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. Descriptive

topics 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 ........... 50

The 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), the

Coastal Monitoring and Bioeffects Assessment Division (CMBAD), the Hazardous Materials Response

and 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 and

C. 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 Gail

Moody at the National Ocean Service's Coastal Service Center, for logistical support during the South

Atlantic Regional Workshop. Finally, we gratefully acknowledge the production support of Miranda Harris and Pam Rubin of the SEA Division.

ORCA Organization Contents
NOAA's Estuarine Eutrophication Survey: Volume 1 - South Atlantic

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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 in

what 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 Survey

is 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 map

and maps illustrating the results for selected parameters. Next are the Estuary Summaries—one-page

summaries 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 data

results. 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 the

references 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 significantly

in 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 many

new 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 statement

of 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 (Nixon

et 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, in

extreme conditions, excess nutrients can stimulate excessive algal blooms that can lead to increased metabolism and turbidity, decreased dissolved oxygen, and

changes 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 conclusions

are 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 a

meaningful 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 define

one or more estuaries as eutrophic. Rather, it is to systematically and accurately characterize the scale and

scope 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

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into a comprehensible whole due to incompatible data

types, formats, time periods, and methods. Alternatively, ORCA elected to systematically acquire 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, 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 upon

existing 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 Trends

For 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 as

those associated with the spring runoff and/or turnover. For chlorophyll a, ORCA collected information

on 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 dissolved

oxygen). 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 impact

on 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.

Methods

The 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 records

and 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 survey

To 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 characterize

eutrophication 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, focused

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

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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 coverage1, Months of occurrence, Frequency of occurrence2

• Secchi disk depths:

High (<1m), Medium (1 m, 3m), Low (>3m), Blackwater area

• Concentrations3,4

• Concentrations:

Problem (significant impact upon biological resources)

No Problem (no significant impact)

• Months of occurrence, Frequency of occurrence2

• 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 coverage1, Months of occurrence

• Limiting factors

• Contributing factors5

• Concentrations3,4

• Contributing factors5

• Event duration3,4

• Frequency of occurrence3,4

• Contributing factors5

• Abundance3,4

• Contributing factors5

• Concentrations3,4

• Contributing factors5

• Concentrations3,4

• Contributing factors5

• Min. avg. monthly bottom

 dissolved oxygen conc.

3,4

• Frequency of occurrence3,4

• Event duration3,4

• Spatial coverage3,4

• Contributing factors5

• Contributing factors5

• Contributing factors5

• Contributing factors5

• Spatial coverage3,4

• Contributing factors5

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 coverage1, Months of occurrence, Frequency of occurrence2

• Months of occurrence, Frequency of occurrence2

• Months of occurrence, Frequency of occurrence2

• Spatial coverage1, Months of occurrence

• Spatial coverage1, Months of occurrence, Frequency of occurrence2

• Spatial coverage1

(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

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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 highly

certain 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 tested

monitoring 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 NEI

salinity zones, are distributed with the survey questions for orientation. Updates and/or revisions to these

maps were made as appropriate.

Collecting the Data

Over 400 experts and managers had agreed to participate in the survey. Survey forms were mailed to the

experts, who then mailed in their responses. The response rate was approximately 25 percent with at least

one 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 that

ORCA 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 revised

strategy 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 original

mailed 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 insight

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

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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 data

are 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 six

months 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 available

over 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 is

funding 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

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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 4,440

square miles of water surface area (Figure 2). The characteristics of this region include extensive coastal and

barrier features and the Atlantic Coastal Plain. This

region 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 Carolina

Capes 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. Due

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

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

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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 sounds

through 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 for

each 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. Regional

maps 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 were

asked to rank the reliability of their responses as either highly certain or speculative inference. Over 80

percent 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 temporally

and 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 epiphyte

abundance (Table 1). High to hypereutrophic concentrations of chlorophyll a (>20 μg/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) also

occur 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 minimum

all of the major river valleys (Mathews, 1980). Lowlying sea islands are erosional remnants of Pleistocene

