United States
Environmental Protection
Agency
ft
Ecological Condition of Coastal Ocean and Estuarine
Waters of the U.S. South Atlantic Bight: 2000 - 2004
NOAA Technical Memorandum NOS NCCOS 114
EPA 600/R-10/046 | May 2010 | www.epa.gov/ord
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NOAA Technical Memorandum NOS NCCOS 114
EPA/600/R-10/046
Ecological Condition of Coastal Ocean and Estuarine
Waters of the U.S. South Atlantic Bight: 2000 - 2004
May 2010
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5
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B
Office of Research and Development
U.S. Environmental Protection Agency
Washington, DC 20460
U.S. Department of Commerce
National Oceanic and
Atmospheric Administration
National Ocean Service
Silver Spring, MD 20910
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Ecological Condition of Coastal Ocean and Estuarine
Waters of the U.S. South Atlantic Bight: 2000 - 2004
May 2010
Prepared by
Cynthia Cooksey1, James Harvey2, Linda Harwell2, Jeffrey Hyland1, and
J. Kevin Summers2
Author Affiliations
1 Center for Coastal Environmental Health and Biomolecular Research
National Oceanic and Atmospheric Administration
219 Fort Johnson Road
Charleston, South Carolina 29412-9110
'N
U.S. EPA Office of Research and Development
National Health and Environmental Effects Research Laboratory
Gulf Ecology Division
1 Sabine Island Drive, Gulf Breeze, FL 32561
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Preface
This document provides an assessment of ecological condition in coastal ocean and estuarine
waters of the U.S. South Atlantic Bight from Cape Henry, Virginia, through the southern end of
the Indian River Lagoon along the east coast of Florida. Data are from sampling conducted in
open shelf waters during March-April 2004 and in estuaries each year from 2000 to 2004. The
project was a large collaborative effort by the U.S. Environmental Protection Agency (EPA), the
National Oceanic and Atmospheric Administration (NOAA), and Southeast U.S. Coastal States
(Florida, Georgia, South Carolina, North Carolina, Virginia). It also represents one of a series of
assessments conducted under EPA's National Coastal Assessment (NCA) program. The NCA is
the coastal component of the nationwide Environmental Monitoring and Assessment Program
(EMAP). The NCA program is administered through the EPA and implemented through
partnerships with a variety of federal and state agencies, universities, and the private sector. The
2004 South Atlantic Bight (SAB) coastal ocean shelf assessment involved the participation and
collaboration of NOAA, EPA, and the State of Florida/Florida Fish and Wildlife Conservation
Commission (FFWCC).
The appropriate citation for this report is:
Cooksey, C., J. Harvey, L. Harwell, J. Hyland, J.K. Summers. 2010. Ecological Condition of
Coastal Ocean and Estuarine Waters of the U.S. South Atlantic Bight: 2000 - 2004. NOAA
Technical Memorandum NOS NCCOS 114, NOAA National Ocean Service, Charleston, SC
29412-9110; and EPA/600/R-10/046, U.S. EPA, Office of Research and Development, National
Health and Environmental Effects Research Laboratory, Gulf Ecology Division, Gulf Breeze FL,
32561. 88pp.
Disclaimer
This document has been subjected to review by the National Ocean Service of NOAA and the
National Health and Environmental Effects Research Laboratory of Environmental Protection
Agency and approved for publication. Approval does not signify that the contents reflect the
official views of these agencies, nor does mention of trade names or commercial products
constitute endorsement or recommendation for use.
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Table of Contents
Preface ii
The appropriate citation for this report is: ii
Disclaimer ii
Table of Contents iii
List of Figures v
List of Tables vii
List of Appendix Tables viii
Executive Summary ix
1.0 Introduction 1
1.1 Coastal Ocean 2
1.2 Estuaries 3
2.0 Methods 5
2.1 Sampling Design and Field Collections 5
2.1.1 Coastal Ocean 5
2.1.2 Estuaries 8
2.2 Water Quality Analysis 11
2.3 Sediment TOC and Grain Size Analysis 11
2.4 Contaminant Analysis 11
2.5 Toxicity Analysis 12
2.6 Benthic Community Analysis 14
2.7 Data Analysis 14
3.0 Results and Discussion 20
3.1 Depth and Water Quality 20
3.1.1 Depth and General Water Characteristics: temperature, salinity, water-column
stratification, DO, pH, water clarity 20
3.1.2 Nutrients and Chlorophyll 28
3.2 Sediment Quality 35
3.2.1 Grain Size and TOC 35
3.2.2 Chemical Contaminants in Sediments 40
3.2.3 Sediment Toxicity (Estuaries Only) 50
3.3 Chemical Contaminants in Fish Tissues 51
3.4 Status of Benthic Communities 55
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3.4.1 Taxonomic Composition 55
3.4.2 Abundance and Dominant Taxa 59
3.4.3 Diversity 68
3.4.4 Non-Indigenous Species 71
3.5 Potential Linkage of Biological Condition to Stressor Impacts 71
4.0 Acknowledgments 74
5.0 Literature Cited 74
IV
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List of Figures
Figure 2.1.1 - Map of South Atlantic Bight study area and station locations. Green dots indicate
National Coastal Assessment estuarine stations (sampled 2000 - 2004; n = 747), and blue dots
indicate coastal ocean stations (sampled 2004; n = 50) 7
Figure 3.1.1 Percent area (solid lines) and 95% Confidence Intervals (dotted lines) of SAB
coastal ocean depth and selected water-quality characteristics 22
Figure 3.1.2. Percent area (solid lines) and 95% Confidence Intervals (dotted lines) of SAB
estuarine depth and selected bottom water-quality characteristics 24
Figure 3.1.3. Percent area of SAB estuarine waters within specified ranges of water clarity 25
Figure 3.1.4. Percent area of SAB coastal ocean and estuarine near-bottom waters within
specified ranges of DO concentrations 26
Figure 3.1.5. Spatial distribution of bottom dissolved oxygen levels in SAB coastal ocean and
estuarine waters 27
Figure 3.1.6. Percent area (solid lines) and 95% Confidence Intervals (dotted lines) of SAB
coastal ocean waters for nurtients, chlorophyll a and TSS concentrations 30
Figure 3.1.7. Percent area (solid lines) and 95% Confidence Intervals (dotted lines) of SAB
estuarine surface water nutrients, chlorophyll a and TSS concentrations 31
Figure 3.1.8. Percent area of SAB within specified ranges of DIN and DIP for near-surface
estuarine waters only 32
Figure 3.1.9. Percent area of SAB within specified ranges of chlorophyll a for near-surface
estuarine waters only 33
Figure 3.1.10. Spatial distribution of surface chlorophyll a levels in SAB coastal ocean and
estuarine waters 34
Figure 3.2.1. Percent area of SAB coastal ocean (blue line) and estuarine (green line) vs. percent
silt-clay of sediment 37
Figure 3.2.2. Percent area of SAB near-bottom waters within specified ranges of TOC levels... 38
Figure 3.2.3. Percent area of SAB coastal ocean (blue line) and estuarine (green line) area vs.
TOC levels of sediment 38
Figure 3.2.4. Spatial distribution of total organic carbon (TOC) levels in SAB coastal ocean and
estuarine sediments 39
Figure 3.2.5. Percent area of SAB sediment contamination, expressed as mean ERM-Q, levels
within specified ranges 45
Figure 3.2.6. Percent area of SAB sediment contamination levels, expressed as number of ERL
and ERM values exceeded, within specified ranges 48
Figure 3.2.7. Spatial distribution of sediment contaminant levels in SAB coastal ocean and
estuarine sediments 49
Figure 3.2.8. Percent area of SAB estuarine toxicity levels within specified ranges 50
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Figure 3.3.1. Percent of sites of SAB fish tissue contamination levels within consumption
guideline ranges 54
Figure 3.4.1. Relative percent composition of major tax onomic groups expressed as (A) percent
of total taxa and (B) percent of abundance for coastal ocean and estuarine waters 56
Figure 3.4.2. Percent area (solid lines) and 95% Confidence Intervals (dotted lines) of SAB
coastal ocean benthic infaunal species richness (A), density (B), and FT diversity (C) 61
Figure 3.4.3. Percent area (solid lines) and 95% Confidence Intervals (dotted lines) of SAB
estuarine benthic infaunal species richness (A), density (B), and FT diversity (C) 67
Figure 3.4.4. Spatial distribution of benthic species richness in coastal ocean and estuarine
sediments 69
Figure 3.4.5. Spatial distribution of benthic species richness in SAB sediments 70
Figure 3.5.1. Summarized assessment of multiple indicators of ecosystem health for SAB
coastal ocean region (A = Coastal Ocean, B = Estuarine). Refer to Table 2.7.1 for indicator
threshold values. Note: There is no benthic index for offshore waters, thus the evaluation of
benthic condition in this case was based on whether there were any co-occurrences of reduced
values of key benthic attributes (i.e. diversity, richness, or density within lower 10th percentile of
all observed values) and evidence of poor sediment or water quality (> 1 chemical in excess of
ERMs, TOC > 50 mg/g, and DO in near-bottom water < 2 mg/L); there were no such co-
occurrences 73
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List of Tables
Table 2.2.1 Number of SAB stations sampled by resource category, institution, and year 10
Table 2.4.1. List of target contaminants analyzed in coastal-ocean and estuarine sediment and
tissue samples 13
Table 2.7.1 Thresholds used for classifying samples relative to various environmental indicators.
16
Table 2.7.2. ERM and ERL guidance values in sediments (Long et al. 1995) 18
Table 2.7.3. Risk based EPA advisory guidelines for recreational fishers (US EPA 2000).
Concentration ranges represent the non-cancer health endpoint risk for four 8-ounce fish meals
per month 19
Table 3.1.1. Summary of depth and water-column characteristics for near-bottom and near-
surface SAB coastal ocean waters 23
Table 3.1.2. Summary of depth and selected water column characteristics for SAB estuarine
waters 25
Table 3.2.1. Summary of sediment characteristics for SAB coastal ocean waters (A) and
estuarine waters (B) 37
Table 3.2.2. Summary of chemical contaminant concentrations in SAB coastal ocean sediments
('N/A' = no corresponding ERL or ERM available) 43
Table 3.2.3. Summary of chemical contaminant concentrations in SAB estuarine sediments
('N/A' = no corresponding ERL or ERM available) 46
Table 3.3.1 Summary of chemical contaminant concentrations (wet weight) measured in tissues
of 20 fish (from 17 coastal ocean stations). Concentrations are compared to human health
guidelines where available (from US EPA 2000, Table 2.7.3 here in). 'N/A' = no corresponding
human health guideline available 52
Table 3.4.1. Summary of maj or taxonomic groups of benthic infauna and corresponding
numbers of identifiable taxa in samples from SAB coastal ocean sites 57
Table 3.4.2 Summary of major taxonomic groups of benthic infauna and corresponding numbers
of identifiable taxa in samples from SAB estuarine sites 58
Table 3.4.3. Mean, range, and selected distributional properties of key benthic variables for (A)
coastal ocean and (B) estuarine sediments 62
Table 3.4.4. Fifty most abundant benthic taxa in the SAB coastal ocean survey. Mean density
per m2 and % frequency of occurrence based on 50 grabs. Classification: Native=native species,
Indeter=Indeterminate 63
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Table 3.4.5 Fifty most abundant benthic taxa in the SAB estuarine survey. Mean density per m
and % frequency of occurrence based on 1039 grabs. Classification: Native=native species,
Indeter=Indeterminate, Non-Ind =non-indigenous 65
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List of Appendix Tables
Appendix A. Locations (latitude, longitude), depths, sampling frame areas, and sediment
characteristics of SAB coastal ocean sampling stations 81
Appendix B. Near-bottom water characteristics by SAB coastal ocean station 82
Appendix C. Near-surface water characteristics by SAB coastal ocean station 84
Appendix D. Summary by station of mean ERM quotients and the number of contaminants that
exceeded corresponding ERL or ERM values (from Long et al. 1995) for coastal ocean stations.
86
Appendix E. Summary by station of benthic macroinfaunal (> 0.5 mm) characteristics for
coastal-ocean stations. One replicate benthic grab (0.04 m ) processed from each station. H'
derived using base 2 logs. * Values within lower 25* percentile of all values of a specific
benthic variable; **values within lower 10th percentile. Also included are selected abiotic
variables for assessing potential benthic-stressor linkages. Table shows that no stations with at
least one benthic variable in lower 10 percentile coincided with indicators of poor sediment or
water quality: > 1 chemical in excess of ERMs, TOC > 50 mg/g, or DO in near-bottom water < 2
mg/L 87
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Executive Summary
In March-April 2004, the National Oceanic and Atmospheric Administration (NOAA), U.S.
Environmental Protection Agency (EPA), and State of Florida (FL) conducted a study to assess
the status of ecological condition and stressor impacts throughout the South Atlantic Bight
(SAB) portion of the U.S. continental shelf and to provide this information as a baseline for
evaluating future changes due to natural or human-induced disturbances. The boundaries of the
study region extended from Cape Hatteras, North Carolina to West Palm Beach, Florida and
from navigable depths along the shoreline seaward to the shelf break (~100m). The study
incorporated standard methods and indicators applied in previous national coastal monitoring
programs — Environmental Monitoring and Assessment Program (EMAP) and National Coastal
Assessment (NCA) — including multiple measures of water quality, sediment quality, and
biological condition. Synoptic sampling of the various indicators provided an integrative
weight-of-evidence approach to assessing condition at each station and a basis for examining
potential associations between presence of stressors and biological responses. A probabilistic
sampling design, which included 50 stations distributed randomly throughout the region, was
used to provide a basis for estimating the spatial extent of condition relative to the various
measured indicators and corresponding assessment endpoints (where available).
Conditions of these offshore waters are compared to those of southeastern estuaries, based on
data from similar EMAP/NCA surveys conducted in 2000-2004 by EPA, NOAA, and partnering
southeastern states (Florida, Georgia, South Carolina, North Carolina, Virginia) (NCA database
for estuaries, EPA Gulf Ecology Division, Gulf Breeze FL). Data from a total of 747 estuarine
stations are included in this database. As for the offshore sites, the estuarine samples were
collected using standard methods and indicators applied in previous coastal EMAP/NCA surveys
including the probabilistic sampling design and multiple indicators of water quality, sediment
quality, and biological condition (benthos and fish).
The majority of the SAB had high levels of DO in near-bottom water (> 5 mg L"1) indicative of
"good" water quality. DO levels in bottom waters exceeded this upper threshold at all sites
throughout the coastal-ocean survey area and in 76% of estuarine waters. Twenty-one percent of
estuarine bottom waters had moderate levels of DO between 2 and 5 mg L"1 and 3% had DO
levels below 2 mg L"1. The majority of sites with DO in the low range considered to be hypoxic
(< 2 mg L"1) occurred in North Carolina estuaries. There also was a notable concentration of
stations with moderate DO levels (2-5 mg L"1) in Georgia and South Carolina estuaries.
Approximately 58% of the estuarine area had moderate levels of chlorophyll a (5-10 ug L"1) and
about 8% of the area had higher levels, in excess of 10 ug L"1, indicative of eutrophication. The
elevated chlorophyll a levels appeared to be widespread throughout the estuaries of the region.
In contrast, offshore waters throughout the region had relatively low levels of chlorophyll a with
100% of the offshore survey area having values < 5 ug L"1.
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Estuaries of the SAB displayed a wide range of sediment types from mud to sands, while the
offshore environment consisted largely of sands with typically < 5% silt-clay. Total Organic
Carbon (TOC) also exhibited a wide range of values across the region, with the highest levels
occurring in estuaries. About 19% of the estuarine survey area had TOC at moderate levels (20-
50 mg g"1) and 7% had values in the high range (> 50 mg g"1) associated with a high risk of
adverse effects on benthic fauna. In comparison, offshore sediments had moderate levels of
TOC in about 10% of the survey area (only three of the 50 stations) and none of the stations had
TOC in the upper range. TOC levels tended to be highest in the upstream portions of estuaries
and along the shelf break in the case of the offshore environment. All three offshore stations
with TOC in excess of 20 mg g"1 were located along the shelf break.
In general, sediment contaminants were at relatively low levels throughout most of the region.
Chemical contaminants in offshore sediments were mostly at low, background levels and there
were no chemicals in excess of Effects-Range Median (ERM) values and < 5 chemicals in excess
of Effects-Range Low (ERL) values at all stations. Sediment contamination was more extensive
in estuaries, though moderate levels (> 5 ERL values exceeded) to high levels (> 1 ERM value
exceeded) were still limited to only 4% of the total estuarine survey area.
Previous surveys of the estuarine portions of the SAB in the 1990s found that Polychlorinated
Biphenyls (PCB) and pesticides were the most pronounced contaminant groups for this region.
The current study found that PCBs and pesticide contamination have become less pronounced
since the earlier surveys. The most prevalent contaminants in the present estuarine survey area
were three metals (arsenic, nickel, and cadmium) and total Dichlorodiphenyltrichloroethane
(DDT). Though spatially extensive, all of these except nickel were present at only moderate
levels between corresponding ERL and ERM guideline values. Nickel in addition to five other
contaminants (mercury, silver, zinc, total PCBs, and 4,4' Dichlorodiphenyldichloroethylene
(DDE)) were present in estuarine sediments at concentrations above the corresponding ERM
values though only at four of 747 stations. For the offshore environment, there were three
metals (arsenic, cadmium, and silver) found at moderate concentrations between corresponding
ERL and ERM values, but no chemicals were found in excess of the higher-threshold ERM
values and none of the offshore stations had more than one chemical that exceeded its
corresponding ERL value.
Of the 20 offshore samples offish that were collected and analyzed for chemical contaminants,
only two had tissue contaminant concentrations (i.e., mercury) in the moderate range with
respect to non-cancer human-health risks and there were none with contaminants in the upper
range. In contrast, of the 166 fish samples from estuaries, three had total PCB concentrations
that exceeded the lower non-cancer effects threshold, one had total PCBs in excess of the
corresponding higher threshold, and three had total PAHs that exceeded both the lower (1.6 ng g"
l) and upper (3.2 ng g"1) cancer effects thresholds (a non-cancer concentration range for PAHs
does not exist) .
The relative proportions of major benthic taxonomic groups were fairly consistent between the
offshore and estuarine habitats. Polychaete worms, followed by crustaceans, were the dominant
taxa both by percent abundance and percent species throughout the region. However, the total
number of species per unit of sampling effort was much higher for the offshore waters. For
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example, while a total of 948 benthic taxa were identified from 746 estuarine sites, almost half
that amount (462 taxa or 49%) was identified from only 50 offshore sites (6.7% of the estuarine
sites).
There was little overlap of dominant benthic taxa between the estuarine and coastal-ocean
habitats. Specifically, only five taxa were common to both the offshore and estuarine lists of
fifty most abundant taxa. These taxa were the amphipod Ampelisca abdita, the polychaete
Mediomastus spp., Actiniaria, Nemertea, and Tubificidae. Diversity of benthic macroinfauna, as
measured by species richness and the Shannon-Weiner diversity index H', was higher in the
offshore than in estuarine portions of the region. As an example, species richness averaged 38
taxa grab"1 in offshore waters and was less than half that number (16 taxa grab"1) in estuaries.
Only three of the 50 offshore stations, representing about 10% of the offshore survey area, had <
16 taxa grab"1 (the estuarine mean).
Benthic species lists were examined for presence of non-indigenous species by comparison to the
USGS Non-indigenous Aquatic Species database (nas.er.usgs.gov). There were no non-
indigenous species found in benthic samples from any of the 50 offshore sites. Three non-
indigenous species — Corbiculafluminea (Asian clam), Petrolisthes armatus (green porcelain
crab), and Rangia cuneata (Atlantic rangia) — were identified in benthic samples from SAB
estuaries sampled as part of the NCA efforts in 2000 - 2004. Still, these three species
represented a relatively small proportion (< 0.01%) of the total 408 taxa that were identified to
species level from the analysis of 1,039 estuarine grab samples (0.04-m each). The SAB
benthos appears to be less invaded than some other coastal regions such as the Pacific Coast
benthos, where non-indigenous species are common in estuaries and occur offshore as well
though in more limited numbers.
