# September 1996 

# NOAA's Estuarine Eutrophication Survey Volume 1: South Atlantic Region

Office of Ocean Resources Conservation and Assessment National Ocean Service National Oceanic and Atmospheric Administration U.S. Department of Commerce

# The National Estuarine Inventory The National Estuarine Inventory (NEI) represents a series of activities conducted by NOAA’s Office of Ocean Resources Conservation and Assessment (ORCA) since the early 1980s to define the nation’s estuarine resource base and develop a national assessment capability. Over 120 estuaries are included (Appendix 3), representing over 90 percent of the estuarine surface water and freshwater inflow to the coastal regions of the contiguous United States. Each estuary is defined spatially by an estuarine drainage area (EDA)—the land and water area of a watershed that directly affects the estuary. The EDAs provide a framework for organizing information and for conducting analyses between and among systems. To date, ORCA has compiled a broad base of descriptive and analytical information for the NEI. Descriptivetopics include physical and hydrologic characteristics, distribution and abundance of selected fishes and invertebrates, trends in human population, building permits, coastal recreation, coastal wetlands, classified shellfish growing waters, organic and inorganic pollutants in fish tissues and sediments, point and nonpoint pollution for selected parameters, and pesticide use. Analytical topics include relative susceptibility to nutrient discharges, structure and variability of salinity, habitat suitability modeling, and socioeconomic assessments.For a list of publications or more information about the NEI, contact C. John Klein, Chief, Physical Environments Characterization Branch, at the address below.



# The Estuarine Eutrophication Survey ORCA initiated the Estuarine Eutrophication Survey in October 1992. The goal is to comprehensively assess the scale and scope of nutrient enrichment and eutrophication in the NEI estuaries (see above) and to provide an information base for formulating a national response that may include future research and monitoring. The Survey is based, in part, upon a series of workshops conducted by ORCA in 1991-92 to facilitate the exchange of ideas on eutrophication in U.S. estuaries and to develop recommendations for conducting a nationwide survey. The survey process involves the systematic acquisition of a consistent and detailed set of qualitative data from the existing expert knowledge base (i.e., coastal and estuarine scientists) through a series of surveys, site visits, and regional workshops.The original survey forms were mailed to over 400 experts in 1993. The methods and initial results were evaluated in May 1994 by a panel of NOAA, state, and academic experts. The panel recommended that ORCA proceed with a regional approach for completing data collection, including site visits with selected experts to fill data gaps, regional workshops to finalize and reach consensus on the responses to each question, and regional reports on the results. The Mid-Atlantic regional workshop was held in January 1995 and a draft regional report has been completed. The South Atlantic regional workshop was held in February 1996 and this document is the regional report. Site visits, regional workshops, and regional reports will be completed for the Gulf of Mexico, North Atlantic, and West Coast in the next six to eight months. A national assessment report of the status and health of the nation’s estuaries will be developed from the survey results. In addition, an “indicator” of ecosystem health will also be published. Both national products will require one or more workshops to discuss and reach consensus on the methods proposed for conducting these analyses. ORCA also expects to recommend a series of follow-up activities that may include additional and/or improved water quality monitoring, and case studies in specific estuaries for further characterization and analysis. For publications or additional information, contact Suzanne Bricker, Project Manager, at the address below. Strategic Environmental Assessments Division/ORCA 1305 East West Highway, SSMC-4, N/ORCA1 Silver Spring, MD 20910 301/713-3000 http://seaserver.nos.noaa.gov

# NOAA's Estuarine Eutrophication Survey Volume 1: South Atlantic Region

Office of Ocean Resources Conservation and Assessment National Ocean Service National Oceanic and Atmospheric Administration Silver Spring, MD 20910



# September 1996

This report should be cited as: National Oceanic and Atmospheric Administration (NOAA), 1996. NOAA's Estuarine Eutrophication Survey. Volume 1: South Atlantic Region. Silver Spring, MD. Office of Ocean Resources Conservation Assessment. 50 p.

## Introduction ........................................... 1 The Problem .............................................. 1 Objectives .................................................. 1 Methods ..................................................... 2 Next Steps .................................................. 5 

## Regional Overview ............................... 6

The Setting: Regional Geography .......... 6 About the Results ..................................... 8 Algal Conditions....................................... 8 Chlorophyll a Turbidity Total Suspended Solids Nuisance Algae Toxic Algae Macroalgae Epiphytes Nutrients .................................................. 12 Nitrogen Phosphorus Dissolved Oxygen ..................................... 13 Anoxia Hypoxia Biological Stress Ecosystem Response .............................. 15 Primary Productivity Planktonic Community Benthic Community SAV Intertidal Wetlands 

## References ............................................ 17 Estuary Summaries ............................. 19 Regional Summary...............................42 Appendix 1: Participants ................... 43 Appendix 2: Estuary References ...... 45 Appendix 3: NEI Estuary List ........... 50The Office of Ocean Resources Conservation and Assessment (ORCA) is one of four major line offices of the National Oceanic and Atmospheric Administration's (NOAA) National Ocean Service. ORCA provides data, information, and knowledge for decisions that affect the quality of natural resources in the nation's coastal, estuarine, and marine areas. It also manages NOAA's marine pollution programs. ORCA consists of three divisions and a center: the Strategic Environmental Assessments Division (SEA), theCoastal Monitoring and Bioeffects Assessment Division (CMBAD), the Hazardous Materials Responseand Assessment Division (HAZMAT), and the Damage Assessment Center (DAC), part of NOAA's Damage Assessment and Restoration Program. 

# Project Team Suzanne Bricker, Project Manager Christopher Clement Scot Frew Michelle Harmon Douglas Pirhalla 

# Acknowledgments The Project Team would like to thank SEA Division Chief Daniel J. Basta as well as Charles Alexander andC. John Klein of the SEA Division for providing direction and support throughout the development of the report and the survey process. Our thanks also go to Elaine Knight of South Carolina Sea Grant, and GailMoody at the National Ocean Service's Coastal Service Center, for logistical support during the SouthAtlantic Regional Workshop. Finally, we gratefully acknowledge the production support of Miranda Harris and Pam Rubin of the SEA Division. 

# ORCA Organization ContentsNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 1 

# Introduction

About This Report This report presents the results of ORCA’s Estuarine Eutrophication Survey for 21 estuaries of the South Atlantic region of the United States. It is the first inwhat is expected to be a series of five regional summaries (South Atlantic, Mid-Atlantic, Gulf of Mexico, North Atlantic, and West Coast). A national report on the overall project results is also expected. The Surveyis a component of ORCA’s National Estuarine Inventory (NEI) - an ongoing series of activities to provide a better understanding of the nation’s estuaries and their attendant resources (see inside front cover).The report is organized into five sections: Introduction, Regional Overview, References, Estuary Summaries and Regional Summary. It also includes three appendices. The Introduction provides background information on project objectives, process, and methods.The Regional Overview presents a summary of findings for each parameter and includes a regional mapand maps illustrating the results for selected parameters. Next are the Estuary Summaries—one-pagesummaries of Survey results for each of 21 South Atlantic estuaries. Each page includes a narrative summary, a salinity map, a table of key physical and hydrologic information, and a matrix summary of dataresults. The Regional Summary displays existing parameter conditions and their spatial coverage across the region. Appendix 1 lists the regional experts who participated in the survey. Appendix 2 presents thereferences suggested by workshop participants for understanding better the status and trends of nutrient enrichment in South Atlantic estuaries. Appendix 3 presents a complete list of NEI estuaries.



## The Problem Between 1960-2010, U.S. population has increased, and it is projected to continue to increase, most significantlyin coastal states (Culliton et al., 1990). This steady influx of people is placing unprecedented stress on the Nation’s coastal and estuarine ecosystems. Ironically, these changes threaten the quality of life that manynew coastal residents seek. One of the most prominent barometers of coastal environmental stress is estuarine water quality, particularly with respect to the inputs of nutrients. This section presents an overview of how the Estuarine Eutrophication Survey is being conducted. It includes a statementof the problem, a summary of the project objectives, and a discussion of the project origins and methods. A diagram illustrates the project process and a table details the data being collected. The section closes with a brief description of the remaining tasks. For additional information, please see inside the front cover of this report. Coastal and estuarine waters are now among the most heavily fertilized environments in the world (Nixonet al., 1986). Nutrient sources include point (e.g. wastewater treatment plants) and nonpoint (e.g. agriculture, lawns, gardens) discharges. These inputs are known to have direct effects on water quality. For example, inextreme conditions, excess nutrients can stimulate excessive algal blooms that can lead to increased metabolism and turbidity, decreased dissolved oxygen, andchanges in community structure—a condition described by ecologists as eutrophication (Day et al., 1989; Nixon, 1995; NOAA, 1989). Indirect effects can include impacts to commercial fisheries, recreation, and even public health (e.g. Boyton et al., 1982; Rabalais and Harper, 1992; Rabalais, 1992; Paerl, 1988; Whitledge and Pulich, 1991; NOAA, 1992; Burholder et al., 1992; Cooper, 1995; Lowe et al., 1991; Orth and Moore, 1984; Kemp et al., 1983; Stevenson et al., 1993; Burkholder et al., 1992a, Ryther and Dunstun, 1971; Smayda, 1989; Whitledge, 1985; Nixon, 1983).Reports and papers from workshops, panels, and commissions have consistently identified nutrient enrichment and eutrophication as increasingly serious problems in U.S. estuaries (National Academy of Science, 1969; Ryther and Dunstan, 1971; Likens, 1972; NOAA, 1991; Frithsen, 1989; Jaworski, 1981). These conclusionsare based on numerous local and regional investigations into the location and severity of nutrient problems, and into the specific causes. However, evaluating this problem on a national scale and formulating ameaningful strategy for improvements requires a different approach.



## Objectives The Estuarine Eutrophication Survey will provide the first comprehensive assessment of the temporal scale, scope, and severity of nutrient enrichment and eutrophication-related phenomena in the Nation’s major estuaries. The goal is not necessarily to defineone or more estuaries as eutrophic. Rather, it is to systematically and accurately characterize the scale andscope of eutrophication related, water-quality parameters in over 100 U.S. estuaries. The project has four specific objectives:NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 2 into a comprehensible whole due to incompatible datatypes, formats, time periods, and methods. Alternatively, ORCA elected to systematically acquire a consistent and detailed set of qualitative data from theexisting expert knowledge base (i.e., coastal and estuarine scientists) through a series of surveys, interviews, and regional workshops. Identifying the Parameters and Parameter Characteristics To be included in the Survey, a parameter had to be (1) essential for accurate characterization of nutrient enrichment; (2) generally available for most estuaries; (3) comparable among estuaries; and (4) based uponexisting data and/or knowledge (i.e., no new monitoring or analysis required). Based upon the workshops described above and additional meetings with experts, seventeen parameters were selected (Table 1).The next step was to establish response ranges to ensure discrete gradients among responses. For example, the survey asks whether nitrogen is high, medium, or low based upon specific thresholds (e.g., High ≥1 mg/ l, Medium ≥0.1 < 1 mg/l, low > 0 <0.1 mg/l, or unknown). The ranges were determined from nationwide data and from discussions with eutrophication experts. The thresholds used to classify ranges are designed to distinguish conditions among estuaries on a national basis and may not distinguish among estuaries within a region. Temporal Framework: Existing Conditions and TrendsFor each parameter, information is requested for existing conditions and recent trends. Existing conditions describe maximum parameter values observed over a typical annual cycle (e.g., normal freshwater inflow, average temperatures, etc.). For instance, for nutrients,ORCA collected information characterizing peak concentrations observed during the annual cycle such asthose associated with the spring runoff and/or turnover. For chlorophyll a, ORCA collected informationon peak concentrations that are typically reached during a bloom period. Ancillary information is also requested to describe the timing and duration of elevated concentrations (or low levels in the case of dissolvedoxygen). This information is collected because all regions do not show the same periodicity, and, for some estuaries, high concentrations can occur at any time depending upon estuarine conditions. For some parameters, such as nuisance and toxic blooms, there is no standard threshold concentration that causes problems. In these cases a parameter is considered a problem if it causes a detrimental impacton biological resources. Ancillary descriptive information is also collected for these parameters (Table 1). 1. To assess the existing conditions and trends, for

the base period 1970 to present, of estuarine eutrophication parameters in 129 estuaries of the contiguous United States; 2. To publish results in a series of regional reports

and a national assessment report; 3. To formulate a national response to identified

problems; and 4. To develop a national “indicator” of estuarine

health based upon the survey results.ORCA also expects to recommend a series of followup activities that may include additional and/or improved water-quality monitoring, and case studies in specific estuaries for further characterization and analysis.



## MethodsThe topic of estuarine eutrophication has been receiving increasing attention recently in both the scientific literature (Nixon, 1995) and in the activities of coastal resource management agencies. In the United States, investigators have generated thousands of data recordsand dozens of reports over the past decade that document seasonal and annual changes in estuarine water quality, primary productivity, and inputs of nutrients. The operative question for this project is how to best use this knowledge and information to characterize these parameters for the contiguous United States. Preparing for a national surveyTo answer this question, ORCA conducted three workshops in 1991-92 with local and regional estuarine scientists and coastal resource managers. Two workshops held at the University of Rhode Island’s Graduate School of Oceanography in January 1991 (Hinga et al., 1991) consisted of presentations by invited speakers and discussions of the measures and effects associated with nutrient problems. The purpose was to facilitate the exchange of ideas on how to best characterizeeutrophication in U.S. estuaries and to consider suggestions for the design of ORCA’s proposed data collection survey. A third workshop, held in April 1992 at the Airlie Conference Center in Virginia, focusedspecifically on developing recommendations for conducting a nationwide survey. Given the limited resources available for this project, it was not practical to try to gather and consolidate the existing data records. Even if it were possible to do this, it would be very difficult to merge these dataNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 3 Table 1: Project parameters and characteristics. CHLOROPHYLL A

TURBIDITY

SUSPENDED SOLIDS

NUISANCE ALGAE TOXIC ALGAE

MACROALGAE EPIPHYTES

NITROGEN

ANOXIA (0 mg/l) HYPOXIA (>0 2 mg/l) BIOL. STRESS (>2 5 mg/l)

PRIMARY PRODUCTIVITY

PLANKTONIC COMMUNITY

SUBMERGED AQUATIC VEG. INTERTIDAL WETLANDS EXISTING CONDITIONS TRENDS

Hypereutrophic (>60 μg chl-a/l) High (>20, 60 μg chl-a/l) Medium (>5, 20 μg chl-a/l) Low (>0, 5 μg chl-a/l) • Surface concentrations:

• Limiting factors to algal biomass (N, P, Si, light, other) • Spatial coverage 1 , Months of occurrence, Frequency of occurrence 2 • Secchi disk depths: High (<1m), Medium (1 m, 3m), Low (>3m), Blackwater area • Concentrations 3,4

• Concentrations: Problem (significant impact upon biological resources) No Problem (no significant impact) • Months of occurrence, Frequency of occurrence 2
• Occurrence

• Dominant species • Event duration (Hours, Days, Weeks, Seasonal, Other)

• Abundance

• Maximum dissolved surface concentration: High ( 1 mg/l), Medium ( 0.1, <1 mg/l), Low ( 0, < 0.1 mg/l)

High ( 0.1 mg/l), Medium ( 0.01, <0.1 mg/l), Low ( 0, < 0.01 mg/l)

• Dissolved oxygen condition

(Surface, Bottom, Throughout water column) (High, Medium, Low, Not a factor) • Stratification (degree of influence): • Water column depth:

• Dominant primary producer: Pelagic, Benthic, Other • Temporal shift

• Dominant taxonomic group (number of cells):

Diatoms, Flagellates, Blue-green algae, Diverse mixture, Other

Crustaceans, Molluscs, Annelids, Diverse mixture, Other • Temporal shift

BENTHIC COMMUNITY • Dominant taxonomic group (number of organisms): • Temporal shift PARAMETERS

PHOSPHORUS • Maximum dissolved surface concentration: • Spatial coverage 1 , Months of occurrence • Limiting factors • Contributing factors 5

• Concentrations 3,4 • Contributing factors 5

• Event duration 3,4 • Frequency of occurrence 3,4 • Contributing factors 5

• Abundance 3,4 • Contributing factors 5

• Concentrations 3,4 • Contributing factors 5

• Concentrations 3,4 • Contributing factors 5

• Min. avg. monthly bottom dissolved oxygen conc. 3,4 • Frequency of occurrence 3,4 • Event duration 3,4 • Spatial coverage 3,4 • Contributing factors 5

• Contributing factors 5

• Contributing factors 5

• Contributing factors 5 • Spatial coverage 3,4 • Contributing factors 5

NOTES (1) SPATIAL COVERAGE (% of salinity zone): High (>50, 100%), Medium (>25, 50% ), Low (>10, 25%), Very Low (>0, 10% ), No SAV / Wetlands in system (2) FREQUENCY OF OCCURRENCE: Episodic (conditions occur randomly), Periodic (conditions occur annually or predictably), Persistent (conditions occur continually throughout the year) (3) DIRECTION OF CHANGE: Increase, Decrease, No trend (4) MAGNITUDE OF CHANGE: High (>50%, 100%), Medium (>25%, 50%), Low (>0%, 25%) (5) POINT SOURCE(S), NONPOINT SOURCE(S), OTHER • Spatial coverage 1 , Months of occurrence, Frequency of occurrence 2

• Months of occurrence, Frequency of occurrence 2

• Months of occurrence, Frequency of occurrence 2

• Spatial coverage 1 , Months of occurrence

• Spatial coverage 1 , Months of occurrence, Frequency of occurrence 2

• Spatial coverage 1 (predominant maximum values observed over a typical annual cycle) (1970 - 1995)

(no trends information requested)

Problem (significant impact upon biological resources) No Problem (no significant impact)

Observed No Occurrence ALGAL CONDITIONS

NUTRIENTS DISSOLVED OXYGEN ECOSYSTEM / COMMUNITY RESPONSE Problem (significant impact upon biological resources) No Problem (no significant impact)NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 4 Trends information is requested for characterization of the direction, magnitude, and time period of change for the past 20 to 25 years. In cases where a trend has been observed, ancillary information is requested about the factors influencing the trend. Spatial Framework A consistently applied spatial framework was also required. ORCA’s National Estuarine Inventory (NEI) was used (see inside front cover). For the survey, each parameter is characterized for three salinity zones as defined in the NEI (tidal fresh 0-0.5 ppt, mixing 0.5-25 ppt, and seawater >25 ppt). Not all zones are present in all NEI estuaries; thus the NEI model provides a consistent basis for comparisons among these highly variable estuarine systems. Reliability of Responses Finally, respondents were asked to rank the reliability of their responses for each parameter as either highlycertain or speculative inference, reflecting the robustness of the data the response is based on. This is especially important given that responses are based upon a range of information sources from statistically testedmonitoring data to general observations. The objective is to exploit all available information that can provide insight into the existing and historic conditions in each estuary, and to understand its limitations.The survey questions were reviewed by selected experts and then tested and revised prior to initiating the national survey. Salinity maps, based upon the NEIsalinity zones, are distributed with the survey questions for orientation. Updates and/or revisions to these maps were made as appropriate. Collecting the DataOver 400 experts and managers had agreed to participate in the survey. Survey forms were mailed to theexperts, who then mailed in their responses. The response rate was approximately 25 percent with at leastone response for 112 of the 129 estuaries being surveyed. The initial survey methods and results were evaluated in May 1994 by a panel of NOAA, state, and academic eutrophication experts. The panel recommended thatORCA continue the project and adopt a regional approach for data collection involving site visits to selected experts to fill data gaps and revise salinity maps, regional workshops to finalize and reach consensus on the responses to each question (including salinity maps), and regional reports on the results. The revisedstrategy was implemented in the summer of 1994 starting with the 22 estuaries of the Mid-Atlantic region. Estuaries are targeted for site visits based upon the completeness of the data received from the originalmailed survey forms. The new information is incorporated into the project data base and summary materials are then prepared for a regional workshop. Workshop participants are local and regional experts (at least one per estuary representing the group of people with the most extensive knowledge and insightabout an estuary). In general, these persons have either filled out a survey form and/or participated in a site visit. Preparations include sending all regional data to participants prior to the workshop. Participants are also encouraged to bring to the workshop relevant data and reports to consult. At the workshop, at least two workgroups are established based upon geography.
Figure 1: Diagram of process.

