United States
Environmental Protection
Agency
Office of Reseiarch and
Development
Washington DC 20460
EPA/620/R-94KJ19
July 1994
&EPA ij Statistical Summary
EM AP-Estuaries
Virginian Province-
1992
Environmental Monitoring and
Assessment Program
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EPA/620/R-94/019
July 1994
Statistical Summary
EMAP-Estuaries
Virginian Province - 1992
by
Charles J. Strobel
Sandra J. Benyi
Science Applications International Corporation
Darryl J. Keith
U.S. Environmental Protection Agency
Environmental Research Laboratory
Narragansett, Rl 02882
Henry W. Buffum
Elise A. Petrocelli
ROW Sciences
Virginian Province Manager
Norman I. Rubinstein
EPA Project Officer
Brian Melzian
United States Environmental Protection Agency
Environmental Research Laboratory
27 Tarzwell Drive
Narragansett, Rl 02882
Printed on Recycled Paper
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ABSTRACT
Annual monitoring of indicators of the ecological condition of bays and estuaries within the Virginian
Province (Cape Cod, MA to Cape Henry, VA) was conducted by the U.S. EPA's Environmental Monitoring and
Assessment Program (EMAP) during July, August, and September, 1992. Data were collected at 126 stations
within the Province. Indicators monitored included water quality (temperature, salinity, water clarity, and dissolved
oxygen concentration), sediment contamination, sediment toxicity, benthic community structure, fish community
structure, and fish gross external pathology. Data are used to estimate the current status of the ecological condition
of Virginian Province estuarine resources, and provide a baseline for identifying future trends. Cumulative distribution
functions (CDFs) and bar charts are utilized to graphically display data. Estimates, with 95% confidence intervals,
are provided of the areal extent of degraded resources within the Province for those indicators where "degradation"
can be defined. Data are also presented by estuarine class: Large estuaries, small estuarine systems, and large
tidal rivers. Included, as an appendix, are sub-population estimates for Chesapeake Bay and Long Island Sound.
KEY WORDS: EMAP; Environmental Monitoring and Assessment Program; Environmental Monitoring;
Virginian Province; Indicators (biology); Estuaries; Estuarine pollution.
pagc ij Statistical Summary, EMAP-E Virginian Province - 1992
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DISCLAIMER
Mention of trade names, products, or.services does not convey, and should not be interpreted as conveying,
official EPA approval, endorsement, or recommendation.
This report represents data from a single year of field operations of the Environmental Monitoring and Assessment
Program (EMAP). Because the probability-based scientific design used by the EMAP necessitates multiple years
of sampling, there may be significant levels of uncertainty associated with some of these data. This uncertainty
will decrease as the full power of the approach is realized by the collection of data over several years. Similarly,
temporal changes and trends cannot be reported, as these require multiple years, of observation. Please note that
this report contains data from research studies in only one biogeographical region (Virginian Province) collected
in a short index period (July to September) during a single year (1992). Appropriate precautions should be exercised
when using this information for policy, regulatory or legislative purposes.
Statistical Summary, EMAP-E Virginian Province - 1992
Page iii
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PREFACE
Contractor support for the preparation of this document was supplied via contract number 68-C1 -0005 to Science
Applications International Corporation and contract number EBC682172 to ROW Sciences.
The appropriate citation for this report is:
Strobel, C.J., S.J. Benyi, D.J. Keith, H.W. Buffum, and E.A. Petrocelli. 1994. Statistical Summary: EMAP-Estuaries
Virginian Province -1992. U. S. Environmental Protection Agency, Office of Research and Development,
Environmental Research Laboratory, Narragansett, RI. EPA/620/R-94/019.
This report is ERL-N Contribution Number 1552.
Page iv
Statistical Summary, EMAP-E Virginian Province - 1992
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ACKNOWLEDGEMENTS
* described b tnis document is
assistance in the preparation of this document.
a, EPA (Cincinnati and Nan* gansett ) .Cove
»A
Sdelphia Academy of Science, and University of Maryland)
- -de island, Rutgers,
* addition to those iisted above, reviewers of *, ^ d,=t inched Richard Latimer, Norman Rubinstein,
Gerald Pesch, Brian Melzian, William Mmr and Judith Pederson.
effort. Despite seasickness, 16-hour days,
weather, the six field crews successfully completed, to ^
phase. Without their dedication to the P 'rogram '
short period of time.
^ The s(a(f
, the success oPf the Program; managing
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CONTENTS
ABSTRACT
ii
DISCLAIMER
Hi
PREFACE
iv
ACKNOWLEDGEMENTS
• v
CONTENTS
vi
FIGURES
via
TABLES
.' xii
ABBREVIATIONS
' xiii
EXECUTIVE SUMMARY
:.... i
I INTRODUCTION
1.1 Objectives of 1992 Virginian PravinceMonitoring Activities " *
1.2 Program Design 6
1.3 Data Limitations ;• • • • 7
1.4 Purpose and Organization of this Report 7
2 OVERVIEW OF FIELD ACTIVITIES
,- . . . 9
3 STATISTICAL SUMMARY OF INDICATOR RESULTS
3.1 Biotic Condition Indicators • • • • 15
3.1.1 Benthic Index 16
3. .2 Number of Benthic Species 16
3. .3 Benthic Infaunal Abundance : ' • • 18, '
3. .4 Number of Fish Species 18
3. .5 Total Finfish Abundance ' : • • • 20
3. .6 Fish Gross External Pathology 20
3.2 Abiotic Condition Indicators ... 22
3.2.1 Dissolved Oxygen 22
3.2.1.1 Bottom Dissolved Oxygen 22 |
3.2.1.2 Dissolved Oxygen Stratification . ' ' ' 24 J
3.2.2 Sediment Toxicity 24 1
3.2.3 Sediment Contaminants 29 f
3.2.3.1 Polycyclic Aromatic Hydrocarbons :" ' ' 29 1
3.2.3.2 Polychlorinated Biphenyls 30 |
3.2.3.3 Chlorinated Pesticides 33 1
3.2.3.4 Butyltins 33 f
3.2.3.5 Total Organic Carbon '.'.'.'.'.".'.'.'.' 37 !
3.2.3.6 Acid Volatile Sulfides 37 I
39 '
Statistical Summary, EMAP-E Virginian Province - 1992
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CONTENTS (continued)
3.2.3.7 Metals
3.2.4 Marine Debris
3.3 Habitat Indicators
3.3.1 Water Depth '.]
3.3.2 Temperature
3.3.3 Salinity
3.3.4 pH
3.3.5 Stratification
3.3.6 Suspended Solids
3.3.7 Light Extinction
3.3.8 Percent Silt-Clay Content
3.4 Integration of Estuarine Conditions
4 SUMMARY OF FINDINGS
4.1 Virginian Province Fact Summary
Findings of the 1992 Sample Year
4.2
LITERATURE CITED
APPENDIX A -
APPENDIX B -
39
42
42
42
42
47
47
54
58
58
58
60
SUB-POPULATION ESTIMATES FOR CHESAPEAKE BAY AND LONG ISLAND
LINEAR REGRESSIONS OF INDIVIDUAL METALS AGAINST ALUMINUM USED IN
THE DETERMINATION OF METALS ENRICHMENT OF SEDIMENTS OF THE
APPENDIX C - QUALITY ASSURANCE
Statistical Summary, EMAP-E Virginian Province - 1992
Page vii
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Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 2-1.
Figure 2-2.
Figure 2-3.
Figure 2-4.
Page viii
FIGURES
Percent area of the Virginian Province by estuarine class with a benthic index |
value below zero in iyy/
Cumulative distribution of fish abundance in numbers per standard trawl as a
percent of area in the Virginian Province, 1992
The percent of area in the large estuaries, small estuaries, and large tidal rivers
that had a low (< 2 mg/L), medium (2 to 5 mg/L), or high (>5 mg/L) oxygen
concentration in the bottom waters
Percent of area in the Virginian Province in 1992, by estuarine class, with low
amphipod survival (<80% of control) in sediment toxicity tesis
Cumulative distribution of combined PAHs in sediments as percent of area in
the Virginian Province, 1992
Percent area of the Virginian Province with enriched concentrations of ,
individual metals in sediments in 1992
The percent of area of the Virginian Province by estuarine class where
anthropogenic debris was collected in fish trawls, iyy/
Cumulative distribution of water depth as a percent of area in the Virginian
Province, 1992
The percent of area of estuarine classes classified as oligohaline (<5 ppt),
mesohaline (5 to 18 ppt), and polyhalme (>l» ppt)
The percent of the area by class that had a low (<1 ACT,), medium (1 to 2 AOt),
or high (>2 ACT,) degree of stratification
The percent of area by estuarine class where water clarity was poor, moderate,
or good
The percent of area in the large estuaries, small estuaries, and large tidal rivers
that had a low (<20), medium (20 to 80), or high (>80) percent silt-clay in the
sediments
Areas of responsibility of the EMAP-VP sampling teams
Team 1 Base Sampling Stations
Team 2 Base Sampling Stations
Team 3 Base Sampling Stations
Statistical Summary, EMAP-E Virginian Province -
2
2
3
3
3
4
4
4
5
5
5
5
10
11
12
13
1992
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FIGURES (continued)
Figure 3-1. Example cumulative distribution of instantaneous bottom dissolved oxygen
concentrations as a percent of area in the Virginian Province 15
Figure 3-2. Cumulative distribution of benthic index values as a percent of area in the
Virginian Province, 1992 17
Figure 3-3. Percent area of the Virginian Province by estuarine class with a benthic index
value below 0 in 1992 17
Figure 3-4. Cumulative distribution of the mean number of benthic species per grab as a
percent of area in the Virginian Province, 1992 18
Figure 3-5. Cumulative distribution of the number of benthic species by estuarine class: a)
Large estuaries, b) Small estuaries, c) Large tidal rivers 19
Figure 3-6. Cumulative distribution of the number of benthic organisms per m2 as a percent
of area in the Virginian Province, 1992 20
Figure 3-7. Cumulative distribution of the number of benthic organisms per in2 by class:
a) Large estuaries, b) Small estuaries, c) Large tidal rivers 21
Figure 3-8. Cumulative distribution of the number of fish species per standard trawl as a
percent of area in the Virginian Province, 1992 22
Figure 3-9. Cumulative distribution of the number of fish species per trawl by estuarine
class: a) Large estuaries, b) Small estuaries, c) Large tidal rivers 23
Figure 3-10. Cumulative distribution of fish abundance in numbers per standard trawl as a
percent of area in the Virginian Province, 1992 24
Figure 3-11. Cumulative distribution of fish abundance in numbers per standard trawl by
estuarine class: a) Large estuaries, b) Small estuaries, c) Large tidal rivers 25
Figure 3-12. Cumulative distribution of bottom dissolved oxygen concentration as a percent
of area in the Virginian Province, 1992 26
Figure 3-13. The percent of area by class that had a low (< 2 mg/L), medium (2 to 5 mg/L),
or high (>5 mg/L) oxygen concentration in the bottom waters 26
Figure 3-14. Cumulative distribution of bottom oxygen concentration by estuarine class: a)
Large estuaries, b) Small estuaries, c) Large tidal rivers . . 27
Figure 3-15. Cumulative distribution of the dissolved oxygen concentration difference
between surface and bottom waters as a percent of area in the Virginian
Province, 1992 28
Statistical Summary, EMAP-E Virginian Province - 1992
Page ix
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FIGURES (continued)
Figure 3-16. The percent of area by estuarine class that had a low (<1 mg/L), medium (1 to
5 mg/L), or high (>5 mg/L) difference in dissolved oxygen concentration
between the surface and bottom waters 28
Figure 3-17. Cumulative distribution of mean survival of amphipods in 10-day laboratory
toxicity tests (expressed as percent of control survival) 29
Figure 3-18. Percent of area in the Virginian Province in 1992, by estuarine class, with low
amphipod survival (<80% of control) in sediment toxicity tests 30
Figure 3-19. Cumulative distribution of combined PAHs in sediments as percent of area in
the Virginian Province, 1992: a) linear scale, b) log scale 32
Figure 3-20. Cumulative distribution of combined PCBs in sediments as percent of area in
the Virginian Province, 1992: a) linear scale, b) log scale 35
Figure 3-21. Cumulative distribution of p, p' -DDE in sediments as percent of area in the :
Virginian Province, 1992 37
Figure 3-22. Cumulative distribution of alpha-chlordane in sediments as percent of area in
the Virginian Province, 1992 • 38
Figure 3-23. Cumulative distribution of tributyltin in sediments as percent of area in the
Virginian Province, 1992 39
Figure 3-24. The cumulative distribution of the percent total organic carbon in sediments as
a percent of area in the Virginian Province, 1992 \ 40
Figure 3-25. Cumulative distribution of the percent total organic carbon in sediments by
estuarine class: a) Large estuaries, b) Small estuaries, c) Large tidal rivers. . 41
Figure 3-26. The cumulative distribution of the acid volatile sulfide concentration in
sediments as a percent of area in the Virginian Province, 1992 42
Figure 3-27. Cumulative distribution of the acid volatile sulfide concentration in sediments
by estuarine class: a) Large estuaries, b) Small estuaries, c) Large tidal rivers 43
Figure 3-28. Linear regression (with upper 95% confidence intervals) of chromium against
aluminum 45
Figure 3-29. Percent area of the Virginian Province with enriched concentrations of
individual metals in sediments in 1992 45
Figure 3-30. The percent of area of the Virginian Province by estuarine class where
anthropogenic debris was collected in fish trawls, 1992 46
page x Statistical Summary, EMAP-E Virginian Province - 1992
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FIGURES (continued)
Figure 3-31. Cumulative distribution of water depth as a percent of area in the Virginian
Province, 1992 . . . 46
Figure 3-32. Cumulative distribution of bottom temperature as a percent of area in the
Virginian Province, 1992 47
Figure 3-33. Cumulative distribution of bottom temperature by estuarine class: a) Large
estuaries, b) Small estuaries c) Large tidal rivers 48
Figure 3-34. The cumulative distribution of bottom salinity as a percent of area in the
Virginian Province, 1992 49
Figure 3-35. Cumulative distribution of bottom salinity by estuarine class: a) Large
estuaries, b) Small estuaries c) Large tidal rivers 50
Figure 3-36. The percent of area by estuarine class classified as oligohaline (<5 ppt),
mesohaline (5 to 18 ppt), and polyhaline (>18 ppt) 51
Figure 3-37. Cumulative distribution of the stratified area in the Virginian Province in 1992
based on the sigma-t (a,) difference between surface and bottom waters 51
Figure 3-38. The percent of the area by estuarine class that had a low (<1), medium (1 to 2),
or high (>2) degree of stratification ( A a, as kg/m3) 52
Figure 3-39. The cumulative distribution of total suspended solids concentration as a percent
of area in the Virginian Province, 1992 52
Figure 3-40. Cumulative distribution of total suspended solids concentration by estuarine
class: a) Large estuaries, b) Small estuaries, c) Large tidal rivers 53
Figure 3-41. The cumulative distribution of light extinction coefficient as a percent of area
in the Virginian Province in 1992 55
Figure 3-42. The percent of area by estuarine class where water clarity was poor, moderate,
or good 55
Figure 3-43. The cumulative distribution of the percentage of silt-clay in the sediments as a
percent of area in the Virginian Province, 1992 56
Figure 3-44. The percent of area by estuarine class with a low (<20), medium (20 to 80), or
high (>80) percent silt-clay in the sediments 56
Figure 3-45. Integration of estuarine conditions based on aesthetic quality (presence of
bottom trash and water clarity), bottom dissolved oxygen (< 5mg/L), and the
benthic index '„ 57
Statistical Summary, EMAP-E Virginian Province - 1992
Page xi
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Table 2-1.
Table 3-1.
Table 3-2.
Table 3-3.
Table 3-4.
Table 3-5.
Table 3-6.
Table 4-1.
TABLES
Summary of collection and processing status of samples collected.
14
Draft Sediment Quality Criteria values for acenaphthene, phenanthrene,
fluoranthene, and dieldrin 30
Range and median PAH concentrations in sediments of the Virginian Province 31
Range and median PCB concentrations in sediments of the Virginian Province 34
Range and median chlorinated pesticide concentrations in sediments of the
Virginian Province 36
Range and median butyltin concentrations in sediments of the Virginian
Province
Range and median metal concentrations in sediments of the Virginian Province.
Percent area of the Virginian Province (with 95% confidence intervals) above
or below values of interest for selected indicators in 1992
38
44
59
Page xii
Statistical Summary, EMAP-E Virginian Province - 1992
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ABBREVIATIONS
AVS Acid Volatile Sulfide
BSS Base Sampling Site
CDF Cumulative Distribution Function
DBT Dibutyltin
DO Dissolved Oxygen
dry wt Dry weight
EMAP Environmental Monitoring and Assessment Program
EMAP-E EMAP-Estuaries
MBT Monobutyltin
mg/L milligrams per liter = parts per million (ppm)
mg/kg milligrams per kiligram = parts per million (ppm)
kg/m3 kilograms per cubic meter
ND Not Detected
ng/g nanograms per gram = parts per billion (ppb)
PAH Polycyclic Aromatic Hydrocarbon
PCB Polychlorinated Biphenyl
QA Quality Assurance
QC Quality Control
SQC Sediment Quality Criteria
TBT Tributyltin
ug/g micrograms per gram = parts per million (ppm)
|a Micron
A Delta
o, Sigma-t
%o parts per thousand (ppt)
Statistical Summary, EMAP-E Virginian Province - 1992
Page xiii
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EXECUTIVE SUMMARY
The Environmental Monitoring and Assessment
Program (EMAP) is a nationwide program initiated by
EPA's Office of Research and Development (ORD).
EMAP was developed in response to the demand for
information about the degree to which existing pollution
control programs and policies protect the nation's
ecological resources.
EMAP-Estuaries (EMAP-E) represents EMAP's
efforts in near-coastal environments. These efforts are
designed to provide a quantitative assessment of the
regional extent of coastal environmental problems by
measuring status and change in selected indicators of
ecological condition. Specific environmental problems
investigated include:
• hypoxia,
• sediment contamination,
• coastal eutrophication, and
• habitat loss.
In 1990, EMAP-E initiated a demonstration project
in the estuaries of the Virginian Province. The 1992
field season represents the third year of sampling in the
Province, which includes the coastal region of the
Northeast United States from Cape Cod south to the
mouth of Chesapeake Bay. It is composed of 23,574
km2 of estuarine resources including 11,469 km2 in
Chesapeake Bay and 3,344 km2 in Long Island Sound.
Estuarine resources in the Virginian Province were
stratified into classes by physical dimension for the
purposes of sampling and analysis. Large estuaries in
the Virginian Province were defined as those estuaries
greater than 260 km2 in surface area and with aspect
ratios (i.e., length/average width) of less than 18. The
areal extent of large estuaries in the Province was
16,097 km2. Large tidal rivers were defined as that
portion of the river that is tidally influenced (i.e.,
detectable tide > 2.5 cm), greater than 260 km2 in
surface area, and with an aspect ratio of greater than
18. Approximately 2,602 km2 were classified as tidal
rivers. The third class was the small estuaries and small
tidal rivers which included those systems whose surface
areas fell between 2.6 km2 and 260 km2. This class represented
4,875 km2 of the Virginian Province.
Three field crews sampled 126 sites in the Virginian
Province during the six-week sampling period beginning
on July 27, 1992. Of these, 103 were "Base Sampling
Sites" (BSS) which were the probability-based sites selected
according to the EMAP-E design for assessing the condition
of the estuarine resources of the Province. Only data
collected at these sites were used in the generation of
this report.
