Estuaries of the South Atlantic Coast of North … and publications/2000...Estuaries Vol. 23, No. 6,...

Estuaries of the South Atlantic Coast of North America Their GeographicalSignatures

Richard Dame Merryl Alber Dennis Allen Michael Mallin Clay Montague Alan LewitusAlice Chalmers Robert Gardner Craig Gilman Bjoumlrn Kjerfve Jay Pinckney Ned Smith

Estuaries Vol 23 No 6 (Dec 2000) pp 793-819

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Estuaries Vol 23 No 6 p 793-819 December 2000

Estuaries of the South Atlantic Coast of North America Their

Geographical Signatures

RICHARDDAMEMERRYL ALL EN^ MICHAEL MONTAGUE~ALBER2 DENNIS CR ALL IN^ CLAY ALAN LEWITUS~ALICE CHALMERS ROBERT CRAIG GILMAN GARDNER~ BJORN KJERFVE~ JAY PINCKNEAND NED SMITH

Coastal Carolina University Conway South Carolina 29528 UniversiQ of Georpa Athens Georgza 30602 Qaruch Marine Laboratory UniversiQ of South Carolina Georgetown South Carolina 29442 4University of North Carolina at Wilmington Wilmington North Carolina 28403 University of Florida Gainesville Florida 3261 1 Texas A ampM University College Station Texas 77843

Harbor Branch Oceanographic Institute Fort Pierce Florida 34946

ABSTRACT Estuaries of the southeastern Atlantic coastal plain are dominated by shallow meso-tidal bar-built systems interspersed with shallow sounds and both low flow coastal plain and high flow piedmont r i v e ~ e systems Three general geographical areas can be discriminated the sounds of North Carolina the alternating series of riverine and ocean dominated bar-built systems of South Carolina Georgia and northeast Florida and the subtropical bar-built estuaries of the Florida southeast coast The regional climate ranges from temperate to subtropical with sea level rise and hurricanes having a major impact on the regions estuaries because of its low and relatively flat geomorphology Primary production is highest in the central region Seagrasses are common in the northern and southern most systems while intertidal salt marshes composed of Spartina alterniJlora reach their greatest extent and productivity in South Carolina and Georgia Nuisance blooms (cyanobacteria dinoflagellates and cryptomonads) occur more frequently in the northern and extreme southern parts of the region Fishery catches are highest in the North Carolina and Florida areas Human population growth with its associated urbanization reaches a maximum in Florida and it is thought that the long-term sustainability of the Florida coast for human habitation will be lost within the next 25 years Tidal flushing appears to play an important role in mitigating anthropogenic inputs in systems of moderate to high tidal range ie the South Carolina and Georampa coasts The most pressing environmental problems for the estuaries of the southeastern Atlantic coast seem to be nutrient loading and poor land use in North Carolina and high human population density and growth in Florida The future utilization of these estuarine systems and their services will depend on the development of improved management strategies based on improved data quality

Introduction framework related to estuarine type and location The southeastern coast of the United States is a Anthropogenic influences resulting from increas-

broad coastal plain bordered with barrier islands ing human population density urbanization in- and beaches interspersed with tidal inlets and riv- dustrial development and changing agricultura~ ers After centuries of relatively low human popu- practices are then addressed Finally we synthesize lation density this highly productive area is now these characteristics into geographical signatures undergoing intense development that is rapidly for southeastern estuaries and point out important impacting the structure and function of regional informational gaps The paper as a whole seeks to estuarine ecosystems In this review we first de- provide a current overview of the status of south- scribe the location and types of estuaries in the eastern Atlantic estuaries and to serve as an infor- region Then the available published data on the mational starting point for those interested in the physical parameters ie salinity water fluxes and structure and function of these ecosystems nutrient fluxes influencing these systems are pre- Geographical and Geological Setting sented comparatively The biotic components of these estuaries are examined in a trophic dynamic The southeastern coastal plain of the United

States is divided into two relatively large geograph-

Corresponding author address Marine Science PO Box ical reaches The South Atlantic Bight (SAB) is lo-

261954 Coastal Carolina University Conway South Carolina cated between Cape Hatteras North Carolina 29528 tele 843349-2216 fax 843349-2926 e-mail (353N and 755W) and Cape Canaveral Florida damecoastaledu (284N and 806W) and the southeastern Florida

O 2000 Estuarine Research Federation 793

794 R Dame et al

coast stretches from Cape Canaveral to the Florida Keys (255ON) This trailing edge coast is distin- guished by mainland Pleistocene terraces and Pleistocene or Holocene barrier islands further seaward and a broad shallow continental shelf The ocean boundary is often demarcated by the presence of the Gulf Stream (Florida current south of Cape Canaveral) a major oceanographic current that flows northward along this area trans- porting heat materials and organisms (Fig 1)

The northern portion (the SAB) is a gently curv- ing bight of about 1000 km (along coast) A band of salt marshes intersected by networks of tidal creeks occupies low elevation areas between the mainland and the barrier islands The salt marshes attain their greatest width (approximately 12 km) at the apex of the SAB between Beaufort South Carolina and Brunswick Georgia where tides for the region reach their maximum range of 3 m Along its entire extent the SAB receives input from many rivers of piedmont and coastal plain (blackwater) origin

Two distinct estuarine areas dominate the southeastern Florida portion of the region the Indian River Lagoon and Biscayne Bay These systems are also confined to the area between the barrier islands and the mainland but instead of salt marshes mangrove wetlands predominate Indian River lagoon system including Mosquito Lagoon and Ba- nana River lagoon stretches north-south from Ponce de Leon Inlet (292N) just north of Cape Canaveral to Jupiter Inlet (26g0N) or about 248 km Biscayne Bay is bounded to the north by Dum- foundling Bay (25g0N) and to the south by Florida Bay (252N) These southeastern Florida estuaries drain the interior of the state east of the northward-flowing St Johns River and the southward- flowing river of grass through the Everglades via an extensive network of drainage canals and small streams

Without the strong and dedicated service of a cadre of scientists working within the region it would be difficult to report on the estuaries of the southeast Atlantic coast For the most part these investigators are associated with university research laboratories state and federal laboratories and specific research or protected areas (Fig 2) While Fig 2 is not an all-inclusive list it does show that there is extensive coverage of the estuarine and coastal environments across the region

Types of Estuaries

Bar-built or lagoonal systems form behind off- shore barrier sand islands and usually have small adjacent upland watersheds Tidal inlets that occur

between the barrier islands allow for the exchange of water between the estuaries and the sea In some cases the water body behind the barrier islands is extensive and referred to as a sound ie Pamlico Sound North Carolina In others where smaller expanses of water occur behind the islands the term lagoon is used (eg Mosquito Lagoon Flor- ida) Throughout the region bar-built systems with extensive marshes and minimal areas of open water are found (eg North Inlet South Carolina) Astronomical tides are the major forces controlling circulation and water height in inlets while wind or freshwater runoff is more controlling in sounds Water flow in the shallow interior portions of lagoons is often controlled by wind action Because the areas behind the barrier islands are subject to less wave action and are generally depositional environments their embayments are dominated by extensive wetlands From North Carolina to Cape Canaveral in Florida Spartina salt marshes dominate while further south mangrove swamps pre- vail Vernberg et al (1992) reported that there are more than 320 small bar-built systems (lt 60 X lo6 m2) between Cape Fear and Cape Canaveral They also calculated that the total area of these small systems in South Carolina exceeds the total combined area of the major riverine systems (eg Winyah Bay Santee Charleston Harbor and Port Royal Sound) Because these systems are smaller individually than riverine systems their surface area to volume ratio is higher than that of riverine estuaries A higher ratio suggests that these small systems may play a greater role in coastal ecological processes than previously thought because they potentially have a greater proportion of surface area over which exchanges of materials can take place

One type of estuary originates in the hilly areas of the piedmont These estuaries have extensive watersheds receive substantial freshwater discharge usually develop two-layered gravitational circulation in a longitudinally compressed saline zone may carry suspended sediment loads of clay particles and have a relatively small proportion of the watershed covered by wetlands Because high freshwater flow rates (average gt 120 m3 s-) carry high loads of suspended clay particles these systems are sometimes high flow estuaries The piedmont estuaries common to the region are the Neuse and Cape Fear River in North Carolina Winyah Bay Santee and Edisto systems in South Carolina and the Savannah and Altamaha of Geor- gia Several of these systems are composites of piedmont and coastal plain tributaries The Cape Fear River originates in the piedmont and is sup- plemented by two coastal plain streams Winyah

Southeast Atlantic US Estuaries 795

r i TIDALRANGE s A - ~ lt - -rgt~g $+ c 1 7

-7 MEAN MINIMUM

MONTHLY TEMPERATURE

Fig 1 A sea surface temperatui nage of the Southeast Coast c e United States (April 14 1996) showing the Gulf Stream Cooler waters are in blue and warmer waters are in red Numbers indicate tidal range in meters and mean monthly minimum temperature in C

796 RDame et al

ECU ( ltgtJ2--a

4 rNORTH CAROLINA -- NCSU

SOUTH CAROLINA CAPE FEAR-NERR

USC

USC-BARUCH

VUCHARLESTON SC-DNR NOAA

3 u G A - s A P E L o LMER

NERR

NERR

FLORIDA

t 4 g

i

e UMIAMI-ROSENSTIEL NOAA

Bay is a complex system where both coastal plain rivers (Sampit Black and Waccamaw) and piedmont rivers (Little Pee Dee and Great Pee Dee) mix and enter the Atlantic Ocean through the bay Also the Ogeechee estuary in Georgia originates in the piedmont but most of its flow comes from the coastal plain

The other type of riverine estuary that occurs in the region is known as a coastal plain system In this case the rivers drain watersheds entirely con- tained within the coastal plain These systems have sluggish flow rates with low and highly variable discharge occupy smaller watersheds possess a larger proportion of wetlands and generally contain a more extensive saline zone These systems are often called blackwater rivers because the high concentrations of humic and tannic acids resulting from tree roots and decaying vegetation give their waters a clear black or tea colored appearance Ex- amples of these estuaries are the New River in North Carolina the Cooper in South Carolina Ogeechee Satilla and St Marys in Georgia and the St Johns in Florida

Most of the estuaries in the continental US are impacted by human manipulation of their freshwater inflow (Dynesius and Nilsson 1994) In a survey of river fragmentation 12 of the 19 large rivers (flow gt 350 mQs1) that flow through the continental US were considered strongly impacted 6 were considered moderately impacted and 1 (the Pascagoula) was considered unimpacted by channel fragmentation and flow regulation (Dynesius and Nilsson 1994) The survey considered four rivers in the southeast Two of these the Santee and the Savannah were classified as strongly impacted with 5 dams in each system The Pee Dee ampth 4 dams and the Altamaha with 3 were each classified as moderately impacted The region also includes some of the few remaining unimpounded rivers in the country and many of the smaller


coastal plain rivers (eg Waccamaw Edisto Ogee- chee Satilla) are free-flowing (Table 1)

In addition to the presence of dams and diver- sions freshwater in the form of both groundwater and surface water is withdrawn from the watersheds of all of the rivers in the region For example coastal Georgia has long been dependent on groundwater from the Upper Floridian Aquifer which underlies all of Florida coastal Georgia and parts of eastern Alabama However of the gquifer are subject to saltwater intrusion (eg Brunswick Savannah Hilton Head Island) (Clarke et al 1990) In 1997 the Georgia Environmental Protection Division imposed upper limits on groundwater use in several coastal counties and in some cases set goals for reductions in groundwater withdrawal (Environmental Protection Division 1997)

Traditionally the water cycle has been presented as water flowing from the land to the sea via rivers and estuaries Recent evidence from groundwater studies that examined the concentrations of the radioactive isotope a in the SAB region (Moore 1996) generate estimates of groundwater fluxes to the coastal ocean that are comparable to those of the regions rivers The magnitude of these fluxes has a number of implications (Church 1996) First our current estimates of the chemical mass balance in coastal waters may be radically altered Second as noted above increasing human population den- sities in the coastal zone are making ever greater demands on the coastal aquifers and this results in larger interaction between saline and freshwater aquifers Further increasing sea level and the con- sequential need to maintain navigational channels at even greater depths are also likely to enhance this interaction As the coastal human population continues to grow this means that any new or ex- panded water use in the region will require an al- ternative water source In other words future development along the coast will likely be coupled to surface water withdrawal Several studies are now underway to understand how increased surface water withdrawal will impact the regions estuaries

Fig 2 Distribution of estuarine data sources along the southeastern Atlantic coast KEY ECU = East Carolina U n i v e r s i ~ NEP = an Environmental Protection Agencys National Estuary Program site DUKE = Duke University Marine Laboratory NMFS = National Marine Fisheries Service UNC = University of North Carolina NCSU = North Carolina State U n i v e r s i ~ UNC-W = University of North Carolina at Wilmington NERR = National Oceanic and Atmospheric Administrations National Estuarine Research Reserve CCU = Coastal Carolina University USC = University of South Carolina BARUCH = Baruch Marine Field Laboratory UCHrUUES TON = University of CharlestonCollege of Charleston SC-DNR = South Carolina Dilsion of Natural Resources Laboratory N O M = National Oceanic and Atmospheric Administration SKIDAWAY = Skidaway Institute of Oceanography UC4-SAPELO = University of Georgia Marine Laboratory at Sapelo Island LMER = a National Science Foundations Land-Margin Ecosystem Research LTER = Long Term Ecological Research site JU = Jacksonrille University UFL-MHITNEY = University of Florida-Uitney Marine Lab- oratory FIT = Florida Institute of Technology HARBOR BRANCH = Harbor Branch Institute of Oceanography UMIAMI-ROSEN- STIEL = University of Miami-Rosenstiel School of Marine and Atmospheric Sciences

798 R Dame et al

TiZBLE 1 Physical and hydrologic characteristics of southeastern Atlantic coast riverine estuaries NC = North Carolina A = lirginia SC = South Carolina GA = Georgia and FL = Florida

State

Albemarle SoundChowanRoanoake Rivers NC VA PamlicoPungo Rivers NC A Neuse River N( Cape Fear River NC Winpah BapPee DeeBlack Rivers SC NorthSouth Santee Rivers SC Charleston HarborVandoCooperAshley Rivers SC St Helena SoundS EdistoCoosaw Rivers SC Savannah River SC GA Ossabaw SoundOgeechee River GA Altamaha River GA St hdrewSt Simons SoundsSatilla River CTA St Marys RiverCumberland Sound GA St Johns River FL Indian River FL Biscavne Bay FL

Coastal Assessment and Data Smthesis System 1999

Understanding the impacts of freshwater input to estuaries and the resulting changes in salinity regimes may be one of the most important chal- lenges facing coastal scientists and managers Salin- ity is a primary indicator of estuarine circulation because of its conservative character it is also a significant determiner of biological productivity faunal distributions and habitat structure Orlan- do et al (1994) synthesized salinity data from 15 estuaries in North Carolina South Carolina and Georgia by characterizing salinity structure and spatial and temporal variability A very abbreviated summary of Orlando et al (1994) findings are pro- vided in Table 2 Three Georgia estuaries the Al- tamaha Satilla and Ogeechee Rivers are among the most variable in salinity River input of freshwater is the primary causative agent of salinity variability in these estuaries Contrastingly Albemarle Sound Charleston Harbor and the Broad River are among the most stable The latter two systems are shallow coastal plain estuaries with minimal freshwater input while one of the two rivers that drains into Albemarle Sound is heavily regulated by dams

The major materials of carbon nitrogen and phosphorus are rapidly translocated transformed and remineralized within estuarine ecosystems Abiotic factors including river flow tides and wind- generated waves and currents are major components in translocating materials Primary production and consumer feeding and metabolism generate both particulate and dissolved materials that

Dralnagr k r a (km) Estuarinr Znnrs (km) Avrr- R V E ~ t u a r r age h l u r n r Intlcw Tidal

T ~ d a l Sea- Area Depth (rn (m Range Fstuarlne Fluial Fresh Mix~ng water (km2) (rn) X 10) s I ) (tn)

influence estuarine nutrient cycles (Dame and Al- len 1996) In general estuaries are large filters or traps (Biggs and Howell 1984) for materials that can be transformed by resident processes

