EPA/62Q/R-96/003
January 1995
STATISTICAL SUMMARY:
EMAP-ESTUARIES
LOUISIANIAN PROVINCE - 1993
by
John M. Maeauley
J. Kevin Summers
U,S. Environmental Protection Agency
National Health and Environmental Effects Research Laboratory
Gulf Ecology Division
Gulf Breeze, FL 32561
Virginia D. Engle
P. Thomas Heitmuller
National Biological Service
A. Matt Adams
Johnson Controls World Services, Inc.
NATIONAL RESEARCH HEALTH AND ENVIRONMENTAL
EFFECTS LABORATORY
GULF ECOLOGY DIVISION
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. E1WIRONMENTAL PROTECTION AGENCY
GULF BREEZE, FLORIDA 32561
Printed on Recycled Paper
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DISCLAIMER
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 biogeographic region (Louisianian Province) collected in a short index period (July-August)
during a single year (1993). Appropriate precautions should be exercised when using this information for
policy, regulatory or legislative purposes.
Statistical Summary, EMAP—E Louisianian Province -1993 Page iu
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PREFACE
\ . -
This document is the third annual statistical summary for the Louisianian Province of the Estuaries
component of the U.S. Environmental Protection Agency's (EPA) Environmental Monitoring and
Assessment Program for estuaries (EMAP-E).
The appropriate citation for this report is:
J.M. Macauley, J.K. Summers, V.D. Engle, P.T. Heitmuller, and A.M. Adams, 1993. Annual Statistical
Summary: EMAP-Estuaries Louisianian Province - 1993. U. S. Environmental Protection Agency, Office
of Research and Development, Environmental Research Laboratory, Gulf Breeze, FL.
Statistical Summary, EMAP-E Louisianian Province -1993 Pageiy
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ACKNOWLEDGMENTS
A large geographically extensive monitoring program such as EMAP in the Louisianian Province
requires the interaction, coordination and cooperation of hundreds of individuals working together to
complete the 1993 Demonstration, Space does not permit the individual citation of all who participated in
the 1993 effort. We would like to to thank everyone who has participated in the success of the Louisianian
Province and specifically acknowledge the following:
CONTRIBUTORS
U.S. EPA - Gulf Breeze . Texas A&M University
Lee Courtney James Brooks
Jack Foumie Roy Davis
Roger Fay
Avanti Corporation James Jobling
Bob Pressley
George Craven Terry Wade
Derek Groves R.J. Wilson
Jeanne Gillet Dan Wilkinson
Linda Harwell
Shannon Phifer University of Mississippi
Johnson Controls World Services. Inc. William Benson
Gary Gaston
Renee Conner James O'Neal
Lois Haseltine Steve Brown
Gulf Coast Research Laboratory TRAC Laboratories
David Burke Barbara Albrecht
Richard Heard Peggy Harris
William Walker
National Oceanic and Atmospheric Administration
Andrew Robertson
Statistical Summary, EMAP—E Louisianian Province —1993 Page v
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STATISTICAL SUMMARY
EMAP-ESTUARIES LOUISIANIAN PROVINCE - 1993
/
Table of Contents
DISCLAIMER . iii
PREFACE ..iv
ACKNOWLEDGEMENTS v
TABLE OF CONTENTS ...,.vi
EXECUTIVE OVERVIEW . 1
BIOTIC INTEGRITY 2
HUMAN USE , 4
INTEGRATION OF ESTUARINE CONDITIONS 7
POLLUTANT EXPOSURE , 8
1 INTRODUCTION 17
1.1 OBJECTIVES OF THE 1993 LOUISIANIAN PROVINCE ESTUARINE SAMPLING 17
1.2 ENVIRONMENTAL VALUES AND ASSESSMENT QUESTIONS 18
1.3 PURPOSE AND ORGANIZATION OF THIS REPORT.. 19
2.1 BIOTIC INDICATORS 21
2 STATISTICAL SUMMARY 21
2.1.1 NUMBER OF BENTHIC SPECIES .'. 21
2.1.2 TOTAL BENTHIC ABUNDANCE 23
2.1.3 BENTHIC ABUNDANCE BY TAXONOMIC GROUP 24
2.1.4 BENTHIC INDEX 29
2.1.5 NUMBER OF FISH SPECIES 29
2.1.6 TOTAL FINFISH ABUNDANCE 31
2.1.7 EXTERNAL GROSS PATHOLOGY 32
2.1.8 MACROPHAGE AGGREGATES 34
2.1.9 MARINE DEBRIS , .35
2.1.10 WATER CLARITY . . 36
2.1.11 FISH TISSUE CONTAMINANTS 36
2.1.12 INTEGRATION OF ESTUARINE CONDITIONS . 39
2.2 EXPOSURE INDICATORS 40
2.2.1 DISSOLVED OXYGEN (INSTANTANEOUS) 40
2.2.2 DISSOLVED OXYGEN - (CONTINUOUS) 44
2.2.3 SEDIMENT TOXICITY - AMPELISCA ABDITA 46
2.2.4 SEDIMENT TOXICITY - MYSIDOPSIS BAHIA 46
2.2.5 SEDIMENT CONTAMINANTS - ALKANES AND ISOPRENOIDS ..47
2.2.6 SEDIMENT CONTAMINANTS - POLYNUCLEAR
AROMATIC HYDROCARBONS 48
Statistical Summary, EMAP—E Louisianian Province —1993 Page yi
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2.2.7 SEDIMENT CONTAMINANTS - POLYCHLORINATED BIPHENYLS 49
2.2.8 SEDIMENT CONTAMINANTS - PESTICIDES 49
2.2.9 SEDIMENT CONTAMINANTS - HEAVY METALS.. 54
2.2.10. CRITERIA COMPARISONS 5 5
2.2.10.1 ANTHROPOGENIC ENRICHMENT 55
2.2.11 SEDIMENT CONTAMINANTS - BUTYLTINS 57
2.3 HABITAT INDICATORS , 5 8
2.3.1 WATER DEPTH 5 8
2.3.2 WATER TEMPERATURE . . 5 8
2.3.3 SALINITY 5 9
2.3.4 PH ...61
2.3.5 STRATIFICATION , ; 62
2.3.6 PERCENT SILT-CLAY CONTENT ........62
2.3.7 PERCENT TOTAL ORGANIC CARBON 63
2.3.8 ACID VOLATILE SULFIDES 64
2.4 CONFIDENCE INTERVALS FOR PROVINCE AND CLASS-LEVEL ESTIMATES...... 6 4
3 SUMMARY OF CONCLUSIONS 69
3.1 OVERVIEW OF PROVINCE CHARACTERISTICS J '. 69
3.2 CONCLUSIONS OF THE 1993 SAMPLING •. 70
4 REFERENCES 71
APPENDIX A SUBPOPULATION ESTIMATION BASED ON EMAP SAMPLING 75
A.1 BIOTIC CONDITION INDICATORS 75
A.1.1 BENTHIC INDEX 76
A.1.2 NUMBER OF FISH SPECIES .........:...... . 76
A.1.3 MARINE DEBRIS 76
A.1.4 WATER CLARITY .76
A.1.5 INTEGRATION OF ESTUARINE CONDITIONS 80
A.2 ABIOTIC CONDITION INDICATORS , 80
A.2.1 DISSOLVED OXYGEN (INSTANTANEOUS).. 80
A.2.2 DISSOLVED OXYGEN (CONTINUOUS) 84
A.2.3 SEDIMENT TOXICITY -AMPELISCA ABDITA 87
A.2.4 ALKANES AND ISOPRENOIDS 87
A.2.5 POLYNUCLEAR AROMATIC HYDROCARBONS 88
A.2.6 POLYCHLORINATED BIPHENYLS 88
'A.2.7 TRIBUTYLTIN '.. 88
A.2.8 PESTICIDES ....88
A.2.9 HEAVY METALS 90
A.3 CONFIDENCE INTERVALS FOR STATE-LEVEL ESTIMATES ...........; 90
Statistical Summary, EMAP—E Louisianian Province —1993 Page vii
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EXECUTIVE OVERVIEW
STATUS OF THE CONDITION OF LOUISIANIAN
PROVINCE ESTUARIES -1993
This statistical summary of the ecological
condition of the estuarine resources is based on
the results of the 1993 Lquisianian Province
Demonstration Project. The population of
estuarine resources within the Louisianian
Province consists of all estuarine areas located
along the coastline of the Gulf of Mexico
between, and including, the Rio Grande, TX,
and Anclote Anchorage, FL.
Estuarine areas are defined as the saline, tidal
ecosystems characterized by harbors, sounds,
bays, and embayments bounded by barrier
islands (seaward boundary) or surrounded by
land with a restricted confluence with Gulf of
Mexico and the portions of tidal rivers having a
detectable tide (> 2.5 cm). These resources have
been classified into three estuarine types:
• Large estuaries (surface area > 250 km2,
aspect (length/mean width) < 18)
• Large tidal rivers (surface area > 250 km2,
aspect > 18)
• Small estuaries and tidal rivers (2 km2<
surface area < 250 km2)
The Environmental Monitoring and Assessment
Program (EMAP) is a national program initiated
by EPA and integrating the efforts of several
federal agencies to evaluate the status and
trends of the ecological resources of the United
States. EMAP-Estuaries (EMAP-E) is a part of
EMAP organized to evaluate the status and
trends of the estuarine resources of the United
States. The Louisianian Province represents a
single biogeographic area of the country
corresponding to the Gulf of Mexico area. The
Louisianian Province Demonstration Project was
conducted during the summer of 1993 (July-
August) using a probability-based sampling
design to evaluate the condition of the estuarine
resources in this geographic region. This
probabilistic sampling design makes it possible to
estimate the proportion or amount of the total
area in the Louisianian Province (25,725 km2)
having defined environmental conditions, based
on sampling only a portion of the province.
One hundred fifty-four sites between Anclote
Anchorage, FL, and the Rio Grande, TX, were
sampled during the eight-week sampling period
(Fig. 1). A total of 19 sites were not sampled in
1993. Nine sites were not sampled due to
inadequate water depth for sampling (i.e., < 1
m). Ten sites in the Mississippi River were not
sampled due to strong water flow from the 1993
flood. Thus, based on the 1993 sampling design,
6.6% of the total estuarine area in the
Louisianian Province could not be sampled with
the present sampling plan. The bulk of this
Statistical Summary, EMAP—E Louisianian Province —1993
Pagel
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Figure 1. Base sampling stations for 1993 Louisianian Province Monitoring.
"unsampleable" area occurred in the shoreline
areas of large estuaries where the average depth
is < 1 m. Of the remaining sites, 96 locations
represented probability-based sampling for the
province and were used for the class and
province estimates produced in this report.
Thirty-nine sites were collected to provide
estimates of variance, local enhancements of
spatial scale for Sabine Lake, TX, and
Choctawahatchee Bay, FL, and long-term trend
estimation.
A series of indicators that are representative of
the overall condition of estuarine resources were
measured at each site. These indicators were
designed to address three major attributes of
concern: 1) estuarine biotic integrity, 2) societal
ralues related to public use of estuarine
resources, and 3) pollutant exposure, or the
environmental conditions under which biota
live.
The use of specific guidance referred to in the
text as "criteria" does not infer the existance of
established regulatory limits.
BIOTIC INTEGRITY
The condition of biological resources in the
Louisianian Province was assessed using two
indicators: one that measured the condition of
estuarine benthos (bottom dwelling organisms)
and one that measured the condition of fish
communities. The benthic and fish indicators
incorporated measures of species composition,
abundance, and health to evaluate the condition
of the benthic and fish assemblages. Indices
were determined from the combined 1991 and
1992 data to represent a combination of
ecological measurements for each assemblage
that best discriminate between good and poor
environmental conditions. These indices
represent EMAP-E's attempt to reduce dozens
of indicators into a simple, interpretive value
that has a high level of discriminatory power
between good and poor environmental
conditions. The indices were developed
separately for fish and benthos using
Statistical Summary, EMAP—E Louisianian Province —1993
Page2
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information from regional reference sites and
sites with known pollution exposure. The
indices have been partially validated, but
additional years of information will be required
for complete validation; therefore, assessments
based on these indices should be considered
preliminary.
Benthic organisms were used as an indicator
because previous studies 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 al. 1986). Their relative
immobility also prevents benthic organisms
from avoiding pollution exposure and
environmental disturbance. A preliminary
benthic index for the Louisianian Province was
developed in 1991 (Engle et. al. 1993).
Preliminary estimates based on the 1993 ...-'^
Louisianian Province Demonstration indicate* *!?
that 37±11% (95% C.I.) of the estuarine
resources in the province had benthic resources
characterized by lower than expected benthic
diversity and low numbers of indicator species.
Of the 25,725 km2 comprising the estuaries of J
the Louisianian Province, about 9500 km2 were
ecologically degraded. For the benthic index,
degraded conditions were defined as an index
value < 4.0.
Although EMAP-E's primary objective is to
describe status and trends at the province level,
estimates can also be generated for
subpopulations. The EMAP sampling design
defined three classes of estuarine resources*
large estuaries, large tidal rivers, and small
estuarine resources/These classes were defined
because estuaries of different sizes may show
markedly different responses to anthropogenic
impacts.
The incidence of degraded benthic resources was
dissimilar among the three classes of estuaries
sampled during 1993. Forty-eight percent
(±26%) of small estuarine resources were
BENTHIC INDEX < 4
LOUISIANIAN PROVINCE 1993
PROVINCE LARGE
CLASS
SHALL
Figure 2. Percent of area having benthic index
value < 4.0 for large estuaries (large), small
estuaries (small), and the entire province, with
95% confidence interval.
degraded on an areal basis and large estuaries
had only 34±12% of their area represented by
degraded benthos (Fig. 2). However, while the
proportion of area degraded in the small
estuarine resources classes was high, the total
area of degraded benthic resources in large
Statistical Summary, EMAP—E Louisianian Province — 1993
PageS
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estuaries was about 6200 km2 as compared with
2700 km2 for small estuaries.
HUMANUSE
Although the major objective of EMAP-E is to
describe the status of estuarine resources using
indicators of ecological condition, certain
characteristics of estuaries, valued by society,
may not be reflected by these indicators. We
have included three indicators of perceptual
condition in our assessment: incidence of marine
debris, clarity of water, and contaminant levels
in edible fish flesh. Data were collected during
the 1993 Louisianian Province Demonstration to
estimate the areal extent of estuaries having
trash and turbid waters. Measurements were
taken to estimate the proportion of fish
populations of selected ecological, recreational,
and commercial fish species having
unacceptable levels of contaminants.
Observations concerning marine debris are
important because debris has multiple
deleterious effects on estuarine biota
(entanglement and ingestion), can economically
affect tourist areas (loss of tourists, beach clean-
up costs), and contributes to the public
perception of the general environmental
condition of estuaries (Ross et al. 1991). It is
estimated that marine debris was present at
10%±6% of the estuarine area in the Louisianian
Province. This accumulates to over 2700 km2 of
estuarine bottom having identifiable marine
debris in the Louisianian Province. No trash was
identified as medical or hospital waste.
Proportion of area having marine debris was
higher in the small estuaries 13.5%, while 9.6%
of the area of large estuaries had trash (Fig. 3).
Clear waters are valued by society and
contribute to the maintenance of healthy ami
MARINE DEBRIS
LOUISIANIAN PROVINCE 1993
•c
U-l
on
az
UJ
o.
100-
90-
80-
70-
§0-
50
PROVINCE LARGE
CLASS
SHALL
Figure 3. Percent of area having marine debris
present for large estuaries (large), small
estuaries (small), and the Louisianian Province,
with 95% confidence interval.
productive ecosystems. Water clarity was
estimated using light transmission data as a
comparison of incident light at the surface and
reduced light at a depth of one meter. Water ,
visibility of 10% at one meter was used to
represent poor visibility (i.e., visibility of <, 1
ft). Approximately 17.8±8% of the province had
waters with visibility of < 10%. Clarity was
much poorer in small estuaries (22.1 ±18%) than
in large tidal estauries (16.4±9%) (Fig. 4).
Contaminant levels in edible fish tissue are
perceived by the public as a negative quality for
estuarine waters even if the concentrations are
below levels that could have harmful effects.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 4
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LIGHT < 10%
LOUISIANIAN PROVINCE 1993
LU
CJ
100-
90-
80-
70-
60-
50-
40-
30-
20-
10
0
PROVINCE LARGE SHALL
CLASS
Figure 4. Percent of area having light transmittance at
one meter depth at < 10% of incident light for large
estuaries (large), small estuaries (small), and the
Louisianian Province.
EMAP-E has compiled contaminant levels of
pesticides, heavy metals, and polycyclic
chlorinated biphenyls (PCBs) in edible fish
tissues for three species groups: Atlantic croaker
(Micropogomas undulatus), commercial
shrimps (JPenaeus aztecus and Penaeus
setiferus), and marine catfish (Arias felts, Bagre
marinas, and Ictalurus/urcatus). The analysis
done for tissue contaminants differs from those
previously discussed in that the results refer to
populations of organisms rather than areal extent
in estuaries.
In general, contaminant concentrations in fish
and shellfish were low with the exception <5f
some heavy metals (arsenic, copper, mercury,
and selenium) (Tables 1-3). Concentrations of
pesticides and PCBs measured in brown and
white shrimp tissue did not exceed existing FDA
or international criteria (USFDA 1982,1984;
Nauen 1983). Criteria levels were exceeded by
9% of the shrimp sampled for concentrations of
arsenic, copper, and mercury (Table 1).
Atlantic croaker is a recreationally and
commercially important fish in the Louisianian
Province. Concentrations of all chlorinated
pesticides and PCBs were below FDA criteria.
Arsenic concentrations exceeding 2.0 ppm
(International criteria) were found in 5% of the
croaker population (Table 2). Criteria for lead
(0.5 ppm) and selenium (1.0 ppm) were
exceeded by 2% of the population.
Concentrations of chromium and copper with
criteria values of 1 ppm and 15 ppm,
respectively, were exceeded by 1% of the
croaker population.
Marine catfish represent a minor recreational
fishery in the Louisianian Province. Because
their feeding habits bring them in direct contact
with sediments, catfish were analyzed to
examine the concentration of contaminants in
their flesh. This category included sea cats
(hardheads), gaff topsail catfish, arid blue catfish.
As was seen with croaker, catfish flesh
contained concentrations of chlorinated
pesticides and PCBs well within established
criteria. Catfish contained elevated levels of
arsenic (62% of samples exceeding 2 ppm).
Lead concentrations exceeded 0.5 ppm in 5% of
the catfish populations. Mercury and cadmium
exceeded 1 ppm in 1% of the catfish populations
(Table3).
Overall, the number of contaminants seen in fish
and shellfish exceeding the FDA action limits
Statistical Summary, EMAP-E Louisianian Province -1993
PagsS
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Contaminant
Observed
Range
Criterion
Pesticides {ng/g wwt)
ODD ND
DDE 0-2.4
DDT 0-2.2
Aidrin 0-4.8
Chlordane ND
Dleldrin ND
Endosulfan 0-3.2
Enddn 0-0.0
Hepwehlor 0-8.0
Hepttehlor Epoxide 0-2,5
Hextchlorobenzene 0-4.5
Undine 0-0.0
Mfrex 0-0.0
Toxaphene 0-0.0
Trans-Nonachlor 0-1.5
PCBf (ng/g wwt)
21 Congeners 0-12.7
ToiaJPCBs 0-14.6
Heavy Metals (jig/gwwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
2,6-56.2
0.18-4.1
0-0.2
0.1-0.3
5.9-18.3
0-0.1
0-1.02
0,03-0.18
0.03-0.07
0-0.05
0-0
14.3-18.7
5000
5000
5000
300
300
300
NA*
300
300
300
200
200
100
5000
NA
500
2000
NA
2
0.5
1
15
0.5
1
NA
1
NA
NA
60
Proportion
Exceeding
Criterion
0%
0%
0%
0%
0%
0%
u3
0%
0%
0%
0%
0%
0%
0%
u
0%
0%
u
9%
0%
0%
9%
0%
9%
U
4%
U
U
0%
1 Criteria were selected from FDA established limits for pesticides
and PCBs (USFDA 1982,1984) except hexachlorobenzene and
Hndane which are based on Swedish limits (Nauen 1983); no ¥Df
limits exist for metals other than mercury; metals criteria reflect
means of international limits (Nauen 1983).