The 1992 data reported in this document represent
only one year of sampling of a four-year cycle; i.e., the
total number of samples needed by EMAP to characterize
the Province are sampled over a four-year period (Holland,
1990). Therefore, the reader must use these data carefully,
and be aware that the proportion of degraded area calculated
for 1992 may differ somewhat from the regional assessment
to be generated following the completion of the four-year
cycle.
All EMAP-VP data used in the generation of this
report were subjected to rigorous quality assurance measures
as described in the 1992 Quality Assurance Project Plan
(Valente et al., 1992).
Biotic Condition Indicators
Biotic condition indicators are characteristics of the
environment that provide quantitative evidence of the
status of ecological resources and biological integrity
of a sample site from which they are collected (Messer,
1990). Ecosystems with a high degree of biotic integrity
(i.e., healthy ecosystems) are composed of balanced
populations of indigenous benthic and water column organisms
with species compositions, diversity, and functional
Statistical Summary, EMAP-E Virginian Province - 1992
Page 1
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organization comparable to undisturbed habitats (Karr
and Dudley, 1981; Karr et al., 1986).
A benthic index which uses measures of organism
health, functionality, and community condition to eval-
uate the condition of the benthic assemblage was
utilized in the assessment of biological resources of the
Virginian Province. The index under development was
determined from the combined 1990/1991 data and is
assumed to represent a combination of ecological
measurements that best discriminates between good and
poor ecological conditions. The reader should be
cautioned that this index has not yet been fully validated
with an independent dataset, and therefore, should be
used with caution.
A benthic index critical value of zero was deter-
mined from the combined 1990/1991 Virginian Province
dataset. Fourteen (± 6) percent of the bottom area of
the Virginian Province sampled in 1992 had an index
value of < 0, indicating likely impacts on the benthic
community (Figure 1). The lowest incidence was found
in the large estuaries (7 ± 8%), and the highest in large
tidal rivers (37 ± 22%).
A "standard" fish trawl (trawling at a specified speed
for a specified time) was performed at each station to
collect information on the distribution and abundance
of fish. Because many factors influence fish abundance,
poor catch may not be an indication of degraded
conditions, but simply the natural habitat. Catches of
<10 fish/trawl (catch per unit effort) occurred at stations
60-i
50-
fO
&
o 30-
1
<5 20-
Q.
10-
All
Large
Small
Tidal
Figure 1. Percent area of the Virginian Province by estuarine
class with a benthic index value below 0 in 1992. (Error bars
represent 95% confidence intervals).
representing approximately 37 ± 12% of the Province,
and "high" catches (>100 fish/trawl) were experienced
at stations representing approximately 26 ± 11 % of the
area of the Province (Figure 2).
The incidence of the four gross external pathologies
(growths, lumps, ulcers, and fin erosion) among fish collected
in the Virginian Province in 1992 was 0.3%. Of the 3,290
fish examined, 10 were identified as having one or more
of these pathologies. These individuals were collected
at nine of the 103 base stations sampled during the index
period.
120 •
100
a
| 80
2 60
(D
§ 40
a.
20
100 200 300 400
Number of Fish per Trawl
500
Figure 2. Cumulative distribution of fish abundance in
number per standard trawl as a percent of area in the
Virginian Province, 1992. (Dashed lines are the 95%
confidence intervals).
Abiotic Condition Indicators
Abiotic condition indicators historically have been
the mainstay of environmental monitoring programs,
because these indicators quantify the levels of stresses
to which organisms are exposed.
One potential stress to aquatic organisms is a low
concentration of dissolved oxygen (DO). Two and five
mg/L are values employed by EMAP to define severe
and moderate hypoxia, respectively. Approximately 29
± 10% of the sampled area of the Province lies in waters
with bottom DO concentrations less than or equal to 5
mg/L (Figure 3). "Bottom" is defined as one meter above
the sediment-water interface. Approximately 5 ± 5%
of the sampled area exhibited bottom DO conditions <2.0
mg/L. Dissolved oxygen conditions <2.0 mg/1 were evident
in 7 ± 8% of the area of the large estuaries sampled within
the Province and none of the small estuaries or large
tidal rivers (Figure 3).
Page 2
Statistical Summary, EMAP-E Virginian Province - 1992
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120-1
100-
80-
o
H 60-|
i
S. 40H
20-
0-
L! 2to5
H >5
AH
Large
Small
Tidal
Figure 3. Percent of area by class that had low (0 to 2 mg/L),
medium (2.1 to 5 mg/L), or high (>5 mg/L) oxygen
concentration in the bottom waters. (Error bars represent
95% confidence intervals).
Sediments collected at each station were analyzed
for both organic contaminants and metals. Because of
the complex nature of sediment geochemistry, the ecological
impact of elevated contaminant levels is not well understood.
Therefore, no attempt is made to estimate the overall
aerial extent of sediment contamination in the Virginian
Province.
Figure 5 shows the distribution of the sum of measured
polycyclic aromatic hydrocarbons (PAHs) in the Virginian
Province. The complete list of analytes included in this
summation can be found in Section 3. Approximately
92 ± 7% of the Province has concentrations of PAHs
below 4,000 ng/g dry weight, with a maximum measured
concentration at any station of 13,219 ng/g.
In addition to measuring individual stressors (e.g.,
individual chemical analytes), sediment toxicity tests
were performed on sediments collected at each site to
determine if they were toxic to the tube-dwelling
amphipod, Ampelisca abdita. Sediments were classified
as toxic if amphipod survival in the test sediment was
less than 80% of that in the control sediment and
statistically different from control survival.
Approximately 6 ± 5% of the sampled area of the
Virginian Province contained sediments which were
toxic to the amphipod during 10-day exposures (Figure
4).
2 4 6 8 10 12 14
Combined PAHs (ng/g dry wt x 1000)
16
Figure 5. Cumulative distribution of combined PAHs in
sediments as percent of area in the Virginian Province, 1992.
(Dashed lines are the 95% confidence intervals).
20 -,
15 -
° 10 -
5 -
0
All
Large
Small
Tidal
Figure 4. Percent of area in the Virginian Province in 1992,
by estuarine class, with low amphipod survival (<80% of
control) in sediment toxicity tests. (Error bars represent 95%
confidence intervals).
Draft EPA Sediment Quality Criteria (SQC) are currently
available for the PAHs acenaphthene, phenanthrene, and
fluoranthene; and the pesticide dieldrin. Draft PAH SQC
were not exceeded at any stations within the Province
in 1992.
The extent to which polluting activities have affected
concentrations of metals in sediments is complicated
by the natural variation of metals in sediments. Crustal
aluminum concentrations are generally many orders of
magnitude higher than anthropogenic inputs; therefore,
aluminum can be used to "normalize" for differing crustal
abundances of trace metals. Figure 6 presents the results
of this normalization. Approximately 31 ± 10% of the
area of the Province showed enrichment of sediments
with at least one metal. Twenty seven (± 13), 43 ± 13,
and 34 ± 39 percent of the large estuary, small estuary,
Statistical Summary, EMAP-E Virginian Province - 1992
Page 3
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30-j
25-
20-
m
S
1 15-
1
a 10-
Q.
5-
&i
/
•
:
•;
' '. r
f
•
1 .
1
j
^
f m
'
1 "
1 F
j j
'; ;
^
;
•
,: ';
1
| |
4K
B
i|
1 i
1 1
1
a s
9 •
j
! ^
1
i I.
\g As Cd Cr Cu Fe Hg Mn Ni Pb Sb Se Sn Zn
Figure 6. Percent area of the Virginian Province with
enriched concentrations of individual metals in sediments in
1992. (Error bars represent 95% confidence intervals).
and large tidal river class areas sampled contained
sediments with metals concentrations exceeding
predicted background levels. This only shows the
percent of the Province with elevated concentrations of
metals, and does not indicate the magnitude of
enrichment, i.e., this does not imply concentrations are
elevated to the point where biological effects might be
expected.
Presence of marine debris in fish trawls was
documented by field crews as being encountered at
stations representing 25 ± 11% of the Virginian
Province area (Figure 7). The small estuary class had
80 -
70-
60-
ra
2 50-
| 40-
1 30-
0.
20-
10-
0-
-
-
-
r
c
4
8
i
1
1
All Large Small Tidal
Figure 7. The percent of area of the Virginian Province by
estuarine class where anthropogenic debris was collected in
fish trawls, 1992. (Error bars represent 95% confidence
Intervals).
the largest percent area (42 ± 20%) where trash was found.
Habitat Characterization
Habitat indicators describe the natural physical and
chemical conditions of the sites sampled. These parameters
are important modifying factors controlling both abiotic
and biotic condition indicators.
Figure 8 shows the distribution of water depth in
the Virginian Province. The area shallower than 2 m
is underestimated because this was the minimum depth
sampled.
20 30
Depth (m)
Figure S. Cumulative distribution of water depth as a
percent of area in the Virginian Province, 1992. (Dashed lines
are the 95% confidence intervals).
Based on the sampling design where a single station
represents a statistical area (e.g., 70 km2 for large estuary
sites), 12.5% of the area of large estuaries could not be
sampled due to inadequate water depth. Small systems
were considered unsampleable if the water depth did
not exceed 2 m anywhere in the system. Such systems
account for approximately 0.5% of the area of small systems
in the Virginian Province. No large tidal river stations
were unsampleable due to water depth in 1992. Overall,
8.5% of the area of the Province was deemed unsampleable
in 1992 due to water depth.
Bottom water temperatures in the Virginian Province
ranged from 11.8°C to 27.8°C during the summer sampling
season.
Page 4
Statistical Summary, EMAP-E Virginian Province - 1992
-------
100-i
80-
40-
20-
5 to 18
All
Large
Small
Tidal
Figure 9. The percent of area by estuarine class classified as
oligohaline (<5 ppt), mesohaline (5 to 18 ppt), and polyhaline
(>18 ppt). (Error bars represent 95% confidence intervals).
Figure 9 illustrates the distribution of oligohaline
(<5%o salinity), mesohaline (5-18%o), and polyhaline
(>18%o) water in the Virginian Province and by class.
Vertical density differences (a function of both
salinity and temperature) in the waters of the Virginian
Province can be large enough to result in a reduction
in mixing between surface and bottom waters,
potentially allowing the bottom waters to become
hypoxic. Degree of stratification in the Virginian
Province was measured as the delta (A) at, which is the
CT, (sigma-t, a density measurement) difference between
surface and bottom waters. Approximately 68 + 11%
of the Province area had a ACT, of <1 unit; thus the
majority of the water in the Virginian Province was
well-mixed (Figure 10). Only 17 ± 10% of the Province
area was strongly stratified (ACT, >2).
140-
120-
100-
80-
o
(5
40 H
20-
S 1 to 2
All
Large
Small
Tidal
Figure 10. The percent of the area by estuarine class that
had a low (<1), medium (1 to 2), or high (>2) degree of
stratification ( A ot). (Error bars represent 95% confidence
intervals).
Water clarity was determined from light extinction
coefficients, which describe the attenuation of light as
it passes vertically through the water column. We are
defining low water quality as water in which a diver would
not be able to see his/her hand when held at arms length
in front. Moderate water clarity, in terms of human vision,
is defined as water in which a wader would not be able
to see his/her feet in waist deep water.
Water clarity was good in 83 ± 8% of the area of
the Virginian Province (Figure 11). Water of low clarity
was found in 5 ± 6% of the Province and an additional
12 ± 6% had water of moderate clarity.
140 -,
120 -
g 100 -
<
"5 80 -
1 6°~
Q_
40 -
20 -
0 -
'I -,
pafca
1
1
Jjfe
^%
Yty
%
1 m \nw
*
1
I
i
1
n Moderate
Hj Good
•n
;
\
All Large Small Tidal
Figure 11. The percent of area by estuarine class where
water clarity was poor, moderate, or good. (Error bars
represent 95% confidence intervals).
The silt-clay (mud) content of sediments (the fraction
<63|u particle diameter) is an important factor determining
the composition of the biological community at a site,
and is therefore important in the assessment of the benthic
community. The distribution of mud (>80% silt-clay)
vs sand (<20% silt-clay) is illustrated in Figure 12.
100-1
Large
Small
Tidal
Figure 12. Percent of area by estuarine class with a low
(<20), medium (20 to 80), or high (>80) percent silt-clay in the
sediments. (Error bars represent 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 5
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SECTION 1
INTRODUCTION
The Environmental Monitoring and Assessment
Program (EMAP) is a nationwide program initiated by
EPA's Office of Research and Development (ORD).
EMAP was developed in response to the need to imple-
ment a monitoring program that contributes to com-
parative ecological risk assessment and decisions related
to environmental protection and management. EMAP
is an integrated federal program; ORD is cpordinating
the planning and implementation of EMAP with other
federal agencies including the Agricultural Research
Service (ARS), the Bureau of Land Management (BLM),
the U.S. Fish and Wildlife Service (FWS), the Forest
Service (FS), the U.S. Geological Survey (USGS), and
the National Oceanic and Atmospheric Administration
(NOAA). These other agencies and offices participate
in the collection and analysis of EMAP data and will
use these data to guide their policy decisions as
appropriate.
EMAP-Estuaries (EMAP-E) represents one portion
of EMAP's efforts in near-coastal environments. These
efforts are designed to provide a quantitative assessment
of the regional extent of coastal environmental problems
by measuring status and change in selected ecological
condition indicators to address specific environmental
problems including:
• hypoxia,
• sediment contamination,
• coastal eutrophication, and
• habitat loss.
In 1990, EMAP-E initiated a demonstration project
in the estuaries of the Virginian Province (i.e., estuaries,
bays and sounds between Cape Cod, MA and Cape
Henry, VA: Weisberg et al., 1993). One of the objec-
tives of the Demonstration Project was to test the EMAP
design, logistical approach and various ecological condition
indicators. Based on the experience of the 1990 Demonstration
Project, EMAP-E modified minor aspects of the logistical
plan for subsequent sampling years. :
1.1 Objectives of 1992 Virginian Province
Monitoring Activities I
The specifics of the planning activities of the 1992
Virginian Province sampling effort are documented in
the 1992 Virginian Province Logistics Plan (Strobel et
al., 1992), the 1992 Field Readiness Report (Reifsteck,
1992), and the 1992 Virginian Province Field Operations
and Safety Manual (Reifsteck et al., 1992). Sampling
was conducted from 27 July through 31 August 1992,
spanning 126 sites (stations). Approximately 30 field
personnel and three extramural contracts or cooperative
agreements were utilized for the sampling program.
The objectives of the 1992 Virginian Province monitoring
program were to:
• continue the routine monitoring of the Province
using selected indicators from the 1990 Demonstration
. Project;
• obtain data on Virginian Province-specific variability
in ecological indicators; and
• develop and refine assessment procedures for
determining the ecological status of estuaries and
apply these procedures to establish baseline conditions
in the Virginian Province.
Page 6
Statistical Summary, EMAP-E Virginian Province - 1992
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As part of establishing baseline conditions in the
Virginian Province, several assessment questions relating
to ecological conditions were addressed. Among these
questions are:
• What proportion of the bottom waters of the
estuaries of the Virginian Province experience
hypoxia (e.g., dissolved oxygen concentrations
< 2 or 5 mg/L)?
• What proportion of the estuarine sediments of the
Virginian Province have a benthic community
structure indicative of polluted environments?
• What is the incidence of gross external pathologies
among fish species in the Virginian Province?
• What proportion of estuarine sediments in the
Virginian Province contain elevated levels of
anthropogenic chemical contaminants?
• What proportion of estuarine sediments in the
Virginian Province contain anthropogenic marine
debris?
1.2 Program Design
Sample collection in the Virginian Province focused
on ecological indicators (described in Holland, 1990 and
Appendix A of the 1991 Statistical Summary; Schimmel
et al., 1994) during the index sampling period (July 1 -
September 30); the period when many estuarine
responses to anthropogenic and natural stresses are
anticipated to be most severe. The proposed sampling
design combines the strengths of systematic and random
sampling with an understanding of estuarine ecosystems
in order to provide a probability-based estimate of
estuarine status in the Virginian Province.
A simple classification scheme based on the physical
dimensions of an estuary was used to develop three
classes of estuaries — large estuaries, large tidal rivers,
and small estuaries/small tidal rivers. Large estuaries
in the Virginian Province were defined as those estuaries
greater than 260 km2 in surface area and with aspect
ratios (i.e., length/average width) of less than 18. Large
tidal rivers were defined as that portion of the river that
is tidally influenced (i.e., detectable tide > 2.5 cm),
greater than 260 km2 in surface area, and with an aspect
ratio of greater than 18. Small estuaries and small tidal
rivers were designated as those systems whose surface
areas fell between 2.6 km2 and 260 km2. These criteria
resulted in the identification of 12 large estuaries; 5 large
tidal rivers; and 144 small estuaries / small tidal rivers.
1.3 Data Limitations
The 1992 data represent only one year of sampling
of a four year cycle; i.e., the total number of samples
needed to characterize the Province with the degree of
confidence required by EMAP are sampled over a four-year
period (Holland, 1990). Therefore, the reader must use
these data carefully, and be aware that single-year results
may differ from those reported following the completion
of the four-year cycle (i.e., 1990 - 1993).
EMAP is designed to provide data on a regional scale.
This design creates an additional limitation for those
interested in smaller scale studies. For example, each
of the 144 small systems (e.g., Raritan Bay or the Elizabeth
River) is represented by a single station, the location
of which is randomly selected. The assumption is made
that this station is representative of an area of the Province
equal to the area of that system. In total, these stations
are expected to provide an accurate portrayal of conditions
in small systems across the Province; however, the design,
at its current scale, does not allow for the study of conditions
in individual small systems. The reader should consult
Appendix A of the 1991 Statistical Summary (Schimmel
et al., 1994) and the Near Coastal Program Plan (Holland,
1990) for additional information on the statistical design.
Lastly, a benthic index is currently under development
to aid in the interpretation of benthic community data.
This index has been developed using combined 1990/1991
data. The 1992 data appeal'to support the Index. However,
the Index may be modified upon analysis of the complete
four-year dataset; therefore, the Benthic Index that will
appear in the four-year assessment report may differ slightly
from the one included in this report.
1.4 Purpose and Organization of This Report
The Statistical Summaries that will be produced by
EMAP-E are meant to provide large quantities of information
without including extensive interpretation of these data.
Interpretive reports are anticipated upon completion of
Statistical Summary, EMAP-E Virginian Province - 1992
Page 7
-------
each four-year cycle or in specialized documents such
as the Virginian Province Demonstration Project Report
(Weisberg et al,, 1993).
The purpose of this report is to provide estimates of
the ecological condition of the estuarine resources of
the Virginian Province for 1992 in a format similar to
that used in the 1991 Virginian Province Statistical
Summary (Schimmel et al., 1994).
This report is organized into sections addressing the
objectives and results of the 1992 Virginian Province
monitoring program. Section 1 describes the objectives
of the Program and limitations on the use of the data
presented in this report.
Section 2 briefly summarizes logistical results of field
sampling activities including station locations, percent
of samples successfully collected, etc.
Section 3 is the statistical summary of the data
collected during the 1992 survey.
Section 4 summarizes the findings of the 1992
monitoring program in the Virginian Province.
Section 5 lists the references cited in this report.
Appendix A provides sub-population estimates of
ecological condition for Chesapeake Bay and Long
Island Sound.
Appendix B presents the plots of the regressions of
individual metals concentrations in sediments against
aluminum concentrations used in the determination of
areal extent of metals enrichment.
Appendix C summarizes the quality assurance/quality
control results of the 1992 survey.