Survey Design National Survey

workshop on

next steps Site Visits Workshops next region
National Workshop(s) Regional Strategy

testing & review Regional Next Steps • national monitoring strategy? • research / case studies?



### 1992-93 1993-94 1995-96 1996-97 (to complete data dollection)

Reports • Inidicator Report • National Report N. Atlantic Mid Atlantic S. Atlantic Gulf of Mexico West CoastNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 5 The survey data and salinity maps for each estuary are then carefully reviewed. ORCA staff facilitate the discussions and record the results. At the close of the workshop, participants are asked to identify "critical" references such as reports and other publications that describe nutrient enrichment in one or more of the region's estuaries. Workshop results are summarized for each estuary and mailed to workshop participants for review. The dataare then compiled for presentation in a regional report that is also reviewed by participants prior to publication. The regional process, from site visits to publication of a regional report, takes approximately sixmonths to complete. Some tasks are conducted concurrently.



## Next Steps Site visits, regional workshops, and regional reports are in progress for the Gulf of Mexico, North Atlantic,and West Coast (Figure 1). A national assessment report of the status and health of the nation’s estuaries will be developed from the survey results. The regional results and final national data base will be availableover the Internet through ORCA’s Web site. Formulation of a national response to estuarine nutrient enrichment and development of a national “indicator” on coastal ecosystem health will require one or more workshops to discuss and reach consensus on the methods and products resulting from these analyses. This work is currently scheduled for 1997. ORCA isfunding a series of small contracts with regional experts to provide additional technical support for these tasks.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 6 

# Regional Overview This section presents an overview of the survey results. It begins with a brief introduction to the regional geography and a summary of how the results were compiled. Narrative summaries are then presented for each parameter in four subsections; Algal Conditions, Nutrients, Dissolved Oxygen, and Ecosystem/ Community Response. Figures include a regional map showing the location of 21 South Atlantic estuaries, a summary of probable-months-of-occurrence by parameter, four maps illustrating existing conditions for selected parameters, and a summary of recent trends by estuary for selected parameters. 

## The Setting: Regional Geography The South Atlantic coastal province includes 21 major estuarine systems and encompasses more than 4,440square miles of water surface area (Figure 2). The characteristics of this region include extensive coastal and barrier features and the Atlantic Coastal Plain. Thisregion can be subdivided into three distinct subregions: the Carolina Capes, the Sea Island Coast, and the Florida Coast. The Carolina Capes extend from Cape Hatteras, North Carolina to Cape Romain, South Carolina (approximately 50 mi. North of Charleston, SC). The Sea Island Coast includes the coastline from Cape Romain south to Cape Canaveral, Florida. The Florida Coast consists of Indian River and Biscayne Bay. Carolina Capes Major geomorphological features of the CarolinaCapes are the extensive shoal structures and the series of barrier islands off North Carolina and South Carolina. Barrier islands are composed of beach dune ridges paralleling the present shoreline. Extensive salt marshes also predominate throughout the area. Dueto the proximity of the Outer Banks region to the westward wall of the Gulf Stream, salinities tend to be higher in this area than other estuaries in the region. In the Carolina Capes, wind plays a major role in both short-term salinity structure and circulation within the estuaries. Tides are a dominant influence on water column mixing, primarily near the inlets (Orlando et

During the summer months, periodic occurrences of hypoxia are observed in 13 estuaries, over 4-11% of the regional estuarine surface area. Less than 1% of the tidal fresh area and equal percentages (about 9%) of the mixing and seawater zones reportedly become hypoxic. 

### Highlights include existing information only. Trends information for the 21 South Atlantic estuaries is sparse and many reported trends are based on speculative information. Refer to text and to Figure 5 for regional trends information. (Note: Tidal Fresh = 10%, Mixing = 67%, Seawater = 23% of regional surface area (4854 mi2). Concentrations of high and hypereutrophic (>20 ug/l) are observed episodically in 11 of 21 estuaries, but only in small localized areas. Concentrations of medium or greater ( 5 ug/l) are observed periodically in 20 estuaries, over 30-55% of the regional estuarine area. These concentrations are observed for 50% of the mixing zone area and 20% of the tidal fresh and seawater zone area. Elevated concentrations occur in the summer months. Toxic algal blooms are reported to occur in 7 Carolina Capes and Florida estuaries (Albemarle/Pamlico Snds., Pamlico/Pungo R., Bogue Snd., Neuse R., New R., St. Johns R., Indian R.), with no occurrences in estuaries of the Sea Island Coast. Blooms occur primarily during summer months with typical durations on the order of days to weeks.
Concentrations of medium or greater ( 0.1 mg/l) are observed in 19 estuaries, over 10-17% of the total regional estuarine area. These concentrations are observed for about 15% of the mixing and seawater zones and about 6% of the tidal fresh zone. Elevated concentrations are observed in spring in the tidal fresh zone and summer in the mixing and seawater zones. Concentrations of medium or greater ( 0.01 mg/l) are observed in 18 estuaries, over 12-20% of the total regional estaurine area. These concentrations are observed for 37% of tidal fresh zone, 12% and 9% of the mixing and seawater zones respectively. Elevated concentrations occur in summer in the mixing and seawater zones, and spring and summer in the tidal fresh zone. During the summer months, periodic occurrences of anoxia in bottom waters are observed in 11 estuaries, over 3-9% of the regional estuarine area. Less than 1% of the tidal fresh zone and equal percentages of the mixing and seawater zones (about 6%) exhibit anoxia. Chlorophyll a Toxic Algal Blooms Phosphorus
Anoxia Nitrogen Hypoxia 

## Highlights of Regional ResultsNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 7 Figure 2: Regional map of South Atlantic showing estuaries.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 8 al., 1994). Freshwater inflow into the Albemarle/ Pamlico Sounds is dominated by discharge from the Roanoke, Chowan, Neuse-Trent and Tar-Pamlico river systems. Sediments are resuspended into the soundsthrough the main river systems and through tidal excursion within the South Atlantic Bight (Menzel, 1993). Sea Island Coast The Sea Island Coast consists of fluvial deposits such as dune sheets, point bars, and terrace formations in water inflow from drainage canals on the western side and tidal exchange through inlets on the eastern side.
The survey results are organized into four sections: Algal Conditions, Nutrients, Dissolved Oxygen, and Ecosystem Response. Each section contains a general overview followed by more detailed summaries foreach parameter. This material is based on the individual estuary summaries presented later in this report. Regional patterns and anomalies are highlighted. Existing conditions and trends are reviewed. Regionalmaps summarizing existing conditions for selected parameters are presented in Figure 4. A summary of recent trends for all parameters is presented in Figure 5. Data Reliability As described in the introduction, participants wereasked to rank the reliability of their responses as either highly certain or speculative inference. Over 80percent of the responses are highly certain. Where relevant, speculative inferences are noted in the narrative below and on the estuary summaries that follow. A highly certain response is based upon temporallyand spatially representative data from long-term monitoring, special studies, or literature. A speculative inference is based upon either very limited data or general observations. When respondents could not offer even a speculative inference, the value was recorded as "unknown".
Algal conditions were examined in the South Atlantic region by characterizing existing conditions and trends for chlorophyll a, turbidity, suspended solids, nuisance and toxic algae, macroalgal abundance, and epiphyteabundance (Table 1). High to hypereutrophic concentrations of chlorophyll a( >2 0 μ g/l) were generally reported as occurring episodically over relatively small areas, while medium concentrations ( >5 μg/l) were more widely reported and occurred more predictably. Medium or greater concentrations of chlorophyll a were reported for 66 percent of the region’s mixing zone surface area, 35 percent of the tidal fresh zone, and 31 percent of the seawater zone. Medium or greater levels of turbidity (secchi disk depths <3 meters) alsooccur primarily in the mixing zone, affecting 39 percent of the region’s mixing zone compared to 5 percent of the tidal fresh zone and 13 percent of the seawater zone. Nuisance and toxic algae events occur fairly evenly across all three zones but are concentrated in the Carolina Capes and Florida systems. Macroalgal and epiphyte abundance are the least problematic of the parameters examined and have had a minimumall of the major river valleys (Mathews, 1980). Lowlying sea islands are erosional remnants of PleistoceneAge sand bodies bordered by salt marshes, and relatively gently sloping marsh islands bound by tidal creeks. Marsh islands are geographically located in tidal marshes and are periodically inundated. Deltaicstructures within the Sea Island Coast resemble sediment-filled drowned river valleys but formation is rather limited (Mathews, 1980). Extensive clearcuttingin post-colonial times has promoted soil erosion processes and added to suspended sediments traversingthe Sea Island Coast estuaries. Estuarine mixing is induced by the turbulence of semidiurnal tide fluxes. Tidal ranges are higher in this subregion than in any other portion of the South Atlantic, with Savannah, Georgia having one of the highest ranges, near 7.2 ft. The major freshwater inflow sources for the Sea Island Coast are from rivers originating in the coastal plain and from sources in the Appalachian Mountains andthe Piedmont. The Black, Cooper, and Waccamaw Rivers of South Carolina, and the Satilla and St. MarysRivers of Georgia, compose the major coastal-plainderived riverine systems. The Pee Dee, Santee, Edisto, Savannah, Ogeechee and Altamaha Rivers originate in the Appalachian/Piedmont provinces. Florida Coast Florida is part of an anticlinal ridge system known as the Peninsular Arch, consisting of lakes and dissolved sinkhole formations with extensive barrier beachesalong the Atlantic Coast (Hunt, 1967). As in the Carolina Capes, the shallow lagoonal estuaries of Floridaare semi-enclosed by barrier island features; tidal influence is less for the Florida Coast than for the SeaIsland Coast estuaries. Salinity structure and circulation in the Indian River are dominated by wind forcing and human impacts in the form of controlledstormwater releases (Zarillo et al., 1993). Water control structures located on canals leading to Biscayne Bay are managed for flood protection. Southern Biscayne Bay consists of interconnected lagoons and a complicated network of tidal inlets with narrow flow channels and water control structures (Lee et al., 1976;Markley, 1996 pers. comm.). Horizontal density gradients can occur in these estuaries as a result of fresh

## About the Results

Algal ConditionsNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 9 impact in this region. There was a greater amount of information available for existing conditions than for trends, and because of this, in most cases it is not very meaningful to make conclusions about regional trends. Chlorophyll a High to hypereutrophic concentrations (>20 μg/l) werereported in 11 of 21 estuaries, occurring across a maximum of 11 percent of the estuarine surface area (Figure 4). These conditions were reported to occur periodically (January to late summer) in the Carolina Capes estuaries, and episodically (summer only) in the Sea Island Coast estuaries and the Indian River. Medium or greater concentrations ( >5 μg/l) of chlorophyll awere reported for 19 of 21 South Atlantic estuaries, occurring in up to 55 percent of the region’sestuarine surface area. The spatial extent of the medium or higher conditions was unknown in four estuaries and, therefore, the area affected could be larger.In general, these conditions were reported as occurring periodically from April to September with some

between 39% and 64% of the estuaries in each zone between 1% and 38% of the estuaries in each zone > 65% of the estuaries in each zone 

### Figure 3: Probable months of occurrence by parameter and by salinity zone (average). This figure illustrates the probable months, over a typical annual cycle, for which parameters are reported to occur at their maximum value. The black tone represents months where maximum values occur in at least 65 percent of South Atlantic estuaries for a particular salinity zone. For example, tidal fresh zones occur in 11 estuaries; therefore, a black tone indicates a maximum value was recorded in 7 or more estuaries. Similarly, for the mixing zone, black represents 13 or more estuaries, and for the seawater zone it represents 12 or more estuaries. Gray represents months where maximum values occur in 39 to 64 percent of the estuaries in that salinity zone, and unshaded boxes (white) represent months where maximum valuesoccur between 1 and 38 percent of the estuaries in that zone. "Months-of-occurrence" data were not collected for Ecosystem/Community Response parameters (i.e., primary productivity, planktonic community, benthic community, SAV, and intertidal wetlands). TIDAL FRESH ZONE MIXING ZONE SEAWATER ZONE 11 estuaries 20 estuaries 18 estuaries J FMAMJ J ASO ND J FMAMJ J ASO ND J FMAMJ J ASO ND Chl-a Turbidity S uspended Solids

Nuisance Algae Toxic Algae Macroalgae

Epiphytes TDN TDP Anoxia Hypoxia Biological Stress J FMAMJ J ASO ND J FMAMJ J ASO ND J FMAMJ J ASO ND 

### winter occurrences in the Carolina Capes subregion. Episodic conditions were reported for the St. Johns River and Albemarle/Pamlico Sounds.Concentrations were reported as unknown for 21 percent of the total regional area, mostly in the mixing zone. Concentrations based on speculative inferences were reported for at least one salinity zone in 10 of 21 estuaries.Limiting factors to algal growth were reported as phosphorus and nitrogen, and sometimes light, in the tidal fresh zone. Light, or phosphorus and light, were thelimiting factors in the mixing zone except in the Carolina Capes, which were reported to be nitrogen limited with silica or light sometimes co-limiting. Limiting factors in the seawater zone were reported to be nitrogen in the Carolina Capes, silica in the Sea Island Coast, and light in the Florida systems. Trends information for the Carolina Capes and the Sea Island Coast is sparse (Figure 5): the upper Pamlico River and the Neuse River were reported to have in-NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 10 were unknown for 75 percent of the region’s estuarine surface area (Figure 5). Suspended SolidsSuspended solids were reported as impacting biological resources (e.g. submerged aquatic vegetation, filter feeders, etc.) in at least one zone for five South Atlantic estuaries. Ten estuaries were reported to have no problem with suspended solids, although four ofthese also have at least one salinity zone in which suspended solids conditions are unknown. Suspended solids information was unknown in at least one zonefor 11 of 21 estuaries. Trends information was not collected for suspended solids. Nuisance/Toxic AlgaeBoth nuisance and toxic algae were reported as impacting biological resources in four estuaries (Albemarle/Pamlico Sounds, Neuse River, New River,and Indian River). In addition, toxic algae were reported as impacting resources in three estuaries (Pamlico/Pungo Rivers, Bogue Sound, and St. Johns River). Conversely, no impacts from nuisance or toxic algae were reported for estuaries along the Sea Island Coast. Nuisance events were reported as mostly periodic during the summer months (except some winter months in New River), and toxic events were reported as mostly episodic during the summer (except some winter months in Bogue Sound). The duration of toxicblooms were reported as lasting days to weeks, as compared to nuisance blooms, which were reported as lasting months to seasons. Nuisance species reported include Anabaena portoricensis , Aphanizomenon flosaquae , Microcystis aeroginosa, Anabaenopsis raciborski, various dinoflagellates, cyclotella species, and sometimes diatoms. Pfiesteria piscicidais the toxic species typically occurring in this region, but there are also some reported occurrences of Phaeocystis poucheti, and rare occurrences of Gymnodinium breve. Information reported on nuisance and toxic algae was based on speculative inferences for seven estuaries. Conditions were unknown for at least one salinity zone in six estuaries. Trends were reported only for the Neuse River, wherethe frequency of occurrence and event duration decreased in the tidal fresh zone, but increased in the mixing zone. Nuisance and toxic algae trends wereunknown in at least one salinity zone for eleven estuaries in the South Atlantic (Figure 5). 

## Blackwater EstuariesFive estuaries in the South Atlantic region are considered blackwater systems: Neuse River, Charleston Harbor, St. Helena Sound, St. Andrew/St. Simons Sounds and St. Marys River/Cumberland Sound. Blackwater estuaries typically have clear, but coffee colored waters. The color is due to the presence of organic substances (i.e. humic acid) derived from swamp drainage. As a result, secchidisc readings are persistently low despite low suspended particle concentrations. creasing chlorophyll aconcentrations in the mixing zone, eight estuaries show no trend in at least one zone, and trends in the rest of the zones are unknown. The Florida systems have had no trends in concentrations with the exception of a low magnitude increase in the St. Lucie River portion of the Indian River estuary. Trends information for Albemarle Sound, Ossabaw Sound, and St. Lucie River are based on speculative inference. Turbidity Medium to high turbidity conditions (secchi disk depths of <3 meters) were reported for at least onesalinity zone in 16 of the 21 estuaries of the South Atlantic (30 percent of the region’s estuarine surface area, largely in the mixing zone). The spatial extent of theseconditions was unknown for five estuaries and, therefore, the area affected could be larger. Furthermore, turbidity conditions were reported as unknown for anadditional 1,126 square miles (23 percent) of the regional estuarine surface area. In the tidal fresh and mixing zones, the medium and high turbidity conditions generally occur either all year (7 estuaries), or periodically during the winter and spring months (5 estuaries). In the seawater zone, medium to high turbidity occurs throughout the year (8 estuaries) or periodically from spring through fall (5 estuaries).Naturally occurring blackwater areas (see sidebar) constitute 174 square miles of estuarine surface area in parts of five South Atlantic estuaries. Secchi diskdepths in these waters typically are not recorded because they are not an accurate measure of turbidity conditions. Decreases in turbidity occurred from 1980 to 1994 in the Chowan River portion of Albemarle Sound, all of the North/South Santee Rivers, and in Biscayne Bay.Increasing turbidity was reported in at least one salinity zone for five estuaries, and no trend was reported in at least one zone for ten estuaries. Turbidity trendsNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 11 Figure 4: Existing conditions for chlorophyll a, nitrogen, phosphorus, and dissolved oxygen. Symbols indicate that an existing condition(s) (e.g., hypereutrophic for chlorophyll a, anoxia and/or hypoxia for dissolved oxygen) was reported in at least a portion of one salinity zone of an estuary at some time during a typical annual cycle. Symbols do not necessarily represent existing conditions across an entire estuary. For a more complete review of individual estuaries, turn to the estuary summaries beginning on page 19.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 12 Macroalgal/Epiphyte AbundanceMacroalgal and epiphyte abundance were characterized by collecting information on existing conditions and trends for concentrations, months of occurrence, Nitrogen High nitrogen concentrations ( ≥ 1.0 mg/l) have been observed in 11 of 21 South Atlantic estuaries (Figure 4). These observations were recorded primarily for the tidal fresh zone (up to 70 square miles or 15 percent of the regional tidal fresh zone) and mixing zone (up to 79 square miles or 2 percent of the regional mixingzone). In the seawater zone, high nitrogen concentrations were reported only for portions of the Indian River. Medium nitrogen concentrations (≥ 0.1-1.0 mg/l) have been reported in 18 of 21 South Atlantic estuaries. Low nitrogen concentrations (>0-0.1 mg/l) were reported in 9 of 21 South Atlantic estuaries. For four estuaries, existing conditions were based on eitherTotal Nitrogen (Cape Fear River and Charleston Harbor), Dissolved Inorganic Nitrogen (Bogue Sound), or ammonia plus nitrate (New River). No trends in nitrogen concentrations were reportedfor all or part of 9 of the 21 estuaries (Figure 5). Speculative increases between 25 and 100 percent over the past 8 to 15 years were reported for St. Catherines/ Sapelo Sounds and St. Andrews/St. Simons Sounds.Low magnitude (0 to 25 percent) increases were reported for the Neuse River and for the northern seawater portion of Biscayne Bay. Decreases of 25 to 100 percent were reported for Winyah Bay, North/South Santee Rivers, Stono/North Edisto River, andAltamaha River. Low magnitude increases were reported for Charleston Harbor. Trends for five estuaries were based on either Total Nitrogen (Cape FearRiver and Charleston Harbor), Total Dissolved Nitrogen (Neuse River and Bogue Sound), or ammonia plus nitrate (New River). Phosphorus High phosphorus concentrations ( ≥ 0.1mg/l) were reported in 9 of 21 South Atlantic estuaries including a small portion of the region’s tidal fresh zone (29-70 square miles or 6-15 percent), the mixing zones of NewRiver, Winyah Bay, and Charleston Harbor (throughout the year) and of Cape Fear and Broad River (during the summer months), and the seawater zone ofportions of the Indian River (Figure 4). Medium phosphorus concentrations ( ≥0.01-0.1) were reported for 16of 21 South Atlantic estuaries. Low phosphorus concentrations (>0-0.01 mg/l) were reported for Bogue Sound, St. Catherines/Sapelo Sounds, and St. Marys/ Cumberland Sounds. For three estuaries (New River,Cape Fear River and Charleston Harbor), existing conditions were based on Total Phosphorus. No trends in phosphorus concentrations were reportedfor 11 of 21 estuaries (Figure 5). Low to medium magand frequency of occurrence. Information on contributing factors influencing trends was also recorded.Charleston Harbor and Indian River are the only estuaries reported to have impacts on biological resources from macroalgal abundance. Impacts from epiphyte abundance were reported only in the St. Johns and Indian Rivers. Reported impacts typically occur from late spring through early fall. Macroalgal and epiphyte abundance was reported as unknown in at least one salinity zone for seven estuaries. An increasing trend in rooted macrophyte abundance was reported for the tidal fresh zone of Charleston Harbor for the time period 1988 to 1995. Decreasing abundances of rooted macrophytes were reported for the tidal fresh zone of Albemarle/Pamlico Sounds during the same time period. No other macrophyte abundance trends were reported. No increasing or decreasing epiphyte abundance trends were reported,although epiphyte trends for 12 estuaries were unknown in at least one salinity zone (Figure 5).
Nutrient concentrations in the South Atlantic region were characterized by collecting existing conditions and trends information for nitrogen and phosphorus. The intent was to collect information for total dissolvednutrients, since it is the dissolved forms that are available for uptake by phytoplankton. Unless specifically noted otherwise, nutrient information presented in this report refers to total dissolved nitrogen (TDN) andphosphorus (TDP), including the inorganic and organic forms. Results indicate that medium and high concentrations of both nitrogen and phosphorus occur throughout all salinity zones in the South Atlantic region. The spatialextent of medium or greater concentrations of nitrogen range from about 6 percent in the tidal fresh zoneup to 21 percent in the seawater zone. The spatial extent of these concentrations of phosphorus range fromabout 8 percent in the seawater zone to almost 50 percent in the tidal fresh zone.Trends information for nutrients, although more complete than other parameters, is still limited, especially in the seawater zone. The trends information reported indicates that in most estuaries, there is no change in nutrient concentrations, especially in the mixing zone, or that there is a decreasing trend, especially in the tidal fresh and mixing zones (Figure 5). 

## NutrientsNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 13nitude decreasing trends were reported for six estuaries. Speculative increasing trends were reported for St. Catherine/Sapelo Sounds and St. Andrew/St. Simons Sounds. Trends for three estuaries (New River, Cape Fear River and Charleston Harbor) were were based on Total Phosphorus.
Dissolved oxygen concentrations in the South Atlantic region were characterized by collecting information on existing conditions and trends for three conditions: anoxia (0 mg/l), hypoxia (>0 mg/l< 2 mg/l), and biological stress (>2 mg/l< 5 mg/l). The locationof these conditions in the water column (surface, bottom, throughout the water column), and the influence of water column stratification (high, medium, low, not a factor) were also recorded. Spatial extent of each condition was also noted.Highly variable concentrations of low dissolved oxygen were reported throughout the region (Figure 4). Eleven of 21 estuaries have anoxic/hypoxic levels ofdissolved oxygen at some point during the year. Anoxia/hypoxia were reported as periodic, mainly during the summer months, in estuaries of the CarolinaCapes and northern Sea Island Coast subregions. However, the spatial extent of these conditions was low (0 to 25 percent). Only minor incidences of low dissolved oxygen were reported for the southern estuaries of theSea Island Coast. Periodic occurrences of anoxia/hypoxia were also reported for the Florida estuaries.Water column stratification is reported as a major factor in the expression of this condition for portions of the Carolina Capes and Florida estuaries only. Minimum average monthly bottom concentrations of dissolved oxygen were reported as decreasing for threeestuaries, increasing for one estuary, and not changing for three estuaries. Anoxia Anoxic conditions were reported in 11 of 21 estuariesfor approximately 13 percent of the total estuarine surface area (563 square miles) (Figure 4). There was only one recorded occurrence of anoxia in the Sea Island Coast estuaries—the Savannah River estuary, where anoxia was observed in the mixing zone. If anoxia waspresent, the spatial extent of this condition was generally very low (0 to 10 percent) to low (10 to 25 percent) except for Neuse River, St. Helena Sound, and Indian River, where it was medium (25 to 50 percent). When anoxic conditions were reported for the mixing zone, it was also observed in the tidal fresh zone. surface area (1,190 mi 2 

### ). A medium (25 to 50 percent)to high (50 to 100 percent) spatial extent of these conditions was predominant throughout much of the Carolina Capes and northern Sea Island Coast systems. Water column stratification was a major factor in the expression of biologically stressed conditions withinthe Pamlico/Pungo, Neuse, and Indian River estuaries only. Biological stress was observed throughout the water column in 11 of 21 estuaries. Biologicallystressed conditions events are mostly periodic, beginWater column stratification was a major factor in the expression of anoxia in the Pamlico/Pungo Rivers,Neuse River, and in Indian River. In each case, it occurred at the bottom of the water column. Anoxicevents are mostly periodic, beginning in June and ending in September, though some occurrences have been reported as early as April in the Carolina Capes and Florida estuaries. Trends were reported for six estuaries: five had no change in conditions, while one (Neuse River) reported increases in spatial extent, frequency of occurrence, and duration of anoxic conditions (Figure 5). Hypoxia Hypoxic conditions of dissolved oxygen (>0mg/l < 2mg/l) were reported in 13 of 21 South Atlantic estuaries, for approximately 17 percent of the region’s estuarine surface area (750 square miles) (Figure 4). Thespatial extent of these conditions was reported as medium (25 to 50 percent) for 8 estuaries, and very low(0 to 10 percent) or low (10 to 25 percent) for the remainder. Water column stratification was a major factor in theexpression of hypoxic conditions within three estuaries (Pamlico/Pungo, Neuse, and Indian Rivers). Hypoxia events are mostly periodic, beginning in June and ending in September, though some occurrences have been reported as early as April in the Neuse and Indian Rivers. Trends were reported for seven estuaries: five reported no change in conditions, while Neuse River reported increases in spatial extent, frequency of occurrence, and duration of hypoxic conditions (Figure 5). Savannah River reported increased spatial coverage of hypoxia, but only in the mixing zone. Biological Stress Biologically stressful levels of dissolved oxygen(>2mg/l<5 mg/l) were reported in 20 of 21 South Atlantic Estuaries (Bogue Sound being the exception), for approximately 30 percent of the region’s estuarine 

## Dissolved OxygenNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 14Figure 5:Recent trends (1970 - present) for selected parameters by estuary by salinity zone (T, tidal fresh; M, mixing; S, seawater). All salinity zones are not presentin all estuaries. Most of the 1,225 possible values are unknown (736). There are 51 decreasing trends, 47 increasing trends, and 389 no trends. Seventy-one values arebased on speculative inferences. For a more complete listing of the trends parameters, see Table 1 on page 3.

T M S M T M M S M S T M S T M S T M T M S M S M S M S M S T M S M S T M S T M S M S T M S S M S

? ?

* ? ???? ? ? ??????????? ??? * ??? ???????? *

? ? ? ? ? ? ? ? ? ? ? ?????? ? ??????

? ? ? ???? ? * * *** ? * ?????? ? ? ? ? * *

? ? ? ???? ? * * * * * ? * ?????? ? ? ? * *

? ? ? ????? ? * * * * * ? * ?????? ? ? ? * *

? ? ? ???? ? * * * * * ? * ?????? ? ? ? * *

???? ? ? ? ??? * * ? ? ???? ??? ?

????? ???? ??? * * ??? ???? ??? ? ?

? ? ???? ? ? ? ? ? * ? ? * * ? ? *

? ? ???? ? ? ? * ? ? * * ? ? *

??? * ???? ??????????????? ?????? ????????

??? ? ???? ??????????????? ??????? ????????

??? ? ???? ??????????????? ??????? ????????

??? ???? ??????????????? ??????? ????????

??? ???? ??????????????? ??????? ????????

??? ???? ??????????????? ?????? ????????

??? ???? ??????????????? ?????? ????????

??? ???? ??????????????? ????? * ? * * ? * * ? * ?

??? ???? ??????????????? ????? * ? ? * * ? * ?

??? ???? ??????????????? ???? * ? * * ? * * ? * ?

? ? * ?????? ??? ??????? ??? ??????? ??????????? * ?

? ? ???? ??? ? ? ???????? ??????? ???????? ? ?

???????

* ???? ??? ??? ???? ?????? ???????? ?

? ?????? ??? ??? ? ???? ??? ? ? *

? ???? ? ? ? * * ????? ??????????? *

Albemarle/Pamlico Sounds Pamlico River Neuse River Bogue Sound New River Cape Fear River Winyah Bay N & S Santee River Charleston Harbor Stono/N. Edisto River St. Helena Sound Savannah River Broad River Ossabaw Sound St. Catherine/Sapelo Sound Altamaha River St. Andrew/St. Simon Sound St Marys/Cumberland Sounnd St. Johns River Indian River Biscayne Bay

? * - unknown - no trend or shift - decreasing trend - increasing trend - shift to diverse mixture - shift to annelids and crustaceans - speculative response

CHLOROPHYLL A (μg/l) TURBIDITY (secchi depth) NUISANCE ALGAE TOXIC ALGAE MACROALGAL ABUNDANCE EPIPHYTE ABUNDANCE NITROGEN (mg/l) PHOSPHORUS (mg/l) BOTTOM DO (mg/l) ANOXIA HYPOXIA BIOLOGICAL STRESS PRIMARY PRODUCTIVITY PLANKTONIC COMMUNITY BENTHIC COMMUNITY SAV (spatial coverage) WETLANDS (spatial coverage) event duration frequency of occurance spatial coverage event duration frequency of occurance frequency of occurance event duration spatial coverage frequency of occurance event duration spatial coverage frequency of occurance event duration ?

T ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

1 2

1 2NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 15 ning in June and ending in September, though some occurrences have been reported as early as April in the Neuse and Indian Rivers. Trends were reported for eleven estuaries: nine had no change, while two (Neuse and Savannah Rivers) were reported to have increases in the spatial extentof biologically stressed levels of dissolved oxygen (Figure 5). Neuse River also observed increases in duration and frequency of occurrence of these events.
The responses of estuarine ecosystems to nutrient inputs were characterized by collecting information onthe status and trends of five parameters: primary productivity, planktonic and benthic communities, submerged aquatic vegetation (SAV), and intertidal wetlands. The information reported for these parameterswas limited, especially for trends, where only 18 percent of the region’s estuarine surface area was characterized. The dominant primary producer varied by estuary andsalinity zone between pelagic, benthic, SAV, and intertidal wetlands. Diatoms were reported as the dominant planktonic group, followed by flagellates, and a diverse mixture of plankton groups. The dominantbenthic community in the region was a diverse mixture of organisms (e.g., annelids, crustaceans, mollusks), followed by annelids and polychaetes. SAV andintertidal wetlands were each reported in approximately two-thirds of the region’s estuarine area, primarily in the mixing and seawater zones. SAV was reported mostly in the Carolina Capes and Florida subregions, while wetlands were present throughout the region. Available trends information suggests that the region’s estuarine ecosystems are generally stable. Only oneinstance of ecosystem shifts in the planktonic community and one in the benthic community were reported. Declining trends in intertidal wetland coverage were reported in three estuaries. Declining trends for SAVwere reported in five estuaries, accounting for 80 percent of the area in which SAV was reported (Figure 5). Primary Productivity Four biological communities were reported as thedominant primary producers in the South Atlantic region: pelagic communities in five estuaries (5 of 9 Carolina Capes estuaries); intertidal wetlands in nine (allnine Sea Island Coast systems); and benthic communities and SAV in two estuaries (Indian River andBiscayne Bay). Each of the four communities was reported as dominant across approximately eight percent of the region’s estuarine surface area. The dominant primary producer was unknown for most of the remaining area. Benthic and seagrass communities were reported as the dominant primary producer almost exclusively inthe seawater zone, while intertidal wetlands were reported in both the seawater and mixing zones. Pelagic communities or a diverse mixture of pelagic, benthic and/or other communities were identified as the dominant primary producer in 3 of the region’s 11 tidal fresh zones; information in the remaining tidal fresh zones was unavailable. Temporal shifts in primary productivity, i.e., shifts in dominance from one primary producer to another, was reported as unknown in all of 13 and parts of 18 South Atlantic estuaries (80 percent of the region’s estuarine surface area). Where information was reported, no shifts occurred. Planktonic CommunityDiatoms were identified as the most dominant plankton group, in terms of abundance, in 12 of 21 South Atlantic estuaries (58 percent of the region’s estuarinesurface area). Most of the remaining estuarine surface area was reported to be dominated by flagellates (three estuaries), or a diverse mixture of diatoms,flagellates, and/or other plankton groups (nine estuaries). An exception was blue-green algae, which was reported to be the most abundant plankton group in a portion of the tidal fresh zone in the Albemarle/ Pamlico Sound. Following diatoms, a diverse mixture of plankton groups were reported to be dominant inthe region’s mixing zones (nine estuaries) and seawater zones (seven estuaries). In tidal fresh estuaries, diatoms were followed in abundance by flagellates.Historical shifts in plankton dominance, from one taxonomic group to another, were reported as unknown for one or more salinity zones in 17 of 21 estuaries (78 percent of the regional estuarine surface area) and forall zones in 13 estuaries. Where information was available, no shifts were reported, with the exception of the tidal fresh zone of the Neuse River, where a shift from blue-green algae to a diverse mixture was attributed to stratification and runoff events. Benthic Community The dominant benthic community (with regard to abundance) reported in the South Atlantic region was a diverse mixture of annelids, crustaceans, mollusks,and/or other benthic organisms. This community occurred in at least one salinity zone in 15 of 21 estuaries, including 80 percent of the region’s seawater zone, 

## Ecosystem/Community ResponseNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 16 66 percent of the mixing zone, but only 1 percent ofthe tidal fresh zone. Annelids were the next most abundant benthic community (reported for at least one salinity zone in eight estuaries), followed by poly-chaetes (mixing zone of Albemarle Sound). Mollusks were thedominant community in the tidal fresh zone (35 percent of the region’s estuarine surface area) though they were reported only in the St. Johns River. Insects were the dominant community in the tidal fresh zone of three other estuaries.Information regarding historical shifts in benthic dominance from one taxonomic group to another were reported in eight estuaries. Where information was available, no shifts were reported, with the exception of the seawater zone of the Indian River, where a shift from annelids to a mixture of annelids and crustaceans was attributed to nonpoint sources. Submerged Aquatic Vegetation (SAV) The presence of SAV was reported in 11 of 21 South Atlantic estuaries, representing 65 percent (3,221square miles) of the region’s estuarine area. SAV density (to depths of one meter below mean low water) was reported to be low (>10 ≤25% surface area) or very low ( ≤ 10% surface area), with the exception of medium densities (>25 ≤50% surface area) in Indian River and Biscayne Bay. SAV was reported in the three Floridaestuaries and in 7 of 9 Carolina Cape estuaries. In contrast, no SAV was reported in North/South Santee Rivers and the entire Sea Island Coast subregion, with the exception of Charleston Harbor, where very lowspatial coverage was reported for the mixing and seawater zones.The spatial coverage of SAV was reported as declining at a low or medium magnitude in five estuaries (80 percent of the region in which it was reported to occur). Declining trends generally occurred in areas where existing spatial coverage was reported as low. A declining trend is also reported for the tidal fresh zone of Albemarle/Pamlico Sounds, suggesting that SAV has disappeared from this zone since no existing coverage was reported. Increases in coverage (of low magnitude) were reported for Charleston Harbor and Biscayne Bay (two percent of the region in which SAVwas reported to occur). Trend information was reported as unknown for 15 estuaries, including 6 of the 11 estuaries in which an existing coverage of SAV was reported (Figure 5). Intertidal Wetlands Wetlands were recorded, in varying degrees of spatialcoverage, in 14 of 21 South Atlantic estuaries. The presence of wetlands was reported as unknown for six estuaries. Seventy percent of the area in which wetlands were reported had a spatial coverage (below high water) of low to very low ( ≤25% surface area). Wetlands were reported in every estuary in the CarolinaCapes subregion, primarily at a very low spatial coverage ( ≤ 10% surface area). Three Sea Island Coast estuaries (Charleston Harbor, St. Helena Sound, and St. Catherines/Sapelo Sounds) reported wetlands in allsalinity zones at a medium or greater spatial distribution (>25% surface area). For the Florida estuaries, wetland distribution was medium (25-50% surface area)in Biscayne Bay, low in the St. Johns River, and unknown in the Indian River. Trends in the distribution of South Atlantic intertidal wetlands were generally reported to be stable; 11 of the 14 estuaries for which wetlands were recordedwere reported as having no trends (Figure 5). Decreasing trends were reported for portions of the SavannahRiver, Indian River, and Biscayne Bay. Trend information was reported as unknown in portions of 11 estuaries.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 17 

