                                       .... ...... ..
                                                                                                                       ..........                     ......    .... ..
                                                                                                                                           ...............



                         Figure 2. Map of Chesapeake Bay showing the location of four tributaries sampled for ambient
                         toxicity In 1994.






























                                                                                               . . . . . . . . ....
























                                          X...... X

                                                         PRINCE
                                                       FREDERICK

                                                                               ........... .......
                                                                                ...................


                                                                                     I .................................:





                                                                                         . . . . . . . . . .





                                                           . .. ...........


                                                                    ... ........                  .... .. .................






                                                                                             MONS








               Figure 3. Map of the Patuxent River showing the locations of the 1994 ambient toxicity.





























































                                                                                                          ..............

                                                                                    .........



                                                                                          ..............



                                                                                        ....... ... .



                                                          ANNAPOLIS
                                                                                              - - ---- ------- ---







                Figure 4. Map of the Severn River showing the locations of the 1994 ambient toxicity sampling
                stations.
















                                                                                     ANNAPOLIS






                                                              IX.







                                                              ...............
                                                              . .. ..... ... .
                                                              . .. ..... ... .
                                                              . .. ..... ... .

                                                              ............
                                             4t"



















                                                                              ... . . .. ...





                                                                                ... .......








                 Figure 5. Map of the South River showing the locations of the 1994 ambient toxicity sampling
                 stations -

































                                                                     ...........










                                                                          ......      ..



                                                                          .......................




                                                                            . . . . . . . . . . .
                                     COBB NECK

                                                                           ..........
                                                                            ................









                  .... . ......
                                                                         ................









                      ..........






                 . ...........






                     . .... . ...

                                                                        ..... ... ..
                   . ......                         .....
                                                      ..... ... . ..
                                                             ............. . . . . . . ...........
                                                                  ..........


                 Figure 6. Map of the Wicomico River showing the locations of the 1994 ambient toxicity
                 sampling stations.




















                     150



                     100    ----- --------------------------------------------------------  --------------------------------------------------



                       50   - -------------- ----------------------------------------------------------------------------------------------



                         0-                                            A
                 0



                      -50   ----------------------------------------------------------------------------------------------- ---------------



                    -100    ----------------------------------------------- ---------------------------------------------------------- ----



                    -150
                            0         1          2          3          4          5          6          7          8         9          10
                                                               Non-Significant Endpts.



                                           Figure 7. Example consistency values for N                    10 endpoints.
                             --- -----------------------------
                                            -----------------





                                    Lepidactylus dystiscus
                                                  (Mortality)


                            Patuxent River                                   Severn River


                      100-                                            100-


                      80-                                              so-



                    t: 60-                                             60-



                      40-                                              40-



                      20-                                              20



                      0                                                 0
                         0     5      10     16      20                  6.      3         5        9
                                     Nautical Mile                                    Nautical Mile






                              South River                                   Wicornico River


                      100-



                      80-                                              80-


                                                                    'a  60-
                      60-



                      40-                                            8  40-


                      20     . . .    . . .                             20 .. . . . . . . . . . .



                         0                                               0-
                         0                  4        a                   0        3                  9
                                      Nautical Mile                                    Nautical Mile





                                       Mud Reference                      Sand Control



                    Fig. 8. Lepidactylus dystiscus percent mortality. Mortality is plotted against
                    distance between site replicates from up-river to mouth.





                                                 Streblospio benedicti
                                                                 (Mortality)


                                    Patuxent River                                                  Severn River.


                                 100-                                                      100-



                                 80-                                                       80-



                                                                                           80-



                                                                                           40-

                                                                                         96

                                 20-                                                       20-
                                 1    0 9                                                      '__9 . . . . . . . ..
                                 0                                                          0-
                                 0       5        10        Is        20                       0.         3           a           9
                                                 Nautical Mile                                                  Nautical Mile






                                        South River                                                Wicomico River


                                 100                                                       100-


                                 80-                                                        80-


                                 a                                                         'a
                                 t: 50-                                                    r60-
                                 0                                                         0


                                 40-                                                        40-



                                 20-                                                        20-



                                 0                                                             0.
                                 0           2            4            6                       0           3            a           9
                                                  Nautical Mile                                                  Nautical Mile





                                 -  Mud Control                        Mud Reference                        - Sand Reference




                          Fig. 9. Streblospio benedfctf percent mortality. Mortality is plotted against distance
                                 I
                          between site replicates from up-river to mouth.





                                                                antocheirus plumulosus
                                                                                 (Mortality)


                                                    Patuxent River                                                         Severn River
                                        100                                                                   100



                                        80 -                                                                  80 -



                                                                                                              so -
                                        60 -                                                                  t
                                        0                                                                     0


                                        040 -                                                                 040 -
                                        2                                                                     2
                                        Q                                                                     ID
                                        IL                                                                    CL

                                        20 -                                                                  20
                                        0                                                                     01
                                        0         5           10          15         20                       0            3              6              9
                                                            Nautical Mile                                                         Nautical Mile






                                                       South River                                                        Wicornico River
                                        100                                                                   100



                                        so-                                                                   so -


                                        Z                                                                     C13
                                        r60-                                                                  t60 -
                                        0                                                                     0


                                                                                                              040 -
                                                                                                              2
                                                                                                              A!
                                        IL
                                        20                                                                    20
                                        40







                                                                                                                                                           9
                                        0                                                                     0
                                        0             2               4               6                       0             3
                                                             Nautical Mile                                                         Nautical Mile



                                                                                               Mud Control







                         Figure 10. Leptocheints plumulosus percent mortality. Mortality is plotted                                                       against distance
                         between site replicates from up-river to mouth. Horizontal baseline is mean control value.
                         Reference sediment is not necessary with L. plwnulosus.