Multi-metric benthic indices are an important tool for detecting pollution-induced signals of a
degraded benthos and have been developed for a variety of estuarine applications including SAB
estuaries. Of the estuarine area represented in the present SAB study, 7% of the total area was
rated as having poor benthic condition (index scores < 1.5), 9% was rated fair (1.5-3.0), and
84% was rated good (> 3.0) based on the Benthic-Index of Biological Integrity (B-IBI) for
southeastern estuaries. No such index exists for the coastal-ocean portion of the SAB. However,
because there were no major indications of poor sediment or water quality in the offshore
environment (i.e., DO < 2 mg/L, TOC > 50 mg/g, or > 1 chemical contaminant in excess of
ERMs), there was no evidence of a linkage between such potential degraded environmental
conditions and impaired benthic communities. Thus, lower values of key biological attributes
(numbers of taxa, diversity, and abundance), defined as the lower 10th percentile of observed
values, appeared to represent parts of a normal reference range controlled by natural factors.
Alternatively, it is possible that for some of these offshore sites the lower values of benthic
variables reflect symptoms of disturbance induced by other unmeasured stressors, particularly
those causing physical disruption of the seafloor (e.g., commercial bottom trawling, cable
placement, minerals extraction), which may pose greater risks to offshore living resources and
have not been adequately captured. Future monitoring efforts in these offshore areas should
include indicators of such alternative sources of disturbance.
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Overall the SAB appears to be in fair to good ecological condition. However, this assessment
also indicates that there are measurable portions, particularly in estuaries compared to the
offshore environment, which are under some chemical or physical stress. It would be prudent to
use such information as an early warning signal and justification for implementing effective
coastal management practices in order to prevent potential growth of future environmental risks
from increasing human activities in the region. In addition, the SAB region provides many
important ecosystem goods and services across a variety of categories. As coastal development
continues throughout the southeastern region, the component estuarine and coastal-ocean
environments should be treated as a connected ecosystem if we are to better understand and
manage these important resources and the functions they provide.
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1.0 Introduction
The National Oceanic and Atmospheric Administration (NOAA) and the U.S. Environmental
Protection Agency (EPA) both perform a broad range of research and monitoring activities to
assess the status and potential effects of human activities on the health of coastal ecosystems and
to promote the use of this information in protecting and restoring the Nation's coastal resources.
Authority to conduct such work is provided through several legislative mandates including the
Clean Water Act (CWA) of 1977 (33 U.S.C. §§ 1251 et seq.), National Coastal Monitoring Act
(Title V of the Marine Protection, Research, and Sanctuaries Act, 33 U.S.C. §§ 2801-2805), and
the National Marine Sanctuary Act of 2000. Where possible the two agencies have sought to
coordinate related activities through partnerships with states and other institutions to prevent
duplications of effort and bring together complementary resources to fulfill common research
and management goals. Accordingly, in March-April 2004, NOAA, EPA, and the State of
Florida combined efforts to conduct a joint survey of ecosystem condition in near-coastal waters
of the U.S. South Atlantic Bight (SAB) using multiple indicators of ecological condition.
The study is an expansion of EPA's Environmental Monitoring and Assessment Program
(EMAP) which assesses condition of the Nation's environmental resources within a variety of
coastal and terrestrial resource categories. The coastal component of EMAP along the
southeastern U.S. began in 1994 and continued in subsequent years with a focus on estuaries
later becoming known as the National Coastal Assessment (NCA) (Hyland et al. 1996, 1998;
U.S. EPA 2001, 2004, 2008). The current assessment expands this work to near-coastal shelf
waters (depths of-10 m -100 m), from Nags Head, North Carolina (NC) to West Palm Beach,
Florida (FL) (see Figure 2.1.1 below), and includes comparisons with adjacent estuaries of the
region, based on NCA data collected from 2000-2004 by EPA, NOAA and partnering
southeastern states - FL, Georgia (GA), South Carolina (SC), NC, and Virginia (VA) (NCA
database for estuaries, EPA Gulf Ecology Division, Gulf Breeze FL).
The SAB refers to coastal waters along the southeastern U.S., generally defined as extending
from Cape Hatteras, NC to West Palm Beach, FL (e.g., Alegria et al. 2000) though some authors
have used Cape Canaveral as the southern boundary (e.g., Allen et al. 1983), and encompassing
aquatic habitats from estuaries seaward to the outer edge of the continental shelf (delineated here
by the 100-m isobath). This region is also roughly equivalent to the Southeast U.S. Continental
Shelf Large Marine Ecosystem (LME), one of 10 LMEs of the U.S. that provide a framework for
managing ocean resources at ecosystem scales (U.S. Commission on Ocean Policy 2004). The
majority of the SAB continental shelf is a sandy environment with infrequent rock outcrops and
other hard bottom habitats (Powles and Barans 1980, Parker et al. 1983). Inshore the SAB
contains large riverine estuaries, bar-built sounds and lagoons, as well as extensive salt marshes
(Dame et al. 2000). SAB estuaries are dominated by un-vegetated soft-bottom habitats with
higher proportions of silts and clays in lower-energy environments and sands in higher-energy
environments (Dardeau et al. 1992). The estuaries of the SAB discharge vast quantities (66 km3
yr"1) of low-salinity water creating a coastal frontal zone along the inner shelf (Menzel et al.
1993), while the Gulf Stream acts as a major influence on the middle and outer portions of the
shelf (Verity et al. 1993).
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The purpose of the present study was to assess the current status of ecological condition and
stressor impacts throughout the SAB region and to provide this information as a baseline for
evaluating future changes due to natural or human-induced disturbances. To address this
objective, the study incorporated standard methods and indicators applied in previous coastal
EMAP/NCA projects (U.S. EPA 200 Ic, 2004, 2008) including multiple measures of water
quality, sediment quality, and biological condition (benthos and fish). Synoptic sampling of the
various indicators provided an integrative weight-of-evidence approach to assessing condition at
each station and a basis for examining potential associations between presence of stressors and
biological responses. Another key feature was the incorporation of a probabilistic sampling
design with stations positioned randomly throughout the study area. The probabilistic sampling
design provided a basis for making unbiased statistical estimates of the spatial extent of
condition relative to the various measured indicators and corresponding thresholds of concern.
Assessments of status relative to these various indicators are presented for both coastal-ocean
and estuarine waters, thus providing a holistic account of ecological conditions and processes
throughout the inshore and offshore resources of the region. Such information should provide
valuable input for future National Coastal Condition Reports, which historically have focused on
estuaries (U.S. EPA 2001c, 2004, 2008). Results of this study should also provide valuable
support to other growing environmental priorities, such as Ecosystem Based Approaches to
Management (EAM) of coastal resources (Murawski 2007; Marine Ecosystems and Management
2007) and relevant Marine Spatial Planning (MSP) actions, especially with respect to the
Southeast U.S. Continental Shelf LME.
1.1 Coastal Ocean
Shelf waters of the SAB are valuable reservoirs of both living and mineral resources and include
one of NOAA's marine sanctuaries, the Gray's Reef National Marine Sanctuary (GRNMS) off
the coast of Georgia. In the spring of 2004, sampling was conducted at 50 stations in shelf
waters throughout the SAB, using the random probabilistic sampling design of EMAP/NCA.
Accordingly, the resulting data can be used to make unbiased statistical estimates of the spatial
extent of the region's health with respect to the various measured indicators, and to provide this
information as a baseline for determining how environmental conditions may be changing in the
future. This is the first such baseline for the near-coastal (shelf) waters of the SAB region.
Scientists involved in the present study also have conducted surveys, using similar protocols and
indicators, to assess the status of ecological condition and stressor impacts within the boundaries
of the GRNMS itself (Cooksey et al. 2004, Hyland et al. 2006, Balthis et al. 2007). Thus,
condition and characteristics of sanctuary resources can be compared to those of the surrounding
SAB ecosystem.
The offshore survey involved the cooperation of multiple organizations. NOAA/Office of
Marine and Aviation Operations provided the research ship (NOAA ship Nancy Foster). Funds
for the project were provided by NOAA's National Ocean Service (NOS) /National Centers for
Coastal Ocean Science (NCCOS) /Center for Coastal Environmental Health and Biomolecular
Research (CCEHBR) (sampling supplies and equipment) and by EPA's National Health and
Environmental Effects Research Laboratory (NHEERL)/Gulf Ecology Division (GED) (sample
processing). Representatives from NOAA/NOS/NCCOS headquarters and two of its Centers
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(CCEHBR and Center for Coastal Monitoring and Assessment), EPA/NHEERL/GED, and the
State of Florida (Florida Wildlife Research Institute) participated on the cruise as members of the
scientific staff. Additional partners involved in the overall program included the
NOAA/GRNMS Office, South Carolina Department of Natural Resources (SCDNR), and the
Georgia Department of Natural Resources (GADNR).
The present offshore survey is part of a series of Regional Ecological Assessments to evaluate
condition of living resources and ecosystem stressors throughout coastal ocean waters of the U.S.
To date such surveys have been conducted throughout the western U.S. continental shelf, from
the Straits of Juan de Fuca, WA to the U.S./Mexican border (see Nelson et al. 2008 for final
report); shelf waters of the mid-Atlantic Bight (MAB) from Cape Hatteras to Cape Cod, MA
(see Balthis et al. 2009 final report); the continental shelf off southern Florida, from West Palm
Beach in the Atlantic Ocean to Anclote Key in the Gulf of Mexico (see Cooksey and Hyland
2007 for cruise report); and shelf waters of the South Atlantic Bight (SAB) from Cape Hatteras,
NC to West Palm Beach, FL (the present assessment). There are plans to complete similar
surveys throughout the remaining portions of the Gulf of Mexico and North Atlantic coasts of
the U.S. by 2012.
1.2 Estuaries
The estuaries addressed in the present study extend from Cape Henry, VA through the southern
end of the Indian River Lagoon along the east coast of FL. These estuarine resources are diverse
and extensive, covering an estimated 4,487 square miles and featuring a variety of habitats such
as salt marshes, tidal rivers, coastal lagoons, and open-water embayments and sounds. They also
provide a wealth of ecological and societal services including buffers against storms and sea-
level rise; corridors for maritime transportation and trade, as exemplified by busy shipping ports
in Miami, Jacksonville, Savannah, and Charleston; reservoirs of marine biodiversity; protected
areas (e.g., National Estuarine Research Reserve System sites) to promote marine research,
education, and conservation; habitat for various migratory birds and protected species; important
commercial and recreational fisheries; and tourism. North Carolina contains the Albemarle-
Pamlico Estuarine System (APES), the second largest estuary in the U.S. APES represents North
Carolina's key resource base for commercial fishing, recreational fishing, and tourism. Similarly,
the coastal resources of other southeastern states support corresponding fishing and tourism
industries and generate vast amounts of sales tax income for those states as well. There is an
increasing need for effective management of these economically and ecologically valuable
resources given the predicted influx of people and businesses to southeastern coastal states over
the next few decades and the ensuing pressures on the coastal zone of this region. Culliton et al.
(1990) estimated that the coastal population in the southeastern United States will have increased
by 181% over the 50 -year period from 1960 to 2010.
Estuarine data used to support the present inshore-offshore comparisons are from NCA surveys
conducted in 2000 to 2004 by EPA, NOAA, and partnering States of FL, GA, SC, NC, and VA
(NCA database for estuaries, EPA Gulf Ecology Division, Gulf Breeze FL). The data represent a
total of 747 sampling sites (Figure 2.1.1). As for the offshore sites, the samples were collected
using standard methods and indicators applied in previous coastal EMAP/NCA projects (U.S.
EPA 200Ic, 2004, 2008) including the probabilistic sampling design and multiple indicators of
-------
water quality, sediment quality, and biological condition (benthos and fish). The data were
produced through funding provided principally by EPA (Office of Research and Development,
National Health and Environmental Effects Research Laboratory).
-------
2.0 Methods
At each station, samples were obtained for characterization of: (1) community structure and
composition of benthic macroinfauna (fauna retained on a 0.5-mm sieve); (2) concentration of
chemical contaminants in sediments (metals, pesticides, PCBs, PAHs); (3) sediment toxicity
using the 10-day amphipod survival assay (estuarine samples only); (4) water clarity/turbidity
measured by light attenuation (estuaries only);(5) other general habitat conditions (water depth,
dissolved oxygen, conductivity, temperature, chlorophyll a, water-column nutrients and total
suspended solids, % silt-clay versus sand content of sediment, organic-carbon content of
sediment); and (6) condition of targeted demersal fish and macroinvertebrate species
(contaminant body burdens and visual evidence of pathological disorders). The following
section describes methods used for the collection, processing, and analysis of each of these
sample types, which were adopted from the protocols developed for EPA's National Coastal
Assessment (USEPA 200la, 200Ib).
2.1 Sampling Design and Field Collections
2.1.1 Coastal Ocean
Sampling was conducted March 30 - April 11, 2004 at 50 stations positioned randomly
throughout shelf waters of the SAB, from about 1 nautical mile offshore (water depth of-10 m)
seaward to the shelf break (100 m isobath) between Nags Head, NC and West Palm Beach, FL
(Figure 2.1.1). One of the 50 stations was located within GRNMS. The sampling frame for
positioning stations was based on a generalized random-tessellation stratified (GRTS) design.
The GRTS design represents a unified strategy for selecting spatially balanced probability
samples of natural resources, in which sampling sites are more or less evenly dispersed over the
extent of the resource (Stevens and Olsen 2004). Sampling for the survey was conducted on
NOAA ship Nancy Foster, Cruise NF-04-08-CL. The cruise consisted of two legs: Leg 1 for the
northern section of the sampling area (Charleston, SC to Nags Head, NC, March 30 - April 5);
and Leg 2 for the southern section of the sampling area (Charleston, SC to West Palm Beach, FL,
April 6-April 11).
r\
Bottom sediments were collected at each station with a 0.04m , Young modified van Veen grab
and used for analysis of macroinfaunal communities, concentration of chemical contaminants, %
silt-clay, and organic-carbon content. A grab sample was deemed successful when the grab unit
was >75% full (with no major slumping). Two replicate grab samples were collected for benthic
infaunal analysis. Each replicate was sieved onboard through a 0.5-mm screen and preserved in
10% buffered formalin with rose bengal stain. The upper 2-3 cm of sediment from additional
multiple grabs (usually at least two) were taken at each station, combined into a single station
composite, and then sub-sampled for analysis of metals, organic contaminants (PCBs, pesticides,
PAHs), total organic carbon (TOC), and grain size.
Both a Seabird 9/11 and Seabird 19 CTD unit, supplied by the NOAA Ship Nancy Foster, were
used to acquire continuous profiles of salinity, temperature, dissolved oxygen, and depth during
the descent and ascent through the water column. The Seabird 9/11 also was equipped with 12
Nisken bottles to acquire discrete water samples at three designated water depths: 1 m below sea
-------
surface, mid-water column, and 1 m off seabed. The water samples were processed for nutrients,
total suspended solids, and chlorophyll.
Hook-and-line fishing methods (up to six fishing rods) were attempted at all 50 stations in an
effort to capture demersal fishes for inspection of external pathologies and for subsequent
analysis of chemical contaminants in tissues. Any captured fish were identified and inspected
for gross external pathologies. A total of 20 fish collected among seven species from 17 of the
50 stations were selected for analysis as follows:
• 7 sand perch (Diplectrum formosuni)
• 6 black seabass (Centropristis striata)
• 3 dusky flounder (Syacium papillosuni)
• 1 whitebone porgy (Calamus leucosteus)
• 1 red porgy (Pagrus pagrus)
• 1 lizardfish (Synodus foetens)
• 1 snake fish (Trachinocephalus my ops)
-------
Sampling Locations
Estuarine Stations
(2000 - 2004; n = 747)
Coastal Ocean Stations
(2004; n = 50)
0 1.000 2,000
Nautical Miles
Figure 2.1.1 - Map of South Atlantic Bight study area and station locations. Green dots
indicate National Coastal Assessment estuarine stations (sampled 2000 - 2004; n = 747),
and blue dots indicate coastal ocean stations (sampled 2004; n = 50).
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2.1.2 Estuaries
Similar to the off-shore component, the GRTS survey design strategy was used to select
approximately 150 estuarine sites per year for sampling years 2000 to 2004 (Table 2.1.1) The
southeastern estuarine target population represented all boatable areas from the head-of-tide
upland out toward the open ocean encompassing all waters within coastal embayments, lagoons,
tidal rivers and creeks, and intracoastal waterways. Stations were sampled once in the summer
months between July and September when coastal conditions are expected to be under the
greatest influence of environmental stress (Summers et al. 1995).
r\
Bottom sediments were collected at each station with a 0.04m , Young modified van Veen grab.
Contents of each grab were used for analysis of macroinfaunal communities, concentration of
chemical contaminants, % silt-clay, and organic-carbon content. Consistent with the offshore
survey, a grab sample was deemed successful when the grab unit was >75% full and without
major slumping. A single grab was collected from the majority of sites for benthic infaunal
analysis. Benthic sample sediments were sieved on site through a 0.5-mm screen and preserved
in 10% buffered formalin with rose bengal stain. The upper 2-3 cm of sediment from additional
grabs were subsequently taken at each station, homogenized into a single station composite, and
then sub-sampled for analysis of metals, organic contaminants (PCBs, pesticides, PAHs), total
organic carbon (TOC), and grain size.
A hand-held water column profiler, such as a Hydrolab® or YSI® sonde, was used at each site to
collect instantaneous measures of temperature, salinity, pH, and dissolved oxygen (DO). The
water column was measured from 0.5m below surface, at 1m intervals throughout the water
column, and within 0.5m from bottom. Instruments were calibrated daily using known solutions,
pre- and post-deployment comparisons, and weekly air-saturated water tests. Photosynthetically
active radiation (PAR) readings were taken using a LICOR® datalogger equipped with both
ambient and submersible 2pi light sensors just beneath the surface at 1m intervals through water
column, and near the bottom. Secchi disk readings were also taken while on station. Water
samples for nutrient and chlorophyll a analysis were collected at 3 prescribed depths (surface,
mid-water, bottom) using horizontal water samplers. At some sites, only surface samples were
collected. These samples were acquired by submerging a pre-cleaned 1-liter Nalgene® bottle
upside down then inverting it to fill.
Fishes and shrimp were collected for analysis of tissue contaminants and visual evidence of
pathological disorders. Tissue samples were typically collected using either a 6.1m high-rise
otter trawl with a 2.5 cm mesh cod end or 21.3m center bag seine with a 0.31cm bar mesh. In
South Carolina, a 15-foot four-seam trawl with 1.9 cm mesh was used to collect tissue samples.
Trawl nets were towed for 10 minutes against the current between 0.7 and 1.0 m s"1. At sites too
shallow to trawl, a seine net was deployed to acquire the necessary fish tissue samples. All
organisms caught were counted and identified to species. As many as 30 individuals from each
species caught were measured to the nearest millimeter. A prescribed list of target species was
used to cull samples from the catch for contaminant analysis. Up to ten individuals of each target
species were reserved for subsequent laboratory analysis. When no target species were available,
-------
species that best represented the catch were selected as surrogates for analysis. Specimens were
labeled, frozen, and shipped to the appropriate processing laboratory where they were stored and
frozen until analyses could be performed. For this assessment, 166 fish-only specimens were
represented in the tissue contaminant results from the 2000-2004 estuarine surveys. Eighty-two
percent of analyses results were based on target species. The complete list of tissue contaminant
species follows (target species are identified with "*");
• 70 Atlantic croaker (Micropogonias undulatus*)
• 47 spot (Leiostomus xanthurus*)
• 16 pinfish (Lagodon rhomboides*)
• 12 weakfish (Cynoscion regalis)
• 4 silver perch (Bairdiella chrysourd)
• 4 hogfish (Lachnolaimus maximus)
• 3 southern flounder (Paralichthys lethostigma*)
• 2 white perch (Morone americand)
• 2 striped mullet (Mugil cephalus)
• 2 pigfish (Orthopristis chrysopterd)
• 1 hardhead catfish (Ariopsis felis)
• 1 southern kingfish (Menticirrhus americanus)
• 1 white mullet {Mugil curemd)
• 1 summer flounder (Paralichthys dentatus)
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Table 2.2.1 Number of SAB stations sampled by resource category, institution, and year.