# References Boynton, W.R., W.M. Kemp, and C.W. Keefe. 1982. A comparative analysis of nutrients and other factors influencing estuarine phytoplankton production. In: V.S. Kennedy (ed.), Estuarine comparisons. New York City: Academic Press. pp. 69-90. Burkholder, J.M., K.M. Mason, and H.B. Glasgow Jr. 1992a. Water-column nitrate enrichment promotesdecline of eelgrass Zostera marina evidence from seasonal mesocosm experiments. Mar. Ecol. Prog. Ser. 81:163-178. Burkholder, J.M., E.J. Noga, C.H. Hobbs, and H.B. Glasgow Jr. 1992. New "phantom" dinoflagellate is the causative agent of major estuarine fish kills. Nature 358:407-410.Cooper, S.R. 1995 (in press). Chesapeake Bay watershed historical land use: Impacts on water quality and diatom communities. Ecol. App. 5. Culliton, T.J., M.A. Warren, T.R. Goodspeed, D.G. Remer, C.M. Blackwell, and J.D. McDonough III. 1990. 50 years of population change along the nation’s coasts 1960-2010. Coastal Trends Series report no. 2. Rockville,MD: National Oceanic and Atmospheric Administration, Strategic Assessment Branch. 41 p.Day, J.W. Jr., C.A.S. Hall, W.M. Kemp, and A. YanezArancibia. 1989. Estuarine ecology. New York City: John Wiley and Sons. 558 p.Frithsen, J.B. 1989 (draft). Marine eutrophication: Nutrient loading, nutrient effects and the federal response. Fellow, American Association for the Advancement of Science/EPA Environmental Science and Engineering. 66 p. Hinga, K.R., D.W. Stanley, C.J. Klein, D.T. Lucid, andM.J. Katz (eds.). 1991. The national estuarine eutrophication project: Workshop proceedings. Rockville, MD: National Oceanic and Atmospheric Administration and the University of Rhode Island Graduate School of Oceanography. 41 p. Hunt, C.B. 1967. Coastal plain and continental shelf. In: Physiography of the United States. W.H. Freeman and Co. pp. 145-147. Jaworski, N.A. 1981. Sources of nutrients and the scale of eutrophication problems in estuaries. In: B.J. Neilson and L.E. Cronin (eds.), Estuaries and nutrients. Clifton, NJ: Humana Press. pp. 83-110. Kemp, W.M., R.R. Twilley, J.C. Stevenson, W.R.Boynton, and J.C. Means. 1983. The decline of submerged vascular plants in upper Chesapeake Bay: Summary of results concerning possible causes. Mar. Tech. Soc. Journal 17(2):78-89.Lee, T.N. and C.G.H. Rooth. 1976. Circulation and exchange processes in southeast Florida’s coastal lagoons. Miami, FL: University of Miami, Rosenstiel School of Marine and Atmospheric Science. 10 p. Likens, G.E. 1972. Nutrients and eutrophication: Thelimiting nutrient controversy. Proceedings of a symposium on nutrients and eutrophication, W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, Feb. 11-12, 1971. Lawrence, KS: Allen Press, Inc., for the American Society of Limnology and Oceanography, Inc. 328 p. Lowe, J.A., D.R.G. Farrow, A.S. Pait, S.J. Arenstam, and E.F. Lavan. 1991. Fish kills in coastal waters 1980-1989. Rockville, MD: Strategic Environmental AssessmentsDivision, NOAA, Office of Ocean Resources Conservation and Assessment. 69 p. Markley, Susan M. 1996. Personal Communication. Environmental Resources Management, Miami, FL.Mathews, T.D. and M.H. Shealy, Jr. 1982. A Description of the Salinity Regimes of Major South Carolina Estuaries. Charleston, SC: South Carolina Marine Resource Center, Tech. Report No. 54. 14 pp. Mathews, T.D., M.H. Shealy, Jr., and N. Cummings. 1981. Hydrography of South Carolina Estuaries, withEmphasis on the North and South Santee and Charleston Harbor-Cooper River Estuaries. Charleston, SC: South Carolina Marine Resource Center, Tech. Report No. 47. 24 pp. Mathews, T.D., F.W. Stapor Jr., C.R. Richter, J.V. Miglarese, M.D. McKenzie, and L.A. Barclay (Eds). 1980. Ecological Characterization of the Sea IslandCoastal Region of South Carolina and Georgia, Volume I: Physical Features of the Characterization Area.FWS/OBS-79/40. Washington, DC: U.S. Fish & Wildlife Service, Office of Biological Services, FWS/OBS79/40. 211 pp.Mathews, T.D. and M.H. Shealy, Jr. 1978. Hydrography of South Carolina Estuaries, with Emphasis on the North and South Edisto and Cooper Rivers.Charleston, SC: South Carolina Marine Resource Center, Tech. Report No. 30. 148 pp.National Academy of Sciences (NAS). 1969. Eutrophication: Causes, consequences, correctives. ProceedingsNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 18 processes: U.S. southeast continental shelf. A summary of research conducted in the South Atlantic Bight under the auspices of the U.S. Department of Energyfrom 1977 to 1991. pp. 9-43. Savannah, GA: University System of Georgia. Rabalais, N.N. 1992. An Updated Summary ofStatus and Trends in Indicators of Nutrient Enrichment in the Gulf of Mexico. Prepared for: Gulf of Mexico Program, Technical Steering Committee, Nutrient Subcommittee, Stennis Space Center, MS. Publication No. EPA/800-R-92-004. 421 pp. Rabalais, N.N. and D.E. Harper Jr. 1992. Studies of benthic biota in areas affected by moderate and severehypoxia. In: Nutrient-enhanced coastal ocean productivity. Proceedings of a workshop at Louisiana Universities Marine Consortium, October 1991. Held in conjunction with National Oceanic and Atmospheric Administration, Coastal Ocean Program Office.Galveston, TX: Sea Grant Program, Texas A&M University. TAMU-SG-92-109. pp. 150-153. Ryther, J.H. and W.N. Dunstan. 1971. Nitrogen andeutrophication in the coastal marine environment. Science 171:1008-1013. Smayda, T.J. 1989. Primary production and the globalepidemic of phytoplankton blooms in the sea: A linkage? In: E.M. Cosper, V.M. Bricelj, and E.J. Carpenter(eds.), Novel phytoplankton blooms: Causes and effects of recurrent brown tides and other unusual blooms. Coastal and Estuarine Series 35. Berlin: Springer-Verlag. pp. 449-483.Stevenson, J.C., L.W. Staver, and K.W. Staver. 1993. Water quality associated with survival of submersedaquatic vegetation along an estuarine gradient. Estuaries 16(2):346-361. Whitledge, T.E. 1985. Nationwide review of oxygen depletion and eutrophication in estuarine and coastalwaters: Executive summary. (Completion report submitted to U.S. Dept. of Commerce.) Rockville, MD: NOAA, NOS. 28 p. Whitledge, T.E. and W.M. Pulich Jr. 1991. Report of the brown tide symposium and workshop, July 15-16,1991. Port Aransas, TX: Marine Science Institute, University of Texas. 44 p.Zarillo, G.A., J.T. Liu, and C. Surak. 1993. Comprehensive analysis of physical processes in a coastal lagoon: New insights for estuarine management. Melbourne, FL: Florida Institute of Technology, Department ofOceanography, Ocean Engineering and Environmental Science. 15 p.of an international symposium on eutrophication, University of Wisconsin, 1967. Washington, DC: NAS Printing and Publishing Office. 661 p. National Oceanic and Atmospheric Administration (NOAA). 1992. Red tides: A summary of issues and activities in the United States. Rockville, MD:Office of Ocean Resources Conservation and Assessment. 23 p.NOAA. 1991. Nutrient-enhanced coastal ocean productivity. Proceedings of a workshop, Louisiana Universities Marine Consortium, October 1991. Held in conjunction with NOAA Coastal Ocean ProgramOftivity. Proceedings of a workshop, Louisiana Universities Marine Consortium, October 1991. Held inconjunction with NOAA Coastal Ocean Program Office. TAMU-SG-92-109 Galveston, TX: Texas A&M University Sea Grant Program. pp. 150-153. NOAA, 1989. Susceptibility and Status of East Coast Estuaries to Nutrient Discharges: Albemarle/Pamlico Sound to Biscayne Bay. Rockville, MD. Office of Ocean Resources Conservation Assessment. 31 p. Nixon, S.W. 1983. Estuarine ecology: A comparative and experimental analysis using 14 estuaries and theMERl mesocosms. Final report to the U.S. Environmental Protection Agency, Chesapeake Bay Program, Grant No. X-003259-01. April 1993. Nixon, S.W. 1995. Coastal marine eutrophication: A definition, social causes, and future concerns. Ophelia 41:199-219. Nixon, S.W., C.D. Hunt, and B.N. Nowicki. 1986. The retention of nutrients (C,N,P), heavy metals (Mn, Cd, Pb, Cu), and petroleum hydrocarbons in NarragansettBay. In: P. Lasserre and J.M. Martin (eds.), Biogeochemical processes at the land-sea boundary. Amsterdam: Elsevier Press. pp. 99-122. Orlando, S.P. Jr., L.P. Rozas, G.H. Ward, and C.J. Klein.1993. Salinity characteristics of South Atlantic estuaries. Silver Spring, MD: NOAA, Office of ocean Resources Conservation Assessment. 209 p. Orth, R.J. and K.A. Moore. 1984. Distribution andabundance of submerged aquatic vegetation in Chesapeake Bay: An historical perspective. Estuaries 7:531- 540. Pearl, H.W. 1988. Nuisance phytoplankton blooms in coastal estuarine and inland waters. Limnology and Oceanography. 33:823-847. Pomeroy, L.R., J.O. Blanton, G.A. Poffenhofer, K.L. Von Damm, P.G. Verity, H.L. Windom, and T.N. Lee. 1993. Inner shelf processes. In: D.W. Menzel (ed.), OceanNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 19 

# Estuary Summaries This section presents one page summaries on the status and trends of eutrophication conditions for the 21 South Atlantic estuaries. The summary information is organized into four sections; algal conditions, nutrients, dissolved oxygen, and ecosystem/community responses. Each page also includes a salinity map depicting the spatial framework for which survey information was collected, selected physical and hydrologic characteristics, and a narrative overview of the survey information. Salinity Maps. Salinity maps depict the estuary extent, salinity zones, and subareas within the salinity zones. Salinity zones are divided into tidal fresh (0.0-0.5 ppt), mixing (0.5-25.0 ppt), and seawater ( >25.0 ppt) based on average annual salinity found throughout the water column. Subareas were identified by survey participants as regions which were either better understood than the rest of a salinity zone or which behaved differently or both. Each map also has an inset showing the location of the estuary and its estuarine drainage area (EDA) (see below). Physical and Hydrologic Data. Physical and hydrologic characteristics data are included so that readers can understand better the survey results and make meaningful comparisons among the estuaries. The EDA is the land and water component of a watershed that drains into and most directly affects estuarine waters. The average daily inflow is the estimated discharge of freshwater into the estuary. Surface area includes the area from the head of tide to the boundary with other water bodies. Average depth is the mean depth from mid-tide level. Volume is the product of the surface area and the average depth. Survey Results. Selected data are presented in a unique format that is intended to highlight survey results for each estuary. The existing conditions symbols represent either the maximum conditions predominating one or more months in a typical year, or whether there are resource impacts due to bloom events. The trends (circa 1970 - 1995 unless otherwise stated) symbols indicate either the direction and magnitude of change in concentrations, or in the frequency of occurrence. The four sections on each page include a text block to highlight additional information such as probable months of occurrence and periodicity for each parameter, limiting factors to algal biomass, nuisance and toxic algal species, nutrient forms, and degree of water column stratification. Some parameters are not characterized by symbols on the estuary pages. These include macroalgal andepiphyte abundance, biological stress, minimum average monthly bottom dissolved oxygen trends, temporal shifts in primary productivity, benthic community shifts, intertidal wetlands, and planktonic community shifts. These parameters are described in the Regional Overview section (starting on page 5) and, where relevant, highlighted in the text blocks under each parameter section on the estuary pages. A key is provided below that explains the symbols used on the summary pages. See Table 1 on page 3 for complete details about the characteristics of each parameter. Estuary page Albemarle/Pamlico Sounds 21 Pamlico/Pungo Rivers 22 Neuse River 23 Bogue Sound 24 New River 25 Cape Fear River 26 Winyah Bay 27 North/South Santee Rivers 28 Charleston Harbor 29 Stono/North Edisto Rivers 30 St. Helena Sound 31 Estuary page Broad River 32 Savannah River 33 Ossabaw Sound 34 St. Catherine/Sapelo Sounds 35 Altamaha River 36 St. Andrew/St. Simon Sounds 37 St. Marys/Cumberland Sounds 38 St. Johns River 30 Indian River 40 Biscayne Bay 41

## 20 NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic 

# Key to Symbols Used on Estuary Summaries

impacts on resources

low d.o. not observed 

# Y

N

? unknown Event Occurrences (Nuisance/Toxic Algae, d.o.)



# VL very low 

# NS no SAV in zone hypereutrophic 

# E H

M

L high

medium

low

Concentrations (Chl- a, Turbidity, Nutrients, SAV)



# ? unknown 

# B blackwater area Parameter Mixing Seawater Tidal Fresh



# H M M

25-50%

50-100% Spatial Coverage: surface area over which condition occurs (not listed for nuisance/toxic algae or low/not observed conditions) 

# *

Reliability: indicates assessment made from speculative inferences

increase

decrease

no trend high

medium

low 

### Trends (circa 1970-1995)



# ? unknown magnitude unknown Direction of Change Magnitude of Change 

# L Subarea X Subarea Y

Salinity Zone Divided: salinity zones are often divided into subareas to account for unique characteristics 50-100%

chl- a: >60 μg/l

chl- a: >20, <60 μg/l turbidity: secchi <1m

? TDN: >1 mg/l TDP: >0.1 mg/l SAV >50, <100 % coverage low d.o. is observed nuisance algae: impacts occur toxic algae: impacts occur

no resource impacts chl- a: >5, <20 μg/l turbidity: secchi >1m, <3m TDN: >0.1, <1 mg/l TDP: >0.01, <0.1 mg/l SAV >25, < 50 % coverage

chl- a: >0, <5μg/l turbidity: secchi >3m TDN: >0, <0.1 mg/l TDP: >0, <0.01 mg/l SAV >10, < 25 % coverage
SAV >0, <10 % coverage anoxia: 0 mg/l hypoxia: >0, <2 mg/l >50%, <100%

>25%, <50%

no nuisance algae impacts no toxic algae impacts

no anoxic events no hypoxic events >0%, <25% 

### Existing Conditions Salinity Zone Absent: if the salinity zone is not present in the estuary the entire box is left blank



### or

or (Concentrations or Frequency of Event Occurrences)NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 21 

# Albemarle/Pamlico Sounds Albemarle/Pamlico Sounds are characterized as having moderate to hypereutrophic levels of chlorophyll-aand moderate to high turbidity levels. Periodic occurrences of nuisance algae and episodic occurrences of toxic algae are reported during late summer months. Nitrogen and phosphorus levels are moderate to high and anoxia and hypoxia are reported for limited bottom areas. Extreme conditions are generally observed in the Chowan River with more moderate conditions reported for Pamlico Sound. Conditions in much of the remainder of the estuary are unknown. Trends are generally unknown throughout the estuary except for a decrease in turbidity in the Chowan River. SAV decreased significantly in the tidal fresh zone and to a lesser degree in the mixing zone of Pamlico Sound. Physical and Hydrologic Characteristics



### Dissolved Oxygen

Anoxia 

## ? Hypoxia 

## ? Mixing Tidal Fresh Seawater 

## ? 

# Y Albemarle Snd. Pamlico Snd.



## ? 

# Y
0-10% 

## ? 

# Y In General Chowan River



## ? 

# Y 10-25% 0-10%

10-25% 

## ? ? ????
?? ? ? *

* *

* 

## ? Nutrients Nitrogen 

## ? Phosphorus Mixing Tidal Fresh Seawater 

# L Albemarle Snd. Pamlico Snd.



## ? 

# M ? 

# H
50-100% In General Chowan River



## ? 

# H
50-100% 

## ? ? ? ?
? ? ??? *

*

In Chowan R. and Pamlico Sound, anoxia/hypoxia occur July to Sept. at bottom of water column. Water column stratification plays moderate role in these conditions. Conditions occur periodically in Chowan R. and episodically in Pamlico Sound. Elevated concentrations of TDN and TDP occur Feb. to April in Chowan R. TDP concentrations in Pamlico Sound occur June to Aug. Nuisance Algae Toxic Algae Algal Conditions



## ? Chlorophyl- a Turbidity 

## ? Mixing Tidal Fresh Seawater Albemarle Snd. Pamlico Snd. In General Chowan River



## ? ?

?
? 

# M

50-100% 

## ? ? ? 

# E

50-100% 

## ? ? ? 

# M
50-100% 

### * *



## ? ? 

# H

50-100% ? 

## ? ? 

# M

25-50% 

## ?


# N ?


# N ? 

# Y ? ? ? 

# Y
Y ? ? ? 

# Y

Chl- a conditions occur in summer in all zones and winter in mixing and seawater zones. Occurrences are periodic in tidal fresh and mixing and episodic in seawater zone. Limiting factors are nitrogen, phosphorus, and light in Chowan R.; nitrogen in mixing and seawater zones.Turbidity conditions occur periodically Feb. to Sept. in Chowan R. and all year in Pamlico Sound. Nuisance/toxic Anabaena portoricensis, Aphanizomenon flosaquae, and Microcystis aeroginsoaoccur periodically June to Sept. in Chowan R. In Pamlico Sound nuisance Anabaena raciborski occurs July to Sept.; toxic Pfiesteria piscicidaoccurred once in 1992.
SAV Ecosystem/Community Responses Mixing Tidal Fresh Seawater 

# L ? L Pamlico Snd. 

## NS In General Chowan River 

# ? 

# ?

* Albemarle Snd. 

## NS Planktonic community dominated by blue-green algae in Chowan R.; diatoms in Pamlico Sound and seawater zone. Polychaetes and mollusks dominate benthic community in mixing and seawater zones. Contributing sources to SAV decline were not reported. Tidal Fresh Mixing Estuary 183 48 765 1670 5.8
16 13.9 15.6 18 6.4 13.5
1063 33 24 350 640 Seawater Albemarle Snd. Pamlico Snd. In General Chowan River Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 46,000

Surface Area (mi 2 ) Depth (ft)

(billion cu ft) Volume Average 12,781

2,7686 101

A large, bar-built lagoonal system bordered on the east side by barrier beaches forming the Outer Banks. Roanoke and Chowan rivers are the major freshwater inputs to Albemarle Sound. Tides range 2 ft near the inlets but are dampened to 0.6 ft within Pamlico Sound. Salinity variabilityand water-column mixing in the sounds is dominated by prevailing winddriven circulation and currents.



## Key on page 20 NCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 22 

# Pamlico/Pungo Rivers Pamlico/Pungo Rivers are characterized as having periodically high levels of chlorophyll-aand moderate turbidity. Biological resource impacts from episodic occurrences of toxic algae are also reported. Nutrient levels are moderateand anoxia and hypoxia occur periodically in limited bottom areas. Trends vary from a significant increase in chlorophyll-ato a modest decrease in phosphorus to no trends for nitrogenand dissolved oxygen. No trends were reported for the limited amount of SAV. Physical and Hydrologic Characteristics

Tidal Fresh Estuary 170.6 170.6

9.4 9.4 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 4,600

Surface Area (mi 2 ) Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 2,118

44.7 44.7 Receives majority of freshwater from Tar River. Moderate stratification occurs especially in Feb-April during high-inflow period. Tides range 2 ft near the inlets of Outer Banks to 1 ft at mouths of Pamlico and Pungo rivers. Winds can significantly influence water elevation and circulation and tend to override tidal influences.

Anoxia 

# Y Hypoxia 

# Y Dissolved Oxygen

Nitrogen 

# M Phosphorus 

# M Nutrients

50-100%

50-100%

0-10%

25-50% Periodic occurrences of anoxia/hypoxia occur June to October, typically at bottom of water column. Water column stratification contributes to these conditions. Minimum average monthly bottom dissolved oxygen concentrations decreased from 1970 to 1990. Mixing Seawater Tidal Fresh

Mixing Seawater Tidal Fresh Elevated concentrations of TDN and TDP occur January to March. Decreasing TDP is associated with point sources modifications. Chlorophyl- a Turbidity 

# M Nuisance Algae 

# N Toxic Algae 

# ?
Y ? Mixing Seawater Tidal Fresh Algal Conditions

50-100% 

# H

50-100%

SAV 

# L Ecosystem/Community Responses 

# H In General Upper Pamlico

50-100%



# ?

Chl- a and turbidity conditions occur periodically in winter and summer. Nitrogen and light are limiting to algal biomass. Increasing chl- a concentrations in upper Pamlico River due to best management practices leading to less light limitation. Toxic Pfiesteria piscicidaoccurs episodically mid to late summer, with durations of less than a week.

Mixing Seawater Tidal Fresh

Primary production is dominated by pelagic community; planktonic community dominated by flagellates; benthic community dominated by annelids and crustaceans. Intertidal wetlands coverage is low. 

## Key on page 20 Pamlico River Pungo River NC

Neuse RiverNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 23 

# Neuse River Nuese River is characterized as having moderate to hypereutrophic chlorophyll- aconditions and moderate turbidity. Nuisance and toxic algae are reported as impactingbiological resources during events that occur from early summer to early fall. Nitrogen and phosphorus are reported at moderate concentrations. Anoxia and hypoxia events occurperiodically from June to October across a moderate portion of the estuary. These conditions occur predominantly in the mixing zone which represents almost the entire estuary. Trends for most parameters are reported as increasing. Decreasing trends are observed for nuisance and toxic algae in the tidal fresh zone.The limited SAV in the mixing zone is also reported as decreasing. Physical and Hydrologic Characteristics

Anoxia Mixing Seawater Tidal Fresh 

# Y Y Hypoxia 

# Y Y Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# M M Phosphorus 

# M M Nutrients

50-100% 25-50%

25-50% 50-100%

25-50% 25-50%

25-50% 25-50% 

# ? *

Periodic occurrences of anoxia/hypoxia occur June to October; typically at bottom of water column. Water column stratification contributes significantly to these conditions. Minimum average monthly bottom dissolved oxygen concentrations have decreased and spatial coverage of anoxic/hypoxic conditions for tidal fresh and mixing zones have increased. In tidal fresh zone, reported elevated concentrations of TDN and TDP occur February to June. In mixing zone, reported elevated concentrations occur January to April for TDN and January to April and June to August for TDP. Trends in nitrogen are for DIN over last five years. Tidal Fresh Estuary 177.6 175.7

11.4 11.5 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 6,200

Surface Area (mi 2 ) 1.9

9.3 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 2,221

56.3 56.8 0.5 Receives majority of freshwater from both the Neuse and Trent rivers. Salinity stratification often occurs near mouth of Neuse River but is more common further upstream. Tides range 1 ft near entrance to the Pamlico Sound. Winds can significantly influence water elevation and circulation and generally override tidal influences on salinity structure. Chlorophyl- a 

# M E
25-50% Turbidity 

# B M Nuisance Algae 

# Y Y Toxic Algae Mixing Seawater Tidal Fresh Algal Conditions

25-50%

25-50%

SAV Mixing Seawater Tidal Fresh 

# NS VL Ecosystem/Community Responses 

# ?



# Y Y

? Chl- a conditions occur periodically spring to early fall and, in mixing zone, in winter. Nitrogen and phosphorus are limiting in tidal fresh zone; nitrogen in mixing zone. Turbidity concentration maximums in mixing zone occur periodically winter to summer and episodically with high flow and algal blooms. Nuisance algae and toxic algae (Pfiesteria piscicida ) events generally occur early summer to early fall and last a month or longer.

Primary production is dominated by pelagic community. Dominance shift occurred from blue green algae to diverse mixture in tidal fresh zone. Annelids are dominant benthic group. Intertidal wetlands coverage is very low. 

