United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/620/R-94/002
January 1994
vvEPA II Statistical Summary
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EMAP-Estuaries
Louisianian
Province-1992
Environmental Monitoring and
Assessment Program
-------
-------
EPA/620/R-94/002
January 1994
STATISTICAL SUMMARY:
EMAP-ESTUARIES
LOUISIANIAN PROVINCE - 1992
by
John M. Macauley
J. Kevin Summers
U.S. Environmental Protection Agency
Environmental Research Laboratory
Gulf Breeze, FL 32561
Virginia D. Engle
P. Thomas Heitmuller
Gary T. Brooks
Maureen Babikow
Technical Resources, Inc.
A. Matt Adams
Computer Sciences Corporation
ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
GULF BREEZE, FLORIDA 32561
'Printed on Recycled Paper
-------
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 (1992). Appropriate precautions should be exercised when using
this information for policy, regulatory or legislative purposes.
Statistical Summary, EMAP-E Louisianian Province - 1992 Page ii
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PREFACE
This document is the second 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, P.T. Heitmuller, V.D. Engle, G.T. Brooks, M. Babikow, and A.M.
Adams. 1994. Annual Statistical Summary: EMAP-Estuaries Louisianian Province - 1992. U.S.
Environmental Protection Agency, Office of Research and Development, Environmental Research
Laboratory, Gulf Breeze, FL. EPA/620/R-94/002.
Statistical Summary, EMAP-E Louisianian Province - 1992
Page in
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ACKNOWLEDGEMENTS
A large geographically extensive monitoring program such as KMAP in the Louisianian Province
requires the interaction, coordination and cooperation of literally hundreds of individuals working
together to complete the 1992 Demonstration. Space does not permit the individual citation of all who
participated in the 1992 effort. We would like to take this opportunity to thank everyone who has
participated in the success of the Louisianian Province and specifically acknowledge the following:
CONTRIBUTORS
U.S. EPA - Gulf Breeze
Lee Courtney
Jack Fournie
Technical Resources, Inc.
Barbara Albrecht
George Craven
Brian Dorn
Derek Groves
Peggy Harris
Jeanne Gillet
Shannon Phifer
Computer Sciences Corporation
Cynthia Cannon
Renee' Conner
Lois Hasettine
Gulf Coast Research Laboratory
David Burke
Richard Heard
William Walker
National Oceanic and Atmospheric
Administration
Texas A&M University
James Brooks
Roy Davis
Roger Fay
James Jobling
Bob Pressley
Terry Wade
R.J. Wilson
Dan Wilkinson
University of Mississippi
William Benson
Gary Gaston
James O'Neal
Steve Brown
Andrew Robertson
Statistical Summary, EMAP-E Louisianian Province -1992
Page iv
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STATISTICAL SUMMARY
EMAP-E LOUISIANIAN PROVINCE - 1991
Table of Contents
DISCLAIMER
PREFACE
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
."
J"
EXECUTIVE SUMMARY
1 INTRODUCTION
17
1.1 OBJECTIVES OF THE 1992 LOUISIANIAN PROVINCE DEMONSTRATION .......... 17
1.2 ENVIRONMENTAL VALUES AND ASSESSMENT QUESTIONS . . ....... 17
1.3 PURPOSE AND ORGANIZATION OF THIS REPORT ......... . .............. 10
* r ...... * ...... ***
2 STATISTICAL SUMMARY ................... 21
2.1 BIOTIC INDICATORS .......................... ......... i ................ 21
NUMBER OF BENTHIC SPECIES ........... . ..... " ' ' ................ 21
TOTAL BENTHIC ABUNDANCE ................ ': ....... ......... 24
BENTHIC ABUNDANCE BY TAXA ............ ..... " " .............. 24
BENTHIC INDEX .............................. ! ' ................ 24
NUMBER OF FISH SPECIES .................... ' ................ 31
TOTAL FEVFISH ABUNDANCE ................ ! ................ 31
GROSS PATHOLOGY .............. ....... ! ................ 31
MACROPHAGE AGGREGATES ............. '.'.'. ...... ! " ............... 34
MARINE DEBRIS ...................... i " " ............. 16
WATER CLARITY ................. ........ " * ............... 3*
FISH TISSUE CONTAMINANTS ............... .' ...... i ................. 37
INTEGRATION OF ESTUARINE CONDITIONS ...... ................ 4O
* " .............
2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
2.1.6
2.1.7
2.1.8
2.1.9
2.1.10
2.1.11
2.1.12
2.2 EXPOSURE INDICATORS
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.2.8
2.2.9
DISSOLVED OXYGEN (INSTANTANEOUS) ......... ! ............. 41
DISSOLVED OXYGEN (CONTINUOUS) ........... ............. 44
SEDIMENT TOXICITY-AMPEL/SCA ABDITA ........... ............. 46
SEDIMENT TOXICITY-MFS/OOPS/S BAHIA ............ ..... ......... 48
SEDIMENT CONTAMINANTS-ALKANES AND ISOPRENOIDS ... ........... 48
SEDIMENT CONTAMINANTS-POLYNUCLEAR AROMATIC HYDROCARBONS ' 50
SEDIMENT CONTAMINANTS-POLYCHLORINATED BIPHENYLS 55
SEDIMENT CONTAMINANTS-PESTICIDES .......... ...... 57
SEDIMENT CONTAMINANTS-HEAVY METALS ......... i . . . ............ 59
' ..... 59
59
...........
2.3
2.2.10. CRITERIA COMPARISONS
2.2.10.1 ANTHROPOGENIC ENRICHMENT
2.1.11 SEDIMENT CONTAMINANTS - BUTYLTINS .........
HABITAT INDICATORS .................... i ............... <£
2.3.1 WATER DEPTH ............................ ........ ! ................ «
2.3.2 WATER TEMPERATURE ...................... *l ................ 65
................
2.3.3 SALINITY
66
Statistical Summary, EMAP-E Louisianian Province - 1992
Pace v
-------
Table of Contents (continued)
2.3.4 pH .................................... ........................
2.3.5 STRATIFICATION .................................................. w
2.3.6 PERCENT SILT-CLAY CONTENT ...................................... »»
2.3.7 PERCENT TOTAL ORGANIC CARBON ................................. 69
2.3.8 ACID VOLATILE SULFIDES ......... ................................. 7J
2.4 CONFIDENCE INTERVALS FOR PROVINCE AND CLASS-LEVEL ESTIMATES .......... 71
3 SUMMARY OF CONCLUSIONS ................................... ......... ..... TL
3.1 OVERVIEW OF PROVINCE CHARACTERISTICS .............................. 77
3.2 CONCLUSIONS OF THE 1992 SAMPLING . . ..................... ............. 78
4 REFERENCES [[[ 79
APPENDIX A SUBPOPULATION ESTIMATION BASED ON EMAP SAMPLING ............ A.1
A.I BIOTIC CONDITION INDICATORS ................
A.I.1 BENTHIC INDEX
A.1.2 NUMBER OF FISH SPECIES ..................................
A.1.3 MARINE DEBRIS
A.1.4 WATER CLARITY ......... ..............
A.1.5 INTEGRATION OF ESTUARINE CONDITIONS ...............
A.2 ABIOTIC CONDITION INDICATORS ....................................... A-»
A.2.1 DISSOLVED OXYGEN (INSTANTANEOUS) ........................ ..... A-»
A.2.2 DISSOLVED OXYGEN (CONTINUOUS) ---- , ............................ A-9
A.2.3 SEDIMENT TOXICTTV-AMPEIISCA ABDITA ............................ A-9
A.2.4 ALKANES AND ISOPRENOIDS ...................................... A-12
A.2.5 POLYNUCLEAR AROMATIC HYDROCARBONS ........................ A-13
A.2.6 POLYCHLORINATED BIPHENYLS ................................... A-J4
A.2.7 TRIBUTYLTIN [[[ A-J;
A.2.8 PESTICIDES [[[ '
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EXECUTIVE OVERVIEW
STATUS OF THE CONDITION OF LOUISIANIAN
PROVINCE ESTUARIES - 1992
This statistical summary of the ecological
condition of the estuarine resources is based on
the results of the 1992 Louisianian 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 the Gulf
of Mexico including 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.
The Louisianian Province Demonstration
Project was conducted during the summer of
1992 (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 and sixty-nine sites between
Anclote Anchorage, FL and the Rio Grande,
TX were sampled during the eight-week
sampling period (Fig, 1). Ten sites were not
sampled, due to inadequate water depth for
sampling (i.e., < 1 m). Thus, based on the
1992 sampling design, 6.6% of the total
estuarine area in the Louisianian Province
cannot be sampled with the present sampling
plan. The bulk of this "unsampleable" area
occurs in the shoreline areas of large estuaries
where the average depth is < 1 m. (locations
in Apalachee Bay, FL; Laguna Madre, TX; and
Mobile Bay, AL account for 96% of this
unsampleable area) We will evaluate methods
for obtaining data from these shallow locations
in 1993. Of the remaining sites, 100 locations
represent probability-based sampling for the
province and are used for the class and
province estimates produced in this report.
Fifty-nine sites were collected to provide
estimates of variance, local enhancements of
Statistical Summary, EMAP-E Louisianian Province - 1992
Page I
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Figure 1. Base Sampling Stations For 1992 Louisianian Province Monitoring.
spatial scale for Lake Pontchartrain, and long-
term trend estimation.
A series of indicators that are representative of
the overall condition of estuarine resources was
measured at each site. These indicators were
designed to address three major attributes of
concern: 1) estuarine biotic integrity, 2)
societal values related to public use of
estuarine resources, and 3) pollutant exposure
or the environmental conditions under which
biota live.
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
use measures of species composition,
abundance, and health to evaluate the condition
of the benthic and fish assemblages. Both use
indices determined from the combined 1991-
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
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
Statistical Summary, EMAP-E Louisianian Province -1992
Page 2
-------
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 1992
Louisianian Province Demonstration indicate
that 27±10% of the estuarine area in the
province had benthic resources characterized
by lower than expected benthic diversity and
low numbers of indicator species. Of the
25,725 km comprising the estuaries of the
Louisianian Province, about 7000 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 1992.
Proportionately, large tidal rivers were the most
degraded with most of the resource having
degraded resources (90+22% of the area of the
tidal portion of the Mississippi River) (Fig. 2).
Thirty-three percent (±24%) of small estuarine
resources were degraded on an area! basis and
large estuaries had only 24±11% of their area
represented by degraded benthos (Fig. 2).
However, while the proportion of area
degraded in the large tidal river and small
estuarine resources classes was high, the total
BENTHIC INDEX < 4.0
LOUISIANIAN PROVINCE 1992
a:
LU
as
o
ae
LARGE:
RIVER
CLASS
SHALL
Figure 2. Percent of area having benthic index value < 4.0
for large estuaries (largo), small estuaries (small), and
large tidal rivers (river). ;
I
area of degraded benthic resources in large
estuaries was about 4^00 km2 as compared to
2500 km2 for small estuaries and 120 km2 for
large tidal rivers.
HUMAN USE
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 ttiese 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 Ithe 1992 Louisianian
Province Demonstration to estimate the area!
Statistical Summary, EMAP-E Louisianian Province -1992
Page 3
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extent of estuaries having trash and turbid
waters. Measurements were taken to estimate
the proportion of fish and shellfish populations
for selected ecological, recreational, and
commercial 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
6±5% of the estuarine area in the Louisianian
Province. This accumulates to over 1500 km2
of estuarine bottom having identifiable marine
debris in the Louisianian Province. No trash
was identified as medical or hospital waste.
MARINE DEBRIS
LOUISIANIAN PROVINCE 1992
C3
OS.
UJ
a-
LARGE
RIVER
CLASS
SMALL
Figure 3. Percent of area having marine debris present
for largo estuaries (large), small estuaries (small), and
large tidal rivers (river).
PAR < 10%
LOUISIANIAN PROVINCE 1992
too-
90-
80
70-
60-
50-
40
30
20-
30' T
:
LARGE RIVER SMALL
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 large tidal
rivers (river).
Proportion of area having marine debris was
higher in the large tidal rivers 45±27%, while
7±7% of the area of large estuaries, and 4±7%
of the area in small estuaries had trash (Fig. 3).
Clear waters are valued by society and
contribute to the maintenance of healthy and
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 12+7% of the province had
waters with visibility of < 10%. Clarity was
much poorer in large tidal rivers (30±29% with
< 10% transmittance) than either small
estuaries (17±14%) or large tidal estuaries
(10±8%)(Fig. 4).
Statistical 5M/«/nary, EMAP-E Louisianian Province -1992
Page 4
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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.
EMAP-E has compiled contaminant levels of
pesticides, heavy metals, and polychlorinated
biphenyls (PCBs) in edible fish and shellfish
tissues for three species groups: Atlantic
croaker (Micropogonias undulatus),
commercial shrimps (Penaeus aztecus and
Penaeus setiferus), and marine catfish (Arius
felis, Bagre marinus, and Ictalurus furcatus).
The analysis done for tissue contaminants
differ from those previously discussed in that
the results refer to populations of organisms
rather than area! extent in estuaries.
In general, contaminant concentrations in fish
and shellfish were low with the exception of
some heavy metals (arsenic, chromium,
mercury, and zinc) (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).
However, selenium, concentrations exceeded the
international criterion in 4% of sampled shrimp
populations (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.
Cadmium concentrations exceeding 0.5 ppm
(International criteria) were found in 4% of the
croaker population (Table 2).