Page 8
Statistical Summary, EMAP-E Virginian Province - 1992
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SECTION 2
OVERVIEW OF FIELD ACTIVITIES
The Virginian Province includes the coastal region
of the northeast United States from Cape Cod south to
the mouth of Chesapeake Bay. It is composed of
23,574 km2 of estuarine resources including 11,469 km2
in Chesapeake Bay and 3,344 km2in Long Island Sound.
The 1992 Virginian Province survey was conducted
during late July through the end of August, 1992. A
probability-based sampling design was used to sample
major estuarine resources proportionately (Overton et
al., 1991; Stevens et al, 1991). This design makes it
possible to estimate the proportion or amount of area
in the Virginian Province having defined environmental
conditions.
One hundred and twenty six (126) stations in the
Virginian Province, located between Nantucket Sound
(MA) and Cape Henry (VA), were sampled during the
six-week sampling period.
Sample collection in the Virginian Province focused
on ecological indicators during the index sampling
period (July 1 - September 30), when responses of
estuarine resources to anthropogenic and natural stresses
are anticipated to be most severe (e.g., high tempera-
tures, low dissolved oxygen). The basic sampling
design provides a probability-based estimate of estuarine
status in the Virginian Province. Additional sites were
also sampled to collect information for specific
hypothesis testing and other specific study objectives
(Strobel et al., 1992).
Base Sampling Sites (BSS) are the probability-based
sites which form the core of the EMAP-E monitoring
design for all provinces, including the Virginian
Province. Data collected from these sites are the basis
of this statistical summary. There were 103 BSS to be
sampled during the 1992 index period, representing
approximately V4 of the total number of base sites that
will be sampled over the four-year cycle. Twenty two
special study sites were also scheduled for sampling.
The 126 stations were divided among three sampling
teams, each covering a specific area of responsibility
(Figure 2-1). Each team was comprised of two, four-
person alternating crews which sampled for six consecu-
tive days. During the six-day period, the crew.was
assigned responsibility for sampling a cluster of stations.
The order in which clusters were to be sampled was
randomized to assure stations were not sampled across
the Province in a North-South series. Each Base
Sampling site was visited once during the index period.
Long-term trends sites were visited twice. Figures 2-2,
2-3, and 2-4 present maps of all the base sampling sites
scheduled for sampling in the 1992 Virginian Province
monitoring program.
The 1992 Virginian Province monitoring program
was successful in its attempt to collect large amounts
of information and samples over a relatively short time
period. The overall effectiveness of the 1992 sampling
plan is reflected in the high percentage of stations for
which usable data were obtained for the variety of
parameters measured (Table 2-1). While all planned
stations were sampled, not every station was sampled
for every parameter, and not every sample was successful-
ly processed. Additional stations were eliminated prior
to the start of field operations due to inadequate water
depth. Overall, 8.5% of the area of the Virginian
Province originally scheduled to be sampled in 1992
could not be sampled due to inadequate water depth.
Statistical Summary, EMAP-E Virginian Province - 1992
Page 9
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NarragansettJl
SAMPLING TE
Edistonf NJ*
SAMPLING TEAM 2
SAMPLING TEAM 3
Figure 2-1. Areas of Responsibility of the EMAP-VP Sampling Teams.
Page 10
Statistical Summary, EMAP-E Virginian Province - 1992
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co
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re
55
en
c
"5.
ca
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cc
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E
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Statistical Summary, EMAP-E Virginian Province - 1992
Page 11
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Figure 2-3. Team 2 Base Sampling Stations.
Page 12
Statistical Summary, EMAP-E Virginian Province - 1992
-------
Figure 2-4. Team 3 Base Sampling Stations.
Statistical Summary, EMAP-E Virginian Province - 1992
Page 13
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Table 2-1. Summary of collection and processing status of samples collected.
# Stations
Expected to
Sample Type be Sampled3
Water Quality (DO, Temp., Salinity)
BSS Only
All Station Classes
Light Attenuation Coefficient (CTD cast)
BSS Only
All Station Classes
Suspended Solids
BSS Only
All Station Classes
Sediment Chemistry
eSS Only
All Station Classes
Sediment Toxicity
BSS Only
All Station Classes
Sediment Grain Size
BSS Only
All Station Classes
Benthic Infauna
BSS Only
All Station Classes
Fish Community Data (successful trawl)
BSS Only
All Station Classes
Anthropogenic Marine Debris
BSS Only
All Station Classes
103
126
103
126
103
126
103
126
103
126
103
126
103
126
103
126
103
126
# Stations Sampled
(% of Expected
Stations)
103
126
103
126
103
126
96
117
96
117
96
117
99
120
94
116
94
116
(100%)
(100%)
(100%)
,(1 00%)
(100%)
(1 00%)
(93.2%)
(92.9%)
(93.2%)
(92.9%)
(93.2%)
(92.9%)
(96.1%)
(95.2%)
(90.2%)
(92.1%)
(90.2%)
(92.1%)
Percent Stations
With Data Passing
Final QCb :
100%
1 00%
98.1%
98.4%
53.8%c
55.6%°
93.2%
92.9%
90.2%
91.5%
93.2%
92.9%
96.1%
95.2% :
90.2%
92.1%
90.2%
92.1%
a Number of stations expected to be sampled excludes all stations determined to be too shallow tp sample prior to the
start of field operations. Activities differed at different station classes resulting in the inconsistency in Expected
Station Numbers for "All Station Classes" between indicators. Station classes are described in Appendix A of the 1991
Virginian Province Statistical Summary (Schimmel et a\., 1994).
b This value takes into account samples not collected, damaged or lost during shipping or processing, or failing to pass
final Quality Control checks. The value for "BSS Only" represents the data utilized in the production of this report.
0 Data are available for remaining samples; however, the representativeness of those data cannot be determined
because appropriate QA samples were not run with all analytical batches.
Page 14
Statistical Summary, EMAP-E Virginian Province - 1992
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SECTION 3
STATISTICAL SUMMARY OF INDICATOR RESULTS
The EMAP indicator strategy includes four types
of ecological indicators: Biotic Condition, Abiotic
Condition, Habitat, and Stressor. In this section, the
statistical results of the 1992 Virginian Province Survey
are described for each indicator with discussions catego-
rized by major indicator type. Stressor data are not
collected as part of the field effort; therefore, they are
not discussed in this report. The following discussion
is organized by indicator type. Indicators will be briefly
described, and in most cases the Cumulative Distribution
Function (CDF) will be shown to delineate the frequen-
cy of occurrence of observations within the Province.
Bar graphs and other figures are also presented, where
appropriate, to delineate the proportions of the Province
or class resources that are degraded, or falling above
or below values of interest.
CDFs display the full distribution of the values ob-
served for an indicator plotted against the cumulative
percentage of area in the class or Province. They
provide information on both central tendency (e.g.,
median) and the range of values in one easily interpreted
graphical format (Holland, 1990). For example, Figure
3-1 shows the cumulative distribution function of
instantaneous bottom dissolved oxygen (DO) concentra-
tions for the Virginian Province.
The x-axis represents DO concentrations observed
ranging from 0 to 10 mg/L. The y-axis represents the
cumulative percentage of estuarine area within the
Virginian Province. The dotted lines represent the 95%
confidence intervals for the CDF. The CDF provides
the reader with a powerful tool to evaluate the extent
of conditions of any indicator within the Province or
class. For example, the reader could be interested in
the portion of area within the Province that was
characterized by a DO concentration of 2 mg/L or less,
a potential biological criterion. This concentration
120
246
Dissolved Oxygen (mg/L)
Figure 3-1. Example cumulative distribution of bottom
dissolved oxygen concentrations as a percent of area in the
Virginian Province. (Dashed lines are the 95% confidence
intervals).
intersects with the cumulative area in the Province at
5 ± 5%. The reader might also be interested in a state
regulatory criterion of 5 mg/L, and the CDF shows that,
based on the 1992 data, 29 ± 11% of the estuarine
bottoms waters had DO concentrations below this level.
From a positive viewpoint, the reader may be interested
in the amount of area above 7 mg/L (e.g., as a criterion
for fish farming) and the CDF shows that in 1992
approximately 16 ± 8% of the bottom waters in the
Province were observed to be at or above 7 mg/L DO.
Criteria values for the assessment of degraded versus
non-degraded areas are often subjective at best. Indeed,
many of the criteria values used in this document, though
based on reasonable scientific judgement, are debatable.
The CDF allows the user to select his/her own criterion
value and re-evaluate the proportion of area in the
Virginian Province which is considered degraded. The
reader must remain avvare that the data included in this
report represents only 1A of the data that will be used
to generate the four-year assessment report.
Statistical Summary, EMAP-E Virginian Province - 1992
Page 15
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Areas reported in the text are determined from the
data, not from the CDF, and may be slightly different
than the reader might obtain from interpreting the CDF.
Data points on the CDF are connected with a straight
line, resulting in an interpolated value if there is no area
associated with the "x" value of interest.
3.1 BIOTIC CONDITION INDICATORS
Biotic condition indicators are characteristics of the
environment that provide quantitative evidence of the
status of ecological resources and the biological integrity
of the sample site from which they are collected
(Messer, 1990). Ecosystems with a high degree of
biotic integrity (i.e., "healthy" ecosystems) are composed
of balanced populations of indigenous benthic and
water column organisms with species compositions,
diversity, and functional organization comparable to
undisturbed habitats (Karr and Dudley, 1981; Karr et
«/., 1986). Biotic condition indicators measured include
measures of both fish and benthic community structure.
Because of budget constraints and the limited distribu-
tion of samples across the Province, no fish samples
were analyzed for chemical contaminants in 1992.
3.1.1 Benthic Index
Benthic organisms were used as an indicator because
previous studies have suggested that they are sensitive
to pollution exposure (Pearson and Rosenberg, 1978;
Boesch and Rosenberg, 1981). They also integrate
responses to exposure over relatively long periods of
time. One reason for their sensitivity to pollutant
exposure is that benthic organisms live in and on the
sediments, a medium that accumulates environmental
contaminants over time (Schubel and Carter, 1984;
Nixon et a/., 1986). The sedentary nature of many
benthic invertebrates also may maximize their exposure
to pollutants which accumulate in sediments.
A benthic index which uses measures of organism
health, functionality, and community condition to eval-
uate the condition of the benthic assemblage was
utilized in the assessment of biological resources of the
Virginian Province. The index under development was
determined from data collected in 1990 and 1991 and
is assumed to represent a combination of ecological
measurements that best discriminates between good and
poor ecological conditions. The index represents
EMAP-E's attempt to reduce many individual indicators
into a single value that has a high level of discriminatory
power between good and poor environmental conditions.
Discriminant Score =
-0.68 * Mean abundance of opportunistic species
+ 0.36 * Biomass/abundance ratio for all species
+ 1.14 * Mean number infaunal species per grab.
A critical value for discriminating between degraded
and reference sites of -0.5 was determined (calculated
as the point giving the optimal correct classification
efficiency for both reference and degraded sites in the
test dataset). A value of 0.5 was then added to all scores
to result in a critical value of zero, i.e., a negative score
indicates degraded conditions. An offset was selected
in place of a scaling factor (i.e., scaling from 0 to 10),
because a scaling factor requires recalculation every year,
resulting in a new critical value each year. An offset
is not affected by the range of values; therefore, the
critical value will remain constant among years. A more
complete description of the development of this index
can be found in Appendix B of the 1991 Virginian
Province Statistical Summary (Schimmel et al., 1994).
The same criteria used for establishing a test dataset
of reference and degraded stations in 1990 and 1991 was
used to create a 1992 test dataset. Fifty-nine reference
stations and four degraded stations were identified based
on bottom dissolved oxygen concentrations and sediment
contaminants/toxicity. The benthic index described above
correctly classified all four of the degraded stations and
83% of the reference stations. Because of the limited
number of stations in this dataset, this does not fully
validate the Index; however, we believe it does support
its use. It should be noted that this Index is still under
development and will be reviewed as part of the four-
year assessment effort.
Fourteen (± 6) percent of the bottom area of the
Virginian Province sampled in 1992 had an index value
of < 0, indicating likely impacts on the benthic communi-
ty (Figure 3-2).
The percent area classified as degraded among the
three classes of estuaries are 7 ± 8 %, 23 ± 12 %, and
37 ± 22 % for large estuaries, small estuarine systems,
and large tidal rivers, respectively (Figure 3-3).
Page 16
Statistical Summary, EMAP-E Virginian Province - 1992
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1
120 T
100
80 --
60 -
40 --
20 -
0 --
-4 -3 -2-10 1
Benthic Index
—i—
3
H
5
Figure 3-2. Cumulative distribution of the benthic index as a percent of area in the Virginian Province, 1992. (Dashed lines are the
95% confidence intervals).
CO
CO
-------
120 T
0 10 20 30 40
Benthic Species (Mean Number per Grab)
Figure 3-4. Cumulative distribution of the mean number of benthic species per grab as a percent of area in the Virginian Province,
1992. (Dashed lines are the 95% confidence intervals).
3.1.2 Number of Benthic Species
Number of infaunal benthic species has been used
to characterize the environmental condition of estuarine
habitats for specific salinity and grain size conditions.
The mean number of species from three replicate 440
cm2 grabs collected at each station resulted in numbers
of infaunal benthic species ranging from 0 to 52 (Figure
3-4), with the maximum number of species per station
being 52, 31, and 24 in the large estuaries, small
estuaries, and large tidal rivers respectively (Figure 3-5).
Because community composition is strongly influenced
by factors other than environmental "health" (e.g.,
salinity and grain size), we cannot infer that a low
number of species necessarily represents an impacted
community. However, the CDFs presented provide
baseline information and can be useful tools in assessing
future trends in community structure.
3.1.3 Benthic Infaunal Abundance
Abundant benthic organisms, particularly in com-
munities characterized by multiple species and feeding
types, suggest a productive estuarine environment.
Infaunal abundances ranged from 0 to over 150,000
organisms per square meter (Figure 3-6). Using <200
organisms per square meter (8.8 per grab) and <500
organisms per square meter (22 per grab) as indicators
of low and moderate abundances, respectively, 5 ± 5%
of the Virginian Province had low abundances, and an
additional 1 ± 6% had moderate abundances. Because
of natural variation in benthic populations and modifying
factors such as salinity and grain size, low abundance,
as defined above, does not necessarily imply degraded
communities; however, this information can be useful
in detecting trends.
The percent area of low abundance was low in all
three estuarine classes. Five ± 7 , 1 ± 1, and 10 ± 20
percent of the area of large estuaries, small estuaries,
and large tidal rivers, respectively,-exhibited benthic
abundances of < 200 organisms per square meter (Figure
3-7). The highest number of individuals (150,591 per
m2) was found in the large estuary class, with maximums
of 54,212 and 17,508 found in the small estuary and large
tidal river classes, respectively.
Page 18
Statistical Summary, EMAP-E Virginian Province - 1992
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a) Large Estuaries
b) Small Estuaries
c) Large Tidal Rivers
Figure 3-5. Cumulative distribution of the
c) Large tidal rivers. (Dashed lines are
U 1 ~- 1 1 1 : 1 1
0 10 20 30 40 50
120 T
100- ....-•}
S 80 - ;•'' f j
< ./ /" •••
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D.
120 •
100 •
80 •
60 -
40 •
20 •
0 •
(
•/r^
f
f
* » i i i i i ii
) 20 40 60 80 100 120 140 160
Total Benthic Abundance (#/m2 x 1000 ) ;
Figure 3-6. Cumulative distribution of the number of benthic organisms per m2 as a percent of area in the Virginian Province, 1992.
(Dashed lines are the 95% confidence intervals).
3.1.4 Number of Fish Species
Zero to 17 species offish were collected from single
standardized, 10 (±2)-min trawls performed at each base
station in the Virginian Province (Figure 3-8). A total
of 68 species were collected in standard trawls through-
out the Province in 1992.
Fish catch can be affected by many variables
including habitat; therefore, a critical value for the
number of species that must be caught in a net for the
area to be considered "healthy" is not available. We
can only report the incidence of high' vs low catches.
Low catch does not imply that the area is degraded in
reference to this indicator. However, as described above
for benthic indicators, these data can be useful in
detecting future trends in fish community structure on
a provincial scale.
Two or fewer species were caught in standard trawls
in approximately 37 ± 12% of the Virginian Province.
Alternatively, at least five fish species were collected
throughout approximately 36 ± 12% of the sampled area
of the Province. No fish were collected at four stations,
representing 4 ± 5% of the area of the Province. The
areas producing no fish catch were located primarily in
large estuaries (5 ± 7% of the area; Figure 3-9). Fish
were collected in all but one small estuary station (99
± 2% of the area) and at all stations in the large tidal
river class (Figure 3-9).
3.1.5 Total Finfish Abundance
Abundant nektonic organisms, especially in
communities characterized by multiple species and
feeding types, suggest a stable and productive food web.
Finfish abundance in standard trawls ranged from 0 to
464 fish per trawl throughout the Province (Figure 3-10).
A total of 4,558 fish were collected in standard trawls
conducted at base sampling sites in 1992.
Figure 3-11 illustrates fish abundance by system class.
Total fish catch in the large tidal river class, although
greater in number, was more variable than the other
classes as evidenced by the wide, confidence intervals
about the curve.
No striking differences occur by class except the
high percentage of area in large and small estuaries with
low fish catch (36 ± 15 and 45 ± 21%, respectively, with
<10 fish collected per trawl), and the high catch of over
100 fish per trawl in 47 ± 42% of the area represented
Page 20
Statistical Summary, EMAP-E Virginian Province - 1992
-------
120 T
a) Large Estuaries
20 40 60 80 100 120 140 160
120 T
b) Small Estuaries
c) Large Tidal Rivers
100 -
CD 80 •
<
° 60 -
c
-------
120 T
t
2
6 8 10 12 14
Number of Fish Species per Trawl
16
Figure 3-8. Cumulative distribution of the number of fish species per standard trawl as a percent of area in the Virginian Province,
1992. (Dashed lines are the 95% confidence intervals).
by large tidal river systems. As with the fish species
indicator, only high versus low catches are reported with
no inference made on the quality of the area relative to
this indicator.
3.1.6 Fish Gross External Pathology
Field crews examined the first 30 individuals of each
fish species for evidence of external pathology (growths,
lumps, ulcers, and fin erosion). Of the 3,290 fish
examined from base stations, 10 fish (0.3%) from nine
of the 103 stations were identified as having one or
more of these pathologies. All individuals with a
pathology were of species which live or feed on the
bottom.
Of the four categories, two growths, five ulcers, and
three cases of fin erosion were reported.
3.2 ABIOTIC CONDITION INDICATORS
Abiotic condition indicators provide information on
the potential exposure of organisms to environmental
stresses, and have historically been the mainstay of
environmental monitoring programs. Indicators of
exposure measured during the 1992 Virginian Province
Survey were dissolved oxygen concentration, sediment
toxicity (Ampelisca abditd), sediment contaminants, and
marine debris.
3.2.1 Dissolved Oxygen
Dissolved oxygen (DO) is critically important to
aquatic systems because it is a fundamental requirement
offish, shellfish and other aquatic biota. Vertical profiles
of dissolved oxygen and other water quality parameters
were obtained using a SeaBird SeaLogger CTD. DO
data included in this report are instantaneous point
measurements taken one meter above the sediment/water
interface.
