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                                                       HISTORICAL TRENDS


                              WATER QUALITY AND FISHERIES:
                                ALBEMARLE-PAMLICO SOUNDS


                                                             With Emphasis on the
                                                            Pamlico River Estuary




                                     .A Report to the
                            National Ocean Pollution Program
                                          and the
                           National Sea Grant College Program




                                   Donald W. Stanley
                            Institute for Coastal and Marine Resources
                                   East Carolina University
                                  Greenville, NC 27858-4353


                                      September 1992





                             U.S. DEPARTMENT OF COMMERCE
                               Barbara Hackman Franklin, Secretary
                         National Oceanic and Atmospheric Administration
                                  John A. Knauss, Under Secretary
                                  COASTAL OCEAN OFFICE
                                    Donald E. Scavia, Director
      Cn
      Cn                         National Ocean Pollution Program
          A"




































                                   W. Lawrence Pugh, Director  LIBRARy
                                                             NOAA/CCEH
                                                          1990 HOBSON AVE.
                                                         CFIAS. SC 29408
                                                                       -2623









                H




                This publication is sponsored by the National Ocean Pollution Program, National
                Oceanic and Atmospheric Administration, U.S. Department of Commerce. The project
                was administered under grant NA86AA-D-SGO46 as project R/SF-2 through the UNC
                Sea Grant College Program, North Carolina State University, Raleigh, NC. Additional
                support came from Texasgulf Chemicals, Inc., and from East Carolina University.




                Additional copies ofthis publication are available from UNC Sea Grant, Box 8605, North
                Carolina State University, Raleigh, NC 27695-8605. Order UNC-SG-92-04.



                This document should be referenced as:
                Stanley, Donald W. 1992. HistoricalTrends: Water Quality and Fisheries, Albemarle-
                Pamlico Sounds, With Emphasis on the Pamlico River Estuary. University of North
                Carolina Sea Grant College Program Publication UNC-SG-92-04. Institute for Coastal
                and Marine Resources, East Carolina University, Greenville, NC. 215 pp.










                Cover Illustration: Drawn by Steve Daniels, and reproduced from Doug Young (editor).
                1980. North Carolina and the Sea, prepared by the North Carolina Marine Science
                Council,N.C. Office ofMarineAffairs, N.C. Department ofAdministration, Raleigh, NC.










                   Contents


                   Preface / v
                   Chapter 1: Profile of the Al bema rle- Pamlico System
                          The Physical-Chemical Environment / I
                                 Geological Origin and Evolution / Climate / Freshwater Inflows / Tidal
                                 Exchange, Circulation, and Flushing / Salinity and Nutrients
                          Principal Uses / 8
                                 Settlement and Population Growth / Land Use / Commercial Fisheries
                                 / Recreation / Industry and Ports
                   Chapter 2: Major Environmental Concerns
                          Eutrophication -- As Evidenced by Blue-Green Algal Blooms / 15
                          Wetlands Loss / 16
                          Loss of Submerged Aquatic Vegetation / 18
                          Declines in Fisheries / 18
                          Fish Diseases and Kills / 19
                          Impairment of Nursery Area Function / 19
                          Shellfish Closures / 20
                          Toxicant Effects / 20
                   Chapter 3: Trends in Nutrient Production: An Estimate Based on
                                 Changing Land Use and Population
                          Methods / 24
                          Results / 29
                                 Land Use / Harvested Cr-opland Nutrient Mass Balance / Farm
                                 Animals Inventory and Nutrient Production / Point Source Nutrient
                                 Production / Trends in Nutrient Production by All Sources
                          Discussion / 46
                   Chapter 4: Pamlico River Estuary Water Quality Trends
                          History of Water Quality Studies in the A/P System / 53
                          Methods / 54
                                 DataSources / Changes inAnalyticalMethods / TrendAnalysis Techniques
                          Results and Discussion / 58
                                 Climatic Factors and River Flow / Water Temperature, Salinity, andpH








                IV                                                                         Contents

                              Nitrogen / Phosphorus / Nutrient Limitation in the Pamlico / Dissolved
                              Oxygen / Chlorophyll a / Phytoplankton Species Composition and
                              Biomass
                Chapter 5: Stratification and Bottom Water Hypoxia in the Pamlico
                              River Estuary
                       Introduction / 78
                       Methods / 79
                       Results and Discussion / 81
                              Seasonal and Spatial Variability / Short-Ter7n Variability / Spear7nan
                              Correlation Results / Interannual Trends / Event Frequency / Effects of
                              Hypoxia on Pamlico Biota
                       Conclusions / 88
                Chapter 6: The Pamlico River: Comparison with Other Estuaries
                       Introduction / 92
                       Nutrients / 92
                       Dissolved Oxygen / 95
                       Chlorophyll a and Phytoplankton Biomass / 97
                Chapter 7: Trends in the Sounds' Fisheries
                       Commercial Fisheries / 103
                              The Database / Edible Finfish   Blue Crabs    Shrimp    Oysters
                       Recreational Fisheries/ 115
                References/ 117
                Appendices / 133










                     Preface

                        Despite great interest in - and large       many stations in Galveston Bay and along
                     expenditures for -estuarine water quality      the Houston Ship Channel since the late
                     and fisheries management, there have not       1960s. Likewise, there is a twenty-rive
                     been evaluations of long-term trends in        year record of water quality from 20-30
                     conditions of most of our estuaries. Conse-    stations in the Pamlico River Estuary in
                     quently, little is known about the effective-  North Carolina. In the third estuary,
                     ness of past and present management            Narragansett Bay, no routine monitoring
                     programs.                                      program has been carried out, but enough
                        This is one of several products of a        independent studies have incorporated
                     study of long-term trends in water quality     water quality parameters to permit con-
                     and fishery resources in three important       struction of a comparable long-term data
                     U.S. estuaries: 1) Narragansett Bay, Rhode     set. In addition to water quality data
                     Island, 2) the Albemarle-Pamlico Sound         bases, there are catch statistics and records
                     system in North Carolina, and 3) Galveston     of management efforts for important fish-
                     Bay, Texas. The project had four specific      eries in each bay.
                     objectives:                                        These estuaries are characterized by a
                        1. To document long-term trends in          range of pollution problems, some of which
                     water quality and, where possible, identify    are unique to each, while others are shared
                     causes, consequences and significance.         by all. Narragansett Bay and Galveston
                        2. To assess whether problems are           Bayrepresent heavily industrialized, urban
                     similar or unique to each estuary.             estuaries with a long history of pollution.
                        3. To assess whether progress is being      They are subjected to intense port and
                     made in improving conditions in water          shipping activities, massive industrial dis-
                     quality and fishery resources and whether      charges and major domestic sewage load-
                     there are examples of success that would       ings from urbanized centers of population:
                     be useful for estuarine managers and           Houston in Galveston Bay; and Providence,
                     researchers elsewhere.                         Central Falls and East Providence in Nar-
                        4. To glean examples of the useful inte-    ragansett Bay. In contrast, the Albemarle-
                     gration of research and policy.                Pamlico Sound system is a relatively un-
                        The three estuaries chosen for this         developed estuary without major shipping
                     study have sufficient long-term data to        lanes, industrial activity ora denselyurban-
                     permit trend analyses and inter-estuarine      ized coastline. Instead, it is characterized
                     comparisons. In two of them, monitoring        by extensive wetlands along its shoreline
                     programs have been carried out for at least    with agriculture and forests as the major
                     two decades. The Texas Department of           land use types within its watershed. Yet it
                     Health and the Texas Water Commission          also is perceived as having a history of
                     and its predecessors, the Water Quality        water quality problems.
                     Board and the Department of Water Re-              This is one of three separate - but
                     sources, have been monitoring dissolved        comparable - reports that have been pre-
                     oxygen, nutrients, metals and bacteria at      pared on trends in pollutant loadings, water








                   V!                                                                                   Preface
                   quality and pertinent fisheries for each of     Pamlico River, has been sampled inten-
                   the estuaries. The other two are:               sively on a continuous basis over the past
                                                                   two decades. Two others, the lower Chowan
                   Stanley, Donald W. 1992. Historical Trends:     River and the Neuse River, have been
                      Water Quality and Fisheries, Galveston       sampled intensively during studies lasting
                      Bay. University of North Carolina Sea        2-to-5 years, and infrequently at other
                      Grant College Program Publication UNC-       times. The open waters ofAlbemarle Sound
                      SG-92-03. Institute for Coastal and Marine   were sampled intensively for a two-year
                      Resources, East Carolina University,         period in the early 1970s, but there has
                      Greenville, NC. 100 pp.                      never been an intensive water quality sam-
                   Desbonnet, A. and V. Lee. 1991. Historical      pling for the open waters of Pamlico Sound.
                      Trends: Water Quality and Fisheries,         Because the Pamlico River data set is, by
                      Narragansett Bay. The University ofRhode     far, the most comprehensive, I have decided
                      Island Coastal Resources Center              to restrict my analysis of trends in water
                      Contribution No. 100 and National Sea        quality to this sub-estuary.
                      Grant Publication #RIU-T-91-001.                 One ofthe most widely-held perceptions
                      Graduate School of Oceanography,             about the Pamlico River is that it has
                      Narragansett, RI. 101 pp.                    worse bottom-water dissolved "problems"
                      Three major topics are covered in this       now than in the past, and that this is
                   report: 1) nutrient production in the drain-    adversely impacting the estuary's fishery
                   age basin, 2) estuarine water quality, and      resources. Hence, Chapter 5 addresses the
                   3) fisheries. Preceding the first of these are  factors responsible for low dissolved oxygen
                   two introductory chapters. The first gives      episodes in the estuary. Chapter 6 sum-
                   some basic information about the physical       marizes some information about compari-
                   setting, hydrology, uses, and living re-        sons between the Pamlico River and other
                   sources oftheAlbemarle-Pamlic6 estuarine        estuaries, in terms of nutrient and phyto-
                   system. Chapter 2 briefly summarizes the        plankton concentrations.
                   major environmental issues for the estuary.         Historical records of commercial land-
                   In Chapter 3 1 attempt to develop an esti-      ings offinfish and shellfish are available on
                   mate of changes in potential point and          a county-by county basis for all of the
                   nonpoint source nutrient loading to the         Albemarle-Pamlico region. Unfortunately,
                   estuary over the past century. Actually,        however, the data reflect where the fish
                   this part of the study was not included in      were brought to shore, not where they
                   the original research plan. Rather, it          were caught, so that it is impossible to
                   evolved from a combination of my curiosity      equate landings in counties around the
                   about what nutrient loading rates to the        Pamlico River Estuary to catch in the
                   estuary might have been in the past, before     estuary. Thus, in Chapter 7 report, which
                   "cultural" eutrophication, and my frustra-      examines trends in fisheries, I was forced
                   tion resulting from the lack of adequate        into looking at the Albemarle-Pamlico re-
                   riverine nutrient concentration data upon       gion as a whole, rather than focusing on
                   which to base a direct estimate of historical   individual sub-estuaries.
                   loading trends.                                    Primary funding for this research was
                      Chapter 4 deals with historical trends       provided by the National Ocean Pollution
                   in water quality within the estuary. For a      Program Office of the National Oceanic
                   number ofreasons, water quality sampling        and Atmospheric Administration, U.S.
                   in the Albemarle-Pamlico region has been        Department of Commerce. The         *  project
                   very uneven. Only one sub-estuary, the          was administered as Grant R/SF-2 through
                                                                   the UNC Sea Grant College Program, North








                    Preface                                                                                    V11
                    Carolina State University, Raleigh, NC.         Community Development, Morehead City;
                    Additional support came from Texasgulf             Ms. KatyWest, Division ofMarine Fish-
                    Chemicals, Inc. and from East Carolina          eries, North Carolina Department of Natu-
                    University.                                     ral Resources and Community Develop-
                        Several persons in North Carolina and       ment, Morehead City;
                    Virginia state agencies provided courteous         Staff of the U.S. Government Docu-
                    and friendly assistance as I collected the      ments Section of the North Carolina State
                    information needed for the study. They          University Library, Raleigh;
                    include:                                           Staff of the Virginia State Library,
                        Mr. David Clawson, District Sanitarian,     Richmond; and
                    Shellfish Sanitation Program, Division of          Ms. Renee Hawkins of the Virginia
                    Marine Fisheries, North Carolina Depart-        State Water Control Board, Richmond.
                    ment ofNatural Resources and Community             Many hundreds of hours were spent
                    Development, Morehead City;                     transcribing data from the printed records
                        Mr. George Gilbert, Assistant Super-        into computer files. East Carolina Univer-
                    visor, Shellfish Sanitation Program, Divi-      sity students and staff involved in this task
                    sion of Marine Fisheries, North Carolina        included Ray Taft, Jeff Taft, Sharon Reid,
                    Department of Natural Resources and             Colleen Reid, Deborah Daniel, Anne
                    Community Development, Morehead City;           Anderson and Kay Evans. I thank M.
                        Mr. JeffFrench, Marine Biologist, Divi-     Brinson, J. Dorney, and K. Evans for re-
                    sion of Marine Fisheries, North Carolina        viewing an earlier draft. Mark Hollings-
                    Department of Natural Resources and             worth provided invaluable assistance in
                                                                    the preparation of the final draft.

                                                                    Greenville, North Carolina            D.W.S.
                                                                    December, 1991











                      CHAPTER


                      Profile of the
                      Albemarle-Pamlico Estuarine System



                          It is not the purpose of this chapter to             Say "coast" in North Carolina, and
                      provide a comprehensive analysis of the              everybody thinks beach, specifically the
                      ecology of the Albemarle-Pamlico Estuary.            broad, sandy aprons of the barrier islands.
                      Rather, it is a briefsketch intended to focus        Everything west of the beach is merely
                      the reader's attention on the system's               something through which to pass en route to
                      features which are most relevant to the              the water. And there is plenty of water.
                      water quality and fisheries data that will               It sometimes seems as if nature created
                      be presented below. Details of the ecology           the Coastal Plain so water would have
                      of the Pamlico River Estuary and Albe-               something to lap against and sky would have
                      marle Sound can be found in two Estuarine            something to rest upon. The Coastal Plain is
                      Profiles by Copeland et al. (1983; 1984).            a beautiful mosaic: sun-bleached tidal marsh
                      Giese et al. (1979) provide details of the           as broad as the eye can follow; level beach
                      hydrology ofeach ofthe major sub-estuaries           planing into the surf; mullet skipping on the
                      in the Albemarle-Pamlico Sound system.               water of the sound; boats of every size,
                                                                           shape and design; and magnificentflights of
                      The Physical-Chemical                                ducks and geese. Arrow-straight highways
                      Environment                                          where rows of crops flicker past the window
                          The Pamlico Sound covers an area of              like pickets on a fence. You can plow it,
                      about 5,335 kM2, making it the largest               graze it, till it, timber it, fish it, trap it, swim
                      sound formed behind the barrier beaches              it, and sail it. Bask in its warmth, boat it,
                      along the Atlantic Coast of the United               run it, drive it and follow it through
                      States. Giese et al. (1979) estimate that            centuries by reading its history in church
                      the total volume of water in the sound               graveyards.
                      averages about 26 billion m, or about 21                 It is, above all, a land in community with
                      million acre-feet. The average depth is              water and plow, where the good earth and
                      only about 4.9 m, and the maximum depth              bountiful sea provide all the rewards needed
                      is only 7.3 m (Figure 1.1 and Table 1.1).            to those who spill their sweat.
                          There are numerous tributaries and                                            G. Morris (1985)
                      embayments along the western shore of              River are one in the same. The Tar River
                      the Pamlico Sound. Two of these - the              is the major freshwater source for the
                      Tar-Pamlico River Estuary and the Neuse            estuary, but downstream from Washing-
                      River Estuary - are by far the largest.            ton, the name Pamlico River has tradi-
                      The Tar-Pamlico extends approximately              tionally been used. The combined surface
                      65 krn from near the town of Washington,           area of the Tar-Pamlico Estuary and its
                      NC to its confluence with Pamlico Sound.           sub-tributaries is about 582 kM2    . However,
                      Actually, the Tar River and the Pamlico








                                                                                              Chapter I









                               CHOWAN





                                                           ALBEMARLE SOUND




                ROANOKE









                         R-PAMLICO



                                                                                  PAMLICO
                                                                                 SOUND

                                                                                                                7



                             NEUSE





                         Ch.                                                 ATLANTIC OCEAN



                                                                                KM
                                                                    0    10   20   30   40                      7
                                                    Ce                      10      20      30
                                                                    0
                                                                               MILES






                Figure 1.1. Map of the Albemarle-Pamlico Estuarine System.








                                Profile of the Albemarle-Pamllco Estuarine System                                                                                           3
                                depths are shallow, averaging only about                                  than 5.5 m deep. Its volume is about
                                3.4 m. The other important Pamlico Sound                                  5,310,000 acre feet (Giese et al. 1979).
                                tributary embayment is the Neuse River
                                Estuary. Beginning near the confluence of                                 Geological Origin and Evolution
                                the Neuse River and the smaller Trent                                          The Albemarle-Pamlico system began
                                River at New Bern, NC, the Neuse River                                    to form sometime after 17,000 years BP,
                                Estuary extends 65 km to the mouth in the                                 when the last major glacial ice advance
                                southwest corner of Pamlico Sound, only a                                 reached its maximum development. At
                                short distance south of the mouth of the                                  that time sea level was as much as 130-160
                                Tar-Pamlico River estuary. The Neuse                                      m lower than today. Consequently, the
                                Estuary is similar in size and depth to the                               shoreline was far out on the continental
                                Tar-Pamlico. The Neuse covers approxi-                                    shelf. Sand dunes were built up along the
                                mately 394 kM2, and averages 3.6 m in                                     shore by winds blowing toward the land.
                                depth.                                                                    As the ice melted and sea level rose again,
                                  The Albemarle Sound, extending about                                    between 17 thousand and 5 thousand years
                                88 km from the mouths of the Roanoke and                                  ago, these dunes were separated from the
                                Chowan Rivers eastward to the outer                                       shore in places, thus forming a string of
                                banks, covers an area of about 2,419 kM2                              .   barrier islands. Breaching during storms
                                It averages about 11 km wide, and has a                                   caused inlets to develop and lagoons to be
                                maximum depth of nearly 9 m, but most of                                  flooded and eventually become wide, shal-
                                the central area of the bay is little more                                low sounds. Further sea level rise, as well
                                                                                                          as continual wave action, caused the islands
                                                                                                          to migrate toward the land (Gade and
                                Table 1.1. Hydrologic datafor Albemarle and                               Stillwell 1986). Today some of these barrier
                                Pamlico Sounds (fi-om, Giese et al. 1979).                                islands (popularly known as the Outer
                                A. Drainage area                                                          Banks) are moving landward each year at
                                    Albemarle Sound                17,879   mi"       46,309     kin'     up to 3 m, while sea level is risingabout 0.3
                                        Chowan River                4,943   mi"       12,802     kin      cm per year (Pilkey et al. 1978).
                                        Roanoke River               9,666   mil       25,035     km'
                                        Other                       3,288   mil        8,516     km'            The sounds are underlain with sedi-
                                    Pamlico Sound                  10,460   mil       27,092     kin      ments and sedimentary rock of marine
                                        Tar-Pamlico River           4,300   m?        11,137     km:
                                        Neuse River                 5,598   Mi2       14,499     km'      origin. These sediments were deposited
                                        Other                         562   mi"        1,456     km'
                                    Total                          28,357   mP        73,445     km,      over at least the past 100 million years
                                B.  Surface area                                                          while the ocean covered portions of the
                                    Albemarle Sound &                                                     coastal plain (Brown et al. 1972). The
                                    tributaries                       934   Mi2        2,419     kin'     uppermost veneer of unconsolidated sedi-
                                    Pamlico.Sound &                                                                                                                           -s
                                    tributaries                     2,064   Mi2        5,335     km'      ments were laid down 25 to 1 million year
                                        Pamlico River estuary         225   mi'           582    kM2      ago in the Miocene and Pliocene epochs.
                                        Neuse River estuary           152   Mill          394    kM2
                                    Total                           2,998   m P        7,765     kmg      These are extremely varied and include
                                C. Volurne                                                                gravels, sands, clays, peats, and all possible
                                    Albemarle Sound            5,310,000    acre-ft          6.5 kM3      combinations (Copeland et al. 1984). The
                                    Pamlico Sound              21,000,000   acre-ft        26    kM3      present day surface sediments of the estu-
                                        Pamlico River
                                        estuary                   662,308   acre-ft          o.82 km'     aries are composed primarily of fine sand,
                                        Neuse River
                                        estuary                1,082,306    acre-ft          1.34 kins    silts and clays. Pickett (1965) noted that
                                                                                                          fine sand covers most of the bottom of
                                D. Avercige Depth                                                         Pamlico Sound, with silt present primarily
                                    Albemarle Sound                    16   ft               4.6 in
                                    Pamlico Sound                      16   It               4.9 in       in the deep areas of the northern basin and
                                        Pamlico  River estuary         11   ft               3.4 in       in the channels extending into the sound
                                        Neuse River estuary            12   ft               3.6 in







                    4                                                                                           Chapter I

                    from the mouths of the Neuse and Pamlico              Climate
                    rivers. Medium sand covers the higher                      North Carolina lies within a general
                    energy areas near shoals and the tidal                climatic region known as Humid Sub-
                    inlets from the ocean. Similarly, Pels (1967)         tropical. Moisture is adequate throughout
                    found the bottom sediments of Albemarle               the year to support forest as well as a
                    Sound to consist mainly of fine-to-medium             variety of agricultural crops, with only
                    sand around the margins of the sound,                 limited, localized needs for irrigation or
                    with a gradation southward to silt and clay           artificial drainage. Temperatures are
                    in the deepest areas.                                 moderate with long summers and brief
                                                                          winters. An extended summer drought
                                                                          may result from dominance ofthe Bermuda
                                                                          high pressure off the east coast. Warm,
                                                                          moist air from the tropics dominates sum-
                    Table 1.2. Water Budget for the Albemarle-            mer conditions while cooler, drier conti-
                    Pamlico Soundsystem (from Giese etal. 1979).          nental polar air controls winter weather
                                                                          (Gade and -Stillwell 1986).
                           Process                            Value            Dailymean air temperatures overmost
                                                                          ofeastern North Carolina and southeastern
                    Albemarle Sound                                       Virginia range between 5*C and 10*C in
                    A. Freshwater Inflow                                  January, the coldest month, and between
                         Chowan River                       4,600 cfs;    24'C and 270C in July, the warmest month.
                         Roanoke River                      8,900 cfs
                         Other                              2,900 cfs     Annual precipitation averages about 127
                         Total                             16,400 cfs     Cm/year throughout the basin, but in some
                    B. Precipitation on Albemarle                         years it may be very much lower or higher
                       Sound and associated open-                         than this. For example, at New Bern, NC,
                       water areas                          3,400 efs     the annual precipitation over the past 100
                                                                          years has ranged between 88 and 203 em/
                    C. Evaporation from Albemarle                         year (Wilder et al. 1978). In northeastern
                       Sound and associated open-                         North Carolina, evapotranspiration aver-
                       water areas                          2,600 cfs     ages about 86 em per year, and results in
                    D. Total outflow of Albemarle                         the return of roughly two thirds of the
                       Sound into Pamlico Sound:                          rainfall back to the atmosphere. Generally,
                       D=A+B-C                             17,200 efs     except in spring and early summer,
                    Pamlico Sound                                         precipitation exceeds evapotranspiration
                    A. Freshwater Inflow                                  (Wilder et al, 1978).
                         Tar-Pan-Aico River                 5,400 cfs
                         Neuse River                        6,100   cfs   Freshwater Inflows
                         Other                                 500  cfs       Mostofthe freshwater for the Albemarle
                       Total                               12,000   cfs   and Pamlico Sounds comes from four large
                    B. Inflow from Albemarle Sound                        rivers: the Chowan, Roanoke, Tar, and
                       to Pamlico Sound                    17,200   cf1s  Neuse. The Roanoke and Chowan, which
                                                                          are the two major rivers in the Albemarle
                    C. Precipitation on Pamlico Sound       8,250   cfs   basin, drain 25,035 kM2        and 12,802 kM2,
                    D. Evaporation from Pamlico Sound       5,740   cf.,  respectively, in northeastern North Caro-
                                                                          lina and southern Virginia. The Roanoke
                    E. Net inflow to Pamlico Sound:                       basin extends to the foothills of the Appala-
                       E=A+B+C-D                           31,710   cfs   chian Mountains. The Tar and Neuse







                     Profile of the Albemarle-Pamlico Estuarine System                                         5
                     Rivers, which supply most of the freshwater     Ocracoke, Hatteras, and Oregon Inlets.
                     to the Pamlico Sound, have watershed            This limited access, in combination with
                     areas equal to 11, 13 7 kM2 and 14,499 kM2'     the broad expanse of the sound, results in
                     respectively.                                   ocean tides being dampened to less than 6
                        The total freshwater discharge from          cm, except near the inlets (Roelofs and
                     theserivers into the Albemarle and Pamlico      Bumpus, 1953; Giese et al. 1979). Often,
                     Sounds cannot be measured, because the          wind-driven tides are dominant over lunar
                     low stream slopes and tidal influence near      tides in both the sound and adjoining trib-
                     the river mouths make measurement of            utary estuaries. The large size of Pamlico
                     stream flow by conventional techniques          Sound allows ample opportunity for wind
                     impossible in these areas. Consequently,        setup over long fetches. U.S. Geological
                     the most downstream gauging stations            studies in the Neuse and Tar-Pamlico estu-
                     operated by the U.S. Geological Survey lie      aries, summarized in Giese et al. (1979),
                     in the higher areas to the west. Wilder et      indicate these wind tides are normally in
                     al. (1978) showed that the data that are        the range of 0.3 to 0.6 m.
                     available from the gauging stations can be         The Albemarle Sound system has no
                     extrapolated to give reasonably accurate        direct outlet to the ocean. Instead, it
                     estimates of runoff from the whole              connects to Pamlico Sound and Oregon
                     Albemarle-Pamlico watershed. They found         Inlet through Croatan and Roanoke
                     that on a long-term basis, average flows on     Sounds; hence, dampeningof lunar tides is
                     a unit basis through all of the major rivers    even greater in the Albemarle than in the
                     are within narrow limits, ranging from          Pamlico. Normal wind tides in the sound
                     0.80 cubic feet per second (CFS) perMi2for      average about the same as in Pamlico
                     the Roanoke River to 1.05 CFS/mi2for the        Sound, and the water level can change
                     Neuse River. Thus, multiplication of these      relatively rapidly with shifting wind
                     unit discharge rates times the total basin      directions and velocities accompanying
                     area yields estimates ofthe total freshwater    frontal storm passage (Giese et al. 1979).
                     input.                                             On a short-term basis, wind driven
                         Giese et al. (1979) presented estimates     currents are often dominant over riverine
                     of inflow calculated by this method, along      flows in both the sounds and adjoining
                     with data on precipitation and evaporation,     estuaries. Within the estuaries, the velocity
                     in their detailed monthly and annual gross      of wind-driven currents may be increased
                     water budgets for the two sounds (Table         because of funneling effects. A second
                     1.2). The runoff is highest in the late         factor which contributes to the relative
                     winter and lowest in the late summer and        importance of wind-driven currents in the
                     fall. This is out of phase with the annual      system is that velocities due to freshwater
                     precipitation cycle described earlier (higher   inflow are low. Pamlico Sound and its
                     rainfall in the summer than in the winter).     estuaries are drowned river valleys. Con-
                     The explanation for the discrepancy is that     sequently, the river channels are oversized
                     evapotranspiration rates are much higher        for the amount of water they now carry,
                     in the summertime than in winter.               resulting in low velocities. In the long
                                                                     term, however, freshwater inflow is more
                     Tidal Exchange, Circulation, and                important than wind in affecting net flow
                     Flushing                                        because the effects of winds blowing from
                         Pamlico Sound is connected with the         various directions tend to cancel each other
                     ocean through several relativelysmall open-     over time. This is true throughout the
                     ings in the Outer Banks, primarily              Albemarle-Pamlico system (Giese et al.
                                                                     1979).







                   6                                                                                   Chapter I

                                                                     up to around 100 days for low flow condi-
                      180                                            tions (Figure 1.2). The average flushing
                      160                                            time, based on long-term flow data, is
                      140
                                                                     about 24 days for the Tar-Pamlico.
                      120-

                   2  100-1
                      So-                                            Salinity and Nutrients
                   z  60                                                 Salinities are generally lower in the
                   CO 40
                                                                     Albemarle system than in the Pamlico
                      20
                   L
                                                                     system for two reasons. First, the fresh-
                      0
                       0    2    4    6    8   10 12 14      16      water input:sound volume ratio for Albe-
                           FRESHWATER INFLOW (CFS X 1000)            marle Sound is larger than that for Pamlico
                   Figure 1.2.    Flushing times for the      Tar-   Sound. The higher current strength result-
                   Pamlico estuary as a function of river flow. Tar  ing from this more effectively blocks saline
                   River flow gauged at Tarboro, NC.                 water intrusion. Secondly, seawater that
                                                                     does reach Albemarle Sound has already
                                                                     been diluted in Pamlico Sound (Giese et al.
                      Giese et al. (1979) computed estimates         1979). Consequently, western Albemarle
                   of the replacement time for freshwater in         Sound is essentially a freshwater system,
                   the Albemarle and Pamlico Sounds by               and even the eastern-most areas of the
                   comparing the estimated freshwater input          sound typically have salinities less than 5
                   per month with the volumes of the sounds.         ppt. Pamlico Sound salinities decrease
                   On average, it would take about 11 months         from around 30 ppt near the barrier island
                   for the flow into Pamlico Sound to equal          inlets to approximately 15 ppt at the
                   the volume of the sound. Based on their           Pamlico River and Neuse River sub-estuary
                   monthly inflow estimates, the water               mouths (Giese et al. 1979; Stanley 1988b).
                   replacement times would vary between 19           Giese et al. (1979) contend that wind
                   and 6 months. Actually, the range is              velocity and direction are the dominant
                   greater than this because of extremes in          short-term influences on salinity in the
                   inflow that occur in some years. Similar          sounds, whereas variations in freshwater
                   estimates for Albemarle Sound range               inflows are the primary influence on the
                   between 9 and 3.5 months with a mean of           seasonal salinity patterns.
                   about 5.5 months. These estimates suggest            Salinity in turn influences to some
                   that the Albemarle flushes about twice as         extent the concentrations ofdissolved plant-
                   rapidly as the Pamlico.                           growth nutrients in the estuary. For
                      A more realistic estimate of estuarine         example, in the lower freshwater tidal
                   residence times requires taking into account      areas of the rivers, nitrate nitrogen (NO     3-
                   tidal exchange effects. To do so, one may         N) generally exceeds 20 AM, but decreases
                   use the method of Ketchum (1950) to calcu-        rapidly downstream with increasing
                   late the amount offreshwater in the estuary       salinity. Part of this decrease is due simply
                   based on the salinity of the system. One          to dilution by low-nitrate ocean water, so
                   then computes the amount of freshwater it         that in the open areas of Pamlico Sound,
                   would take to flush that freshwater from          the nitrate concentrations are probably
                   the system (Pilson 1985). Using this proce-       less than 1 AM most of the time. Other
                   dure, I calculated flushing times for the         forms of nitrogen and phosphorus also are
                   Tar-Pamlico River estuary as a function of        generally most concentrated in the upper
                   freshwater inflow. The results are that the       ends of the estuaries (Stanley 1988b;
                   residence times for this estuary range from       Bowden and Hobbie 1977; Hobbie and the
                   around 10 days under high flow conditions








                         Profile of the Albemarle-Pamlico Estuarine System                                                        7

                         Smith 1975). Of course, rates of biological            budgets, several general conclusions seem
                         uptake and remineralization, and rates of              obvious (Table 1.3). First, there are not
                         input from the watershed also are factors              drastic differences in the nonpoint areal N
                         regulating the estuarine nutrient concen-              and P loading rates from one basin to
                         trations. Because there are so many                    another. For N the range is from 216 kg/
                         dynamic processes affecting estuarine                  square km in the Tar-Pamlico to 365 kg/
                         nutrients, their concentrations vary widely,           square km in the Neuse. The nonpoint P
                         both spatially and temporally, and it is               loadingvaries from 21 kg/square km in the
                         difficult to generalize.                               Chowan to 33 kg/square km in the Neuse.
                             Annual nutrient loading rates have                 Second, point-source N loading (on an areal
                         beenestimated forseveral oftheAlbemarle-               basis) is highest in the Neuse and lowest in
                         Pamlico sub-estuaries (NCDNRCD 1982,                   the Tar-Pamlico, but in all cases is only
                         1983,1987b). While detailed comparisons                about 20% of the total N load. Point
                         mustbe made with caution, since no uniform             sources contribute about half the total P
                         methodology was used to construct the                  loading, except in the Pamlico where they



                                     Table 1.3. Nutrient loading estimates for sub-basins of the Albemarle-
                                     Pamlico Sound system.


                                                                         N             N            P            P
                                     Basin                Land Area      Annual        Annual       Annual       Annual
                                                          (kM2)          Loading       Loading      Loading      Loading
                                                                         (kg/sq. km)   (kg x 10')   (kgtsq. km)  (kg x 101)

                                     Chowan               12,673                         4,197                       443
                                          Point                                            881                       165
                                          Nonpoint                         261           3,316          21           278

                                     Roanoke              25,063                         5,436                       486
                                          R.R. Res.       21,780                         3,845                       279
                                          Bel. Res.         3,283
                                            Point                                          593                       133
                                            Nonpoint                       303             998          22             73

                                     Tar-Pan-ilico        11,650                         3,223                       933
                                          Point                                            625                       201
                                          Nonpoint                         216           2,522          26           312
                                          Texasgulf                                          76                      419

                                     Neuse                15,979                         7,358                       962
                                          Point                                          1,513                       430
                                          Nonpoint                         365           5,845          33           532

                                     Total                65,365                       20,214                      2,824
                                          Point
                                          Nonpoint                         290                          27

                                     Notes:
                                     1. Roanoke and Chowan data from NCDNRCD (1982)
                                     2. Tar-Pamlico dat from NCDNRCD (1987)
                                     3. Neuse data from NCDNRCD (1983)
                                     4. "R.R. Res." refers to the Roanoke River Reservoir
                                     5. 'rexasgulF refers to discharge from the Texasgulf phosphate mining facility







                   8                                                                                        Chapter 1

                   are two-thirds of the total because of the           The population was overwhelmingly rural
                   large input from Texasgulf Chemicals,                at this time. There were only two small
                   which accounts for about one-half the total          urban areas, New Bern at the head of the
                   P going into the Tar-Pamlico. Finally,               Neuse River estuary and Raleigh in the
                   except for the Tar-Pamlico phosphorus load-          upper Neuse basin. Each had about 4,500
                   ing, none of the Albemarle-Pamlico tribu-            inhabitants.
                   tary areal loading rates are unusually high               Since 1850 there has been only modest
                   in comparison to other U.S. river basins for         population growth in the Chowan Basin,
                   which estimates have been made (e.g.,                but much more rapid growth in the
                   Clesceri et al. 1986; Rast and Lee 1983).            Roanoke, Tar-Pamlico, and Neuse basins
                                                                        (Figure.1.3). In 1987, it was estimated that
                   Principal Uses                                       2.37 million persons lived in the Albemarle-
                   Settlement and Population Growth                     Pamlico basin, with most of these in the
                       The Albemarle-Pamlico region was the
                   first area of North Carolina to be settled by        to 2500 - -------- ------- ---
                                                                        a
                   Europeans, but the development proceeded             z
                                                                        9  20M -
                   slowly until recent times, so that at present        5
                                                                        0  1500-
                   the area remains one of the State's most             I
                   rural. Sir Walter Raleigh explored the               z
                                                                        0
                   Pamlico Sound, landing at Roanoke Island
                   in 1584. In 1587, Raleigh appointed John                  0           Will                MR  MR MR
                                                                        0     1790 1810 1830 1850 1870 1890 1910 1930 1950 1970 1087
                   White governor of what was to become the             a'
                   "Lost Colony" on Roanoke Island. Settle-                                     YEAR
                   ments in the Jamestown, Virginia area                           Chowan       Roanoke M Tar
                   after 1607 became the nucleus for the                           Neuse        Coastai
                   colonization of northeastern North Caro-
                   lina. Early communities began north of               Figure 1.3. Growth ofhumanpopulation in each
                   Albemarle Sound in the mid and late 1600s,           ofthe mcjorAlbemarle-Pamlico estuarine system
                   and migration farther south led to the               sub-basins.
                   establishment of the town of Bath on the
                   Pamlico River estuary in 1704. At the time
                   of the first United States census in 1790,
                   the total basin population was about                                                 Roanoke
                   380,000. The Roanoke and Chowan sub-                                     --           24796
                   basins in the northeastern part of North                                        36%
                   Carolina and southern Virginia contained                Neuse
                   about three-fourths of the total, with                  14306     21%
                   140,000 and 100,000 inhabitants, respec-
                   tively (Figure 1.3).                                                                 10%
                      Southern and western migration con-                                18%       15%          Coastal
                   tinued with the founding of New Bern at                                                       7025
                   the head of the Neuse estuary in the early
                   18th century (Lefler 1965). By 1850 there                   Chowan                    Tar
                   were over 600,000 persons in the basin,                      12730                   10448
                   with most of the growth having occurred in           Figure 1.4. Distribution of Albemarle-Pamlico
                   the western Roanoke basin and in the Tar-            land areas (square kilometers) among the major
                   Pamlico and Neuse basins to the south.               sub-basins.
                                                                                                        10%








                      Profile of the Albemarle-Pamlico Estuarine System                                           9

                      Roanoke and Neuse basins.                        no effect from seasonal visitors (Tschetter
                          Most areas immediately adjacent to           1989).
                      the Sounds are sparsely populated in
                      comparison to more inland areas. For             Land Use
                      example, although 10% of the Albemarle-             Current land use patterns in the
                      Pamlico watershed drains directly into the       Albemarle-Pamlico also reflect its rural
                      sounds (i.e., is downstream from the mouths      nature. The region is predominantly for-
                      of the four major rivers), those "coastal"       ested and agricultural (Figure 1.5). Forest
                      areas contain only about 5% of the total         lands comprise 60% of the total basin area,
                      basin population today (Figures 1.3 and          and about 20% of the land is in crops. The
                      1.4). However, present growth rates in           percentage of the basin that is urbanized is
                      three of the coastal counties - Dare,            estimated to be no more than about 2%.
                      Currituck and Carteret - are among the           There are modest differences in land use
                      highest in the State, and this trend is          among the sub-basins of the system (Figure
                      projected to continue in the near future         1.6). The forest land coverage ranges from
                      (Tschetter 1989). Nevertheless, the              54% in the Neuse River, Tar-Pamlico River,
                      Albemarle-Pamlico basin in general, and          and Albemarle Sound "coastal" basins to
                      the immediate coastal area in particular,        63% and 67% in the Roanoke River and
                      continue to be more rural than areas             Chowan River basins, respectively. Con-
                      surrounding most of the large estuaries          versely, the cropland acreage is highest in
                      farther north along the Atlantic coast.          the Neuse, Tar-Pamlico and Albemarle
                          The coastal counties experience wide         Sound regions (25-28%) and lowest in the
                      fluctuations in population due to seasonal       Roanoke River basin (14%). The Neuse
                      tourism. Tschetter (1989) estimated that         Basin as a whole is more urban (4%) than
                      Dare Countys population increased to over        any of the other sub-basins, but of course
                      4 times that of the permanent population         almost all of this is in the upper end of the
                      during the peak seasonal day in 1987.            basin, in the Raleigh-Durham area.
                      Other coastal counties and some counties
                      on the west side of the sound experience         Commercial Fisheries
                      smaller population fluctuations, perhaps             The Albemarle-Pamlico system is a
                      in the 20-50 percent range. Counties farther     major contributor to the commercial fish-
                      inland in the AP basin experience little or      eries catch in North Carolina, as evidenced
                                                                       by the fact that about 80% of the total
                                                                       edible harvest each year is landed there.
                                                                       Pamlico Sound is very different from
                                Forest
                                 W%                                    Albemarle Sound, however, both in terms
                                                                       of the commercial catch poundage and the
                                                           Pasture     composition of the catch. It has been
                                                            5%         estimated that in 1980, for example,
                                                                       Pamlico Sound contributed 78% ofthe total
                                                          Other        inshore catch, in contrast to Albemarle
                                                           14%         Sound, which contributed only 14% of the
                                Uxrban                                 total commercial catch (Copeland et al.
                                 2%           Crops                    1984).
                                              20%                          Freshwater and anadromous species of
                      Figure 1.5.   Land use within the Albemarle-     finfish dominate the catch in Albemarle
                      Pamlico estuarine system watershed (1985).       Sound and its tributary rivers, the Chowan







                      1 0                                                                                                   Chapter I


                                       Albemarle River                                               Chowan River

                                         Forest
                                         54%
                                                                                             Forest
                                                                                              67%


                                                                   Pasture                                                      Pasture
                                                      .......................
                                                                                                                                   3%
                                                                     1%


                            Urban
                             0%                                                                                                 Other
                                                                   Other                                                         11%
                                                                   17%

                                     Crops                                                          Urban           Crops
                                     28%                                                             0%              19%



                                         Neuse River                                                 Pamlico River


                                      Forest                                                        Forest
                                       54%                                                          59%



                                                                   Pasture                                                     Pasture
                                                                    3%                                                            1 %

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

                            Urban                                  Other
                             4%                                    15%                                                     Other
                                                                                                 Crops                      26%
                                        Crops                                                    15%
                                         25%




                                       Roanoke River                                              Tar-Pamlico River


                                                                                                   Forest
                              Forest                                                                54%-
                              63%
                                                                   Pasture
                                                                    8%                                                         Pasture
                                                                                                                                  3%


                                                                   Other                 Urban                                 Other
                                                                   13%                     1 %                                 15%

                                        Urban          Crops                                         Crops
                                         2%             14%                                          26%

                     Figurel.6. Land use within each ofthe mqjor sub-basins of the Albemarle-Pamlico estuarine system
                     watershed.








                       Profile of the Albemarle-Pamlico Estuarine System                                              1 1

                       and the Roanoke, where most of the catch          Ross 1986; Godwin et al. 1971).
                       is made during the spring spawning runs.              Farther south, in Pamlico Sound and
                       In recentyears the most important anadro-         its tributary estuaries, the commercial
                       mous species have been the alewife (Alosa         catch consists primarily of blue crabs
                       pseudoharengus) and blueback herring              (Callinectes sapidus), white, brown and
                       (Alosa aestivalis). In the official landing       pink shrimp (Penaeus sp.), oysters
                       statistics of the National Marine Fisheries       (Crassostrea virginica), hard clams
                       Service, these two species are combined as        (Mercenaria mercenaria), bay scallops
                       "alewives." Another common name is "river         (Argopecten irradians), and seasonally
                       herring" (Godwin et al. 1971). American           abundant species ofedible marine finfishes.
                       shad (Alosa sapidissima) and striped bass         These include grey seatrout, or "weakfish"
                       (Morone saxatilis) are two other anadro-          (Cynoscion regalis), flounder (mostly Para,
                       mous species in the Albemarle. The shad           lichthys dentatus and P. lethostigma),
                       were once very abundant, but the catch            Atlantic croaker (Micropogon undulatus),
                       declined drastically in the early 1900s.          bluefish (Pomatomus saltatrix), spot
                       Striped bass is perhaps the best known,           (Leiostomus xanthurus) and mullet (Mugil
                       and certainly the most studied, finfish in        cephalus and M. curema).
                       theAlbemarle region. Amodest commercial               Between 1980 and 1987, the annual
                       fishery for resident species of catfish and       landings of edible finfish in the Albemarle-
                       bullheads (genus Ictalurus) has developed         Pamlico system averaged 57.3 million
                       in the last 25 years or so (Epperley and          pounds, and the shellfish harvest averaged


                        Table 1.4. Albemarle-Pamlico Commercial landings catch composition (1980-1987 auerages).
                        Data are from N.C. Diuision of Marine Fisheries (1980-1987).

                                                                         % oftotal       % of finfish     % of shellfish
                        Species                          lbs/year          catch             catch            catch

                        Edible Finfish                   57,298,432        60.2
                          1.  Grey Seatrout              12,325,898        12.9              21.6
                          2.  Flounder                   10,071,075        10.6              17.6
                          3.  Croaker                     9,678,043        10.2              16.9
                          4.  Alewives                    6,578,158          6.9             11.5
                          5.  Bluefish                    4,180,627          4.4              7.3
                          6.  Spot                        3,593,872          3.8              6.3
                          7.  Mullet                      1,312,485          1.4              2.3
                          8.  Catfish                     1,108,679          1.2              1.9
                          9.  American Shad                 261,034          0.3              0.5
                          10. Striped Bass                  230,140          0.2              0.4
                          11. Other                       7,958,421          8.4             13.8

                        Shellfish                        37,876,224        39.8
                          1.  Blue Crabs                 30,311,632        31.8                                80.0
                          2.  Shrimp                      4,969,160          5.2                               13.1
                          3.  Hard Clams (meat)             846,452          0.9                               2.2
                          4.  Oysters (meat)                633,781          0.6                               1.4
                          5.  Bay Scallops (meat)           533,781          0.6                               1.4
                          6.  Other                         962,270          1.0                               2.7
                              (Squid, Sea Scallops)







                1 2                                                                              Chapter I
                about 38 million pounds (Table 1.4). Four       Sounds remains largely unknown. Other
                species -grey seatrout, flounder, croaker       than for striped bass, there are essentially
                and alewives - account for about two-           no historical ecological data upon which to
                thirds of the total edible finfish harvest.     base recreational fishing trend analyses.
                Averaging 30 million pounds landed per
                year, blue crabs have dominated the shell-      Industry and Ports
                fish landings (80% of the total), and are the       North Carolina is currently the nation's
                most abundant single species in the entire      eighth largest state in manufacturing em-
                commercial edible harvest (32%). About 5        ployment. Manufacturing is fairly uni-
                million pounds of shrimp are landed             formly distributed throughout the state
                annually, along with lesser quantities of       except in two areas where it is much less
                hard clams and other mollusks (.25-1            intense: the southwestern Mountain and
                million pounds per year).                       northeastern Tidewater areas (Gade and
                   Atlantic menhaden (Brevoortia                Stillwell 1986). Large firms (with over 250
                tyrannus) is an industrial finfish species      employees) are especially scarce in the
                that spends part of its life in the estuaries   Albemarle-Pamlico region; in 1980, there
                but is harvested offshore in theAtlantic. In    were fewer than 30 of them in the 14
                terms of volume, no other fishery in North      counties adjacent to the Sounds (Wilms
                Carolina has ever come close to menhaden        and Powell [no date given]). In fact, there
                (Whitehurst 1973). In 1984, 178 million         are only three large water-dependent
                pounds of menhaden were landed at North         manufacturing plants that discharge
                Carolina ports (North Carolina Division of      directly into an estuary of the Albemarle-
                Marine Fisheries 1984).                         Pamlico system. Two are Weyerhaeuser
                                                                pulp and paper mills; one on the lower
                Recreation                                      Roanoke River at Plymouth, NC, and
                   Tourism, already one of North Caro-          another above New Bern, NC, on the lower
                lina's larger industries, is projected to grow  Neuse River. The third is a phosphate
                even larger in the near future, surpassing      mine and manufacturing plant owned by
                three ofthe States traditional major indus-     Texasgulf Inc. on the south shore of the
                tries: tobacco, textiles, and furniture. Dare   Pamlico River estuary.
                County is by far the leader in tourism in the       In the early 1950s, large deposits of
                coastal region. Revenues there have in-         phosphate were discovered in Beaufort and
                creased at an explosive rate fromiust $11.6     Hyde Counties. The deposits were formed
                million in 1971 to nearly $350 million in       25 million years ago as thick layers ofsmall
                1987 (both figures adjusted to 1984 dollars)    calcium phosphate pellets; theywere subse-
                (Tschetter 1989).                               quently covered with up to 30 meters of
                   Fishing was the first major water-           sand and clay. By 1966, the Texas Gulf
                related recreational activity to develop in     Sulphur Company (now Texasgulf, Inc.)
                the Albemarle-Pamlico region, and today,        mine was in full-scale operation in an area
                recreational fishing is a major activity in     immediately adjacent to the Pamlico River
                the coastal region (see Chapter 7). Recent      near Aurora, NC. At the Aurora facility
                studies have quantified it in social and        Texasgulf concentrates the ore and uses
                economic terms (Johnson et al. 1986). Also,     part of it in the manufacture of phosphoric
                Johnson and Perdue (1986) estimated the         acid. The rest is sold to fertilizer manu-
                marina and marine manufacturing income          facturers. The plant also discharges phos-
                attributable to recreational fishing. Unfor-    phorus and fluoride enriched freshwater
                tunately the ecological impact on the           into the estuary. Controversy surrounding







                      Profile of the Albemarle-Pamlico Estuarine System                                           1 3

                      the impact of Texasgulf on the Pamlico           Philadelphia, etc.
                      River has grown steadily over the past               Pamlico River tonnage rose rapidly in
                      decade. The company's reputation has             themid-1960s, coincident withtheopening
                      been tarnished by a series of Clean Air Act      ofthe Texasgulfphosphate mine, and today
                      violations and small-scale chemical spills,      about half of the total Albemarle-Pamlico
                      some of which have led to hefty fines.           waterborne commerce is related to the
                      Today fisherman and other local citizens,        mine. Liquid sulphur (17% of the total
                      along with some North Carolina state offi-       tonnage) is brought to the Texasgulf plant
                      cials and scientists, suspect that the dis-      and fertilizer materials (34% of the total)
                      charges are responsible for widespread           are barged south to Morehead City for
                      damage to the estuary, but so far, the           shipment out of the region. The third
                      evidence is mostly circumstantial.               largest cargo in the sounds is pulpwood
                          The Albemarle-Pamlico probably has           (25% of total tonnage) en route to mills on
                      the lowest amount of port activity of any        the lower Neuse and Roanoke Rivers and
                      estuarine system, in its size category, in       upstream in the Chowan River.
                      the nation. The only ports of any signif-            The fact that no significant port develop-
                      icance in North Carolina are to the south,       ment occurred in the Albemarle-Pamlico
                      at Morehead City and at Wilmington.              region has been attributed to the difficulties
                      Waterborne commerce, as reflected by ship-       of navigating the shallow, shifting inlets
                      ping tonnage, is trivial in the sounds. In       through the Outer Banks and the large
                      1984, only 2 million tons of waterborne          expanse of shallow waters between the
                      cargo were transported in the all of the         Banks and the mainland to the west (Gade
                      sounds and rivers in the Albemarle-Pamlico       and Stillwell 1986). Poor transportation
                      system (Morehead City port activity not          between the coastal counties and other
                      included). By way of comparison, during          regions of the state may have been a factor
                      the same year the Port of Wilmington, NC,        also, but of course it is difficult to ascertain
                      alone handled about three times as much          whether this was primarily a cause for, or
                      cargo. And Wilmington is a very smal I port      effect of, the lack of port development.
                      in comparison to Charleston, Norfolk,







                       CHAPTER2

                       Major Environmental Concerns


                           During the past decade, concerns about          A decade after the environmentalmovement
                       the environmental health of various parts           spawned a great surge of new laws and
                       the Albemarle-Pamlico system have been              commitments to clean up and protect
                       voiced more and more frequently in                  threatened resources, the people ofNorth
                       magazine and newspaper articles, on                 Carolina are losing the battle against water
                       television news reports, and by environ-            pollution. Meanwhile, the life ofour coastal
                       mental groups, scientists and government            waters continues to ebb away, choking on
                       agency personnel. At the present time, the
                       estuary is being studied more intensively           mud, algae, chemical poisons and the
                       than ever before because of the U           . S.    threat and promise of ever more. State
                       Environmental Protection Agency's on-               regulators say the pollution problems
                       goingAlbemarle-Pamlico Estuarine Study              confronting the coast are so complex, they
                       (APES). The APES 5-Year Study Plan                  are strugglingiust to understand them, let
                       (NCDNRCD 1987b) lists a number of so-               alone implement controls.
                       called "major environmental concerns" for                                    P. Haskins (1981)
                       the Albemarle-Pamlico. A draft Status
                       and Trends Report for the Albemarle-             documented in 1980,         1981, and 1983
                       Pamlico estuarine system includes much           (Christian et al. 1986). The Chowan blooms
                       more detailed information on some ofthese        were largely composed of the nitrogen-
                       topics (Copeland 1989). The followingsum-        fixing species Aphanizomenon flos aquae,
                       mary is based, in part, on material from         Anabaena spiroides and Anabaena flos
                       that document. Several ofthe concerns are        aquae, while in the Neuse Microcystis
                       addressed in other Chapters of this report;      aeruginosa has been the dominant blue-
                       hence, they are discussed only briefly here.     green (Paerl 1982, 1987).
                                                                            Fortunately, the blooms have been
                       Eutrophication - As                              limited to the riverine and freshwater tidal
                       Evidenced by Blue-Green                          portions of the estuaries because the blue-
                       Algal Blooms                                     green species comprising them cannot
                           Blooms of noxious phytoplankton are          tolerate saltwater. In the Chowan, the
                       often a very obvious indication of cultural      blooms extended over a 30 km stretch
                       enrichment of estuarine waters with              between Holiday Island and the river's
                       nutrients, primarily nitrogen and phos-          mouth near Edenton, NC. The Neuse
                       phorus. Such blooms have occurred during         blooms persist for a period ranging from
                       some, but not all, recent summers along          several weeks to months. Chlorophyll a
                       the lower Chowan and Neuse Rivers. The           levels typically are several hundred /ig(
                       most spectacular blooms in the Chowan            liter (NCDNRCD 1982; Christian et al.
                       occurred in 1972, 1978, and 1983                 1986).
                       (NCDNRCD 1987b). Neuse blooms were                   Research has improved our knowledge
                                                                        ofseveral factors contributingto the blooms,








                1 6                                                                               Chapter 2

                but scientists have not yet integrated all      and more regularly, than any other estuary
                the information needed to explain when          in North Carolina (Stanley 1988b). In fact,
                and where the blooms will occur. The            it is one of the few areas of the Albemarle-
                relationship between increased nitrogen         Pamlico system for which there is a complete
                and phosphorus and blue-green blooms is         enough record to permit an analysis of
                well established for freshwater lakes, but      historical trends (see Chapter 4).
                is not nearly so well understood for estuaries
                like the Chowan and Neuse. Generally,           WetlandS LOSS
                estuarine algal growth is considered to be          Although the Albemarle-Pamlico region
                more nitrogen limited than phosphorus           is relatively undeveloped, human activities
                limited (Boynton et al. 1982), but trying to    in the area have altered and destroyed
                quantify this has proven very difficult, for    habitats that are part of, or tightly-linked
                several reasons. For one thing, the flo,        to, the estuarine ecosystem. Dredging,
                through nature ofestuaries causes them to       draining and f illing are the activities caus-
                behave like rivers sometimes, when              ingmost ofthe changes and these activities
                freshwater input is high, and like lakes at     are usually associated with one of three
                other times when inflow is low. This hydro-     industries: agriculture, residential housing
                logic variability causes problems in predict-   development, or commercial forestry.
                ing water and nutrient flushing rates, as       Reproductive, migratory and feeding pat-
                well as algal concentrations. For the Neuse,    terns for a wide variety of aquatic and
                Christian et al. (1986) showed that blue-       terrestrial organisms are thought to be
                green blooms could not form unless water        affected, but details are lacking for most
                temperature is high and river discharge is      species. Thus, the relative values of the
                low, because otherwise the water is swept       wetlands are poorly known and, in most
                into Pamlico Sound before the blue-green        cases, restoration or mitigation forimpacted
                algae densities have time enough to build       areas has yet to be evaluated on an economic
                up to bloom levels. This probably explains      basis.
                why blooms develop only in low-flow                 Adams et al. (1989) recently prepared
                summers, despite the fact that plenty of        a report on the status and trends of the
                the nutrients are present every year.           wetlands in the Albemarle-Pamlieo region;
                   There is much uncertainty whether the        some of their findings are summarized
                blue-green problem is worse now than in         below.
                past decades. It is said that the blooms are        A. Tidal Salt Marshes: In 1962, there
                more frequent now (e.g., NCDNRCD 1987b),        were estimated to be a total of 4,897 hect-
                but there is no historical systematic sam-      ares of salt marsh in Pamlico Sound, and
                pling record to confirm this. It is certainly   none in the Albemarle Sound. Most of the
                possible that blooms werejustas common          marsh area was in Carteret County (83%),
                earlier, but, like most other symptoms of       with the remainder in Hyde (13%) and
                environmental degradation, were paid little     Dare (4%) Counties (Wilson 1962). Amore
                attention. This is unfortunate, because         recent estimate is not available. Tidal salt
                such a record would give support to the         marshes are ofdirect benefit for humankind
                popular opinion that reduction of nutrient      due to their function in supporting finfish
                loading (and presumably nutrient concen-        and shellfish fisheries, waterfowl popula-
                tration) in the estuaries will reduce or        tions, and aesthetics. These benefits have
                eliminate the blooms in the future.             been appreciated for at least three decades;
                   The Pamlico River Estuary has been           thus, salt marshes are afforded a relatively
                monitored for nutrients and algae longer,








                      Major Environmental Concerns                                                               1 7
                      high level of protection in most states,         which has a long history of water quality
                      including North Carolina.                        problems and is undergoing rapid develop-
                          B. Nontidal Brackish Marshes: These          ment and land use changes. It is thought
                      are eight times as extensive as salt marshes     to be functionally similar to the nontidal
                      in Pamlico Sound; in 1962, there were            brackish marsh, although obviously the
                      about 40,000 hectares. Carteret County           plant and animal species composition is
                      had 15,621 hectares (39% of total), and          somewhat different. Where it is abundant,
                      most of the rest was in Hyde, Pamlico and        much importance is given to waterfowl and
                      Dare Counties (Wilson 1962). Tradition-          sports fishing resources. A relatively large
                      ally, these marshes have been altered to         number of permits were issued allowing
                      create impoundments to attract waterfowl,        alteration of wetlands in the Currituck
                      with little attention being paid to the costs    Sound area between 1970 and 1984 (Stock-
                      of such alteration. Despite their large          ton and Richardson 1987). The proximity
                      areal coverage, less is known about the          of this area to a major metropolitan area
                      ecological functioning of these marshes          (Norfolk and Virginia Beach, Virginia)
                      than is known for tidal salt marshes. In         makes it very attractive for outdoor recre-
                      addition, large areas of marsh were altered      ation and development of second homes.
                      in the past by digging ditches for mosquito          E. Riparian lAlluvial Forested Wet-
                      control, a practice that elicited a call for a   lands: North Carolina and other southern
                      moratorium on ditching (Kuenzler and             states have extensive forested wetlands.
                      Marshall 1973). The ditching no longer           There are several types, including bottom-
                      occurs, but the potential for these areas to     land hardwood forests along rivers and
                      recover to their original, unaltered condition   streams, cypress strands, willow strands,
                      is not known. The brackish marshes are           and small headwater branches and drains.
                      protected by the same mechanisms used            Functionally, however, they have many
                      for other wetlands.                              similarities. One is their capacity to act as
                          C. Fringe Swamps: These are forested         water pollution filters. A very good syn-
                      wetlands that occupy the shorelines of           thesis of past research on this subject was
                      Albemarle Sound and the mouths of some           made by Kuenzler (1989). He found that
                      of its major tributaries. They represent a       those alongstrearns can remove large quan-
                      transition between aquatic ecosystems and        tities ofsuspended sediments from cropland
                      interior wetlands. Near the shoreline,           runoff as well as nitrogen and phosphorus
                      they are characterized by groves of dead or      from both point sources and nonpoint
                      dying cypress trees under permanently            sources of pollution. For example, it was
                      flooded conditions, a very common - and          estimated that the systems removed 64%
                      picturesque - sight in the Albemarle             of the total nitrogen and 43% of the total
                      region. Brinson (1989) estimates that they       phosphorus from upland sources in the
                      occupy about three-fourths of the southern       Chowan River watershed (Kuenzler and
                      shoreline of Albemarle Sound and almost          Craig 1986).
                      all the shoreline of the Alligator River.           These wetlands have been destroyed
                      They were harvested for timber in the            rapidly in recent decades. Turner et al.
                      past, but no studies have been made to           (1981) reported the combined loss of 30,000
                      document the effects of the harvesting on        acres ofbottornland hardwood forests from
                      the ecology of the swamps.                       about 1960 to 1975 in North Carolina and
                         D. Nontidal Freshwater Marsh: Most            South Carolina. Such losses represent a
                      of this marsh type (3,500 hectares) occurs       small fraction of the total forest land so
                      in the northern part of Currituck Sound,         that they are not reflected by the statistics








                1 8                                                                           Chapter 2

                in total forest land acreage trends (see      Currituck Sound (Adams et al. 1989). In
                Chapter 3). Nevertheless, the decrease        terms of present conditions, Brinson and
                represents a substantially larger fraction    Davis (1989) carried out one of the most
                of the total wetland area. Such reductions    recent surveys and found great variability
                must be affectingwater quality, given their   in SAV abundance from one area to another.
                high pollutant removal capacities. The            The marine SAV community in the
                National Wetlands Policy Forum is develop-    Albemarle-Pamlico system appears rela-
                ingrecommendations designed to stop, then     tively stable, according to Thayer et al.
                reverse, wetland losses. (Kuenzler 1989).     (1984). Eelgrass, a major component of
                Implementation of these and other policies    this community, recovered substantially
                developed by Federal and State authorities    from the wasting disease of the 1930s.
                mayturn.out tobe one ofthe most important     However, there is concern about future
                estuarine water quality management            development activities that might affect
                actions in the near future.                   SAV habitat, and about clam-kicking, a
                                                              mechanical clam harvesting procedure
                Loss of Submerged Aquatic                     which is thought to damage SAV (Peterson
                Vegetation                                    et al. 1983, 1987).
                   Reduction in submerged aquatic vegeta-     Declines in Fisheries
                tion is of crucial environmental concern
                because a decline represents a reduction in       Declines in commercial fisheries have
                fisheries and waterfowl habitats. In the      occurred in the Albemarle-Pamlico region
                mid-1970s and before, submerged aquatic       following historic highs in the 1970s. For
                vegetation (SAV) was common in the upper      nearly 40 years, the total finfish catch
                half of the Pamlico River estuary (Davis      remained relatively stable. But between
                and Brinson 1976). By 1985, however,          1968 and 1981, it rose dramatically to
                biomass had been reduced to about 1% of       about three times what it had been pre
                that of the 1970s and only widgeongrass       viously. Since then, it has fallen back to
                was present (Davis and Brinson 1989). An      about 1.5 times the 1930-1970 mean. It is
                after-the-fact analysis of the decline sug-   this short-term decline in the past 8 years
                gests that unusual weather conditions in      that has caught the attention of many
                1978 contributed to the problem.        Any   people, and it has been widely publicized.
                tendency toward reestablishment of            Similarly, the total commercial shellfish
                Vallisneria canericana (wild celery), previ-  harvest rose gradually until the late 1960s,
                ously the most important species in the       fell back slightly in the early 1970s, then
                estuary, probably was negated by ex-          began a very steep increase in the late
                tremely high salinities prevalent in 1981     1970s, reaching an all-time high in 1979
                (Davis and Brinson 1989).                     that was about twice the average for the
                   The decline of SAV in the Pamlico River    preceding two decades. But again, it has
                has been mentioned frequently in discus-      been the decline since 1980 (down to about
                sions of the problems in the Albemarle-       1.5 times the 1950-1970 mean) that has
                Pamlico, and it is usually compared to the    been the focus of attention. Trends for
                SAV decline documented in the Chesapeake      individual fisheries are very mixed, with
                Bay (Orth and Moore 1982). There has          some commercial catches risingat the same
                been a tendency to extrapolate the Pamlico    time others were declining. For example,
                situation to other areas of the sounds. But   since 1950, blue crab landings have
                actually, there is no historical evidence on  doubled, shrimp landings have shown little
                SAV abundance for any other region except     trend (but have displayed great inter-








                       Major EnvIronmental Concerns                                                              1 9

                       annual fluctuations), while oysters have        other fish species examined during the
                       declined. Flounder, croaker, and spot           study were infected (Noga et al. 1989).
                       landings all skyrocketed in the early 1970s,        No primary causes for the diseases
                       and since 1980 have fallen back, but remain     have been established. The current working
                       high in relation to the long-term means.        hypothesis is that environmental stress
                       Anadromous species generally have de-           increases the susceptibility of the fishes to
                       clined, either on a long-term, more-or-less     the diseases. Salinity, in particular, is one
                       continuous basis (alewives and American         factor that is being examined, but to date
                       shad), or in recentyears followingan earlier    there have been no controlled experiments
                       increase (striped bass and catfish). The        performed to test a specific hypothesis.
                       fishery declines are generally attributed to        Another widely publicized perception
                       a combination of over-fishing declining         in North Carolina is that the number of
                       water quality, and critical habitat loss or     fish kills in the estuaries has increased in
                       alteration (NCDNRCD 1987b). Reasons for         recent years. Once again, unfortunately,
                       the earlier increases in harvest are seldom     there is no program to sample system-
                       discussed. Trends in commercial fisheries       atically; rather, the number of kills reported
                       are covered in more detail in Chapter 7 of      toauthorities is thebasis forthis conclusion.
                       this report.                                    Most reported kills occur in the Pamlico
                                                                       River, and menhaden are most often the
                       Fish Diseases and Kills                         species involved (see Chapter 5). The most
                          Episodes of infectious diseases that are     frequent cause given by State agency scien-
                       associated with the presence of some            tists for the kills is low dissolved oxygen in
                       microbes or parasites have been observed        the bottom waters of the estuary (Stanley
                       in the Albemarle-Pamlico system, as well        1985). Many feel that bottom water anoxia
                       as elsewhere along the U.S. east coast. A       is more common in the Pamlico now than
                       "red sore" disease reached epidemic pro-        in the past, even though the available data
                       portions in some commercial species in          for the past 20 years suggests otherwise
                       Albemarle Sound during the 1970s (Esch          (see Chapters 4 and 5).
                       and Hazen 1980). In the Pamlico River
                       estuary, the most prevalent of these prob-      Impairment of Nursery Area
                       lems seems to be ulcerative mycosis (UM),       Function
                       a fungal infection (Noga et al. 1989). The          Initial development of the post-larval
                       perception that these diseases are more         stages of many fish and shellfish species
                       serious nowthan in the past is not strongly     occurs in primary nursery areas (PNAs)
                       debated, despite the lack of any long-term      located in the uppermost areas of estuaries
                       systematic monitoring record. A recent,         and their tributaries. The marshes and
                       two-year monitoring effort (1985-1987) was      small embayments fringingAlbemarle and
                       conducted in the Pamlico River to assess        Pamlico Sounds provide essential nursery
                       the occurrence and species distribution of      functions for a majority of the commercial
                       ulcerative mycosis. Overall, 16% of the         species in the North Carolina coastal area.
                       menhaden sampled had UM lesions, but            Because of their location, PNAs are very
                       there was a strong seasonality in disease,      sensitive to activities on adjacent uplands.
                       with the highest incidences occurring in        Freshwater drainage, land-use changes
                       the Spring and Fall. At those times, up to      and eutrophication can jeopardize the
                       100% of the menhaden in individual trawl        functional aspects ofthe primary nurseries.
                       samples were infected. Less than 1% Of          However, the exact extent of impairment








                 2,0                                                                               Chapter 2

                 apparently is difficult to estimate, even        area, but Core Sound and Bogue Sounds
                 when historical data are present. For            are affected (See Chapter 7 for more details).
                 example, in North Ca    *rolina, the Wildlife    New techniques to more accurately mea-
                 Resources Commission, the Division of            sure contamination and potential human
                 Marine Fisheries, and university research-       impact are needed so that management
                 ers have collected information concerning        can more effectively allocate shellfish
                 abundance of juvenile fishes in PNAs of          resources. Relationships between contami-
                 Pamlico Sound for some two decades, but          nation and land-use characteristics are
                 there has never been a definitive analysis       poorly understood.
                 of environmental or fish population trends
                 in the nursery areas (Adams et al. 1989).        Toxicant Effects
                    The nursery areas are defined, for               Very little is known about the effects of
                 management purposes, on the basis of the         toxicants on estuarine organisms or the
                 numbers of juvenile fishes caught in a           distribution of toxic substances in the
                 standardized samplingroutine. Suchdesig-         Albemarle-Pamlico Estuarine System. A
                 nated areas are protected against damag-         preliminary report has just been issued on
                 ing fishing practices through regulations        the first-ever systematic survey of
                 of the Marine Fisheries Commission and           Albemarle-Pamlico sediment heavy metals
                 enforced by the Division of Marine Fish-         concentrations. This report deals with the
                 eries. Trawling, as well as oyster and clam      Pamlico River estuary, the first of foursub-
                 kicking (using propeller wash to excavate        regions to be sampled over the next several
                 clams) are prohibited in such areas. Impacts     years (Riggs et al. 1989). The results of the
                 from land use activities are less well-con-      report are summarized in Table 2. 1. The
                 trolled, and there is suspicion that in the      authors of the report concluded that the
                 future, these activities will pose the most      low metals concentrations within Choco-
                 serious threats to the long-term health of       winity Bay surface sediments are similar
                 the nursery areas. More specifically, the        to concentrations occurring in subsurface
                 greatest weakness in existing regulatory         samples throughout the Pamlico (data not
                 programs is thought to lie in controlling        shown). The subsurface samples are inter-
                 non-point sources of water pollution and in      preted to represent the natural background
                 regulating development landward of the           during preindustrial conditions. If this is
                 nurseries (Adams et al. 1989).                   the case, then the Chocowinity Bay sedi-
                                                                  ments show little metals enrichment from
                 Shellfish Closures                               man's activities. On the other hand,
                    Closure due to pathogenic microbial           averages for all the Pamlico samples were
                 contamination of shellfish waters in North       about twice those for Chocowinity Bay,
                 Carolina has remained relatively constant        and in Kennedy Creek, a very 'Small
                 over the past few years. About 50,000            tributary in the upper estuary at Wash-
                 acres of productive shellfish bottoms are        ington, NC, toxic metals may have been
                 currently closed on temporary or perma-          enriched by up to ten times the pre-man
                 nent basis. Often, after heavy rainfall,         concentrations. One factor not considered
                 additional acreage is closed for several         by the report's authors is the effect of
                 days to several weeks. Albemarle Sound is        sediment composition on metals concentra-
                 not a contributor to commercial shellfish,       tions. The percent organic matter and the
                 but Pamlico Sound has oysters, clams, and        sand-clay ratio are known to affect the
                 bay scallops in several areas. Most of the       affinity of estuarine sediments exposed to
                 closure is to the south of the Pamlico Sound     (otherwise) equal loadings ofmetals (White








                        Major Environmenfal Concerns                                                                        2 1

                        A al. 1985). Riggs et al. (1989) did present
                        data indicating that both of these factors
                        varied considerably among their sampling
                        locations, but their metals data apparently
                        were not normalized with regard to these
                        differences (J. Bray, personal communica-
                        tion). The Pamlico concentrations data,
                        taken as a whole, appear to be typical of
                        estuaries that are considered to be relatively
                        unpolluted with the metals.