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), gafftopsail catfish, and blue
Contaminant
Observed Criterion1 Proportion
Range Exceeding
Criterion
Pesticides (ng/g wwt)
ODD
.DDE
DDT
Aldrin
Chlordane
Dieldrin
Endosulfan
Endrin
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Lindane
Mirex
Toxaphene
Trans-Nohachlor '
PCBs (ng/g wwt)
21 Congeners
Total PCBs
0-4.5 5000 0%
0-0.5 5000 0%
0-14.0 5000 0%
0-0.7 300 0%
0-0.0 300 0%
0-0.0 300 0%
0-0.0 NA2 0%
0-0.0 300 0%
0-4.2 300 0%
0-0.4 300 0%
0-0.0 200 0%
0-0.0 200 0%
0-16.0 100 0%
0-0.0 5000 0%
0-0.0 NA U3
0-16.0 500 0%
0-27.4 2000 0%
Heavy Metals (|ig/g wwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
Criteria were selec
0-5.1 NA U
0-1.4 2 0%
0-0.4 0.5 0%
0-0.4 1 0%
0-2.4 15 0%
0-0.2 0.5 0%
0-0.2 1 0%
0-0.4 NA U
0-1.1 1 4%
0-0.5 NA U
0-1.0 NA U
1-11.5 60 0%
fed from FDA esfablished limits for
pesticides and PCIls (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
U = Unknown because no criterion level available
Table 1. Overview of the contaminant levels observed in edible
flesh of brown shrimp and white shrimp (N=523).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 5
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Contaminant
Observed
range
Criterion Proportion
Exceeding
Criterion
Pesticides (ng/g wwt)
DDD 0-6.1
DDE 0-9.3
DDT 0-36.6
Aldrin 0-8.6
Chlordane 0-3.5
Dicldrin 0-3.5
Emlosulfan 0-2.0
Endrin 0-1.1
Hcplachlor 0-3.0
Heptachlor Epoxide 0-2.9
Hcxachlorobenzcnc 0-2.9
Lindanc 01.3
Mirex 0-42.1
Toxaplicne 0-0
Trans-Nonachlor 0-5.6
PCBs (ng/g wwt)
21 Congeners 0-30.3
Total PCBs 0-98.9
Heavy Metals (ug/g wwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
0-4.1
0-0.9
0-0.7
0-0.5
0-1.3
0-0.2
0-0.4
0-0.8
0-0.6
0-0.5
0-0.9
1-5.8
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
0%
0%
0%
0%
0%
0%
II
0%
0%
0%
0%
0%
0%
0%
u
0%
0%
u
0%
4%
0%
0%
0%
0%
u%
0%
u%
u%
0%
'Criteria were selected from FDA established limits for
pesticides and PCBs (USFDA 1982, 1984) except
hcxachlorobcnzcne 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
(Naucn 1983)
Contaminant
Observed
Range
Criterion Proportion
Exceeding
Criterion
Pesticides (ng/g wwl)
DDD 0-13.0
DDE 0-20.9
DDT 0-37.8
Aldrin 0-16.7
Chlordane 0-79.9
Dieldrin 0-5.0
Endosulfan 0-2.8
Endrin 0-12.5
Heptachlor 0-49.2
Heptachlor Epoxide 0-2.3
Hexachlorobenzene 0-2.5
Lindane 0-15.4
Mirex 0-72.6
Toxaphene 0-0
Trans-Nonachlor 0-3.2
PCBs (ng/g wwt)
21 Congeners 0-44.8
Total PCBs 0-79.9
Heavy Metals (ug/g wwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
0-16.7
0-10.3
0-0.5
0-0.7
0-2.0
0-0.3
0-1.2
0-2.2
0-1.3
0-0.5
0-2.6
1-18.2
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
0%
0%
0%
0%
0%
0%
U
0%
0%
0%
u
u
15%
1%
0%
0%
0%
1%
u
2%
U
U
* 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)
Tabla 2. Overview of the contaminant levels observed in
edible flesh of Atlantic croaker (N=571). NA= Not available;
Us Unknown, no criterion level is available.
Table 3. Overview of the contaminant levels observed in
edible flesh of catfish (N=633). NA= Not available; U=
Unknown as no criterion level is available.
Statistical Summary, EMAP-E Louisianian Province -1992
Page 6
-------
ECOLOGICAL CONDITIONS
LOUISIANIAN PROVINCE 1992
Inpoired Use
9±lU
Degraded Biology
17±1D*
Both
10i5 *
Figure 5. Summary of environmental conditions in Louisianian Province in 1992.
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 (15% of samples exceeding 2 ppm).
Selenium concentrations exceeded 1 ppm in
2% of the catfish populations. Mercury and
cadmium exceeded 1 ppm and 0.5 ppm,
respectively, in 1% of the catfish populations
(Table 3).
Overall, the number of contaminants seen in
fish and shellfish exceeding the FDA action
limits 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,
selenium, mercury, and cadmium. 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
i
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,
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 tcj estimate overall
environmental conditions in the estuaries.
Thirty-six percent of the estuarine area in the
Louisianian Province showed evidence of
Statistical Summary, EMAP-E Louisianian Province -1992
Page 7
-------
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, 9,650 km2 were potentially degraded
based on the 1992 sampling.
The locations of degraded biological resources
were sometimes different from those having
aesthetic problems. Both sets of conditions
were found in 10% of the estuarine area,
whereas degraded biological conditions alone
were found in 17% of the province, and poor
aesthetics were found in 9% (Fig. 5).
POLLUTANT EXPOSURE
While EMAP-E's major objective is to
describe the status of estuaries using indicators
BOTTOM DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1992
2-5 ppri
I7±10*
> 5 pp»
7B±10*
Rgure 6. Percent of area of Louisianian Province with
instantaneous dissolved oxygen concentrations in bottom waters
< 2ppm, 2-5 ppm, and > 5ppm.
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 22%±10% of the Louisianian
Province had point measurements of dissolved
oxygen concentrations that failed to meet the
5 ppm 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 1992
Louisianian Province Demonstration indicate
that point measurements of bottom dissolved
oxygen concentrations below this threshold
were found in 5±5% of the province (Fig.
6).
Two types of dissolved oxygen
measurements were taken in 1992: 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 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. In general, the continuous
dissolved oxygen concentration
measurements mimic the point
measurements (Figs. 7-9).
Statistical Summary, EMAP-E Louisianian Province -1992
PageS
-------
BOTTOM DISSOLVED
OXYGEN < 2 ppm
LOUISIANIAN PROVINCE 1992
z
Ul
CJ
50
40
30
20
LARGE RIVER SMALL
CLASS
Figure 7. Percent of area having instantaneous dissolved
oxygen concentrations in bottom waters of < 2 ppm for
large estuaries (large), small estuaries (small), and large
tidal rivers (river).
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 chemically-
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
Louisianian Province were toxic to
representative estuarine organisms. Based
upon the results of these tests, 10+6% of the
Louisianian Province contained sediments that
were toxic to estuarine organisms. Because
Ampelisca abdita, the test organism used in the
bioassays is not common to the Louisianian
Province, additional-testing was conducted
using a common mysid. The results of this
mysid testing generally agree with those found
using Ampelisca with 5±4% of the province
showing toxicity. Trie proportion of area
containing toxic sediments was very different
among the three estuarine classes (Fig. 10)
with the highest proportion occurring in the
large tidal river class (30+22%) and
significantly smaller proportion in large
estuaries (12±8%). j
i
Measurements of concentrations of
contaminants in sediments were used to
estimate the areal extent: of sediment having
pollutant concentrations that are above
MINIMUM DISSOLVED
OXYGEN < 2
LOUISIANIAN PROVINCE 1992
40
30-
20-
10-
0J
LARGE SMALL
CLASS
Figure 8. Percent of area having minimum dissolved oxygen
concentrations in bottom waters of <2 ppm for large estuaries
(large), small estuaries (small!), and large tidal rivers (river).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 9
-------
MINIMUM DISSOLVED OXYGEN
LOU1SIANIAN PROVINCE 1992
2-5 ppn
29±11x
JgP
< 2 ppn
6±5 s
5 pp«
65±11*
Rguro 9. Percent of area of Louisianian Province with minimum dissolved oxygen concentrations in bottom waters < 2ppm,
2-5 ppm, and > 5 ppm based on 24 hours of data.
AMPELISCA MORTALITY > 20%
LOUISIANIAN PROVINCE 1992
o
ce
LARGE RIVER SHALL
CLASS
Figure 10. Percent of area with 95% confidence intervals
having sediment toxicity for large estuaries (large), small
eatuariea (small), and large tidal rivers (river).
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 polychlorinated 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) 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.
Statistical Summary, EMAP-E Louisianian Province -1992
Page 10
-------
Criterion Criterion
for Potential for
Degradation Degradation
Chemical
Analyte 10% Effects 50% Effects
Trace Elements (ppm)
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Silver
Tin
Zinc
Polychlorinated Biphenyls (ppb)
Total PCBs
DDT and Metabolites (ppb)
DDT
ODD
DDE
Total DDT
Other Pesticides (ppb)
Lindane
Chlordane
Heptachlor
Dieldrin
Aldrin
Endrin
Mirex
2 25
33 85
5 9
80 145
70 390
35 110
0.15 1.3
30 50
1 2.2
NA NA
120 270
50 400
1 7
2 20
2 15
3 350
NA NA
0.5 6
NA NA
0.02 8
NA NA
0.02 45
NA NA
Polynuclear Aromatic Hydrocarbons (ppb)
Acenaphthene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(e)pyrene
Biphenyl
Chrysene
Dibenz(a,h)anthracene
2,6-dimethylnaphthylene
Fluoranthene
Fluorene
1 -methylnaphthalene
2-methylnaphthalene
1 -methylphenanthrene
Naphthalene
Perylene
Phenanthrene
Pyrene
2,3,5-trimethylnaphthalene
Total PAH
150 650
85 960
230 1600
400 2500
NA NA
NA NA
400 2800
60 260
NA NA
600 3600
35 640
NA NA
65 670
NA NA
340 2100
NA NA
225 1380
350 2200
NA' NA
4000 35000
Table 4. Criteria values used to characterize degraded
sediments (from Long and Morgan 1990). NA= Not
available.
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, 17±9% of the
Louisianian Province has sediments with
elevated concentrations.of one or more heavy
metals based on the criteria values and 20±9%
of the area has heavy metal concentrations that
were higher than would be expected based on
aluminum background concentrations (Fig. 11).
These elevated metals! were primarily copper,
arsenic, lead, mercury, and zinc. Enriched
metal concentrations yaried widely among
classes with the greatest enrichment (21±23%
of sediments) occurring in the small estuaries,
SEDIMENT METALS
LOUISIANIAN PROVINCE 1982
110
IEnrichtd
> 10» Criteria
Figure 11. 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 concentration^ (bars represent 95% confidence
intervals).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 11
-------
16±10% of the sediments being enriched in
large estuaries, and only 5±22% of sediments
in large tidal river systems.
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. A
criteria value of >7000 ppb total alkanes was
used to characterize a degraded estuarine
condition. An intermediate criterion of 5000-
7000 ppb total alkanes was used as indicative
of potential contamination. Eleven percent of
the sediments in the Louisianian Province had
elevated levels of alkanes. Elevated levels of
alkanes were observed in 60+29% of the
sediments of the large tidal rivers class and the
proportion of area displaying elevated alkane
concentrations in large and small estuaries
were similar, 7±7% and 13+13%, respectively
(Fig. 12).
Polynuclear aromatic hydrocarbons represent a
common component of the contaminants
released by point source industrial effluents. A
total of 44 individual PAHs was examined but
criteria levels were available for only 12 of
these compounds (Long and Morgan 1990).
However, a criterion is available for total
PAHs based on the Long and Morgan (1990)
estimate for sediment concentrations resulting
in biological effects 50% of the time
>35,000 ppb. Due to the magnitude of this
concentration, we also examined the
concentration range that produced ecological
effects >10% of the time - >4000 ppb total
PAHs. No total PAH concentrations in the
observed Louisianian Province sediments
exceeded 35,000 ppb. Only 4+4% of the
province is characterized by the intermediate
total PAH concentration of > 4000 ppb. No
elevated PAH values were observed in large
estuaries or large tidal rivers. The intermediate
level of PAHs was found primarily in large
estuarine systems comprising 5±6% and
30±32% of the total sediments in large tidal
rivers (Fig. 1-3).
Polychlorinated biphenyls (PCBs) represent
very toxic compounds in Hie environment.
Twenty-five individual PCB congeners were
examined in the 1992 Louisianian Province
Demonstration. Long and Morgan (1990)
provide a criterion of >400 ppb total PCBs as
the concentration likely to result in ecological
effects. They provide a secondary
concentration of >50 ppb at which some effects
might be expected. Total PCB concentrations
in observed Louisianian Province sediments did
not exceed 400 ppb. None of the Louisianian
Province sediments were characterized by total
PCB concentrations > 40 ppb.
Pesticides are introduced into the estuarine
environment through three pathways: direct
emission as a result of point source discharge
TOTAL ALKANES > 7000 ppb
LOUISIANIAN PROVINCE 1802
LARGE RIVER SHALL
CLASS
Figure 12. Percent of area with 95% confidence intervals having
total PAH concentrations in sediment > 7000 ppb for large
estuaries (large), small estuaries (small), and large tidal rivers
(river).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 12
-------
TOTAL PAHs > 4000 ppb
LOUISIANIAN PROVINCE 1992
UJ
u
LARGE
RIVER
CLASS
SHALL
Figure 13. Percent of area and 95% confidence intervals having
total PAH concentrations in sediment > 4000 ppb for large estuaries
(large), small estuaries (small), and large tidal rivers (river).
TOTAL CHLORDANE > 0.5 ppb
LOUISIANIAN PROVINCE 1982
LARGE RIVER SHALL
CLASS
Figure 14. Percent of area and 95% confidence intervals having
chlordane concentrations in sediments > 0.5 ppb for large estuaries
(large), large tidal rivers (river), and small estuaries (small).
(generally through manufacture or disposal),
non-point emission through agricultural or
horticultural application, and atmospheric
through deposition of volatilized materials.
In the 1992 Louisianian Province
Demonstration, 25 pesticides and derivatives
were examined. For this summary, total
pesticides, total D:DT, and total chlordane
are reported. Generally accepted sediment
quality criteria are not yet available and
even reasonable criteria are only available
for 9 of the 25 pesticides examined. Long
and Morgan (1990) report the following
critical concentrations for DDT, DDD, DDE,
chlordane, dieldrm, and endrin: 7 ppb, 20
ppb, 15 ppb, 6 ppb, 8 ppb, and 45 ppb,
respectively. ;
The DDT criteria value of 7 ppb was not
exceeded for the sediments in the
Louisianian Province. However, 17±9% of
the sediments showed total DDT (including
DDE and DDD) concentrations exceeding 1
ppm.
Total chlordane showed concentrations > 0.5
ppb in 8±6% of the sediments of the
Louisianian Province with some individual
sediment samples exceeding 4 ppb.
Elevated chlordanie concentrations were
observed in all three estuarine classes (Fig.
14) with 85+20% of the sediments in large
tidal rivers showing elevated concentrations;
12±17% in small estuaries and 5±6% in
large estuaries.
Tributyltin was measured at sediment
concentrations > 1 ppb in 42±11% and > 5
ppb in 3±3% of trie sediments of the
Louisianian Province. Using 5 ppb as a
clear indicator of degraded conditions, most
of the high-TBT sediments were found in
large tidal rivers (20±4% of sediments) and
to a lesser extent in large (3±2%) and small
(2±1%) estuarine sediments (Figure 15).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 13
-------
TRIBUTYLTIN > 5 ppb
LOUISANIAN PROVINCE 1892
50
3D
LARGE RIVER SUALL
CLASS
Ninc(y-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 cstuarine classes.
Figure 15. Percent of area and 95% confidence intervals having
sediments with tributyltin > 5 ppb for large estuaries, large tidal
rivers, and small estuaries.