Because of the high productivity of southeastern estuaries there have been extensive investigations into the fate of materials produced in these systems In riverine estuaries transport of dissolved and particulate materials is generally seaward due to the net flux of water down slope due to gravity Estimates of physical and hydrological parameters for a number of southeastern coastal plain and piedmont riverine estuaries are given in Table 1 The average annual water discharge data clearly distinguishes the two types

To estimate the amount of nutrients being loaded into southeastern riverine estuaries data on dissolved inorganic nutrient concentrations were compiled from water quality surface sampling stations in 8 of the major riverine systems in the SAB Water quality data were obtained from EarthInfo (1997) and daily discharge data were obtained from the United States Geological Service (USGS) web site (waterUSGSgov) Only those rivers with systematic sampling programs and consistent analysis protocols were included in this analysis Sta- tions chosen were located the furthest downstream in each system In most cases dissolved inorganic nitrogen (NH NO+NO) records ranged from 1979 through 1994 and dissolved orthophosphate (PO) records covered from 1981 through 1994

When examined on a quarterly basis concentrations of ammonium and nitrate plus nitrite did not vary greatly over the course of the year (Fig 3ab) However maximum concentrations were observed


TABLE 2 The character of salinity structure and variability in southeastern Atlantic coast estuaries Data from Orlando et al (1994) Salinity variability Very Low = lt2c Low = 3 4 Medium 6-10~ High = 11-20

Estoar Dolnlnant Trrnporal Scalr lechin~srn(s) b r ~ a h i l ~ r v

UbemarlePamlico Sounds North Carolina Months-Years Tides winds Bogue Sound (Beaufort North Carolina) Hours-Years Freshwater Tides New River North Carolina Hours-Years Freshwater Tides Cape Fear River North Carolina Hours-Years Freshwater Tides LVinyah BavNorth Inlet South Carolina Hours-Years Freshwater Tides Sorth and South Santee Rivers South Carolina Hours-Years Freshwater Tides Charleston Harbor South Carolina Hours-Years Episodic Freshwater Tides St Helena Sound South Carolina Hours-Years Freshwater Tides Broad River South Carolina Hours-Years Freshwater Tides Savannah River Georgia Hours-Years Freshwater Tides Ossabaw SoundOgeechee River Georgia Hours-Years Freshwater Tides St CatherinesSapelo SoundsSatilla River Gec ~rgia Hours-Years Freshwater Tides Altamaha River Georgia Hours-Years Freshwater Tides St kndrewsSt Simons Sounds Georgia Hours-Years Freshwater Tides St Marys RiverCumberland Sound Georgia Hours-Years Freshwater Tides

Low-Medium Medium-High Medium-High Medium Medium Medium

Winds Very Low-Low LowMedium Low LowRledium Medium-High Medium Medium-High High Low-Medium

during the spring quarter (April-June) Ortho-phosphate concentrations were more variable (Fig 3c) These were highest during the summer months (July-September) and lowest during late winter (January-March)

Average annual nutrient concentrations (Fig 4) were multiplied by average annual discharge or freshwater inflow (Fig 5) to obtain an estimate of the loads of dissolved inorganic nutrients in each river (Fig 6) It should be noted that these loads reflect what enters the upper end of the estuaries and not what is loaded to the coastal ocean Many of these systems have extensive estuarine areas with additional nutrient sources located down-stream of the riverine USGS sampling stations (ie point-source discharges and tidal and non-tidal creeks draining areas of significant human usage) Moreover the amount of time river water spends in the estuary before being discharged to the coastal ocean will influence the amount of material processing that occurs within the estuary For example in the Richmond River estuary in Australia Eyre and Twigg (1997) found that flushing times controlled whether nutrients were internally processed or discharged to the shelf In a study of flushing times in the Georgia riverine estuaries Al- ber and Sheldon (1999) found that median annual flushing times ranged from 6 d in the Savannah to 72 d in the St Marys but that there was consid- erable interannual and intra-annual variability in these estimates The highest inorganic nutrient inputs enter into the estuaries of the Cape Fear Pee Dee and Savannah Rivers The Pee Dee and Sa- vannah are the two largest systems considered with large fluvial drainage basins that likely contribute nutrients in the form of fertilizer runoff The Cape Fear although a relatively large river has about half of the fluvial drainage area and a lower river

discharge rate than the Pee Dee and Savannah However the highest concentrations of all nutrients were reported in the Cape Fear River which averaged 080 mg lkl N and 011 mg lP1 P as compared to an average of 027 mg lP N and 005 mg 1 - I P in the remaining 7 rivers The Cape Fear Riv- er basin contains more than one-quarter of North Carolinas population and is the most industrial- ized river basin in the state (641 National Pollution Discharge Evaluation System monitored discharges) Agricultural nutrient sources are also abundant with approximately 24 of the land usage devoted to agricultural operations (North Carolina Division of Water Quality 1996) The basin also contains over five million head of swine (North Carolina Division of Water Quality 1996) mainly in concentrated animal operations (CAOs) that have only primitive animal waste treatment facili- ties (Mallin 2000)

Recently Alberts and Takacs (1999) did a similar compilation of USGS water quality data to estimate dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) loads into southeastern US estuaries They had data from the same rivers used above for inorganic nutrients with the excep- tion of the Cape Fear and the addition of the Al- tamaha DOC concentrations were higher in rivers that originate in the Coastal Plain (average concentrations in the Satilla and St Marys Rivers were 191 and 279 mg C lP1 respectively) than in those that originate in the Piedmont (average concentrations in the Altamaha and Pee Dee were 85 and 59 mg C I- respectively) DON concentrations followed similar patterns with average concentrations of 075 and 066 mg N 1- in the Satilla and St Marys Rivers respectively and 035 and 046 mg N 1- in the Altamaha and Pee Dee respectively Although bulk DOC measures generally indicate

800 R Dame et al

NH Concentrat ion NH Concentration

O 2

NO + NO Concentration

NO + NO Concentrat ion

0 PO Concentration

010

Jan-Mar Apr-Jun Jul-Sep Oct-Dec

Fig 4 Average quarterly nutrient concentrations (with SE) for selected coastal plain and piedmont estuaries on the southeast Atlantic coast

PO Concentrat ion simple conservative mixing of freshwater dissolved organic material (DOM) through estuaries the use of fluorescence signals to trace terrestrial DOM within the Georgia estuaries suggests a highly dy-

Discharge 400

7

Fig 3 Average annual concentration (with SE) of inorganic nutrients in selected coastal plain and piedmont estuaries on the southeast Atlantic coast

Fig 5 Average discharge of selected coastal plain and piedmont estuaries on the southeast Atlantic coast

1000 NH L o a d

NO + NO Load

PO Load


slowly settling material which are likely transported out of the estuary with the net residual flow Meade (1972) argued that most of the fine-grained sediments that reach the Atlantic Continental Shelf are actually transported back into the estuaries This contention is supported by an observed rapid decrease in the concentration of inorganic material between the inner and outer shelf which suggests that river sediment is not being moved seaward (Manheim et al 1970) and evidence for net landward transport of fine material (Meade 1969 Windom et al 1971 Mulholland and Olsen 1992) Meade (1972 1982) further suggested that coastal marshes are important traps for fine- grained sediment along the Atlantic coast of North America This is supported by the observation that marsh elevations are generally keeping up with the relative rate of sea level rise (Vogel et al 1996) which suggests they are sites of net deposition However material that is deposited in marshes may undergo a much longer period of net deposition and resuspension in exchange with tidal creeks (Chalmers et al 1985) before it is eventually buried (Stevenson et al 1986 1988)

In a recent study of carbon exchange between the Georgia riverine estuaries and the extensive intertidal marshes that border these systems Cai et

800 0al (1999) noted that CO concentrations mea-

Fig 6 Average nutrient loads in metric tons (with SE) for selected coastal plain and piedmont estuaries on the southeast Atlantic coast A ammonium B nitrate + nitrite C ortho-phosphate

namic picture of the DOM pool with inputs from freshwater sources intertidal marsh sources and even marine sources for some systems (Moran personal communication)

The concentrations of particulate material in an estuary can range widely For example observed concentrations of suspended sediment in Georgia estuaries ranges from 8-200 mg 1-I depending upon sampling depth tidal stage and current speed (Georgia Rivers Long Term Ecological Re- search [GARLMER] data) In the Ogeechee River Estuary Alber (2000) demonstrated that the biological constituents of the suspended sediment were preferentially associated with fine-grained

sured in estuarine waters could not be explained by respiration within the estuarine water column itself They demonstrated that CO and HCO are produced in the marsh and then funneled into the estuarine water by tidal action Interestingly the outwelling of organic matter to the estuaries was minor in comparison to the release of inorganic carbon Their data show that in a brackish water marsh in the Satilla River Estuarv nitrate that is brought to the marsh via estuarine water is removed most likely via denitrification (Cai et al in press)

Bar-built and lagoonal systems usually lack significant river flow and have extensive vascular plant subsystems (Kjerfve 1989) In these systems the transport of particulate material is typically gov- erned by the flux of tidal waters In the Duplin River Georgia (Chalmers et al 1985) and North Inlet South Carolina (Dame et al 1986) the tidal-

velodity asymmetry also known as ebb dominance leads to the seawird transport of suspended ma terials (Ward 1981 Kjerfve 1989) In some systems particulate materials may be imported probably as a result of ~assive and active filtration bv subsvs- tems ie salt marshes oyster reefs etc (Dame et al 1989) In an effort to explain this diversity of material transport Dame e t al (1992) propdsed the geohydrologic continuum theory of marsh-estuarine ecosystem development In this theory ma-

802 R Dame et al

ture components are at the ocean-estuary interface and export particulate and dissolved materials Young or immature subsystems are at the land-estuary interface and import particulate and dissolved materials Intermediate systems are mid-aged and import particulate materials and export dissolved materials Some bar-built estuaries mav have all three developmental stages or subsystems eg North Inlet (Dame et al 1992) while others may only have one or two subsystems In lagoonal systems many materials are processed and re-tained by the estuary so that only some substances are transported to the adjacent sea Which materials are processed retained or transported depends on the specific subsystem Tidal marshes for example function as giant filters or traps removing and processing large quantities of suspended particulate and dissolved materials from tidal waters and releasing other materials into ebbing tides or during rain events at low tide (Chalmers et al 1985 Dame 1989) This high retention efficiency is well documented in North Inlet where more nitrogen and phosphorus are recycled within the marsh than are transported to or from the adjacent water column (Dame et al 1991) In contrast Northern Indian River Lagoon has little opportu- nity for export because there is little tidal flux or river input (Montague and Odum 1997)

As sea level rises the active and passive retention of materials by salt marshes is imbortant in main- taining the size and elevation of the major estuarine subsystems Vogel et al (1996) have calculated that the amount oflinorganic sediments exported by South Carolina riverine systems is about equal to the amount of this material necessary for salt marsh elevation to keep pace with sea level rise

In an effort to develop regional nitrogen budgets and riverine nitrogen and phosphorus fluxes for drainages to the North Atlantic Ocean Ho- warth et al (1996) estimated discharge and material exports for the southeastern Atlantic coast To- tal phosphorus fluxes were estimated to be 0011 Tg and total nitrogen was 024 Tg yr-lor about 32 and 676 kg km- yr- respectively Our loading estimates (Fig 3) were not for the whole region (we only used rivers with consistent water quality records) and only took into account dissolved inorganic nutrients They are therefore much less than the totals reported in Howarth et al (1996) It should be noted that both of these estimates are for material reaching the head of the estuaries only and so do not take into account either addi- tions or subtractions that may take place as the water moves to the coastal ocean They do not account for potential inputs from lagoonal systems with little or no river flow which dominate the southeastern Atlantic coast At present it is unclear

whether these systems represent net sources or sinks of nutrients to coastal water Finally groundwater flow needs to be taken into account because it can be an additional direct source of nutrients to the nearshore (Moore 1996)

Vogel et al (1996) computed a first approxi- mation of the relative contribution of tidal water exchange by bar-built and lagoonal systems and discharge by riverine systems in South Carolina They estimated that tidal water exchange was over an order of magnitude higher than river discharge and that nutrient exports by bar-built systems were at least an order of magnitude greater than riverine delivery to the coastal ocean If the Howarth et al (1996) estimates for the southeast Atlantic coast are increased an order of magnitude then this region would be more comparable to the Mis- sissippi Basin of the Gulf Coast in material fluxes and water discharges

Climate The climate of the southeastern coast is Carolin-

ian temperate from Cape Hatteras to north Florida and transitional to subtropical from there to Bis- c a p e Bay Water temperatures in shallow estuaries lagoons and sounds often exceed 30degC during July and August and can drop to less than 10degC at the northern extremes of the region during February Seasonality is well defined in the Carolinas and Georgia Along the south Florida coast there is a pronounced wet period between May and October and a dry period from November to April The wet-dry season periodicity in south Florida results in an alternation between brackish and hypersaline conditions in many parts of the Indian River La- goon

The entire region is vulnerable to tropical storms hurricanes and tornadoes Occasionally tropical storms cross the Gulf Stream and make landfall in the region During the past century Florida has been the most hurricane-prone state in the US with 57 strikes (including 24 category 3 or greater) making landfall (National Oceanic and Atmospheric Administration 1997) In the last decade hurricanes Hugo (1989) near Charleston South Carolina Andrew near Miami Florida (1992) and Bertha and Fran (1996) Bonnie (1998) and Dennis and Floyd (1999) near Wil-mington North Carolina struck the southeast coast These storms brought significant winds waves flooding erosion and associated damage to maritime forests and property High river dis-charge associated with rainfall rerouting of human sewage because of power outages and extensive animal waste pollution from industrial hog farms

in river floodplains combined to produce severe anoxiahypoxia for weeks following these events (Van Dolah and Anderson 1991 Mallin et al 1999 Mallin 2000)

Within estuaries hurricanes have been shown to build washover fans on barrier islands form new tidal inlets by cutting barrier islands move large quantities of sediments both into and out of estuarine areas destroy forest alter adjacent watersheds and dramatically modify estuarine circulation due to extensive water runoff from rain and storm surges The impact of a given storm depends on its size location speed the state of the tide shoreline configuration and slope of the adjacent continental shelf (Hayes 1978) Besides these factors the water quality-damage associated with hurricanes depends on the amount and type of flood- plain development and whether the hurricane impacts well-flushed systems or poorly-flushed rivers and estuaries (Mallin et al 1999)

For example in 1989 the eye of Hurricane Hugo struck-the South Carolina coastjust north of Charleston Harbor estuary and about 75 km south of Winyah Bay and North Inlet estuaries This Cat- egory 4 storm with sustained winds of 39 m s- (140 km h-I) and a central pressure of 935 mbars moved onto the coast at a velocitv of 12 m s- at high tide resulting in massive property damage along the coast (Gardner et al 1992) In Charles- ton County where there were wind gusts over 200 km h-I and a storm surge of up to 9 m above sea level Tissue et al (1994) reported that the storm not only resuspended and winnowed sediments and eroded channel banks but also scoured and exported older deposits in large quantities At North Inlet the geomorphology of the landscape and the estuary showed little change although several small new washover fans were formed on the adjacent barrier islands The nearby maritime forest however experienced extensive wind damage tree mortality and loss of terrestrial animals in the surge-affected forest immediately after the storm Major changes in the age structure of the forest and related ecological functions due to this hurricane will be recognized for decades (Gardner et al 1992)