Page 22
Statistical Summary, EMAP-E Virginian Province - 1992
-------
a) Large Estuaries
b) Small Estuaries
c) Large Tidal Rivers
140 ••
120 -
co 100
CD
I 30
| 60 +
IX 40
20 -•
0
0
4 6 8 10 12 14
Number of Fish Species per Trawl
16 18
Figure 3-9. Cumulative distribution of the number of fish species per trawl by estuarine class: a) Large estuaries, b) Small
estuaries, c) Large tidal rivers. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 23
-------
120
0
100 200 300
Number of Fish per Trawl
400
500
Figure 3-10. Cumulative distribution offish abundance in numbers per standard trawl as a percent of area in the Virginian Province,
1992. (Dashed lines are the 95% confidence intervals).
3.2.1.1 Bottom Dissolved Oxygen
Data collected in 1992 indicate that approximately
29 ± 11 % of the sampled area of the Province contains
bottom waters with a dissolved oxygen concentration
less than or equal to 5 mg/L (Figure 3-12). Approxi-
mately 5 ± 5% of the Province exhibited bottom DO
conditions £2 mg/L, defined by EMAP-E as severely
hypoxic.
Dissolved oxygen conditions <2 mg/L were evident
only in large estuaries sampled within the Province
(Figures 3-13 and 3-14). Approximately 7 ± 8% of the
areas of large estuaries contained measured concentra-
tions of bottom DO of ^ 2 mg/L. An additional 31 ±
15%, 10 ± 8%, and 12 ± 16% of the area of large
estuaries, small estuaries, and large tidal rivers,
respectively, fell within the range of 2 to 5 mg/L DO.
The occurrence of low dissolved oxygen in Chesa-
peake Bay and Long Island Sound is an area of
importance to both scientists and managers; therefore,
sub-population estimates for these systems are included
in Appendix A.
3.2.1.2 Dissolved Oxygen Stratification
The difference between surface and bottom DO
concentrations measured at base sampling stations is
illustrated in Figure 3-15. Differences between bottom
and surface DO were less than 1 mg/L in 59 ± 12% of
the area of the Province. Approximately 10 ± 9% of the
area of the Province showed differences greater than 5
mg/L. It should be noted that stratification is affected
by many factors including stage of the tide and recent
rainfall events. The data presented here have not been
normalized or adjusted for any such factors.
Figure 3-16 illustrates DO differences by estuarine
class. All of the highly stratified area was found in the
large estuaries (14 ± 10% of the area with a difference
exceeding 5 mg/L), with the largest A DO measured being
6.4 mg/L.
Page 24
Statistical Summary, EMAP-E Virginian Province - 1992
-------
1
a) Large Estuaries
100
200
300
400
500
b) Small Estuaries
100
200
300
400
500
c) Large Tidal Rivers
100 200 300
Number of Fish per Trawl
400
500
Figure 3-11. Cumulative distribution of fish abundance in numbers per standard trawl by estuarine class: a) Large estuaries,
b) Small estuaries, c) Large tidal rivers. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 25
-------
120 T
34567
Dissolved Oxygen (mg/L)
8
Figure 3-12. Cumulative distribution of bottom oxygen concentration in the Virginian Province, 1992 (Dashed lines are the 95% confidence
Intervals).
120-
100-
OJ
80H
c 60H
8
I 40-
20-
0
Q 2 to 5
W >5
All
Large
Small
Tidal
Figure 3-13. Percent area by class that had a low (< 2 mg/L), medium (2 to 5 mg/L), or high (>5 mg/L) oxygen
concentration in the bottom waters. (Error bars represent 95% confidence intervals).
Page 26
Statistical Summary, EMAP-E Virginian Province - 1992
-------
a) Large Estuaries
b) Small Estuaries
120 T
c) Large Tidal Rivers
34567
Dissolved Oxygen (mg/L)
10
Figure 3-14. Cumulative distribution of bottom oxygen concentration by estuarine class: a) Large estuaries, b) Small estuaries,
c) Large tidal rivers. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 27
-------
120 T
0123456
Dissolved Oxygen Difference (mg/L)
Figure 3-15. Cumulative distribution of the D.O concentration difference between surface and bottom waters as a percent of area
In the Virginian Province, 1992. (Dashed lines are the 95% confidence intervals).
Large
Small
Tidal
Figure 3-16. Percent area by class that had a low, medium, or high difference in dissolved oxygen concentration
between the surface and bottom waters. (Error bars represent 95% confidence intervals).
Page 28
Statistical Summary, EMAP-E Virginian Province - 1992
-------
3.2.2 Sediment Toxicity
3.2.3 Sediment Contaminants
Sediment toxicity tests were performed on the
composite sample of surficial sediments (top two cm)
collected from each sampling site. Solid-phase sediment
toxicity tests (Swartz et al., 1985) with the tube-
dwelling amphipod, Ampelisca abdita, were conducted
according to procedures described in U.S. EPA/ACE
(1991) and ASTM (1991). Sediments were classified
as toxic if amphipod survival in the test sediment was
less than 80% of that in the control (a.k.a. "reference")
sediment and significantly different from the control.
The relative health of test organisms was determined
via the use of reference toxicant tests as described in
Appendix C. Approximately 6 ± 5% of the sampled area
of the Virginian Province exhibited toxic sediments
(Figure 3-17). However, only 0.4 ± 0.5% of the area
had sediments where survival was below 60% of control
survival (i.e., sediments were very toxic). The estuarine
class with the largest proportion of toxic sediments was
the large estuarine class (8 ± 8%); with the small
estuaries and large tidal river classes exhibiting a lesser
extent of toxicity (2 ± 2% and 3 ± 5%, respectively:
Figure 3-18). All of the highly toxic sediments were
found in the small estuarine class, where 2 ± 2% of the
area had sediments producing survival less than 60%
of control survival.
A wide variety of contaminants have been released
to marine systems due to human activities. Some of these
compounds and elements have properties which cause
them to associate with particulate material, and many
of these chemicals are also persistent in the environment.
Contaminants with this combination of properties can
accumulate to high concentrations in sediments and may
become available to aquatic organisms. The organic
compounds measured included selected polycyclic
aromatic hydrocarbons (PAHs), polychlorinated biphenyl
(PCB) congeners, chlorinated pesticides, butyltins and
several metals. Because of the complex nature of sediment
geochemistry, and additive, synergistic, and antagonistic
interactions among multiple pollutants, the ecological
impact of elevated contaminant levels is not well under-
stood. Therefore, definitive estimates of percent area
of the Province with overall contaminant concentrations
high enough to cause ecological impacts cannot be
provided. However, the data collected will form a
baseline for monitoring trends in sediment contamination
and are extremely valuable in that respect.
EPA is currently in the process of establishing
Sediment Quality Criteria (SQC). Draft SQC are
presently available for four of the analytes EMAP-VP
is measuring: Acenaphthene, phenanthrene, fluoranthene,
120 T
100 -
80 --
•g 60 |
o>
I 40
20 --
20 40 60 80
Mean Amphipod Survival (% of Control)
100
Figure 3-17. Cumulative distribution of mean survival of amphipods in 10-day laboratory toxicity tests (expressed as percent of control
survival). (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 29
-------
co
20-i
15H
o
•S 10H
-------
Range and median concentrations for PAHs
measured in 1992 are listed in Table 3-2. Combined
PAH values reported in this table reflect the summation
of the concentrations of all of the PAH compounds that
were measured. This summation is not listed as "total"
PAH because only a select list of PAHs were measured
and many other PAH compounds could be found in
these sediments. Combined PAH concentrations for
low level samples are artificially low because analytes
that were not detected (ND) were assigned a value of
zero for calculation of the Combined concentration.
Combined PAH concentrations (Table 3-2) showed a
large range (ND -13,219 ng/g) with a median concentra-
tion of 661 ng/g in Virginian Province sediments.
This large range of PAH concentrations can be seen
in the cumulative distribution of combined PAHs shown
in Figure 3-19. This figure shows that the sediments
of the vast majority of the area of the Province contain
low concentrations of PAHs; for example, about 92 ±
7% of the sampled area of the Province had a combined
sediment PAH concentration of less than 4,000 ng/g dry
Table 3-2. Range and median PAH concentrations in sediments of the Virginian Province, 1992.
Analyte (weight3)
Concentration (ng/g dry weight)
MIN
MAX
Median
Median
Detection Limitb
Acenaphthene (L)
Acenaphthlylene (L)
Anthracene (H)
Benz(a)anthracene (H)
Benzo(b+k)fluoranthene (H)
Benzo(g,h,i)perylene (H)
Benz(a)pyrene (H)
Benz(e)pyrene (H)
Biphenyl (L)
Chrysene (H)
Dibenz(a,h)anthracene (H)
Fluoranthene (H)
Fluorene (L)
lndeno(1,2,3-c,d)pyrene (H)
Naphthalene (L)
1-methylnaphthalene (L)
2-methylnaphthalene (L)
2,6-dimethylnaphthalene (L)
2,3,5-trimethylnaphthalene (L)
Perylene (H)
Phenanthrene (H)
1-methylphenanthrene (H)
Pyrene (H)
Combined PAHs
a Letter in parenthesis indicates high
C f\r r\r-*f^\~\ "t-» yit *-J/-t+«-i «-i+*-\.-4" +l-k A 1 A l^ A » nX,
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
molecular
342
209
447
964
1,790
876
1,150
925
292
1,120
215
2,020
501
933
1,500
477
1,120
489
182
1,670
1,120
341
2,670
13,219
weight compound
ND
ND
ND
26.0
77.7
27.9
28.8
29.7
ND
37.3
ND
57.4
ND
36.25
15.6
ND
10.6
ND
ND
39.5
50.4
ND
71.35
661
(H) or low molecular
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
na
weight compound (L).
For each "not detected" the laboratory supplied a detection limit. This value is the median of these values
for each analyte.
na = not applicable
ND = not detected
Statistical Summary, EMAP-E Virginian Province - 1992
Page 31
-------
120 T
4 6 8 10
Combined PAHs (ng/g dry wt x 1000)
12
14
120 T
100 -
§80 +
~ eo •-
§
® 40 +
20 -•
0
1
10 100 1000 10000
Combined PAHs (ng/g dry wt)
100000
Figure 3-19a&b. Cumulative distribution of combined PAHs in sediments as percent of area in the Virginian Province, 1992: a) Linear
seals, b) Logarithmic scale. (Dashed lines are the 95% confidence intervals).
Page 32
Statistical Summary, EMAP-E Virginian Province - 1992
-------
weight. This value is used not because of ecological
significance but rather because it appears to be an
inflection point in the CDF. Figure 3-19b is the CDF
plotted on a log scale to better illustrate the distribution
of concentrations at the lower end of the scale.
As discussed above, draft Sediment Quality Criteria
are available for three PAHs: Acenaphthene, phenan-
threne, and fluoranthene. The SQCs (see Table 3-1) for
freshwater and saltwater sediments were not exceeded
at any station visited in 1992. Applying the more
conservative Lower SQC values in Table 3-1 does not
change these percentages. It is important to note that
these estimates were based on only those sediments with
a total organic carbon content of >0.2% (75 ± 10 % of
the area of the Province). For the purpose of this
exercise, those stations excluded were treated statistical-
ly as missing values.
Petroleum and combustion-type PAH sources contain
very different PAH compound distributions. Because
of this, the distributions of PAHs in a sample can
provide information on the relative importance of petro-
leum versus combustion PAH sources (Lake et al.,
1979). Petroleum products contain relatively large
amounts of lower molecular weight compounds relative
to combustion sources which are dominated by higher
molecular weight compounds (listed in Table 3-2).
Examination of the distribution of PAHs in samples
reveals that high molecular weight compounds dominate
in almost all samples, indicating that combustion is the
major source of PAHs in Virginian Province sediments.
3.2.3.2 Polychlorinated Biphenyls
Environmental measures of PCBs have been
conducted using a variety of techniques including their
measurement as industrial mixtures (e.g., Aroclors)
(Hutzinger, 1974), by level of chlorination (Gebhart et
al., 1985) and as individual congeners (Mullin et al.,
1984; Schantz et al., 1990). Each of these techniques
have both positive and negative aspects based on the
specific application for which the PCB data are needed.
For this study, PCBs were measured as a series of 18
selected congeners (Table 3-3). These congeners were
selected to produce data consistent with the National
Oceanographic and Atmospheric Administration's,
National Status and Trends Program. The congeners
included on this list are some of the more abundant
chlorobiphenyls found in environmental samples as well
as some (congeners 105 and 118) that are considered
to have a high potential for toxicity (McFarland and
Clarke, 1989).
The PCB congeners measured are identified based
on the numbering convention proposed by Ballschmiter
and Zell (1980). Concentration ranges and median values
measured for the individual congeners are listed in Table
3-3. Also included in this table is a summation of the
measured congeners referred to as combined PCBs. This
term was used instead of "total" PCBs to differentiate
it from measurements of all of the PCBs in a sample.
Combined PCB concentrations for low level samples
are artificially low because congeners that were not
detected were assigned a value of zero for calculation
of the combined concentration. Combined PCB
concentrations ranged from the detection limit to 577
ng/g dry weight with a median concentration of 6 ng/g.
The cumulative distribution of combined PCBs in the
Virginian Province is shown in Figure 3-20. This plot
shows that low concentrations of PCBs were found in
the majority of the area of the Province. PCBs were
not detected in 43 ± 12% of the area of the Province
and approximately 96 ± 6% of the Province contained
sediments with PCB concentrations below 50 ng/g dry
weight. This value is used not because of ecological
significance but rather because it appears to be an inflec-
tion point in the CDF. Figure 3-20b is the CDF plotted
on a log scale to better illustrate the distribution of
concentrations at the lower end of the scale.
3.2.3.3 Chlorinated Pesticides
In addition to PCBs, several other chlorinated com-
pounds were monitored in the sediments of the Virginian
Province (Table 3-4). Most of these chemicals are
banned in the United States although some are still used
in other countries. Several of the compounds measured
(e.g., DDEs, DDDs and heptachlor epoxide) are
environmental metabolites of the original pesticides
(Ernst, 1984) instead of the active ingredients of the
original pesticide formulations.
Six DDT-series compounds were measured. These
included the original insecticide, p,p'-DDT, and o,p'-DDT
which is a contaminant in p,p'-DDT formulations. The
four remaining compounds (p,p'-DDE, o,p'-DDE, p,p'-
DDD and o,p'-DDD) are metabolites or degradation
Statistical Summary, EMAP-E Virginian Province - 1992
Page 33
-------
Table 3-3. Range and median PCB concentrations in sediments of the Virginian Province, 1992.
Analyte
MIN
Concentration (ng/g dry weight)
MAX
Median
Median
Detection Limit3
PCB8
PCB18
PCB28
PCB44
PCB52
PCB66
PCB101
PCB105
PCB118
PCB128
PCB138
PCB153
PCB170
PCB180
PCB187
PCB195
PCB206
PCB209
Combined PCBs
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
32.6
44.7
156
38.0
57.1
85.9
34.4
22.8
33.0
3.87
31.9
25.4
5.44
9.86
7.23
2.81
21.6
29.4
577
0.291
ND
0.387
ND
0.260
0.597
0.474
ND
0.515
ND
0.728
0.720
ND
0.379
0.274
ND
ND
ND
6.04
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250 !
0.250
0.250
0.250 ,
0.250'
0.250
na
8 For each "not detected" the laboratory supplied a detection limit. This value is the median of these values
for each analyte.
na s not applicable
ND = not detected
Page 34
Statistical Summary, EMAP-E Virginian Province - 1992
-------
100 200 300 400
Combined PCBs (ng/g dry wt)
500
600
120
100
S 80 +
•2 60
CD
H
£ 40 +
20
0
0.1
1 10 100
Combined PCBs (ng/g dry wt)
1000
Figure 3-20a&b. Cumulative distribution of combined PCBs in sediments as percent of area in the Virginian Province, 1992: a) Linear
scale b) Logarithmic scale. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 35
-------
120 T
100 ••
£ 80
60 "j
I
o 40
20 -•
0
10 15
p,p'DDE(ng/gdrywt)
20
25
Figure 3-21. Cumulative distribution of p, p1 -DDE in sediments as percent of area in the Virginian Province, 1992. (Dashed lines
are the 95% confidence intervals).
Table 3-4. Range and median chlorinated pesticide concentrations in sediments of the Virginian Province,
1992.
Concentration (ng/g dry weight)
Analyte
MIN
MAX
Median
Median
Detection Limit3
O.p'-DDD
p,p'-DDD
o.p'-DDE
p.p'-DDE
0,p'-DDT
p.p'-DDT
Aldrin
Alpha-Chlordane
Dfeldrin
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Lindane (gamma-BHC)
Mi rex
Trans-Nonachlor
Total Chlordanes
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
9.44
21.7
11.6
21.8
4.31
4.80
ND
7.03
2.60
0.52
1.18
1.47
0.63
0.95
5.44
13.7
ND
0.281
ND
0.804
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
0.250
na
a For each "not detected" the laboratory supplied a detection limit. This value is the median of these values
for each analyte.
b Total Chlordanes is the sum of alpha-chlordane, heptachlor, heptachlor epoxide, and trans-nonachlor.
ND = not detected
Page 36
Statistical Summary, EMAP-E Virginian Province - 1992
-------
products of p,p'-DDT and o,p'-DDT, respectively. The
use of DDT is now banned in the United States. DDT-
series compounds were generally the most abundant of
the chlorinated pesticides measured in the Virginian
Province sediments (Table 3-4). The CDF of p,p'-DDE
is presented in Figure 3-21 as an example of the
distribution of DDT- series compounds measured in the
Virginian Province. As was previously seen for PAHs
and PCBs, the majority of the area of the Province con-
tains low p,p'-DDE levels (93 ± 8% of the area with
concentrations less than 4 ng/g). This This value is used
not because of ecological significance but rather because
it appears to be an inflection point in the CDF.
Chlordane is a pesticide that was widely used to
control termites and other insects, but its use was
severely restricted in 1987. It was sold as a technical
mixture containing well over 100 chlorinated compounds
(Dearth and Kites, 1991), many of which are persistent
in the environment and have been found widely
distributed in marine sediments. Two of these com-
pounds (alpha-chlordane and trans-nonachlor) were
measured in the sediments of the Virginian Province
(Table 3-4). The maximum concentrations observed for
these compounds were 7.03 and 5.44 ng/g dry weight
for alpha-chlordane and trans-nonachlor, respectively.
Figure 3-22 shows the cumulative distribution observed
for alpha-chlordane in sediments of the Virginian Prov-
ince. This plot shows that alpha-chlordane was not
detected in 84 ± 7% of the area of the Province. The
remaining pesticides measured generally showed
concentrations near the analytical detection limits in
most samples (Table 3-4).
The only chlorinated pesticide measured by EMAP-
VP in sediments for which there is a draft Sediment
Quality Criteria value is dieldrin. Draft EPA criteria
were not exceeded at any station within the Virginian
Province in 1992. It is important to note that this
estimate was based on only those sediments with a total
organic carbon content of >0.2% (75 ± 10% of the area
of the Province). For the purpose of this exercise, those
stations excluded were treated statistically as missing
values.
3.2.3.4 Butyltins
Until its recent ban for most uses (Huggett et al.,
1992), tributlytin (TBT) was used in many boat anti-
fouling paint formulations. As a result of this usage,
TBT and its breakdown products, dibutyltin (DBT) and
monobutyltin (MBT) have subsequently been detected
in many harbors (Seligman et al., 1989). The presence
of TBT in aquatic systems has generated considerable
concern because of the potent effects of this compound
on some species (Rexrode, 1987; Heard et al., 1989).
Tributlytin can be rapidly converted to DBT and MBT
in the water column but may be relatively resistant to
degradation in marine sediments (Adelman et al., 1990).
The concentrations of butyltin compounds in this report
are reported as nanograms of the respective butyltin ion
per gram of dry sediment. Caution should be used when
comparing TBT concentrations among studies because
of the different ways that it is reported (e.g., sometimes
reported as ng tin /g sediment).