Resource
Category
Estuaries
Coastal
Ocean
Totals
Institution
Florida Fish and Wildlife
Research Institute
Georgia Department of
Natural Resources
North Carolina Department
of Environmental and
Natural Resources
South Carolina Department
of Natural Resources
NOAA National Ocean
Service, Charleston, SC
2000
7
50
34
60
151
2001
6
50
34
55
145
2002
4
50
35
60
159
2003
5
50
34
60
149
2004
8
50
35
60
50
153
All
Years
30
250
172
295
50
797
10
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2.2 Water Quality Analysis
Preliminary processing of water samples for nutrients, chlorophyll, and TSS was conducted in
the field at the end of each sampling day (estuaries) or immediately after collection onboard the
research ship (coastal ocean). A portion of the water (-0.5 - 1.0 L) from each station was
vacuum-filtered using microfiltration glassware and a GF/F 47mm filter. The filtered water
sample was then transferred to a polypropylene bottle, frozen (< -20°C), and analyzed within 30
days for dissolved nutrients including ammonium (NFLj. +), nitrate/nitrite (NO2/s),
orthophosphate (PCV 3"), silicate (Si), total dissolved phosphorus (TDP), and total dissolved
nitrogen (TDN)). The filter was folded and wrapped in a foil pouch, frozen, and analyzed within
30 days for chlorophyll a. An additional sample of water (-0.5 - 1.0 L) was filtered on a pre-
weighed GF/F 47mm filter for analysis of total suspended solids (TSS). Whole water samples
were frozen in polypropylene bottles and later analyzed for total nitrogen (TN) and total
phosphorus (TP).
Water chemistry was measured with autoanalyzers using standard EPA methods (USEPA
methods 349.0, 353.4, 365.5). Chlorophyll a samples were extracted using a modified
Welshmeyer (buffered methanol) method and analyzed on a Turner Designs® fluorometer
(USEPA method 445.0m). Total suspended solids was measured using the methods outlined in
EMAP - Estuaries Laboratory Methods Manual Volume 1 - Biological and Physical Analyses,
Section 6 - Residue, Non-Filterable (Suspended Solids) (USEPA 1995).
2.3 Sediment TOC and Grain Size Analysis
Sediment characterization included analyses for TOC and silt-clay content. TOC analysis
followed USEPA Method 9060. A minimum of 5g (wet weight) of sediment was initially dried
for 48 h. Weighed subsamples were ground to fine consistency and acidified to remove sources
of inorganic carbon (e.g., shell fragments). The acidified samples were ignited at 950°C and the
carbon dioxide evolved was measured with an infrared gas analyzer. Silt-clay samples were
prepared by sieve separation followed by timed pipette extractions as described in Plumb (1981).
Results for both analyses were reported as percent of sample.
2.4 Contaminant Analysis
Both offshore and estuarine sediment and tissue samples were examined for inorganic and
organic contaminants. The list (Table 2.4.1) comprises 25 polycyclic aromatic hydrocarbons
(PAHs), 21 polychlorinated biphenyls (PCBs), 20 chlorinated pesticides, and 15 metals.
2.4.1 Sample Preparation
2.4.1.1 Sediments
Samples were stored on ice while on station then shipped (overnight) to a laboratory where
samples were kept at < -20°C until analyzed. A 24-hour thawing period was used to bring sample
temperature to approximately +4°C. Composited sediment samples were re-homogenized prior
to obtaining sample aliquots. Separate aliquots were drawn for each of the contaminant tests
11
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(Table 2.4.1). For metals analysis, sediments were prepared using microwave-assisted extraction
(EPA Method 3052) while organic samples were prepared using ultrasonic extraction (EPA
Method 3550a). All results were reported in dry weight units.
2.4.1.2 Tissues
Fish samples were stored on ice while on station then shipped (overnight) to a laboratory where
samples were kept at <-20°C until analyzed. Samples were partially thawed prior to dissection
and individuals were filleted for muscle tissue with skin and scales intact. Fillets from a single
species collected from a site were blended together to create a homogenate from which aliquots
were retrieved. A separate aliquot was drawn for each contaminant group (Table 2.4.1).
Microwave-assisted extraction was used for metals analysis preparation (EPA Method 3052).
Solvent extraction (EPA Method 3540c) was used to prepare samples for organic analysis. All
results reported in wet weight units.
2.4.2 Analytical Methods
The same analytical methods were used to examine both tissue and sediment samples for
contaminants. These were:
Trace: Inductively Coupled Plasma Mass Spectrometry
Heavy metals (except mercury): Inductively Coupled Plasma Emission
Spectrometry or Graphite Furnace Atomic Absorption Spectrometry
Mercury: Graphite- or Cold-Vapor Atomic Absorption Spectrometry
PAHs: Gas Chromatography/Mass-Spectrometry Selected Ion Monitoring
PCBs and Pesticides: Gas Chromatography/Mass-Spectrometry or
Electron Capture Detection
2.5 Toxicity Analysis
Sediment toxicity, measured only during the estuarine studies, was assessed using the standard
10-day, solid-phase test for survival of the marine amphipod Ampelisca abdita (ASTM, 1993).
Tests were performed at each station using the same sediment homogenates on which analysis of
chemical contaminants and other abiotic sediment variables were conducted. Tests were run on
five replicate samples of sediment from each site under static conditions at 20°C and 30 ppt.
Samples were considered toxic if mean survival relative to a corresponding negative control
(sediment from a reference site) was < 80% and statistically different at a = 0.05.
12
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Table 2.4.1. List of target contaminants analyzed in coastal-ocean and estuarine
sediment and tissue samples.
Polycyclic Aromatic Hydrocarbons
(PAHs)
1 -Methylnaphthalene
1 -Methylphenanthrene
2,3,5 -Trimethy Inaphthalene
2,6-Dimethylnaphthalene
2-Methylnaphthalene
Acenaphthene
Acenaphthylene
Anthracene
Benz [a] anthracene
Benzo[a]pyrene
Benzo [b]fluoranthene
Benzo[e]pyrene
Benzo [g,h,i]perylene
Benzo [kjfluoranthene
Biphenyl
Chrysene
Dibenz[a,h]anthracene
Dibenzothiophene
Fluoranthene
Fluorene
Indeno [1 ,2,3 -c,d]pyrene
Naphthalene
Perylene
Phenanthrene
Pyrene
Pesticides
2,4'-DDD
2,4'-DDE
2,4'-DDT
4,4'-DDD
4,4'-DDE
4,4'-DDT
Aldrin
Alpha-chlordane
BHC-alpha
Endosulfan I
Endosulfan II
Dieldrin
Endosulfan
Endosulfan Sulfate
Endrin
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Lindane
Mirex
Toxaphene
Trans-nonachlor
C.A.S.
90-12-0
832-69-9
2245-38-7
581-42-0
91-57-6
83-32-9
208-96-8
120-12-7
56-55-3
50-32-8
205-99-2
192-97-2
191-24-2
207-08-9
92-52-4
218-01-9
53-70-3
132-65-0
206-44-0
86-73-7
193-39-5
91-20-3
198-55-0
85-01-8
129-00-0
C.A.S.
53-19-0
3424-82-6
789-02-6
72-54-8
72-55-9
50-29-3
309-00-2
5103-71-9
319-84-6
959-98-8
33213-65-9
60-57-1
115-29-7
1031-07-8
72-20-8
76-44-8
1024-57-3
118-74-1
58-89-9
2385-85-5
8001-35-2
39765-80-5
Polychlorinated Biphenyls (PCBs)
2,2',3,3',4,4',5,5',6-Nonachlorobiphenyl
2,2',3,3',4,4'-Hexachlorobiphenyl
2,2',3,4,4',5,5'-Heptachlorobiphenyl
2,2',3,4,4',5'-Hexachlorobiphenyl
2,2',3,5'-Tetrachlorobiphenyl
2,2',4,4',5,5'-Hexachlorobiphenyl
2,2',5,5'-Tetrachlorobiphenyl
2,2',5-Trichlorobiphenyl
2,3,3',4,4'-Pentachlorobiphenyl
2,3 ',4,4'-Tetrachlorobiphenyl
2,4,4'-Trichlorobiphenyl
3 ,3 ',4,4',5 -Pentachlorobiphenyl
3 ,3 ',4,4'-Tetrachlorobiphenyl
2,2',3,3',4,4',5,5',6,6'-Decachlorobiphenyl
PCB 110/77
PCB congener 101/90
PCB congener 118/108/149
PCB congener 170/190
PCB congener 187/182/159
PCB congener 195/208
PCB congener 8/5
Metals
Aluminum
Antimony
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese (sediment only)
Mercury
Nickel
Selenium
Silver
Tin
Zinc
C.A.S.
40186-72-9
38380-07-3
35065-29-3
35065-28-2
41464-39-5
35065-27-1
35693-99-3
37680-65-2
32598-14-4
32598-10-0
7012-37-5
57465-28-8
32598-13-3
2051-24-3
38380-03-9
37680-73-2
31508-00-6
35065-30-6
52663-68-0
52663-78-2
34883-43-7
C.A.S.
7429-90-5
7440-36-0
7440-38-2
7440-43-9
7440-47-3
7440-50-8
7439-89-6
7439-92-1
7439-96-5
7439-97-6
7440-02-0
7782-49-2
7440-22-4
7440-31-5
7440-66-6
13
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2.6 Benthic Community Analysis
Once in the laboratory, samples were transferred from formalin to 70% ethanol. Macroinfaunal
invertebrates were sorted from the sample debris under a dissecting microscope and identified to
the lowest practical taxon (usually species). Data were used to compute density (m~2) of total
fauna (all species combined), densities of numerically dominant species (m~2), numbers of
species, H' diversity (Shannon and Weaver 1949) derived with base-2 logarithms, and estimates
of condition based on the Southeastern benthic index of biotic integrity for estuarine stations (B-
IBI, Van Dolah et al. 1999). Computation of the B-IBI was based on the procedures and habitat
designations of Van Dolah et al. (1999). B-IBI scoring criteria are presented here in Table 2.7.1.
A B-IBI has not been developed yet for the coastal ocean portion of the SAB.
2.7 Data Analysis
A probabilistic, stratified-random sampling design was used in these surveys in order to provide
a basis for making unbiased statistical estimates of the spatial extent of condition, with 95 %
confidence intervals, of the coastal and estuarine waters of the SAB based on the status of
various measured ecological indicators and corresponding thresholds of interest (Table 2.7.1).
A similar approach has been applied throughout EPA's EMAP, related NCA programs, and other
coastal-ocean surveys (e.g., Summers et al. 1995; Strobel et al. 1995; Hyland et al. 1996; USEPA
2004, 2006; Nelson et al. 2008). Results of the above type of spatial estimates are presented
throughout this report as the percent area of the SAB within specified ranges of a particular
indicator. Thresholds defining such ranges (see Table 2.7.1) include, where possible, those
having known biological significance (e.g., dissolved oxygen < 2 mg L"1). Additional data
summaries presenting key distributional properties (e.g., mean, range) and other basic data
tabulations are provided as well. Data presented graphically in this report are primarily in the
form of cumulative distribution functions (CDFs) and pie charts. These are useful tools for
portraying the percentage of coastal area corresponding to varying levels of a given indicator
across the full range of its observed values and for estimating the percentage of area falling
below or above some designated threshold of interest. This is a useful feature for management
applications; for example, if valid thresholds can be defined for a particular indicator or suite of
indicators, they could be used as ecosystem quality targets for tracking how well the system is
doing and for triggering any necessary management actions.
The biological significance of sediment contamination was evaluated by comparing measured
chemical concentrations in sediments to corresponding Effects Range-Low (ERL) and Effects
Range-Median (ERM) sediment quality guideline (SQG) values developed by Long et al. (1995)
and listed here in Table 2.7.2. The ERL values are lower-threshold bioeffect limits, below which
adverse effects on sediment-dwelling organisms are not expected to occur. ERM values
represent upper-threshold concentrations, above which bioeffects are likely to occur in some
sediment-dwelling species. Overall sediment contamination from multiple chemicals was
expressed as the mean ERM quotient (ERM-Q) (Long et al. 1998; Long and MacDonald 1998;
Hyland et al. 1999), which is the mean of the ratios of individual chemical concentrations in a
sample relative to corresponding ERM values. Mean ERM-Qs < 0.018 and > 0.057 have been
associated with a low and high incidence of stress, respectively, in benthic communities of
southeastern estuaries (Hyland et al. 2003).
14
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The biological significance offish and shrimp tissue contamination was evaluated from a
human-health perspective using risk-based consumption limits for cancer and non-cancer
(chronic systemic effects) endpoints derived by U.S. EPA (2000) for a variety of organic and
inorganic contaminants (Table 2.7.3). Concentrations of contaminants measured in fish tissues
were compared to the corresponding endpoints for cancer and chronic health risks associated
with the consumption of four 8-ounce meals per month for the general adult population. Fish
tissue contamination data were only available for a subset of stations; therefore, tissue
contaminant data were not evaluated on a percent areal basis.
For estuarine data only, a water quality index was developed based on evaluations stemming
from dissolved oxygen, DIN, DIP, and Chi a analysis and a sediment quality index was created
by combining results from sediment contaminant, TOC, and toxicity data evaluations. Methods
used for the development of these two indices are consistent with methods used in the National
Coastal Condition Reports (USEPA 200 Ic, 2004, 2006, 2008).
15
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Table 2.7.1 Thresholds used for classifying samples relative to various environmental indicators.
Indicator
Estuaries Threshold
Coastal Ocean
Threshold
Reference
Water Quality
Salinity (PSU)
< 5 = Oligohaline
5 - 18 = Mesohaline
>18-30=Polyhaline
> 30 = Euhaline
< 5 = Oligohaline
5 - 18 = Mesohaline
>18-30=Polyhaline
> 30 = Euhaline
Carriker 1967
Low: < 5.0
Chlorophyll a (ug/L) Moderate: 5.0 - 10.0
High: >10.0
Potentially Elevated:
> upper 90th percentile
U.S.EPA2008
Dissolved Oxygen
(mg/L)
Good: >5.0
Moderate: 2.0 - 5.0
Poor: < 2.0
Good: >5.0
Moderate: 2.0 - 5.0
Poor: < 2.0
U.S. EPA 2008
Dissolved Inorganic
Phosphorus (mg/L)
Low: < 0.01
Moderate: 0.01-0.05
High: > 0.05
Potentially Elevated:
> upper 90th percentile
U.S. EPA 2008;
Nelson et al. 2008
Dissolved Inorganic
Nitrogen (mg/L)
Low:<0.1
Moderate: 0.1 -0.5
High: >0.5
Potentially Elevated:
> upper 90th percentile
U.S. EPA 2008;
Nelson et al. 2008
DIN/DIP
Phosphorus Limitation: > 16 Phosphorus Limitation: > 16 Geider and LaRoche
Nitrogen Limitation: < 16 Nitrogen Limitation: < 16 2002
Water Clarity Less Turbid: >20%
(light penetration @ 1 Mod. Turbid: 10 - 20%
m) High. Turbid: <10%
Data not available
Smith et al. 2007
A5T
Strong Vertical Stratification: Strong Vertical
> 2 Stratification: > 2
Nelson et al. 2008
Sediment Quality
Overall Chemical
Contamination of
Sediments (ERM-Q):
Potential Benthic Risk
Levels
Very High: > 0.196
High: XX057-0.196
Moderate: > 0.018-0.057
Low: < 0.018
Very High: > 0.196
High: >0.057-0.196
Moderate: > 0.018-0.057
Low: < 0.018
Hyland et al. 2003
16
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Indicator
Estuaries Threshold
Coastal Ocean
Threshold
Reference
Overall Chemical
Contamination of
Sediments (# ERL/ERM HiSh: ^ l ERM exceeded
Probability of adverse
biological affect
. >
Moderate: > 5 ERLs exceeded , , , ' ~ ^ „ ™T
- Moderate: > 5 ERLs
and no ERMs exceeded ~
Low: < 5 ERLs and no ERMs
exceeded
Low: < 5 ERLs
TTC ,-,„ . ~AAO
US. EPA 2008
Individual chemical
contaminant
concentrations in
sediments
Bioeffects likely: > ERM Bioeffects likely: > ERM
Bioeffects not likely: < ERL Bioeffects not likely: < ERL
Longetal. 1995
Sediment Toxicity
(%A. abdita control
corrected survival)
Not Toxic: > 80
Data not available
U.S. EPA 2008
TOC (mg/g)
Low: < 20
Moderate: 20 - 50
High: >50
Low: < 20
Moderate: 20 - 50
High: >50
High: > 35
U.S. EPA 2008;
Hyland et al. 2005
Biological Condition
Benthic Community
(potential degraded
condition)
SE Benthic Index
Healthy Benthos: > 3.0
Some Stress: 1.5-3.0
Degraded Benthos: < 1.5
Potentially Degraded
Benthos: < lower 10th
percentile for key benthic
variables
U.S. EPA 2008;
Nelson et al. 2008;
Van Dolah et al.
1999
Tissue Contaminants
(# guidelines exceeded)
Any contaminant
concentration:
High: Exceeded range
Moderate: within range
Low: below range
Any contaminant
concentration:
High: Exceeded range
Moderate: within range
Low: below range
U.S. EPA 2000
17
-------
Table 2.7.2. ERM and ERL guidance values in sediments (Long et al. 1995).
ERL
Metals (ppm)
Arsenic*f 8.2
Cadmium*t 1.2
Chromium* 81
Copper* 34
Lead * 46.7
Mercury* 0.2
Nickel* 20.9
Silver*f 1
Zinc* 150
Pesticides (ppb)
4,4'-DDE (p,p*-DDE)* 2.2
Total DDTs* 1 .6
ERM
70
9.6
370
270
218
0.71
51.6
3.7
410
27
46.1
PAHs (ppb)
Acenaphthene*
Acenaphthylene*
Anthracene*
Benzo[a]anthracene*
Benzo[a]pyrene*
Chrysene*
Dibenz[a,h,]anthracene
Fluoranthene*
Fluorene*
2-Methylnaphthalene*
Naphthalene*
Phenanthrene*
Pyrene*
Total PAHs
PCBs (ppb)
Total PCBs*
ERL
16
44
85.3
261
430
384
63.4
600
19
70
160
240
665
4020
22.7
ERM
500
640
1100
1600
1600
2800
260
5100
540
670
2100
1500
2600
44800
180
ERL exceeded: *- Estuaries f - Coastal Ocean
18
-------
Table 2.7.3. Risk based EPA advisory guidelines for recreational fishers (US EPA 2000).
Concentration ranges represent the non-cancer health endpoint risk for four 8-ounce fish meals
per month.
Metals (ppm)
Arsenic (inorganic)1
Cadmium
Mercury
(methylmercury)2
Selenium
Pesticides (ppb)
Chlordane
Total DDTs
Dieldrin
Endosulfan
Endrin
Lower
0.35
0.35
0.12
5.9
590
59
59
7000
350
Upper
0.70
0.70
0.23
12.0
1200
120
120
14000
700
Pesticides (continued)
Heptachlor epoxide
Hexachlorobenzene
Lindane
Mi rex
Toxaphene
PCBs (ppb)
Total PCBs
PAHs (ppb)
Total PAHs3
Lower
15
940
350
230
290
23
1.6
Upper
31
1900
700
470
590
47
3.2
1. Inorganic arsenic estimated as 2% of total arsenic.
2. Conservative assumption was made that all mercury is present as methylmercury because most
mercury in fish and shellfish is present primarily as methylmercury.
3. Cancer concentration range used, a non-cancer concentration range for PAHs does not exist.
19
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3.0 Results and Discussion
3.1 Depth and Water Quality
3.1.1 Depth and General Water Characteristics: temperature, salinity, water-column
stratification, DO, pH, water clarity
Coastal Ocean
Key bottom-water characteristics, as measured during the 2004 survey, throughout the coastal
ocean waters of the SAB (Figure 3.1.1, Table 3.1.1, Appendix A, B, C) can be summarized as
follows: (1) water depths ranging from 8.9 - 68.1 m and averaging 29.4 m (water depths were
not corrected to Mean Low Low Water); (2) a narrow range of euhaline bottom salinity (PSU)
values of 32.9 - 36.5 (overall mean of 35.6); (3) high bottom DO levels ranging from 6.8 - 9.9
mg L"1 and averaging 7.8 mg L"1; (4) bottom temperatures ranging from 6.4 - 23.7 °C and
averaging 17.1 °C; (5) a narrow range of pH levels from 8.2 - 8.6 and averaging 8.4; and (6) low
levels of surface-water total suspended solids (TSS) ranging from 0.97 - 15.93 mg L"1 and
averaging 3.64 mg L"1.