Statistical Summary, EMAP-E Louisianian Province -1992
Page 14
-------
Parameter Province Large
Estuary
N 100 58
Estuarine Condition 36(1.1) 33(12)
(% of Province showing degraded biological resources or impaired use)
BIOTIC CONDITION
Benthic Index 27(10) 24(11)
Abundance < 10 15(9) 9(7)
# Species < 2 10(9) 3(5)
# Species < 5 21(10) 16(9)
Fish
Abundance < 2 13(8) 14(9)
Abundance <, 5 20(9) 22(11)
# Species < 1 4(4) 5(6)
# Species < 2 11(8) 12(8)
Fish Pathology1 < 27(11) < 27(12)
Fish Contaminants1
Shrimp
All > FDA Limits 0(0) 0(0)
Croaker
All > FDA Limits 0(0) 0(0)
Marine Catfish
Hg > FDA Limits 1(1) 1(1)
Others > FDA Limits 0(0) 0(0)
Bottom DO2 < 2 ppm 5(5) 7(7)
Bottom DO2 < 5 ppm 22(10) 24(11)
Minimum DO < 2 ppm 6(5) 9(7)
Sediment Toxicity 10(6) 12(8)
Percentage based on sample size rather than estuarine area
Instantaneous dissolved oxygen measurements
Large
Tidal
River
32
100(17)
90(22)
20(21)
25(22)
70(26)
60(29)
90(26)
15(20)
40(29)
< 29(30)
0(0)
0(0)
0(0)
0(0)
0(0)
10(19)
30(22)
Small
Estuaiy
43
42(25)
33(24)
30(26)
25(26)
33(26)
12(16)
13(16)
9(15)
28(26)
i 0(0)
0(0)
0(0)
0(0)
: 1(1)
113(20)
f KD
4(6)
i--- . -.. B.VM.V.MIIIUII ivBiifw an**
-------
Parameter
N
ABIOTIC CONDITION
Marine Debris
Water Clarity
PAR < 10%
PAR < 25%
Sill-Clay Content
<20%
>80%
Alkancs
Total > 7000 ppb
PAHs
Total > 4000 ppb
PCBs
Total > 200 ppb
Pesticides
Chlordanc > .5 ppb
Dieldrin > .02 ppb
Endrin > .02 ppb
DDT > 1 ppb
DDE > 2 ppb
ODD > 2 ppb
Metak
Ag > 1 ppm
As>33 ppm
Cd> 5 ppm
Cr > 80 ppm
Cu > 70 ppm
Hg > .15 ppm
Ni > 30 ppm
Pb>35 ppm
Sb> 2 ppm
Sn> 3 ppm
Zn > 120 ppm
Tribulyllin
TBT> 1 ppb
TBT > 5 ppb
Province
100
6(5)
12(7)
45(10)
18(8)
29(10)
9(6)
4(4)
0(0)
8(6)
34(11)
4(4)
-------
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), Forest Service
(FS), U.S. Geological Survey (USGS), and the
National Oceanic and Atmospheric
Administration (NOAA). These other agencies
and offices participate in the collection and
analysis of EMAP data and will use 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
1992, 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 River, TX and Anclote
Anchorage, FL). This Statistical Summary
reports on the 1992 sampling effort.
1.1 OBJECTIVES OF THE 1992
LOUISIANIAN PROVINCE
ESTUARINE SAMPLING
The specifics of the planning activities of the
Louisianian Province Demonstration are
documented in Summers et al. (1991). This
continuing demonstration was held in the
Louisianian Province to show the utility of
regional monitoring; programs for assessing the
condition of estuariae resources. Sampling was
conducted from July through August spanning
169 sites utilizing 3D field personnel and three
program/logistical coordinators.
I
The objectives of the 1992 Louisianian
Province Continuing Demonstration were to:
i
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
baseline conditions in the Louisianian
Province. j
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
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 17
-------
integrity and societal values.
Ecological integrity is comprised of ecosystem
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 is the total acreage of submerged
aquatic vegetation in the Louisianian
Province?
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 tissues greater than
FDA action limits?
What proportion of target species in the
Louisianian Province has external gross
pathologies in excess of 0.5%?
What proportion of 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 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
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 al. 1993a).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 18
-------
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 1992. This report is meant to be a
summarization of all the data collected in the
1992 Demonstration. As a result, different
topics are dealt with using varying levels of
detail based t>n 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 et al. 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 1992 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 1992 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 -1992
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 included
in the 1992 Louisianian Province
Demonstration included both measured and
derived indicators: number of benthic species,
abundance of total benthos, benthic 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 total number of
benthic species mean ranging from 0 to nearly
90 species (Fig. 2-1). There are no significant
differences among the 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 "diverse" benthic
communities based on comparisons of
impacted and reference sites of similar salinity
(Summers et al 1993b) results in 10±9% of the
sediments in the province having near mono-
specific stands of benthos, while 21±10% 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 large tidal river and
small estuaries classes (Fig. 2-3).
As a more meaningful comparison than simple
total species numbers, the proportion of
expected benthic species was estimated for the
1992 monitoring samples. This comparison
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 21
-------
BENTHIC SPECIES RICHNESS
LOUISMNIAN PROVINCE 1992
100
90
80
70
SO
50
40
30
20-1
10-
10 20 50 40 50 SO 70 BO
MEAN NUMBER OF BEHTHIC SPECIES (per grab)
90
100
Figure 2-1. Cumulative distribution of mean benthic species richness in estuarine sediments in the Louisianian Province in 1992 (-) and its
associated 95% confidence interval (--).
MEAN NUMBER OF BENTHIC SPECIES
LOUSUN1AH PROVINCE 1982
{-5 Spietit
IlilOl
c I Spiel in
10iJ x
7lit9«
MEAN BENTHIC SPECIES < 2
LOUISIANIAN PROVINCE 1992
LARGE RIVER SHALL
CLASS
Figure 2-2. Percent of area of the Lonisianian Province
esluarinc nedimcnt associated with mean number of benthic
species categories in 1992.
Figure 2-3. Percent of area having sediments with mean
benthic species < 2 for large estuaries, large tidal rivers, and
small estuaries (bars represent 95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 22
-------
was based on the 1991-1992 regression of
salinity and mean number of benthic species
per grab (Engle et al. 1993). This proportion
of expected number of species, normalized for
salinity differences, ranged from 0.0 to 2.1
(Fig. 2-4). About 29±10% of the sediments of
the Gulf of Mexico estuaries had < 33% of the
expected number of species based on salinity
zone; 32±10% had between 33 to 66% of
expected species; and, 39±10% had > 66% of
the number species expected based on salinity
zone (Fig. 2-5). These areas of reduced
expected numbers of benthic species are
primarily located in the large tidal river and
small estuary/small tidal river classes (Fig. 2-
6). Benthic diversity associated with the three
grabs varies widely over the province (Fig. 2-
7) with 14±9% of the province having a
benthic Shannon-Weiner diversity index of
< 0.2 and 26±10% less than 0.4 (Fig. 2-8).
PROPORTION OF EXPECTED
MEAN NUMBER OF SPECIES
LOUKIIANIAN PROVINCE 1992
$«« EXPECTED
39±10«
Figure 2-5. Percent area of the Louisianian Province estuarine sediments
associated with proportion of expected benthic species categories in 1992.
EXPECTED NUMBER OF SPECIES
LOUISIANIAN PROVINCE 1992
0.0
2.4
Proportion of Expected
ilson Number of Species
Figure 2-4. Cumulative distribution of proportion of expected number of benthic species observed in the estuarine sediments of the
Louisianian Province in 1992 (-) and its associated 95% confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 23
-------
< 33% EXPECTED MEAN
NUMBER OF SPECIES
LOUISIANIAN PROVINCE 1992
==
LU
CJ>
a*
LU
Q-
LARGE RIVER SMALL
CLASS
Figure 2-6. Percent area having sediments with proportion of
expected bcnthic species < 33% in large estuaries, large tidal rivers,
and small estuaries (bars represent 95% confidence intervals).
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 1400 organisms per grab or over 30,000
organisms/m2. Using 10 organism/grab (about
200/m2) and 25/grab (about 500/m2) as
indicators of poor or marginal condition,
respectively, 15±9% of Louisianian Province
sediments have poor benthic abundance and an
additional 13±11% have marginal abundance
(Fig. 2-10). These areas of low abundance are
primarily associated with small estuaries and
large tidal rivers (30±26% and 20±21%,
respectively,) (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). Over 30% of the sediments sampled in
the 1991 Louisianian Province Demonstration
did not have amphipods as part of the
community (Fig. 2-12) while 24% did have
gastropods (Fig. 2-13). Tubificids are absent
from 70% of sediments while polychaetes were
found in 85-90% of the sediments sampled
(Figs. 2-14 and 2-15).
2.1.4 BENTHIC INDEX
The construction of the 1991 benthic index was
described in Summers et al. (1993b) and Engle
et al. (1993). Initial validation of the 1991
benthic index model using 1992 data revealed
some difficulties. About 20% of the stations
sampled in 1992 were misclassified based on
the 1991 benthic index model and the
contaminant and hypoxia criteria used in 1991.
The discriminant model that was developed in
1991 used the proportion of expected species
diversity adjusted by numbers of indicator
species to differentiate between a priori
selected reference and affected sites according
to the relationship:
91 Benthic Index =
(2.3841) * Proportion of Expected Diversity +
(-1.6728) * Percent Tubificid Abundance +
(0.6683) * Percent Bivalve Abundance
Statistical Summary, EMAP-E Louisianian Province -1992
Page 24
-------
100
90
80
70
60
50
40
30
20
10
0
MEAN BENTHIC DIVERSITY
LOUISIANIAN PROVINCE 1992
0.00 0.25 0.50 0.75 1.00 1.25
MEAN DIVERSITY INDEX
1.75 2.00
Figure 2-7. Cumulative distribution of benthic diversity in estuarine sediments in the Louisianian Province in 1992 (-) and its associated
95% confidence interval (-).
MEAN BENTHIC DIVERSITY INDEX
LOUISIANIAN PROVINCE 1992
INDEX .2-.4
12±10x
INDEX > .5
74±10x
INDEX < .2
14±S s
Figure 2-8. Percent area of the Louisianian Province estuarine sediments associated with benthic diversity categories in 1992.
Statistical Summary, EMAP-E Louisianian Province -1992
Page 25
-------
BENTHIC ABUNDANCE
LOUISIANIAN PROVINCE 1992
tu
a:
O
oc
LU
a.
150 300 450 600 750 900 1050
UEAH ABUNDANCE (per grab)
1200 1350 1500
Figaro 2-9. Cumulative distribution of mean abundance per grab in estuarine sediments in the Lonisianian Province in 1992 (-) and its
«sod«icd 95% confidence interval (--).
MEAN BENTHIC ABUNDANCE
LOUISIANIAN PROVINCE 1992
10-25
13±11x
MEAN BENTHIC ABUNDANCE < 10
LOUISIANIAN PROVINCE 1992
u
ee
LARGE RIVER SMALL
CLASS
Figure 2-10. Percent area of the Louisianian Province estuarine
sediments associated with benthic abundance categories in 1992.
Figure 2-11. Percent area having sediments with benthic
abundance < 10 organisms per grab in large estuaries, large tidal
rivers, and small estuaries (bars represent 95% confidence
intervals).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 26
-------
BENTHIC AMPHIPOD ABUNDANCE
UXIISIANUN PROVINCE 1982
140 280 420 560 700 840 980
MEAN ABUNDANCE (per grab)
11201 1260
1400
Figure 2-12. Cumulative distribution of mean amphipod abundance per grab in estuarine sediments in the Loirisianian Province in 1992
(-) and its associated 95% confidence interval (--). :
Ul
ae
<
i
ae
Ul
o
ae
Ul
a.
BENTHIC GASTROPOD ABUNDANCE
LOUISANIAN PROVINCE 1992
90 in
80 'f
70-F
60 jl
50 j|
40|
30|
20 1
lot
oJ
T 1 i i i i J 1 1
0 140 280 420 560 700 840 980 1
MEAN ABUNDANCE (per grab)
1120 1260 1400
Figure 2-13. Cumulative distribution of mean gastropod abundance per grab in estuarine sediments in the Lonisianian Province in 1992
(-) and its associated 95% confidence interval (--). i
Statistical Summary, EMAP-E Louisianian Province -1992
Page 27
-------
^
llj
tie
«C
1-
UI
C3
oe
tu
QL
BENTHIC TUBIFICID ABUNDANCE
LOUISIANIAN PROVINCE 1992
100"! 1.^^""^"""*
90 JT
80-|
7fl|
1i
60-
50-
40-
30-
20-
10-
0-
0 140 280 420 560 700 840 980 1120 1260 1400
MEAN ABUNDANCE (per grab)
Figure 2-14. Cumulative distribution of mean tubificid oligochaetc abundance per grab in estuarine sediments in the Louisianian Province
in 1992 (-) and its associated 95% confidence interval (--)
LU
cs
BENTHIC POLYCHAETE ABUNDANCE
LOUIStANIAN PROVINCE 1992
T
140
~r
280
1 1 r
420 560 700 840 980
MEAN ABUNDANCE (per grab)
1120 1260 1400
Figure 2-15. Cumulative distribution of mean polychaete abundance per grab in estuarine sediments in the Louisianian Province in 1992
(-) and its associated 95% confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 28
-------
The normalized benthic index scores for the
Louisianian Province in 1991 ranged from 0 to
10.8 with the break point between stressed
("degraded") and reference ("undegraded")
occurring at 4.1.
Use of the 1991 model on the 1992 data,
showed several stations that were significantly
more "degraded" than the 1991 test data set
resulting in negative index values ranging to
-11.5 (Fig. 2-16). As a result, we revised the
benthic index based on the combined 1991-
1992 benthic data. The 1991-1992 benthic
index represents a refined version of the earlier
model and encompasses a broader range of
community conditions particularly for stressed
environments. The 1991-1992 index ranged
from -2.5 to 10.5 (Fig. 2-17) and is
characterized by mean benthic diversity
adjusted by indicator species presence and
abundance:
91-92 Benthic Index = (2.028) * Species Diversity +
(0.763) * Percent Gastropod Abundance +
(0.561) * Percent Amphipod Abundance +
(-0.742) * Tubificid Abundance +
(-0.666) * Capitcllid Abundance
This adjusted model accounts for 82% of the
variability in the test data set with less than a
5% misclassification rate. A comparison of the
1991 and the 1991-1992 models showed no
significant differences between the two models
beyond the adjusted model better describing
the range of the bentliic data (i.e., sites with
poor benthic conditions are predicted to be
poor regardless of index). The combined
1991-1992 benthic data set better depicts the
range of conditions observed in Gulf of
Mexico estuarine environments over the two
year span, particularly those in the Mississippi
River. As a result, the adjusted 1991-1992
index described abovR is used to describe the
condition of Louisianian Province benthic
communities.