## Key on page 20 Neuse River NCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 24 

# Bogue Sound

Chlorophyl- a 

# M M
50-100% Turbidity 

# H M Nuisance Algae 

# N N Toxic Algae Mixing Seawater Tidal Fresh Algal Conditions

50-100%

50-100%

SAV Mixing Seawater Tidal Fresh 

# L L Ecosystem/Community Responses 50-100%



# N Y ?
?

? ? Chl- a maximums occur in spring in mixing zone and in summer in seawater zone. Nitrogen is limiting factor in mixing and seawater zones. Turbidity conditions occur continuously throughout the year. A one time event of Gymnodinium brevis occurred 11/87 to 2/88 due to Gulf transport. However, conditions in the estuary allowed it to sustain.

Planktonic community dominated by diatoms; benthic community dominated by annelids and diverse mixture. Intertidal wetlands range from low to medium coverage. Bogue Sound is characterized as having moderate levels of cholorophyll-aand moderate to high turbidity. There are no biological resource impacts associated with nuisance algae and toxic algae events are extremely rare. Moderate levelsof dissolved inorganic nitrogen are reported for the seawater zone. No anoxia or hypoxia are observed. These conditions are observed in the mixing and seawater zones. Trends are reported as either unknown or no trend. Limited SAV is present in the mixing and seawater zones. Physical and Hydrologic Characteristics

Tidal Fresh Estuary 104.4 27.6

2.4 4.6 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 1,300

Surface Area (mi 2 ) 76.8
5.1 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 691

1.9 11 12.9 A shallow, lagoonal estuarine system containing numerous shoals and disposal areas for dredged material. Tidal mixing promotes a fairly uniform seasonal salinity structure. Vertically homogeneous salinities are common in Bogue and Back sounds. White Oak, Newport, and North rivers have strong horizontal salinity gradients during late winter and spring. Moderate vertical stratification is common.

Anoxia Mixing Seawater Tidal Fresh 

# N N Hypoxia 

# N N Dissolved Oxygen

Nitrogen Mixing Seawater Tidal Fresh 

# L M Phosphorus 

# L L Nutrients

50-100%

Concentrations in mixing zone for nitrogen are reported as DIN; concentration of nitrogen in seawater zone is more than 90% DON. Trends for nitrogen are for DIN.



## Key on page 20 Bogue Sound Shackleford Banks Core Banks North River White Oak R. Bogue Banks

NCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 25 

# New River New River is characterized as having moderate to hypereutrophic levels of chlorophyll-aand moderate to highlevels of turbidity. Biological resource impacts from periodic nuisance algae and episodic toxic algae occur in summer and winter months. Nitrogen and phosphorus are moderate to high though they occur at different times of the year. Bottom-water hypoxia in late summer months is reported. These conditions occur primarily in the mixing zone which represents more than 80 percent of the estuary. More extremeconditions generally occur in Morgan Bay. Trends information is unknown for all parameters. SAV is present in very limited amounts in the seawater zone.

Mixing Seawater Tidal Fresh Chlorophyl- a Turbidity Nuisance Algae 

# Y Toxic Algae 

# ?


# Y ? Algal Conditions

SAV 

# NS Ecosystem/Community Responses Morgan Bay Stones Bay 

# E

25-50% 

# H

50-100% 

# ? 25-50% Farnell Bay 

# H ??? 

# H

50-100% 

# H

50-100% 25-50% 

# M ??? 

# ?
?


# N ?

? ?

VL ? ? *

In mixing zone, maximum chl- a and turbidity concentrations occur periodically summer and winter with nitrogen and silica limiting biomass. Nuisance and toxic algae also occur during summer and winter months. Toxic algal events are episodic and are days in duration.

Primary production is dominated by pelagic community; planktonic community dominated by mixture of diatoms and flagellates; benthic community dominated by annelids in seawater zone. Mixing Seawater

Tidal Fresh ? 

# M * Physical and Hydrologic Characteristics

Mixing Seawater Tidal Fresh Anoxia Hypoxia 

### Dissolved Oxygen

Nitrogen Mixing Seawater Tidal Fresh Phosphorus 

### Nutrients


# H

25-50% 

# M

25-50% 25-50% 

# M ???


# HMM ??? 

# ?
?

NNN ???


# Y

25-50% 

# Y

25-50% 

# N ??? 

# ?
?
Periodic, bottom-water hypoxia occurs in mixing zone June to September. Water column stratification plays a moderate role in these conditions. 25-50% 25-50% 25-50% Concentrations of nitrogen are for ammonia and nitrate; concentrations of phosphorus are for total phosphorus and orthophosphate. In Farnell Bay and Stones Bay elevated nitrogen concentrations occur December to March; elevated phosphorus concentrations occur May to October. Morgan Bay Stones Bay Farnell Bay

Morgan Bay Stones Bay Farnell Bay 

# L

50-100% 

# M

N
N Tidal Fresh Estuary
32.8 12.0
6.1 5.8 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 800

Surface Area (mi 2 ) 4.0
5.4 4.8
4.4 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 471

2.0 0.6 5.2 0.6 12.0
5.9

2.0 Morgan Bay Farrell Bay Stones Bay

Consists of three major bays (Morgan, Farnell, Stones) in upper estuary, and smaller features to the south in lower or seawater portion. Freshwater from the New River is dominant influence on salinity structure, especially above Pollocks Point. Tidal influence generally restricted to lower estuary where increases in vertical mixing cause relatively stable salinities to persist. Moderate stratification is fairly common in upper portion of New River, especially during high-inflow conditions.



## Key on page 20 New River Morgan Bay Farnell Bay

Stones Bay Northeast Creek

NCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 26 

# Cape Fear River Cape Fear River is characterized as having moderate to high levels of chlorophyll- aand turbidity. Biological resource im- pacts from nuisance and toxic algae do not occur. Nitrogenand phosphorus are reported at moderate to high concentrations throughout most of the estuary. No anoxia or hypoxia are observed. These conditions occur primarily in the mixing zone which represents more than 75 percent of the estuary. Trends are almost all unknown. Very low amounts of SAV are present in all salinity zones. Physical and Hydrologic Characteristics

Tidal Fresh Estuary 38.3 29.4

10.2 11.5 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 10,100

Surface Area (mi 2 ) 0.35

20.2 8.9
11.7 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 4,364

8.4 2.9 11.3 0.023 Receives the majority of freshwater inflow from the Cape Fear, Black, and Northeast Cape Fear rivers. Seasonal variability in freshwater inputs, governed by shifting precipitation patterns, has major effects on salinity structure. Discharge from main river systems is three times greater during early spring than in fall months. Tides are dominant influence on salinity structure and range 4.2 ft near estuary mouth. Stratification is common within navigation channels. Chlorophyl- a 

# H M
50-100% Turbidity 

# H H Nuisance Algae 

# N N Toxic Algae

Maximum chl- a concentrations occur periodically April to Sept. In mixing zone; limiting factors are phosphorus, nitrogen, and light in spring, summer, and winter. In seawater zone, limiting factor is nitrogen, and light under high turbidity conditions. High turbidity concentrations occur periodically in winter in all zones and episodically with heavy rainfall or dredging activities. Mixing Seawater Tidal Fresh Algal Conditions

25-50%

50-100% 50-100%



# N N ?

?

? 

# H
N 50-100%



# N ?

? 

## ?

???

? ?

SAV Mixing Seawater Tidal Fresh 

# VL VL Ecosystem/Community Responses



## ? ? 

# VL ?

Planktonic community is dominated by mixture of diatoms and flagellates; benthic community dominated by annelids. Intertidal wetlands coverage is high in tidal fresh zone, medium in mixing zone, and low in seawater zone. 

# M
25-50%

Anoxia Mixing Seawater Tidal Fresh 

# N N Hypoxia 

# N N Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# H M Phosphorus 

### Nutrients

50-100% 

# H
50-100% 50-100%



# H
50-100% 

# H
50-100% 

# M
50-100% 

# ?? ?

? ? ?



# N
N ?

? ? ? ? ? Concentrations are reported as total nitrogen and total phosphorus. TIN is 50-60% of total in tidal fresh zone, 40-50% in mixing zone, and 25% in seawater zone. Orthophosphate is 75% of total in tidal fresh zone, 60% in mixing zone, and 35% in seawater zone.



## Key on page 20 NCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 27 

# Winyah Bay Winyah Bay is characterized as having moderate to high levels of chlorophyll-aand high turbidity. Based on specula- tive inference, biological resource impacts from nuisance andtoxic algae do not occur. Nitrogen and phosphorus are generally reported at moderate to high levels. Bottom-water anoxia and hypoxia periodically occur in the mixing zone of Winyah Bay and the seawater zone of North Inlet. Trends reported indicate moderate increases in turbidity in the tidal fresh and mixing zones, no trends for nuisance andtoxic algae, and decreasing trends for nitrogen and phosphorus. Distribution and trends for SAV are generally unknown.

Nuisance Algae Toxic Algae Algal Conditions

SAV Ecosystem/Community Responses 

# N N N Chlorophyl- a 

# M

50-100% Turbidity 

# H Mixing Tidal Fresh Seawater 

# M

50-100% Winyah Bay North Inlet



# H H
50-100% 

# M M

50-100% Winyah Bay North Inlet



# H H
50-100% 

# N N


# N

Mixing Tidal Fresh Seawater 

# ? ?? ?
?

? NS Winyah Bay North Inlet 

# ? ? Winyah Bay North Inlet 

# ? 

# ? ?
50-100% 

# M

50-100%

50-100% 50-100% 

# ?

N N N N 50-100%



### * * * * * * ** **

* * * * * * * * **



# ? ? Chl- a maximums occur periodically late spring to fall. Phosphorus is limiting in tidal fresh and mixing zone of Winyah Bay; nitrogen is limiting in North Inlet mixing zone and all of seawater zone. Light is co-limiting in all zones. Turbidity maximums occur continuously throughout the year.

Primary production is dominated by macrophytes and diverse aquatic community in tidal fresh zone; intertidal wetlands and pelagic communities in mixing and seawater zones. Planktonic community dominated by diatoms; benthic community dominated by insects in tidal fresh zone; annelids and diverse mixture in mixing and seawater zones. Intertidal wetlands coverage high. Physical and Hydrologic Characteristics

Tidal Fresh Estuary

41.1 2.8
9.3 11.0 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 20,400

Surface Area (mi 2 ) 22.3
7.4

Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 9,561

0.73
9.4 3.3
9.7 Winyah Bay North Inlet Winyah Bay North Inlet 12.0
13.9

Receives majority of freshwater inflow from Pee Dee and Little Pee Dee rivers. Seasonal inflows alter salinities approximately 10 ppt throughout most of estuary. Tides range 4.5 ft at North Inlet and salinities are generally unstratified in that area. Moderately stratified conditions are most common within mixing zone and navigation channels during early Spring but typically shift northward in Fall. 0.9 18.5 5.4 4.7 0.2 0.7



### Dissolved Oxygen Nutrients Nitrogen 

# H Phosphorus Mixing Tidal Fresh Seawater

Anoxia 

# N Hypoxia 

# N Mixing Tidal Fresh Seawater 

# H M M
L M H M
50-100% Winyah Bay North Inlet



# H L ? ?
? ?



# ? ? ? Y Winyah Bay North Inlet



# ? Y
10-25% 

# Y ? Winyah Bay North Inlet



# Y ? 0-10% 

# ?? ?? ?? ? ? Winyah Bay North Inlet

50-100% 50-100% 50-100% 50-100%

50-100% 50-100% 50-100%

10-25%

25-50% Periodic occurrences of anoxia/hypoxia have been reported May to September in mixing zone, typically at bottom of water column. In North Inlet, periodic occurrences occur August to September only. Water column stratification was not a factor. Trends in tidal fresh zone and mixing zone are associated with best management practices, new regulations, and a phosphate ban. In seawater zone, trends are associated with drought conditions.



## Key on page 20 Mud Bay Mud BayNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 28 

# North/South Santee Rivers North/South Santee Rivers are characterized by unknown levels of chlorophyll-aand turbidity and no occurrence of nuisance or toxic algae throughout the estuary. Nitrogen andphosphorus are reported at moderate concentrations during the late summer months. Anoxia and hypoxia are unknown throughout the estuary. The conditions reported occur predominantly in the mixingzone which represents approxiately 90 percent of the estuary. Trends for turbidity, nitrogen, and phosphorus are reported as decreasing significantly due to rediversion of water in the estuary. Nuisance and toxic algae are reported as having no recent trends. The current distribution and trends for SAV are unknown. Physical and Hydrologic Characteristics

Tidal Fresh Estuary

9.1
6.1 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 12,450

Surface Area (mi 2 ) 4.0
7.2 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 718

5.0
6.4 Western Half Eastern Half

2.7 0.8 0.97
5.3

1.0 0.9 A drowned river valley system that is highly variable with regard to freshwater and salinity structure. Changes in salinity occurred following a rediversion of freshwater inflow back into Santee River system from Lake Moultrie in 1985. Currently, horizontal salinity gradients exist, mainly in lower estuary, but stratification is generally weak. Salinities in lower rivers can vary significantly between successive high and low tides, ranging 4.2 ft near estuary mouth.

Anoxia Hypoxia 

### Dissolved Oxygen Nitrogen Phosphorus 

### Nutrients

Western Half Eastern Half 

# M ? ?
? ? 50-100%

50-100% 

# M M 25-50% 

# M

25-50%

Western Half Eastern Half 

# ? ? 

# ?
? ? 

# ? ? ? ? ?
? ? Mixing Seawater Tidal Fresh

Mixing Seawater Tidal Fresh Elevated TDN concentrations occur July to September; Elevated TDP concentrations occur August to October. Trends are associated with changes in flow patterns due to water diversions. Chlorophyl- a Turbidity Nuisance Algae Toxic Algae Mixing Seawater Tidal Fresh 

### Algal Conditions

SAV Mixing Seawater Tidal Fresh 

### Ecosystem/Community Responses Western Half Eastern Half 

# ?
?


# N
N ? ? ? ? ?
? ?

? ? Western Half Eastern Half 

# ? ? ? ? * * 

# N * * 

# N * *

* * 

# N * * 

# N * *

Decreasing turbidity conditions are associated with rediversion of water in the estuary.

Planktonic community is dominated by diatoms; benthic community by insects in tidal fresh zone and diverse mixture and crustaceans in mixing zone. Intertidal wetlands have high spatial coverage. 

## Key on page 20 SCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 29 

# Charleston Harbor Charleston Harbor is characterized as having moderate to high levels of chlorophyll-aand high levels of turbidity. Bio- logical resource impacts from nuisance and toxic algae areunknown in the tidal fresh zone and do not occur in the mixing and seawater zones. Nitrogen and phosphorus are reported at moderate levels except for high concentrations of both in the Ashley River. Anoxia and hypoxia are unknown in the tidal fresh zone and occur periodically during the late spring and summer in the mixing and seawater zones. Trends reported indicate increasing turbidity, particularly in the Ashley River, and decreasing nutrients based upon improved wastewater treatment and a phosphate ban. Verylow amounts of SAV are reported as increasing in the mixing zone.

Anoxia Mixing Seawater Tidal Fresh Hypoxia Dissolved Oxygen

Nitrogen Phosphorus Nutrients Mixing Seawater Tidal Fresh In General Ashley River 

# M
50-100%

50-100% 

# M
M 50-100% 

# M
50-100%



# N ? ? 50-100%

50-100% 

# M
M H

10-25% 

# H
10-25%

In General Ashley River 

# Y

10-25% 

# Y
25-50% 0-10%

0-10% 

# Y Y Y

10-25% 

# Y
25-50% 

# ? ?
? ? 

# ? ?

Periodic occurrences of anoxia in mixing and seawater zones May through September. Hypoxic conditions occur in tidal fresh zone. Bottom-water occurrences were reported for anoxia; hypoxic conditions occur throughout entire water column. Water column stratification was not a factor. Concentrations are reported as total nitrogen and total phosphorus. In seawater zone, elevated TN concentrations occur May to September; elevated TP concentrations occur July to September. Trends are associated with improved wastewater treatment and a phosphate ban.



# Y
0-10% Physical and Hydrologic Characteristics

Tidal Fresh Estuary

46.4
18.3 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 5,996

Surface Area (mi 2 ) 22.0
15.9 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 1,215

7.0
12.0 In General Ashley River

21.6 10.9 6.5
15.0
3.2 2.3 10.8
17.3

5.2 Formed at the confluence of the Cooper, Ashley, and Wando rivers. Since the rediversion of flow away from the Cooper river system in 1985, regulated flow from the Cooper and low flow from the Ashley results in small inter-annual salinity distributions. Tides range approximately 5.2 ft near harbor mouth and have dominant influence on salinity variability in upper portions of Ashley and Cooper rivers. Vertical stratification is more pronounced within Cooper River than in other parts of estuary. Chlorophyl- a Turbidity Nuisance Algae Toxic Algae Mixing Seawater Tidal Fresh Algal Conditions

SAV Mixing Seawater Tidal Fresh Ecosystem/Community Responses In General Ashley River 

# ?

N 

# ?

N N 

# ? H M ? E ?

N

VL VL

In General Ashley River 

# ? ? ?



# N
N M

* * 50-100% 50-100% 0-10% 50-100% 

# B H

50-100% 

# H

50-100% 

# H
50-100%



### * * 

# ?
?

VL ? Chl- a and turbidity maximums occur periodically in summer in all zones and episodically February to March in tidal fresh zone. Algal biomass is limited by phosphorus and light in tidal fresh and mixing zones, and by nitrogen and light in seawater zone.

Primary production is dominated by macrophytes and intertidal wetlands in tidal fresh and mixing zones and pelagic communities in seawater zone. Diatoms dominate planktonic community; benthic community dominated by insects in tidal fresh zone and mixture of annelids and mollusks in mixing and seawater zones. Intertidal wetlands have high spatial coverage. 

## Key on page 20 Back River Wando River

North SCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 30 

# Stono/North Edisto Rivers Stono/North Edisto Rivers have minimal information on existing conditions but are characterized as having slight increases in turbidity, and moderate decreases in nitrogen andphosphorus. Anoxia and hypoxia occur periodically in limited areas of the seawater zone. The reported conditions occur primarily in the seawater zone which represents more than 80 percent of the estuary. Very low amounts of SAV are reported for the seawater zone.

Chlorophyl- a Turbidity Nuisance Algae 

# N Toxic Algae Mixing Seawater Tidal Fresh 

### Algal Conditions

SAV Mixing Seawater Tidal Fresh 

# NS VL Ecosystem/Community Responses 

# N ?

? ? ??

? ? 

# ? ?



# N ? ? ? 

# N

Primary producer is intertidal wetlands. Planktonic community is dominated by diatoms and benthic community by diverse mixture. Trends are associated with nonpoint sources. Physical and Hydrologic Characteristics

Tidal Fresh Estuary 39.1 5.5

13.9 15.6 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs)
Surface Area (mi 2 ) 33.6

17.3 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average N/A

2.1 16.2 18.3 N/A

Consists of the North Edisto River, Stono River and an intricate network of tidal creeks and tributaries. Relatively high salinities exist, especially near the mouth. Generally well mixed with low seasonal salinity variability. Freshwater inflow driven by local precipitation events and inflow from tributaries.

Anoxia Mixing Seawater Tidal Fresh 

# N Y Hypoxia 

# N Y Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh Phosphorus 

### Nutrients


# ?
? ?
? ?

10-25%

10-25% 

# ? ?
? ?

Periodic occurrences of hypoxia occur June to October in mixing zone, and June to July in seawater zone. Conditions are mainly observed at bottom of water column. Water column stratification not a factor. Trends are associated with improvements in point sources.



## Key on page 20 North SCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



### 31 

# St. Helena Sound

Physical and Hydrologic Characteristics St. Helena Sound is characterized as having low levels of chlorophyll-a . Turbidity is characterized as blackwater in themixing zone and high in the seawater zone. Biological resource impacts from nuisance and toxic algae are unknownand nutrients are moderate. Anoxia and hypoxia occur periodically during the summer. These conditions are reported primarily for the mixing zone.Trends information is generally unknown, with the exception of decreases in nitrogen in the mixing zone, and notrends for turbidity and phosphorus in the mixing zone. Distribution and trends for SAV are unknown.