Water-column stratification expressed as Act, an index of the variation between surface and
bottom water densities, was calculated from temperature and salinity data. The index is the
difference between the computed bottom and surface ot values, where ot is the density of a parcel
of water with a given salinity and temperature relative to atmospheric pressure (Nelson et al.
2008). The Act index ranged from 0.003 to 1.715. One hundred percent of the area of waters of
the SAB shelf had Aot index values less than 2, indicating weak vertical stratification of the
water column (Table 2.7.1). These results agree with previous assessments that have shown
October through May to be periods of low vertical stratification for coastal-ocean waters of the
SAB (Martins and Pelegri 2006).
Estuaries
A summary of key water-column characteristics is presented in Table 3.1.2 for estuarine waters
of the SAB. Bottom-water salinities ranged from oligohaline (< 5 ppt) to euhaline (> 30 ppt),
with the average salinity (23.5 ppt) falling in the polyhaline range of 18 - 30 ppt. Bottom DO
varied widely from 0.2 to 11.6 mg L"1 and averaged 4.9 mg L"1. Bottom-water pH also exhibited
a wide range (4.8 - 9.2) and averaged 7.6. Water clarity as measured by the light attenuation
coefficient ranged from 0.3 to 23.3 and averaged 2.3.
Seventy-four percent of southeast estuaries had low turbidity (indicative of high water clarity).
Conversely, 12% of the area exhibited considerably higher turbidity. Twenty-six percent of the
survey area did not meet the light-penetration threshold (> 20% transmissivity @ 1m) associated
with optimum growth conditions of submerged aquatic vegetation (SAV) (Figure 3.1.3).
20
-------
SAB Region-wide
The majority of the SAB had bottom-water DO levels in the high range (> 5 mg L"1) considered
good for marine life (Figure 3.1.4, Table 2.7.1). DO levels in bottom-waters exceeded this upper
threshold at all coastal-ocean stations and in 76% of the estuarine waters. Twenty-one percent of
the estuarine bottom-waters had moderate levels of DO between 2 and 5 mg L"1 and 3% had DO
levels below 2 mg L"1. The majority of the lowest DO levels (< 2 mg L"1) occurred in North
Carolina waters where low-DO conditions have previously been reported (Figure 3.1.4; Hyland
et al. 2000). There is an interesting cluster of moderate DO levels (2-5 mg L"1) in the estuaries
of Georgia and South Carolina, which corresponds to results of Verity et al. (2006) indicating a
long-term trend of declining DO throughout Georgia estuaries.
21
-------
100 n
(0
0)
E
D
O
50 -
100
0 10 20 30 40 50 60 70 0.0
Depth (m)
0.5 1.0 1.5
Delta sigma-t
2.0
ro
0)
E
D
O
50 -
100 n
6 12 18
T (°C): Bottom
24 0 6 12 18
T (°C): Surface
24
ro
0)
E
D
O
50 -
0 31 32 33 34 35 36 37 0 31 32 33 34 35 36 37
Salinity (PSU): Bottom Salinity (PSU): Surface
100 n
ro
0)
E
D
O
50 -
100 n
06 8
DO (mg/L): Bottom
10
10
DO (mg/L): Surface
ro
0)
E
D
O
50 -
0.0 8.2 8.4
pH: Bottom
8.6 0.0 6.0 6.6 7.2 7.8 8.4
pH: Surface
Figure 3.1.1 Percent area (solid lines) and 95% Confidence Intervals (dotted lines)
of SAB coastal ocean depth and selected water-quality characteristics.
22
-------
Table 3.1.1. Summary of depth and water-column characteristics for near-bottom and near-surface SAB coastal ocean waters.
Near-Bottom Water
Depth (m)
A5T
D0(mgl_-1)
Salinity (PSU)
Temperature (°C)
PH
DIN (mg L'1)
DIP (mg I'1)
DIN/DIP
Chla(ugl_-1)
TSS (mg L'1)
Mean
29.4
0.472
7.8
35.6
17.1
8.4
0.045
0.024
4.01
0.67
3.30
Range
8.9
0.003
6.8
32.9
6.4
8.2
0.012
0.010
1.07
0.15
0.27
-68.1
- 1.715
-9.9
-36.5
-23.7
-8.6
- 0.269
- 0.080
-8.46
-2.83
-24.9
CDF
10th%
14.3
0.097
7.1
33.5
7.8
8.2
0.012
0.011
2.74
0.23
1.17
CDF
50th%
25.7
0.275
7.6
36
17.9
8.3
0.026
0.017
3.75
0.41
2.17
CDF
90th%
44.5
1.048
8.9
36.4
21.3
8.5
0.064
0.031
6.01
1.39
5.76
Mean
N/A
N/A
7.7
35.3
17.7
8.2
0.038
0.028
3.69
0.44
3.64
Near-Surface Water
Range
N/A
N/A
6.8-9.8
31.2-36.6
6.7-24.3
5.8-8.6
0.011 -0.232
0.010-0.110
0.53 - 9.00
0.09 - 2.02
0.97- 15.93
CDF
10th%
N/A
N/A
6.9
33.2
8.7
7.3
0.015
0.011
1.92
0.15
1.4
CDF
50th%
N/A
N/A
7.5
35.8
18.6
8.3
0.028
0.017
3.81
0.26
3.18
CDF
90th%
N/A
N/A
8.7
36.3
23.2
8.5
0.043
0.037
5.23
1.08
6.21
23
-------
100 n
CD
0
E
3
O
50 -
100 n
CD
0
E
3
O
50 H
100 -i
CD
0
E
O
50 -
100 -i
CD
0
E
O
50 -
5 10 15
Depth (m)
20
6 12 18 24 30 36 42
Salinity (PSU): Bottom
4 6 8 10
DO (mg/L): Bottom
12
056789
pH: Bottom
Figure 3.1.2. Percent area (solid lines) and 95% Confidence Intervals (dotted
lines) of SAB estuarine depth and selected bottom water-quality characteristics.
24
-------
Table 3.1.2. Summary of depth and selected water column characteristics for SAB estuarine
waters.
Depth (m)
Bottom DO (mg L"1)
Bottom Salinity (PPT)
Bottom pH
DIN (mg L'1)
DIP (mg L1)
Chla(|jgL-1)
Water Clarity (light
attenuation co-efficient)
Mean
3.5
4.9
23.5
7.6
0.099
0.042
10.16
2.3
Range
0.1 -16.7
0.2-11.6
0-42
4.8-9.2
0-1.388
0-1.07
0.26-97.74
0.3 -23.3
CDF
10th%
0.9
3.9
0.9
7.2
0
0.001
2.3
0.7
CDF
50th%
2.7
6.3
20.2
7.8
0.022
0.012
6.75
1.3
CDF
90th%
5.7
8.1
31.7
8.3
0.131
0.054
17.45
2.5
Percent of Survey Area by
Water Clarity Classification:
Estuaries
Les Turbid: > 20%
Moderately Turbid: 10 - 20%
Turbid: < 10%
Figure 3.1.3. Percent area of SAB estuarine waters within specified ranges of water
clarity.
25
-------
Percent of Survey Area by
Dissolved Oxygen Range:
Good: > 5.0 mg/L
Moderate: 2.0 - 5.0 mg/L
Poor: < 2.0 mg/L
Coastal Ocean
Estuaries
Figure 3.1.4. Percent area of SAB coastal ocean and estuarine near-bottom waters
within specified ranges of DO concentrations.
26
-------
Bottom DO (mg/L)
> 5 mg/L
2-5 mg/L
• < 2 mg/L
0 1,000 2,000
Nautical Miles
Figure 3.1.5. Spatial distribution of bottom dissolved oxygen levels in SAB coastal
ocean and estuarine waters.
27
-------
3.1.2 Nutrients and Chlorophyll
Coastal Ocean
Surface-water concentrations of total dissolved inorganic nitrogen (DIN: nitrate + nitrite +
ammonium as nitrogen) ranged from 0.011 - 0.232 mg L"1 and averaged 0.038 mg L"1 (Figure
3.1.6, Table 3.1.1, Appendix C). The 50th percentile of the surface-water sampling area
corresponded to a DIN concentration of 0.028 mg L"1 and the 90th percentile corresponded to a
DIN concentration of 0.043 mg L"1. Surface-water concentrations of dissolved inorganic
phosphate (DIP: orthophosphate as phosphate) ranged from 0.010 -0.110 mg L"1 and averaged
0.028 mg L"1 (Figure 3.1.6, Table 3.1.1). The 50th percentile of the surface-water sampling area
corresponded to a DIP concentration of 0.017 mg L"1 and the 90th percentile corresponded to a
DIP concentration of 0.037 mg L"1.
The ratio of DIN concentration to DIP concentration (N/P ratio) was calculated as an indicator of
which nutrient may be controlling primary production. A ratio above 16 is generally considered
indicative of phosphorus limitation, and a ratio below 16 is considered indicative of nitrogen
limitation (Geider and La Roche 2002). The N/P ratio in surface waters ranged from 0.53 to 9.0
and averaged 3.69. One hundred percent of the offshore survey area had N/P ratios < 16,
indicative of a nitrogen limited environment. The SAB coastal ocean has previously been
reported as being primarily nitrogen limited (Pomeroy et al. 1993; Verity et al. 1993).
DIN and DIP thresholds developed for evaluation purposes in estuarine habitats are not
applicable to the coastal-ocean environment and thus are not used in this report for evaluating the
offshore nutrient data (Table 2.7.1). Estuaries experience a continuum of nitrogen and phosphate
cycling and if the estuarine thresholds were applied to the nitrogen-limited offshore environment,
the result might indicate erroneously that a large percentage of coastal ocean waters have "high"
levels of DIP. Specifically, nearly 100% of the coastal ocean area exceeded the moderate DIP
threshold for estuarine waters (0.01 mg L"1) and approximately 8% of the coastal ocean area
exceeded the high threshold for estuarine waters (0.05 mg L"1). In contrast, only 2% of the
coastal-ocean area exceeded the moderate DIN threshold for estuarine waters (0.1 mg L"1) and
none of the coastal-ocean area exceeded the high DIN threshold for estuarine waters (0.5 mg L"
l). The baseline data collected in the 2004 coastal-ocean survey may be used to develop
applicable nutrient thresholds in the future.
Chlorophyll a (Chi a) levels in surface waters ranged from 0.09 - 2.02 ug L"1 and averaged 0.44
ug L"1 (Figure 3.1.5, Table 3.1.1, Appendix C). The 50th percentile of the surface-water
sampling area corresponded to a Chi a concentration of 0.26 ug L"1 and the 90th percentile
corresponded to a Chi a concentration of 1.08 ug L"1. All offshore stations, representing 100%
of the offshore survey area, had Chi a below the 5.0 ug L"1 threshold used to denote the
beginning of the high range for estuarine waters (U.S. EPA 2004). These data are in good
agreement with prior studies of Chi a levels in coastal-ocean waters off South Carolina (Verity et
al. 1998) and Georgia (Paffenhofer et al. 1994).
The amount of TSS in the water column has a direct effect on turbidity (a measure of water
clarity) by causing the attenuation or scattering of light, though TSS itself is not a measure of
28
-------
turbidity. Generally as TSS increases, the water becomes murkier or more turbid. Excessively
high turbidity and TSS may be harmful to marine life (e.g., by reducing light penetration and
photosynthesis, increasing biological oxygen demand of high organic content, interfering with
normal respiratory and feeding activities) and distract from the aesthetic value of a coastal area.
TSS levels in both surface- and bottom-waters of the coastal ocean portion of the SAB were
relatively low (Figure 3.1.6, Table 3.1.1). The 50* percentile of the survey area had a TSS
concentration of 3.18 mg L"1 for surface-waters and 2.17 mg L"1 for bottom-waters.
Estuaries
Surface water concentrations of total dissolved inorganic nitrogen (DIN: nitrate + nitrite +
ammonium as nitrogen) ranged from 0.0 - 1.388 mg L"1 and averaged 0.099 mg L"1 (Figure
3.1.7, Table 3.1.2). The 50th percentile of the surface water sampling area in estuaries
corresponded to a DIN concentration of 0.022 mg L"1 and the 90th percentile corresponded to a
DIN concentration of 0.131 mg L"1. Surface-water concentrations of dissolved inorganic
phosphate (DIP: orthophosphate as phosphate) ranged from 0.0 - 1.07 mg L"1 and averaged 0.042
mg L"1 (Figure 3.1.7, Table 3.1.2). The 50th percentile of the surface-water sampling area
corresponded to a DIP concentration of 0.012 mg L"1 and the 90th percentile corresponded to a
DIP concentration of 0.054 mg L"1.
Less than 1% of the SAB estuarine area had DIN concentrations that exceeded 0.5 mg L"1,
considered a high level of DIN, while 15% had moderate levels of DIN (0.1 - 0.5 mg L"1)
(Figure 3.1.8, Table 2.7.1). DIP concentrations exceeded 0.05 mg L"1, considered a high level of
DIP, in 11% of the estuarine area and moderate levels of DIP (0.01 - 0.05 mg L"1) were detected
in 45% of the estuarine area (Figure 3.1.8).
Chlorophyll a (Chi a) levels in SAB estuarine surface waters ranged from 0.26 - 97.74 ug L"1
and averaged 10.16 ug L"1 (Figure 3.1.7, Table 3.1.2). The 50th percentile of the surface-water
sampling area corresponded to a Chi a concentration of 6.75 ug L"1 and the 90th percentile
corresponded to a Chi a concentration of 17.45 ug L"1. Sixty-six percent of the southeast coastal
estuarine area had chlorophyll a concentrations in the moderate to high range in excess of 5 ug L"
1 (Figure 3.1.9, Table 3.1.2).
SAB Region-Wide
Estuaries throughout the SAB have shown symptoms of low to moderate eutrophication with
some areas reported as being highly eutrophic (Mallin et al. 2000, Bricker et al. 2007). Such
assessments are supported by the results presented here, which suggest that about 58% of the
estuarine area is experiencing moderate levels of Chi a (5-10 ug L") and 8% of the area is
experiencing higher levels in excess of 10 ug L"1 (Figure 3.1.9). The elevated Chi a levels are
widespread throughout the estuaries of the region (Figure 3.1.10). In contrast, at the time of
sampling, coastal-ocean waters throughout the region had relatively low levels of Chi a with
100% of the offshore survey area having values < 5 ug L"1 (Figure 3.1.10).
29
-------
CO
CD
E
^
O
CO
CD
100
50
0
0.0
100 -,
50 -
0.1 0.2
DIN (mg/L): Bottom
0.3 0.0 0.1 0.2
DIN (mg/L): Surface
E
3
O
0
0.00 0.02 0.04 0.06 0.08 0.10 0.00
DIP (mg/L): Bottom
100 -i
CO
CD
E
^
O
50 -
246
DIN/DIP: Bottom
100 -i
CO
CD
E
^
O
50 -
0
CO
CD
0
100 -,
50 -
1 2
CHL a: Bottom
E
O
0.03 0.06 0.09
DIP (mg/L): Surface
246
DIN/DIP: Surface
1 2
CHL a: Surface
0
0.3
0.12
15
5 10 15 20 25 0 5 10
TSS: Bottom TSS: Surface
Figure 3.1.6. Percent area (solid lines) and 95% Confidence Intervals (dotted lines)
of SAB coastal ocean waters for nurtients, chlorophyll a and TSS concentrations.
30
-------
100 -i
CD
0
E
3
O
50 -
0
0.0 0.2
0.4 0.6 0.8 1.0
DIN (mg/L): Surface
1.2 1.4
100 -i
CD
0
E
d
50 -
0.0 0.1 0.2
DIP (mg/L): Surface
0.3 1.1
100 n
CD
CD
50 -
E
3
O
25 50 75
CHL a (ug/L): Surface
100
Figure 3.1.7. Percent area (solid lines) and 95% Confidence Intervals (dotted
lines) of SAB estuarine surface water nutrients, chlorophyll a and TSS
concentrations.
31
-------
Percent of Survey Area by
Surface Nutrient Ranges:
0.1%
Estuaries: DIN
Low: < 0.1 mg/L
Moderate: 0.1 - 0.5 mg/L
High: > 0.5 mg/L
Estuaries: DIP
i i Low: < 0.01 mg/L
I I Moderate: 0.01 - 0.05 mg/L
I • High: > 0.05mg/L
Figure 3.1.8. Percent area of SAB within specified ranges of DIN and DIP for near-
surface estuarine waters only.
32
-------
Percent of Survey Area by
Chlorophyll a Range:
Low: < 5.0 pg/L
Moderate: 5.0 -10.0 |jg/L
High: > 10.0 M9/L
Estuaries:
Near-Surface
Figure 3.1.9. Percent area of SAB within specified ranges of chlorophyll a for near-
surface estuarine waters only.
33
-------
Surface CHLa (ug/L)
• < 5.0 (jg/L
5.0- 10.0 M9/L
• > 10.0 jjg/L
1,000 2,000
Nautical Miles
Figure 3.1.10. Spatial distribution of surface chlorophyll a levels in SAB coastal
ocean and estuarine waters.
34
-------
3.2 Sediment Quality
3.2.1 Grain Size and TOC
Coastal Ocean
The percentage of silt-clay in sediments ranged from 0.4% to 11.5% and averaged 1.9%
throughout the survey area (Table 3.2.1, Appendix A). One hundred percent of the overall
coastal-ocean survey area had sediments composed of sands (< 20% silt-clay). None of the
stations were composed of muds (> 80% silt-clay; Figure 3.2.1).
Total organic carbon (TOC) in sediments exhibited a wide range (0.01 to 39.94 mg g"1)
throughout the SAB region (Table 3.2.1). The majority of the coastal-ocean survey area (90%)
had relatively low TOC levels of < 20 mg g"1 and none had high levels (> 50 mg g"1) associated
with a high risk of adverse effects on benthic fauna. About 10% of the offshore survey area,
represented by three stations located consistently along the outer shelf, had intermediate levels of
TOC (20-50 mg g'1) (Figure 3.2.3).
Estuaries
The percentage of silt-clay in sediments ranged widely from 0.1% to 98.8% and averaged 25.3%
throughout the survey area (Table 3.2.1). Approximately 54% of the estuarine survey area had
sediments composed of sands (< 20% silt-clay), 41% was composed of intermediate muddy
sands (20-80% silt-clay), and 5% was composed of muds (> 80% silt-clay).
TOC exhibited a wide range of 0 to 166.54 mg g"1 and averaged 11.40 mg g"1 (Table 3.2.1).
Seventy-four percent of the estuarine survey area had low levels of TOC (< 20 mg g"1 and only
7% had high levels (> 50 mg g"1). These data are similar to those recorded for SAB estuaries
during earlier surveys, although the maximum reported here (166.54 mg g"1) is slightly higher
than the maximum (148 mg g"1) previously reported by Hyland et al. (1996, 1998).
SAB Region-Wide
Estuaries of the SAB are characterized by a wide range of sediment types from muds to sands,
while the coastal-ocean environment consists largely of sands with typically < 5% silt-clay
(Figure 3.2.1). TOC also exhibited a wide range of values across the SAB, with the highest
levels occurring in estuaries (Table 3.2.1, Figure 3.2.2 and 3.2.3). About 19% of the estuarine
survey area had TOC at moderate levels (20-50 mg g"1) and 7% had values in the high range (>
50 mg g"1) associated with a high risk of adverse effects on benthic fauna (U.S. EPA 2008). In
comparison, offshore sediments had moderate levels of TOC in about 10% of the survey area and
did not exhibit evidence of TOC in the upper range. The lower and upper thresholds of 20 and
50 mg g"1 used here for evaluating the biological significance of sediment TOC content are
adopted from earlier EPA National Coastal Condition Reports (e.g., U.S. EPA 2004, 2008).
Hyland et al. (2005) also identified TOC concentrations > 35 mg g"1 as an upper range associated
with a high risk of degraded benthic condition from multiple coastal areas around the world. The
portion of the present offshore survey area with TOC in excess of this slightly more conservative
35
-------
cut point also was relatively small, 5%, represented by one station along the shelf break west of
Cape Fear. For comparison, estuaries had TOC > 35 mg g"1 in about 11% of the survey area.