*NA = Not available
i>0 = Unknown because no criterion level available
'ND * Not detected.
Contaminant
Observed
Range
Criterion1
Pesticides (ng/g wwt)
ODD
DDE
DDT
Aidrin
Chlordane
Dieldrin
Endosulfan
Endrin
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Lindane
Mirex
Toxaphene
Trans-Nonachlor
PCBs (ng/g wwt)
21 Congeners
Total PCBs ,
0-49.4
0-8.9
0-6.5
0-2.8
0-2.4
0-2.0
0-2.3
0-11.1
0-0
0-1.7
0-6.1
0-0
0-10.5
0
0-2.3
0-91.3
0-95.3
Heavy Metals (ng/g wwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
0-36.1
0-7.0
0-0.18
0.02-1.1
0-25.4
0-1.6
0-0.7
0-1.0
0-.12-L4
0-0.14
0-1.1
1-14.6
5000,
5000
5000
300
300
300
NA2
300
300
300
200
200.
100
5000
NA
500
2000
NA
" 2
0.5
', I,
15
0.5
1
NA,
, 1
NA
NA
60
Proportion
Exceeding
Criterion
0%
0%
0%
0%
0%
0% '
u3,
0%
0%
0%
0%
0%
u.
0%
0%
u
5%
0%
1%
1%
2%
0%
U%
2%
U%
U% •
0%
'Criteria were selected from FDA established limits fpr pesticides
and PCBs (USFDA 1982,1984) except hexachlorobenzene arid
lindane which are based on Swedish limits (Nauen 1983); no FDA.
limits exist for metals other than mercury; metals criteria reflect
means of international limits (Nauen 1983). ,.:.>.
2NA = Not available ' - . "'' '..-'.
3U = Unknown because no criterion level available
Table 1. Overview of the contaminant levels observed in
edible flesh of brown shrimp and white shrimp.
Table 2. Overview of the contaminant levels observed in
edible flesh of Atlantic croaker.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 6
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Contaminant
Observed Criterion1
Range
Pesticides (ng/g wwt)
ODD
DDE
DDT
Aldrin
Chlordane
Dieldrin
Endosulfan
Endrin
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Lindane
Mirex
Toxaphene
Trans-Nonachlor
PCBs (ng/g wwt)
21 Congeners
Total PCBs
0-18,5
0-104.8
0-20.7
0-22.5
0-4.2
0-83.6
0-0
0-1.9
0-2.6
0-1.6
0-6.3
0-2.0
0-2.4
0
0-6.1
0-20.6
0-56.7
Heavy Metals (ug/gwwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
0-88.6
0-39.9
0-0
0-1.04
0-11.6
0-6.5
0-1.6
0-30.5
0.1-0.6
0-0.1
0-0.1
4.8-28.4
5000
5000
5000
300
300
300
NA2
300
300
300
200
200
100
5000
NA
500
2000
NA
2
0.5
1
15
0.5
1
NA
1
NA
NA
60
Proportion
Exceeding
Criterion
0%
0%
0%
0%
0%
0%
' U>
0%
0% '
0%
0%
0%
0%
0%
u
0%
0%
u
62%
0%
1%
0%
5%
1%
U
0%
u
u
0%
1 Criteria were selected from FDA established limits for pesticides
and PCls (USFDA 1982, 1984) except hexachlorobenzene and
lindane which are based on Swedish limits (Nauen 1983); no FDA
limits exist for metals other than mercury; metals criteria reflect
means of international limits {Nauen 1983).
!NA = Not available
3U = Unknown because no criterion level available
Table 3. Overview of the contaminant levels observed in edible
flesh of catfish.
was low. However, a few contaminants
(selected heavy metals) occurred in high enough
concentrations to exceed international guidelines
in small portions of the populations examined.
These contaminants were arsenic, lead, mercury,
chromium and copper. Concentrations of arsenic
are a total of both organic and inorganic forms
and may not be available to the organisms.
Because of the paucity of information
concerning U.S. standards for heavy metals
other than mercury in fish, the criteria levels
used for metals in Table 1 through 3 (i.e., World
Health Organization guidelines) may not be
acceptable. However, the contaminant data are
available to be compared to any criteria and can
be used to track potential trends in contaminant
concentrations in flesh for the croaker, catfish,
and shrimp populations in the Louisianian
Province.
INTEGRATION OF ESTUARINE
CONDITIONS
The overall condition of the estuaries in the
Louisianian Province has been summarized by
combining the benthic index, marine debris,
water clarity and tissue contaminants, weighted
equally. This single value includes an index of
societal values (aesthetics) and estuarine biotic
integrity based on benthic assemblages (Fig. 5).
Indicators relating to biotic integrity and
aesthetics were used to estimate overall
environmental conditions in the estuaries. Forty-
six percent of the estuarine area in the
Louisianian Province showed evidence of
degraded biological resources or was impaired
with respect to its ability to support activities
valued by society (Fig. 5). Of the 25,725 km2 of
estuarine surface area in the Louisianian
Province, 11,834 km2 were potentially degraded
based on the 1993 sampling.
Statistical Summary, EMAP—E Louisianian Province — 1993
Page?
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ECOLOGICAL CONDITIONS
LOUISIANIAN PROVINCE 1993
Degraded Biology
29±B t
Impaired Use
Undegtadsd
Still*
Figure 5, Summary of environmental conditions in Louisianian Province in 1993,
The locations of degraded biological resources
were sometimes different from those having
aesthetic problems. Both sets of conditions were
found in 9±6% of the estuarine area, whereas
degraded biological conditions alone were found
in 29±6% of the province, and poor aesthetics
were found in 8±11% (Fig. 5).
POLLUTANT EXPOSURE
While EMAP-E's major objective is to describe
the status of estuaries using indicators of
ecological condition, we have taken numerous
measurements of the magnitude and extent of
pollutant exposure in order to ascertain some
preliminary links between observed estuarine
degradation and observed pollutant exposure.
Many of these pollutant measures are described
in detail in Section 2; however, a few exposure
indicators are discussed below: dissolved
oxygen concentrations, sediment toxicity, and
sediment contaminants.
Dissolved oxygen is a fundamental requirement
for all estuarine organisms. A threshold
concentration of 4 to 5 ppm is used by many
states to set water quality standards. Bottom
waters in 33%±11% of the Louisianian Province
had point measurements of dissolved oxygen
concentrations that failed to meet the 5ppm
criterion (Fig. 6). A concentration of
approximately 2 ppm is often used as a
threshold for oxygen concentrations thought to
be extremely stressful to most estuarine
organisms. Results from the 1993 Louisianian
Province Demonstration indicate that point
measurements of bottom dissolved oxygen
concentrations below this threshold were found
in 7±6% of the province (Fig. 6).
Two types of dissolved oxygen measurements
were taken in 1993: point measurements and
continuous measurements. Continuous
measurements were used to supplement point
measures, as some estuaries appear to undergo
severe dissolved oxygen stress during nighttime
Statistical Summary, EMAP-E Louisianian Province —1993
Pags 8
-------
BOTTOM DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1993
2-5 ppn
2 ppi
7i6 *
> 5 ppm
67i1U
Figure 6. Percent of area of Louisianian Province with instantaneous
dissolved oxygen concentrations in bottom waters < 2 ppm, 2-5 ppm,
and > 5 ppm. '
BOTTOM DISSOLVED
OXYGEN < 2 ppm
LOUISIANIAN PROVINCE 1993
loo-i
90
80-
70-
60-
50-
40-
30-
20-
10-
0
PROVINCE LARGE
CLASS
SMALL
Figure 7, Percent of area having instantaneous dissolved
oxygen concentrations in bottom waters of < 2 ppm for large
estuaries (large), small estuaries (small), and the
Louisianian Province, with 95% .confidence interval.
hours. Point measurements taken during daylight
hours could erroneously characterize a site as
having acceptable dissolved oxygen
concentrations when that site receives severe
dissolved oxygen stress for several hours every
night. Dissolved oygen concentrations <2.0 ppm
were found in a higher percentage of estuaries
£2.6%) based on the use of the continuous
measurements versus the instantaneous
measurements (Figs. 6-9).
Sediment bioassays are the most direct measure
available for estimating the potential for
contaminant-induced effects in biological
communities. These tests provide information
that is independent of chemical characterizations
and ecological surveys (Chapman 1988). Direct
measures of sediment contaminant
concentrations do not show which
concentrations may adversely affect biological
resources because many chemicals are bound
tightly to sediment particles or are ehemically-
complexed (USEPA 1989, Long and Morgan
1990). Sediment toxicity tests avoid this
problem by indicating when contaminant
concentrations have the potential to impact
biological resources. Laboratory bioassays were
conducted to determine if the sediments in the
Statistical Summary, EMAP—E Louisianian Province —1993
Page 9
-------
MINIMUM DISSOLVED
OXYGEN < 2 ppm
LOUISIANIAN PROVINCE 1993
LJ
O
QC
100
90
80
70
60
50
40
30
20-j
10
0
PROVINCE LARGE
CLASS
SMALL
Figure 8. Percent of area having minimum dissolved oxygen
concentrations in bottom waters of<2 ppm for large
estuaries (large), small estuaries (small), and the
Loulslanlan Province, with 95% confidence interval.
Louisianian Province were toxic to
representative estuarine organisms. Based upon
the results of these tests, 1.4±2.5% of the
Louisianian Province contained sediments that
were toxic to estuarine organisms (Figure 10).
Because Ampelisca abdita, the test organism
used in the bioassays is not common to the
touisianian Province, additional testing was
completed using a common mysid. The results
of this mysid testing generally agree with those
found using Ampelisca with 9.9±6.9% of the
province showing toxicity. The proportion of
area containing toxic sediments was very
different between the two classes (Fig. 10), with
the highest proportion occurring in the large
estuaries (1,6±2,2%) and a smaller portion in the
small estuaries (0.9±1.6%).
Measurements of concentrations of
contaminants in sediments were used to estimate
the areal extent of sediment having pollutant
concentrations that are above hypothesized
levels that could cause biotic effects and that
could be attributed to human activities. For this
summary, sediment contaminants will be
discussed as five major groups: heavy metals,
alkanes and isoprenoids, polynuclear aromatic
hydrocarbons (PAHs), pesticides, and polycyclic
chlorinated biphenyls (PCBs), and as a single
group of contaminated substances. For all
contaminants, the criteria used to assess
potential for degradation were the Long and
Morgan (1990) and Long etal (1995) median
values (ER-M) associated with biological
effects. All values above these median criteria
were assessed as being representative of
sediment degradation. In addition, the 10%
Long and Morgan values (ER-L) were used to
assess locations where some contamination
occurred, but at levels that could result in
ecological problems some of the time. These
criteria levels are not available for all toxic
substances. The criteria used for contaminants
are shown in Table 4.
Natural sources of metals and chemical and
physical processes in estuaries may concentrate
metals in fine-grained sediments or in
depositional areas of estuaries. In addition to the
criteria-based assessments described above,
analyses were conducted to distinguish areas
with elevated concentrations of metals as a
result of anthropogenic enrichment by adjusting
for aluminum sediment concentrations. Based
upon these two approaches, 20±7% of the
Louisianian Province has sediments with
Statistical Summary, EMAP-E Louisianian Province —1993
Page 10
-------
MINIMUM DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1993
2-5 ppm
25±11x
< 2 ppm
18±9 x
> 5 ppra
57411x
Figure 9. Percent of area of Louisianian Province with minimum dissolved oxygen concentrations in bottom waters < 2 ppm, 2-5 ppm,
and > 5 ppm based on 24 hours of data.
elevated concentrations of one or more heavy
metals based on the criteria values, and 16±7%
of the area has heavy metal concentrations that
were higher than would be expected based on
aluminum background concentrations (Fig. 11).
Alkanes and isoprenoids are hydrocarbons
associated with the petrochemical industry
(drilling, transport, refinement). While 27
individual alkanes were examined, total alkanes
were used to provide an overall assessment of
sediment contamination due to alkanes. No
biological effects guidelines exist for alkanes.
However, a criteria value of >7000 ppb total
alkanes was used to characterize a degraded
estuarine condition. An intermediate criterion on
5000-7000 ppb total alkanes was used as
indicative of potential contamination. None"bf the
sediments in the province collected in 1993 are
characterized by alkane concentrations in excess
of 7000 ppb.
However, a criterion is available for total PAHs
based on the Long et al (1995) estimate for
sediment concentrations resulting in biological
effects 50% of the time >44,792 ppb. Due to the
magnitude of this concentration, we also
examined the concentration range that produced
ecological effects >10% of the time >4022 ppb
total PAHs. No total PAH concentrations in the
observed Louisianian Province sediments
exceeded 44,792 ppb. Only 4±4% of the
province is characterized by the intermediate
total PAH concentration of > 4022 ppb. The
intermediate level of PAHs was found primarily
in large estuarine systems comprising 5±6% of
Statistical Summary, EMAP-E Louisianian Province - 1993
Page 11
-------
AMPELISCA MORTALITY > 20%
LOU
20-
IS-
U)
oc
_ O
111
Q*
5-
s-i
ISIANLAN PROVINCE 1993
•.. .
• i- •
• ,
T I T
_l_V_au
PROVINCE LARGE SMALL
CLASS
Figure 10. Percent of area having sediment toxicity for large
estuaries (large), small estuaries (small), and the
Louisi«ni»n Province, with 95% confidence interval.
those sediments.
Polycyclic chlorinated biphenyls (PCBs)
represent a very toxic compound in the
environment. Twenty individual PCB congeners
were examined in the 1993 Louisianian
Province Demonstration. Long et al 1995
provide a criterion of >180 ppb total PCBs as
the concentration likely to result in ecological
effects. They provide a secondary concentration
of >22.7 ppb at which some effects might be
expected. Total PCB concentrations in observed
Louisianian Province sediments did not exceed
400 ppb. Less than 1% of the Louisianian
Province sediments were characterized by total
PCB concentrations > 22.7 ppb.
Pesticides are introduced into the estuarine
environment through three pathways: direct
Contaminant
Inorganic (ppm)
Antimony
Arsenic ,
Cadmium
Chromium'
Copper
Lead
Mercury
Nickel
Silver
Zinc
Qrganie (ppW
Accnaphthene
Aeenaphthylene
Anthracene
Fluorene
2-methylnaphthalene
Naphthalene
Phenanthrene
Benzo(a) anthracene
Chrysene
Dibenzo(a,h)anthracene
Fluoranthene
Pyrene
Total PAH
Total LMW PAH
Total BMW PAH
p,p-DDE
Total DDT
Total PCBs
ODD
DDE
DDT
Chlordanc '
Dicldrin
Endrta
ER-L
Z
8.2
1.2
81
34
46.7
0.15
20.9
1.0
150
16
44
85.3
19
70
160
240 .
261
384
63.4
600
665
4022
' 552
1700
2.2
1.6
22,7
2.0
2.0
1.0
0.5
0.02
0.02
ER-M
~25
70
9.6
370
270
218 '
0.71
51.6
3.7 . ,
410
500
640
! 1100
' 5*40
;670
•; 2100
1500
1600
2800
260
5100
' 2600 '
44792
3160
9600
27
46.1
180
• , , 20 : . .
15
?•-.'-
! - 6 • .;-
8
45 '•
Table 4. Guidelines used to determine sediment contamination
where ER-L indicates the concentration at which 10% of
bioassays showed adverse biological effects and ER-M
indicates the concentration at which 50% of bioassays showed
adverse biological effects (Long and Morgan, 1990; Long ef of
1995).
Statistical Summary, EMAP-E Louisianian Province—1993
Page 12
-------
y a
SEDIMENT METALS
UIUI9UIUIKIWMCEn95
tc u to ci cu BE
SB tt
Figure 11. Percent of area of the Louisianian Province with sediment
metal concentrations > 10% Long-Morgan criteria or greater than
expected based on aluminum concentrations.
Endrin or Dieldrin concentrations did not exceed
the median criterion. However, 18% of the
sediment contained endrin at > 0.02 ppb and
57% of the sediments had dieldrin
concentrations > 0.02 ppb.
Ninety-five percent confidence intervals (95%
CI) were calculated for all parameters described
in this summary. Table 5 provides the 95%
confidence intervals for the major indicators for
the proportion of the province and the three
estuarine classes.
emission as a result of point source discharge
(generally through manufacture or disposal),
non-point emission through agricultural or
horticultural application, and atmospheric through
deposition of volatilized materials. In the 1993
Louisianian Province Demonstration, 25
pesticides and derivatives were examined. For
this summary, total pesticides, total DDT, and
total chlordane are reported. Generally accepted
sediment quality criteria are not yet available and
even reasonable criteria are available for only 9
of the 25 pesticides examined. Long and Morgan
(1990) report the following critical concentrations
for DDT, DDD, DDE, chlordane, dieldrin, and
e"ndrin: 7 ppb, 20 ppb, 15 ppb, 6 ppb, 8 ppb, and
45 ppb, respectively.
Neither DDT criteria value of 7 ppb or the
chlordane criteria value of 6 ppb were exceeded
for the sediments in the Louisianian Province.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 13
-------
Parameter
N
ABIOTIC CONDITION
Marine Debris
Water Clarily
PAR<10%
PAR < 25%
Sill-Clay Content
<20%
>BO%
Alkanes
Total > 7000 ppb
PAHs
Total > 4000 ppb
PCBs
Ton! > 22,7 ppb
Pesticides
Chlordane > ,5 ppb
Dieldrin > .02 pjpb
Endrin > .02 ppb
DDT >1 ppb
DDE > 2 ppb
ODD > 2 ppb
Mcttls
Ag> 1 ppra
As>33 ppm
Cd> 5 ppm
Cr>80 ppm
Cu>70 ppm
Hg > .15 ppm
Ni > 30 ppm
Pb>35 ppm
St» 2 ppm
Sn> 3 ppm
Zn > 120 ppm
Tributyliin
TBTMJppb
TBT>Spj3b
Province
93
11(7)
18(8)
45(12)
21(9)
35(11)
9(6)
4(4)
-------
Parameter Province Large Small
Estuary Estuary
N 93 62 31
BIOTIC CONDmON
Benthic Index 37(11) 34(12) 48(26)
Abundance < 10 - 5(5) 6(6) 2(3)
# Species < 2 <1(0) 0(0) 1(1)
#Speciess5 14(7) 18(10) 5(4)
Fish Contaminants'
Shrimp
All > FDA Limits 13(0) 0(0) 33(0)
Croaker
All > FDA Limits 0(0) 0(0) 0(0)
Marine Catfish
Hg> FDA Limits 2(1) 0(0) 2(0)
Otheis> FDA Limits 0(0) 0(0) 0(0)
Bottom DOZ< 2 ppm 7(6) 10(7) 1(1)
Bottom DOZ<5 ppm 32(11) 34(12) 30(25)
Minimum DO < 2 ppm 18(9) 20«0) 12(21)
Sediment Toxicity 1(2) 2(3) 1(2)
1 Percentage based on sample size rather man estuarine area
1 Instantaneous dissolved oxygen measurements
Table 5 (con/.)Estiraates of the proportion of the Louisianian Province and estuarine classes experiencing the levels of the listed
parameters and their associated 95% confidence interval in parentheses (N=number of sampling sites).
Statistical Summary, EMAP—E Louisianian Province —1993 Page IS
-------
-------
SECTION 1
INTRODUCTION
The Environmental Monitoring and Assessment
Program (EMAP) is a national program initiated
by EPA's Office of Research and Development
(ORD) (USEPA, 1992). EMAP is an integrated
federal program; ORD is coordinating the
planning and implementation of EMAP with
other federal agencies including the Agricultural
Research Service (ARS), Bureau of Land
Management (BLM), U.S. Fish and Wildlife
Service (FWS), National Biological Service
(NBS), Forest Service (FS), U.S. Geological
Survey (USGS), and the National Oceanic and
Atmospheric Administration (NO A A). These
other agencies and offices participate in the
collection and analysis of EMAP data and will
use it to guide their policy decisions, as
appropriate.
EMAP-Estuaries (EMAP-E) represents one
portion of EMAP's efforts in near coastal
environments and is jointly conducted by EPA/
ORD and NOAA. 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. In 1993, EMAP-
E continued a demonstration project in the
estuaries of the Louisianian Province (i.e., all
estuarine areas located along the coastline of the
Gulf of Mexico between the Rio Grande RtVer,
TX, and Anclote Anchorage, FL). This
Statistical Summary reports on the 1993
sampling effort.