Inter-annual global climate changes also affect the southeastern Atlantic coast of North America The best know of these cycles is the El Niiio-South- ern Oscillation (ENSO) climate event El Niiio and La Niiia are terms used to denote opposite phases of this cycle This climatic cycle occurs every 2 to 7 yr and generally begins in October and ends in March (Ropelewski and Halpert 1986) Individual ENS0 events are quite variable in North America


and this variability has been attributed to differences in Eastern Pacific sea surface temperatures and internal atmospheric processes in North America The latter is thought to account for a majority of the variability in the southeastern US (Hoerling and Kumar 1997) ENS0 events are thought to influence the southeastern Atlantic coast in a number of ways First during El Niiio years winter temperatures are cooler and precipitation may exceed normal values by 3 cm or more (Ropelewski and Halpert 1986 Philander 1990 Hanson and Maul 1991) Although higher than normal freshwater discharge to southeastern estuaries with a higher groundwater table should be expected during these events these features are only statistically observed from the northeastern coast of South Carolina to Florida (Kuhnel et al 1990) Second hurricane frequency in the Atlantic is usually reduced during El Niiio years and that implies fewer storm impacts along the southeast coast During the La Niiia phase the southeastern Atlantic coast experiences warmer winter temperatures with drier conditions when compared to average years A recent synthesis by Sun and Furbish (1997) found that El Niiio and La Niiia are re- sponsible for up to 40 of the annual precipitation variation and up to 30 of the river variations in Florida During the recent 1997-1998 El Niiio few Atlantic hurricanes were observed and rainfall was heavy throughout the region from December through March Florida and the coastal zone of the Carolinas received over 200 of normal precipitation for this period while inland areas received 150 of normal precipitation In North Inlet a normally euhaline estuary the increased rainfall depressed salinities below 20 psu for over 3 mo and below 10 psu for one extended period setting a 20-yr record

Sea level is another indicator of global climate change both on seasonal and annual time scales Mean sea level varies seasonally due to changes in surface pressure (inverse barometer effect) and steric variations largely the result of heating of estuarine and shallow shelf waters during the summer months and cooling during winter months (Patullo et al 1955) Measurements of water level at North Inlet South Carolina indicate that sea level in mid-September on average is 025 m higher than mean sea level in February (Kjerfve et al 1978)As a result complete flooding of salt marshes occurs most commonly during high tides in Sep- tember Similarly water level in Indian River is 027 m higher in October than in most of the rest of the year This results in a high tide level in winter that is lower than the low tide level in October

804 R Dame et al

Long-term water level measurements at Charles- ton South Carolina and calculations of mean sea level there indicate that relative sea level has increased 025 m since 1922 (33 mm yr-) both as a result of eustatic sea level rise (50) and coastal land subsidence (50) Recent analyses of cores using the lead910 technique at North Inlet South Carolina show a rate of sea level rise of about 32 mm yr- (Vogel et al 1996) or about the same rate as the Charleston data Water level records (1913 to present) at Key West show an average rise of 17 mm yr-l almost entirely the result of eustatic sea level rise There is little doubt that sea level is ris- ing along the southeastern Atlantic coast and it will gradually force the transgression of the barrier islands and estuaries of the region upslope along the coastal plain (Dame et al 1992) These are the same areas where human population density is rapidly increasing with associated increases in build- ings and infrastructure Eventually sea level rise and human development will compete for the same coastal landscape but before that significant damage due to storms will likely increase

Primary Producers Primary production is relatively high in south-

eastern estuaries and is partitioned amongst a va- riety of plant and algal communities A predominant contribution by vascular plants is suggested by their vast aerial coverage over much of the southeastern coast especially in South Carolina and Georgia Compared to more northern tem-perate estuaries the relative expansiveness of marsh area and high vascular plant productivity in South Carolina and Georgia has been attributed to characteristically high tidal amplitude low tidal energy the prevalence of barrier islands high solar input a lower seasonal temperature differential and the absence of snow cover or ice rafting influence (Turner 1976 Haines and Dunn 1985) Mea- surements of macrophytic primary productivity have generally exceeded algal-based estimates in those southeastern estuaries studied (see Total Pri- mary Production section below) but too few systems have been adequately examined to draw strong general conclusions Although in North Carolina and Florida estuaries research efforts tar- geting phytoplankton production are somewhat equitable with those examining vascular plant production our understanding of the relative importance of these groups in South Carolina and Geor- gia estuaries suffers from a dearth of information on phytoplankton community production (Bricker et al 1999) Studies on benthic microalgal production are even scarcer but recently have drawn at- tention as potentially significant sources of fixed carbon (eg Pinckney and Zingmark 1993a Sig-

mon and Cahoon 1997 Cahoon et al 1999) Even less is known about the relative activity of macroalgae traditionally considered insignificant to over- all estuarine production but more recently recognized as seasonally important primary producers in some systems (see below) Generally there are no submerged seagrasses in South Carolina and Georgia because of restricted light penetration

Microalgal communities from the southeastern area can be broadly classified as phytoplankton or benthic microalgae (which includes periphyton and edaphic algae) Tidal flushing and wind events in shallow waters may result in benthic microalga resuspension effectively mixing the two commi- nities- While several estuaries hampe been well-studied there remain many systems in which little or nothing is known about the microalgae Species composition and community dynamics vary between estuaries and are dependent on salinity distribution turbidity light -penetration nutrient loading and mixing characteristics Phytoplankton biomass rarely exceeds 50 mg chl a m- but extensive phytoplankton blooms do occur in 2ome systems particularly in North Carolina and Florida (Mallin 1994 National Oceanic and Atmospheric Administration 1996) Although nitrogen is the macro-nutrient most common$ limiting to phytoplankton population growth in southeastern estuaries limitation by silicate or phosphorus has also been reported particularly in the more southern regions ltsouth of Cape ~ o m a i n National Oceanic and Atmospheric Administration 1996) Light can also be an important limiting factor and may be a more influential regulatory factor than nutrients in shallow and very turbid South Carolina and Geor- gia salt marsh estuaries (Pomeroy et al 1981 Vern- berg 1993 Lewitus et al 2000) Microzooplankton grazing and iron have been also been suggested as limiting factors in certain South Carolina salt marsh estuaries (Kawaguchi et al 1997 Lewitus et al 1998)

In ~ o r t h Carolina phytoplankton production and abundance typically exhibit peaks in the March-May and July-September periods (Carpen- ter 1971 Thayer 1971 Mallin 1994) However pe- riodic winter blooms of estuarine dinoflagellates and cryptomonads linked to nitrate loading puls- es occur in some estuaries in North Carolina (Mal- lin 1994 Mallin and Paerl 1994 Pinckney et al 1998) Diatoms generally dominate the spring bloom phytoplankton communities in North Car- olina (Dardeau et al 1992 Mallin 1994 Tester et al 1995) but dinoflagellates and cryptophytes can also be prevalent during all seasons and can dominate during the summer (Mallin 1994) Although


TABLE 3 Phytoplankton primary production in southeastern Atlantic estuaries

Pnrnal-1 Production Estuarv (g C nir ur-I)

Pamlico North Carolina 288-300 Neuse North Carolina 280-370 Beaufort horth Carolina 52-68 Murrells Inlet South Carolina 76 North Inlet South Carolina 100-355 Sapelo Island Georgia 190-375 Indian River Florida 328-441 Bisca)ne Bay Florida 13-46

phytoplankton dynamics in South Carolina and Georgia estuaries have been evaluated for only a few systems (Table 3) some distinctions from ~ o r t h Carolina estuaries are suggested below However because several North Carolina estuaries are moderately-to-highly eutrophic as a result of anthropogenic practices (Bricker et al 1999) it is difficult to sort differences due to anthropogenic influences from those due to geography Nutrient loading may be a much more influential driving force for regulating phytoplankton dynamics in North Carolina especially in poorly flushed areas than in the South Carolina and Georgia systems that are weakly-to-moderately eutrophic and typically well-flushed In this respect the prevalence of high dinoflagellate and cryptophyte populations intermittently throughout the year in North Car- olina estuaries may result largely from the influence of weather-driven loading of anthropogeni- callv-derived nutrients

In those South Carolina and Georgia estuaries studied diatoms were the predominant contribu- tors to phytoplankton biomass during much of the year (Marshall 1985 Verity et al 1993 Lewitus et al 1998) However during the summer bloom the relative contribution of phytoflagellates ap-proached that of diatoms and in terms of abundance the phototrophic nanoflagellates (several groups such as chrysophytes prasinophytes prym- nesiophytes cryptophytes and dinoflagellates) and picoplankton (primarily coccoid cyanobacteria such as Synechococcus spp) can exceed that of diatoms Lewitus et al (1998) found that microplank- tonic diatom abundance in North Inlet estuarv decreased from spring to summer while phototrophic nanoplankton increased suggesting that the bloom formed as a result of an increasing standing stock of the latter group The bloom was characterized by a microbial ioop structure similar to summer bloom communi6es in more northern temperate estuaries such as Chesapeake Bay Phy- toplankton population growth was not limited by nitrogen but rather controlled by microzooplankton grazing In comparison to more northern tem-

Source

Mallin (1994) Mallin (1994) Thayer et al (1975) Lewitus unpublished data Pinckney and Zingmark (1993) Lewitus unpublished data Pomeroy et al (1981) Jensen and Gibson (1986) Roman et al (1983)

perate estuaries the relative predominance of summer phytoflagellate-dominated bloom communi-ties with microbial loop dynamics and microzoo- planktonic grazing control may be a result of the shorter springprolonged summer characterizing the lower latitudes which favors the regeneration of N-nutrients such as NH and DON bacterial production the growth of flagellates over diatoms and grazing activity of microzooplankton over ma- crozooplankton (Glibert et al 1982 Sherr et al 1986 1992 Keller et al 1999 Lomas and Glibert 1999)

Benthic microalgae are found on tidal flats the surface of salt marshes and subtidal areas Their biomass may be as high as 250 mg chl a m- in the upper 5 cm of sediment but typically ranges from 10 to 100 mg chl a m- depending on sediment type and depth of overlying water (Pinckney and Zingmark 1993b Sigmon and Cahoon 1997 Ca- hoon et al 1999) A study of five salt marsh habitats (Pinckney and Zingmark 1993b) found the highest benthic algal biomass in sediments within Spartina habitats and on intertidal mudflats and lowest biomass in shallow subtidal areas In a broad scale study that included the subtidal and intertidal areas of eight North Carolina estuaries Cahoon et al (1999) found a negative relationship between the proportion of fine sediments and benthic microalgal biomass

Annual benthic microalgae production ranges from about 50 to over 200 g C m- (Pomeroy 1959 Pinckney and Zingmark 1993a) In North Inlet South Carolina combined microalgal productivity can be as high as 50 of the total macrophyte primary production (Pinckney and Zingmark 1993a) Additional primary production can be attributed to epiphytic microalgae The production of epiphytic microalgae in southeastern estuaries is highly variable and species-specific (Coleman and Burk- holder 1994) but can range from 20 to 200 of that of host seagrasses or marsh macrophytes (Pen- hale 1977 Mallin et al 1992)

806 R Dame et al

TABLE 4 Distribution of salt marshes along the southeastern Atlantic coast

Area (ha)

State 5finrlzrcn lunruc

North Carolina South Carolina Georgia Florida

42923 112766 121335 10536

40712 36882 30337 28304

Increasing anthropogenic nutrient inputs from a rapidly growing human population in the coastal zone industrial and municipal effluents changing land-use practices and atmospheric nitrogen deposition are rapidly exceeding the processing ability of impacted systems (Paerl 1997) Symptoms of eutrophication (nuisance and toxic algal blooms hypoxiaanoxia fish and shellfish mortality) have been documented in nearly half of major southeastern estuaries (Bricker et al 1999) Harmful algal blooms such as red tides or brown tides occur infrequently in most southeastern Atlantic coastal systems outbreaks of red tides caused by Gymno- dinium breve are more common along the southern portion of the area however in 1987 one was car- ried by the Gulf Stream as far north as Onslow Bay in North Carolina (Tester et al 1991) Cyanobac- terial (blue-green algal) and dinoflagellate blooms have resulted in significant ecological and economic damage in some rivers and estuaries of North Carolina and Florida In the late 1980s a group of toxic dinoflagellate species were found in several North Carolina estuaries (Burkholder et al 1992) One recognized species in this group qesteria pis-cicida has been identified as the causative agent of approximately 50 of the fish kills in the Pamlico Neuse and New River estuaries of North Carolina in the past decade (Burkholder and Glasgow 1997 Burkholder et al 1995 Burkholder 1998) A second less virulent toxic PJiestena species has also been cultured identified and tested for toxicity from waters of this region (Burkholder and Glas- gow 1997) Both species have also been found in sub-estuaries of the Chesapeake Bay (Lewitus et al 1995)

Reports of harmful algal blooms in South Car- olina and Georgia estuaries are rare To our knowl- edge Pomeroy et als (1956 1972) report of a dinoflagellate bloom (Kryptoperidinium sp) in the Sa- pel0 Island salt marsh estuary is the only potential harmful algal bloom documented in Georgia estuarine waters The first reported red tide localized to a South Carolina estuary occurred in Spring 1998 when a new species of dinoflagellate (Smpps- iella carolinium Morton personal communication) formed a bloom in Bulls Bay McClellanville (Lew-

Total Source

83633 Critcher 1967 149648 Alexander et al 1986 151672 Alexander et al 1986 Eleuterius 1976 38840 Eleuterius 1976

itus et al in press) This same species formed red tides in several sites in spring 1999 ranging from North Inlet to Hilton Head Island estuaries over 100 miles apart Although the environmental factors promoting harmful algal blooms are not well- understood and events are unpredictable and vary with species the relative lack of harmful algal blooms in the estuaries of South Carolina and Georgia may relate to the high tidal flushing short water residence time and low anthropogenic nutrient loading that characterize these systems The recent recurrent (1998-1999) and widespread appearance of the Scrippsiella red tide in South Car- olina is worrisome and it is unknown whether its origin was related to natural events or anthropogenic influence In contrast high nutrient loading and long water residence times characterize the sites where qestena-induced fish kills tend to occur (Burkholder et al 1995 Burkholder and Glasgow 1997) Tidal flushing and short water residence times in many southeastern systems may minimize the occurrence of both toxic and nuisance phytoplankton blooms In order to prevent or control harmful algal blooms in the region the development of ecologically sound and economically fea- sible watershed-based nutrient management strategies must be addressed in the coming years

The southeastern Atlantic coast of the US has been characterized as inhospitable to macroalgae (seaweeds) and without its own flora (Humm 1969 Coutinho 1987) For example in Georgia and South Carolina estuaries macroalgae is primarily found in shallow creeks during the winter months when turbidity levels are low The typical distribution of macroalgae in estuaries is that of marine species colonizing most of the length of the estuary with freshwater species predominating only near the head (Wilkinson 1980) In North Inlet South Carolina the highest numbers of macroalgal species were found in winter with peak reproductive activity occurring during the spring (Coutinho 1987) The area averaged annual net primary production of macroalgae in North Inlet is 197 g C m- (Coutinho 1987) The magnitude of macroal-


TABLE 5 Vascular plant and rnacroalgal primary production for several estuaries along the southeastern Atlantic coast

Estual-u Form

Beaufort North Carolina seagrass horth Inlet South Carolina marsh grass

rnacroalgal Sapelo Island Georgia rnarsh grass

Indian River Florida seagrass Biscalne Bav Florida seagrass

gae production is usually low relative to vascular plant production in the area (Table 4)

Vascular plants common to estuaries along the southeastern Atlantic coast include salt marshes sea grasses and mangroves The intertidal salt marsh grass Spartina alterniJirora is the dominant species in most estuaries from North Carolina through Georgia (Table 4) In north Florida Jun-cus marshes tend to dominate at higher intertidal elevations Salt marshes reach their greatest extent in Georgia and South Carolina South of Daytona Beach the black mangrove Avicennia germinans in the intertidal zone gradually replaces S alterniJire ra Spartina alternzJirora is the most common salt marsh plant with distinctive height forms depending on location in the marsh The dominant vegetation shifts as salinity changes from salt to freshwater (Odum et al 1984) Spartina alterniJirora S qnosuroides and Juncus roemamianus are important in brackish water and Zizaniopsis milacea Zizanaia aquatica Pontedma cordat Scirpus validus Eleochans albida Peltandra virgznicus and Typha dominogensis occur in tidal freshwater marshes (Gallagher and Reimold 1973 Schubauer and Hopkinson 1984) Hefner et al (1994) recently reported that there was almost no salt marsh wetland loss along the southeastern Atlantic coast in the 1970s to 1980s

Annual net primary production of S alterniJirora (above + belowground) ranges from 01 to over 25 kg C m- in short form stands and 08 to 21 kg C m- for stands of the tall form (Dame 1989 Montague and Wiegert 1990 Dai and Wiegert 1996) Highest values are in South Carolina and Georgia with low values in North Carolina and Florida (Table 5)