TOC levels tended to be the highest in the upstream portions of estuaries and along the shelf
break in the case of the offshore environment (Figure 3.2.4). All three offshore stations with
TOC in excess of 20 mg g"1, inclusive of the one station off Cape Fear with TOC > 35 mg g"1,
were located along the shelf break. The offshore pattern is consistent with results observed
previously along a cross-shelf transect off the coast of Georgia (Hyland et al. 2006) and may be
related to intrusions of deep, nutrient-rich water onto the continental shelf (Verity et al. 1993).
36
-------
Table 3.2.1. Summary of sediment characteristics for SAB coastal ocean waters (A) and
estuarine waters (B).
A.
B. Estuaries
Mean
Range
CDF 10th% CDF 50th% CDF 90th%
TOCCmgg1)
% silt-clay
Mean ERM-Q
3.53
1.9
0.008
0.01 -39.94
0.4-11.5
0.003 - 0.028
0.07
0.72
0.003
0.53
0.98
0.006
18.2
5.8
0.013
Mean
Range
CDF 10th% CDF 50ffi% CDF 90ffi%
TOC (mg g1)
% silt-clay
Mean ERM-Q
11.40
25.3
0.019
0-166.54
0.1-98.8
0-0.968
0.46
1.2
0.003
5.9
13.3
0.013
35.8
73.7
0.076
100
03
0)
E
O
50
0
Intermediate Muddy Sands
0
20
40 60
Percent Silt-Clay
80
100
Figure 3.2.1. Percent area of SAB coastal ocean (blue line) and estuarine (green line)
vs. percent silt-clay of sediment.
37
-------
Percent of Survey Area by
TOC range:
Low: < 20 mg/g
Moderate: 20 - 50 mg/g
High: > 50 mg/g
Coastal Ocean
Estuaries
Figure 3.2.2. Percent area of SAB near-bottom waters within specified ranges of TOC
levels.
100
20
40
60
TOC (mg/g)
80
100
120
Figure 3.2.3. Percent area of SAB coastal ocean (blue line) and estuarine (green line)
area vs. TOC levels of sediment.
38
-------
TOC (mg/g)
• < 20 mg/g
20 - 50 mg/g
• > 50 mg/g
0 1.000 2,000
Nautical Miles
Figure 3.2.4. Spatial distribution of total organic carbon (TOC) levels in SAB coastal
ocean and estuarine sediments.
39
-------
3.2.2 Chemical Contaminants in Sediments
Effects Range-Low (ERL) and Effects Range-Median (ERM) sediment quality guideline (SQG)
values from Long et al. (1995) were used to help interpret the biological significance of observed
chemical contaminant levels in sediments. ERL values are lower-threshold bioeffect limits,
below which adverse effects of the contaminants on sediment-dwelling organisms are not
expected to occur. In contrast, ERM values represent mid-range concentrations of chemicals
above which adverse effects are more likely to occur. A list of 26 chemicals, or chemical groups,
for which ERL and ERM guidelines have been developed is provided in Table 2.7.2 along with
the corresponding SQG values (from Long et al. 1995). Any site with one or more chemicals
that exceeded corresponding ERM values was rated as having poor sediment quality, any site
with five or more chemicals between corresponding ERL and ERM values was rated as fair, and
any site that had less than five ERLs exceeded and no ERMs exceeded was rated as good (sensu
USEPA 2004).
Overall sediment contamination from multiple chemicals also was expressed as the mean ERM
quotient (ERM-Q) (Long et al. 1998; Long and MacDonald 1998; Hyland et al. 1999), which is
the mean of the ratios of individual chemical concentrations in a sample relative to
corresponding ERM values (using all chemicals in Table 2.7.2 except nickel and total PAH).
Mean ERM-Qs < 0.018 and > 0.058 have been associated with a low and high incidence of
stress, respectively, in benthic communities of southeastern estuaries (Hyland et al. 2003).
Coastal Ocean
Sediments throughout the coastal-ocean survey area were relatively uncontaminated with all
stations (100%) having contaminant concentrations in the low range (Table 3.2.2, Figure 3.2.5,
Appendix D). Three trace metals (arsenic, cadmium, and silver) were found at moderate
concentrations between corresponding ERL and ERM values, but no chemicals were found in
excess of the higher-threshold ERM values (Table 3.2.2). ERL values were exceeded by these
metals only at nine of the 50 offshore stations and none of these stations had more than one ERL
exceedance. Mean ERM-Q values were also low throughout SAB coastal ocean sediments,
ranging from 0.003 to 0.028 and averaging 0.008 (Table 3.2.1, Appendix D). Values in the
moderate range (> 0.018-0.057) were found at three stations representing approximately 5% of
the offshore survey area (Figure 3.2.5). None of the offshore sediments had mean ERM-Qs in
the high to very high range (i.e., >0.057). Arsenic, cadmium, and silver are naturally occurring
trace metals in crustal rocks, thus it is likely that the moderately elevated levels are due to natural
geological conditions (Kimbrough et al. 2008).
Estuaries
Sediment contamination in estuaries was also fairly limited, although individual chemical
contaminants exceeded their corresponding ERL values at many of the stations and ERM values
at a few stations (Table 3.2.3). Overall, about 96% of the estuarine survey area had sediments
with contaminants at low levels, 2% at moderate levels, and 2% at high levels based on numbers
of ERL and ERM values exceeded (Figure 3.2.6). Three metals (arsenic, nickel, and cadmium)
and total DDT were the predominant contaminants in estuarine sediments. Out of the 747
40
-------
estuarine stations where sediment contaminants were measured, lower-level ERL values were
exceeded at 131 stations for arsenic, 70 stations for nickel, 35 stations for cadmium, and 30
stations for total DDT. Arsenic, cadmium, and total DDT did not exceed their corresponding,
higher-threshold ERM values at any of the estuarine sites. As with the offshore environment,
arsenic, nickel, and cadmium are naturally occurring trace elements in crustal rocks, thus it is
likely that the moderately elevated levels are due to natural geological conditions (Kimbrough et
al. 2008). The higher-level ERM values were exceeded for six contaminants (mercury, nickel,
silver, zinc, total PCBs, and 4,4' DDE) at four of the estuarine stations. One station, FL04-0050,
located in Doctors Lake, Florida on the St. John's River, accounted for the majority of this
contamination. For example, mercury, nickel, and 4,4' DDE exceeded their corresponding ERM
values only at this station. Additionally, ERM levels for zinc and total PCBs were exceeded at
Station FL04-0050. This area of the St. John's River, FL has been reported previously as
containing high levels of chemical contaminants (Cooksey and Hyland 2007).
Mean ERM-Qs for estuarine sediments ranged from 0.0 to 0.968 and averaged 0.019 (Table
3.2.1). Values in the low range (< 0.018) accounted for about 59% of the estuarine survey area,
values in the moderate range (> 0.018-0.057) accounted for about 30% of the area, values in the
high range (> 0.057-0.196) accounted for about 10% of the area, and values in the very high
range (> 0.196) accounted for about 1% of the area (Figure 3.2.5).
SAB Region-Wide
In general, sediment contamination across the majority of the SAB was at low levels. Chemical
contaminants in offshore sediments were at low, background levels throughout the entire survey
area. Sediment contamination, expressed as number of ERL and ERM values exceeded, was
more extensive in estuarine sediments, though moderate to high levels were still limited to 4% of
the total estuarine survey area (Figure 3.2.6). The spatial extent of sediment contamination in
estuaries was somewhat higher, however, if expressed as mean ERM-Qs, with about 11% of the
estuarine survey area having mean ERM-Qs in the high to very high range (Figure 3.2.5).
Specific areas of high sediment contamination were located in Biscayne Bay and St. John's
River, FL, and Winyah Bay, SC (Figure 3.2.7).
Hyland et al. (1996, 1998) previously completed surveys of environmental quality of estuaries of
the SAB, in 1994 and 1995, using methodology nearly identical to that used in the current
survey. They found that PCBs (1994) and pesticides (1995) were the most pronounced
contaminant groups for this region. The current survey finds that PCBs and pesticide
contamination have become less pronounced during the five to ten years between the earlier
surveys and the data presented here. The most prevalent contaminants in the present estuarine
survey area were three metals (arsenic, nickel, and cadmium) and total DDT. Though spatially
extensive, all of these except nickel were present at moderate levels between corresponding ERL
and ERM guideline values. Nickel and five other contaminants (mercury, silver, zinc, total
PCBs, and 4,4' DDE) were present in estuarine sediments at concentrations above the
corresponding ERM values. However, areas with elevated chemical contaminant concentrations
were spatially limited; ERM values were exceeded at only four of 747 stations. For the offshore
environment, there were three metals (arsenic, cadmium, and silver) found at moderate
concentrations between corresponding ERL and ERM values, but no chemicals were found in
41
-------
excess of the higher-threshold ERM values and none of the offshore stations had more than one
chemical that exceeded its corresponding ERL value.
42
-------
Table 3.2.2. Summary of chemical contaminant concentrations in SAB coastal ocean sediments
('N/A' = no corresponding ERL or ERM available).
Analyte
Metals (% dry wt.)
Aluminum
Iron
Trace Metals (ug/g)
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Tin
Zinc
PAHs (ng/g)
Acenaphthene
Acenaphthylene
Anthracene
benz[a]anthracene
benzo[a]pyrene
benzo [b]fluoranthene
Benzo [g,h,i]perylene
Benzo [kjfluoranthene
Biphenyl
Chrysene
Dibenz[a,h] Anthracene
Dibenzothiophene (Synfuel)
2,6-Dimethylnaphthalene
Fluoranthene
Fluorene
Indeno [ 1 ,2,3 -c,d]Pyrene
Naphthalene
2-Methylnaphthalene
1 -Methylnaphthalene
1 -Methylphenanthrene
Phenanthrene
Pyrene
2,3 ,5 -Trimethylnaphthalene
Total PAHs
PCBs (ng/g)
Total PCBs
Pesticides (ng/g)
2,4'-DDD
Mean
0.28
0.41
0.0318
5.2
0.114
11.17
1.0884
4.33
98.15
0.00088
2.0968
0.4022
0.06976
3.772
7.28
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Concentration >
ERL < ERM
Range # Stations
0-1.3
0.11 -2.1
0-0.48
1.1 -20.8
0-1.5
1.6-24.9
0-4.8
1.6-12.1
26.1-603
0-0.025
0.76 - 8.2
0-0.93
0.011-1.9
3 - 14.9
2.3-34.3
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
N/A
N/A
N/A
7
1
0
0
0
N/A
0
0
N/A
1
N/A
0
0
0
0
0
0
N/A
N/A
N/A
N/A
0
0
N/A
N/A
0
0
N/A
0
0
N/A
N/A
0
0
N/A
0
N/A
N/A
Concentration
>ERM
# Stations
N/A
N/A
N/A
0
0
0
0
0
N/A
0
0
N/A
0
N/A
0
0
0
0
0
0
N/A
N/A
N/A
N/A
0
0
N/A
N/A
0
0
N/A
0
0
N/A
N/A
0
0
N/A
0
N/A
N/A
43
-------
Concentration > Concentration
ERL < ERM > ERM
Analyte Mean Range # Stations # Stations
2,4'-DDE 0 0-0 0 0
2,4'-DDT 0 0-0 N/A N/A
4,4'-DDD 0 0-0 N/A N/A
4,4'-DDE 0 0-0 N/A N/A
4,4'-DDT 0 0-0 N/A N/A
Total DDT 0 0-0 0 0
Aldrin 0 0-0 N/A N/A
Alpha-Chlordane 0 0-0 N/A N/A
Atrazine 0 0-0 N/A N/A
Dieldrin 0 0-0 N/A N/A
EndosulfanI 0 0-0 N/A N/A
Endosulfanll 0 0-0 N/A N/A
Endosulfan Sulfate 0 0-0 N/A N/A
Endrin 0 0-0 N/A N/A
Gamma-BHC (Lindane) 0 0-0 N/A N/A
Heptachlor 0 0-0 N/A N/A
HeptachlorEpoxide 0 0-0 N/A N/A
Hexachlorobenzene 0 0-0 N/A N/A
Mirex 0 0-0 N/A N/A
Toxaphene 0 0-0 N/A N/A
Trans-Nonachlor 0 0-0 N/A N/A
44
-------
Percent of Survey Area by
mean ERM-Q Levels:
I I Low: < 0.018
I I Moderate: : > 0.018 - 0.057
I 1 High: > 0.057-0.196
I • Very High: > 0.196
Coastal Ocean
1% Estuaries
Figure 3.2.5. Percent area of SAB sediment contamination, expressed as
mean ERM-Q, levels within specified ranges.
45
-------
Table 3.2.3. Summary of chemical contaminant concentrations in SAB estuarine sediments
('N/A' = no corresponding ERL or ERM available).
Analyte
Metals (ug/g)
Aluminum
Iron
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Tin
Zinc
PAHs (ng/g)
Acenaphthene
Acenaphthylene
Anthracene
Benz[a]anthracene
Benzo[a]pyrene
Benzo [b]fluoranthene
Benzo[e]pyrene
Benzo [g,h,i]perylene
Benzo[j+k]fluoranthene
Benzo [kjfluoranthene
Biphenyl
Chrysene
Dibenz[a,h]anthracene
Dibenzothiophene
2,6-Dimethylnaphthalene
Fluoranthene
Fluorene
Indeno [ 1 ,2,3 -c,d]pyrene
1 -Methylnaphthalene
2-Methylnaphthalene
1 -Methylphenanthrene
Naphthalene
Perylene
Phenanthrene
Pyrene
2,3 ,5 -Trimethylnaphthalene
Total PAHs
PCBs (ng/g)
Total PCBs
Mean
21464.11
13846.71
0.22161
4.81
0.2221
24.281
5.8
11.92
197.59
0.026676
7.7511
0.4543
0.0647
3.087
31.66
0.604
0.782
2.075
5.558
5.182
6.966
4.307
3.236
8.246
3.231
0.809
4.971
0.125
0.285
0.848
13.044
0.840
2.973
1.033
1.383
0.364
2.562
45.119
4.355
12.860
0.241
97.450
4.640
Concentration >
ERL < ERM
Range # Stations
0 - 180000
0 - 100000
0-5.4
0-26.8
0-4.85
0-250
0-130
0-180
0 - 1426.9
0-1.2
0-90
0-46
0-5.8
0 - 248.2
0-628
0-123.1
0-96
0-442
0-602
0-640
0-770
0-389
0-700
0-487
0-690
0-97.9
0-560
0-5.9
0-91
0-91
0-1100
0-93
0-560
0-92
0-88
0-100
0-470
0-1813.5
0-330
0 - 1200
0-90
0 - 7580
0 - 2526
N/A
N/A
N/A
131
35
21
7
10
N/A
15
70
N/A
4
N/A
7
9
4
4
3
2
N/A
N/A
N/A
N/A
N/A
N/A
1
0
N/A
N/A
2
7
N/A
N/A
o
J
N/A
1
N/A
2
1
N/A
2
1
Concentration
>ERM
# Stations
N/A
N/A
N/A
0
0
0
0
0
N/A
1
1
N/A
1
N/A
2
0
0
0
0
0
N/A
N/A
N/A
N/A
N/A
N/A
0
N/A
N/A
0
0
N/A
N/A
0
N/A
0
N/A
0
0
N/A
0
2
46
-------
Analyte
Mean
Range
Concentration >
ERLERM
# Stations
Pesticides (ng/g)
2,4'-DDD
2,4'-DDE
2,4'-DDT
4,4'-DDD
4,4'-DDE
4,4'-DDT
Total DDT
Aldrin
Alpha-Chlordane
Dieldrin
Endosulfan I
Endosulfan II
Endosulfan Sulfate
Endrin
Gamma-BHC (Lindane)
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Mirex
Toxaphene
Trans-Nonachlor
0.015
0.004
0.003
0.058
0.173
0.0308
0.280
0.120
0.005
0.048
0.002
0.007
0.026
0.0072899
0.011
0.002
0.003
0.053
0.019
0
0.001
0-1.7
0-0.66
0-0.82
0-5.7
0-35
0-5.8
0-35
0-88
0-0.58
0-30.28
0-0.69
0-2.6
0-8.5
0-1
0-1.2
0-0.34
0-1
0-7.7
0-3.3
0-0
0-0.25
N/A
N/A
N/A
N/A
4
N/A
30
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1
N/A
0
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
47
-------
Percent of Survey Area with
Sediment Contamination Levels:
Low: No ERM eceeded and < 5 ERLs exceeded
Moderate: > 5 ERLs exceeded
High: > 1 ERM exceeded
Coastal Ocean
2o/0 Estuaries
2%°
Figure 3.2.6. Percent area of SAB sediment contamination levels, expressed
as number of ERL and ERM values exceeded, within specified ranges.
48
-------
Sediment
Contaminants
No ERM exceeded
and < 5 ERLs exceeded
No ERM exceeded and
> 5 ERLs exceeded
• > 1 ERM exceeded
0 1.000 2,000
Nautical Miles
Figure 3.2.7. Spatial distribution of sediment contaminant levels in SAB coastal
ocean and estuarine sediments.
49
-------
3.2.3 Sediment Toxicity (Estuaries Only)
Ninety-five percent of the estuarine survey area showed no signs of sediment toxicity based on
the 10-day survival assay with the marine amphipod Ampelisca abdita, (Figure 3.2.6). This low
incidence of sediment toxicity is consistent with results from previous surveys of sediment
quality throughout the southeastern estuaries (Hyland et al. 1996, 1998).
Percent of Survey Area by
Sediment Toxicity Range:
Ampelisca abdita
control corrected survival
Good: > 80%
Poor: < 80%
Figure 3.2.8. Percent area of SAB estuarine toxicity levels within specified ranges.
50
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3.3 Chemical Contaminants in Fish Tissues
Coastal Ocean
Analysis of chemical contaminants in fish tissues was performed on homogenized fillets
(including skin) from 20 samples of seven fish species collected from 17 stations. The fish
species were sand perch (Diplectmm formosum), black seabass (Centropristis striata\ dusky
flounder (Syacium papillosum\ whitebone porgy (Calamus leucosteus), red porgy (Pagrus
pagrus), lizardfish (Synodusfoetens), and snake fish (Trachinocephalus myops). Many of the
measured contaminants in these samples were below corresponding minimum detection limits
(MDL)(Table 3.3.1). However, 16 of the 22 inorganic trace metals that were measured (Al, As,
Ba, Cr, Cu, Fe, Pb, Mn, Ni, Hg, Se, Ag, Sr, Ti, V, and Zn) were present at detectable levels and
nine of the 26 measured PAHs were present at detectable levels. Additionally, there were
several other organic contaminants that were present at detectable levels including total PCBs
and 4,4'-DDT.
USEPA (2000) developed human-health consumption limits for cancer and non-cancer (chronic
systemic) health endpoints for a variety of contaminants (Table 2.7.3). Measured contaminant
concentrations (Table 3.3.1) fell well below the non-cancer consumption limits for most
chemicals. However, one red porgy (Station 42) and one sand perch (Station 2) had mercury
levels that exceeded the lower threshold for non-cancer effects (0.12 ug g"1), but did not exceed
the higher non-cancer effects threshold (0.23 ug g"1).
Estuaries
Analysis of chemical contaminants in fish issues was performed on whole bodies from 166
samples of 14 fish species collected from 153 estuarine stations. Nearly all of the measured
contaminants were found at detectable levels in at least a portion of the samples (Table 3.3.2).
However, most samples had contaminants below both the lower and upper thresholds for non-
cancer human-health risks. Four fish samples had mercury concentrations between the lower and
upper thresholds (0.12 ug g"1 and 0.23 ug g"1, respectively). Three fish samples had total PCB
concentrations that exceeded the lower threshold (23 ug g"1) and one fish had total PCBs in
excess of the corresponding higher threshold (47 ng/g). Three fish samples also had total PAHs
that exceeded both the lower (1.6 ug g"1) and upper (3.2 ug g"1) cancer effects thresholds.