Chlorophyl- a 

# L L Turbidity 

# B H Nuisance Algae 

# ? ? Toxic Algae Mixing Seawater Tidal Fresh 

### Algal Conditions

SAV Mixing Seawater Tidal Fresh 

# ? ? Ecosystem/Community Responses 

# ? ? ? * * 

# ?
?


# ? ?
? ? ?



# ? ? The frequency and months of occurrence for high turbidity conditions are unknown.

Primary productivity is dominated by intertidal wetlands; planktonic community is dominated by diatoms and benthic community by mixture of annelids and crustaceans. Tidal Fresh Estuary 97.7 54.8
14.5 12.9 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 4,600

Surface Area (mi 2 ) 42.9

11.3 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 1,558

22.2 13.5 35.7 A drowned river valley/bar built system with numerous tributaries and island formations. Major freshwater source is South Edisto River. Semi-diurnal tides range 6.9 ft near estuary mouth and are dominant forcing mechanism to salinity structure. Weak stratification of salinities and seasonal variability is common in lower Combahee and South Edisto rivers. Vertically homogeneous conditions prevail in lower St. Helena Sound.

Anoxia Mixing Seawater Tidal Fresh 

# Y ? Hypoxia 

# Y ? Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# M Phosphorus 

# M ? Nutrients 

# ? 50-100%

50-100% 

# ?
? ?

25-50%

25-50% 

# ? ?
? ?
Periodic occurrences of anoxia/hypoxia occur in mixing zone June to September. Bottom-water occurrences were reported for anoxia; hypoxic conditions occur throughout water column. Water column stratification not a factor. Elevated TDN concentrations occur June to September; elevated TDP concentrations occur June to October.



### Key on page 20 SC

NorthNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 32 

# Broad River

Physical and Hydrologic Characteristics Broad River is characterized as having moderate levels of chlorophyll-aand low levels of turbidity. Based on specula- tive inference, biological resource impacts from nuisance and toxic algae do not occur. Nitrogen and phosphorus levelsare reported at moderate to high concentrations. Bottomwater anoxia and hypoxia occur periodically during the summer. These conditions are observed in the mixing and seawater zones. Trends are generally unknown with the exception of turbidity (increasing in the mixing zone and no trend in the seawater zone), nitrogen (no trend in the mixing zone), and phosphorus (no trend in both mixing and seawater zones). Distribution and trends for SAV are unknown.

Tidal Fresh Estuary 107.5 15.5

23.7 24.0 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 900

Surface Area (mi 2 ) 92.0

23.2 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 1,010

10.2 59.5 69.7 A drowned river valley system with intricate tidal creeks and marsh islands. The Coosawhatchee River is major freshwater source, but little seasonal variability exists due to the relatively low discharge into estuary. Tides range an average of 6.9 ft near estuary mouth. Port Royal Sound exhibits vertically homogeneous salinity structure due to tidal mixing. Chlorophyl- a 

# ? M Turbidity 

# L Nuisance Algae Toxic Algae Mixing Seawater Tidal Fresh 

### Algal Conditions

SAV Mixing Seawater Tidal Fresh 

# ? ? Ecosystem/Community Responses 

# ? ?
? ?

? ? 10-25% 

# ? ?
L ? 

# N * 

# N *


# N * 

# N *

Medium chl- a conentrations occur periodically in the Beaufort River portions of the seawater zone.

Primary productivity is dominated by intertidal wetlands; planktonic community dominated by diatoms; benthic community by mixture of annelids and crustaceans. Anoxia Mixing Seawater Tidal Fresh 

# Y Hypoxia 

# Y Dissolved Oxygen

Nitrogen Mixing Seawater Tidal Fresh 

# H Phosphorus 

# H M Nutrients 

# M
50-100%

50-100% 

# ?

10-25%

10-25% 

# ? ?
? ? 50-100%

50-100%



# Y
10-25% 

# Y
10-25% Anoxia/hypoxia occur periodically in mixing and seawater zones June to September. Bottom-water occurrences were reported for anoxia; hypoxic conditions occur throughout water column. Water column stratification not a factor. Elevated TDN concentrations occur in mixing zone in January and August to October; in seawater zone in February and August to October. Elevated TDP concentrations occur in mixing zone July to August and November; in seawater zone June to August.



## Key on page 20 Broad River SC

NorthNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 33 

# Savannah River Savannah River is characterized as having moderate levels of cholorophyll-aand moderate to high levels of turbidity, particularly in the mixing zone. Biological resource impacts from nuisance and toxic algae do not occur. Nutrients are reported as moderate to relatively high, particularly in the tidal fresh zone. Bottom-water anoxia and hypoxia occur periodically during the summer. The spatial extent of most of these conditions is unknown. Trends are reported as either unknown or no trends with the exception of a possible increase in turbidity in the tidal fresh zone. SAV is unknown in the tidal fresh zone and not present in the rest of the estuary. Physical and Hydrologic Characteristics

Tidal Fresh Estuary 71.8 17.7

16.2 15.2 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 12,800

Surface Area (mi 2 ) 18.7

9.3 35.4
17.3 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 1,316

8 17 29.9 4.8 Part of a drowned river valley system receiving the majority of freshwater inflow from the Savannah River. Discharge is determined by controlled releases of freshwater. Salinity structure is moderately stratified and salinity variability within the estuary is more significant below Hutchinson Island. Tides range 6.5 ft at estuary mouth and are a dominant forcing mechanism to the overall salinity structure. Chlorophyl- a 

# M M Turbidity 

# H M Nuisance Algae 

# N N Toxic Algae Mixing Seawater Tidal Fresh Algal Conditions

SAV Mixing Seawater Tidal Fresh 

# NS NS Ecosystem/Community Responses 

# N N ? 

# L
?
N
N ?

? 

# ?



# ? * * * 

# ?



# ? ? ?

? ?

Maximum chl- a concentrations occur periodically June to August with light limiting in mixing zone and silica in seawater zone. Turbidity maximums occur continuously throughout year.

Primary productivity is dominated by intertidal wetlands. Planktonic community dominated by diatoms and diverse mixture; benthic community dominated by crustaceans in tidal fresh zone and annelids in mixing zone. Anoxia Mixing Seawater Tidal Fresh 

# Y N Hypoxia 

# Y N Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# M M Phosphorus 

### Nutrients 

# H
HMM

N
N ?
? ? ? ? ? 10-25%

25-50% ? ? ?

? ? ?

Anoxia occurs periodically June to August, and hypoxia May to September, both typically at bottom of water column. Water column stratification contributes moderately to these conditions. There was an increase in minimum average monthly bottom dissolved oxygen concentrations and an increase in the spatial coverage of hypoxic conditions in mixing zone. Nonpoint sources are associated with the trends. More than 50% of TDN is organic nitrogen. Elevated concentrations occur May to August in tidal fresh and mixing zones.



## Key on page 20 Calibogue Sound GA SC NorthNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 34 

# Ossabaw Sound Ossabaw Sound is characterized as having high to moderate levels of chlorophyll- aand turbidity. Biological resourceimpacts from nuisance and toxic algae generally do not occur. Nutrients are reported at low to moderate levels. Anoxia and hypoxia do not occur. The conditions reported occur primarily in the mixing zone. Trends are either unknown or reported as no trend. SAV is not present. Physical and Hydrologic Characteristics

Tidal Fresh Estuary 39.9 18.1

14.2 14.3 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 3,000

Surface Area (mi 2 ) 4.8

6.5 17.0

13.1 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 1,473

7.2 6.2 14.3 0.9 A small coastal plain system receiving freshwater from Ogeechee and Canoochee rivers. Seasonal variability in rainfall can alter salinity by 10 ppt in most of estuary. Tides range an average of 6.9 ft throughout Ossabaw Sound. Vertically stratified circulation pattern can persist during low salinity period within lower Ogeechee River and Ossabaw Sound.

Anoxia Mixing Seawater Tidal Fresh 

# N N Hypoxia 

# N N Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# M ? Phosphorus 

### Nutrients 

# L
L M ?

N
N ?
? ? ? ? ? 

# ? ? *

* ?

? More than 50% of TDN is organic nitrogen. Maximum concentrations occur May to September. Chlorophyl- a 

# H M Turbidity 

# H M Nuisance Algae 

# N N Toxic Algae Mixing Seawater Tidal Fresh Algal Conditions

SAV Mixing Seawater Tidal Fresh 

# NS NS Ecosystem/Community Responses 

# N N L
?
?
?

? * * *



# ? 25-50% 25-50% 

# ?? ? ? ?

?
?

? ? *

* * ? ?

Maximum chl- a concentrations occur episodically in mixing zone and periodically in seawater zone April to July. Medium concentrations occur periodically in mixing zone. Turbidity concentrations occur periodically from April to July.

Primary productivity is dominated by intertidal wetlands. Planktonic community dominated by diverse mixture. 

## Key on page 20 Ogeechee River

North GANOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 35 

# St. Catherines/Sapelo Sounds St. Catherines/Sapelo Sounds are characterized as having moderate levels of chlorophyll-aand high levels of turbid-ity. No occurrences of biological resource impacts from nuisance or toxic algae are reported. No anoxic or hypoxic conditions are reported. Nitrogen and phosphorus levels are low.These conditions occur primarily in the mixing and seawater zones. Trends for nitrogen and phosphorus indicate significant increases in the mixing zone. Other trends were reported as unknown or, for nuisance/toxic algae, as no trend.SAV is not present. Several of the values reported for chlorophyll- a, nutrients, and dissolved oxygen are based on speculative inference. Physical and Hydrologic Characteristics

Anoxia Mixing Seawater Tidal Fresh 

# N N Hypoxia 

# N N Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# L L Phosphorus 

# L L Nutrients



## * *

* * *

* 

# ?
?

*

* 

# ? ?
? ? Trends are associated with nonpoint sources. Tidal Fresh Estuary 92.2 54.9

14.7 14.5 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 800

Surface Area (mi 2 ) 0.4

7.6 36.9

22.7 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 963

22.5 23.4 45.9 0.09 A drowned river valley-barrier island system comprised of small tidalcreeks. Receives minimal freshwater from mainland runoff, groundwater, and lateral flow from nearby rivers. Weak stratification occurs within Doboy Sound. Elsewhere, salinities are generally vertically homogeneous. Tides range 6.5 to 9 ft and are dominant forcing mechanism on salinity structure throughout most of estuary. Chlorophyl- a 

# M M

50-100% Turbidity 

# H H Nuisance Algae 

# N N Toxic Algae Mixing Seawater Tidal Fresh Algal Conditions

50-100%

50-100%

SAV Mixing Seawater Tidal Fresh 

# NS NS Ecosystem/Community Responses 50-100%



# N N ?
? * *

* * 

# ?
?

Maximum chl- a concentrations occur periodically in summer with light limiting in mixing zone and silica limiting in seawater zone. Turbidity maximums occur periodically throughout year.

Primary productivity dominated by intertidal wetlands. Planktonic and benthic communities dominated by diverse mixture. * Tidal Fresh area not characterized for this estuary



## Key on page 20 North GANOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 36 

# Altamaha River Altamaha River is characterized as having moderate to high levels of chlorophyll-aand high levels of turbidity. No oc- currences of biological resource impacts from nuisance or toxic algae are reported. No hypoxic or anoxic conditionsare reported. Nutrients were reported as low in the seawater zone and moderate in the rest of the estuary. These conditions occur primarily in the mixing zone which represents approximately 80 percent of the estuary. Trendsare generally reported as unknown or no trend with the exception of significant decreases in nitrogen in the tidal fresh and mixing zones. SAV is not present.

Chlorophyl- a 

# H M Turbidity 

# H H Nuisance Algae 

# N N Toxic Algae Mixing Seawater Tidal Fresh Algal Conditions

SAV Mixing Seawater Tidal Fresh 

# NS NS Ecosystem/Community Responses 

# N N L
?
?

? * * *



# ? 50-100% 50-100% * *

50-100% 50-100% 

# ? ?? ?
?

? ? ?

Maximum chl- a concentrations occur episodically in mixingzone and periodically in seawater zone in summer. Medium chla concentrations occur periodically in mixing zone. Light is limiting in mixing zone and silica in seawater zone. Turbidity maximums occur continuously throughout year.

Primary productivity dominated by intertidal wetlands. Planktonic and benthic communities dominated by diverse mixture. Physical and Hydrologic Characteristics

Tidal Fresh Estuary 16.7 12.0

12.1 10.2 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 14,900

Surface Area (mi 2 ) 2.5

4.3 2.2

13.1 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 1,512

4.1 0.8 5.2 0.3 A coastal plain system consisting of the Altamaha River and several tidal creeks. Seasonal freshwater discharge is dominant forcing mechanism on salinity variability. Moderate to highly stratified conditions exist in central and lower estuary. During high-inflow, vertically homogeneous conditions occur in Altamaha River above Onemile Cut. Semi-diurnal tides range an average of 6.5 ft near estuary mouth.

Anoxia Mixing Seawater Tidal Fresh 

# N N Hypoxia 

# N N Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# M L Phosphorus 

### Nutrients 

# M
M M L

N N ? ? ? ? ? ? * * *

50-100%

50-100% 50-100%

50-100% * *

* * 

# ?
?

*

* In tidal fresh zone, elevated nutrient concentrations occur March to May, and in mixing zone, May to August.



## Key on page 20 South Altamaha River Altamaha River

Threemil e Cut Little Mud Creek

Onemil e Cut

North GANOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 37 

# St. Andrew/St. Simons Sounds

Physical and Hydrologic Characteristics St. Andrew/St. Simon Sounds are characterized as having moderate levels of chlorophyll-a . Turbidity is not character-ized because the estuary is classified as a blackwater system. No occurrences of biological resource impacts from nuisance or toxic algae are reported. No hypoxic or anoxic conditions are reported. Nitrogen is reported as generally moderate to high, and phosphorous is reported as generally moderate. The conditions reported occur primarily in the mixing andseawater zones which represent over 95 percent of the estuary. Trends are generally reported as unknown or no trend with the exception of significant nutrient increases in the tidal fresh and mixing zones. SAV is not present. Several of the values reported for chlorophyll-a, nutrients and dissolved oxygen are based on speculative inference.

Anoxia Mixing Seawater Tidal Fresh 

# N N Hypoxia 

# N N Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# M L Phosphorus 

### Nutrients 

# H
M M L

N
N ? ? ? ? ? ? * *

50-100%

50-100% 50-100%

50-100% * *

* * 

# ?
?

*

* *

* *

* *

More than 50% of TDN is organic nitrogen. Elevated nutrient concentrations in tidal fresh zone occur March to May; in mixing zone May to August. Trends associated with nonpoint sources. Chlorophyl- a 

# M M Turbidity 

# B B Nuisance Algae 

# N N Toxic Algae Mixing Seawater Tidal Fresh 

### Algal Conditions

SAV Mixing Seawater Tidal Fresh 

# NS NS Ecosystem/Community Responses 

# N N L
B
?

? * *



# ? 50-100% 50-100% * * 

# ? ???
?

? ? ? ?

Maximum chl- a concentrations occur episodically in mixing and periodically in seawater zone in summer. Medium chl- a concentrations occur periodically in mixing zone. Light is limiting in mixing zone and silica in seawater zone.

Primary producer is intertidal wetlands. Planktonic and benthic communities dominated by diverse mixture. Tidal Fresh Estuary 82.9 54.8

12.9 14.3 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 2,500

Surface Area (mi 2 ) 3.7

10.3 24.4

13.0 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 3,213

20 8.8 29.9 1.1 A drowned river valley system surrounded by barrier island features. Receives majority of freshwater from Satilla River, although seasonal salinities are also influenced by Altamaha River to the north. Salinity is weakly stratified and dominated primarily by tidal mixing. Tides range 6.5 ft at entrances of estuary to 7.8 ft near Hermitage Point.



## Key on page 20 Cumberland River

North GANOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 38 

# St. Marys River/Cumberland SoundSt. Marys River/Cumberland Sound is characterized as having moderate levels of chlorophyll-a . Turbidity is not char- acterized because the estuary is classified as a blackwater system. No occurrences of biological resource impacts from nuisance or toxic algae are reported. No hypoxic or anoxic conditions are reported. Nutrients are generally low except for moderate nitrogen levels in the seawater zone. The conditions reported occur primarily in the seawater zone which represents approximately 90 percent of the estuary.Trends are generally reported as unknown or no trend except for a decrease in phosphorus in the mixing zone. SAV is not present. Physical and Hydrologic Characteristics

Tidal Fresh Estuary 33.8 3.7

8.4 19.7 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 8,171

Surface Area (mi 2 ) 0.1

5.7 30.0

21.1 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 1,737

0.9 17.6 18.5 0.02 A bar-built estuary receiving the majority of freshwater inflow from St. Marys River, with discharge usually highest in late winter and spring. Salinity structure is determined primarily by seasonal pulses from the St. Marys River. Vertically homogeneous conditions occur throughout most of lower river and within Cumberland Sound due to tidal mixing. Tides average 6 ft near St. Mary’s Entrance.

Anoxia Mixing Seawater Tidal Fresh 

# N N Hypoxia 

# N N Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# L M Phosphorus 

# L L Nutrients

50-100% 

## * *

* 

# ?
?

*

* 

# ? ?
? ? More than 50% of TDN is organic nitrogen. Elevated nutrient concentrations occur April to September. Chlorophyl- a 

# M M

50-100% Turbidity 

# B B Nuisance Algae 

# N N Toxic Algae Mixing Seawater Tidal Fresh 

### Algal Conditions

50-100%

SAV Mixing Seawater Tidal Fresh 

# NS NS Ecosystem/Community Responses 

# N N ?
? * *

* * 

# ?
?

Maximum chl- a concentrations occur periodically June through August. Limiting factor to algal biomass is light in mixing zone and silica in seawater zone.

Primary producer is intertidal wetlands. Planktonic and benthic communities are dominated by diverse mixture. * Tidal Fresh

area not characterized for

this estuary



## Key on page 20 Cumberland River
Cumberland Sound

North GA

FLNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 39 

# St. Johns River

Physical and Hydrologic Characteristics St. Johns River is characterized as having high to moderate levels of chlorophyll- aand turbidity along with periodic occurrences of nuisance algae and episodic occurrences of toxic algae. Nitrogen and phosphorus levels are relatively moderate except for high phosphorus levels recorded for the seawater zone. No anoxia or hypoxia are observed. The conditions observed generally occur in the tidal fresh and mixing zones which represent more than 95 percent of the estuarine surface area. No trends were reported for these conditions. Trends are observed for SAV with relatively minor declines in the tidal fresh and mixing zones.

Chlorophyl- a 

# M M Turbidity 

# H H Nuisance Algae 

# Y N Toxic Algae Mixing Seawater Tidal Fresh Algal Conditions

SAV Mixing Seawater Tidal Fresh 

# VL NS Ecosystem/Community Responses 

# N N H

H/M



# Y

L 25-50% 10-25%



# Y 25-50%

Chl- a maximums occur periodically April to early fall. Light and nitrogen are limiting factors in tidal fresh and mixing zones; residence time is limiting in seawater zone. Turbidity maximums occur April to July in tidal fresh and July to December in mixing and seawater zones. Nuisance microcystis species occur periodically June to July; toxic dinoflagellates occur episodically.

Diatoms dominate planktonic community; benthic community is dominated by annelids in seawater zone and mollusks in tidal fresh and mixing zones. Tidal Fresh Estuary 264.1 60.1

11.1 12.0 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) 7,800

Surface Area (mi 2 ) 197.5

10.5 6.5

20.0 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 6,389

18.6 3.6 80.0 57.8 An elongated estuarine system comprised of large lakes along most of the rivers main stem. Tidal influences are most apparent near the river mouth where tides range approximately 4 ft. Moderate vertical stratification results as freshwater overrides more dense sea water. Wind and precipitation contribute to complexity of tidal influences within estuary.

Anoxia Mixing Seawater Tidal Fresh 

# N N Hypoxia 

# N N Dissolved Oxygen Nitrogen Mixing Seawater Tidal Fresh 

# M M Phosphorus 

### Nutrients 

# L MMH

N
N 50-100% 50-100% 50-100%

50-100% 50-100% More than 50% of TDN is organic nitrogen.



## Key on page 20 Atlanti c Ocea n FLNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 40 

# Indian River

Physical and Hydrologic Characteristics Indian River is characterized as having high to hypereutrophic levels of chlorophyll- aand high levels of turbidity. Biological resource impacts from nuisance andtoxic algae occur periodically during the summer. Nutrients are reported as moderate to high. Bottom-water anoxia and hypoxia occur periodically over limited areas during spring and summer. These conditions occur only in seawater zone. Trends aregenerally reported as unknown or no trend except for increasing cholorophyll- ain the St. Lucie River. SAV is present in low to moderate amounts though trends indicate it is decreasing in both areas for which it is reported. Many ofthe values reported for this estuary are based on speculative inference.