In south Florida Rhizophora mangle red man-grove is the most typical mangrove plant particularly in areas heavily influenced by seawater The structure of mangrove swamps is usually attributed to topography substrate tidal action and freshwater hydrology (see Lugo and Snedaker 1974) Moving up riverine systems into lower salinities and higher intertidal elevations other vascular

Pnmal-y Production (g C m- yr- ) Source

134-700 Thayer et al 1975 Penhale 1977 800-2100 Darne 1989 Coutinho 1987

197 815-2000 Pornery et al 1981 749-1421 Dai and biegert 1996

159 Jensen and Gibson 1986 520-2000 Rornan et al 1983

plant species besides R mangle can be found Avi-cennia black mangrove and Lagunculama white mangrove are common to this group Mangrove annual net primary production ranges from 04 to 44 kg C m- with an average of 1kg C m- (Mitsch and Gosselink 1993 Odum and McIvor 1990)

Seagrasses are found in the northernmost estuaries of North Carolina and in Florida In many areas there has been a drastic decline in seagrass abundance that has been attributed to declining water quality These subtidal vascular plants inhabit soft sediments and appear to be light limited (Day et al 1989) which may be a primary cause for their absence in South Carolina and Georgia estuaries In North Carolina the dominant form is eelgrass Zostera mamna and in Florida turtlegrass Thalassia testudinum dominates Seagrass annual net primary production (Table 5) in North Carolina ranges from less than 01 to 07 kg C m- and in Florida from 01 to 25 kg C m- (Thayer et al 1975 Pen- hale 1977 Zieman and Wetzel 1980 Zieman 1982)

There have been estimates of the various components of total primary production in only a few locations within the southeastern Atlantic coastal region (Table 6) In the estuarine area near Beau- fort North Carolina Thayer et al (1975) estimated a total annual primary production of 02 kg C m- distributed among eelgrass (64) phytoplankton (28) and salt marsh grass (8) At North Inlet South Carolina estimated total annual primary production including belowground root- rhizome production is 10 to 16 kg C m- (Dame 1989 Pinckney and Zingmark 1993a) Using minimal values and adjusting for the total system annual production is partitioned as S alterniJirora (46) benthic microalgae (29) macroalgae (13) and phytoplankton (12) In the Duplin River system near Sapelo Island Georgia total annual primary production was estimated to be 14 kg C m- apportioned as S alterniJora (84) benthic microalgae ( lo) and phytoplankton (6) Pomeroy et al (1981) suggests that on the bottom

808 R Dame et al

TABLE 6 Relative primary production at five estuaries along the southeastern Atlantic coast Data sources given in text

Relatlve Primal-) Product~on ()

Brnthic Estuarv Phvto~lankton Microaleae

BeaufortNorth Carolina 337 horth Inlet South Carolina 120 290 Sapelo Georgia 76 144 Indian River Florida 33 146 Biscalme Bay Florida 67

and in the water column turbidity limits light penetration and thus photosynthesis In Biscayne Bay Florida Roman et al (1983) showed that phytoplankton (27 g C m-2 yr-) accounted for less than 10 of total system production with the seagrass Thalassia and seaweeds accounting for the majority (06 kg C m--I)

From these widely distributed sites it appears that macrophytes are by far the dominant produc- er of fixed carbon in southeastern estuaries Phy- toplankton production is relatively low except at Beaufort North Carolina where it accounts for over one-fourth of the total production of the system Some eutrophic systems such as the Neuse River differ from the above systems the main source of fixed carbon is phytoplankton because seagrasses are rare or absent and salt marshes are confined to river fringes in lower reaches of the estuary

The importance of vascular plant primary production in many southeastern estuarine ecosystems supports Peters and Schaafs (1991) empirical modeling exercise that suggests that there is insuf- ficient microalgae production to support the current catch of finfish and shellfish along the Atlantic coast of the US Opposing views exist that argue the significance of algae (particularly edaphic microalgae) to carbon trophic transfer in southeastern estuarine food webs The Peters and Schaaf (1991) model probably underestimated the relative contribution of algae to fish production by using a 20 trophic transfer efficiency which does not account for the need for vascular plant detritus and is high relative to the prevalent 10 efficiency found by Pauly and Christensen (1995) in their worldwide survey of primary productivity needs for fishery sustenance and failing to ac-count for the production of edaphic microalgae in salt marshes and seagrass beds (Mallin et al 1992) Also stable isotope analyses from the Sapelo Island salt marsh (Haines 1976 Peterson and Howarth 1987 Sullivan and Moncreiff 1990) indicated that algae accounted for 50 of the transfer of fixed carbon to fauna despite their much lower absolute primary production compared to vascular plants ie suggesting that the efficiency of trophic trans-

Prorated Total Macroalrae ascular ( g C m-2XT-)

663 202 130 460 1600

780 1445 819 441 933 686

fer is higher in algae than vascular plants in this system

Consumers With their high primary production estuaries of

the southeastern Atlantic coast also have abundant and often commercially important consumers Be- cause macrophytic production dominates the es-tuaries of the region both detrital and grazing food paths are well represented Frequently many macro-consumers are feeding on organisms from both of these pathways Furthermore many consumers are predominantly found in either bottom sediment or water column habitats but mecha- nisms coupling these subsystems abound

The decomposer food web in coastal waters is dominated by microorganisms that are either using DOM in the water column or particulate or-ganic matter (POM) The community of attached microbial organisms and POM is usually referred to as detritus Organic carbon enters estuaries from other environments and from macrophytes epiphytes benthic microalgae macroalgae and phytoplankton

In North Inlet DOC concentrations range from 10 to 130 g C m-3 and particulate organic carbon (POC) concentrations vary greatly about seasonal mean concentrations of 12 to 15 g C m-3 (Dame et al 1986) In the Duplin River near Sapelo Is- land DOC varies over the year from 2 to about 11 g C m-3 and POC range from 3 to 11 g C m-3 over the same period (Chalmers et al 1985) Both systems trap sufficient particulate carbon (organic and inorganic) to maintain elevation as sea level rises and export carbon to the adjacent ocean

The source of the majority of dissolved and particulate carbon in southeastern Atlantic coast estuaries is usually attributed to the decomposition of organic materials Odum and de la Cruz (1967) gave the original description of the aerobic decomposition of Spartina alterniJlora for conditions at Sa- pel0 Island After the initial leaching stage of decomposition during which a large pulse of DOM is released from post senescent tissues (Valiela et


TABLE 7 Comparison of means zooplankton abundance and biomass for estuaries along the southeastern Atlantic coast

Estuarv

Plankton Net Mesh Sire

( I L ~ )

Beaufort area North Carolina 156

Neuse River North Carolina 76 76

North Inlet South Carolina

Biscayne Bay Florida

60 156 153

64 and 200 239

Sample Period

1970 1971 30 mo 20 mo 1989 22 mo 20 mo 6 mo (summer) 1978 14 mo

Biomass Denslw (mg dry

(No mL9) wt m-$) Source

4000 Thaver et al (1974) 8400 Thaver et al (1974)

21000 Fulton (1984) 34530 Mallin (1991) 31224 Mallin (1991)

137150 Mallin and Paerl (1994) 9257 Lonsdale and Coull (1977)

21555 Houser and Allen (1996) 47000 Roman et al (1983)

MToodmansee (1958)

al 1985) fibrous tissues are initially colonized by fungi and bacteria that structurally weaken the tissues so that macroconsumers can process them into smaller particles (Newel1 1996) As the particles get smaller the surface area increases and the microbes increase their colonization The original vascular plant material is gradually converted into microbial biomass and CO as a byproduct Various detrital feeders then ingest these small particles the microbes are removed and the POM repack- aged as fecal pellets that are egested and then re- colonized by microbes with the particles again in- gested by consumers A comparison of vascular plant decomposition shows that the seagrasses de- compose the fastest followed by red mangroves and salt marsh grasses the slowest (Odum and de la Cruz 1967 Heald 1969 Zieman 1975)

In addition to the decomposition of organic material aerobically much vascular plant material is also buried in estuarine sediments where it decom- poses anaerobically and plays a role in a number of bacterially mediated biogeochemical cycles

In the water column the microbial food web has been identified as a major pathway for processing of DOM (Azam et al 1983) In this web DOM produced by various sources both living and non-living is taken up by bacteria that are then consumed by protozoans and finally the protozoans are eaten by macroconsumers (LeGall et al 1997) DOM fiom producers may also be converted via microbial mediation to organic aggregates that are in turn consumed by metazoa (Alber and Valiela 1995)

he role of microzooplankton (eg protists such as flagellates and ciliates) in processing bacterial or primary production is unknown for many estuaries in the southeast and in fact most information comes from two salt marshes Sapelo Is- land Georgia and North Inlet South Carolina In both systems estimates of abundances and grazing rates of microzooplankton were at the high end of those reported in the literature (Sherr et al 1986

1991 Capriulo 1990 Zeitzschel 1990 Sanders et al 1992 Wetz et al 1999) Sherr et al (1986 1989 1991) estimated that depending on season and proximity to the land-margin small (lt 20 pm) aloricate ciliates or heterotrophic flagellates were the major bacterivore Lewitus et al (1998) demonstrated the importance of microzooplankton grazing in limiting phytoplankton population growth during the summer bloom in North Inlet Heterotrophic flagellate abundance peaked at 6000 to 9000 cell ml- during the summer in several North Inlet tidal creeks (Wetz et al 1999) These numbers are exceptionally high relative to literature values consistent with the h i ~ h bacterial

0

abundance typically measured during the summer in North Inlet (up to 108 cell ml-l Lewitus et al 2000) Research is need to determine whether the relatively high heterotrophic flagellate ciliate and bacterial abundances and the predominance of microzooplankton grazing in controlling bacterial and phytoplankton population growth are char- acteristic of other southeast estuaries (and thus may reflect the generally higher temperatures and prolonged summer compared to more northern temperate estuaries)

Macroconsumers of southeastern Atlantic coast estuaries are abundant diverse and often com-mercially important In the water column the macroconsumers are mainly zooplankton and nekton Many of these animals are meroplanktonic with larval stages that live in the water column and adult stages that are nektonic or benthic (Dame and Al- len 1996) There are only a few estimates of annual zooplankton density and biomass in southeastern estuaries most of these being from North and South Carolina (Table 7) These data represent contrasting estuarine geophysical types with Beau- fort North Carolina estuaries consisting of several interconnected high-salinity sounds the Neuse a mesohaline riverine system North Inlet a high-sa-

810 R Dame et al

linity marsh-estuarine system and Biscayne Bay a subtropical open body of water Recorded zoo-plankton abundance was highly dependent upon net mesh size used in collections with use of smaller (60-76 pm) mesh sizes yielding much greater abundance and biomass (Table 7) Season was also important in these systems with summers yielding the highest abundances Fulton (1984) Mallin (1991) and Mallin and Paerl (1994) found a pos- itive correlation between water temperature and zooplankton abundance and biomass At the southern end of the range Roman et al (1983) attributed the higher zooplankton concentrations in Biscayne Bay to the availability of large amounts of macroalgal detritus It should also be noted that these subtropical estuarine waters are considerably less turbid than those of the more temperate systems

Mallin and Paerl (1994) estimated that zoo-plankton grazed between 38 and 45 of daily phytoplankton production on an annual basis in the Neuse River Estuary in North Carolina Holo- planktonic consumers (eg copepods) are primary sources of food for fish (Weinstein 1979 Boze- man and Dean 1980) and zooplanktivorous fishes (Allen et al 1995) that arrive in the estuarine nursery ground in the spring Predation peaks in the spring and summer when the transfer of phytoplankton carbon to zooplankton is highest and most fishes depart in the autumn when phytoplankton productivity and zooplankton abundance have decreased (Mallin and Paerl 1994)

Benthos composition and abundance generally reflects the latitude type and geomorphology of estuaries within the region Sediments currents salinity temperature and many other abiotic and biotic factors influence the benthos over a wide range of spatial and temporal scales

Infauna and epifauna associated with salt marshes are similar from North Carolina to Florida Spe- cies composition and abundance varies within each estuary as a function of elevation within the tidal range bottom type and distance from the ocean Low energy environments (mud-silt) typically support higher diversities of meiofauna than higher energy sandy habitats (Coull 1985) Although macrobenthos biomass often surpasses that of meiofauna the smaller animals are more diverse and have much higher turnover rates (Coull and Bell 1979) Microcrustaceans and oligochaetes are the primary source of food for shrimps fishes and other epibenthic species that use the estuarine nursery Polychaetes dominate the macrobenthos in mud bottoms whereas amphipods and small bivalves are most abundant on sand bottoms and echinoderms may dominate carbonate sediments (Dardeau et al 1992) Seasonal variations in nu-

merical abundance and species richness may be large with maxima usually occurring between fall and spring (Service and Feller 1992)

Hard bottoms are not abundant within the region but where they do occur they are often very important Benthic filter feeding bivalves often comprise the most obvious consumer community forming dense beds and in the case of oysters reefs with complex structural attributes Intertidal oyster reefs are common to bar-built and lagoonal systems throughout the region In North Inlet they have been shown to be capable of removing more phytoplankton from the water column than is produced by the estuary resulting in a regular total import of phytoplankton from the adjacent ocean (Dame et al 1986 1989) At North Inlet Dame et al (1989) calculated that zooplankton grazing was several orders of magnitude below oyster grazing on phytoplankton Because of their high rates of water pumping and filtration oyster reefs have also been shown to play a major role in the cycling of nutrients in these systems (Dame 1996)

Benthic diversity and productivity are especially high in vegetated subtidal areas Seagrass beds in North Carolina and south Florida are habitats for hundreds of species of benthic epiphytic and mobile invertebrates (Dardeau et al 1992) Dominat- ed by polychaetes and amphipods the density and diversity of benthos in these habitats increases to- wards the south (Virnstein et al 1984) Mangrove habitat supports a distinct speciose and productive benthos and epifauna in the southern portion of the region (Odum and Heald 1972)

Mobile macroconsumers or nekton are also prominent components of southeastern Atlantic estuaries Whereas many of these animals are per- manent (year round) residents warm season tran- sients (mostly young of the year fish and shrimps) often account for most of the mobile annual consumers in these estuaries Estuarine nekton use the shallow tidal creeks marshes mangrove swamps and vascular plant grass beds as nursery grounds and habitat (Hettler 1989 Gilmore 1995 McIvor and Rozas 1996) Resident and transient nekton can potentially move production from these shallow habitats into the subtidal estuary and coastal ocean (Kneib 1997) Nelson et al (1991) surveyed 20 mostly riverine estuaries on the southeastern At- lantic coast for the distribution and abundance of fishes and shellfish Sufficient information about commercial value recreational value indicators of environmental stress and ecological value for about 40 species were available to develop a general analysis Penaeid shrimps and blue crabs dominated the invertebrate component of the nekton and both groups have life cycles that strongly cou- ple the estuary to the coastal ocean Blue crabs

-- - - - -- - --


Total annual commercial fisheries (all marine and estuarine species) Relative total commercial landings (pounds) of estuarine fish and landings for SE US states shellfish In South Carolina

25 I 25000 I

Fig 7 A comparison of fisheries landings in North Carolina South Carolina Georgia and Eastern Florida for 1988-1998

were abundant or highly abundant in all systems across the region while the abundance of shrimp varied with different species dominating across the region The most abundant finfish (the bay ancho- vy spot and striped mullet) occur across a wide range of salinities and dominate most southeastern estuaries In a 16-year continuing study Allen (personal communication) found that young of the year of dominant nekton species in North Inlet varied considerably in abundance and biomass from year-to-year but that the total production of nekton seemed to be much less variable

A review of commercial landings of finfish and shellfish (shrimp crabs and bivalves) data from 1988 to 1998 for each state in the region showed that total catch per year was stable with North Car- olinas loadings being greater than those of the other three states combined (Fig 7) Finfish dominate the catches in North Carolina and Florida (Figs 8 and 9) while the greater proportion of catch in South Carolina and Georgia is shellfish