                        Table 2.1.      Heavy metal concentrations (Ag1g) in the most and leastpollutedportions of the
                                        PamlicoRiver. "Pamlico average"is the trimmed mean for the whole system (i.e.,
                                        all values more than 2 standard deviations from the mean were eliminated).
                                        Kennedy Creek is the most polluted and Chocowinity Bay is the least polluted
                                        portion of the system (from Riggs et al. 1989).

                        Metal            Pamlico              Kennedy Creek                           Chocowinity Bay
                                         Average       Average         Min        Max           Average       Min         Max

                        Arsenic            12.80        21.20          5.80       35.40         7.80          3.60        12.60
                        Cadmium              0.36         0.85         0.30         1.70        0.18          0.00         0.40
                        Chromium           10.50        27.30          5.90       58.80         4.60          2.50         8.30
                        Copper             13.60        51.50         17.60       84.40         6.40          3.50         9.80
                        Nickel               2.70         8.40         1.50       13.30         1.00          0.10         2.10
                        Lead               35.90        68.50         29.80       86.90         21.70        11.90        40.90
                        Zinc               77.00        377.90       151.20       490.30        35.60        17.10        56.60
                        Mercury              0.09         0.44         0.16         1.30        0.06          0.03         0.08







                     CHAPTER3
                     Trends in Nutrient Production: An
                     Estimate Based on Changing Land
                     Use and Population

                         Of the wide variety of chemicals                 The ultimate question is: Even if stringent
                     discharged into estuaries, two plant growth          point and nonpoint source nutrient controls
                     nutrients, nitrogen (N) and phosporus (P),           are adopted, can [estuaries] survive in a
                     have been identified again and again as              desirable natural state in the face of
                     among the most critical, with the potential          continuing increases in nutrient sources
                     for widespread impact on estuarine re-               resulting from population growth and
                     sources. Frequently, increases in popula-            changing land use? Only time will tell.
                     tion density, fertilizer use and conversion          C.F. D'Elia (1987)
                     of forest land to agriculture are cited as the
                     causes for increased nutrients leading to         3) the amount contained in the manure of
                     eutrophication in estuaries (e.g., Macknis        farm animals. Loading, on the other hand,
                     1985; North Carolina DNRCD 1987).                 refers to the quantities of nutrient actually
                         While it is intuitively obvious that in-      reaching the estuary. There is a difference
                     creased estuarine nutrient loading ought          between the two because ofprocess ingthat
                     to occur as the basin population grows,           occurs as nutrients are transported from
                     usually there are little or no historical data    the sources toward the estuary. The produc-
                     to clearly show the quantitative relation-        tion rate normally exceeds the loading
                     ships between the anthropogenic changes           rate, because there are losses along the
                     and changes in nutrient loading. Scores of        way, due to such processes as sedimentation
                     current N and P loading estimates have            (for P) and denitrification (for N).
                     been made for various estuarine drainage             The reader should keep in mind that
                     basins, including the Neuse, Chowan, and          the estimates made in this study are for
                     Tar-Pamlico River estuaries in NorthCaro-         production, not loading. Loading from the
                     lina (see Chapter 1), but studies ofhistorical    basin can be measured directly by multiply-
                     trends in nutrient loadinghave rarelybeen         ing stream discharges times nutrient con-
                     made. The objective of this study was to          centrations. The data for the computations
                     use historical population and agriculture         normally come from monitoring flows and
                     statistics for estimating trends in annual        concentrations at the head of the estuary.
                     N and P production within each of the             The advantage of this method is obvious; it
                     major Albemarle-Pamlico sub-basins.               gives a direct measure of the actual quantity
                         Actually, there is probably a large differ-   of nutrient discharged from the watershed.
                     ence between nutrientproduction within a          However, the technique could not be used
                     watershed and loading to an estuary. For          in this study because of a lack of long-term
                     purposes ofthis study, nutrientproduction         monitoring of N and P concentrations at
                     refers to the sum of 1) the nutrients dis-        the mouths of the streams and rivers empty-
                     charged from point sources, 2) that esti-         inginto the estuaries in North Carolina. In
                     mated to come from each non-point source          fact, there are very few estuaries for which
                     (e.g. field, forest, or the atmosphere), and








                  24                                                                               Chapter 3

                  such a data set is available. Another           cropland, 3) other non-forested farmland
                  disadvantage is that this method gives no       (mostly idle cropland), 4) forests, 5) pas-
                  indication of the sources of the nutrients.     tureland, 6) urban land, and 7) all other
                                                                  land areas. Point sources included munici-
                  Methods                                         pal wastewater treatment plant and indus-
                     Trends    in land use and nutrient           trial discharges. Atmospheric N depo-
                  production in theAlbemarle-Pamlico basin        sition was also included in the estimates.
                  were estimated for the period 1880 through          The primary sources for agricultural
                  1987 by summing computed estimates of           land use, crop and animal statistics were
                  annual point and nonpoint source produc-        the censuses conducted by the U.S. Bureau
                  tion for each county in the basin. The          of the Census and the North Carolina and
                  procedures were based on those of Thomas        Virginia Departments ofAgriculture. Num-
                  and Gilliam (1978), Craig and Kuenzler          bers of each type of farm animals, acreages
                  (1983), and Lowrance et al. (1985). For         and harvests of the major crop types, and
                  counties that are partly inside the basin,      acreages of the pastureland and "other
                  all data were weighted by the percentage        farm land" categories came from the census
                  of the county within the basin (Figure 3. 1,    reports (Table 3.2). Forest acreage statistics
                  Table 3. 1, Appendix 3. 1). Nonpoint sources    were compiled from U.S. Department of
                  considered included 1) eight categories of      Agriculture Forest Service Resource Bulle-
                  farm animals, 2) harvested agricultural         tins for North Carolina and Virginia (Table


                         40 53       3      8     1 11                 16     52  5
                          1     22      51     28       ...... 37 6          59                            N
                        47     30                        39            26       55   33 .67   68       69
                               54                                                    23@-         14
                   58 56                10   49         61                   42
                                                              63                 31
                                                                                              46
                                                    24                                     1,
                             27                                                          12.
                      20
                                               17         21     41              4
                                                                       18
                                                                                       It' 64
                       KILOMETERS                                                              60
                                                    62                           38                    Is
                     0 20 40     60 80                           66
                                                                           "1 50     2
                                                        34           25                         32
                                                                 6S
                                                                     36        3
                                       ................
                                    . ...............
                                                                                     45
                                                                          3S
                                                                                           9



                  Figure 3.1. Map showing counties in each of the Albemarle-Pamlico 8ub-basins. The counties are
                  identified in Table 3. 1.









                       Trends in Nutrient Production                                                                       25

                       Table 3.1. North Carolina and Virginiacounties in   Table 3.2. Sources ofdataon agricultural landuse,
                       the Albemarle-Parnlico basin (numbers correspond    crop harvests, farm animals, fertilizer sales, forest
                       to those on map in Kgure 3. 1).                     and urban land areas, population, and municipal
                                                                           and industrial discharges.
                       Map             Map             Map
                       No. Name        No. Name        No.  Name           Agricultural Land Use, Crop Harvests and Farm
                                                                                Animals Inventory
                       1. Appomattox   24. Granville   47.  Patrick          U.S. Bureau of the Census. 1880-1982. Primary source.
                       2. Beaufort     25. Greene      48   Perquimane       N.C. Department of Agriculture. 1923-1988. North
                       3. Bedford      26. Greeneville 49.  Person              CarolinaAgricultural statistics. Annual Bulletins and
                       4. Bertie       27. Guilford    60.  Pitt                Reports.
                       5. Botetourt    28. Halifax (VA) 61. Pittsylvania     Virginia DepartmentofAgricultur-e. 1920-1988. Virlinia
                       6. Brunswick    29. Halifax (NQ 62.  Prince George       Agriculture Statistics (Annual Reports).
                       7. Camden       30. Henry       53.  Roanoke
                       8. Campbell     31. Hertford    64.  Rockingham     Forest Data
                       9. Carteret     32. Hyde        65.  Southampton      Virginia
                       10.Caswell      33. Isle of Wight 66. Stokes          U.S. Forest Service (1943); Cruilmhank and Evans (1945);
                       11. Charlotte   34. Johnston    67.  Surry (VA)          Larson and Bryan (1959); Sheffield (1976, 1977a,
                       12.Chowan       35. Jones       68.  SurTy (NC)          1977b); Cost (1976); Brown (1985, 1986); Brown and
                       13. Craven      36. Lenoir      59.  Sussex              Craver (1985).
                       14. Currituck   37. Lunenburg   60.  Tyrrell          North Carolina
                       16. Dare        38. Martin      61.  Vance            U.S. Forest Service (1943); Cruikshank (1940);
                       16. Dinwiddie   39. Mecklenberg 62.  Wake                Cruikshank and Evans (1945); Larson (1957); Knight
                       17. Durham      40. Montgomery  63.  Warren              and McClure (1966); Welch and Knight (1974); Cost
                       18. Edgecombe   41. Nash        64.  Washington          (1974); Welch (1975); Bechtold (1985).
                       19. Floyd       42. Northampton 66.  Wayne
                       20. Forsyth     43. Nottoway    66.  Wilson         Fertilizer Sales
                       21. Franklin (NQ 44. Omnge      67.  Suffolk          Virgiiiia Department ofAgriculture. 1956-1988. Fertilizer
                       22. Fmnklin (VA) 46. Pamlico    68.  Chesapeake          used and results of inspection (annual reports).
                       23. Gates       46. Pasquotank  69.  Virginia Beach      Richmond.
                                                                             U.S. Bureau of the Census. 1954, 1959, 1964. County
                                                                                data on fertilizer materials applied to croplands.
                                                                             Hargett and Berry (1985).
                                                                             Mehring et al. (1985).
                                                                             North Carolina Department of Agriculture. Various
                                                                                dates between 1956 and 1988. Data for some years
                       Table 3.3. Coefficients used to compute nitrogen         contained in the N.C. agricultural statistics mports
                       and phosphorus production by five different land         issued annually.
                       use categories and by different types offarm animals.
                       Values for forest are from Loehr (1974), values for Population and Urban Land Areas
                       other land Uses are from Beaulac and Reckhow          U.S. Bureau of the Census. 1880-1983. Census of
                       (1980); values for animals are fi-om Barker (1987).      Population.
                                                                             U.S. Bureau of the Census. 1949-1988. County and City
                       Land use category      Nitrogen      Phosphorus          Data Book.
                        or animal type        (kglyear)       ft/year)     Municipal and Industrial Discharges
                                                                             N.C. Stream Sanitation Committee (1946, 1957, 1959,
                       Other Farmland         3.00/ha         0.40/ha           1961)..
                       Other Land             3.00/ha         0.40/ha        U.S. Public Health Service (1944, 1951, 1958, 1963).
                       Forest                 1.50/ha         0.20/ha        U.S. Environmental Protection Agency (1971).
                       Pastureland            4.00/ha         0.60/ha        Hall (1970).
                       Urban Land             6.00/ha         1. 10/ha       Vir%inia State Water Control Board (1976).
                                                                             N.C. DivisionofEnvir-onmental Management (1986,1989)
                                                                             Virginia State Water Control Board: NPDES Self-
                       Cattle                                                   Monitoring Data (1989).
                        Dairy              121.00/animal    22.00/animal     North Carolina Division ofErivironmental Management:
                        Beef               48.10/animal     13.10/animal        NPDES Self-Monitoring Data (1986-1989).
                       Swine               11.90/animal     4.20/animal      N.C. Board of Health. Various Dates. Annual reports.
                       Horses              46.40/animal     11.00/animal
                       Sheep                6.80/animal     1.50/animal
                       Poultry
                        Broilers            0.40/animal     0.10/animal
                        Layers              0.56/animal     0.20/animal
                        Turkeys             1.36/animal     0.52/animal







                       26                                                                                                        Chapter 3
                       3.2). Urban land areas were tallied from                       of non-forested, nonagricultural lands out-
                       U.S. Bureau of Census data (Table 3.2).                        side the boundaries of the towns and cities
                       Here "urban" areas are defined as the land                     (i.e., business properties, house lots, roads,
                       areas within the limits of towns and cities                    ponds, cleared power line right-of-ways,
                       with populations greater than 2,500. The                       etc.).
                       "other" land use categorv was calculated as                         Quantities of N and P released in the
                       the total basin land area minus the sum of                     excreta of farm animals were estimated by
                       all the other land use type acreages. This                     multiplying numbers of animals times co-
                       miscellaneous category consists primarily                      efficients (Table 3.3). Mass balance models



                            Table 3.4. Atmospheric deposition of (D) in kglhalyear and mean concentration (C) in @kgl I
                            of nitrogen andphosphorus at several locations within, or near, the AP watershed.

                                                                           N03-N               NH4-N              Total-P

                            Location                Year      Precip. (D)          (C)       (D)       (C)        (D)      (C)       Ref.
                                                              (in.)

                            North Carolina          1975                5.54 (NO,+NH   4)    0.21                                      1

                            Duke Forest, NC         1972                1.46                 0.74                 0.28     21          2


                            Tar River
                            Swamp,NC                1976                                                          0.49     63          8

                            Rhode River             1974      108.6     3.91       360                            0.57     53          3
                            Watershed, MD           1975      142.4     4.65       327                            1.13     79          3
                                                    1976      115       5.57       484                            0.74     65          3

                            Creeping
                            Swamp,NC                1977                                                          0.70     64          7

                            Clinton, NC             1980      116.5     2.60       223       1.66      134        ...                  4
                                                    1981      113       2.37       210       1.66      138        ---                  4
                                                    1983      127.2     2.24       176       1.71      136        ---                  4

                            Lewiston, NC            1980       87.3     2.53       290       1.32      161        ---                  4
                                                    1981       79.5     1.69       213       1.01      127        ---                  4
                                                    1982      116.4     2.53       217       1.71      147        ---                  4
                                                    1983      106.1     2.75       262       0.00                                      4
                                                    1984      133.7     3.75       280       1.32      99         ---                  4
                                                    1986      117.6     1.96       167       1.24      153        ---                  4


                            Raleigh, NC             1980       94.1     2.39       254       1.79      190        ---                  4
                                                    1981       81.3     1.56       192       1.24      163        ---                  4
                                                    1982      114.7     2.48       217       2.10      183        ---                  4
                                                    1983      126.7     2.64       209       0.00                                      4
                                                    1984      123.9     2.30       186       1.84      149                             4
                                                    1985       93.3     1.76       189       1.61      173        ---                  4


                            Greenville, NC          1968      119       8.00       672       1.30      109                             5

                            Roanoke, VA             1958      127       8.90       701       2.40      189                             5

                            Cape Hatteras, NC       1958      137       3.20       234       1.20      88                              6


                            1. Wells and Jorgensen 1975; 2. Wells et al. 1972; 3. Miklas et al. 1977; 4. Olsen and Watson 1986; Olsen and
                            Slavich 1986; 5. Junge 1958; 6. Galloway et al. 1984; 7. Kuenzler et al. 1980; 8. Holmes 1977.









                            Trends In Nutrient Production                                                                                           27

                            for N and P were calculated for agricultural                        The amount of fertilizer applied
                            cropland, following the methods of Craig                       annually to cropland was assumed to be
                            and Kuenzler (1983) and Lowrance et al.                        equal to the amounts sold in, or shipped to,
                            (1985). The annual cropland nutrient bud-                      the counties. Historical data on fertilizer
                            gets for each AP sub-basin were estimated                      sales were taken from a number of sources
                            by:                                                            (Table 3.2). Actually, most of the data are
                                 (Precipitation + Fertilizer + Symbiotic N-Fixation) -     reported as tons of "mixed fertilizer" and
                                      (Harvest + Denitrification) = N Balance; and         "fertilizer materials" either received in the
                               (Precipitation + Fertilizer) - (Harvest) = P Balance.       counties from manufacturers for retailers
                                 The "balances" when positive, were                        and consumers (North Carolina), orsold by
                                                                                           each county (Virginia). To convert tons of
                            assumed to represent the maximum "crop-                        mixed fertilizer and fertilizer materials
                            land pollution potential"; i.e., the quantity                  into tons of elemental N and P, I multiplied
                            of nutrient that could leave the watershed                     by the percentages of N and P in each type
                            through surface or subsurface flow. Of                         of material sold. The N fixation rate used
                            course, this assumes that nutrient storage                     for soybeans was 105 kg/ha per year (93.5
                            in the soil system is not changing (Frissel                    lb/acre per year) (Frissel 1978), and for
                            1978).                                                         peanuts the rate was assumed to be 112
                                 Wet precipitation inputs for each year                    kg1ha per year (99.7 lb/acre peryear) (Craig
                            were calculated by multiplying the total                       and Kuenzler 1983). The amounts of N
                            annual precipitation (average of several                       and P harvested were determined by multi-
                            sites within the Albemarle-Pamlico (AP)                        plying the nutrient content by the annual
                            basin, times the estimated N and P concen-                     yields (e.g., bushels/acre) ofthe majorcrops
                            trations, times land areas. N and P concen-                    (Gilbertson et al. 1978; Romaine 1965)
                            trations in precipitation for the mid-1980s                    (Table 3.5). Finally, denitrification rates
                            were based on measurements from                                were assumed to be 15% of the applied
                            National Atmospheric Deposition Program                        fertilizer N (Porter 1975; Thomas and
                            stations in the AP basin, and on other
                            recent measurements (Table 3.4); but his-
                            torical Nconcentrations had to be calculated
                            indirectly. This was done by assuming                          Table 3.5. Nitrogen and phosphorus content in
                            that N deposition in 1880 was 20% of the                       harvested crop materials (Gilbertson et al. 1978,
                            rate today, and that the rate of change                        Romaine 1965).
                            since 1880 has been exponential. These                                                Harvest    Pounds/Harvest Unit
                            assumptions are, in turn, based on mea-                        Crop                   Unit       Nitrogen Phosphorus
                            sured (present-day) atmospheric N deposi-
                            tion rates in remote areas (Table 3.4) and                     Com (gmin)             Bushel       0.900         0.153
                                                                                           Com (silage)           Ton          4.0           0.45
                            on estimated historical trends in N oxide                      Oats (grain)           Bushel       0.625         0.113
                            production in the southeastern U.S. (see                       Wheat (grain)          Bushel       1.250         0.275
                            Discussion). The total atmospheric N                           Hay
                                                                                              Alfalfa             Ton        45.000          4.500
                            deposition was twice the wet precipitation                        Bluegrass           Ton        30.000          4.600
                            loading, based on the assumption that dry                         Coastal Bermuda     Ton        23.125          3.876
                                                                                              Cowpea              Ton        60.000          5.500
                            deposition equals wet deposition (see                             Peanut              Ton        46.667          4.889
                            Discussion). No information on historical                         Red Clover          Ton        40.000          4.400
                            trends in atmospheric P production or                             Soybean             Ton        45.000          4.600
                                                                                              Timothy             Ton        24.000          4.400
                            deposition were available; therefore, a con-                   Cotton                 Pound        0.018         0.002
                            stant rate of deposition (0.5 kg/ha/yr) was                    Peanuts (nuts)         Pounds       0.036         0.002
                            assumed, based on measurements in the                          Soybeans (grain)       Bushels      3.750         0.375
                            AP region (Table 3.4).                                         Tobacco (leaves)       Pounds       0.038         0.004








                        28                                                                                                          Chapter 3

                        Gilliam 1978).                                                   discharges within eachAP sub-basin (>O.l
                             Nutrient production was not calculated                      mgd), as well as information on N and P
                        by this mass balance approach for any land                       concentrations in the industrial discharges.
                        use category other than harvested cropland.                      The most difficult parameters to estimate
                        Instead, export coefficients (kg N and P per                     were the treatment factors that would be
                        ha per year) were multiplied times total                         applied to each discharge. Fortunately,
                        sub-basin acreages to give the "expected"                        there were periodic inventories ofmunicipal
                        nutrient yields from pastureland, forests,                       wastewater facilities from 1942 through
                        urban, other farm lands, and "other"areas.                       1985 (Table 3.2) which included detailed
                        N and P "yield" coefficients foreach of these                    information on the levels of treatment pro-
                        land-use categories were taken from the                          vided by each facility and the size of the
                        literature (Table 3.3).                                          "sewered" population. Another valuable
                             Both municipal and industrial dis-                          source was the N.C. Department of Health
                        charges     *were included in the point-source                   annual reports, which yielded information
                        nutrient production estimates. For indus-                        on the early history of municipal waste-
                        trial sources the annual production was                          water treatment in North Carolina. For
                        calculated by multiplying daily discharge                        years before 1942, the sewered population
                        times thetotal NorP effluent concentration                       was assumed to be equal to the city
                        times 365. Municipal production was                              population (U.S. Census Bureau data), back
                        computed as                                                      to the time when the sewage collection
                                                                                         system for the town was first constructed.
                        kg N or P/year                                                        The per capita annual N and P produc-
                        Sewered * Per capita                Treatment * 365              tion was taken as 4.6 kg N and 1.2 kg P
                        population       daily N or P factor                             (Gakstatter et al. 1978), and the N treat-
                                         production                                      ment factors ranged from 1 (untreated) to
                                                                                         0.47 (secondary treatment), depending on
                        where sewered population is the estimated                        the type of wastewater treatment practiced
                        number of persons served by the citys                            by the municipal treatment plant. P treat-
                        wastewater collection system. Information                        ment factors ranged from 1.0 to 0.74 (Table
                        on industrial and municipal discharges                           3.6)_
                        was gleaned from several sources. The                                 From 1880 through 1920 the nutrient
                        NPDES Compliance Monitoring data files                           production estimates were computed at
                        were searched to provide lists of all current                    10-year intervals, correspondingto the U.S.
                                                                                         Agricultural census dates. After 1920,
                                                                                         more frequent agriculture census data were
                        Table 3.6. Per capita total nitrogen and total                   available so that I was able to make
                        phosphorus loads (kglyear) in wastewater effluents               calculations at 4-to-5 year intervals. Many
                        as a function of treatment type (Gakstatter et al.               of the data were first compiled in the
                        1978). -Treatment factors are equal to the load for a            English units of measure (acres of land,
                        given treatment type divided by the load for no                  pounds of crop harvest, tons of fertilizer
                        treatment.                                                       sold, square miles of county land area, etc.)
                                                 Nitrogen           Phosphorus           in which they were originally recorded
                        Treatment type       kg/year Factor kg/year Factor               (e.g., Appendix 3.3). But at some stage in
                        None                     4.6      1.00        1.2     1.00       the procedure, all these values were
                        Primary                  4.2      0.90        1.1     0.90       converted to metric units, and the summed
                        Secondary
                           Trickling filter      2.9      0.62        1.0     0.82       nutrient production rates are expressed as
                           Activated sludge      2.2      0.47        1.0     0.82       kg(ha/year, or metric tons per year.
                           Stabilization pond    1.9      0.42        0.9     0.74            Results are presented for the whole









                    Trends in Nutrient Production                                                                29

                    Albemarle-Pamlico watershed, as well as           Pastured land increased from about 0.8
                    for each of the major sub-basins: Chowan          million acres (0.32 million ha) in 1925 to a
                    River, Roanoke River, Tar-Pamlico River,          peak of 1.1 million acres (0.44 million ha)
                    Neuse River, and "Coastal". The Coastal           in the mid-1950s, and has since declined to
                    sub-basin includes all land area down-            around 0.85 million acres (0.34 million ha).
                    stream from the mouths of the river estu-         In addition to the 1.1 million acre decline in
                    aries, primarily parts of Camden, Curri-          harvested cropland since 1925, there must
                    tuck, Dare, Hyde, Pamlico, Pasquotank,            have been about 2 million acres of other
                    Perquimans, Tyrrell and Washington                land in farms "lost" duringthat time period,
                    Counties in North Carolina (Figure 3.1,           since the total "acres in farms"has declined
                    Appendix 3.1). In some of the figures and         from 11 million to around 8 million (4.45
                    tables (especially Appendix tables), the          million to 3.2 million ha) (Figure 3.3a).
                    "Coastal" sub-basin is further sub-divided        Finally, urban land areas (defined here as
                    into the "Albemarle" and "Pamlico" sub-           land in towns and cities >2,500 population)
                    basins, in reference to the sound into which      increased rapidly beginning about 1930,
                    the land drains.                                  and today amounts to around 0.3 million
                                                                      acres (0.12 million ha), or about 2% of the
                    Results                                           total AP basin land area.
                    Land Use                                             There are not good data on any of the
                        There have been relatively small              major land use categories, except harvested
                    changes in the amounts of land in each of         cropland, before 1930, so that the 1880-
                    the major land-use categories in the              1925 values used in the nutrient production
                    Albemarle-Pamlico basin use during the            calculations are only estimates, but prob-
                    past century (Figures 3.2 and 3.3, Appendix       ably are not far off. Judging from the
                    3.2). Forest has always been the most             number of cattle on farms, the known
                    prevalent land use in the basin, ranging          cropland acreages, and the total land in
                    between 57.6% and 63.7% of the total              farms values, and assuming that urban
                    basin land area. There was a peak in forest       land use was much less than 1% before
                    acreage in the 1960s. Harvested cropland,         1930, the forested areas must have been
                    the second most prevalent land use, peaked        about the same in the late 1800s as in
                    at 3.55 million acres (1.4 million ha) in         1925. That is the assumption I have made
                    1940 and has generally declined since, to         for purposes of the nutrient production
                    2.43 million (1.0 million ha) in 1987.            calculations. Actually, the errors in this
                                                                      assumption are probably much less impor-


                    Figure 3.2. Percentages of land use by six 7-
                    major categories for the Albemarle-Pamlico to     M  Urban
                                                               a
                    estuarine system drainage area, 1925-1982. M      =  01ther
                                                                  75%-=  Other Farmland
                                                               Is
                                                               S         Pasture
                                                               0         crops
                                                               CO  50%_
                                                               0      M  Forest



                                                               CL
                                                                  25%-


                                                               E      A

                                                                  0%
                                                                      80 90  0   10  20 25 30 35 40 45 50 54 50 64 69 74 78 52 87
                                                                                     Year (1880-1987)








                        30                                                                                              Chapter 3


                                                                                                         Figure 3.3. Historical
                                        Chowan             Roanoke             Tar          A            trends in land areas (land in
                                                                                                         farms, harvested cropland,
                        0-15            Neuse              Coastal                                       Pasture-land, forest, and
                        C                                                                                urban) by sub-basin in the
                        .2
                                                                                                         Albemarle-Pamlico
                                                                                                         drainage basin.
                        E   9-
                        cd
                        LL
                        .G  6



                            3-



                            0
                              80     90   0     10    20 25 30 35 40 45 50 54 59 64 69 74 78 82 87
                                                      Year (1880-1987)

                            4000
                                                                                             B
                                        Coastal

                        0               Neuse
                            3000-       Ter

                                        Roanoke

                                        Chowan
                            2000


                        CI
                        e
                        0   1000-



                              0
                                 80     90  0     10    20 25 30 35 40 45 50 54 59 64 69 74 78 82 87
                                                        Year (1880-1987)


                            1200
                                                                                              C
                                        Coastal
                            "00   M N.use

                        0               Tar
                            800-
                                        Roanoke

                                        Chowan
                            600-



                            400-



                            200-
                        Cd
                        CL
                                 80     90   0    10    20 25 3@ 315 410 415 510 514 519 614 619 714 78 82 87
                                                        Year (1880-1987)









                              Trends in Nutrient Production                                                                                                      31


                              Figure 3.3. continued                             12 -                                                                           D
                                                                                         Coastal
                                                                                lo-      Neuse

                                                                                         Tar
                                                                         .2     8-
                                                                                         Roanoke

                                                                                         Chowan
                                                                         0)     6-



                                                                                4


                                                                         0
                                                                         LL     2-



                                                                                0.. . . . .
                                                                                  80     90         0  10     20 25 30 35 40 45 50 54 59 64 69 74 78 82 87
                                                                                                              Year (1880-1987)

                                                                                350 -
                                                                                                                                                               E
                                                                                           Coastal
                                                                                300 -
                                                                                           Neuse

                                                                                250 -      Tar

                                                                                           Roanoke
                                                                         0
                                                                         M      200 -      Chowar.

                                                                         U)     ISO-
                                                                         0)



                                                                                100-



                                                                                50-



                                                                                0-
                                                                                   80               0   10     20 25 30 35 40 45 50 64 59 64 69 74 78 82 87
                                                                                                               Year (1880- 1987)



                              tant than those in choosing the export                                planted in significant acreages in the 1930s
                              coefficients (see Discussion).                                        and 1940s, but up until about 1960 never
                                    Some crops are much more important                              made up more than 5-10% of the total.
                              in the AP basin now than in the past, while                           However, by 1987 there were 0.85 million
                              others have become relatively unimportant                             acres (0.34 million ha) of soybeans, which
                              over the years (Figure 3.4, Appendix 3.3).                            was about one-third of the total harvested
                              In terms of acres harvested, corn has been                            cropland.
                              dominant throughout the past century,                                      In contrast, tobacco and, especially cot-
                              accounting for between 0.8 million acres                              ton, acreages have declined in the
                              and 1.5 million acres (0.32-0.61 million                              Albemarle-Pamlico basin (Figure 3.4).
                              ha), or, on average, about 35% of the total                           Annual tobacco plantings peaked in the
                              harvested cropland. The second most wide-                             1930s and 1940s at around 0.6 million
                              ly planted crop today, soybeans, was first                            acres (0.24 million ha), but now are down







                      32                                                                                                    Chapter 3


                           1000-                                                                            Figure 3.4. Historical trends
                                                                                                 A          in amount offarm land used
                                                                                       Coastal
                                                                                                            for six major crops, by sub-
                        r_ 800-                                                        Nauss                basin, in the Albemarle-
                        cc
                        cc                                                                                  Pamlico basin, 1880-1987.
                        M                                                              Tar
                        0
                                                                                       Roanoke
                           600-
                        4)                                                             Chowan
                        CD

                           400-



                        C
                        0  200-
                        0


                              0-
                                 80   90     0    10    20 25 30 35 40 45    54 59 64 69 74 78 82 87
                                                        Year (1880-1987)

                           2000-
                                                                                                 B
                      0    1800-         Chowan              Roanoke              Tar

                      cc   1600-         Neuse               Coastal
                      cc
                      :3
                      0    1400-


                           1200-


                           1000-
                      <    800-

                      0    600-


                           400-
                      cc
                           200-


                              0-
                                 80   90    0     10    20 25 30 35 40 45 50 54 59   @9 ;4 ;8     8`7
                                                        Year (1880-1987)


                           800-
                                                                                                 D
                           700-       Coastal

                                      Neuse
                      (A
                           600-
                                      Tar
                      cc
                      w
                      =    500-       Roanoke
                      0
                                      Chowan
                           400-


                           300-


                      >%   200-
                      to
                      X                                                             NMI
                           too-      I          !
                           O_q
                                     90          0    20 25 30 35 40 45 50 64 5
                              so           0    1                               9 64 69 74 78 82 87
                                                       Year (1880-1987)








                          Trends In Nutrient Production                                                                                       33



                          Figure 3.4. continued                        400-

                                                                                    Coastal

                                                                                    Neuse
                                                                   to  300-         Tar
                                                                   0
                                                                                    Roanoke
                                                                   t                Chowan
                                                                       200-
                                                                   .PC


                                                                       too-





                                                                        0-
                                                                            80      90  0     10    20 25 30 35 40 45 50 54 59 64 69 74 78 82 87
                                                                                                    Year (1880-1987)


                                                                       1200-
                                                                                                                                             G
                                                                                    Coastal
                                                                   'Oa 'ODO
                                                                   Cd
                                                                                    Tar
                                                                   0    800-
                                                                                    Roanoke

                                                                                    Chowan
                                                                        GDO -



                                                                   r-   400-


                                                                   .0
                                                                        200-



                                                                            0 --F   I---- I ---
                                                                             80     90   0     10    20 26 30 36 40 45 50 54 59 64 69 74 78 82 87
                                                                                                     Year (1880-1987)


                                                                       700-

                                                                              =     Coastal
                                                                       6w -
                                                                                    Neuse

                                                                   CIS 500-         Tar
                                                                   0)
                                                                   :3
                                                                   0                Roanoke
                                                                       400-         Chowan


                                                                       300-



                                                                   0   200-


                                                                   J2  100-
                                                                   10-

                                                                            so      90  0     10    20 25 30 354 0 45 @O 64 @9 @4 @9    78 82 87
                                                                                                    Year (1880-1987)








                   34                                                                                      Chapter 3

                   to around 0.2 million acres (0.08 million           million acres orO.12 million ha) but declined
                   ha), or approximately 7% of total cropland          rapidly, then rose slightly in the 1950s,
                   acreage. Cotton production in the basin             and have since fallen back to become
                   was very important up until the 1930s, but          insignificant in recent times in comparison
                   then it declined rapidly and had practically        to other crops. Peanut production in the
                   ceased by about 1970. At its peak in the            AP basin increased rapidly in the early
                   1920s, cotton was the second most widely            part of this century, and in terms of acres
                   planted crop, taking up as much as 35% of           grown, peaked around 1945 at 0.35 million
                   the total cropland in some years. Wheat             acres (0.14 million ha). Since 1954, the
                   and other small grains have never been              peanut acreage has remained nearly con-
                   dominant crops in this area. In 1987 only           stant at about 0.23 million (0.09 million
                   about 12% ofAP basin cropland (0.3 million          ha). Finally, hay crops are a relatively
                   acres or 0.12 million ha) was devoted to            minor part of the total cropland use today
                   wheat, and this was the second highest              (<10% of total). This crop was somewhat
                   acreage planted in wheat, at least during a         more important in the past, but was never
                   census year, over the past 100 years. Oats          dominant. The largest hay acreages were
                   were widely grown in the late 1800s, (0.3           in the 1940s, when they peaked at around





                      160-
                                                                           A
                      140- = Coastal                                                      Figure 3.5. Trends in nitrogen
                   Cd                                                                     and phosphorus sold as
                   0
                           M Nauss                                                        commercial fertilizer, by sub-
                   =0          Tar
                                                                                          basin, in theAlbemarle-Parnlico
                      loo-     Roanoke                                                    drainage basin, 1880-1987.
                           M Chowan
                      80-
                   t

                      Go-


                      40-
                   0

                   Z  20-
                   a,
                   C   0 -
                   9      80   @O      1@   20 25 30 35 40 45 50 54 59 64 69 74 78 82 87
                                            Year (1880-1987)


                   M  50-
                   V
                                                                           B
                               Coastal

                   0  4o-      Nauss

                               Tar

                               Roanoke
                      30-
                          M Chowan


                   LL
                      20-


                   0
                   CL to-
                   OD
                   0
                      0_@Al
                   12     80  90  0   10   20 25 @0 35 40 45 50 54 69 64 69 74 78 82 87
                                           Year (1880-1987)









                           Trends In Nutrient Production                                                                                                  35

                           0.7 million acres (0.28 million ha).                               increased about 7-fold between 1940 and
                                                                                              1978, when a peak of 140,000 tons N (127.6
                           Harvested Cropland Nuffient Mass                                   million kg N) was reached. N fertilizer
                           Balance                                                            sales, like P sales, have declined slightly in
                                Since about 1900, the major nutrient                          the 1980s, but some of the apparent decline
                           inputs to croplands have been N and P                              may be attributable to low demand (i.e.,
                           fertilizer. Large increases in the use of                          poor weather) during the census years,
                           fertilizers have occurred in the AP basin                          rather than to a long-term downward trend.
                           over the past 50 years (Figure 3.5, Appendix                       That was certainly the case in 1987, when
                           3.4). Annual P sales peaked in the 1960s                           acres planted, fertilizer use, and harvest
                           at around 45,000 tons P (40.9 million kgp),                        were all lower than normal due to drought
                           but have declined to 25,000-30,000 tons P                          conditions in much of the region.
                           (22.7-27.3 million kgP) in the 1980s (Figure                            The other variable nutrient input on
                           3.5b). Meanwhile, however, there has                               the cropland has been atmospheric deposi-
                           been a very rapid rise in the amount of N                          tion. As will be discussed below, there
                           fertilizer sold. In fact, annual sales                             probably has been about a five-fold increase
                                                                                              in the areal rate ofatmospheric N deposition




                           Figure 3.6. Trends in yield (pounds                        120-                                                                A
                           and bu8hels per acre) for 8even major
                           crop8 in theAlbemarle-Pamlico basin,                       too-
                           1880-1987.
                                                                                                                                                Com
                                                                                      80-


                                                                                                                                                  oats
                                                                                      Go -


                                                                                                                                                    Wheat
                                                                                 V    40-


                                                                                      20-                                                          Soybeans


                                                                                      0__
                                                                                           80 90    0     10    20 25 30 35 40 45 @O @4 5@ @4 6@ 74 78 82 87
                                                                                                                 Year (1880-1987)
                                                                                      35M -
                                                                                                                                                          B
                                                                                      3000 -                                                 PeanLft


                                                                                      2500-


                                                                                      2000-


                                                                                 0                                                              Tobacco
                                                                                 S    1500-
                                                                                                                                                    Wheat




                                                                                                                                                   Soybeans


                                                                                                                                           4Nanul
                                                                                                                                                Tobacco



                                                                                 .LD  1000-
                                                                                                                                                     Coldon

                                                                                      500


                                                                                           0
                                                                                           80  90    0     10    20 26 30 35 40 45 50 54 59 64 69 74 78 82 87
                                                                                                                 Year (1880-1987)







                                36                                                                                                                Chapter 3

                                TableS.7. Croplands N and P mass balance, on a per hectare basis, for selected years.

                                Input/Output        1880              1900             1920            1940              1959             1974              1987

                                (kg N/ha)
                                N fertilizer        0.84              5.07             17.40           16.34             41.25         111.04             96.70
                                Harvest             -8.77          -12.78              -19.42         -29.73             -47.71        -80.41             -83.99
                                N fixation          0.00              6.26             9.01            17.31             19.79          36.17             46.02
                                Denitrification     -0.12             -0.76            -2.61           -2.45             -6.18         -16.65             -14.50
                                Precipitation       0.80              0.80             1.10            2.25              3.32              3.93             4.32
                                Balance             -7.25             -1.40            5.48            3.71              10.47          54.08             48.54


                                (kg P/ha)
                                Fertilizer          1.69              8.45             22.41           16.70             32.68          36.05             24.96
                                Precipitation       0.27              0.29             0.31            0.36              0.55              0.54             0.59
                                Harvest             -1.48             -1.94            -2.70           -2.70             -6.03         -10.17             -10.24
                                Balance             0.48              6.81             20.02           14.36             27.19          26.42             15.30




                                250-                                                                                     in the AP basin over the past
                                               Fort                Nft                 Precip                            century.          However, the
                                2W -           Harv                Dent                Balance                           atmospheric N input to crop-
                                iso-                                                                                     lands today is still very small
                                'a 11)0-                                                                                 in comparison to fertilizer N
                                r_      Inputs
                                0                                                                                        and N fixation.
                                50-
                                                                                                                            With increasing fertilizer
                                  0                          soon                                                        and pesticides use, and more
                                -510    Outputs                                                                          productive crop varieties, in-
                                -iou -                                                                                   creases in yields (bushels or
                                _150-                                                                                    pounds per acre) for some
                                        8@ 9`0      0   10   20    30     40   5@ @9             78    87                crops      has         been          very
                                                              Year (1880-1987)                                           impressive (Figure 3.6,
                                                                                                                         Appendices 3.5, 3.6). The
                                so-                                                                                      greatestyield increases came
                                          Balance                                                                        between about 1940 and the
                                          Harv                                                                           1970s. For example, corn
                                3o-       Precip                                                                         yield increased about 5-fold,
                                          Fart                                                                           from around 20 bushels/acre
                                r- 20-
                                0                                                                                        to over 100 bushels/acre.
                                        Inputs
                                @i 10-                                                                                   Wheat yields improved about
                                22                                                                                       4-fold, oats by a factor ofabout
                                         001 M                                                                           2.5, and soybean yield
                                -10-    Outputs                                                                          approximately doubled over
                                -2U -                                                                                    the past 40 years or so. There
                                                 0   10    20      30    40   50       59 _T_  69 78   87                ave       been         impressive
                                                             Yew (1880-1987)                                             increases in the tobacco and
                                                                                                                         peanut yields also (Figure
                                Figure 3.7. Historical trends in croplandnitrogen andphosphorus                          3.6).
                                mass balances in the Albemarle-Pamlico basin, 1880-1987.                                    Cropland nutrient mass
                                                                                                                         balances for all of the AP basin








                            Trends in Nutrient Production                                                                                                 37


                            Figure 3.8. Historial trends in                  16DO -
                            numbers ofeightmajorcategories                                                                                              A
                            of farm animals, by sub-basin,                   1400-     M Chowan              ME Roanoke                  Tar
                            in theAlbemarle-Pamlico basin,                                   NeuSe                 coastal
                            1880-1987.                                       1200-


                                                                             10DO -


                                                                         0    800-


                                                                              6w -
                                                                         S
                                                                         @:   400-


                                                                              200

                                                                                   so     90     0     10    20 253  03 5 40 4550   64 59 64 69 74 ; 8 @2 87
                                                                                                             Year (1880-1987)


                                                                             600-


                                                                                            Chowan                Roanoke               Tar
                                                                             5M             Neuse                 Coastal


                                                                             400-



                                                                             300-
                                                                         0


                                                                             200-



                                                                             100



                                                                               0
                                                                                   80     90    0     10     20 25 30 35 40 45 50 64 59 64 69 74 78 82 87
                                                                                                             Year (1880-1987)


                                                                             200-


                                                                                          Coastal

                                                                                          Neuse
                                                                             ISO-         Tar

                                                                                          Roanoke

                                                                                          Chowan
                                                                         0   loo-



                                                                         to
                                                                         4)        11111111111111                                                      '11
                                                                                                                                        Tar












































                                                                              50 -





                                                                               0
                                                                                   80     90    0     10     20 25 30 35 40 45 50 54 59 64 69 74 78 82 87
                                                                                                             Year (1880-1987)








                     38                                                                                             Chapter 3

                        140-                                                             D               Figure 3.8. continued
                                                                                Coastal
                        120-
                                                                                Neuse


                     V
                        too-                                                    Tar
                     C
                                                                                Roanoke
                        So-                                                     Chowan
                     o


                        60-



                        40-
                     0


                        20



                          0-
                             so    90   0    10    20 26 30 35 40 45 50 64 69 64 69 74 78 82 87
                                                   Year (1880-1987)


                        180-


                        ISO-                                                    Coastal
                        140-                                                    Neuse
                                                                                Tar
                        120-                                                    Roanoke

                        100-                                                    Chowan


                        80-


                        60-


                        40


                        20-


                          0-
                             80    90   0    10    20 25 30 35 40 45 50 64 59 @4 @9 74 78 82 87
                                                   Year (1880-1987)


                        20-
                                                                                       F
                                    Chowan             Roanoke             Tar

                                    Neuse              Coastal



                     .2

                        to-



                        0-1
                             so 90     0    10    20 26 30 35 40 45 So 54 59 64 69 74 78 82 87
                                                  Year (1880-1987)









                Trends In Nutrient Production                                              39

                                             20-
                Figure 3.8. continued            M Chowan        Roanoke       Tar      G
                                                 M Nauss         Coastal
                                             16-


                                          0


                                             to-



                                          0
                                          L.
                                          CO  6-




                                              0-
                                               so 90    0 10  20 25 30 36 40 45 50 54 59 64 69 74 78 82 87
                                                              Year (1880-1987)

                                             2500-
                                                                                         H
                                                     coastal

                                            20DO -   Nauss

                                                     Tar

                                                     Roanoke
                                             1500-
                                                     Chowan
                                          0







                                              500




                                               0
                                                 so  90 0   10 20 25 30 35 40 45 50 54 59 S4 69 74 78 82 87
                                                               Year (1880-1987)



                are shown in Figure 3.7. The N "balance", about the same as that described above for
                which represents the difference between the whole AP basin; what differences there
                inputs and outputs, has increased gradually are due simply to differences in the amount
                from near zero, or less than zero, in the late of harvested cropland. There was a rapid
                1800s, to around 50 million kg N per year increase in the 1950-1970 period, with a
                by 1964, but appears to not have changed leveling off since then (Table 3.7). Excess
                greatly since then. The P "balance", on the cropland P also followed about the same
                other hand, increased most rapidly in the pattern described above forthe whole basin,
                early 1900s, reaching a peak of about 36 and the per hectare values have ranged
                million kg P in the 1950s. Since, then, the from 0.5 kg in 1880 to as high as 31.3 kg in
                P balance has declined to about 20 million 1969. In recent years the excess P has been
                kg P, or about the same amount as in the around 15 kg/ha.
                period 1910-1940.
                   The annual excess cropland N has
                ranged from -7.2 kg/ha in the late 1880 to
                as high as 54.1 kg/ha in 1974. The trend is








                    40                                                                                           Chapter 3

                                                                            of increase, so that now there are more
                    Farm AnImal Inventories and                             than ever (1.4 million) of these animals.
                    Nutrient Production                                     The increases in swine since 1959 have
                         In every census since 1880, swine have             taken place in the Tar, Neuse, and Coastal
                    been the most numerous large farm animal                sub-basins, while inventories in the
                    in the Albemarle-Pamlico basin (Figure                  Roanoke and Chowan basins have fallen
                    3.8, Appendix 3.7). Between 1880 and                    slightly. Swine production is concentrated
                    1940, the swine inventory fluctuated be-                in the central coastal plain in North Caro-
                    tween 500,000 and 850,000 head, but after               lina; thus the Tar River Basin has 23% of
                    1945 it rose steadily, and by 1959 there                all the hogs in the AP system, and 38% are
                    were over 1 million head. A decline in the              in the Neuse River basin.
                    early 1960s was followed by another period                  Cattle, on the other hand, have always
                                                                            been most numerous in the northwestern





                        80-
                                                                                                  Figure 3.9. Historical trends
                                                                                                  in annual nitrogen and
                    z                   Chowan            Roanoke= Tar
                                                                                                  phosphorus produced in
                        60 -                                                                      excreta of farm animals
                                        Neuse             Coastal
                                                                                                  (millions of kg) in each sub-
                                                                                                  basin of the Albemarle-
                        40-                                                                       Pamlico drainage area, 1880-
                                                                                                  1987.

                    W

                    ,-20-
                    z
                    2
                         0-
                            80 90       0 10 20 30 40 50 59 69 78                        87
                                                YEAR (1880-1987)

                        25-

                                      CHOWAN             ROANOKE= TAR
                    Z 20 -
                    0           E3 NEUSE                 COASTAL




                        10-
                    Uj


                         5-

                         01
                            80 90           10    20 30 40 50 59 69 78 87
                                               YEAR (1880-1987)









                           Trends In Nutrient Production                                                                                     41

                           part ofthe AP basin. Total numbers ranged                   Table 3.8. Major nutrient point sources in the
                           between 250,000 and 350,000 up until the                    Albemarle-Pamlico basin. Numbers correspond to
                           1940s, but showed no particular trend.                      ranks inFigure3.10. M =Municipal; I= Industrial.
                           Since then, there has been a general                        Number      Facility                 Type     Sub-basin
                           increase, to around 570,000 today (Figure
                           3.8). Most of the increase has been in the                        1     Raleigh, NC                  M    Neuse
                                                                                             2     Weyerhaeuser                 I    Roanoke
                           Roanoke River basin, probably in the                              3     Union Camp                   I    Chowan
                           western Piedmont and Appalachian foot-                            4     Weyerhaeuser                 I    Neuse
                           hills sections. Since 1930, the number of                         6     Roanoke, VA                  M    Roanoke
                                                                                             6     Durham, NC (Northaide)       M    Neuse
                           cattle in that basin has nearly tripled, and                      7     Rocky Mount, NC              M    Tar
                           there has been nearly a doubling in the                           8     Danville, VA                 M    Roanoke
                                                                                             9     Greenville, NC               M    Tar
                           Chowan basin. But in the more southerly                           10    Cary, NC                     M    Neuse
                           Tar, Neuse, and Coastal basins, the                               11    Wilson, NC                   M    Neuse
                           increases have been much smaller.                                 12    Goldsboro, NC                M    Neuse
                                                                                             13    Martinsville, VA             M    Roanoke
                                Numbers of mules peaked in the 1940s                         14    Kinston, NC                  M    Neuse
                           at around 180,000, but they, along with                           16    Texasgulf Chemicals          I    Tar
                           horses and sheep, have become an                                  16    Havelock, NC                 M    Neuse
                                                                                             17    New Bern, NC                 M    Neuse
                           insignificant part of the total farm animals                      18    Reidsville, NC               M    Roanoke
                           inventory in the past two decades (Figure                         19    Salem, VA                    M    Roanoke
                           3.8). Mules could not compete with tractors,                      20    Eden, NC                     M *  Roanoke
                           which rapidly began to take the place of
                           human and animal power in southern                          transportation for farm families.             Finally,
                           agriculture in the late 1940s. In just two                  sheep raising in the AP basin                 declined
                           decades, between 1950 and 1970, the mule                    rapidly during the first quarter of this
                           had practically disappeared from farms in                   century, as reflected in the inventories,
                           the AP region. Likewise, inventories of                     which went from 155,000 animals in 1880
                           horses had shown a steep decline earlier in                 to only 30,000 by 1925 (Figure 3.8).
                           the 1920s, as automobiles and trucks                              Poultry production in some areas of the
                           became the more common method of                            AP basin has increased dramatically in the




                           Figure 3.10. Rankingofpoint                600-
                           sources in the Albemarle-              cr)
                           Pamlico basin, in terms ofkgN          0   500-
                           producedper year in 1986.              z                          Nitrogen                Phosphorus
                                                                  M   400-
                                                                  0
                                                                      300-


                                                                      200-
                                                                  cc

                                                                  W
                                                                      100-


                                                                         0
                                                                              1     3        5    7     9 11 13            15 17 19
                                                                                                   1986 RANKING








                 42                                                                                   Chapter 3

                 past two decades. Growth of the poultry            today. Some Piedmont and coastal areas in
                 industry has been one of the most notable          North Carolina have become areas of in-
                 developments in southern agriculture since         tense poultry production. The industry
                 World War 11. Historically, poultry on             tends to be locally concentrated. For
                 most southern farms had been a barnyard            example, in 1987 about one half the total
                 business to provide eggs for the table and         numberof chickens in North Carolina were
                 to earn a little "egg money" for groceries         in only 6 of the State's 100 counties (N.C.
                 and other things. Chicken was not eaten            Department of Agriculture 1988). One
                 regularly but was something families ate           such area is in the central coastal plain,
                 on Sunday and on special occasions.                within the Tar and Neuse River watersheds.
                 Chickens were kept mainly for the eggs.            Thus nearly half of the total broilers and
                 But by the mid- 1940's, there had developed        chickens inventoried in the AP region in
                 "businessmen-farmer teams" for the com-            1987 were in those two sub-basins (Figure
                 mercial production of "eating chickens", or        3.8). Turkey farming is even more focused;
                 "broilers." The businessman hatched the            in 1987, 80% of the total inventory was in
                 eggs, contracted with farmers to raise the         the Neuse basin (Figure 3.8). Total AP
                 chicks on feed that he supplied from his           poultry inventories (broilers, chickens, and
                 mill to growers on credit, and finally pro-        turkeys) grewslowly from around 2 million
                 cessed and marketed the birds. Farmers             in 1880 to approximately 6 million in 1959.
                 provided the housing, labor, and manage-           Since then, however, poultry inventories
                 ment in return for an assured market (Fite         have increased at an amazing rate, so that
                 1984).                                             by 1987 there were over 37 million of these
                     This "vertical integration"of the indus-       animals in the Albemarle-Pamlico Basin.
                 try, along with increased efficiency of feed           N production from farm animals in-
                 utilization, led to lower prices (relative to      creased slowly between 1880 and 1969,
                 other meats). This, i n turn, helped increase      but has increased rapidly since 1969, so
                 consumer demand, producing a boom in               that over the past century this N source
                 broiler and egg production that continues          has almost doubled (Figure 3.9, Appendix




                    5-  ALBEMARLE-PAMLICO BASIN                                           Figure 3.11. 77rends in
                                                                                          point source loadings of
                 -C0 4 -M Industrial                                                      nitrogen     (N)      and
                 Z                                                                        phosphorus (P) fi-om point
                 0             Municipal                                                  sources in the Albemarle-
                    3-                                                                    Pamlico watershed, 1880-
                        N = NITROGEN
                        P = PHOSPHORUS                                                    1887.
                 cr 2 -

                 W





                      80 90 00 10         20 30 40 50          60 70 80       86
                      NP NP NP NP         NP NP NP NP         NP NP NP        NP
                                                YEAR
                                                                                n









                      Trends In Nutrient Production                                                                    43

                      3.8). In 1880 animal produced about 40             there is little variation in the level of treat-
                      million kg N, compared to 45 million kg in         ment (i.e., percent N and P removal) within
                      1969. But the 1987 value was almost 75             the region. However, the rate of increase
                      million kg/year. Cattle have contributed           slowed, at least temporarily, about mid-
                      40%-60% of the total animal N in most              century as secondary treatment became
                      census years, and swine have usually made          more widespread (Figure 3.11).
                      the second largest contribution (15%-25%).             In 1986 the estimated total municipal
                      In the past, horses, mules, and poultry also       N and P loading's were 3.07 million kg and
                      made significant contributions to the              1.06 million kg, respectively. About half
                      animal excreta N. But in recent yearsJust          the total N came from cities and towns in
                      three animal types - cattle, swine, and            the Neuse basin, 28% from the Roanoke
                      poultry - have been responsible for more           basin, 16% from the Tarbasin, 5% from the
                      than 95% of the total. Since 1978, the             Chowan basin, and only about 3% from the
                      percentages have been about 50% from               coastal areas (Figure 3.11). Municipal P
                      cattle, 20% from swine, and 30% from               loading was distributed among the basins
                      poultry.                                           in about the same proportions.
                          Animal excreta P amounted to about                 Although the AP basin is relatively
                      11 million kgin 1880, and was only slightly        unindustrialized, there are a few major
                      higher (12 million kg) in 1969. By 1987 the        industries that contribute large quantities
                      animal P had increased to over 21 million          of N and P; in some cases much more than
                      kg/year. The pattern has been similar to           the municipal sources. In 1986 the indus-
                      that for N, both in terms of the changes in        trial sources contributed about 1.04 million
                      production rate, and the percentages con-          kg N and 0.56 million kg P. This amounts
                      tributed by each animal type. In recent            to about one-fourth and one-third the total
                      years about 40% of the P has come from             AP basin point source N and P, respectively.
                      cattle, about 30% from swine, and about            Two types of industries - pulp and paper
                      30% from poultry.                                  mills and phosphate mining - predomi-
                                                                         nate, in terms of N and P production. Most
                      PoInt-Source Nutrient Production                   of these have come to the region since
                          The urban population, and hence the            World War II. There are pulp/paper mills
                      estimated sewered population, in the               on the lower Roanoke River, tributaries of
                      Albemarle-Pamlico, has risen rapidly in            the Chowan river, and the lower Neuse
                      recent years, and today the largest urban          River. Point source loading in the Chowan
                      centers are in the western areas of the sub-       River basin is especially dominated by the
                      basins, primarily in the Raleigh-Durham            industrial sources, which produce about
                      area in North Carolina (Neuse Riverbasin)          twice as much N and P as the municipal
                      and in the Roanoke, Virginia area (Roanoke         plants in this relatively unurbanized basin
                      Riverbasin). A high percentage ofthe total         (Figure3.11). The Tar-Pamlico River pre-
                      municipal loadingcomes from a small num-           sents an unusual situation also. There, the
                      ber of the largest cities (Figure 3.10 and         Texasgulf phosphate mine discharge
                      Table 3.8). Tracking this population in-           dominates the point source P loading. Since
                      crease, point source loading in the AP             it was built in 1964, this single source has
                      basin rose rapidly during the first half of        accounted for two-thirds to three-fourths
                      this century (Figure 3.11, Appendix 3.9),          of the total annual point source P produced
                      and the geographical distribution of the           in the Tar-Pamlico basin.
                      municipal loadinghas corresponded closely
                      to the population patterns, suggestingthat








                 44                                                                             Chapter 3


                    60-

                           A

                    50-


                 z
                 2  40-
                                                                             POINT SOURCES

                    30-                                                      URBAN RUNOFF

                                                                             FARM ANIMALS
                 W
                 >- 20-                                                      CROPLAND RUNOFF
                 1-1
                 z                                                           PASTURE RUNOFF
                 0
                 @61. 10-                                                    OTHER RUNOFF

                                                                             FOREST RUNOFF

                      0-
                        80 90 0 10 20 30 40 50 59 69 78 87
                                         YEAR



                 Figare3.12. Trends in estimated total nitrogen production, from all point and non-point sources, in the
                 Albemarle-Pamlico watershed and from each major sub-basin, 1880-1987.