Age 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. Deltaic

structures within the Sea Island Coast resemble sediment-filled drowned river valleys but formation is

rather limited (Mathews, 1980). Extensive clearcutting

in post-colonial times has promoted soil erosion processes and added to suspended sediments traversing

the 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 and

the Piedmont. The Black, Cooper, and Waccamaw Rivers of South Carolina, and the Satilla and St. Marys

Rivers 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 beaches

along the Atlantic Coast (Hunt, 1967). As in the Carolina Capes, the shallow lagoonal estuaries of Florida

are semi-enclosed by barrier island features; tidal influence is less for the Florida Coast than for the Sea

Island Coast estuaries. Salinity structure and circulation in the Indian River are dominated by wind forcing and human impacts in the form of controlled

stormwater 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 freshAbout the Results

Algal Conditions
NOAA'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) were

reported 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 a were reported for 19 of 21 South Atlantic estuaries, occurring in up to 55 percent of the region’s

estuarine 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

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

occur 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

Suspended 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 the

limiting 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 Solids

Suspended 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 of

these also have at least one salinity zone in which suspended solids conditions are unknown. Suspended

solids information was unknown in at least one zone

for 11 of 21 estuaries. Trends information was not collected for suspended solids.

Nuisance/Toxic Algae

Both 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 toxic

blooms 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 piscicida is 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, where

the frequency of occurrence and event duration decreased in the tidal fresh zone, but increased in the

mixing zone. Nuisance and toxic algae trends were

unknown in at least one salinity zone for eleven estuaries in the South Atlantic (Figure 5).

Blackwater Estuaries

Five 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, secchi

disc readings are persistently low despite low suspended particle concentrations.

creasing chlorophyll a concentrations 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 one

salinity 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 these

conditions was unknown for five estuaries and, therefore, the area affected could be larger. Furthermore,

turbidity conditions were reported as unknown for an

additional 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 disk

depths 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 trends
NOAA'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 Abundance

Macroalgal 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 mixing

zone). 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 either

Total Nitrogen (Cape Fear River and Charleston Harbor), Dissolved Inorganic Nitrogen (Bogue Sound), or

ammonia plus nitrate (New River).

No trends in nitrogen concentrations were reported

for 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, and

Altamaha River. Low magnitude increases were reported for Charleston Harbor. Trends for five estuaries were based on either Total Nitrogen (Cape Fear

River 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 New

River, Winyah Bay, and Charleston Harbor (throughout the year) and of Cape Fear and Broad River (during the summer months), and the seawater zone of

portions of the Indian River (Figure 4). Medium phosphorus concentrations (≥0.01-0.1) were reported for 16

of 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 reported

for 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 dissolved

nutrients, 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) and

phosphorus (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 spatial

extent of medium or greater concentrations of nitrogen range from about 6 percent in the tidal fresh zone

up to 21 percent in the seawater zone. The spatial extent of these concentrations of phosphorus range from

about 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).

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

13

nitude 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 location

of 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 of

dissolved oxygen at some point during the year. Anoxia/hypoxia were reported as periodic, mainly during the summer months, in estuaries of the Carolina

Capes 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 the

Sea 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 three

estuaries, increasing for one estuary, and not changing for three estuaries.

Anoxia

Anoxic conditions were reported in 11 of 21 estuaries

for 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 was

present, 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 mi2

). 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 within

the Pamlico/Pungo, Neuse, and Indian River estuaries only. Biological stress was observed throughout

the water column in 11 of 21 estuaries. Biologically

stressed 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. Anoxic

events 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 < 2

mg/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). The

spatial 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 the

expression 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 Oxygen
NOAA'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 present in 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 are

based 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

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Albemarle/Pamlico Sounds Pamlico River Neuse River Bogue Sound New RiverCape Fear River Winyah Bay N & S Santee River Charleston Harbor Stono/N. Edisto River St. Helena SoundSavannah 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

?