Chlorophyl- a 

# H E Turbidity 

# H H Nuisance Algae 

# Y Y Toxic Algae Algal Conditions

SAV 

# ? L Ecosystem/Community Responses 

# Y Y H
H
Y

M * *



# Y ? ? ? * *

*

*

*



# ? * ? ? ?

? ? ?

Maximum chl- a concentrations occur episodically spring to fall with light limiting in all zones. Maximum turbidity occurs episodically spring to summer in tidal fresh zone, all year in mixing zone, and periodically spring to summer in seawater zone. Nuisance and toxic algae events occur periodically June to August, lasting less than a week, and episodically in tidal fresh and seawater zones. Mixing Seawater Tidal Fresh Indian River St. Lucie River Urban Areas

Mixing Seawater Tidal Fresh Indian River St. Lucie River Urban Areas

SAV is dominant primary producer and flagellates are dominant planktonic group. Benthic shift from annelids to mixture of annelids and crustaceans occurred in Indian River lagoon. Nonpoint sources associated with benthic shift and declining SAV. Anoxia 

# Y Hypoxia 

# Y Y Dissolved Oxygen Nitrogen 

# H H Phosphorus 

### Nutrients 

# M MH H

Y Y ? ? ? ? ? ? *

*

* *

* *



# Y

10-25% 10-25%

25-50% 10-25%

25-50% 25-50%

* * *

* ? ? ?

? ? ?

Periodic occurrences of anoxia/hypoxia occur April to September, typically at bottom of water column. Water column stratification was a major factor. Mixing Seawater Tidal Fresh Indian River St. Lucie River Urban Areas

Mixing Seawater Tidal Fresh Indian River St. Lucie River Urban Areas Elevated nutrient concentrations occur April to September. Tidal Fresh Estuary

336 11
9.0 6.6 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) N/A

Surface Area (mi 2 ) 296
6.6 Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 1,184

2.8 64.4 55 36
6.6

6.6 Indian River St. Lucie R. Urban Areas

A narrow, lagoonal system influenced by wind forcing mechanisms, storm events, freshwater runoff and evaporation. Short-term wind events coupled with longer-term seasonal storms affect overall salinity structure. Freshwater runoff from landward sources determines lateral salinity stratification and variability. Saltwater intrusion creates vertical stratification within estuary. Tidal influence is mainly through 3 inlet structures: Sebastian, Ft. Pierce and St. Lucie. Tides range 1 ft near Ft. Pierce Inlet.



## Key on page 20 Indian River FLNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 41 

# Biscayne Bay

Physical and Hydrologic CharacteristicsBiscayne Bay is characterized as having generally low levels of chlorophyll-aand low to moderate levels of turbidity. No biological resource impacts from nuisance or toxic algae are reported. Nitrogen levels range from low to medium and phosphorus levels are low. Bottom-water anoxia and hypoxiaoccur only in localized areas that have been artificially deepened. Surface waters in canals and adjacent areas may be anoxic or hypoxic during flood discharge events. These conditions occur in the mixing and seawater zones.Trends are generally reported as no trends except for decreasing turbidity in the seawater zone and increasing nutrients in some parts of both the mixing and seawater zones. SAV is widely distributed and generally stable except with slight increases reported for the north end of the seawaterzone. Values for nuisance and toxic algae are based on speculative inference.

Nuisance Algae Toxic Algae Algal Conditions

SAV Ecosystem/Community Responses 

# N N Chlorophyl- a Turbidity Mixing Tidal Fresh Seawater 

# L North South



# M L L L

North South



# L L
N N

Mixing Tidal Fresh Seawater 

# M M L H L

0-10%



# N N N N * * * * * * **

* * * * * * **



# ? North South North South Chl- a maximums occur periodically September to October with phosphorus and light limiting algal biomass. Turbidity maximums occur continuously in northern mixing zone and periodically in northern seawater zone. Impacts from suspended solids occur October to December in northern mixing zone.

Benthic community is dominated by seagrass, and some hardbottom areas are dominated by soft corals and sponges. Diatoms dominate planktonic community. Tidal Fresh Estuary

269.5 209.2
7.7 7.7 Estuarine Drainage Area (mi 2 ) Avg. Daily Inflow (cfs) N/A
Surface Area (mi 2 ) 1.2
8.4

Mixing Seawater

Depth (ft)

(billion cu ft) Volume Average 2,876

34.0
7.7 26.7
8.4 North Area South Area North Area South Area

6.3 58.9 0.3 7.3 45 A shallow, lagoonal estuary highly influenced by flood control and upstream intrusion of saltwater. Salinity patterns are affected by periodic discharges from water control structures on canals and tributaries. Circulation is tidally driven. Wind and tidal influences generally maintain a vertically mixed water column throughout the estuary.

Dissolved Oxygen Nutrients Nitrogen Phosphorus Mixing Tidal Fresh Seawater

Anoxia Hypoxia Mixing Tidal Fresh Seawater 

# M L
L L H M
L L

N N
N N 10-25% 

# Y Y
Y Y

0-10% 10-25%

10-25%

10-25% North South North South

North South North South

10-25%

Anoxia and hypoxia occur in the north mixing zone from June to September primarily in dredged areas and at the water surface in or near canals. In the south mixing zone, anoxia and hypoxia are rare and occur only during extraordinary releases of freshwater from canals. In the channels and canals, water column stratification contributed moderately to anoxic and hypoxic conditions freshwater discharges. The seawater zones are unstratified and have high oxygen levels. Elevated nutrient concentrations occur September to January in both zones. Trends are associated with nonpoint sources. 10-25%



## Key on page 20 Card Sound Barnes

Sound North FLNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 42 

# Regional Summary Regional classification status of existing conditions for twelve parameters as a cumulative percent of total estuarine surface area for three salinity zones.



# AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA A A AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA A A AAAAAAAAAAAAAAAAAAAAAAA A A AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA A A AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA

6 7 8 9 10 11 12 13 Chlorophyll a

Turbidity Nitrogen Phosphorus
Anoxia Hypoxia Biological Stress Tidal Fresh (481.0 sq. mi) Mixing (3264.6 sq. mi) Seawater (1108.2 sq. mi)

Medium/Observed

Low-end Range High-end Range / Unknown Spatial

Coverage Concentration / Condition

Low/Not Observed Unknown

Spatial Extent ( Chl- a , Turb., N, & P) ( Anoxia, Hypoxia, Bio. Stress) The spatial extent of existing conditions was recorded for each salinity zone in each estuary when concentrations of chl-a, turbidity, nitrogen, or phosphorus were indicated as medium or greater, and when anoxia, hypoxia, or biologically stressful dissolved oxygen conditions were observed. Four broad ranges of spatial extent were used; high (100-51% of the surface area in a particular zoneof an estuary), medium (50-26%), low (25-11%), and very low (10-1%). For some estuaries, existing conditions were reported but spatial extent was unknown. The figure represents a method for quantifying these results. Black shows conservative estimates of cummulative spatial extent(e.g. high spatial extent equals 51% of an estuary’s surface area). Black with white lines shows liberal estimates (e.g. high equals 100%, and unknown spatial extent also equals 100%). White shows the cummulative total surface area reported to have low concentrations or no observed conditions. Gray shows the cummulative total surface area reported as unknown concentrations or conditions.



# AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA A A A A AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAA

0.0 1 2 3 4 5 Suspended Solids

Nuisance Algae Toxic Algae Macroalgae Epiphytes

2000.0
Impacts Resources No Resource Impact Unknown Condition ( Susp. Solids, Nuisance/Toxic Algae, Macroalgae, Epiphytes) Tidal Fresh (481.0 sq. mi) Mixing (3264.6 sq. mi) Seawater (1108.2 sq. mi) The presence of suspended solids, nuisance algae, toxic algae, macroalgae, and epiphytes in each salinty zone were reported as either impacting resources, not impacting resources, or unknown. The spatial extent of these conditions was not recorded.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 43 

# Appendix 1: Participants

South Atlantic Regional Workshop The persons below supplied the information included in this report. Survey participants provided the initial data to ORCA via survey forms sent through the mail. Site visit participants provided additional data through on-site interviews with project staff. These persons also reviewed initial survey data where available. Workshop participants reviewed and revised, in a workshop setting, preliminary aggregate results and, where possible, provided additional data that was still missing. All participants also had the opportunity to provide comments and suggestions on the estuary salinity maps.

North Section (Albemarle/Pamlico Sounds to Broad R.) Elizabeth Blood J.W. Jones Ecological Research Center David Chestnut South Carolina Department of Health & Environmental Conservation Mark Evans Coastal Services Center/ NOAA Fred Holland South Carolina Department of Wildlife & Marine Resources Jeff Hyland Office of Ocean Resouces Conservation and Assessment/NOS/NOAA Michael Mallin Univeristy of North Carolina Department of Biological Sciences Hank McKellar University of South Carolina, Department of Environmental Health Science Joe Rudek North Carolina Environmental Defense Fund Donald Stanley East Carolina University, Institute for Coastal & Marine Research PatriciaTestor Southeast Fisheries Science Center/NMFS/NOAA BobVan Dolah South Carolina Department of Wildlife & Marine Resources South Section (Savannah R. to Biscayne Bay) Merryl Alber University of Georgia Department of Marine Science Jim Alberts University of Georgia Marine Institute Ramesh Buch Dade County Environmental Resources Management Division Wayne Magley Florida Department of Environmental Protection Jay Pinckney University of North Carolina Institute of Marine Science Peter Verity Skidaway Institute of Oceanography ConradWhite Brevard County Natural Resources Management Division JohnWindsor Florida Institute of Technology, Department of Oceanography 

# Survey/Site Visits Bogue Sound Larry Cahoon* Univ. of NC/Wilmington Michael Mallin• “ “ “ “ Lisa Levin Scripps Inst. of Oceanog. Jimmie Overton NC Div. of Env. Mgt. Frederick T. Short Univ. of NH 

### New River Larry Cahoon* Univ. of NC/Wilmington Michael Mallin• “ “ “ “ Jimmie Overton NC Div. of Env. Mgt. 

### Cape Fear River Larry Cahoon Univ. of NC/Wilmington Michael Mallin “ “ “ “ Donald W. Stanley E. Carolina Univ. Steve Tedder NC Div. of Env. Mgt. 

### Winyah Bay Dennis Allen Univ. of SC Daniel L. Childers Natl. Marine Fisheries Svc. Russell W. Sherer SC Dept. of Health & Env. Con. * participated in site visit • participated in survey and site visit 

### Albemarle/Pamlico Sounds JoAnn Burkholder* NC State Univ. John E. Cooper E. Carolina Univ. Donald W. Stanley “ “ “ “ Jess H. Hawkins III NC Div. of Marine Fisheries Jimmie Overton NC Div. of Env. Mgt. Hans Paerl Univ. of NC 

### Pamlico/Pungo Rivers Vincent J. Bellis E. Carolina Univ. Donald W. Stanley “ “ “ “ Jimmie Overton NC Div. of Env. Mgt. 

### Neuse River Richard Barber Duke Univ. JoAnn Burkholder* NC State Univ. William W. Kirby-Smith “ “ “ “ Larry Cahoon* Univ. of NC/Wilmington Michael Mallin• “ “ “ “ Robert R. Christian E. Carolina Univ. Donald W. Stanley “ “ “ “ Jimmie Overton NC Div. of Env. Mgt. Hans Paerl Univ. of NCNOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 44 Lawrence Pomeroy* Univ. of GA Richard Wiegert* “ “ “ “ Clark Alexander* Skidaway Inst. of Oceanog. Jackson Blanton* “ “ “ “ James Nelson* “ “ “ “ Peter Verity* “ “ “ “ Randy Walker* “ “ “ “ Herb Windom* “ “ “ “ Jim Henry* GA State Univ. Stuart Stevens? GA Dept. of Nat. Res. 

### St. Andrew/St. Simons Sounds Clark Alexander* Skidaway Inst. of Oceanog. Jackson Blanton* “ “ “ “ James Nelson* “ “ “ “ Peter Verity* “ “ “ “ Randy Walker* “ “ “ “ Herb Windom* “ “ “ “ Deborah Bronk* Univ. of GA Robert Hodson* “ “ “ “ Mary Ann Moran* “ “ “ “ Richard Wiegert* “ “ “ “ Jim Henry* GA State Univ. Stuart Stevens? GA Dept. of Nat. Res. 

### St. Marys River/Cumberland Sounds Clark Alexander* Skidaway Inst. of Oceanog. Jackson Blanton* “ “ “ “ James Nelson* “ “ “ “ Peter Verity* “ “ “ “ Randy Walker* “ “ “ “ Herb Windom* “ “ “ “ Deborah Bronk* Univ. of GA Robert Hodson* “ “ “ “ Mary Ann Moran* “ “ “ “ Richard Wiegert* “ “ “ “ Jim Henry* GA State Univ. Stuart Stevens? GA Dept. of Nat. Res. 

### St. Johns River Bob Brody St. Johns R. Water Mgt. Dist. Betsy J. Deuerling City of Jacksonville A. Quinton White Jacksonville Univ. 

### Indian River Diane D. Barile Marine Res. Council of E. FL Bob Frease “ “ “ “ David L. Correll Smithsonian Env. Research Ctr. Terry L. Davis FL Dept. of Env. Reg. Greg A. Graves “ “ “ “ Guy P. Hadley “ “ “ “ John C. Higman St. Johns R. Water Mgt. Dist. Robert W. Virnstein “ “ “ “ 

### Biscayne Bay Richard W. Alleman S. FL Water Mgt. Dist. Susan M. Markley Dade Cty. Env. Res. Mgt. Div. Cecelia A. Weaver “ “ “ “ 

### North/South Santee Rivers David M. Knott SC Dept. Wildlife & Mar. Res. Russell W. Sherer SC Dept. of Health & Env. Con. 

### Charleston Harbor Phillip Dunstan College of Charleston A. Fred Holland* SC Dept. of Nat. Res. Hank McKellar Univ. of SC Russell W. Sherer SC Dept. of Health & Env. Con. Bob Van Dolah SC Dept. Wildlife & Mar. Res. Stono/North Edisto Rivers David Chestnut SC Dept. of Health & Env. Con. Bob Van Dolah SC Dept. Wildlife & Mar. Res. St. Helena Sound Russell W. Sherer SC Dept. of Health & Env. Con. Broad River Russell W. Sherer SC Dept. of Health & Env. Con. Savannah River James Alberts• Univ. of GA Robert Hodson* “ “ “ “ Jackson Blanton* Skidaway Inst. of Oceanog. James Nelson* “ “ “ “ Peter Verity• “ “ “ “ Richard Wiegert* “ “ “ “ David M. Knott SC Dept. Wildlife & Mar. Res. Louis E. Sage Acad. of Nat. Sciences Russell W. Sherer SC Dept. of Health & Env. Con. Stuart Stevens* GA Dept. of Nat. Res. Ossabaw Sound James Alberts• Univ. of GA Deborah Bronk* “ “ “ “ Robert Hodson* “ “ “ “ Mary Ann Moran* “ “ “ “ Richard Wiegert* “ “ “ “ Clark Alexander* Skidaway Inst. of Oceanog. James Nelson* “ “ “ “ Peter Verity• “ “ “ “ Randy Walker* “ “ “ “ Jim Henry* GA State Univ. Stuart Stevens* GA Dept. of Nat. Res. 

### St. Catherines/Sapelo Sounds James Alberts• Univ. of GA Deborah Bronk* “ “ “ “ Robert Hodson* “ “ “ “ Mary Ann Moran* “ “ “ “ Richard Wiegert* “ “ “ “ Clark Alexander* Skidaway Inst. of Oceanog. Jackson Blanton* “ “ “ “ James Nelson* “ “ “ “ Peter Verity* “ “ “ “ Randy Walker* “ “ “ “ Herb Windom* “ “ “ “ Jim Henry * GA State Univ. Stuart Stevens* GA Dept. of Nat. Res. 

### Altamaha River James Alberts• Univ. of GA Deborah Bronk* “ “ “ “ Robert Hodson* “ “ “ “ Mary Ann Moran* “ “ “ “NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 45 

# Appendix 2: Estuary References The following references were recommended by one or more Eutrophication Survey participants as critical background material for understanding the nutrient enrichment characteristics of individual South Atlantic estuaries. In some cases,the survey results are based directly upon these publications. This list is not comprehensive. Some estuaries are not included because no suggestions were received. 

## Albemarle/Pamlico SoundsHarned, D.A., and M.S. Davenport. 1990. Water-quality trends and basin activities and characteristics forthe Albemarle-Pamlico Estuarine System, North Carolina and Virginia. U.S.G.S. Open File Report 90-398. Raleigh, NC. 164 p. Harned, D.A., G. McMahon, T.B. Spruill, and M.D. Woodside. 1995. Water-quality assessment of the Albemarle-Pamlico Drainage Basin, North Carolina and Virginia. U.S.G.S. Open File Report 95-191. Raleigh, NC. 132 p. Hyland, J.L. Personal communication. Unpublishedquantitative database on ecological conditions of southeastern estuaries based on EMAP sampling in the Carolinian Province, 1994-1995. NOAA Carolinian Province Office, Charleston, SC.Kuenzler, E.J., K.L. Stone, and D.B. Albert. 1982. Phytoplankton uptake and sediment release of nitrogen andphosphorus in the Chowan River, North Carolina. Report No. 186. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Paerl, H.W. 1982. Environmental factors promoting and regulating N 2

### fixing blue-green algal blooms in the Chowan River. N.C. Report No. 176. Water ResourcesResearch Institute, University of North Carolina, Raleigh, NC.Sauer, M.M. and E.J. Kuenzler. 1981. Algal assay studies of the Chowan River, North Carolina. Report No. 161. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Witherspoon, A.M., C. Balducci, O.C. Boody, and J. Overton. 1979. Response of phytoplankton to water quality in the Chowan River system. Report No. 129. Water Resources Research Institute, University of North Carolina, Raleigh, NC. 

## Pamlico/Pungo Rivers Burkholder, J.M., H.B. Glasgow, Jr., and C.W. Hobbs.1995. Fish kills linked to a toxic ambush-predator dinoflagellate: distribution and environmental conditions. Marine Ecology-Progress Series 124:43-61. Burkholder, J.M., H.B. Glasgow, Jr., and E.J. Noga. 1993. The role of a new toxic dinoflagellate in finfish andshellfish kills in the Neuse and Pamlico Estuaries. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Carpenter, E.J. 1971a. Effects of phosphorus mining wastes on the growth of phytoplankton in the Pamlico River Estuary. Chesapeake Science 12:85-94. Copeland, B.J. and J.E. Hobbie. 1972. Phosphorus and eutrophication in the Pamlico River Estuary, NC, 1966-1969-A summary. Report No. 65. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Copeland, B.J., R.F. Hodson, and S.R. Riggs. 1984. Theecology of the Pamlico River, North Carolina: An estuarine profile. United States Fish and Wildlife Service FWS/OBS-82-06. Slidell, LA.Davis, G.J., M.M. Brinson, and W.A. Burke. 1978. Organic carbon and deoxygenation in the Pamlico RiverEstuary. Report No. 131. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Garret, R.G. 1994. Water quality from continuouslymonitored sites in the Pamlico and Neuse River Estuaries, North Carolina, 1991-1992. U.S. Geological Survey Report 94-27.Hobbie, J.E., 1971. Phytoplankton species and populations in the Pamlico River Estuary of North Carolina. Report No. 56. Water Resources Research Institute, University of North Carolina, Raleigh, NC.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 46 Hobbie, J.E., B.J. Copeland, and W.G. Harrison. 1972. Nutrients in the Pamlico River Estuary, NC, 1969-1971. Report No. 76. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Kuenzler, E.J., D.B. Albert, G.S. Allgood, S.E. Cabaniss, and C.G. Wanat. 1984. Benthic nutrient cycling in thePamlico River. Report No. 215. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Kuenzler, E.J., D.W. Stanley, and J.P. Koenings. 1979. Nutrient kinetics in the Pamlico River, North Carolina. Report No. 139. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Stanley, D.W. 1987. Water quality in the Pamlico River Estuary 1986. Technical Report 87-01. Institute forCoastal and Marine Resources, East Carolina University, Greenville, NC. Stanley, D.W. 1992. Historical trends: Water quality and fisheries, Albemarle-Pamlico Sounds, with emphasis on the Pamlico River Estuary. UNC Sea Grant College Program Publication UNC-36-92-04. Institute forCoastal and Marine Resources, East Carolina University, Greenville, NC. 215 p. Stanley, D.W. 1993a. Long-term trends in the Pamlico River Estuary nutrients, chlorophyll, dissolved oxygen, and watershed nutrient production. Water Resources Research 29:2651-2662. Stanley, D.W. 1993b. Texas gulf effluent dispersal in the Pamlico River Estuary: 1992. Technical Report 93-01.Institute for Coastal and Marine Resources, East Carolina University, Greenville, NC. Stanley, D.W., and R.R. Christian. 1984. Nutrients in estuaries: Research needs and priorities, pp. 203-277. In: B. J. Copeland (ed.), Research for Managing the Nation’s Estuaries. University of North Carolina Sea Grant, Publ. 84-08, Raleigh, NC.Stanley, D.W., and D.A. Daniel. 1985. Seasonal phytoplankton density and biomass changes in South Creek, North Carolina. Journal of the Elisha Mitchell Scientific Society 101:130-141. Stanley, D.W., and D.A. Daniel. 1986. Phytoplankton in the Pamlico River Estuary 1985. Technical Report 86- 05. Institute for Coastal and Marine Resources, East Carolina University, Greenville, NC. Stanley, D.W., and J.E. Hobbie. 1981. Nitrogen recyclingin a North Carolina coastal river. Limnology and Oceanography 26:30-42. Stanley, D.W., and S. W. Nixon. 1992. Stratification and bottom-water hypoxia in the Pamlico River Estuary. Estuaries 15:270-281. 