                                                                   Similar assumptions were made for P,
                 Trends In Total Nuffient Productlon            with one difference; the cropland P produc-
                 by All Sources                                 tion was assumed to be one-fifth of the
                    Time series plots for trends in estimated   computed P balance.
                 total N production from all sources, both         For the whole Albemarle-Pamlico basin,
                 nonpoint and point, are given in Figure        the total annual N production from all
                 3.12. Several important assumptions have       sources is estimated to have nearly doubled
                 been made regarding these estimates:           over the past century, from around 30
                    1. The production by forests, other land    million kg in 1880 to 55 million kg in 1987.
                 (here the sum of two land use types            Between 1880 and 1959, the increase was
                 described above: "other farmland" and          only about5 million kg(18%). Then, prima-
                 "other land"), pasture, and urban lands        rily because of the rapid increase in the
                 was calculated by multiplying acreages         cropland balance in the 1960s, the total N
                 times constant yield coefficients.          I  production rose rapidly, but appears to
                    2. The cropland N production was            have remained nearly constant in the 1970s
                 assumed to be equal to one-third of the        and 1980s.
                 cropland N balance calculated above.              The percentage contributions by each
                    3. Animal N production was assumed          N source have changed greatly over the
                 to be equal to 5% ofthe animal N in excreta. past century. In 1880, the most important









                     Trends in Nutrient Production                                                            45





                         14-
                               B
                      "12 -
                      z
                      210 -
                      _j
                      _j                                                          POINT SOURCES
                          8-                                                      URBAN RUNOFF

                                                                                  FARM ANIMALS
                          6-
                      W
                                                                                  CROPLAND RUNOFF

                          4-
                                                                                  PASTURE RUNOFF
                      0
                      @e  2-                                                      OTHER RUNOFF
                                                                                  FOREST RUNOFF
                          0-
                             80 90 0 10 20 30 40 50 59 69 78 87
                                              YEAR




                     Figure 3.13. Trends in estimated phosphorus production, from all point and non-point sources, in the
                     Albemarle-Pamlico watershed, and from each mqjor sub-basin.


                     sources were forest (45%) and "other" lands    1900s, but is no greater today than in
                     (35%). Pasture and farm animals contrib-       1930, although there have been relatively
                     uted almost all the remainder (Figure 3.12).   large short-term fluctuations. The Coastal
                     Today, according to these estimates, the       basin N production also rose fairly gradu-
                     forest, other lands, and pasture N produc-     ally, from around 3 million kg in 1880 to
                     tion is about the same, in terms of kglyear,   about 5.3 million kg in 1978. In this area,
                     but new sources have diminished the            the increases from cropland have been
                     relative importance of these three. The        offset, to some extent, by decreases from
                     most important new N source is cropland        forest and "other" land. The Roanoke
                     excess N, which now makes up about 30%         basin followed a pattern similar to that for
                     of the total. Animals, urban runoff, and       the Tar and Neuse; i.e., a gradual increase
                     point sources together contribute about        up until the 1950s, followed by a rapid rise
                                                                    in
                     17% of the total.                                 N production in the 1960s. But in the
                         Two of the sub-basins, the Tar and the     Roanoke, the overall increase has not been
                     Neuse, appear to have experienced larger       as great as in the other two sub-basins. In
                     relative increases in N production than the    other words, the Roanoke N product        ion
                     Chowan, Roanoke, or Coastal sub-basins         has increased by about 50% over the past
                     (Figure 3.12). In the Chowan basin, N          century, whereas in the Tar and the Neuse
                     production rose gradually in the early         basins, the increases have been 80% and








               46                                                                              Chapter 3

               115 %respectively. Most of this difference      variable. The long-term, gradual increase
               appears to be due to much greater increases     in P production appears to be continuing,
               in cropland N balance in the Tar and Neuse      although there was less P produced in 1982
               than in the less agricultural Roanoke basin.    and 1987 than in the two previous census
                   The most notable difference between         years.
               total N production and total P production
               in theAP basin is that P production appears     DiScussion
               to have declined in recent years, particu-         Likely sources of error associated with
               larly in the Chowan and Roanoke sub-            the municipal loading estimates include
               basins (Figure 3.13). For the whole AP          the sewered population values and the
               watershed, total P production rose rapidly      treatment factors used in the calculations.
               from around 4.5 million kg in 1880 to           As noted above (see Methods) the sewered
               nearly 10 million kg by 1920. Following a       population for years before the first munic-
               decline in the 1930s, the P production rates    ipal treatment plant inventory in 1942
               began to increase again, reaching an all-       was assumed to be equal to the populations
               time high of about 12.5 million kg/year         of the cities and towns. This caused some
               around 1960. Since then, P production has       overestimation of the nutrient loading.
               fallen back to about 10 million kg/year. So,    However, this errorwouldmake little differ-
               overall the increase duringthe past century     ence in the overall loading estimates since
               has been about 110%, but during the past        the "potential" sewered population then
               quarter century there may have actually         was so small. The problem with using
               been a 20% decrease. As in the case of N        "treatment factors" is that the facilities in
               production, much of the change in P pro-        a given city often have not performed at the
               duction has been caused by changes in the       expected efficiencies, for a number of
               cropland balance. In recent years, this         reasons, includingstorm-related bypassing
               source has accounted for about 30% of the       of rawsewage in combined systems, waste-
               total P; in some years in the 1960s it was      water flows exceeding the design capacity
               as much as 60% ofthe total. The other new       of the systems, and poor maintenance of
               P sources, point and urban runoff, make up      the equipment. The latter was reported to
               about 10% and 3%, respectively, of the          be a serious problem in many cities and
               total today.                                    towns in the AP basin during the 1950s
                   There are quite large differences in the    (N.C. Stream Sanitation Committee 1959).
               trends for each of the sub-basins. In the       Thus, the actual nutrient loading would be
               Chowan and Roanoke, the decreases in            greater than I estimated if this type of
               recent years are most noticeable, particu-      error became serious.
               larly in the Chowan. There, the cropland            Nevertheless, comparison of my esti-
               P mass balance has declined by almost           mates with those made by others using
               75% since 1954, causing about a 50%             different techniques shows that, for recent
               decrease in the estimated total P produc-       times at least, the "treatment factors"
               tion. The same pattern in the Roanoke has       method gives reasonably accurate esti-
               led to about a 30% decrease. P production       mates. The data I used for comparison
               in the Tar and Neuse basins appears not to      come primarily from calculations made by
               have changed greatly in recent times,           multiplying average effluent discharges
               although there are substantial year-to-         (MGD) times average N and P concentra-
               year changes. The coastal sub-basin is the      tions in the effluent (mg/1). The products
               area in the AP watershed where the P            for all municipal plants in the basin are
               production trend has been the least             then summed to give the total expected









                          Trends In Nutrient Production                                                                                   47

                                  TableS.9. Comparison ofpointsource loadings e8timatedby two different techniques. "Flow
                                  x Con."refem to multiplication ofeffluent discharge rates WGD) times nutrientconcentrations
                                  (mg1 1). "T. Factom"refers to the use oftreatmentfactor8, usedin combination with estimates
                                  ofseweredpopulation. Numbers inparenthe8es (beside kg 1year values) refer to data sources
                                  given at bottom of table.

                                                                     Nitrogen (Ikg@)                       Phosphorus ftlyr)

                                                            "Flow x Con."         'T. Factors"     "Flow x Con."        "T. Factors"
                                  Basin/Year                   Method                Method          Method               Method

                                  Tar-Pamlico (1986-88)
                                      Municipal               545,496(l)            490,542           95,598(1)           165,046
                                      Texasgulf                71,373(l)             70,000         346,647(l)            391,000

                                  Chowan (1980)               881,000(2)            722,798         165,300(2)            136,631

                                  Neuse (1980-82)           1,510,000 (3)         1,470,626         430,000(3)            437,911

                                  'N.C. Division of Environmental Management (1989)
                                  2N.C. Division of Environmental Management (1982)
                                  'N.C. Division of Environmental Management (1983)

                          loading. The results (Table 3.9) agree                     median Neuse Riverbasin N and P effluent
                          reasonably well with my calculations. Note                 levels were 13 mg N/liter and 6 mg P/liter
                          that the 1988 Tar River values reflect a                   (data provided by NC Division of Environ-
                          reduction in P loading that resulted from a                mental Management), which is typical for
                          1987 ban ofphosphate detergents in North                   secondary treatment processes such as
                          Carolina. Thus, this value is approximately                trickling filters and activated sludge.
                          40% lower than my estimate for 1987 (before                     Before 1950 there was no significant N
                          the ban), which is about the same as the                   or P removal from wastewater discharged
                          percentage reduction attributed to the P                   into the rivers of the AP basin. Although
                          detergent ban by state officials (N.C.                     sewage collection systems had been con-
                          DNRCD 1989). 1 had to use the less direct                  structed for most of the larger cities in the
                          "treatment factors"approach because moni-                  early 1900s, as late as 1945 about two
                          toring of treatment plant effluent N and P                 thirds of the sewered population was using
                          concentrations in North Carolina and Vir-                  systems that provided no treatment (N.C.
                          ginia did not begin until about 1980; thus,                Stream Sanitation Committee 1946).
                          the "flow times concentration" method com-                 Rather, the raw sewage was simply dis-
                          monly used today could not be used for                     charged into nearby streams and rivers.
                          estimating historical loadings.                            About half of the sewage that was treated
                               Gakstatter et al. (1978) surveyed medi-               received only primary treatment, which
                          an P and N concentrations in the effluents                 removes, at best, only about 10% of the N
                          from over 800 municipal wastewater plant                   and P. Thus, N and P loading was growing
                          using various treatment processes. Their                   at about the same rate as the sewered
                          data show that conventional secondary                      population. As secondary treatment came
                          treatment removes little P and only about                  into widespread use in the 1950s and 1960s,
                          25-45% ofthe N. Tertiary treatment consid-                 the overall nutrient removal efficiencies
                          erably increases the N and P removal, but                  increased, causing a slowing in the rate of
                          this advanced treatment is not yet used in                 increase in municipal nutrient loading.
                          enough plants to make a difference in the                  But there has been little additional im-
                          overall loading. For example, in 1985 the                  provement since then because further in-








                 48                                                                                   Chapter 3

                 creases in treatment efficiencies have not         under laboratory or greenhouse conditions.
                 occurred, or have occurred more slowly to          Thomas and Gilliam (1978) concluded that
                 keep up with increases in urban population.        it is generally accepted as beingas accurate
                     The greatest source of error in the non-       as any.
                 point nutrient production estimates un-                The very large increase in the cropland
                 doubtedly comes from uncertainties in the          N balance (inputs minus outputs) between
                 areal export coefficients, rather than from        1959 and 1964 is probably somewhat
                 the acreages. Measured export coefficients         misleading, since N (and P) fertilizer sales
                 were compiled by Beaulac (1980) from               in 1964 seem to have been unusually large,
                 scores of studies and presented in tabular         especially in comparison to the relatively
                 and graphical form in Beaulac and Reckhow          small (for that time) harvest. Nevertheless,
                 (1980). They discussed factors that affect         there was apparently a rather steep
                 the coefficients for each land-use type and        increase in the "excess N"duringthe period
                 urged that for application to a particular         1954-1964. Apparently, yields were not
                 geographic area, only those coefficients           increasing as rapidly as was the rate of
                 from studies in similarareas be considered.        application of N to the croplands. Later, in
                 However, there are two potential problems          the 1970s and 1980s, the fertilization rate
                 in usingthis simple, obvious criterion. First,     seemed to level off, or perhaps decline
                 there may be no data available that seems          slightly. This appears to be the main
                 suitable for a given area, or secondly, there      reason for the stabilization in theNbalance.
                 maybe so much variability in the area to be        It is interestingto note however, that since
                 modeled that choosing a truly representa-          the early 1960s, there appears to have
                 tive coefficient value is very difficult. Unfor-   been no increase in the amount of excess N
                 tunately, most of the studies have been            on croplands. The trend in cropland P
                 made for watersheds with mixed land uses           balance in recentyears is even more surpris-
                 rather thanjust one. Nevertheless, I tried         ing, in that there seems to have been about
                 to choose coefficients as carefully as pos-        a 50% reduction in the cropland "excess" P
                 sible, considering those presented in              since 1954.
                 Beaulac and Reckhow (1980), and in other               Estimating historical trends in
                 sources (e.g., Loehr 1974).                        atmospheric N oxide concentrations is
                     Soil scientists are much more certain          difficult, because of the weak historical
                 about what factors affect rates of                 data base for precipitation chemistry.
                 denitrification than they are about the            Before 1955 there were only sporadic
                 actual rates in the field. Studies in North        measurements (apparently none in the AP
                 Carolina and elsewhere have shown that             basin) and Stansland et al. (1986) have
                 the rate is inversely related to drainage          concluded that their reliability is so
                 and directly related to the presence of soil       questionable that they should not be used
                 horizons which restrict water movement.            for trend analysis. C.E. Junge (1958)
                 Gambrell et al. (1975) measured essentially        published results of the first large scale
                 no denitrification on one moderately well          study of rain water chemistry in the U.S.,
                 drained soil and as much as 60 kg/ha on a          for the period July 1955-July 1956. His set
                 poorly drained soil; both sites were within        of 60 stations included one at Cape
                 the AP basin. The figure of 15% loss of            Hatteras, NC, where NO, concentrations
                 applied N lost by denitrification that I used      ranged generally between 0.15 and 0.30
                 is very frequently used in computations of         mg/liter. Ammonia was also measured; it
                 N balances. Apparently it originated from          fluctuated seasonally but averaged about
                 denitrification experiments conducted              0.04 mg/liter. A more thorough study was








                     Trends in Nutrient Production                                                                49
                     made in the AP basin area about ten years        burned. It is the uncertainty about changes
                     later, and the results were reported in          in the emission factors that is most prob-
                     Fisher (1968). A trend ofincreasingnitrate       lematic. Based on estimates of emission
                     northwest from the coast was found; from         factors and data on fuel consumption, Husar
                     0. 17 to 0.40 mg NO./liter (average annual)      (1986) estimated that in the southeastern
                     in the Pamlico Sound area to 1.00 mg/liter       U.S., N oxides production increased in an
                     in the western end of the Roanoke River          exponential fashion from less than 1 million
                     basin. Ammonium concentrations were              ton/year in 1900 to around 6 million tons/
                     considerably lower, averaging about 0.1          year by the mid- 1970s. Husar showed that
                     mg NH./liter over the whole AP basin.            his results were similar to those of
                     Calculated annual nitrate and ammonium           Gschwandtner et al., (1985) who also esti-
                     loadings for the AP basin were about 2           mated trends in atmospheric N oxide emis-
                     tons/square mile and 0.35 tons/square mile,      sions since 1900.
                     respectively (Fisher 1968).                          Since there are no reliable measure-
                         The most recent data are from stations       ments of AP basin atmospheric N levels
                     that was established in 1978, as a part of       before 1950, 1 was forced to make historical
                     the National Atmospheric Deposition              estimates by combining data on present-
                     Program (NADP). Data from several NADP           day concentrations from remote areas,
                     stations in the AP basin (most in the            current concentration data for the AP basin,
                     Piedmont and Central Coastal Plain areas)        and the suspected exponential rate of in-
                     indicate that between 1981 and 1985 the          crease described above. The remote areas
                     precipitation weighted mean NO,                  values are assumed to represent condi-
                     concentrations (mg/liter) averaged about         tions in the AP area in the late 1800s. The
                     0.9; whereas the NH, averaged around 0.2         values came from NADP data summarized
                     (Olsen and Watson 1984; Olsen and Slavich        by Galloway et al. (1984). They showed
                     1985, 1986; Sweeney and Olsen 1987).             that in the remote areas, the (presumably)
                    .Thus, for purposes of the loading                "background" nitrate levels are around 4
                     calculations, I assumed that total               IiM N (0.23 mg NO./liter). Assuming that
                     atmospheric N concentrations in                  the nitrate:ammonia ratio has not changed,
                     precipitation (NO, + NHS + other combined        I estimated the atmospheric precipitation
                     forms) was approximately 0.36 mg/liter           N for 1880 to have been 0.07 mg/liter (as
                     (as N) in the mid-1980s. Over eastern            N). If this estimate is close to the real 1880
                     North America the total wet and total dry        concentration, then the current (mid 1980s)
                     deposition are thought to be of approxi-         levels would represent about a 5-fold
                     mately equal magnitude (Stansland et al.         increase over the past century.
                     1986); therefore I doubled the calculated           Yet another problem concerningatmos-
                     precipitation loadingto give the total atmo-     pheric N deposition effects on nutrient
                     spheric N loads.                                 production in the AP basin has to do with
                         Another problem in estimating his tori-      the uncertainty about the percentage of
                     cal trends in atmospheric N oxides is that       the increased deposition that actually
                     they are formed primarily by the fixation of     leaves the forest, pasture, or other land.
                     atmospheric N at high temperatures of            Recently, a controversial report on the role
                     combustion rather than by oxidation of the       of acid rain in polluting coastal waters with
                     N contained in the fuels. Thus the "emission     N was prepared by the Environmental
                     factors" (i.e., the rate of N oxide emission     Defense Fund (Fisher et al. 1988). This
                     per unit of fuel N) have to be taken into        EDF report contended that one-fourth of
                     account, as well as the quantities of fuel       all N contributed by human activity to the








                 50                                                                                 Chapter 3

                 Chesapeake Bay originates in acid rain            came to a similar conclusion after compar-
                 and associated dry deposition falling             ingprecipitation nitrate loadingand stream
                 directly on the bay or onto its watershed.        nitrate transport for several areas within
                 Atmospheric N, it was concluded, exceeds          the AP basin.
                 sewage outfalls and runoffof animal waste            The relatively low values and small
                 as a N source to the bay. These results           geographical variability in forest may also
                 were based on an assumption that forests          give some indirect indication that historical
                 retain 80% of the atmospheric N, pasture          increases in atmospheric N deposition have
                 and croplands, retain 70%, and urban lands        not made such a large impact on the total
                 35%. Given that atmospheric N deposition          AP basin nutrient export as might be ex-
                 is so large in comparison to other present-       pected. Forest N yield estimates available
                 day inputs, it is no surprise that even if        in the literature are nearly all from studies
                 0%-30% (from forests and croplands) of            carried out during the past two decades;
                 the atmospheric N is assumed to leave the         i.e., recent enough to reflect effects of the
                 and, then this becomes an important               relatively high atmospheric N deposition
                 contribution to the streams and estuaries         rates that developed by the middle of this
                 - especially when it is assumed (as both          century.
                 EDF and I did) that only 5% of animal N              The N and P loading estimates made by
                 leaves the pastures and other sites of            others for the Chowan, Neuse and Tar
                 production.                                       River basins are roughly one-third to one-
                     But as the re* port noted, there is consid-   half the 1987 estimated total N and P
                 erhble variability in measures losses of          production calculated above (compare Table
                 atmospheric N from various land use cate-         1.3, Chapter 1 with Figures 3.12 and 3.13).
                 gories; in some studies in areas similar to       But those other estimates were also made
                 those drainedby the rivers in the AP basin,       using-in most cases -some combination
                 the retention of atmospheric N has been           of land use yield coefficients, instream. flow
                 found to be very high. Weller et al. (1986),      times nutrient concentration calculations,
                 for example, found that a coastal plain           and summed point source loading. It would
                 watershed in Virginia retained 97% of the         probably be futile to try to determine the
                 atmospheric N deposited on it, and in a           reasons for the differences in each case, but
                 recently-published book on forest nutrition       I suspect that the major difference has to
                 management it was stated that"withsome            do with the use oftheir instream concentra-
                 notable exceptions (such as high elevation        tion times flow calculations vs. my reliance
                 spruce/fir forests in the northeastern United     on cropland mass balances, and land use
                 States), the majority of forest ecosystems        coefficients. In general, the actual instream.
                 are N limited, so most nitrate deposited in       nutrient loads, and the loading to the
                 acid rain is retained - indeed, nitric acid       estuaries, is considerably less than the
                 may fertilize forest ecosystems" (Binkley         quantities of nutrients produced at the
                 1986, p. 208). Thus, forests appear to            sources, as was mentioned in the intro-
                 "buffer" a large part of the atmospheric N        duction to this chapter.
                 they intercept. For example, Lowrance et             Of course, there is no long-term his-
                 al. (1985) showed that for several                torical instream data for any part of the AP
                 agricultural-forested watersheds in Geor-         basin that could be used for comparison
                 gia, the N output via streamflow was always       with the nutrient production estimates
                 considerably less than the atmospheric N          presented here, but there are at least some
                 input, despite considerable additional N          recent instream data for comparison. Chris-
                 input from fertilization. Fisher (1968)           tian et al. (1987) have monitored N and P









                       Trends in Nutrient Production                                                                51

                       concentrations in the lower Neuse River         basins, has lead to greatly increased N and
                       above New Bern. They multiplied N and P         P loading in recent years. I have assumed
                       concentrations in grab samples times mean       that only 5% of the N and P produced by
                       daily river flows to give total annual in-      farm animals leaves the pastures, feedlots,
                       stream loading estimates. Their results,        and barns. However, if the loss were
                       3.5 million kg N per year and 0. 8 million kg   increased to 10% or 15%, then there would
                       P/year, are 1/4 as large as my N estimate       be a substantial impact on the total nutrient
                       and 1/3 as large as my P estimate for           production. Such an increase may not be
                       nutrient production in the Neuse Basin.         unrealistic, given that many ofthese animal
                       This difference is similar to what Craig and    operations involve the use of feed lots or
                       Kuenzler (1983) found in a similar              buildings in which hundreds (swine) to
                       comparison for the Chowan River. Their          tens-of-thousands (poultry) of animals are
                       explanation was that lowland swamp              confined in very small areas. In such cases,
                       forests along these coastal rivers represent    these become essentially point discharges,
                       a major sinks for nutrients, removing 83%       and indeed the wastes are now often treated
                       of the total N and 51% of the total P from      by aeration lagoons or other techniques
                       water draining into the lower Chowan.           similar to those employed by conventional
                       Such losses, Kuenzler (1989) noted, are         municipal treatment plants. Unfortu-
                       within the range of values derived from         nately, however, the animal waste treat-
                       detailed input-output studies of swamp          ment facilities are not nearly as strongly
                       forests within the Southeast.                   regulated as municipal point sources, but
                           It is clear from the historical trend data  North Carolina State officials are becoming
                       presented above that the rapidly increasing     increasingly wary ofthe potential problems
                       farm animal numbers, particularly swine         (North Carolina DNRCD 1986).
                       and poultry, in the Neuse and Tar-Pamlico








                      CHAPTER4
                      Pamlico River Estuary
                      Water Quality Trends

                      History of Water Quality Studies                     "In reality, nutrients are choking us.
                      in the Albema rle- Pamlico                           There's no doubt about it. That river out
                      System                                               there is dying because of its nutrient load.
                                                                           That's my opinion and many other
                         Very   little hydrographic and water              fishermen's opinion on this river. "
                      quality data have been collected for the             I                        W. Phillips (1987)
                      open waters of the Pamlico Sound. The            small boats that are often used to sample
                      North Carolina Division of Environmental         in the river estuaries.
                      Management has never included the sound              Also, there are no major permanent
                      proper in its water quality monitoring pro-      university or government research labora-
                      gram, and university researchers also have       tories on the shores of either the Albemarle
                      shied away from the sound as a site for          or Pamlico Sounds. Researchers from the
                      their studies. Before 1963, temperature          Duke University and University of North
                      and salinity were the only hydrographic          Carolina labs in the Morehead City-Beau-
                      variables that had been monitored there.         fort, NC, area seldom venture northward
                      The data were from surveys published by          into Pamlico Sound. Rather, most of the
                      Winslow (1889), Grave (1904), Coker              research on water quality in the Pamlico
                      (1907), and Roelofs and Bumpus (1953).           and Albemarle Sound region has been car-
                      Woods (1967) collected temperature, salin-       ried out by scientists from three State
                      ity, dissolved oxygen, chlorophyll a, and        university campuses farther inland: North
                      total phosphorus data from June 1963 to          Carolina State University in Raleigh, the
                      October 1966. His stations were located in       University of North Carolina at Chapel
                      southwestern Pamlico Sound and in the            Hill, and East Carolina University at
                      lower Tar-Pamlico and Neuse River estu-          Greenville.
                      aries, and they were sampled monthly.                Since the early 1960s, researchers from
                      Apparently, these are the only Do and            these institutions have, for the most part,
                      nutrient data ever collected in the Sound.       focused their attention in three areas:
                      Data for the open waters of Albemarle            1) the Pamlico River Estuary, 2) theNeuse
                      Sound are also sparse, except for a two-         River Estuary, and 3) western Albemarle
                      year period of intensive sampling during         Sound (Chowan River and the lower
                      the early 1970s (Bowden and Hobbie 1977).        Roanoke River). These are also the sites
                         Probably the most important reason            where the North Carolina state agencies,
                      for this lack of attention to the sounds is the  principally the Division of Environmental
                      perception that the most serious water           Management and the Division of Marine
                      quality problems are confined to the tribu-      Fisheries, have made most of their studies.
                      tary river estuaries along their western             The Pamlico River is one of the few
                      shores. Another factor is that the sounds        areas in the Albemarle-Pamlico system for
                      are too shallow for even small oceanographic     which there is enough water quality data
                      research vessels, and too large for the          to permit a time series analysis of trends.








                 54                                                                               Chapter 4

                 It is, in fact, one of the most thoroughly       for most other estuaries in the region.
                 monitored estuaries in the Southeast             Routine monitoring of nutrients began in
                 region. Since the mid-1960s, there have          1967 and was continued through 1973.
                 been numerous ecological research and            Various hydrographic variables (salinity,
                 monitoring projects, funded by both the          dissolved oxygen, temperature, pH, and
                 phosphate mining industry (Texasgulf, Inc.       chlorophyll a) were also measured. Since
                 and North Carolina Phosphate Corpora-            1975, the sampling for N and P nutrients
                 tion) and government agencies (principally       and related hydrography has continued
                 the University of North Carolina Water           uninterrupted, thanks to a co-operative
                 Resources Research Institute and the UNC         agreement between Texasgulf, Inc. and
                 Sea Grant College Program).                      the Institute for Coastal and Marine Re-
                     Research topics have included basic          sources at East Carolina University. In
                 hydrography and water-column nutrient            addition to these monitoring efforts, two
                 dynamics (Hobbie 1970a, 1970b, 1974;             Pamlico research projects (Davis et al.
                 Hobbie et al. 1972; Copeland and Hobbie          1978; Kuenzler et al. 1979) collected signif-
                 1972; Harrison and Hobbie 1974; Hobbie           icant amounts of nutrient and hydrography
                 et al. 1975; Lauria and O'Melia 1980;            data between 1975 and 1977. Despite the
                 Kuenzler et al. 1979; Stanley 1984b, 1986a,      accumulation of a large quantity of data, it
                 1986b, 1987, 1988a, 1989), sediment bio-         has never been analyzed in the kind of
                 geochemistry and benthic nutrient cycling        thorough, systematic fashion that would
                 (Matson et al. 1983; Kuenzler et al. 1984),      be needed to address some of the growing
                 organic carbon and deoxygenation (Sick           environmental issues for the estuary.
                 1967; Davis et al. 1978), bacteria hetero-
                 trophy (Crawford et al. 1974), phyto-            Methods
                 plankton ecology (Sherk 1969, Hobbie 197 1;      Data Sources
                 Carpenter 1971a, 1971b; Stanley 1983,               The nutrient and hydrographic data
                 1984a; Stanley and Daniel 1985a, 1985b,          used in this study were produced by two
                 1986), submerged macrophytes (Davis and          long-term monitoring studies and two
                 Brinson 1976, 1989), distribution and bio-       shorter-term research projects. The first
                 mass of ctenophores (Miller 1974), zoo-          monitoring study ran from 1967 to 1973
                 plankton abundance (Peters 1968), meio-          and was led by John Hobbie of North
                 benthos (Reid 1970, 1978), macrobenthos          Carolina State University. It was supported
                 (Tenore 1968, 1970, 1972), fish (Miller and      by funds from two sources: 1) the Office of
                 Dunn 1980; Currin et al. 1984); and fish         Water Resources Research, U.S. Depart-
                 disease (Noga et al. 1989). Much of this         ment ofthe Interior, through the University
                 work has been summarized in an estuarine         of North Carolina Water Resources Re-
                 profile prepared for the U.S. Fish and           search Institute, and 2) Texas Gulf Sulfur
                 Wildlife Service by Copeland et al. (19,84).     Company (nowTexasgulf, Inc.). The initial
                 In addition, several studies of the tribu-       objective was to study the effects of phos-
                 taries of SouthCreekwere presentedinthe          phorus from the phosphate mining opera-
                 Journal of the Elisha Mitchell Scientific        tion (Copeland and Hobbie 1972). Later
                 Society (Volume 10 1, No. 2, 1985).              the scope of the project was broadened to
                     Nitrogen and phosphorus dynamics             include nitrogen.
                 have continued to receive a great deal of           After the NC State University sampling
                 attention by Pamlico investigators since         ended, there was an 18-month lapse until
                 the late 1960s. Consequently, there is           East Carolina University began a new
                 much more nutrient data for the river than       program in January 1975. This study was








                     Pamlico River Estuary Water Quality Trends                                                   55
                     made possible by funds provided by Texas-        phosphorus measurements were substi-
                     gulfto the University's Institute forCoastal     tuted for the total N and P analyses, but
                     and Marine Resources (ICMR). This pro-           the totals can still be computed by summa-
                     gram has run continuously since 1975.            tion of the dissolved and particulate
                         In addition to these two long-term moni-     fractions.
                     toring programs, there were two research            Texasgulf has maintained weather in-
                     projects in the mid-1970s which produced         struments at their plant on the south shore
                     significant amounts of nutrient and hydro-       of the Pamlico River since before 1969. The
                     graphic data. One was an investigation of        company provided data on wind (total miles
                     nitrogen and phosphorus cycling in the           per day), precipitation, and air temperature
                     estuary that was headed by Ed Kuenzler of        for the trend analyses. The U.S. Geological
                     the University ofNorth Carolina at Chapel        Survey maintains a flow gauging station
                     Hill. The other research project, under the      on the Tar River near Tarboro, NC. Their
                     direction of Graham Davis and Mark Brin-         data (daily average cfs) are published each
                     son from the Biology Department at East          year in the "Water Resources Data" series
                     Carolina University, dealt primarily with        (e.g., USGS 1987).
                     organic carbon and deoxygenation in the             I have also compiled information on
                     Pamlico River. Both of these projects were       station locations and identification num-
                     funded by the UNC Water Resources                bers used by the four studies (Appendix
                     Research Institute.                              4.2). The exact locations of the ICMR
                         Nutrient and hydrographic data from          stations (1975-1986) are known. However,
                     these studies are contained in 18 project        I had to estimate the latitude and longitude
                     completion reports and technical reports         for each of the stations used in the three
                     (Appendix 4.1). Rather than cite each of         other studies, because the reports show
                     these, I will often refer to the four projects   them on maps, but give no precise locations.
                     as: 1) "Hobbie," 2) 91CMR," 3) "Davis et         Notice that in some cases, stations from
                     al.," and 4) "Kuenzler et al    ... ..  Hobbie"  different projects were located at the same
                     refers to all the data collected between         position. For example, stations 22 and 1
                     1967 and 1973, and "ICMW' to the East            used by Davis et al. were at the same
                     Carolina University monitoring program           position as ICMR station 11 sampled be-
                     (1975-1990).                                     tween January and June 1975, and ICMR
                        In 1967, only surface water tempera-          station 12 sampled since July 1975.
                     ture, salinity and phosphorus concentra-
                     tions were monitored. Bottom water tem-          Changes in Analytical Methods
                     perature and salinity were added in mid-            A potentially serious problem in a study
                     1968, and surface and bottom water oxygen        of this kind is that samplingand analytical
                     in late 1968. Then in mid-1969, Hobbie           methodologies may have varied so much
                     expanded the program again to include            over the years that comparison of the data
                     surface water pH, and two surface nitrogen       is impossible. Therefore, I have reviewed
                     fractions (ammonia and nitrate). Finally,        and compiled notes on the methods used by
                     in 1970, surface water total nitrogen, total     the four projects. These notes are in Appen-
                     dissolved nitrogen and chlorophyll a were        dix 4.3 and are summarized in Table 4.1.
                     added to the suite of parameters analyzed.
                     Fortunately, all these parameters except         Trend Analysis Techniques
                     two have continued to be measured up                It soon became apparent that the time
                     until the present. In 1985 surface water         series analyses would be impossible unless
                     particulate nitrogen and particulate             I grouped the stations, because in the early








                      56                                                                                                       Chapter 4

                      Table 4.1. Methods used for Pamlico nutrient and hydrographic measurement8.
                      Parameter                   Study              Instrument or Method                                          Reference

                      1. Water temperature        Hobbie             Thermistor                                                               A
                                                  Kuenzler           Thermistor                                                               A
                                                  Davis              Thermistor                                                               B
                                                  ICMR               Thermistor                                                               B

                      2. Salinity                 Hobbie             Induction salinometer                                                    A
                                                  Kuenzler           Induction salinometer                                                    A
                                                  Davis              Conductivity probe                                                       B
                                                  ICMR               Conductivity probe                                                       B
                      3. Dissolved oxygen         Hobbie             Winkler titration                                                        C
                                                  Kuenzler           Winkler titration                                                        D
                                                  Davis              Oxygen electrode                                                         E
                                                  ICMR               Oxygen electrode                                                         E
                      4. pH                       Hobbie             Electrode                                                                F
                                                  Kuenzler           Electrode                                                                F
                                                  Davis              Electrode                                                                G
                                                  ICMR               Electrode                                                                H
                      6. Total phosphorus         Hobbie             Persulfate digestion/mixed color reagent                                 1,J,K
                                                  Kuenzler           Persulfate digestion/automated mixed color reagent                       L
                                                  Davis              Persulfate digestion/mixed color reagent                                 M
                                                  ICMR               Persulfate digestion/mixed color reagent (automated in 1985)            L,M,N

                      6. Total dissolved          Hobbie             Persulfate digestion/mixed color reagent                                 IK
                        phosphorus                Kuenzler           Persulfate digestion/automated mixed colore reagent                      L
                                                  Davis              Persulfate digestion/mixed color reagent                                 M
                                                  ICMR               Persulfate digestion/mixed color reagent (automated in 1985)             N
                      7. Orthophosphate,          Hobbie             Mixed color reagent                                                      I,K
                        phosphorus                Kuenzler           Mixed color reagent (automated)                                          L
                                                  Davis              Mixed color reagent                                                      M
                                                  ICMR               Mixed color reagent (automated in 1985)                                  N
                      8. Ammonia nitrogen         Hobbie             Alkaline hypochlorite/nitrite diazotization                              O,K
                                                  Kuenzler           Indophenol.                                                              L
                                                  Davis              Indophenol                                                              P,Q
                                                  ICMR (1975-79)     Ion selective electrode                                                  R
                                                         (1980-86)   Indophenol.                                                              P
                      9. Nitrate nitrogen         Hobbie             Cadmium reduction/nitrite diazotization                                  S,K
                                                  Kuenzler           Cadmium reduction (automated/nitmte diazotization                       L
                                                  Davis              UV spectrophotometric                                                    T
                                                  ICMR (1975)        Brucine                                                                  T
                                                         (1975-86)   Cadmium reduction/nitrite diazotization. (automated 1985)                U

                      10. Total dissolved         Hobbie             UV oxidation/nitrite diazotization                                       V,K
                         nitrogen                 Kuenzler           Keldahl (automated)                                                     L
                                                  Davis              Keldahl                                                                 M
                                                  ICMR (1975-79)     Keldahl/ammonia electrode                                               L
                                                         (1980-86)   Kjeldahl/indophenol                                                     L,P
                                                         (1985-86)   Persulfate digestionfindophenol                                          N
                      11. Total nitrogen          Hobbie             UV oxidation/nitrite diazotization                                       V,K
                                                  Davis              Keldahl                                                                M
                                                  ICMR (1975-79)     Keldahl/ammonia electrode                                               L
                                                         (1980-85)   Keldahl/indophenol                                                      L,P
                                                         (1985-86)   Persulfate digestion/indophenol                                         N
 







                         Pamlico River Estuary Water Quality Trends                                                                        57

                         Table 4.1. continued


                         Parameter                 Study            Instrument or Method                                         Reference

                         12. Particulate N and P   ICMR (1986-86)   Persulfate digestion/indophenol                                    N

                         13. Chlorophyll a         Hobbie           Acetone extraction/spectrophotometric                             FU
                                                   KuenzIer         Acetone extraction/spectrophotometric                              w
                                                   Davis            Acetone extraction/spectrophotometric                              U
                                                   ICMR             Acetone extraction/spectrophotometric                              U

                         14. Phytoplankton         Hobbie           Utermohl concentration/light microscopy                            X
                                                   ICMR             Membrane filtration ooncentration/light microscopy                 D

                         A. Beckman induction Salinometer Model RS5-3 meter and probe
                         B. Yellow Springs Instrument Co. Model 33 S-C-T meter and probe
                         C. Carpenter (1965)
                         D. American Public Health Association (1976)
                         E. Yellow Springs Instrument Co. Model 61A meter and probe
                         F. Unknown
                         G. Coming Model 10
                         H. Various instruments used
                         1. Menzel and Corwin (1965)
                         J. Murphy and Riley (1962)
                         K. Strickland and Parsons (1968)
                         L. U.S. Environmental Protection Agency (1974)
                         M. U.S. Environmental Protection Agency (1976)
                         N. U.S. Environmental Protection Agency (1979)
                         0. Richards and lGetch (1961)
                         P. Solorzano (1969)
                         Q. Scheiner (1976)
                         R. Orion Model ?
                         S. Morris and Riley (1963)
                         T. American Public Health Association (1971)
                         U. Strickland and Parsons (1972)
                         V. Armstrong et al. (1966)
                         W. Lorenzen (1967)
                         X. Utermohl (1958)


                         years many of them were sampled for                         Results and Discussion
                         relatively short periods. Also there have                        It is very important that the reader
                         been only a few locations sampled during                    keep in mind the purpose and limitations
                         all of the 20-year study period. Therefore,                 of trend analysis. First, one wishes to
                         I partitioned the river into ten segments,                  know whether or not there has been a
                         A-J, with boundaries as shown in Figure                     statistically significant change in the
                         4. 1. Appendix 4.2 indicates which sampling                 parameter under examination. This is the
                         stations fall into each of the segments.                    one question which is directly addressed by
                             The Seasonal Kendall-Tau test indi-                     the Seasonal Kendall test. If a trend is
                         cated there were no long-term trends in                     determined to be significant, the next ques-
                         flow, salinity, delta Sigma-t, or DO in the                 tion is: "How large is the changeT'Remem-
                         Pamlico between 1975 and 1989. For each                     ber that "significant change," as used in a
                         of the four stations, none of the test results              statistical context, does not necessarily
                         were significant at the 90% level (a<0.1)                   mean large. The Kendall slope gives an
                                                                                     estimate of the average rate of change over
                                                                                     the whole test period. But even though the
                                                                                     slope estimate might be large, it is meaning-
                                                                                     less unless the trend is determined to be








                  58                                                                                 Chapter 4
                  statistically significant. Ontheotherhand,        there is a functional relationship between
                  some statistically significant trends might       the variables. As long as one remembers
                  have very small slopes.                           that the statistical results cannot prove or
                      Also, keep in mind that the Kendall           disprove the connection, there is nothing
                  test measures monotonic changes over the          wrongwith consideringthem to be evidence
                  whole test period; it cannot detect short-        of a possible relationship.
                  term ups and downs during that period.
                  Therefore, the outcome ofthe test naturally       Climatic Factors and River Flow
                  will be influenced somewhat by the time              Three climatic variables (air tempera-
                  interval chosen. Even in instances where          ture, wind, precipitation) and river flow
                  there are no reversals in the trend, the rate     were included in the Pamlico trend analysis
                  of increase or decrease might vary, but the       because changes in these variables, espe-
                  slope estimator will give no information          cially river flow, might help explain trends
                  about these rate changes.                         in some of the other variables of more
                      Obviously, the trend analysis results         direct concern. However, as will be shown
                  cannot explain the causes for significant         below, only one of these four factors has
                  trends in the variables. Nevertheless, it is      changed significantly over the past twenty
                  tempting to assume a cause and effect             years.
                  relationship between two parameters when             Air temperatures at the Texasgulfplant
                  the trend in one could logically explain a        on the south side of the river are usually
                  trend in the other. This is a dangerous trap      lowest in January, averaging around 42'F
                  which one must constantly be aware of             (5.5'Q, while July temperatures average
                  during the course of a study like this. On        higher than any other month, around 80'F
                  the other hand, it is certainly possible that



                                                                                                7111-30-



                                                           KILOMETERS

                                                     0     5     10    is


                                       WASHINGTON



                                             J6
                                       A
                           35*30'



                                                     C
                                                                                   o.
                                                             D                   Y.
                                                                       E           !te
                                                                 T6              F
                                                                                        G






                  Figure 4.1. Map showing division of the Pamlico River estuary into ten segments used in the trend
                  analyses.








                           Pamlico River Estuary Water Quality Trends                                                                            59

                                                     Table 4.2. Seasonal Kendall Test results for air temperature,
                                                     wind, precipitation and Tar River flow.

                                                                                                          Time Interval


                                                     Parameter                                      1967-1986       1975-1986

                                                     Monthly Mean Air Temperature          z           0.307           1.821
                                                                                           Slope       0.017           0.129
                                                                                           P           0.719           0.069*


                                                     Total Wind Miles                      z           0.831           1.128
                                                                                           Slope       0.192           0.409
                                                                                           P           0.407           0.358

                                                     Total Monthly Precipitation           z           0.447
                                                                                           Slope       0.000
                                                                                           P           0.653


                                                     Monthly Mean Tar River Flow           z           0.253
                                                                                           Slope       1.750
                                                                                           P           0.803

                                                     P<0.1     (Significant)
                                                     P<0.01      (Highly Significant)


                           (26.60C) (Figure 4.2). Over the past 20
                           years, the variation in the monthly means
                           has been greater in the winter (up to 12"F                            90
                           above normal for January) than in the                                 80   A
                           summer. This difference is also clearly                       Z E. 70
                           shown in Figure 4.2, which shows that                         6 -@
                                                                                             a.  60
                                                                                             m
                           there has been little variability in the                          w   50
                           summers, while the winters were relatively                    7( @    40
                           warm in the 1971-1975 period, very cold in                            301                                                1
                           1976 and 1977, and have tended to be                                  1965      1970      1975     1980      1985      1990
                           warmer each year since the late 1970s.                                                        YEAR
                                Despite these fluctuations in the winter                   ir    90    B
                           and summer maxima temperatures, the                             ;-(   80
                           Seasonal Kendall test results were that                         Z C 70
                                                                                           6-
                                                                                                 Q: 60
                           there was no statistically significant trend                    22
                           in the mean monthly air temperature be-                               50    M
                           tween 1967 and 1986 (Table 4.2). However,                             40           IN.
                                                                                                 30
                           since 1975, there has been a significant (p                                 J F    M A M J J A S 0 N D
                           = .069) upward trend, averaging 0.13'F                                                        MONTH
                           per year.                                                     Figure 4.2. Daily mean air temperature (7),
                                For any given month there can be great                   averaged by month, at the Texasgulf Chemicals Co.
                           year-to-year variability in the average daily                 plant on the south shore of the Pamlico River
                           wind (Figure 4.3) but the overall pattern is                  estuary. (A) monthly averages, January 1969-
                           that average velocities are highest in late                   December 1986. (B) maximum, minimum and
                           winter and lowest in late summer. The                         median of averages for each month.
                           difference between the March and August
                           wind velocities averages around 30 percent








                    60                                                                                      Chapter 4

                    (115 total miles vs. 78 total miles per day).       evapotranspiration that occurs during the
                    Again, however, the interannual variability         summer. Daily mean flows at Tarboro,
                    is great, so that some summer months                averaged by month, normally vary from
                    have had higher winds than the average              about 800 cfs in September to around 4000
                    for the winter months. Overall, there was           efs in March (Figure 4.5b). Changes i      'n flow
                    no trend toward increasing or decreasing            can be very sudden and of great magnitude
                    winds during the 1967-1986 period (Table            (Figure 4.5a).
                    4.2).                                                    There have been some short-term
                         Monthly precipitation at the Texasgulf         trends in Tar River flow, but no overall,
                    plant has ranged from less than 0.5 inches          long-term change since 1967. Figure 4.5a
                    to over 17 inches during the study period           shows, for example, that between 1984
                    (Figure 4.4), but normally it peaks at around       and 1986, there was a decrease in the late
                    6 inches in July and is lowest in November,         winter and early spring flows. A decline in
                    about 2.5 inches. The Seasonal Kendall              winter flows also occurred between 1979
                    test showed no significant trend in the             and 1981. Overall, 1981 was the lowest
                    monthly precipitation totals between 1967           flow year in the study period. Other low
                    and 1986 (Table 4.2).                               flow years were 1967, 1974, and 1986.
                         Even though precipitation onto the             However, the Seasonal Kendall test for the
                    watershed is highest in the summer, Tar             two decades between 1967 and 1986 gave
                    River flow is usually highest in the late           no significant upward or downward trend
                    winter months, a pattern that is typical for        in the mean monthly flow (Table 4.2).
                    eastern North Carolina (Giese et al. 1979)
                    and the region (Nixon 1983). This seasonal                  2
                    pattern is caused by the increased                     >, 6     A
                                                                           @ 1': 15
                                                                           z 0
                      a  150                                               0    10
                      W                   VIM.                     A
                                                                           _j
                         120    ME j I
                                                                             W   5
                                                                             cc
                          go    MIN.                                         IL  0
                                                                                 1969      1974     1979      1984      1989
                          60
                      Z                                                                             YEAR
                          30
                              J F M A M J J A S 0 N D
                                              MONTH                          20

                         160
                      W                                           B          15
                         120
                      _j                                                   < 10
                      @<- 80                                               z        AX               MEAN
                      0
                      t__                                                      5
                          40
                      Z
                                                                               0.
                            0
                            1965   1970    1975   1980    1985    1990            J F M A M J J           A S 0 N D

                                              YEAR
                    Figure 4.3. Wind (total milesper day), averaged by  Figure4.4. Total monthlyprecipitation (inches) at
                    month, at the Texasgulf Chemicals Co. plant on the  the Texa8gulf Chemicals Co. plant on the south
                    south shore of the Pamlico River estuary. (A)       shore of the Pamlico River estuary. (A) Monthly
                    Monthly averages, January 1969-December 1986.       totals, January 1969-December 1986. (B) Maximum,
                    (B) Maximum, minimum, and median of monthly         minimum, and median of totals for each month.
                    averages.









                         Pamlico River Estuary Wafer Quality Trends                                                                    61
                         Water Temperature, SalInIty and pH                             10000                                     A
                             Water temperature is the most predict-                         8000
                                                                                        
                         able of all the parameters that have been                      6000
                                                                                        
                         monitored in the Pamlico studies. Surface                      4000
                         temperatures in the estuary typically range                          2000
                         from around 4C to about 3C over the                        
                                                                                             
                         course of the year (Figure 4.6). The lowest                           1965 1970 1975 1980 1985 1990
                         temperatures occur in January in most
                         years, and the peak temperatures come in                                                   YEAR
                         JulyandAugust. On some samplingdates,                          12000
                                                                                                                                        B
                         there is as much as 5C variation in temper-                    10000
                         atures, but much ofthis difference probably                     8000
                         results from the samples being taken at                         6000
                         different times of the day. It takes 4-6                                 MEAN
                                                                                        4000
                         hours to visit all the stations in the estuary.             
                         Bottom water temperatures exhibit the                          2000
                         same seasonal pattern and range as the                              0  J   F M A M J J A S 0 N D
                         surface temperatures. Occasionally there                                                MONTH
                         is strongthermal stratification in the water
                         column, but this is rare. Normally the                  Figure 4.5.      Daily mean flow cfs), averaged by
                         difference between surface and bottom tem-                month, of the Tar River at Tarboro, NC. (A)
                                                                                   Monthly averages, January 1967-December 1986.
                         peratures is less than 2C (e.g., Stanley                 (B) Maximum, minimum, and median of averages
                         1988a). The Seasonal Kendall test indi-                   for each month.
                         cated no significant trend in surface water
                         temperature (Table 4.3) for the three river
                         segments examined. Likewise, no trends
                         were found in the bottom water tempera-
                         ture data (Table 4.3).





                         Figure 4.6. Surface water                   12
                         temperature (C)in  thePamlico              11
                                                                                                                                                                                        10
                         River estuary during 1984, as a               9
                         function of time (x-axis) and                  8
                         distance (-axis). Top of plot is       T       
                                                                        
                         station 12 upriver (see Methods        A    7N
                         for explanation of distance            T    TS
                                                                I    6
                         scale).
                                                                0     5
                                                                N    4
											   3
												2
											1A
											1
											J   F    M  A   M   J   J   A  S   O   N   D
                                                                     SURFACE TEMPERATURE (O)
                                                                           S-12   12-18   18-24 24-38  30    
                                                                                                   




























































                                                                          







                     62                                                                                        Chapter 4

                     Table 4.3. Seasonal Kendall Test results. Segment B = Upriver, Segment E = Midriver, Segment H
                     Downriver. P<0.1      (Signiftcant); P<0.01      (Highly Significant).

                                                                           River Segments and Time Intervals

                                                                        1967-1986                       1975-1986


                     Parameter                                     B        E         H           B         E         H


                     Surface Dissolved Oxygen         z          3.745     3.292     4.301      1.172     3.089     2.268
                                                      Slope      0.060     0.050     0.080      0.030     0.090     0.090
                                                      P          0.002     0.002    <0.002      0.242    <0.002     0.023



                     Bottom Dissolved Oxygen          z          -1.560    1.310    -1.830     -0.930    -0.880     -0.180
                                                      Slope      0.040     0.030    -0.060     -0.040    -0.040     -0.020
                                                      P          0.120     0.190     0.067      0.352     0.384     0.857


                     Bottom Dissolved Oxygen          z          -1.624    1.593    -2.217     -1.696    -0.376     -0.721
                     % Saturation                     Slope      -0.406    0.400    -0.523     -1.100    -0.130     -0.446
                                                      P          0.103     0.112     0.027      0.091     0.704     0.472



                     Surface Salinity                 z          2.220     0.600    -1.530      0.690     0.930     -1.070
                                                      Slope      0.050     0.030    -0.100      0.030     0.090     -0.130
                                                      P          0.026     0.555     0.124      0.490     0.352     0.285



                     Bottom Salinity                  z          1.930    -1.090    -2.830     -1.280     0.930     -0.100
                                                      Slope      0.070    -0.060    -0.130      0.110     0.090     -0.010
                                                      P          0.054     0.276     0.005      0.201     0.352     0.920



                     Surface Temperature              z          -0.240   -0.100    -0.430      0.420     0.890     0.870
                                                      Slope      -0.025   -0.019    -0.060      0.144     0.231     0.317
                                                      P          0.810     0.920     0.667      0.674     0.373     0.384


                     Bottom Temperature               z          0.103     0.270     1.456      0.409     1.067     0.830
                                                      Slope      0.003     0.006     0.046      0.022     0.033     0.050
                                                      P          0.912     0.787     0.147      0.682     0.285     0.412


                     pH                               z          -0.716   -3.543    -3.752      0.397     2.158     0.070
                                                      Slope      -0.006   -0.039    -0.037      0.012     0.042     0.021
                                                      P          0.478    <0.002    <0.002      0.697     0.032     0.484



                     Orthophosphate P                 z          1.390     2.070     2.880      1.489    -1.136     3.141
                                                      Slope      0.025     0.080     0.040      0.051    -0.077     0.086
                                                      P          0.165     0.040     0.004      0.136     0.254     0.003



                     Total Phosphorus                 z          4.453     4.699     5.547      1.546     0.085     4.882
                                                      Slope      0.149     0.234     0.146      0.142     0.013     0.255
                                                      P          <0.002   <0.002 <0.002         0.124     0.940     <0.002








                      Pamlico River Estuary Water Quality Trends                                                         63

                      Table 4.3. continued


                                                                           River Segments and Time Intervals

                                                                        1967-1986                      1975-1986

                      Parameter                                    B        E         H           B        E         H

                      Total Dissolved P               z          5.723     4.644    5.156       2.487    0.327      2.917
                                                      Slope      0.115     0.222    0.112       0.198    0.061      0.213
                                                      P          <0.002    <0.002   <0.002      0.013    0.741      0.004


                      Ammonia Nitrogen                z          -5.512    -5.357   -6.131      -1.642   -1.073     -2.003
                                                      Slope      -0.303    -0.250   -0.228      -0.179   -0.100     -0.233
                                                      P          <0.002    <0.002   <0.002      0.101    0.285      0.046

                      Nitrate Nitrogen                z          -2.813    1.327    3.010       0.062    0.838      -0.333
                                                      Slope      -0.280    -0.019   0.026       0.005    0.015      -0.017
                                                      P          0.005     0.187    0.003       0.522    0.407      0.741


                      Total Nitrogen                  z          4.721     4.536    2.871       2.618    2.923      0.238
                                                      Slope      1.547     1.356    0.845       1.664    1.807      0.150
                                                      P          <0.002    <0.002   0.004       0.009    0.004      0.818


                      Total Dissolved N               z          1.169     1.467    0.183       1.385    1.488      -1.059
                                                      Slope      0.260     0.292    0.040       0.450    0.619      -0.709
                                                      P          0.242     0.142    0.857       0.168    0.136      0.289

                      Chlorophyll A                   z          2.648     -1.398   -1.293      3.218    2.937      -0.034
                                                      Slope      0.294     -0.156   -0.140      0.635    0.451      -0.004
                                                      P          0.008     0.165    0.197      <0.002    0.003      0.976


                         Seasonal salinity patterns in the                    There are also interannual variations
                      Pamlico are affected mainly by variation in          in salinity which become obvious only when
                      freshwater runoff (Copeland and Hobbie               data from a number of years are compared
                      1972; Stanley 1986). Typically, salinity is          (Figure 4.8). For example, 1967-1970,
                      lowest during the late winter and early              1976-1977,1981,1985 and 1986 were rela-
                      spring when freshwater inflow is highest             tively high salinityyears, while 1978-1979
                      (Figure 4.7). The salinity increases to              and 1983-1984 were low salinity years. In
                      maximum values during the summer and                 some periods, the salinity graduallytrended
                      fall, coincident with lowest river flow. In          downward (1968-1971) or upward (1983-
                      some years this seasonal pattern may be              1986), but in other instances, the change
                      upset by unusually high or low freshwater            was more abrupt. For example, between
                      inflow associated with hurricanes orperiods          the 1979-1980 winter and the 1980-1981
                      of drought. Examples of such events are              winter, the mean salinity appears to have
                      given in descriptions ofdata from individual         increased about 8 ppt.
                      years by Hobbie (1974) and Stanley (1986a,              The Seasonal Kendall test indicated
                      1986b, 1987).                                        that surface salinity has increased upriver
                                                                           in segment B since 1967. The trend was








                   64                                                                            Chapter 4
                   statistically significant (p = 0.026) with a  trend in river flow which would be expected
                   slope of 0.05 ppt per year, or 0.9 ppt during if the upriver salinity is trending upward.
                   the 18-year sampling period. In the down-     On the other hand, trends in pH and nitrate
                   river segment, H, the trend was downward      nitrogen described belowcould be explained
                   but the significance level (p = .124) was not by these salinity trends. In short, no
                   quite low enough to be classified as statis-  definitive conclusions can be drawn from
                   tically significant. Salinity has not changed these data regardinga salinity trend in the
                   in the middle segment (Table 4.3).            river since 1968.
                       Bottom water salinity upriver in seg-         The Pamlico report prepared by North
                   ment B has also trended upward slightly       Carolina DNRCD (1987a) cited an analysis
                   during the past two decades. The change       by Sholar (1980), and included a time-
                   detected by the Kendall test was statis-      series salinity plot from his report, which
                   tically significant (p = 0.054) at a rate of  showed a decrease in the mean annual
                   0.07 ppt per year, or about 1.25 ppt during   salinity for the"Painlico Sound area" (sta-
                   the sampling period. Farther downriver,       tions not given) over the period 1948-1980.
                   no significant trend was detected in seg-     Comparison of Sholar's trend plot with the
                   ment E (mid-river), but a highly significant  "Mean of All Stations" plot in Figure 4.8
                   (p = 0.005) downward trend was detected       suggests to me that if Sholar's analyses
                   in segment H nearthe mouth ofthe estuary.     were extended to include the highersalinity
                   The rate ofdecrease was -0. 13 ppt per year,  years following 1980, it is likely that no
                   which amounts to 2.3 ppt, or about 15%,       overall (1948-1986) trend would be seen.
                   during the 18 year sampling interval.             The pH in estuaries is influenced by the
                       It is difficult to explain the salinity   mixing of seawater and freshwater and by
                   trend results, or to see a pattern in them.   the rates of microbial (algal and bacterial)
                   The fact that there were significant trends   respiration and algal photosynthesis in
                   for the 1968-1986 period, but none for the    the water. Freshwater typically has pH's
                   1975-1986 period, suggests that most of       lower than seawater, and the situation can
                   the change occurred between 1968 and          be complicated in estuaries like the Pamlico
                   1975. The trend upriver was positive, but     bythe inflowofwater flushed from swamps
                   downriver it was negative, and I can think    that is often quite acid (low pH) (Hobbie et
                   of no explanation for this contradiction.     al. 1972). When algal photosynthesis is
                   Also, there was no significant downward       high, the pH is also high because the algae


                       12                                                          Figure 4.7. Surface salinity
                                                                                   (ppt) in the Pamlico River
                       10
                                                                       77          estuary during 1984, as a
                                                                                   function of time (x-axis) and
                   T                                                                         -axis). Top ofplot is
                       7                                                           distance (y
                   A   7W        M MatmMAWMEWTIM                WIM
                   T   is        MARMIMEMNEUMM                  N1031hi            station 12 upriver (see Methods
                   1   6             0"MMIMM3008                UMM"               for explanation of distance
                   0   5                                                           scale).
                   N   4
                                      ARM
                                        MINH


                          i    F  M    A   M   J    J   A    S   0 N D
                                     SURFACE    SALINrrY (ppt)


                            4        2-4     4-6      6-10     19-15   3.15








                    Pamlico River Estuary Water Quality Trends                                              65

                    have removed most of the carbon dioxide       this pattern is that freshwater from the
                    and made the water basic. Respiration, on     Tar River has much higher nitrate concen-
                    the other hand, adds carbon dioxide to the    trations than does Pamlico Sound water at
                    water, thus increasing the acidity and        the other end of the estuary. But a second-
                    lowering the pH.                              ary cause is that nitrate often behaves
                       The pH in the Pamlico usually ranges       nonconservatively in the estuary. That is
                    from around 6.5 to over 8.5, but because it   to say, the decline in nitrate concentration
                    is influenced by several variables, there     in the estuary is caused by more than
                    are not very clear spatial or temporal pat-   simple dilution by seawater. Nitrate is
                    terns. About all that can be said is that it  used up (assimilated) by phytoplankton,
                    tends to be lower upriver than downriver,     which are scarce in the Tar River but
                    and it sometimes goes up during the algal     abundant in the upper estuary, and there
                    blooms that occur in the river in the late    is apparently little replacement of the
                    winter and early spring.                      assimilated nitrate. Consequently, nitrate
                       Highly significant downward trends in      concentrations usually exhibit a temporal-
                    pH (p <0.002) were detected by the Seasonal   spatial pattern in the estuary that is the
                    Kendall trend test for segments H and E       inverse of the salinity pattern, but nitrate
                    between 1975 and 1986 (Table 4.3). The        levels decrease more rapidly than salinity
                    slopes were about 0.04 pH units per year,     increases, especially in the upper end ofthe
                    which amounts to a change of 0.68 units       estuary. This accounts for the nonlinear
                    over the sampling period. The lower pH        relationship between salinity and nitrate
                    could be related to declining salinity, at    (Figure 4.9).
                    least in segment H. As explained above,           The most significant change in nitrate
                    lower salinity (i.e., increased freshwater    nitrogen in the Pamlico during the past 20
                    inflow) should lead to lower pH.              years occurred upriver, where there appar-
                                                                  ently has been a decline. The Seasonal
                    Nitrogen                                      Kendall test results indicated a highly
                       Nitrate Nitrogen: Nitrate nitrogen is      significant (p = 0.005) decrease in nitrate
                    one of the most variable nutrients in the     for river segment B (upriver) during the
                    Pamlico, but there is a seasonal pattern in   period between 1967 and 1986. But there
                    this variability. In most years, highest      was no significant change for the 1975-
                    concentrations occur upriverduringwinter,     1986 period, suggesting that the decline
                    coincident with peak Tar River flows, and     occurred during the early 1970s. The
                    lowest concentrations occur downriver         average rate of change was about 0.3 PNV
                    during the summer. The primary cause of       year, or 5.1 @Mduringthe 17-yearsampling

                       is MEAN OF AL. STAn ONS                        100
                    P  15                                              80
                    0.
                    E@, 12                                         z   60
                       9
                    z                                                  40
                       6
                       3                                               20

                       0                                                0
                       1965   1970    1975   1980   1985    1990        0       5      10     15      20     25
                                         YEAR                                        SALINITY (ppt)
                    Figure 4.8. Surface salinity (ppt) in the Parnlico Figure 4.9. Nitrate nitrogen (,@LM) versus salinity
                    River estuary, 1967-1986. Values plotted are  (ppt). Dataarefrom stations 1, 5,8, 10and 12 (1975-
                    averages of all stations 8cunpled.            1986).