1.1 OBJECTIVES OF THE 1993
LOUISIANIAN PROVINCE
ESTUARINE SAMPLING
The specifics of the planning activities of the
Louisianian Province Demonstration are
documented in Summers etal. (1991). This
continuing demonstration was held in the
Louisianian Province to show the utility of
regional monitoring programs for assessing the
condition of estuarine resources. Sampling was
conducted from July through August spanning
154 sites utilizing 30 field personnel and three
program/logistical coordinators.
The objectives of the 1993 Louisianian Province
Continuing Demonstration were to:
1) assess the condition of estuarine resources
in the Louisianian Province using a
probability-based sampling design; and,
2) develop and refine analytical procedures
for using regional-scale monitoring data to
assess the ecological status of estuaries and
apply these procedures to establish the
Statistical Summary, EMAP—E Louisianian Province —1993
Page 17
-------
jm
baseline conditions in the Louisianian
Province.
1,2 ENVIRONMENTAL VALUES
AND ASSESSMENT QUESTIONS
The environmental value depicted by the
EMAP-E in the Louisianian Province, as well as
other provinces, is estuarine condition. The
subvalues comprising condition are ecological
integrity and societal values.
Ecological integrity is comprised of ecosysten
quality (estuarine trophic state and acreage of
unique habitats) and biotic integrity (benthic
index and fish index). The primary assessment
questions relating to ecological integrity
addressed by the demonstration in the
Louisianian Province are:
• What proportion of the bottom waters of ,
the estuaries in the Louisianian Province
experience hypoxia (i.e., dissolved oxygen
concentrations < 2 ppm greater than 20%
of the time)?
• What proportion of the estuarine sediments
of the Louisianian Province has benthic
community structure indicative of polluted
environments?
* What proportion of the estuarine waters of
the Louisianian Province is eutrophic?
• What proportion of fish populations in the
Louisianian Province has characteristics
, similar to those indicative of polluted
environments?
Societal values are characterized by
consumptive uses (i.e., quantity and quality of
fishery stocks) and non-consumptive uses (i.e.,
aesthetics and water contact). The primary -
assessment questions related to societal values
are:
°>
• What proportion of target fish in the
Louisianian Province has contaminant
concentrations in edible tissue greater than
FDA action limits?
• What proportion of target fish in the
Louisianian Province has external gross
pathologies in excess of 0.5%?
• What proportion of the estuarine sediments
in the Louisianian Province contains
anthropogenic marine debris?
• What proportion of estuarine waters in the
Louisianian Province has insufficient water
, clarity to permit < 10% of incident
sunlight to reach a depth of 30 cm?
• What proportion of the estuarine waters in
the Louisianian Province has unacceptable
levels of pathogenic microbial agents?
In addition, several assessment questions relate
to the relationships among the response
indicators measured to address the above
assessment questions and stressor conditions in
the estuaries of the Louisianian Province. These
questions are:
• Are observed areas of eutrophic condition
in the Louisianian Province associated
with stressor conditions?
• Are observed areas of poor biotic
community conditions in the Louisianian
Province associated with stressor
conditions?
• Are observed areas of poor societal value
conditions in the Louisianian Province
Statistical Summary, EMAP-E Louisianian Province -1993
Page 18
-------
associated with stressor conditions?
Many of these assessment questions are
addressed in this statistical summary; however,
some of the associational questions are not
addressed in this summary but are addressed in
the Louisianian Province Demonstration Report
(Summers et at. 1993a).
1.3 PURPOSE AND
ORGANIZATION OF THIS
REPORT
The purpose of this report is to provide
estimates of the ecological condition of the
estuarine resources of the Louisianian Province
during 1993. This report is meant to be a
summarization of all the data collected in the
1993 Demonstration. As a result, different topics
are dealt with using varying levels of detail
based on their importance to the estimation of
ecological condition of the estuarine resources
of the Louisianian Province,
The Statistical Summaries that will be produced
by EMAP-E are meant to provide large
quantities of information without extensive
interpretation of these data. Interpretive reports
are anticipated every 4 to 5 years or in
specialized documents such as the
Demonstration Report for the Louisianian
Province (Summers etal. 1993a). As a result,
the Statistical Summaries will not provide
information concerning sampling
methodologies, field logistics, the development
of indicators, and design modifications.
Additional or expanded sections on methods,
logistics, designs, and indicators were included
in the 1991 EMAP-E Statistical Summary
(Summers et. al. 1993b). Also, to demonstrate
the flexibility of the EMAP-E sampling design
in the Louisianian Province, additional data
presentations (i.e., across states and EPA
regions) are provided which may not be
presented in other future EMAP-E Statistical
Summaries.
Section 2 provides information about the results
of the 1993 Demonstration with details of the
regional ecological "report card" for the "
estuaries of the Gulf of Mexico.
Section 3 summarizes the conclusions that can
be drawn from the 1993 Demonstration in the
Louisianian Province as they relate to the stated
objectives.
Section 4 lists the literature'cited in this report.
Appendix A provides a series of subpopulation
estimates created from the base monitoring data
to represent the conditions in the estuarine
resources in the five Gulf states and in the
portions of EPA Regions IV and VI located in
the Louisianian Province.
Statistical Summary, EMAP—E Louisianian Province — 1993
Page 19
-------
-------
SECTION 2
STATISTICAL SUMMARY
The following discussion is organized by
indicator type into biotic and abiotic condition
indicators and habitat indicators. In each
instance, an indicator will be described
minimally with text; the cumulative distribution
function (CDF) for that indicator will delineate
the frequency of occurrence of observations
within the province, and pie charts and bar
graphs will delineate the proportions of the
province or estuarine class showing particular
magnitudes.
2.1 BIOTIC 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 drawn (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 natural habitats
(Karr and Dudley 1981). Response measures
include measurements of the kinds and
abundances of biota present and human use
parameters that describe human perceptions of
the condition of estuarine systems. Biotic
condition indicators in the 1993 Louisianian
Province Demonstration included both measured
and derived indicators: number of benthic
species, abundance of total benthos, benthifi
community composition, benthic abundance by
taxonomic group, a benthic index of condition
based on bioindicators, number of fish species,
abundance of finfish, fish community
composition, target species abundances, fish
lengths, a fish index of condition, and
contaminants in fish and shellfish (i.e.,
pesticides, PCBs, and heavy metals).
2.1.1 NUMBER OF BENTHIC
SPECIES
Total number of benthic species has been used
to characterize the environment of estuarine
habitats. Three replicate benthic grabs at each
sampling location in the Louisianian Province
resulted in a distribution of mean number of
benthic species at a site ranging from 0 to
nearly 90 species (Fig. 2-1). There are no
significant differences in the cumulative
distribution function of species richness based
on 1 vs. 2 vs. 3 replicates, suggesting that, at
least for region-wide characterizations of species
distribution, a single replicate is acceptable.
Selecting 2 and 5 species as critical values for
"healthy" benthic communities based on
comparisons of impacted and reference sites of
similar salinity (Summers etal 1993b) results in
none of the sediments in the province having
near mono-specific stands of benthos, while
14±7% of the sediments have communities
comprised of 5 or fewer species (Fig. 2-2).
These areas with reduced numbers of benthic
species are primarily located in the small estuary
Statistical Summary, EMAP—E Louisianian Province —1993
Page 21
-------
BENTHIC SPECIES RICHNESS
LOUISIANIAN PROVINCE 1993
100
90
80-
70
60-1
50
40
30
20
10
10 20 30 40 50 60 70 80
MEAN NUMBER OF BENTHIC SPECIES (per grab)
90
100
Figure 2-1. Cumulative distribution of mean benthic species richness in estuarine sediments in the Louisianian Province in 1993 (-) and its
associated 95% confidence interval(-).
BENTHIC SPECIES RICHNESS
LOUtSSUiUH PROVINCE 1(93
1117 I
Figure 2-2. Percent of area of the Louisianian Province
cstuarine sediment associated with mean number of benthic
species categories In 1993.
BENTHIC SPECIES <2
LOUISIANIAN PROVINCE 1993
10
PROVINCE URGE SMALL
CLASS
Figure 2-3 Percent of area having sediments with mean benthic
species < 2 for large estuaries, small estuaries, and the
entire Province, with 95% confidence interval.
Statistical Summary, EMAP—E Louisianian Province —1993
Page '22
-------
EXPECTED NUMBER OF SPECIES
LOUISIANIAN PROVINCE 1993
100-1
90
80-
70-
60-
50
40-
30-
20
10
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
PROPORTION OF EXPECTED
Mean Number of Species
Figure 2-4. Cumulative distribution of proportion of expected number of bent hie species observed in the estuarine sediments of the
Louisianian Province in 1993 (-) and its associated 95% confidence interval (--).
classes (Fig. 2-3).
As a more meaningful comparison than simple
total species numbers, the proportion of
expected benthic species was estimated for the
1993 monitoring samples. This comparison was
based on the 1991-1992 regression of salinity
and mean number of benthic species per grab
(Engle et al. 1994). This proportion of expected
number of species, normalized for salinity
differences, ranged from 0.0 to 3.1 (Fig. 2-4).
About 20±9% of the sediments of the Gulf of
Mexico estuaries had < 33% of the expected
number of species based on salinity zone;
25±11% had between 33 to 66% of expected
species; and, 55±11% had > 66% of the number
of species expected based on salinity zone (Fig.
2-5). These areas of reduced expected numbers
of benthic species are primarily located in the
large estuaries (Fig. 2-6). Benthic diversity
associated with the three grabs varies widery
over the province (Fig. 2-7) with 3±4% of the
province having a benthic Shannon-Weiner
diversity index of less than 0.2 and 10±7% less
than 0.4 (Fig. 2-8).
2.1.2 TOTAL BENTHIC
ABUNDANCE
Benthic abundance is another indicator of the
condition of biotic estuarine resources.
Abundant benthic organisms, particularly in
communities characterized by multiple species
and feeding types, suggest a productive
estuarine environment. Mean benthic abundance
(Fig. 2-9) shows a range in benthic abundance in
the Louisianian Province of 0 to about 2200
organisms per grab or over 44,000 organisms/
m2. Using 10 organism/grab (about 200/m2) and
25/grab (about 500/m2) as indicators of low or
marginal benthic abundance, respectively, 5±5%
of Louisianian Province sediments have low
Statistical Summary, EMAP—E Louisianian Province —1993
Page 23
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PROPORTION OF EXPECTED
MEAN NUMBER OF SPECIES
LOUISIANIAN PROVINCE 1993
33-86* EXPECTED
25411*
<33i EXPECTED
20±9 r
>66* EXPECTED
55±11*
In 1993.
. Percent area of the Louisianian Province estuarine sediments associated with proportion of expected benthic species categories
< 33% EXPECTED MEAN
NUMBER OF SPECIES
LOUISIANIAN PROVINCE 1993
100
90
80
70
60
50
40
PROVINCE LARGE
CLASS
SMALL
benthic abundance and an additional 15±8%
have marginal abundance (Fig. 2-10), These
areas of low abundance are primarily associated
with large estuaries (Fig. 2-11).
2.1.3 BENTHIC ABUNDANCE BY
TAXONOMIC GROUP
The cumulative distribution functions can be
used to describe the breakdown of the total
benthic abundance described above into major
taxonomic groups (Figs. 2-12, 2-13, 2-14, 2-15).
Forty percent of the sediments sampled in the
1993 Louisianian Province Demonstration did
not have amphipods as part of the community
(Fig. 2-12), while 20% did not have gastropods
(Fig. 2-13). Tubificids are absent from 60% of
sediments while polychaetes were found in most
of the sediments sampled (Figs. 2-14 and 2-15).
Figure 2-6. Percent area having sediments with
proportion of expected benthic species < 33% in targe
estuaries, small estuaries, and the entire Province,
With 95% confidence interval.
Statistical Summary, EMAP—E Louisianian Province -1993
Page 24
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BENTHIC DIVERSITY
LOUISIANIAN PROVINCE 1993
.00
0.25
0.50 0.75 1.00 1.25 1.50
MEAN SHANNON-WEINER DIVERSITY INDEX
1.75
2.00
Figure 2-7. Cumulative distribution of benthic diversity in estuarine sediments in the Louisianian Province in 1993 (-) and its
associated 95% confidence interval (--)•
BENTHIC DIVERSITY
LOUISIANIAN PROVINCE 1993
INDEX > .+
90±7 x
INDEX .2-.4
7±7 x
INDEX < .2
Figure 2-8. Percent area of the Louisianian Province estttarine sediments associated with benthic diversity categories in 1993.
Statistical Summary, EMAP-E Louisianian Province - 1993
Page 25
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BENTHIC ABUNDANCE
LOUISIANIAN PROVINCE 1993
UI
2
UI
100-1
90
80-
70-
60-
50-
40
30-
20-
10
OH
200 400 600 BOO 1000 1200 1400 1600 1800 2000 2200
MEAN ABUNDANCE (per grab)
Figure 2-9. Cumulative distribution of mean abundance per grab in estuarine sediments in the Louisianian Province in 1993 (-) and its
associated 95% confidence interval (—).
BENTHIC ABUNDANCE
LOUISIANIAN PROVINCE 1993
10-25
15±8 *
< 10
5±5
Figure 2-10. Precent area of the Louisianian Provinc£estuarine sediments associated with benthic abundance categories in 1993.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 26
-------
BENTHIC ABUNDANCE < 10
LOUISIANIAN PROVINCE 1993
50
40-
30
20-
10-
PROVINCE LARGE SMALL
CLASS .':•'•'••' -:'
Figure 2-11. Percent area having sediments with benthic abundance < 10 organisms per grab in large estuaries, small estuaries, and the
entire Province, with 95% confidence interval. ,
BENTHIC AMPHIPOD ABUNDANCE
LOUISIANIAN PROVINCE 1993
200 400 600 800 1000 1200 1400 1600 1800 2000
MEAN ABUNDANCE (pir grab)
Figure 2-12. Cumulative distribution of mean amphipod abundance per grab in estuarine sediments in the Louisianian Province in 1993 (-)
and its associated 95% confidence interval (--). '
Statistical Summary, EMAP—E Louisianian Province —1993
Page 27
-------
BENTHIC GASTROPOD ABUNDANCE
LOUISIANIAN PROVINCE 1993
UJ
o
100
90
80
70
60
SO
40
30
20
10
20 40 60 80 100 120 140 160 180 200
MEAN ABUNDANCE (per grab)
Figure 2-13. Cumulative distribution of mean gastropod abundance per grab in estuarine sediments in the Louisianian Province in 1993
{-) and its associated 95% confidence interval (-•)•
BENTHIC TUBIFICID ABUNDANCE
100-
90-
80-
70-
| 60-
£ 50-
£ 40-
UJ
°" 30-
20-
» 10-
0-
LOUISIANIAN PROVINCE 1993
r'
-
.
•
f
i
t
0 10 20 30 40 50 60 70 80 90 100
MEAN ABUNDANCE (per grab)
Figure 2-14. Cumulative distribution of mean tubiflcid oligochaete abundance per grab in estuarine sediments in the Louisianian Province
In 1993 (•) and its associated 95% confidence interval (--).
Statistical Summary, EMAP—E Louisianian Province —1993
Page 28
-------
UJ
a.
BENTHIC POLYCHAETE ABUNDANCE
LOUISIANIAN PROVINCE 1993
40 80 120 160 200 240 280
MEAN ABUNDANCE (per grab)
320
360
400
Figure 2-15. Cumulative distribution of mean polychaete abundance per grab in estuarine sediments in the Louisianian Province in 1993
(-) and its associated 95% confidence interval (--)•
2.1.4 BENTHIC INDEX
About 37±11% of the sediments in the
Louisianian Province contained stressed or
degraded benthic communities as indicated by
benthic index < 4.0 (Fig. 2-16). The highest
proportion of the communities occurred in small
estuaries (48±26%) (Fig. 2-17). These figures do
not suggest that these stressed communities are
solely the result of anthropogenic influences.
Some of the p'oor benthic communities
described could be the result of natural
conditions (e.g., naturally induced hypoxia).
However, 40% of the differences observed
between stressed and unstressed benthic
communities were associated with elevated
concentrations of sediment contaminants
(namely, copper, silver, mercury, and PAHs)
and sediment toxicity, while none of the
differences were attributable to low dissolved
oxygen concentrations. The associations for the
remaining 60% of the differences were either
unknown or related to habitat variations (e.g.,
sediment enrichment).
2.1.5 NUMBER OF FISH SPECIES
Total number of fish species has been used to
characterize the environmental condition of
estuarine habitats. Dual 10-min trawls, taken at
each sampling location in the Louisianian
Province, resulted in a distribution of total
number of nekton species per trawl ranging from
0 to 9 species (Fig. 2-18), with a total of 88
Statistical Summary, EMAP-E Louisianian Province -1993
Page 29
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BENTHIC INDEX
LOUISIANIAN PROVINCE 1993
INDEX < 4
37±11x
HDEX 4-6
25±11*
INDEX > 6
37±11x
BENTHIC INDEX < 4
LOUISIANIAN PROVINCE 1993
PROVINCE LARGE SHALL
CLASS
Figure 2-16. Percent of area of the Louisianian Province estuarine
sediments associated with 1991-1992 revised benthic index
categories in 1993.
Figure 2-17. Percent of area having sediments with benthic
index <4.0 in large estuaries, small estuaries, and
the entire Province, with 95% confidence interval.
100
90
80
70
60-
50-
40-
30-
20-
10-
NEKTON SPECTES RICHNESS
LOUISIANIAN PROVINCE 1993
6 8 10 12 14
NUMBER OF SPECIES (in 2 trawls)
16
IB
20
Figure 2-18. Cumulative distribution of number offish species per trawl in the Louisianian Province estuaries in 1993 (-) and its
associated 95% confidence interval (—). , ' ... .-
Statistical Summary, EMAP—E Louisianian Province - 1993
Page 30
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NEKTON SPECIES RICHNESS
LOUISIANIAN PROVINCE 1993
>2 SPECIES
87±8
1-2 SPECIES
11±8 *
0 SPECIES
2±2 *
Figure 2-19. Percent of area of the Louisianian Province estuaries associated with the number offish species per trawl categories in 1993.
NEKTON SPECIES < 2
LOUISIANIAN PROVINCE 1993
50
30
20-
10
PROVINCE LARGE SMALL
CLASS
Figure 2-20. Percent area of estuaries with mean number of
species per trawl < 2 species in large estuaries, small estuaries,
and the entire Province, with 95% confidence interval.
species collected throughout the province.
Selecting 0 and < 2 species as comparative
values for fish communities with low species
abundance results in 2±2% of the province
having no fish taken in multiple trawls, while
11 ±8% had nekton communities comprised of 1
or 2 species per trawl (Fig. 2-19). Areas having
< 2 nekton species are primarily located in the
small estuary class (Fig. 2-20).
2.1.6 TOTAL FINFISH
ABUNDANCE
Finfish abundance is another indicator of the
condition of biotic estuarine resources.
Abundant nektonic organisms particularly in
communities characterized by multiple species
and feeding types suggest a productive estuarine
food web. Finfish abundance in the trawls taken
ranged from 0 to over 450 organisms per trawl
(Fig. 2-21). Using 2 organisms/trawl and 5/trawl
Statistical Summary, EMAP—E Louisianian Province —1993
Page 31
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NEKTON ABUNDANCE
LOUISIANIAN PROVINCE 1993
Ul
OS
LJ
O
ce
UJ
0.
100
90
80
70
50
40
30
20
10
OH
50 100 150 200 250 300 350
MEAN ABUNDANCE (per trawl)
400
450
500
Figure 2-21. Cumulative distribution of mean fish abundance per trawl in the Louisianian Province in 1993 (-) and its associated 95%
confidence interval (••)•
NEKTON ABUNDANCE
LOUISIANIAN PROVINCE 1993
ABUNDANCE 2-5
I0±9 x
ABUNDANCE > 5
79±9 x
ABUNDANCE
11±7 x
< 2
Figure 2-22. Percent are* of the Louisianian Province estuaries associated with the
mean fish abundance species'categories in 1993.
as values representing low and
marginal numbers of fish
abundance respectively, 11 ±7% of
Louisianian Province waters have
low f inf ish abundances and an
additional 10±9% have marginal
abundance (Fig. 2-22). These areas
of low abundance are primarily
associated with small estuaries
where 10±7% of waters in the class
have finfish abundances < 2 (Fig. •
2-23).