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- unknown

- no trend or shift

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- 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

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NOAA'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 extent

of 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 on

the status and trends of five parameters: primary productivity, planktonic and benthic communities, submerged aquatic vegetation (SAV), and intertidal wetlands. The information reported for these parameters

was limited, especially for trends, where only 18 percent of the region’s estuarine surface area was characterized.

The dominant primary producer varied by estuary and

salinity 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 dominant

benthic community in the region was a diverse mixture of organisms (e.g., annelids, crustaceans, mollusks), followed by annelids and polychaetes. SAV and

intertidal 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 one

instance 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 SAV

were 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 the

dominant primary producers in the South Atlantic region: pelagic communities in five estuaries (5 of 9 Carolina Capes estuaries); intertidal wetlands in nine (all

nine Sea Island Coast systems); and benthic communities and SAV in two estuaries (Indian River and

Biscayne 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 in

the 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 Community

Diatoms 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 estuarine

surface 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 in

the 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 for

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

16

66 percent of the mixing zone, but only 1 percent of

the 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 the

dominant 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 (3,221

square 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 Florida

estuaries 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 low

spatial 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 SAV

was 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 spatial

coverage, 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 Carolina

Capes 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 all

salinity 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 recorded

were reported as having no trends (Figure 5). Decreasing trends were reported for portions of the Savannah

River, 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

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comparative analysis of nutrients and other factors

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Day, J.W. Jr., C.A.S. Hall, W.M. Kemp, and A. YanezArancibia. 1989. Estuarine ecology. New York City:

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Kemp, W.M., R.R. Twilley, J.C. Stevenson, W.R.

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NOAA'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 and

epiphyte 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

E hypereutrophic 

H

M

L

high

medium

low

Concentrations

(Chl-a, Turbidity, Nutrients, SAV)

? unknown

B blackwater area Parameter

Tidal Fresh Mixing Seawater

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, <5 μg/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-a and 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

?

Tidal Fresh Mixing Seawater

? Y

Albemarle Snd. Pamlico Snd.

? Y0-10%

? Y

In General Chowan River

? Y

10-25% 0-10%

10-25%

?

???? ?

?? ? ?

*

*

*

*

?

Nutrients Nitrogen

?

Phosphorus

Tidal Fresh Seawater Mixing

L

Albemarle Snd. Pamlico Snd.

? M

? H50-100%

In General Chowan River

? H50-100%

? ? ? ?

??? ? ?

*

*

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

?

Tidal Fresh Seawater Mixing

In General Chowan River Albemarle Snd. Pamlico Snd.

?

?

?

?

M50-100%E ? ? ? 50-100%

? ? ? 50-100%

M* *

? ? H50-100%

? ? ? M25-50%

?

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 

aeroginsoa occur periodically June to Sept. in Chowan R. In Pamlico 

Sound nuisance Anabaena raciborski occurs July to Sept.; toxic 

Pfiesteria piscicida occurred once in 1992. SAV

Ecosystem/Community Responses

Tidal Fresh Seawater Mixing

? 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.

Estuary Tidal Fresh Mixing

183 48 765 1670

5.8

16

13.5 6.4 18 15.6 13.9

1063 33 24 350 640

Seawater

In General Chowan River Albemarle Snd. Pamlico Snd.

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 46,000

Surface

Area (mi2)

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 variability 

and water-column mixing in the sounds is dominated by prevailing winddriven circulation and currents. 

Key on page 20

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

22

Pamlico/Pungo Rivers

Pamlico/Pungo Rivers are characterized as having periodically high levels of chlorophyll-a and moderate turbidity. Biological resource impacts from episodic occurrences of

toxic algae are also reported. Nutrient levels are moderate

and anoxia and hypoxia occur periodically in limited bottom areas.

Trends vary from a significant increase in chlorophyll-a to a

modest decrease in phosphorus to no trends for nitrogen

and dissolved oxygen. No trends were reported for the limited amount of SAV.