About 27±10% of the! sediments in the
Louisianian Province contained stressed or
degraded benthic communities (Fig. 2-18) with
the highest proportion of the communities
occurring in large tidal rivers (90±22%) and
small estuaries (33±24%) (Fig. 2-19). These
figures do not suggest that these stressed
communities are solely the result of
anthropogenic influences. Some of the poor
BENTHIC INDEX
LOUISIANIAN PROVINCE 1982
100-
90-
80
70-
i.t
5= «0
£ 50-
S 40-
til
°- 30-
20-
10-
0-
..
r gl
f f ,
!ff
f m f
/j'
f" j*i
~ ' ^^ f
f J s
/ ' ^^^ f
f *^T ^ +*
^-£^£<''~
-12 -10 -8-6-4-20 2 4 6 8
BENTHIC INDEX
3f~
Y
10 12
Figure 2-16. Cumulative distribution of 1991 benthic index applied to 1992 benthic data in the Louisianian Province (-) and its associated
95% confidence interval (--).
Statistical
Summary, EMAP-E Louisianian Province - 1992
Page 29
-------
BENTHIC INDEX
LOUISIAMIAN PROVINCE 1992
100-
90-
80-
70-
60-
50-
40-
30-
20
fO
0-1
-2
4 6
BENTHIC INDEX
10
12
Figure 2-17. Comulalivc distribution of revised 1991-1992 benthic index applied to the estnarine sediments of the Lonisianian Province
in 1992 (-) and its associated 95% confidence interval (--).
benthic communities described could be the
result of natural conditions (e.g., naturally
induced hypoxia). However, 56% of the
difference observed between stressed and
unstressed benthic communities were
associated with elevated concentrations of
sediment contaminants or sediment toxicity
while only 5% of the differences were
attributable to low dissolved oxygen
concentrations. The associations for the
remaining 39% of the differences were either
unknown or related to habitat variations (e.g.
sediment enrichment).
BENTHIC INDEX
LOUISIANIAN PROVINCE 1982
INDEX < I
27±IO»
INDEX 4-6
35111*
INDEX > 6
38±11»
Figure 2-18. Percent of area of the Louisianian Province estuarine
sediments associated with 1991-1992 revised benthic index categories
in 1992.
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 30
-------
BENTHIC INDEX < 4.0
LOUISIANIAN PROVINCE 1992
o
LARGE
RIVER
CLASS
SMALL
Figure 2-19. Percent of area having sediments with benthic index
< 4.0 in large estuaries, large tidal rivers, and small estuaries
(bars represent 95% confidence intervals).
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 15 species (Fig. 2-20) with a total of
88 species collected throughout the province.
Selecting 0 and < 2 species as comparative
values for fish communities with low species
abundance results in 4±4% of the province
having no fish taken in multiple trawls, while
11±8% of the province had nekton
communities comprised of < 2 species per
trawl (Fig. 2-21). Areas having minimal < 2
nekton species are primarily located in the
large tidal river class (Fig. 2-22).
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 250
organisms per trawl (Fig. 2-23). Using 2
organisms/trawl and 5/trawl as values
representing low and marginal numbers of fish
abundance respectively, 13±8% of Louisianian
Province waters have low finfish abundances
and an additional 7±9% have marginal
abundance (Fig. 2-24). 'These areas of low
abundance are primarily associated with large
tidal rivers where 60±29% of waters in the
class have finfish abundances < 2 (Fig. 2-25).
2.1.7 EXTERNAL GROSS
PATHOLOGY
i
The frequency and type of external gross
pathology associated with nekton taken in the
fish trawls is an indicator of the overall
condition of fish collected in trawls. All fish
that were collected during the 1992 Louisianian
Province Demonstration were examined by the
field crews for external gross pathologies, such
as tumors and lesions. Over 20,000 fish were
examined for gross pathologies and a total of
271 external pathologies were noted.
Fourteenth 10% of the area of the Louisianian
Province produced trawls with > 2
pathologies/trawl (Fig. 2-26). Overall in the
Statistical Summary, EMAP-E Louisianian Province -1992
Page 31
-------
100
DO
BO
60
50
«
3D
20
10
NEKTON SPECIES RICHNESS
UJUISiANIAN PROVINCE 1992
0 2 4 6 8 10 12 14
NUMBER OF SPECIES (per trawl)
16
18 20
Figure 2-20. Cumulative distribution of number of fish species per trawl in the Louisianian Province estuaries in 1992 (-) and its associated
95% confidence interval (--).
province, 1% of the fish examined had visible
pathological disorders (Fig. 2-27). The
prevalence of abnormalities for demersal and
commercially harvested fish (0.4% and 1.1%,
respectively) was about the same as the
background level observed for all fish (1.0%).
However, upper trophic level fish (e.g.,
NEKTON SPECIES RICHNESS
LDUBtANIAN PROVINCE 1892
1 SPECIES
7±B
>1 SPECIES
Mil x
NUMBER OF NEKTON
SPECIES < 2
LOUISIANIAN PROVINCE 1992
UJ
o
UJ
Q.
LARGE
RIVER
CLASS
SHALL
Figure 2-21. Percent of area of the Louisianian Province estuaries
nssodntcd with the number of fish species per trawl categories in
1992.
Figure,2-22. Percent area of estuaries with mean number of
species per trawl < 2 species in large estuaries, large tidal rivers,
and small estuaries (bars represent 95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 32
-------
NEKTON ABUNDANCE
LOUISIANIAN PROVINCE 1992
o
n-
bj
a.
50
-r
100 150 200
NEKTON ABUNDANCE {per tra»!)
25D
300
Figure 2-23. Cumulative distribution of mean fish abundance per trawl in the Louisianian Province in 1992 (-) and its associated 95%
confidence interval (--).
piscivores) and pelagic species demonstrated a
significantly higher incidence of pathology
(2.7% and 4.2%, respectively) (Fig. 2-27).
Examples of upper trophic level fish are
seatrouts, permits, and spadefish. Pelagic
species included menhaden and bumper. Hie
NEKTON ABUNDANCE
LOUISIANIAN PROVINCE 1992
ABUNDANCE 2-5
7±J
ABUNDANCE > 3
8019 i
ABUNDANCE < 2
13±B i
NEKTON ABUNDANCE <2
LOUISIAMAN PROVINCE 1992
<
UJ
o
LU
Q-
LARGE
RIVER
CLASS
SMALL
Figure 2-24. Percent area of the Louisianian Province estuaries Figure 2-25. Percent area of estuaries with mean fish abundance per
associated with the mean fish abundance species categories in 1992. trawl < 2 species in large estuaries, large tidal rivers, and small
estuaries (bars represent 95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 33
-------
FISH PATHOLOGIES
LOUISIANIAN PROVINCE 1992
Figure 2-26, Percent oT fish examined from the Louisianian Province
estuaries associated with the number of external pathologies per trawl
categories in 1992.
majority of pelagic pathologies were noted at a
single site. Removal of this site reduced the
incidence of pelagic pathologies to 1.4%. Sand
seatrout, threadfin shad, Gulf menhaden,
Atlantic bumper and blue catfish had visible
pathology rates that were clearly higher than
the observed background. Although
statistically significant from the background
rate, the higher incidence of pathologies in
permit, harvestfish, Spanish mackerel, and
yellowfin menhaden are not supportable due to
the small number of individuals of these
species examined (< 100 fish).
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) (Wolke et al. 1985).
FREQUENCY OF
FISH PATHOLOGIES
LDUISIANIAN PROVINCE 1992
ALL lEHERSAL PELACIC UPPER COWERCIAL
FISH TROPHIC
Figure 2-27. Percent of fish examined from the Louisianian
Province with external pathologies by fish class (bars represent
95% confidence intervals).
Suggested functions for these aggregates
include the centralizations of foreign materials
and cellular debris for destruction,
detoxification, and/or reuse (Ferguson 1976;
Ellis et al. 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 et al. 1993b, Blazer et al.
1993). By comparing the MA number and
percent area occupied by MAs, the general
distribution of health condition of fish in the
Louisianian Province can be described (Fig. 2-
28).
About 10±0.1% of the fish sampled in the
Louisianian Province contained macrophage
aggregate concentrations > 40/mm2 (Fig. 2-29).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 34
-------
too
80
80
70
60
50
40
30
20
10
0
MACROPHAGE AGGREGATES
LOUISIANIAN PROVINCE 1992
25
50 75
NuRber per sq Bin
100
r
125
Figure 2-28. Cumulative distribution of number of macrophagc aggregates per nun2 in fish examined from the Louisianian Province in
1992 (associated 95% confidence interval too narrow to portray). i
MACROPHAGE AGGREGATES
LOUISIANIAN PROVINCE 1992
<40/»q m
901.05*
>40/tq UK
10l.05>
Figure 2-29. Percent area of fish examined from the Louisianian
Province estuaries with number of macrophage aggregates per mm2
in 1992.
The distribution of peircent area occupied by
macrophage aggregates is similar to number of
aggregates with the proportion of the fish
populations showing :> 5% of spleen area
covered by aggregates being 12±0.1% (Fig. 2-
30). These figures do not suggest that these
stressed communities are solely the result of
anthropogenic 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, 54% of the differences observed
between locations with fish with high or low
levels of macrophage aggregates were
associated with sediment contaminants or
sediment toxicity while only 4% of the
differences were attributable to low dissolved
oxygen concentrations. The associations for
the remaining 42% of the differences were
either unknown or related to habitat variations.
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 35
-------
100-
90-
80-
70-
£ 80-
Ul _
o 50H
" 40-1
30
20
10
0
MACROPHAGE AGGREGATES
LOUISIANIAN PROVINCE 1992
10
12
14 16
18 20
22
24 28
i AREA OCCUPIED BY
MACROPHAGE AGGREGATES
Figure 2-30. Cumulative distribution of percent area of spleen occupied by macrophage aggregates per mm2 in fish examined from the
Louisianian Province in 1992 (associated 95% confidence interval to narrow to portray).
2.1.9 MARINE DEBRIS
2.1.10 WATER CLARITY
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 1992 Louisianian
Province Demonstration the presence of marine
debris was noted in bottom sediments and the
water column and the type of the trash was
determined (e.g., plastic, anthropogenic wood,
metal, glass, etc.). In 1992, over 6±5% 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 large
tidal rivers with 45+27% coverage. Large
estuaries and small estuaries had 7±7% and
4±4% of their sediments containing marine
debris, respectively (Fig. 2-31).
Another "social" or human use criterion for
good condition of an estuary is water clarity
and the lack of noxious odors. The presence
of odors was noted at each sampling site
during the Demonstration; 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 56% (Fig. 2-32).
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),
Statistical Summary, EMAP-E Louisianwn Province -1992
Page 36
-------
MARINE DEBRIS
LOUISIANIAN PROVINCE - 1992
LjJ
o
LARGE RIVER SMALL
CLASS
Figure 2-31. Percent area of estuaries with presence of marine debris
in sediments in large estuaries, large tidal rivers, and small estuaries
(bars represent 95% confidence intervals).
12+7% of the Louisianian Province
experienced turbid water clarity (Fig. 2-33).
Alternatively, using 25% transmittance as a
measure of moderate clarity (cannot see your
toes in waist deep water), resulted in 45±10%
of the Louisianian Province had water clarity
that could not pass this visual test. The
poorest water clarity Occurred in large tidal
rivers and small estuaries with 30±29% and
17±14%, respectively. (Fig. 2-34).
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
WATER CLARITY
LOUISIANIAN PROVINCE 1992
0.0 0.1 0.2 0.3 0.4 0.5
PAR
0.9 1.0
Figure 2-32. Cumulative distribution of water clarity as measured as percent of surface light reaching a depth of 1 m in the Louisianian
Province in 1992 (-) and its associated 95% confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 37
-------
WATER CLARITY
LOUIS1AN1AN PROVINCE 1992
PAR 10-251
33±IO»
PAR < IDs
12i7 i
PAR >25i
55±IOi
Figure 2-33. Percent area of Ihe Lomsianian Province estuaries
sjjodalcd with PAR categories in 1992.
skin for Atlantic croaker, and as the fillet
without skin for the catfish. All samples
represented a composite of 4 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
PAR< 10%
LOUISIANIAN PROVINCE 1992
LU
o_
LARGE RIVER SMALL
CLASS
Figure 2-34. Percent area of estuaries with PAR < 10% at a depth of
1 m in large estuaries, large tidal rivers, and small estuaries (bars
represent 95% confidence intervals).
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, PCB, or heavy metal
concentrations exceeded the specified criteria
for shrimp (Table 2-1). The highest
concentration of an organic contaminant found
was 27 ppb total PCBs (compared to the
standard of 2000). Mirex and DDT were the
pesticides found in highest concentrations in
Statistical Summary, EMAP-E Louisianian Province -1992
Page 38
-------
Contaminant
Observed
Range
Criterion1 Proportion
Exceeding
Criterion
Pesticides (ng/g wwt)
ODD 0-4.5
DDE 0-0.5
DDT 0-14.0
Aldrin 0-0.7
Chlordane 0-0.0
Dieldrin 0-0.0
Endosulfan 0-0.0
Endrin 0-0.0
Heptachlor 0-4.2
Heptachlor Epoxide 0-0.4
Hexachlorobenzene 0-0.0
Lindane 0-0.0
Mirex 0-16.0
Toxaphene 0-0.0
Trans-Nonachlor 0-0.0
PCBs (ng/g wwt)
21 Congeners 0-16.0
Total PCBs 0-27.4
Heavy Metals (ug/g wwt)
Aluminum 0-5.1
Arsenic 0-1.4
Cadmium 0-0.4
Chromium 0-0.4
Copper 0-2.4
Lead 0-0.2
Mercury 0-0.2
Nickel 0-0.4
Selenium 0-1.1
Silver 0-0.5
Tin 0-1.0
Zinc 1-11.5
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
0%
0%
0%
0%
0%
0%
U3
0%
0%
0%
0%
0%
U
0%
U
0%
0%
U
4%
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
U = Unknown because no criterion level available
Table 2-1. Overview of the contaminant levels observed in edible
flesh of brown shrimp and white shrimp (N=523).