2.1.7 EXTERNAL GROSS
PATHOLOGY
The frequency and type of external
gross pathology associated with
nekton taken in the fish trawls is an
indicator of the overall condition of
Statistical Summary, EMAP—E Louisianian Province —1993
Page 32
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NEKTON ABUNDANCE < 2
LOUISIANIAN PROVINCE 1993
100-
90-
80-
SO
50
PROVINCE LARGE
CLASS
SMALL
Figure 2-23. Percent area of estuaries with mean fish
abundance per trawl < 2 species in large estuaries, small
estuaries, and the entire Province, with 95%
confidence interval.
fish collected in trawls. All fish that were
collected during the 1993 Louisianian Province
Demonstration were examined by the field
crews for external gross pathologies, such as
tumors and lesions. Over 22,570 fish were
examined for gross pathologies and a total of 97
external pathologies were noted. Three±3% of
the area of the Louisianian Province produced
trawls with > 2 pathologies/trawl (Fig. 2-24).
Overall in the province, 0.43% of the fish
examined had visible pathological disorders
(Fig. 2-25). The prevalence of abnormalities for
demersal and pelagic fish (0.4% and 0.3%,
respectively) was about the same as the
background level observed for all fish (0.43%),
However, upper trophic level fish (e.g.,
piscivores) and commercially harvested species
demonstrated a higher incidence of pathology
(0.63% and 0.83%, respectively) (Fig. 2-25).
Examples of upper trophic level fish are
seatrouts, permits, and spadefish. Hardhead
catfish, pinfish, and Atlantic croaker had visible
FISH PATHOLOGIES
LOUISIANIAN PROVINCE 1993
Figure 2-24. Percent offish examined from the Louisianian Province estuaries associated with the
number of external pathologies per trawl categories in 1993.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 33
-------
FREQUENCY OF
FISH PATHOLOGIES
LOUISIAN1AN PROVINCE 1993
UJ
CJ
OS
UJ
a.
2.0
J.5
1.0-
0.5-
Figure 2-25. Percent offish examined from the Louisianian Province
with external pathologies by fish class, with 95% confidence
interval. ' ' ' •• " "
MACROPHAGE AGGREGATES
LOUISIANIAN PROVINCE 1993
25/jq nn
92±0 x
Figure 2-26. Percent area offish examined from the Louisianian Province estuaries
with number of mncrophage aggregates per mm2 in 1993;
pathology rates that were clearly higher than the
observed background.
2.1.8 MACROPHAGE
AGGREGATES
Pigment-bearing macrophages are a prominent
feature of fish spleen, kidney, and liver (Agius
1980) and, in advanced telosts, they form
discrete aggregations called macrophage
aggregates (MAs) (Wo\keet al. 1985).
Suggested functions for these aggregates include
the centralizations of foreign materials and
cellular debris for destruction, detoxification,
and/or reuse (Ferguson 1976; Ellis etal. 1976).
It has been demonstrated that MAs' occurrence
may vary depending on the size, nutritional
state, or health of a particular fish (Agius 1979,
1980; Agius and Roberts 1981; Wolke et al.
1985) with the number and size of MAs
increasing with age, starvation, and/or disease.
Recent studies suggest that MAs may be
sensitive histological indicators of
fish health and environmental
quality (Summers etal.l993b,
Blazer etal. 1993).
About 1±0% of the fish sampled in
the Louisianian Province contained
macrophage aggregate
concentrations > 40/mm2 (Fig. 2-
26). The distribution of percent
area occupied by macrophage
aggregates is similar to the
distribution of number of
aggregates with the proportion of
the fish populations showing > 5%
of spleen area covered by
aggregates being 0.1% (Fig. 2-27).
These figures do not suggest that
these stressed communities are
solely the result of anthropogenic
> 40/sq nn
liO x
25-40/sq nn
7±0 x
Statistical Summary, EMAP-E Louisianian Province - 1993
Page 34
-------
% AREA OCCUPIED BY
MACROPHAGE AGGREGATES
LOUISIANIAN PROVINCE 1993
Figure 2-27. Cumulative distribution of percent area of spleen occupied
by macrophage aggregates in fish examined from the Louisianian
Province in 1993 (associated 95% confidence interval too narrow to
portray).
influences. Some of the high level of
macrophage aggregates described could be the
result of natural conditions (e.g., naturally
induced hypoxia, low food supply). However,
24% of the differences observed between
locations with fish with high or low levels of
macrophage aggregates were associated with
tissue contaminants, mercury and
hexachlordane, as well as low dissolved oxygen
concentration. The associations for the
remaining 76% of the differences were either
anknown or related to habitat variations.
2.1.9 MARINE DEBRIS
The presence of marine debris is one of the
obvious indicators of estuarine "degradation"
from a human use perspective. The presence of
trash in the water and along the bottom reduces
the value of the water body as a recreational
resource and may have ecological effects as
well. During the 1993 Louisianian Province
Demonstration the presence of marine debris
was noted in bottom sediments and in the
water column, and the type of the trash was
determined (e.g., plastic, anthropogenic wood,
metal, glass, etc.). In 1993, over 11±7% of the
surface area of the Louisianian Province
contained at least one item of marine debris.
The estuarine class with the largest proportion;
of sediment having marine debris was the
small estuaries with 14±18% coverage. Large
estuaries had 10±7% of their sediments
containing marine debris, respectively (Fig. 2-
28).
M
LOUI
100-
90-
80-
UJ
2g 60-
5 so-
o
5 40"
30-
20-
10-
ARINE DEBRIS
SIANIAN PROVINCE 1993
T "T
m 1 H
J ^ •Illilll •« 1
PROVINCE LARGE SHALL
CLASS
Figure 2-28. Percent area of estuaries with presence of
marine debris in sediments in large estuaries, small
estuaries, and the entire Province, with 95%
confidence interval.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 35
-------
2.1.10 WATER CLARITY
Another "social" or human use criterion for good
condition of an estuary is water clarity and the
lack of noxious odors. At each sampling site
during the Demonstration odors were noted
when present; however, no sites were classified
as having any unusual odor. Water clarity was
measured using a comparison of surface ambient
light, photosynthetically active radiation (PAR),
and the amount of light reaching any depth
(measurements were taken every meter to the
bottom). For the sake of relative comparison, the
proportion of incident light reaching 1 meter was
used as the standard for all sites (i.e., all sites
were at least 1 m in depth). The proportion of
light transmittance at 1 meter ranged from near
0% to about 62% (Fig. 2-29). Using 10%
transmittance (i.e., 10% of surface light) as a
measure of "turbid" clarity (i.e., cannot see your
hand in front of your face), 18±8% of the
Louisianian Province experienced turbid water
clarity (Fig. 2-30). Alternatively, using 25%
transmittance as a measure of moderate clarity
(cannot see your toes in waist deep water),
resulted in 45±12% of the Louisianian Province
with water clarity that could not pass this visual
test. The poorest water clarity occurred in small
estuaries with 22±18% (Fig. 2-31).
2.1.11 FISH TISSUE
CONTAMINANTS
Three sets of target species were examined for
the concentrations of selected contaminants in
edible flesh. These were: shrimp (brown and
white), Atlantic croaker, and catfish (hardhead,
gafftopsail, and blue catfish). The edible
portions of the shrimps were defined as the tail
meat with the shell removed, as the fillet with
skin for Atlantic croaker, and as the fillet
without skin for the catfish. All samples
WATER CLARITY
LOUISIANIAN PROVINCE 1993
100
90
80
-c 70
UJ
2: 60
£ 50
UJ
as 40-
UJ
°- 30
20-
10-
0-
10
20
30
40
50
60
70
80
90 100
% AMBIENT LIGHT
TRANSMITTED AT 1 METER
Figure 2-29. Cumulative distribution of water clarity as .pleasured as percent of surface light reaching a depth of 1 m in the Louisianian
Province in 1993 (-) and its associated 95% confidence interval (••)•
Statistical Summary, EMAP-E Louisianian Province -1993
Page 36
-------
WATER CLARITY
LOUISIANIAN PROVINCE 1993
LIGHT 10-25*
27±12*
LIGHT » 25%
Figure 2-30, Percent area of the Louisianian Province estuaries
associated with light categories in 1993.
LIGHT < 10%
LOUISIANIAN PROVINCE 1993
lu
o
a:
iu
Q_
100
90-
, 80
70
60
50
PROV1HCE LARGE
CLASS
SHALL
Figure 2-31. Percent area of estuaries with less than 10%
ambient light penetrating to a depth of 1.0 meter in large
estuaries, small estuaries, and the entire Province, with
95% confidence interval.
represented a composite of 3 to 10 individuals
collected from a single site. Initially, criteria
levels for pesticides, PCBs, and mercury were
taken from USFDA standards (USFDA 1982,
1984) with the exception of hexachlorobenzene,
lindane, endosulfan, and trans-nonachlor for
which U.S. standards were not available.
Swedish standards were substituted for
hexachlorobenzene and lindane (Nauen 1983).
Other than mercury, no USFDA standards were
available for metals; therefore, metals criteria
reflect the means of international limits (Nauen
1983).
This comparison of fish population contaminant
distributions to FDA action limits represents a
slight misuse of these criteria. The EMAP-
Estuaries data for the Louisianian Province do
not represent only market-size fish (i.e., most
fish were less than market size) or those fish
transported across state lines for sale. However,
the FDA action limits do provide a convenient
point of comparison to track potential trends in
tissue residue levels in juvenile fish.
No pesticide, or PCB concentrations exceeded
the specified criteria for shrimp (Table 2-1). The
highest concentration of an organic contaminant
found was 14.6 ppb total PCBs (compared to the
standard of 2000). Heptachlor and aldrin were
the pesticides found in highest concentrations in
shrimp tailmeat at 8 and 4.8 ppb respectively.
This represents 2.7% of the FDA limit for
heptachlor and .1.6% of the limit for Aldrin. A
total of 9% of the shrimp exceeded 2 ppm
arsenic, 15 ppm copper, and 1 ppm mercury
respectively. Four percent exceeded 1 ppm
selenium.
No pesticide or PCB concentrations exceeded
the specified FDA action limits for Atlantic
croaker (Table 2-2). DDD, endrin and rnirex
Statistical Summary, EMAP-E Louisianian Province -1993
Page 37
-------
Contaminant Observed Criterion' Proportion
Range Exceeding
Criterion
Pesticides (ng/g wwt)
DDD ND 5000 0%
DDE 0-2.4 5000 0%
DDT 0-2.2 5000 0%
Aldrin 0-4.8 300 0%
Chlordane ND 300 0%
Dleldrin ND 300 0%
Endosulfan 0-3.2 NA* U3
Endrin 0-0.0 300 0%
Hepuchlor 0-8.0 300 0%
Heptwhlor Epoxide 0-2.5 300 0%
Hexaehlorebenzene 0-4.5 200, 0%
Lindane 0-0.0 200 0%
Mirex 0-0.0 100 0%
Toxaphene 0-0.0m 5000 0%
Trans-Nonaehior 0-1.5 NA U
PCBs (ng/g wwt)
21 Congeners 0-12.7 500 0%
Total PCBs 0-14.6 2000 0%
Heavy Metals (jig/gwwt)
Aluminum 2.6-56.2 NA U
Arsenic 0.18-4.1 2 9%
Cadmium 0-0.2 0.5 0%
Chromium 0.1-0.3 1 0%
Copper 5.9-18.3 15 9%
Lead 0-0.1 ,0.5 0%
Mercury 0-1.02 1 9%
Nickel 0.03-0.18 NA U
Selenium 0.03-0.07 1 4%
Silver 0-0.05 NA U
Tin 0-0 NA U
Zinc 14.3-18.7 60 0%
1 Criteria were selected from FDA-established limits for pesticides
and PCBs (USFDA 1982, 1984) except hexachlorobenzene and
lindane which sic based on Swedish limits (Nauen 1983); no FDA
limits exist for metab other than mercury: metals criteria reflect
'means of international limits (Nauen 1983).
SNA = Not available
JU = Unknown because no criterion level available
*ND » Not Detected
Contaminant Observed Criterion' Proportion
Range . Exceeding
; Criterion
Pesticides (ng/g wwt)
DDD 0-49.4 5000 0%
DDE 0-8.9 5000 0%
DDT 0-6.5 5000 0%
Aldrin 0-2.8 300 0%
Chtordane 0-2.4 300 0%
Dieldrin , 0-2.0 300 0%
Endosulfan 0-2.3 NA2 UJ
Endrin 0-11.1 300 0%
Heptachlor 0-0 300 0%
Heptaehlor Epoxide 0-1.7 300 We
Hexachlorobenzene 0-6.1 200 0%
Lindane 0-0 200 0%
Mirex . 0-10.5 100 0%
Toxaphene 0-0 5000 0%
Trans-Nonachior 0-2.3 NA U
PCBs (ng/g wwt)
21 Congeners 0-91.3 500 0%
Total PCBs 0-95.3 2000 0%
Heavy Metals (ug/gwwt)
Aluminum 0-36.1 NA U
Arsenic 0-7.0 2 5%
Cadmium 0-0.18 0.5 0%
Chromium 0.02-1.1 1 1%
Copper 0-25.4 15 We
Lead 0-1.6 0.5 2%
Mercury 0-0.7 1 0%
Nickel 0-1.0 NA U%
Selenium 0-.12-1.4 12%
Silver 0-0.14 NA U«
Tta 0-1.1 NA U%
Zinc 1-14.6 60 0%
'Criteria were selected from FDA-established limits for pesticides
and PCBs (USFDA 1982, 1984) except hexachlorobenzene and
lindane which are based on Swedish limits (Nauen 1983); no FDA
limits exist for metals other than mercury; metals criteria reflect
means of international limits (Nauen 1983),
2NA = Not available
3U - Unknown because no criterion level available
Table 2-1, Overview of the contaminant levels observed in
edible flesh of brown shrimp and white shrimp.
Table 2-2. Overview of the contaminant levels observed in
edible flesh of Atlantic croaker.
Statistical Summary, EMAP-E Louisianian Province —1993
Page 38
-------
represented the highest fillet pesticide organic
residues found in Atlantic croaker at 49.4,11,1
and 10.5 ppb, respectively. These concentrations
represent < 1%, 3.7% and 10.5% of the action
limits for these contaminants. Heavy metal
criteria for arsenic (5%), cadmium (4%), lead
(2%), selenium (2%),chromium (1 %), and
copper (1%) were exceeded in croaker.
No pesticide or PCB concentrations exceeding
the specified FDA action limits were found in
marine catfish (Table 2-3). Several heavy metals
exceeded the international standards with 62%
of marine catfish in excess of 2 ppm arsenic, 1%
in excess of 1 ppb chromium, 1% in excess of 1
ppm mercury, and 5% in excess of 0.5 ppm
lead.
Organic and inorganic forms of arsenic were not
distinguished by our analyses. The high
percentage of catfish exceeding the standard
value may not pose a problem, as the organic
form of arsenic is not readily bioavailable.
2.1.12 INTEGRATION OF
ESTUARINE CONDITIONS
The overall condition of the estuaries in the
Louisianian Province has been summarized by
combining the benthic index, marine debris,
water clarity and tissue contaminants, weighted
equally. This single value includes an index of
societal values (aesthetics) and estuarine biotic
integrity based on benthic assemblages and fish
health condition (Fig. 2-32). Indicators relating
to biotic integrity and aestiietics were used to
estimate overall environmental conditions in the
estuaries. Forty-six percent (±11%) of the
estuarine area in the Louisianian Province
showed evidence of degraded biological
resources or was impaired with respect to its
ability to support activities valued by society; (Fig.
Contaminant
Observed Criterion1
Range
Pesticides* (ng/g wwt)
ODD 0-18,5
DBE 0-104,8
DDT 0-20.7
Aldrin ' ' 0-22.5.
Chlordane 0-4,2
Dieldrin 0-83.6
Endosulfan ND
Endrin 0-1,9
Heptachlor 0-2.6
Heptachlor Epoxide 0-1.6
Hexachlorobenzene 0-6; 3
Lindane ', 0-2\Q
Mire* , 0-2.4
Toxaphene • * 0-0
Trah's-Nonaehior 0-6.1
PCBs (ng/g wwt)
21 Congeners 0-20.6
Total PCBs 0-56.7
Heavy Metals (ng/g wwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel ,
Selenium
Silver
Tin
Zinc
0-88.6
0-39.9
ND
0-1-.04
0-11.6
0-6.5
0-1.6
0-30.5
0.1-0.6
0-0.1
0-0.1
4.8-28.4
5000
5000
5000
300
300
300
NA*
300
300
300
200
200
100
5000
NA
500
2000
NA
2
0.5
1
15
0.5
1
NA
1
NA-
NA
60
Proportion
Exceeding
Criterion
Wo
0%
0%
0%
0%
0%
u3
0%
0%
0%
0%
0%
u
u
62%
U
2%
U
U
1 Criteria were selected from FDA-established limits for pesticides
and PCBs (USFDA 1982,1984) except hexachlorobenzene and
lindane which are based on Swedish limits (Nauen 1983); no FDA
limits exist for metals other than mercury; metals criteria reflect
means.of international limits (Nauen 1983).
2NA= Not available ". . • , . ' •
= Unknown because no criterion level available
4ND = Not Detected
Table 2-3. Overview of the contaminant level observed in edible
flesh of catfish.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 39
-------
ECOLOGICAL CONDITIONS
LOUISIANIAN PROVINCE 1993
Degraded Biology
29±6 x
Inpaired Use
Undegraded
54±11x
Figure 2-32. Percent area of the Louisianian Province estuaries in
1993 associated with degraded biology and impaired use.
2-32). Of the 25,725 km2 of estuarine surface
area in the Louisianian Province, 11,833±2,830
km2 were potentially degraded.
The location of degraded biological resources
were sometimes different from those having
aesthetic problems. Both sets of conditions were
found in 9±6% of the estuarine area, whereas
degraded biological conditions alone were found
in 29±6% of the province and degraded human
use alone was found in 8±11% of the
Louisianian Province.
2.2 EXPOSURE INDICATORS
Exposure indicators have historically been the
mainstay of environmental monitoring
programs. Indicators of pollutant exposure
measured during the 1993 Louisianian Province
Demonstration were dissolved oxygen
concentration (instantaneous and
continuous), sediment toxicity
(Ampelisca abdita and Mysidopsis
bahia), and sediment contaminants (27
alkanes, 43 PAHs, 25 pesticides, 20
PCB congeners, 4 butyltins, and 15
heavy metals).
2.2.1 DISSOLVED OXYGEN
(INSTANTANEOUS)
As stated earlier, dissolved oxygen (DO)
concentration is important because it is
a fundamental requirement of
populations of benthos, fish, shellfish,
and other aquatic biota. DO was
measured in two ways during the 1993
Louisianian Province Demonstration:
instantaneous point measures at 1-m
depth intervals during sampling and
deployed continuous recordings of dissolved
oxygen for a 24-hour period at a depth of
0.5m above the bottom.
The cumulative distribution functions of
instantaneous dissolved oxygen concentrations
at depth intervals showed, as would be expected,
an increased tendency toward lower
concentrations with depth (Figures 2-33 through
2-37). Minimum DO concentrations derived
from province-wide instantaneous estimates
decreased from 4.8 ppm at the surface to 0.9
ppm at 1 m, 0.3 ppm at 2 m, 0.2 ppm at 3 m,
and 0.2 at the bottom. The minimum values show
this steady decline with depth reflecting the
stratified nature of some estuaries. However, the
median values change very little (ranging from
7.0 at the surface to 5.8 at the bottom)
suggesting that most estuaries in the Louisianian
Province are well mixed. Surface dissolved
oxygen concentrations were rarely observed to
Statistical Summary, EMAP-E Louisianian Province- 1993
Page 40
-------
SURFACE DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1993
100
90-
80-
70-
60
50
40
30
20
10
68 10 12
DISSOLVED OXYGEN (ppn)
14
16
18
Figure 2-33. Cumulative distribution of surface dissolved oxygen concentration in the Louisianian Province in 1993 (-) and its associated
95% confidence interval (--).