Physical and Hydrologic Characteristics

Estuary Tidal Fresh

170.6 170.6

9.4 9.4

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 4,600

Surface

Area (mi2)

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.

Tidal Fresh Mixing Seawater

Tidal Fresh Mixing Seawater

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 ?

Tidal Fresh Mixing Seawater

Algal Conditions

50-100%

H50-100%

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 piscicida occurs episodically mid to late summer, with 

durations of less than a week.

Tidal Fresh Mixing Seawater

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

23

Neuse River

Nuese River is characterized as having moderate to

hypereutrophic chlorophyll-a conditions and moderate turbidity. Nuisance and toxic algae are reported as impacting

biological resources during events that occur from early summer to early fall. Nitrogen and phosphorus are reported at

moderate concentrations. Anoxia and hypoxia events occur

periodically 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

Tidal Fresh Mixing Seawater

Y Y

Hypoxia

Y Y

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

M M

Phosphorus

M M

Nutrients

50-100% 25-50%

50-100% 25-50%

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.

Estuary Tidal Fresh

177.6 175.7

11.5 11.4

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 6,200

Surface

Area (mi2)

1.9

9.3

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

2,221

56.8 0.5 56.3

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 E25-50%

Turbidity

B M

Nuisance Algae

Y Y

Toxic Algae

Tidal Fresh Mixing Seawater

Algal Conditions

25-50%

25-50%

SAV

Tidal Fresh Mixing Seawater

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

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

24

Bogue Sound Chlorophyl-a

M M50-100%

Turbidity

H M

Nuisance Algae

N N

Toxic Algae

Tidal Fresh Mixing Seawater

Algal Conditions

50-100%

50-100%

SAV

Tidal Fresh Mixing Seawater

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-a and moderate to high turbidity. There are no biological resource impacts associated with nuisance algae

and toxic algae events are extremely rare. Moderate levels

of 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

Estuary Tidal Fresh

104.4 27.6

4.6 2.4

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 1,300

Surface

Area (mi2)

76.8

5.1

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

691

12.9 1.9 11

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

Tidal Fresh Mixing Seawater

N N

Hypoxia

N N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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

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

25

New River

New River is characterized as having moderate to

hypereutrophic levels of chlorophyll-a and moderate to high levels 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 extreme

conditions generally occur in Morgan Bay. Trends information is unknown for all parameters. SAV is present in very

limited amounts in the seawater zone.

Tidal Fresh Mixing Seawater

Chlorophyl-a Turbidity Nuisance Algae

Y

Toxic Algae

?

Y ?

Algal Conditions SAV

NS

Ecosystem/Community Responses

Morgan Bay Stones Bay

E25-50%H50-100%

?

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.

Tidal Fresh Mixing Seawater

?

M*

Physical and Hydrologic Characteristics

Tidal Fresh Mixing Seawater

Anoxia Hypoxia

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

Phosphorus

Nutrients

H25-50%M25-50% 25-50%

??? M

HMM ???

?

?

NNN ???

Y25-50%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

Estuary Tidal Fresh

32.8 12.0

5.8 6.1

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 800

Surface

Area (mi2) 4.0

5.4

4.8

4.4

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

471

5.2 0.6 2.0 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

Morgan New River

Bay

Farnell

Bay

Stones

Bay

Northeast Creek

NC
NOAA'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-a and turbidity. Biological resource im- pacts from nuisance and toxic algae do not occur. Nitrogen

and 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

Estuary Tidal Fresh

38.3 29.4

11.5 10.2

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 10,100

Surface

Area (mi2)

0.35

20.2

8.9

11.7

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

4,364

11.3 0.023 8.4 2.9

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 M50-100%

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.

Tidal Fresh Mixing Seawater

Algal Conditions

25-50%

50-100% 50-100%

N N

?

?

?

H

N

50-100%

N

?

? ?

???

? ?

SAV

Tidal Fresh Mixing Seawater

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.