                  66                                                                              Chapter 4

                  period. This change represents approxi-        offset losses from assimilation and dilution,
                  mately a 25% decrease from the 1970            and at some times of the year it is a more
                  median nitrate level. Based on the relation-   important source of ammonia than inflow-
                  ship between nitrate and salinity described    ingTar River water (Kuenzler et al. 1979).
                  above, it would be reasonable to conclude          Ammonia abundance in the estuary
                  that this decrease was due, at least in part,  appears to be trending downward at a
                  to the salinity increase detected in this      rapid rate. During the period 1967-1986,
                  segment.                                       the decline was highly significant (p< 0.002)
                     The Seasonal Kendall test indicated a       for all three river segments examined
                  highly significant (p = 0.003), but small      (Table 4.3). The average rate of decrease
                  (0.4 pM), nitrate increase downriver (seg-     was quite rapid - about 0.3 gM/year up-
                  ment H) over the 1967-1986 period. Again,      river (segment B) and around 0.23 AMI
                  this change could be explained by salinity,    year farther downriver (segment H). For
                  which was shown above to have decreased        segment B, this is equivalent to about a
                  in this segment. But this could also be        60% decline over the 17-year period of
                  simply an artifact resulting from changes      record. The decline is especially noticeable
                  in analytical sensitivities. Before 1975,      when one compares values from the early
                  nitrate levels lower than 0.1 /.LM were        1970s with those for 1984-1986. Once
                  reported frequently, but after 1980, the       again, it should be remembered that data
                  values less than 0.71 14M were reported as     from the period 1975 through the end of
                  0.71 jLM, the lower limit of detection         1979 had to be eliminated from consider-
                  (Appendix 4.3). This change in data            ation in the trend test because of the high
                  reporting probably had little effect on the    minimum detection limit associated with
                  upriver trend results, because the nitrates    the method used for the analyses in those
                  there were usually higher than 0.71 gM,        years.
                  but it may have contributed to the apparent        Total Nitrogen: Total nitrogen (TN),
                  upward trend in the downriver segment,         which consists of total dissolved nitrogen
                  H, where nitrate is much less abundant.        plus particulate nitrogen, is the most diffi-
                  The nitrate data from 1975 through 1979        cult nitrogen fraction to measure accu-
                  were omitted from the Kendall test because     rately. The problem has to do with uncer-
                  of the very high (3.57,4M) lower detection     tainties about the completeness ofthe diges-
                  limit reported during that period. In any      tion used to break down the organic con-
                  case, there has been no significant change     stituents. There have been several changes
                  in nitrate levels downriver since 1975.        in the methodology used to analyze Pamlico
                     AmmoniaNitrogen: Ammonia nitrogen           TN, and there is much uncertainty about
                  is also more abundant in Tar River water       the efficiency of some of the methods used
                  than in Pamlico Sound water, but in the        (see Appendix 4.3).
                  Pamlico River estuary, concentrations do           TN concentrations have fluctuated
                  not range as widely as nitrate concentra-      widely, and sometimes abruptly, during
                  tions. In general, they are between 1 and      the 17-year period of record (see Figure 31
                  8 ttM upriver (segment B), <0.71 pLM to 6      in Stanley 1988). However, I strongly
                  gM downriver (segment H) and inter-            suspect that much ofthis variability can be
                  mediate in the middle segments. This rela-     traced to methodological problems. For
                  tively constant pattern probably results       example, I doubt that the abrupt decline in
                  from ammonia production in the sediments       1977 and the sudden rise in 1980 are real.
                  and water associated with organic matter       There were changes in the methodologies
                  decomposition. This production tends to        at each of these times. Also, the apparent








                     Pamlico River Estuary Water Quality Trends                                                        67
                     wide fluctuations during 1975-1977 prob-               changes in biology and hydrography
                     ably are due in part to the fact that data             of the river. The very high values for
                     from this period are from three different              dissolved organic nitrogen in 1970-
                     sampling programs (Kuenzler et al., Davis              1971 (August through December)
                     et al., and ICMR), each of which used a                correlate well with the very low stream
                     different method for the TN analyses. Of               flow. On the other hand, when the
                     course, this is only speculation and unfortu-          streams started to flow again in mid-
                                                                            January there was a reduction in
                     nately there is noway to determine whether             dissolved organic nitrogen concentra-
                     or not this is the correct explanation. The            tion followed by an eventual increase
                     methods used to measure TN have been                   which may well correlate with the
                     less variable since 1980, and during this              increased biological productivity at
                     period there have not been such abrupt                 that time. During 1971-1972, the dis-
                     fluctuations as in the earlier years.                  solved organic nitrogen concentrations
                         The trend test indicated highly signif-            were very low during the heavy rains
                     icant increases in TN in all three segments            of October and November. On the
                     between 1967 and 1986 and in segments B                other hand, the high rates of flow in
                     and E between 1975 and 1986. But, as                   May seem to contain quite high
                                                                            amounts ofdissolved organic nitrogen.
                     indicated above, there are reasons to doubt            A number of hypotheses can be put
                     the validity of these results. I think the             forth as to the reason for abrupt
                     most likely explanation for the apparent               changes, such as there is a flushing
                     trends is that the digestion method used in            effect of high waters on swamps that
                     the early analyses (ultraviolet radiation),            increases the dissolved organic nitro-
                     gave less complete breakdown ofthe organic             gen in the rivers and streams. Also it
                     nitrogen than the more rigorous wet chem-              is possible that DON is being produced
                     ical digestions used later (see Appendix 4.3           during algal blooms. At this time,
                     for more details). This would explain the              however, we do not have enough infor-
                     apparent increase in the TN concentrations.            mation as to the source and fates of
                                                                            these compounds that are lumped
                     Once again, however, this is only specula-             under the name dissolved organic
                     tion, and I cannot be sure that had the                nitrogen. Certainly the biologically
                     methodology remained constant, there                   active part is very small ... Yet, these
                     would not have been an upward trend in                 compounds are still potentially impor-
                     the concentrations.                                    tant as they contain a great deal of
                         Total Dissolved Nitrogen: Total dis-               nitrogen and their total concentrations
                     solved nitrogen is not a particular chemical           are always greater than the total con-
                     form of nitrogen, but rather includes a                centrations of the dissolved inorganic
                     large number of compounds, including                   nitrogen" (Hobbie 1974, pages 73-75).
                     ammonia and nitrate, that passed through               The Seasonal Kendall test showed that
                     the glass fiber filter when the dissolved         there has been no significant change in
                     and particulate fractions are separated.          total dissolved nitrogen in the Pamlico
                     Hobbie (1974) subtracted the inorganic            (Table 4.3). However, as noted above, the
                     forms (nitrate and ammonia) from TDN to           methods used to measure TN and TDN
                     obtain estimates ofdissolved organic nitro-       have changed several times over the study
                     gen (DON), but could not explain changes          period, so this result may not be valid.
                     in the DON data:
                         ". . . The yearly cycle of the dissolved      Phosphorus
                         organic nitrogen concentration is also             Concentrations of all three forms of
                         difficult to interpret in terms of known      phosphorus measured in the Pamlico








                  68                                                                                    Chapter 4
                  samples (total phosphorus [TP1, total dis-          topic in every Pamlico report he prepared.
                  solved phosphorus [TDP], and orthophos-             In a 1971 report, he made these comments:
                  phate phosphorus [OP]) are generally high-
                  er in the summer than in the winter. For                    Earlystudies centered around the
                  example, in 1984, dissolved orthophosphate              possible effects that the establishment
                  concentrations were often >2 pM during                  of a phosphate mine on the south side
                  the summer and fall, and less than 2 gm                 of the river (Texas Gulf Sulfur Corp.)
                  during the winter. Both TDP and TP fol-                 would have on the water chemistry
                                                                          andbiology. It is nowapparent(Hobbie
                  lowed the same temporal pattern as OP.                  1970a) that there is enough phosphorus
                  TDP ranged from around 2- 10 I.LM in winter             naturally present in the river and that
                  samples to 10-20 1AM in summer samples.                 the phosphorus added from the phos-
                  TP was only slightly higher, indicating                 phate mine operations has no added
                  that particulate phosphorus makes up a                  effect on the biology."
                  relatively small fraction of the total P in                 "The natural levels of P in the
                  the estuary.                                            estuary are in the 1-2 jkg-at P/liter
                       Nixon (1983) noted that this summer                range (1 gg-at P equals 31 @Lg) for
                  increase in phosphorus is a feature common              [orthophosphate phosphorus]. As a
                  to many estuaries, and he discussed several             result of the mining activities, levels
                  possible explanations, but concluded that               as high as 93 pg-at/liter have been
                                                                          measured. However, the release is
                  no single factor can explain the pattern in             intermittent and the higher phos-
                  all the estuaries. Judging from the informa-            phorus water is found as patches that
                  tion presented in Nixon's discussion, and               move seaward along the south shore of
                  other available information, I suspect that             the estuary. Because of removal of
                  two factors are important in the Pamlico.               phosphorus by the sediments, removal
                  The first is increased bottom water hypoxia             by microorganisms, and dispersion
                  in the summer. As shown by Kuenzler et                  dilution, the patches of high phos-
                  al. (1984) for the Pamlico River, and by                phorus water do not reach Pamlico
                  similar studies for many other estuaries                Sound. There does appear to be, how-
                  (e.g., TaftandTaylor [1976] forChesapeake               ever, an increase over the past three or
                                                                          fouryears in the concentration ofphos-
                  Bay), this hypoxia increases the release of             phorus entering the estuary in the
                  phosphate from the sediments. Second,                   river water. This may be the result of
                  Tar River flowdecreases in the summer, so               increased sewage treatment and of
                  that there is less dilution ofthe phosphorus-           increased use of detergents" (Hobbie
                  rich Texasgulfeffluent and s lower flushing             1971, pages 5-8).
                  of the discharge from the estuary.                      In another report (Copeland and Hobbie
                       There is also spatial variability in the       1972) summarizing the 1967-1969 sam-
                  phosphorus -levels that usually follows a           pling, three conclusions were given regard-
                  pattern. Highest concentrations are found           ing phosphorus in the estuary: 1) there
                  in the middle section-of the river, especially      had been a tripling of total phosphorus
                  adjacent to the Texasgulf discharge, with           levels in the upper river, 2) the middle
                  intermediate concentrations upriver and             river was greatly affected by the high con-
                  lowest concentrations at the outer end of
                  the estuary near Pamlico Sound.                     centrations of total phosphorus entering
                       For obvious reasons, there has always          from Texas Gulf Sulfur, and 3) the lower
                  been a great deal of interest in trends in          section ofthe river also seemed to be strongly
                  phosphorus in the Pamlico, so it is not             affected by Texas Gulf Sulphur's activities.
                  surprising that Hobbie wrote about this








                      Pamlico River Estuary Water Quality Trends                                                         69
                          Finally, after his monitoring program           there were also increases in TDP in seg-
                      ended in 1973, Hobbie had this to say               ments H and B, but not in the middle river
                      about the 1971-1973 phosphorus data:                segment, E. Orthophosphate increased in
                                                                          segments H and E between 1967 and 1986,
                               It is interesting to remember the          but only in the downriver segment, H,
                          increase of phosphorus in the upper             since 1975. The average annual rate of
                          stations and the entire river that were         increase varied from 0.04 AM/year to about
                          seen over the first four or five years of       0.086/.kl%Vyear. For the downriver segment,
                          phosphorus measurements. Although               H, these rates translate to an overall in-
                          high amounts of phosphorus are still
                          seen in the upper parts ofthe river, the        crease of about 0.7 AM since 1967.
                          increase does not appear to have con-               The fact that phosphorus abundance
                          tinued past 1970 or so" (Hobbie 1974,           has not changed in the mid-river segment
                          page 50).                                       since 1975 probably is a reflection ofdeclin-
                                                                          ing P loading from Texasgulf, counter-
                          Results of the Seasonal Kendall tests           balanced, to some extent, by increased
                      seem to confirm Hobbie's observation that           loading from the Tar River. Monthly load-
                      phosphorus was increasing in the river in           ing of P (in tonnes) from the plant site has
                      the late 1960s. The increase in TP was              decreased by about two-thirds since the
                      shown to be highly significant (p<0.002) in         mid-1970s (Figure 4.10). It would seem
                      all three river segments examined for the           that this large reduction ought to have
                      time period 1967-1986 (Table 4.3). The              produced a significant downward trend in
                      average rate of increase at the middle              phosphate in the river, given that the
                      segment, E, was 0.23 AM/year, or about 4.4          Texasgulf discharge accounts for approxi-
                      AM over the 19-year sampling period. This           mately 40% of the total P loading to the
                      amounts to approximately a doubling of              river (North Carolina DNRCD 1987). But,
                      the 1967 TP levels. In the upriver and              the decreased TG load probably has been
                      downriver segments, B and H, the TP levels          offset to some extent by increased loading
                      trended upward at about half this rate.             from the Tar River, so that the overall
                      However, when only the period 1975-1986             pattern is one of little change since 1975.
                      was examined, it was found that there was           Unfortunately, there are no historical Tar
                      a significant increase in TP only downriver         River loading data which could be used to
                      in segment H (p<0.002). But the average             test this hypothesis.
                      annual rate of increase in this segment
                      since 1975 has been 0.25 AM/year, nearly            Nutrient Limitcytion in the Pamlico
                      twice the rate over the longer period.                  Nitrogen-to-phosphorus ratios are often
                          Total dissolved phosphorus and ortho-           computed for aquatic ecosystems to indicate
                      phosphate phosphorus have also increased            which of the two nutrients is most likely to
                      signif icantly, particularly in the lowerestu-      be limiting to phytoplankton growth. The
                      ary. The trend test results are about the           ratios can be calculated several ways, but
                      same as for TP, which is not surprising             most often they are made by dividing the
                      since OP and TDP are the major fractions            water-column concentrations of total dis-
                      comprising TP. For TDP, the increases               solved inorganic nitrogen (DIN) by the con-
                      between 1967 and 1986 were highly signif-           centration of orthophosphate phosphorus
                      icant (p<0.002 for all three segments), and         (OP). The significance of this ratio stems
                      the rate of increase was highest in the             from the fact that algal production is deter-
                      middle segment (Table 4.3). During the              mined in part by the need for nitrogen and
                      more recent sampling period, 1975-1986,             phosphorus in proportions (atomic) of 16:1,








                     70                                                                                                 Chapter 4

                     respectively (Redfield 1934). Water-column                 ity in algal composition ratios, and hence it
                     DIN:OP ratios less than the "Redfield Ratio"               is probably more realistic to view
                     indicate that nitrogen is less abundant                    composition ratios as ranging from around
                     than phosphorus relative to the phytoplank-                10:1 to 20:1 (Boynton et al. 1982).
                     ton's need. On the other hand, values                          Calculated ratios of water column
                     higher than 16:1 indicate that phosphorus                  DIN:OP suggest that nitrogen is more likely
                     is less abundant. Thus, ifthe phytoplankton                than phosphorus to be limiting upriver in
                     continue to grow and there is no N or P                    the Pamlico during the summer and down-
                     replenishment in the water, one nutrient                   river at all times of the year. Figures 4. 11-
                     will be exhausted (i.e., become "limiting'l                4.13 give the ratios at five stations along
                     before the other, depending on the ratio.                  the salinity gradient 'between 1979 and
                     Studies by Parsons et al. (1961) and Rhee                  1986. In the lower half of the estuary
                     (1978) indicated that there is some variabil-              (stations 1 and 5), DIN:OP ratios are almost
                       W                                                        always less than the ideal Redfield ratio
                       0     150                                                (16: 1), or the 10: 1-20:1 range of N:P ratios
                       ;;z -
                          F_ 120                                                normally found in algal cells. Upriver, the
                          Z
                       00    90                                                 ratios increase, more because of increasing
                       0
                       a.
                       @3 W  60                                                 DIN (principally nitrate), rather than
                       M z         k@
                          z                                                     decreasing phosphate. There is also a
                             30                          AA1*4                  strong seasonal pattern in the ratios at all
                                01            -
                                1973        1978          1983           19M    stations. This pattern is determined prima-
                                                  YEAR                          rily by the nitrate levels, which vary more
                                                                                than either ammonia or nitrate over the
                     Figure     4.10. Texasgulf phosphorus discharge            course ofthe year. Figure 4.14 more clearly
                     (tonnes), by month, 1974-1986.


                           100  STA11ON 1                                             1000  STATION 8
                                                                                       100
                       a.  10                                                     a.
                                                                                  0
                                                                                        10 -





                           0.1                                                         0.1
                             80     81    82    83     84    85    86      87             80    81     82    83    84     85    86    87

                                                  YEAR                                                        YEAR
                           100   TATION 5                                             1000  STATION 10
                                                                                       100
                       a. 10                                                      CL
                                                                                         10



                           0.11                                                        0.1
                             80     al    82     83    84    85     86     87             80    81     82    83    84     85    86    87
                                                  YEAR                                                        YEAR
                     Figure 4.11. Ratio of total dissolved inorganic            Figure 4.12. Ratio of total dissolved inorganic
                     nitrogen (DIN) to orthophosphatephosphorus (OP)            nitrogen (DIN) to orthophosphatephosphorus (OP)
                     in the Pamlico River estuary, 1979-1986. (A)station        in the Pamlico Riverestuary, 1979-1986. Wstation
                     1, (B) station 5.                                          8, (B) station 10.








                      Pamlico River Estuary Water Quality Trends                                                     71
                      shows the decline in the N:P ratio with           there were no statistically significant trends
                      increasing salinity. Most instances of N:P        in the concentrations, but the percent satu-
                      higher than 16:1 occur upriver in the winter      ration data did show a significant down-
                      months when river flows, and hence nitrate        ward trend in segment H (Table 4.3). The
                      levels, are highest. Similar results for          annual average percent saturation declined
                      other estuaries are discussed later in this       from about 70% to 60% over 18 years.
                      report.                                           There was no significant trend in the seg-
                          It is very important to realize that          ment B and segment E data. Dissolved
                      these N:P ratios are only evidence for pos-       oxygen dynamics in the Pamlico River are
                      sible N or P limitation, not proof that such      described in more detail in Chapter 5.
                      limitation exists. Phytoplankton must con-
                      sume the nutrients faster than they are           Chlorophyll a
                      resupplied, from either internal recycling           Chlorophyll a is a reliable indicator of
                      or outside input, in order for one or the         algal biomass that has been monitored in
                      other to become limiting. In fact, other          the Pamlico since 1970. The most impor-
                      factors, such as light or temperature, often      tant findings from this sampling are that
                      control algal growth to such an extent that       blooms of algae occur each late winter or
                      the nutrients are not exhausted. In these         early spring, but the median chlorophyll a
                      circumstances, the N:P ratio has no influ-        levels peak in the summer months. The
                      ence on the growth. In other words, both          winter blooms occur in the middle reaches
                      the absolute and the relative N and P
                      concentrations must be considered (along
                      with the resupply rate!) when one specu-               1000  TATI ON 12
                      lates on algal nutrient limitation. The                 100
                      importance of limitation by factors other           a-
                                                                          0
                      than nutrients is often overlooked in the                  10
                      heat of debate associated with the long-            Q
                      running N vs. P limitation controversy.                    1
                      But given the high turbidity, particularly              0.1
                      upriver in winter (Kuenzler et al. 1979),                  80  81    82   83   84    85   86     87
                      and the wide temperature fluctuations that                                 YEAR
                      characterize estuaries like the Pamlico,          Figure 4.13.  Ratio of total dissolved inorganic
                      these factors probably override nutrient          nitrogen (DIN) to orthophosphatephosphorus (OP)
                      influences, at least during some parts of         in the Pamlico River estuary, 1979-1986, at station
                      the year.                                         12.

                      Dissolved Oxygen                                       100
                         The trend test (Table 4.3) showed a
                                                                              10                  t
                      highly significant (p<0.002) upward trend           IL               %
                      in surface water dissolved oxygen for all           O@     1
                      three river segments tested. The estimated                          A  I
                                                                              0.1
                      slopes were 0.05-0.08 mg/liter per year,
                      which amounts to an increase of 0.9-1.4 mg             0.01
                      02/liter, or approximately 10%, over the                   0       5        10       15         20
                      18-year period of record. The reasons for                              SALINITY (ppt)
                      this apparent increase are unknown.               Figure 4.14. DIN. OP ratio versus salinity in the
                         For bottom water dissolved oxygen,             Pamlico River estuary, 1979-1986. Data from
                                                                        stations 1, 5, 8, 10 and 12.








                   72                                                                                    Chapter 4
                   of the estuary (Stanley 1987; Hobbie 1974).            For the mid-river segment, E, there
                   Two other features of the blooms are that          was no significant change in chlorophyll a
                   theyare short-lived, and they usually occur        over the whole samplingperiod, 1970-1986.
                   at only one or two sampling stations. Also,        But when the shorter period 1975-1986
                   river flow can play an important role in the       was tested, a significant increase (p = 0.003)
                   timing and location of the winter blooms.          was detected. In other words, chlorophyll
                   In some years, high water inflow from the          apparently declined in this river segment
                   Tar flushes out much ofthe algal population        duringthe 1970s, and then increased again
                   from the river.                                    in the 1980s. The time-series plot (Figure
                      The trend test results indicate that            51 in Stanley 1988) for this segment clearly
                   chlorophyll a concentrations have increased        shows the decrease from concentrations
                   in the middle and upper segments, B and            typically between 10 and 20 jig/liter in the
                   E, of the Pamlico, but not in the downriver        early 1970s to often < 10 jkg/liter in the mid-
                   segment, H. Upriver in segment B, the              1970s. Of course, these data are from
                   increase was highly significant (p<0.01),          different sampling programs, but I could
                   during both time intervals tested. The             find no evidence ofchanges in the analytical
                   average annual rates of increase were 0.29         techniques that could explain the differ-
                   ;kg/liter per year and 0.64 /ig/liter per year     ences. Therefore, I must assume that the
                   for 1967-1986 and 1975-1986, respectively.         decline was real.
                   This is equivalent to about a 50 percent               A very noticeable feature of the chloro-
                   increase duringthe 16-year period ofrecord.        phyll time-series plots is that in recent
                                                                      years the bloom peaks appear to be more
                                                                      frequent and higher, particularly upriver
                                                                      in segment B. But closer examination
                         25  A                                        showed no clear long-term trend in the
                         20               DECEMBER-MARCH              frequency of high values. I made a plot of
                         15                                           the percentage ofvalues over 40 gg/liter for
                                                                       ach year since the sampling began in
                                             VEMBE
                    (L   10                  0    R                   e
                    <                  7
                          5
                                                                      1970 (Figure 4.15). Note that there were
                                                                      no data for 1974, and the 1985 data were
                          01970        1975       1980        1985    not used because some of them are suspect.
                                             YEAR                     In 1979, the North Carolina Environmental
                                                                      Management Commission adopted a chlo-
                         30  B                                        rophyll a quality standard of 40 gg/liter for
                         25            LOWER             UPPER             all lakes, sounds, estuaries, reservoirs
                         20
                                                                      and other slow-moving waters not desig-
                                         MIDDLE                       nated as trout waters" (North Carolina
                         10                                           Department ofNatural Resources and Com-
                          5
                          0                                           mun ity Development 1987, page 38). This
                           1970        1975       1980       1985     standard applies during the months April
                                             YEAR                     through November. In most years, the
                                                                      highest number ofPamlico samples exceed-
                   Figure 4.15. Pamlico River estuary chlorophyll a.  ing4O pg/liter occurred in the wintermonths
                   Percentage of sample values greater than 40 AgI    of December through March, when the
                   liter for eachyear (1970-1986). (A)Datagroupedby   standard is not applicable (Figure 4.15a).
                   twoperiods (April-November andDecember-March).
                   (B) Data grouped by river segment: "upper" =       The percentage ofApril-November samples
                   segments A, Band W@niddle"= segments D, E and      violating the standard has ranged from
                                   PM
                            oil










                   F, "lower" = segments G, H and L








                          Pamlico River Estuary Water Quality Trends                                                                  73

                          <1% in 1970, 1975-1976 and 1980, to                     5-10. Farther downriver in the middle
                          around 10% in 1986. There has been no                   reach (segments D, E and F), the percent-
                          clear trend in these percentages. Overall               ages were about the same, but in the lower
                          the early 1970s values are about the same               river (segments G-I), no more than 6% of
                          as those for the early-to-mid 1980s. The dip            the samples had over 40 lig chlorophyll a/
                          in the mid-1970s maybe real, ormaybe an                 liter in anyyear. Again, there has been no
                          artifact associated with the relatively infre           obvious change in this pattern since the
                          quent late winter sampling between 1975                 sampling was begun in 1970.
                          and 1979.
                              Inmost years, high chlorophyll a values             Phytoplankton Species Composition
                          were more frequent in the upper and middle              and Biomass
                          river areas than in the lower estuary                        Phytoplankton have not been moni-
                          (Figure4.15b). In the upper area - encom-               tored regularly for a long period in the
                          passing river segments A, B and C -up to                Pamlico River. Therefore, there are not
                          24% of the values were >40 /ig/liter (1986).            sufficient data to permit analysis of trends
                          More typically, the percentage was around               by the Seasonal Kendall procedure. How-

                                                                         A
                                                                      100 -
                          Figure 4.16. Phytoplankton
                          biomass (averaged by sampling               so -                                          X
                                                                                                           X
                          date) in the Pamlico River for (A)
                          1966-1968 and (B) 1983-1985.
                          Wet weight (mg1liter) for each
                          cla8s expressed aspercent oftotal                            DIN                             I    X:
                                                                      so -
                          biomos8. BAC = Bacillario-
                          phyceae, CHL = Chlorophyceae,               ao -
                          CHR = Chry8ophyceae, black
                          Cyanophyceae, DIN = Dino-                   40 -
                          phyceae, UNK      Unknown.                  30-                tt- nt

                                                                      20-




                                                                      0
                                                                               1966                  1967                     1968
                                                                         B
                                                                      100

                                                                                                                   UNK




                                                                      70




                                                                      50-

                                                                      40 -                           CHL

                                                                      30 -


                                                                      20




                                                                                                                      .... . ..   ........
                                                                               1983                  1984                  1985








                74                                                                              Chapter 4

                ever, there have been two major studies of      the same ones used for the nutrient and
                phytoplankton species, numbers and bio-         hydrography study.
                mass in the Pamlico. Since these studies            The data suggest that phytoplankton
                were separated by a time interval ofapprox-     species composition in the Pamlico has not
                imately 15 years, I thought it might be         changed substantially during the past two
                useful to compare the results, which might      decades. Figure 4.16 shows phytoplankton
                at least give clues about the presence or       biomass broken down by class, for both the
                absence of long-term changes in the estu-       1966-1968 samples and the 1983-1983 sam-
                ary's phytoplankton. The first study was        ples. The plotted data are means of all
                by Hobbie (197 1) for the time period August    stations sampled on each date. In both
                1966 through April 1968. Samples came           sample periods, four classes made up the
                from the same stations used for nutrient        bulk of the total biomass. These were
                and hydrographic monitoring. The second         diatoms (Class Bacillariophyceae), green
                phytoplankton study, sponsored by North         algae (Class Chlorophyceae), chrysophytes,
                Carolina Phosphate Corporation, was made        (Class Chrysophyceae), and dinoflagellates
                during the period April 1982 through            (Class Dinophyceae). Diatoms usually com-
                December 1985 (Stanley 1983, 1984a;             prised around 10-20% of the total biomass,
                Stanley and Daniel 1985a, 1985b, 1986).         although there is considerable scatter, as
                Samples were collected approximately            there also is for each of the other algal
                every other week from stations in the river     classes. Diatoms were most important in
                and in South Creek. River stations were         the winter and spring. The green algae
                                                                were also relatively important in the spring,
                                                                comprising, on average, 58% and 17% of
                                                                the total biomass in 1983 and 1984, respec-
                      10                                        tively (Stanley and Daniel 1985b). At
                      9 A
                                                                other times of the year in 1983 and 1984,
                      8                                         and in all of 1966-1968, they were an
                      7                                         insignificant part ofthe total. The seasonal
                  z
                  W   6                                         pattern for the chrysophytes is clearer;
                  0
                  (9  5                                         they definitely were more abundant in the
                      4                                         summer than at other times, both during
                      19W         1967        1968        1969  the 1966-1968 and 1983-1985 sampling
                                       YEAR                     periods. In some instances, they averaged
                      8                                         70-90% of the total biomass. Overall, the
                        B                                       most abundant algal class was the dino-
                      7
                                                                flagellates, which made up 80% or more of
                      6                           %     %       the total on many dates, particularly in the
                                             6M %
                  z   5                                         fall and winter.
                                                                   From the data presented in Figure
                      4
                      3                                    1    4.17, it would appear that algal cell density
                      1983       1984        1985          1986 and biomass (data not shown) were sub-
                                       YEAR                     stantially higher in the late 1960s than
                Figure 4.17. Averagephytoplankton      de       now. Between 1966 and 1968, the cell
                                                   cell ns'ty   densities (averaged on each sample date
                (logcell8 Iliter) in the Pamlico Riverestuary during
                two 8amplingperiods. (A) 1966-1968 and (B) 1983- for all stations) were mostly between    107
                1985.                                           and 1011 ceils/liter, which was 10- 100 times
                        B












                                                                higher than the typical 1983-1985 cell den-








                       Pamlico River Estuary Water Quality Trends                                                            75
                       sity. Similarly, biomass in the 1966-1968            that data from different periods would be
                       period appears to have been about ten                comparable. Unfortunately, turnover in
                       times higher than in the 1983-1985 sam-              technical personnel and the tendency to
                       pling period. There is considerable scatter          conduct short-term studies make this an
                       in the data from both periods.                       unlikely solution.
                           However, there are four reasons to                    In his report on the 1966-1968 data,
                       suspect that these apparent declines in cell         Hobbie made some interesting comments
                       density and biomass are not real. First,             regarding phytoplankton and eutrophica-
                       about three-quarters of the samples col-             tion in the Pamlico:
                       lected during the 1966-1968 study were
                       from the winter when dinoflagellate blooms                     Overall, the algae indicate that
                       (Heterucapsatriquetra) are greatest. Conse-               the Pamlico River estuary is a highly
                       quently, there were a few samples with                    eutrophic body of water. Whether or
                       very high densities and biomasses which                   not it should be called polluted depends
                       greatly affected the means. If there had                  upon the definition of pollution chosen
                                                                                 and also upon someone's opinion as to
                       been more (presumably low biomass) sam-                   the state of the river before man's
                       ples from otherseasons, the average would                 activities began in the drainage basin.
                       have been considerably lower. Second, in                  Because the algae are not a menace or
                       several samples, Hobbie found extremely                   hindrance to fishing or recreation, I do
                       high numbers of a very small unidentified                 not believe the estuary is polluted.
                       alga that was less than 2 gnis in volume.                 The natural fauna are still present
                       This species contributed nothing to the                   and so far the algae are the only indi-
                       biomass but considerably increased the                    cator showing pollution. Of course,
                       average cell density. Third, a check of the               any more nutrient enrichment should
                       cell volumes assigned to some of the most                 be avoided as the next step may be
                                                                                 deoxygenation of the water. This de-
                       abundant species showed that Hobbie's                     oxygenation would undoubtedly kill
                       estimates were, in some cases, higher than                many fish and shellfish. Although it is
                       those used in the more recent study. For                  just speculation at this point, it is very
                       example, Hobbie estimated the volume for                  likely that if the algae bloom occurred
                       Heterocapsa triquetra as 3360 jzms, com-                  during the summer months, the in-
                       pared to 2011 /-tm-1 by Stanley and Daniel                creased respiration associated with the
                       (1985a). And finally, the trend in chloro-                higher water temperature might well
                       phyll a in the river over the past two                    reduce the oxygen to a low level. For
                       decades contradicts these phytoplankton                   this reason, it is important to under-
                       biomass results.                                          stand how the phytoplankton are
                                                                                 operating and to avoid any changes to
                           It is unfortunate that the algal biomass              the estuary regime that would create
                       data are not comparable, but perhaps there                an algal bloom in summer" (Hobbie
                       is a lesson to be learned from this attempt.              1971, page 35).
                       It would seem that estimating algal cell
                       density and biomass is an "art" as much as                Some comments should also be made
                       a "science," because of the difficulty asso-         regarding blue-green algae in the Pamlico,
                       ciated with identifyingthe extremely small           since blooms of these nuisance algae have
                       forms that make up so much of the phyto-             become common in some areas of coastal
                       plankton. Perhaps the only solution is to            North Carolina in recent years. In particu-
                       have one person commit himself or herself            lar, the lower Chowan River and the lower
                       to making counts for an estuary over a long          Neuse River experience severe blue-green
                       period of time. This would at least insure           algae blooms during some, but not all,
                       internal consistency in the time series so








                76                                                                             Chapter 4
                summers (North Carolina Department of           lies in the difficulty, alluded to above, of
                Natural Resources and Community Devel-          correctly identifying these tiny algae. Most
                opment 1982; Christian et al. 1988). First,     are less than 2 Pm in diameter, so that they
                it should be noted that the blooms in these     appear as tiny dots under the 40OX mag-
                two systems have been restricted to fresh       nification used to make the cell counts.
                waters, or waters of very low salinity. The     One person may count these as algae,
                comparable region in the Tar-Pamlico            while another might disregard them as
                would be upstream of Washington (i.e.,          pollen grains or other non-algal items.
                upriver from station 12 used for the Texas-     This is certainly possible, but there is no
                gulf monitoring program). Although no           way to know if this actually happened.
                sampling for algae has been done in that           Whether or not blue-green algae are
                area, it is probably safe to assume that no     present in the Pamlico estuary, it is clear
                blooms have occurred there of the magni-        from both the 1966-1968 and 1983-1983
                tude and spatial extent comparable to those     studies that they do not contribute signifi-
                in the Chowan and Neuse. Hobbie (1971)          cantly to the total algal biomass. Using
                apparently found blue-greens to be numeri-      Hobbie's raw data, I calculated that the
                cally abundant at some times in the Pamlico     blue-greens usually made up less than
                River estuary, but Stanley and Daniel           10% of the total biomass in the late 1960s.
                (1985b) did not find them in large numbers      Similarly, duringthe more recent sampling
                in the more recent study. It is possible that   period (1983-1985), there were only a few
                this discrepancy represents a change in         species of blue-green algae and they
                the river's algal species composition, but I    accounted for less than 1% of the algal
                suspect that the more likely explanation        density and biomass in the river (Stanley
                                                                and Daniel 1985).







                      CHAPTER5
                      Stratification and Bottom Water
                      Hypoxia in the Pamlico River Estuary*

                      Introduction                                        "One of the things we can do is to look at
                          The severity of dissolved oxygen (DO)           places like the Chesapeake Bay, the
                      depletion in the bottom waters of estuaries         Hudson River and the San Francisco Bay.
                      appears to range widely, depending on a             They were showing the same signs of stress
                      combination of factors includingmorphom-            about 10 years ago that the Pamlico is
                      etry, vertical density stratification, and          showing now . . . the signals are there.
                      perhaps nutrient and organic matter in-                                  B.J. Copeland (1987)
                      puts. Persistent bottom-water hypoxia is        obvious need for better description and
                      common in stratified estuaries that have
                      deep channels. Examples include Chesa-          quantification of the roles of freshwater
                      peake Bay and some of its tributaries (Taft     discharge, lunar tides, and winds as physi-
                      et al. 1980; Officer et al. 1984; Kuo and       cal energy inputs influencing vertical mix-
                      Neilson 1987; Kuo et al. 1991) and parts of     ing. But so far, only a few such studies
                      the Puget Sound System (Christensen and         have been made. In Chesapeake Bay,
                      Packard 1976). Coastal ocean areas such         multi-year observations and mathematical
                      as the Atlantic inner continental shelfsouth    modeling have shown that wind is respon-
                      of Long Island, NY (Swanson and Sinder-         sible for breakup of the summer stratifica-
                      mann 1979; Falkowski et al. 1980) and the       tion in the early fall and that wind-induced
                      northern Gulf of Mexico (Boesch 1983;           destratification continues through mid-
                      Harper et al. 1981) also have experienced       spring (Goodrich et al. 1987; Blumberg
                      severe hypoxia. Fortnightly mixingrelated       and Goodrich 1990). It has been determined
                      to spring-neap tidal cycles has been ob-        that for Mobile Bay - a shallow, bar-built
                      served in some estuaries, including the         estuary - the tide is less important than
                      James, Rappahannock, and York rivers            river flow and wind-driven circulation
                      (Haas 1977; D'Elia et al. 198 1; Ruzecki and    (Schroeder and Wiseman 1986; Schroeder
                      Evans 1986). In shallow estuaries wind          et al. 1990). It seems reasonable that wind
                      mixing tends to decrease water column           and river flow may strongly influence
                      stratification more frequently, so that bot-    stratification and bottom oxygen condi-
                      tom water hypoxia is generally of short         tions in many of our nation's estuaries,
                      duration and limited in spatial extent. In      given that over half have mean depths <5
                      Mobile Bay, forexample, periods ofstratif-j-    in (Nixon 1988), and that many of those
                      cation and mixing occur as frequently as        along the southern Atlantic and Gulfcoasts
                      daily (Turner et al. 1987; Schroeder et al.     are isolated from strong lunar tides by
                      1990).                                          chains of barrier islands.
                         Given that stratification is a key factor        In this paper we examine the relation-
                      in the establishment of hypoxia, there is an    ships amongbottom water oxygen, vertical
                                                                      stratification, and the factors responsible
                      *coauthored by S. W. Nixon, Graduate School of Oceanography, University ofRhode Islanc4 Narragansett,
                      Rhode Island








                78                                                                               Chapter 5

                for stratification-destratification in the       Banks, a chain ofbarrier islands separating
                Pamlico River Estuary in North Carolina.         Pamlico Sound from the Atlantic Ocean.
                The study is based primarily on a 15-year        However, "wind tides" of 0.5-1.0 m are not
                set of biweekly oxygen, salinity, tempera-       uncommon, and are most likely following
                ture, and nutrient concentration measure-        several days of sustained winds from
                ments, but we also have incorporated some        directions approximately parallel to the
                recent continuous monitoring results.            estuarine axis (Giese et al. 1979). Prevail-
                   The Pamlico is a shallow (2.7 m mean          ing summertime winds in the Pamlico
                depth), oligohaline-mesohaline estuary ex-       region are from the SW and NE.
                tending 65 km from Washington, NC, to               Seasonal salinity patterns in the estu-
                the western edge of Pamlico Sound (Figure        ary are set primarily by variation in Tar
                5.1). The estuary varies in width from           River flow. Typically, surface salinity is <8
                about 0.5 km near Washington to about            ppt duringthe late winterand earlyspring.
                6.5 km at its mouth. The Pamlico "River" is      The salinity increases to maximum values
                actually the estuary ofthe Tar River, which      (10-15 ppt) during fall. However, there is
                drains most of the 14,000 kM2basin area.         considerable interannual variability. Dur-
                Total freshwater flow into the Pamlico           ingdrought years the salinitymay approach
                typically ranges between 28 mls-1 in October     that ofPamlico Sound (20-24 ppt). Temper-
                and 112 m3s-1 in February (Giese et al.          atures in the estuary typically range from
                1979). Freshwater flushing times corre-          40C in January to 300C in August. Details
                sponding to this flow range are estimated        of the hydrography and ecology of the
                to be between 80 and 28 days. Lunar tides        estuary are given in Giese et al. (1979) and
                in the estuary are almost negligible (7 cm),     Copeland et al. (1984).
                due to restrictions imposed by the Outer


                                                                 NORTH
                                                                 CAROLINA


                      2


                              a
                                                                                              W
                                       3                                                       J 200,
                                                                                                    Tiw
                                    2
                                         USGS




                                                                      3
                                                     3         5

                                                          2
                                                                    3
                                                   TEXASGU
                                                         LF
                          N
                                                                                                 5
                                                                           2
                                                                                                              .3
                                                                                                          6


                                                                                     2
                  0    2   4   6   8

                       KILOMETERS
                                                                                                              2,


                Figure 5.1. Location ofwater quality scunpling stations (10,8,5, and 1) and the U.S. Geological
                Survey continuous monitoring station (USGS) in the Pamlico River Estuary. Depth contours in
                M.








                      Stratification and Bottom Water Hypoxia                                                    79

                          Hypoxia, or "dead water" as it is known     concentrations read from the air-calibrated
                      locally, has become one of the most impor-      meter were corrected to ambient water
                      tant environmental issues for the Pamlico.      temperature and salinity. Measurements
                      Hypoxia in the estuary was first docu-          were made at two depths: approximately
                      mented in the late 1960s (Hobbie et al.         one-half meter below the surface and one-
                      1975), and was investigated more thor-          half meter above the bottom. These will be
                      oughly in the mid- 1970s (Davis et al. 1978),   referred to as "surface" and "bottom" read-
                      but knowledge about it seems to have            ings. Samples for chlorophyll a, and N and
                      become widespread only in more recent           P were collected only at the surface. Chlo-
                      times. A recurring theme in many news-          rophyll a was measured by the method of
                      paper articles, regulatory agency docu-         Strickland and Parsons (1972), and the N
                      ments, and some of the scientific literature    and P analyses were by methods given in
                      written during the late 1980s is that nutri-    USEPA (1979) and APHA (1985).
                      ent inputs promote large blooms of phyto-          In addition, we will present excerpts
                      plankton that eventually die, decompose,        from a time-series (3-hr measurement inter-
                      andcontribute inamajorwayto lowoxygen           val) of near-surface and near-bottom DO,
                      conditions during summer. In addition,          temperature, and salinity (determined from
                      most fish kills in the estuary in recent        temperature and specific conductance mea-
                      years have been attributed to hypoxia in        surements). The data are from a study
                      the bottom waters. Many citizens, and           carried out by the U.S. Geological Survey,
                      some scientists, suspect that bottom water      using a Minimonitor, a U.S.G.S. designed
                      anoxia and fish kills are more common in        instrument controlled by a CR10 micro-
                      the estuary now than in the past.               logger with data storage in an SM-192,
                                                                      which has permanent memory. The moni-
                      Methods                                         tor was mounted on the piling supporting
                          Most of the data used in this study are     Pamlico River Light 5 (a U.S. Coast Guard
                      from an ongoing water quality monitorin         navigation channel marker) about halfway
                      program sponsored by Texasgulf Che @            between our stations 5 and 8 (Figure 5.1).
                                                                mi-
                      cals, Inc. and carried out by East Carolina     The near-bottom. and near-surface probes
                      University since 1975. Salinity, tempera-       were 1.2 in and 3.6 in above streambed,
                      ture, dissolved oxygen, NO.,-N, NH  4-N, PO 4-  respectively. Mean low water depth at this
                      P, and chlorophyll a are among the suite of     marker is estimated to be 4.5 in. The
                      variables measured approximately every          Minimonitor was serviced at 2-week inter-
                      other week at 20 sampling stations in the       vals. Vertical profiles of temperature, spe-
                      Pamlico. For this study we chose to use         cific conductance, and Do were measured
                      data from four of these stations; they are      and compared to monitor readings. After
                      all located near mid-channel along the axis     the probes were cleaned, monitor and field
                      of the estuary. Station 1 is near the mouth     readings were again compared. If the field
                      at Pamlico Sound, and Stations 5,8, and 10      and monitor readings differed only by a
                      are progressively farther toward the head       relatively small amount, the monitor was
                      of the estuary (Figure 5.1). Mean low tide      adjusted to agree with field readings. If the
                      water depths are approximately 5.0 in, 4.5      difference between the monitor and field
                      m, 4.5 in, and 3.5 in, respectively. Tempera-   readings was large, probes or the entire
                      ture and salinity were measured with a          monitor were replaced with a laboratory-
                      YSI Model 33 S-C-T meter, and dissolved         calibrated unit. The monitor was returned
                      oxygen was measured with a YSI Model 51         to the laboratory for routine recalibration
                      oxygen meter and electrode. Oxygen              at 3-month intervals (Bales 1990).









                          80                                                                                                                      Chapter 5

                               Wind velocity data, provided by Texas-                            freshwater drainage into the estuary is
                          gulf Chemicals, Inc., were recorded at their                           proportional to the gauged flow (Giese et
                          plant site about midway down the estuary                               al. 1979).
                          on the south shore (Figure 5.1). Wind                                         We used the Spearman Rank Correla-
                          speeds were converted to stress using the                              tion procedure to investigate relationships
                          quadratic law with a drag coefficient of 1.5                           among the hydrographic variables. This is
                          x 10-8 (Garratt 1977). Daily mean Tar                                  a nonparametric test of the presence or
                          River discharge data are' from the U.S.                                absence of association between two vari-
                          Geological Survey gage at Tarboro, NC,                                 ables. It can also estimate the strength of
                          which is 80 km upstream from the estuary;                              the relationship, if one exists (Conover
                          consequently there can be substantial                                  1980; Daniel 1978). The computed coeffi-
                          travel time lags between it and the estu-                              cient (R) will range between -1 (perfect
                          arine sampling stations. Aboutone-halfof                               inverse relationship) and + 1 (perfect direct
                          the drainage basin is ungauged, but pre-                               relationship). The Spearman test is in-
                          cipitation rates and runoffgrates are similar
                          to those in the gauged areas, so that total
                                                                                                     100-


                                                                                                                   60-% SAT.
                                                                                                   80-
                                                                                                                   40-60% SAT.
                          80.      4-5 MG/1                                                    A            so-           2040% SAT
                          60       3-4 MG/1                                                                       0-20% SAT.
                          4O-       
                          20                                                                          40 
                                        2-3 Mg/l                                                  
                          FREQUENCY (%OF SAMPLES)                                                                      
                          p 40-        1-2 Mg/l                                                      20
                                       .1mg/10 
                          
                          20                                                                        0        
                                                                                                             0-5      5-10     10-15     15-20     20-25      25
                          0
                                                                                                                                PERATURE(06
                                                                                                                              
                                                                                                                           uency of four DO percent
                                  J F  M A M J J A S O N D                      F6       Figure        5.3.  Freq
                                                         MONTH                                   saturation ranges for six temperature ranges.
                                                                                                 Includes all data from fourmonitoring stations
                                                                                                 for the period 1975-89.
                            140-
                            120-           <20 96           20-40 %          40-60 %    B            8O
                            100.           60-80%          80-100 %                             70            0-20% SATURATION

                          U. 80.                                                                 AL
                          60                                                                      60

                            
                                                                                                     50.
                           40
                         
                                                                                                    40-
                          20
                                                                                                 
                                                                                                   30
                           0
                                  J F M A M J J A S 0 N D                                        
                                                          MONTH                                      10-


                          Figure 5.2. Frequency of five DO concen-                                         0-1        1-2       2-3       34         4-6       >5
                                                                                                                               DELTA SIGMA-T
                          tration ranges (A) and percent saturation                              Figure 5.4. Frequency of Sample8 with <20%
                          ranges (B) for each month. All data from four                          DO saturation for six delta SigmaT ranges.
                          monitoring stations for the -period 197326-89                            Includes only measurements made when water
                          included.
                                                                                                 temperature was >150C.
 








                      Stratification and Bottom Water Hypoxia                                                      81

                      eluded in SYSTAT, a statistics package           was considered to show statistical
                      available for microcomputers. We imple-          significance.
                      mented Version 4.0 of SYSTAT, which is
                      documented in the user's manual byWilkin-        Results and Discussion
                      son (1988), on a microcomputer.                  Seosonal and Spatial Variabillty
                         The Seasonal Kendall-Tau test was                  Frequency distribution plots ofall mea-
                      used to examine the flow, salinity, delta        surements made between 1975 and 1989
                      s igma-t, and bottom Do data for long-term       show a distinct seasonal pattern in Pam-
                      trends. The test, which was developed by         lico bottom water oxygen (Figure 5.2a).
                      Hirsch et al. (1982) is a nonparametric          Concentrations <5 mg 1-1 are least common
                      procedure suitable for application to water-     in the winter months (0-15%) and most
                      quality parameters which are often skewed,       common in July (75%). About one-third of
                      serially correlated, and affected by season-     the July measurements are < 1 mg 1-1. This
                      ality. The test compares all possible            pattern is in part a reflection of the effect
                      combinations of pairs of values over time,       that annual water temperature and salinity
                      assigning a plus if an increase occurs from      cycles in the estuary have on oxygen solu-
                      one value to the next, or a minus if a           bility. But other factors must be involved,
                      decrease occurs. If more pluses occur than       since the percent saturation frequency plot
                      minuses, then an increasing trend is indi-       shows the same pattern (Figure 5.2b).
                      cated; conversely, more minuses than
                      pluses indicate a decreasing trend. The             60
                      pairs of values compared are from the                   4-5 mg/1              JANUARY-DECEMBER
                      same "seasonal" period - in this case,              40 3-4mg/1
                      months. In other words, only January                    2-3 mg/1
                      values were compared with other January          130     1-2 mg/1
                      values, only June values were compared               : 1 Mg/1
                      with June values, etc. The data within           20
                      each month were summarized as means,                   A
                                                                       10
                      and the test was run on the monthly means.      
                      A significance level (alpha) of 0.10 or less        0
                                                                                       10       8       5      1
                                                                                             STATION



                                                                          100-
                        100                                              100%              JANUARY-DECEMBER
                                                            >6            80-  
                      9L bu -                                          IL         40-60 %
                                                            4-6        2
                                                                       1          20-40 %
                       60.                                2-4        060-   20 %
                      80                                                
                         40                                              40    B
                                                                     
                         20                                              20
                     
                         0                                                20
                             J F M A M J J A S 0 N D                        10       8
                                             MONTH                                            STATION

                      Figure 5.5. Frequency of three delta Sigma-t     Figure 5.6. Frequency of five DO concentration
                      ranges (bottom water - surface water) for each   ranges (A) and percent saturation ranges (B)
                      month. Includes all data from our monitoring     for each monitoring station. Includes all data
                                                                          for the period 1975-89      


















                      stations for t 








                            82                                                                                                                                        Chapter 5

                            Instances of strongundersaturation (<40%)                                            hypoxia increases with increasing strength
                            are rare in the, winter but frequent in the                                         ofwater-column stratification, as measured
                            summer months (39-61%).                                                             by delta Sigma-t. On the other hand, the
                                   A plot of all bottom water DO percent                                        scarcity of hypoxia during winter (< 150C)
                            saturations, grouped into six water temper-                                         cannot be due to a lack of water-column
                            ature ranges (Figure 5.3), reveals a sharp                                          stratification because a frequency plot of
                            increase in the probability of moderate                                             delta Sigma-t indicates that stratification
                            hypoxia at temperatures >150C. Below                                                is even more common in the winter than in
                            this temperature, only 4% of the DO mea-                                            the summer (Figure 5.5). Thus, it appears
                            surements, were *less than 40% saturation,                           that the combination of stratification and
                            but above 150C, 38% were< 40% saturation,                                           warm water temperature is most conducive
                            andabove 256C over halfthe measurements                                             to the development ofbottom water hypoxia
                            (52%) were <40% saturation. Severe hy-                                              in the Pamlico.
                            poxia (<20% saturation) is also most preva-                                                Severe hypoxia occurs more frequently
                            lent at the higher water temperatures. In                                           in the upper half of the estuary than near
                            addition, Figure 5.4 shows that for tempera-                                        the mouth (Figures 5.6 and 5.7). When
                            tures above 150C the frequency of severe                                            data for all months are considered, around



                                                                                                                          SW   SE NW W SW            SSWW NESW WSW
                                                                                                                       NW     S   W   NW    W    SE    W   SW    NE    S   SW NW         SW  
                                   80
                                                                                 JUNE-SEPTEMBER
                                                                                                                                                       A
                             70     4-5mg/1                                                              224   . . . . . .
                                                                                                                                                                            4
                                      3-4 mg/1                                                                              FLOW
                                                                                                                                                                                          
                             60 -                                                                             168-                                                                   3
                                           2-3 mg.1
                                   50    1.2 mg/1                                                               112                                                                     2
                                                                                                                   56-
                                   40-
                                                                                                                                                                                          0
                                                                       WIND STRESS (dyne cm)-2                               0
                                   30								WIND
                                           A                                                                           2-                         SURFACE                            
                                 20                                                                                  4-
                                 10                                                                                  6-
                            
                                                                                                                                     0
                                   0                                                                                   8-
                                                        10                         5             1
                                                                     8                                                                                  . . . . . . . . . . . .
                                                                 STATION                                               10 12i     16        20         24        28         1      1     15
                                                                                                                                      MAY                                       JUNE

                                                                                                                         W    NE   NE NE     NE    N     N   NW SW SW SW NE                  E
                                                                                                                  112                                                                  4
                                                                                 JUNE-SEPTEMBER
                                   100      80-100%                                                                                                     B                                   C
                                                                                                                                       WND
                                                                                                                     84-                                                               -3
                                       EEI 80-W %                                                                             . . .                    . . . . . .
                            
                                   80 60 40 %
                                                                                                                       56-                                                               -2  CD
                                                                                                                                                                                             W
                                             20-40 %                                                                   
                                                                                                                                                             FLOW
                                 60-                                                                              28-
                            
                                                                                                                       0      . . . . ..                                                 0   z
                                             B
                                                                                                                       4-
                            
                                   20                                                                                 8                                   SURFACE.
                                                                                                                16                                                                                                            
                                                                                                                    12-
                                   0-
                                                                      a             5                                          BOTTOM
                                                         10
                                                                  STATION
                                                                                                                          2345678910111213
                                                                                                                                             SEPTEMBER 1989
                            Figure 5.7. Frequency offive DO concentration                                       Figure 5.8. Surface and bottom salinity, Tar
                            ranges (A) and percent saturation ranges (B)                                        River flow, and wind stress and direction for
                            for each monitoring station. Includes only                                          two periods during 1989. Salinity and wind
                            June-September data for the period 1975-89.                                         data are plotted at 3-hr intervals, and flow is
                                                                                                                the daily mean.
 







                       StratIfIcation and Bottom Water HypoxIa                                                     83
                       15% of the upper- and mid-estuary mea-           estuary are important factors influencing
                       surements (Stations 10, 8, and 5) give           the timingofthese events. Three sequences,
                       oxygen concentrations <1 mg 1-1, while at        representing a variety of wind and flow
                       Station 1 near the mouth only 2% of the          conditions between May and November,
                       values are below 1 mg 1-1 (Figure 5.6a).         will be summarized.
                       However, there is less spatial variation in          The first time-series covers a period
                       the frequency of oxygen concentrations in        characterized by rapidly decliningTarRiver
                       the 1-5 mg 1-1 range. About 30% of Station       discharge (Figure 5.8a). On May 12 the
                       10 values fall in this range, compared to        discharge at Tarboro was 250 mss-I -
                       25% at stations farther down the estuary.        about three times the long-term average
                       The percent saturations also showa greater       for that time of year. By late May flow had
                       spatial difference in the lowest range than      fallen to more typical rates, around 40 mss-
                       in the higher ranges (Figure 5.6b). From         1, and it changed little from then until the
                       18 to 23% of samples from the upper- and         end of the interval on June 5. Surface
                       mid-estuary stations are less than 20%           salinity responded to the declining fresh-
                       saturated, compared to only 4% at Station        water input by rising from 1 ppt early in
                       1. A similar analysis of data from the           the period to 5 ppt at the end. Despite
                       summer months (June -September) shows            relatively low wind stress (<0.5 dyne cm-2)
                       that even though the frequency of low            early in the period, there was little strati-
                       oxygen increases during warm weather,            fication, as evidenced by the small differ-
                       the spatial pattern does not change; i.e.,       ences between surface and bottom salini-
                       low oxygen is still most common in the           ties. Thus, river flow appeared to be the
                       upper regions of the estuary (Figure 5.7).
                       Concentrations less than 1 mg 1-1 occur in
                       one-third of the samples from the upper
                       estuary, but in only 4% ofthe samples from             S SW SW N NE NE NE NWNE NE SW SW SW NW SE
                                                                            S SW W NW NE NE NE NW NNW NE SW SW SW SE
                       near the mouth. The percent saturation
                                                                            12 .........
                                                                                         is ii -it   i..
                       data show the same pattern. One possible
                                                                        -10-
                       explanation for these spatial patterns is
                                                                            6-
                       that because of its orientation in relation to   A
                                                                            4-
                                                                        0
                       the directions of the prevailing winds, the      0   2-1111
                                                                                                                      E
                       upper estuary is not as well mixed as the            0
                                                                            20-
                                                                                                                   -4
                       lower estuary. Correlation analysis evi-                         PLOW
                                                                                                                   3
                       dence that supports this conclusion will be      Sao-
                                                                                                                   2
                       presented below.
                                                                        LL
                                                                                                        Nb@        1

                                                                            0                                      0  Z
                       Short-Term Variability
                          Unfortunately, the long-term monitor-         -9  4- ;;M-
                                                                   he
                       ing data provide little insight into t
                       short-term dynamics of stratification and
                                                                                       TTO
                       hypoxia in the Pamlico, due to the relatively                              .......
                                                                            16   20   24   28   1    5    9    13
                       long sampling interval (two-three weeks).                  OCTOBER            NOVEMBER
                       But data from the 1989 continuous monitor-       Figure 5.9. Surface and bottom aalinity, Tar
                       ing study show that stratification/hypoxia       River flow, wind stress and direction, and
                       events can develop and break down very           bottom water DO concentration for the period
                       rapidly. These data also stronglysuggest         October 16-November 14,1989. Salinity, wind,
                       that wind and freshwater flow into the           and DO data areplotted at 3-hr interval8; flow
                                                                        is the daily mean.








                      84                                                                                                       Chapter 5

                      dominant control then. But as flow de-                         seiching within the estuary. As the storm
                      creased, wind became more important, as                        approached, wind stress increased and
                      demonstrated by the development of weak                        shifted to the NE. This mixed the water
                      stratification (2 ppt) on 19 May after wind                    column and began to drive saltier water in
                      stress subsided below 1 dyne                CM-2   . This      from the eastern end of the estuary, so that
                      stratification was broken up three days                        by the time the storm had passed on 6
                      later as the winds increased. From then                        September, salinities throughout the water
                      until the end of the period, wind velocities                   column had risen to about 11 ppt. Grad-
                      were variable, with only brief periods of                      ually, over the next 4-5 days, the wind
                      calm. Consequently, there were no sus-                         shifted back to the SW, and surface salinities
                      tained stratification events.                                  decreased slowly to 8-9 ppt. Also, the wind
                           The second sequence (2-13 September)                      velocities declined, allowinga vertical salin-
                      was highlighted by below normal                                ity gradient of about 5 ppt to develop. After
                      freshwater discharge and a strong wind                         9 September both increasi ng bottom sali n-
                      event associated with the passage of a                         ity and decreasing surface salinity con-
                      storm front. The period began with weak                        tributed to the widening vertical salinity
                      westerly winds, high surface salinity (9                       gradient.
                      ppt), and weak stratification (Figure 5.8b).                          No oxygen data are available for these
                      Alens ofsaltier water in the vicinity appears                  first two sequences, but there are Do data
                      to have intruded twice for brief periods on                    for the final sequence, spanning the period
                      2 and 3 September. This movement may                           mid-October to mid-November, 1989 (Fig-
                      havebeen related totidal forcingor internal                    ure 5.9). This sequence is also interesting

                      Table 5.1. Spearman Rank Correlations                          Table 5.2. Spearman Rank Correlations
                      between bottom water DO and selected                           between D Sigma4 and selected variables.
                      variables. F=flow on day ofDO measurement;                     F=flow on day of DO measurement; F-5, F-10,
                      F-5, F-10, and F-15=5, 10, and 15-day lagged                   and F-15=5, 10, and 15-day lagged flows;
                      flows; WS=Wind stress on day of DO                             WS=wind stress on day of DO measurement;
                      measurement; WS-1 and WS-2=1 and 2-day                         WS-1 and WS-2=1 and 2-day lagged wind
                      lagged wind stress; BSAL=bottom water                          stress; BSAL=bottom water salinit . Surface
                                                                                                                                  y
                      salinity; CHLA=chlorophyll a; andDSIGMAT                       samples were analyzed for N and P
                      =deltaSigma-t. Surface samples were analyzed                   concentrations.
                      for N and P concentrations.
                                                                                                                    Station
                                                      Station                        Variable
                      Variable                                                                       10          8           5            1
                                      10           8           5           1
                                                                                     F             -0.210*     -0.081      0.009       0.111
                      F             0.149       -0.030        0.030      -0.167      F-5           -0.204*     -0.085      0.027       0.128
                      F-5           0.139       0.034         0.026      -0.361**    F-10          -0.173      0.110       0.114       0.205
                      F-10          0.112       -0.150        -0.012     -0.201      F-15          -0.199*     .0.030      0.159       0.231*
                      F-15          0.166       -0.087        -0.045     -0.108      WS            -0.184*     -0.257*     -0.197*     -0.221*
                      WS            0.072       0.279**       0.184*     0.062       WS-1          -0.202*     -0.319**    -0.234*     -0.300**
                      WS-1          0.199*      0.293**       0.279**    0.344**     WS-2          -0.108      -0.178      0.028       -0.127
                      WS-2          0.140       0.305***      0.134      0.178       BSAL          0.732***    0.560***    0.452***    0.266*
                      BSAL          -0.477***   -0.446***     -0.400***  _0.145      NO     3-N    -0.262**    0.203*      -0.109      -0.484***
                      NO,-N         0.284**     0.298**       0.146      0.357**     NH     4-N    -0.225*     -0.288**    -0.160      -0.377**
                      NH,-N         0.104       0.241*        0.134      0.366**     P04-P         -0.066      -0.060      -0.160      -0.377**
                      PO'-P         0.113       -0.066        -0.113     -0.067        P<.05
                      CHIA          -0.175      -0.155        0.035 *    -0.023      .-P<01
                      DSIGMAT       -0.665***   -0.674***     -0.742**   -0.432***   ... P<.ooi

                      *P<05
                      **P<01
                      .*.P<.001








                      Stratification and Bottom Water Hypoxia                                                      85
                      because it includes large, short-term fluctu-   ing wind stress combined to turn the water
                      ations in Tar River discharge and wind          column over in a matter of a few hours
                      stress, which interacted to produce four        during the evening.
                      distinct episodes of stratification. The first      Within 48 hours, another stratification
                      was in progress at the beginning of the         event had begun to develop (30 October).
                      sequence on 16 October. Tar River flow          This time, winds switched from the NE to
                      had declined from a previous peak to 20         the NW, and decreased in velocity. This
                      m8s'l, winds were blowing slowly from the       event lasted about 4 days, with a vertical
                      south, and there was a 6 ppt difference         salinity gradient of about 4-6 ppt and bot-
                      between surface and bottom salinities. Also,    tom water DO reduced to around 2 mg 1-1.
                      bottom water DO was extremely low -             It ended late on 2 October following in-
                      well below 1 mg 1-1. The next day, a strong     creased wind stress the previous night.
                      afternoon wind from the south eroded the        The fourth episode began almost
                      salinity gradient, but was not sufficient to    immediately, and for the next three days
                      destroy it. Even stronger winds on the          (4-6 November), there was weak stratifi-
                      19th temporarily broke up the gradient,         cation that was nearly broken on several
                      and finally on the 20th it was destroyed        occasions, but apparently did not com-
                      following a third day of strong afternoon       pletely disappear, since the bottom water
                      wind. At this time, the bottom water DO         DO continued to fall, reaching 1 ing 1-1 on
                      rose dramatically, reaching saturation con-     the 6th. The vertical salinity gradient
                      centration (9 mg 1-1) by 21 October. Subsid-    strengthened on the next day, weakened
                      ing winds on the 22nd and 23rd led to brief     on the 9th following stronger winds, and
                      periods of stratification and lowered DO.       fluctuated between 2 and 6 ppt for the
                      Again, these very sharp fluctuations may        remainder of the sampling period. Bottom
                      have been caused by short-term tidal or         DO also fluctuated, mostly between 2 and
                      seiching effects.                               4 mg 1-1.
                         Meanwhile, in response to widespread             In summary, these time series data
                      precipitation over the Tar basin, a flow        suggest that, at least in the mid-estuary,
                      pulse had been building steadily for about      stratification events and bottom water
                      4 days, reaching a peak of 125 m3s-1 at         oxygen levels are tightly coupled with varia-
                      Tarboro on 22 October. That pulse reached       tions in freshwater discharge and wind
                      the estuary station three days layer, quickly   stress. Stratification can change in a matter
                      reducing the surface salinity to 5 ppt, and     of hours, and episodes lasting from one to
                      setting up the second stratification event,     several days seem to be common.
                      which eventually amounted to a 5 ppt
                      vertical gradient. Bottom water DO fell         Spearman Correlation Results
                      rapidly from 6 ing 1-1 on 27 October to             Results of the Spearman Rank Correla-
                      around 1 mg 1-1 the following day. This         tion analyses tended to corroborate conclu-
                      seems to be a clear example ofstratification    sions drawn from the frequency plots and
                      caused by a moderate pulse of freshwater        the continuous monitoring data. Several
                      spreading out over the estuary surface          variables were tested for correlation with
                      under low wind stress conditions. In addi-      bottom water DO concentration at each of
                      tion, encroachment of saline Sound water,       the four long-term monitoring stations.
                      as evidenced by the slowly increasing bot-      Only data from 1975-89 samplings when
                      tom salinity, strengthened the density gra-     the water temperature was > 150C were
                      dient even more. On the 28th, both the          used (Table 5. 1). Delta Sigma-t (bottom -
                      pass ingof the Tar River pulse and increas-     surface), gave the highest correlation co-







                  86                                                                                  Chapter 5
                  efficient. The oxygen vs. delta Sigma-t            sponse to the strength of the flushing
                  relationship was inverse and was strongest         exerted by freshwater inflow.
                  at the three stations farthest up the estuary.        Wind stress was significantly correlated
                  The only physical variable showinga signifi-       with stratification (Table 5.2) at all stations
                  cant positive correlation to bottom water          when the previous day's wind was
                  Do was wind stress lagged by one day,              considered, but only at one station when a
                  another indication of the rapidity with            2-day lag was used. In addition, the
                  which stratification events are established        strength of these correlations trended
                  and broken up. Tar River discharge, lagged         upward toward the lower end ofthe estuary.
                  5, 10, or 15 days, seemed to be less impor-        This seems logical, since the shape and
                  tant, as the only significant combination          orientation of the Pamlico is such that
                  was the 5 -day lagged flow at Station 1. The       fetch over which the prevailing SW and NE
                  significant positive correlations between          winds blow increases toward the mouth.
                  bottom oxygen and surface N03     -N are inter-
                  preted to result from the presence of larger       Interannual Tr6nds
                  fractions of high No. river water during              Seasonal and interannual variability
                  mixing periods when there is no hypoxia.           of salinity in the Pamlico is determined
                  Note that there was a strong negative              primarily by freshwater runoff. Typically,
                  correlation between DO and bottom salin-           salinity is lowest during the late winter
                  ity. The positive correlation between bot-         and early spring when freshwater inflow is
                  tom oxygen and surface NH      Vandthenega-        highes. The salinity increases to maximum
                  tive correlation between delta Sigma-t and         values in the summer and fall, coincident
                  surface NH, (see Table 5.2) are interesting        with lowest Tar River flow. In some years
                  in that they suggest that stratification in        this seasonal pattern may be upset by
                  the Pamlico may lead to depletion of this          extended periods of precipitation or
                  nutrient in the surface layer.                     drought. For example, 1978, 1979, and
                      Additional Spearman analyses were              1987 were relatively high flow and low
                  made to test for associations between delta        salinity years, while droughts in 1981 and
                  Sigma-t, and two factors that could influ-         1988 resulted in unusually high salinities
                  ence the strength of the stratification -          (see Chapter 4).
                  Tar River flow and wind stress (Table 5.2).           Watercolumn stratification in the estu-
                  Flows were lagged 0, 5, 10, and 15 days,           ary is much more variable than bottom
                  and wind stress was lagged 0, 1 and 2 days.        salinity on a short-term basis. The only
                  The computed correlation coefficients be-          apparent long-term pattern in stratifica-
                  tween flow and delta Sigma-t were signifi-         tion is that its strength and variability are
                  cant (p<.05) for only Station 10 at the            reduced duringyears when bottom salinity
                  upper end of the estuary. As would be              is relatively low, such as 1978-79 and 1987.
                  expected, time lags of 0 and 5 days gave the       This is to be expected, since delta sigma-t
                  strongest correlation for the upper stations,      is influenced primarily by differences
                  whereas 10 and 15-day lags gave the highest        between bottom and surface salinities.
                  coefficients for the outer end of the estuary.         The Seasonal Kendall-Tau test indi-
                  There is a curious trend in the flow vs. delta     cated there were no long-term trends in
                  Sigma-t coefficients, from negative in the         flow, salinity, delta Sigma-t, or DO in the
                  upper estuary to increasingly positive at          Pamlico between 1975 and 1989. For each
                  the lower station. This result could be            of the four stations, none of the test results
                  interpreted to be a result of the salt wedge       were significant at the 90% level (alpha
                  moving up and down the estuary in re-              <0.1).