                                              Cypnnodon vanegatus
                                                                  (Mortality)


                                     Patuxent River                                                           Sevem River



                                                                                                 so-



                         80                                                                      ao.



                         40                                                                      40-

                                                                                                       a a

                         20                                                                      20


                           0                                                                      a-V-
                              0                  10        15        20                             0            3            6
                                                Nautical Mile                                                          Nautical Mile







                                          South River                                                        Wicorn Ico River


                         100                                                                      00



                           ao                                                                     00



                           ac                                                                     ao



                           40                                                                      40



                           20-



                              0
                               0             2                         6                               0            3            a            9
                                                  Nautical Mile                                                           Nautical Mile




                                    Mud Control                         -     Mud Reference                         - - Sand Reference



                        Fig. ii. Cyprinodon varfegatus percent total mortality. Mortality is plotted against
                        distance between site replicates from up-river to mouth.






                                Cyprinodon variegatus
                                     (Hatching Failure)


                           Patuxent River                              Severn River

                  100



                   80 -                                         80-



                   50-                                          60-
                  U                                          CY
                  0
                  ja
                  :)40.i.  ...man         .. Z.                 40 i..........

                   20                                           20-


                                              20                or     7.        6
                                Nautical Mile                               Nautical Mile







                             South River                              Wicornico River

                                                                100



                   80-                                          Bo-



                                                                Go
                  U
                                                             Z
                                                             f
                   '10 . . . . . . .                            40 -\ . . . . . .

                    20-                                         20-


                    0 @- -g- W q- @                             106-
                     o       2                                   0       3        6       9
                                 Nautical Mile                               Nautical Mile





                        Mud Control               Mud Reference                Sand Reference



                  Fig. L2. Cyprinodon variegatus percent hatched. Mortality is plotted against distance
                  between site replicates from up-river to mouth.





                                    Cyprinodon variegatus
                                      (Percent Dead Eggs)


                              Patuxent River                                   Severn River

                      100



                                                                      80-



                        60-
                                                                      60-
                   LAJ                                             LU


                        40],                                          40-


                        20                                            20&



                        0                                             0-
                        0     5      10      is     20                  0       3        e         9
                                    Nautical Mile                                    Nautical Mile







                                South River                                  Wicorn i co River


                        100                                           100



                        80-                                           80-



                    C
                        60 -                                          60
                    0
                   LU
                                                                           A
                                                                      4o


                        20     a a 0 a  a a a a  0 a  a 6             20  ff M a a  a
                        OT
                        0        2         4        6                   0        3                  9
                                     Nautical Mile                                   Nautical Mile





                           Mud Control                  Mud Reference                  Sand Reference



                   Fl,,.1-3. Cyprinodon variegatus percent egg mortality. Mortality is plotted against
                        .-1                                      0
                                                                        D
                                                                        0[










                   distance between site replicates from up-river to mouth.






                                                 Cyprinodon variegatus
                                                     (Percent Dead Fish)


                                         Patuxent River                                                     Severn River


                             100                                                              100



                                 60 -                                                              80-



                                 60-
                          Ll                                                                 V     Go-
                                                                                             LL.
                                                                                             '0

                                 40                                                                40-


                                 20                                                                20-                 all

                                 0 ME                                                              C_
                                 0       5         1@@                20                           0         3            6           9
                                                 Nautical Mile                                                     Nautical Mile







                                           South River                                                    Wicomico River


                                 100                                                               100



                                 so-                                                               80-


                                                                                             C
                                 50                                                          t     Go-
                           Lz                                                                LL

                                                                                             ca

                                 40 -                                                              40
                           aR


                                 20 -                                                              20




                                 0           2            4                                        0          3                         9
                                                  Nautical Mile                                                     Nautical Mile





                                     Mud Control                            Mud Reference                     - - Sand Reference



                          Fl,,,.',4. Cyprinodon variegatus percent fish mortality. Mortality is plotted against
                          distance between site replicates from up-river to mouth.




















                          100



                           80   -------------------- ------------------------------------------------------ ---------------
                    W
                    Q@
                    0      60   - -------------------------- -------------------------------------    ---------------
                    U)


                                  ----------    ---------    --------------           - -----         ---------------
                    U)     40


                           20



                              0



                           -20
                                   Patuxent R.           Severn R.            South R.          Wicornico R.

                                                                  STATION
                                            April          May MI june Ej juiy                       Augus


                              Figure 15. Risk scores for water from four tributaries of Chesapeake Bay
                              sampled in 1994.