SAB Region-Wide
Of the seventeen coastal-ocean stations where fish were collected and analyzed for chemical
contaminants, only two (12% of sites) had moderate levels of tissue contaminants, between
lower and upper non-cancer effect thresholds, and none of the measured fish had high levels of
tissue contaminants above the upper threshold (Table 2.7.1). At estuarine sites, in contrast, six
stations (4% of sites) had high levels of tissue contaminants, exceeding the upper end of the
human-health guideline range, and eight stations (5% of sites) had moderate levels of tissue
contaminants (Figure 3.3.1).
51
-------
Table 3.3.1 Summary of chemical contaminant concentrations (wet weight) measured in tissues
of 20 fish (from 17 coastal ocean stations). Concentrations are compared to human health
guidelines where available (from US EPA 2000, Table 2.7.3 here in). 'N/A' = no corresponding
human health guideline available.
Analyte
Trace Metals (ug g"1)
Aluminum (Al)
Antimony (Sb)
Arsenic (As)
Inorganic Arsenic
Cadmium (Cd)
Chromium (Cr)
Copper (Cu)
Iron (Fe)
Lead (Pb)
Manganese (Mn)
Mercury (Hg)
Nickel (Ni)
Selenium (Se)
Silver (Ag)
Tin (Sn)
Zinc (Zn)
PAHs (ng g1)
Total Detectable PAHs1
PCBsCngg1)
Total Detectable PCBs
Pesticides (ng g"1)
2,4'-DDD
2,4'-DDE
2,4'-DDT
4,4'-DDD
4,4'-DDE
4,4'-DDT
Aldrin
BHC-alpha
Chlordane-alpha
Dieldrin
Endosulfan Sulfate
Endosulfan-I
Endosulfan-II
Endrin
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Lindane
Mirex
Toxaphene
trans-Nonachlor
Total Detectable DDTs
Mean
2
0
4.92
0.098
0
0.82
0.3
7.35
0.029
0.31
0.068
0.1
0.415
0.1
0
5.2
0.545
0.06
0
0
0
0
0
0.3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.015
Range
1-5
0-0
0.7 - 14.3
0.014-0.286
0-0
0.1-1.7
0.2-0.67
3-10
0.01-0.09
0.1-0.7
0.025-0.158
0.1 -0.1
0.3 -0.8
0.1 -0.1
0-0
4-7
0-4.15
0-1.19
0-0
0-0
0-0
0-0
0-0
0.3 -0.3
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0.3
No. of Fish Exceeding
Endpoints
Lower
N/A
N/A
0
N/A
0
N/A
N/A
N/A
N/A
N/A
2
N/A
0
N/A
N/A
N/A
0
0
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0
N/A
0
N/A
0
N/A
0
0
0
0
0
N/A
0
Non-Cancer
Upper
N/A
N/A
0
N/A
0
N/A
N/A
N/A
N/A
N/A
0
N/A
0
N/A
N/A
N/A
0
0
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0
N/A
0
N/A
0
N/A
0
0
0
0
0
N/A
0
1. Cancer concentration range used, a non-cancer concentration range for PAHs does not exist.
52
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Table 3.3.2 Summary of chemical contaminant concentrations (wet weight) measured in tissues
of 166 fish samples (from 153 estuarine stations). Concentrations are compared to human health
guidelines where available (from US EPA 2000, Table 2.7.3 here in). 'N/A' = no corresponding
human health guideline available.
No. of Fish Exceeding Non-Cancer
Endpoints
Analyte Mean Range Lower Upper
Trace Metals (ug g"1)
Aluminum (Al)
Antimony (Sb)
Arsenic (As)
Inorganic Arsenic
Cadmium (Cd)
Chromium (Cr)
Copper (Cu)
Iron (Fe)
Lead (Pb)
Manganese (Mn)
Mercury (Hg)
Nickel (Ni)
Selenium (Se)
Silver (Ag)
Tin (Sn)
Zinc (Zn)
PAHs (ng g1)
Total Detectable PAHs1
PCBs (ng/g)
Total Detectable PCBs
Pesticides (ng g"1)
Aldrin
Chlordane-alpha
Dieldrin
Endosulfan
Endrin
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Lindane
Mirex
Toxaphene
trans-Nonachlor
Total Detectable DDTs
9.934
0.059
1.097
0.02194
0.004
0.355
0.642
21.211
0.285
3.409
0.029
0.043
0.690
0.003
1.555
10.624
13.934
4.789
0.060
0.060
0.076
0.181
0.060
0.060
0.060
0.069
0.060
0.076
7.530
0.060
1.379
0 -121
0-0.580
0-5.0
0-0.1
0-0.080
0-9.9
0.2-7.93
1.9-273
0-23.9
0.27-37.3
0-0.2
0-0.730
0.25 - 1.3
0-0.085
0-17.2
4.05-32
0-460
0-54.0
0-2.0
0-2.0
0-2.0
0-6.0
0-2.0
0-2.0
0-2.0
0-2.0
0-2.0
0-2.0
0-250
0-2.0
0 - 16.00
N/A
N/A
0
N/A
0
N/A
N/A
N/A
N/A
N/A
4
N/A
0
N/A
N/A
N/A
0
3
N/A
N/A
0
N/A
0
N/A
0
0
0
0
0
N/A
0
N/A
N/A
0
N/A
0
N/A
N/A
N/A
N/A
N/A
0
N/A
0
N/A
N/A
N/A
3
1
N/A
N/A
0
N/A
0
N/A
0
0
0
0
0
N/A
0
1. Cancer concentration range used, a non-cancer concentration range for PAHs does not exist.
53
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Percent of Fish Sampling Sites by Tissue
Contaminants Level:
Low: Below consumption guideline range
Moderate: Within consumption guideline range
High: Exceeds consumption guideline range
Coastal Ocean
Estuaries
Figure 3.3.1. Percent of sites of SAB fish tissue contamination levels within
consumption guideline ranges.
54
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3.4 Status of Benthic Communities
Macrobenthic infauna (> 0.5 mm) were sampled at a total of 50 coastal ocean stations and 746
estuarine stations throughout the SAB. A single grab (0.04 m2) was collected at all stations
except for South Carolina estuaries, at which duplicates were taken, thus resulting in a total of
1,039 benthic grabs. The duplicate samples were averaged for the calculation of CDFs and other
analysis purposes. The resulting data are used here to assess the status of benthic community
characteristics (taxonomic composition, diversity, abundance and dominant species),
biogeographic patterns, incidence of non-indigenous species, and potential linkages to ecosystem
stressors.
3.4.1 Taxonomic Composition
Coastal Ocean
A total of 462 taxa were identified across the coastal ocean portion of the SAB, of which 313
were identified to the species level. Polychaetes were the dominant taxa, both by percent
abundance (47%) and percent taxa (47%; Figure 3.4.1, Table 3.4.1). Crustaceans were the
second most dominant taxa, both by percent abundance (28%) and percent taxa (30%).
Collectively, these two groups represented 75% of the total faunal abundance and 77% of the
taxa throughout these offshore waters. Crustaceans were represented mostly by amphipods (65
identifiable taxa, 14% of the total number of taxa). Mollusca accounted for 17% of taxa
identified in coastal ocean samples, but only 9% of total faunal abundance. Echinoderms
accounted for a small portion of total fauna by both percent abundance (2%) and percent taxa
Estuaries
A total of 948 taxa were identified across the estuarine portion of the SAB, of which 545 were
identified to the species level. Polychaetes were the dominant taxa, both by percent abundance
(58%) and percent taxa (37%; Figure 3.4.1, Table 3.4.2). Crustaceans were the second most
dominant taxa, both by percent abundance (18%) and percent taxa (29%). Collectively, these two
groups represented 76% of the total faunal abundance and 66% of the taxa throughout the
estuaries of the SAB. Crustaceans were represented mostly by amphipods (124 identifiable taxa,
13.1% of the total number of taxa). Mollusca accounted for 25% of taxa identified in coastal
ocean samples, but only 9% of total faunal abundance.
SAB Region-Wide
Taxonomic composition, based on major taxonomic groups, was very consistent between the
coastal-ocean and estuarine portions of the SAB survey area (Figure 3.4.1). Polychaetes,
followed by crustaceans, were the dominant taxa both by percent abundance and percent taxa
across the region. However, the total number of taxa per unit of sampling effort was much
higher for the offshore waters. For example, while a total of 948 benthic taxa were identified
from 746 estuarine sites, almost half the number of taxa (462 or 49%) were identified from only
55
-------
50 offshore sites (6.7% of the estuarine sites). This observation is consistent with the observed
patterns of species diversity discussed below.
Major Taxonomic Groups:
Polychaeta
Crustacea
Mollusca
Echinodermata
Other
Coastal Ocean:
Percent of Taxa
Estuaries:
Percent of Taxa
Coastal Ocean:
Percent of Abundance
Estuaries:
Percent of Abundance
Figure 3.4.1. Relative percent composition of major taxonomic groups expressed as (A)
percent of total taxa and (B) percent of abundance for coastal ocean and estuarine waters.
56
-------
Table 3.4.1. Summary of maj or taxonomic groups of benthic infauna and corresponding
numbers of identifiable taxa in samples from SAB coastal ocean sites.
Taxonomic Group
Phylum Cnidaria
Class Anthozoa
Phylum Platyhelminthes
Phylum Nemertea
Phylum Sipuncula
Phylum Annelida
Class Polychaeta
Class Clitellata
Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Stomatopoda
Order Decapoda
Order Mysidacea
Order Cumacea
Order Tanaidacea
Order Isopoda
Order Amphipoda
Class Ostracoda
Subphylum Chelicerata
Class Arachnida
Phylum Mollusca
Class Polyplacophora
Class Gastropoda
Class Bivalvia
Class Scaphopoda
Phylum Phoronida
Phylum Ectoprocta
Phylum Brachiopoda
Phylum Echinodermata
Class Asteroidea
Class Ophiuroidea
Class Echinoidea
Class Holothuroidea
Phylum Chordata
Total
Number identifiable taxa
1
1
1
3
6
215
2
1
18
1
11
9
14
65
20
1
1
24
45
7
1
1
1
2
4
3
2
2
462
% Total identifiable taxa
0.2
0.2
0.2
0.6
1.3
46.5
0.4
0.2
3.9
0.2
2.4
1.9
3.0
14.1
4.3
0.2
0.2
5.2
9.7
1.5
0.2
0.2
0.2
0.4
0.9
0.6
0.4
0.4
100
57
-------
Table 3.4.2 Summary of major taxonomic groups of benthic infauna and corresponding numbers
of identifiable taxa in samples from SAB estuarine sites.
Taxonomic Group
Phylum Porifera
Phylum Cnidaria
Class Hydrozoa
Class Anthozoa
Phylum Platyhelminthes
Phylum Nemertea
Phylum Sipuncula
Phylum Annelida
Class Polychaeta
Class Clitellata
Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Leptostraca
Order Stomatopoda
Order Decapoda
Order Mysidacea
Order Lophogastridae
Order Cumacea
Order Tanaidacea
Order Isopoda
Order Amphipoda
Subphylum Hexapoda
Class Insecta
Subphylum Chelicerata
Class Pycnogonida
Phylum Mollusca
Class Polyplacophora
Class Gastropoda
Class Bivalvia
Class Scaphopoda
Phylum Phoronida
Phylum Brachiopoda
Phylum Echinodermata
Class Asteroidea
Class Ophiuroidea
Class Holothuroidea
Phylum Chaetognatha
Phylum Hemichordata
Total
Number identifiable taxa
1
1
5
3
3
7
2
1
350
11
1
1
1
1
74
13
1
15
13
35
124
18
9
3
108
122
1
2
1
2
9
7
1
2
948
% Total identifiable taxa
0.1
0.1
0.5
0.3
0.3
0.7
0.2
0.1
36.9
1.2
0.1
0.1
0.1
0.1
7.8
1.4
0.1
1.6
1.4
3.7
13.1
1.9
0.9
0.3
11.4
12.9
0.1
0.2
0.1
0.2
0.9
0.7
0.1
0.2
100
58
-------
3.4.2 Abundance and Dominant Taxa
Coastal Ocean
A total of 6,236 individual specimens were collected across the 50 coastal-ocean stations (50,
9 9 9
0.04 m" grab samples). Densities ranged from 275 to 23,650 m" and averaged 3,118m" (Figure
3.4.2, Table 3.4.3, Appendix E). Thus there were no offshore samples that were devoid of
benthic fauna. Spatially, 90% of the shelf area had densities > 635 m"2 and 50% of the shelf area
had densities > 2350 m"2 (Table 3.4.3). The average densities reported from this survey for the
entire coastal-ocean portion of the SAB are similar to densities previously reported for the
continental shelf off Georgia, inclusive of GRNMS, where inner-shelf densities averaged 4958
m"2, middle-shelf densities averaged 5901 m"2, and outer-shelf densities averaged 1550 m"2
(Hyland et al. 2006). There were no apparent patterns of increasing or decreasing abundance in
relation to depth or latitudinal variation in the current survey.
The 50 most abundant taxa found in shelf waters throughout the region are listed in Table 3.4.4.
The 10 most abundant taxa on this list include the polychaetes Spiophanes bombyx,
Protodorvillea kefersteini, Mediomastus spp., Synelmis ewingi, and Exogone lourei; the
amphipods Ampelisca abdita and Protohaustorius wigleyi; tubificid oligochaetes; the chordate
Branchiostoma spp.; and the Nemertea. Ampelisca abdita was the most abundant taxon overall,
although it was only found at one station located north of Cape Hatteras (station 37) in very high
numbers. The three taxa with the highest frequency of occurrence were the Nemertea, the
Tubificidae, and the polychaete S. bombyx. Four of the top-five dominant taxa (S.bombyx, P.
wigleyi; tubificid oligochaetes; and Branchiostoma spp.) found in the current survey were also
among the dominant taxa previously reported at GRNMS and nearby shelf waters (Hyland et al.
2006).
Estuaries
A total of 160,378 individual specimens were collected across 746 estuarine stations (1,039 0.04
m"2 grab samples). Densities ranged from 0 to 103,350 m"2 and averaged 3,525 m"2 (Figure 3.4.3,
Table 3.4.3). Eleven stations, accounting for 1.9% of estuarine area, were devoid of benthic
fauna. Spatially, 90% of the estuarine area had densities > 180, and 50% of the estuarine area
had densities > 1610 m"2 (Table 3.4.3). The overall mean density reported here for SAB
estuaries during 2000-2004 is in good agreement with previously reported mean densities for the
same region — 4,125 m"2 in 1994 and 3,100 m"2 in 1995 (Hyland et al. 1996; Hyland et al. 1998).
The fifty most abundant taxa found in SAB estuaries are listed in Table 3.4.5. The ten most
abundant taxa on the list include several polychaetes: Streblospio benedicti, Mediomastus spp.,
Lumbrineris tennis, Caulleriella spp., Tharyx acutus, and Exogone spp. Two oligochaete taxa,
Tubificidae and Tubificoides wasselli, and two amphipod taxa, Ampelisca abdita and Ampelisca
vadorum, are also among the top ten dominants. The most abundant taxon overall, S. benedicti,
also had the highest frequency of occurrence (52%). Two of the current dominant taxa, S.
benedicti and Mediomastus spp., were also among the top five dominant taxa during previous
surveys of benthic fauna from southeastern estuaries (Hyland et al. 1996, 1998).
59
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SAB Region-Wide
Mean densities were similar between the coastal-ocean and estuarine environments, i.e. 3,118m"
2 and 3,525 m"2 respectively (Table 3.4.3). Inner-quartile ranges (middle 25th to 75th percentile of
observed values) were similar as well, i.e. 1400 m"2 to 3725 m"2 and 650 m"2to 4250 m"2 for
offshore and estuarine waters respectively. However, the overall range of densities among
stations was much larger for estuaries (0 to 103,350 m"2) than for the offshore waters (275 to
23,650 m"2). The low end of the density range for estuaries included azoic conditions at 11 of the
stations.
There was little overlap of dominant benthic taxa between the estuarine and coastal-ocean
environments. Specifically, only five taxa were common to both the offshore and estuarine lists
of fifty most abundant taxa. These taxa were the amphipod Ampelisca abdita, the polychaete
Mediomastus spp., Actiniaria, Nemertea, and Tubificidae. As noted earlier, although^, abdita is
the dominant taxon in the coastal-ocean environment, it was only collected at one station where
it was found in very high numbers. No taxa identified to the species level, other than A. abdita,
were among the fifty most abundant taxa in both the estuarine and coastal-ocean environments.
60
-------
100
CD
E
3
O
50
0 20 40 60 80 100 120
# Species/Grab
100
50
0 5000 10000 15000 20000 25000
Density (#/m2)
100 -i
CD
0
E
3
O
50 H
C.
2 4
H'/grab
Figure 3.4.2. Percent area (solid lines) and 95% Confidence Intervals (dotted lines) of
SAB coastal ocean benthic infaunal species richness (A), density (B), and H' diversity
(C).
61
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Table 3.4.3. Mean, range, and selected distributional properties of key benthic variables for (A) coastal ocean and (B) estuarine
sediments.
A. Coastal Ocean
Overall
# Taxa per
grab
Density
(#/m2)
H'per
grab
Mean
38
3118
4.17
Overall Range
10-114
275 - 23650
1.98-6.13
Areal-Based Percentiles1 :
CDF 10th %
15
635
2.88
CDF 50th %
34
2350
4.07
CDF 90th %
64
5150
5.43
10m
16
650
2.92
Frequency-Based
25m
23
1400
3.50
50m
34
2362
4.12
Percentiles2
75m
48
3725
4.84
90m
67
5425
5.50
B. Estuaries
Overall
# Taxa per
grab
Density
(#/m2)
H'per
grab
Mean
16
3525
2.60
Overall Range
0-83
0 - 103350
0-5.32
Areal-Based Percentiles1
CDF 10m %
4
180
1.17
CDF 50m %
11
1610
2.60
CDF 90m %
32
6638
3.86
Frequency-Based
10m
4
225
1.09
25m
6
650
1.91
50m
12
1825
2.65
Percentiles2
75m
23
4250
3.44
90m
37
8400
3.99
Value of response variable corresponding to the designated cumulative % area point along the y-axis of the CDF graph.
2 Corresponding lower 10th percentile, lower quartile, median, upper quartile, and upper 10th percentile of all values for each of the 3
benthic variables.
62
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Table 3.4.4. Fifty most abundant benthic taxa in the SAB coastal ocean survey. Mean density
per m2 and % frequency of occurrence based on 50 grabs. Classification: Native=native species,
Indeter=Indeterminate.
Taxa Name
Ampelisca abdita
Tubificidae
Branchiostoma spp.
Spiophanes bombyx
Protohaustorius wigleyi
Nemertea
Protodorvillea kefersteini
Mediomastus spp.
Synelmis ewingi
Exogone lourei
Solen viridis
Prionospio spp.
Cnidaria
Pisione remota
Goniadides carolinae
Chone spp.
Glyceridae
Lumbrineris verrilli
Metharpinia floridana
Apseudes sp. A
Caecum johnsoni
Maldanidae
Polygordius spp.
Ophiuroidea
Unciola irrorata
Caecum pulchellum
Bathyporeia par her i
Apseudes olympiae
Lumbrinerides dayi
Bhawania goodei
Nephtyidae
Dentatisyllis carolinae
Branchiomma nigromaculata
Spionidae Genus F
Armandia maculata
Bhawania heteroseta
Cirrophorus lyra
Euchone spp.
Spionidae
Taxon
Amphipod
Oligochaete
Chordate
Polychaete
Amphipod
Nemertean
Polychaete
Polychaete
Polychaete
Polychaete
Bivalve
Polychaete
Cnidarian
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Amphipod
Tanaid
Gastropod
Polychaete
Polychaete
Ophiuroid
Amphipod
Gastropod
Amphipod
Tanaid
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Spionid
Polychaete
Polychaete
Polychaete
Polychaete
Spionid
Classification
Native
Indeter
Indeter
Native
Native
Indeter
Native
Indeter
Native
Native
Native
Indeter
Indeter
Native
Native
Indeter
Indeter
Native
Native
Native
Native
Indeter
Indeter
Indeter
Native
Native
Native
Native
Native
Native
Indeter
Native
Native
Indeter
Native
Native
Native
Indeter
Indeter
Mean
Density
356.5
123.5
103.5
102
79.5
57
54
51.5
51
42.5
38
37.5
36.5
36.5
35.5
31
31
30.5
30.5
30
29.5
29
28.5
27.5
26
25
24.5
23
22
21.5
21.5
20.5
19.5
19
17.5
17.5
17.5
17.5
17.5
% Frequency of
Occurrence
2
62
48
62
18
66
44
18
26
20
20
42
10
30
30
28
42
6
32
10
20
26
32
32
20
12
16
26
14
32
46
30
4
14
26
10
24
16
36
63
-------
Taxa Name
Goniadella sp. A
Terebellidae
Cirratulidae
Actiniaria
Notomastus latericeus
Oxyurostylis smithi
Phtisica marina
Laevicardium spp.