The maximum TBT concentration observed was 473
ng/g; DBT and MBT levels were generally lower than
those of TBT (Table 3-5). Figure 3-23 shows the cumula-
tive distribution of TBT in sediments as a percent of
area in the Virginian Province. TBT was not detected
(detection limit of approximately 12 ng/g) in 25 ± 10%
of the area of the Province and 53 + 12% of the area
contained sediments with TBT concentrations of less
than 25 ng/g. Concentrations exceeding 100 ng/g were
detected at two stations representing only 0.6 (± 5)
percent of the area of the Province.
3.2.3.5 Total Organic Carbon
Organic carbon, as measured by EMAP in the sedi-
ments, includes all forms of carbon except carbonate.
Organic carbon accumulates in sediments of the marine
environment as a function of the proximity and magnitude
of the various sources of organic matter and the physical,
and biological factors that influence erosion and
deposition. The presence of organic matter is an
important modifier of the physical and chemical condi-
Statistical Summary, EMAP-E Virginian Province - 1992
Page 37
-------
120 ••
100 ••
80 •:~V
60 +
40 ••
20 ••
0
H 1 1 1 H-
234 5 6
Alpha-Chlordane (ng/g dry wt)
8
Figure 3-22. Cumulative distribution of alpha-chlordane in sediments as percent of area in the Virginian Province, 1992. (Dashed
linos are the 95% confidence intervals).
Table 3-5. Range and median butyltin concentrations in sediments of the Virginian Province, 1992.
Concentration (ng ion /g dry weight)
Analyte
Monobutyltin (MBT+3)
Dibutyltin (DBT+2)
Tributyltin (TBT+)
MIN
ND
ND
ND
MAX
54.8
25.1
473
Median
ND
ND
23.0
Median
Detection Limit3
17.8
9.8
12.2
a For each "not detected" the laboratory supplied a detection limit. This value is the median of these values
for each analyte.
ND SB not detected
Page 38
Statistical Summary, EMAP-E Virginian Province - 1992
-------
120 T
100 -
80
£ 60
o
i2 40
20
0
100 200 300
Tributyltin (ng TBT+ / g dry wt)
400
500
Figure 3-23. Cumulative distribution of tributyltin in sediments as percent of area in the Virginian Province, 1992. (Dashed lines
are the 95% confidence intervals).
tions in the benthic ecosystem and serves as the primary
source of food for the bottom fauna. As discussed
earlier, organic carbon also plays a critical role in the
geochemistry of organic contaminants in sediments.
The organic carbon content measured in sediments
of the Virginian Province ranged from 0.01 to 4.65%
by weight. The CDF of percent area as a function of
the total organic carbon present in the sediments for all
estuaries is shown in Figure 3-24. The pattern is largely
determined by the large estuaries (Figure 3-25) which
account for the largest part of the Province area.
3.2.3.6 Acid Volatile Sulfides
Acid volatile sulfides are defined as the fraction of
sulfide in the sediments that can be extracted with cold
hydrochloric acid. They exist in sediments mainly as
iron monosulfide complexes, and are important in
determining the biological availability of a number of
cationic metals, primarily zinc, lead, copper, nickel, and
cadmium. Acid volatile sulfides measured in sediments
of the Virginian Province ranged from 0.86 to 3,870
mg/kg dry weight sediment. The CDFs of percent area
as a function of AVS concentration is shown in Figures
3-26 and 3-27.
3.2.3.7 Metals
The median and range of metals concentrations
measured in 1992 are listed in Table 3-6. Elemental
concentrations in sediments are highly variable, due not
only to contaminant inputs, but to natural differences
in sediment types as well. Several approaches have been
used to normalize sediment metals concentrations for
variations due to sediment type differences. The approach
taken in the 1991 Virginian Province Statistical Summary
(Schimmel et al., 1994) was to normalize against
aluminum. Determination of metal-aluminum relation-
ships in background sediments enables estimation of the
extent of enrichment of metals in sediments.
Figure 3-28 presents an example of a metal regression
plot (for Cr). The predicted metal- aluminum relationship
(solid line) is obtained from the regression, along with
the upper bound of the 95% confidence interval for
predicted values (dashed line). Values above the upper
bound are greater than expected (i.e., enriched) based
on the aluminum concentration measured in the sediment.
This "excess" metal is derived from additional sources
other than crustal background sediment, presumably,
although not necessarily, from anthropogenic activity.
Regressions for the remaining metals are presented in
Statistical Summary, EMAP-E Virginian Province - 1992
Page 39
-------
120 T
01234
Total Organic Carbon (% dry wt)
Figure 3-24. The cumulative distribution of the percent total organic carbon in sediments as a percent of area in the Virginian
Province, 1992. (Dashed lines are the 95% confidence intervals).
Appendix B. Some of the metals, e.g., Ni, Cr, Se, Sb
and the crustally-derived elements Fe and Mn, are not
highly enriched (the highest measured concentrations
arc generally less than 2-3 times higher than the upper
bound of predicted concentrations). Two metals, Hg and
Ag, are found at a number of stations in concentrations
more than 10-60 times higher than predicted from the
metal-aluminum relationship. The highest concentra-
tions of other metals (Pb, Sn, Cu, As, Cd and Zn) are
generally 2-10 times higher than predicted. Often a
given station exhibits substantial enrichment of more
than one metal. The aerial extent of enriched metals
concentrations in sediments can be estimated once
Stations with enriched metals concentrations are
identified (Figure 3-29). For several metals, the
proportion of the Province in which metals concentra-
tions are enriched is substantial, e.g., Ag, Cr, and Sn.
One station in Chesapeake Bay exhibited sediment con-
centrations of both Pb and Sb several orders of mag-
nitude higher than any other station. This is likely due
to lead shot (presumably from duck hunters) included
in the sample. The co-occurrence of lead and antimony
(Sb is a hardener used in lead shot) at this station
supports this hypothesis.
Approximately 31 ±10% of the area of the Province
showed enrichment of sediments with at least one metal.
Twenty seven (± 13), 43 ± 13, and 34 ± 39 percentof
the large estuary, small estuary, and large tidal river class
areas sampled contained sediments with metals concen-
trations exceeding predicted background levels. Although
a significant proportion of the Province contains
sediments with potentially enriched levels of metals, this
does not imply ecological impact. The level of
enrichment is generally low, and most of the metals
present are likely bound by AVS or organic carbon,
making them biologically unavailable.
3.2.4 Marine Debris
Anthropogenic debris is perhaps the most obvious
sign of human use and environmental degradation. The
presence of anthropogenic debris in the field of view
or the inconvenience caused when it fouls a boat propeller
or fishing line can diminish the recreational value of
the estuarine environment. "Trash" is most likely to
be found in large tidal rivers and small estuaries where
human settlement and recreational activities are most
intense.
The debris collected in bottom trawls was examined
as an indicator of environmental degradation in the
Virginian Province. Debris was found on the bottom
of approximately 25 ± 11 % of the Virginian Province
area sampled in 1992 (Figure 3-30). The small estuary
Page 40
Statistical Summary, EMAP-E Virginian Province - 1992
-------
a) Large Estuaries
b) Small Estuaries
120 T
c) Large Tidal Rivers
1 2 3
Total Organic Carbon (% dry wt)
Figure 3-25. Cumulative distribution of the percent total organic carbon in sediments by estuarine class: a) Large estuaries,
b) Small estuaries, c) Large tidal rivers. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 41
-------
120 •
100 -
(8
£ 80 -
40 -
- ./ r
//
V
20
500 1000 1500 2000 2500 3000
Acid Volatile Sulfides (mg/kg)
3500 4000
Figure 3-26. The cumulative distribution of the acid volatile sulfide concentration in sediments as a percent of area in the
Virginian Province, 1992. (Dashed lines are the 95% confidence intervals).
class had the largest percent area (41 ± 19%) where
trash was found. Trash was found in 21 ± 13% of the
area of the large estuaries and 24 ± 45% of the area of
large tidal rivers.
3.3 Habitat Indicators
Habitat indicators describe the natural physical and
chemical conditions of the sites sampled in the 1992
Virginian Province study.
3.3.1 Water Depth
The depth distribution in the Virginian Province
is shown in Figure 3-31. The area shallower than 2 m
is underestimated because this is the minimum depth
. sampled. Based on the sampling design where a single
station represents a given area, 12% of the area of large
estuaries was unsampleable due to inadequate water
depth. Small estuaries were considered unsampleable
if the water depth did not exceed 2 m anywhere in the
system. Such systems account for approximately 1.5%
of the area of small systems in the Virginian Province.
Overall, 8.5% of the area of the Province was deemed
unsampleable in 1992 due to water depth.
3.3.2 Temperature
Bottom water temperature in the Virginian Province
ranged from 11.8°C to 27.8°C during the summer
sampling period. The cumulative distribution function
of bottom temperature is shown in Figure 3-32. The
lowest bottom temperatures measured in the Province
occurred in a small estuary at the eastern end of Cape
Cod, MA.
Bottom temperature in the small estuaries ranged
from 11.8°C to 27.8°C (Figure 3-33b). Large tidal rivers
had a steep CDF (Figure 3-33c) and exhibited the smallest
temperature range (22.6°C to 27.5°C).
3.3.3 Salinity
Salinity is determined by freshwater discharge and
seawater intrusion. Salinity in the broad sounds of the
northern extent of the Province is, in general, higher than
salinity in the coastal plain estuaries south of the Hudson
River. The CDF for bottom salinity (Figure 3-34) reflects
the different salinity characteristics of the large estuarine
systems (Figure 3-35).
Page 42
Statistical Summary, EMAP-E Virginian Province - 1992
-------
a) Large Estuaries
500 1000 1500 2000 2500 3000 3500 4000
b) Small Estuaries
120 T
500 1000 1500 2000 2500 3000 3500 4000
c) Large Tidal Rivers
140 T
120 •
cc 100 -
0)
S 80-
§ 60 •
a3
°- 40 -
20-
n -
/
/
/
1 1 1 1 1 1 1 1
0 500 1000 1500 2000 2500 3000 3500 4000
Acid Volatile Sulfides (mg/kg)
Figure 3-27. Cumulative distribution of the acid volatile sulfide concentration in sediments by estuarine class: a) Large estuaries,
b) Small estuaries, c) Large tidal rivers. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 43
-------
Table 3-6. Range and median metal concentrations in sediments of the Virginian Province, 1992.
Analyte
MIN
Concentration (ug/g dry weight)
MAX
Median
Median
Detection Limit3
Major
Aluminum
Iron
Manganese
Trace
1,890
1,360
23.9
83,000
64,700
5,850
41,800
22,100
424
na
na
na
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
ND
0.423
ND
1.90
1.05
ND
ND
ND
ND
ND
ND
3.15
152
30.8
2.39
147
201
13,600b
1.57
66.7
0.86
8.77
30.4
402
0.386
7.18
0.207
42.0
156.3
24.0
0.054
17.3
0.258
0.124
2.17
85.0
0.051
na
0.031
na
na
1.80
0.004
1.70
0.110
0.007
0.120
na
ffl For each "not detected" the laboratory supplied a detection limit. This value is the median of these values
for each analyte.
b Lead shot is suspected as the cause of this elevated concentration. An elevated antimony level was also
detected in this sample, and antimony is a hardener used in lead shot.
na « not applicable
ND = not detected
Page 44
Statistical Summary, EMAP-E Virginian Province - 1992
-------
160 T
120 -
O 80
40 -
2468
Aluminum (%)
Figure 3-28. Linear regression (with upper 95% confidence intervals) of chromium against aluminum.
10
30-,
CO
-------
80-
70-
co BO-
S'
< 50
o
I 40"!
§ 30
Q.
20-
10-
All
Large
Small
Tidal
Fiaure 3-30. Percent area of the Virginian Province by estuarine class where anthropogenic
debris was collected in fish trawls, 1992. (Error bars represent 95% confidence intervals).
120 T
100 •
£ 80 -
60
o>
I 40
20 ••
0
10
20 30
Depth (m)
40
50
Figure 3-31. Cumulative distribution of water depth as a percent of area in the Virginian Province, 1992. (Dashed lines are the
95% confidence intervals).
Page 46
Statistical Summary, EMAP-E Virginian Province - 1992
-------
120 T
12
14
16
18 20 22
Temperature (°C)
Figure 3-32. Cumulative distribution of bottom temperature as a percent of area in the Virginian Province, 1992 (Dashed lines
are the 95% confidence intervals).
The CDF for small estuaries (Figure 3-35) is
dominated by small systems in the Chesapeake Bay
which account for most of the area between 12 and
20%0. The low salinity tail of the CDF is due to the
contribution of small river systems, whereas the high
salinity component is due to embayments supplied with
high salinity waters from the northern sounds. The range
of salinities was greatest in small estuaries (0.1 to 32
%o), with the ranges for large estuaries and large tidal
rivers being 4 to 31 and 0.1 to 22 %0, respectively
(Figure 3-36).
The 1992 data showed 26 ± 20% of the large tidal
river area to be fresh water (salinity < 0.5%0). Large
tidal rivers contain the largest oligohaline area (44 ±
22% < 5 %0) compared to 11 ± 8% for small estuaries
and 2 ± 5% for the large estuaries (Figure 3-36).
3.3.4 pH
The negative log of the hydrogen ion concentration,
or pH, of estuarine and coastal waters, similar to
salinity, depends on the mixing of sea water and fresh
water from land drainage. Sea water is well-buffered,
with its pH usually falling between 8.1 and 8.4. The
pH of fresh water runoff depends upon the characteris-
tics of the land drained and can be quite variable.
The measured pH of Virginian Province estuaries
ranged from 6.8 to 9.2, with 64 ± 8% of the Province
area between pH 7.7 and 8.2. The lowest pH values
occurred in large tidal rivers, upper Chesapeake Bay,
and in small estuaries associated with tidal rivers or other
fresh water inflows. High pH values were generally
associated with sea water inflow; however, the highest
pH value was found in the upper Potomac River near
Washington DC.
3.3.5 Stratification
Vertical density differences (i.e., stratification), if
large enough, can result in a reduction of mixing between
surface and bottom waters, potentially allowing the
bottom waters to become hypoxic. Stratification may
also create conditions that enhance phytoplankton growth,
which might ultimately result in increased biomass
settling to the bottom contributing an additional biological
oxygen demand in the stratified environment.
Fresh water runoff can be an important factor in this
process because it both provides low density water which
helps to maintain stratification and often carries high
nutrient concentrations which support plant growth.
Stratification may also be caused by warming of the
surface waters, especially where salinity is uniform.
Statistical Summary, EMAP-E Virginian Province - 1992
Page 47
-------
a) Large Estuaries
120-
100-
80 •
60
! 40
20
0
12 14
16 18 20 22 24 26 28
120 T
b) Small Estuaries
12
14 16
18 20 22 24 26 28
c) Large Tidal Rivers
140
120 •
ca 100 -
I
15 80
60
40
20
0
12
14 16
18 20 22
Temperature (°C)
24
26 28
Figure 3-33. Cumulative distribution of bottom temperature by estuarine class: a) Large estuaries, b) Small estuaries, c)
Large tidal rivers. (Dashed lines are the 95% confidence intervals).
Page 48
Statistical Summary, EMAP-E Virginian Province - 1992
-------
10 15 20
Salinity (%o)
25
30
Figure 3-34. The cumulative distribution of bottom salinity as a percent of area in the Virginian Province, 1992. (Dashed lines
are the 95% confidence intervals).
The development of stratification depends not only on
the magnitude of the density difference between surface
and bottom waters, but also on the depth of those waters
and the physical energy available for mixing. Although
affected by tidal stage, rainfall and other factors, no
attempt was made to normalize density data.
Stratification in the Virginian Province is shown as
a CDF of Aat, which is the a, (sigma-t) difference
between surface and bottom waters (Figure 3-37).
Sigma-t is a density measurement commonly used in
oceanographic studies. It is a measurement of the
density a parcel of water with a given temperature and
salinity would have at the surface (i.e., atmospheric
pressure), and is presented as:
(density - 1) x 1000
The CDF for all estuaries shows that 68 ± 11% of
the Province area had a Aat of <1 unit, with 38 ± 11%
being <0.2; thus the majority of the water in the
Virginian Province was well-mixed. Seventeen ± 10%
of the Province area was stratified (Aat >2). The bar
chart for stratification by class (Figure 3-38) shows that
small estuaries and large tidal rivers were least stratified
(2 ± 39% with Arjt >2) and best mixed (94 ± 8% and
98 ± 39%, respectively with Arjt <1.0). Large estuaries
had the greatest range of Aat (0 to 6).
3.3.6 Suspended Solids
The amount of suspended matter in the water is
dependent on the physical and biological conditions at
the site. Both the concentration and composition (i.e.,
size distribution and organic vs inorganic origin) of
suspended material affects light extinction and water
clarity; and thus the productive and aesthetic qualities
of the water.
The data presented in this section represent surface
values only. Suspended solids concentrations in the
waters of the Virginian Province ranged from 2.7 to 58
mg/L in 1992 (Figure 3-39). The relative condition of
Virginian Province waters in large estuary, small estuary,
and large tidal river classes are similar (Figure 3-40).
3.3.7 Light Extinction
The light extinction coefficient is a measure of the
attenuation of sunlight in the sea. It is the natural
logarithm of the ratio of the intensity of light of specified
wavelength on a horizontal surface to the intensity of
the same wavelength light on a horizontal surface 1 m
deeper. The extinction coefficient of photosynthetically
active radiation (PAR) was calculated from depth and
PAR measurements made with the SeaBird CTD. The
Statistical Summary, EMAP-E Virginian Province - 1992
Page 49
-------
a) Large Estuaries
25
30
b) Small Estuaries
30
c) Large Tidal Rivers
10
15 20
Salinity (%o)
30
Figure 3-35. Cumulative distribution of bottom salinity by estuarine class: a) Large estuaries, b) Small estuaries, c) Large
Udal rivers. (Dashed lines are the 95% confidence intervals).
Page 50
Statistical Summary, EMAP-E Virginian Province - 1992
-------
100-1
80-
cc
S 60
o
CD
E
(D
Q_
40-
20H
I
P
M 5 to 18
All
Large
Small
Tidal
Figure 3-36. Percent area by estuarine class classified as oligohaline (<5 ppt), mesohaline (5 to 18 ppt), and
polyhaline (>18 ppt). (Error bars represent 95% confidence intervals).
CO
120
100 --
80
60
CD
E
s. 40
20 -/
0
3
Aot
4
Figure 3-37. Cumulative distribution of the stratified area in.the Virginian Province in 1992 based on the CT, difference between
surface and bottom waters. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 51
-------
140-
120-
100-
9 60 H
o 80-
*->
CD
Q
Q>
CL 40-
20-
0
1 to 2
>2
All
Large Small Tidal
Figure 3-38. The percent of the area by estuarine class that had a low (<1), medium (1 to 2), or high (>2)
degree of stratification ( A a,). (Error bars represent 95% confidence intervals).
120 T
10 20 30 40
Suspended Solids (mg/L)
50
60
Figure 3-39. The cumulative distribution of total suspended solids concentration as a percent of area in the Virginian Province,
1992. (Dashed lines are the 95% confidence intervals).