                             50





                                     -------------------------------------------  -------------------------------        ----


                             40



                          0          --------------------------              ----                   -------              ----
                         U)  30
                          V
                          cn
                                                       -------               ----                   -------               ....


                             20




                                                       -------               ----                    -------


                              10




                                0
                                      Patuxent R.             Severn R.              South R.           Wicornico R.

                                                                          Station


                            Figure 16. Average risk scores for water from four tributaries of the Chesapeake
                            Bay sampled in 1994.





















                              350

                        W
                        W 300         ------      ----------      ------------------  -- --------------------------------------
                        0


                                                                                         --- ----------------------------------
                        (D    250      ------     -----------     ------------------



                                                         --- ------------------           - ----------          ------          ---
                              200

                        X                         --- ---
                                                                  ------------------                 ------
                        0     150


                              100



                                50


                                                                  IX
                                          I Z"
                                  0      1"',            A
                                         Patuxent R.              Severn R.               South R.            Wcomico R.

                                                                           STATION

                                                         El upstream -+M down

                              Figure 17. Toxicity scores for individual sediment samples from four tributaries of
                              Chesapeake Bay sampled in 1994. Station scores from upstream to downstream are
                              plotted from left to right.




































                                      ---------------------------------------------------------------------------------------------


                            150

                                       --------------------- ---------------------------                ----------------------------
                       w    130
                       0    110
                       C)
                       U)     90

                                          ----------------------------------------------                  ---------------------------


                              70

                                        --------------


                               50

                                        ------------------------------------------- -----                 ----------------------------


                               30

                                                              .....               -------                .............................


                               10


                              -10
                                         Patuxent R.              Sevem R.                South R.             Wicomico R.

                                                                            STATION


                                   Figure 18. Pooled risk scores for sediments from four tributaries of
                                   Chesapeake Bay sampled in 1994.
                                      -------------









                                       ------------














                    120

                    100

                             ------------------------------------------------
                     80

                             ------------------------------------------------- ........ -------------------
                 0
                     60
                                          ------------- I- -------------- ----------------------------
                 in  40
                 E                        ------------------------------- ----------------------------
                     20
                        0     ------------------------------------ -------------------------------------
                     -20

                     -40
                               Patuxent R.      Severn R.       South R.       Wicornico, R.

                                                        Station


                         Figure 19. Risk scores for combined sediment and Water samples from
                         four tributaries of Chesapeake Bay sampled in 1994.














                40                                                                                25
                                                                                                      0

                                                                                                      X
                                                                                                      X
                                                                                                  20
                35   . ........
                                            ...... ...... $Go .... >
                                                                               ..................
                                                                            A
                30                                                                                15
                                        ..............
                                                                 on Mow M
                                                                               MMMM-lool



                25-                                                                               10
                                                                                                      E
                                                                                                      0
                                                                                                      +J
                                                                                                      +j
                                                                                                      0
                                                                                                      M
                20                                                                                5
                     20                      30                      40                      50
                                             Water Risk Score


                                                 I I    BDI     RDI
                                                      lose... Mwm







               Figure 20. Mean risk scores for water sanples from four tributaries of Cbesapeake Bay
               san-pled in 1994 vs fish conminity metrics. (Bottom diversity index - BDI; Resident
               diversity index - RDI; Index of Biotic Integrity - IBD













                 40                                                                                 25
                                                                                                         0
                                                                                                         r-
                                                                                                         X
                                                                                                         X
                 35   -                                                                             20


                                                                                                         Cn

                                                                                                         CD
            co   30                                                                                 15



                 25                                                                                 10
                                                                                                         E
                                                                                                         0


                                                                                                         0
                 20                                                                                 5
                   -20 0 20 40 60 80 100 120 140 160
                                            Sediment Risk Score


                                                  I I    BDI     RDI








             Figure 21. Pooled risk scores for sedirnent saniples from four tributaries of Chesapeake Bay
             san-pl ed in 1994 vs fish cornamrity rnetrics. (Bottom diversity index - BDI; Resident
             diversitv index - RDI; hidex. of Biotic hitegrity - IBD













               40                                                                             25


                                                                                                   X
                                                                                                   X
                35-                                                                           20


                                                                                                   Cn
                              A
           M 30                                                                               15


                                                                                                   CD
                25-                                                                                0
                                                                                              10   cc
                                                                                                   E
                                                                                                   0

                                                                                                   0
                20                                                                            5
                  -40 -20              0      20 40            60 80 100 120
                                         Combined Risk Score


                                                 I    BDI     RDI








            Figure 22. Combined risk scores for water and sedimnt mTles from four tributaries of
            Chesapeake Bay san-pled in 1994 vs fish cornnuity nrtrics. (Bottom diversity index - BDI;
            Resident diversity index RDI; Index of Biotic Irtegrity - IBI)






                                                              NOAA COASTAL SERVICES CTR LIBRARY



                                                              3 6668 14111758 2






q





















                                       " OF-

                                       LAKE SHORE PARK BMT LAUNCH RAIIP
                                               Ashtabula_, Ohio
                                                Final Report
                                          Grant No. NA-79;-AA-D-CZ085








                                 il








                                           I