Scoloplos capensis
Sphaerosyllis glandulata
Acanthohaustorius millsi
Taxon
Polychaete
Polychaete
Polychaete
Cnidarian
Polychaete
Cumacean
Amphipod
Bivalve
Polychaete
Polychaete
Amphipod
Classification
Native
Indeter
Indeter
Indeter
Native
Native
Native
Indeter
Native
Native
Native
Mean
Density
17
17
15.5
15
15
15
15
14.5
14.5
14.5
14
% Frequency of
Occurrence
14
20
34
16
10
12
16
14
8
18
20
64
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Table 3.4.5 Fifty most abundant benthic taxa in the SAB estuarine survey. Mean density per m
and % frequency of occurrence based on 1039 grabs. Classification: Native=native species,
Indeter=Indeterminate, Non-Ind =non-indigenous.
Taxa Name
Streblospio benedicti
Mediomastus spp.
Tubificidae
Lumbrineris tennis
Tubificoides wasselli
Ampelisca abdita
Caulleriella spp.
Ampelisca vadorum
Tharyx acutus
Exogone spp.
Sabellaria vulgaris
Parapionosyllis spp.
Scoloplos rubra
Polydora cornuta
Actiniaria
Tubificoides brownae
Paraprionospio pinnata
Mediomastus ambiseta
Nemertea
Cirratulidae
Aphelochaeta spp.
Ampelisca spp.
Mulinia lateralis
Heteromastus filiformis
Acteocina canaliculata
Tharyx spp.
Protohaustorius deichmannae
Neanthes succinea
Batea catharinensis
Aricidea wassi
Streptosyllis spp.
Spiochaetopterus costarum
oculatus
Mediomastus californiensis
Marenzelleria viridis
Polydora socialis
Poly cirrus spp.
Clymenella torquata
Cirrophorus spp.
Bivalvia
Taxon
Polychaete
Polychaete
Oligochaete
Polychaete
Oligochaete
Amphipod
Polychaete
Amphipod
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Actiniarian
Oligochaete
Polychaete
Polychaete
Nemertean
Polychaete
Polychaete
Amphipod
Bivalve
Polychaete
Gastropod
Polychaete
Amphipod
Polychaete
Amphipod
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Polychaete
Bivalve
Classification
Native
Indeter
Indeter
Native
Native
Native
Indeter
Native
Native
Indeter
Native
Indeter
Native
Native
Indeter
Native
Native
Native
Indeter
Indeter
Indeter
Indeter
Native
Native
Native
Indeter
Native
Native
Native
Native
Indeter
Native
Native
Native
Native
Indeter
Native
Indeter
Indeter
Mean % Frequency of
Density Occurrence
432.1
193.5
167.1
153.5
126.4
124.8
114.1
96.8
90.0
81.4
65.5
57.8
57.7
50.7
50.2
49.9
46.9
45.9
45.9
45.8
44.9
37.5
36.0
35.1
34.4
32.9
31.9
30.2
29.8
29.6
27.1
26.7
26.1
26.0
23.8
23.0
22.0
21.5
21.3
52
49
41
35
15
19
12
6
29
17
13
7
26
19
13
19
28
21
46
23
11
7
12
31
14
9
4
24
12
10
11
13
10
7
12
4
10
11
23
65
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Taxa Name
Taxon
Classification
Mean
Density
% Frequency of
Occurrence
Tellina agilis
Carinomella lactea
Thy one pawsoni
Unciola serrata
Leptocheirus plumulosus
Melita nitida
Cyathura burbancki
Veneroida
Rangia cuneata
Paracaprella tennis
Ampelisca verrilli
Bivalve
Nemertean
Holothuroid
Amphipod
Amphipod
Amphipod
Isopod
Bivalve
Bivalve
Amphipod
Amphipod
Native
Native
Native
Native
Native
Native
Native
Indeter
Non-Ind
Native
Native
21.1
20.4
19.9
18.2
17.6
17.2
17.0
15.3
15.0
14.8
14.7
13
17
0
4
O
10
9
8
6
10
66
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100
CD
0
I
d
50
20 40 60 80
# Species/Grab
100
100 -i
CO
CD
E
d
50
5000 10000 15000
Density (#/m2)
105000
100 -i
CO
0
E
3
O
50 H
c.
2 4
H'/grab
Figure 3.4.3. Percent area (solid lines) and 95% Confidence Intervals (dotted
lines) of SAB estuarine benthic infaunal species richness (A), density (B), and H'
diversity (C).
67
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3.4.3 Diversity
Coastal Ocean
r\
Species richness, expressed as the number of taxa present in a 0.04 m grab, was relatively high
in the coastal-ocean assemblages. A total of 462 taxa were identified region-wide from the 50
benthic grabs. Species richness ranged from 10 to 114 taxa/grab and averaged 38 taxa grab"1
(Table 3.4.3, Figure 3.4.2, Appendix E). Approximately 50% of the offshore survey area had >
34 taxa grab"1 and 10% of the area had > 64 taxa grab"1.
The high species richness, plus an even distribution of species abundance within stations,
resulted in high values of the diversity index H' (log base 2) for the coastal ocean portion of the
SAB. Diversity values ranged from 1.98 to 6.13 grab"1 and averaged 4.17 grab"1 (Table 3.4.3,
Figure 3.4.2, Appendix E). Approximately 50% of the offshore survey area had H' > 4.07 grab"1
and 10% of the area had H' > 5.43 grab"1.
Estuaries
Species richness values for estuarine waters, expressed as the number of taxa present in a 0.04
m2 grab, were consistent with previous reports of southeastern estuarine benthic assemblages
(Hyland et al. 1996, Hyland et al. 1998). A total of 948 taxa were identified region-wide from
the 1,039 benthic grabs. Species richness ranged from 0 to 83 taxa grab"1 and averaged 16 taxa
grab"1 (Table 3.4.3, Figure 3.4.3). Approximately 50% of the estuarine survey area had > 11 taxa
grab"1 and 10% of the area had > 32 taxa grab"1.
Values for the diversity index H' (log base 2) ranged from 0 to 5.32 grab"1 and averaged 2.60
grab"1 (Table 3.4.3, Figure 3.4.3). Approximately 50% of the estuarine survey area had H' > 2.60
grab"1 and 10% had H' > 3.86 grab"1. These values are very similar to results for estuaries
sampled in this same region in the mid-1990s (Hyland et al. 1996; Hyland et al. 1998).
SAB Region-Wide
Diversity of benthic macroinfauna, as measured by species richness and the diversity index H',
was higher in the offshore than in estuarine portions of the region. As an example, species
richness averaged 38 taxa grab"1 in offshore waters and was less than half that number (16 taxa
grab"1) in estuaries. Only three of the 50 offshore stations, representing about 10% of the
offshore survey area, had < 16 taxa grab"1 (the estuarine mean). A more detailed examination of
species richness, using quartile ranges, across the SAB shows a general pattern of decreasing
species richness with increasing latitude for the coastal ocean portion of the sampling area,
though no such pattern was apparent for the estuarine portion of the region (Figure 3.4.4). Also,
within the offshore environment, the highest species richness values tend to occur more in the
outer shelf areas. When species richness is examined with the offshore and estuarine data
combined, it is clear that the highest values occur primarily offshore while the lowest values
occur inshore (Figure 3.4.5).
68
-------
Species Richness
Coastal Ocean
E < 23 (lower 25th quartile)
H 23-34 (25-50th quartile)
35-48 (50-75th quartile)
> 48 (upper 25th quartile)
Estuaries
< 6 (lower 25th quartile)
6- 12 (25-50th quartile)
13-23 (50-75th quartile)
> 23 (upper 25th quartile)
0 1,000 2.000
Nautical Miles
Figure 3.4.4. Spatial distribution of benthic species richness in coastal ocean and
estuarine sediments.
69
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Species Richness
• < 7 (lower 25th quartile)
7- 13 (25-50th quartile)
14-25 (50-75th quartile)
• > 25 (upper 25th quartile)
0 1.000 2.000
Nautical Miles
Figure 3.4.5. Spatial distribution of benthic species richness in SAB sediments.
70
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3.4.4 Non-Indigenous Species
The region-wide scale of the current survey, from estuaries seaward to the continental shelf
break, provides a unique opportunity to examine the benthic macroinfauna data for the
occurrence of non-indigenous species throughout the SAB region. Overall, based on coastal-
ocean and estuarine data combined, there were a total of 1,168 taxa identified from 1,139 grabs.
Of those 1,168 taxa, 721 were identified to the species level. Of the 721, three species were
identified as non-indigenous based on a comparison with the USGS Non-indigenous Aquatic
Species database (nas.er.usgs.gov). These were Corbicula fluminea (Asian clam), Petrolisthes
armatus (green porcelain crab), and Rangia cuneata (Atlantic rangia). All three non-indigenous
species were collected from estuarine stations; none were from coastal-ocean waters. These
three non-indigenous species account for < 0.01% of the total species identified in the SAB
database. The SAB benthos appears to be less invaded than some other coastal regions such as
the Pacific Coast benthos, where non-indigenous species are common in estuaries and occur
offshore as well though in more limited numbers (e.g., 1.2% of the identified species in a survey
of the western U.S. continental shelf by Nelson et al. 2008).
3.5 Potential Linkage of Biological Condition to Stressor Impacts
Multi-metric benthic indices are an important tool for detecting signals of degraded sediment
quality and have been developed for a variety of estuarine applications (Engle et al. 1994,
Weisberg et al. 1997, Van Dolah et al. 1999, Llanso et al. 2002a, 2002b). An important feature
of a multi-metric benthic index is the ability to combine multiple benthic community attributes
(e.g., numbers of species, diversity, abundance, relative proportions of groups of species) into a
single measure that maximizes the ability to distinguish between degraded versus non-degraded
benthic condition while taking into account biological variability associated with natural
controlling factors (e.g. latitude, salinity, sediment particle size). Van Dolah et al. (1999)
developed a Benthic-Index of Biological Integrity (B-IBI) for southeastern estuaries, which
provides a sensitive tool for assessing adverse effects of degraded habitat quality on benthic
communities. Of the estuarine area represented in the present SAB study, 7% was rated poor (<
1.5), 9% was rated fair (1.5 - 3.0), and 84% was rated good (> 3.0) based on the B-IBI.
No such multi-metric benthic index exists for the coastal-ocean portion of the SAB. In the
absence of a benthic index, potential stressor impacts in offshore waters were assessed by
looking for obvious linkages between reduced values of key benthic characteristics (diversity,
richness, density) and synoptically measured indicators of poor sediment or water quality. To be
consistent with related offshore studies where multi-metric benthic indices have been lacking
(Nelson et al. 2008, Balthis et al. 2009), low values of benthic attributes were defined as the
lower 10th percentile of observed values and evidence of poor sediment or water quality was
defined as: > 1 chemical in excess of ERMs, TOC > 50 mg/g, or DO in near-bottom water < 2
mg/L. Because none of the offshore stations were rated as having poor sediment or water quality
based on these latter guidelines, there was little evidence to suggest linkages between impaired
benthic condition and measured stressors (Appendix E). One site, Station 41 on the outer shelf
off North Carolina, had low values of species richness and abundance that co-occurred with a
moderate level of sediment TOC (39.9 mg/g). This was the only site that came close to
71
-------
exceeding the above guidelines. The lack of such an association suggests that lower-end values
of biological attributes represent parts of a normal reference range controlled by natural factors.
Results of this study show that conditions throughout the SAB are predominantly fair to good
with respect to many of the measured ecological indicators (Figure 3.5.1). However, this
assessment also indicates that there are portions, particularly in estuaries compared to the
offshore environment, which are under some chemical or physical stress. It would be prudent to
use such information as an early warning signal and justification for implementing effective
coastal management practices in order to prevent potential growth of future environmental risks
from increasing human activities in the region. In addition, the SAB region provides many
important ecosystem goods and services across a variety of categories: supporting (e.g., nutrient
cycling, reservoirs of biodiversity, habitat for protected species and other natural populations),
provisional (e.g., mineral extraction, alternative energy, food, corridors for maritime trade),
regulating (e.g., pollutant sequestering, hurricane buffering), and cultural (e.g., swimmable and
fishable waters for recreation; protected areas for research, education, and nature conservation).
As coastal development continues throughout the southeastern region, the component estuarine
and coastal-ocean environments should be treated as a connected ecosystem if we are to better
understand and manage these important resources and the functions they provide.
72
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A. Tissue -
Benthic Condition -
Total Organic Carbon -
Sediment Toxicity -
Sediment Contaminants -
Sediment Quality Index -
Bottom Dissolved Oxygen -
Dissolved Inorganic Phosphorus -
Dissolved Inorganic Nitrogen -
Chlorophyll a -
Water Quality Index -
(
B. Tissue -
Benthic Index -
Total Organic Carbon -
Sediment Toxicity -
Sediment Contaminants -
Bottom Dissolved Oxygen -
Dissolved Inorganic Nitrogen -
Chlorophyll a -
Water Quality Index -
(
I
Not Measured
Not Calculated
Measured but
guidelines not
available.
Not Calculated
^H Ponrl 1 Fair 1 1 Good
) 20
40 60
™ r
™ i
^™
80 100
i
^^
• i
•
I
i
^™
•
i
i
) 20
40 60
Percent Area
80 100
Figure 3.5.1. Summarized assessment of multiple indicators of ecosystem health for SAB
coastal ocean region (A = Coastal Ocean, B = Estuarine). Refer to Table 2.7.1 for indicator
threshold values. Note: There is no benthic index for offshore waters, thus the evaluation of
benthic condition in this case was based on whether there were any co-occurrences of reduced
values of key benthic attributes (i.e. diversity, richness, or density within lower 10th percentile
of all observed values) and evidence of poor sediment or water quality (> 1 chemical in
excess of ERMs, TOC > 50 mg/g, and DO in near-bottom water < 2 mg/L); there were no
such co-occurrences.
73
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4.0 Acknowledgments
The coastal-ocean portion of this study was made possible through the coordination of resources
and staff under a General Collaborative Agreement (MOA 2005-003/6764) between the NOAA
National Ocean Service's (NOS) National Centers for Coastal Ocean Science (NCCOS) and the
EPA Office of Research and Development (ORD)/National Health and Environmental Effects
Research Laboratory (NHEERL). Funding was provided primarily by the NOAA/NCCOS
Center for Coastal Environmental Health and Biomolecular Research (CCEHBR) to support
field work and by EPA/NHEERL-Gulf Ecology Division for the processing of samples. Field
work was conducted on the NOAA Ship Nancy Foster Cruise NF-04-08-CL by scientists from
NOAA/NCCOS, EPA/NHEERL-Gulf Ecology Division, and Florida Fish and Wildlife Research
Institute. Several institutions participated in the processing of samples. These included Barry
Vittor and Associates (Mobile, AL) for the analysis of benthic samples; GPL Laboratories
(Frederick, MD) for chemical contaminants in sediments; CRG Laboratories for chemical
contaminants in tissues, and B&B Laboratories (College Station, TX) for nutrients and
chlorophyll in water samples, and sediment grain size and TOC.
The estuarine portion of this study involved the participation of numerous representatives from a
variety of federal and state agencies including EPA, NOAA, Florida, Georgia, South Carolina
and North Carolina. Additional contributions were made by the following organizations:
• Arthur D. Little, Inc. (Boston, MA) - Sediment and Tissue Contaminants
• Barry A. Vittor & Associates, Inc (Mobile, AL) - Benthic Taxonomy
• CRG Environmental Laboratories Inc (Torrance, CA) - Sediment and Tissue
Contaminants
• Environmental Research Institute (Storrs, CT) - Sediment and Tissue Contaminants,
Nutrients, Total Suspended Solids, Sediment Grain Size, and Sediment Total Organic
Carbon
• GPL Laboratories (Frederick, MD) - Sediment and Tissue Contaminants
• TAI Scientist - Division of Strand and Associates, Inc (Mobile, AL) -Benthic Taxonomy
• TDI-Brooks Laboratories (College Station, TX) - Nutrients, Total Suspended Solids,
Sediment Grain Size, and Sediment Total Organic Carbon
• TRAC Laboratories (Pensacola, FL) - Amphipod Sediment Toxicity Assay
Technical reviews of this report were provided by Len Balthis with NOAA and Richard
Devereux and John Kiddon with EPA.
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Appendix A. Locations (latitude, longitude), depths, sampling frame areas, and sediment
characteristics of SAB coastal ocean sampling stations.
Station
SE04001
SE04002
SE04003
SE04004
SE04005
SE04006
SE04007
SE04008
SE04009
SE04010
SE04011
SE04012
SE04013
SE04014
SE04015
SE04016
SE04017
SE04018
SE04019
SE04020
SE04021
SE04022
SE04023
SE04024
SE04025
SE04026
SE04027
SE04028
SE04029
SE04030
SE04031
SE04032
SE04033
SE04034
SE04035
SE04036
SE04037
SE04038
SE04039
SE04040
SE04041
SE04042
SE04043
SE04044
SE04045
SE04046
SE04047
SE04048
SE04050
SE04A1 1
Latitude
(DD)
31.36625
32.27212
33.06317
27.95232
31.63705
30.23263
31.57760
27.54257
33.52407
31.00938
32.19853
31.50058
33.87035
31.92925
32.12618
34.49895
29.04322
36.01737
29.82830
30.19302
33.95535
29.65300
33.22947
34.09792
33.78810
30.79113
34.36198
34.34528
28.27788
32.87658
30.79103
32.74693
31.77548
33.17650
35.85053
33.23763
35.98105
32.44360
34.98853
35.43008
33.58008
32.49767
33.78847
32.71425
29.48200
32.31815
31.10745
35.27827
33.48602
27.99100
Longitude Depth Sampling Frame
(DD) (m) Area (km2)
-80.87812
-79.34330
-78.99763
-80.07897
-80.57387
-81.14682
-79.71103
-80.17257
-78.34247
-80.64163
-80.29453
-80.38985
-77.51060
-79.86140
-79.52537
-76.43633
-80.83685
-75.26730
-80.78468
-80.25955
-76.53930
-80.36010
-77.44340
-77.39780
-78.08550
-80.90655
-77.09250
-77.47862
-80.49652
-78.61013
-81.19778
-79.35072
-80.14060
-78.23268
-75.42660
-77.34313
-74.89810
-79.79097
-75.56278
-74.95900
-77.06697
-78.81927
-78.33452
-78.86517
-80.37595
-79.73765
-81.27568
-75.29312
-77.92563
-80.28477
20
41
14
40
20
21
60
18
23
25
16
29
28
35
41
13
21
33
27
53
42
43
45
26
15
25
23
16
16
43
15
19
30
33
24
47
83
16
37
41
40
50
16
33
40
25
10
23
28
22
57.26
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
110883.70
TOC
(mg/g)
0.78
0.50
0.30
2.65
0.13
0.09
0.39
29.56
0.37
0.01
0.30
0.20
0.20
0.05
0.09
0.17
3.00
0.01
0.49
1.86
0.88
2.98
0.54
0.80
3.98
0.27
0.76
0.58
3.31
1.08
0.20
0.28
0.24
1.32
0.30
0.34
4.74
0.32
0.18
1.10
39.94
16.40
2.16
1.07
26.48
0.34
0.37
0.04
0.75
17.28
% Coarse
(sand/gravel)
98.75
99.06
99.51
93.46
99.10
99.29
98.38
98.74
98.90
99.43
99.16
98.91
99.13
99.20
99.07
99.24
92.33
99.17
99.17
99.16
99.24
98.91
98.97
99.56
90.97
99.23
98.72
99.16
88.53
97.77
99.16
99.27
98.93
99.05
98.73
99.27
99.09
99.28
92.04
98.14
99.01
96.24
94.28
98.79
98.56
99.09
98.91
98.71
98.53
98.48
% silt-
clay
1.25
0.94
0.49
6.54
0.90
0.71
1.62
1.26
1.10
0.57
0.84
1.09
0.87
0.80
0.93
0.76
7.67
0.83
0.83
0.84
0.76
1.09
1.03
0.44
9.03
0.77
1.28
0.84
11.47
2.23
0.84
0.73
1.07
0.95
1.27
0.73
0.91
0.72
7.96
1.86
0.99
3.76
5.72
1.21
1.44
0.91
1.09
1.29
1.47
1.52
81
-------
Appendix B. Near-bottom water characteristics by SAB coastal ocean station.