Page 52
Statistical Summary, EMAP-E Virginian Province - 1992
-------
a) Large Estuaries
120 T
100 -•
b) Small Estuaries
<0
2
120
100 -
80 --
o>
e
- 60 -•
40 -•
20 -
0
0
10
20
30
40
H H
50
60
c) Large Tidal Rivers
140
120 •
a 100 ••
2
^ 80
ffl 60
40
20
0
o
10 20 30 40
Suspended Solids (mg/L)
50
60
Figure 3-40. Cumulative distribution of total suspended solids concentration by estuarine class: a) Large estuaries, b) Small
estuaries, c) Large tidal rivers. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page 53
-------
extinction coefficient is an important measure of the
light available for photosynthesis and of the aesthetic
qualities of the water for human use.
We are defining low water clarity as water in which
a diver would not be able to see his/her hand when held
at arms length. This corresponds to an attenuation
coefficient £2.303 which is equivalent to the transmis-
sion of 10% of the light incident on the surface to a
depth of 1 m. Moderate water clarity corresponds to
an extinction coefficient of >1.387, which is equivalent
to the transmission of 25% of the light incident on the
water surface to a depth of 1 m. In terms of human
vision, a wader in water of moderate clarity would not
be able to see his/her feet in waist-deep water.
Water clarity was good in 83 ± 8% of the sampled
area of the Virginian Province (Figure 3-41). Water of
low clarity was found in 5 ±6% of the Province and
an additional 12 ± 7% of the Province had water of
moderate clarity. Thus, in 17 ± 8% of the waters in the
Virginian Province waders would not be able to see their
toes in waist deep water. Water of low clarity was
found in 3 ± 5% of the large estuarine area, 4 ± 4% of
the small estuarine area, and in 20 ± 40% of the large
tidal river area (Figure 3-42). These differences in
water clarity may be due to fundamental differences in
the dynamic properties of the classes as well as
differences in the intensity of human use. Large
estuaries had the greatest percent area of high water
clarity (90 ± 9%).
3.3.8 Percent Silt-Clay Content
The silt-clay (mud) content of sediments (the
fraction <63u) is an important factor determining the
composition of the biological community at a site, and
is therefore important in the assessment of the benthic
community. Percent mud is also useful when examining
sediment chemistry data because the available surface
area for sorption of contaminants is partially a function
of grain size, with fine-grained sediments (i.e., mud)
generally being more susceptible to contamination than
sands exposed to the same overlying water.
All silt-clay results presented in this report are for
the surficial sediments (0-2 cm) collected as part of the
chemistry /toxicity homogenate.
The CDF of silt-clay content for the Virginian
Province is shown in Figure 3-43. Forty-five (± 12)
percent of the area had sandy sediments (<20% silt-clay),
and 21 + 10% of the area had muddy sediments (>80%
silt-clay). The sediment size distribution in large
estuaries was dominated by sands, in small estuaries by
muds, and in tidal rivers it was variable (Figure 3-44).
Sediment size distribution is primarily a result of
the different physical characteristics of the separate
system classes. For example, small systems are often
estuaries, bays, tidal creeks and rivers with low flow
rates, which result in high deposition rates of fine-
grained material. The large area of sandy sediments
found in the large estuaries of the Virginian Province
are most likely the result of either the winnowing of
sediments or the transport of marine sands. The mouth
of the Chesapeake Bay is an example of the latter where
sands are carried in from the ocean (Hobbs et al., 1992).
Long Island Sound is an example of a system where the
coarser sediments at the entrance are mainly a result of
strong tidal currents transporting away the fine fraction
(winnowing), leaving behind the coarser sands and gravel
(Akapati, 1974; Gordon, 1980).
3.4 Integration of Estuarine Conditions
The condition of estuaries of the Virginian Province
to use can be estimated through the examination of
multiple indicators. As an example, we have integrated
data on stations that can be considered "degraded" based
on aesthetic quality (poor water clarity or the presence
of anthropogenic trash caught in fish trawls), low bottom
dissolved oxygen concentration (< 5mg/L), and the
benthic index. The summation of these indicators was
used as an indicator of the maximum extent of potential
degradation. Figure 3-45 shows that, in this example,
49 ± 11 % of the Province is potentially degraded in terms
of its benthic biology and ability to support desired
human commercial or recreational uses. Aesthetic value
(water clarity and presence of trash) was degraded in
25% of the Province, whereas 34% of the area may be
degraded as a result of subnominal benthic communities
or low levels of dissolved oxygen. In 9% of the Province
area subnominal benthic communities or hypoxia existed
along with evidence of aesthetic degradation, and in one
percent of the area of the Province all three indicators
of degradation co-existed.
Page 54
Statistical Summary, EMAP-E Virginian Province - 1992
-------
0
1 2
Light Extinction Coefficient
Figure 3-41. The cumulative distribution of light extinction coefficient as a percent of area in the Virginian Province in 1992.
(Dashed lines are the 95% confidence intervals).
140-i
120-
| 100-
? 80-
•4-*
o
a eo H
-------
120 T
20
40 60
Silt/Clay (%)
100
Figure 3-43. The cumulative distribution of the percentage of silt-clay in the sediments as a percent of area in the Virginian
Province, 1992. (Dashed lines are the 95% confidence intervals).
100-1
Large
Small
Tidal
Figure 3-44. Percent of area by estuarine class with a low (<20), medium (20 to 80), or high (>80) percent
silt-clay in the sediments. (Error bars represent 95% confidence intervals).
Page 56
Statistical Summary, EMAP-E Virginian Province - 1992
-------
16%
51%
4%
5%
4%
Low DO.B1,
Aesthetics
Figure 3-45. Integration of estuarine conditions based on aesthetic quality (presence of bottom trash and water clarity), bottom
dissolved oxygen (< 5mg/L), and the benthic index.
Poor water clarity and the presence of anthropogenic
debris may dictate impairment of some human uses, but
are probably not good indicators of ecological degrada-
tion; therefore, the area of the Virginian Province that
is, in fact, degraded is probably much less than indicated
in this example.
This evaluation is intended solely as an example of
how these data may be used. To truly estimate the
percent area degraded, all indicators should be included.
Due to the current state of understanding of sediment
geochemistry and its relationship with the biota, such
an exercise could not be undertaken at this time.
Statistical Summary, EMAP-E Virginian Province - 1992
Page 57
-------
SECTION 4
SUMMARY OF FINDINGS
Thousands of pieces of information on the condition
of estuarine resources in the Virginian Province in 1992
were collected and analyzed. The major findings of the
1992 study year are highlighted in this section.
4.1 Virginian Province Fact Summary
• The Virginian Province includes the coastal
region of the Northeast United States from Cape
Cod south to the mouth of Chesapeake Bay.
It is composed of 23,574 km2 of estuarine
resources including 11,469 km2 in Chesapeake
Bay and 3,344 km2 in Long Island Sound.
• Estuarine resources in the Virginian Province
were stratified into classes for purposes of
sampling and analysis. The classes and their
areal extent are as follows: Large estuaries,
16,097 km2; small estuaries, 4,875 km2; and
large tidal rivers, 2,602 km2.
• The large estuary class includes Chesapeake Bay
(main stem plus lower Potomac River), Delaware
Bay, Long Island Sound, Block Island Sound,
Buzzard's Bay, Narragansett Bay, and Nantucket
Sound.
• The large tidal river class includes the James,
Rappahannock, Potomac, Delaware, and Hudson
Rivers.
• The small estuary class includes 144 estuarine
systems of various types between 2.6 and 260
km2 in area of which 39 were sampled in 1992.
4.2 Findings of the 1992 Sample Year
• All of the 126 scheduled stations were successful-
ly sampled. The majority of the data collected
at these stations met the quality control standards
set by the Program.
• A benthic index was developed to discriminate
between good and poor environmental conditions.
Based on this index, approximately 14 ± 6% of
the Province area could be classified as potential-
ly degraded relative to the benthic community.
• Bottom dissolved oxygen concentrations <2 mg/L
were measured at stations representing 5 ± 5%
of the Province area. Concentrations <5 mg/L
were measured in 29 ±11% of the area of the
Province.
• Draft EPA Sediment Quality Criteria (SQC) are
currently available for four of the analytes
EMAP measures in sediments: acenaphthene,
phenanthrene, fluoranthene, and dieldrin. SQC
were not exceeded at any Virginian Province
station sampled in 1992.
• Sediments collected from stations representing
approximately 31 ± 10% of the Province area
were determined to contain elevated levels of
metals.
• Table 4-1 summarizes the data presented in
Section 3 for selected Biotic Condition, Abiotic
Condition, and Habitat indicators.
Page 58
Statistical Summary, EMAP-E Virginian Province - 1992
-------
Overall, approximately 49 + 11% of the area of
the.Province is potentially degraded in terms of
its benthic biology, bottom dissolved oxygen,
or aesthetic appeal.
Table 4-1. Percent area of the
interest for selected
Virginian Province (with 95% confidence intervals) above or below values of
indicators in 1992.
Percent area
Estuarine Condition
Benthic Index
<0
Total Benthic Abundance
<200 / m2
Bottom DO
<2 mg/l
<5 mg/l
Sediment Toxicity
(% control survival)
<80%
Enriched metals
any metal
above background
Marine Debris
presence
Salinity
Polyhaline (>18%0)
Mesohaline (5 to 18%0)
Oligohaline (< 5%o)
Province
14
5
5
29
6
31
25
73
18
9
±6
±5
±5
± 10
±5
± 10
± 11
±9
±9
±4
Large
Estuary
10
5
7
38
8
27
21
86
12
2
± 10
±7
±8
± 15
±8
± 13
± 13
± 11
± 11
±5
Large
Tidal
River
37
10
0
12
3
34
24
7
49
44
±22
±20
±0
± 16
±5
±39
±45
±40
±48
±22
Small
Estuary
23
1
0
10
2
43
41
65
24
11
± 12
± 1
±0
±8
±2
± 13
±19
± 12
± 12
±8
Statistical Summary, EMAP-E Virginian Province - 1992
Page 59
-------
SECTION 5
REFERENCES
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ecosystem. Environ. Sci. Technol. 24: 1027-1032.
Akapati, B.N. 1974. Mineral composition and sediments in eastern Long Island Sound. Maritime Seds. 10:
19-30.
ASTM (American Society of Testing and Materials). 1991. Standard guide for conducting 10-day static
sediment toxicity tests with marine and estuarine amphipods. Annual Book of ASTM Standards Volume
II. 04:1052-1075.
Ballschmiter , K., and M. Zell. 1980. Analysis of polychlorinated biphenyls (PCBs) by glass capillary gas
chromatography. Fresenius Z. Anal. Chem. 302: 20-31.
Boesch, D.F. and R. Rosenberg. 1981. Response to stress in marine benthic communities. In: G.W. Barret
and R. Rosenberg, eds., pp. 179-200. Stress Effects on Natural Ecosystems. New York: John Wiley and
Sons.
Dearth, M.A. and R.A. Kites. 1991. Complete analysis of technical chlordane using negative iohization mass
spectrometry. Environ. Sci. Technol. 25: 245-254. ;
Ernst, W. 1984. Pesticides and technical organic chemicals. In: Otto Kinne ed., pp. 1627-1709. Marine
Ecology. New York: John Wiley & Sons.
Gebhart, J.E., T.L. Hayes, A.L. Alford-Stevens and W.L. Budde. 1985. Mass spectrometric determination of
polychlorinated biphenyls as isomer groups. Anal. Chem. 57: 2458-2463.
Gordon, R.B. 1980. The sedimentary system of Long Island Sound. Advances in Geophysics 22:1-39.
Heard, C.S., W.W. Walker and W.E. Hawkins. 1989. Aquatic toxicological effects of organotins: An
overview. Proceedings, pp. 554-563. Oceans '89 Conference and Exposition on Science and Engineering.
Washington, DC: Institute of Electrical and Electronics Engineers.
Hobbs, C.H., III, J.P. Halka, R.T. Kerhin, and M.J. Carron. 1992. Chesapeake Bay sediment budget. J.
Coast. Res. 8(2): 292 - 300.
Page 60
Statistical Summary, EMAP-E Virginian Province - 1992
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Holland, A.F., ed. 1990. Near Coastal Program Plan for 1990: Estuaries. EPA 600/4-900/033.
Narragansett, RI: U.S. Environmental Protection Agency, Environmental Research Laboratory, Office of
Research and Development.
Huggett, R.J., M.A. Unger, P.P. Seligman and A.O. Valkirs. 1992. The marine biocide tributyltin. Environ.
Sci. Technol. 26: 232-237. :
Hutzinger, O, S. Safe and V. Zitko. 1974. The Chemistry ofPCBs. Cleveland, OH: CRC Press. 269pp.
Karr, J.R., and D.R. Dudley. 1981. Ecological perspective on water quality goals. Environ. Manage. 5:55-
68.
Karr, J.R., K.D. Fausch, P.L. Angermeier, P.R. Yant, and I.J. Schlosser. 1986. Assessing biological
integrity in running waters: a method and its rationale. Special Publication 5. Champaign, II: Illinois
Natural History Survey.
Lake, J.L., C. Norwood, C. Dimock and R. Bowen. 1979. Origins of polycyclic aromatic hydrocarbons in
estuarine sediments. Geochimica et Cosmochimica Acta 43: 1847-1854.
McFarland, V.A. and J.U. Clarke. 1989. Environmental occurrence, abundance, and potential toxicity of
polychlorinated biphenyl congeners: Considerations for a congener-specific analysis. Environ. Health
Perspectives 81: 225-239.
Messer, J.J. 1990. EMAP Indicator Concepts. In: C.T. Hunsaker and D.E. Carpenter, eds., Ecological
Indicators for the Environmental Monitoring and Asssessment Program. EPA 600/3-90/060. Research
Triangle Park, NC: U.S. Environmental Protection Agency, Office of Research and Development.
Mullin, M.D., C.M. Pochini, S. McCrindle, M. Romkes, S.H. Safe and L.M. Safe. 1984. High-resolution
PCB analysis: Synthesis and chromatographic properties of all 209 PCB congeners. Environ. Sci. Technol.
18: 468-476.
Nixon, S.W., C.D. Hunt and B.L. Nowicki. 1986. The retention of nutrients (C,N,P), heavy metals (Mn,
Cd, Pb, Cu), and petroleum hydrocarbonds in Narragansett Bay. In: P. Lasserre and J.M. Martin, eds.,
pp. 99-122. Biogeochemical Processes at the Land-sea Boundary. New York: Elsevier.
Overton, W.S., D.L. Stevens and D. White. 1991. Design Report for EMAP, Environmental Monitoring and
Assessment Program. Corvallis, OR: U.S. Environmental Protection Agency, Environmental Research
Laboratory.
Pearson, T.H. and R. Rosenberg. 1978. Macrobenthic succession in relation to organic enrichment and
pollution of the marine environment. Oceanogr. Mar.-Biol. Ann. Rev. 16:229-311.
Reifsteck, D.M. 1992. EMAP-Estuaries 1992 Virginian Province Effort: Field Readiness Report.
Narragansett, RI: U.S. Environmental Protection Agency, Environmental Research Laboratory, Office of
Research and Development, July 1992.
Reifsteck, D.M., C.J. Strobel, and S.C. Schimmel. 1992. EMAP-Estuaries 1992 Virginian Province Field
Operations and Safety Manual. Narragansett, RI: U.S. Environmental Protection Agency, Office of
Research and Development, June 1992.
Statistical Summary, EMAP-E Virginian Province - 1992
Page 61
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Rexrode, M. 1987. Ecotoxicity of tributyltin. Proceedings, pp. 554-563. Oceans '87 Conference and
Exposition on Science and Engineering. Washington, DC: Institute of Electrical and 'Electronics
Engineers.
Schantz, M.M., B.A. Benner, Jr., S.N. Chesler, BJ. Koster, K.E. Hehn, S.F. Stone, W.R. Kelly, R. Zeisler
and S.A. Wise. 1990. Preparation and analysis of a marine sediment reference material for the
determination of trace organic constituents. Fresenius J. Anal. Chem. 338: 501-514.
Schimmel, S.C., B.D. Melzian, D.E. Campbell, C.J. Strobel, S.J. Benyi, J.S. Rosen, and H.W. Buffum. 1994.
Statistical Summary: EMAP-Estuaries Virginian Province - 1991. EPA/620/R-94/005 Narragansett, RI:
U.S. Environmental Protection Agency, Environmental Research Laboratory, Office of Research and
Development.
Schubel, J.R. and H.H. Carter. 1984. The estuary as a filter for the fine-grained suspended sediment. In:
V.S. Kennedy, ed., pp. 81-104. The Estuary as a Filter. Orlando, FL: Academic Press.
Seligman, P.P., J.G. Grovhoug, A.O. Valkirs, P.M. Stang, R.Fransham, M.O. Stallard, B. Davidson and R.F.
Lee. 1989. Distribution and fate of tributyltin in the United States marine environment. Applied
Orsanometalic Chem. 3: 31-47.
Stevens, D.L., Jr., A.R. Olsen, D. White. 1991. Environmental Monitoring and Assessment Program --
integrated sampling design. Draft report. Corvallis, OR: Environmental Research Laboratory, U.S.
Environmental Protection Agency.
Strobel, C.J., D.M. Reifsteck, and S.C Schimmel. 1992. Environmental Monitoring and Assessment Program
EMAP-Estuaries, Virginian Province Logistics Plan for 1992. Narragansett, RI: U.S. Environmental
Protection Agency, Environmental Research Laboratory, Office of Research and Development, January
1992.
Swartz R.C., W.A. DeBen, J.K. Jones, J.O. Lamberson, and F.A. Cole. 1985. Phoxocephalid amphipod
bioassay for marine sediment toxicity. In: R.D. Cardwell, R. Purdy, and R.C. Bahner, eds., pp. 284-307.
Aquatic Toxicology and Hazard Assessment: Seventh Symposium. Philadelphia, PA: American Society for
Testing and Materials.
U.S. EPA/ACE. 1991. Evaluation of dredged material proposed for ocean disposal (Testing manual).
Prepared by the U.S. Environmental Protection Agency, Office of Marine and Estuarine Protection and
Department of the Army, United States Army Corps of Engineers, February 1991.
U.S. EPA. 1991. EMAP Laboratory Methods Manual: Estuaries. Cincinnati, OH: U.S. Environmental
Protection Agency, Environmental Monitoring Systems Laboratory, Office of Research and Development.
U.S. EPA. 1993a. Proposed Sediment Quality Criteria for the Protection of Benthic Organisms:
Acenaphthene. Washington DC: U.S. Environmental Protection Agency, Office of Science and
Technology. In Review.
U.S. EPA. 1993b. Proposed Sediment Quality Criteria for the Protection of Benthic Organisms:
Phenanthrene. Washington DC: U.S. Environmental Protection Agency, Office of Science and
Technology. In Review.
Page 62
Statistical Summary, EMAP-E Virginian Province - 1992
-------
U.S. EPA. 1993c. Proposed Sediment Quality Criteria for the Protection of Benthic Organisms:
Fluoranthene. Washington DC: U.S. Environmental Protection Agency, Office of Science and
Technology. In Review.
U.S. EPA. 1993d. Proposed Sediment Quality Criteria for the Protection of Benthic Organisms: Dieldrin.
Washington DC: U.S. Environmental Protection Agency, Office of Science and Technology. In Review.
Valente, R., C.J. Strobel and S.C. Schimmel. 1992. EMAP'-Estuaries Virginian Province 1992 Quality
Assurance Project Plan. Narragansett, RI: U.S. Environmental Protection Agency, Office of Research and
Development, Environmental Research Laboratory. July 1992.
Weisberg, S.B., J.B. Frithsen, A.F. Holland, J.F. Paul, K.J. Scott, J.K. Summers, H.T. Wilson, R.M.Valente,
D.G. Heimbuch, J. Gerritsen, S.C. Schimmel, and R.W. Latimer. 1993. EMAP'-Estuaries, Virginian
Province 1990 Demonstration Project Report. EPA/620/R-93/006. Narragansett, RI: U.S. Environmental
Protection Agency, Environmental Research Laboratory, Office of Research and Development.