DISSOLVED OXYGEN AT 1 METER
LOUISIANIAN PROVINCE 1993
100
90
80
70
50
40
30
20
10
O-l
6 8 10 12
DISSOLVED OXYGEN (ppn)
14
16
18
Figure 2-34. Cumulative distribution of dissolved oxygen concentration at a depth of 1 m in the Louisianian Province in 1993 (-) and
its associated 95% confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1993
Page 41
-------
DISSOLVED OXYGEN AT 2 METERS
LOUISIANIAN PROVINCE 1993
100-
90-
80-
70-
60-
50-
30
20
10-
0-
6 8 10 12
DISSOLVED OXYGEN (ppn)
14
16
18
Figure 2-35. Cumulative distribution of dissolved oxygen concentration at a depth of 2 m in the Louisianian Province in 1993 (-) and
Its associated 95% confidence interval (--).
DISSOLVED OXYGEN AT 3 METERS
LOUISIANIAN PROVINCE 1993
100
90
80
70
60
50
40
30
20
10
6 8 10 12
DISSOLVED OXYGEN (ppn)
14
16
18
Figure 2-36. Cumulative distribution of dissolved oxygen concentration at a depth of 3 m in the Louisianian Province in 1993 (-) and its
associated 9596 confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1993
Page 42
-------
BOTTOM DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1993
100-1
90
80-
70"
LU
2=' 60
£ 50-
LU
£ 40-
UJ
o_
30-
20
10
(H
6 8 10 12
DISSOLVED OXYGEN (ppm)
U
16
18
Figure 2-37. Cumulative distribution of bottom dissolved oxygen concentration in the Louisianian Province in 1993 (-) and its
associated 95% confidence interval (--).
SURFACE DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1993
> 5 ppn
96±5 i
2-5 ppra
+±5 *
Figure 2-38. Percent area of the Louisianian Province estuaries associated with
surface dissolved oxygen categories in 1993.
be below 5 ppm during the daylight
sampling (Fig. 2-38) while bottom DO
concentrations were below 5 ppm for
32±11% of the province and below 2
ppm for 7±6% of the province (Fig. 2-
39). Bottom dissolved oxygen
concentrations < 5 ppm were seen in
both estuarine classes with large
estuaries displaying the greatest extent
at 34±12% of the class resources, and
small estuaries at 30±25% (Fig. 2-40).
However, the proportion of class
resources that experienced DO
concentrations < 2 ppm were almost
exclusively within the large estuary
class where 10±7% were characterized
by these conditions. Small estuaries had
virtually no incidence of DO
concentrations below 2 ppm (1±1%)
during daylight sampling (Fig. 2-41).
Statistical Summary, EMAP—E Louisianian Province —1993
Page 43
-------
BOTTOM DISSOLVED OXYGEN
LOU1SIANIAN PROVINCE 1993
2-5 ppn
25±l1i
2 ppn
746 x
> 5 ppn
67111*
Figure 2-39, Percent area of the LouLsianian Province
estuaries associated with bottom dissolved oxygen categories
in 1993.
2.2.2 DISSOLVED OXYGEN -
(CONTINUOUS)
Unlike the instantaneous measures, the
continuous dissolved oxygen concentration
measurements provide a more complete picture
of the DO conditions within an estuary by
including periods of high water column and
sediment respiration (i.e., night). The continuous
measures were collected because earlier studies
(Summers and Engle 1993) showed that a
combination of daily minimum DO
concentration and the incidence of DO
concentrations < 2 ppm for > 20% of the
deployed period could be used to successfully
characterize an estuary as "good" or "hypoxic"
with regard to index period DO conditions. -
BOTTOM DISSOLVED
OXYGEN < 5 ppm
LOUISIANIAN PROVINCE 1993
o
0»
PROVINCE LARGE SHALL
CLASS
Figure 2-40. Percent area of estuaries with bottom dissolved
oxygen < S ppm in large estuaries, small estuaries, and the
entire Province, with 95% confidence interval.
BOTTOM DISSOLVED
OXYGEN < 2 ppm
LOUISIANIAN PROVINCE 1993
o
a:
Lk)
Q.
100
9(H
80
70-
60-
50
40
30-
20-
10
0
PROVINCE LARGE
CLASS
SHALL
Figure 2-41. Percent area of estuaries with bottom dissolved
oxygen < 2 ppm in large estuaries, small estuaries, and the
entire Province, with 95% confidence interval.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 44
-------
MINIMUM DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1993
2-5 ppn
25±11x
> 5 ppn
57±11*
Figure 2-42. Percent area of the Louisianian Province estuaries
associated with minimum bottom dissolved oxygen (continuous
sampling) categories in 1993.
Minimum DO concentrations resulting from
continuous recordings showed that 18±9% of the
province experienced DO conditions below 2
ppm while 43±11% of the province had minimal
dissolved oxygen concentrations < 5 ppm (Fig.
2-42). Based on the above estimation technique,
this represents only a 1% increase in the
estuarine bottom area experiencing low DO
conditions based on instantaneous measurements
during daylight hours. Thus in 1993, only an
additional 1% of province estuaries experience
cyclic DO conditions so that high concentrations
are observed during the day and concentrations
< 2 ppm are observed at night. Similarly, an
additional 13% of estuaries in the Louisianian
Province experience DO conditions < 5 ppm at
night. In 1993, where lower DO conditions were
predominant in large estuaries during daylight
hours, continuous measurements also showed
that large estuaries experience DO conditions
MINIMUM DISSOLVED
OXYGEN < 2 ppm
LOUISIANIAN PROVINCE 1993
cm
UJ
a.
10(H
90
80-I
70
60
50
40
30
20-
10-
0
PROVINCE LARGE
CLASS
SMALL
Figure 2-43. Percent area of estuaries with minimum bottom
(continuous sampling) dissolved oxygen < 2 ppm in large
estuaries, small estuaries, and the entire Province,
with 95% confidence interval.
below 2 ppm more frequently than other
estuaries (Fig. 2-43). Thus, unlike the conditions
observed in 1991, DO conditions in 1993 rarely
portrayed extreme cyclic patterns showing DO
conditions < 2 ppm only at night. Systems
experiencing low bottom DO conditions
continuously (day and night) include about 5%
of the large estuarine surface area within the
province (e.g., Mobile Bay, parts of Chandeleur
Sound).
All estuaries exhibit DO cycling to some degree.
However, the cyclic nature described here
suggests wide amplitude changes in
concentrations from day to night in many small
estuaries although few estuaries cycle lower
than 2 ppm. Examination of the duration of low
Statistical Summary, EMAP—E Louisianian Province —1993
Page 45
-------
> 20% DO < 2 ppm
LOUISIANIAN PROVINCE 1993
o
as
100-i
90
80
70
60
50
40
30
20
10H
PROVINCE LARGE
CLASS
SMALL
sediments collected in the Louisianian Province
were toxic to the amphipods (Fig. 2-45), In these
sediments, mortality rates were >20% higher
than, and significantly higher than, those
observed in the controls. The estuarine sampling
class with the largest proportion of toxic
sediment was the large estuary class (1.6±3.2%)
while small estuaries showed toxicity to a lesser
extent (0.9±1.6%) (Fig. 2-46). On a province-
wide scale, large estuaries contributed 299 km2
with small estuaries contributing 67.5 km2 of
toxic sediments.
2.2.4 SEDIMENT TOXICITY -
MYSIDOPSIS B AHIA
Because Ampelisca abdita is relatively
uncommon in the estuaries of the Louisianian
Province and had to be purchased and
Figure 2-44. Percent area of estuaries with bottom dissolved
oxygen < 2 ppm for greater than 20% of the observations in
large estuaries, small estuaries, and the entire
Province, with 95% confidence interval.
AMPELISCA SEDIMENT TOXICITY
DO conditions in the Louisianian LOUISIANIAN PROVING! 1993
Province showed that 17±9% of the
province exhibited DO concentrations
below 2 ppm for greater than 5 hours
during the day (20% of time). These
measurements were seen primarily in
the large estuarine class (Fig. 2-44).
2.2.3 SEDIMENT TOXICITY-
AMPELISCA ABDITA
pediment toxicity tests were performed
on the composited surface sediments
collected from each sampling site.
Tests included a standard 10-day acute
test (Swartz et al. 1985; ASTM 1990)
using the tube-dwelling amphipod,
AmpellSCa abdita. About 1±2% Of the Rgu£e2-45. Percent area of the Louisianian Province estuaries associated with
Ampelisca sediment toxicity categories in 1993.
NON-TOXIC
89i2 *
TOXIC
1±2 *
Statistical Summary, EMAP—E Louisianian Province —1993
Page 46
-------
AMPELISCA MORTALITY > 20%
LOUISIANIAN PROVINCE 1993
LU
o
2(H
15-
10-
PROVINCE LARGE SHALL
CLASS
Figure 2-46. Percent area of estuaries with Ampelkca mortality
> 20% in large estuaries, small estuaries, and the entire
Province,
MYSID SEDIMENT TOXICITY
LOUISIANIAN PROVINCE 1993
.HOM-TOXIC
9017
transported from California, a second organism,
Mysidopsis bahia, was tested to see whether it
provided the same results on a province-wide
scale as did the amphipod. Mysids are readily
culturable but do not clearly associate
themselves with sediments. Mysid contact with
the sediments is frequent but not continuous
whereas the tube-dwelling amphipod is
generally in contact with the tested sediments.
About 10±7% of the sediments in the
Louisianian Province was toxic to mysids
resulting in mortalities >20% higher than those
observed in control tests (Fig. 2-47), This figure
compares favorably with the 1% observed for
Ampelisca toxicity. The major differences
between amphipod and mysid testing are shown
in Figures 2-45 and 2-47 where the percentage
of area demonstrating toxicity appears to be
greater for mysids.
2.2.5
TOXIC
10i7
Figure 2-47. Percent area of the Louisianian Province estuaries associated
with Mysidopsis sediment toxicity categories in 1993.
SEDIMENT CONTAMINANTS -
ALKANESAND
ISOPRENOEDS
Alkanes and isoprenoids include
contaminants associated with the
petroleum industry. Sediments
collected throughout the Louisianian
Province were analyzed for 27
individual alkanes and total alkanes.
The distribution of observed
concentrations for total alkanes in
Louisianian Province sediments is
shown in Figure 2-48 depicting
concentrations ranging from 60 to
5,853 ppb. None of the sediments in
the province collected in 1993 are
characterized by alkane concentrations
in excess of 7000 ppb. The ranges of
concentrations and the percentage
province-wide areas in excess of 1000
ppb for the 27 individual alkanes
Statistical Summary, EMAP—E Louisianian Province —1993
Page 47
-------
UJ
Of.
0
o:
UJ
a.
100
90
80
70
60
50
40
30
20
10
OH
TOTAL ALIPHATIC HYDROCARBONS
LOUisi'ANIAN PROVINCE 1993
2 3 4 5 6 78
TOTAL ALIPHATIC HYDR.OCARBONS (ppb x 1000)
10
Figure 2-48. Cumulative distribution of alkanes and isoprenoids in the Louisianian Province sediments in 1993 (-) and its associated 95%
confidence interval (--).
analyzed are shown in Table 2-4.
2.2.6 SEDIMENT CONTAMINANTS-
POLYNUCLEAR AROMATIC
HYDROCARBONS
Forty-three individual polynuclear aromatic
hydrocarbons (PAHs) were analyzed from the
collected Louisianian Province sediments. The
distribution of the total of these 43 PAHs is
sjhown in Fig. 2-49, ranging from 4 ppb to about
1948 ppb. None of the sampled sediments
exceeded either the median (Long et. a/. 1995)
criterion of 44,792 ppb or the lower criterion of
4022 ppb. (The ranges of individual PAHs, and
the criteria used are shown in Table 2-5).
For 1993 the cumulative distribution function of
the relative percent of high molecular weight
compounds shown in Figure 2-50 continues to
show a shift in the distribution towards high-
weight PAHs (see Table 2-5 for a listing of high
and low molecular weights). This indicates that
combustion processes are most likely the
dominant sources of these compounds
contributing to the observed PAHs in the
Louisianian Province estuarine sediments. No
differences were noted among the three
estuarine classes with regard to molecular
weight of PAH's. However, a slight dominance
of low molecular weight PAHs was observed
east of the Mississippi River while high
molecular weight PAHs slightly dominated in
western Gulf of Mexico estuaries. (Figures 2-51
Statistical Summary, EMAP—E Louisianian Province —1993
Page 48
-------
Percent Area
Alkanc
CIO
CI1
ci2
C13
C14
CIS
C16
C17
Pristane
C18
Phytane
C19
C20
C21
C22
C23
C24
C25
C26
C27
C28
C29
C30
C31
C32
C33
C34
TOTAL
Range (ppb)
0-
0-
1-
0-
1 ' 1-
2-
1-
'3-
0-:
0-
0-
0-
0-
1-
1-
1-
1-
2-
1-
3-
1-
3-
0-
1-
0-
0-
0-
60-
68
77
88
77
72
2S9
56
345
98
35
49
77
92
389
61
168
98
261
125
646
182
1894
164
1431
261
245
63
S8S3
> 1000 ppb
0%
• 0%
0%
0%
0%
0%
0%
0%
We
: o%
0%
0%
, 0%
0%
0%
0%
0%
0%
0%
0%
0%
2%
0%
2%
0%
0%
0%
0%
and 2-52).
2.2.7 SEDIMENT CONTAMINANTS -
POLYCHLORINATED BIPHENYLS
Louisianian Province sediments were analyzed
for twenty polyehlorinated biphenyl (PCB)
congeners. Concentrations of total PCBs (sum
of the twenty congeners) ranged from 0 to 73.3
ppb (Fig. 2-53). Given that the criterion for low-
level ecological effects is 22.7 ppb for total
PCBs {Long et al 1995), < 1% of the area in the
province had concentrations that exceeded this
criterion (Table 2-6).
2.2.8 SEDIMENT CONTAMINANTS -
PESTICIDES
Pesticides constitute a major portion of nonpoint
source runoff from agricultural fields, suburban
Table 2-4. Alkane concentration ranges measured in the 1993
Demonstration and the percentage of province sediments
exceeding 1000 ppb for individual alkanes and 7000 ppb for
total alkanes.
TOTAL POLYNUCLEAR AROMATIC HYDROCARBONS
. LOUISIANUN PROVINCE 1993
100
90
80
70-
60-
50
40
30-
20
10-
0-
B 10 12
TOTAL PAHs (ppb X 100)
14
IS
18
20
Figure 2-49. Cumulative distribution of PAH concentrations in the Louisianian Province sediments in 1993 (-) and its associated 95%
confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1993
Page 49
-------
PAH
AcenaphtIiene{L)
Acenaphthylene(L)
Amhracene(H)
Bcnzo(a)anthracene(H)
Benzo(a)pyrene(H)
Benzo!b)fluoranthene(H)
Benzo(e)pyrene(H)
Benzo(g,h,iJperylene(H)
Benzo(k)fluoranthene{H)
Biphenyl(L)
Chiysene(H)
Cl-chiysene{H)
C2-chfysene(H)
C3-chiysene{H)
C4-ohiysene{H)
Dibenzo(a,h)anthracene(H)
Dibcnzothio(H)
Cl-diben«>thio{H)
C2-dibenzothio(H)
C3-dibenzothio(H)
Huoranihenc(H)
Cl-fluoranthpyrene(L)
Ruorene(L)
Cl-fluorene(L)
C2-fIuorenc(L)
C3-fIuorene(L)
Naphlhalene(L)
CI-imphthalene(L)
C2-naphthaIene(L)
C3-naphtha!ene(L)
C4-naphthaIene(L)
PerytenefH)
Phenfutthrene(H)
Cl-phcninthrene(H)
C2-phenanthrene(H)
C3-phenanthj*ne(H)
C4-phenanthrene(H)
Pyrene(HJ
(i)l,2,3-c,d-pyrene(H)
l-mcthylnaphtha!ene(L)
2-methyInaphlha!ene(L)
2,3,5 TrimethylnapthaleneflLJ
2,6 Dimethylnapthalene(L)
l-methylphenanthrene(H)
High Molecular Wt. PAHs
Low Molecular Wt. PAHs
, Total PAHs
Range (ppb)
0-11
0-12
0-30
0-91
0 -625
0-122
0-84
0-94
0-122
0-8
0-88
0-71
0-49
0-8
0-50
0-21
0-5
0-14
0-24
0-23
0-191
0411
0-10
0-7
0-16
0-23
0-22
0-20
0-21
0-24
0-19
0-124
0-87
0-44
0-36
0-43
0-47
0-154
0-97
0-9
0-11
0-6
0-8
0-8
1-1777
2-173
4-1948
Criteria (ppb)
16/500
44/640
85.3/1000
261/1600
430/1600
NA
430/1600
NA
NA
NA '
384/2800
384/2800
384/2800
63.4/2800
63.4/2800
63.4/260
NA
NA
NA
NA
600/5100
NA
19/540
19/540
19/540
19/540
160/2100
160/2100
160/2100.
160/2100
160/2100
NA
240/1500
240/1580
240/1580
240/1580
240/1580
665/2200
NA
NA
70/670
NA
NA
1 NA
1700/9600-
552/3160
4022/44792
Percent
flO%l
0%
0%
0%
0%
0%
u
0%
u
u
u
0%
0%
0%
0%
0%
0%
u
u
u
u
0%
u
0%
0%
0%
5%
0%
m
0%
0%
0%
u
0%
0%
0%
0%
0%
0%
u
u
0%
u
u
u
1%
0%
0%
Exceeded
(50%)
0%
0%
0%
0%
0%
u
0%
u •
u
u
0%
0%
0%
0%
0%
0%
u
u
u
u
0%
u
0%
0%
0%
0% !
0%
0%
0%
0%
0%
u
0%
0% '
0%
0%
0%
0%
u
u
0%
u
u
u
0%
0%
0%
Table 2.5 Ranges of PAH concentrations found in the 1993 Louisianian Province Demonstration, criteria used for comparison from Long
and Morgan (1990) [x/y where x = concentration where biological effects occurred 10% of the time and y = median concentration for
effects to occur], and the percent of sediments exceeding these criteria. (NA = None Available! U = Unknown)
Statistical Summary, EMAP—E Louisianian Province - 1993
Page 50
-------
PAHs - HIGH MOLECULAR WEIGHT
LOUISIANIAN PROVINCE 1993
100-
90-
80-
70-
.
60-
50
40H
30-
20
10
0-1
10 20 30 40 50 60 70
x of TOTAL PAHs as HHW
80 90
100
Figure 2-50. Cumulative distribution of high molecular weight PAH concentrations in the Louisianian Province sediments in 1993 (-) and
its associated 95% confidence interval (--).
100
90
80
70
50
40-
30
20
10
0
PAHs - LOW MOLECULAR WEIGHT
EPA REGION IV 1993
10 20 30 40 50 60 70
-* of TOTAL PAHs as LMW
80 90
100
Figure 2-51. Cumulative distribution of low molecular weight PAH concentrations in the Louisianian Province sediments in 1993 east of
the Mississippi River (-) and its associated 95% confidence interval (--).
Statistical Summary, EMAP—E Louisianian Province — 1993
Page 51
-------
PAHs - HIGH MOLECULAR WEIGHT
EPA REGION VI 1993
UJ
o
a:
100
90
80
70
60
50
40
30
20
10
10 20 , 30 40 50 60 70
x of TOTAL PAHs as HHW
80
90
100
Figure 2-52. Cumulative distribution of the proportion of high molecular weight PAHs in the Louisianian Province sediments in 1993 west
or the Mississippi River delta (-) and its associated 95% confidence interval (--).
TOTAL POLYCHLORINATED BIPHENYLS
100-
90-
80-
70-
UJ
^ 60-
£ 50-
UJ
2 40-
UJ
Q.
30-
20-
10-
0-
LOUISIANIAN PROVINCE 1993
i/'
lit'
i
I
1
.
1
0 10 20 30 40 50 60 70 80 90 100
TOTAL PCBs (ppb)
Figure 2-53. Cumulative distribution of total PCB concentrations in the Louisianian Province sediments in 1993 (-) and its associated 95%
confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province - 1993
Page 52
-------
PCB # (Congener!