Contaminant * Observed Criterion1 Proportion
Pesticides (ng/g wwt)
ODD
DDE
range Exceeding
Criterion
0-6.1 5000 0%
0-9.3 5000 0%
DDT 6-36.6 5000 0%
Aldrin
Chlordane
Dieldrin
Endosulfan
Endrin
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Lindane
0-8.6 300 0%
0-3.5 300 0%
0-3.5 300 0%
0-2.0 NA U
0-1.1 300 0%
0-3.0 300 0%
0-2.9 300 0%
0-2.9 200 0%
01.3 200 0%
Mirex 0-42.1 100 0%
Toxaphene
Trans-Nonachlor
PCBs (ng/g wwt)
0-0 5000 0%
0-5.6 NA U
21 Congeners 0-30.3 500 0%
Total PCBs 6-98.9 2000 0%
Heavy Metals (ug/g wwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Tin
Zinc
Criteria were selected
pesticides and PCBs
0-4.1 NA U
0-0.9 2 0%
0-0.7 0.5 4%
0-0.5 1 0%
0-1.3 15 0%
0-0.2 0.5 0%
0-0.4 1 0%
0-0.8 NA U
0-0.6 1 0%
0-0.5 NA U
0-0.9 NA U
1-5.8 60 0%
from FDA established limits for
(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 i
(Nauen 1983)
effect means of international limits
Table 2-2. Overview of the contaminant levels observed in edible
flesh of Atlantic croaker (N=i!71). NA= Not available; U=
Unknown, no criterion level is available.
Statistical Summary, EMAP-E Louisianian Province -1992
Pase 39
-------
Contaminant
Observed
Range
Criterion Proportion
Exceeding
Criterion
Pesticides (ng/g wwt)
DDD 0-13.0
DDE 0-20.9
DDT 0-37.8
Aldrin 0-16.7
Chlordane 0-79.9
Dicldrin 0-5.0
Endosulfan 0-2.8
Endrin 0-12.5
Hcptachlor 0-49.2
Hcptachlor Epoxide 0-2.3
Hexachlorobcnzcnc 0-2.5
Lindanc 0-15.4
Mirex 0-72.6
Toxaphene 0-0
Trnns-Nonachlor 0-3.2
PCBs (ng/g wwt)
21 Congeners 0-44.8
Total PCBs 0-79.9
Heavy Metals (fig/g wwt)
Aluminum
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
TIB
Zinc
0-16.7
0-10.3
0-0.5
0-0.7
0-2.0
0-0.3
0-1.2
0-2.2
0-1.3
0-0.5
0-2.6
1-18.2
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
0%
0%
0%
0%
0%
0%
U
0%
0%
0%
0%
0%
0%
0%
U
0%
U
15%
1%
0%
0%
0%
1%
U
2%
U
U
Criteria were selected from FDA established limits for
pesticides and PCBs (USFDA 1982, 1984) except
hcxachlorobcnzcnc 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)
Table 2-3. Overview of the contaminant levels observed in edible
flesh of catfish (N=633). NA= Not available; U= Unknown as no
criterion level is available.
shrimp tailmeat at 14 to 16 ppb. This
represents < 1% of the FDA limit for DDT and
16% of the limit for Mirex.
No pesticide or PCB concentrations exceeded
the specified FDA action limits for Atlantic
croaker (Table 2-2). As with shrimp, total
PCBs, DDT and mirex represented the highest
fillet organic residues found in Atlantic croaker
at 99, 37, and 42 ppb, respectively. These
concentrations represent 1 to 42% of the action
limits for these contaminants. Cadmium
exceeded the international standards of 0.5 ppm
in 4% of the croakers examined.
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 15% of marine catfish in excess of 2 ppm
arsenic, 2% in excess of 1 ppm selenium, 1%
in excess of 1 ppm mercury, and 1% in excess
of 0.5 ppm cadmium.
2.1.12 INTEGRATION OF
ESTUARINE CONDITIONS
A single value has been developed to
summarize me overall condition of the
estuaries in the Louisianian Province by
combining the benthic index, marine debris,
water clarity and tissue contaminants, weighted
equally. This single value includes ah index of
societal values (aesthetics) and estuarine biotic
integrity based on benthic assemblages and fish
health condition (Fig. 2-35). Indicators relating
to biotic integrity and aesthetics were used to
estimate overall environmental conditions in
the estuaries. Thirty-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. 2-35). Of the 25,725 km2 of estuarine
surface area in the Louisianian Province,
Statistical Summary, EMAP-E Louisianian Province -1992
Page 40
-------
ECOLOGICAL CONDITIONS
LOUISIANIAN PROVINCE 1992
(paired Use
9±11i
Degraded Bfology
17±10»
Both
10±6
Undegroded
64±11i
Figure 2-35. Percent area of the Lonisianian Province estuaries in
1992 associated with degraded biology and degraded use.
9,261±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 10±6% of the estuarine area,
whereas degraded biological conditions alone
were found in 17+10% of the province and
degraded human use alone was found in
9±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 1992 Louisianian Province
Demonstration were dissolved oxygen
concentration (instantaneous and continuous),
sediment toxicity (Ampelisca and Mysidopsis),
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
1992 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 2-36
through 2-40). Minimum DO concentrations
derived from province-wide instantaneous
estimates decreased, from 3.4 ppm at the
surface to 2.9 ppm at 1 m, 1.5 ppm at 2 m, 0.6
ppm at 3 m, and 0.0 at the bottom. The
minima show this steady decline with depth
reflecting the stratified nature of some
estuaries. However, the median values change
very little (ranging from 6.4 at the surface to
5.4 at the bottom) suggesting that most
estuaries in the Louisianian Province are well
mixed. Surface dissolved oxygen
concentrations were rarely observed to be
below 5 ppm during the daylight sampling
(Fig. 2-41) while bottom DO concentrations
were below 5 ppm for 22±10% of the province
and below 2 ppm for 5±5% of the province
(Fig. 2-42). Bottom dissolved oxygen
concentrations < 5 ppm were seen in all three
estuarine classes with large estuaries displaying
the greatest extent at 24±11% of the class
resources, with small estuaries at 13±20%, and
large tidal rivers at lp±19% (Fig. 2-43).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 41
-------
<
UJ
or
F-
ae
UJ
ca
as
LL!
CL
SURFACE DISSOLVED OXYGEN
LOUISWNIAN PROVINCE 1992
100-
90-
80-
70-
60-
50-
40-
30-
20-
10-
0-
/'
.
0 2 4 6 8 10 12 14 16 IB
DISSOLVED OXYGEN (ppa)
Figure 2-36. Cumulative distribution of surface dissolved oxygen concentration in the Louisianian Province in 1992 (-) and its associated
95% confidence interval (~).
o
oe
ui
DISSOLVED OXYGEN AT 1 METER
LOUISIANIAN PROVINCE 1992
4 6 8 10 12
DISSOLVED OXYGEN (ppii)
14
IB
Figure 2-37. Cumnlrfve distribution of dissolved oxygen concentration at a depth of 1 m in the Lonisianian Province in. 1992 (-) and its
usodBted 95% confidence interval (-).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 42
-------
DISSOLVED OXYGEN AT 2 METERS
lOUISMNIAN PROVINCE 1992
100H
90
80
70
80
50
40
30
20
10
0
8
10
12
18
18
DISSOLVED OXYGEN (ppn)
Figure 2-38. Cumulative distribution of dissolved oxygen concentration at a depth of 2 m in the Louisisinian Province in 1992 (-) and its
associated 95% confidence interval (--). .
DISSOLVED OXYGEN AT 3 METERS
LOUISIANIAN PROVINCE 1992
100-
90-
80-
50
40H
3fl:
20-
10-
0-
6 8 10 12
DISSOLVED OXYGEN (ppn)
14
16
18
Figure 2-39. Cumulative distribution of dissolved oxygen concentration at a depth of 3 m in the Louisif inian Province in 1992 (-) and its
associated 95% confidence interval (--). i
Statistical Summary, EMAP-E Louisianian Province -1992
Page 43
-------
ac
ui
o
100
90
80-
70-
60
50
40
30
20
10-
0-
BOTTOM DISSOLVED QXYQEN
LOUISIANIAN PROVINCE 1992
68 fO 12
DISSOLVED OXYGEN (ppa)
18
Figure 2-40. Cumulative distribution of bottom dissolved oxygen concentration in the Louisianian Province in 1992 (-) and its associated
95% confidence interval (-).
However, the proportion of class resources that
experienced DO concentrations < 2 ppm were
almost exclusively within the large estuary
class where 7±7% were characterized by these
conditions. Small estuaries and large tidal
rivers had virtually no incidence of DO
concentrations below 2 ppm during daylight
sampling (Fig. 2-44).
2.2.2 DISSOLVED OXYGEN -
(CONTINUOUS)
Unlike the instantaneous measures, the
continuous dissolved oxygen concentration
measurements provide a 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)
SURFACE DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1992
Figure 2-41. Percent area of the Louisianian Province estuaries
associated with bottom dissolved oxygen categories in 1992.
Statistical Summary, EMAP-E Louisianian Province -1992
Page 44
-------
BOTTOM DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1992
2-5 ppn
> 5 pp«
7B410*
< 2 ppu
5±5 x
Figure 2-42. Percent area of the Lonisianian Province estuaries
associated with bottom dissolved oxygen categories in 1992.
showed that a combination of daily minimum
BOTTOM DISSOLVED
OXYGEN < 5 ppm
LOUISIANIAN PROVINCE 1992
50
40
LARGE RIVER SHALL
CLASS
DO concentration and the incidence of DO
concentrations < 2 ppm for > 20% of the
deployed period coulld be used to successfully
characterize an estuary as "good" or "hypoxic"
with regard to index period DO conditions.
Minimum DO concentrations resulting from
continuous recordings showed that 6±5% of the
province experienced DO conditions below 2
ppm (Fig. 2-45) while 35±11% of the
province had minimal dissolved oxygen
concentrations < 5 ppm (Fig. 2-46). Based on
the above estimation teclmique, this represents
only a 1% increase in the estuarine bottom area
experiencing low DO conditions based on
instantaneous measurements during daylight
hours. Thus in 1992, 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 bight. Similarly, an
additional 13% of estuaries in the Louisianian
Province experience DO conditions < 5 ppm at
BOTTOM DISSOLVED
OXYGIIN < 2 ppm
LOUISIANIAN PROVINCE 1992
50
40
30-
S 20
10- i
.ill
LARGE RIVER SHALL
i CLASS
Figure 2-43. Percent area of estuaries with bottom dissolved oxygen Figure 2-44. Percent area of estuaries with bottom dissolved oxygen
< 5 ppm in large estuaries, large tidal rivers, and small estuaries < 2 ppm in large estuaries, large tidal rivers, and small estuaries (bars
(bars represent 95% confidence intervals). represent 95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 45
-------
night. In 1992, where lower DO conditions
were predominate in large estuaries during
daylight hours, continuous measurements also
showed that large estuaries experience DO
conditions below 2 ppm more frequently than
other estuaries (Fig. 2-47). Thus, unlike the
conditions observed in 1991, DO conditions in
1992 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 DO conditions in the Louisianian Province
showed that 5±5% of the province exhibited
DO concentrations below 2 ppm for greater
than 5 hours during the day (20% of time).
These measurements were primarily seen in the
large estuarine class (Fig. 2-48).
2.2.3 SEDIMENT TOXICITY -
AMPEL1SCA ABDITA
Sediment 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,
Ampelisca abdita. About 10±6% of the
sediments collected in the Louisianian Province
were toxic to the amphipods (Fig. 2-49). In
these sediments, mortality rates were >20%
higher than those observed in the controls .
The estuarine sampling class with the largest
proportion of toxic sediment was the large tidal
river class (30±22%) while small estuaries
(4±6%) and large estuaries (12±8%) showed
toxicity to a lesser extent (Fig. 2-50).
However, on a province-wide scale, most of
the toxic sediments occur in large estuaries
(2,240 km2) with small estuaries contributing
300 km2 of toxic sediments and the large tidal
rivers showing toxicity in only 41 km .
MINIMUM DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1992
4 E 8
DISSOLVED OXYGEN (ppm)
12
14
Figure 2-45. Cumulative distribution of minimum bottom dissolved oxygen concentration in the Louisianian Province in 1992 based on 24
hoars of measurements (_) and its associated 95% confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 46
-------
MINIMUM DISSOLVED OXYGEN
LOUISIANIAN PROVINCE 1992
2-5 pp.
28111i
2 ppu
6±5 s
5 ppi
65±11»
Figure 2-46. Percent area of the Louisianian Province estuaries
associated with minimum bottom dissolved oxygen categories in 1992.
> 20% DO < 2 ppm
LOUISIANIAN PROVINCE 1992
30
20
id
LARGE SHALL
CLASS
MINIMUM DISSOLVED
OXYGEN < 2
LOUISIANIAN PROVINCE 1992
5Q
40
30
20
10
LARGE SMALL
CLASS
Figure 2-48. Percent area of estuaries with bottom dissolved oxygen
< 2 ppm for greater than 20% of the observations in large estuaries,
large tidal rivers, and small estuaries (bars represent 95% confidence
ntervals).
AMPELISOA SEDIMENT TOXICITY
LOUiSIANIAN PROVINCE 1992
NON-TOXIC
90±7
TOXIC
1016 i
Figure 2-47. Percent area of estuaries with minimum bottom
dissolved oxygen < 2 ppm in large estuaries, large tidal rivers, and
small estuaries (bars represent 95% confidence intervals).
Figure 2-49. Percent area of the Louisianian Province estuaries
associated with Ampelisca sediment toxicity categories in 1992.
Statistical Summary, EMAP-E Louisianian Province -1992
Page 47
-------
AMPELISCA MORTALITY > 20%
LOUISIAN1AN PROVINCE 1992
LU
O
OS
LU
OU
LARGE RIVER SHALL
CLASS
Figure 2-50. Percent area of estuaries with Ampelisca mortality
> 20% in Iiirgc estuaries, large tidal rivers, and small estuaries
(bars represent 95% confidence intervals).
2.2.4 SEDIMENT TOXICITY-
MYSIDOPSIS BAHIA
Because Ampelisca abdita is relatively
uncommon in the estuaries of the Louisianian
Province and had to be purchased and
transported from California, a second organism,
Mysidopsis bahia, was tested to see whether it
provided the same results on a province-wide
scale as 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 contact with the tested
sediments. About 5±4% of the sediments in
the Louisianian Province was toxic to mysids
resulting in mortalities >20% higher than those
observed in control tests (Fig. 2-51). This
figure compares favorably with the 10%
observed for Ampelisca toxicity. The major
differences between amphipod and mysid
testing are shown in Figures 2-50 and 2-52
where the percentage of area in the large tidal
river class varies widely; 30±22% for
Ampelisca and 65±27% for mysids. However,
the observed toxicities in the large and small
estuaries are similar.
MYSID SEDIMENT TOXICITY
LOUISIANIAN PROVINCE 1W2
NOH-TOXIC
9515 x
Figure 2-51. Percent area of the Louisianian Province estuaries
associated with Mysidopsis sediment toxicity categories in 1992.