M25-50%

Anoxia

Tidal Fresh Mixing Seawater

N N

Hypoxia

N N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

H M

Phosphorus

Nutrients

50-100%

H50-100% 50-100%

H 50-100%H 50-100% 50-100%M

?? ?

? ? ?

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

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

27

Winyah Bay Winyah Bay is characterized as having moderate to high levels of chlorophyll-a and high turbidity. Based on specula- tive inference, biological resource impacts from nuisance and

toxic 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 and

toxic 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

50-100%

M

Turbidity

H

Tidal Fresh Seawater Mixing

M50-100%

Winyah Bay North Inlet

H H50-100%

M M50-100%

Winyah Bay North Inlet

H H50-100%

N N

N

Tidal Fresh Seawater Mixing

?

?? ?

?

? NS

Winyah Bay North Inlet

? ?

Winyah Bay North Inlet

? ?

? 50-100%

M50-100%

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

Estuary Tidal Fresh

41.1 2.8

11.0 9.3

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 20,400

Surface

Area (mi2) 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. 

18.5 5.4 4.7 0.2 0.9 0.7

Dissolved Oxygen

Nutrients Nitrogen

H

Phosphorus

Tidal Fresh Seawater Mixing

Anoxia

N

Hypoxia

N

Tidal Fresh Seawater Mixing

H

M M

L M

H M50-100%

Winyah Bay North Inlet

H L

? ?

? ?

?

? ? Y

Winyah Bay North Inlet

? Y10-25%

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

28

North/South Santee Rivers

North/South Santee Rivers are characterized by unknown

levels of chlorophyll-a and turbidity and no occurrence of nuisance or toxic algae throughout the estuary. Nitrogen and

phosphorus 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 mixing

zone 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

Estuary Tidal Fresh

9.1

6.1

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 12,450

Surface

Area (mi2) 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%

M25-50%

Western Half Eastern Half

? ? ?

? ? ?

?

?

? ?

? ?

Tidal Fresh Mixing Seawater

Tidal Fresh Mixing Seawater

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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

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

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

29

Charleston Harbor

Charleston Harbor is characterized as having moderate to

high levels of chlorophyll-a and high levels of turbidity. Bio- logical resource impacts from nuisance and toxic algae are

unknown 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. Very

low amounts of SAV are reported as increasing in the mixing zone. Anoxia

Tidal Fresh Mixing Seawater

Hypoxia

Dissolved Oxygen Nitrogen Phosphorus

Nutrients

Tidal Fresh Mixing Seawater

In General Ashley River

M 50-100%

50-100%

M

M

50-100%

M50-100%

N ?

?

50-100%

50-100%

M

M

H10-25%

H10-25%

In General Ashley River

Y

10-25%

Y25-50%

0-10%

0-10%

Y

Y

Y

10-25%

Y25-50%

? ?

? ?

?

?

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.

Y0-10%

Physical and Hydrologic Characteristics

Estuary Tidal Fresh

46.4

18.3

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 5,996

Surface

Area (mi2) 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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

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 H50-100%

H50-100%

H50-100%

* * ?

?

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

SC
NOAA'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 and

phosphorus. 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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

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

Estuary Tidal Fresh

39.1 5.5

15.6 13.9

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs)

Surface

Area (mi2)

33.6

17.3

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

N/A

18.3 2.1 16.2

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

Tidal Fresh Mixing Seawater

N Y

Hypoxia

N Y

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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

SC
NOAA'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 the mixing zone and high in the seawater zone. Biological resource impacts from nuisance and toxic algae are unknown

and 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 no

trends 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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

? ?

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.

Estuary Tidal Fresh

97.7 54.8

12.9 14.5

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 4,600

Surface

Area (mi2)

42.9

11.3

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

1,558

35.7 22.2 13.5

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

Tidal Fresh Mixing Seawater

Y ?

Hypoxia

Y ?

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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

North
NOAA'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-a and low levels of turbidity. Based on specula- tive inference, biological resource impacts from nuisance and

toxic algae do not occur. Nitrogen and phosphorus levels

are 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.