Relative total commercial landlngs (pounds) of estuarine fish and shellfish in North Carolina

1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh

Fig 8 Total commercial fish and shellfish landings in North Carolina from 1988-1998

Fig 9 Total commercial fish and shellfish landings in Geor- gia from 1988-1998

(Figs 10 and 11) In North Carolina South Caro- lina and Georgia estuarine related finfish and shellfish species dominated the catch but in Flor- ida catches were slightly dominated by marine species (Fig 12) The commercial landings data support the idea that the South Carolina and Georgia fisheries are very similar both in terms of total catch and proportion of shellfish and estuarine species that North Carolinas fisheries are dominated by finfish have greater annual yields compared to South Carolina and Georgia but are also primarily based on estuarine species and that Flor- idas fisheries are more equally divided between shellfish and finfish but estuarine species account for less than half the catch This characterization of the southeastern estuaries by states corresponds to the geomorphological distribution of sounds dominating in North Carolina barrier islands with bar-built estuaries most common in South Carolina and Georgia and rnarine factors dictating in Flor- ida These data indicate a relationship between dif-

Relative total commercial landings (pounds) of estuarine fish and shellfish in Georgia

1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998

rtaleffirh OGaershhsh

Fig 10 Total commercial fish and shellfish landings in eastern Florida from 1988-1998

81 2 R Dame et al

Relative total commsrclal landings (pounds) of estuarine fish and shellfish In Florida (east cout only)

Fig 11 Total commercial fish and shellfish landings in South Carolina from 1988-1998

fering levels of primary production and fisheries harvest across the region which is consistent with ecological theory regarding food chain structure and productivity (Pauley and Christensen 1995)

At the top of southeastern estuarine food webs are a number of highly mobile predators including raptorial birds sharks and rays turtles alligators and crocodiles as well as marine mammals the most dominant of which is the bottle nosed dolphin (Hoese 1971) Without any significant predators these animals with highly developed sensory systems and behaviors are well adapted to feeding on larger fish shrimp and turtles in the highly turbid shallow estuarine waters of the region

Anthpogenic Effects Human population density has steadily in-

creased along the southeastern Atlantic coast since Europeans first colonized it centuries ago Over the 30-yr period between 1980 and 2010 human population density in coastal counties of the region is expected to continue to rise (Fig 13) with the average growth rate by state expected to range between 15 and 45 with Florida leading the way (Culliton et al 1990) In Florida coastal counties occupy 57 of the land but contain 78 of the population (Montague 1997 Montague and Odum 1997) With a human population growth rate of over 600 individuals per day Florida is already ex- hibiting environmental stress in many areas At this rate of human population growth it is projected that Florida will lose the ability to sustain its estuarine environments within the next 20 years (Mon- tague and Odum 1997) In contrast to Florida Georgia and South Carolina have some of the smallest coastal human populations in the country but their growth rates are still high (10 to 20 per decade) In the Carolinas and Georgia there

Proportion of total fisheries landings cornprlsed dfinfish and shellfish spceies associated with estuaries of the SE US states

Fig 12 Proportion of total fisheries landings comprised of finfish and shellfish species associated with estuaries along the southeastern Atlantic coast for 1988-1998

is also a well-defined seasonal change in population due to recreational tourism The net effect of millions of tourist visiting this area annually is the doubling of the average daily population Devel- opment of infrastructure has had significant environmental impact Along the northeast coast of South Carolina there are over 1 10 golf courses that are essentially intensely maintained grasslands developed in response to human recreational demands In addition to problems associated with routine management there is mounting concern that golf course ponds will not be able to contain their contents during a significant hurricane induced storm surge

S O U T H E A S T E R N ATLANTIC COAST POPULATION G R O W T H

POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -

Fig 13 Past and projected human population numbers in coastal counties of the southeastern Atlantic coast Data sources North Carolina Office of State Planning State Demographics South Carolina Budget and Control Board Omce of Research Statistics Georgia CIS Data Clearinghouse and State Data and Research Center and Florida Office of Economic and Demo- graphic Research The Florida Legislature


TABLE 8 Southeast Atlantic estuarine eutrophication assessment L = LOW ML = Moderate Low M = Moderate MH = Moderate High H = High IH = Improved High IL = Improved Low NC = No Change WL = Worse Low WH = Worse High (Coastal Assessment and Data Synthesis System 1999 National Oceanic and Atmospheric Administration 1999)

Eutrophication Symptoms Anthropogenic influences Prognos~s(2020)

Estuarv L ML M MH

Albemarle Sound X Pamlico Sound PamlicoPungo Rivers X Neuse River Bogue Sound X New River X Cape Fear River X Winyah BayNorth Inlet X NorthSouth Santee Rivers X Charleston HarborWandoCooperAshley Rivers X StonoNorth Edisto Rivers X St Helena SoundS EdistoCoosaw Rivers X Broad River X Savannah River X Ossabaw SoundOgeechee River X St CatherinesSapelo Sounds X Altamaha River X St Andrew Simons SoundsSatilla River X St Marys RiverCumberland Sound X St Johns River X Indian River X Biscayne Bay X

South Atlantic Coast 1 1 1 5 3

Estuarine water quality is often used as an indicator of environmental stress in coastal areas with nutrient concentrations being the most common measure (National Oceanic and Atmospheric Ad- ministration 1996) The sources of additional nutrients to estuaries are point (eg wastewater treatment industry etc) and non-point (eg agricul- ture golf courses lawns etc) discharges These inputs have both direct effects (ie algal blooms increased turbidity decreased oxygen concentrations etc) and indirect effects (ie decreases in commercial fisheries impacts on recreation and public health risks) (National Oceanic and Atmo- spheric Administration 1996)

A recently published National Oceanic and At- mospheric Administration (1996) report focused on existing information on nutrient loading or eutrophication in 21 south Atlantic estuaries (Table 8) Medium concentrations (gt 5 kg 1-I) of chl a are observed periodically in 20 estuaries and 11 of these systems had high or hypereutrophic (gt 20 pg 1-l) concentrations episodically Medium or greater (gt 01 mg 1-) concentrations of nitrogen are found in 19 estuaries Phosphorus concentrations of medium or greater (gt 001 mg 1-l) are observed in 18 estuaries During the summer months small percentages of 13 estuaries are hyp- oxic and 11 systems exhibit anoxic occurrences The trends data were sparse but the Neuse River

H L ML M MH H IH IL NC IWH

X X X X X

X X X X X

X X X X

X X X X

X X X X

X X X X

X X X X

X X X X

X X X X

X X X X

X X X X

X

2 5 5 8 2 1 0 3 8 4 7

appeared to have a number of increasing and de- creasing trends depending on location within the estuary In contrast data from a number of South Carolina estuaries indicated a decrease in nitrogen and phosphorus loading

As noted earlier water flow and watershed physical characteristics play a major role in estuarine dynamics Biggs et al (1989) developed a classifi- cation scheme designed to evaluate the potential ability of an estuary to flush pollutants From this scheme the Santee River in South Carolina is most susceptible to population heavy industry and agricultural activities Fortunately the Santee has no industry or large cities but is mainly an agricultural watershed The St Johns River is projected to be most susceptible to population and agricultural activities Charleston Harbor would be most susceptible to heavy industry while Winyah Bay Al-bemarle Sound and the Neuse River would be most susceptible to agricultural activities Unfor- tunately for the latter 5 estuaries the scheme pre- dicts these systems actual situation

Conclusions This review of the characteristics of southeastern

Atlantic estuaries has taken an ecosystem approach to include as many components and cross disci- pline interactions as possible Three types of estuaries play major roles in the region The marshes

814 R Dame et al

in all three system types (bar-built coastal plain and piedmont) have high primary production and provide extensive nursery grounds for secondary consumers Both coastal plain and piedmont systems flush extensive highly productive freshwater wetlands Piedmont estuaries with large water flows connect the coast to large interior watersheds These highly productive estuarine systems can be both directly and indirectly influenced by management decisions both locally and as far away as the foothills of the Appalachian mountains

The discharges of the southeastern riverine systems carry large quantities of dissolved and particulate materials to the coastal ocean Lagoonal and bar-built systems that are tidally dominated may export large amounts of inorganic and organic materials Water fluxes in all three estuarine types a p pear to play a major role in the accumulation or lack of accumulation of anthropogenic materials nuisance algae blooms and marine diseases

Vascular plant production dominates estuaries of the region and is decomposed through extensive foodwebs in both the water column and the sediment This high primary production combined with extensive vascular plant habitat supports large populations of commercially and recreationally important secondary consumers

The estuaries of the southeastern Atlantic coast can be divided into three general areas The North Carolina coast is dominated by extensive and poorly flushed sounds These estuaries are characterized by modest primary production and they support the largest estuarine fishery in the southeastern Atlantic region Although human population density is low and growth is moderate high nutrient loading results from poor land use for industrial animal production This area harbors several of the most polluted estuaries in the country

The central region that makes up most of the South Atlantic Bight is dominated by the estuaries of South Carolina and Georgia Well-flushed bar- built and riverine estuaries are common Primary production is very high and dominated by emergent salt marshes Commercial fishery landings are relatively low but shellfish dominate catches and estuarine species comprise more than 75 of the catch Human population density and growth are low to moderate and nutrient loading reflects this land use pattern

The Florida coast particularly south of Jackson- ville is dominated by moderate to poorly flushed bar-built estuaries with little freshwater input A va- riety of plant types support a modest level of primary production Fisheries catches are moderate and equally divided between shellfish and finfish but estuarine species are much less important than marine species in the landings Human population

density and growth rate are high and probably cause high nutrient loading With continued high population growth urbanization and habitat de- struction Florida presents the scenario of potential environmental collapse

One of the points to emerge from this synthesis is that although a few representative bar-built systems are very well studied (eg North Inlet South Carolina and Duplin River Georgia) very little is known about most of the estuaries in the southeast Atlantic region In contrast to other areas of the country this region has received relatively little at- tention and the data do not exist for evaluating historic trends for many parameters

As reflected in several of the federal government reports that are the results of scientific panels the future utilization of these estuarine systems and their essential services will depend on the development of improved management strategies based on enhanced data quality These approaches must be increased comprehensive long-term environ-mental monitoring linked to integrated regional planning in order to maintain the viability and us- ability of southeastern Atlantic estuarine and coastal systems In particular the magnitude and sources of freshwater inputs the nature of material processing by the different types of estuaries and how coastal fisheries are coupled to these estuaries clearly need comprehensive study Most impor- tantly there is an evident need for large or regional scale approaches focused on the estuarine coupling of the landscape to the sea

The authors wish to thank the many state federal and private resources that have supported their research on southeastern estuaries in the past and present This work was heavily s u p ported by National Science Foundation awards DEB95095 to Coastal Carolina University and the Georgia Rivers Land Margin Ecosystem Research DEB-94120898to the University of Georgia This is publication number 1252 of the Belle W Baruch Insti- tute for Marine Biology and Coastal Research This work was presented at the Estuarine Federation Meeting in Providence Rhode Island October 1997

ALBERM 2000 Settable and non-settable suspended sediments in the Ogeechee River Estuary Georgia USA Estuarine Coast- al and Shelf Science 50805-816

ALBERM AND J E SHELDON 1999Use of a date-specific meth- od to examine variability in the flushing times of Georgia estuaries Estuarine Coastal and Shelf Science 49469-482

ALBERM AYD I VALIEW 1995 Organic aggregates in detrital food webs Incorporation by bay scallops Argopecten irradians Marine Ecolog~ Progress Smes 12 1 1 17-1 24

ALBERTSJ J AYD M T ~ c s 1999 Importance of humic substances for carbon and nitrogen transport into southeastern United States estuaries Organic Geochemistry 30385-395

ALEX~LUDER ~ L U D 1986AnC E M A BRONTMAN D U FIELD Inventory of Coastal Uktlands in the USA National Oceanic

and Atmospheric Administration National Ocean Service De- partment of Commerce Washington DC

ALLEND M W S JOHNSON ASD 1995I OGBURS-MATTHEMS T r o ~ h i crelationshi~s and seasonal utilization of salt marshes by zooplanktivorous fishes Environntental Biology of Fishes 42 37-50

ampAM F T FENCHEL J G FIELD J S G K ~ Y L A MEYER-REIL AND F THINGSTAD 1983 The ecological role of water-column microbes in the sea Marine Ecolog Progress S h e s 10237-263

BIGGS R B T B D~Moss M M CARTER AVD E L BEASLEY 1989 Susceptibility of US estuaries to pollution Revzerus zn Aquatic Sciences 1 189-207

BIGGSR B LXD B A HOWELL 1984 The estuary as a sediment trap Alternate approaches to estimating its filtering efficiency p 107-129 In V S Kennedy (ed) The Estuary as a Filter Academic Press New York

BOZEMASE L AVD J M DELX 1980 The abundance of estuarine larval and juvenile fish in a South Carolina intertidal creek Estuanes 389-97

BRICKER D E P I W U S B C G CLEMENT S P ORLANDO AXD D R G F ~ O W 1999 National Estuarine Eutrophica- tion Assessment Effects of Nutrient Enrichment in the Na- tions Estuaries National Oceanic and Atmospheric Admin- istration National Ocean Senice Special Projects Office and the National Centers for Coastal Ocean Science Silver Spring Maryland

BURKHOLDERJ M 1998 Implications of harmful marine microalgae and heterotrophic dinoflagellates in management of sustainable marine fisheries Ecological Applications 8S37-S62

BCRKHOLDERJ M AVD H B GL~SGOW JR 1997 PJiesteria piscicida and other PJiesterielike dinoflagellates Behavior impacts and environmental controls Limnology and Oceanographj 421052-1075

BURKHOLDER JR~LUDC Mr HOBBS 1995 J M H B GLISGOW Distribution and environmental conditions for fish kills linked to a toxic ambush predator dinoflagellate ~VarineEcol-ogy Progress Series 12443-61

BURKHOLDERJ M E J NOGA C H HOBBS H B GUSGOW LXD S A SMITH 1992 New phantom dinoflagellate is the causative agent of major estuarine fish kills Nature 358407-410

CWOONL B J E NEMOOF AVD C L TILTON 1999 Sedi- ment grain size effect on benthic microalgal biomass in shallow aquatic ecosystems Estuaries 22735-741

Cu Mr J L R POMEROY M A MOK~SLVD Y MLxG 1999 Oxygen and carbon dioxide mass balance for the estuarine- intertidal marsh complex of five rivers in the southeastern US Limnology and Oceanographj 44639-649

CAI W J W J MIEBE Y MLxG LVD J E SHELDON in press Intertidal marsh as a source of dissolved inorganic carbon and a sink of nitrate in the Satilla River-estuarine complex in the southeastern US Limnology and Oceanography

CWRIULOG M 1990 Feeding-related ecology of marine protozoa p 186-259 In G M Capriulo (ed) Ecology of Marine Protozoa Oxford University Press New York

C~RPENTERE J 1971 h n u a l phytoplankton cycle of the Cape Fear River Estuary North Carolina Chesapeake Science 1295-104

CKUMERS A G R G WIEGERT P L MTOLF 1985 Carbon LXD

balance in a salt marsh Interactions of diffusive export tidal deposition and rainfall-caused erosion Estuarine Coastal and Shelf Science 21757-771

CHURCHT M 1996 An underground route for the water cycle Nature 380379-580

CL~RKE ~LUDM F PECK 1990 Geology and J S C M HACKE ground water resources of the coastal area of Georgia Georgia Coastal Geologzcal Suruty Bulletin 113l-106

COASTALASSESSMENT SWTEMAVD DATA S ~ T H E S I S 1999 Physical


and Hydrological Characteristics of Coastal Watersheds Na- tional Coastal Assessments Branch Special Projects Office National Ocean Service National Oceanic and Atmospheric Administration Silver Spring Maryland

COLEMAN 1994 Community struc- V L ASD J M BURKHOLDER ture and productivity of epiphytic microalgae on eelgrass (Zos-tern ntarina L) under water-column nitrate enrichment Jour-nal of Experimental anti Marine Biology and Ecology 17929-48

COCLL B C 1983 Long-term variability of estuarine meioben- thos h 1 1-year study Marine Ecologq Progress S h e s 24205-213