2.2.5 SEDIMENT
CONTAMINANTS - ALKANES
AND ISOPRENOIDS
Alkanes and isoprenoids are contaminants
associated primarily with the petroleum
industry. Sediments collected throughout the
Louisianian Province were analyzed for 27
individual alkanes and total alkalies. The
distribution of observed concentrations for total
alkanes in Louisianian Province sediments is
shown in Figure 2-53 depicting concentrations
ranging from 84 to 20,805 ppb. About 9±6%
Statistical Summary. EMAP-E Louisianian Province -1992
Page 48
-------
MYSID MORTALITY > 20%
LOUISIANIAN PROVINCE 1992
LU
CJ
LARGE RIVER SMALL
CLASS
of the sediments in the province are
characterized by alkane concentrations in
excess of 7000 ppb (Fig. 2-54). Alkanes at
concentrations > 7000 ppb were most often
observed in the large tidal river class (60±29%)
but these concentrations were seen in 7±7% of
TOTAL ALIPHATIC HYDROCARBONS
LOUISIANIAN PROVINCE 1992
5000-7000 »t>
11±B *
< 5000 ppb
8019
> 7000 ppb
918 «
Figure 2-52. Percent area of estuaries with Mysidopsis
mortality > 20% in large estuaries, large tidal rivers, and small
estuaries (bars represent 95% confidence intervals).
Figure 2-54. Percent area of the Lonisianian Province estuaries
associated with sediment alkane concentration "categories in 1992.
TOTAL ALIPHATIC HYDROCARBONS
LOUISIANIAN PROVINCE 1992
100
90
80
70
80
50
40
30
S 9 12 15
TOTAL ALIPHATIC HYDROCARBONS (ppb x 1000)
21
Figure 2-53. Cumulative distribution of alkalies and isoprenoids in the Louisianian Province sediments in 1992 (-) and its associated 95%
confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 49
-------
TOTAL ALKANES > 7000 ppb
LOUISIANIAN PROVINCE 1992
LU
O
LARGE
RIVER
CLASS
SMALL
Figure 2-55. Percent area of estuaries with sediment altkane
concentrations > 7000 ppb in large estuaries, large tidal rivers, and
small estuaries (bars represent 95% confidence intervals).
the large estuarine sediments and 13±13% of
small estuarine sediments (Fig. 2-55). The
ranges of concentrations and the percentage
province-wide areas in excess of 1000 ppb for
the 27 individual alkanes 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
shown in Fig. 2-56 ranging from 115 ppb to
about 21000 ppb. None of the sampled
sediments exceeded the median Long and
Percent Area
Alkaiie
CIO
Cll
C12
C13
C14
C15
C16
C17
Pristane
CIS
Phytane
C19
C20
C21
C22
C23
C24
C25
C26
C27
C28
C29
C30
C31
C32
C33
C34
TOTAL
Range (ppb)
0
0
1
0
4
6
5
6
2
2
2
3
1
1
1
2
1
3
1
2
1
3
0
1
0
0
0
84-
- 1018
- 525
- 1043
- 1256
- 951
- 1976
- 2383
- 2708
- 774
- 1404
- 1970
- 1179
- 999
- 757
- 497
- 488
- 228
- 919
- 310
- 1581
- 380
- 2453
- 379
- 1841
- 410 ,
- 907
- Ill
20805
> 1000 ppb
1%
0%
1%
4%
0%
3%
4%
7%
0%
2%
4%
1%
0%
0%
0%
0%
0%
0%
0%
1%
<0%
4%
0%
4%
0%
<1%
0%
9%
Table 2-4. Alkane concentration ranges measured in the 1992
Demonstration and the percentage of province sediments
exceeding 1000 ppb for individual alkanes and 7000 ppb for
total alkanes.
Morgan (1990) criteria of 35,000 ppb although
4±4% of the sediments did exceed their lower
criterion (4000 ppb) for ecological effects (Fig.
2-57). None of the PAH concentrations
exceeding 4000 ppb were found in small
estuaries. These conditions comprised over
30±32% of the sediments in the large tidal
river class and 5±6% in the large estuary class
(Fig. 2-58). The ranges of individual PAHs, the
criteria used, and the extent to which
observations exceeded these criteria are shown
in Table 2-5.
EPA is currently in the process of establishing
Sediment Quality Criteria (SQC). Draft SQC
are presently available for three of the PAH
analytes EMAP-Estuaries is measuring and one
Statistical Summary, EMAP-E Louisianian Province -1992
Page 50
-------
TOTAL POLYNUCLEAR AROMATIC HYDROCARBONS
UJ
ae
t
o
OL
LOUISIANIAN PROVINCE 1992
... i 1 =
1 IIW
80
80-
70-
80-
SO-
40-
30-
20-
10-
0-
'
"
0 2 4 6 8 10 12 14 16
TOTAL PAHs (ppb x 1000)
18 20 22
Figure 2£6. Cumulative distribution of PAH concentrations in the Louisianian Province sediments in 1992 (-) and its associated 95%
confidence interval (--).
TOTAL PAHs
10U3UNUN ntOVMCE 1992
< 400D
Hit I
4000-35000 ppt
Figure 2-57. Percent area of the Louisianian Province estuaries
associated with sediment PAH concentration categories in 1992.
TOTAL
LOUI
too-
90-
80-
^ 70'
^ 60-
B 50"
1 4°"
30-
20-
10-
PAHs > 4000 ppb
SIANIAN PROVINCE 1992
^, 1
Q * im^^i ^^mm i^i^^ i
LARGE RIVER SMALL
CLASS
Figure 2-58. Percent area of estuaries with sediment PAH
concentrations > 4000 ppb iin large estuaries, large tidal rivers,
and small estuaries (bars represent 95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 51
-------
PAH
Accnaphlhenc(L)
Accnaphthylcne(L)
Anlhraccnc(H)
Bcnzo(a)anthracene(H)
Bcnzo(a)pyrene(H)
Bcnzo(b)fluoranthene(H)
Bcnzo(c)pyrene(H)
Bcnzo(g,h,i)perylGne(H)
Bcnzo(lc)fluoranUiene(H)
Biphenyl(L)
Chtysene(H)
Cl-chryscnc(H)
C2-chrysene(H)
C3-chrysene(H)
C4-chrysene(H)
Dibcnzo(a,h)anthracene(H)
Dibenzothio(H)
Cl-dibcnzotliio(H)
C2-dibenzothio(H)
C3-dibcnzothio(H)
FIuoRmthcDc(H)
Cl-fluoranthpyrcnc(L)
Fluotene(L)
Cl-nuotcnc(L)
C2-fluorcne(L)
C3-nuorenc(L)
Nap5nhalcne(L)
Cl-naphthalene(L)
C2-nap)ithakne(L)
C3-naphtha1cnc(L)
C4-nnphthalcnc(L)
P,erylcne(H)
Phcnanlhrcne(H)
Cl-phenanthrcnc(II)
C2"phenanthtcne(H)
C3-phenanthrcne(H)
C4-phcnanlhrene(H)
Pyrcnc(H)
C01,2,3-c,d-pyrcne(H)
l-njcthylnapbthalcne(L)
2-mcthylnaphthalene(L)
2,3,5 Trimelhylnapthalene(L)
2,6 Dimcthylnapthalcne(L)
1 -me thylphenanthrcnc(H)
High Molecular Wt. PAHs
Low Molecular Wt PAHs
Total PAHs
Range (ppb)
0- 43
0- 13
0- 86
0-278
0-317
0-335
0-260
0-281
0-339
0-102
0-295
0-907
0-851
0-161
0 -1263
0-106
0- 75
0 - 382
0-812
0 - 813"
0-653
1-351
0-126
0-373
0-250
0 -1435
0-219
0-581
0-1509
0-3401
0 -3298
0-517
1-416
3 -1427
4-2148
0 -1572
3-702
1 -1545
0-291
0-303
0-327
0-773
0-590
0-306
46-7170
9-13949
115-21119
Criteria
150/650
NA
85/960
230/1600
400/2500
NA
400/2500
NA
NA
NA
400/2800
400/2800
400/2800
400/2800
400/2800
60/260
NA
NA
NA
NA
600/3600
NA
35/640
35/640
35/640
35/640
340/2100
340/2100
340/2100
340/2100
340/2100
NA
225/1380
225/1380
225/1380
225/1380
225/1380
350/2200
NA
NA
NA
NA
NA
NA
NA
NA
4000/35000
P
(lUTo)
0%
u
< 1%
< 1%
0%
u
0%
u
u
u
0%
< 1%
< 1%
0%
< 1%
< 1%
u
u
u
u
< 1%
u
6%
16%
42%
54%
'0%
1%
3%
5%
3%
U
1%
2%
3%
3%
1%
< 1%
U
U
u
u
u
u
1%
1%
4%
E
\5\J7c)
0%
u
0%
0%
0%
u
0%
u
u
u
0%
0%
0%
0%
0%
0%
u
u
u
u
0%
u
0%
0%
0%
1%
0%
0%
0%
1%
1%
u
0%
0%
0%
0%
0%
0%
u
u
u
u
u
u
0
0
0
Table 23 Ranges of PAH concentrations found in the 1992 Lonisianian Province Demonstration, criteria used for comparison from
Long and Morgan (1990) [x/y where x=conccntration 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 -1992
Page 52
-------
pesticide: acenaphthalene, phenanthrene,
fluoranthene, and dieldrin (US EPA 1993b-e).
SQC are expressed as ng analyte/g organic
carbon; therefore, concentrations must first be
normalized for the organic carbon content of
the sediment. Only those sediments with
organic carbon concentrations > 0.2% can be
examined using this approach. Separate SQC
values have been tentatively established for
freshwater and saltwater sediments.
SQC values for the four analytes measured are
listed in Table 2-6, along with the upper and
lower bounds. It is important to note that
these values are still in draft form and are
subject to change as the documents proceed
through the peer review process.
The distributions of three of these four analytes
in the Louisianian Province in 1992 normalized
for organic carbon of the sediments are shown
in Figures 2-59 through 2-61. The percent
areas exceeding SQC in freshwater and
saltwater habitats in the estuaries of the
Louisianian province in 1992 shows that 0% of
the estuarine sediments exceeded these criteria
Analytc
Acenaphthene
F
S
Phenanthrene
Fluoranthene
Dieldrin
F
S
F
S
F
S
SQC Upper- Lower
F/S SQC SQC
130
230
ISO
240
510
650
11
20
280
500
390
510
1100
1400
24
44
62
110
85
110
240
300
5.2
9.5
Table 2.6 U.S. EPA drafli Sediment Quality Criteria (SQC) for
analytes measured. Freshwater (F), Saltwater (S), and upper and
lower confidence intervals are included. All values are fig/g organic
carbon. !
for acenapthene, phenanthrene, and
fluoranthene.
ACENAPHTHENE
100-
90-
80-
70
! 60-
£ 50-
ca . _
OS 40*
" 30-
20-
:;
IjOUISIANIAN PROVINCE 1992
(f~~~
$
j
t
1
I
|
0 1 2 34 S S
ACENAPHTHENE (pg/g TOO
7 B
Figure 2-59. Cumulative distribution of acenaphthalene concentrations normalized for organic carbon content of sediments in the
Louisianian Province sediments in 1992 (-) and its associated 95% confidence interval (--).
Statistical
Summary, EMAP-E Louisianian Province - 1992
Page 53
-------
Ul
S
100
80
80
70
60
50-
40-
30;
20
10-
0
PHENANTHRENE
LOUISIANIAN PROVINCE 1992
10 15 20 25 30 35
PHENANTHRENE (/ig/g TOC)
40
45
50
Figure 2-60. Comnlative distribution of phenanthrene concentrations normalized for organic carbon content of sediments in the Louisianian
Province sediments in 1992 (-) and its associated 95% confidence interval (--).
FLUORANTHENE
100
00
80
UJ
oc SO-
z 50-
Ul
£ 40-
Ul
20-
10-
0-
LOUISIANIAN PROVINCE 1992
t
\
1
f
I I 1 II 1
D 15 30 45 60 75
FLUORANTHENE (/*g/g TOC)
Figure 2-61. Cumulative distribution of fluoranthene concentrations normalized for organic carbon content of sediments in the Louisianian
Province sediments in 1992 (-) and its associated 95% confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province - 1992 Page 54
-------
Petroleum and combustion-type PAH sources
contain very different PAH compound
distributions. Because of this, the distributions
of PAHs in a sample can provide information
on the relative importance of petroleum versus
combustion PAH sources (Lake et al. 1979).
Petroleum products contain relatively large
amounts of lower molecular weight compounds
relative to combustion sources which are
dominated by higher molecular weight
compounds.
The cumulative distribution function of the
relative percent of high molecular weight
compounds (see Table 2-5 for a listing of high
and low molecular weights) shown in Figure 2-
62 shows the relatively even distribution of
high and low weight PAHs. This indicates that
neither combustion processes or petroleum
products are dominant sources of these
compounds but rather both contribute to the
observed PAHs in the Louisianian Province
estuarine sediments. No differences were
noted among the three estuarine classes with
regard to dominant scjurces of PAHs.
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 2-63 and 2-64).
2.2.7 SEDIMENT
CONTAMINANTS -
POLYCHLORINATED
BIPHENYLS
Twenty polychlorinated biphenyl (PCB)
congeners were analyzed from the Louisianian
Province sediments. Concentrations of total
PCBs (sum of the twenty congeners) ranged
from 0 to 38 ppb (Fig. 2-65). Given that the
criterion for low-level ecological effects is 400
ppb for total PCBs arid 25 ppb for individual
congeners (Long and Morgan 1990), no PCB
concentrations exceeded these criteria (Table 2-
7).
100
90
80-1
70
SO-
SO-
40-
30-
20-
10-
0-
PAHs - HIGH MOLECULAR WEIGHT
LOUISIANIAN PROVINCE 1992
10 20 30 40 50 60 70
i of TOTAL PAHs OB HUW
80
90
100
Figure 2-62. Cumulative distribution of high molecular weight PAH concentrations in the Louisianian Province sediments in 1992 <-) and
its associated 95% confidence interval (--). i
Statistical Summary, EMAP-E Louisianian Province -1992
Page 55
-------
100-
80-
80
UJ
s B0-
£ 50
40
30
20
10
0
O
Of
tu
PAHs - LOW MOLECULAR WEIGHT
EPA REGION IV 1992
10 20 30 40 50 60 70 80
* of TOTAL PAHs OB LUW
90 100
figure 2-63. Cumulative distribution of low molecular weight PAH concentrations in the Louisianian Province sediments in 1992 east of
the Mississippi River (-) and its associated 95% confidence interval (-).