Windsor, J.G., Jr. and R.A. Hites. 1979. Polycyclic aromatic hydrocarbons in Gulf of Maine sediments and
Nova Scotia soils. Geochimica et Cosmochimica Acta 43: 27-33.
Statistical Summary, EMAP-E Virginian Province - 1992
Page 63
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-------
APPENDIX A
SUB-POPULATION ESTIMATES FOR CHESAPEAKE BAY
AND LONG ISLAND SOUND
The two largest systems within the Virginian
Province are Chesapeake Bay (11,469 km2) and Long
Island Sound (3,344 km2). Combined, these two
systems represent 63% of the surface area of the entire
Province. Because of their size, and therefore the
number of sampling locations in each, estimates of
ecological condition of these systems are possible using
the EMAP design. However, the level of uncertainty
will remain higher than for estimates for the Province
as a whole or individual classes.
This appendix provides the tools for generating these
estimates, i.e., data for these two systems are
summarized using CDFs and bar charts. Each system
is defined as including all adjacent tributaries and small
systems. For example, the data set for Chesapeake Bay
includes the Potomac, James, and Rappahannock Rivers,
and all the small systems connecting to the mainstem
of the Bay. Since the Long Island Sound data set
contains no large tidal rivers and fewer small systems
than Chesapeake Bay, this may account for some of the
differences observed between these two systems. Fifty
three stations are included in the Chesapeake Bay data
set and 14 in the Long Island Sound data set.
A.I Biotic Condition Indicators
A. 1.1 Benthic Index
A benthic index value below zero is indicative of
a degraded benthic community. Approximately 20 ±
13% of the sampled area of Chesapeake Bay produced
a benthic index value below zero, and the corresponding
area of Long Island Sound was 3 ± 4% (Figure A-l).
CO
CD
D.
40 -i
30 -
20 -
10
Chesapeake Bay Long Island Sound
Figure A-1. Percent area of Chesapeake Bay and Long
Island Sound in 1992 with a benthic index below 0. (Error
bars are the 95% confidence intervals).
A.I.2 Number of Benthic Species
The total number of species collected at each station,
as percent area in these systems, is illustrated in Figure
A-2. The distribution, and maximum (41 and 36 species)
values are similar for Chesapeake Bay and Long Island
Sound, respectively.
A.1.3 Total Benthic Infauna Abundance
Figure A-3 shows the distribution of total number
of benthic individuals per m2 measured in Chesapeake
Bay and Long Island Sound. The maximum number
of individuals collected at a station was higher in the
Sound than in the Bay (21,265 and 16,712, respectively).
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 1
-------
Chesapeake Bay
10 20 30
Benthic Species (Mean #/ Station)
40
Long Island Sound
10 20 30
Benthic Species (Mean #/ Station)
40
Figure A-2. Cumulative distributions of the mean number of benthic invertebrate species per station as a
percent of area of Chesapeake Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence
intervals).
Page A - 2
Statistical Summary, EMAP-E Virginian Province - 1992
-------
120
0
Chesapeake Bay
4 6 8 10 12 14 16 . 18
Total Benthic Abundance (#/m2 x 1000)
20 22
120 T
0
Long Island Sound
4 6 8 10 12 14 16 18
Total Benthic Abundance (#/m2 x 1000)
20 22
Figure A-3. Cumulative distributions of the number of benthic invertebrates collected per m2 as a percent
of area of Chesapeake Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence
intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 3
-------
A.1.4 Number of Fish Species
A.2.2 Dissolved Oxygen Stratification
The number of fish species collected per standard
trawl is shown in Figure A-4. Between 0 and 7 species
the distributions are similar; however the maximum
number of individuals caught at a station in Chesapeake
Bay was approximately double that in Long Island
Sound (17 and 9, respectively).
A.1.5 Total Finfish Abundance
The total number offish captured per standard trawl
(catch per unit effort) was greater at Chesapeake Bay
stations than Long Island Sound stations (Figure A-5).
The maximum catch in the Bay was 424 individuals;
whereas, no more than 212 were collected at any station
in Long Island Sound. This is presumably due to
habitat and cannot be related to man's impact.
A.1.6 Fish Gross External Pathology
All fish species were examined for evidence of gross
external pathologies. Only two pathologies were
observed in Chesapeake Bay and none in Long Island
Sound; however, only 314 fish were collected and
examined in Long Island Sound compared to 1,756 in
Chesapeake Bay (Table A-l).
A.2 Abiotic Condition Indicators
A.2.1 Dissolved Oxygen Concentration
CDFs for bottom dissolved oxygen concentration
in Chesapeake Bay and Long Island Sound are shown
in Figure A-6. Approximately 11 ± 11% of sampled
area of Chesapeake Bay contained severely hypoxic
water (DO ^2 mg/1). A DO of less than 2 mg/L was
not measured at any station in Long Island Sound in
1992. Approximately 55 ± 29% of the Sound was
marginal, with DO values less than 5 mg/L (compared
to40± 15% for the Bay).
The difference in measured DO concentrations at
the bottom compared with surface measurements taken
at those same stations are illustrated in Figure A-7. The
stations with the greatest A DO were found in Chesapeake
Bay.
A.2.3 Sediment Toxicity
Sediments were classified as toxic if amphipod survival
in the test sediment was less than 80% of that in the control
sediment, and significantly different from the control.
Sediments sampled from Chesapeake Bay in 1992 representing
0.6 ± 1% of the Bay's area exhibited toxicity. Approximately
10 ± 20% of the area sampled in Long Island Sound contained
toxic sediments (Figure A-8).
A.2.4 Sediment Contaminants - Organics
Draft EPA Sediment Quality Criteria (SQC) exist
for four compounds for which EMAP is monitoring:
acenaphthene, phenanthrene, fluoranthene, and dieldrin.
No station in Chesapeake Bay or Long Island Sound exceeded
any of the SQCs.
CDFs for combined PAHs are presented in Figure
A-9. Although the maximum concentration measured
was higher in Chesapeake Bay than Long Island Sound
(13,219 and 8,235 ng/g dry weight, respectively), the
distributions are similar with 97 ± 3% of the sampled
area of Long Island Sound containing concentrations
less than 4,000 ng/g compared to 87 ± 12% for Chesapeake
Bay.
A.2.5 Sediment Contaminants - Metals
Table A-2 lists minimum, maximum, and median
bulk sediment concentrations of metals measured in
Chesapeake Bay and Long Island Sound in 1992. Median
values for most metals were higher in Long Island Sound
than in Chesapeake Bay.
A.2.6 Marine Debris
The incidence of trash collected in trawls is illustrated
in Figure A-10. Trash was found in 27 ± 17% of the
area of Chesapeake Bay and 18 ± 22% of the area of
Long Island Sound.
Page A-4
Statistical Summary, EMAP-E Virginian Province - 1992
-------
Chesapeake Bay
120 T
4 6 8 10 12 14
Number of Fish Species per Trawl
120 T
CO
•4— •
0)
CD
a.
0
Long Island Sound
4 6 8 10 12 14
Number of Fish Species per Trawl
Figure A-4. Cumulative distributions of the number of fish species collected in standard trawls as a
percent of area of Chesapeake Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence
intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 5
-------
Chesapeake Bay
100 200 300
Number of Fish per Trawl
400
500
Long Island Sound
100
200 300
Number of Fish per Trawl
400
500
Figure A-5. Cumulative distributions of the number of fish collected in standard trawls as a percent of
area of Chesapeake Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence intervals).
Page A - 6
Statistical Summary, EMAP-E Virginian Province - 1992
-------
Table A-1. Incidence of gross external pathology for Chesapeake Bay and Long Island Sound observed by
field crews in 1992.
Lumps
Growths
Ulcers
Fin Rot
Total
Chesapeake Bay
Frequency
Total # Fish Examined
Percent Incidence
Number Stations
Represented
0
1,756
0%
0
1,756
0%
2
1,756
0.11%
0
1,756
0%
2
1,756
0.11%
Long Island Sound
Frequency
Total # Fish Examined
Percent Incidence
Number Stations
Represented
00000
314 314 314 314 314
0% 0% 0% 0% 0%
0
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 7
-------
Chesapeake Bay
0
4 6
Dissolved Oxygen (mg/L)
8
120 T
100
1 80}
1 60*
o>
§ 40 +
a.
20
0
0
Long Island Sound
4 6
Dissolved Oxygen (mg/L)
8
10
Figure A-6. Cumulative distributions of dissolved oxygen in the bottom waters as a percent of area of
Chesapeake Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence intervals).
Page A - 8
Statistical Summary, EMAP-E Virginian Province - 1992
-------
0
Chesapeake Bay
12345
Dissolved Oxygen Difference (mg/L)
120
CO
0
Long Island Sound
1 2 345
Dissolved Oxygen Difference (mg/L)
6
Figure A-7. Cumulative distributions of the DO difference between surface and bottom waters as a
percent of area of Chesapeake Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence
intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 9
-------
Chesapeake Bay
CO
120 T
100
80
2 60
CD
I 40
o.
20 •
75
80 85 90 95
Mean Amphipod Survival (% of Control)
100
Long Island Sound
05
>
CD
0)
DL
100
80 ••
60 ••
40 -
20
75
80 85 90 95
Mean Amphipod Survival (% of Control)
100
Figure A-8. Cumulative distributions of amphipod survival (% of control) in 10-day toxicity tests as a
percent of area of Chesapeake Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence
intervals).
Page A - 10
Statistical Summary, EMAP-E Virginian Province - 1992
-------
Chesapeake Bay
CO
-------
Table A-2. Range and median metal concentrations in Chesapeake Bay and Long Island Sound sediments,
1992. Concentrations are as ug/g dry weight.
Analyte
Major
Aluminum
Iron
Manganese
Ttaca
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
Major
Aluminum
Iron
Manganese
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
MIN
3,100
2,700
52.1
ND
0.423
ND
6.19
1.91
ND
ND
ND
ND
ND
ND
9.05
25,800
15,000
464
0.228
3.48
0.063
22.9
4.85
5.34
ND
9.7
ND
0.017
1.05
32.0
MAX
Chesapeake Bay
83,000
64,700
5,850
152a
30.8
2.39
147
118
13,600a
0.21
66.7
0.86
8.77
11.6
402
Long Island Sound
59,300
34,600
1,230
0.820
17.7
2.23
136
201
147
1.26
37.1
0.760
6.44
16.3
309
Median
44,500
27,700
447
0.451
7.93
0.206
50.3
22.5
24.3
0.054
19.8
0.314
0.112
2.15
91.5
43,950
26,700
605
0.445
6.83
0.168
66.8
43.3
44.2
0.088
22.9
0.336
0.541
4.47
125
ND = Not Detected
a Lead and antimony were elevated by several orders of magnitude in sediments from one station in
Chesapeake Bay. Lead shot is suspected as the cause.
Page A - 12
Statistical Summary, EMAP-E Virginian Province - 1992
-------
50 -,
40
< 30
"o
'c
2). All of Long Island Sound fell between Aa 's
of 0 and 1.5. '
A.3.6 Percent Silt-Clay Content
The CDFs of silt-clay content for Chesapeake Bay
and Long Island Sound are similar, with approximately
the same percent area of mud and sand in each system
(Figure A-15).
The large area of sandy sediments found in the mouth
of Chesapeake Bay is likely due to sands being carried
in from the ocean (Hobbs et al., 1992). In Long Island
Sound coarser sediments at the mouth are mainly a result
of strong tidal currents transporting away the fine fraction
(winnowing), leaving behind the coarser sands and gravel
(Akapati, 1974; Gordon, 1980).
A.3.5 Light Extinction (water clarity)
Water clarity showed definite differences between
Chesapeake Bay and Long Island Sound. Approximately
19 ± 13% of the water of Chesapeake Bay was classified
as poor or marginal (light extinction coefficient >1.387),
meaning that a wader could not see his/her toes in waste
deep water, compared to 2 ± 2% of the area of Long
Island Sound (Figure A-16).
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 13
-------
Chesapeake Bay
120 T
100 •
CO
| 80
| 60
CD
§ 40
Q.
20
10
20 30
Depth (m)
40
50
Long Island Sound
120 T
Depth (m)
Figure A-11. Cumulative distributions of water depth as a percent of area aof Chesapeake Bay and Long
Island Sound, 1992. (Dashed lines are the 95% confidence intervals).
Page A - 14
Statistical Summary, EMAP-E Virginian Province - 1992
-------
Chesapeake Bay
CO
CD
120
100
80
60
8
Ju 40
Q.
20
0
18
20
22 24
Temperature (°C)
26
28
120
100
CO
I 80
«4—
~ 60
CD
§ 40
a.
20
0
18
20
Long Island Sound
22 24
Temperature (°C)
26
28
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 15
-------
Chesapeake Bay
120 T
0
0
10
15 20
Salinity (%o)
25
30
Long Island Sound
120 T
100
£ 80 •
2 60
Q)
g 40
Q.
20
0
10
15 20
Salinity (%°)
, cumulative distributions of bottom water s_a,inity as a percent of area of Chesapeake Bay
Figure A-13
and Long Island Sound, 1992.
are the 95% confidence Intervals).
-------
Chesapeake Bay
CO
CD
fS
CD
y
CD
D_
120
100
80
60
40 -
20
0
C
_______ \
__ — ^^^m^
..,---V" •"
1 i i . ,
i i 1 — . 1
1 2 3 4 5 6
Ao(kg/m3)
Long Island Sound
0
Figure A-14. Cumulative distributions of surface to bottom sigma-t difference as a percent of area of
Chesapeake Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 17
-------
Chesapeake Bay
0
20
40 60
Silt/Clay (%)
100
120 T
0
Long Island Sound
20
40 60
Silt/Clay (%)
100
Figure A-15. Cumulative distributions of sediment silt/clay content as a percent of area of Chesapeake
Bay and Long Island Sound, 1992. (Dashed lines are the 95% confidence interval).
Page A - 18
Statistical Summary, EMAP-E Virginian Province - 1992
-------
100 -,
80
Seo
<
§40
o
CD
D.
Low
Moderate
Good
Chesapeake Bay Long Island Sound
Figure A-16. Percent area of Chesapeake Bay and Long Island
Sound with water clarity classified as low, moderate, or good based on
light extinction coefficients. (Error bars represent 95% confidence
intervals).
Statistical Summary, EMAP-E Virginian Province - 1992
Page A - 19
-------
-------
APPENDIX B
LINEAR REGRESSIONS OF INDIVIDUAL METALS AGAINST
ALUMINUM USED IN THE DETERMINATION OF METALS
ENRICHMENT OF SEDIMENTS OF THE VIRGINIAN PROVINCE
As discussed in Section 3.2.3.7, concentrations of
individual metals were normalized against the crustal
element aluminum in an attempt to provide a basis for
estimating the areal extent of enrichment of these metals
in Virginian Province sediments. The method utilized
is described in Appendix A (Section A.8.2.3) of the
1991 Virginian Province Statistical Summary (Schimmel
et al., 1994). For each metal, a regression and an upper
95% confidence interval was determined and plotted
(Figures B-l to B-14). Stations with concentrations
falling above the upper 95% confidence interval were
classified as enriched for that metal. Regression
parameters (slope, intercept, and correlation coefficient)
are listed in Table B-l.
As described in Appendix D of the 1991 Virginian
Province Statistical Summary (Schimmel et al., 1994),
results of this method compare well with those obtained
by other researchers.
Statistical Summary, EMAP-E Virginian Province - 1992
Page B - 1
-------
10 •
8 -•
6 ••
4--
2 ••
0 -F
4 6
Aluminum (%)
10
Figure B-1. Linear regression of silver against aluminum (dashed line is the upper 95%
confidence interval). Metal concentrations are as ug/g dry weight.
-H
4 6
Aluminum (%)
Figure B-2. Linear regression of arsenic against aluminum (dashed line is the upper
95% confidence interval). Metal concentrations are as ug/g dry weight.
Page B-2
Statistical Summary, EMAP-E Virginian Province - 1992
-------
2.5 --
2 --
1.5 --
1 •-
0.5 --
0
4 6
Aluminum (%)
Figure B-3. Linear regression of cadmium against aluminum (dashed line is the upper
95% confidence interval). Metal concentrations are as ug/g dry weight.
160 i
120 --
O 80 --
40 -
4 6
Aluminum (%)
Figure B-4. Linear regression of chromium against aluminum (dashed line is the upper
95% confidence interval). Metal concentrations are as ug/g dry weight.
Statistical Summary, EMAP-E Virginian Province - 1992
Page B - 3
-------
o
250 T
200 ••
150 ••
100 ••
50 | '
0
0
4 6
Aluminum (%)
10
Figure B-5. Linear regression of copper against aluminum (dashed line is the upper 95%
confidence interval). Metal concentrations are as ug/g dry weight.
80000 T
60000 -•
40000 ••
20000 -•
246
Aluminum (%)
10
Figure B-6. Linear regression of iron against aluminum (dashed line is the upper 95%
confidence interval). Metal concentrations are as ug/g dry weight.
Page B - 4
Statistical Summary, EMAP-E Virginian Province - 1992
-------
1.6 T
1.2 -•
0.8 -
0.4 --
4 6
Aluminum (%)
10
Figure B-7. Linear regression of mercury against aluminum (dashed line is the upper
95% confidence interval). Metal concentrations are as ug/g dry weight.
6000 -
5000 -•
4000 --
3000 --
2000 -
1000 -
0
0
4 6
Aluminum (%)
10
Figure B-8. Linear regression of manganese against aluminum (dashed line is the upper
95% confidence interval). Metal concentrations are as pg/g dry weight.;
Statistical Summary, EMAP-E Virginian Province - 1992
Page B - 5
-------
80 T
60 •-
Z 40 ••
20 ••
4 6
Aluminum (%)
10
Figure B-9. Linear regression of nickel against aluminum (dashed line is the upper 95%
confidence interval). Metal concentrations are as ug/g dry weight.
14000 -I
12000 -
10000 -
8000 •
6000 •
4000 •
2000 •
0 •
(
•
) 2 4 6 8 10
Aluminum (%)
Figure B-10. Linear regression of lead against aluminum (dashed line is the upper 95%
confidence interval). Metal concentrations are as ug/g dry weight.
Page B - 6
Statistical Summary, EMAP-E Virginian Province - 1992
-------
160 i
140 -
120
100 -
OT 80 -
60 •
40 -
20 -
0 -
•
0 2 4 6 8 10
Aluminum (%)
Figure B-11. Linear regression of antimony against aluminum (dashed line is the upper
95% confidence interval). Metal concentrations are as ug/g dry weight.
4 6
Aluminum (%)
10
Figure B-12. Linear regression of selenium against aluminum (dashed line is the upper
95% confidence interval). Metal concentrations are as ug/g dry weight.
Statistical Summary, EMAP-E Virginian Province - 1992
Page B - 7
-------
35 T
30 ••
25 •
20 •-
15 ••
10 ••
5 ••
0
4 6
Aluminum (%)
Figure B-13. Linear regression of tin against aluminum (dashed line is the upper 95%
confidence interval). Metal concentrations are as ug/g dry weight.
4 6
Aluminum (%)
10
Figure B-14. Linear regression of zinc against aluminum (dashed line is the upper 95%
confidence interval). Metal concentrations are as ug/g dry weight.
Page B - 8
Statistical Summary, EMAP-E Virginian Province - 1992
-------
Table B-1.