COCLL B C LVD S BELL 1979 Perspectives of meiofaunal ecology p 189-216 In R J Livingston (ed) Ecological Processes in Coastal and Marine Systems Plenum New York

COUTINHOR 1987 Ecology of macroalgae in North Inlet estuary SC PhD Thesis University of South Carolina Colum- bia South Carolina

CRITCHERT S 1967 The Mildlife Values of North Carolina Estuarine Lands and Waters North Carolina Mildlife Resourc- es Commission Raleigh North Carolina

CCLLITONT J M A I~u(REN D G REMER T R GOODSPEED C M BL~CKUTELL 1990 30 Years of LVD J J MCDONOUGH Population Change Along the Nations Coast 1960-2010 Na- tional Ocean Service National Oceanic and Atmospheric Ad- ministration US Department of Commerce Rockbille Mary- land

DM T LXD R G MIEGERT 1996 Ramet population dynamics and net aerial primary productibity of Spartina alternzjora Ecolog 77276288

DAME R F 1989 The importance of Spartina alternzjora to At- lantic coast estuaries Cntzcal Reviews in Aquatzc Sciences 1639-660

DAME R F 1996 Ecology of Marine Bivalves An Ecosystem Approach CRC Press Boca Raton Florida

DAMER F f i n D M ALLEN 1996 Between estuaries and the sea Journal ofExpmmenta1 Marine Biologq and Ecolog 200169-185

DLIE R F D CHILDERS 1992 A geohydro- LVD E KOEPFLER logic continuum theory for the spatial and temporal evolution of marsh-estuarine ecosystems Vetherlands Journal of Sea Research 3063-72

DAME R F T H CHRZ~LUOWSKI B K J E ~ X K BILDSTEIN H M C K E L L ~ J D SPCRRIER H STEVEN- D NELSOT S STLVC~K SON F J VEFXBERG LVD R G ZINGMWC 1986 The outwelling hypothesis and North Inlet South Carolina MarineEcologq Progress Series 33217-229

DAME R F J D SPCRRIER B K J E ~ T T M WILLIAMS R G ZING T G WOLMR T H CHRZ~LUOWSKI H MCKELL~R LVD F J VERNBERG 1991 Annual material processing by a salt marsh-estuarine basin in South Carolina ~Vanne Ecologq Pre gress Saes 72153-166

DAMERF J D SPCRRIER LXD T G MoL~zR 1989 Carbon nitrogen and phosphorus processing by an oyster reef ~Vanne Ecolog Progress Saes 54249-256

D~ZKDEAUM R R F MACDLIN U U SCHROEDERAVD J P STOCT 1992 Estuaries p 615-744 In C T Hackney S M Adams and W H Martin (eds) Biodiversity of the South- eastern United States Aquatic Communities John Miley amp Sons Inc New York

Dk J Mr C A S HALL Mr M KEMP LVD S YANEZ-ARANCIBIA 1989 Estuarine Ecology Wiley New York

D ~ E S I U S C NILSSON 1994 Fragmentation and flow M AXD

regulation of river systems in the northern third of the world Science 266353-762

EARTHINFOINC 1997 EarthInfo CD2 US Geological Survey Daily Values Boulder Colorado

ELEUTERIUSL N 1976 The distribution of Juncus roemenanus

816 R Dame et al

in the salt marshes of North America Chesapeake Science 17 289-292

ENVIRONMENTAL DIVISIONPROTECTION 1997 Interim Strategy for Managing Salt Water Intrusion in the Upper Floridian Aquifer of Southeast Georgia April 23 1997 Environmental Protection Division Georgia Department of Natural Resourc- es Atlanta Georgia

E m B LVD C ~ G G 1997 Nutrient behaviour during post- flood recovery of the Richmond River Estuary Northern NSW Australia Estuarine Coastal and ShelfScience 44311-326

FULTONR S 1984 Distribution and community structure of estuarine copepods Estuaries 738-50

GALLAGHER 1973 Tidal marsh plant J L LVD R J REIMOLD distribution and productivity patterns from the sea to freshwater-A challenge in resolution and discrimination p 163- 183 In IV Biennial Workshop on Color Aerial Photography in Plant Sciences and Related Fields American Society of Photography Mashington DC

G ~ N E R T M UILLIAMS L R U K MICHENER E R BLOOD B K J E ~ T L A SMOCK D J LIPSCOMB LVD C GRESHAM 1992 Disturbance effects of Hurricane Hugo and a pristine coastal landscape North Inlet South Carolina USA ether-lands Journal of Sea Research 30249-263

GILMORER G 1995 Environmental biogeographic factors influencing ichthyofaunal diversity Indian River Lagoon Bul-letin of Marine Science 57153-170

GLIBERTP M J C GOLDMAS m~ E J C~ENTER1982 Sea- sonal variations in the utilization of ammonium and nitrate by phytoplankton in Vineyard Sound Massachusetts USA Maine Bzologq 70237-249

HAINESB L AND E L DUNN 1985 Coastal marshes p 323- 347 In B F Chabot and H A Mooney (eds) Physiological Ecology of North American Plant Communities Chapman and Hall New York

HAINES E B 1976 Stable carbon isotope ratios in the biota soils and tidal water of a Georgia salt marsh Estuarine Coastal Marine Science 4609-616

HANSONK m~ G MALL 1991 Florida precipitation and the Pacific El Nifio 1895-1989 Flonda Scientist 54160-168

HAYESM 0 1978 Impact of hurricanes on sedimentation in estuaries bays and lagoons p 323-346 In M L Wiley (ed) Estuarine Interactions Academic Press New York

HEALD E J 1969 The production of organic detritus in a south Florida estuary PhD Dissertation University of Miami Mi- ami Florida

HEFNER T E DwL ~LUD 1994J M B 0 WILLEN W E FRAYER Southeast Metlands US Department of the Interior Fish and Wildlife Service and US Environmental Protection Agency Washington DC (httpwwwnwifwsgovsewet)

HETTLERJR Mr F 1989 Nekton use of regularly flooded salt marsh cordgrass habitat in North Carolina USA Fisherj Bul- letin 36lll-118

HOERLING 1997 Uy do North American M P AND A KCMAR climate anomalies differ from one El Nifio event to another Geophjsical Research Letters 24 1059-1 062

HOESEH D 1971 Dolphin feeding out of water in a salt marsh Journal of ~ t fammalog 52222-223

HOCSER D S ~ W DD M ALLEN 1996 Zooplankton dynamics in an intertidal salt-marsh basin Estuaries 19639-673

HOWARTHR W G BILLEN D SWILUEI A TOWMENDN JA- WORSKIK LAJTHA R ELMGREN J A DOMZING N C m c o T JORDAYF BERENDSE V KCDEYROFJ FRENEY P MCRDOCH m D Z ZHAO-LIampYG 1996 Regional nitrogen budgets and riverine N and P fluxes for the drainages to the North Atlantic Ocean Natural and human influences Biogeochemisty 3575-139

HUMMHJ 1969 Distribution of marine algae along the Atlan- tic coast of North America Phjcologza 743-33

JENSENP R i ~ u ~R A GIBSON 1986 Primary production in three subtropical seagrass communities A comparison of four autotrophic components Flmda Sczenttst 49129-141

KAL~GCCHI H N MG T A J LEWTCS C M ampLION AND

KELL~R1997 Can urbanization limit iron availability to estuarine algae Journal ofExpamenta1 Marine Biolog and Ecolog 21333-69

KELLERA A C A OWATT H A MALKER AXD J D HAWAK 1999 Predicted impacts of elevated temperature on the magnitude of the winter-spring phytoplankton bloom in temperate coastal waters A mesocosm study Limnolog and Oceanog- raphy 44344-356

KJERFIEB 1989 Estuarine geomorphology and physical oceanography p 47-78 In J Day C Hall M Kemp and A Yanez- Arancibia Estuarine Ecology Miley New York

KJERFIXB J E GREER LVD R L CROUT 1978 Low-frequencv

response of estuarine sea level to non-local forcing p 497- 313 In M Wiley (ed) Estuarine Interactions Academic Press New York

KNEIB R T 1997 The role of tidal marshes in the ecology of estuarine nekton Oceanography and Marine Bioloa A n Annual h i m 35163-220

KCHNEL I T A MCMAHON B L FINLAWON A HAINES P H WHETTONampYD T T GIBSON 1990 Climatic influences on streamflow variability A comparison between Southeastern Australia and Southeastern United States of America Water Resources Researh 262483-2496

LE GALL S M B HASSEN ampYD P LE GALL 1997 Ingestion of a bacterivorous ciliate by the oyster Crassostrea gzgas Protozoa as a trophic link between picoplankton and benthic suspen- sion-feeders Marine Ecolog Progress Saes 152301-306

LEWTUSA J K C H 4 ~ 3 S G GKSDSEN H B GLASGOW JR J M BCRKHOLDER ~ W DS MORTON in P M GLIBERT press Ecological characterization of a widespread red tide in South Carolina estuaries A newly observed phenomenon Proceedings of the Harmful Algal Blooms 2000 9th Confer- ence Tasmania Australia February 7-1 1 2000

LEWTTCS HA J R V JESIENT M Km4 J M BURKHOLDER B GMGOW JR m~ E MAY 1995 Discovery of the phantom dinoflagellate in Chesapeake Bay Estuaries 18373-378

LEWTTCS ILUDJ T MORRIS A J E T KOEPFLER 1998 Seasonal variation in the regulation of phytoplankton by nitrogen and grazing in a salt-marsh estuary Lzmnolog and Oceanography 43 636646

LEWTTCS ANDA J E T KOEPFLER R PIGG 2000 Use of dissolved organic nitrogen by a salt marsh phytoplankton bloom community Archivfur Hjdrobiologle Spenal Issues in Advances in Limnoloampv 55441-436

L o m M Mr m o P M GLIBERT 1999 Temperature regulation of nitrate uptake A novel hypothesis about nitrate uptake and reduction in cool-water diatoms Limnology and Oceanography 44556-572

LONSDALED J ~LUDB C COCLL 1977 Composition and seasonality of zooplankton of North Inlet South Carolina Ches-apeake Science 18272-283

Lcco A E AND S C SNEDAKER 1974 The ecology of mangroves Annual Review ofEcolog and Sjstematics 339-64

MALLINM A 1991 Zooplankton abundance and community structure in a mesohaline North Carolina estuary Estuaries 14 481-488

MALLINM A 1994 Phytoplankton ecology of North Carolina estuaries Estuaries 17561-374

MALLINM A 2000 Impacts of industrial animal production on rivers and estuaries American Scientist 8824-37

IMALLIN M A J M BCRKHOLDER m n M J SULLIVAY 1992 Contributions of benthic microalgae to coastal fishery yield Transactions of the American Fisheries Society 121691-693

MALLINM A ~ W DH Mr PAERL 1994 Planktonic trophic trans-


fer in an estuary Seasonal diel and community structure effects Ecology 732168-2184

MALLINM A M H POSEY G C SHANK M R MCIVER S H ENSIGNampUD T D ALPHIN 1999 Hurricane effects on water quality and benthos in the Cape Fear Watershed Natural and anthropogenic impacts Ecologcal Applzcations 9330-362

MANHEIM AND G C BOND 1970 Suspended F T R H MEADE matter in surface waters of the Atlantic Continental Margin from Cape Cod to the Florida Keys Science 167371-376

~LWSHALLH G 1985 Phytoplankton assessment of the Duplin River Georgia Castanea 50187-194

M c I v o ~ C C f i n L P R o z ~ s 1996 Direct nekton use of intertidal salt marsh habitats A rebiew from the southeastern United States p 311-334 In K F Nordstrom and C T Ro- man (eds) Estuarine Shores Evolution Environments and Human Alterations Wiley New York

MEADER H 1969 Landward transport of bottom sediments in estuaries of the Atlantic Coastal Plain Journal of Sedimentary Petrology 39222-234

MEADER H 1972 Sources and sinks of suspended matter on continental shelves p 249-262 In D J P Swift D B Duane and 0 H Pilkey (eds) Shelf Sediment Transport Process and Pattern Dowden Hutchinson and Ross Stroudsburg

MEADER H 1982 Sources sinks and storage of river sediment in the Atlantic drainage of the United States The Journal of Geology 90235-252

MITSCH W J AND J G GOSSELINK 1993 MTetlands Van Nos- trand Reinhold New York

MONTAGUEC L 1997 The future of Floridas coast Journal of Public Interest in the Enuironment 151-59

MONTAGCEC L iLUD H T OnCM 1997 Intertidal marshes of Floridas Gulf Coast p 1-33 In C L Coultas and Y P Hsieh (eds) Ecology and Management of Tidal Marshes A Model from the Gulf of Mexico St Lucie Press Delray Beach Flor- ida

MONTAGUE 1990 Salt marshes p 481- C L ampUD R G WIEGERT 516 In R L Myers and JJ Ewel (eds) Ecosystems of Florida University of Central Florida Press Orlando Florida

MOORE Mr S 1996 Large groundwater inputs to coastal waters revealed by 226Ra enrichments Nature 380612-614

MCLHOLLAND C R OLSEN 1992 Marine origin of P J ampUD

Savannah River sediments Evidence from radioactive and stable isotope tracers Estuarine Coastal and Shelf Science 3495-107

NATIONALOCFANIC ATMOSPHERIC 1996ampUD ADMINISTRATION NOAAs Estuarine Eutrophication Survey Volume 1 South Atlantic Region Office of Ocean Resources Conservation As- sessment Silver Spring Maryland

NATIONAL OCEAKlC iLUD ATMOSPHERIC 1997~DMINISTR~TION The Deadliest Costliest and Most Intense United States Hur- ricanes of this Century Technical Memorandum NMTS TPC- 1 Silver Spring Maryland

NATIONALOCEANICAND ~ D M ~ N ~ s T R ~ T ~ o N ATMOSPHERIC 1999 Coastal Assessment and Data Synthesis System Eutrophica- tion Assessment-Regional Summary Silver Spring Mary land

NELSOND M E A IKWNDI L R SETTLE M E MONACO ~LUD

L E COSTON-CLEMENTS 1991 Distribution and Abundance of Fishes and Invertebrates in Southeast Estuaries Estuarine Living Marine Resources Report No 9 National Oceanic and Atmospheric AdministrationNational Ocean Service Strate- gic Environmental Assessments Division Rockville Maryland

NEWELLS Y 1996 Established and potential impacts of eu- karyotic mycelial decomposers in marineterrestrial eco-tones Journal of Expamental Marine Biology and Ecology 200 187-206

ODUME P iLUD A DE LA CRUZ 1967 Particulate organic detritus in a Georgia salt marsh-estuarine ecosystem p 383-388

In G H Lauff (ed) Estuaries American Association for the Advancement of Science MTashington DC

ODUMW E ~LUDE J HE~LD1972 Trophic analysis of an estuarine mangrove community Bulletine of ~Manne Science 22 671-738

ODUMMr E AND C C MCIVOR 1990 Mangroves p 517-548 In R L Myers and J J Ewel (eds) Ecosystems of Florida University of Central Florida Press Orlando Florida

ODCMMr E T J SMITHJ E HOOLER ~LUDC C MCIVOR 1984 The Ecology of Tidal Freshwater Marshes of the United States East Coast A Community Profile US Fish and MTildlife Ser- ice FMTSOBS8717 Washington DC

ORLANDOS P P H M T ~ x n ~ C J KLEI M E PATTILLO K C DENNIS~LUDG H MTm 1994 Salinity Characteristics of South Atlantic Estuaries National Oceanic and Atmospheric Administration Ocean Resource Conservation and ssess- ment Silver Spring Maryland

PAERL H W 1997 Coastal eutrophication and harmful algal blooms Importance of atmospheric deposition and groundwater as new nitrogen and other nutrient sources Lzmnol-ogy and Oceanography 42 1132-1 163

P~TCLLOJ Mr H MUNK R RETLLE ampYD E STRONG 1955 The seasonal oscillation in sea level Journal of~Manne Research 1488-156

PACLY D ampYD V CHRISTENSEV re-1995 Primary production quired to sustain global fisheries Nature 374255-237