8 (CL2)
18 (CL3)
28 (CL3)
44(CL4)
52 (CL4)
66 (CL4)
101 (CL5)
105 (CL5)
1 10/77 (CL5/4)
1 18/108/149 (CL 5/5/6)
126 (CL5)
128 (CL6)
138 (CL6)
153 (CL6)
170 (CL7)
180 (CL7)
187/182/159 (CL 7/7/6)
195 (CL8)
206 (CL9)
209 (CLIO)
TOTAL PCBs
Range (ppb)
0-1.0
0-0.5
0-0.9
0-0.3
0-1.0
0-0.6
0-1.2
0-0.3
0-2.0
0-1.1
0-0.9
0 - 0.4
0-1.3
0 -1.5
0 - 72.4
0 - 0.6
0-0.2
0-0.1
0-0.1
0-0.7
0 - 73.3
Table 2.6 Ranges of polycyclic chlorinated biphenyl
concentrations determined from Louisianian Province
sediments.
lawns, and golf courses. Twenty-five chlorinated
insecticides, including DDT and its derivatives,
and one fungicide were analyzed from
Louisianian Province sediments. No pesticides
have accepted sediment criteria; therefore, we
used the few criteria available from Long and
Morgan (1990) for DDT and its derivatives,
chlordane, endrin, and dieldrin. The criterion for
4,4'DDE is from Long et. al. 1995. The ranges
of observed concentrations of all pesticides
examined are shown in Table 2-7.
No DDT or chlordane concentrations above the
Criteria were found in the sediments of the
Louisianian Province.
Endrin concentrations did not exceed its median
criterion (45 ppb) in any of the sediments
examined from the Louisianian Province;
however, 18% of sediment contained endrin at >
Percent Exceeded
Pesticide
2,4 ODD
4,4 ODD
2,4 DDE
4,4 DDE
2,4 DDT
4,4 DDT
Total DDTs
Aidrin
AIpha-BHC
beta-BHC
delta-BHC
alpha-Chlordane
gamma-Chlordane
Dieldrin
Endosulfan
Endrin
Hexachlorobenzene
Heptachlor
Heptachlor Epoxide
Mirex
cis-Nonachlor
trans-Nonachlor
Oxychlordane
Lindane
Chlorpyritos
Docotol
Total BHCs
Range (ppb)Criteria (nob) (10%) (50%)
0 - 0.31
0 - 1.49
0-1.01
0-2.43
0 - 0.51
0 - 0.92
0-3.90
0-0.31
0 - 0.30
0 - 0.41
0-0.22
0 - 0.27
0 - 0.37
0 - 0.68
0 - 0.46
0-0.19
0 - 22.60
0-0.17
0-11.83
0 - 2.58
0-0.16
0 - 0.23
0-0.19
0 - 0.59
0 - 0.54
0 - 0.04
0- 4.13
2.0/20
2.0/20
2.2/22
2.2/22
1.0/7
1.0/7
22.7/180
NA
NA
NA
NA
.5/6
.5/6
.02/8
NA
.02/45
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0%
0%
0%
0%
0%
0%
0%
U
U
U
U
0%
0%
57%
U
18%
U
U
U
U
U
U
U
U
U
U
U
0%
0%
0%
0%
0%
0%
0%
U
U
U
U
0%
0%
0%
U
0%
U
U
U
U
U
U
U
U
U
U
U
Table 2.7. Ranges of pesticide concentrations found in the 1993
Louisianian Province Demonstration, criteria used for comparison
from Long and Morgan (1990) [x/y where x=concentrations where
biological effects occurred 10% of the time and y=median
concentration for effects to occur], and the percent of sediments
exceeding these criteria. (NA = None Available; U = Unknown)
0.02 ppb (Fig. 2-54).
Dieldrin concentration did not exceed its median
criterion of 8 ppb in any sediments collected
from the Louisianian Province; however, 57% of
sediments had dieldrin concentrations > 0.02 ppb,
(Fig. 2-55) the 10% effects-level listed by Long
& Morgan (1990).
Statistical Summary, EMAP—E Louisianian Province — 1993
Page 53
-------
ENDRIN > O.O2
LOUISIANIAN PROVINCE 1993
50H
PROVINCE LARGE SMALL
CLASS
Figure 2-54. Percent of area having sediments with Endrin >
0.02 ppb for large estuaries, small estuaries, and the entire
Province,
DIELDRIN > O.O2
LOUISIANIAN PROVINCE 1993
PROVINCE LARGE
CLASS
SMALL
Metal
Aluminum
Antimony
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Tin
Zinc
Ranee(ppm)
770-10400
0- 1.3
0.3- 30.4
0- 1.5
0-104.4
0- 31.3
330-74600
1- 35
0-1710
0- 0.2
0- 36.7
0- 1.8
0- 0.3
0- 3.9
5.2- 200
Criteria
(ppm)
NA
2/25
33/85
1.2/9
51/370
24/270
NA
46.7/218
NA
.15/.71
20.9/51.6
NA
3/3.7
NA
150/410
Percent Exceeded
(10%) (50%)
U
0%
33%
0%
U
0%
U
3%
35%
U
0%
U
U
0%
0%
0%
0%
0%
U
0
U
0%
0%
U
0%
U
Figure 2-55. Percent of area having sediments with Dieldrin
> 0.02 ppb for large estuaries, small estuaries, and the entire
Province.
Table 2-8. Ranges of heavy metal concentrations found in the 1993
Louisianian Province Demonstration, criteria used for comparison from
Long and Morgan (1990) [x/y where x = concentration where biological
effects occurred 10% of the time and y = median concentration for effects
to occur], and the percent of sediments exceeding these criteria. NA =
None Available; U = Unknown)
2.2.9 SEDIMENT CONTAMINANTS-
HEAVY METALS
Fifteen heavy metals were analyzed for the
sediments collected in the 1993 Louisianian
Province Demonstration. These metals were
examined from two perspectives: (1) Criteria-
based and (2) Anthropogenic enrichment.
Criteria-based analyses were conducted
similarly to those for other contaminants where
a criterion of degradation was selected for each
metal and distributional analysis showed the
proportion of the sediments exceeding that
criterion value. Anthropogenic enrichment was
determined using a reduced data set and
regressing metal concentrations against
aluminum concentrations. The data set
reduction required the removal of clearly
elevated concentrations (i.e., metal
concentrations > 10% Long and Morgan
Values). Once the regression is completed, the
Statistical Summary, EMAP—E Louisianian Province — 1993
Page 54
-------
complete data set is compared to the upper 95%
confidence interval of the regression. All sites
with concentrations exceeding the upper 95%
confidence interval are considered to be
anthropogenically enriched with regard to
metals.
2.2.10. CRITERIA COMPARISONS
Table 2-8 shows the ranges of heavy metals
concentrations found during the 1993
Louisianian Province Demonstration and their
criteria values for comparison. Only arsenic,
chromium, nickel, and to a lesser extent,
cadmium, mercury, and zinc exceed the selected
criteria values (Table 2-8). Using the lower
criteria (i.e., concentrations resulting in effects
10% of the time), 39±11% of sediments in the
Louisianian Province have at least one metal
1+ METALS > ER-L
LOUISIANIAN PROVINCE 1993
CJ
as
PROVINCE LARGE
CLASS
SMALL
Figure 2-56. Percent area of estuaries with at least one
metal concentration greater than Long et al.'s ERL
(concentrations resulting in effects 10% of the tine)
value in large estuaries, small estuaries, and the-
entire Province, with 95% confidence interval.
concentration in excess of these values (Fig. 56)
whereas only 1±4% of the sediments has at least
one metal which exceeds the higher criteria.
Over 29% of the sediments have two or more
metals exceeding the lower criteria. The high
percentage of sediments with metals that exceed
criteria is due, in part, to the change in ERL
criteria for arsenic from 33 to 8.2 ppm and for
nickel from 30 to 20.9 ppm. This change in
criteria resulted in an increase in the percent of
sediments that have values of arsenic and nickel
that are greater than criteria. In 1992, 0% of the
sediments had high arsenic values whereas in
1993, 32% of the sediment in the Province had
arsenic values greater than ERL criteria. Nickel
changed from exceeding criteria in 10% of the
sediments in 1992 to exceeding criteria in 34%
of the sediments in 1993. The range of values
between the two years, however, did not change
(maximum value for arsenic was 28.8 ppm in
1992 and 30.4 ppm in 1993; maximum value for
nickel was 36.9 in 1992 and 36.2 in 1993).
These high metal concentrations are found
primarily in large estuary classes (42±12%) with
27±23% in small estuaries (Fig.56).
2.2.10.1 ANTHROPOGENIC
ENRICHMENT
Aluminum concentrations vary greatly (770-
10400 ppm) in the Louisianian Province. As
aluminum content in sediments is primarily
derived from the natural crust of the earth, this
wide variation generally is accompanied by wide
variations in the portion of other metals observed
that are attributable to the earth's crust.
Therefore, the observed metal concentrations
should be adjusted for a reference metal (i.e.,
aluminum). This approach has been used
numerous times in estuarine environments
(Klinkhammer and Bender 1981, Trefry etal.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 55
-------
1985, Windomef al. 1989, Schroppef al. 1990).
Simple log-log regressions were completed using
aluminum and each of the other observed metals.
All regressions were significant (< 0.05); thus,
aluminum was used as the adjustment reference
metal.
Sampling sites that were within the 1991,1992
and 1993 Louisianian Province Demonstration
data sets that were determined to be
representative of natural, unenriched areas were
selected to develop the regressions (Summers et
al 1995). The results of these regressions are
shown in Table 2-9. The metal-specific
regression slope and its associated 95%
confidence intervals were then compared with
the complete data set and all locations falling
above the 95% confidence interval represented
sites that were anthropogenically enriched. The
results of these regression analyses for all metals
revealed some enrichment of all metals except
silver, although the technique would be expected
to show 1-2% enrichment as an artifact of the
technique. Even with this slight bias, enrichment
of Louisianian Province sediments is evident for
arsenic, cadmium, chromium, mercury, and zinc
(3 to 17% of sediments) (Fig. 2-57).
By comparison, the two methods yielded very
similar results with 61±11% of the sediments
meeting the criteria levels and 71±10% of the
sediments being "unenriched" (Fig. 2-58). While
the overall picture is the same, inspection of
Fig.2-57 shows some marked differences. While
arsenic and nickel levels exceed criteria values
for 32-34% of sediments, aluminum-adjusted
concentrations show much reduced enrichment
(1 to 17%). This is most likely the result of the
change in criteria values discussed in the
previous section. Conversely, copper and lead
never exceed their criteria but, based on
regressions with aluminum are enriched in 1-3%
of Louisianian Province sediments.
Metal (y)
Arscnic-1
Anenic-2
Cadmium
Chromium
Copper
Lead
Mercury
Nickel-1
Nickcl-2
Silver
Zinc
Transform
Vx
Iny
Vy
none
wtd by 1/x
Vy, >/x
Vy
none
"Vy
none
Vy.Vx
N
340
496
485
444
483
476
448
319
497
491
480
R2
0.70
0.73
0.41
0.84
.0.89
0.91
0.50
0.84
0.87
0.43
0.88
Slope
2.562
0.213
0.041
8.148
2.155
1.443
0.017
2.864
0.549
0.016
3.316
Intercept
-0.139
0.906
0.183
4.909
0.290
0.762
0.124
0.889
1.291
0.041 ,
0.711
Table 2-9. Transformations and results of regressions that were applied to 1991-1993 aluminum vs. metals data. Correlations between all
metals and Al were significant (p<0.001). Nickel-1 and Arsenic-1 were regressed using only values less than ERL guidelines. Nickel-2 and
ArjenIc-2 were regressed using all of the data except statistical outliers, (reprinted with permission from Summers etal 1995).
Statistical Summary, EMAP-E Louisianian Province - 1993
Page 56
-------
SEDIM ENTT/T ETALS
LOUISIANIAN PROVINCE 1993
50-
AG
PB
SB
ZN
Figure 2-57. Percent area of estuaries in Louisianian Province with sediment metal concentrations > 10% Long-Morgan
criteria (concentration resulting in effects 10% of the time) or greater than expected based on aluminum
cconcentrations, with 95% confidence interval.
2.2.11 SEDIMENT CONTAMINANTS
-BUTYLTINS
SEDIMENT METALS
LOUISIANIAN PROVINCE 1993
0
1
2
3
Figure 2-58. Percent area of estuaries in Louisianian Province
with one or more sediment heavy metal concentrations > 10%
Long-Morgan sediment criteria or greater than expected
based on aluminum concentrations, with 95% »
confidence interval.
Tributyltin (TBT), a compound found in anti-
fouling paints until recently, was an effective
and widespread means of protecting recreational
and commercial craft from fouling organisms in
seawater. TBT is considered highly toxic and is
a serious environmental concern. TBT has been
shown to affect shell generation in oysters (Weis
and Perlmutter 1987, Weis 1988) and alter the
reproductive dynamics of whelks (Weis and
Perlmutter 1987). Although TBT is not believed
to be a persistent chemical, having a half-life of
7 to 12 days, its continual release through
leaching remains a persistent environmental
problem. Determination of tributyltin was made
for all sediments collected in the 1993
Louisianian Province Demonstration with
concentrations expressed as ng (Sn)/g dwt. Only
9±6% of the sediments analyzed showed no
traces of TBT. Ninety-one percent (±6%) of the
Statistical Summary, EMAP-E Louisianian Province - 1993
Page 57
-------
TRIBUTYLTIN
UOUISIANIAN PROVINCE 1993
< 1 ppb
69±1J*
5 ppb
7±5 *
1-5 ppb
24i5 *
Figure 2-59. Percent of area of the Louisianian Province sediment
associated with tributyltin concentration categories in 1993.
sediments had concentrations of TBT > 0, with
7±5% having concentrations > 5 ppb (Fig. 2-59).
According to Laughlinefa/. (1984), long-term
tests of tributyltin compounds on fish and
invertebrates suggest that the maximum
acceptable concentration for TBT would be < 1
ppb. Using 1 ppb TBT as an indicator of
potential ecological effects results in all sampling
classes being represented with 21% of sediments
in small estuaries, and 34% of sediments in large
estuaries having measurable TBT (Fig. 2-60).
2.3 HABITAT INDICATORS
Habitat indicators describe the natural physical
and chemical conditions of the locations
sampled in the 1993 Louisianian Province
Demonstration. These parameters are discussed
below.
2.3.1 WATER DEPTH
The Louisianian Province is comprised primarily
of large and small shallow estuaries with water
depths rarely exceeding 3 to 4 m except in
dredged channels or the Mississippi River. The
distribution of water depth observed in the
Louisianian Province in 1993 is shown in Fig. 2-
61. The proportions of the estuarine classes that
have water depths of less than three meters are
shown in Fig. 2-62, with large and small estuaries
showing significant expanses of shallow water
(58±13% of large estuaries and 88±20% of small
estuaries).
2.3.2 WATER TEMPERATURE
Water temperature remained relatively constant,
regardless of location, over the six-week
sampling period of the Louisianian Province
TRIBUTYLTIN > 1 ppb
LOUISIANIAN PROVINCE 1993
PROVINCE LARGE SHALL
CLASS
Figure 2-60. Percent of area having sediments with
tributyltin > 5 ppb for large estuaries, small estuaries,
and the entire Province, with 95% confidence
interval.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 58
-------
1001
90
8(H
70
60-
50-
40
30
20
10
0-i
0
BOTTOM DEPTH
LOUISI-ANIAN PROVINCE 1993
ry /
4 5 6
Depth (m)
10
Figure 2-61. Cumulative distribution of water depth in the Louisianian Province in 1993 (-) and its associated 95% confidence interval (--).
Demonstration. The total range of bottom water
temperature observed in July and August
spanned only ten degrees Celsius (Fig. 2-63),
from 24° C to 34° C. Estuarine biota and habitats
in the Louisianian Province are exposed to water
temperature above 24° C continuously
throughout the index sampling period (July and
August).
2.3.3 SALINITY
Salinity varied widely among sampling locations.
Popular opinion would suggest that salinities in
Gulf of Mexico estuaries in late summer would
»
be predominately polyhaline (i.e., > 18 ppt). In
1993 51±11% of the Louisianian Province was
made up of polyhaline waters. Salinity ranged
from 0 to 38 ppt throughout the province (Fig. 2-
64). Continuous salinity measurements did not
show any changes in the observed salinity range
DEPTH < 3 METERS
LOUISIANIAN PROVINCE 1993
PROVINCE LARGE
CLASS
SMALL
Figure 2-62. Percent area of estuaries with water depth < 3 m in
the large estuaries, small estuaries, and the entire
Province, with 95% confidence interval.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 59
-------
BOTTOM TEMPERATURE
LOUISIAN1AN PROVINCE 1993
100-
90-
80-
60
50-
40-
30-
20-
10-
0-
20
22
24 26 28
TEMPERATURE (C)
30
32
34
Figure 2-63. Cumulative distribution of water temperature in the Louisianian Province in 1993 (-) and its associated 95% confidence
Interval (••).
BOTTOM SALINITY
LOUISIANIAN PROVINCE 1993
100
90
80
70
60
40-
30-
20-
10-
0
12
18 24
SALINITY (ppt)
30
36
42
Figure 2-64. Cumulative distribution of bottom salinity in the Louisianian Province in 1993 (-) and its associated 95% confidence
interval (»).
Statistical Summary, EMAP-E Louisianian Province -1993
Page 60
-------
BOTTOM SALINITY
LOUISIANIAN PROVINCE 1993
5-18 ppt
26±n*
< 5 ppt
24±9 x
> 18 ppt
POLYHALINE WATERS
LOUISIANIAN PROVINCE 1993
PROVINCE LARGE SMALL
CLASS
Figure 2-65. Percent area of estuaries with oligohaline,
mesohaline, and polyhaline bottom waters in the Louisianian
Province in 1993.
or distribution. Oligohaline waters (0 to 5 ppt)
comprised 24±9% of the province estuarine
waters, mesohaline waters (5 to 18 ppt)
contributed 26±11%, while polyhaline waters
made up the majority of the resource at 51±11%
(Fig. 2-65). As expected, the large estuarine
waters were primarily polyhaline in 1993 (Fig. 2-
66). Large and small estuaries are about 27 to
11% oligohaline (Fig. 2-67).
2.3.4 PH
9 -
Estuaries are primarily neutral bodies of water
with changes in pH often quickly modified by
the ions associated with salinity. However, as
stated above, about one-third of the estuarine
waters of the Louisianian Province were tidal
fresh to brackish in 1993. Bottom pHs ranged
Figure 2-66. Percent area of estuaries with polyhaline salinities
in large estuaries, small estuaries, and the entire
Province, with 95% confidence interval.
Tl DAL7FRES FTARD
OLIGOHALINE WATERS
LOUISIANIAN PROVINCE 1993
100
90
80
70
60
50
40
30
PROVINCE LARGE
CLASS
SMALL
Figure 2-67. Percent area of estuaries with oligohaline bottom
waters in large estuaries, small estuaries, and the
entire Province, with 95% confidence interval.
Statistical Summary, EMAP-E Louisianian Province - 1993
Page 61
-------
100-
90-
80-
70-
60-
50
40
30
20
10-
0-
BOTTOM pH
LOUISIANIAN PROVINCE 1993
8
pH
10
11
2-68. Cumulative distribution of bottom pH in the Louisianian Province in 1993 (-) and its associated 95% confidence interval (--)•
from 6.4 to 9.0 (Fig. 2-68) during the sampling
period. In 1993 2±3% of large estuaries and
2±3% of small estuaries had pH values < 7.0.
2.3.5 STRATIFICATION
Previous studies have shown that the probability
of finding low dissolved oxygen concentrations
is greater in areas where there is density
stratification of the water column. This occurs
because stratification reduces exchange between
oxygen-poor bottom and oxygen-rich surface
waters. Results from the 1993 Louisianian
Province Demonstration show that surf ace-to-
bottom salinity differences range from 0.5 to 25
ppt often over only 2 to 3 m of water column
(Fig. 2-69). Normally, density stratification or
delta sigma-T is calculated using both salinity
and temperature differences. However, because
water temperature is relatively constant from
surface to bottom throughout the province,
stratification has been approximated based
solely on salinity differences. Significant
stratification (i.e., salinity differences of > 6 ppt)
occurs in only about 19±8% of the estuarine
waters in the province and is primarily seen in
large estuaries.
2.3.6 PERCENT SILT-CLAY
CONTENT
The composition of bottom sediments in terms of
grain size or percentage of silts and clays can be
an important determinant of the types of
estuarine organisms utilizing the bottom. The
Louisianian Province is comprised of 35±11%
mud (> 80% silts and clays), 44±11%
intermediate muddy-sand (20-80% silts and
clays), and 21 ±9% sand (< 20% silts and clays)
(Fig. 2-70). Large estuaries are comprised of
Statistical Summary, EMAP-E Louisianian Province - 1993
Page 62
-------
SALINITY STRATIFICATION
LOUISIANIAN PROVINCE 1993
«c
LjJ
ae.