                     Stratification and Bottom Water Hypoxia                                                        87

                                                                           There is evidence that, at this frequency
                     Event Frequency                                   of reoxygenation, oxygen demand by the
                         Using hourly wind measurements col-           sediments and water column is sufficient
                     lected by Texasgulf duringthe summers of          to lead to hypoxia or anoxia. If the average
                     1980-1985, we calculated the resultant            summer Pamlico benthic oxygen uptake
                     daily vectors ofthe axial (alongthe channel,      rate of 378 PMOI M-2  h-1 measured by Kuen-
                     2950NW or 1150SE) and coaxial (cross-             zler et al. (1984) is applied to the area of
                     channel, 250NE or 2050SW) components of           sediment in the upper and mid sections of
                     the relative wind stress on the Pamlico. At       the estuary where hypoxia is most frequent
                     this level of analysis, the definition of a       (142.4 kM2,   see Nixon 1989, Appendix A),
                     "strong" wind is somewhat arbitrary, but          it appears that the total benthic oxygen
                     the choice of a cross-channel vector equal        uptake might amount to about 41,339 kgd-
                     or greater than 100,000 kM2d-2or an axial         1. If we assume that one-half of the total
                     vector equal or greater than 50,000 kM2       d-  volume of 322.2 x 10'3ins ofwater contained
                     2 (0.24 and 0.12 dyne cm,2)   seemed reason-      in this part of the estuary is below the
                     able based on the frequency with which            pycnocline, then the sediments could lower
                     such winds occur and a consideration that         the oxygen content of the bottom water
                     the generally weaker axial winds may pro-         only by some 0.26 mg 1-1 d-1. At this rate, the
                     duce vertical mixing at lower speeds be-          total oxygen consumed by the sediments
                     cause of their longer fetches. It would be        duringthe longest average interval between
                     useful in subsequent work to consider this        strong wind events (12.4 days in August)
                     problem in more detail.                           would lower the concentration by about 3.2
                         If the preliminary definition is accepted,    mg I`.
                     strong cross -channel and axial wind events           Respiration by plankton and bacteria
                     occurred, on average, with the frequencies        in the water appears to be somewhat
                     given in Table 5.3 during the summers of          greater. Data presented by Davis et al.
                     1980-1985. Thus, there might be, on aver-         (1978, their Figure 4) show concentrations
                     age, a vertical mixingand reoxygenation of        of 2-3 ing 1-1 ofparticulate organic carbon in
                     the bottom water approximately every 8.6          the waters of the Pamlico during summer.
                     days during June, every 11.5 days during          At this concentration, their oxygen uptake
                     July, every 12.4 days during August, and          regressions (see their Figure 52) indicate
                     every 6.5 days during September.                  that 8-14 ing 1-1 of oxygen were consumed
                                                                       during five days in July and 3-5 ing 1-1 were
                                                                       consumed during five days in August.
                     Table 5.3. Frequency of occurrence (number        These rates of water column respiration
                     per month) of strong cross4hannel and axial       are 2.3 to 10.8 times greater that the five-
                     windevents duringthe summers of1980-1985.         day oxygen uptake by the sediments and
                     Assuming that only one day of strong wind is      are sufficiently great that hypoxia and
                     needed to destratify the estuary, we have         anoxia could eas ily result if the water were
                     considered two or more sequential days Of         only mixed every 6.5 to 12.4 days. The sum
                     strong wind as one event. Eventaareaeparated      of these estimated benthic and water col-
                     by two or more days of weaker wind.               umn respiration rates (0.82-2.95 ing I-ld-1)
                     Month      Cross-Channel Axial          Total     compares reasonably well with the ob-
                                                                       served oxygen loss rates during periods of
                     June              1.8          1.7       3.5      stratification in the fall of 1989 (Figure
                     July              2.0          0.7       2.7      5.9). It seems clear that it is the balance
                     August            2.2          0.3       2.5      between oxygen uptake and the frequency
                     September         3.0          1.6       4.6      of strong wind events that largely deter-








                 88                                                                                Chapter 5
                 minesthe spatial extent and duration of          volved in most episodes, and the great
                 the low oxygen problem in the bottom             majority of the kills were reported during
                 waters of the Pamlico.                           the summer. In some cases, dissolved oxy-
                                                                  gen was measured and found to be low in
                 Effects of Hypoxia on Pamlico Blota              the kill vicinity; in other instances low DO
                     Anoxia or hypoxia in estuarine bottom        was inferred from circumstantial evidence
                 waters obviously has the potential to seri-      (e.g., "sulfide-like odors'). Unfortunately,
                 ously impact benthic organisms, either           most of these investigations took place
                 acutely via kills or chronically via physio-     several days after the kills, so that precise
                 logical stress. The short-term effects were      determination of circumstances at the time
                 documented in the Pamlico during the late        of the kill was very difficult. It should also
                 1960s by Tenore (1972), who found that           be noted that hypoxia-related kills of fish,
                 macrobenthos in deeper waters of the estu-       particularly menhaden, occur frequently
                 ary had low species diversity and density        in many other estuaries along the mid-
                 in the summer, and that variations in the        Atlantic and Gulf coasts of the U.S. (e.g.,
                 density were correlated positively with          Turner et al. 1987), under circumstances
                 anoxia/hypoxia. Large kills of the benthos,      similar to those surrounding the Pamlico
                 occurred quickly in the affected areas fol-      episodes.
                 lowing the onset of hypoxia. However,
                 these areas were recolonized by the follow-      Conclusions
                 ing winter. There have been no follow-up             While hypoxia is not the only environ-
                 studies to determine whether the benthos         mental issue of concern in the Pamlico, it is
                 density and distributions have changed in        certainly one of the most important. Be-
                 the Pamlico over the past two decades. It        cause there are documented and potential
                 would be helpful to be able to correlate the     links between low oxygen and kills of fish
                 degree of impact on the benthos with             and commercially valuable shellfish, the
                 changes in the areal extent, frequency,          public has been more attentive to this issue
                 and persistence of hypoxia events. But the       than to most others. As noted above, many
                 data base to allow such an analysis is not       believe that increasing nutrient inputs are
                 available.                                       promoting larger blooms of phytoplankton
                     '71ounder walk" is the local term de-        that eventually lead to more "dead water"
                 scribing movements of large numbers Of           and fish kills than in the past.
                 the fish into shallow waters along the               However, the results of our analysis of
                 Pamlico. The phenomenon typically occurs         the historical data do not support such a
                 in the summer during extended periods of         view. 'Mere has been no trend toward
                 hot weatherandcalm winds, and is usually         lower bottom water DO over the past 15
                 interpreted as evidence ofan hypoxic event       years. In addition, the Spearman Correla-
                 in the estuary. Data obtained from the           tion results detected no cause-and-effect
                 North Carolina Division of Environmental         relationship between nutrients or algal
                 Management show that low DO was                  abundance and bottom water DO. Of
                 suspected to be the cause of most fish kills     course, it could be argued that lag effects
                 investigated in the Pamlico during the           are involved which would not be detected
                 past two decades (NCDNRCD, unpublished           by comparing contemporaneous measure-
                 data). Most of the reported kills were not       ments. However, one of us (Nixon 1989)
                 in the main stem of the estuary, but rather      has searched - without success - for
                 near the heads of relatively small tributary     evidence of a link between either: 1) the
                 creeks. Menhaden were the species in-            size of the winter-spring blooms of phyto-








                    Stratification and Bottom Water Hypoxia                                                  89
                    plankton in the estuary and the frequency      in reducing the rate of increase in nutrient
                    and extent of hypoxic conditions in the        loading may be beneficial in the future.
                    bottom waters of the estuary the following     But reduction in N loading, at least within
                    summer, or 2) the summer bloom and the         any practical constraint, may not result in
                    severity of hypoxia.                           an increase in the oxygen content of the
                        The North Carolina Division ofEnviron-     stratified bottom water of the estuary
                    mental Management has recently desig-          during summer. At that time of year, the
                    nated the Tar-Pamlico as "Nutrient Sens i-     waters of the Pamlico are "wind sensitive,"
                    tive Water,"with the goal ofreducing nitro-    and we will have to accept the intermittent
                    gen loadingto improve water quality in the     hypoxia and anoxia as natural features of
                    estuary. We would not argue that success       the system.







                     CHAPTER6
                     The Pamlico River:
                     Comparisons with Other Estuaries

                     Introduction                                        "One of the things we can do is to look at
                        In the past, relatively few comparative          places like the Chesapeake Bay, the
                     studies of estuarine water quality have             Hudson River and the San Francisco Bay.
                     been made. It has been speculated that the          They were showing the same signs of stress
                     reasons for this include: 1) the widespread         about 10 years ago that the Pamlico is
                     belief among ecologists that estuaries are          showing now. . . the signals are there.
                     so variable that attempts to generalize                                  B.J. Copeland (1987)
                     from one to another are bound to fail; and      information contained in the Nixon report.
                     2) the great difficulty oforganizing, funding,  Anyone interested in comparative estuarine
                     and executing studies of more than one          ecology should consult this source; it is one
                     system (Nixon 1983). During the 1990s,          of the most comprehensive reports on the
                     the U.S. Environmental Protection Agency        subject available at this time.
                     plans to carry out a major, national com-           Another comparative study that pro-
                     parative study of estuaries as part of its      vided useful data was authored by Boynton
                     Environmental Monitoring and Assess-            etal. (1982). Theyrevi       ddataconcerning
                     ment Program (EMAP).                                                   ewe
                        In addition, few comparative analyses        nutrients, phytoplankton production, and
                     ofexistingdata for different estuaries have     chlorophyll a from 63 different estuarine
                     been published. S.W. Nixon, an estuarine        systems. Finally, I have attempted to
                     ecologist experienced in comparative syn-       make some comparisons between the Pam-
                     theses, points out that attempts at such        lico River and the nearby Neuse River
                     reviews are hampered by the relatively          estuary. Unpublished 1985 and 1986 nutri-
                     small number of estuaries that have been        ent and hydrographic data from the Neuse
                     thoroughly studied, by differences in           study were used to illustrate similarities
                     methodology used to produce the data, and       and differences between it and the Pamlico
                     by the problems that arise from spatial and     River.
                     temporal variability within each system         N utrients
                     (Nixon 1983).
                        Nixon (1983) used previously published           Comparing cycles of orthophosphate
                     and unpublished information for his com-        phosphorus in 14 estuaries, Nixon (1983)
                     parative study of fourteen estuaries on the     found that annual mean concentrations
                     Atlantic, Gulf, and Pacific Coasts of the       were less than 1 pM in Chesapeake Bay, in
                     United States. Fortunately, the Pamlico         the mid and lower regions of the Potomac
                     River was one of the estuaries included in      River Estuary, in Apalachicola Bay, Flor-
                     the study. Topics covered include physical      ida, and in Kaneohe Bay, Hawaii. Highest
                     characteristics, nutrients, phytoplankton       mean concentrations were found in the
                     and primary production, zooplankton,            Pamlico River (approximately 4 gM) and in
                     icthyoplankton, benthos, and fish. In this      South San Francisco Bay (about 25 pM).
                     chapter, I have relied heavily on               All the other systems had mean annual








                   92                                                                                 Chapter 6
                   phosphate levels of 1-3 1AM. One feature          effects ofdifferent flushingrates were taken
                   common to most of the estuaries, including        into account (Figure 6.1b). This correction
                   the Pamlico River, is the summer increase         was made by multiplying the annual input
                   in phosphate, particularly at their lower         by the approximate mean annual fresh-
                   reaches. Presumably, the high Pamlico             water replacement time. The estuarine
                   phosphate is due to the large discharge           data appeared to follow the same relation-
                   from the Texasgulf phosphate mine on the          ship found for lakes by Schindler (1978).
                   south shore of the estuary (see Chapter 3).          A comparison of salinity and nutrients
                       The relationship between phosphate            in the Pamlico River and the Neuse River
                   input and concentrations that Nixon devel-        showed that except for orthophosphate
                   oped may provide a clue as to whether or          phosphorus, there was little difference be-
                   not the Pamlico phosphate levels would            tween the two estuaries. Volume-weighted
                   decrease if loadingfrom Texasgulf, orother        monthly medians for the period January
                   sources, were decreased. From a plot of           1985 to December 1986 were calculated
                   phosphate input versus mean annual phos-          and are plotted in Figure 6.2. This method
                   phate concentration for all the estuaries         of presenting the data eliminates bias aris-
                   surveyed (Figure 6.1a), Nixon concluded           ing from different sampling station loca-
                   that indeed there is a correlation between        tions in each estuary relative to the salinity
                   the two. There was considerable scatter in        gradients. The problem is most severe for
                   the data, but this was reduced when the           factors that vary greatly along the salinity
                                                                     gradient. The weighted monthly median
                                                                     salinities ranged from 8 ppt to about 13 ppt
                       2,100                                         in the Neuse and from 8-12 ppt in the
                       :3
                       4.   A                                        Pamlico. Both estuaries had highest
                       0
                       CL  10                                        salinities in the fall and lowest salinities in
                                                                     the late winter. Nitrate nitrogen was
                       z                        MP                   around 1 1LM in both the Neuse and Pamlico
                       z  1           M%
                       <                                             during the summer, and 5-12 tkM in the
                       z
                       <                                             winter (Figure 6.2b). February and March
                       W 0.1
                           1           10          100         1000 median values were higher in the Pamlico,
                                  P04 INPUT (M MOL M  3 Y1           but November and December values were
                                                                     higher in the Neuse. Overall, there seems
                        100                                          to be no significant difference in the nitrate
                            B
                                                                     between the two estuaries. Similarly,
                       0
                       a-  10                                        ammonia nitrogen was higher in the Neuse
                       _j
                                                                     some months and in the Pamlico during
                       z                  0 a USE
                       z  1                                          other months (Figure 6.2c), but there
                       z         E S                                 appears to be no substantial difference
                       W 0.1                                         overall.
                           1                  10                100      Both estuaries, had highest orthophos-
                                   P04 LOADING (M MOL M              phate phosphorus in the summer months
                                                                     (Figure 6.2d), and lowest values in the
                   Figure 6.1. A. Mean annual concentrations of      winter. The winter values were. similar for
                   inorganicphosphorus (ILM) in several estuaries as aboth - around 1 /iM - but the Pamlico
                   function of the estimated annual inputs       of  had higher summer phosphate than the
                   phosphorus. P = Pamlico River estuary. B. Same as
                   above except that inputs have been corrected for  Neuse. The difference was nearly two-fold
                   differences in flushing times (Redrawn fi-om Kgure for most months between June and Decem-
                   14 in Nixon 1983).








                        The Pamlico River: Comparisons with Other Estuaries                                                   93
                        ber. This difference probably reflects the           Bay. The Pamlico average was 18 AM,
                        influence of P loading from the Texasgulf            about the same as the Patuxent River
                        (TG) facility into the Pamlico. The more-or-         Estuary, Chesapeake Bay, Potomac River,
                        less constant TG loading ought to be most            and North San Francisco Bay (Nixon 1983).
                        noticeable in the low-flow periods (i.e.,            Nixon's plots of mean annual DIN concen-
                        summer and fall) when Tar River P loading            tration versus DIN input and loading
                        is reduced.                                          (Figure 6.3), prepared in the same manner
                            Nixon (1983) also compiled data on               as the DIP loading versus concentration
                        annual cycles of inorganic nitrogen (DIN)            plots described above, led him to conclude
                        for a number of estuaries, including the             that there is a linear relationship between
                        Pamlico River. Two of his general conclu-            nitrogen loadingand the average concentra-
                        sions about DIN cycles apply to the Pamlico:         tions observed in the estuaries. But the
                        1) nitrate is often more abundant than               slope of a line drawn through this data
                        ammonia during spring and fall in the                would be less than one, indicating that DIN
                        lower salinity systems, and 2) concentra-            concentrations do not rise or fall in estuaries
                        tions of nitrate appear highest in the upper         in 1:1 proportion to changing loading. It
                        portion of the estuaries. However, the               appears that a doubling in the loading rate
                        range in annual mean concentrations was              ought to produce about a 50% increase in
                        very large; from about 1 AM in Kaneohe               mean concentration.
                        Bay, Hawaii, to over 100 AM in Delaware



                          20-                                                m 14 -
                                                                             = 12-                                    B
                                                                             z
                        a.15-          NEUSE             PAMLICO             W10-         NEUSE            PAMLICO
                        IL                                                   0
                                                                             0  8-
                        M                                                       6-
                                                    X
                                                                             z
                        -j  5-                                               W  4-
                                                                                2-
                                                                             Ir
                            0-                                                  0-
                              J F M A M J J A S 0 N D                               J F M A M J J A S 0 N D
                                             MONTH                                                  MONTH

                                                                             M12-
                        =L                                         C         a                                           D
                        z                                                    a.10-
                        W6-         NEUSE             PAMLICO                W            NEUSE            PAMLICO
                        8                                                    !R 8-
                        04 -                                                    6-

                        z
                        <2-                                                  0  4-
                                                                                2
                        20-
                                                                             0
                        0                                                               K
                        2 J     F  M   A M    J   J A    S  0 *'N   D        cr     J  F M A M       J  J  A   S  0   N D
                                             MONTH                           0                      MONTH


                        Figure6.2. Salinity, nitrogen andphosphorus in the Pamlico River and Neuse River estuaries, 1985-1986.
                        Values are volume-weighted monthly medians. (A) Salinity (ppt), (B) Nitrate nitrogen (AM), (C)Ammonia
                        nitrogen (AM), (D) orthophosphate phosphorus (AM).









                     94                                                                                                                   Chapter 6

                            1000
                                     A                                                          There continues to be much controversy
                            Z                                                                and uncertainty surrounding the issue of
                                100
                                                                                          nutrient limitation in estuaries. Over the
                                                                                             past two decades, the general consensus
                            
                                  10
                                                                                            has been that nitrogen is more likely than
                                                                                            phosphorus to limit algal growth. Boynton
                            l       
                                   10             100            1000            10000     et al. (1982) compiled data on N:P concen-
                                               DIN INPUT (M MOL M -3y                        trations and ratios from nearly 30 estuaries,
                                                                                             including the Pamlico River (Figure 6.4).
                            1000                                                            Here are their conclusions:
                                       B
                            
                                  100                                                             'The data ... support the notion that
                                                                                                  nitrogen is consistently less abundant
                                                               P
                                  10                                                             than phosphorus during periods of
                                                                                                  peak [algal] productivity in a wide
                                                                                                  variety of estuarine ecosystems. In
                                     0.1          1           10        100         1000          most cases, those those that do not
                                            DIN   LOADING (M MOL       M  .3 Y-1                  follow this patternare heavilyenriched
                                                                                                  by point and diffuse nutrient sources
                         Figure 6.3. A. Mean annual concentrations of                             throughout the year (e.g., HighVenice
                         inorganic nitrogen (IM) in several estuaries as a                       Lagoon, Hudson River). On the right
                         function ofthe estimated annual inputs ofnitrogen.                       side of [Figure 6.4], actual concentra-
                         P = Pamlico River estuary. B. same as above except                       tions of DIN and DIP [orthophosphate
                         that inputs have been corrected for differences in                       phosphorus] at the time of peak produc-
                         flushing times (Redrawn from Figure 17 in Nixon
                         1983).
                                                                              Nitrogen         Phosphorus Ratios                      ug-at 14
                                     RIVER DOMINATED                      0            10           20           30           40
                                                                                                                                          N P

                                     PAMLICO RIVER, NORTH CAROLINA
                                     NARRAGANSETT BAY, RHODE ISLAND
                                                                                              
                                     WESTERN WADDEN SEA, NETHERLANDS                                           1.5     120         3.0/ 2.0
                                     EASTERN WADDEN SEA, NETHERLANDS                                                0.5                  4.0/2.5
                                     KID-PATUXENT RIVER. MARYLAND                                                                     4.2/2.3
                                     LONG ISLAND SOUND. N.Y.
                                     LOWER SAN FRANCISCO BAY, CALIF.
                                                                                                                                        20.6 / 3.8
                                     BARATARIA BAY. LOUISIANA                                                                             4.6/0.8
                                     UPPER SAN FRANCISCO BAY,   CALIF.
                                     VICTORIA HARBOR, BRITISH   COLUMBIA
                                                                                                                                        1.5
                                     MID-CHESAPEAKE BAY,MD.                                                           0.5 20.6.
                                     UPPER PATUXENT RIVER, MARYLAND                                                                     1.12.0
                                     HUDSON RIVER, NEW YORK                                                             60.0 /3.0
                                     APALACHICOLA BAY. FLORIDA                            .............                61              5.0 /0.16
                                     UPPER CHESAPEAKE BAY. NO.                                                                  240     10.0 /0.1
                                                                                                              52


                         Figure6A. Seasonal mean DIN.DIP ratios from16 river-dominated estuarine ecosystems. Horizontalbar8
                         indicate the annual ranges in DIN.DIP ratios, solid triangles represent ratio at time of maximum
                         productivity. Absolute concentrations (AM) at time ofpeak productivity are on the right. Vertical band
                         represents the typical range of algal composition ratios (part of figure 5 in Boynton et al. 1982).
 







                      The Pamlico River: Comparisons with Other Estuaries                                            95

                          tion are shown. Clearly, actual concen-       estuary during the late spring, while N
                          trations vary considerably between            limitation is more significant at the mouth
                          various estuaries and it is an open           of the estuary during the summer.
                          question whether these concentrations
                          are limiting. However, nitrogen enrich-
                          ment in estuarine areas often stimu-          Dissolved oxygen
                          lates algal growth, indicating that de-           Chesapeake Bay was one of only two
                          spite relatively high ambient concen-         estuaries found to have serious low Do
                          trations, nitrogen limitation of phyto-       problems in a review of 14 systems by
                          planktonic production can occur               Nixon (1983) (the other was Mobile Bay).
                          (Ryther and Dunstan 1971; Williams            The low oxygen phenomenon has been
                          1972; Goldman et al. 1983; Thayer             experienced for many years in the Chesa-
                          1974)"     (Boynton et al. 1982, page 78).    peake, he noted, and may be, in part at
                                                                        least, a natural feature of the system. The
                          Some ecologists, after making detailed        Bay's deep channel, lying between broad,
                      studies of individual estuaries, have come        shallow, very productive waters, maycollect
                      to the conclusion that phytoplankton              and concentrate much ofthe organic matter
                      growth limitation shifts from N to P at           fixed in the shallows. Nixon speculated
                      different times of the year. There seems to       that this enrichment, combined with a
                      be a seasonal pattern in the shifts. For          well-stratified water column, may cause
                      example, Webb and Eldridge (1988) con-            the anomalous low oxygen feature. In
                      ducted experiments in the lowerYork River         Mobile Bay, the deep channel (Mobile Ship
                      that showed the phytoplankton were P              Channel) is well oxygenated and the low
                      limited in the late fall and winter, and N        oxygen water is spread out over shallows
                      limited in the late spring and summer,            that have been isolated from much of the
                      They speculated that seasonal shifts in p         tidal circulation by shoals and dredge spoil
                      and N inputs to the estuary were the most         (Nixon 1983).
                      likely cause of the shift. In the York River,         I recently attempted an assessment of
                      P shows maximum concentrations in sum-            dissolved oxygen conditions in the twenty-
                      mer and the minimum in winter; the major          three estuaries in North Carolina, South
                      input ofN is nitrate from wintertime runoff.      Carolina, and Georgia for which some data
                      Recall that this is the same as the pattern       were available (Stanley 1985). One con-
                      for the Pamlico River (see Chapter 4).            clusion from this review was that none of
                          These results parallel those from stud-       these estuaries suffer from extended,
                      ies in a low salinity portion of the Chesa-       widely-ranginghypoxia. Rather, the events
                      peake Bay system (D'Elia et al. 1986), and        appear to be of short duration and do not
                      inotherareas ofthebay (Fisheretal. 1988-,         appear to have a serious impact on the
                      Malone 1988; Love et al. 1988). Despite           estuaries, although benthic fauna are
                      extreme nutrient enrichment in the head-          affected temporarily. Lack of long-term
                      waters of the Delaware estuary, phyto-            monitoringdata for all these systems except
                      plankton productivity in the middle and           the Pamlico River makes it impossible to
                      lower estuary alternates between light,           determine exactly how much impact cul-
                      phosphorus and nitrogen limitation over           tural eutrophication has had on the oxygen
                      the seasonal cycle, according to (Pennock         conditions.
                      and Sharp 1988). It is also their view th--'-         Turner et al. (1987) showed that oxygen
                      these factors var*y spatially over the salinity   depletion in the bottom waters of Mobile
                      gradient. In general, Delaware Bay P              Bay is caused by the same factors operating
                      limitation is most prominent in the mid-          in the Pamlico River. They found that









                       96                                                                                                      Chapter 6

                       hypoxia was directly related to the intensity                 their new findings as follows:
                       of water column stratification, which, in
                       turn, was coincidental with low wind                               "Analysis of the complete data base on
                       speeds. More than 80% of the variation in                          measurements of dissolved oxygen in
                       DO content in their samples was explained                          the Chesapeake Bay for the period
                       by variations in the vertical salinity                             1950-1985 results in two conclusions:
                       gradient.                                                          a) there has been no statistically
                                                                                          significant pattern of increase in
                            An analysis showing a trend toward                            summer anoxia of bay waters over the
                       worsening dissolved oxygen conditions in                           past 36 years, and b) annual
                       the bottom waters of Chesapeake Bay has                            stream flow-induced stratification is the
                       been widely publicized (e.g., Officer et al.                       controlling factor in the annual volume
                       1984), but the study conclusions have been                         of summer anoxic waters in the bay, at
                       questioned by other bay-area scientists                            greater than the 99.99% confidence
                       (Seliger and Boggs 1988) who have re-                              level. These conclusions are in sharp
                       examined the data. They summarized                                 contrast with those of an EPA-funded
                                                                                          5-year study of the bay and with those


                                                                                      Chlorophyll a, Mg m-3
                                                                    0              65         10           15            20          2-5
                                                                    1              1           1          1         

                       MEYERS CREEK. MEW JERSEY                     SP Su
                       GULF OF ST. LAWRENCE , CANADA                W  Sp
                       FRASER RIVER. BRITISH COLUMBIA               W 
												SU
                       STRAIT OF GEORGIA, BRITISH COLUMBIA          W SU
                       VICTORIA HARBOR, BRITISH COLUMBIA            W- Su
                       HUDSON RIVER, NEW YORK                       W Su
                       ALTAMAHA RIVER MOUTH, GEORGIA                     W
                       MID-ALTAMAHA RIVER, GEORGIA                   W               Su
                       WACCASASSA RIVER. FLORIDA                       
                       BURRARD INLET, BRITISH COLUMBIA              W,F                            Sp
                       YTHAN ESTUARY, SCOTLAND                           Sp        0       Su
                       APALACHICOLA BAY, FLORIDA                                   F      S P
                       DUWANISH RIVER, WASHINGTON                    W                                   Su
                       LONG ISLAND SOUND, N.Y.                        W              Su
                       NARRAGANSETT BAY. R.I.                       W,   F                          Sp
                       MID-CHESAPEAKE BAY, NO.                       W                                 F
                       COLUMBIA RIVER, WASH.                               W                         Su
                       WESTERN WADDEN SEA. NETHERLANDS                     W                                  W.-Su
                       EASTERN WADOEN SEA, NETHERLANDS
                       BARATARIA BAY. LOUISIANA                                    F            66            W. Sp
                       UPPER CHESAPEAKE BAY. NO.                                                                                      a Suq, F
                      MID-PATUXENT RIVER, NO.                                                                                         38 Su
                       LOWER PAMLICO RIVER. N.C.                                          Su. F                                         W. Sp
                       RARITAN BAY, N.J.                                 W                                                             12& 45 Su
                       UPPER PATUXENT RIVER. NO.                           W                                                 Su


                       Figure 6.5. Summary ofchlorophyll aconcentrations in 25 estuaries. Annual ranges and Seasons in which
                       maximum and minimum concentrations occurred are indicated. Solid triangle indicates chlorophyll a
                       concentration at time of maximum productivity (part of Figure 4 in Boynton et al. 1982).
 








                      The Pamlico River: Comparisons with Other Estuaries                                                     97

                          of a major review of anoxia published                  any evidence for increased summer
                          in Science [Officer et al. 19841, namely               anoxia since the 1950s, the scientific
                          that anoxia in the bay has increased                   basis of this program should be re-
                          by a factor of 15 since 1950 and that                  evaluated"
                          benthic respiration, rather than strati-                                 (Seliger and Boggs 1988).
                          fication, has been the controlling factor
                          in this 15fold increase in anoxia. This           Chlorophyll a and
                          apparent increase in anoxia has been               Phytoplankton Biomass
                          attributed to increased nutrients and
                          has been assumed to be a major factor                  In his comparative estuarine study,
                          in the decline of fish and shellfish               Nixon (1983) also presented data on the
                          species in the bay. A federal and                  standing crop of phytoplankton, as esti-
                          multi-state program for restoring the              mated by chlorophyll a. The estimated
                          bay biota is based on reversing this 15-            annual mean for the Pamlico River was
                          fold increase in anoxia by reducing                about 16 ug/liter. For all the estuaries, the
                          nutrients in the bay. In the absence of            range was from about 2 jig/liter in Kaneohe


                                                                 Phytoplankton Production, g C m-2 d (net)
                                                                 0        0.5        1.0           1.5        2.0          2.5
                                                                 W SU           I          I            I           I           I
                      ST. LAWRENCE RIVER, CANADA                 W   Su
                      UPPER SAN FRANCISCO BAY, CALIF.            W-. SU
                      FRASER RIVER, BRITISH COLUMBIA               2qo
                      UPPER PATUXENT RIVER, MD.                  w -su 
                      STRAIT OF GEORGIA. BRITISH COLUMBIA          W Su
                      WESTERN WADDEN SEA, NETHERLANDS             W             Su
                      SWARTVLEI, SOUTH AFRICA                             Sp
                      WACCASASSA RIVER, FLORIDA                  W       a   SU
                      EASTERN WADDEN SEA, NETHERLANDS           W       0        SU
                      MEYERS CREEK, NEW JERSEY                    SPSu
                      UPPER CHESAPEAKE BAY, NO.             W.   SP6                                 Su
                      HUDSON RIVER, NEW YORK                     W                                                    Su
                      LONG ISLAND SOUND. NY                                 , Su
                      DUMANISH RIVER, WASH.                       W                        Su
                      COCHIN BACKWATER, INDIA                            W       S P
                      BARATARIA BAY, LOUISIANA                   W                                   SU
                      LOWER SAN FRANC1SCO DAY, CALIF.                    W      sis, r
                      mio-PATXUEANT RIVER. MD.                            W                         SU
                      RARITAN BAY, NEW JERSEY                                                        Su
                      NARRAGANSETT DAY. RHODE   ISLAND                   W                                     4                      BURRARD INLET. BR1T1SH COLUMBIA          W                                     Sp
                      APALACHICOLA BAY, FLORIDA                                W-SP
                      MID-CHESAPEAKE BAY. RD.                              W                         F
                      PAMLICO RIVER, NORTH CAROLINA                                 F                                Su
                                                                                  W                                         SU
                      ALTAMAHA RIVER MOUTH, GEORGIA


                      Figure6.6. Summary of average daily phytoplanktonproduction rates (solid dot) in 25 estuarine systems.
                      Horizontal bars indicate annual ranges. Season in which maximum and minimum rates occurred is also
                      indicated W, winter, Sp, spring, Su, summer, F, fall) (part of Figure 3 in Boynton etal. 1982).
 







                    98                                                                                        Chapter 6

                                                                          Bay, Hawaii, to almost 20 jig/liter for the
                           10
                        _J       A                                        Patuxent River estuary. A winter-spring
                                                  P
                                                                          bloom was found to occur in a number of
                                                                          the estuaries, including the Pamlico, of
                        z   10
                        z                                                 course, but was inconspicuous or absent in
                        z                                                 others. Some estuaries had strong mid-
                                                                          summer blooms.
                               0.1      1        10       100      1000       Boynton et al. (1982) also presented
                                     DIN LOADING (M MOL M    -3           comparative data on chlorophyll a and
                                                                          average daily primary production rates in
                        <  10                                             thePamlico Riverand in 44 other estuarine
                        _J       B
                                                                          systems (Figures 6.5 and 6.6). The Pamlico
                                                  P
                                                                 %
                                                                          data used in this comparison were from the
                        z   10                                            early-to-mid 1970s. In terms ofboth chloro-
                        z
                        <                                                 phyll a and primary productivity, the
                        z
                                                                          Pamlico ranked as one of the highest of the
                                                                          river-dominated estuaries included in the
                              0.01     0.1        1        10       100   comparison. However, there is so much
                                     P04 LOADING (M MOL M                 overlap amongthe top third of the systems,
                    Figure 6.7.    Mean annual chlorophyll     a as a     that real differences, if they exist, are
                    function oftheestimatedannual loadingofdissolved      obscured. These plots also cannot take into
                    inorganic nitrogen (top) and dissolved inorganic      account the considerable year-to-year vari-
                    phosphorus (bottom). P = Pamlico River. The           ability in algal biomass and productivity
                    regression line relating mean annual chi a in lakes   within each estuary, so that individual
                    toPloading is from Schindler (1978) (redrawnfi-om
                    Figure 20 in Nixon 1983).                             rankings are impossible. The authors of
                                                                          this paper drew no conclusions regarding
                                                                          the order of the rankings, such as effects of
                                                                          nutrient loading, hydrography, or climate.
                    _40-                                                      One of the most interesting of all the
                    ;:z                                                   comparisons in the Nixon study described
                    ca
                    =   30-      NEUSE              PAMLICO               above was between nutrient loading and
                    to                                                    chlorophyll a (Figure 6.7). The results were
                    _J                                                    described as follows:
                    -J20-

                                                                                     I have made a preliminary
                    010-
                                              . . . . . . . . . . . .
                                                                              attempt to relate the annual mean chl
                        0                                                     a averaged over each estuary to the
                                                                              input of inorganic nitrogen and phos-
                           J F M A M J J A S 0 N D
                                           MONTH                              phorus... The results are not without
                                                                              scatter, but as abeginningl thinkthey
                                                                              are impressive enough to merit
                    Figure6.8. Chlorophyll a in the Pamlico River and         attention and further effort.... The
                    Neuse River estuaries, 1986. Values plotted are           response of estuarine phytoplankton
                    volume-weighted monthly medians.                          may not be as dramatic as that of
                                                                              lakes. While nitrogen and phosphorus
                                                                              loadings increased 2000 times from
                                                                              Kaneohe Bay to the most heavily
                                                                              enriched MERL microcosm, the annual
                                                                              standing crop of chl a only increased








                       The Pamlico River: Comparisons with Other Estuaries                                                      99

                       Table 6.1. Summary ofphytoplankton data fi-om several east coast estuaries. BAC = Bacillariophyceae
                       (diatoms), CHL Chlorophyceae, CYA = Cyanophyceae, CHR = Chrysophyceae, and DIN = Dinophyceae.
                       S =total number ofspecies found;- D =average cell density (cells 1"), andB =averagebiomass (mgwetmass
                       1-1).

                       South Creek,                     S: 146          47       17        2        7       10       21      0-10
                       This Study                       D: 3.9 x 1(r    14       11        6       61        6        2
                                                        B: 1.60         14       14       <1       16       51        4


                       South Creek,                     D: 52.7 x 106                                                <15
                       Hobbie (1971)                    B: 9.11

                       Pamlico River,                   S: 173          50       18        3        6        8       15      0-20
                       Stanley and Daniel (1985)        D: 4.2 x 106      3      14       <1       59       20        3
                                                        B: 3.37           3       7       <1        8       80        1

                       Gales Creek, NC,                 S: 339          55        7       -         5       22       11
                       Campbell (1973)

                       Cape Fear River, NC              S: 203          66       12        4        1        7       10      11-15
                       Carpenter (1971)

                       Chowan River, NC                 B: 5.61         20       11       22        1       29       17          0
                       Stanley and Hobbie (1981)

                       Neuse River, NC                  S: 297          23       37       14        9        4       13      0-10
                       Stanley (unpublished)            D: 12.5 x 100   12       16       63        3       <1        5
                                                        B: 3.48         15       34        2        6       17       26

                       Currituck Sound, NC,             S: 204
                       Tyndall (1980)                   D: 6.6 x 106
                                                        B: 0.48         13       20       22        5       17       22

                       Chesapeake Bay,                  S: 149          49       13        2        6       17       13      5-20
                       Van Valkenburg et al. (1978)     D: 10 x 106     21       21       10       18       10       20
                                                        B: 3.97         28       <1       <1        6       56        8

                       Chesapeake Bay,                  S: 219          59        1        4        4       19       13        >20
                       Old Plantation Creek,
                       Marshall (1980)

                       James River Estuary,             S: 74           70        9        1        0       11        9       >15
                       Marshall (1967)                  D: 1.3 x 106

                       Narragansett Bay,                S:75            57        2        0        3       19       19     28-30
                       Smayda (1957)                    D: 6.7 x 106    94                                   6








                  100                                                                                Chapter 6

                      about 30-fold. The consequences of            studies were nonquantitative, emphasiz-
                      such an increase may still be pro-            ing systematics, rather than cell counts, or
                      found, of course, and evidence of an          had used preservation techniques (e.g.,
                      apparently linear response to nutrient        formalin solutions) that destroy the micro-
                      input confirms the importance of              flagellates which make up so much of the
                      eutrophication as a concern in estu-
                      arine management. Since maximum               total phytoplankton biomass in estuaries.
                      chl a levels increase with increasing         Hobbie was able to compare his results
                      average values ... it follows that more       with those from a study by Patten et al.
                      intense blooms are part ofthe response        (1963) of the phytoplankton in the York
                      to increased nutrient input. These            River estuary, and he concluded that the
                      blooms, more than the average                 yearly cycles in these two systems were
                      standing crops, may have the greatest         similar. Both rivers had mostly flagellates
                      impact on estuarine water quality"            upriver and more diatoms toward the
                                  (Nixon 1983, page 25-26).         mouth. Also, both had blooms of the
                      Of course, individual estuaries like the      dinoflagellateHeterocapsatriquetra (called
                                                                    Peridinium t7iquetrum inthe Hobbie [19711
                  Pamlico are unlikely to experience changes
                  in nutrient loading as great as the range         report) in late winter and early spring.
                  among these estuaries. Figure 6.7 shows           Although he gave no details, Hobbie com-
                  that the rates of change of chlorophyll a         mented that "the rest of the algae species
                                                                    found in the Pamlico Riverestuaryare also
                  with increasingN and P loadingare actually        found in Chesapeake Bay and farther
                  quite small. This suggests that if N or P         north" (Hobbie 1971, page 30).
                  loading in the Pamlico were to decrease by            By 1985, quantitative phytoplankton
                  50%, the chlorophyll might be expected to         studies had been made for several east
                  decline by only about 10%.                        coast estuaries. Stanley and Daniel (1985b)
                      Chlorophyll a concentrations in the           compiled the results from these for com-
                  Pamlico were similar to those in the Neuse        parison with their more recent Pamlico
                  River estuary in 1985 and 1986, despite           survey (Table 6. 1). They discussed several
                  the higher phosphorus levels in the Pamlico       similarities between the Pamlico phyto-
                  (Figure 6.8). The volume-weighted monthly         plankton pattern and those from the other
                  median chlorophyll a's were highest in            estuaries. First, the Pamlico species com-
                  both estuaries in the summer months and           position, as reflected in the percentages of
                  lowest in the winter months. Fifteen to           species in each algal class, was similar to
                  twenty-five jig/liter values were typical         those for most other estuaries included in
                  during the summer, while the winter con-          the comparison. Generally, diatoms (class
                  centrations were generally 8 4g/liter or          Bacillariophyceae) was the most diverse
                  less. Summer chlorophyll a values seemed          group, followed by the Chlorophyceae
                  to be slightly higher in the Neuse, although      (green algae) and Dinophyceae (dino-
                  the difference is probably not statistically      flagellates). Together, these three groups
                  significant. It should be noted that data         usually comprised 75% or more of the total
                  from the lower Neuse River, where blue-           species.
                  green algal blooms occur, were not used in            Another similarity was that chryso-
                  these comparisons.                                phytes and dinoflagellates appear to be
                      At the time of Hobbie's 1971 Pamlico          predominant in terms of average cell den-
                  study, there had been very few studies            sity and biomass. In addition, the average
                  published of phytoplankton species com-           wet weight biomass and density did not
                  position and biomass along the south-             range widely among those estuaries for
                  eastern U.S. coast. Most of the earlier








                    The Pamlico River: Comparisons with Other Estuaries                                      101

                    which estimates were available. Biomass        most other estuaries. The overall similari-
                    averaged 3.37 mg/liter in the Pamlico, 5.61    ties in patterns of algal abundance in estu-
                    mg/liter in the lower Chowan River, 3.48       aries of this region are striking, given the
                    mg/liter in the lower Neuse River, 3.97 mg/    great seasonal and spatial variability with-
                    liter in Chesapeake Bay, and 0.48 mg/liter     in each of the estuaries. In fact, it appears
                    in Currituck Sound.                            from this comparison that average algal
                       Finally, the microflagellates have been     abundance in the estuaries of this region is
                    found to contribute heavily to the total       much less variable than the seasonal and
                    algal biomass in the Pamlico (Stanley and      spatial variation within any one of the
                    Daniel 1985), in Chesapeake Bay (Van           systems.
                    Valkenburg et al. 1978), and probably in







                      CHAPTER7


                      Trends in the Sounds' Fisheries


                          TheAlbemarle-Pamlico system has sup-              The fish, oyster and game problem of North
                      ported commercial fisheries for over a                Carolina demands serious attention and
                      century, but as the newspaper editorial               vigorous remedies for their restoration.
                      excerpt (at right) suggests, there were               We hang our heads in shame when
                      problems for the industry almost from its             Wilmington restauranteurs advertise
                      beginning. This editorial was prompted by             Norfolk oysters, while the once famous
                      a fisheries convention held at Wilmington,            New River oyster has practically
                      NC in December 1911 "to take some action              disappearedfrom the market Instead of
                      in regard to the great depletion of the               robbing our rivers and bays and sounds of
                      fishingindustries in the State" (Pratt 1912).         their fish and oysters, we should be
                      Politicians, fisheries "experts" and local            conserving theM taking plenty and leaving
                      fishermen participated in the convention.             plenty to increase the supply. But like
                      Many hypotheses were raised to explain                many other matters that have to be solved
                      the demise of the fisheries, and the                  by our law-making bodies, it is hard to get
                      discussion was intense - at times heated;             an application of common sense.
                      but little concrete evidence was available                               Wilmington Star (1911)
                      to substantiate most of the claims and
                      counterclaims. However, the convention            commercial species are reported by county,
                      was followed by some new state regulations        and annual totals are published in the
                      intended to "protect and perpetuate" the          North CarolinaLandings series. Chestnut
                      fishing industry.                                 and Davis (1975) compiled the data from
                          This scenario has, of course, been            the annual reports for the 1880-1973 pe-
                      repeated many times since, as North               riod in their Synopsis of Marine Fisheries
                      Carolina and other coastal states have            in North Carolina. I used the data in that
                      struggled to balance diverse, often               synopsis, along with statistics for more
                      competing, interests in various schemes to        recentyears in theAnnual Summary (1974-
                      manage the commercial and recreational            1979) or monthly reports (1980-1987) of
                      fisheries in our nations estuaries.               North Carolina landings published jointly
                                                                        by the North Carolina Division of Marine
                      Commercial Fisheries                              Fisheries and the U.S. National Marine
                      The Database                                      Fisheries Service (National Marine Fish-
                          The first comprehensive statistical sur-      eries Service 1974-1979; North Carolina
                      vey for North Carolina was made in 1880           Division of Marine Fisheries 1980-1987).
                                                                     '  Only the data from counties in the N.C.
                      and partial or complete surveys have been
                      made at varying intervals since then. Com-        Division of Marine Fisheries Central and
                      plete statistics are available for the years:     Northern Districts were tallied to give the
                      1880, 1887-1890, 1897, 1902, 1908, 1918,          totals reported in this study. These dis-
                      1923, 1927-1932, 1934, 1936-1940, 1945,           tricts include all the coastal counties from
                      and 1950 to date. Monthly landings ofeach         Carteret northward (Chestnut and Davis








                 104                                                                             Chapter 7
                 1975).                                          analysis of the status and trends of the
                     The usual limitations of commercial         Albemarle-Pamlico commercial and recre-
                 landings statistics should be kept in mind.     ational fisheries was made by Hogarth et
                 First, and most important, they measure         al. (1989).
                 the quantity of fish landed, which is not
                 necessarily a good indicator of the abun-       Edible Finfish
                 dance of the species. One reason for this          The development of commercial
                 discrepancy is that fishing"effort" is gener-   fisheries in the Albemarle-Pamlico region,
                 ally not taken into account. Effort fluctu-     especially along the Outer Banks, was
                 ates in response to changes in demand (i.e.,    retarded in the 1800s by the difficulty of
                 price per pound) for the species, fishery       delivering seafoods, while they were fresh,
                 technology, the cost of fishing (e.g., fuel     from these remote areas to the inland
                 prices), weather, and restrictions imposed      consumers. Consequently, the earliest
                 by state and federal agencies. Second, the      fisheries were engaged in catching those
                 fact that fish are landed in a particular       types of fish which could be preserved for
                 county does not necessarily mean that           later sale. Thus, the first commercial
                 they were caught in nearby waters. Even         fisheries up the rivers and sounds
                 worse, no distinction is made in the sum-       concentrated on such species as alewives
                 mary landings reports between fish caught       (herring) and shad, which could be smoked
                 in the sounds and those caught offshore in      orsaltedwithoutlos ing their flavor. These
                 the Atlantic Ocean. Finally, the older data     anadromous species were caught in large
                 are somewhat suspect because there prob-        numbers during their annual spawning
                 ably was underreporting and because dif-        migrations with seines operated from the
                 ferent species in the same group were not       mainland along the shores of Albemarle
                 always tallied separately (Chestnut and         Sound and the Chowan River. These
                 Davis 1975).                                    fisheries, along with whaling, were the
                     A good description ofthe biology ofeach     limit ofcommercial fishingalongthe North
                 of the major commercial species and some        Carolina coast until the mid-1800s (Stick
                 analyses of trends in the North Carolina        1958; Godwin et al. 1971).
                 commercial landings up through the mid-             Commercial fishing really began on a
                 1940s were made by the following con-           large scale in North Carolina following the
                 tributors to the Study of Marine Fisheries      Civil War, as coastal residents came to
                 in North Carolina (Taylor 1951): E.W.           recognize the potential income represented
                 Roelofs (for edible finfishes), A.F. Chestnut   by the seafood in the nearby waters. Seine
                 (oysters), C. Broad (shrimp), J.C. Pearson      fishing spread, and by the 1870s, shad
                 (blue crabs), and WA. Ellison, Jr. (menha-      fisheries were operating around Roanoke
                 den). Later reviews of the catch data can       Island and in Pamlico Sound. An important
                 be found in reports by Godwin et al. (1971)     mullet fishery developed in Core Sound at
                 and the North Carolina Division of Marine       about the same time. The catch was salted
                 Fisheries (1984). David Stick's (1958) book,    and taken to Morehead City where it could
                 entitled The Outer Banks of North Caro-         be shipped out by train (Stick 1958). Pound
                 lina, contains a chapter on the history of      nets were introduced about 1869 and, along
                 fisheries along the North Carolina coast,       with gill nets, proved so efficient that most
                 with interesting details gleaned from a         of the Albemarle haul-seines gradually
                 review of the late nineteenth century           went out of business. During the late
                 printed material and from interviews with       1800s and early 19008, extensive fisheries
                 residents of the area. The most recent          developed for sturgeon near some of the








                         Trends In the Sound's FIsheries                                                                        .105

                         inlets. But this lasted only a few years               Albemarle-Pamlico edible finfish harvest,
                         before sturgeon became scarce (Stick 1958;             but the fishery has been characterized by
                         Godwin et al. 1971).                                   tremendous year-to-year variations. For
                               Improvements in transportation were              example, the highest landings on record
                         very slow in coming to this area, so that              occurred in 1969, but a sharp drop (about
                         around the turn of the century, when
                         statistics began to be kept on the
                         commercial fisheries, the most important                  25-
                         ones were still alewives and shad, along                        ALEWIFE
                         with the sound and beach mullet fishery.               U) 20 -
                         Between 1887 and 1900, these three                     z  15-
                         accounted for about two-thirds of the total            3
                                                                                0-
                         edible finfish harvest (Figures 7.1-7.3). It           Z10-
                         was not until after World War II that                  0
                         extensive ocean trawling began for species             -3
                         such as flounder (Godwin et al. 1971).                        0
                               Up until the early 1970s, alewives, or                  1885 1905 1925 1945 1965 1985
                         "river herring," continued to be the single                                      YEAR
                         most important component of the                           2.5-
                                                                                         CATFISH & BULLHEADS
                                                                                       2-
                                                                                z
                               100-
                                   EDIBLE FINFISH
                               80-                                              z 1-
                         z                                                      0
                         :)    60-                                              -J 0.5
                         0                                                      _j
                         IL
                         Z     41D -                                                   01
                         0                                                             1885 1905 1925 1945 1965 1985
                         -J    20-
                                                                                                          YEAR
                               0-
                               1885 1905 1925 1945 1965 1985                       10-
                                                   YEAR                                8-                   AMERICAN SHAD
                               50                                               z
                                                                                D      6-
                                 SHELLFISH                                      0
                         840.                                                   CL
                         z                                                      Z      4
                         030-                                                   0
                         fl@                                                    -J     2-
                         Z20-
                         0                                                             0
                         _j
                         _J10-                                                         1885 1905 1925 1945 1965 1985
                                                                                                          YEAR
                               0
                               1885 1905 1925 1945 1965 1985
                                                  YEAR                          Figure 7.2. Trends in anadromous species
                                                                                landings in the Albemarle-Pamlico Sound
                         Figure 7.1. Trends in total edible finfish and         system. "Alewife" includes alewives (Alo8a
                                                                                pseudoharengus) and blueback herring (Aloaa
                         shellfish commercial landings in the                   aeetivalis). Another common name for the
                         Albemarle-Pamlico Sound system. Data                   group is "river herring." Data are from sources
                         sources are given in text.                             given in text.









                     106                                                                                         Chapter 7


                    20                                                  _20
                    
                           GREY SEATROUT                                           FLOUNDER
                                                                           
                     15                                                  15
                     
                     
                     l0                                                  10

                      5                                                       5
                                                                         
                     0   
                                                                          0
                       1885      1910      1935       1960      1985          1885     1910      1935       1960      1985
                                           YEAR                                                    YEAR

                     25                                                  7
                          CROAKER                                       
                     20                                                  6   BLUEFISH
                                                                         5
                                                                        
                     15                                               4
                                                                          3
                     10                                                   2                                                                         
                     5-
                                                                          1
                     0                                                     0
                    
                       1885      1910      1935      1960       1985         1885       1910      1935       1960       1985
                                           YEAR                                                    YEAR
                     10   SPOT                                             4  MULLET
                      8                                                 3
                                                                       
                                                                            
                       6-                                                
                                                                           2
                       4
                                                                           1
                     2
                                                                         0
                             0                                                  
                    1885     1910      1935      1960      1985          1885       1910      1935       1960       1985
                                           YEAR                                                    YEAR


                     Figure 7.3. Trends in annual landings of the major types of edible finishes in the Albemarle-
                     Pamlico Sound system. Data are from sources given in text.


                     50%) occurred the following year (Figure              catch (Godwin et al. 1971). However, the
                     7.2). The fishery declined to around 7                report went on to say that "the failure of
                     million pounds per year in the mid-1970s              the fisheryto recoversince thereduction of
                     and has fluctuated around that level since,           foreign fishing is probably related to poor
                     although an all-time low was reached in               water quality in the Chowan River and
                     1987. ADivision ofMarine Fisheries report             Albemarle Sound." No specific hypotheses
                     in 1984 attributed at least the initial decline       linking water quality to the fishery were
                     to increases in offshore landings by foreign          mentioned.
                     vessels, which apparently led to later                     Around 1900, six-to-eight million
                     agreements with the foreign governments               pounds of shad (primarily American shad)
                     involved to reduce their offshore herring             were caught in the Albemarle region each









                       Trends in the Sound's Fisheries                                                              107

                       year, but during the first half of this cen-          Besides the increased fishing pressure,
                       tury, the fishery declined precipitously in       there may be other factors involved in the
                       North Carolina, and in other states along         striped bass decline. ManoochandRulifson
                       the Atlantic seaboard. Since that time, the       (1989) used results from long-term studies
                       fishery has not recovered, and during the         ofstriped bass reproduction in the Roanoke
                       last decade has lingered around 0.2 to 0.5        River to develop a hypothesis linking river
                       million pounds per year (Figure 7.2). Due         flow and the survival ofyoungstriped bass.
                       to the drastic decline of this species, it was    Theiranalyses are based primarily on data
                       studied extensively in the 1950s and 1960s.       collected each year since 1956 by a North
                       Walburgand Nichols (1967) cited the three         Carolina State University researcher, W.W.
                       factors which are so frequently mentioned         Hassler. The followingdescription oftrends
                       in discussions of fishery declines: 1) habi-      in those data is excerpted from the Manooch
                       tat destruction, 2) pollution, and 3) over-       and Rulifson report:
                       fishing. Dams on some of the rivers have
                       prevented the shad from reaching their                "Although no apparent trends were
                       natural spawning grounds and eliminated               detected in the total striped bass egg
                       many miles of nursery areas. Pollution,               production in the river, the viability
                       particularly that which lowers dissolved              rate of those eggs declined drastically
                       oxygen levels in the water, are thought to            beginning in the mid-1970s. Egg
                                                                             viability ranged from 80% to 96% from
                       be harmful, particularly forjuvenile shad.            1960 through 1974, but declined to
                       Paper mills located on the lower reaches of           56% in 1975 and ranged from 23% to
                       the Chowan, Roanoke and Neuse rivers in               74% in the succeeding years through
                       North Carolina produce high oxygen-de-                1987 (Figure 7.5). In the past, the
                       manding organic wastes (i.e., BOD) which              Roanoke/Albemarle striped bass popu-
                       may have contributed significantly to this            lation has been supported by dominant
                       problem, particularly in the past when                yearclasses produced at approximately
                       there was little treatment to remove the              5-year intervals. A dominant year
                       BOD. Finally, Walburgand Nichols (1967)               class, indicated by a juvenile
                       concluded that fishing pressure has been              abundance index of at least 10 young-
                                                                             of-year fish per trawl tow, has notbeen
                       an important factor in shad abundance,                produced since 1976 (Figure 7.5). The
                       but up until at least 1971, there were no             estimated number of striped bass in
                       laws or regulations in North Carolina which           the spawning migration remained
                       specifically applied to the management of             within historical levels through the
                       the shad fishery (Godwin et al. 1971).                mid-1970s, but in 1980, that number
                          After an apparent decline in the early             also declined. Since 1981, the
                       1900S catches ofstriped bass rose gradually           estimated spawning population has
                       between 1920 and the mid 1960s (Figure                remained below 100 thousand fish."
                       7.4). Then, beginningin 1967, striped bass            The authors of this report go on to
                       were caught by ocean trawlers fishing off         discuss several aspects of the life cycle of
                       the northern Outer Banks. The landings            striped bass which are affected by river
                       quadrupled, from one-half million pounds          flow. They conclude that the construction
                       to 2 million pounds, and remained high for        ofsix upstream dams on the Roanoke River
                       several years. Then, after a record catch of      in the 1950s and 1960s, and the resulting
                       2.3 million pounds in 1970, the landings          water flow regulation, has had a negative
                       began a decline that was not halted until         impact on the striped bass. Finally, the
                       the early 1980s, but by then the catches          report makes recommendations to the U.S.
                       were at historic lows of 100-200 thousand         Army Corps of Engineers and the electric
                       pounds.








                   108                                                                                             Chapter 7



                     2.5-                                                      6-
                   -          LANDINGS                                            EGGSSPAWNED
                   V)                                                          5-
                   z     2-
                   0                                                           4-
                     1.5-
                                                                            Z3-
                                                                            0
                                                                            -J2-
                   z 0.5
                   n
                   0 0                                                         01
                   CL    1885    1910       1935      1960      1985           1956     1964       1972       1980      1988
                                            YEAR                                                    YEAR

                     80-                                                       100-
                           RECREAT10NAL CATCH
                                                                                80-
                     60-
                   U_
                   0                                                            60-
                   U)40-                                                    z
                                                                            W
                                                                            0   40-
                   z                                                        cc
                   @20-                                                     Uj
                                                                                20- EGG VIABILITY
                   0
                         0.                                                       0-
                         1956   1964        1972     1980       1988             1956      1964      1972      1980      1988
                                            YEAR                                                     YEAR



                     0.6-                                                      30-
                     0.5-   SPAWNERS                                                    JUVENILE ABUNDANCE INDEX

                     0.4 -                                                     20-
                   U_
                   00.3-
                   CO
                   z 0.2-
                   0
                   :3
                     0.1 -
                         01
                         1956    1964       1972     1980       1988            1956      1964       1972      1980       1988
                                            YEAR                                                     YEAR


                   Figure 7.4. Trends in Albemarle-Pamlico                  Figure 7.5. Trends in eggs spawned, egg
                   region commercial catch of striped bass, and             viability, andjuvenile abundance indexfor the
                   Roanoke River recreationalcatch, andnumbers              Roanoke River striped bass population. Data
                   of spawning striped bass. Commercial catch               are from Mannoch and Rulifson (1989).
                   data arefrom sourcesgiven in text. Recreational
                   catch and spawningpopulation data are from
                   Mannoch and Rulifson (1989).









                      Trends in the Sound's Fisheries                                                              109

                      power company, who operate the dams. In
                      order to increase striped bass reproductive           "Blue crabs are very abundant on this
                      success, discharges from the reservoirs               coast, but they are not much in demand
                      should be regulated during the spawning               as food. Above Morehead City and
                      period so that flow in the lower Roanoke is           Beaufort, the fishermen take them in
                                                                            immense numbers in their drag-nets
                      kept as close as possible to the average              while fishing for sea-trout, mullet and
                      rate, for that time of year, that existed             other fish, and consider them a great
                      before the dams were built (Manooch and               annoyance, as it is difficult to remove
                      Rulifson 1989).                                       them from the nets. They kill nearly
                          The declines in anadromous species                all that are captured in this way by a
                      landings have been more than offset since             blow from a stick carried along for the
                      1960 by dramatic increases in catches of              purpose, and then throw them away,
                      five edible marine finfishes: grey seatrout,          or use them as manure. A few are kept
                      flounder, croaker, bluefish and spot. Trends          for food, but none are sold, beyond an
                      in landings of these five have been very              occasional barrel-full, mostly soft-
                      similar. They all increased rapidly in the            shelled, which are sent to some of the
                      1970s, peaked around 1980, and have fallen            larger inland towns."
                      back somewhat since then (Figure 7.3).                In the 1930s, the crab industry began
                          The North Carolina Division of Marine         to grow, partly because of new crabbing
                      Fisheries has monitoredjuvenile fish abun-        methods, but mainly because of an
                      dance within the Albemarle-Pamlico sys-           increasing demand for imported crabmeat
                      tem since 1979. The data are used to              in northern markets. Pearson (1951)
                      generate year-class strengths for four fin-       described the close inverse relationship
                      fish species: Atlantic croaker, spot, south-      that existed in the 1930s and 1940s between
                      ern flounder, and weakfish (grey sea trout).      crab harvests in North Carolina and the
                      No significant trends for any of these speies     Chesapeake Bay. In years when the abun-
                      are indicated between 1979 and 1988.              dance of crabs in Chesapeake Bay was
                      Years of relatively high abundance were           insufficient to satisfy the markets, more
                      1982 and 1986 for southern flounder, 1981         North Carolina crabs were harvested and
                      and 1986 for weakf ish, and 1983 for Atlan-       exported to markets in the Chesapeake
                      tic croaker. The absence of downward              region. This led to the beliefby some North
                      trends indicates that any stress on these         Carolina fishermen that a high natural
                      species (such as overfishing) is not great        abundance of crabs in one region was
                      enough to cause a decline in relative juve-       accompanied by a low abundance in the
                      nile production. Fluctuations are most            other and vice versa.
                      likely due to yearly variations in environ-           The rapid increase in North Carolina
                      mental parameters, such as temperature,           crab landings after 1950 (Figure 7.6) was
                      salinity, weather patterns, and/or currents-      undoubtedly due in part to decreased
                      These factors all affect larval transport         dependence on the Chesapeake markets.
                      and survival (Hogarth, et al. 1989).              At the same time, more and more processing
                      Blue Crabs                                        factories were beingbuilt in North Carolina.
                                                                        Prior to 1930, there were no more than half
                          There was a minor blue crab fishery in        a dozen crab-picking plants in the state.
                      North Carolina as early as the 1880s and          Although a crab meat canning industry
                      1890s, but the demand was apparently              had been established in Beaufort in 1943,
                      much smaller than the catch, as indicated         by 1946, there were still only 16 crab
                      in this 1887 report by Rathbun:                   houses in the state, compared to over 100








                110                                                                            Chapter 7
                on Chesapeake Bay (Pearson 195 1). How-         who fished for spot, croaker and butterfish
                ever, in the late 1960s, several factories,     in Pamlico Sound (Earll 1887). But later
                each employing hundreds ofworkers, were         the demand began to increase gradually.
                built along the western shores of Pamlico       Between 1912 and 1915, Federal Bureau
                Sound (Godwin et al. 1971), and by 1984,        of Fisheries personnel at Beaufort used an
                there were more than 25 processing plants       otter trawl to collect specimens for their
                in the area (North Carolina Division of         research. North Carolina fishermen
                Marine Fisheries 1984).                         adapted and modified this gear and the
                   After reaching historic highs of around      shrimp fishery began to grow rapidly
                20 million pounds in 1964 the landings          (Figure 7.6). The landings increased to an
                declined nearly 50% by 1968, presumably         all-time peak of 13 million pounds in 1953
                due to mass mortalities of blue crabs that      (Godwin et al. 1971).
                occurred from North Carolina to Florida.           'Destruction of the estuarine habitat of
                An emergency investigation was authorized       young shrimp" was mentioned by Godwin
                to find the cause, but by the time the study    et al. (1971) as the probable cause of the
                finally began, the mortalities were over        decline in shrimp harvests after 1953, but
                and landings had returned to their former       no details were given. There has been no
                levels. The study showed the presence of        obvious trend in the shrimp landings since
                several pesticides and disease organisms        1960, but often they have fluctuated widely
                in blue crabs, but failed to make any           from one year to the next (Figure 7.6).
                conclusions concerning possible causes for      Such variations are to be expected in a
                the mortalities (Godwin et al. 1971).           fishery based on an annual crop which is
                   After 1969, the crab harvest again           greatly dependent on environmental
                declined for several years, to a low of 11      conditions duringthe critical growth period
                million pounds in 1975. Briefnotes included     (North Carolina Division of Marine
                in the Annual Summaries of landings             Fisheries 1984). Salinity and temperature
                during that period included suggestions         are two variables widely thought to have
                that since demand was good and prices           great influence on the annual harvests.
                were high, "only a general scarcity of crabs    Although no statistical analysis appears to
                could account for the decline in landings"      have been made between these factors and
                (National Marine Fisheries Service 1974).       the shrimp landings, they are frequently
                But in a few years, the annual catches          mentioned in discussions of fluctuations in
                began a steep rise again, so that by 1980,      the annual catches. For example, the low
                they were higher than ever - nearly 35          catches in 1978, 1981 and 1984 were
                million pounds. Landings for all years in       attributed to unusually cold winters and
                this decade except one have been above 25       heavy springrains (North Carolina Division
                million pounds (Figure 7.6), making crabs       of Marine Fisheries 1984; National Marine
                the single most important component of          Fisheries Service 1978, 1981).
                the North Carolina commercial fishery, in
                terms of pounds harvested.                      Oysters
                                                                   Before the Civil War, shellfish such as
                Shrimp                                          the oyster were more important as an
                    Shrimp, like blue crabs, have shown a       industry in the northeastern states than in
                remarkable growth in popularity as a choice     the southern states primarily because of
                seafood since the early part of this century.   better railroad systems, but in the late
                In the 1880s, shrimp were also regarded as      1800s, it became an even bigger industry
                "trash," and thrown away by haul-seiners        in the north due to a new steam canning









                                 Trends In the Sound's Fisheries


                                     40                                                                       14-
                                     35-    BLUE CRABS                                                               SHRIMP
                                                                                                          212-
                                 Z 30-                                                                    z
                                 025-                                                                     :110-
                                 (L                                                                       0
                                 LL 20-                                                                   CL    8-
                                 0                                                                        LL
                                     15.                                                                  0     6-
                                 U)                                                                       (0
                                 z 10-                                                                    Z     4-
                                 0                                                                        0
                                                                                                                2-
                                      0
                                      1885         1910          1935         1960         1985           2     0-
                                                                 YEAR                                           1885        1910          1935         1960           1985
                                                                                                                                          YEAR

                                     1.2                                                                      8-
                                 Cn         HARD CLAMS (MEAT)                                             U)
                                 0 1-                                                                     07-                              OYSTERS (MEAT)
                                 z                                                                        z
                                                                                                          :)6-
                                     0.8-                                                                 0
                                 0                                                                        IL5-
                                 IL
                                 U. 0.6 -                                                                 U.4-
                                 0                                                                        0
                                 rn 0.4 -                                                                 co3-
                                 z                                                                        z
                                                                                                          02-
                                 C) 0.2 -                                                                 :1
                                      0                                                                   20-                                                             _J
                                      1885         1910          1935         1960         1985               1885         1910          1935          1960          1985
                                                                 YEAR                                                                    YEAR
                                     2-                                                                       3.5-
                                         BAY SCALLOPS (MEAT)                                                         OTHER SHELLFISH
                                 z                                                                              3-
                                 n                                                                        z
                                 0                                                                        :) 2.5-
                                                                                                          0
                                                                                                          CL 2-
                                 U.1 -                                                                    U_
                                 0                                                                        01.5-
                                 co
                                 z                                                                        U)
                                 0                                                                        z
                                 .J                                                                       0
                                 _J
                                 2 0                                                                          0.
                                     1885        1910          1935          1960         1985                  1885         1910         1935         1960          1985
                                                               YEAR                                                                       YEAR
                                 Figure 7.6. Trends in annual landings of the major types ofshellfish in the Albemarle-Pamlico
                                 Sound region (N.C. Dividion of Marine Fisheries "Central and Northern Districts"). Shrimp
                                 landing pounds are "heads on. " Data sources are given in text.