PAHs - HIGH MOLECULAR WEIGHT
EPA REGION V11992
20
30
40 50 60
* of TOTAL PAHs as HMW
70
BO
90
100
Figure 2-64. Cumulative distribution of the proportion of high molecular weight PAHs in the Louisianian Province sediments in 1992 west
of the Mississippi River delta (-) and its associated 95% confidence interval (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 56
-------
TOTAL PCBs
LOUIS1ANIAN PROVINCE 1992
10 15 20 25 30 35 ! 40 45 50
TOTAL PCBs (ppb)
Figure 2-65. Cumulative distribution of total PCB concentrations in the Louisianian Province sediments in 1992 (-) and its associated 95%
confidence interval (--). !
i
2.2.8 SEDIMENT CONTAMINANTS
- PESTICIDES
PCB # (Chlorination)
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
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
- 0.8
- 1.2
- 2.0
- 2.5
- 10.5
- 1.4
- 2.9
- 0.7
- 5.1
- 1.6
- 1.4
- 0.4
-3.5
-3.0
- 0
- 1.8
- 0.7
- 0.2
- 0.2
- 2.0
- 38
Table 2.7 Ranges of polychlorinated biphenyl concentrations
determined from Louisianian Province sediments.
Pesticides constitute a major portion of
nonpoint source runoff from agricultural fields,
suburban lawns, and golf courses. Twenty-
three 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 title few criteria available
from Long and Morgan (1990) for DDT and its
derivatives^ chlordane, endrin, and dieldrin.
The ranges of observed concentrations of all
pesticides examined are shown in Table 2-8.
Total DDT concentrations (2,4'DDT and
4,4'DDT) above the criterion (7 ppb) were not
found in the sedimeitrts of the Louisianian
Province (Fig. 2-66). However, < 1±1% of
sediments contained! DDT at concentrations > 1
ppb. These concentrations were found
primarily in the large tidal river class
Statistical Summary, EMAP-E Louisianian Province -1992
Page 57
-------
Pesticide Range (ppb)
2,/DDD
4/DDD
2/DDE
4/DDE
2/DDT
4/DDT
Aldrin
Alpha-BBC
bcta-BHC
delta-BHC
alpha-Clilordanc
gamma-CMordanc
Dieldrin
Endosulfan
Endrin
Hcxachlorobcnzenc
Hcpfachlor
HepUchlor Epoxidc
Mircx
cis-Nonachlor
trans-Nonachlor
Oxychlordane
Toxaphcnc
Tocal BHCs
0 - 1.29
0-2.25
0 - 1.80
0 - 2.18
0 - 0.15
0-1.44
0 - 0.98
0 - 1.67
0-1.52
0-0.61
0 - 3.21
0 - 4.94
0 - 1.17
0.- 0
0 - 0.30
0 - 4.90
0-0.25
0 - 1.87
0 - 0.08
0 - 0.91
0-Z61
0 - 0.21
0- 0
0-4.13
Criteria
Exceeded
2.0/20
2.0/20
2.0/15
2.0/15
1.0/7
1.0/7
NA
NA
NA
NA
.5/6
.5/6
.02/8
NA
.02/45
NA
NA
NA
NA
NA
NA
NA
NA
NA
Percent
(10%)
0%
<1%
0.02 ppb.
Dieldrin concentration did not exceed its
median criterion of 8 ppb in any sediments
collected from the Louisianian Province:
TOTAL CHLORDANE > 0.5
LOUISIANIAN PROVINCE 1992
<
LU
OS
«c
i
ae
ui
oe
ui
a.
LARGE
RIVER
CLASS
SMALL
Figure 2-67. Percent of area of estuaries with total chlordane
concentrations > 0.5 ppb in large estuaries, large tidal rivers, and
small estuaries (bars represent 95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 58
-------
however, 34±11% of sediments had dleldrin
concentrations > 0.02 ppb, the 10% effects-
level listed by Long & Morgan (1990).
2.2.9 SEDIMENT
CONTAMINANTS - HEAVY
METALS
Fifteen heavy metals were analyzed for the
sediments collected in the 1992 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 log-transformed metal concentrations
against log-transformed 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 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 anthropogenically enriched with regard to
metals.
2.2.10. CRITERIA COMPARISONS
Louisianian Province have metal concentrations
in excess of these values (Fig. 2-69) whereas
only 3±1% of the sediments exceed the higher
criteria. Over 5% of the sediments have two
or more metals exceeding the lower criteria
values.
These high metal concentrations are found
primarily in large estuary classes (21±8%, Fig.
2-70) and small estuaries (18±8%, Fig. 2-71).
Only 5±5% of the sediments in large tidal
rivers (Fig. 2-72) showed metal concentrations
in excess of criteria levels.
Metal
Aluminum
Antimony
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Tin
Zinc
I
Range (ppm)
j
76 - 97388
0- 3.2
0- 28.8
0- 0.6
0 - 104.4
0- 41.6
0 - 71177
0 - 127.0
0- 1260
0- 0.2
0 - 36.9
0- 1.2
0- 0.9
0- 6.3
5 -625.1
Criteria
(ppm)
NA
2/25
33/85
5/9
80/145
70/390
NA
35/110
NA
.15/1
30/50
NA
1/2
1/3
120/270
Percent Exceeded
(10%)
u
1%
0%
0%
4%
0%
U
3%
U
1%
10%
U
0%
68%
11%
(50%)
U
0%
0%
0%
0%
0%
u
1%
u
0%
0%
u
0%
10%
1%
Table 2.9 Ranges of heavy met:i] concentrations found in the 1992
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)
Table 2.9 shows the ranges of heavy metals
concentrations found during the 1992
Louisianian Province Demonstration and their
criteria values for comparison. Only nickel,
zinc, tin, and to a lesser extent lead, mercury,
antimony, and chromium exceed the selected
criteria values (Fig. 2-68). Using the lower
criteria (i.e., concentrations resulting in effects
10% of the time), 20±7% of sediments in the
2.2.10.1 ANTHROPOGENIC
ENRICHMENT
Aluminum concentrations vary over three
orders of magnitude (76 to 97000 ppm) in the
Louisianian Province: As aluminum content in
sediments is primarily derived from the natural
crust of the earth, this wide variation generally
Statistical Summary, EMAP-E Louisianian Province -1992
Page 59
-------
SEDIMENT METALS
LOUISIAMIAN PROVINCE 1992
50-
40-
-c
ui
" 30
x
bJ
o
Enriched
I 1 > 10s Criteria
PD
SB
SN
ZH
Figure 2-68. Percent area of estuaries in Lora'sianian Province with sediment metal concentrations > 10% Long-Morgan criteria or greater
than expected based on aluminum concentrations (bars represent 95% confidence intervals).
SEDIMENT METALS
LOUISIANIAN PROVINCE 1992
Enriched
> 10* Crltcrio
Figure 2-69. 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 (bars represent 95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 60
-------
SEDIMENT METALS
LARGE ESTUARY 1992
Enriched
> 10> Criteria
t
Figure 2-70. Percent area of large estuaries in Louisianinn Province with 0 to 6 sediment heavy metal concentrations > 10% Long-Morgan
sediment criteria or greater than expected based on aluminum concentrations (bars represent 95% confidence interval).
SEDIMENT METALS
SMALL ESTUARY 1992
Enriched
> 10i Criteria
Figure 2-71. Percent area of small estuaries in Louisiaiiian Province with 0 to 6 sediment heavy metal concentrations > 10% Long-Morgan
sediment criteria or greater than expected based on aluminum concentrations (bars represent 95% confidence interval).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 61
-------
SEDIMENT METALS
TIDAL RIVER 1992
oe
LLJ
Enriched
> 10» Crlterio
FJgnrc 2-72. Percent area of large tidal rivers in Louisianian Province with 0 to 6 sediment metal concentrations > 10% Long-Morgan
sediment criteria or greater than expected based on aluminum concentrations (bars represent 95% confidence interval).
is accompanied by wide variations in the
portion of other metals observed that is
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 et al. 1985, Windom et al.
1989, Schropp et 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 and
1992 Louisianian Province Demonstration data
sets that were determined to be representative
of natural, unenriched areas were selected to
develop the regressions. The results of these,
regressions are shown in Table 2-10. The
slopes and intercepts of these regressions were
similar in 1991 and 1992. The metal-specific
regression slope and its associated 95%
confidence intervals were then compared to the
complete data set and all locations falling
above the 95% confidence interval represent
sites that are 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, mercury,
copper, lead and zinc (3 to 6% sediments),
(Fig. 2-68).
By comparison, the two methods yielded very
similar results with 80±8% of the sediments
meeting the criteria levels and 84±8% of the
sediments being "unenriched" (Figure 2-69).
While the overall picture is the same,
inspection of Fig. 2-68 shows some marked
differences. While zinc, tin, and nickel levels
exceed criteria values for 10 to 12% of
Statistical Summary, EMAP-E Louisianian Province -1992
Page 62
-------
Table 2-10. Relationship between sediment metal concentration and aluminum, using only those sites with levels below criteria
values. The significance level for all models was < .001. Model: ln(metal) = intercept + slopc*ln(Al)
Metal
Ag
As
Cd
Cr
Cu
Hg
Ni
Pb
Sb
Sn
Zn
criteria value
1
33
5
80
70
.15
30
35
2
3
120
1991
r2
.51
.61
.38
.84
.80
.50
.90
.90
.38
.79
.85
slope
.439
.574
.457
.611
.790
.435
.814
.695
.290
.608
.923
intercept
-2.650
1.015
-2.601
2.904
1.140
-3.447
1.512
1.747
-0.904
-0.582
2.625
1992
r2
.56
.67
.46
.77
.79
.39
.87
.93
.24
.63
.80
slope
.489
.630
.599
.660
.781
.401
.791
.665
.371
.753
.777
intercept
-2.873 *
0.874
-2.704
2.707
1.139
-3.833
1.531
1.623
-1.203 *
-0.902 *
2.859
r2 = the correlation coefficient for the linear model on the transformed data.
* = slope and intercept represent combined 91 and 92 data as individual year estimates were significantly different
sediments, aluminum-adjusted concentrations
show much reduced enrichment (2 to 5%).
Conversely, arsenic, cadmium, and copper
never exceed their criterion but based on
regressions with aluminum are enriched in 1 to
7% of Louisianian Province sediments.
2.2.11 SEDIMENT
CONTAMINANTS - BUTYLTINS
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 (Kelly et al. 1990). 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 continuing
environmental problem. Determination of
tributyltin was made for all sediments collected
in the 1991 Louisiaiiian Province
Demonstration with concentrations expressed
as ng (Sn)/g dwt. Only 29±10% of the
sediments analyzed showed no traces (0 ppb)
of TBT. Seventy-one percent (±10%) of the
sediments had concentrations of TBT > 0, with
3±3% having concentrations > 5 ppb (Fig. 2-
73). According to Laughlin et al. (1984), long-
term tests of tributyltin compounds on fish and
invertebrates suggest that the maximum
acceptable concentration for TBT would be < 1
ppb. Using 5 ppb as a clear indicator of
degraded conditions,! most of the high-TBT
sediments are found: in large tidal rivers
(20±24% of sediments) and to a lesser extent
Statistical Summary, EMAP-E Louisianian Province -1992
Page 63
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TRIBUTYLTIN
LOUISUWIAN PROVINCE 1M2
0 ppb
291111
5 ppb
3±3 s
1-5 ppb
68*3 i
Figure 2-73. Percent of area of the Lonisianian Province sediment
associated with tributyltin concentration categories in 1992.
TRIBUTYLTIN > 5 ppb
LOUISIANIAN PROVINCE 1992
5(H
40-
30-
o
0£
LU
Q.
LARGE RIVER SMALL
CLASS
Figure 2-74. Percent of area having sediments with tributyltin > 5
ppb for large estuaries, large tidal rivers, and small estuaries (bars
represent 95% confidence intervals).
TRIBUTYLTIN > 0 ppb
LOUISIANIAN PROVINCE 1992
LU
O
oe
LARGE RIVER SHALL
CLASS
Figure 2-75. Percent of area having sediments with tributyltin
> 0 ppb for large estuaries, large tidal rivers, and small
estuaries (bars represent 95% confidence intervals).
in small and large estuarine sediments (2+3%
and 3±5%, respectively) (Fig. 2-74). Using 1
ppb TBT as an indicator of potential ecological
effects results in all sampling classes being
represented with 100% of the sediments in
large tidal rivers, 67% of sediments in small
estuaries, and 74% of sediments in large
estuaries having measurable TBT (Fig. 2-75).
2.3 HABITAT INDICATORS
Habitat indicators describe the natural physical
and chemical conditions of the locations
sampled in the 1992 Louisianian Province
Demonstration. These parameters are
discussed below.
Statistical Summary, EMAP-E Louisianian Province < 1992
Page 64
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BOTTOM DEPTH
LOUISIANIAN PROVINCE 1902
o
a:
ui
100
BO
80
70-
60-
50-
40
30-
20-
10
OH
8 10 12
DEPTH (m)
H 16 18 20
Figure 2-76. Cumulative distribution of water depth in the Louisianinn Province in 1992 (-) and its associated 95% confidence interval (--).
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 1992
is shown in Fig. 2-76. The proportions of the
estuarine classes that have water depths of less
than three meters are shown in Fig. 2-77 with
large and small estuaries showing significant
expanses of shallow water (57±13% of large
estuaries and 99±1% 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
Demonstration. The total range of bottom
water temperature observed in July and August
spanned only eight degrees Celsius (Fig. 2-78)
DEPTH < 3 METERS
LOUISIANIAN PROVINCE 1992
UJ
ae
o
Ul
o.
LARGE
RIVER
CLASS
SMALL
Figure 2-77. Percent area of estuaries with water depth < 3m in
large estuaries, large tidal irivera, and small estuaries (bars represent
95% confidence intervals),1
Statistical Summary, EMAP-E Louisianian Province -1992
Page 65
-------
ui
ee
Of
ui
' V
20
BOTTOM TEMPERATURE
LOUISIANIAN PROVINCE 1982
T
22
24
-r
26 28
TEMPERATURE (C)
Figure 2-78. Cumulative distribution of water temperature in the Lonisianian Province in 1992 (-) and its associated 95% confidence interval
from 24°C to 32°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). However, 1992 was a very
wet year, particularly in early spring. As a
result, the Louisianian Province was
characterized by a wide variety of salinity
conditions. Salinity ranged from 0 to 38 ppt
throughout the province (Fig. 2-79).
Continuous salinity measurements did not show
any changes in the observed salinity range or
distribution. Oligohaline waters (0 to 5 ppt)
comprised 18±9% of the province estuarine
waters, mesohaline waters (5 to 18 ppt)
contributed 28±11%, while polyhaline waters
made up the majority of the resource at
54±11% (Fig- 2-80). As expected, the large
estuarine waters were primarily polyhaline in
1992 (Fig. 2-81). Large tidal rivers are
predominantly (89+23%) oligohaline, while
large and small estuaries are about 14 to 25%
oligohaline (Fig. 2-82). Almost all of the
oligohaline observations that comprise these
numbers come from locations within Louisiana.