1001
90
80-
70-
60
50^
40
30
20-
10-
0-1
-5
5 10 15 20
BOTTOM - SURFACE SALINITY . (ppt)
25
30
Figure 2-69. Cumulative distribution of stratification in the Louisianian Province in 1993 (-) and its associated 95% confidence
interval (--).
SILT-CLAY
LOUISIANIAN PROVINCE 1993
20-80*
44±11»
Figure 2-70. Percent area of estuaries in the Louisianian Province
associated with percent silt-clay categories in 1993.
mainly intermediate muddy-sand (47±12%) while
small estuaries were mainly mud (38±25%).
2.3.7 PERCENT TOTAL ORGANIC
CARBON
Another important physico-chemical
characteristic of estuarine sediments is the
proportion of organic carbon in the sediments.
High levels (> 2%) of total organic carbon
(TOC) suggest possible organic enrichment,
whether naturally through detrital accumulation
or anthropogenically through point source
discharges. Based on the results of the 1993
Louisianian Province Demonstration, sediments
in the province range from nearly pure sand (no
organic carbon) to highly enriched sediments
approaching 14% TOC (Fig. 2-71). Low to
normal organic carbon content (0-1%) was
found in 49%±11% of province sediments,
Statistical Summary, EMAP—E Louisianian Province —1993
Page 63
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TOTAL ORGANIC CARBON
LOUISIANIAN PROVINCE 1993
< U
Figure 2-71. Cumulative distribution of percent organic carbon in sediments in the Louisianian Province in 1993 (-) and its associated
9556 confidence interval (-).
37%±8% of the province was slightly enriched,
while 14%±8% was enriched to the extent of
producing a sediment that was > 2% TOC (Fig.
2-71). About 14 to 17% of the sediments from
large and small estuarine systems have organic
carbon content > 2% (Fig.2-72).
2.3.8 ACID VOLATILE SULFIDES
Acid volatile sulf ides (AVS) measure the
amorphous or moderately crystalline
monosulfides in sediments that are important in
Controlling the bioavailability of metals under
anoxic conditions (DiToro etal, 1991). AVS in
the Louisianian Province ranged from 0 to 20
micromoles AVS/ g dwt sediment (Fig. 2-73).
2.4 CONFIDENCE INTERVALS FOR
PROVINCE AND CLASS-LEVEL
ESTIMATES
Ninety-five percent confidence intervals (95%
CI) were calculated for all parameters described
in this section. The methods for these
calculations were described in Summers, etal
(1993b). Table 2-10 provides these intervals for
the major indicators for the proportion of the
province and the three estuarine classes.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 64
-------
TOTAL OF
LOUI
100-
90-
80-
-c 70-
UJ
~ 60-
g 50-
u
£ 40-
Q.
30-
20-
10-
IGANIC CARBON > 2%
SIANIAN PROVINCE 1993
iii
PROVINCE LARGE SMALL
CLASS
Figure 2-72. Percent area of estuaries with TOC > 2% in
large estuaries, small estuaries, and the entire Province.
100-
90-
80
7(H
60
50
40-1
30-
20-
10-
0-
ACID VOLATILE SULFIDES
LOUISIAN1AN PROVINCE 1993
456
AVS (/tmoles/g dry wt)
10
Figure 2-73. Cumulative distribution of AVS in the Louisianian Province in 1993 (-) and its associated 95% confidence interval (--).
Statistical Summary, EMAP—E Louisianian Province — 1993
Page 65
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Parameter
N
ABIOTIC CONDITION
Marine Debris
Water Clarity
PAR < 10%
PAR < 25%
Sill-Clay Content
<20%
>80%
Alkancs
Total > 7000 ppb
PAHs
Total > 4022 ppb
PCBs
Total > 22.7 ppb
Pesticides
Chlordano > .5 ppb
Dlddrin>,02ppb
Endrin > .02 ppb
DDT >1 ppb
DDE>2ppb
ODD > 2 ppb
Mewls
Ag> 1 ppm
As > 82 ppm
Cd> 1,2 ppm
Cr>81 ppm
Cu > 34 ppm
Hg > .15 ppm
Ni > 20,9 ppm
Pb > 46.7 ppm
Sb> 2 ppm
Zn > 150 ppm
Tributyltin
TBT>Oppb
TBT>5ppb
Province
93
11(7)
18(8)
45(12)
21(9)
35(11)
0(0)
0(0)
-------
Parameter
N
BIOTIC CONDITION
Benthic Index
Abundance < 10
# Species < 2
# Species<5
Fish
Abundance < 2
Abundance<5
'# Species < 1
# Species < 2
Fish Pathology'
Fish Contaminants'
Shrimp
All > FDA Limits
Croaker
All > FDA Limits
Marine Catfish
Hg > FDA Limits
Others > FDA Limits
Bottom DO2 < 2 ppm
Bottom DO2 <5 ppm
Minimum DO < 2 ppm
Sediment Toxicity
Province
93
37(11)
5(5) ;
-------
-------
SECTION 3
SUMMARY OF CONCLUSIONS
The Demonstration Project in the Louisianian
Province in 1993 produced thousands of pieces
of information about the estuarine resources of
die Gulf of Mexico and their present condition.
The following discussion summarizes key
information concerning the conduct of the
demonstration and highlights the findings.
3.1 OVERVIEW OF PROVINCE
CHARACTERISTICS
• The Louisianian Province is comprised of
25,725 km2 of estuarine resources spanning
from Anclote Anchorage, FL to the:Rio;
Grande, TX, ,
• Estuarine'resources are defined as those
water bodies located between sources of
freshwater and the Gulf of Mexico,
bounded on the seaward region by barrier
islands and on the landward side by head
of tide. For example, this would include as
estuarine resources the lower Mississippi
River from the delta to roughly New
Orleans, LA and Apalachee Bay, FL,
which is bordered on the seaward margin
by submerged barrier islands.
* All estuarine resources in the Louisianian
province were divided among three
estuarine classes: large estuaries, large tidal
rivers, and small estuaries/tidal rivers.
Their delineation was based primarily on
size.
Large estuaries include Laguna Madre,
Baffin Bay, Corpus Christi Bay, San
Antonio Bay, Matagorda Bay, Galveston
Bay, Calcasieu Lake, Vermilion Bay, Cote
Blanche Bays, Atchafalaya Bay,
Terrebone/Timbalier Bays, Caillou Bay,
Barataria Bay, Chandeleur Sound, Breton
Sound, Lake Borgne, Lake Pontchartrain,
Lake Maurepas, Lake Salvador,
Mississippi Sound, Mobile Bay, Bon
Secour Bay, Pensacola Bay,
Choctawhatchee Bay, St. Andrews Bay,
St. George Sound and Apalachee Bay.
Large tidal river class is comprised solely
of the Mississippi River.
Small estuary/tidal river class incorporates
165 estuarine systems between 2 to 260
km2 of which 31 were selected for
sampling in 1993.
The total area of estuarine resources in the
Louisianian Province can be subdivided
among these three estuarine classes: large
estuaries comprise km2 (72%), large tidal
rivers constitute 138 km2 (<1%), and small
estuaries make up km2 (28%). Thus,
province-wide conclusions, based on areal
weighting, will be dominated by
information from the large estuaries.
154 stations were selected for sampling
using multiple indicators of estuarine
Statistical Summary, EMAP—E Louisianian Province —1993
Page 69
-------
condition (e.g., benthic abundance, fish
community composition, sediment
chemistry, sediment toxicity).
9 selected sites could not be sampled due
to insufficient depth (< 1 m). In terms of
areal extent, these sites represent 6% of the
estuarine resources in the province. The
majority of these unsampleable sites
occurred in the shallow zones of large
estuaries.
• 10 Mississippi River sites could not be
sampled due to flood conditions.
3.2 CONCLUSIONS OF THE 1993
SAMPLING
• Nearly 46% of the Louisianian Province
estuarine resources were determined to be
degraded in terms of biotic integrity or
human use indicators. Twenty-nine (±6%)
percent of the province experienced only
low levels of biotic integrity, 8±11%
experienced either marine debris or poor
water clarity, and 9±6% experienced both
forms of degradation.
» About 11±7% of the bottom sediments in
Louisianian Province estuaries were
littered with marine debris.
• 18±8% of the estuarine waters in the
province had poor water clarity with >
10% ambient light reaching 1.0 meter.
* Estuarine sediments in the Louisianian
Province generally contained
concentrations of organic contaminants
that were below criteria values expected to
result in significant ecological effects.
Endrin and Dieldrin were above these
criteria for 18 to 57% of the sediments
(respectively).
Louisianian Province sediments were
shown to be enriched with several heavy
metals. Three to 17% of Louisianian
Province sediments were enriched with at*
least one metal (arsenic, cadmium,
chromium, mercury and zinc).
Metal enrichment was observed in large
and small estuarine resources.
Approximately 10±7% of the sediments in
the Louisianian Province (2050 km2)
proved to be toxic to Mysids while only
1±2% of sediments were toxic to
Ampelisca,
Tributyltin was measurable in 31±11% of
Louisianian Province sediments; however,
only 3±3% of sediments had 7±5%
concentrations > 5 ppb.
The edible portions of shrimp, Atlantic
croaker, and catfish contained contaminant
concentrations below FDA limits for
PCBs, and pesticides. Shrimp, croakers
and catfish contained levels of arsenic,
chromium, and selenium in their edible
tissues that was higher than international
standards; Nine percent of the shrimp
exceeded 2 ppm arsenic, 15 ppm copper,
and 1 ppm mercury, with 4% exceeding 1
ppm selenium. A total of 5% of the croaker
exceeded criteria for arsenic, 4% for
cadmium, 2% lead and selenium, and 1%
chromium and copper. Sixty-two percent»
of the catfish exceeded criteria for arsenic,
5% lead, and 1% chromium and mercury.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 70
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SECTION 4
REFERENCES
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Fish Dis. 2:337-343.
Agius, C. 1980. Phylogenetic development of melano-macrophage centers in fish. J. Zool., London
191:111-132.
Agius, C. and Roberts, R.J. 1981. Effects of starvation on the melano-macrophage centers in fish. J.
FishBiol. 19:161-169.
ASTM (American Society of Testing and Materials). 1990. Standard guide for conducting 10-day static
sediment toxicity tests with marine and estuarine amphipods. Annual Book of ASTM Standards
Volume 11.04:1052-1075.
Blazer, V.S., D.E. Facey, J.W. Fournie, L.A. Courtney, and J.K. Summers. 1994. Macrophage aggregates
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Boesch, D.F. and R. Rosenberg. 1981. Response to stress in marine benthic communities. Pages 179-
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and Sons, New York.
Chapman, P.M. 1988. Marine sediment toxicity tests. In: J.J. Lichtenberg, F.A. Winter, C.I. Weber and
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DiToro, D.M., J.D. Mahony, DJ. Hansen, K.J. Scott, A.R. Carlson, G.T. Ankley. 1991. Acid volatile
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Ellis, A.E., Munro, A.L.S., and Roberts, R.J. 1976. Defense mechanisms in fish. I. A study of the
phagocytic system and the fate of intraperitoneally injected particulate material in plaice
(Pleuronectes platessa). J. Fish Biol. 8:67-78.
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Engle, V.D., J.K. Summers and G.R. Gaston. 1994. A benthic index of environmental condition of Gulf
of Mexico estuaries. Estuaries 17:372-384.
Ferguson, H.W. 1976. The relationship between ellipsoids and melano-macrophage centers in the spleen
of turbot (Scopthalmus maximus). J. Comp. Path. 86:377-380.
Karr, J.R. and D.R. Dudley. 1981. Ecological perspective on water quality goals. Environmental
Management 5:55-68.
Klinkhammer, G.P. and M.L. Bender. 1981. Trace metal distributions in the Hudson River estuary.
Estuarine, Coastal and Shelf Science 12: 629-643.
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.
Laughlin, R.B., K. Nordlund, and O. Linden. 1984. Long-term effects of tributyltin compounds on the
Baltic amphipod, Gammarus oceanicus. Mar. Environ. Res. 12:243-271.
Long, E.R. and L.G. Morgan. 1990. The potential for biological effects of sediment-sorbed
contaminants tested in the National Status and Trends Program. NOAA Technical Memorandum
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National Ocean Service, Rockville, MD.
Long, E.R., D.D. MacDonald, S.L. Smith, and F.D. Calder. 1995. Incidence of adverse biological
effects within the ranges of chemical concentrations in marine and estuarine sediments.
Environmental Management 19:81-97.
Messer, J.J. 1990. EMAP indicator concepts. Chapter 2. In C.T. Hunsaker and D.E. Carpenter (eds)
Ecological indicators for the Environmental Monitoring and Assessment Program. EPA 600/3-90/
060. U.S. Environmental Protection Agency, Office of Research and Development, Research
Triangle Park, NC.
Nauen, C.E. 1983. Compilation of legal limits for hazardous substances in fish and fishery products.
FAO fisheries Circular No. 764, Food and Agriculture Organization of the United Nations, Rome,
Italy, 102 pp.
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 hydrocarbons in Narragansett Bay. Pages 99-122. In: P. Lasserre and
J.M. Martin, eds. Biogeochemical Processes at the Land-sea Boundary Elsevier, NY.
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.
Ross, J.B., R. Parker and M. Strickland. 1991. A survey of shoreline litter in Halifax Harbour 1989.
Marine Pollution Bulletin 22:245-248.
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Schropp, S.J., F.G. Lewis, H.L. Windom, J.D. Ryan, F.D. Calder and L.C. Burney. 1990. Interpretation
of metal concentrations in estuarine sediments of Florida using aluminum as a reference element.
Estuaries 13:227-235.
Schubel, J.R., and H.H. Carter. 1984. The estuary as a filter for fine-grained suspended sediment, pgs.
81-104. In: V.S. Kennedy, ed. The Estuary as a Filter. Academic Press, Orlando, FL.
Summers, J.K. and V.D. Engle. 1993. Evaluation of sampling strategies to characterize dissolved
oxygen conditions in northern Gulf of Mexico estuaries. Environmental Monitoring and
Assessment 24:219-229.
Summers, J.K., J.M. Macauley, and P.T. Heitmuller. 1991. Implementation plan for monitoring the
estuarine waters of the Louisianian Province -1991. U.S. Environmental Protection Agency, Office
of Research and Development, Environmental Research Laboratory, Gulf Breeze, FL. EPA/600/R-
91/228.
Summers, J.K., J.M. Macauley, V.D. Engle, G.T. Brooks, P.T. Heitmuller, and A.M. Adams. 1993a.
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Breeze, FL. EPA/600/R-94/001.
Summers, J.K., J.M. Macauley, P.T. Heitmuller, V.D. Engle, A.M. Adams, and G.T. Brooks. 1993b.
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Summers, J.K., T.L. Wade, V.D. Engle, and Z.A. Malaeb. 1995. Normalization of metal concentrations
in estuarine sediments from the Gulf of Mexico. Estuaries (in press).
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bioassay for marine sediment toxicity. Pages 284-307. In: R. D. Cardwell, R. Purdy, and R.C.
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Statistical Summary, EMAP—E Louisianian Province —1993 Page 74
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APPENDIX A
SUBPOPULATION ESTIMATION BASED
ON EMAP SAMPLING
One of the major advantages of the probability-
based sampling design used by all elements of
the Environmental Monitoring and Assessment
Program (EMAP) is the ability to use the; data to
address questions and/or objectives other than
those specified by the program. Essentially, the
only negative aspect associated with these
additional analyses is an increase in the
uncertainty associated with the estimates due to
a decrease in the sample size (i.e., not all the
data are used). This process is called
"subpopulation estimation." For EMAP-E, for
example, the process might involve using a
specific portion of the collected data to examine
a question concerning a subset of the ecological
community (i.e., only surface measures), a
subset of estuarine resources (e.g., those in a
particular state or EPA Region), or a subset for
an individual estuary (e.g., Galveston Bay,
Mississippi Sound).
In this appendix, all of the major ecological
indicators described in Chapter 2 are evaluated
in terms of state specific resources. The
Statistical methods used to perform this level of
evaluation are the same as used in the Province
analysis but are adapted to the estuarine
resources of each estuarine class within the
boundaries of each of the five Gulf states.
A.1 BIOTIC CONDITION
INDICATORS
Biotic condition indicators are characteristics of
the environment that provide quantitative
evidence of the status of ecological resources
and biological integrity at a sampling site.
Biotic condition measures examined here
include .measurements of the kinds and
abundances of biota present and human use
parameters that describe human perceptions of
the condition of estuarine systems. No state-
level estimates have been made for fish
pathologies or tissue contaminant levels.
Subpopulation estimation for these indicators,
based on spatial reduction, is not possible
without using complex statistical methods to fit
spatial response surfaces to estimate these
indicators where fish were not collected in
adequate numbers.
The following presentation does not represent all
the analyses completed at the state-level for each
indicator. For example, a set of five individual
state CDFs and pie charts exist for each
indicator, but only one CDF and pie chart for a
selected state will be shown in this appendix.
However, the proportion of estuarine resources
in each state associated with the criterion for
subnominal condition is shown in the bar charts.
Statistical Summary, EMAP—E Louisianian Province — 1993
Page 75
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The uncertainty associated with the state
estimates is directly proportional to the total
number of sites within the state boundaries. This
uncertainty ranges, in general, from a low of
about 5 to 7% for Louisiana (N=38) to a high
for Mississippi of approximately 20 to 30%
(N=7). The 95% confidence intervals are shown
for each CDF shown in Appendix A and in
tabular form for all states at the end of the
appendix.
Although the sample size for Alabama estuarine
waters is small (N=7), the corresponding
variance estimates are also small (see Table A-
1).
A.1.1 BENTHIC INDEX
The construction of the benthic index is
described in Summers et al. (1993b) and Engle
et al. (1993). The cumulative distribution
functions for the benthic index in Mississippi
and Texas are shown in Figures A-l and A-2.
About 7±5% of the estuarine sediments in
Mississippi contained benthic communities
similar to those observed at known
environmentally-degraded sites (Fig. A-3). The
highest proportions of degraded benthic
communities within the Gulf states in 1993 were
still found in Louisiana and Texas (Fig. A-4).
A.1.2 NUMBER OF FISH SPECIES
Total number of fish species has been used to
characterize the environmental condition of
estuarine habitats. A single 10-min trawl, taken
at each sampling in the Louisianian Province,
resulted in a distribution of total number of
species for sites in Louisiana and Texas shown
in Figures A-5 and A-6. About 7±8% of the
estuarine waters in Louisiana produced < 2
species in a single 10-min trawl (Fig. A-7).
Seven (±8) to 8±13% of the estuarine waters in
Louisiana and Florida were characterized by
these small numbers of species (Fig. A-8).
A.1.3 MARINE DEBRIS
The presence of marine debris is one of the
obvious indicators of estuarine "degradation"
from a human use perspective. Over 17% of the
estuarine sediments in Louisiana contained
marine debris, with about 3% of Florida and
12% in Texas estuarine sediments containing
marine debris (Fig. A-9).
A.1.4 WATER CLARITY
Another social or human use criterion for good
estuarine condition is water clarity. Water clarity
was measured using a comparison of surface
ambient light and the amount of light reaching 1
meter in depth. The cumulative distribution
function for water clarity in Louisiana is shown
in Fig. A-10 where proportional light reaching 1
meter ranged from 0-50%. A value of 10%
transmittance reaching a depth of one meter was
used as a measure of turbid conditions. Most of
the water of lower transmissivity in Gulf
estuaries is located in Louisiana (30±12%) and
Texas (42±27%) (Fig. A-ll).
Statistical Summary, EMAP—E Louisianian Province —1993
Page 76
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BENTHIC INDEX
MISSISSIPPI 1993
o
o:
100-
90-
.80-
70-
60-
50-
40-
30-
20-
10-
O-l
-2
4 6
BENTHIC INDEX
10
12
Figure A-l. Distribution of benthic index values in the estuarine resources of Mississippi (-) with 95% confidence intervals (--).
BENTHIC INDEX
TEXAS 1993
100
90
80
70
i •
60
50-
40
30-
20-
10-
0-
-2
4 6
BENTHIC INDEX
10
12
Figure A-2. Distribution of benthic index values in the estuarine resources of Texas (-) with 95% confidence intervals (-•).