Estuary Tidal Fresh

107.5 15.5

24.0 23.7

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 900

Surface

Area (mi2)

92.0

23.2

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

1,010

69.7 10.2 59.5

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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

? ?

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

Tidal Fresh Mixing Seawater

Y

Hypoxia

Y

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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

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

33

Savannah River

Savannah River is characterized as having moderate levels

of cholorophyll-a and 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

Estuary Tidal Fresh

71.8 17.7

15.2 16.2

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 12,800

Surface

Area (mi2)

18.7

9.3

35.4

17.3

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

1,316

29.9 4.8 8 17

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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

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

Tidal Fresh Mixing Seawater

Y N

Hypoxia

Y N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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

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

34

Ossabaw Sound

Ossabaw Sound is characterized as having high to moderate levels of chlorophyll-a and turbidity. Biological resource impacts 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

Estuary Tidal Fresh

39.9 18.1

14.3 14.2

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 3,000

Surface

Area (mi2)

4.8

6.5

17.0

13.1

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

1,473

14.3 0.9 7.2 6.2

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

Tidal Fresh Mixing Seawater

N N

Hypoxia

N N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

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

GA
NOAA'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-a and 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

Tidal Fresh Mixing Seawater

N N

Hypoxia

N N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

L L

Phosphorus

L L

Nutrients

* *

* *

*

*

?

?

*

*

? ?

? ?

Trends are associated with nonpoint sources.

Estuary Tidal Fresh

92.2 54.9

14.5 14.7

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 800

Surface

Area (mi2)

0.4

7.6

36.9

22.7

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

963

45.9 0.09 22.5 23.4

A drowned river valley-barrier island system comprised of small tidal 

creeks. 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 M50-100%

Turbidity

H H

Nuisance Algae

N N

Toxic Algae

Tidal Fresh Mixing Seawater

Algal Conditions

50-100%

50-100%

SAV

Tidal Fresh Mixing Seawater

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

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

36

Altamaha River

Altamaha River is characterized as having moderate to high

levels of chlorophyll-a and high levels of turbidity. No oc- currences of biological resource impacts from nuisance or

toxic algae are reported. No hypoxic or anoxic conditions

are 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. Trends

are 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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

NS NS

Ecosystem/Community Responses

N N

L

?

?

?

* * *

?

50-100% 50-100% * *

50-100% 50-100%

?

?? ?

?

? ?

?

Maximum chl-a concentrations occur episodically in mixing 

zone 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

Estuary Tidal Fresh

16.7 12.0

10.2 12.1

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 14,900

Surface

Area (mi2)

2.5

4.3

2.2

13.1

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

1,512

5.2 0.3 4.1 0.8

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

Tidal Fresh Mixing Seawater

N N

Hypoxia

N N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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 Threemile

Cut

Little

Mud

Creek

Onemile

Cut

North

GA
NOAA'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 and

seawater 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

Tidal Fresh Mixing Seawater

N N

Hypoxia

N N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

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.

Estuary Tidal Fresh

82.9 54.8

14.3 12.9

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 2,500

Surface

Area (mi2)

3.7

10.3

24.4

13.0

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

3,213

29.9 1.1 20 8.8

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

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

38

St. Marys River/Cumberland Sound St. 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

Estuary Tidal Fresh

33.8 3.7

19.7 8.4

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 8,171

Surface

Area (mi2)

0.1

5.7

30.0

21.1

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

1,737

18.5 0.02 0.9 17.6

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

Tidal Fresh Mixing Seawater

N N

Hypoxia

N N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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 M50-100%

Turbidity

B B

Nuisance Algae

N N

Toxic Algae

Tidal Fresh Mixing Seawater

Algal Conditions

50-100%

SAV

Tidal Fresh Mixing Seawater

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

FL
NOAA'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-a and 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

Tidal Fresh Mixing Seawater

Algal Conditions SAV

Tidal Fresh Mixing Seawater

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.