PENHALEP A 1977 Macrophyte-epiphyte biomass and productibity in an eelgrass (ampstamp maamp L) community ~ amp r n a l of Expwimental Marine Biology and Ecology 2621 1-224

PETERS D S ~LUDW E SCHAM 1991 Empirical model of the trophic basis for fishery yield in coastal waters of the Eastern USA Transactions of the Amencan Fishaes Society 120459-473

PETERSON 1987 Sulfur carbon and B J ampyo R Mr HOWARTH nitrogen isotopes used to trace organic matter flow in the salt- marsh estuaries of Sapelo Island Georgia Limnology and Oceanography 3231 195-1213

PHIUUDERS G H 1990 El Niiio La Niiia and the Southern Oscillation Academic Press New York

PINCKNEY ~LUDK HOMEJ L H Mr PAERL M H ~ N G T O N 1998 Annual cycles of phytoplankton community structure and bloom dynamics in the Neuse River Estuary NC Marine Biolog 131371-381

PINCKNEY 1993a Modeling the annual J L ampVD R G ZINGMARK production of intertidal benthic microalgae in estuarine eco- systemsJournal of Phycolog 29396-407

PINCKNEYJ L AND R G Z I N G I V L ~ K 1993b Biomass and p r e duction of benthic microalgal communities in five typical estuarine habitats Estuaries 16887-897

POMEROYL R 1959 Algal productibity in salt marshes in Geor- gia Limnology and Oceanographj 4386397

POMEROYL R W DAF~EY E HMNES E DCNNJ GALLAGHER f i n D WHITNEY 1081 Primary production p 39-67 In L R Pomeroy and R G Miegert (eds) The Ecology of a Salt Marsh Springer-Verlag New York

POMEROY 1956 Ob- L R H H HASKIN ampYD R A UGOTZKIE servations on dinoflagellate blooms Limnolog and Oceanog- raphj 154-60

POMEROYL R L R SHENTON R D H JONES AND R J REI-Mom 1972 Nutrient flux in estuaries Nutrients and E u t r e phication Amacan Societj oflimnology and Oceanography Special Sjmposium 1274-291

Robtlu M R M R REET ampYD J L FROGGAT 1983 Carbon production and export from Biscayne Bay Florida Temporal patterns in primary production seston and zooplankton Es-tuarine Coastal and Shelf Science 1745-39

ROPELEWSKIC F ILUI) M S I-IALPERT 1986 North American precipitation and temperature patterns associated with the El

818 R Dame et al

NiiioSouthern Oscillation (ENSO) Monthly Weather h i e w 1142352-2362

SLVDERS R Mr DA CARON iLUD 1992u G BERINGINGER Relationships between bacteria and heterotrophic nanoplankton in marine and fresh waters An inter-ecosystem comparison Marine Ecology Progress Saes 86 1-1 4

SCHUBAUERJ P AVD D S HOPKINSON 1984 Above and belowground emergent macrophyte production and turnover in a coastal marsh ecosystem Georgia Limnolog7 and Oceanographj 291052-1065

SERVICES K ~ L U DR E FELLER 1992 Long-term trends o f s u b tidal macrobenthos in North Inlet South Carolina Hydrobiol-opa 23113-40

SHERRB F E B SHERR J MCD~LUIELLYD 1992 Effect o f p r e tistan grazing o n the frequency o f dividing cells i n bacterioplankton assemblages Applied and Environmental 1Microbiology 582381-2385

SHERRB F E B SHERR C PEDROS-ALIO AVD 1989 Simulta- neous measurement o f bacterioplankton production and pro- tozoan bacterivory in estuarine water 1Marine Ecology Progress Saes 54209-219

SHERRE B B F SHERR ~ L U DS Y NEWTELL R D FALLON 1986 Small aloricate ciliates as a major component o f the marine heterotrophic nanoplankton Lzmnology and Oceanography 33 177-183

SHERRE B B F SHERR~ L U DJ MCDANIEL1991 Clearance rates o f lt 6 b m fluorescently labeled algae (FLA) by estuarine protozoa Potential grazing impact o f flagellates and ciliates Marine Ecology Progress Saes 6981-92

SIGMOND E AVD L B C-VIOON 1997 Comparative effects o f benthic microalgae and phytoplankton o n dissolved silica fluxes Aquatic Microbial Ecology 13275-284

STETENSON M S KEVUTEY 1986 Vertical J C L G W m AVD

accretion in marshes with varying rates o f sea level rise p 241-259 In D A Mblfe ( e d ) Estuarine Variability Academic Press Orlando

STETNSONJ C L G U T m AND M S KEARYEY 1988 Sedi- ment transport and trapping i n marsh systems Implications o f tidal flux studies Marine G e o l o ~ 8037-59

S U L L ~ ~ ~ L U 1990 Edaphic algae are M J ~ L U DC A MONCREIFF an important component o f salt marsh food-webs Evidence from multiple stable isotope analyses 1Marine Ecology Progress Saes 623149-159

SCN H AVD D J FURBISH1997 Annual precipitation and river discharges i n Florida i n response to El Nifio- and La Niiia-sea surface temperature anomalies Journal of Hydrology 1 9 9 7 4 87

TESTERP M GEESEY ampYD 1995C GUO H P~ERL D MILLIE Evaluating phytoplankton dynamics in the Neuport River estuary (North Carolina USA) by HPLC-derived pigment pro- files ~VtarineEcology Progress Smes 124237-245

TESTERP A R STCMPF F M VUKOTCH P K FOWZER LYD J T TLIRNER1991 An expatriate red tide bloom Transport distribution and persistence Limnology and Oceanography 36 1053-1061

THAYER G W 1971 Phytoplankton production and the distribution o f nutrients in a shallow unstratified estuarine system near Beaufort NC Chesapeake Science 12240-253

TKAYER G UT D E HOSS M A KJELSON ANDUr F HETTLER M WLACROIX1974 Biomass o f zooplankton in the Neuport River Estuary and the influence o f postlarval fishes Chesapeake Science 159-16

THAER G W D A WOLFE ASD 1975 T h e R B WILLIAMS impact o f man on seagrass systems American Scientist 63288-296

T ISSUET S LEWTS H WOOD ASDJ KENDER J K ABOH 1994 Effects o f Hurricane Hugo o n sediment quality and disuibu- tion in the Charleston harbor estuary USA p 61-66 In K

R Dyer and R J Orth (eds) Changes in Fluxes in Estuaries Implications from Science to Management Olsen and Olsen Fredensborg Denmark

TURNERR E 1976 Geographic variations i n salt marsh macrophyte production A review Contributions in Marine Science (Texas) 2047-68

VALIELAI J M TEAL S D ALLENR V VAN ETTEN D GOEH- RINGERLVD S VOLKWANN 1985 Decomposition in salt marsh ecosystems T h e phases and major factors affecting disap pearance o f aboveground organic matter Journal ofExpampmamp- tal 1Marine Biology and Ecology 8929-54

VAY DOL-VI R F LYD G S ~ N D E R S O N 1991 Effects o f Hurri- cane Hugo o n salinity and dissolved oxygen conditions in Charleston Harbor estuary Journal of Coastal Research 833-94

VERITYP G J A YODER J R NELSON J S BISHOP D B CRA- TN J 0 BUYDON C Y ROBERTSON C R TRONZO AND

1993 Composition productivity and nutrient chemistry o f a coastal ocean planktonic food web Continental ShelfResearch 13741-776

VERNBERGF J 1993 Salt-marsh processes A review Envzron-mental Toxicolo~ and Chemistrj 122167-2195

VERNBERG E BLOOD A FORTNERF J W B VERNBERG M FCLTON H MCKELM UT MICHENER G SCOTT T S IEWCKI LYD K EL FIGI 1992 Impact o f urbanization o n high-salinity estuaries in the Southeastern United States LVetherlands Jour- nal of Sea Research 30239-248

V I R N S T E I N F G LEMTS R K HOW R W W G NELSON 111 ampYD

ARD 1984 Latitudinal patterns in seagrass epifauna Do patterns exist and can they be explained Estuaries 7310-330

VOGELR L B KJERFVE L R G ~ N E R LVD 1996 Inorganic sediment budget for North Inlet salt marsh South Carolina USA ~Vtangroves and Salt Marshes 123-35

UARD L G 1981 Suspended-material transport in marsh tidal channels Kiawah Island South Carolina ~Vtarine G e o l o ~ 40 139-1 54

W E I N S T E I N M P 1979 Shallow marsh habitat as primary nurs- eries for fishes and shellfish Cape Fear River North Carolina Fisherj Bulletin 77339-357

W E T Z M A J LEMTTUS AVDE T KOEPFLER K C HAES 1999 Seasonal and spatial variation within the microzooplankton community o f North Inlet estuary SC p 1265-1267 In R D Yearout (ed) Proceedings National Conference o n Under- graduate Research 1999 Volume 4 T h e University o f North Carolina at Asheville Ashbille North Carolina

WILKINSONM 1980 Estuarine benthic algae and their environ- ment A rebiew p 425-486 In J H Price D E G Irvine and UTF Farnham (eds) T h e Shore Enbironment Volume 2 Academic Press New York

W I N D O M H L W J N E ~ L AND K C BECK 1971 Mineralogy o f sediments in three Georgia estuaries Journal of Sedimentary Petrology 41497-504

WOODMANSEER A 1958 T h e seasonal distribution o f the zooplankton o f f Chicken Key in Biscayne Bay Florida E c o l o ~39 247-262

ZEITZSCHEL 1990 Zoogeography o f marine protozoa An B overview emphasizing distribution o f planktonic forms p 139-185 In G M Capriulo ( e d ) Ecology o f Marine Proto- zoa Oxford University Press New York

Z I E W J C 1975 Tropical seagrass systems and pollution p 63-74 In E J F Wood and R E Johannes (eds) Tropical Marine Pollution Elsevier New York

Z I E W J C 1982 T h e Ecology o f the Seagrasses o f South Flor- ida A Community Profile US Fish and Wildlife Service O f - fice o f Biological Services Washington DC

Z I E W J C ASD R WETZEL 1980 Methods and rates o f productivity in seagrasses p 87-116 In R C Phillips and C P McRoy (eds ) Handbook o f Seagrass Biology Garland STMP Press New York

Southeast Atlantic US Estuaries 81 9

SOURCESOF UNPUBLISHEDMATERIALS NORTH CAROLINA OF WATER QUALITY DEPARTMENT 1996 Cape Fear River Basinwide Water Quality Management Plan North

MORANM A personal communication Department of Marine Carolina Division of Water Quality Water Quality Section Sciences University of Georgia Athens Georgia 30602 PO Box 29535 Raleigh North Carolina

MORTONS L personal communication Marine Biotoxins Pro- gram National Ocean Service Charleston Laboratory 219 Received f m consideration November 16 1998 Fort Johnson Road Charleston South Carolina 29422 Accepted for publication September 22 2000

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Estuaries of the South Atlantic Coast of North America Their Geographical SignaturesRichard Dame Merryl Alber Dennis Allen Michael Mallin Clay Montague Alan LewitusAlice Chalmers Robert Gardner Craig Gilman Bjoumlrn Kjerfve Jay Pinckney Ned SmithEstuaries Vol 23 No 6 (Dec 2000) pp 793-819Stable URL


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Literature Cited

The Abundance of Estuarine Larval and Juvenile Fish in a South Carolina Intertidal CreekEarl L Bozeman Jr John Mark DeanEstuaries Vol 3 No 2 (Jun 1980) pp 89-97Stable URL

httplinksjstororgsicisici=0160-8347281980062933A23C893ATAOELA3E20CO3B2-P

Implications of Harmful Microalgae and Heterotrophic Dinoflagellates in Management ofSustainable Marine FisheriesJoAnn M BurkholderEcological Applications Vol 8 No 1 Supplement Ecosystem Management for Sustainable MarineFisheries (Feb 1998) pp S37-S62Stable URL

httplinksjstororgsicisici=1051-0761281998022983A13CS373AIOHMAH3E20CO3B2-G

Pfiesteria piscicida and Other Pfiesteria-Like Dinoflagellates Behavior Impacts andEnvironmental ControlsJoAnn M Burkholder Howard B Glasgow JrLimnology and Oceanography Vol 42 No 5 Part 2 The Ecology and Oceanography of HarmfulAlgal Blooms (Jul 1997) pp 1052-1075Stable URL

httplinksjstororgsicisici=0024-35902819970729423A53C10523APPAOPD3E20CO3B2-G

httpwwwjstororg

LINKED CITATIONS- of 7 -

Sediment Grain Size Effect on Benthic Microalgal Biomass in Shallow Aquatic EcosystemsL B Cahoon J E Nearhoof C L TiltonEstuaries Vol 22 No 3 Part B Selected Papers Third Annual Marine and Estuarine ShallowWater Science and Management Conference (Sep 1999) pp 735-741Stable URL

httplinksjstororgsicisici=0160-83472819990929223A33C7353ASGSEOB3E20CO3B2-I

Oxygen and Carbon Dioxide Mass Balance for the Estuarine-Intertidal Marsh Complex ofFive Rivers in the Southeastern USWei-Jun Cai Lawrence R Pomeroy Mary Ann Moran Yongchen WangLimnology and Oceanography Vol 44 No 3 Part 1 (May 1999) pp 639-649Stable URL

httplinksjstororgsicisici=0024-35902819990529443A33C6393AOACDMB3E20CO3B2-P

Annual Phytoplankton Cycle of the Cape Fear River Estuary North CarolinaEdward J CarpenterChesapeake Science Vol 12 No 2 (Jun 1971) pp 95-104Stable URL

httplinksjstororgsicisici=0009-32622819710629123A23C953AAPCOTC3E20CO3B2-B

Ramet Population Dynamics and Net Aerial Primary Productivity of Spartina AlternifloraTing Dai Richard G WiegertEcology Vol 77 No 1 (Jan 1996) pp 276-288Stable URL

httplinksjstororgsicisici=0012-96582819960129773A13C2763ARPDANA3E20CO3B2-M

Fragmentation and Flow Regulation of River Systems in the Northern Third the WorldMats Dynesius Christer NilssoScience New Series Vol 266 No 5186 (Nov 4 1994) pp 753-762Stable URL

httplinksjstororgsicisici=0036-807528199411042933A2663A51863C7533AFAFROR3E20CO3B2-H