Statistical Summary, EMAP—E Louisianian Province —1993
Page 77
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BENTHIC INDEX
MISSISSIPPI 1993
INDEX 4-6
17±30x
INDEX > 6
76±30x
INDEX < 4
7±5 x
BENTHIC INDEX < 4
TX
Figure A-3. Proportion of Mississippi estuarine resources with benthic index Figure A-4. Proportion of Gulf states' estuarine resources with
values in selected categories. benthic index values < 4.0, with 95% confidence interval.
100-
90-
80-
70-
60-
50-
40-
30-
20
10H
0
NEKTON SPECIES RICHNESS
LOUISIANA 1993
4 6 8 10 12 14
.- NUMBER OF SPECIES (in 2 trawls)
16
18
20
Figure A-5. Distribution of number offish species per trawl in the estuarine resources of Louisianian (-) with 95% confidence intervals (•-).
Statistical Summary, EMAP-E Louisianian Province -1993
Page 78
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NEKTON SPECIES RICHNESS
TEXAS 1993
100-
90-
80-
70-
«e
u_>
S 60"
£ 50
LU
K 40
LU
" 30-
20-
10
8 8 10 12 14
NUMBER 'OF SPECIES (in 2 trawls)
16 11
20
Figure A-6. Distribution of number offish species per trawl in the estuarine resources of Texas (-) with 95% confidence intervals (--).
NEKTON SPECIES RICHNESS
LOUISIANA 1993
>1 SPECIES
93*8 i
1 SPECIES
5i8 *
0 SPECIES
2±5 *
Figure A-7. Proportion of Louisiana estuarine resources with number of fish species per trawl in selected categories.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 79
-------
UJ
0=
£
0
CC
UJ
CL
100-
90-
80-
70-
60-
50-
40-
30-
20-
10-
0-
NEKTON SPECIES < 2
1 -
FL AL MS LA TX
STATE
Figure A-8. Proportion of Gulf states' estuarine
resources with number of fish species per trawl s_l, with
95% confidence interval.
MARINE DEBRIS
LU
Q-
FL
A.1.5 INTEGRATION OF
ESTUARINE CONDITIONS
A single index value has been developed to
summarize the overall condition of the estuaries
in the Louisianian Province by combining the
benthic index, marine debris and water clarity,
weighted equally. This single value can also be
used to summarize the overall condition of
estuaries in each of the Gulf states. Figure A-12
shows that 21±18% of the estuarine resources in
the portion of Florida in the Louisianian
Province were degraded with regard to biotic
communities or human uses. Similar
summarizations are shown in Figures A-13
through A-16 for Alabama, Mississippi,
Louisiana and Texas and ranged from 7±5%
degraded estuarine area in Mississippi to
71±22% in Texas.
A.2 ABIOTIC CONDITION
INDICATORS
Abiotic condition indicators have historically
been the mainstay of state environmental
monitoring programs. The results for Gulf
states are shown for dissolved oxygen,
sediment toxicity, and sediment contaminants.
A.2.1 DISSOLVED OXYGEN
(INSTANTANEOUS)
Dissolved oxygen (DO) concentration is a
fundamental requirement of populations of
benthos, fish, shellfish, and other aquatic biota.
DO was measured in two ways: instantaneous
point measures at 1-m depth intervals during
the sampling and deployed continuous
recordings of dissolved oxygen for a 24-hour
period.
Figure A-9. Proportion of Gulf states' estuarine resources with marine
debris present in bottom sediments, with 95% confidence
interval.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 80
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WATER CLARITY
LOUISIANA 1993
IOOH
90
80-
-c 70-
UJ
^ 60
£ 50
UJ
£ 40-1
UJ
°- 30-
20-
10
10 20 30 40 50 60 70 80 90 100
x AMBIENT LIGHT
TRANSMITTED AT 1 METER
Figure A-10. Distribution of water clarity as % surface light reaching a depth of 1 meter (PAR) in the estuarine resources of Louisiana (-)
with 95% confidence intervals (--).
LIGHT < 10%
FL AL US LA TX
Figure A-ll. Proportion of Gulf states' estuarine-resources with percent surface light reaching a depth of
one meter < 10%, with 95% confidence interval.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 81
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ECOLOGICAL CONDITIONS
FLORIDA 1993
Inpoired Use
4±18x
Undigraded
79±21x
Degraded Biology
17±18x
?lgurc A-12. Proportion of estuarine resources having degraded biology, impaired use, or both problems in Florida.
ECOLOGICAL CONDITIONS
ALABAMA 1993
Undigraded
62±0 x
Degraded Biology
18±0 x
Figure A-13. Proportion of estuarine resources having degraded biology, impaired use, or both problems in Alabama.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 82
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ECOLOGICAL CONDITIONS
MISSISSIPPI 1993
Undegraded
93±5 «
Deg. Biology
7±5 i
Figure A. 14. Proportion of estuarine resources having degraded biology, impaired use, or both problems in Mississippi.
ECOLOGICAL CONDITIONS
MISSISSIPPI 1993
Undegraded
93±5 x
Deg. Bi ology
7±5 *
Figure A. 15. Proportion of estuarine resources having degraded biology, impaired use, or both problems in Mississippi.
Statistical Summary, EMAP-E Louisianian Province — 1993
Page 83
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ECOLOGICAL CONDITIONS
TEXAS 1993
Degraded Biology
46±22x
Both
19±22*
Impaired Use
Undegroded
29±22*
Figure A. 16. Proportion of estu wine resources having degraded biology, impaired use, or both problems in Texas.
The cumulative distribution function of bottom
dissolved oxygen in Florida estuaries is shown
in Figure A-17. All Gulf states experienced DO
conditions < 5 ppm Alabama, Louisiana and
Florida predominated with almost 32 to
7Q%(±14 to 53) of their resources below this
figure (Fig, A-18). All dissolved concentrations
< 2 ppm were observed primarily in Louisiana
and Alabama (Fig. A-19),
A.2.2 DISSOLVED OXYGEN
(CONTINUOUS)
Unlike the instantaneous measures, the
continuous dissolved oxygen concentration
measurements provide a complete picture of the
DO conditions at a site by including day and
night conditions as well as all tidal conditions.
The minimum bottom DO concentrations from
the continuous measurements in Louisiana
ranged from 0 to 10 ppm (Fig. A-20). Minimum
dissolved oxygen concentrations below 2 ppm
were most often observed in Alabama (Fig. A-
21). ,
Statistical Summary, EMAP—E Louisianian Province —1993
Page 84
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100-
90-
80-
70-
60-
50-
40
30
20
10
OH
BOTTOM DISSOLVED OXYGEN
FLORIDA 1993
4 6 8
DISSOLVED OXYGEN (ppm)
to
12
Figure A-17. Distribution of instantaneous dissolved oxygen in bottom waters in the estuarine resources of Florida (-) with 95%
confidence intervals (--).
BOTTOM DISSOLVED
OXYGEN < 5 ppm
FL
TX
125
100-
75
50
BOTTOM DISSOLVED
OXYGEN < 2 ppm
FL
TX
Figure A-18. Proportion of Gulf states' estuarine resources with Figure A.,9< Pr0pOrtion of Gulf states' estuarine resources with
instantaneous dissolvedjjxygejn^concentration < 5 ppm in instantaneous dissolved oxygen concentration < 2 ppm in
bottom waters, with 95% confidence interval.
bottom waters, with 95% confidence interval.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 85
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MINIMUM DISSOLVED OXYGEN
LOUISIANA 1993
100
90
80
70
fjj
« 60
£ 50
UJ
ce 40
UJ
" 30
20
10
4 6
DISSOLVED OXYGEN (ppm)
10
12
Figure A-20. Cumulative distribution of continuous dissolved oxygen in the estuarine resources of Louisianian (-) with 95% confidence
intervals (~).
MINIMUM DISSOLVED
OXYGEN < 2 ppm
TX
Figure A-2I. Proportion of Gulf states' estuarine resources with dissolved oxygen minima < 2 ppm in
bottom waters, with 95% confidence interval. -
Statistical Summary, EMAP-E Louisianian Province -1993
Page 86
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A.2.3 SEDIMENT TOXICITY-
AMPELISCA ABDITA
Sediment toxicity tests were performed on the
composited surface sediments collected from
each sampling site. Tests included a 10-day
acute test using the tube-dwelling amphipod,
Ampelisca abdita. The continuous distribution
function for sediment toxicity testing results are
shown for Florida in Figure A-22. Most of the
sediments proving significantly toxic to
Ampelisca (control-corrected mortality > 20%)
were located in Florida (7±13%) and Louisiana
(1±2%) estuarine waters (Fig. A-23).
A.2.4 ALKANESAND
ISOPRENOIDS
Alkanes and isoprenoids are contaminants
associated primarily with the petroleum industry
and uses of its products. None of the sediments
in the province collected in 1993 are
characterized by alkane concentrations in excess
of 7000 ppb.
AMPELISCA - SEDIMENT TOXICITY
FLORIDA 1993
110
100^
90
80
70
60
50
40
30-
20-
10-
0-
10
20
30
40
SO
60
70
80
90
100
110 120
x SURVIVAL (CONTROL-CORRECTED)
of Ampelisca abdita
Figure A-22. Distribution of toxicity of estuarine sediments in Florida to amphipods <-) with 95% confidence intervals (--).
Statistical Summary, EMAP—E Louisianian Province- 1993
Page 87
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Ul
OS
•C
PERCENT
AM
100-
60-
50-
40-
30-
20-
to-
0-
PELISCA MORTALITY > 20%
I
FL AL MS LA TX
STATE
Figure A-2J. Proportion of Gulf states' estuarine resources with
toxlclty to amphlpods resulting in < 80% survival, with
95% confidence interval.
A.2.5 POLYNUCLEAR AROMATIC
HYDROCARBONS
Forty-three individual polynuclear aromatic
hydrocarbons (PAHs) were analyzed from
collected Louisianian Province sediments. None
of the sediments in the province collected in
1993 are characterized by PAH concentrations
in excess of 4022 ppb.
A.2.6 POLYCHLOWNATED
BIPHENYLS
t
Twenty polychlorinated biphenyl (PCB)
congeners were analyzed from the Louisianian
Province sediments.Less than 1% of the
sediments in Texas collected in 1993 had
concentrations of PCB's in excess of 22.7 ppb.
A.2.7 TRIBUTYLTIN
Tributyltin (TBT), a compound found in
antifouling paints until recently, was an effective
and widespread means of protecting recreational
and commercial craft from fouling organisms.
The continuous distribution function of TBT in
Texas is shown in Fig. A-24, ranging from 0 to
238 ppb. Using 1 ppb TBT as an indicator of the
presence of TBT results in a more even
distribution of TBT among the estuarine
sediments of all the Gulf states (Fig. A-25).
A.2.8 PESTICIDES
Pesticides constitute a major portion of nonpoint
source runoff from agricultural fields, suburban
lawns, and golf courses. Twenty-four pesticides,
including DDT and its derivatives, were
analyzed from Louisianian Province sediments.
Concentrations of chlordane in estuarine
sediments were in excess of 0.5 ppb in Florida
(8±15%), Louisiana (14±10%), and Texas
(19±22%) (Fig. A-26). Dieldrin concentrations
were > 0.02 ppb in sediments from all five gulf
states: Alabama (89±5%), Louisiana (80±12%),
Texas (48±27%), Florida (29±25%), and
Mississippi (19±30%) (Fig. A-27). Endrin
concentrations in excess of 0.02 ppb were also
found in sediments collected at five states,
Alabama (60±54%)» Louisiana (23±13%), Texas
(20±20%), Florida (12±16%), and Mississippi
(4±5%) (Fig. A-28). There were also measurable
concentrations of DDT > 1.0 ppb found in
sediments collected from Louisiana (3±4%).
Statistical Summary, EMAP—E Louisianian Province —1993
Page 88
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TRIBUTYLTIN
TEXAS 1993
Ul
0.
40
80 120 160
TRIBUTYLTIN (ppb)
200
240
Figure A-24. Distribution of tributyltin in estuarine sediments of Texas (-) with 95% confidence intervals (--).
TRIBUTYLTIN > 1 ppb
TX
Figure A-25. Proportion of Gulf states estuarine sediments with TBT > 1 ppb, with 95% confidence interval.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 89
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CHLORDANES > 0.5
FL
Figure A-Z6. Proportion of Gulf states' estuarine resources with total
chlordsncs > 0.5 ppb, with 95% confidence interval.
DIELDRIN > 0.02
•<
CE
•<
O
ce
UJ
o.
TX
Figure A-27. Proportion of Gulf states' estuarine sediments with
dleldrln > 0.02 ppb. with 95% confidence Interval.
A.2.9 HEAVY METALS
Fifteen heavy metals were analyzed for the
sediments collected in 1993. Examining the
metal concentrations based on Long and Morgan
criteria, several heavy metals exceeded the 10%
criteria. The percentage of estuarine area in each
state that exceeded the 10% Long and Morgan
criteria for each analyzed metal is compared
with the percentage of area in each state with
heavy metal enrichment (Figs. A-29 to A-33).
A.3 CONFIDENCE INTERVALS
FOR STATE-LEVEL ESTIMATES
Ninety-five percent confidence intervals
(95%CI) were calculated for all parameters
described in this section. The methods for these
calculations were described in Summers et at.
(1993b). Table A-l provides these intervals for
the major indicators for the proportion of the
five Gulf States assessed as degraded for each
parameter.
Statistical Summary, EMAP—E Louisianian Province-1993
Page 90
-------
ENDRIN > 0.02
FL
Figure A-28. Proportion of Gulf states' estuarine sediments with endrin
> 0.02 ppb.
SEDIMENT METALS
FLORIDA 1993
Figure A-29. Proportion of Florida's estuarine area with sediment metal concentrations > Long et at (1995) ER-L criteria or greater than
expected based on aluminum concentrations, with 95% confidence interval.
Statistical Summary, EMAP—E Louisianian Province —1993
Page 91
-------
SEDIMENT METALS
ALABAMA 1993
PB
SB
ZN
Figure A-30. Proportion of Alabama's estuarine area with sediment metal concentrations > Long et al (1995) ER-L criteria or greater
than expected based on aluminum concentrations, with 95% confidence interval.
110-
100-
90-
80-
UJ 7n.
K /U
*«;
H- 60-
1 50-
°- 40-
• 30-
20-
10-
0-
AG
r -,
t
AS
SEDIMENT METALS
MISSISSIPPI 1993
1
CD CR CU HG Nl
••• Enr ! chad
i— — i > ER-L
PB SB ZN
Figure A-31. Proportion of Mississippi's estuarine area with sediment metal concentrations > Longe/ al (1995) ER-L criteria or greater
than expected based on aluminum concentrations, with 95% confidence interval.
Statistical Summary, EMAP-E Louisianian Province -1993
Page 92
-------
110-
100-
90-
80-
£ 70-
•<
£ 60-
UJ
g 50-
UJ
°- 40-
30-
20-
10-
0
A6
SEDIMENT METALS
LOUISIANA 1993
•S3 Enr iched
I 1 > ER-L
1 A
i
• ^ r^J. J. JL
AS CD CR CU . HG Nl PB SB ZN
Figure A-32. Proportion of Louisiana's estuarine area with sediment metal concentrations > Long et al (1995) ER-L criteria or greater
than expected based on aluminum concentrations, with 95% confidence interval.
SEDIMENT METALS
TEXAS 1993
110-
100-
90-
80-
£ 70-
•^
£ 60-
UJ
o 50-
UJ
°- 40-
30-
20-
10-
AG
Enriched
I 1 > ER-L
••
T T II
• ii, 1 it, 1 ir1
AS CD CR CU HG Nl PB SB ZN
Figure A-33. Proportion of Texas' estuarine area with sediment metal concentrations > Long et al (1995) ER-L criteria or greater than
expected based on aluminum concentrations, witfi 95% confidence interval.
Statistical Summary, EMAP—E Louisianian Province — 1993 Page 93
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Parameter
H
Estuarinc Condition
Biottc Condition
Benthfc Index
Abundance < 10
* Species < 2
# Species < 5
Fish
Abundance < 2
Abundance 5
#Speeies FDA Limits
Croaker
AH > FDA Limits
Marine Catfish
Hg> FDA Limits
Others > FDA Limits
Bottom DOZ<2 ppm
Bottom DO2 < S ppm
Minimum DO < 2 ppm
Sediment Toxicity
Florida
20
21(21)
17(18)
7(13)
0(0)
14(17)
20(21)
34(24)
1(2)
14(16)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
48(27)
20(20)
7(13)
Alabama
7
18(3)
18(0)
5(4)
3(4)
32(54)
0(0)
5(4)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
33(54)
71(53)
87(4)
0(0)
Mississippi
7
7(5)
7(5)
0(0)
0(0)
15(30)
0(0)
15(30)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
22(30)
15(30)
0(0)
Louisiana
38
59(14)
49(14)
7(8)2(4)
0(0)
12(10)
10(9)
19(12)
2(5)
16(11)
15(11)
0(0)
0(0)
34(1)
0(0)
12(10)
31(14)
18(11)
1(2)
Texas
21
71(22)
66(26)
0(0)
16(18)
7(13)
14(18)
0(0)
7(13)
22(21)
25(0)
0(0)
0(0)
0(0)
0(0)
7(17)
9(18)
'0(0)
1 Percentage based on sample size rather than estuarine area
1 Instantaneous dissolved oxygen measurements
Table A-l. Estimates of the proportion of the individual Gulf states experiencing the listed parameters and their associated 95%
confidence intervals in parentheses (N = number of sampling sites).
Statistical Summary, EMAP—E Louisianian Province —1993
Page 94
-------
Parameter
N.
Abiotic Condition
Marine Debris3
Water Clarity
PAR < 10%
PAR < 25%
Silt-Clay Content
<20%
>80%
Alkanes
Total > 7000 ppb
PAHs
Total > 4022 ppb
PCBs
Total > 22.7 ppb
Pesticides
Chlordane > .5 ppb
Dieldrin > .02 ppb
Endrin > .02 ppb
DDT > 1 ppb
DDE > 2 ppb
ODD > 2 ppb
Metals
Ag > 1 ppm
As > 8.2 ppm
Cd>1.2ppm
Cr>81 ppm
Cu > 34 ppm
Hg>.15ppm .
Ni > 20.9 ppm
Pb > 46.7 ppm
Sb > 2 ppm
Zn > 150 ppm
Tributyltin
TBT > 0 ppb
TBT>5ppb
Florida
20
3(12)
3(6)
28(22)
57(27)
23(20)
0(0)
0(0)
0(0)
8(15)
28(25)
12(16)
0(0)
0(0)
0(0)
0(0)
30(22)
0(0)
20(20)
0(0)
7(13)
23(20)
0(0)
0(0)
0(0)
83(21)
0(0)
Alabama
7
0(0)
8(5)
19(0)
16(2)
55(53)
0(0)
0(0)
0(0)
0(0)
89(5)
60(54)
0(0)
27(53)
0(0)
0(0)
82(0)
0(0)
55(53)
0(0)
0(0)
82(0)
0(0)
0(0)
27(53)
89(5)
27(53)
Mississippi
7
0(0)
0(0)
24(30)
45(40)
15(30)
0(0)
0(0)
0(0)
30(19)
51(40)
4(5)
0(0)
0(0)
0(0)
0(0)
17(30)
0(0)
0(0)
0(0)
0(0)
17(30)
0(0)
0(0)
0(0)
85(30)
15(30)
Louisiana
38
17(12)
30(10)
53(14)
5(7)
46(14)
0(0)
0(0)
0(0)
14(10)
80(12)
23(13)
3(4)
0(0)
0(0)
0(0)
46(14)
0(0)
5(7)
0(0)
0(0)
49(14)
0(0)
0(0)
0(0)
93(7)
9(8)
Texas
21
12(19)
42(27)
81(23)
14(18)
34(26)
0(0)
0(0)
0(0)
19(22)
48(27)
20(20)
0(0)
0(0)
0(0)
0(0)
14(22)
4(9)
0(0)
0(0)
4(9)
28(26)
0(0)
0(0)
11(16)
93(13)
7(13)
3 Estimate based on presence-absence, so 95% confidence intervals are not calculated.
Table A-l. (cont.) Estimates of the proportion of the individual Gulf states experiencing the listed parameters and their associated 95%
confidence intervals in parentheses (N = number of sampling sites).
Statistical Summary, EMAP—E Louisianian Province —1993 Page 95
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