Station
SE04001
SE04002
SE04003
SE04004
SE04005
SE04006
SE04007
SE04008
SE04009
SE04010
SE04011
SE04012
SE04013
SE04014
SE04015
SE04016
SE04017
SE04018
SE04019
SE04020
SE04021
SE04022
SE04023
SE04024
SE04025
SE04026
SE04027
SE04028
SE04029
SE04030
SE04031
SE04032
SE04033
SE04034
SE04035
Temp. Salinity DO
(°C) (psu) (mg/L)
16.9
18.6
13.9
20.2
16.6
18.2
18.5
23.7
14.3
19.5
15.7
16.9
16.2
18.2
19.3
13.4
19.8
7.2
20.0
20.8
22.8
21.0
20.7
15.4
13.9
18.7
14.6
13.2
21.4
19.4
17.6
17.2
17.4
19.0
7.4
34.4
36.4
34.7
36.4
35.1
35.2
36.0
36.4
35.9
36.0
35.5
35.2
36.4
36.3
36.4
33.4
35.8
33.6
36.2
36.4
36.3
36.3
36.4
36.1
35.0
35.4
35.4
34.7
36.5
36.5
34.8
36.1
36.2
36.5
33.0
7.9
7.5
8.3
7.3
7.9
7.6
7.5
6.9
8.2
7.4
8.0
7.8
7.9
7.6
7.4
8.5
7.4
9.7
7.3
7.2
7.0
7.2
7.2
8.0
8.3
7.5
8.2
8.4
7.1
7.4
7.7
7.7
7.7
7.5
9.7
PH
8.5
8.4
8.2
8.4
8.5
8.5
8.4
8.5
8.3
8.5
8.4
8.5
8.3
8.4
8.4
8.3
8.4
8.2
8.5
8.4
8.4
8.5
8.4
8.3
8.2
8.5
8.3
8.2
8.5
8.4
8.5
8.3
8.6
8.4
8.2
DIN
(mg/L)
0.013
0.032
0.012
0.226
0.032
0.033
0.046
0.043
0.022
0.04
0.025
0.022
0.012
0.032
0.034
0.012
0.034
0.032
0.032
0.162
0.034
0.099
0.035
0.021
0.033
0.022
0.021
0.02
0.029
0.024
0.032
0.02
0.035
0.032
0.033
Nitrite Nitrate Ammonia DIP
(mg/L) (mg/L) (mg/L) (mg/L)
0.003
0.012
0.002
0.016
0.002
0.003
0.006
0.013
0.002
0.02
0.005
0.002
0.002
0.002
0.004
0.002
0.004
0.002
0.002
0.012
0.004
0.019
0.005
0.001
0.003
0.002
0.001
0
0.009
0.004
0.002
0
0.005
0.002
0.003
0.01
0.01
0.01
0.2
0.02
0.02
0.03
0.02
0.02
0.01
0.02
0.02
0.01
0.02
0.02
0.01
0.02
0.01
0.02
0.14
0.02
0.07
0.03
0.02
0.02
0.02
0.01
0.02
0.01
0.02
0.02
0.02
0.02
0.02
0.02
0
0.01
0
0.01
0.01
0.01
0.01
0.01
0
0.01
0
0
0
0.01
0.01
0
0.01
0.02
0.01
0.01
0.01
0.01
0
0
0.01
0
0.01
0
0.01
0
0.01
0
0.01
0.01
0.01
0.02
0.02
0.02
0.05
0.02
0.02
0.03
0.02
0.01
0.02
0.02
0.02
0.03
0.02
0.02
0.02
0.03
0.04
0.02
0.04
0.02
0.03
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.03
Silicate Chlorophyll TSS
N/P (mg/L) a (|jg/L) (mg/L)
2.5
3.2
2.8
8.5
3.9
5.6
5.0
4.9
3.4
4.2
3.3
2.1
1.1
3.2
3.0
2.5
2.9
3.1
4.0
7.2
4.4
5.4
3.5
3.4
6.2
2.9
3.4
3.8
3.2
3.2
3.9
2.9
4.1
3.1
1.6
0.28
0.39
0.5
0.88
0.66
0.53
0.91
1.12
1.23
0.23
0.85
0.26
0.27
0.36
0.56
0.58
0.55
0.35
0.32
0.91
0.54
0.73
0.48
0.27
0.51
0.14
0.3
0.13
1.05
0.46
0.34
0.2
0.27
0.43
0.43
0.37
0.30
0.49
0.35
0.20
0.64
0.22
0.15
0.59
0.24
0.23
0.31
0.50
0.28
0.27
1.81
1.37
0.57
0.36
0.77
0.37
0.67
0.45
0.30
2.41
0.31
0.84
0.33
1.09
0.44
0.63
0.31
0.38
0.35
1.26
4.90
2.20
3.47
1.54
1.77
2.87
1.89
0.86
5.60
1.81
1.87
2.03
5.31
2.58
1.51
7.37
4.46
1.85
1.89
0.93
1.85
2.10
2.40
1.50
7.50
1.20
4.90
2.30
4.30
1.73
6.83
4.00
1.23
3.29
25.00
82
-------
Station
SE04036
SE04037
SE04038
SE04039
SE04040
SE04041
SE04042
SE04043
SE04044
SE04045
SE04046
SE04047
SE04048
SE04050
SE04A1 1
Temp. Salinity DO
(°C) (psu) (mg/L)
20.5
6.4
16.7
18.6
7.7
21.6
20.0
13.5
19.3
21.3
17.6
17.6
7.8
14.0
22.6
36.4
33.7
36.2
35.4
33.7
36.4
36.4
35.2
36.5
36.4
36.3
33.3
32.9
35.9
36.4
7.3
9.9
7.8
7.6
9.6
7.1
7.3
8.4
7.4
7.1
7.7
7.8
9.6
8.2
7.0
PH
8.3
8.2
8.4
8.3
8.3
8.3
8.4
8.2
8.4
8.5
8.4
8.4
8.2
8.3
8.5
DIN
(mg/L)
0.099
0.269
0.032
0.034
0.05
0.051
0.036
0.03
0.031
0.061
0.03
0.028
0.041
0.03
0.033
Nitrite Nitrate Ammonia DIP
(mg/L) (mg/L) (mg/L) (mg/L)
0.009
0.009
0.002
0.004
0.03
0.021
0.016
0.01
0.001
0.021
0
0.008
0.001
0
0.003
0.08
0.25
0.02
0.02
0
0.02
0.01
0.01
0.02
0.03
0.02
0.01
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.02
0.01
0.01
0.03
0.08
0.02
0.02
0.04
0.02
0.02
0.01
0.02
0.02
0.01
0.03
0.03
0.03
0.02
Silicate Chlorophyll TSS
N/P (mg/L) a (Mg/L) (mg/L)
6.1
6.0
4.0
3.8
3.8
4.8
5.0
5.7
5.2
6.1
5.4
3.3
3.9
2.9
3.2
0.52
0.48
0.45
0.46
0.24
0.21
0.25
0.15
0.23
0.33
0.18
0.55
0.51
0.31
1.17
0.24
0.40
0.19
0.64
0.85
0.39
0.48
0.98
0.28
1.06
0.25
1.68
2.83
0.76
2.39
1.43
1.90
0.27
2.80
1.20
1.60
1.43
3.07
3.18
2.36
1.91
4.00
6.20
3.90
2.90
83
-------
Appendix C. Near-surface water characteristics by SAB coastal ocean station.
Station
SE04001
SE04002
SE04003
SE04004
SE04005
SE04006
SE04007
SE04008
SE04009
SE04010
SE04011
SE04012
SE04013
SE04014
SE04015
SE04016
SE04017
SE04018
SE04019
SE04020
SE04021
SE04022
SE04023
SE04024
SE04025
SE04026
SE04027
SE04028
SE04029
SE04030
SE04031
SE04032
SE04033
SE04034
SE04035
Temp. Salinity DO
(°C) (psu) (mg/L)
18.3
19.0
14.0
23.3
17.3
19.5
24.3
23.7
14.4
19.3
15.9
17.3
18.6
18.4
19.5
13.4
20.0
7.7
20.7
22.7
23.6
23.7
20.8
16.0
14.0
19.0
14.9
13.6
21.6
19.4
18.8
17.2
18.6
19.4
8.5
33.7
36.3
34.6
36.4
35.3
34.8
36.3
36.3
35.8
35.8
35.5
35.1
36.3
36.5
36.4
33.3
35.8
33.3
36.0
36.3
35.8
36.3
35.8
36.3
33.6
35.2
35.5
34.5
36.5
36.4
34.2
36.1
36.2
36.4
31.4
7.7
7.5
8.3
6.9
7.8
7.5
6.8
6.9
8.2
7.4
8.0
7.8
7.5
7.5
7.4
8.5
7.4
9.6
7.2
7.0
6.9
6.9
7.2
7.9
8.4
7.5
8.1
8.4
7.1
7.4
7.6
7.7
7.5
7.4
9.6
PH
8.5
8.4
6.7
8.5
8.6
8.5
8.4
8.2
7.4
8.5
8.4
8.5
8.2
8.4
8.4
7.2
8.4
8.0
8.4
8.4
8.3
8.5
8.0
8.2
7.8
8.5
8.3
8.2
8.4
8.3
8.5
7.3
8.6
8.3
8.2
DIN
(mg/L)
0.027
0.031
0.033
0.033
0.032
0.033
0.039
0.039
0.052
0.037
0.036
0.012
0.023
0.026
0.038
0.033
0.033
0.036
0.034
0.044
0.033
0.023
0.044
0.022
0.032
0.031
0.032
0.032
0.033
0.023
0.024
0.032
0.04
0.046
0.047
Nitrite Nitrate Ammonia DIP
(mg/L) (mg/L) (mg/L) (mg/L)
0.007
0.011
0.003
0.013
0.002
0.003
0.009
0.019
0.002
0.007
0.006
0.002
0.003
0.006
0.008
0.003
0.003
0.006
0.004
0.004
0.003
0.003
0.004
0.002
0.002
0.001
0.002
0.002
0.003
0.003
0.004
0.002
0.01
0.006
0.007
0.02
0.01
0.02
0.01
0.02
0.02
0.02
0.01
0.03
0.02
0.02
0.01
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0.02
0.03
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.02
0.01
0.01
0
0
0
0.01
0.01
0.01
0.01
0.01
0.01
0
0
0.01
0
0.01
0.01
0.01
0.01
0.01
0
0
0.01
0.01
0.01
0.01
0.02
0.04
0.02
0.02
0.02
0.02
0.03
0.02
0.02
0.02
0.03
0.01
0.03
0.03
0.04
0.03
0.02
0.04
0.02
0.03
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.1
0.02
0.02
0.02
0.02
0.03
Silicate Chlorophyll TSS
N/P (mg/L) a (|jg/L) (mg/L)
3.0
1.7
5.2
4.3
4.4
3.9
4.0
4.9
9.0
3.7
3.5
2.9
2.2
2.8
1.9
2.4
3.1
2.1
4.8
3.8
3.1
2.6
3.6
2.1
4.3
5.1
4.2
2.9
4.3
0.6
3.8
4.0
4.9
4.8
3.9
0.78
0.37
0.42
0.59
0.89
1.23
0.68
0.99
1.12
0.41
1
0.76
0.5
0.53
0.64
0.49
1.06
0.32
0.84
0.36
0.48
0.6
0.71
0.94
0.32
0.17
0.28
0.62
0.73
0.79
0.52
0.33
0.26
0.71
0.64
0.20
0.22
0.28
0.23
0.14
0.39
0.09
0.14
0.22
0.17
0.26
0.25
0.15
0.16
0.26
1.58
1.07
0.41
0.23
0.25
0.19
0.17
0.48
0.19
1.44
0.17
0.20
0.14
0.60
0.24
0.41
0.30
0.23
0.26
1.36
3.00
1.35
3.93
2.50
2.14
3.20
2.13
1.25
3.53
2.12
3.16
3.61
1.75
2.17
4.35
4.78
5.04
2.35
1.38
1.40
1.50
4.14
4.08
3.75
9.20
1.42
3.15
1.43
6.20
3.10
2.95
15.93
2.54
1.77
6.46
84
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Station
SE04036
SE04037
SE04038
SE04039
SE04040
SE04041
SE04042
SE04043
SE04044
SE04045
SE04046
SE04047
SE04048
SE04050
SE04A1 1
Temp. Salinity DO
(°C) (psu) (mg/L)
21.5
6.7
16.6
18.6
8.0
22.0
20.4
13.6
19.3
21.7
17.5
18.1
8.7
14.1
23.3
35.7
33.7
36.1
35.3
32.8
36.1
36.4
34.9
36.4
36.6
36.3
33.2
31.2
35.5
36.4
7.2
9.8
7.8
7.6
9.6
7.1
7.3
8.4
7.4
7.1
7.7
7.7
9.5
8.3
6.9
PH
8.1
8.1
8.4
8.2
7.5
8.4
8.3
7.8
8.4
8.2
8.4
8.4
5.8
7.7
8.5
DIN
(mg/L)
0.045
0.232
0.063
0.036
0.036
0.043
0.026
0.022
0.03
0.032
0.011
0.038
0.041
0.031
0.04
Nitrite Nitrate Ammonia DIP
(mg/L) (mg/L) (mg/L) (mg/L)
0.005
0.012
0.003
0.006
0.006
0.023
0.016
0.012
0
0.002
0.001
0.008
0.001
0.001
0.01
0.03
0.21
0.04
0.02
0.02
0.01
0
0
0.02
0.02
0.01
0.02
0.03
0.02
0.02
0.01
0.01
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0
0.01
0.01
0.01
0.01
0.02
0.07
0.03
0.02
0.03
0.02
0.06
0.02
0.11
0.02
0.02
0.02
0.02
0.02
0.02
Silicate Chlorophyll TSS
N/P (mg/L) a (Mg/L) (mg/L)
3.9
5.4
5.6
4.6
2.5
4.8
1.4
3.3
0.5
3.0
2.6
3.8
5.1
5.5
5.4
0.64
0.42
0.39
0.45
0.21
0.24
0.19
0.33
0.44
0.41
0.43
0.58
0.38
0.53
1.37
0.29
0.65
0.17
0.53
0.62
0.36
0.55
0.50
0.32
0.21
0.23
1.36
2.02
0.36
0.76
5.68
3.95
4.83
2.80
4.35
4.35
1.77
3.80
5.17
2.55
0.97
3.85
7.00
6.95
1.40
85
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Appendix D. Summary by station of mean ERM quotients and the number of contaminants that
exceeded corresponding ERL or ERM values (from Long et al. 1995) for coastal ocean stations.
# of ERLs # of ERMs Mean
Station Exceeded Exceeded ERM-Q
SE04001
SE04002
SE04003
SE04004
SE04005
SE04006
SE04007
SE04008
SE04009
SE04010
SE04011
SE04012
SE04013
SE04014
SE04015
SE04016
SE04017
SE04018
SE04019
SE04020
SE04021
SE04022
SE04023
SE04024
SE04025
SE04026
SE04027
SE04028
SE04029
SE04030
SE04031
SE04032
SE04033
SE04034
SE04035
SE04036
SE04037
SE04038
SE04039
SE04040
SE04041
SE04042
SE04043
SE04044
SE04045
SE04046
SE04047
SE04048
SE04050
SE04A1 1
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
1
0
0
0
0
0
0
1
1
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.006
0.006
0.004
0.007
0.004
0.003
0.005
0.007
0.004
0.003
0.004
0.004
0.008
0.003
0.004
0.013
0.007
0.004
0.003
0.006
0.008
0.006
0.028
0.012
0.012
0.007
0.007
0.008
0.012
0.011
0.003
0.007
0.005
0.006
0.006
0.008
0.019
0.005
0.008
0.010
0.014
0.008
0.010
0.007
0.006
0.004
0.007
0.019
0.012
0.015
86
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Appendix E. Summary by station of benthic macroinfaunal (> 0.5 mm) characteristics for
coastal-ocean stations. One replicate benthic grab (0.04 m ) processed from each station. H'
derived using base 2 logs. * Values within lower 25th percentile of all values of a specific
benthic variable; **values within lower 10th percentile. Also included are selected abiotic
variables for assessing potential benthic-stressor linkages. Table shows that no stations with at
least one benthic variable in lower 10 percentile coincided with indicators of poor sediment or
water quality: > 1 chemical in excess of ERMs, TOC > 50 mg/g, or DO in near-bottom water < 2
mg/L.
Station
SE04001
SE04002
SE04003
SE04004
SE04005
SE04006
SE04007
SE04008
SE04009
SE04010
SE04011
SE04012
SE04013
SE04014
SE04015
SE04016
SE04017
SE04018
SE04019
SE04020
SE04021
SE04022
SE04023
SE04024
SE04025
SE04026
SE04027
SE04028
SE04029
SE04030
SE04031
SE04032
SE04033
SE04034
SE04035
SE04036
SE04037
SE04038
SE04039
SE04040
SE04041
SE04042
SE04043
# Taxa per
Grab
35
64
32
41
19*
63
52
40
20*
39
18*
39
22*
73
38
10**
35
18*
32
37
59
20*
44
29
37
31
15**
26
25
114
27
43
24
91
19*
31
48
23
11**
17*
-1 4**
75
35
Density
(#/m2)
1700
3725
3100
5150
1475
5700
2575
3225
1150*
2850
625**
2325
650**
4925
1775
275**
3175
1425
1175*
2400
3800
1250*
1875
1325*
3450
3075
500**
2325
1150*
8400
1400*
4250
1625
7900
2525
1775
23650
2250
650**
1900
375**
4450
3000
H'per
Grab
4.56
5.26
4.07
3.80
2.88**
5.10
5.22
4.58
3.34*
4.69
4.00
4.60
4.39
5.57
4.84
3.28*
3.84
3.46*
4.79
3.88
4.86
3.29*
5.18
4.52
3.97
2.96*
3.72
3.70
4.47
6.13
4.39
3.29*
3.97
5.64
2.55**
4.21
1 .99**
3.50*
3.14*
2.59**
3.77
5.69
3.97
TOC
(mg/g)
0.78
0.50
0.30
2.65
0.13
0.09
0.39
29.56
0.37
0.01
0.30
0.20
0.20
0.05
0.09
0.17
3.00
0.01
0.49
1.86
0.88
2.98
0.54
0.80
3.98
0.27
0.76
0.58
3.31
1.08
0.20
0.28
0.24
1.32
0.30
0.34
4.74
0.32
0.18
1.10
39.94
16.40
2.16
DO
(mg/L)
7.9
7.5
8.3
7.3
7.9
7.6
7.5
6.9
8.2
7.4
8.0
7.8
7.9
7.6
7.4
8.5
7.4
9.7
7.3
7.2
7.0
7.2
7.2
8.0
8.3
7.5
8.2
8.4
7.1
7.4
7.7
7.7
7.7
7.5
9.7
7.3
9.9
7.8
7.6
9.6
7.1
7.3
8.4
#ERMs
exceeded
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
87
-------
Station
SE04044
SE04045
SE04046
SE04047
SE04048
SE04050
SE04A1 1
# Taxa per
Grab
70
52
27
34
12**
62
50
Density
(#/m2)
3850
2525
1150*
3150
1700
6450
4775
H'per
Grab
5.63
5.43
4.16
3.72
2.21**
5.07
4.65
TOC
(mg/g)
1.07
26.48
0.34
0.37
0.04
0.75
17.28
DO
(mg/L)
7.4
7.1
7.7
7.8
9.6
8.2
7.0
#ERMs
exceeded
0
0
0
0
0
0
0
88
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V
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