Estuary Tidal Fresh

264.1 60.1

12.0 11.1

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) 7,800

Surface

Area (mi2)

197.5

10.5

6.5

20.0

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

6,389

80.0 57.8 18.6 3.6

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

Tidal Fresh Mixing Seawater

N N

Hypoxia

N N

Dissolved Oxygen Nitrogen

Tidal Fresh Mixing Seawater

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

Atlantic

Ocean

FL
NOAA'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-a and high levels of turbidity. Biological resource impacts from nuisance and

toxic 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 are

generally reported as unknown or no trend except for increasing cholorophyll-a in 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 of

the 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.

Tidal Fresh Mixing Seawater

Indian River St. Lucie River Urban Areas

Tidal Fresh Mixing Seawater

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. 

Tidal Fresh Mixing Seawater

Indian River St. Lucie River Urban Areas

Tidal Fresh Mixing Seawater

Indian River St. Lucie River Urban Areas

Elevated nutrient concentrations occur April to September.

Estuary Tidal Fresh

336 11

6.6 9.0

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) N/A

Surface

Area (mi2) 296

6.6

Mixing Seawater

Depth (ft)

(billion cu ft)

Volume

Average

1,184

64.4 55 2.8

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

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

41

Biscayne Bay

Physical and Hydrologic Characteristics

Biscayne Bay is characterized as having generally low levels of chlorophyll-a and 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 hypoxia

occur 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 seawater

zone. 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

Tidal Fresh Mixing Seawater

L

North South

M L

L L

North South

L L

N N

Tidal Fresh Mixing Seawater

L H M M

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. 

Estuary Tidal Fresh

269.5 209.2

7.7 7.7

Estuarine Drainage Area (mi2) Avg. Daily Inflow (cfs) N/A

Surface

Area (mi2) 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

58.9 0.3 7.3 45 6.3

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

Tidal Fresh Mixing Seawater

Anoxia Hypoxia

Tidal Fresh Mixing Seawater

M L

L L

H M

L L

N N

10-25%

N N

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

FL
NOAA'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 zone of 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

Suspended Solids5

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

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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* “ “ “ “
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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 Sounds

Harned, D.A., and M.S. Davenport. 1990. Water-quality trends and basin activities and characteristics for

the 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. Unpublished

quantitative 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 and

phosphorus 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 N2 fixing blue-green algal blooms in the

Chowan River. N.C. Report No. 176. Water Resources

Research 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 and

shellfish 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. The

ecology 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 River

Estuary. Report No. 131. Water Resources Research Institute, University of North Carolina, Raleigh, NC.

Garret, R.G. 1994. Water quality from continuously

monitored 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 the

Pamlico 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 for

Coastal 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 for

Coastal 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 recycling

in 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 River

Boyer, 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

aeruginosa blooms 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, North

Carolina, 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 continuously

monitored 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 an

estuary: 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. Water

Resources 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, and

B.L. Peierls. 1995. Determining the role of nitrogen-enriched acid rain in estuarine eutrophication: The Neuse

River Estuary, North Carolina. Report No. 291. Water

Resources 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 algal

blooms 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 by

natural 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. Report

No. 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 Sound

Brett, 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. Unpublished

quantitative 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-term

environmental 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-term

environmental 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 the

distribution of nutrients in a shallow unstratified estuarine system near Beaufort, NC. Chesapeake Science

12:240-253.

Thayer, G.W. 1974. Identity and regulation of nutrients

limiting 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 Studies

in 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. Unpublished

quantitative 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 nutrient

patterns 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 Impacts

of 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, Winyah

Bay 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 and

seasonality 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 and

the 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. Unpublished

quantitative 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 the

Month 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 and

trends 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, and

J. Hussey. 1990. Organic carbon and nutrient dynamics in the Cooper River Estuary. p. 47-48. In: R. Van

Dolah 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, and

R. 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 southeastern

coastal 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 the

Charleston 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. Unpublished

quantitative 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. Unpublished

quantitative 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.
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