                                 process for oysters, the expanded railroad                               were located in New Bern, Beaufort,
                                 systems to carry them to markets, and a                                  Washington, and other small cities in the
                                 booming postwar economy which allowed                                    region. The most important beds were in
                                 more people to buy products like oysters. It                             the vicinity of Ocracoke Inlet (Winslow
                                 was not long before the supply was                                       1889). The late 18808 scarcity of oysters in
                                 exhausted in estuaries such as the                                       the Chesapeake Bay region had an
                                 Chesapeake Bay, and new sources ofoysters                                important impact on oyster production in
                                 were needed.                                                             North Carolina; experienced Chesapeake
                                      Before about 1890, Oysters were                                     oystermen and their dredging fleet moved
                                 harvested in North Carolina only to supply                               into North Carolina waters. The influx of
                                 local markets. In the 18808, these markets                               these oystermen, with their more efficient








                  112                                                                                    Chapter 7

                  dredging and tonging methods used in                cluded that the reason for the decline was
                  Maryland and Virginia, led to sudden                "close and indiscriminate dredging in the
                  increased production for North Carolina,            past two seasons."
                  coinciding with the decline in Maryland                 In the 1880s, conservation groups,
                  (Chestnut 1951). North Carolina                     scientists and concerned citizens were
                  oystermen complained bitterly:                      becoming aware that certain fisheries were
                                                                      declining. The American Fisheries Society,
                     "The people here are poor and depend             founded in 1870, was one of the first groups
                     entirely upon the waters for support.            to call for government action, and in 1872,
                     But the Virginia men are down here               the federal government created the United
                     and have taken entire possession ofall           States Fish Commission to investigate
                     the oyster grounds; their boats are              fishery problems. North Carolina, like
                     much largerthan those here, and when
                     these are at work the Virginians will            other states, was prompted to follow the
                     run down upon them and tear them                 federal government's example, and in 1887,
                     up; and when they try to retaliate it is         formed its first shell-fish commission to
                     useless, for they are armed to the teeth         examine local fishery problems much of
                     with Winchester rifles and some have             the early efforts of the commission were
                     36 lb. guns. Unless something is done            directed at oysters.
                     to stop their dredging, these people                 Through a series of laws and regulations
                     will be in a starving condition in twelve        enacted particularly in the period from
                     months" (Whitehurst 1891).                       1891 to 1925, the Fisheries Commission
                     The exploitation of Pamlico Sound by             attempted to control the growth and
                  the northern fleet was brief, for laws were         development of the shellfish industry in
                  immediately passed shortening the season            North Carolina. But the agency had only
                  and prohibiting non-residents from dredg-           marginal success early on, for at least
                  ing in the State (Thorson 1982). Mean-              three reasons, accordingto Thorson (1982):
                  while, the local residents adopted the dredg-       1) commercial fisheries are difficult to
                  ing methods that had been introduced, so            manage because they are affected by so
                  that when the season was lengthened in              many variables; 2) there was little known
                  1897, production of oysters greatly in-             about the ecology of the fishes and
                  creased. The followingyear new and exten-           shellfishes, and the Fisheries Commission
                  sive beds were discovered two miles or              carried out very little scientific research of
                  more offshore in Pamlico Sound. More                its own; and 3) the agency was
                  oysters were harvested that year (1898)             underfunded and understaffed.
                  than ever before or since in the history of             Oyster landings in the Albemarle-
                  the industry. The supply seemed inex-               Pamlico system have trended downward
                  haustible, and increased preparations were          almost continuously since the late 1890s
                  made for the next year. But when the                (Figure 7.6), a pattern similar to that for
                  season opened in 1899, oysters were scarce.         most other oyster producing areas. With
                  What followed was typical of the debates,           one exception, annual catches since 1953
                  and uncertainties, that have persisted ever         have all been less than 1 million pounds,
                  since about the reasons for fluctuations in         generally fluctuating between 200
                  annual harvests of oysters and other com-           thousand and 500 thousand pounds. The
                  mercial fish and shellfish. Some attrib-            catch in 1987 was 1.2 million pounds, the
                  uted the scarcity to overfishing, others to         highest in 34 years.
                  severe storms that had occurred in August               Trends in the North Carolina oyster
                  and October of 1899. Grave (1904) con-              harvests up until 1945 were discussed by








                      Trends in the Sound's Fisheries                                                             113
                      Chestnut (1951), who attributed the ups          and threatened the economy of shellf"ish
                      and downs to a variety of causes. These          producingstates. Consequently, the indus-
                      included varying intensity of harvesting         try, along with various state and federal
                      effort, changes in laws and regulations,         health agencies, began to formulate a plan
                      planting of oysters and shells, the Great        for sanitary control oftheshellfish industry
                      Depression, and fears about disease              (N.C. State Board of Health 1956). One of
                      outbreaks in other parts of the country          the responsibilities of the Shellfish
                      which presumably were caused by eating           Sanitation Program in each state is to
                      oysters.                                         monitor shellfish growing areas for the
                          Chestnut's discussion is most notable        purpose of determining which areas shall
                      for the one variable not mentioned as a          be open to shellfish harvesting. In North
                      factor in the NC oyster harvest: water           Carolina, the first survey was made
                      quality. Ina companion paper summarizing         sometime between 1925 and 1930, and
                      the hydrography of the sounds, by Nelson         additional surveys have been made
                      Marshal, it was surmised that at the time        periodically since then. In recent years,
                      (the late 1940s) "pollution of North             the most thorough surveys ofall the State's
                      Carolina's marine waters is restricted to a      shellfishing grounds are made about every
                      few local situations mostly in the vicinity of   three years - Data collected during these
                      towns and cities where toilet sewage, and,       surveys provides some information about
                      in a few instances, industrial sewage, is        trends in sewage pollution in various
                      either untreated or inadequately handled"        regions. Today, waters are closed to
                      (Marshall 195 1, p 58). He cited as evidence     oystermen when tests show there are more
                      for this conclusion the State Board ofHealth     than 14 fecal coliform organisms per 100
                      statistics on areas closed to the harvesting     ml of water, a standard established by the
                      of oysters. As of April, 1949, about 27,000      U.S. Food and Drug Administration and
                      acres were closed. In fact, this is one ofonly   the Public Health Service. The original
                      two references to pollution in the volume        measures set up in the 1920s were 70 fecal
                      containing this paper. The other concerns        coliform bacteria per 100 ml ofwater (Peters
                      the effect of poor water quality on the shad     1989).
                      fishery farther inland in some ofthe coastal        North Carolina has about 2 million
                      rivers. This lack of emphasis on water           acres of coastal waters, but portions of
                      qualityas an issue affectingthe NC fisheries     these waters are low-salinity and freshwa-
                      in the 1940s is significant, in light of the     ter areas that do not support shellfish.
                      fact that this was probably the most             Waters suitable for shellfish comprise 1.42
                      thorough synthesis ofavailable knowledge         million acres ofthis total, accordingto N.C.
                      of the estuaries of North Carolina up until      Shellfish Sanitation Program estimates.
                      that time.                                       In 1988, 51.7 thousand acres (3.6%) of
                         Shellfish Sanitation Programs designed        these waters were closed to shellfishing
                      to monitor and regulate oyster and clam          (North Carolina Division of Health Ser-
                      harvesting in North Carolina and other           vices 1988). Only about 30% (15 thousand
                      producer states have been in existence for       acres) of the total closed area was in the
                      about 65 years. During 1924 and 1925,            Pamlico-Albemarle region north of Core
                      outbreaks of typhoid fever in Chicago, New       Sound. Most of the prohibited areas were
                      York, Washington and several other cities        south of Pamlico Sound, in the Morehead
                      were determined to have been caused by           City/Beaufort area and in Brunswick
                      sewage-polluted oysters. The resulting           County south of Wilmington.
                      publicity paralyzed the oyster industry             The data collected since 1971 indicate








                 114                                                                            Chapter 7
                 that in the Albemarle-Pamlico region           industry in North Carolina is heavily
                 closures in some areas are increasing much     influenced by economic factors, some
                 more rapidly than in others. Figure 7.7        originating outside the state. Forexample,
                 shows that, since 197 1, the total amount of   clams are normally more important in the
                 prohibited area in the Pamlico-Albemarle       Albemarle-Pamlico region than oysters,
                 area has not changed a great deal.             but fluctuations in clam prices can have an
                 However, the lack of a trend is somewhat       effect on the oyster harvest. Most North
                 misleading, as was pointed out in a recent     Carolinaclams areexportedto the northern
                 Shellfish Sanitation Program report.           states. But in years when the supply there
                 Improvements in some areas have been           is plentiful, clam prices may decline so
                 offset by increases in closures in a few       much that N.C. fishermen go after the
                 areas with the most rapid population           oysters with more effort than. at other
                 growth, such as Dare County, where the         times when clam prices are higher.
                 permanent population increased 40%                 Early attempts at oyster rehabilitation
                 between 1980 and 1986. Dare County             by the state began in the 1920s and 1930s,
                 increased 65% in prohibited shellfishing       but were later judged to have been
                 acreage during the same period. In Hyde        unsuccessful due to a lack of knowledge of
                 County, the population growth was              oyster biology and selection of unsuitable
                 negligible, but there were agricultural        planting areas. In 1947, the state enacted
                 activities that led to an increase of 818      legislation to begin a new program of
                 acres closed since 1980 (North Carolina        planting seed oysters and shells by the
                 Division of Health Services 1988).             Division of Commercial Fisheries, which
                 Naturally, state officials are worried that    was augmented by University of North
                 such rapid growth in some of these coastal     Carolina Institute of Fisheries Research
                 areas could greatly increase the shellfish     studies. An analysis of the oyster program
                 closures in the future.                        in 1970 showed that despite the efforts to
                    In addition to sewage pollution, other      improve the fishery, the landings had
                 factors such as weather, diseases,             continued to decline. In 1970, the return of
                 economics, and management activities play      commercial production to the fishery was
                 important roles in setting the annual
                 harvest of oysters and clams in the
                 Albemarle-Pamlico region. In some years,          20-
                 the conditionally-approved areas may be                                ACRES CLOSED
                 closed for several days or weeks following        15-
                 heavy rains, which lead to temporary           co
                 increases in the fecal coliform counts. Also,  z
                                                                610-
                 parasitic organisms that kill oysters are a    n
                 serious threat to the fishery. "Dermo" (the    ox 5 -
                 infectious protozoan Dermocystidium
                 marinum = Perkinsus marinus) is the most           01
                 prevalent disease, but.another, named             1970      1975     1980     1985      1990
                 MSX, showed up in 1988 in some beds                                 YEAR
                 (Davis 1989). In the same year, red tides      Figure 7.7. Trends in saline waters closed to
                 came to North Carolina for the first time in   shellfishing in the Albemarle-Pamlico region
                 memory, causing all oystering to cease         (Pamlico, Craven, Beaufort, Hyde, Dare, and
                 just one week after the season had opened.     part of Carteret Counties). Dataprovided by
                 Finally, like other fisheries, the oyster      N.C. Division of Health Services, Shellfish
                                                                Sanitation Program.









                       Trends In the Sound's FIsherles                                                               115

                       only three-tenths of a bushel of oysters for      mainland, there were few roads near the
                       each bushel of seed oysters and shell             sounds. It was 1919 before the first
                       planted. Thus, it was concluded that "the         automobile reached the Outer Banks. In
                       present oyster rehabilitation program             the late 1920s, a hard-surfaced road was
                       cannot improve oyster production and              built on Roanoke Island and a toll bridge
                       probably cannot even prevent further              was built to connect the island with Nags
                       decline in the industry" (Godwin et al.           Head, on Bodie Island. However, there
                       1971).                                            was no bridge linkingRoanoke Island with
                          Nevertheless, the Oyster Rehabilita-           the mainland. About 1930, the state began
                       tion Program has been continued. The              a road and bridge program that would
                       quantities of shell planted increased from        gradually link the entire region. By 1940,
                       around 100 thousand bushels in the late           theAlbemarle Soundarea was crisscrossed
                       1970s to an average of about 300 thousand         with paved roads and linked by bridges,
                       bushels peryear by the mid- 1980s. A 1984         but the Banks remained inaccessible to
                       report predicted that the outlook for the         automobile traffic. AfterWorldWarII,the
                       oyster fishery was good, based on the             state built a paved road between Oregon
                       Division's strong commitment to a large           Inlet and Hatteras Village. RoanokeIsland
                       scale cultch planting and relaying pro-           was finally linked to the mainland by a
                       grain (North Carolina Division of Marine          bridge completed in 1963 (Johnson et al.
                       Fisheries 1984). One Division official re-        1986), and later another bridge was opened
                       cently estimated that this activity increases     to traffic between Kitty Hawk and the
                       the oyster harvest by 50% in North Caro-          mainland. Since then, a fourth bridge link
                       lina.                                             has been built, connecting Bodie Island
                                                                         (Nags Head, Kitty Hawk, and Kill Devil
                       Recreational Fisheries                            Hills) with Hatteras Island to the south.
                           By the mid-1800s, recreational fishing        Today, the barrier islands southofHatteras
                       had attained the status of a recognized           still have no bridge links to the mainland,
                       sport in coastal North Carolina. Most of          but the state operates a regular (car-
                       the fishing was in the rivers, creeks and         carrying) ferry schedule between Hatteras
                       lakes, but sound waters, and even the             and Ocracoke and between Ocracoke and
                       ocean, were becoming increasingly                 Swan Quarter and Cedar Island.
                       attractive. In 1838, the first hotel at Nags          Accessibility by automobile spurred
                       Head on the Outer Banks was completed,            rapid growth of recreation on the Outer
                       and by the 1850s, there were cottages             Banks. By 1957, tourism had replaced
                       belonging to non-residents on the banks.          commercial fishing as the number one
                       BytheCivilWar, itwas popular forplanters          industry in Dare County. In 1940, there
                       and businessmen from eastern North                were no motels in Hatteras Village or on
                       Carolina to take their families to the Outer      Roanoke Island and only two at Nag's
                       Banks duringthe summer months (Johnson            Head. By 1955, there were 15 hotels, 60
                       et al. 1986; Stick 1958).                         motels, and approximately 500 rental
                           But the growth of sport fishing in the        cottages in Dare County. Duringthe 1970s,
                       region - particularly on the Outer Banks          Dare County's growth rate exceeded the
                       - was slow in the early 20th century,             state average rate by almost 6 times, and
                       because the area was so isolated and              between 1971 and 1986, travel and tourism
                       inaccessible. Until well into the century,        revenues in the county increased from $11
                       water transportation was the only way to          million to over $340 million, making Dare
                       reach the Outer Banks. And even on the            the states' leader in the tourism industry








                 116                                                                            Chapter 7
                 (Brower et al. 1989).                          1970s. The estimated harvest has ranged
                     Obviously then, there is indirect          from a high of 65,399 fish in 1971 to only
                 evidence that recreational fishing in the      3,131 fish in 1985 (Figure 7.4). The catch
                 Albemarle-Pamlico system has grown,            per unit effort for 1981, 1982 and 1983
                 especially since World War 11. Today, the      were the lowest on record for the 28-year
                 recreational fisheries are an important        period of record. However, as Hassler and
                 component of the overall fishery harvest.      Taylor (1984) noted in their analysis of
                 In fact, for a number of important species,    these data, it should be noted that striped
                 the recreational harvest probably exceeds      bass size limits and creel limits were
                 the commercial harvest. Some of these          changed in 1981. Also, bow netting and
                 species are bluefish, spotted scatroot, red    fight netting were eliminated in that year.
                 drum, and Spanish mackerel. The North          The new and more restrictive regulations
                 Carolina Division of Marine Fisheries          were responsible for some part of the
                 (DMF)began collectingdataon recreational       decreased catches and catches per unit
                 landings in 1987.                              effort.
                     Unfortunately, however, there is no            In fact, since 1980, the regulations on
                 long-term record of catch, or any direct       both commercial and sport harvesting of
                 measure of effort, for the important           striped bass have become more and more
                 recreational fish species, with one            restrictive, in an effort by the North
                 exception. Beginningin 1956, W.W. Hassler      Carolina Division of Marine Fisheries and
                 and his colleagues conducted studies to        the Wildlife Resources Commission to
                 provide long-term information on the status    preserve the Roanoke striped bass stock.
                 and abundance of striped bass in the           Manooch and Rulifson (1989) presented a
                 Roanoke River and Albemarle Sound. Sport       summary table showing a total of 42
                 catch and effort data for striped bass in the  regulation changes between 1979 and 1988
                 Roanoke River were tabulated over a 140-       concerning striped bass fishing. Included
                 mile area from the mouth of the river to the   were many new regulations that would
                 Roanoke Rapids dam. Most years, about          tend to decrease the recreational catch,
                 75% of the total striped bass catch was        such as increased minimum size limits,
                 made in the area just below the dam, and       creel limits, shortened seasons and the
                 about 25% in downstream locations.             elimination of some gear types.
                     The recreational striped bass catch,       Environmental factors that may be
                 like the commercial catch, had generally       affecting the Roanoke striped bass have
                 declined in the Roanoke since the early        been discussed above.









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                       Sweeney, J.K and A.R. Olsen, A.R. and A.L.             Tukey, J.W. 1977. Exploratory data analysis.
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                   Appendices                                                                                133



                   Appendices



                   Appendix 1. 1. Population of North Carolina and Virginia counties in the Albemarle-
                   Pamlico basin. The total population figures given for the individual sub-basins have been
                   adjusted (i.e., reduced) according to the percentage of the county land areas within the AN
                   watershed.



                   County          State      1790      1800      1810      1820      1830      1840      1850


                   Beaufort        NC       5,462     6,242     7,203     9,850    10,969    12,225    13,816
                   Bertie          NC      12,606    11,249    11,218    10,805    12,262    12,175    12,851
                   Camden          NC       4,033     4,191     5,347     6,347     6,733     5,663     6,049
                   Carteret        NC       3,732     4,399     4,823     5,609     6,597     6,591     6,939
                   Caswell         NC      10,096     8,701    11,757    13,253    15,185    14,693    15,269
                   Chowan          NC       5,011     5,132     5,297     6,464     6,697:    6,690     6,721
                   Craven          NC      10,469    10,245    12,676    13,394    13,734    13,438    14,709
                   Currituck       NC       5,219     6,928     6,985     8,098     7,655     6,073     7,236
                   Dare            NC
                   Durham          NC
                   Edgecombe       NC      10,255    10,421    12,423    13,276    14,935    15,708    17,189
                   Forsyth         NC                                                                  11,168
                   Franklin        NC       7,559     8,529    10,166     9,741    10,665    10,980    11,713
                   Gates           NC       5,392     5,881     5,965     6,837     7,866     8,161     8,426
                   Granville       NC      10,982    14,015    15,476    18,222    19,355    18,187    21,249
                   Greene          NC       6,893     4,128     4,867     4,533     6,413     6,595     6,169
                   Guilford        NC       7,191     9,442    11,420    14,511    18,737    19,175    19,754
                   Halifax         NC      13,965    13,945    13,620    17,237    17,739    16,865    16,589
                   Hertford        NC       5,828     6,701     6,052     7,712     8,537     7,484     8,142
                   Hyde            NC       4,120     4,829     6,029     4,967     6,184     6,458     7,636
                   Johnston        NC       5,634     6,301     6,867     9,607    10,938    10,599    13,726
                   Jones           NC       4,822     4,339     4,968     5,216     5,608     4,945     5,038
                   Lenoir          NC                 4,005     5,572     6,799     7,723     7,605     7,828
                   Martin          NC       6,080     5,629     5,987     6,320     8,539     7,637     8,307
                   Nash            NC       7,393     6,975     7,268     8,185     8,490     9,047    10,657
                   Northampton     NC       9,981    12,353    13,082    13,242    13,391    13,369    13,335
                   onslow          NC       5,387     5,623     6,669     7,016     7,814     7,527     8,283
                   Orange          NC      12,216    16,362    20,135    23,492    23,908    24,356    17,055
                   Pamlico         NC
                   Pasquotank      NC       5,497     5,379     7,674     8,008     8,641     8,514     8,950
                   Perquimans      NC       5,440     5,708     6,052     6,587     7,419     7,346     7,332
                   Person          NC                 6,402     6,642     9,029    10,027     9,790    10,781








                134                                                                      Appendices


                Appendix 1.1. Continued


                County         State     1790      1800     1810     1820      1830     1840     1850

                Pitt           NC      8,275     9,084    9,169   10,001    12,093   11,806   13,397
                Rockingham     NC      6,187     8,277   10,316   11,474    12,935   13,442   14,495
                Stokes         NC      8,528   11,026    11,645   14,033    16,196   16,265     9,206
                Surry          NC      7,191     9,805   10,366   12,320    14,504   15,079   18,443
                Tyrrell        NC      4,744     3,395    3,364    4,319     4,732    4,657     5,113
                Vance          NC
                Wake           NC     10,192   13,437    17,086   20,102    20,398   21,118   24,888
                Warren         NC      9,207   11,284    11,004   11,158    11,887   12,919   13,912
                Washington     NC                2,422    3,464    3,986     4,552    4,525     5,664
                Wayne          NC      6,133     6,772    8,687    9,040    10,331   10,891   13,486
                Wilson         NC
                Appomattox     VA                                                               9,193
                Bedford        VA     10,531   14,125    16,148   19,305    20,246   20,203   24,080
                Botetourt      VA     10,524   10,427    13,301   13,589    16,354   11,679   14,908
                Brunswick      VA     12,827   16,339    15,411   16,687    15,767   14,346   13,894
                Campbell       VA      7,685     9,866   11,001   16,569    20,350   21,030   23,245
                Charlotte      VA     10,078   11,912    13,161   13,290    15,252   14,595   13,955
                Dinwiddie      VA     13,934   15,374    18,190   20,482    21,901   22,558   25,118
                Floyd          VA                                                     4,453     6,458
                Franklin       VA      6,842     9,302   10,724   12,017    14,911   15,832   17,430
                Greensville    VA      6,362     6,727    6,853    6,858     7,117    6,366     5,639
                Halifax        VA     14,722   19,377    22,133   19,060    28,034.  25,936   25,962
                Henry          VA      8,479     5,259    5,611    5,624     7,100    7,335     8,872
                Isle of  WightVA       9,028     9,342    9,186   10,139    10,517    9,972     9,353
                Lunenburg      VA      8,959   10,381    12,265   10,662    11,957   11,055   11,692
                Mecklenberg    VA     14,733   17,008    18,453   19,786    20,477   20,724   20,630
                Montgomery     VA     13,228     9,044    8,409    8,733    12,306    7,405     8,359
                Mottoway       VA                9,401    9,278    9,658    10,130    9,719     8,437
                Patrick        VA                4,331    4,695    5,089     7,395    8,032     9,609
                Pittsylvania   VA     11,579   12,697    17,172   21,232    26,034   26,398   28,796
                Prince GeorgeVA        8,173     7,425    8,050    8,030     8,367    7,175     7,596
                Roanoke        VA                                                     5,499     8,477
                Southampton VA        12,864   13,925    13,497   14,170    16,074   14,525   13,521
                Surry          VA      6,227     6,535    6,885    6,594     7,109    6,480     5,679
                Sussex         VA     10,549   11,062    11,362   11,884    12,720   11,229     ï¿½,820
                Total                449,134   519,415   579,126  640,248  720,507   711,144 772,244


                Chowan  River        100,869   116,649   120,885  127,550  135,533   127,832 127,015
                Roanoke River        139,952   164,236   184,885  204,916  242,690   244,086 263,537
                Albemarle Sound       29,127   31,495    36,252   40,902    43,668   40,853   44,275
                Tar-Pamlico R.        53,033   58,541    64,036   71,628    78,866   80,797   89,025
                Meuse River           56,851   66,869    80,183   91,520    99,888   99,937  108,301
                Pamlico sound          2,296     2,691    3,340    2,801     3,475    3,620     4,255







                  Appendices                                                                     135
                  Appendix 1.1. Continued


                  County        State      1860     1870       1880       1890       1900

                  Beaufort      NC      14,766   13,011     17,474     21,072     26,404
                  Bertie        NC      14,310   12,950     16,399     19,176     20,538
                  Camden        NC       5,343    5,361      6,274      5,667      5,474
                  Carteret      NC       8,186    9,010      9,784     10,825     11,811
                  Caswell       NC      16,215   16,081     17,825     16,028     15,028
                  Chowan        NC       6,842    6,450      7,900      9,167     10,258
                  Craven        NC      16,268   20,516     19,729     20,533     24,160
                  Currituck     NC       7,415    5,131      6,476      6,747      6,529
                  Dare          NC                2,778      3,243      3,768      4,757
                  Durham        NC                                     18,041     26,233
                  Edgecombe     NC      17,376   22,970     26,181     24,113     26,591
                  Forsyth       NC      12,692   13,050     18,070     28,434     35,261
                  Franklin      NC      14,107   14,134     29,829     21,090     25,116
                  Gates         NC       8,443    7,724      8,897     10,254     10,413
                  Granville     NC      23,396   24,831     31,286     24,484     23,263
                  Greene        NC       7,925    8,687     10,037     10,039     12,038
                  Guilford      NC      29,056   21,736     23,585     28,052     39,074
                  Halifax       NC      19,442   29,408     30,300     28,908     30,793
                  Hertford      NC       9,504    9,273     11,843     13,851     14,294
                  Hyde ,        NC       7,732    6,445      7,765      8,903      9,278
                  Johnston      NC      15,656   16,897     23,461     27,239     32,250
                  Jones         NC       5,730    5,002      7,491      7,403      8,226
                  Lenoir        NC      10,220   10,434     15,344     14,879     18,639
                  Martin        NC      10,195    9,647     13,140     15,221     15,383
                  Nash          NC      11,687   11,077     17,731     20,707     25,478
                  Northampton   NC      13,372   14,749     20,032     21,242     21,150
                  Onslow        NC       8,856    7,569      9,829     10,303     11,940
                  Orange        NC      16,947   17,507     23,689     14,948     14,690
                  Pamlico       NC                           6,323      7,146      8,045
                  Pasquotank    NC       8,940    8,131     10,369     10,748     13,660
                  Perquimans    NC       7,238    7,945      9,466      9,293     10,091
                  Person        NC      11,221   11,170     13,719     15,151     16,685
                  Pitt          NC      16,080   17,376     21,794     25,519     30,889
                  Rockingham    NC      16,746   15,708     21,744     25,363     33,163
                  Stokes        NC      10,402   11,208     15,353     17,199     19,866
                  Surry         NC      10,380   11,252     15,302     19,282     25,515
                  Tyrrell       NC       4,944    4,173      4,545      4,225      4,980
                  Vance         NC                                     17,581     16,684
                  Wake          NC      28,627   35,617     47,939     49,207     54,626
                  Warren        NC      15,726   17,768     22,619     19,360     19,151
                  Washington    NC       6,357    6,516      8,928     10,200     10,608
                  Wayne         NC      14,905   18,144     24,951     26,100     31,356
                  Wilson        NC       9,720   12,258     16,064     18,644     23,596
                  Appomattox    VA       8,889    8,950     10,080      9,589      9,662
                  Bedford       VA      25,068   25,327     31,205     31,213     30,356
                  Botetourt     VA      11,516   11,329     14,809     14,854     17,161








              136                                                                  Appendices

              Appendix 1.1. Continued


              County         State      1860    1870       1880       1890       1900

              Brunswick      VA     14,809   13,427     16,707     17,245     18,217
              Campbell       VA     26,197   28,384     36,250     41,087     23,256
              Charlotte      VA     14,471   14,513     16,653     15,077     15,343
              Dinwiddie      VA     30,198   30,702     32,870     13,515     15,374
              Floyd          VA       8,236   9,824     13,255     14,405     15,388
              Franklin       VA     20,098   18,364     25,084     24,985     25,953
              Greensville    VA       6,374   6,362       8,407     8,230       9,758
              Halifax        VA     26,520   27,828     23,588     34,424     37,197
              Henry          VA     12,105   12,303     16,009     18,208     19,265
              Isle of  WightVA        9,977   8,320     10,572     11,313     13,102
              Lunenburg      VA     11,983   10,403     11,535     11,372     11,705
              Mecklenberg    VA     20,096   21,318     24,610     25,359     26,551
              Montgomery     VA     10,617   12,556     16,693     17,742     15,852
              Nottoway       VA       8,836   9,291     11,156     11,582     12,366
              Patrick        VA       9,359  10,161     12,833     14,147     15,403
              Pittsylvania   VA     32,104   31,343     52,589     50,941     46,894
              Prince GeorgeVA         8,411   7,820     10,054      7,872       7,752
              Roanoke        VA       8,048   9,350     13,105     30,101     15,837
              Southampton VA        12,915   12,285     18,012     20,078     22,848
              Surry          VA       6,133   5,585       7,391     8,256       8,469
              Sussex         VA     10,175    7,885     10,062     11,100     12,082
              Total                846,102  873,324   1,116,259  1,198,807  1,289,775


              Chowan  River        136,252  129,470    159,100    149,971    161,296
              Roanoke River        286,223  295,286    373,454    421,261    407,307
              Albemarle Sound       43,965   41,908     51,105     52,768     58,159
              Tar-Pamlico R.       100,488  112,434    150,083    152,551    171,460
              Neuse River          131,542  149,205    197,858    215,333    254,546
              Pamlico Sound           4,344   4,853       8,490     9,699     10,729








                  Appendices                                                                    137
                  Appendix 1.1. Continued


                  County       State         1910       1920      1930       1940

                  Beaufort      NC        30,877     31,024    35,026     36,431
                  Bertie        NC        23,039     23,993    25,844     26,201
                  Camden        NC         5,640      5,382     5,461      5,440
                  Carteret      NC        13,776     15,384    16,900     18,284
                  Caswell       NC        14,858     15,759    18,214     20,032
                  Chowan        NC        11,303     10,649    11,282     11,572
                  Craven        NC        25,594     29,048    30,685     31,298
                  Currituck     NC         7,693      7,268     6,710      6,709
                  Dare          NC         4,841      5,115     5,202      6,041
                  Durham        NC        35,276     42,219    67,196     80,244
                  Edgecombe     NC        32,101     37,995    47,894     49,162
                  Forsyth       NC        47,311     77,269    111,681    126,475
                  Franklin      NC        24,692     26,667    29,456     30,382
                  Gates         NC        10,455     10,537    10,551     10,060
                  Granville     NC        25,102     26,846    28,723     29,344
                  Greene        NC        13,083     16,212    18,656     18,548
                  Guilford      NC        60,497     79,272    133,010    153,916
                  Halifax       NC        37,646     43,766    53,246     56,512
                  Hertford      NC        15,436     16,294    17,542     19,352
                  Hyde          NC         8,840      8,386     8,550      7,860
                  Johnston      NC        41,401     48,998    57,621     63,798
                  Jones         NC         8,721      9,912    10,428     10,926
                  Lenoir        NC        22,769     29,555    35,716     41,211
                  Martin        NC        17,797     20,838    23,400     26,111
                  Nash          NC        33,727     41,061    52,782     55,608
                  Northampton   NC        22,232     23,184    27,161     28,299
                  Onslow        NC        14,125     14,703    15,289     17,939
                  orange        NC        15,064     17,895    21,171     23,072
                  Pamlico       NC         9,966      9,060     9,299      9,706
                  Pasquotank    NC        16,693     17,670    19,143     20,568
                  Perquimans    NC        11,054     11,137    10,668      9,773
                  Person        NC        17,356     18,973    22,039     25,029
                  Pitt          NC        36,340     45,569    54,466     61,244
                  Rockingham    NC        36,442     44,149    51,083     57,898
                  Stokes        NC        20,151     20,575    22,290     22,656
                  Surry         NC        29,705     32,464    39,749     41,783
                  Tyrrell       NC         5,219      4,849     5,164      5,556
                  Vance         NC        19,425     22,799    27,294     29,961
                  Wake          NC        63,229     75,155    94,757     109,544
                  Warren        NC        20,266     21,593    23,364     23,145
                  Washington    NC        11,062     11,429    11,603     12,323
                  Wayne         NC        35,698     43,640    53,013     58,328
                  Wilson        NC        28,269     36,813    44,914     50,219
                  Appomattox    VA         8,904      9,255     8,402      9,020
                  Bedford       VA        29,549     30,669    29,091     29,687
                  Botetourt     VA        17,727     16,557    15,457     16,447








               138                                                                  Appendices

               Appendix I. I. Continued


               County       State         1910       1920       1930       1940

               Brunswick     VA        19,244     21,025     20,486     19,575
               Campbell      VA        23,043     26,716     22,885     26,048
               Charlotte     VA        15,785     17,540     16,061     15,861
               Dinwiddie     VA        15,442     17,949     18,492     18,166
               Floyd         VA        14,092     13,115     11,698     11,967
               Franklin      VA        26,480     26,283     24,337     25,864
               Greensville   VA        11,890     11,606     13,388     14,866
               Halifax       VA        40,044     41,374     41,283     41,271
               Henry         VA        18,459     29,238     20,088     26,481
               Isle of WightVA         14,929     14,433     13,409     13,381
               Lunenburg     VA        12,780     15,260     14,058     13,844
               Mecklenberg   VA        28,956     31,208     32,622     31,933
               Montgomery    VA        17,268     18,595     19,605     21,206
               Nottoway      VA        13,462     14,161     14,866     15,556
               Patrick       VA        17,195     16,850     15,787     16,613
               Pittsylvania  VA        50,709     56,493     61,424     61,697
               Prince GeorgeVA           7,848    12,915     10,311     12,226
               Roanoke       VA        19,623     22,395     35,289     42,897
               Southampton VA          26,302     27,555     26,870     26,442
               Surry         VA          9,715      9,305      7,096      6,193
               Sussex        VA        13,664     12,834     12,100     12,485
               Total                1,457,881   1,664,437  1,919,348  2,078,286


               Chowan River           176,392    187,148    188,454    191,659
               Roanoke River          437,061    491,723    525,304    564,084
               Albemarle.Sound         64,365     64,446     65,729     67,371
               Tar-Pamlico R.         198,375    225,741    267,433    281,927
               Neuse River            299,103    358,655    438,650    488,704
               Pamlico Sound           11,417     10,950     11,222     11,425









                  Appendices                                                                      139
                  Appendix 1.1. Continued


                  County      State          1950       1960       1970       1980       1987


                  Beaufort       NC       37,134     36,014     35,980     40,355     45,000
                  Bertie         NC       26,439     24,350     20,528     21,024     22,000
                  Camden         NC        5,223      5,598      5,453      5,829      6,000
                  Carteret       NC       23,059     30,940     31,603     41,092     52,000
                  Caswell        NC       20,870     19,912     19,055     20,705     22,000
                  Chowan         NC       12,540     11,729     10,764     12,558     13,000
                  Craven         NC       48,823     58,733     62,554     71,043     83,000
                  Currituck      NC        6,201      6,601      6,976     11,089     13,000
                  Dare           NC        5,405      5,935      6,995     13,377     18,000
                  Durham         NC      101,639    111,995    132,681    152,785    166,000
                  Edgecombe      NC       51,634     54,226     54,226     55,988     59,000
                  Forsyth        NC      146,135    189,428    215,118    243,683    262,000
                  Franklin       NC       31,341     28,755     26,820     30,055     33,000
                  Gates          NC        9,555      9,254      8,524      8,875      9,000
                  Granville      NC       31,793     33,110     32,762     34,043     37,000
                  Greene         NC       18,024     16,741     14,967     16,117     17,000
                  Guilford       NC      191,057    246,520    288,645    317,154    328,000
                  Halifax        NC       58,377     58,956     53,884     55,286     56,000
                  Hertford       NC       21,453     22,718     23,529     23,368     24,000
                  Hyde           NC        6,479      5,765      5,571      5,873      8,900
                  Johnston       NC       65,906     62,936     61,737     70,599     79,000
                  Jones          NC       11,004     11,005      9,779      9,705     10,000
                  Lenoir         NC       45,953     55,276     55,204     59,819     60,000
                  Martin         NC       27,938     27,139     24,730     25,948     26,000
                  Nash           NC       59,919     61,002     59,122     67,153     72,000
                  Northampton    NC       28,432     26,811     23,099     22,584     22,000
                  Onslow         NC       42,047     82,706    103,126    112,784    129,000
                  Orange         NC       34,435     42,970     57,567     77,055     84,000
                  Pamlico        NC        9,993      9,850      9,467     10,398     11,000
                  Pasquotank     NC       24,347     25,630     26,824     28,462     29,000
                  Perquimans     NC        9,602      9,178      8,351      9,486     11,000
                  Person         NC       24,361     26,394     25,914     29,164     31,000
                  Pitt           NC       63,789     69,942     73,900     90,146     99,000
                  Rockingham     NC       64,816     69,629     72,402     83,426     86,000
                  Stokes         NC       21,520     22,314     23,782     33,086     36,000
                  Surry          NC       45,593     48,205     51,415     59,449     62,000
                  Tyrrell        NC        5,048      4,520      3,806      3,975      4,000
                  Vance          NC       32,101     32,002     32,691     36,748     39,000
                  Wake           NC      136,450    169,082    229,006    301,327    371,000
                  Warren         NC       23,539     19,652     15,810     16,232     17,000
                  Washington     NC       13,180     13,488     14,038     14,801     14,000
                  Wayne          NC       64,267     82,059     85,408     97,054    100,000
                  Wilson         NC       54,506     57,716     57,486     63,132     65,000
                  Appomattox     VA        8,764      9,148      9,784     11,971     13,000
                  Bedford        VA       29,627     31,028     26,728     34,927     40,000
                  Botetourt,     VA       15,766     16,715     18,193     23,270     25,000







              140                                                                    Appendices

              Appendix 1.1. Continued


              County      State          1950       1960       1970        1980       1987

              Brunswick     VA        20,136     17,779     16,172      15,632     16,000
              Campbell      VA        28,877     32,958     34,248      45,424     49,000
              Charlotte     VA        14,057     13,368     12,366      12,266     12,000
              Dinwiddie     VA        18,839     22,183     21,668      22,602     22,000
              Floyd         VA        11,251     10,462       9,775     11,563     12,000
              Franklin      VA        24,560     25,925     28,163      35,740     38,000
              Greensville   VA        16,319     16,155       9,604     10,903     11,000.
              Halifax       VA        41,442     33,637     30,076      30,599     30,000
              Henry         VA        31,219     40,335     50,901      57,654     58,000
              Isle of  wightvA        14,906     17,164     18,285      21,603     24,000
              Lunenburg     VA        14,116     12,523     11,687      12,124     12,000
              Mecklenberg   VA        33,497     31,428     29,426      29,444     30,000
              Montgomery    VA        29,780     32,923     47,157      63,516     69,000
              Nottoway      VA        15,479     15,141     14,260      14,666     14,000
              Patrick       VA        15,642     15,282     15,282      17,647     18,000
              Pittsylvania  VA        66,096     58,296     58,789      66,147     68,000
              Prince GeorgeVA         19,697     20,270     24,371      25,733     27,000
              Roanoke       VA        41,486     61,693     53,817      72,945     78,000
              Southampton VA          26,522     27,195     18,582      18,731     19,000
              Surry         VA          6,220      6,220      5,882       6,046      6,000
              Sussex        VA        12,785     12,411     11,464      10,874     10,000
              Total                2,319,010   2,587,025  2,757,979  3,174,859   3,431,900

              Chowan  River          202,199    201,504    180,563     185,925    187,500
              Roanoke River          591,367    622,439    627,608     728,357    763,470
              Albemarle Sound         69,813     70,856     71,045      83,398     90,595
              Tar-Pamlico R.         294,867    297,327    290,695     319,906    342,664
              Neuse River            568,141    645,904    721,831     858,542    964,740
              Pamlico Sound           10,693     10,712     10,909      14,435     18,567








                 Appendices                                                                     141
                 A p p e n d ix 3. 1 . County land areas in five major sub-basins of the
                 Albemarle/Pamlico Estuarine system watershed. "Percent of County Area" is the
                 value used to adjust county totals (for population, agricultural acreages and yields,
                 and all other non-point source variables) to give estimates of the county's
                 contribution to the basin



                                     County Area (sq. m.)     Land Area in Basin

                 County        state    Land   Water    Sum       Square   Percent
                                                                  Miles    of C. Area


                 CHOWAN  RIVER
                 Bertie          MC     698       33    731          170     24.4
                 Brunswick       VA     563                          518     92.0
                 Chowan          MC     172       57    230          110     63.9
                 Dinwiddie       VA     507                          466     92.0
                 Gates           MC     337        7    344          252     74.8
                 Greensville     VA     300                          300    100.0
                 Hertford        NC     353        6    359          353    100.0
                 Isle of Wight   VA     319                          160     50.0
                 Lunenburg       VA     432                          432    100.0
                 Mecklenberg     VA     616                          105     17.0
                 Northampton     NC     547             547          357     65.3
                 Nottoway        VA     316                          167     53.0
                 Prince George   VA     266                          136     51.0
                 Southampton     VA     603                          603    100.0
                 Suffolk City    VA     409                          123     30.0
                 Surry           VA     281                          169     60.0
                 Sussex          VA     491                          491    100.0
                 TOTAL                 7,210                       4,911


                 ROANOKE RIVER
                 Appomattox      VA     336                          95      28.4
                 Beaufort        NC     826      135    961             8     1.0
                 Bedford         VA     747                          641     85.8
                 Bertie          NC     698       33    731          518     74.2
                 Botetourt       VA     545                          71      13.1
                 Brunswick       VA     563                          45       8.0
                 Campbell        VA     505                          427     84.6
                 Caswell         NC     428             428          383     89.5
                 Charlotte       VA     477                          477    100.0
                 Floyd           VA     381                          31       8.2
                 Forsyth         NC     419             419          124     29.6
                 Franklin        VA     683                          683    100.0
                 Granville       NC     544             544          186     34.2
                 Guilford        NC     657             657          12       1.8
                 Halifax         NC     742             742          302     40.7
                 Halifax         VA     816                          816    100.0
                 Henry           VA     382                          382    100.0
                 Martin          NC     462             462          342     74.0
                 Mecklenburg     VA     616                          511     83.0
                 Montgomery      VA     390                          168     43.0








              142                                                                 Appendices

              Appendix 3. 1. Continued


                                 County Area (sq. m.)     Land Area in Basin

              County       State    Land   Water    Sum       Square   Percent
                                                              Miles   of C. Area


              Northampton    NC      547            547          190      34.7
              Orange         NC      400            400            7       1.8
              Patrick        VA      481                         425      88.3
              Person         NC      401            401          250      62.3
              Pittsylvania   VA      995                         995     100.0
              Roanoke        VA      251                         228      90.8
              Rockingham     NC      569            569          476      83.7
              Stokes         NC      457            457          386      84.5
              Surry          NC      536            536            15      2.8
              Vance          NC      269            269          145      53.9
              Warren         NC      441            441          171      38.8
              Washington     NC      343      85    428            56     16.3
              TOTAL               16,907                        9,567


              TAR-PAMLICO
              Beaufort       NC      826    135     961          776      93.9
              Edgecombe      NC      511            511          511     100.0
              Franklin       NC      494            494          426      86.2
              Granville      NC      544            544          220      40.4
              Halifax        NC      742            742          440      59.3
              Hyde           NC      613    736 1,349            159      25.9
              Martin         NC      462            462          120      26.0
              Nash           NC      544            544          402      73.9
              Pamlico        NC      338    228     566            27      8.0
              Person         NC      401            401            32      8.0
              Pitt           NC      655            655          372      56.8
              Vance          NC      269            269          124      46.1
              Warren         NC      441            441          270      61.2
              Washington     NC      343      85    428            89     25.9
              Wilson         NC      375            375            63     16.8
              TOTAL                7,558                        4,031


              NEUSE RIVER
              Beaufort       NC      826    135     961            43      5.2
              Carteret       NC      536    532    1,068.        ill      20.7
              Craven         NC      699       60   759          643      92.0
              Durham         NC      299            299          216      72.2
              Franklin       NC      494            494            65     13.2
              Granville      NC      544            544          138      25.4
              Greene         NC      269            269          269     100.0
              Johnston       NC      793            793          793     100.0
              Jones          NC      468            468          369      78.8
              Lenoir         NC      400            400          400     100.0
              Nash           NC      544            544          142      26.1
              Orange         NC      400            400          209      52.3








                     Appendices                                                                                143
                     Appendix 3. 1. Continued


                                           County Area (sq. m.)         Land Area in Basin

                     County         state      Land   Water      Sum        Square    Percent
                                                                           Miles      of C. Area


                     Pamlico           NC      338      228      566            165      48.9
                     Person            NC      401               401            119      29.7
                     Pitt              NC      655               655            283      43.2
                     Wake              NC      859               859            723      84.2
                     Wayne             NC      557               557            520      93.4
                     Wilson            NC      375               375            312      83.2
                     TOTAL                    9,457                           5,520


                     COASTAL
                     Albemarle Sound
                     Bertie            NC      698       33      731             10        1.4
                     Camden            NC      239       77      316            239     100.0
                     Chowan            NC      172       57      230             62      36.1
                     Currituck         NC      246      177      423            246     100.0
                     Dare              NC      391      880   1,271             225      57.6
                     Gates             NC      337         7     344             85      25.2
                     Hyde              NC      613      736   1,349             128      20.9
                     Pasquotank        NC      228       65      293            228     100.0
                     Perquimans        NC      246       89      335            246     100.0
                     Tyrrell           NC      390      169      559            390     100.0
                     Washington        NC      343       85      428            198      57.8
                     TOTAL                    3,903                           2,057
                     Pamlico Sound
                     Carteret          NC      536      532   1,068              15         2.8
                     Dare              NC      391      880   1,271             167      42.4
                     Hyde              NC      613      736   1,349             326      53.2
                     Pamlico           NC      338      228      566            145      42.9
                     TOTAL                    1,877                             653



                     Notes:
                     a. Area south of 35' latitude (i.e., Core and Bogue Sounds) excluded from Coastal sub-
                     basin
                     b. Pamlico-Albemarle boundary is a line running east-west through Manteo, N.C.
                     c. Tar-Pamlico River estuary basin includes all coastal drainage west of the mouth of the
                     estuary. The boundary between Tar-Pamlico and Pamlico Sound (Coastal) corresponds
                     to the eastern edge of USGS cataloging unit 03020104 (see maps in NOAA National
                     Estuarine Atlas for identification of these units (NOAA 1985)).
                     d. The southern boundary of Pamlico Sound is a line between Hog Island and Swash Inlet
                     (southwest of this line is Core Sound) - Note that NOAA National Estuarine Atlas has
                     this boundary farther southwest, at a line between Marshallberg and Core Banks.
                     e. The boundary between Chowan River Basin and Albemarle Sound is mouth of
                     Chowan River near Edenton, corresponding to boundary between USGS cataloging units
                     03010203 and 03010205.








              144                                                                     Appendices

              Appendix 3.1 Continued

              f. Albemarle Sound corresponds to USGS cataloging unit 03010205.
              g. Pamlico Sound corresponds to USGS cataloging unit 03020105.
              h. Eastern boundary of Neuse River basin = boundary between USGS cataloging units
              03020204 and 03020106.
              i. Eastern boundary of Roanoke River basin boundary between USGS cataloging units
              03010107 and 03010205.







                   Appendices                                                                      145
                   Appendix 3.2a. Acres of Land in Farms


                                           1880       1890       1900        1910       1920

                   Chowan River          2464949    2365240    2456909   2313583    2097147
                   Roanoke River         4967022    5068506    5283595   5315135    5076096
                   Albemarle Sound       666732     600988     549003    1269179    492413
                   Tar-Pamlico R.        1859608    1824614    1878555   1836714    1650105
                   Neuse River           2684615    2679392    2677646   2671131    2359364
                   Pamlico Sound         100326     93821      91390       89467      83981
                   Total Coastal         767058     694810     640393    1358646    576394
                   Total                 12743253   12632562   12937098  13495209  11759107

                                           1925       1930       1935       1940       1945

                   Chowan River          1938618    1928197    2058922   2002257    1945566
                   Roanoke River         4785518    4901548    5037644   4823633    4678175
                   Albemarle Sound       431990     446340     445547    457963     448986
                   Tar-Pamlico R.        1518034    1531564    1800901   1723753    1738125
                   Neuse River           2153428    2113459    2424232   2282723    2325327
                   Pamlico Sound         76134      69267      77256       70737      59460
                   Total Coastal         508124     515607     522803    528700     508447
                   Total                 10903722   10990375   11844502  11361065  11195640

                                           1950       1954       1959       1964       1969

                   Chowan River          2036286    1964801    1678576   1505628    1435360
                   Roanoke River         4741180    4470567    4094046   3787973    3303075
                   Albemarle sound       476410     456960     446638    430965     406375
                   Tar-Pamlico R.        1851346    1775610    1685385   1565672    1497199
                   Neuse River           2459176    2351979    2133319   1974766    1775826
                   Pamlico Sound         67413      69741      70407       66588      62602
                   Total Coastal         543823     526702     517045    497554     468977
                   Total                 11631811   11089659   10108371  9331593    8480437

                                          1974        1978       1982       1987

                   chowan River          1346248    1295363    1214301   1177872
                   Roanoke River         2841138    2752780    2655110   2575457
                   Albemarle Sound       405070     447050     469384    455303
                   Tar-Pamlico R.        1257590    1285257    1202536   1166460
                   Neuse River           1597807    1592321    1473881   1429665
                   Pamlico Sound         69163      69634      80138      77734
                   Total Coastal         474233     516684     549523    533037
                   Total                 7517017    7442404    7095350   6882489








              146                                                                   Appendices
              Appendix 3.2b. Acres of Harvested Cropland


                                      1880       1890       1900        1910       1920

              Chowan River          428302                477991                529202
              Roanoke River       1045276                 1096797              1114829
              Albemarle Sound       174349                156921                192890
              Tar-Pamlico R.        472982                485395                551255
              Neuse River           628622                715262                806725
              Pamlico sound          19829                 17983                  30145
              Total Coastal         194178                174904                223035
              Total               2769360                 2950347              3225045

                                      1925        1930       1935       1940       1945

              Chowan River          514563     553523     536273     563039     578564
              Roanoke River       1068344     1113728     1063036   1156245    1102232
              Albemarle Sound       203374     205196     212333     214223     217026
              Tar-Pamlico R.        589380     623476     623346     672674     646010
              Neuse River           812425     801286     853217     919896     915909
              Pamlico Sound          30104       28884      29498      30645      29944
              Total Coastal         233478     234080     241831     244868     246970
              Total               3218190     3326093     3317703   3556722    3489685

                                       1950       1954       1959       1964       1969

              Chowan River          550976     525518     500087     444313     442954
              Roanoke River       1009016      964181     846882     707756     592530
              Albemarle sound       209160     216972     221581     213997     228732
              Tar-Pamlico R.        668130     642814     607239     518450     454082
              Neuse River           919543     897536     797235     673052     599697
              Pamlico Sound          28070       28798      29862      29798      32049
              Total Coastal         237231     245770     251442     243795     260781
              Total               3384895     3275818     3002886   2587367    2350043

                                       1974       1978       1982       1987

              chowan River          507897     521092     552496     458237
              Roanoke River         638962     658832     693834     412340
              Albemarle sound       271252     320775     348359     313078
              Tar-Pamlico R.        537258     592236     618788     529547
              Neuse River           715831     782523     808933     665532
              Pamlico Sound          38967       44916      55826      49081
              Total Coastal         310219     365691     404185     362159
              Total               2710167     2920374     3078236   2427815








                  AppendIces                                                                      147
                  Appendix 3.2c. Acres of Pastureland. "E" Indicates interpolated (i.e., estimated
                  values)


                                         1880E      1890E      1900B      1910E      1920E


                  chowan River          102597     102597      10259     710259     7102597
                  Roanoke River         577820     577820     577820     577820     577820
                  Albemarle Sound        11624      11624      11624      11624      11624
                  Tar-Pamlico R.         54387      54387      54387      54387      54387
                  Neuse River            59654      59654      59654      59654      59654
                  Pamlico Sound           1772       1772       1772       1772       1772
                  Total Coastal          13397      13397      13397      13397      13397
                  Total                 807855     807855     807855     807855     807855


                                          1925       1930       1935       1940       1945


                  Chowan River          102597     119365      99317     105373     111430
                  Roanoke River         577820     604630     604854     644213     683571
                  Albemarle Sound        11624      16380      14292      14651      15010
                  Tar-Pamlico R.         54387      52271      57147      63361      69574
                  Neuse River            59654      73687      70303      79901      89500
                  Pamlico Sound           1772       2380       2918       2528       2138
                  Total Coastal          13397      18760      17210      17179      17148
                  Total                 807855     868713     848831     910027     971223


                                          1950       1954       1959       1964       1969


                  Chowan River          134737     158095     125814     122233     114944
                  Roanoke River         677105     649190     573672     585665     533586
                  Albemarle Sound        18742      30597      21423      17969      18789
                  Tar-Pamlico R.         87827     118383     101139     105367     104417
                  Neuse River           115986     137943     120729     121578     110111
                  Pamlico sound           2136       3883       4798       3087       4885
                  Total Coastal          20878      34480      26221      21056      23674
                  Total                1036534     1098091    947576     955899     886733


                                          1974       1978       1982      1987E


                  Chowan River          154561     102693     103336     103336
                  Roanoke River         566171     496487     505091     505091
                  Albemarle Sound        18420      14590      10336      10336
                  Tar-Pamlico R.        122847      91387      78804      78804
                  Neuse River           137980     106237      93067      93067
                  Pamlico Sound           5187       4294       2459       2459
                  Total coastal          23607      18884      12794      12794
                  Total                 1005165    815688     793092     793092









               148                                                                   Appendices
               Appendix 3.2d. Acres of "other land" in farms; generally the sum of two land
               categories in the agriculre census reports: 1) Other Cropland (Idle, Crop Failure, etc.) and
               2) Other Land - Not Pasture and Range (i.e., house lots, ponds, roads, etc.). Harvested
               cropland, non-forested pastureland, and forested lands are not included in this landuse
               category. "E" indicates values estimated by interpolation



                                         1880E      1890E      1900E      1910E      1920E


               Chowan River             300461     300461     300461     300461     300461
               Roanoke River            951039     951039     951039     951039     951039
               Albemarle Sound           43533      43533      43533      43533      43533
               Tar-Pamlico R.           196642     196642     196642     196642     196642
               Neuse River              285889     285889     285889     285889     285889
               Pamlico Sound             18491      18491      18491      18491      18491
               Total                   1796054    1796054    1796054     1796054    1796054
               Coastal                   62024      62024      62024      62024      62024


                                           1925      1930       1935       1940        1945


               Chowan River             300461     255712     247368     170800     137025
               Roanoke River            951039     854695     815374     638900     523509
               Albemarle Sound           43533      41655      35929      29707      16847
               Tar-Pamlico R.           196642     156457     182137     119154     123019
               Neuse River              285889     232745     212408     171269     142240
               Pamlico sound             18491       5198       8845       6327        4789
               Total                   1796054    1546462    1502061     1136157    947429
               Coastal                   62024      46853      44774      36034      21636


                                           1950      1954       1959       1964        1969


               Chowan River             156098     107639     111867     124987     156938
               Roanoke River            622008     475913     508789     492693     465201
               Albemarle sound           36012      18343      23795      42397      44102
               Tar-Pamlico R.           146107     113000     139261     173697     226112
               Neuse River              194216     156896     189233     216248     301567
               Pamlico Sound               7288      5421       6874       7548        5310
               Total                   1161729     877212     979819     1057569    1199231
               Coastal                   43299      23764      30669      49945      49413


                                         1974       1978       1982       1987E


               Chowan River             98802     109107      91147       91147
               Roanoke River           323489     376364     317112      317112
               Albemarle Sound          27570      29476      29325       29325
               Tar-Pamlico R.          120576     151130     107819      107819
               Neuse River             172335     181918     132203      132203
               Pamlico Sound             2751       4866       5013        5013
               Total                   745523     852860     682619      682619
               Coastal                  30322      34342      34338       34338







                  Appendices                                                                      149
                  Appendix 3.2e. Acres of Forest. "Ell Indicates interpolated (i.e., estimated) values


                                          1880E      1890E   1900B         1910E      1920E

                  Chowan River         2063556    2063556    2063556    2063556   2063556
                  Roanoke River        3375191    3375191    3375191    3375191   3375191
                  Albemarle Sound      857692     857692     857692     857692     857692
                  Tar-Pamlico R.       1342457    1342457    1342457    1342457   1342457
                  Neuse River          1914105    1914105    1914105    1914105   1914105
                  Pamlico Sound        298843     298843     298843     298843     298843
                  Total Coastal        1156535    1156535    1156535    1156535   1156535
                  Total                9851844    9851844    9851844    9851844   9851844

                                         1925E      1930E      1935E      1940       1945E

                  Chowan River         2063556    2063556    2063556    2063556   2082702
                  Roanoke River        3375191    3375191    3375191    3375191   3506594
                  Albemarle Sound      857692     857692     857692     857692     882699
                  Tar-Pamlico R.       1342457    1342457    1342457    1342457   1389694
                  Neuse River          1914105    1914105    1914105    1914105   1949371
                  Pamlico sound        298843     298843     298843     298843     302491
                  Total Coastal        1156535    1156535    1156535    1156535   1185190
                  Total                9851844    9851844    9851844    9851844   10113551

                                         1950E      1954E       1959       1964      1969E

                  Chowan River         2101848    2120994    2140140    2178594   2208389
                  Roanoke River        3637997    3769399    3900802    4021611   4008157
                  Albemarle Sound      907706     932713     957720     890980     865470
                  Tar-Pamlico R.       1436932    1484169    1531406    1527421   1508630
                  Neuse River          1984637    2019902    2055168    2060987   2032545
                  Pamlico Sound        306139     309787     313435     281047     277998
                  Total Coastal        1213845    1242500    1271155    1172027   1143468
                  Total               10375258   10636964    10898671  10960640   10901189

                                          1974      1978E       1982       1987

                  chowan River         2238184    2166571    2094957    2094957
                  Roanoke River        3994704    3929931    3865158    3865158
                  Albemarle Sound      839960     773923     707887     707887
                  Tar-Pamlico R.       1489839    1444911    1399982    1399982
                  Neuse River          2004102    1952878    1901654    1901654
                  Pamlico Sound        274949     260658     246366     246366
                  Total Coastal        1114909    1034581    954253     954253
                  Total               10841738   10528871    10216003  10216003







              150                                                                  Appendices
              Appendix 3.2f. Acres of Urban Land. "E" Indicates interpolated (i.e., estimated) values


                                    1880B      1890E      1900E      1910B      1920E

              Chowan River                0          0         0          0          0
              Roanoke River               0          0         0          0          0
              Albemarle sound             0          0         0          0          0
              Tar-Pamlico R.              0          0         0          0          0
              Neuse River                 0          0         0          0          0
              Pamlico sound               0          0         0          0          0
              Total Coastal               0          0         0          0          0
              Total                       0          0         0          0          0

                                    1925E      1930E      1935E       1940      1945E

              chowan River                0          0         0          0          0
              Roanoke River               0      2000      5000      10240      16000
              Albemarle Sound             0          0         0'         0          0
              Tar-Pamlico R.              0      1000      2000       3840       3840
              Neuse River                 0      3000      7000      13440      14000
              Pamlico Sound               0          0         0          0          0
              Total Coastal               0          0         0          0          0
              Total                       0      6000     14000      27520      33840

                                      1949     1954E       1959      1964E       1969

              Chowan River                0       960      1920       1920       1920
              Roanoke River         21120      40000      62720      70000      76160
              Albemarle Sound             0      2000      4480       5000       5760
              Tar-Pamlico R.          3840     12000      18560      23000      27520
              Neuse River           15360      30000      58880      70000      85120
              Pamlico sound               0          0         0          0          0
              Total Coastal               0      2000      4480       5000       5760
              Total                 40320      84960      146560     169920     196480

                                    1974E      1978E       1982       1987

              Chowan River            3100       4400      5760       7000
              Roanoke River         82000      89000      95360      100000
              Albemarle Sound         5400       5200      5120       5000
              Tar-Pamlico R.        30000      33000      36480      39000
              Neuse River           95000      110000     126080     150000
              Pamlico Sound               0          0         0          0
              Total coastal           5400       5200      5120       5000
              Total                 215500     241600     268800     301000








                 Appendices                                                                     151
                 Appendix 3.2g. Acres "Other Land", calculated by subtracting sum of harvested
                 cropland, pasture, other farmland, forested land and urban land from total land area


                                      1880       1890       1900       1910       1920


                 Chowan River       248189     245361    198499     167122     147289
                 Roanoke River      172914     206666    121394     166274     103361
                 Albemarle Soun     229281     237954    246709     246919     210741
                 Tar-Pamlico R.     513051     485735    500640     454492     434779
                 Neuse River        643890     571417    557250     536196     465787
                 Pamlico Sound       78985      80715     80831       73724      68668
                 Total            1886310    1827848    1705323    1644727     1430625
                 coastal            308266     318669    327540     320643     279409


                                      1925       1930       1935       1940        1945


                 Chowan River       161928     150947    196590     240336     233383
                 Roanoke River      149846     171997    258784     297452     290334
                 Albemarle Soun     200256     195557    196233     200206     184898
                 Tar-Pamlico R.     396653     403859    372433     378034     347382
                 Neuse River        460087     507336    475128     433548     421141
                 Pamlico Sound       68710       82615    77816       79577      78558
                 Total            1437481    1512311    1576984    1629153     1555697
                 coastal            268966     278172    274049     279783     263456


                                      1950       1954       1959       1964        1969


                 Chowan River       199445     229897    263276     271057     217959
                 Roanoke River      154995     223557    229375     244515     446606
                 Albemarle Soun     144860     115854     87482     146137     153627
                 Tar-Pamlico R.     236684     209155    181915     231585     258758
                 Neuse River        302418     289883    310915     390294     403120
                 Pamlico Sound       74287       70032    62951       96441       97678
                 Total            1112689    1138378    1135913    1380029     1577748
                 coastal            219147     185886    150433     242578     251305


                                      1974       1978       1982       1987


                 Chowan River       140560     239241    295407     479574
                 Roanoke River      516915     571626    645686    1239652
                 Albemarle Soun     153877     172516    215454     280180
                 Tar-Pamlico R.     279001     266857    337647     532188
                 Neuse River        406912     398604    470223     721907
                 Pamlico sound       96065     103186    108256     120014
                 Total            1593330    1752030    2072673    3373513
                 Coastal            249942     275702    323709     400194







               152                                                                  Appendices
               Appendix 3.3a. Acres of Cotton


                                      1880        1890       1900       1910      1920

               Chowan River          88793        82613      53869      49240    78840
               Roanoke River         70835        79539      55479      61555    65597
               Albemarle sound       26617        28447      20792      32705    36445
               Tar-Pamlico R.       177765     198983        125439     188211  173018
               Neuse River          218561     258981        201940     250561  248026
               Pamlico Sound          3398        3313       2682       7096      8029
               Total Coastal         30015        31760      23475      39801    44474
               Total                585970     651877        460202     589368  609954

                                      1925        1930       1935       1940      1945

               Chowan River         131248     114726        67794      44336    47847
               Roanoke River        109380        93829      58149      36765    37771
               Albemarle Sound       47896        36180      17723      9772     13366
               Tar-Pamlico R.       255884     209202        120769     78933    83691
               Neuse River          318540     263494        155061     88517    99389
               Pamlico Sound          5413        4925       2281       1925      2505
               Total Coastal         53309        41105      20004      11697    15871
               Total                868361     722355        421776     260248  284568

                                      1950        1954       1959       1964      1969

               Chowan River          58204        37028      32360      43949    23589
               Roanoke River         49128        33119      27138      39170    19172
               Albemarle Sound        8633        5018       3523       2666         743
               Tar-Pamlico R.       104717        65138      54174      62812    24843
               Neuse River          117427        69780      57240      40509     6045
               Pamlico Sound          1090         188         166         53          2
               Total Coastal          9723        5206       3688       2719         746
               Total                339198     210270        174601     189159   74395

                                      1974        1978       1982       1987

               Chowan River          18717        4085       10861      16782
               Roanoke River         16475        3586       8781       15192
               Albemarle sound           561       145       2055       5010
               Tar-Pamlico R.        21246        6847       16010      23540
               Neuse River            2018         379         813      3243
               Pamlico Sound               0          0          0          0
               Total Coastal             561       145       2055       5010
               Total                 59017        15041      38521      63767







                  Appendices                                                                      153
                  Appendix 3.3b. Acres of Corn