Element
Ag
As
Cd
Cr
Cu
Fe
Hg
Mn
Ni
Pb
Sb
Se
Sn
Zn
Metal-aluminum regression parameters obtained
slope, b = intercept, r2 = correlation coefficient).
from 1992 Virginian
Province sediment data (m =
Regression parameters
m
0.0243
1 .5462
0.0549
10.1341
5.6758
5,763
0.0122
139.67
5.0110
6.6833
0.1067
0.0646
0.4453
23.3211
b ;
0.0128
2.0021
-0.0149
0.0220
-2.2951
-133.14
0.0087
-32.1638
-1.7338
2.5058
0.0895
0.0597
0.1523
-3.1249
r2
0.35
0.44
0.47
0.85
0.55
0.87
0.39
0.56
0.75
0.32
0.28
0.31
0.69
0.66
Statistical Summary, EMAP-E Virginian Province - 1992
Page B - 9
-------
-------
APPENDIX C
QUALITY ASSURANCE
The 1992 Virginian Province monitoring effort was
implemented using a quality assurance program to
ensure comparability of data with those collected in
other EMAP-E provinces, and to assure data quality
consistent with the goals of the Program. As described
in the Quality Assurance Project Plan (Valente et al.,
1992), Measurement Quality Objectives (MQOs) were
established for data quality. Quality control steps taken
to assure that MQOs were met included intensive
training of field and laboratory personnel, field perfor-
mance reviews of sampling crews, laboratory certifica-
tion and audits. This document provides only a brief
summary of QA results for 1992. A more comprehen-
sive QA document is currently being prepared.
C.I CREW TRAINING
One of the most critical components of the EMAP-
VP QA Program was the thorough training of field
personnel. Training was divided into two distinct
courses: crew chief training and crew training.
Crew chiefs, who were all returnees from previous
years, underwent a refresher training course during the
last week of May, 1992. This training was conducted
at the U.S. EPA Environmental Research Laboratory-
Narragansett, RI (ERL-N) and focused mainly on the
sampling methods, with emphasis placed on the
electronic measurements and the computer system.
Crew chief training was conducted by SAIC and CSC
(Computer Sciences Corporation) personnel with
oversight by EPA ERL-N staff.
Crew training was held from 15 June to 17 July
1992. Both safety and sampling methods were impor-
tant components of training. Crew training was broken
into two phases: formal training which lasted for
approximately 3 weeks, and one week (per crew) of dry
runs.
Dry runs consisted of five days in the field during
which crews operated as they would during the sampling
season, monitoring practice stations for all parameters.
Crew members stayed in motels, prepared samples for
shipment, entered data into the field computer, and
electronically transmitted all data to the Field Operations
Center (FOC) just as they would during actual field opera-
tions. In addition, the Field Coordinator or the QA
Coordinator visited each crew during dry runs, completing
a performance review sheet to determine the crew's
readiness. All crews were deemed properly prepared
to begin sampling activities on 27 July, 1992.
Certification examinations for crew chiefs and field
crew members were administered at the end of each
course and proved to be very useful. Unlike previous
years, no crew chiefs were found to need additional
training, and all subjects covered during training appeared
to have been adequately covered.
C.2 FIELD DATA AND SAMPLE
COLLECTION - QUALITY
CONTROL CHECKS
Several measures were taken during the 1992 field
season to assure the quality of the data collected. These
consisted of QC checks, the collection of QC samples,
and performance reviews by senior Program personnel
(QA Coordinator or Field Coordinator).
Statistical Summary, EMAP-E Virginian Province - 1992
Page C - 1
-------
C.2.1 Water Quality Measurements
Generally the first activity performed at each station
was to obtain a vertical profile of the water column for
key parameters. The instrument chosen for this
operation was the SeaBird SEE 25 SeaLogger CTD.
This instrument is generally regarded as a very sensitive,
accurate and reliable device. All CTDs were calibrated
according to manufacturers instructions at the EMAP-VP
calibration facility just before the field season began.
The procedures for calibration and checks are described
in the 1992 Quality Assurance Project Plan (Valente et
«/., 1992).
Field QC checks on the performance of the CTD
fell into two categories: daily and weekly. The daily
check consisted of taking duplicate surface and bottom
measurements with a YSI Model 58 dissolved oxygen
meter (instrument air calibrated at each station), a
refractometer (salinity), and a thermometer (temperature)
at every station. Acceptable differences are listed in
the QA Plan. It is worth noting that the salinity values
produced by the CTD are expected to be much more
accurate than those from the refractometer, and are more
accurate than is required by EMAP. The refractometer
only provided a "gross" check to determine if there was
an electrical problem with the CTD's conductivity
sensor; it provided no information about gradual drift.
If the instrument failed QC, the cast was repeated. If
it failed on the second attempt, the cast was saved but
flagged. Of the 143 casts for which separate dissolved
oxygen measurements were successfully obtained with
the YSI meter, 91.6% passed QC, showing differences
of ^ 0.5 mg/L. Values obtained using the YSI meter
were used in this assessment for those stations where
the CTD failed QC. All temperatures and salinities
passed QC.
In addition to the daily checks, a more thorough
weekly (once per 6-day shift) check was also performed.
First, a bucket of water was bubbled with air for at least
two hours to reach saturation for dissolved oxygen. The
YSI meter was air-calibrated according to manufacturer's
instructions, and the dissolved oxygen concentration of
the water determined. At the same time multiple water
samples were drawn off for Winkler titration using a
Hach digital titrator. The YSI value was compared to
the concentration determined by titration. Since the YSI
meter was calibrated prior to each use, this served as
a check on the validity of the air calibration method.
Following this check of the YSI meter, the CTD was
immersed in water and the DO, temperature, and salinity
compared with values obtained from the YSI, thermome-
ter, and refractometer respectively. The unit was brought
back on the deck and the pH probe immersed in a pH
10 standard for comparison (pH 10 was used instead of
pH 7 because the instrument defaults to a reading of 7
when malfunctioning). If the unit failed for any variable
it was returned to the Field Operations Center for
recalibration. A total of 17 checks were performed during
the field season, with all meeting the criteria for
acceptance.
C.2.2 Benthic Indicators
As described in Section 3, several different benthic
samples were obtained at each station. Three of the
samples were processed for benthic community structure
and biomass determination.
Crews were observed closely during field performance
reviews to ensure that standard protocols were being
followed for all benthic sampling. Laboratory QA
measures are described below in Section C.3.
In addition to the infaunal samples, sediment was
collected for chemical analysis, toxicity testing, and grain
size determination. Additional QC samples were collected
for chemistry at one station per crew. A second duplicate
sample was removed from the homogenate, and a "blank"
bottle was left open whenever the sample was exposed
to the atmosphere. The purpose of the blank was to
determine if atmospheric contamination was a significant
problem. Additional analytical measures are described
in Section C.4. Grain size and toxicity QA results are
discussed in Section C.3.
C.2.3 Fish Indicators
The two fish indicators for which field data, as
opposed to samples, were collected were fish community
structure and gross external pathology. The QA Project
Plan (Valente et al, 1992) called for QA samples to be
collected for both of these indicators.
To verify each crew's ability to correctly identify
fish species for the community structure indicator, the
first individual of each species collected by each crew
was shipped to ERL-N or Versar for verification by an
expert taxonomist.
Page C - 2
Statistical Summary, EMAP-E Virginian Province - 1992
-------
Three types of errors were detected: misspelled or
incomplete species names (in the database), misidentifi-
cations, and fish that could not be identified in the field.
Errors falling into the first category were easily
detected, corrected in the database, and documented.
The second type of error was mis-identifications.
Of the 397 fish sent in for taxonomic verification, 36
were misidentified. In all cases the crew identified a
closely-related species, such as longspine porgy instead
of scup, or brown bullhead catfish instead of the yellow
bullhead. An additional eight individuals were sent in
as unknowns or partial unknowns (e.g., herring uncl.).
Most mis-identified or partially identified individuals
were juveniles.
The total of 44 incomplete identifications or
misidentifications represent 116 fish records in the
database (including other fish of the same species caught
in the same trawl). A total of 14,704 fish were collected
in all trawls (both standard and non-standard) from all
station types during the 1992 field season representing
78 species. The percentage of errors detected was
therefore less than one percent.
C.2.4 Field Performance Reviews
In addition to the crew certification visits performed
during dry runs, each crew was visited by a senior
EMAP staff member during field operations. All
aspects of sampling, from boat operations to shipping,
were observed by the reviewer. Some of the activities
included confirming the presence/absence of external
pathologies, re-measuring fish, assuring that all
precautions were taken to avoid contamination of the
chemistry samples, assuring proper processing of benthic
infauna samples, observing data entry, and assuring that
all necessary safety precautions were observed. The
reviewer used a "field review check-off sheet" to
provide guidance during the review, and to document
the crew's performance. Both reviewers concluded that
the crews were sufficiently concerned with all QA
issues, and that the data generated were representative
of ambient conditions.
C.3 LABORATORY TESTING AND
ANALYSIS
Quality control requirements for laboratory testing
and sample analysis are covered in detail in the 1992
EMAP-VP QA Project Plan (Valente et al., 1992) and
the EMAP-E Laboratory Methods Manual (U.S. EPA,
1991) and will not be reiterated here. All laboratories'
were required to perform QA activities, and the results
of those activities will be discussed in this report.
Because of the complexity of chemical analyses, QA
results for those analyses are listed separately in Section
C.4.
C.3.1 Sediment Toxicity Testing
All sediment toxicity testing was performed at the
SAIC Environmental Testing Center (ETC) in
Narragansett, RI. Certification of the ETC occurred in
1990 and those results will not be discussed here, with
the exception of stating that the laboratory successfully
met EMAP requirements.
As per the QA Project Plan, the laboratory was
required to maintain a control chart for toxicity testing
using a reference toxicant. The ETC used SDS (sodium
dodecyl sulfate) as their reference material, running a
standard 48-hour water-only toxicity test with SDS
whenever EMAP samples were run. The control chart
shows that the LC50 for SDS ranged from < 2.57 to 11.2
mg/L, with all but the lowest value falling within two
standard deviations of the mean as required in the QA
Plan. Results of the one reference toxicity test falling
outside two standard deviations of the mean were
examined, as were all testing performed during the same
time period. No anomalies in the tests were apparent
and no re-testing was performed.
C.3.2 Grain Size Analysis
All "sediment grain size" and "benthic grain size"
samples were analyzed for the determination of percent
silt/clay. Approximately 10% of these analyses were
performed in duplicate and the Relative Percent
Difference (RPD) determined as per the EMAP-E Labora-
tory Methods Manual (U.S. EPA, 1991). The maximum
allowable percent difference for the predominant fraction
(silt/clay or sand) is 10%. The mean difference for the
samples analyzed was less than 1%, with none exceeding
10% so no remedial action or retesting was required.
Statistical Summary, EMAP-E Virginian Province - 1992
Page C - 3
-------
C.3.3 Benthic Infauna Analysis
Two QA steps were required by the EMAP-VP 1992
QA Project Plan: 10% recounts and independent
verification of species identification. The recounts
(multiple types - see Table C-l) and preliminary species
verification were performed by the laboratory perform-
ing the analyses. All of these met the requirements
established in the QA Plan. Definitive verification of
species identification was performed by an independent
laboratory and the results are described below.
C.3.4 Total Suspended Solids Analysis
The QA Plan requires that at least 10% of all
samples analyzed for Total Suspended Solids (TSS)
concentration be analyzed in duplicate. The RPD
between the duplicates is then calculated. To pass QA,
this value must be less than 10%. If it exceeds 10%,
all samples analyzed since the last successful QC check
must be repeated.
Due to an apparent mis-communication at the
analytical laboratory, the first group of samples did not
have the appropriate QA samples run. Therefore, the
quality of the resultant data cannot be evaluated and are
"flagged" in the EMAP database. A sufficient number
of duplicate analyses were performed with the remainder
of the samples; however, several failed QA, with the
RPD exceeding 10%. Unfortunately this was not
discovered until several months after the analyses were
completed, and the original samples (degradable) had
been discarded. As a result, approximately 44.4% of
the data have been flagged as being of questionable
quality.
Table C-1. Results of recounts performed by the laboratory processing benthic infauna samples. Approximately
10% of all samples were processed in duplicate.
C.4 LABORATORY CERTIFICATION
AND CHEMICAL ANALYSIS
EMAP-E requires that analytical laboratories partici-
pate in an extensive certification process prior to the
analysis of any EMAP-E chemistry samples. This
certification is in addition to normal quality control
measures that are required during analysis to ensure
quality data (e.g., blanks, spikes, controls, duplicates,
etc.). Standard Reference Materials (SRMs) with known
or certified values for metals and organic compounds
were used by the Virginian Province laboratories
conducting analyses to confirm the accuracy and precision
of their analyses. Many of the SRMs used extensively
in the EMAP-E program are naturally-occurring materials
(e.g., marine sediments or oyster tissue) in which the
analytes of interest are present at levels that are environ-
mentally realistic, and for which analyte concentrations
are known with reasonable certainty. The certification
results for the laboratory conducting the sediment analy-
ses can be found in Table C-2.
The 1992 Virginian Province QA Project Plan
(Valente et al., 1992) lists warning and control limit
criteria for the analysis of Certified (or Standard) Refer-
ence Materials. The more conservative warning limit
for all organics is stated to be "Lab's value should be
within ± 25% of true value on average for all analytes;
not to exceed ± 30% of true value for more than 30%
of individual analytes for each batch". The laboratory's
performance during certification resulted in permission
being granted for the analysis of samples to begin.
Measurement
Benthic sorting
Species identification and enumeration
Biomass
Weighing blanks for biomass
Mean Error
1 .7%
1 .8%
1 .2%
7 x 10~5g
Range of Error
0 - 1 8%
0- 12%
0 - 1 .4%
0 - 7 x 1 0"4 g
Page C - 4
Statistical Summary, EMAP-E Virginian Province - 199^
-------
Table C-2. Results of certification analysis for sediment contaminants performed by EMSL-Cinn. The
Reference Material for the organics certification was NIST SRM 1941. The SRM for inorganics
was the National Research Council of Canada BCSS-1 CRM. For organic analyses, only
those analytes with certified values at least 10x the detection limit are included.
Analyte
Inorganics (ug/g dry weight
Al
As
Cd
Cr
Cu
Fe
Mn
Ni
Pb
Sb
Se
Sn
Zn
Certified
Concentration
62700 ±2173
11.1 ± 1.4
0.25 ± 0.04
123 ±14
18.5 ±2.7
32900 ± 980
229 ± 15
55.3 ± 3.6
22.7 ± 3.4
0.59 ± 0.06
0.43 ± 0.06
1.85 ±0.20
119±12
Measured
Concentration
. 58,600
11.0
0.20
81.3
18.4
29,800
199
47.0
27.8
0.56
0.42
2.24
96.4
Oraanics (PCBs/pesticides - ng/g dry weight)
PCB 18
PCB 28
PCB 52
PCB 66
PCB 101
PCB 118
PCB 153
PCB 187
PCB 180
PCB 170
PCB 206
PCB 209
4,4' DDE
4,4' DDD
4,4' DDT
9.90 ± 0.251
16.1 ±0.41
10.4± 0.41
22.4 ± 0.71
22.0 ± 0.71
15.2 ±0.71
22.0 ± 1.41
12.5 ±0.61
14.3 ±0.31
7.29 ± 0.261
4.81 ±0.151
8.35 ± 0.21 1
9.71 ±0.171
10.3 ±0.11
1.11 ±0.051
2.82
12.8
11.6
20.4
15.1
16.2
14.5
7.50
13.2
4.95
3.11
6.49
8.43
8.24
1.47
(continued)
Statistical Summary, EMAP-E Virginian Province - 1992
Page C - 5
-------
Table C-2 continued.
Analyte
Certified
Concentration
Measured
Concentration
Organics (PAHs - ng/g dry weight)
Phenanthrene 577 ± 59
Anthracene 202 ± 42
Fluoranthene 1220 ± 240
Pyrene 1080 ± 200
Benz(a)anthracene 550 ± 79
Benzo (b & k) fluoranthene 1224 ± 239
Benzo(a)pyrene 670 ±130
Perylene 422 ± 33
ldeno(1,2,3-cd)pyrene 569 ± 40
Benzo(g,h,i)perylene 516 ± 83
Naphthalene 1322±141
2-Methylnaphthalene 406 ± 361
1-Methylnaphthalene 229 ± 191
Biphenyl 115±151
2,6-Dimethylnaphthalene 198 ± 231
Fluorene 104±51
Benzo(e)pyrene 5731
Chrysene 4491
535
170
1100
1020
572
983
494
252
609
526
722
355
191
94
203
101
579
709
' Value provided by MIST but not considered a "certified" value, meaning the values were determined via a
single method. Despite not being certified, these values are still considered accurate.
During sample analysis, the laboratory was required
to analyze a Laboratory Control Material (LCM) with
each batch of samples being analyzed. An LCM is
identical to an SRM with the exception that the true val-
ues need not be certified by an external agency
(however, in these cases the same SRMs used during
certification were used as the LCM). In addition to the
LCM, duplicate "matrix-spiked" samples were required
for each batch.
In addition to the analysis of the required QA data,
summary data have been reviewed by an environmental
chemist to verify that they are "reasonable" based on
past studies and known distributions of contaminants
in East Coast estuaries. This included examining the
ratios of individual congeners (e.g., PCBs); and PAH
and DDT analytes. Any data that were deemed
"questionable" were flagged for further study.
As stated earlier, at each sediment chemistry QA
station crews opened a blank bottle whenever the sample
was exposed to the atmosphere. The analytical laboratory
solvent rinsed this bottle and then analyzed the solvent
for contamination. Results showed no evidence of
contamination, which if present, could have come from
either the field or the laboratory.
C.5 DATA MANAGEMENT
To expedite the process of data reporting, all field
data were entered into field computers and transmitted
electronically to the Information Management Center.
Upon receipt of the "hard copy" data sheets, a 100%
check was performed by the EMAP data librarian (i.e.,
every record in the computer was manually compared
to the data sheet). Following corrections, a different
individual then performed a second 100% check. A third
Page C - 6
Statistical Summary, EMAP-E Virginian Province - 1992
-------
check (20%) was then performed by a third person. By
the completion of this exercise we were confident that
the computer data base accurately reflected what the
crew reported.
The number of data errors detected can be classified
as "record" errors or "value" errors. A value refers to
a single observation recorded as part of a record. A
record refers to an entire set composed of "n" values,
such as a data sheet. Record errors generally refer to
duplicate or missing data sheets. Duplicate electronic
data sheets can result from the crew accidentally saving
the same page twice, but with different page numbers.
Value errors refer to missing or incorrect values
recorded on a data sheet.
Results of the checks described above showed a
value error rate of 0.3%. The rate of record errors was
approximately 1.35%.
The next step in data QA was data verification and
validation. Verification was another step in assuring
that the data were correct (e.g., assuring that each CTD
cast was associated with the correct station). Validation
was the process of checking to make sure all data were
reasonable (e.g., making sure that fish lengths were all
entered in mm, not cm). These processes were exten-
sive; therefore, only a few examples will be provided
here.
Part of the process of verifying CTD dissolved oxy-
gen profiles was to compare cast depth to water depth.
If they were significantly different, the cast was flagged
for additional investigation. Validation then consisted
of an expert examining every cast to assure the DO
values were realistic and that the profile appeared
reasonable.
One of the steps in validation of the fish community
data set was to compare each fish length to the reported
size range for that species. Geographic distributions
were also examined to determine if the species had
previously been reported where EMAP crews found
them.
OU.S. GOVERNMENT PRINTING OFFICE:
Statistical Summary, EMAP-E Virginian Province - 1992
Page C - 7
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