The Distribution of Juncus roemerianus in the Salt Marshes of North AmericaLionel N EleuteriusChesapeake Science Vol 17 No 4 (Dec 1976) pp 289-292Stable URL

httplinksjstororgsicisici=0009-32622819761229173A43C2893ATDOJRI3E20CO3B2-2

httpwwwjstororg

LINKED CITATIONS- Page 2 of 7 -

Distribution and Community Structure of Estuarine CopepodsRolland S Fulton IIIEstuaries Vol 7 No 1 (Mar 1984) pp 38-50Stable URL

httplinksjstororgsicisici=0160-8347281984032973A13C383ADACSOE3E20CO3B2-0

Dolphin Feeding out of Water in a Salt MarshH D HoeseJournal of Mammalogy Vol 52 No 1 (Feb 1971) pp 222-223Stable URL

httplinksjstororgsicisici=0022-23722819710229523A13C2223ADFOOWI3E20CO3B2-A

Zooplankton Dynamics in an Intertidal Salt-Marsh BasinDorian S Houser Dennis M AllenEstuaries Vol 19 No 3 (Sep 1996) pp 659-673Stable URL

httplinksjstororgsicisici=0160-83472819960929193A33C6593AZDIAIS3E20CO3B2-U

Regional Nitrogen Budgets and Riverine N amp P Fluxes for the Drainages to the North AtlanticOcean Natural and Human InfluencesR W Howarth G Billen D Swaney A Townsend N Jaworski K Lajtha J A Downing RElmgren N Caraco T Jordan F Berendse J Freney V Kudeyarov P Murdoch Zhu Zhao-LiangBiogeochemistry Vol 35 No 1 Nitrogen Cycling in the North Atlantic Ocean and Its Watersheds(Oct 1996) pp 75-139Stable URL

httplinksjstororgsicisici=0168-25632819961029353A13C753ARNBARN3E20CO3B2-A

Predicted Impacts of Elevated Temperature on the Magnitude of the Winter- SpringPhytoplankton Bloom in Temperate Coastal Waters A Mescosm StudyAimee A Keller Candace A Oviatt Henry A Walker Jamie D HawkLimnology and Oceanography Vol 44 No 2 (Mar 1999) pp 344-356Stable URL

httplinksjstororgsicisici=0024-35902819990329443A23C3443APIOETO3E20CO3B2-P

httpwwwjstororg


Discovery of the Phantom Dinoflagellate in Chesapeake BayAlan J Lewitus Roman V Jesien Todd M Kana JoAnn M Burkholder Howard B Glasgow JrEric MayEstuaries Vol 18 No 2 (Jun 1995) pp 373-378Stable URL

httplinksjstororgsicisici=0160-83472819950629183A23C3733ADOT22DI3E20CO3B2-J

Seasonal Variation in the Regulation of Phytoplankton by Nitrogen and Grazing in aSalt-Marsh EstuaryAlan J Lewitus Eric T Koepfler James T MorrisLimnology and Oceanography Vol 43 No 4 (Jun 1998) pp 636-646Stable URL

httplinksjstororgsicisici=0024-35902819980629433A43C6363ASVITRO3E20CO3B2-B

Temperature Regulation of Nitrate Uptake A Novel Hypothesis about Nitrate Uptake andReduction in Cool-Water DiatomsMichael W Lomas Patricia M GlibertLimnology and Oceanography Vol 44 No 3 Part 1 (May 1999) pp 556-572Stable URL

httplinksjstororgsicisici=0024-35902819990529443A33C5563ATRONUA3E20CO3B2-V

Composition and Seasonality of Zooplankton of North Inlet South CarolinaDarcy J Lonsdale Bruce C CoullChesapeake Science Vol 18 No 3 (Sep 1977) pp 272-283Stable URL

httplinksjstororgsicisici=0009-32622819770929183A33C2723ACASOZO3E20CO3B2-7

The Ecology of MangrovesAriel E Lugo Samuel C SnedakerAnnual Review of Ecology and Systematics Vol 5 (1974) pp 39-64Stable URL

httplinksjstororgsicisici=0066-41622819742953C393ATEOM3E20CO3B2-M

Zooplankton Abundance and Community Structure in a Mesohaline North Carolina EstuaryMichael A MallinEstuaries Vol 14 No 4 (Dec 1991) pp 481-488Stable URL

httplinksjstororgsicisici=0160-83472819911229143A43C4813AZAACSI3E20CO3B2-R

httpwwwjstororg


Phytoplankton Ecology of North Carolina EstuariesMichael A MallinEstuaries Vol 17 No 3 (Sep 1994) pp 561-574Stable URL

httplinksjstororgsicisici=0160-83472819940929173A33C5613APEONCE3E20CO3B2-H

Planktonic Trophic Transfer in an Estuary Seasonal Diel and Community Structure EffectsMichael A Mallin Hans W PaerlEcology Vol 75 No 8 (Dec 1994) pp 2168-2184Stable URL

httplinksjstororgsicisici=0012-96582819941229753A83C21683APTTIAE3E20CO3B2-23

Hurricane Effects on Water Quality and Benthos in the Cape Fear Watershed Natural andAnthropogenic ImpactsMichael A Mallin Martin H Posey G Christopher Shank Matthew R McIver Scott H EnsignTroy D AlphinEcological Applications Vol 9 No 1 (Feb 1999) pp 350-362Stable URL

httplinksjstororgsicisici=1051-0761281999022993A13C3503AHEOWQA3E20CO3B2-2

Suspended Matter in Surface Waters of the Atlantic Continental Margin from Cape Cod tothe Florida KeysFrank T Manheim Robert H Meade Gerard C BondScience New Series Vol 167 No 3917 (Jan 23 1970) pp 371-376Stable URL

httplinksjstororgsicisici=0036-807528197001232933A1673A39173C3713ASMISWO3E20CO3B2-Y

Coastal Eutrophication and Harmful Algal Blooms Importance of Atmospheric Depositionand Groundwater as New Nitrogen and Other Nutrient SourcesHans W PaerlLimnology and Oceanography Vol 42 No 5 Part 2 The Ecology and Oceanography of HarmfulAlgal Blooms (Jul 1997) pp 1154-1165Stable URL

httplinksjstororgsicisici=0024-35902819970729423A53C11543ACEAHAB3E20CO3B2-R

httpwwwjstororg


Sulfur Carbon and Nitrogen Isotopes Used to Trace Organic Matter Flow in the Salt-MarshEstuaries of Sapelo Island GeorgiaBruce J Peterson Robert W HowarthLimnology and Oceanography Vol 32 No 6 (Nov 1987) pp 1195-1213Stable URL

httplinksjstororgsicisici=0024-35902819871129323A63C11953ASCANIU3E20CO3B2-23

Biomass and Production of Benthic Microalgal Communities in Estuarine HabitatsJ Pinckney R G ZingmarkEstuaries Vol 16 No 4 (Dec 1993) pp 887-897Stable URL

httplinksjstororgsicisici=0160-83472819931229163A43C8873ABAPOBM3E20CO3B2-O

Algal Productivity in Salt Marshes of GeorgiaLawrence R PomeroyLimnology and Oceanography Vol 4 No 4 (Oct 1959) pp 386-397Stable URL

httplinksjstororgsicisici=0024-3590281959102943A43C3863AAPISMO3E20CO3B2-3

Observations on Dinoflagellate BloomsLawrence R Pomeroy Harold H Haskin Robert A RagotzkieLimnology and Oceanography Vol 1 No 1 (Jan 1956) pp 54-60Stable URL

httplinksjstororgsicisici=0024-3590281956012913A13C543AOODB3E20CO3B2-8

Above-and Belowground Emergent Macrophyte Production and Turnover in a Coastal MarshEcosystem GeorgiaJ P Schubauer C S HopkinsonLimnology and Oceanography Vol 29 No 5 (Sep 1984) pp 1052-1065Stable URL

httplinksjstororgsicisici=0024-35902819840929293A53C10523AABEMPA3E20CO3B2-W

Small Aloricate Ciliates as a Major Component of the Marine Heterotrophic NanoplanktonEvelyn B Sherr Barry F Sherr Robert D Fallon Steven Y NewellLimnology and Oceanography Vol 31 No 1 (Jan 1986) pp 177-183Stable URL

httplinksjstororgsicisici=0024-35902819860129313A13C1773ASACAAM3E20CO3B2-Y

httpwwwjstororg


An Expatriate Red Tide Bloom Transport Distribution and PersistencePatricia A Tester Richard P Stumpf Fred M Vukovich Patricia K Fowler Jefferson T TurnerLimnology and Oceanography Vol 36 No 5 (Jul 1991) pp 1053-1061Stable URL

httplinksjstororgsicisici=0024-35902819910729363A53C10533AAERTBT3E20CO3B2-T

Phytoplankton Production and the Distribution of Nutrients in a Shallow UnstratifiedEstuarine System near Beaufort N CGordon W ThayerChesapeake Science Vol 12 No 4 (Dec 1971) pp 240-253Stable URL

httplinksjstororgsicisici=0009-32622819711229123A43C2403APPATDO3E20CO3B2-S

Biomass of Zooplankton in the Newport River Estuary and the Influence of Postlarval FishesGordon W Thayer Donald E Hoss Martin A Kjelson William F Hettler Jr Michael W LacroixChesapeake Science Vol 15 No 1 (Mar 1974) pp 9-16Stable URL

httplinksjstororgsicisici=0009-32622819740329153A13C93ABOZITN3E20CO3B2-Y

Latitudinal Patterns in Seagrass Epifauna Do Patterns Exist and Can They be ExplainedRobert W Virnstein Walter G Nelson F Graham Lewis III Robert K HowardEstuaries Vol 7 No 4 Part A Faunal Relationships in Seagrass and Marsh Ecosystems (Dec1984) pp 310-330Stable URL

httplinksjstororgsicisici=0160-8347281984122973A43C3103ALPISED3E20CO3B2-R

The Seasonal Distribution of the Zooplankton off Chicken Key in Biscayne Bay FloridaRobert A WoodmanseeEcology Vol 39 No 2 (Apr 1958) pp 247-262Stable URL

httplinksjstororgsicisici=0012-96582819580429393A23C2473ATSDOTZ3E20CO3B2-5

httpwwwjstororg


Estuaries Vol 23 No 6 p 793-819 December 2000

Estuaries of the South Atlantic Coast of North America Their

Geographical Signatures

RICHARDDAMEMERRYL ALL EN^ MICHAEL MONTAGUE~ALBER2 DENNIS CR ALL IN^ CLAY ALAN LEWITUS~ALICE CHALMERS ROBERT CRAIG GILMAN GARDNER~ BJORN KJERFVE~ JAY PINCKNEAND NED SMITH

Coastal Carolina University Conway South Carolina 29528 UniversiQ of Georpa Athens Georgza 30602 Qaruch Marine Laboratory UniversiQ of South Carolina Georgetown South Carolina 29442 4University of North Carolina at Wilmington Wilmington North Carolina 28403 University of Florida Gainesville Florida 3261 1 Texas A ampM University College Station Texas 77843

Harbor Branch Oceanographic Institute Fort Pierce Florida 34946

ABSTRACT Estuaries of the southeastern Atlantic coastal plain are dominated by shallow meso-tidal bar-built systems interspersed with shallow sounds and both low flow coastal plain and high flow piedmont r i v e ~ e systems Three general geographical areas can be discriminated the sounds of North Carolina the alternating series of riverine and ocean dominated bar-built systems of South Carolina Georgia and northeast Florida and the subtropical bar-built estuaries of the Florida southeast coast The regional climate ranges from temperate to subtropical with sea level rise and hurricanes having a major impact on the regions estuaries because of its low and relatively flat geomorphology Primary production is highest in the central region Seagrasses are common in the northern and southern most systems while intertidal salt marshes composed of Spartina alterniJlora reach their greatest extent and productivity in South Carolina and Georgia Nuisance blooms (cyanobacteria dinoflagellates and cryptomonads) occur more frequently in the northern and extreme southern parts of the region Fishery catches are highest in the North Carolina and Florida areas Human population growth with its associated urbanization reaches a maximum in Florida and it is thought that the long-term sustainability of the Florida coast for human habitation will be lost within the next 25 years Tidal flushing appears to play an important role in mitigating anthropogenic inputs in systems of moderate to high tidal range ie the South Carolina and Georampa coasts The most pressing environmental problems for the estuaries of the southeastern Atlantic coast seem to be nutrient loading and poor land use in North Carolina and high human population density and growth in Florida The future utilization of these estuarine systems and their services will depend on the development of improved management strategies based on improved data quality

Introduction framework related to estuarine type and location The southeastern coast of the United States is a Anthropogenic influences resulting from increas-

broad coastal plain bordered with barrier islands ing human population density urbanization in- and beaches interspersed with tidal inlets and riv- dustrial development and changing agricultura~ ers After centuries of relatively low human popu- practices are then addressed Finally we synthesize lation density this highly productive area is now these characteristics into geographical signatures undergoing intense development that is rapidly for southeastern estuaries and point out important impacting the structure and function of regional informational gaps The paper as a whole seeks to estuarine ecosystems In this review we first de- provide a current overview of the status of south- scribe the location and types of estuaries in the eastern Atlantic estuaries and to serve as an infor- region Then the available published data on the mational starting point for those interested in the physical parameters ie salinity water fluxes and structure and function of these ecosystems nutrient fluxes influencing these systems are pre- Geographical and Geological Setting sented comparatively The biotic components of these estuaries are examined in a trophic dynamic The southeastern coastal plain of the United

States is divided into two relatively large geograph-

Corresponding author address Marine Science PO Box ical reaches The South Atlantic Bight (SAB) is lo-

261954 Coastal Carolina University Conway South Carolina cated between Cape Hatteras North Carolina 29528 tele 843349-2216 fax 843349-2926 e-mail (353N and 755W) and Cape Canaveral Florida damecoastaledu (284N and 806W) and the southeastern Florida

O 2000 Estuarine Research Federation 793

794 R Dame et al





Types of Estuaries






-7 MEAN MINIMUM

MONTHLY TEMPERATURE


796 RDame et al

ECU ( ltgtJ2--a



USC

USC-BARUCH



NERR

NERR

FLORIDA

t 4 g

i










798 R Dame et al


State





















800 R Dame et al


O 2



0 PO Concentration

010




Discharge 400

7



1000 NH L o a d

NO + NO Load

PO Load











802 R Dame et al
















804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

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1 1980 1990 2000 2010

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- -





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X X X X

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X X X X

X X X X

X X X X

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814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


794 R Dame et al





Types of Estuaries






-7 MEAN MINIMUM

MONTHLY TEMPERATURE


796 RDame et al

ECU ( ltgtJ2--a



USC

USC-BARUCH



NERR

NERR

FLORIDA

t 4 g

i










798 R Dame et al


State





















800 R Dame et al


O 2



0 PO Concentration

010




Discharge 400

7



1000 NH L o a d

NO + NO Load

PO Load











802 R Dame et al
















804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

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1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

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1 1980 1990 2000 2010

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814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































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httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg




-7 MEAN MINIMUM

MONTHLY TEMPERATURE


796 RDame et al

ECU ( ltgtJ2--a



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798 R Dame et al


State





















800 R Dame et al


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802 R Dame et al
















804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

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1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

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1 1980 1990 2000 2010

-- YEAR

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814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


796 RDame et al

ECU ( ltgtJ2--a



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NERR

NERR

FLORIDA

t 4 g

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798 R Dame et al


State





















800 R Dame et al


O 2



0 PO Concentration

010




Discharge 400

7



1000 NH L o a d

NO + NO Load

PO Load











802 R Dame et al
















804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

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1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

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1 1980 1990 2000 2010

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- -





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X X X X X

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814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg










798 R Dame et al


State





















800 R Dame et al


O 2



0 PO Concentration

010




Discharge 400

7



1000 NH L o a d

NO + NO Load

PO Load











802 R Dame et al
















804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

X X X X X

X X X X

X X X X

X X X X

X X X X

X X X X

X X X X

X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg












800 R Dame et al


O 2



0 PO Concentration

010




Discharge 400

7



1000 NH L o a d

NO + NO Load

PO Load











802 R Dame et al
















804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

X X X X X

X X X X

X X X X

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X X X X

X X X X

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X X X X

X X X X

X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


1000 NH L o a d

NO + NO Load

PO Load











802 R Dame et al
















804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

X X X X X

X X X X

X X X X

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X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


802 R Dame et al
















804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg









804 R Dame et al













Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

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X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































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Literature Cited







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httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg








Source





806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































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httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


806 R Dame et al


Area (ha)



42923 112766 121335 10536

40712 36882 30337 28304



Total Source






Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

X X X X X

X X X X

X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







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httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg




Estual-u Form















808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







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httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


808 R Dame et al









663 202 130 460 1600

780 1445 819 441 933 686









Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

X X X X X

X X X X

X X X X

X X X X

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X X X X

X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







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httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg




Estuarv


( I L ~ )





60 156 153

64 and 200 239

Sample Period








MToodmansee (1958)






0



810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


810 R Dame et al









-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

X X X X X

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X X X X

X X X X

X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


-- - - - -- - --



25 I 25000 I





1988 1989 1990 1991 1992 1993 1994 1995 1998 1997 1998 p-

Ncerllm nNcrrhtlh





1988 1989 1990 1991 1991 1993 1994 1995 19 1997 1998



81 2 R Dame et al











POPULATION

( X 101

b 2 P

1 1980 1990 2000 2010

-- YEAR

- -





Estuarv L ML M MH






X X X X X

X X X X X

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X X X X

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2 5 5 8 2 1 0 3 8 4 7





814 R Dame et al



























































816 R Dame et al























































































818 R Dame et al


















































Literature Cited







httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg














httpwwwjstororg












httpwwwjstororg


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Estuaries of the South Atlantic Coast of North … and publications/2000...Estuaries Vol. 23, No. 6,...

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Transcript of Estuaries of the South Atlantic Coast of North … and publications/2000...Estuaries Vol. 23, No. 6,...