                                         1880       1890       1900        1910       1920

                  Chowan River         250538     223285      247696    227704     218000
                  Roanoke River        438406     405352      469645    439683     435434
                  Albemarle Sound      130990     123063      123291    106009     105400
                  Tar-Pamlico R.       227416     215942      251102    218008     210797
                  Neuse River          310732     320067      382387    342766     338137
                  Pamlico Sound         14765      12787      13630      14905      15727
                  Total Coastal        145755     135850      136921    120914     121126
                  Total                1372847    1300496    1487751    1349075    1323494

                                         1925       1930       1935        1940       1945

                  Chowan River         167531     168164      189603    206713     196529
                  Roanoke River        360268     369001      397501    406418     356745
                  Albemarle Sound       82458      63821      96254      99345      96222
                  Tar-Pamlico R.       174197     180371      243641    263587     238970
                  Neuse River          270262     284565      364595    375396     383849
                  Pamlico Sound         12832      13560      17364      17439      14095
                  Total Coastal         95290      77381      113618    116784     110317
                  Total                1067548    1079483    1308958    1368898    1286410

                                         1950       1954       1959        1964       1969

                  chowan River         187997     196799      163185    122244     122487
                  Roanoke River        306596     270905      220661    159497     110830
                  Albemarle Sound       87304      90849      98910      78459      71830
                  Tar-Pamlico R.       240621     244216      253064    161115     140425
                  Neuse River          407992     428207      448365    298669     274622
                  Pamlico Sound         10146      10953      49696        9166       9139
                  Total Coastal         97451     101802      148606     87625      80968
                  Total               1240657     1241929    1233881    829150     729333

                                         1974       1978       1982        1987

                  chowan River         170285     192011      163193    107545
                  Roanoke River        143423     156428      139871     93580
                  Albemarle Sound      109513     138304      136877    101746
                  Tar-Pamlico R.       198971     223166      187257    162888
                  Neuse River          321874     322969      294461    256582
                  Pamlico Sound         15845      16373      21956      15731
                  Total Coastal        125358     154677      158833    117477
                  Total                959911    1049251      943615    738071







               154                                                                  Appendices
               Appendix 3.3d. Acres of Hay


                                       1880      1890       1900        1910      1920

               Chowan River            2833      13146      15560     35712      36812
               Roanoke River           35658     67925      77205     98942     125720
               Albemarle Sound         1195      2239       2959        5199     14069
               Tar-Pamlico R.          1692      6046       9913      19061      27175
               Neuse River             1803      9173       14818     32196      37473
               Pamlico Sound             50        243        570       1922      2005
               Total Coastal           1245      2482       3529        7121     16074
               Total                   43232     98773      121026    193032    243253

                                       1925      1930       1935        1940      1945

               Chowan River            42355   174382       180169    173971     39437
               Roanoke River           131498  144099       191857    258985    264423
               Albemarle Sound         15795     21764      31302     23926       7039
               Tar-Pamlico R.          31118     48939      103188    104084     64779
               Neuse River             36540     41341      108717    120655    124524
               Pamlico Sound           1858      1285       4698        1829      1553
               Total Coastal           17653     23049      36000     25755       8593
               Total                   259163  431811       619931    683450    501756

                                       1950      1954       1959        1964      1969

               Chowan River            44746     77269      62507     43164      20645
               Roanoke River           276568  322427       251549    177750    136053
               Albemarle Sound         2314      9800       3883        4166      1339
               Tar-Pamlico R.          59615     81630      60094     33795      13534
               Neuse River             88847     71991      41947     23911      15364
               Pamlico Sound            614        521        335        254         335
               Total Coastal           2928      10321      4218        4421      1674
               Total                   472704  563638       420315    283040    187270

                                       1974      1978       1982        1987


               Chowan River            20377     23008      25020     26951
               Roanoke River           139586  157796       169578    176775
               Albemarle Sound         1563        672         532      1158
               Tar-Pamlico R.          12603     14954      15743     21013
               Neuse River             16947     22813      23082     23218
               Pamlico Sound             315       291         126        224
               Total Coastal           1877        963         658      1382
               Total                   191391  219534       234081    249339







                  Appendices                                                                      155
                  Appendix Me. Acres of Oats


                                         1880       1890        1900      1910        1920

                  chowan River           50531     41540      16339       10074       2890
                  Roanoke River         211057     175138     110177      57683     25164
                  Albemarle Sound        6741       9866        3047      2568        1075
                  Tar-Pamlico R.         34304     47167      18338       10882       4061
                  Neuse River            37656     53483      26171       18823       7683
                  Pamlico Sound           891       1692        975       1040          849
                  Total Coastal          7631      11558        4022      3608        1925
                  Total                 341180     328887     175048     101071     41721

                                         1925       1930        1935      1940        1945

                  chowan River            692        972        927       1051        2741
                  Roanoke River          7004       5936        6253      7785        9634
                  Albemarle Sound         287        261        333        617        1845
                  Tar-Pamlico R.          489        621        1375      3903        9228
                  Neuse River             905        999        1088      2750        8314
                  Pamlico Sound           586        512        326        498        1705
                  Total Coastal           873        773        659       1115        3550
                  Total                  9963       9301      10302       16604     33467

                                         1950       1954        1959      1964        1969

                  chowan River           4387      16739        7491      2992        2640
                  Roanoke River          14892     27036      24038       11205       9715
                  Albemarle sound        1433       2269        2260      4219        4951
                  Tar-Pamlico R.         8873      17977      15659       7068        5974
                  Neuse River            11921     24547      21480       10790       9673
                  Pamlico Sound          1592       1508        806        494         917
                  Total Coastal          3025       3777        3066      4712        5868
                  Total                  43096     90075      71733       36767     33870

                                         1974       1978        1982      1987

                  Chowan River           1176       1168        1016       141
                  Roanoke River          6334       8582        4931      2745
                  Albemarle Sound        1874       1494        820       1481
                  Tar-Pamlico R.         3658       4452        6263      5603
                  Neuse River            5270      10582        7812      9408
                  Pamlico Sound           161          98       221          52
                  Total Coastal          2035       1591        1042      1533
                  Total                  18474     26376      21063       19430








                156                                                                  Appendices
                Appendix 3.3f. Acres of Peanuts


                                       1880       1890       1900       1910       1920

                Chowan River                     43593     107910     156465     139240
                Roanoke River                     1833      26947      54044      45511
                Albemarle Sound                   1393       6640      10173       8821
                Tar-Pamlico R.                    2040      20352      46721      23425
                Neuse River                       1035       3350       8448       1330
                Pamlico Sound                        14         36         86          7
                Total Coastal                     1407       6677      10259       8827
                Total                            49908     165236     275936     218334

                                       1925       1930       1935       1940       1945

                Chowan River         135647     166071     170454     168057     176011
                Roanoke River         55275      61234      67678      68230      75478
                Albemarle Sound       15412      19636      19696      19494      23358
                Tar-Pamlico R.        31045      45324      53889      56417      69992
                Neuse River            2371       7365       8119       6885      10096
                Pamlico Sound             40         62        127         63         25
                Total Coastal         15452      19699      19823      19557      23383
                Total                239789     299693     319964     319145     354959

                                       1950       1954       1959       1964       1969

                Chowan River         160008     119086     120134     121017     127649
                Roanoke River         65477      48899      47984      50255      53498
                Albemarle Sound       13807      10125      10057      10180       9806
                Tar-Pamlico R.        56024      43081      42957      45031      42063
                Neuse River            5547       4481       4514       4581       4620
                Pamlico Sound              7          5          1          1          1
                Total Coastal         13815      10129      10058      10181       9807
                Total                300871     225676     225646     231065     237636

                                       1974       1978       1982       1987


                Chowan River         129255     129644     123493     108993
                Roanoke River         48493      50655      47186      46577
                Albemarle Sound        9378       9523       8610       8817
                Tar-Pamlico R.        40863      42655      37836      37615
                Neuse River            3826       4363       3794       3265
                Pamlico Sound              0          0          0          0
                Total Coastal          9378       9523       8610       8817
                Total                231816     236840     220919     205267








                  Appendices                                                                       157
                  Appendix 3.3c. Acres of Corn for Silage


                                         1880       1890       1900        1910      1920

                  Chowan River
                  Roanoke River
                  Albemarle Sound
                  Tar-Pamlico R.
                  Neuse River
                  Pamlico sound
                  Total Coastal
                  Total


                                         1925        1930       1935       1940       1945

                  Chowan River             846       1375                  1134
                  Roanoke River          3727        4252                  3849
                  Albemarle sound            78       113                   212
                  Tar-Pamlico R.           313        554                   494
                  Neuse River              763       1524                  1557
                  Pamlico sound               0          0                     1
                  Total Coastal              78       114                   213
                  Total                  5728        7819                  7246


                                         1950        1954       1959       1964       1969

                  Chowan River           1619        4037       2992       5317       9503
                  Roanoke River          5462       11634      14497       29016     47205
                  Albemarle sound          335        249        359        763         821
                  Tar-Pamlico R.           746       2264       3130       3962       5999
                  Neuse River            1252        3911       4270       6951      10717
                  Pamlico Sound               1         27       239        241         445
                  Total Coastal            336        276        597       1004       1266
                  Total                  9416       22121      25486       46250     74689

                                         1974        1978       1982       1987

                  Chowan River           7397        6812       5759       5499
                  Roanoke River          39163      46626      40682       38316
                  Albemarle sound          908        298       1252        440
                  Tar-Pamlico R.         5449        6051       9833       5020
                  Neuse River            7822       10292       9743       6200
                  Pamlico Sound            538        341        427        161
                  Total Coastal          1446         639       1679        600
                  Total                  61277      70419      67695      55636








                158                                                                  Appendices
                Appendix 3.3g. Acres of Soybeans


                                       1880       1890       1900       1910       1920


                Chowan River                                                       2949
                Roanoke River                                                      1397
                Albemarle Sound                                                   26374
                Tar-Pamlico R.                                                     5339
                Neuse River                                                        5120
                Pamlico Sound                                                      3169
                Total Coastal                                                     29544
                Total                                                             44349


                                       1925       1930       1935       1940       1945


                Chowan River                      8933      12513      18790      90183
                Roanoke River                    14777      19338      26125      27507
                Albemarle Sound                  42193      57143      65478      78317
                Tar-Pamlico R.                   11168      29198      57222      61972
                Neuse River                      14941      39769      71296     109879
                Pamlico Sound                     6310       6696       7726       8101
                Total Coastal                    48503      63840      73205      86418
                Total                            98322     164657     246637     375958


                                       1950       1954       1959       1964       1969


                Chowan River          13709      31156      66400      69531      76568
                Roanoke River          6473      12498      26025      31957      49190
                Albemarle sound       73605      85081      84354     104840     118302
                Tar-Pamlico R.        41547      56355      81861     111900     121313
                Neuse River           23013      26223      52555     114592     109261
                Pamlico Sound         10451      12262      14732      18020      18601
                Total Coastal         84056      97343      99086     122860     136903
                Total                168797     223575     325928     450840     493234


                                       1974       1978       1982       1987


                Chowan River         123513     136243     174778     167038
                Roanoke River         82613     100538     127257     108167
                Albemarle Sound      136261     157918     182765     138418
                Tar-Pamlico R.       163577     208060     238801     180141
                Neuse River          161536     252510     297729     228632
                Pamlico Sound         20014      24329      30638      24009
                Total Coastal        156275     182247     213403     162427
                Total                687514     879598     1051967    846405








                 Appendices                                                                      159
                 Appendix 3.3h. Acres of Tobacco


                                         1880       1890       1900       1910       1920

                 Chowan River           11165      10042      18886      18399      32064
                 Roanoke River         108719     106789     156046     170347     216137
                 Albemarle Sound             5          0         32         19       388
                 Tar-Pamlico R.          5280      12343      47566      41952      98919
                 Neuse River             5721      11570      53540      67735     145568
                 Pamlico Sound               7          0         24          9       239
                 Total Coastal              13          0         56         27       627
                 Total                 130897     140744     276094     298460     493315

                                         1925       1930       1935       1940       1945

                 Chowan River           28068      31943      23787      37470      29090
                 Roanoke River         186729     216422     140627     196871     155236
                 Albemarle Sound          366       1429       5683       1143       1070
                 Tar-Pamlico R.         79407     141815      83896     136672     112652
                 Neuse River           128633     220503     127651     229675     189140
                 Pamlico Sound            233        451      12942        798        586
                 Total Coastal            600       1880      18624       1941       1656
                 Total                 423437     612563     394586     602630     487774

                                         1950       1954       1959       1964       1969

                 Chowan River           27470      30982      23479      19120      16168
                 Roanoke River         146410     160193     109731      98666      86564
                 Albemarle sound         1096       5791        842        772        634
                 Tar-Pamlico R.        103466     115046      77909      69810      63185
                 Neuse River           171673     190239     126790     114722      98907
                 Pamlico Sound            580        764        466        423        330
                 Total Coastal           1676       6555       1307       1194        964
                 Total                 450695     503015     339215     303513     265788


                                         1974       1978       1982       1987

                 Chowan River           17403      16973      14782       9613
                 Roanoke River          86936      92758      73742      47323
                 Albemarle Sound          469        509        567        344
                 Tar-Pamlico R.         62357      67683      55613      36753
                 Neuse River           102543     115434      97329      63606
                 Pamlico Sound            355        486        281        214
                 Total Coastal            824        995        849        558
                 Total                 270062     293844     242316     157853








               160                                                                  Appendices
               Appendix     3.3i, Acres of Wheat


                                      1880        1890       1900       1910       1920


               chowan River          24441      16910      17730      11775      18408
               Roanoke River        180601     174947     201298     169663     199870
               Albemarle Sound        8801         669        159         39        318
               Tar-Pamlico R.        26525      17777      12683        6706       8521
               Neuse River           54149      46786      33055      15787      23387
               Pamlico Sound            717         49         66         31        120
               Total Coastal          9519         717        225         70        438
               Total                295235     257139     264991     204001     250625


                                      1925        1930       1935       1940       1945


               Chowan River          11540      12778      17797      12062      18395
               Roanoke River        117466     141902     147326     104118     103720
               Albemarle Sound          124          20         81        77        921
               Tar-Pamlico R.         2238        3467     12806        8382     18452
               Neuse River            7596        9605     17459      12417      35555
               Pamlico Sound              13          0          4          1       159
               Total Coastal            137          20         86        78       1081
               Total                138977     167773     195473     137057     177202


                                      1950        1954       1959       1964       1969


               Chowan River          13334      14334      21462      12826      12805
               Roanoke River         89233      80048     106233      63502      38854
               Albemarle Sound          125       1272       8754     19569      19253
               Tar-Pamlico R.         8434      13068      28698      17984      18589
               Neuse River           16818      21010      43602      33247      22985
               Pamlico Sound              66        186        899      2338       1739
               Total Coastal            190       1458       9653     21907      20992
               Total                128009     129918     209648     149466     114225


                                      1974        1978       1982       1987


               Chowan River          28469      10058      64870      31886
               Roanoke River         61646      29983      84923      50776
               Albemarle Sound       26694      19426      70587      49483
               Tar-Pamlico R.        28048      14890      91088      65576
               Neuse River           35863      18566      99534      78998
               Pamlico Sound          3673        1656       9425       7765
               Total Coastal         30367      21081      80012      57248
               Total                184393      94578     420426     284483








                 Appendices                                                                      161
                 Appendix 3.4a. Tons of Nitrogen Sold as Fertilizer


                                         1880       1890       1900       1910       1920

                 Chowan River             164        440       1043       2378       3907
                 Roanoke River            247        664       1573       3587       5894
                 Albemarle Sound            51       138        327        747       1227
                 Tar-Pamlico R.           211        568       1346       3069       5044
                 Neuse River              316        850       2013       4591       7545
                 Pamlico Sound               5         13         30         68        112
                 Total Coastal              56       151        357        815       1338
                 Total                   1046       2818       6671      15214      25000

                                         1925       1930       1935       1940       1945

                 Chowan River            6663       4575       3417       3759       5230
                 Roanoke River           9503       8064       6146       6362       9110
                 Albemarle Sound         1785       1487        994       1491       2037
                 Tar-Pamlico R.          8275       7143       5038       4910       7015
                 Neuse River           11837      10248        7567       7229      10575
                 Pamlico sound            197        171        225        205         208
                 Total Coastal           1982       1658       1218       1696       2245
                 Total                 40185      33618      25322       25895      36120

                                         1950       1954       1959       1964       1969

                 Chowan River            6016       9076       8390      17134      14248
                 Roanoke River         10822      14613      14104       30498      25881
                 Albemarle Sound         2632       3035       3095       7243       8613
                 Tar-Pamlico R.          8638     10997      10898       24648      19373
                 Neuse River           13765      16446      16370       36624      33921
                 Pamlico Sound            252        369        377        718         846
                 Total Coastal           2883       3403       3473       7961       9459
                 Total                 44075      56490      55194      118829     104851

                                         1974       1978       1982       1987

                 Chowan River          18773      19142      17035       11762
                 Roanoke River         26999      28488      25801       21223
                 Albemarle Sound       15085      17645      17440       14338
                 Tar-Pamlico R.        28382      29976      25055       21612
                 Neuse River           41668      44641      39992       32044
                 Pamlico sound           1186       1352       1792       1629
                 Total Coastal         16271      18996      19232       15967
                 Total                 134068     143222     129097     104595








               162                                                                  Appendices
               Appendix 3.4b. Tons of Phosphorus Sold as Fertilizer


                                       1880       1890       1900       1910       1920


               Chowan River             432        930       2293       5228       6639
               Roanoke River            601       1294       3192       7280       9245
               Albemarle Sound            81       175        432        985       1251
               Tar-Pamlico R.           334        720       1776       4049       5142
               Neuse River              500       1077       2656       6058       7692
               Pamlico Sound               7         16        39          90        114
               Total Coastal              89       191        471       1075       1365
               Total                   2093       4508     11119      25357       32199


                                       1925       1930       1935       1940       1945


               Chowan River            6807       4673       4472       4964       6524
               Roanoke River           8961       7604       7424       7756      10490
               Albemarle Sound         1094        912        780       1181       1525
               Tar-Pamlico R.          5073       4379       3956       3891       5250
               Neuse River             7256       6282       5942       5728       7915
               Pamlico sound            121        105        177        162         156
               Total Coastal           1215       1017        957       1344       1680
               Total                 31237      25885      24686      25623       33804


                                       1950       1954       1959       1964       1969


               Chowan River            6970     10442        9505       9480       7858
               Roanoke River         11574      14242      13863      14705       13369
               Albemarle Sound         1830       1816       1852       2123       2557
               Tar-Pamlico R.          6005       6580       6521       7225       5752
               Neuse River             9569       9840       9795     10736       10071
               Pamlico Sound            175        221        226        211         251
               Total Coastal           2005       2036       2078       2334       2808
               Total                 38073      45095      43721      46443       41827


                                       1974       1978       1982       1987


               Chowan River            6208       5921       5150       3486
               Roanoke River           9583       9309       7577       6016
               Albemarle Sound         4503       4630       4135       3194
               Tar-Pamlico R.          8473       7866       5941       4814
               Neuse River           12440      11714        9482       7138
               Pamlico Sound            354        355        425        363
               Total Coastal           4858       4985       4560       3557
               Total                 43535      41773      34691      26998








                 AppendIces                                                                      163
                 Appendix 3.5a. Bales of Cotton


                                        1880        1890       1900       1910       1920

                 Chowan River          36767       17971      24443      23821      44543
                 Roanoke River         27184       16805      25959      30617      37445
                 Albemarle sound        9611        8063      10229      13407      22855
                 Tar-Pamlico R.        81565       50841      65111      98006     134161
                 Neuse River          104197       80523    100556      138952     178777
                 Pamlico Sound          1372         927         711      4175       5699
                 Total Coastal         10983        8991      10939      17582      28554
                 Total                260696     175131     227008      308979     423480

                                        1925        1930       1935       1940       1945

                 Chowan River          62331       63383      60825      30970      50064
                 Roanoke River         51462       49041      40055      15141      38501
                 Albemarle Sound       21117       11432      13047       3860      12446
                 Tar-Pamlico R.       136751       88898      82523      30050      79109
                 Neuse River          157801     101745       97313      38709      96914
                 Pamlico sound          2047        1910       1650         956      1783
                 Total Coastal         23164       13342      14697       4816      14229
                 Total                431509     316410     295412      119687     278818

                                        1950        1954       1959       1964       1969

                 Chowan River          33778       27508      28154      46517      15124
                 Roanoke River         32947       26910      23232      41056      13013
                 Albemarle sound        4703        3356       3398       2852         498
                 Tar-Pamlico R.        73595       50830      44815      63826      16269
                 Neuse River           84040       60573      47930      35551       3744
                 Pamlico Sound            311        167         145         51          3
                 Total Coastal          5014        3523       3543       2904         501
                 Total                229374     169343     147674      189854      48651

                                        1974        1978       1982       1987

                 Chowan River          17378        4908      14419      18017
                 Roanoke River         14924        4351      10608      15148
                 Albemarle Sound          578        168       2540       5214
                 Tar-Pamlico R.        20060        8293      17559      21897
                 Neuse River            1485         264        891       2965
                 Pamlico Sound              0           0          0          0
                 Total coastal            578        168       2540       5214
                 Total                 54424       17985      46017      63241







               164                                                                  Appendices
               Appendix 3.5b. Bushels of Corn


                                      1880       1890       1900       1910        1920


               Chowan River        2580321    1783225    3395444    3029246    3990502
               Roanoke River       6390943    5835343    8012306    7472801    7608621
               Albemarle Sound     1652943    1310229    1618098    1087012    1682459
               Tar-Pamlico R.      2374348    1798219    3051659    2858427    3932986
               Neuse River         3208132    2846654    4335728    5076657    6465703
               Pamlico sound         181492     183185     153446     308657     361435
               Total Coastal       1834435    1493414    1771543    1395669    2043894
               Total              16388179   13756855   20566681   19832800   24041707


                                      1925       1930       1935       1940        1945


               Chowan River        2704572    3372395    3435016    4376747    4513973
               Roanoke River       6613568    7331185    6806592    7816335    8130134
               Albemarle Sound     1344970    1308184    2008679    2494120    2401026
               Tar-Pamlico R.      2698231    3420667    4433788    5611212    5099416
               Neuse River         4341535    5559168    6597272    8809941    8084821
               Pamlico Sound         232955     275169     286255     405263     263539
               Total Coastal       1577925    1583353    2294934    2899383    2664564
               Total              17935831   21266768   23567602   29513618   28492908


                                      1950       1954       1959       1964        1969


               Chowan River        6494775    5738784    7201377    6818532    9302938
               Roanoke River       9233717    6868661    8226236   10379137    6443124
               Albemarle Sound     2587068    3894377    6213976    5801976    6540886
               Tar-Pamlico R.      7644613    6476970   11018351    9463849   10394339
               Neuse River        12148043    8885929   17251153   19536249   19426012
               Pamlico Sound         245768     443082     628593     780275     865986
               Total Coastal       2832835    4337460    6842569    6582251    7406871
               Total              38353983   32307804   50539686   52780018   52973285


                                      1974       1978       1982       1987


               chowan River       13611823   15785668   16169257    5953410
               Roanoke River       9492475   11544728   12593749    4748006
               Albemarle sound    10990675   13156736   15444793    7250844
               Tar-Pamlico R.     14698451   17080824   18367998    9900133
               Neuse River        24502563   24347440   29374311   13487117
               Pamlico sound       1489838    1484495    2362476    1319660
               Total Coastal      12480513   14641231   17807269    8570504
               Total              74785826   83399891   94312584   42659170







                 Appendices                                                                      165
                 Appendix 3.5c. Tons of Corn Silage


                                         1880       1890       1900       1910       1920


                 Chowan River
                 Roanoke River
                 Albemarle sound
                 Tar-Pamlico R.
                 Neuse River
                 Pamlico Sound
                 Total Coastal
                 Total


                                         1925       1930       1935       1940       1945

                 Chowan River            4075       9046                  8955
                 Roanoke River          28929      37497                 36250
                 Albemarle Sound           352      1053                  1656
                 Tar-Pamlico R.          1589       3387                  3601
                 Neuse River             4220       7519                 10073
                 Pamlico Sound               0          2                     4
                 Total Coastal             352      1056                  1661
                 Total                  39164      58505                 60540

                                         1950       1954       1959       1964       1969

                 Chowan River           14835      30458      37518      77414      90188
                 Roanoke River          55945      96680    135691      321846      542101
                 Albemarle Sound         3163       2629       3825       8318      12606
                 Tar-Pamlico R.          5790      15341      27109      40897      83793
                 Neuse River             8334      26652      40248      82221      145385
                 Pamlico Sound               5        215      2304       3684       6678
                 Total Coastal           3168       2844       6129      12002      19284
                 Total                  88071    171975     246695      534379      880750

                                         1974       1978       1982       1987

                 Chowan River           98726      91645      90982      45867
                 Roanoke River         519828    625478     588957      340074
                 Albemarle Sound        12570       4808      21270       5821
                 Tar-Pamlico R.         69044      84118    147682       64657
                 Neuse River           122850    126897     152093       63289
                 Pamlico sound           6910       4736       6829       1686
                 Total Coastal          19480       9544      28099       7507
                 Total                 829928    937683     1007813     521393








               166                                                                  Appendices
               Appendix 3.5d. Tons of Hay


                                      1880       1890       1900       1910       1920


               Chowan River                     12159      17826      30547      71328
               Roanoke River                    56644      74909     100828     267320
               Albemarle Sound                   2490       3623       5841      16934
               Tar-Pamlico R.                    6992      10466      17859      43976
               Neuse River                      11650      14328      29311      49570
               Pamlico Sound                       237       589       1495       1810
               Total Coastal                     2728       4212       7336      18743
               Total                            90172     121742     185881     450937


                                      1925       1930       1935       1940       1945


               Chowan River          29560      86940      93913     122374      66452
               Roanoke River        121940     136268     165126     259755     294935
               Albemarle Sound       14673      17120      23567      20771      18212
               Tar-Pamlico R.        20900      36523      93189      93189     105376
               Neuse River           30521      44008      98366     131238     126279
               Pamlico Sound          1323       1358       3530       2039       1666
               Total Coastal         15995      18478      27097      22810      19878
               Total                218917     322217     477690     629366     612920


                                      1950       1954       1959       1964       1969


               Chowan River          53629      63377      56810      47990      31850
               Roanoke River        331596     301569     310592     214602     210094
               Albemarle sound        2733       7707       3599       4405       2187
               Tar-Pamlico R.        60710      71853      57547      27453      19347
               Neuse River           93879      66066      45361      30035      26618
               Pamlico Sound            666        648       528         460        748
               Total Coastal          3399       8354       4126       4865       2934
               Total                543214     511219     474435     324946     290844


                                      1974       1978       1982       1987


               Chowan River          32328      34199      43668      46380
               Roanoke River        225393     242063     271379     288225
               Albemarle sound        2642       1344        719       1824
               Tar-Pamlico R.        18052      25816      24680      35723
               Neuse River           30047      44757      42492      42408
               Pamlico Sound            685        988       331         395
               Total Coastal          3327       2332       1050       2219
               Total                309148     349167     383269     414954








                   Appendices                                                                          167
                   Appendix 3.59. Bushels of Oats


                                           1880        1890        1900        1910        1920

                   Chowan River          386707      341517     168181      136679       35084
                   Roanoke River         1886163    1722809    1123882      678405      301943
                   Albemarle Sound        67624       90663       35006      34214       21984
                   Tar-Pamlico R.        305308      381034     191441      150210       70350
                   Neuse River           298664      389653     243286      268022      111296.
                   Pamlico Sound          11966       24361       20204      22626       24813
                   Total Coastal          79590      115024       55209      56839       46797
                   Total                 2956432    2950038    1781999      1290156     565470

                                           1925        1930        1935        1940        1945

                   Chowan River           11755       17703       12581      23608       65555
                   Roanoke River         111841       82064     107769      158210      239399
                   Albemarle Sound         8714        7097        5703      14107       57463
                   Tar-Pamlico R.         13085       14935       31859     113601      281787
                   Neuse River            13274       22805       23259     120010      240640
                   Pamlico Sound          19932       15177        7677      52219       49859
                   Total Coastal          28645       22275       13379      66327      107322
                   Total                 178600      159782     188846      481756      934704

                                           1950        1954        1959        1964        1969

                   Chowan River          131267      310629     279104      127631      151914
                   Roanoke River         409194      948772     831315      827771      456825
                   Albemarle Sound        35936       88759       91170     275456      512172
                   Tar-Pamlico R.        242227      692799     646177      344859      359026
                   Neuse River           355281     1040658     878348      555153      572605
                   Pamlico Sound          38041       55422       30892      25327       64176
                   Total Coastal          73977      144181     122062      300783      576348
                   Total                 1211947    3137038    2757007      2156197    2116718

                                           1974        1978        1982        1987

                   chowan River           63068       55811       47604      15388
                   Roanoke River         326768      349033     248465      204652
                   Albemarle Sound       128250      104960       61917     108318
                   Tar-Pamlico R.        133162      248459     430836      338685
                   Neuse River           323151      666404     467676      539835
                   Pamlico sound          11598        7926       19304        2918
                   Total Coastal         139848      112885       81221     111236
                   Total                 985997     1432592    1275801      1209796







               168                                                                  Appendices
               Apendix 3.5f. Pounds of Peanuts


                                      1880       1890       1900       1910       1920

               Chowan River                    868127    3435236    4574972    6289441
               Roanoke River                    54276    1016758    1746418    1934532
               Albemarle Sound                  44089     283921     368065     502844
               Tar-Pamlico R.                   54415     774099    1309557     919211
               Neuse River                      22242     116395     252704       45432
               Pamlico Sound                       346        704      2159         189
               Total Coastal                    44436     284625     370224     503033
               Total                          1043496    5627113    8253875    9691649


                                      1925       1930       1935       1940       1945


               Chowan River        4852267    7857887    8376692  203529487 209273601
               Roanoke River       2222494    2907866    3541864   79771795  94679528
               Albemarle Sound       637763    852723    1078052   24067774  30077984
               Tar-Pamlico R.      1090946    2058876    2627873   63326752  79864486
               Neuse River            57752    195316     200009    4477110  10743407
               Pamlico Sound            318        868      2451       3481       16196
               Total Coastal         638081    853591    1080504   24071255  30094179
               Total               8861541   13873536   15826942  375176399 424655202


                                      1950       1954       1959       1964       1969


               Chowan River      207193638  160840580  204276530  237366038 282612868
               Roanoke River      69206953   67487920   72818431  101851750 109207568
               Albemarle Sound 15156266      14887880   15074636   22544474  23070871
               Tar-Pamlico R.     53779524   51555148   61993240   88275842  79416764
               Neuse River         4500102    4382160    5781551    7612521    8283414
               Pamlico sound          2451       5188         462        348      1139
               Total coastal      15158717   14893068   15075098   22544821  23072011
               Total             349838934  299158876  359944850  457650973 502592624


                                      1974       1978       1982       1987


               Chowan River      328300754  382115025  341206623  295386590
               Roanoke River     111797996  135771715  127294528  124277990
               Albemarle Sound    22639236   25969901   25345996   27115030
               Tar-Pamlico R.     89562118  146562587   98692782   92197940
               Neuse River         6998270   35740533    8806143    7797900
               Pamlico sound            216          0          0          0
               Total Coastal      22639452   25969901   25345996   27115030
               Total             659298589  726159761  601346070  546775450








                  Appendices                                                                      169
                  Appendix 3.5g. Bushels of Soybeans


                                          1880       1890       1900       1910       1920


                  Chowan River                                                       45548
                  Roanoke River                                                       9584
                  Albemarle Sound                                                   289658
                  Tar-Pamlico R.                                                     60596
                  Neuse River                                                        46004
                  Pamlico Sound                                                      42957
                  Total Coastal                                                     332615
                  Total                                                             494347


                                          1925       1930       1935       1940       1945


                  chowan River                       34323      46794      52104    116156
                  Roanoke River                      29069      33684      47453     42204
                  Albemarle Sound                  464078     537930     704247     731619
                  Tar-Pamlico R.                   104572     170183     361723     283479
                  Neuse River                      163651     167586     250994     192794
                  Pamlico Sound                      93359      53649      58735     83836
                  Total Coastal                    557437     591579     762982     815455
                  Total                            889052    1009827    1475255    1450089


                                          1950       1954       1959       1964       1969

                  Chowan River          236466     465038    1487899    1518075    2045949
                  Roanoke River         112219     275584     602187     704143    1178296
                  Albemarle Sound     1316943     1693153    1866033    2368258    3475810
                  Tar-Pamlico R.        666069    1022885    1866714    2617079    3062273
                  Neuse River           368139     375981    1089787    2778967    2760935
                  Pamlico Sound         139682     230326     351806     447476     536108
                  Total Coastal       1456625     1923479    2217839    2815733    4011918
                  Total               2839518     4062966    7264427    10433998   13059371


                                          1974       1978       1982       1987


                  chowan River        2929171     3512261    4828998    3557430
                  Roanoke River       1723080     2187226    2924666    2196480
                  Albemarle Sound     3817049     4533536    5479864    4025264
                  Tar-Pamlico R.      3540330     4791327    6084392    4482856
                  Neuse River         4245568     5236890    7366296    5374026
                  Pamlico Sound         497502     702853     935811     719397
                  Total Coastal       4314551     5236389    6415675    4744661
                  Total               16752701   20964094   27620026   20355453








              170                                                                  AppendIces
              Appendix 3.5h. Pounds of Tobacco


                                     1880       1890       1900       1910        1920


              Chowan River        6269098    4220492   13699551   15876712   16265270
              Roanoke River      56073138   42368301   91989652   86590815   93269843
              Albemarle Sound        1212           0      18840      10635    238419
              Tar-Pamlico R.      2757909    4760453   31558725   26181703   64068964
              Neuse River         2892930    4103194   38346601   45289260   98497641
              Pamlico Sound            937          0      17187      7991     189562
              Total Coastal          2149           0      36027      18626    427981
              Total              67995224   55452441  175630555  173957115  272529699


                                     1925       1930       1935       1940        1945


              Chowan River       18424320   22331862   15855802   32123338   31517197
              Roanoke River     149172059  135730521  100850413  167347622  159318828
              Albemarle sound      326747     583447     515514    4923557    1048656
              Tar-Pamlico R.     46043627   88175177   77013284  126920402  118536048
              Neuse River        78861495  145151157  129685318  217519328  199018836
              Pamlico sound        408669     234638     169135      681150    489941
              Total Coastal        735416     818085     684649    5604707    1538597
              Total             293236916  392206802  324089466  549515398  509929506


                                     1950       1954       1959       1964        1969


              Chowan River       28969457   30041395   29734396   38666393   28165711
              Roanoke River     149750682  174097894  140131708  202389028  152428157
             .Albemarle Sound      836629    1710682    1793296    2562191    1122894
              Tar-Pamlico R.    117955288  138088449  110966851  154115035  113444082
              Neuse River       179626088  234193810  183553067  260415723  182744698
              Pamlico Sound        459520     905577    2329885    3223609     546659
              Total Coastal       1296149    2616258    4123181    5785800    1669553
              Total             477597644  579037806  468509202  661371979  478452200


                                     1974       1978       1982       1987


              Chowan River       31000432   32375653   26119977   24507040
              Roanoke River     158764930  176451829  143526408   94965940
              Albemarle sound      874867    1474616    1212179      818740
              Tar-Pamlico R.    104214173  118533466  115527339   76950630
              Neuse River       213084360  243842750  204103936  136178610
              Pamlico Sound        591018     914422     555941      439710
              Total Coastal       1465886    2389038    1768121    1258450
              Total             508529780  573592737  491045782  333860670








                  Appendices                                                                       171
                  Appendix 3.5i. Bushels of Wheat


                                          1880       1890        1900       1910       1920


                  Chowan River          213776     159017     171018      128393     156907
                  Roanoke River        1235672    1507691    1367172    1472155     2131825
                  Albemarle Sound        40203       3956          997       355       3511
                  Tar-Pamlico R.        169908     120911       68390       53916     94652
                  Neuse River           306268     304797     179663      133703     191829
                  Pamlico Sound           5779         436         453       258       1275
                  Total Coastal          45982       4392        1450        613       4785
                  Total                1971605    2096808    1787693    1788781     2579998


                                          1925       1930        1935       1940       1945


                  Chowan River          140283     258350     194871      158889     336152
                  Roanoke River        1320564    1400670    1333794    1214630     1681375
                  Albemarle sound         1913         294       1092        719      16616
                  Tar-Pamlico R.         21900      37910     156452      106429     312899
                  Neuse River            72842      94246     164333      147263     644666
                  Pamlico Sound             ill           0         26         12      2500
                  Total Coastal           2024         294       1118        731      19116
                  Total                1557614    1791470    1850568    1627942     2994209


                                          1950       1954        1959       1964       1969


                  Chowan River          236507     350810     263400      344314     629845
                  Roanoke River        1666350    1879971    1390338    1741241     1563666
                  Albemarle Sound         1402      30130        1402     664247     959675
                  Tar-Pamlico R.        115155     315693     115555      603972     848491
                  Neuse River           214187     514359     214437    1162102     1060861
                  Pamlico Sound             871      5492          871      77881     77890
                  Total Coastal           2273      35622        2273     742128    1037566
                  Total                2234472    3096455    1986003    4593758     5140428


                                          1974       1978        1982       1987


                  Chowan River         1055139     324018    1970039    1245035
                  Roanoke River        2161180     896969    2460805    2027765
                  Albemarle Sound      1033841     477510    2975475    2653952
                  Tar-Pamlico R.        998769     514940    3092312    2684475
                  Neuse River          1252918     602222    3258152    3156290
                  Pamlico Sound         130467      68359     417439      361765
                  Total Coastal        1164308     545869    3392914    3015717
                  Total                6632315    2884017    14174221   12129282








              172                                                                  Appendices
              Appendix 3.6. Crop Yields, calculated by dividing harvest by harvested acres


                                     1880       1890       1900       1910       1920


              COTTON (lb/acre)        222        134        247        262        347
              CORN (bu/acre)         11.9       10.6       13.8       14.7       18.2
              HAY (tons dry/acre)               0.91       1.01       0.96       1.85
              OATS (bu/acre)          8.7        9.0       10.2       12.8       13.6
              PEANUTS (lb/acre)                  523        851        748       1110
              SILAGE (tons green/acre)
              SOYBEANS (bu/acre)                                                 11.1
              TOBACCO (lb/acre        519        394        636        583        552
              WHEAT (bu/acre)         6.7        8.2        6.7        8.8       10.3


                                     1925       1930       1935       1940       1945


              COTTON (lb/acre)        248        219        350        230        490
              CORN (bu/acre)         16.8       19.7       18.0       21.6       22.1
              HAY (tons dry/ac       0.84       0.75       0.77       0.92       1.22
              OATS (bu/acre)         17.9       17.2       18.3       29.0       27.9
              PEANUTS (lb/acre        924       1157       1237       1176       1196
              SILAGE (tons gre       6.84       7.48                  8.35
              SOYBEANS (bu/acre)                 9.0        6.1        6.0        3.9
              TOBACCO (lb/acre        693        640        821        912       1045
              WHEAT (bu/acre)        11.2       10.7        9.5       11.9       16.9


                                     1950       1954       1959       1964       1969


              COTTON (lb/acre)        338        403        423        502        327
              CORN (bu/acre)         30.9       26.0       41.0       63.7       72.6
              HAY (tons dry/ac       1.15       0.91       1.13       1.15       1.55
              OATS (bu/acre)         28.1       34.8       38.4       58.6       62.5
              PEANUTS (lb/acre       1163       1326       1595       1981       2115
              SILAGE (tons gre       9.35       7.77       9.68       11.55      11.79
              SOYBEANS (bu/acr       16.8       18.2       22.3       23.1       26.5
              TOBACCO (lb/acre       1060       1151       1381       2179       1800
              WHEAT (bu/acre)        17.5       23.8        9.5       30.7       45.0


                                     1974       1978       1982       1987


              COTTON (lb/acre)        461        598        597        496
              CORN (bu/acre)         77.9       79.5       99.9       57.8
              HAY (tons dry/ac       1.62       1.59       1.64       1.66
              OATS (bu/acre)         53.4       54.3       60.6       62.3
              PEANUTS (lb/acre       2413       3066       2722       2664
              SILAGE (tons gre      13.54      13.32      14.89       9.37
              SOYBEANS (bu/acr       24.4       23.8       26.3       24.0
              TOBACCO (lb/acre       1883       1952       2026       2115
              WHEAT (bu/acre)        36.0       30.5       33.7       42.6













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             174                                                                   Appendices
             Appendix 3.7. Continued


             Animal/Basin                               Year


             TURKEYS       1959E     1964E      1969      1974     1978      1982      1987E


             chowan         4241     12359         40        30      143        40        68
             Roanoke       11245     10567      1153       592     1421       716      1217
             Tar            4812     26547        149     1726   384445     210164    357279
             Neuse         17850     21765     64491    123743   612472    1006477   1711011
             Coastal       12724     17827          2        41         0         0         0
             Total         50871     89065     65834    126132   998480    1217397   2069575


             SHEEP          1880      1890      1900      1910     1920      1925


             Chowan        22798     25089     19014    14766      7665      5154
             Roanoke       67916     62638     56381    50636     19130     18024
             Tar           21433     18769     14146      8721     4588      2942
             Neuse         32793     25000     16497      8159     3165      2398
             coastal       10967     12390     12057    15587     10398      5406
             Total        155907    143886    118095    97870     44946     33924


             SHEEP          1930      1935      1940      1945     1950      1954


             Chowan         9446      6328      4114      4063     4011      5518
             Roanoke       34171     18572     12896    10393     12732      9781
             Tar            4108      3755      2561      3039     2570      2665
             Neuse          2954      2306      1731      1868     1879      1899
             coastal       11856      8128      6177      6596     6114      4861
             Total         62534     39089     27479    25960     27306     24724


             SHEEP          1959      1964      1969      1974     1978      1982      1987E


             Chowan         5700      4218      3594      1759     2271      3107      3107
             Roanoke       12075      7683      6467      5483     4716      4141      4141
             Tar            2848      1440        640       325        66     149        149
             Neuse          3077      1787      1613      1054        328     865        865
             Coastal        3297      2701      1504        657       902     525        525
             Total         26997     17829     13819      9277     8283      8786      8786


             MULES          1880      1890      1900      1910     1920      1925


             Chowan         5789      5674      7425      9905    26089     25321
             Roanoke       15079     16212     17910    23645     42357     44583
             Tar            8108      8768     10344    14462     26915     30100
             Neuse         11385     13610     19212    25107     45625     46320
             Coastal        2432      2362      2761      2998     6666      8412
             Total         42793     46627     57652    76117    147654     154735








                   Appendices                                                                       175
                   Appendix 3.7. Continued


                   Animal/Basin                                Year


                   MULES          1930      1935      1940      1945      1950      1954


                   Chowan        27166     26612     28341     26372     23506     15614
                   Roanoke       52385     51350     57500     52596     52634     39347
                   Tar           37227     36208     38848     36516     40077     29871
                   Neuse         50469     50681     54213     52153     52364     35229
                   Coastal        9110      9689      8891      6793      3943      2050
                   Total         176356    174540    187793    174430    172523    122112


                   MULES         1959E     1964E      1969      1974      1978      1982      1987E

                   Chowan        10699      5784       869       236         86         9         9
                   Roanoke       27702     16057      4412      1324       639        134       134
                   Tar           20817     11763      2709       488       208         42        42
                   Neuse         24003     12777      1551       217       115          9         9
                   Coastal        1378        706        33         1         1         0         0
                   Total         84600     47087      9574      2266      1049        194       194

                   HORSES         1880      1890      1900      1910      1920      1925

                   Chowan        14268     14313     21887     22308     20566     14696
                   Roanoke       39600     41003     54279     58562     59183     47397
                   Tar           11230     10630     16385     16995     17293     11416
                   Neuse         15208     13222     16704     18966     19236     12975
                   Coastal        6144      6919      8285      8927      8671      7137
                   Total         86450     86087     117541    125757    124949    93620

                   HORSES         1930      1935      1940      1945      1950      1954

                   Chowan         9728      6094      5881      6539      7043      3820
                   Roanoke       35106     23388     23173     24847     25460     17595
                   Tar            7127      3960      3552      3889      4628      3507
                   Neuse          8016      4776      3801      4649      5895      4485
                   Coastal        4642      3546      2997      2721      2440      1222
                   Total         64620     41764     39404     42646     45466     30629

                   HORSES        1959E     1964E      1969      1974      1978      1982      1987E

                   Chowan         2751      1683       614      1434      1319      1555      1555
                   Roanoke       12603      7611      2619      5743      5407      6099      6099
                   Tar            2607      1707       806      1081      1213      1154      1154
                   Neuse          3364      2242      1121      2111      2459      2708      2708
                   Coastal          868       514      160       326       288        324       324
                   Total         22193     13757      5321     10694     10685     11841      11841

















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                          L8OV6EE      PEVOEOE      9S6LT6Z      VSVEE8       019ZSC       OELV8V      888VSS          UL*Aoqo


                          HL86T        Z86T         8L6T         tL6T         696T         096T        6G6T          SNZXDIHO


                                       80VVVSV      ZSZELEV      OLLEVLS      8OLVE8E      Z8tT6ZS     TOME              TV401
                                       SS99LZ       TLZVLZ       69VOOV       9E610C       LE968t      8VSV6Z         T94svOO
                                       L89EOVT      8VETZZT      OT908ST      6SBEV6       SL89EZT     OVLZES            esnoN
                                       896tTL       OL86EL       V06SP6       8LTS19       LT9TO8      STOLVS              avL
                                       ZMtST        VTEVZST      L88ZTOZ      8VZ6StT      OT6SELT     LSTS6ET        95[OuvO-d
                                       9L966S       OStET9       006EO8       LSMS         MLZOT       6L98SS          uvmolqo


                                       tS6T         OS6T         MT           Ot6T         SE6T        OE6T          SNHXDIHO


                                       9S6T80       THEM         tSLETOE      60666ZZ      ZSSME       90Z691            [leqol
                                       9TELLE       99SZtE       OSLOSZ       18TOZZ       OTtStE      88T98T         TVISVOO
                                       8868tll      Z98EZOT      tZTSOL       08S99t       89SBES      99ETSE            asnem
                                       6MLL         OT8OL9       OZEL9t       8080SE       E86LZG      69t99Z              aVj
                                       tT686LT      T908tST      9896ZTT      689EL8       OtMT        TES609         8310uvo-d
                                       60EZ89       Z86LE9       MM           OS98SE       MM          EUM             uvmoqo


                                       SZ61         OZ61         OT6T         006T         0681        088T          SNZXDIHO


                                                                                                              uTsvg/TlewTuY


                                                                                             penulluo:D TC XIPUeddV
                    sgolpueddV                                                                                             9LI








                   Appendices                                                                      177
                   Appendix 3.7. Continued


                   Animal/Basin                               Year

                   CATTLE         1959     1964       1969      1974      1978     1982       1987

                   Chowan       60893     65341     61632     72546     56612     61250     76640
                   Roanoke     220866    229758    245456    313944    257871    303281     356357
                   Tar          52409     59887     51059     63681     46568     44567     53464
                   Neuse        64633     74388     70624     78839     70559     71233     70686
                   Coastal      16617     21240     18266     18783     11102      8325     11092
                   Total       415418    450613    447037    547792    442712    488656     568239

                   BROILERS     1880E     1890E     1900E     1910E     1920E     1925E

                   Chowan            0     6628     13255     19883     26511     29824
                   Roanoke           0    44999     89998    134998    179997    202496
                   Tar               0    48325     96650    144974    193299    217461
                   Neuse             0   119239    238477    357716    476954    536574
                   Coastal           0       232       463       695       926     1042
                   Total             0   219422    438843    658265    877687    987398

                   BROILERS     1930E     1935E     1940E     1945E     1950E     1954E

                   Chowan       33138     36452     39766     43080     46394     49045
                   Roanoke     224996    247496    269995    292495    314994    332994
                   Tar         241624    265786    289949    314111    338273    357603
                   Neuse       596193    655812    715432    775051    834670    882366
                   Coastal        1158     1273       1389      1505      1621     1713
                   Total       1097109   1206820  1316530   1426241  1535952   1623721

                   BROILERS     1959E     1964E       1969      1974      1974     1982     1987E

                   Chowan       52358     55672     58986    405246  2527410   2934388   3667985
                   Roanoke     355494    377993    400493    417427  2073553   2327470   2909337
                   Tar         381766    405928    430090    384696  1016318   2745128   3431410
                   Neuse       941985   1001604   1061223   1382506  1963347   3868738   4835922
                   Coastal        1829     1945       2061    78521    805238  1217358   1521697
                   Total      1733432   1843143   1952853   2668395  8385866   13093081  16366351








              178                                                                    Appendices
              Appendix 3.8. Annual nitrogen and phosphorus production (kg/year) by farm animals in the
              Albemarle-Pamlico basin (1880-1987).


              Nutrient/Basin                                 Year



              NITROGEN        1880     1890      1900       1910      1920      1925

              Chowan      6302054   6228903   7108818   7265782   7944822   6071906
              Roanoke 14879492     14540027  15308356   16804815  18221559  15269092
              Tar         6378220   5152520   5951295   6364301   6689057   5437007
              Neuse       8852011   7437139   8092455   9057791   9733398   8145700
              Coastal     3414161   3412757   3257875   3409853   3548036   2776870
              Total      39825938  36771346  39718799   42902541  46136873  37700574

              NITROGEN        1930     1935      1940       1945      1950      1954

              Chowan      5540085   6437336   5155960   7508731   7658501   9177731
              Roanoke    14073506  15969026  14980296   18230935  19444816  21159331'
              Tar         4961073   6220553   5471179   6764858   7111455   7869522
              Reuse       7242715   8962816   8043846   9806272   10090225  11276384
              Coastal     2538904   2823247   2188981   2781296   2328735   2720594
              Total      34356283  40412979  35840263   45092092  46633732  52203562

              NITROGEN        1959     1964      1969       1974      1978      1982       1987

              Chowan      7635426   6759978   6937741   7830546   8933804   9305266  10797441
              Roanoke    19495283  18066928  18379813   22867892  21155313  24296835 27655762
              Tar         7355499   6470679   5913871   7317532   8430494   11444897 12622176
              Neuse      10226898   9067086   9893474   11685701  14013146  14601000 17430805
              Coastal     2336814   2391444   2411419   2597154   3736367   3927342    4420564
              Total      47049920  42756116  43536318   52298825  56269125  63575340 72926749

              PHOSPHORUS      1880     1890      1900       1910      1920      1925

              Chowan      1687262   1664229   1955084   2151673   2182893   1682618
              Roanoke     3911243   3821383   4039684   4518506   4732874   4022536
              Tar         1714675   1413390   1664164   1858726   '1873610  1553401
              Neuse       2433313   2114302   2304296   2730436   2694946   2274100
              Coastal       919114    926708    883378    969992  1012074     797343
              Total      10623434   9818735  10643488   11442435  12418499  10092167

              PHOSPHORUS      1930     1935      1940        1945     1950      1954

              Chowan      1535994   1821381   1359372   2081977   2084575   2531156
              Roanoke     3610253   4160759   3755277   4661720   4824546   5273977
              Tar         1330043   1704605   1433532   1876072   1837216   2039961
              Neuse       1970498   2452351   2153667   2692247   2611209   3000478
              Coastal       727860    777248    579855    756408    658424     773717
              Total       9194633  10770553   9428702   12089393  12570494  14031928








                   Appendices                                                                     179
                   Appendix 3.8. Continued


                   Nutrient/Basin                               Year



                   PHOSPHORUS     1959      1964      1969      1974      1978     1982      1987
                   Chowan     2117461   1852749   1983687  2200765   2582615   2653854   3024132
                   Roanoke    4896531   4521467   4624691  5715358   5428682   6191163   6953380
                   Tar        1964310   1731155   1666269  2089553   2588221   3561435   3877072
                   Neuse      2811170   2493617   2900085  3464430   4332556   4430399   5403074
                   Coastal      682272    679787    715638   772850  1188220   1251666   1387302
                   Total      12884382  11361302  11906450  14246302  16122645  18088517  20647094


























                    86968T      LLTLZL     ESLZET      988809       LZLO8      ZSV60E    0          0                  -[P-401
                    0           0          0           0            0          0         0          0           TleTa4snpui
                    8696ST      LLTLZL     ESLZET      98880S       LZLO8      ZSV60E    0          0            IledToTunH
                                                                                                                 qV1101 d/V


                    MOOT        S698E      8T9L        IOZ6Z        T06E       SS6VT     0          0                  Ile-4ol
                    0           0          0           0            0          0         0          0           Tie-p-4snpui
                    V600T       9698C      819L        TOZ6Z        T06E       SGOT      0          0            TiedTOTunK
                                                                                                                     7visvoo


                    TS699       St99SZ     68tEV       60L99T       9699Z      9EEZOI    0          0                  IR-401
                    0           0          0           0            0          0         0          0           TPTiqsnpui
                    TS699       Gt99SZ     68tEt       60L99T       9699Z      9EEZOT    0          0            TedTOTunN
                                                                                                                       asnam


                    scost,      EE9ZLI     ZESOZ       90L8L        8TS8       TS9ZE     0          0                  'p-461
                    0           0          0           0            0          0         0          0           Tv-rzr-4snpui
                    SEOSV       EE9ZLT     ZESOZ       90M          8TS8       TG9ZE     0          0            TvdTDTunjj


                    Z9T6S       68L9ZZ     86TLS       6SZ6TZ       9EPOV      90OSSI    0          0                  -[Vqol
                    0           0          0           0            0          0         0          0           TieTaqsnpui
                    Z9T6S       68L9ZZ     86TLS       6SZ6TZ       9EVOt      90OSST    0          0            liedTOTunN
                                                                                                                     axoNvoll


                    9M          EIVZE      916E        ZIOST        SLIT       Vost      0          0                  TV-401
                    0           0          0           0            0          0         0          0           TRT:r-4snpuj
                    9ST78       ETtZE      9T6E        ZTOST        SLIT       Vost,     0          0            liedTOTunN
                                                                                                                       NVMOHD



                    A/f)Xcl     A/f)XK     A/!)Xcl     A/E)XN       A/!)Xcl    A/f)XN    A/!)Xcl    A/f)XN      9dAL/UTsieS
                       OT6T      OT6T         006T      006T        068T       068T       08ST        088T


                                                                             a5utAas poluoijun ui juoA/uosjad/23j 1-1 puu
               juoA/uosiad/N 231 9-t, sQwnssV '9861-0881 IsSuipuol aoinos juiod pjuwijs3 .6-1@ xipueddV
                   sao!pueddv                                                                                              091








                  Appendices                                                                    181
                  Appendix 3.9. Continued


                                1920     1920     1930    1930     1940     1940    1950     1950
                  Basin/Type    NKG/Y    PKG/Y    NKG/Y   PKG/Y    NKG/Y    PKG/Y   NKG/Y    PKG/Y



                  CHOWAN
                  Municipal     40060    10450    58888   15362   110144    20907  143644    39646
                  Industrial         0        0   10000     2500   95000    25000  190000    50000
                  Total         40060    10450    68888   17862   205144    45907  333644    89646


                  ROANOKE
                  municipal    495599   129287  680745   177586   817491  213258  1017891   265537
                  Industrial         0        0 100000    35000   336000    64000  336000    64000
                  Total        495599   129287  780745   212586   1153491 277258  1353891   329537

                  TAR
                  Municipal    231679    60438  316969    82688   374602    97722  441187   115092
                  Industrial         0        0       0       0        0         0        0      0
                  Total        231679    60438  316969    82688   374602    97722  441187   115092


                  NEUSE
                  municipal    430714   112360  596170   155523   826471  215601  1066754   278284
                  Industrial         0        0       0       0        0         0     500       0
                  Total        430714   112360  596170   155523   826471  215601  1067254   278284

                  COASTAL
                  municipal     69860    18224    78375   20446    90781    23682   99921    26066
                  Industrial         0        0       0       0        0         0        0      0
                  Total         69860    18224    78375   20446    90781    23682   99921    26066

                  A?P TOTAL
                  Municipal 1267913     330760  1731147  451604  2219489  571171  2769397   724625
                  Industrial         0        0 110000    37500   431000    89600  526500   114600
                  Total        1267913  330760  1841147  489104  2650489  660771  3295897   839225








              182                                                                  Appendices

              Appendix 3.9. Continued


                            1960     1960     1970     1970     1980    1980     1986     1986
              Basin/Type     NKG/Y   PKG/Y    NKG/Y    PKG/Y    NKG/Y   PKG/Y    NKG/Y    PKG/Y



              CHOWAN
              Municipal     174653   48969   151543    48363  144798    47731   148919    47895
              Industrial 578000      88800   578000    88800  578000    88800   379000    88800
              Total         752653  137769   729543   137163  722798   136531   527919   136695


              ROANOKE
              Municipal   1189291   312130   826474   294070  844729   304012   857012   310711
              Industrial    336000   64000   336000    64600  336000    64600   336000    64600
              Total       1525291   376130  1162474   358670  1180729  368612  1193012   375311


              TAR
              Municipal     401132  122638   382847   129738  427546   143756   490542   165046
              Industrial          0        0  70000   400000    70000  535000    70000   391000
              Total         401132  122638   452847   529738  497546   678756   560542   556046


              NEUSE
              Municipal   1138754   335908  1067645   358045  1214426  415634  1490523   510820
              Industrial       1000     1200 256229    22277  256200    22277   256200    22277
              Total       1139754   337108  1323874   380322  1470626  437911  1746723   533097


              COASTAL
              Municipal     107166   27956    73921    24141    79966   26155    87584    28610
              industrial          0        0       0        0        0        0       0        0
              Total         107166   27956    73921    24141    79966   26155    87584    28610


              A/P TOTAL
              Municipal   3010996   847602  2502429   854356  2711465  937289  3074580   1063082
              Industrial 915000     154600  1240229   575677  1240200  710677  1041200   566677
              Total       3925996   1002202 3742658   1430033 3951665  1647966 4115780   1629759








                   Appendices                                                                          183
                   Appendix 4. 1. Pamlico River estuary sampling dates, parameters sampled, and data
                   sources



                   Abbreviations:

                    ST            Surface water temperature (OC)
                    BT            Bottom water temperature (OC)
                    SS            Surface water salinity (ppt)
                    BS            Bottom water salinity (ppt)
                    SDO           Surface water dissolved oxygen (mg/liter)
                    BDO           Bottom water dissolved oxygen (mg/liter)
                    PH            Surface water pH
                    P04           Surface water orthophosphate phosphorus (uM)
                    TDP           Surface water total dissolved phosphorus (uM)
                    TP            Surface water total phosphorus (uM)
                    PP            Surface water particulate phosphorus (uM)
                    N03           Surface water nitrate nitrogen (uM)
                    NH4           Surface water ammonia nitrogen (uM)
                    TDN           Surface water total dissolved nitrogen (uM)
                    TN            Surface water total nitrogen (uM)
                    PN            Surface water particulate nitrogen (uM)
                    CHL           Surface water chlorophyll a (ugAiter)


                   Key to data source references (see REFERENCES for full citations):
                    1. Hobbie (1970b)
                    2. Hobbie (1970a)
                    3. Hobbie et al. (1972)
                    4. Hobbie (1974)
                    5. Stephenson et al. (1975)
                    6. ICMR (1976)
                    7. ICMR (1977)
                    8. ICMR (1978)
                    9. ICMR (1980)
                    10. ICMR (1981)
                    11. ICMR (1982)
                    12. ICMR (1983)
                    13. Stanley (1984b)
                    14. Stanley (1986a)
                    15. Stanley (1986b)
                    16. Stanley (1987)
                    17. Davis et al. (1978)
                    18. Kuenzler et al. (1979)
                    Note: The data from 23 October 1978 through 14 December 1978 are in none ofthe reports. I
                   have access to the data however. (D.W.S.)