## Neuse RiverBoyer, J.N., R.R. Christian, and D.W. Stanley. 1993. Patterns of phytoplankton primary productivity in the Neuse River Estuary, NC, USA. Marine Ecology Progress Series 97:287-297. Christian, R.R., J.N. Boyer, and D.W. Stanley. 1991. Multi-year distribution patterns of nutrients within the Neuse River Estuary, North Carolina. Marine Ecology Progress Series 71:259-274. Christian, R.R., W.L. Bryant, and D.W. Stanley. 1986. The relationship between river flow and Microcystis aeruginosablooms in the Neuse River, NC. Report No. 223. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Christian, R.R., W.M. Rizzo, and D.W. Stanley. 1989.Influence of nutrient loading on the Neuse River Estuary, North Carolina, pp. 19-40. In: R. Y. George and A.W. Hulbert (eds.), N.C. Coastal Oceanography Symposium. National Oceanic and Atmospheric Administration, National Undersea Research Program. Report 89-2. Christian, R.R., D.W. Stanley, and D.A. Daniel. 1984.Microbiological changes occurring at the freshwaterseawater interface of the Neuse River Estuary, NorthCarolina, pp. 349-36. In: V.S. Kennedy (ed.), The estuary as a filter. Academic Press, New York.Fisher, T.R., P.R. Carlson, and R.T. Barber. 1982. Carbon and nitrogen primary productivity in three North Carolina estuaries. Estuarine, Coastal and Shelf Science 15:621-644. Garret, R.G. 1994. Water quality from continuouslymonitored sites in the Pamlico and Neuse River Estuaries, North Carolina, 1991-1992. U.S. Geological Survey Report 94-27. Harned, D. A. 1980. Water quality of the Neuse River,N.C. U.S. Geological Survey. Water Reources Investigations No. 80-86. Mallin, M.A. 1992. Planktonic trophic transfer in anestuary: Seasonal, diel, and community structure effects. PhD dissertation. The University of North Carolina at Chapel Hill, Chapel Hill, NC.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 47 Mallin, M.A. 1994. Phytoplankton ecology of North Carolina Estuaries. Estuaries 17:561-574. Mallin, M.A. and H.W. Paerl. 1992. Effects of variable irradiance on phytoplankton productivity in shallow estuaries. Limnology and Oceanography 37:54-62. Mallin, M.A. and H.W. Paerl. 1994. Planktonic trophic transfer in an estuary: Seasonal, diel, and community structure effects. Ecology 75:2168-2184. Mallin, M.A., H.W. Paerl, and J. Rudek. 1991. Seasonal phytoplankton composition, productivity and biomass in the Neuse River Estuary, North Carolina. Estuarine, Coastal and Shelf Science 32:609-623. Mallin, M.A., H.W. Paerl, J. Rudek, and P. W. Bates. 1993. Regulation of estuarine primary production by watershed rainfall and river flow. Marine Ecology Progress Series 93:199-203. Paerl, H.W. 1987. Dynamics of blue-green algal blooms in the lower Neuse River, North Carolina: Causative factors and potential controls. Report No. 229. WaterResources Research Institute, University of North Carolina, Raleigh, NC.Paerl, H.W. 1983. Factors regulating nuisance bluegreen algal bloom potentials in the lower Neuse River,N.C. Report No. 188. Water Resources Research Institute, University of North Carolina, Raleigh, NC. Paerl, H.W., P.T. Bland, J.H. Blackwell, and N.D. Bowles.1984. The effects of salinity on the potential of a bluegreen algal (Microcystis aeruginosa ) bloom in the Neuse River Estuary, NC. Working Paper 84-1, University of North Carolina Sea Grant College Program, Raleigh, NC. Paerl, H.W., M.A. Mallin, C.A. Donahue, M. Go, andB.L. Peierls. 1995. Determining the role of nitrogen-enriched acid rain in estuarine eutrophication: The Neuse River Estuary, North Carolina. Report No. 291. WaterResources Research Institute, University of North Carolina, Raleigh, NC. Paerl, H.W., M.A. Mallin, J. Rudek, and P.W. Bates. 1990. The potential for eutrophication and nuisance algalblooms in the lower Neuse River Estuary. AlbemarlePamlico Estuarine Study Project No. 90-15. NC Department of Natural Resources and Community Development, Raleigh, NC.Paerl, H.W., J. Rudek, and M.A. Mallin. 1990. Stimulation of phytoplankton production in coastal waters bynatural rainfall inputs: Nutritional and trophic implications. Marine Biology 107:247-254. Rudek, J.H., H.W. Paerl, M.A. Mallin, and P.W. Bates.1991. Seasonal and hydrological control of phytoplankton nutrient limitation in the lower River Neuse Estuary, North Carolina. Marine Ecology Progress Series 75:133-142.Stanley, D.W. 1983. Nitrogen cycling and phytoplankton growth in the Neuse River, North Carolina. ReportNo. 204. Water Resources Research Institute, University of North Carolina, Raleigh, NC.Stanley, D.W. 1988. Historical trends in nutrient loading to the Neuse River Estuary, NC, pp. 155-164. In: W.L. Lyke and T.J. Hoban (eds.), Proceedings of the American Water Resources Association, Symposium on Coastal Water Resources. American Water Resources Association Technical Publication Series TPS-88-1., Bethesda, MD. Tedder, S.W., J. Sauber, J. Ausley and S. Mitchell. 1980.Working Paper: Neuse River Investigation 1979. Division of Environmental Management, NC Dept. of Natural Resources and Community Development, Raleigh, NC. 

## Bogue SoundBrett, C.E. 1963. Relationships between marine invertebrate infauna distribution and sediment type distribution in Bogue Sound, North Carolina, Chapel Hill, NC.Fisher, T.R., P.R. Carlson, and R.T. Barber. 1982a. Sediment nutrient regeneration in three North Carolina estuaries. Estuarine and Coastal Shelf Science 14:101-116.Fisher, T.R., P.R. Carlson, and R.T. Barber. 1982b. Carbon and nitrogen primary productivity in three North Carolina estuaries. Estuarine and Coastal Shelf Science 15:621-644. Hyland, J.L. Personal communication. Unpublishedquantitative database on ecological conditions of southeastern estuaries based on EMAP sampling in the Carolinian Province, 1994-1995. NOAA Carolinian Province Office, Charleston, SC.Kirby-Smith, W.W., and J.D. Costlow. 1989. The Newport River estuarine system. University of North Carolina Sea Grant College Publication UNC-SG-89-04, Raleigh, NC. pp. 58. Litaker, W., C.S. Duke, B.E. Kenney, and J. Ramus. 1988. Diel chl- a and phaeopigment cycles in a shallow tidal estuary: potential role of microzooplankton grazing. Marine Ecology Progress Series 47:259-270.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 48 Litaker, W., C.S. Duke, and J. Ramus. 1987. Short-termenvironmental variability and phytoplankton abundance in a shallow tidal estuary. I. Winter and summer. Marine Biology 96:115-121. Litaker, W., C.S. Duke, and J. Ramus. 1993. Short-termenvironmental variability and phytoplankton abundance in a shallow tidal estuary. II. Spring and fall. Marine Ecology Progress Series 94:141-154.Paerl, H. W. 1985. Enhancement of marine primary production by nitrogen-enriched acid rain. Nature 316:747- 749.Rudek, J. 1992. The effect of nutrient loading on primary production and nitrogen kinetics in Bogue Sound, NC. PhD Dissertation, Department of Environmental Science and Engineering, University of North Carolina, Chapel Hill. 133 p. Thayer, G.W. 1971. Phytoplankton production and thedistribution of nutrients in a shallow unstratified estuarine system near Beaufort, NC. Chesapeake Science 12:240-253. Thayer, G.W. 1974. Identity and regulation of nutrientslimiting phytoplankton production in the shallow estuaries near Beaufort, NC. Oecologia 14:75-92. Williams, R.B. 1966. Annual phytoplankton production in a system of shallow temperate estuaries. pp. 699- 716. In: H. Barnes (ed.), Some Contemporary Studiesin Marine Science. George, Allen and Unwin Ltd., London, England.Williams, R.B. 1972. Nutrient levels and phytoplankton productivity in the estuary. pp. 59-89. In: R.H. Chabreck (ed.), Proceedings of the Coastal Marsh and Estuary Management Symposium, Louisiana State University, Baton Rouge, LA.Williams, R.B. and M.B. Murdoch. 1966. Phytoplankton production and chlorophyll concentration in the Beaufort Channel, NC. Limnology and Oceanography 11:73-82. 

## Cape Fear River Carpenter, E.J. 1971. Annual phytoplankton cycle of the Cape Fear River Estuary, North Carolina. Chesapeake Science 12:95-104. EA Engineering. 1991. Lower Cape Fear water quality and fisheries literature review, final report. EA Report No. 11747, EA Engineering, Science, and Technology, Inc. Smyrna, GA. Hyland, J.L. Personal communication. Unpublishedquantitative database on ecological conditions of southeastern estuaries based on EMAP sampling in the Carolinian Province, 1994-1995. NOAA Carolinian Province Office, Charleston, SC. Mallin, M.A., G.C. Shank, M.R. McIver, and J.F. Merritt.1996. Water quality in the lower Cape Fear River system, 1995-1996. Center for Marine Science Research, University of North Carolina at Wilmington, Wilmington, N.C. Mallin, M.A., M.R. McIver, G.C. Shank, L.B. Cahoon, and D.C. Parsons. 1996. Spatial and temporal nutrientpatterns in the lower Cape Fear River system. In Solutions: Proceedings of a Technical Conference on Water Quality. North Carolina State University, Raleigh, N.C. 

## Winyah Bay Allen, D.M., W.K. Michener, and S.E. Stancy, (eds.).1984. Pollution Ecology of Winyah Bay, SC: Characterization of the Estuary and Potential Impacts of Petroleum. Baruch Institute Special Publication No. 84-1. 271 p. Allen, D.M., S.E. Stancyk, and W.K. Michener (eds.). 1982. Ecology of Winyah Bay, SC and Potential Impactsof Energy Development. Baruch Institute Special Publication No. 82-1. 275 p. Blood, E.R. and P.A. Smith. (in press). Water quality in two high salinity estuaries: An evaluation of watershed alteration effects on spatial and temporal patterns in urbanization in SE estuaries. J. Vernberg, W. Vernberg, and T. Siewicki (eds). Blood, E.R. and F.J. Vernberg. 1992. Characterization of the physical, chemical and biological conditions and trends in three South Carolina estuaries, vol. 2, WinyahBay and North Inlet estuaries: 1970-1985. National Marine Pollution Program Office, NOAA. SC Sea Grant Consortium, Charleston, SC. 155 p. Coull, B.C. 1985. Long-term variability of estuarine meiobenthos: An 11-year study. Marine Ecology Progress Series 24:205-218. Coutinho, R. 1987. Ecology of macro algae In: North Inlet Estuary, SC. PhD dissertation, University of South Carolina, Columbia, SC. 228 p. Gardner, L.R. and C. Gorman. 1984. Summertime net transport of dissolved oxygen, salt and heat. In: A salt marsh basin, North Inlet, SC. Estuarine and Coastal Shelf Science 19:331-339.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



## 49 Hall, M. 1979. The species composition and abundance cycle of the phytoplankton. In: North Inlet Estuary, South Carolina with special reference to tidal effects.Masters thesis. University of South Carolina, Columbia, SC. 61 p. Hinde, R., M.C.A. Wenner, J. Smith, and D.R. Calder. 1981. Benthic and nektonic studies of Winyah Bay for the proposed channel deepening project and dredging of the western turning basin. U.S. Army Corps of Engineers. Contract Report DACW60-80-C0029. 141 p. Lonsdale, D.J. and B.C. Coull. 1977. Composition andseasonality of zooplankton of North Inlet, South Carolina. Chesapeake Science 18:272-283. Ogburn, M.V., D.M. Allen, and W.K. Michener. 1988. Fishes, shrimps, and crabs of the North Inlet Estuary, SC: A four year seine and trawl study. Baruch Institute, Baruch Institute Technical Report 88-1. University of South Carolina, Columbia, SC. 299 p. Van Dolah, R.F., D.M. Knott, E.L. Wenner, T.D.Mathews, and M.P. Katuna. 1984. Benthic and sedimentological studies of the Georgetown ocean dredged material disposal site. South Carolina Marine Resources Center technical report no. 59. 97 p. Zeeman, S.I. 1981. Phytoplankton photosynthesis and its relation to light intensity. In: A turbid estuary andthe nearshore coastal ocean. PhD dissertation. University of South Carolina, Columbia, SC. 210 p. Zingmark, R.G. 1977. Studies on the phytoplankton and microbenthic algae. In:The North Inlet Estuary., pp. 35- 39. In: F.J. Vernberg, R. Bonnell, B. Coull, R. Dame Jr., P. Decoursey, W. Kitchens Jr., B. Kjerfve, H. Stevenson, W. Vernberg, and R. Zingmark (eds.), The dynamics of an estuary as a natural ecosystem. USEPA EPA-600/3- 77-016. Gulf Breeze, FL. 86 p. 

## North Santee/South Santee Rivers Hyland, J.L. Personal communication. Unpublishedquantitative database on ecological conditions of southeastern estuaries based on EMAP sampling in the Carolinian Province, 1994-1995. NOAA Carolinian Province Office, Charleston, SC. 

## Charleston Harbor Blood, E.R., K. Davis, R. Van Dolah, H.N. McKellar, T. Sicherman, and C. Connelly. 1989. Charleston Harbor water quality-status and trends. NOAA Estuary of theMonth seminar series No. 12. Charleston Harbor. Washington, DC. April 1989. pp. 25-35. Davis, K. and R. Van Dolah. 1992. Characterization of the physical, chemical and biological conditions andtrends in three South Carolina estuaries, vol. 1, Charleston Harbor Estuary: 1970-1985. National Marine Pollution Program Office, NOAA. SC Sea Grant Consortium, Charleston, SC. 123 p. McKellar, H., E. Blood, T. Sicherman, K. Connelly, andJ. Hussey. 1990. Organic carbon and nutrient dynamics in the Cooper River Estuary. p. 47-48. In: R. VanDolah et al. (eds.), A physical and ecological characterization of the Charleston Harbor estuarine system. Marine Resources Division, South Carolina Department of Natural Resources, Charleston, SC. McKellar, H., A. Douglas, A. Smith, T. Munnerlyn, andR. Rao. 1995. Nutrient dynamics and water quality interactions in the Goose Creek sub-basin of the Charleston Harbor Estuary. Final report to South Carolina Department of Health and Environmental Control and the South Carolina Sea Grant Consortium.Osemere, P. 1985. Distributions and fluxes of phosphorus, nitrogen, and organic carbon in a southeasterncoastal plain river: Implication of river flow and floodplain interactions (Santee River). PhD dissertation. University of South Carolina, Columbia, SC. Sicherman, T. 1989. Spatial and temporal variation of chlorophyl-a and organic carbon in the Cooper River estuary, South Carolina. MSPH thesis. University of South Carolina, Columbia, SC. Van Dolah, R.F., P.H. Wendt, E.L. Wenner (eds). 1990. A physical and ecological characterization of theCharleston Harbor estuarine system. Final Report submitted to the South Carolina Coastal Council under Grant No. NA87AA-D-CZ068. 634 p. 

## St. Helena Sound Hyland, J.L. Personal communication. Unpublishedquantitative database on ecological conditions of southeastern estuaries based on EMAP sampling in the Carolinian Province, 1994-1995. NOAA Carolinian Province Office, Charleston, SC. 

## Broad River Hyland, J.L. Personal communication. Unpublishedquantitative database on ecological conditions of southeastern estuaries based on EMAP sampling in the Carolinian Province, 1994-1995. NOAA Carolinian Province Office, Charleston, SC.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



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# Appendix 3: NEI Estuaries

North Atlantic (16) Passamaquoddy Bay Englishman Bay Narraguagus Bay Blue Hill Bay Penobscot Bay Muscongus Bay Damariscotta River Sheepscot Bay Kennebec/Androscoggin Rivers Casco Bay Saco Bay Great Bay Merrimack River Massachusetts Bay Boston Bay Cape Cod Bay 

### Mid-Atlantic (22) Buzzards Bay Narragansett Bay Gardiners Bay Long Island Sound Connecticut River Great South Bay Hudson River/Raritan Bay Barnegat Bay New Jersey Inland Bays Delaware Bay Delaware Inland Bays Maryland Inland Bays Chincoteague Bay Chesapeake Bay Patuxent River Potomac River Rappahannock River York River James River Chester River Choptank River Tangier/Pocomoke Sounds 

### South Atlantic (21) Albemarle/Pamlico Sounds Pamlico/Pungo Rivers Neuse River Bogue Sound New River Cape Fear River Winyah Bay North/South Santee Rivers Charleston Harbor Stono/North Edisto Rivers St. Helena Sounds Broad River Savannah River Ossabaw Sound St. Catherines/Sapelo Sounds Altamaha River St. Andrew/St. Simons Sounds St. Marys R./Cumberland Snd St. Johns River Indian River Biscayne Bay 

### Gulf of Mexico (36) Florida Bay South Ten Thousand Islands North Ten Thousand Islands Rookery Bay Charlotte Harbor Caloosahatchee River Sarasota Bay Tampa Bay Suwannee River Apalachee Bay Apalachicola Bay St. Andrew Bay Choctawhatchee Bay Pensacola Bay Perdido Bay Mobile Bay Mississippi Sound Lake Borgne Lake Pontchartrain Breton/Chandeleur Sounds Mississippi River Barataria Bay Terrebonne/Timbalier Bays Atchafalaya/Vermilion Bays Mermentau Estuary Calcasieu Lake Sabine Lake Galveston Bay Brazos River Matagorda Bay San Antonio Bay Aransas Bay Corpus Christi Bay Upper Laguna Madre Baffin Bay Lower Laguna Madre 

### West Coast (34) Tijuana Estuary San Diego Bay Mission Bay Newport Bay San Pedro Bay Alemitos Bay Anaheim Bay Santa Monica Bay Morro Bay Monterey Bay Elkhorn Slough San Francisco Bay Cent. San Francisco Bay/ San Pablo/Suisun Bays Drakes Ester Tomales Bay Eel River Humboldt Bay Klamath River Rogue River Coos Bay Umpqua River Siuslaw River Alsea River Yaquina Bay Siletz Bay Netarts Bay Tillamook Bay Nehalem River Columbia River Willapa Bay Grays Harbor Puget Sound Hood Canal Skagit Bay

West Coast North Atlantic Mid-Atlantic

Gulf of Mexico South Atlantic 

### One hundred twenty-nine estuaries are included in the National Estuarine Inventory. New systems are occasionally added.Some estuaries are actually subsystems of larger estuaries, although each is being evaluated indepedently for the Eutrophication Survey project (e.g., Potomac River is a subsystem of Chesapeake Bay). For more information on the National Estuarine Inventory, see inside the front cover of this report.NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic



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