              184                                                             Appendices

              Appendix 4. 1. Continued


                Sample                Parameters Sampled and Data Sources
                Date


              MO DA YR  ST  BT SS BS SDO BDO PH P04 TDP TP PP M03 NH4 TDN TN PN CHL



                3  967   2    2
                322 67   2    2
                323 67
                411 67   2    2
                5  967   2    2                 1    1  1
                6  767   2    2
                627 67   2    2
                628 67                          1    1  1
                713 67   2    2                 1    1  1
                731 67   2    2                 1    1  1
                823 67   2    2                 1    1  1
                830 67   2    2                 1    1  1
                .9 20 67 2    2                 1    1  1
              10   367   2    2
              10   467                          1    1  1
              10 17 67   2    2                 1    1  1
              10 30 67   2    2                 1    1  1
              11 14 67   2    2                 1    1  1
              11 28 67   2    2                 1    1  1
              12 19 67   2    2                 1    1  1
                1  868   2    2                 1    1  1
                129 68   2    2                 1    1  1
                213 68   2    2
                214 68                          1    1  1
                226 68   2    2                 1    1  1
                629 68   2  2 2 2               1    1  1
                716 68   2  2 2 2               1    1  1
                8  668   2  2 2 2               1    1  1
                823 68   2  2 2 2               1    1  1
                9  668   2  2 2 2               1    1  1
                930 68   2  2 2 2               1    1  1
              10 11 68   2  2 2 2               1    1  1
              11 21 68   2  2 2 2               1    1  1
              12 13 68   2  2 2 2   2    2
                1  669   2  2 2 2   2    2
                2  669   2  2 2 2   2    2      1    1  1
                226 69   2  2 2 2   2    2      1    1  1
                4  169   2  2 2 2   2    2      1    1  1
                415 69   2  2 2 2   2    2      1    1  1
                5  269   2  2 2 2   1    2      1    1  1
                6  369   2  2 2 2   2    2      1    1  1
                619 69   2  2 2 2   2    2      1    1  1
                7  469   2  2 2 2   2    2      1    1  1








                 Appendices                                                               185
                 Appendix 4. 1. Continued


                   Sample              Parameters Sampled and Data Sources
                   Date


                 MO DA YR  ST  BT SS BS SDO BDO PH P04 TDP TP PP N03 NH4 TDN TN PN CHL



                   8 6 69  3  3 3  3   3   3  3   1   1  1      3    3
                   821 69  3  3 3  3   3   3  3   1   1  1      3    3
                   9 3 69  3  3 3  3   3   3  3   1   1  1      3    3
                   917 69  3  3 3  3   3   3  3   1   1  1      3    3
                 10  1 69  3  3 3  3   3   3  3   1   1  1      3    3
                 10 17 69  3  3 3  3   3   3  3   1   1  1      3    3
                 10 29 69  3  3 3  3   3   3  3   1   1  1      3    3
                 11 12 69  3  3 3  3   3   3  3   1   1  1      3    3
                 12  3 69  3  3 3  3   3   3  3   1   1  1      3    3
                 12 15 69  3  3 3  3   3   3  3   1   1  1      3    3
                   1 2 70  3  3 3  3   3   3  3   1   1  1      3    3
                   126 70  3  3 3  3   3   3  3   3   3  3      3    3
                   211 70  3  3 3  3   3   3  3   3   3  3      3    3
                   225 70  3  3 3  3   3   3  3   3   3  3      3    3             3
                   311 70  3  3 3  3   3   3  3   3   3  3      3    3             3
                   325 70  3  3 3  3   3   3  3   3   3  3      3    3             3
                   4 8 70  3  3 3  3   3   3  3   3   3  3      3    3             3
                   422 70  3  3 3  3   3   3  3   3   3  3      3    3             3
                   5 6 70  3  3 3  3   3   3  3   3   3  3      3    3             3
                   520 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   6 3 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   617 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   7 1 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   715 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   730 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   812 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   826 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   910 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   923 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                 10  7 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                 10 22 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                 11  4 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                 11 19 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                 12  3 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                 12 17 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                 12 30 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   114 70  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   2 5 71  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   218 71  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   3 5 71  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   331 71  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   416 71  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3
                   428 71  3  3 3  3   3   3  3   3   3  3      3    3   3  3      3








             186                                                             Appendices

             Appendix 4, 1. Continued


               sample               Parameters Sampled and Data Sources
               Date


             MO DA YR  ST  BT SS BS SDO BDO PH P04 TDP TP PP N03 NH4 TDN TN PN CHL



               512 71   3  3 3  3   3   3  3   3    3  3      3   3   3  3      3
               526 71   3  3 3  3   3   3  3   3    3  3      3   3   3  3      3
               6 9 71   3  3 3  3   3   3  3   3    3  3      3   3   3  3      3
               624 71   3  3 3  3   3   3  3   3    3  3      3   3   3  3      3
               7 8 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               721 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               8 4 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               831 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               915 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             10  6 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             10 20 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             11 10 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             11 23 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             12 13 71   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               1 4 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               119 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               2 3 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               223 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               3 8 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               323 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               4 6 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               419 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               522 72   4  4A   4   4   4  4   4    4  4      4   4   4  4      4
               614 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               719 72'  4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               8 9 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               9 7 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             10  5 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             10 18 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             11  1 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
             12  6 72   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               119 73   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               221 73   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               321 73   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               4 4 73   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               419 73   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               7 9 73   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               726 73   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               822 73   4  4 4  4   4   4  4   4    4  4      4   4   4  4      4
               127 75   5  5 5  5   5   5  5   5    5  5      5   5   5  5      5
               214 75   5  5 5  5   5   5  5   5    5  5      5   5   5  5      5
               228 75   5  5 5  5   5   5  5   5    5  5      5   5   5  5      5
               328 75   5  5 5  5   5   5  5   5    5  5      5   5   5  5      5








                  Appendices                                                                   187
                  Appendix 4. 1. Continued


                   Sample                 Parameters Sampled and Data Sources
                    Date


                  MO DA YR  ST BT  SS BS SDO BDO PH P04 TDP  TP PP N03 NH4 TDN  TN PN CHL



                   4 17 75   5  5  5 5    5   5  5   5   5   5      5   5    5  5      5
                   5 19 75   5  5  5 5    5   5  5   5   5   5      5   5    5  5      5
                   5 30 75   5  5  5 5    5   5  5   5   5   5      5   5    5  5      5
                   6 18 75   5  5  5 5    5   5  5   5   5   5      5   5    5  5      5
                   6 24 75   5  5  5 5    5   5  5   5   5   5      5   5    5  5      5
                   7 11 75   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   7 21 75   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   8   275  17     17
                   8   575   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   8 16 75  17     17
                   8 19 75   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   9   275   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   9   675  17     17     17
                   9 18 75   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                  10   675  17     17     17
                  10 10 75   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                  10 19 75  18 18  18 18  18  18 18  18  18  18 18  18  18   18 18 18
                  10 21 75   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                  11   575   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                  11   575  17     17     17
                  11   975  18 18  18 18  18  18 18  18  18  18 18  18  18   18 18 18
                  12   575   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                  12   775  18 18  18 18  18  18 18  18  18  18 18  18  18   18 18 18
                  12   975  17     17     17
                  12 14 75  18 18  18 18  18  18 18  18  18  18 18  18  18   18 18 18
                  12 15 75  18 18  18 18  18  18 18  18  18  18 18  18  18   18 18 18
                  12 17 75   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   1 12 76   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   1 15 76  17     17     17
                   2 24 76   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   2 26 76  17     17     17
                   2 27 76  18 18  18 18  18  18 18  18  18  18 18  18  18   18 18 18
                   3 11 76   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   3 24 76  16  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   3 25 76  17     17     17
                   4   376  18 18  18 18  18  18 18  18  18  18 18  18  18   18 18 18
                   4   476  18 18  18 18  18  18 18  18  18  18 18  18  18   18 18 18
                   4   676   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   4 21 76   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   5   576   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   5 11 76  17     17     17
                   6   776   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6
                   6 23 76   6  6  6 6    6   6  6   6   6   6      6   6    6  6      6








              188                                                                Appendices

              Appendix 4. 1. Continued


               Sample                 Parameters Sampled and Data Sources
                Date


              MO DA YR ST  BT SS BS SDO BDO PH P04 TDP TP PP N03 NH4 TDN     TN PN CHL



               6 23 76 17     17      17
               7  6 76 6    6 6  6    6   6  6   6    6  6      6    6   6   6      6
               7 19 76 6    6 6  6    6   6  6   6    6  6      6    6   6   6      6
               7 25 76.18  18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               7 26 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               7 27 76  17    17      17
               8 11 76  17    17      17     17  17   17 17 17  17   17  17  17 17  17
               8 15 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               8 16 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               8 23 76   6  6 6  6    6   6  6   6    6  6      6    6   6   6      6
               9  5 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               9  6 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               9  9 76   6  6 6  6    6   6  6   6    6  6      6    6   6   6      6
               9 24 76   6  6 6  6    6   6  6   6    6  6      6    6   6   6      6
               9 26 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               9 27 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
              10  7 76   6  6 6  6    6   6  6   6    6  6      6    6   6   6      6
              10 16 76  17    17      17     17  17   17 17 17  17   17  17  17 17  17
              10 17 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
              10 18 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
              11  5 76   7  7 7  7    7   7      7    7  7      7    7   7   7      7
              11 14 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
              11 15 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
              12  5 76  17    17      17     17  17   17 17 17  17   17  17  17 17  17
              12 10 76   7  7 7  7    7   7      7    7  7      7    7   7   7      7
              12 12 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
              12 13 76  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               1  8 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               1  9 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               1 10 77   7  7 7  7    7   7  7   7    7  7      7    7   7   7      7
               1 30 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               2  4 77   7  7 7  7    7   7  7   7    7  7      7    7   7   7      7
               2  5 77  18 18 18 18   18  18 18  .18  18 18 18  18   18  18  18 18
               2  9 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               2 19 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               2 20 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               3  2 77  17 18 17 18   17  18 17  17   17 17 17  17   17  17  17 17  17
               3  2 77  18    18      18     18  18   18 18 18  18   18  18  18 18
               3 10 77   7  7 7  7    7   7  7   7    7  7      7    7   7   7      7
               3 12 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               3 13 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18
               3 30 77   7  7 7  7    7   7  7   7    7  7      7    7   7   7      7
               4  2 77  18 18 18 18   18  18 18  18   18 18 18  18   18  18  18 18








                  Appendices                                                                   189

                  Appendix 4. 1. Confinued


                   sample                 Parameters Sampled and Data Sources
                    Date


                  MO DA YR  ST BT SS BS SDO BDO  PH P04 TDP  TP PP N03 NH4 TDN  TN PN CHL



                   4  3 77  18 18 18 18   18  18 18  18  18  18 18  18  18   18 18 18
                   4 14 77   7  7 7  7    7   7  7   7   7   7      7   7    7  7      7
                   4 25 77  18 18 18 18   18  18 18  18  18  18 18  18  18   18 18 18
                   4 24 77  18 18 18 18   18  18 18  18  18  18 18  18  18   18 18 18
                   4 26 77   7  7 7  7    7   7  7   7   7   7      7   7    7  7      7
                   5 12 77   7  7 7  7    7   7  7   7   7   7      7   7    7  7      7
                   5 15 77  18 18 18 18   18  18 18  18  18  18 18  18  18   18 18 18
                   5 16 77  18 18 18 18   18  18 18  18  18  18 18  18  18   18 18 18
                   5 23 77  17    17      17     17  17  17  17 17  17  17   17 17 17  17
                   6  5 77  18 18 18 18   18  18 18  18  18  18 18  18  18   18 18 18
                   6  6 77  18 18 18 18   18  18 18  18  18  18 18  18  18   18 18 18
                   6  8 77   7  7 7  7    7   7  7   7   7   7      7   7    7  7      7
                   6 30 77   7  7 7  7    7   7  7   7   7   7      7   7    7  7      7
                   7  7 77  17    17      17     17  17  17  17 17  17  17   17 17 17  17
                   7 10 77  18 18 18 18   18  18 18  18  18  18 18  18  18   18 18 18
                   7 11 77   7  7 7  7    7   7  7   7   7   7      7   7    7  7      7
                   7 25 77   7  7 7  7    7   7  7   7   7   7      7   7    7  7      7
                   8 10 77   7  7 7  7    7   7  7   7   7   7      7   7    7  7      7
                   9  9 77   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   9 29 77   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                  11  9 77   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                  12 16 77   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   1 10 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   2 15 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   3 17 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   4  7 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   4 28 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   5 11 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   5 23 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   6  7 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   6 20 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   7 13 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   7 26 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   8 15 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                   8 23 78   8  8 8  8    8   8  8   8   8   8      8   8    8  8      8
                  10 23 78   *  * *  *
                  11  9 78   *  * *  *
                  11 29 78   *  * *  *
                  12 14 78   *  * *  *
                   2 16 79   9  9 9  9    9   9  9   9   9   9      9   9    9  9      9
                   3 16 79   9  9 9  9    9   9  9   9   9   9      9   9    9  9      9
                   4 25 79   9  9 9  9    9   9  9   9   9   9      9   9    9  9      9
                   5  8 79   9  9 9  9    9   9  9   9   9   9      9   9    9  9      9








             190                                                              Appendices

             Appendix 4. 1. Continued


              Sample                Parameters Sampled and Data Sources
               Date


             MO DA YR  ST BT SS BS SDO BDO PH P04 TDP TP PP N03 NH4 TDN  TN PN CHL



              5 28 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              6  7 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              6 14 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              7 17 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              7 24 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              8 22 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              8 28 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              9 20 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              9 27 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
             10  2 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
             10 18 79   9  9 9  9   9   9  9   9   9  9       9   9   9  9      9
              1 17 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              2 15 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              2 28 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              3 27 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              3 31 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              4 16 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              4 28 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              5  6 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              5 19 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              6  2 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              6 16 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              7  7 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              7 14 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              8  1 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              8 14 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              8 25 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              9  9 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              9 29 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
             11  4 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
             11 20 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
             12  4 80  10 10 10 10  10  10 10  10  10 10      10  10  10 10     10
              1 16 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              1 29 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              2 16 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              2 27 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              3  9 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              3 25 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              4  7 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              4 22 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              5 15 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              6 10 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11
              6 22 81  11 11 11 11  11  11 11  11  11 11      11  11  11 11     11








                 Appendices                                                                191
                 Appendix 4. 1. Continued


                   Sample               Parameters Sampled and Data Sources
                   Date


                 MO DA YR ST  BT SS BS  SDO  BDO PH  P04  TDP TP PP N03  NH4  TDN TN PN CHL




                   7 7 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                   716 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                   729 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                   825 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                   910 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                   918 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                 10  1 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                 10  9 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                 10 22 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                 11  3 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                 12  4 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                 12 23 81 11  11 11 11  11  11 11  11  11 11     11   11  11 11     11
                   1'7 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   220 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   211 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   224 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   3 9 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   319 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   4 2 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   5 3 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   511 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   524 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   610 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   625 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   716 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   722 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   8 5 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   819 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   9 1 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   916 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                 10  8 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                 10 21 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                 10 29 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                 11 10 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                 11 30 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                 12 15 82 12  12 12 12  12  12 12  12  12 12     12   12  12 12     12
                   1 6 83 13  13 13 13  13  13 13  13  13 13     13   13  13 13     13
                   125 83 13  13 13 13  13  13 13  13  13 13     13   13  13 13     13
                   2 9 83 13  13 13 13  13  13 13  13  13 13     13   13  13 13     13
                   216 83 13  13 13 13  13  13 13  13  13 13     13   13  13 13     13
                   222 83 13  13 13 13  13  13 13  13  13 13     13   13  13 13     13
                   310 83 13  13 13 13  13  13 13  13  13 13     13   13  13 13     13
                   4 1 83 13  13 13 13  13  13 13  13  13 13     13   13  13 13     13








             192                                                              Appendices
             Appendix 4. 1. Continued


               Sample               Parameters Sampled and Data Sources
               Date


             MO DA YR ST BT SS  BS  SDO  BDO PH  P04  TDP TP PP N03  NH4  TDN TN PN CHL



               412 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               422 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               5  583 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               5  683 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               6  283 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               613 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               630 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               712 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               727 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               8  883 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               831 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               9  883 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               923 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
             10   483 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
             11   383 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
             11 17 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
             11 22 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
             12 29 83 13 13 13  13  13  13 13  13  13 13      13  13  13 13     13
               1  684 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               126 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               2  284 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               215 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               3  884 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               316 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               327 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               420 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               427 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               5  984 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               523 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               6  884 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               621 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               7  584 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               720 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               8  284 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               815 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               829 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               921 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
               926 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
             10 10 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
             10 24 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
             11 14 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
             11 27 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14
             12 13 84 14 14 14  14  14  14 14  14  14 14      14  14  14 14     14








                 Appendices                                                                193
                 Appendix 4. 1. Continued


                  sample                Parameters Sampled and Data Sources
                   Date


                 MO DA YR  ST BT SS BS  SDO  BDO PH  P04  TDP TP PP  N03  NH4  TDN TN PM  CHL



                 12 19 84  14 14 14 14  14  14 14  14  14 14     14  14  14 14      14
                  2  6 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  2 21 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  3 28 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  4 12 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  4 24 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  4 30 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  5  7 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  5 21 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  5 31 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  6 11 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  6 20 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  7  9 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  7 17 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  8  1 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  8  6 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  8 19 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  8 28 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  9 19 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  9 30 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                 10 14 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                 11 15 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                 11 26 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                 12  9 85  15 15 15 15  15  15 15  15  15    15  15  15  15     15  15
                  1 15 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  2  4 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  2 18 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  3 26 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  4  2 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  4 17 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  5  1 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  5  8 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  5 22 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  6  4 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  6 19 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  7 10 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  7 16 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  7 30 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  8 13 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  8 27 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  9 10 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                  9 24 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16
                 10  8 86  16 16 16 16  16  16 16  16  16    16  16  16  16     16  16








              194                                                                Appendices
              Appendix 4. 1. Continued


              Sample                 Parameters Sampled and Data Sources
               Date


              MO DA YR ST BT SS BS SDO BDO PH P04 TDP TP PP N03    NH4 TDN TN PN CHL




              10 30 86 16 16 16 16   16  16 16   16  16     16  16  16  16     16  16
              11  7 86 16 16 16 16   16  16 16   16  16     16  16  16  16     16  16
              12  9 86 16 16 16 16   16  16 16   16  16     16  16  16  16     16  16
              12 27 86 16 16 16 16   16  16 16   16  16     16  16  16  16     16  16








                   Appendices                                                                            195
                   Appendix 4.2. Pamlico River estuary water quality sampling station locations


                   Note 1. Sample station numbers are arranged by investigator (columns)
                   and river segment (A-J) (rows).

                   Note 2. Investigator codes:        Hl =  Hobbie (March 1967-February 1968)
                                                      H2 =  Hobbie (June 1968-July 1969)
                                                      H3 =  Hobbie (July 1969-July 1971) -
                                                      H4 =  Hobbie (August 1971-August 1973)
                                                      Dl =  Davis (August 1975-July 1976)
                                                      D2 =  Davis (August 1976-July 1977)
                                                      K  =  Kuenzler (1975-1977)
                                                      Il =  ICMR (January 1975-June 1975)
                                                      12 =  ICMR (July 1975-December 1986)
                                                            Station 7 sampled 1/77-12/86
                                                            Station 2N sampled 7/75-7/77
                                                            Station 1A sampled 7/80-12/86

                   Note 3. The "location" notes below refer to geographic features named
                   on National Ocean Survey Charts 11554 (13th. ed., 1981) and 11548 (31st.
                   ed., 1985), published by the U.S. Department of Commerce, National
                   Oceanic and Atmospheric Administration (NOAA),            Washington, D.C.



                    River
                   Segment         Investigator



                         H1 H2 H3 H4 D1 D2 K Il 12             Latitude/Longitude/Location


                      A                   22   1     11 12    N35032 I 07"-W77002 155"
                                                              Mid-river, RR bridge     at Washington

                      A                   21            11    N35029151 "-W77001138"
                                                              Mouth of Chocowinity     Bay

                      B                              10 10    N35028155 "-W76059115 "
                                                              Marker "12" off Camp     Hardee

                      B      H17 H17    1                     N35'28122 "-W76058,27 "
                                                              Marker "10", mid-river off Hills Pt.








                 196                                                                         Appendices

               Appendix 4.2. Continued



                 River
                Segment        Investigator



                     H1 H2 H3 H4 D1 D2 K Il 12               Latitude/Longitude/Location




                  B                                    9S   N350271 04 "-W76057 132 "
                                                            South Blounts Bay



                  B                                    9N   N35028150 "-W76057 124 "
                                                            Marker "1", mouth of Broad Ck.


                  B      H16 H16 2 20 2         1           N35027 142"-W76057 133"
                                                            Marker "9", Blounts Bay

                  B             A5                          N350281 00 "-W760581 00"
                                                            West Blounts Bay

                  C                 3                       N35027 1 27 "-W760561 11
                                                            Marker "8", NW of Maules Pt.


                  C      H11 H11                   9    8   N350271 10"-W76055 1 10"
                                                            Marker "7", NE of Maules Pt.

                  C                 4 19                    N35026142 "-W76054 113 "
                                                            Test Well "D" off Jack Ck.


                  C    3                                    N35027 120"-W76053 135 "
                                                            Off Mallard Ck., N side of river

                  C    2                                    N35026148"-W76053137"
                                                            Between Tripp Pt. and Mallard Ck.

                  C    1                                    N350261 10"-W760531 40"
                                                            Off Tripp Point, south side of river

                  D      H10 H10    5 18       2   8        N35026130"-W76052 1 22"
                                                            Between Sparrow Bay and Duck Ck.

                  D    4                                    N35026145 "-W76050145
                                                            Off Hawkins Landing, N side of river

                  D       H9 H9        16               7   N35025 I 50"-W76050130"
                                                            Marker "5" off Core Pt.








                     Appen.dices                                                                                  197
                     Appendix 4.2. Continued


                       River
                      Segment         Investigator



                            Hl H2 H3 H4 Dl D2 K Il 12                Latitude/Longitude/Location




                        D                  6                       N350261 03"-W760501 05
                                                                   Mid-river between Core Pt. and Bath Ck.


                        D    5                                     N350261 10"-W76050150"
                                                                   Between Hawkins Lndg. and Core Pt.

                        D    6                                     N35025 143 "-W76050151 "
                                                                   off Core Pt., near s. shore of river


                        D                                    7S    N35024 1 04 "-W76049, 04 "
                                                                   Marker "2" at mouth of Durham Ck.


                        D                     17             7N    N35027 103 "-W76049 115"
                                                                   Marker "1" at mouth of Bath Ck.


                        D        H8   H8   8               7       N35024 145 "-W76048,43 "
                                                                   Mid-river between TG and Bayview

                        D       SH8 SH8    9  15                   N35024108 "-W76048140 "
                                                                   off mouth of Durham Creek


                        D                          3   3           N35025 115 "-W76048130"
                                                                   Mid-river between Durham Ck. & Bath Ck.

                        D    7                                     N35023 145 "-W76047 152 "
                                                                   Off TG, near south shore

                        D    10               14                   M350251 55 "-W76047 140"
                                                                   Off Bayview, near north shore

                        D    8                                     N35024 120"-W76047 145 "
                                                                   Off TG, near south shore


                        D    9                                     N350251 05 "-W76047 145"
                                                                   Mid-river between TG and Bayview








                198                                                                          Appendices

               Appendix 4.2. Continued


                River
                Segment        Investigator


                     Hl H2 H3 H4 Dl D2 K Il 12               Latitude/Longitude/Location




                  D      NH8 NH8 7                          N3502513 0"-W7 604 613 6"
                                                            off Mixon Creek, N side of river

                  E                                     6   N35023112"-W76046107 "
                                                            Off TG outfall


                  E      SH7 SH7 12                         N35023128 "-W76046,20 "
                                                            Marker "1" at TG barge canal

                  E       H7 H7 11                          N350241 10 "-W76046103"
                                                            Between Gum Pt. and TG barge canal

                  E      NH7 NH7 10                         N35024147 "-W76045152 "
                                                            Marker "4" off Gum Pt.


                  E            A3 14                        N35023 157 "-W76044 139
                                                            Between St. Clair Ck. and Long Pt.

                  E  14                11          5 5S     N35023103"-W76044 139"
                                                            Marker "1" at Ferry Landing

                  E  12                                     N35024137 "-W76044125"
                                                            Between Gaylord Bay and Ferry Lndg.

                  E                    12       4  6 5      N35024110"-W76044118"
                                                            Between Gaylord Bay and Huddles Gut

                  E            A2 13                        N35025 I 10"-W76044135"
                                                            Off St. Clair Ck., N side of river

                  E  13                                     N35024145"-W76044,35"
                                                            off ferry landing, south side of river

                  E  11                13              5N   N35025119"-W76044110"
                                                            Marker "i" in Gaylord Bay








                    Appendices                                                                            199

                    Appendix 4.2. Continued


                     River
                     Segment        Investigator


                          H1 H2     H3 H4 Dl D2 K Il 12         Latitude/Longitude/Location




                       E  15                                   N35022 103 "-W76041140 "
                                                               Off Hickory Pt., south side of river

                       E           A4 15                       N35023 I 00"-W76041140 "
                                                               Off Long Pt., S side of river

                       E  17                                   N35023 125 "-W76041, 10"
                                                               Between Cousin Pt. and Hickory Pt.

                       E  16                                   N35022 147 "-W76041122
                                                               Off Hickory Pt., S side of river

                       E  18                                   N35024 I 03"-W76040,55 "
                                                               Off Cousin Pt., N side of river

                       E  19                                   N35024 140"-W760401 45"
                                                               Off Cousin Pt., N side of river

                       F  26                                   N35021122 "-W76041, 05 "
                                                               Marker "5" off South Ck.


                       F  25  H13 H13 32                 4S    N35021128"-W76040,37 "
                                                               Marker "4" off South Ck.

                       F       H6 H6 17                        N35023 145 "-W76040,16"
                                                               Between Hickory Pt. & Cousin Pt.

                       F      NH6 NH6 16                 4N    N35024 146"-W760401 11 "
                                                               Marker "1" at mouth of North Ck.


                       F      SH6 SH6 18                       N35022 130"-W76040,29 "
                                                               Between Hickory Pt. & Cousin Pt.

                       F  24               10                  N35021120 "-W76039135 "
                                                               South of Indian island


                       F  23                                   N35021155 "-W760391 00 "
                                                               North of Indian Island








                200                                                                       Appendices

               Appendix 4.2. Continued


                River
                Segment        Investigator


                     Hl H2     H3 H4 Dl D2 K Il 12         Latitude/Longitude/Location



                  F 21                                    N35023103 "-W7603 8120 "
                                                          North of Indian Island


                  F 22 H5 H5           9 4        4 3     N35022123 "-W76038,47 "
                                                          Marker "3", north of Indian Island

                  F  20                8                  N35023 140"-W760381 07 "
                                                          North of Indian Island


                  F      H12 H12                          N35021112 "-W76038,25 "
                                                          Marker "2" south of Indian Island


                  G      SH4 SH4  20                      N350211 10"-W76037 1 00"
                                                          Off Reed Hammock


                  G      NH4 NH4  19                      N35022 136"-W76036,06"
                                                          Off Cousin Pt., north side of river

                  G  35                                   N35020,36"-W76036,32"
                                                          Off Reed Hammock, s. side of river

                  G       H4 H4               5           N35022 I 00"-W76036130"
                                                          Between Reed Hammock and Adams Pt.


                                                  3       N3502114 0 " -W7 603 6119 "
                                                          Mid-river between Wades Pt. & Goose Ck.


                  G  34                                   N35021,02"-W76036,08"
                                                          Between Reed Hammock and Wades Pt.


                  G                    5            2S    N35020'22 "-W76035 147"
                                                          Marker "1" at mouth of Goose Ck.








                     Appendices                                                                               201

                    Appendix 4.2. Continued


                      River
                      Segment        Investigator



                           H1 H2     H3 H4 D1 D2 K 11 12          Latitude/Longitude/Location



                       G 33                                      N35021124 "-W76035,48
                                                                 Mid-river between Wades Pt. & Reed Ham.


                       G 31                                      N35022124 "-W76035 1 00"
                                                                 Between Reed Hammock and Wades Pt.


                       G   32                 6                  N35021152 "-W76035 124 "
                                                                 Between Reed Hammock      and Wades Pt.


                       G   30                 7                  N35022 154"-W76034 142"
                                                                 Off Wades Pt.


                       G                 21                      N35022138 " -W76033124"'
                                                                 Marker "PR" at mouth of Pungo R.

                       G                 23                      N35020118"-W76033 154 "
                                                                 Between Goose Ck. and Cedar Is.


                       G                 22                      N35021124 "-W76033 133 "
                                                                 Mid-river south of mouth of Pungo R.

                       H              Al 31                2N    N35023 136"-W76033 1 00"
                                                                 At mouth of Pungo River

                       H      SH3 SH3    26                      N350201 00 "-W76032 1 06"
                                                                 North of Cedar Island


                       H        H3 H3    25      5       2 1A    N35021120"-W76031,30 "
                                                                 Mid-river between Abel B. & Cedar Is.


                       H      NH3 NH3    24                      N35023113 "-W76030130"
                                                                 S. of Indian Is. Marker "1" at Abel B.

                       1   38                                    N35020154 "-W76029114 "
                                                                 Between Marker "1" and Willow Pt.








                202                                                                       Appendices

               Appendix 4.2. Continued


                River
                Segment        Investigator


                     H1 H2     H3 H4 D1 D2 K Il 12         Latitude/Longitude/Location




                  1  37                                   N35019152 "-W76029,12
                                                          Between Pamlico Pt. & Willow Pt.


                  1  39  NH2 NH2 27    2                  N35021148 " -W76028150 "
                                                          Marker at Willow Pt. shoal


                  1  36  SH2 SH2 29    4                  N35019,00"-W76028158"
                                                          Marker "i" at Pamlico Pt.


                  I       H2   H2 28   3                  N35020130"-W76028 1 54 "
                                                          Mid-river between Willow Pt. & Pam. Pt.


                  1                30             1   1   N35020106"-W76027136"
                                                          Mid-river between Pam. Pt. & Rose Bay

                  I       Hl   H1      1   6  6           N35018 147 "-W76027 120"
                                                          Pamlico Pt. light

                  1  29                                   N350201 31 "-W76044 119"
                                                          Marker "9" in South Creek


                  i      H15 H15 34                       N350211 09"-W76043 143"
                                                          Marker "8" in South Ck.


                  J  28                                   N350211 03 "-W76042 120"
                                                          off Old Field Pt., South Creek

                  i      H14 H14 33              12 4P    N35021114"-W76042115"
                                                          Marker "7", South Ck.


                  J  27                                   N35020145"-W76041140"
                                                          Marker "2", mouth of Bond Creek









                     Appendix 4.3.
                     Changes in sampling and analytical methods

                         To the best of my knowledge, all the       al. (1978) used a salinity-conductivity-tem-
                     hydrographic and nutrient data reported        perature (SCT) meter (Model 33) manu-
                     by Hobbie for the period 1967-1973 were        factured by Yellow Springs Instrument
                     from analyses carried out by students and      Company (YSI). Beginning in 1975, and
                     research technicians at the Pamlico Estua-     continuing to the present, the ICMR moni-
                     rine Laboratory (PEL) near Aurora, NC.         toring program at ECU has also made use
                     After East Carolina University (ECU) took      of the YSI SCT meter for temperature and
                     over the monitoring program in 1975, the       salinity measurements. There is no reason
                     analyses continued to be performed at the      to suspect that data from these two instru-
                     PEL under the supervision of Mr. Dan           ments are incomparable. All the data have
                     Kornegay. In mid- 1980 the procedure was       been reported in units of OC for tempera-
                     changed so that samples were transported       ture, and parts per thousand (ppt) for Sa-
                     to the Institute for Coastal and Marine        linity.
                     Resources on the ECU campus in Greenville          Dissolved oxygen measurements in
                     for analysis. Finally, in March 1985 analy-    the Pamlico studies have been made by
                     sis of the Pamlico samples was shifted to      two methods: 1) the classical Winkler titri-
                     the ECU Biology Department's Central           metric technique, and 2) oxygen sensing
                     Environmental Laboratory, under the su-        electrodes. The Winkler method was used
                     pervision of Ms. Martha Jones. Samples         for all the dissolved oxygen analyses re-
                     collected by Davis et al. (1978) were also     ported by Hobbie. Water samples were
                     analyzed in the ECU Biology Department         taken with a Kemmerer sampler, fixed in
                     lab. Kuenzler et al. (1979) transported        the field, and titrated in the laboratory. No
                     their samples to the U.N.C. Chapel Hill        other details of the procedure are given in
                     campus foranalysis in the Limnology LabO-      Hobbie's reports. Instead, the reader is
                     ratory of the Department of Environmen-        referred to Carpenter (1965), who described
                     tal Sciences and Engineering.                  the method as "a modified ... Winkler
                                                                    determination", and he detailed the modi-
                        Water Temperature, Salinity, Dis-           fications, most of which involve the titra-
                     solved Oxygen, and pH: Two kinds of            tion equipment. Kuenzler at al. (1979)
                     instruments have been used to measure          used an "APHA-type" oxygen sampler to
                     water temperature and salinity in the          collect replicate D.O. samples from 0.5 in
                     Pamlico studies. Hobbie used a conductiv-      below the surface and 0.5 in above the
                     ity bridge with built-in thermistor            bottom. Samples were fixed by the addi-
                     (Beckman RS5-3 induction salinometer) to       tion of manganous sulfate and alkaline
                     measure salinity and temperature in situ,      iodide for Winkler analysis by procedures
                     except for a few times in 1967 when hy-        given in American Public Health Associa-
                     drometers were used for salinity measure-      tion (1975). Davis et al. (1978) and ICMR
                     ment. Presumably a mercury thermom-            both measured dissolved oxygen by means
                     eter was used on these occasions to mea-       of a Yellow Spring Instrument Company
                     sure water temperature, although such is       Model 51A oxygen meter and electrode.
                     not stated in the report (Hobbie 1970b).           All of the Hobbie dissolved oxygen data
                     The induction salinometer was used also        was reported as ml 02/liter. To permit
                     by Kuenzler et al. (1979) in their Pamlico     comparison with later data, I have con-
                     samplingin 1975,1976 and 1977. Davis et        verted the ml 02/liter values to mg02/liter,








                 204                                                                            Appendices
                 by multiplying times 1.429 (Head 1985).         was measured in the laboratory, but since
                 Dissolved oxygen (DO) percent saturation        then a portable instrument has been used
                 values were included for some years in the      to make measurements on freshly-drawn
                 previous Pamlico reports, but the method        samples in the field (Stanley 1987).
                 ofealculation was not always given. There-
                 fore, in order to have the data for all years       Nitrogen and Phosphorus: Proce-
                 and to insure consistency, I have recalcu-      dures for the collection ofsamples, for nitro-
                 lated percent saturations (DOPS) by the         gen and phosphorus analyses have varied
                 following formula:                              somewhat among the four studies. Hobbie
                   I DOPS = (mgDO/liter * 100XDO Satu-           stated simply that "surface samples were
                 ration Value),                                  taken at each station and returned to the
                     where                                       laboratory for analysis" (Hobbie 1970a,
                     DO Saturation Value = (475 - (2.65 *        page6). Davisetal. (1978) collected samples
                 S)X33.3 + T).                                   0.5 m below the surface, immediately fil-
                     S is salinity (ppt) and T is the tempera-   tered aliquots for dissolved nutrients, and
                 ture (OC). This is the same formula used by     stored all the samples in the dark on ice for
                 Hobbie (1970b) forsomeofthe earlyPamlico        transport back to the laboratory. Kuenzler
                 data. He indicated that it was developed        et al. (1979) filled polyethylene carboys
                 by Truesdale and Gameson (1957).                with water from a depth of 0.5 m by means
                     Of course, no percent saturation values     of a Guzzler R Pump (Cole-Parmer Instru-
                 could be calculated when there was not a        ment Company) fitted with a plastic hose
                 dissolved oxygen value. However, in those       covered at the intake end with 153 um
                 few cases where there was a DO value, but       mesh nylon netting to exclude zooplank-
                 no temperature and/or salinity data, I did      ton. The samples were returned to the
                 estimate the percent saturation. I did this     Pamlico Estuarine Laboratory (PEL)
                 by interpolating to give the missing salin-     within a few hours for filtration, followed
                 ity or temperature values needed for the        by freezingand transport to Chapel Hill for
                 calculation.                                    later analysis. Finally, samples collected
                   . I have not found in any of the Hobbie       since 1975byICMR were taken by dipping
                 reports a description of the method used        1-liter polyethylene bottles into the water
                 for pH measurements. However, I believe         just below the surface. The bottled samples
                 that a pH meter with electrode (model           were held on ice in the dark until they were
                 unknown) was used, and that measure-            returned to either the PEL or ECU (within
                 ments were made on samples after they           6 hours of collection), where they were
                 were returned to the Pamlico Estuarine          filtered and frozen (e.g., ICMR 1982;
                 Laboratory, usually within a few hours          Stanley 1987).
                 after collection. Davis et al. (1978) stored        Other variables associated with the
                 samples in the dark at mean ambient             nutrient sample processing include the
                 water temperature for up to 4 hours until       type of filter used to separate dissolved and
                 pH could be measured with a Corning             particulate fractions, and the type and
                 Model 10 meter. Kuenzler at al. (1979) also     length of storage of samples between col-
                 used a pH electrode, but I don't recall the     lection and analysis. Hobbie used Gelman
                 meter model; no reference to it is made in      A glass fiber filters. Reactive phosphorus
                 the project report. Since 1975 various pH       was measured as soon as the samples were
                 meters with electrodes (manufacturers and       returned to the laboratory, but water (fil-
                 models have varied) have been used for the      tered and unfiltered) for the total phospho-
                 ICMR pH measurements. Until 1985 pH             rus, total dissolved phosphorus, and nitro-








                     Appendices                                                                                  205

                     gen fractions was frozen in plastic bags         in 1969 that the calibration curve was not
                     immediately after collection byplacingthe        linear above 10 ug-at P/liter and the previ-
                     bags onto dry ice (Hobbie et al. 1972).          ous readings obtained were underesti-
                     Similarly, Kuenzler et al. (1979) filtered       mates. Therefore, the concentrations mea-
                     samples through Whatman GF/C glass               sured prior to 14 October 1969 are low and
                     fiber filters and stored the filtered (or        can be corrected by multiplying by a factor
                     unfiltered) water frozen in polyethylene         of 1.0 at 10 ug-at P/liter and 1.6 at 20 ug-
                     until the nutrient analyses were run.            at P/liter. Since this correction makes no
                     Gelman type A/E glass fiber filters were         difference to the conclusions of this report,
                     used by Davis et al. (1978), and they also       it was not applied to the data. It was also
                     froze the samples pending analyses of nu-        found that the curves for total (digested)
                     trients. Since 1984 Whatman 934-AH               and reactive (undigested) phosphate con-
                     glass fiber filters have been used for the       centrations versus extinction had different
                     samples analyzed in the ICMR program.            slopes. Again the differences are slight,
                     There is no record of the kind of filters used   but this correction and the correction for
                     between 1975 and 1983. Both filtered and         the differing factors at high concentrations
                     unfiltered samples have been stored fro-         of phosphorus will clear up most of the
                     zen, for up to several months in some            discrepancies of the data where the reac-
                     instances, until the analyses were made.         tive phosphorus is higher than the total
                         1. Phosphorus: Nearly all the samples        phosphorus" (Copeland and Hobbie 1972,
                     taken during these studies were analyzed         pages 24-25).
                     for at least three phosphorus fractions;            Apparently the phosphorus methodol-
                     total phosphorus (TP), total dissolved phos-     ogy did not change between 1969 and
                     phorus (TDP), and orthophosphate phos-           August 1973 when Hobbie's sampling
                     phorus (OK TP analyses were performed            ended, since his 1974 report on the 1971-
                     on unfiltered water samples, while the           1973 data states on page 12 that "details of
                     other two measurements used filtered             the phosphorus analysis are given in Hobbie
                     water. All the TP and TDP samples were           (1970a)", and the references he cites re-
                     first digested by some variation of the          garding methodology are the same ones
                     persulfate oxidation method of Menzel and        cited in the earlier report; i.e., Menzel and
                     Corwin (1965). Subsequent analyses of            Corwin (1965) for the persulfate digestion
                     these digested samples, and undigested           and Strickland and Parsons (1968) for the
                     orthophosphate samples, was by manual            use of the mixed reagent. The same spec-
                     or automated colorimetric methods. All           trophotometer that had been used earlier
                     projects used the mixed reagent developed        was used to read the sample color following
                     by Murphy and Riley (1962), containing           addition of the mixed reagent.
                     ammonium molybdate, ascorbic acid, and              Davis et al. (1979) seem to have used
                     trivalent antimony.                              the same basic procedure as Hobbie, al-
                         Copeland and Hobbie give further de-         though they reported few details regard-
                     tails on the methodology used between            ing their phosphorus methodology. They
                     1967 and 1969: "The color development            simply state that "phosphorus analyses
                     was read in a Beckman DU II spectropho-          involved conversion of phosphorus to or-
                     tometer and the optical density calibrated       thophosphate by persulfate digestion, and
                     against standards. These standards proved        subsequent colorimetric determination of
                     to be constant and a factor of 5.0 multiplied    soluble orthophosphate." They cite the
                     by this spectrophotometer reading gave           manual on water and wastewater chemi-
                     the concentration. However, it was noted         cal analyses published by the Environ-








                 206                                                                              Appendices
                 mental Protection Agency (EPA) (1976) as         the annual reports to Texasgulf (Stanley
                 a reference to their procedures. The meth-       1986a, 198b, 1987). The most significant
                 ods outlined in this document do indeed          change in recent years came in 1985 when
                 involve the use of persulfate digestion for      the procedures were automated using a
                 TDP and TP and the use of the three-part         Scientific Instruments autoanalyzer simi-
                 mixed reagent for phosphate determina-           lar to the Technicon equipment used ear-
                 tion.                                            lier by Kuenzler et al. (1979). Details of the
                    An earlier edition of the EPA manual          autoanalyzer procedure are given in
                 (1974) was referenced by Kuenzler et al.         Stanley (1987).
                 (1979) to describe the phosphorus method-            On 28 March 1985 the total phospho-
                 ology they used for Pamlico samples ana-         rus analysis was dropped and particulate
                 lyzed in their study between 1975 and            phosphorus (PP) measurements were be-
                 1977. They used slightly different termi-        gun. PP is the fraction of TP that remains
                 nology to describe the phosphorus frac-          on the filter pad following filtration. There-
                 tions - "filterable reactive P" instead of       fore, the total phosphorus data used in this
                 orthophosphate phosphorus, and "total fil-       study for the period 28 March 1985 through
                 terable P" instead of total dissolved phos-      December 1986 are not direct measure-
                 phorus. The main difference between their        ments, but rather the sums of the total
                 procedure and that of Hobbie and Davis et        dissolved phosphorus and PP values.
                 al. was that they automated the analyses             It has been determined recently that
                 using Technicon Autoanalyzer equipment.          all the total dissolved phosphorus (TDP)
                 They state in their report that ". . . preci-    data presented in the 1986 annual report
                 sion was controlled in these analyses by         (Stanley 1987) and part of the data in the
                 runningall samples in duplicate. Accuracy        1985 report (Stanley 1986b) are in error.
                 was checked in two ways. Where avail-            This error arose duringthe transition from
                 able, EPA controls were analyzed with            manual to automated methods of analysis
                 every run. Also approximately 10% of             of TDP during 1985. The problem is that
                 routine analysis time was spend [sic] de-        the automated analysis gives erroneously
                 termininarecoverv of known increments of         high TDP results. The solution to this
                 standar& (spike;) to samples. . . Stan-          problem is described above in the Methods
                 dards were routinely run at the beginning        section of the report.
                 and end of each sample run" (Kuenzler et             2. Nitrogen: From 1969 through 1973
                 al. 1979, pages 17-19). .                        Hobbie analyzed several nitrogen fractions,
                     Finally, all ICMR samples from 1975 to       including nitrate nitrogen, ammonia ni-
                 the present have been analyzed for phos-         trogen, total dissolved nitrogen (TDN), and
                 phorus using the same basic chemistry            total nitrogen (TN). The first three analy-
                 described above; i.e., the mixed color re-       ses were run on filtered samples, while the
                 agent for OP and persulfate digestion to         fourth (TN) used unfiltered water. Hobbie
                 convert TP and TDP to OP. Notes provided         (1974) referred to the total dissolved nitro-
                 to me by the analyst who performed the           gen as "total filtered nitrogen", and to the
                 tests from 1975 through 1980 show that           total nitrogen as "total unfiltered nitro-
                 EPA (1974, 1976, 1979) procedures were           gen".
                 followed. A block digestor was used be-              Hobbie's nitrogen analyses consisted of
                 tween 1975 and sometime in 1977, when it         various pre-treatments of a sample fol-
                 was replaced by an autoclave. Since 1984         lowed by analysis as nitrite. The nitrite
                 the methods for phosphorus analyses have         was analyzed as an azo dye produced by
                 been described in detail in appendices in        sulphanilamide plus N-(l-napthyl)-








                    Appendices                                                                              207
                    ethylenediamine. This diazotization tech-      were automated using Technicon
                    nique was adapted for sea water by             Autoanalyzer equipment and EPA meth-
                    Bendschneider and Robinson (1952), and         ods. Cadmium reduction followed by ni-
                    it is described in full in Strickland and      trite analysis was the method they chose
                    Parsons (1968), which is the reference cited   for nitrate nitrogen determinations. They
                    by Hobbie in his reports. The nitrate was      cited EPA (1974) as their reference. Like
                    analyzed as nitrite following reduction in a   Davis et al., they also used the indophenol
                    copper-cadmium column (Morris and Riley        method for ammonia, and they cited EPA
                    1963). Ammonia also was analyzed as            (1974) as the reference for the method.
                    nitrite after oxidation of the sample with     Their total dissolved nitrogen analyses
                    alkaline hypochlorite, a method developed      were by automated Kjeldahl methods (EPA
                    by Richards and YJetch (1961). It really       1974). Total nitrogen was not measured.
                    gives ammonia plus amino acids,                    For a brief period (January-June 1975)
                    (Strickland and Parsons 1968), although        the ICMR nitrate analyses were made
                    the error is small, since amino acids are      using the brucine colorimetric method,
                    usually much less abundant than ammo-          which is based on the formation ofa colored
                    nia. Finally, the TN and TFN analyses          complex between nitrate and brucine sul-
                    were carried out using oxidation by strong     fate in a 13 N sulfuric acid solution at a
                    ultraviolet (UV) light to convert organic      temperature of 1000C (EPA 1974). How-
                    forms to a mixture of nitrate and nitrite      ever, since July 1975 the ICMR samples
                    (Armstrong et al. 1966; Strickland and         have been analyzed by the cadmium re-
                    Parsons 1968).                                 duction method, which was automated in
                        Davis et al. (1978) indicated that they    mid-1985.
                    used the UV spectrophotometric method             From 1975 through 1979 the ICMR
                    (APHA 1971) for nitrate determinations.        ammonia analyses were made using an
                    They analyzed ammonium nitrogen by the         Orion Ammonia Probe (D. Kornegay, per-
                    indophenol method, often referred to as the    sonal communication). Unfortunately, this
                    Solorzano (1969) method. Scheiner (1976)       ion-selective electrode was not very sensi-
                    modified the method slightly and Davis et      tive. It could not detect concentrations
                    al. cited this paper as their reference. In    below 0.1 mg ammonia N/liter (7.14 uM),
                    the indophenol method samples are treated      so that most of the normal range in ammo-
                    with sodium hypochlorite and phenol in an      nia levels in the estuary was missed. Be-
                    alkaline citrate medium. Sodium                ginning in 1980, the indophenol method
                    nitroprusside is used as a catalyst, and the   was adopted (Solorzano 1969), and it has
                    blue indophenol color formed with ammo-        been used continuously since then, al-
                    nia is measured spectrophotometrically         though minor modifications have been
                    (Parsons et al. 1984). Kjeldahl digestions     made at various times. Details of the
                    (EPA 1976) were used for the total nitro-      procedure from 1984 onward, including
                    gen and total dissolved nitrogen analyses.     the switch to the automated procedure in
                    This is one of the oldest and most widely-     1985, are given in the annual reports.
                    used methods for TN and TDN. Organic              Kjeldahl digestions were used for the
                    matter is converted to ammonia by heat-        ICMR total and total dissolved nitrogen
                    ing with sulphuric acid, and the ammonia       analyses beginning in January 1975. Be-
                    determined spectrophotornetrically by one      tween 1975 and the end of 1979, a block
                    of the methods given above.                    digester was used and the ammonia pro-
                       All of the nitrogen analyses performed      duced in the reaction was measured by
                    during the study by Kuenzler et al. (1979)     means of the same Orion ammonia probe








                 208                                                                             Appendices
                 used for the ammonia analyses. Beginning         from 1975 through 1980, although no de-
                 in 1980, the ammonia was determined by           tails are certain for that time period. Since
                 the indophenol blue method, modified             1980, this has been the method, with slight
                 slightly at various times. When the analy-       modifications, mostly involvingthe method
                 ses were automated in 1985, a combined           of extraction (e.g., grinding or no grinding
                 nitrogen-phosphorus digestion reagent            of filter pads), and the time allowed for
                 came into use. (Stanley 1987). The ammo-         extraction before the readings were made.
                 nia produced by this digestion was ana-          The chlorophyll data from part of 1985 are
                 lyzed by the indophenol method.                  suspect because of a problem involving
                                                                  unequal dispersion ofthe pigment in tubes
                      ChlorophyU a: Essentially the same          following centrifugation to sediment the
                 method has been used for chlorophyll a           glass fiber filter fragments. It seems that
                 analyses in all four of the Pamlico studies.     mostofthe pigment was collecting near the
                 Hobbie (1974) gave the following outline of      bottom of the tube, so that when the sample
                 the method: "Water samples were returned         was decanted into the spectrophotometer
                 to the laboratory ... and a part of the          cell, erroneously low readings were ob-
                 sample filtered through Gelman A glass           tained. This problem was corrected in
                 fiber filters for later chlorophyll analysis     -early 1986.
                 (filters were frozen)... Chlorophyll a was
                 measured by grinding the filters, extract-           Phytoplankton CeU Density and
                 ing with 90% acetone, and estimating the         Wet Weight Biomass: There have been
                 pigment           spectrophotometrically         two major studies of phytoplankton spe-
                 (Strickland and Parsons 1968). The spec-         cies, numbers, and biomass in the Pamlico.
                 trophotometric results were corrected for        The first was by Hobbie (1971) for the time
                 phaeophyton (Strickland and Parsons              period August 1966 through April 1968.
                 1968)" (Hobbie 1974, page 12). It is impor-      Two series of stations were sampled; one
                 tant to note that all the chlorophyll results    series from August 1966 to August 1967
                 from the other three studies were also           and the other from March 1967 to Febru-
                 corrected for phaeophyton.                       ary 1968. These were the same stations
                      Davis etal. (1978) filtered their samples   sampled for nutrients and hydrographic
                 within 12 hours of collection (filter type not   parameters during these time periods
                 given), and the filters were stored frozen in    (Hobbie 1970a, 1970b). The first series
                 a dessicator. Analyses of chlorophyll were       was sampled to examine the effects of the
                 made within 30 days of sample collection.        effluent from the phosphate slime (mining
                 They cited Strickland and Parsons (1972)         waste) pond located close to South Creek.
                 as the reference for the procedure they          When the effect could not be found, the
                 used. Kuenzler et al. (1979) also froze the      sampling was expanded to include most of
                 filter pads (Whatman GF/C) and analyzed          the estuary (Hobbie 1971).
                 for chlorophyll a by means of the acetone            Phytoplankton in the samples were
                 extraction-spectrophotometric method, fol-       identified and counted by the Utermohl
                 lowing the procedure given in Lorenzen           technique (Utermohl 1958). Briefly, the
                 (1967).                                          organisms were preserved in a Lugol's type
                      ICMR analyses ofchlorophyll a, like all     solution, settled into asmall countingcham-
                 the others described above, were made by         ber, the excess water removed, and the
                 measuring the extinction of an acetone           organisms counted with an inverted micro-
                 extract of the pigment. The method prob-         scope. Details are given in Hobbie's report.
                 ably followed Strickland and Parsons (1972)      The. most important advantage of this







                    Appendices                                                                                209
                    method is that it enables counting of the       identified and counted by D. Daniel. The
                    flagellates and nannoplankton as well as        membrane filtration method was used to
                    less fragile, larger forms (Hobbie 1971).       concentrate the Lugol's preserved algae
                        The second Pamlico phytoplankton            prior to counting at 40OX magnification
                    study, sponsored by North Carolina Phos-        (see Stanley and Daniel 1985a for details).
                    phate Corporation, was made during the          This method of concentrating the algae is
                    period April 1982 through December 1985         more rigorous than the Utermohl settling
                    (Stanley 1983, 1984a; Stanley and Daniel        method usedbyHobbie in the earlierstudy,
                    1985a, 1985b, 1986). The objective was to       but it apparently did not destroy the fragile
                    collect baseline data for future impact as-     flagellates and nannoplankton, so that
                    sessment of increased phosphate mining          results from the two studies are compa-
                    in the area. There was a concern that           rable.
                    higher nutrient loads could trigger nui-           In both of these phytoplankton studies,
                    sance blooms of algae in the Pamlico like       the algal biomass was calculated. Vol-
                    those that had become common by this            umes of representative individuals of each
                    time in the Chowan River and the Neuse          species were estimated by means of geo-
                    River. Samples were collected approxi-          metric formulae. These volumes were
                    mately every other week from stations in        multiplied by the species cell densities and
                    the river and in South Creek, a tributary       summed to give the total wet weight bio-
                    near the mining sites. The River stations       mass (ug/liter) for each sample. A specific
                    were the same ones used for the Texasgulf       gravity of unity was assumed (i.e., 1 ming
                    nutrient and hydrography study.                 = 1 ing wet mass) (Hobbie 1971; Stanley
                        Phytoplankton in the samples were           and Daniel 1985a).








                   210                                                                                Appendices

                   Appendix 4.4.
                   Review of methods for analyzing water quality time series data

                       The problem of testing water quality           However, if the type of change is not known,
                   monitoringdata fortrend intime has received        a two-tailed test should be used. It should be
                   increasing attention during the last decade,       stressed that, when possible, the one-tailed
                   primarily fortwo reasons (Hirsch et al. 1982).     alternative should be chosen.
                   First, there is interest in the question of           In order to apply trend detection tech-
                   changingwater quality arising from environ-        niques, there can be only one data point for
                   mental concern and activity. State and Fed-        each time unit. This data preparation prob-
                   eral legislation has resulted in the expendi-      lem arises when numerous observations are
                   ture of large sums of public and private           located in the same time unit, yet one value is
                   money for the purpose of water quality im-         needed to represent that discrete time unit.
                   provement, and there is naturally interest in      Means or median values may be used as a
                   evaluating the consequences of these expen-        measure of central tendency to represent the
                   ditures. Second, data sets covering a substan-     time period. When dealing with multiple
                   tial number of years are becoming increas-         data sources, an important consideration is
                   ingly common because of the establishment          whether the data are mutually compatible.
                   of monitoring programs in the early and mid-       Similar sampling designs, sampling devices,
                   1970's. Many of the trend analyses have            laboratory techniques and instruments may
                   involved data from national water quality          be a prerequisite to data merging; otherwise
                   networks such as the U.S. Geological Survey's      apparent trends may simply be an artifact of
                   NASQAN network (e.g., Smith et al. 1982).          a change in analytical methods. Under some
                       Montgomery and Reckhow (1984) out-             circumstances, the analyst may be able to
                   lined a four-step trend detection method: 1)       remove this analytical method effect from the
                   hypothesis formulation - statement of the          data series.
                   problem to be tested, 2) data preparation -            Once a hypothesis is formed and the data
                   selection of water quality variables and data,     are properly arranged (i.e., one datavalue per
                   3) exploratory data analysis, and 4) statistical   unit time) the data are ready to be explored
                   tests - tests for detecting trends.                and analyzed. The data analysis step will
                       Typically, the null hypothesis, H., is that    provide the necessary information to deter-
                   there is no change (notrend) in the population     mine which statistical test should be used to
                   of water quality values from which the data        test the null hypothesis. Of particular interest
                   were drawn. Consequently, the alternate            are characteristics of the data related to fre-
                   hypothesis, H1, may be either that a trend         quently invoked assumptions. Montgomery
                   does exist in the data (two-sided test) or that    and Reckhow (1984) and Smith et al. (1982)
                   a positive (or a negative) trend exists in the     discuss these assumptions and corrective
                   data (one-sided test). If it is known that a       measures to deal with assumption violations.
                   parameter either increased or decreased, a             Some of the techniques available for the
                   one-tail H, should be used. A one-tailed test      exploratory data analysis include a graph of
                   will maximize the probabilities of each out-       the data against time, the five number sum-
                   come by placing all the rejection region           mary graph which Tukey (1977) calls the
                   (alpha) at one tail ofthe outcome distribution.    box-and-whisker plot, Tukey smoothing, and








                         Appendices                                                                                             211
                         the autocorrelation function (McLeod et al.            any of these characteristics. The following
                         1983). Because no single method can clearly            discussion, taken from Letterunaier et al.
                         portray everything there is to learn about the         (1982), describes these common features of
                         data, it is advisable to use a number of               water quality data which must be recognized
                         exploratory techniques.                                before statistical methods can be selected.
                             Hypothesis testing, the final step for trend           1. Seasonality: Most water quality vari-
                         detection, consists of the following steps, as         ables are affected directly or indirectly by
                         summarized by Smith et al. (1982):                     seasonal climatic changes. For instance,
                             1. State the null hypothesis and back-             water temperature responds directly to air
                         ground assumptions for the test.                       temperature, although there is usually some
                             2. Calculate an appropriate test statistic         lag which depends on the rate of heat transfer
                         from the data.                                         into and out of the ground and water. Water
                             3. Interpret the value of the statistic in         temperature affects both the saturation con-
                         light of the known probability distribution of         centration of dissolved oxygen and the rates
                         the statistic.                                         of oxygen consumption and production by
                             4. If the value of the test statistic is within    plants and animals in the water column and
                         preselected limits on the distribution, accept         sediments. Nutrient concentrations reflect
                         the null hypothesis; or,                               both levels of biological activity and fresh-
                             5. If the value ofthe test statistic is outside    water inflow to the estuary, both of which in
                         the preselected limits, the null hypothesis            turn may have large seasonal variability.
                         cannot be accepted and a "statistically sig-           Most trend analysis techniques require that
                         nificant trend" is claimed.                            some procedure be employed to remove sea-
                             The limits are calculated from a                   sonality. Montgomery and Reckhow (1984)
                         preselected probability - typically denoted by         reviewed some of these procedures.
                         the Greek letter alpha - such that the probabil-           2. Nonnormal probability distributions:
                         ity that the test statistic would fall outside the     Most water quality variables are positively
                         limits is (alpha) if the null hypothesis and all       skewed, since they cannot be negative, but
                         background assumptions were true. A typi-              may occasionally take on large positive val-
                         cal value selected for alpha is 0.1. Then one          ues. Examples of variables from the Pamlico
                         may say that a trend is, or is not, statistically      data set exhibiting this characteristic include
                         significant at the 10% level. That is, in 90%          nutrients and chlorophyll a. On the other
                         of the cases, one will correctly say there is no       hand, some variables have small ranges and
                         trend when such is true. One may also report           often are nearly symetric, and if seasonal
                         test results by a probability value (denote p).        variations are removed, may be nearly nor-
                         This is the probability that the test statistic        mally distributed. Examples include tem-
                         would depart from its expectation by at least          perature, dissolved oxygen, and pH.
                         the observed amount, under the null hypoth-                Most parametric statistical tests require
                         esis.                                                  that the data come from a population that is
                             Most water quality data exhibit certain            normally distributed. A combination of in-
                         characteristics which can strongly influence           tuitive knowledge, graphical methods, and
                         the choice of an appropriate statistical trend         statistical tests should be used to determine
                         test. Thus it is very important that the data be       whether or not to use parametric tests, or
                         examined to determine whether they exhibit             nonparametric tests, which do not require a








                   212                                                                                Appendices
                   normal distribution of the parameter. Graphi-      tion" (Montgomery and Reckhow 1984).
                   cal techniques, involving visual compari-          Positive correlation between samples arises
                   sons, can be used to provide qualitative infor-    because fluctuations from the mean tend to
                   mation on the form of the underlying distri-       continue for a period that is usually long
                   bution. For larger samples (n>50), the             compared to the sampling interval. Such
                   Kolmogorow-Smirnov test (Sokal and Rohl f          variations are, from a statistical standpoint,
                   1981) can be used to test statistically the        "noise", and may obscure underlying trends.
                   assumption of normality. This test, it should      Persistence is usually not a major issue when
                   be noted, determines only whether the data         monthly sampling frequencies are used; for
                   exhibit significant deviations from normality      highersampling frequencies, such asbiweekly
                   and not whether they are normal (i.e., sup-        or weekly, it becomes increasingly impor-
                   ports the alternative hypothesis and not the       tant.     Various tests for detecting
                   null hypothesis) (Montgomery and Reckhow           autocorrelation are discussed in Montgom-
                   1984).                                             ery and Reckhow (1984), Kenkel (1975), and
                       3. Missing or nonuniformly sampleddata:        Sen (1978,1979).
                   Because of foul weather, equipment break-              5. Streamflow interaction: Some water
                   down, analytical errors, and changing ideas        quality variables display strong concentra-
                   as to appropriate sampling strategies, long-       tion gradients between freshwater and sea-
                   term time series are likely to have missing        water. For example, nitrate nitrogen is often
                   data. There may be long periods when no            100-fold or more concentrated in rivers than
                   samples were taken, and the intervals be-          in in the ocean. Consequently, in a low-
                   tween sampling dates are hardly ever uni-          salinity estuary like the Pamlico Riverwhere
                   form over a long period of time. Regardless        there is a strong riverine influence, the con-
                   of the cause, most traditional time series         centration of nitrate depends largely on Tar
                   techniques, which assume equal sample in-          River flow, especially in the upper half of the
                   tervals, are not appropriate to water quality      estuary where most of the mixing occurs.
                   data. Techniques exist to deal with a few              6. Censored data: Censored data are
                   isolated data gaps (Lettenmaier 1976;              those observations reported as being "less
                   D'Astous and Hipel 1979) by estimating             than" or "greater than" some specific value.
                   values for the missing data. However,ifthere       Examples include concentrations of nitrogen
                   are a lot of missing values, or one or more        and phosphorus which fall below the limits of
                   long gaps exist, the effect of data interpola-     detection (LD) of the analytical procedures.
                   tion on the identification of the stochastic       Where "less than LD" observations arise in
                   process and the ultimate trend testing become      the Pamlico data set, the LD values are used
                   very problematic (Hirsch and Slack 1984).          in the trend tests. This causes the distribution
                       4. Persistence: Water quality measure-         of the data to deviate even farther from
                   ments are not, in general, independent, but        normality, and so parametric tests become
                   are instead positively correlated (i.e., small     less exact. However, provided that the LD
                   values tend to be followed by small values         does not change over the period of record,
                   and large by large), and the correlation usu-      nonparametric tests such as the one used in
                   ally increases as the sampling interval de-        this study (see below), may be used with no
                   creases. This phenomenon is also sometimes         difficulty (Hirsch and Slack 1984).
                   termed "autocorrelation" or "serial coffela-           Statistical tests used for trend analyses








                       Appendices                                                                                          213
                       fall under one of two categories: 1) classical,      tions are present and not removed.
                       or parametric or 2) distribution-free, or non-           Another common parametric test for trend
                       parametric (Bradley 1968). Classical tests,          is based on linear regression of the variable of
                       such as those used in regression, require the        interest against time. The null hypothesis is
                       estimation of one or more parameters (for            that the variable and time are uncorrelated,
                       example, the slope of the regression line)           and the background assumptions are that the
                       based on the observed values of the variable         data are normal, independent, and identically
                       and the distribution of the test statistic under     distributed in time. If the slope of the regres-
                       the null hypothesis follows from an assump-          sion equation is found to be statistically sig-
                       tion about the underlying probability distri-        nificant, a trend is claimed. Unfortunately,
                       bution of the random variable.                       several of the assumptions underlying the
                           Distribution-free, or nonparametric, tests       derivation of the necessary probability distri-
                       typically ignore the magnitudes of the the           bution to test for significance are violated by
                       data in favor of the relative values or ranks of     natural data. In general, water quality data
                       the data. The major advantage of distribu-           have seasonality, are skewed, and serially
                       tion-free tests is that the underlying probabil-     correlated. These features contradict the
                       ity distribution of the random variable is           assumptions of stationarity, normality, and
                       immaterial. In fact, any strictly increasing         independence of the random variable (the
                       monotonic transformation - such as taking            water-quality variable) required for comput-
                       logarithms - changes the values of the data,         ing the probability distribution of the test
                       but does not affect the relative rankings.           statistic in the regression test for trend. The
                       However, because the magnitudes are ig-              seasonality inflates thevariance used inthe t-
                       nored, the test provides only a yes-or-no, not       tests, the skewness increases the standard
                       a how-much, answer.                                  error in the estimated slope, and the serial
                           The pros and cons of several parametric          correlation raises the actual alpha level rela-
                       and nonparametric tests for trend are dis-           tive to the selected alpha level. Any one of
                       cussed by Montgomery and Reckhow (1984),             these defects may be sufficient to render the
                       Hirsch and Slack(1984), Lettenmaier(1976),           test invalid, especially since the amount by
                       and Montgomery and Loftis (1987). Mont-              which they are present - and therefore, the
                       gomery and Loftis (1987) found that one of           amount by which the test is being distorted -
                       the most widely-used parametric tests, the t-        cannot be known.
                       test, is robust (i.e., is not appreciably affected       The same or similar objections can be
                       by a violation of a given underlying assump-         raised against virtually every test for trend
                       tion) for non-normal distributions if the dis-       when applied to almost any water-quality
                       tributions have the same shape (either symetric      variable. Attempts have been made to alter
                       or skewed) and sample sizes are equal. The           (transform) the data to remove or reduce the
                       Nest is also robust for unequal variances if         undesirable features. To remove seasonality,
                       the sample sizes are equal. The West appears         one might fit a sine curve to the data (Steele
                       not to be robust when 1) samples come from           et al. 1974) and use the deviations from the
                       two distributions ofdifferent shape, 2) samples      curve as the random variable to be tested. But
                       have unequal variances and unequal sample            with the exception of a few variables such as
                       sizes, 3) serial dependence in observations is       water temperature, there is little reason to
                       present, or 4) seasonal changes in concentra-        believe that the form of seasonality is a pure








                    214                                                                                    Appendices

                    sine curve. The extent to which the cure
                    works is largely unknowable. To eliminate
                    skewness, one might use the logarithms of the
                    data. Again, the extent to which this is proper
                    is only a guess. Compensating for serial
                    correlation is at best an art. Trying to do all
                    three is extremely difficult, if not impossible.
                    What is needed is a test that is largely unaf-
                    fected by the three above-mentioned charac-
                    teristics of the data. That is, the distribution
                    of the test statistic is influenced little by these
                    three characteristics of the data.








                      Appendices                                                                                     215
                      Appendix 4.5.
                      The Seasonal Kendall Trend test for water qulalty data



                         The distribution-free test which serves as     identical. A complete specification of the
                      the basis for trend testing in this study is      Seasonal Kendall test is given below. Its
                      Kendall's Tau (Kendall 1975). The null            derivation is given by Hirsch et al. (1982).
                      hypothesis for this test is that the random           When all assumptions for the regression
                      variable is independent of time. The only         test are met, the regression test is the most
                      necessary background assumption is that the       powerful test for linear trend (Kendall and
                      random variable is independent and identi-        Stuart 1968). The Seasonal Kendall test is
                      cally distributed (with any distribution). In     almost as powerful, based on a series of tests
                      this test, all possible pairs of data values are  using generated random numbers (Hirsch et
                      compared; if the later value (in time) is         al. 1982). When skewness and seasonality
                      higher, a plus is scored; if the later value is   were introduced into the experiments, the
                      lower, a minus is scored. If there is no trend    Seasonal Kendall test performed better than
                      in the data, the odds are 50-50 that a value is   the test based on linear regression; and when
                      higher (or lower) than one of its predecessors.   serial correlation was introduced, it's effect
                      In the absence of a trend, the number ofpluses    on the Seasonal Kendall test was no more
                      should be about the same as the number'of         severe than it's effect on linear regression.
                      minuses. If however, there are many more              In addition to indicating whether a trend
                      pluses than minuses, the values later in the      exists, it may be desirable to estimate the
                      series are more frequently higher than those      trend rate, or slope. Hirsch et al. (1982)
                      earlier in the series, and so an uptrend is       defined the Seasonal Kendall Slope Estima-
                      likely. Similarly, if there are many more         tor to be the median of the differences (ex-
                      minuses than pluses, a downtrend is likely.       pressed as slopes) of the ordered pairs of data
                         As discussed above, the one common             values that are compared in the Seasonal
                      pattern to water-quality variables is that they   Kendall test. Instead of recording a plus or
                      have a period of one year (other periodicities    minus for each comparison, one simply
                      may exist). Comparing, for example, a Janu-       records the difference divided by the number
                      ary value with a May value does not contrib-      of years seperating the data points. The
                      ute any information about the existence of a      median of these differences is taken to be the
                         trend, if aseasonal cycle of a 1-yearperiod    change per year due to the trend. A math-
                      exists. Thus, Hirsch et al. (1982) defined the    ematical description of the Seasonal Kendall
                      Seasonal Kendall test to be the Kendall's Tau     Test is given inAppendix B, page 32 inSmith
                      test restricted to those pairs of data which are  et al. (1982).
                      multiples of 12 months apart. Since compari-
                      sons are made only between data from the the
                      same month of the year, the problem of sea-
                      sonality is avoided. The random variables
                      may be nonidentically distributed, provided
                      that the distributions 12 months apart are




                                                                                     U.S. G.P.D.:1992-313-153:60516































































































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