The large tidal river class is equivalent to the
Mississippi River. Vermilion and East Cote
Blanche Bays (large estuaries in Louisiana)
were virtually fresh during sampling due to
increased drainage through the Atchafalaya
River system, the old drainage for the
Mississippi River. The remainder of large
estuarine systems are largely polyhaline while
small estuarine systems are predominantly
mesohaline (49±22%) (Fig. 2-83).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 66
-------
BOTTOM SALINITY
LOUISIANIAN PROVINCE 1982
100
80
80
70
60
50
40
30
20
10
0
12 18 24
SALINITY (ppt)
30
36
42
Figure 2-79. Cumulative distribution of bottom salinity in the Louisianian Province in 1992 (-) and its associated 95% confidence interval
BOTTOM SALINITY
LOUISIANIAN PROVINCE 1992
5-18 ppt
28±1U
> 18 ppt
54±11«
< 5 ppt
18*9 s
POLYHAL1NE WATERS
LOUISIANIAN PROVINCE 1992
Lul
O
LARGE RIVER SMALL
CLASS
Figure 2-80. Percent area of estuaries with oligohalinc, mesohaline, Figure 2-81. Percent area of estuaries with polyhaline salinities in
and polyhaline bottom waters in the Louisianian Province in 1992. large estuaries, large tidal rivers, and small estuaries (bars represent
95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 67
-------
TIDAL FRESH AND
OLIGOHALINE WATERS
LOUISIANIAN PROVINCE 1992
ui
o
LARGE RIVER SUALL
CLASS
Figure 2-82. Percent area of estuaries with oligohaline bottom
waters in large estuaries, large tidal rivers, and small estuaries (bars
represent 95% confidence intervals).
MESOHALINE WATERS
LOUISIANIAN PROVINCE 1992
o
a:
LARGE
RIVER
CQSS
SMALL
Figure 2-83. Percent area of estuaries with mesohaline bottom
waters in large estuaries, large tidal rivers, and small estuaries (bars
represent 95% confidence intervals).
2.3.4 pH
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 1992. Bottom pHs ranged
from 6.1 to 9.4 (Fig. 2-84) during the sampling
period in 1992 with all of the pH values < 7
occurring in large estuaries (Fig. 2-85).
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 bottom and oxygen-rich surface
waters. Results from the 1992 Louisianian
Province Demonstration show that stratification
salinity differences range from -5 to 22 ppt
often over only 2 to 3 m of water column (Fig.
2-86). 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 4±4% of the
estuarine waters in the province (Fig..2-86) and
is primarily seen in large estuaries and the
lower portions of large tidal rivers.
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
Statistical Summary, EMAP-E Louisianian Province 1992
Page 68
-------
BOTTOM pH
LOUISIANIAN PROVINCE 1992
100
00
80
70
60
50
40
30
20
10
0
8
pH
10
Figure 2-84. Cumulative distribution of bottom pH in the Louisianian Province in 1992 (-) and its associated 95% confidence interval (~).
LOU
100-
90-
80-
^ 70-
LU
% 60
g 50
£ 40
Q.
30-
20-
10-
o-
pH < 7.0
SIANIAN PROVINCE 1992
"T*
A
LARGE RIVER SMALL
CLASS
Figure 2-85. Percent area of estuaries with bottom waters with pH
< 7 in large estuaries, large tidal rivers, and small estuaries (bars
represent 95% confidence intervals).
Louisianian Province: is comprised of 29±10%
mud (> 80% silts and clays), 53±10%
intermediate muddy-sand (20-80% silts and
clays), and 18±8% sand (< 20% silts and
clays) (Fig. 2-87). This distribution also holds
for the three sampling classes with the
exception of large tidal rivers which have no
sand and 45±27% miiid (Figs. 2-88 through 2-
90).
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 enrichment, whether
naturally through detrital accumulation or
anthropogenically through point source
discharges. Based on the results of the 1992
Louisianian Province Demonstration, sediments
in the province range from nearly pure sand
(no organic carbon) to highly enriched
Statistical Summary, EMAP-E Louisianian Province -1992
Page 69
-------
STRATIFICATION
L0UISUNIAN PROVINCE 1992
100-j
90
80-j
70
60
50
40
30
20
10
0
-5
5 10 15
BOTTOM - SURFACE SALINITY (ppt)
20
25
figure 2-S6. Cumulative distribution of stratification in the Louisianian Province in 1992 (-) and its associated 95% confidence interval
PERCENT SILT-CLAY
LOUISIANIAN PROVINCE 1992
20-BQi
53±10i
>BO*
29±10i
Figure >S7. Percent area of estuaries in the Louisianian Province
usodBted with percent sjlt-day categories in 1992,
SIL
LOUI
100-
90-
80
< 70"
UJ
2s 60-
z 50-
I 40
a.
30-
20-
10-
o-
T-CLAY < 20%
SIANIAN PROVINCE 1992
1 1
j ^
LARGE RIVER SMALL
CLASS
figure z-HH. rercent area 01 csiuants yjiiii swwj i?"'1''^!!*3 fr
estuaries, large tidal rivers, and small estuaries (bars represent 95%
confidence intervals).
Statistical Summary, EMAP-E Louisianian Province ^ 1992
Page 70
-------
SILT-CLAY 20-80%
UHHSIANIAN PROVINCE 1892
UJ
o
LARGE
RIVER
CLASS
SMALL
Figure 2-89. Percent area of estuaries with mixed sediments in large
estuaries, large tidal rivers, and small estuaries (bars represent 95%
confidence intervals).
SILT-CLAY > 80%
LOUISANIAN PROVINCE 1992
CJ
ee
LLJ
LARGE RIVER SHALL
CLASS
Figure 2-90. Percent area of estuaries with muddy sediments in
large estuaries, large tidal rivers, and small estuaries (bars represent
95% confidence intervals).
sediments approaching 8% TOC (Fig. 2-91).
Low to normal orgjinic carbon content (0-1%)
was found in 53%±12% of province sediments,
28%±8% of the province was slightly enriched,
while 19%±8% was enriched to the extent of
producing a sediment that was > 2% TOC
(Fig. 2-91). No organically enriched sediments
were found in the large tidal rivers of the
province (Fig. 2-92). About 17 to 19% of the
sediments from large and small estuarine
systems have organic carbon content > 2%.
2.3.8 ACID VOLATILE SULFIDES
Acid volatile sulfides (AVS) measure the
amorphous or moderately crystalline
monosulfides in sediments that are important in
controlling the bioavailability of metals under
anoxic conditions (DiToro et al. 1991). AVS
in the Louisianian Province ranged from 0 to
20 micromoles AVS/ g dwt sediment (Fig. 2-
93). !-..
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,
et al (1993b). Table 2-11 provides/these
intervals for the major indicators.for the
proportion of the prpvince and the three
estuarine classes, i
Statistical Summary, EMAP-E Louisianian Province -1992
Page 71
-------
TOTAL ORGANIC CARBON
LOUISIANIAN PROVINCE 199,2
Figure 2-91. Cumulative distribution of percent organic carbon in sediments in the Louisianian Province in 1992 (-) and its, associated 95%
confidence interval (-).
TOTAL OF
LOUI
tQO-
IB-
8Q-
oc «n.
^ aw
| 40-
a.
35-
J
5GANIC CARBON >
SIANIAN PROVINCE; 1992
LARGE RIVER SHALL
CLASS
ocar
*/^
Rgnrc 2-S>2, Percent are* of estuaries \rtlK TQq ?> 2% in large
cstnariea, large tidd rivers, and small estuaries (bars represent. 95%
confldcncc intervals).
Statistical Summary, EMAP-E Louisianian Prdvime -1992
Page 72
-------
ACID VOLATILE SULFIDES
LOUISIANIAN PROVINCE 1992
8 10 12
AYS Otffloles/g dry wt)
14
16
T
18
T
20
Figure 2-93. Cumulative distribution of AVS in the Louisianian Province in 1992 (-) and its assodaSdft??, confidence interval (-).
Statistical Summary, EMAP-E Louisianian Province -1992
Page 73
-------
Paramttcr
N
Estuarine Condition
Province
100
36(11)
Large
Estuary
58
33(12)
Large
TidsjJ
River
10
100(17)
Small
Estuary
32.
42(25)
(% of Province showing degraded biological resources or impaired use.)
BIOTIC CONDITION
Dcnlhic Index
Abundance < 10
# Species < 2
H Species S 5
Ksh
Abundance < 2
Abundance S 5
# Species < 1
# Species < 2
Fish Pathology1
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
27(10)
15(9)
10(9)
21(10)
13(8)
20(9)
4(4)
11(8)
1(0)
0(0)
0(0)
1(1)
0(0)
5(5)
22(10)
6(5)
10(6)
24(11)
9(7)
3(5)
16(9)
14(9)
23(11)
5(6)
12(8)
1(0)
0(0)
0(0)
10)
0(0)
7(7)
24(11)
9(7)
12(8)
90(22)
20(21)
25(22)
70(26)
60(29)
90(26)
15(20)
40(29)
1(0)
0(0)
0(0)
0(0)
0(0)
0(0)
10(19)
30(22)
33(24)
30(26)
25(26)
33(26)
12(16)
13(16)
-------
Parameter
N
ABIOTIC CONDITION
Marine Debris
Water Clarity
PAR < 10%
PAR < 25%
Silt-Clay Content
<20%
>80%
Alkanes
Total > 7000 ppb
PAHs
Total > 4000 ppb
PCBs
Total > 200 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 > 33 ppm
Cd> 5 ppm
Cr > 80 ppm
Cu > 70 ppm
Hg > .15 ppm
Ni > 30 ppm
Pb > 35 ppm
Sb > 2 ppm
Sn> 3 ppm
Zn > 120 ppm
Tributyltin
TBT > 0 ppb
TBT > 5 ppb
Province
100
6(5)
12(7)
45(10)
18(8)
29(10)
9(6)
4(4)
0(0)
8(6)
34(11)
4(4)
<1(1)
2(3)
< KD
0(0)
0(0)
0(0)
4(4)
0(0)
1(2)
10(7)
3(3)
1(2)
10(7)
11(7)
71(10)
3(3)
Large
Estuary
58
7(7)
10(8)
29(12)
21(10)
33(12)
7(7)
5(6)
0(0)
5(6)
31(12)
5(6)
0(0)
2(3)
0(0)
0(0)
0(0)
0(0)
5(6)
0(0)
2(3)
12(8)
3(5)
2(3)
10(8)
12(8)
72(12)
3(5)
Large Smtdl
Tidal Estuairy
River
10
45(27)
30(29)
80(28)
0(0)
45(27)
60(29)
32
4(4)
17(14)
84(16)
11(10)
21(19)
13(13)
j
30(32) < 1(1)
0(0) 0(0)
85(20) 12(17)
100(0) 39(27)
45(30) 1(2)
10(22) < 1(1)
0(0) 1(2)
15(25) < 1(1)
0(0) 0(0)
0(0) 0(0)
0(0) 0(0)
0(0) 0(0)
0(0) 0(0)
0(0) ; < 1(1)
0(0) 6(9)
0(0) ; < 1(1)
0(0) 0(0)
0(0) 12(17)
0(0) 7(10)
100(0) j 67(23)
20(24)
2(3)
Table -2-11 Estimates of the proportion of the Louisianian Province and estuarine classes experiencing (he levels of
the listed parameters and their associated 95% confidence interval in parentheses (N = number of sampling sites).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page 75
-------
-------
SECTION 3
SUMMARY OF CONCLUSIONS
The Demonstration Project in the Louisianian
Province in 1992 produced thousands of pieces
of information about the estuarine resources of
the Gulf of Mexico and their present condition.
The following 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 km 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, Atehafalaya 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, Ciiioctawhatchee 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
km of which 43 were selected for sampling
in 1992. |
i
The total area of estuarine resources in the
Louisianian Province can be subdivided
among these threes estuarine classes: large
estuaries comprise km2 (72%), large tidal
rivers constitute 138 Ian2 (<1%), and small
estuaries make up km2 (28%). Thus,
province-wide conclusions, based on area!
weighting, will be dominated by information
from the large estuaries.
169 stations were selected for sampling
using multiple indicators of estuarine
condition (e.g., benthic abundance, fish
community composition, sediment
chemistry, sediment toxicity ).
10 selected sites could not be sampled due
to insufficient depth (< 1 m). In terms of
areal extent, these sites represent 7% of the
Statistical Summary, EMAP-E Louisianian Province -1992
Page 77
-------
estuarine resources in the province. The
majority of these unsampleable sites
occurred in the shallow zones of large
estuaries.
3.2 CONCLUSIONS OF THE 1992
SAMPLING
Nearly 36±11% of the Louisianian Province
estuarine resources were determined to be
degraded in terms of biotic integrity or
human use indicators. Seventeen percent of
the province experienced only low levels of
biotic integrity, 9±11% experienced either
marine debris or poor water clarity, and
10±6% experienced both forms of
degradation.
About 6±5% of the bottom sediments in
Louisianian Province estuaries were littered
with marine debris.
12±7% of the estuarine waters in the
province had poor water clarity with 99% of
these areas occurring w.est of the Mississippi
River Delta.
Estuarine sediments in the Louisianian
Province generally contained concentrations
of organic contaminants that were below
criteria values expected to result in
significant ecological effects. Some
contaminants were above these criteria for
3 to 9% of the sediments.
Louisianian Province sediments were shown
to be enriched with several heavy metals.
16±8% of Louisianian Province sediments
were enriched with at least one metal.
Three to six percent of sediments were
enriched with mercury, copper, arsenic,
lead, and zinc.
Metal enrichment was observed in large
estuarine resources.
Approximately 10±6% of the sediments in
the Louisianian Province (2050 km^) proved
to be toxic to tested estuarine organisms.
Nearly 30+22% of the Mississippi River
sediments were toxic while 12±8% of
sediments and 4±6% of small estuary
sediments were toxic.
Tributyltin was measurable in 71±11% of
Louisianian Province sediments; however
only 3±3% of sediments had concentrations
£ 5 ppb.
The edible portions of shrimp, Atlantic
croaker, and catfish contained contaminant
concentrations below FDA limits for PCBs,
pesticides, and mercury. Shrimp, croakers
and catfish contained levels of arsenic,
cadmium, mercury and selenium in their
edible tissues that was higher than
international standards. One to four percent
of croaker and marine catfish contained
cadmium levels above 0.5 ppm, 15% of
marine catfish contained arsenic
concentrations above 2 ppm, and 1% of
marine catfish exceeded 1 ppm mercury.
Concentrations of selenium greater than 1
ppm were observed in 4% of shrimp and
2% of marine catfish.
Statistical Summary, EMAP-E Louisianian Province -1992
Page 78
-------
SECTION 4
REFERENCES
Agius, C. 1979. The role of melano-macrophage centers in iron storage in normal and diseased fish
J. Fish Dis. 2:337-343.
Agius, C. 1980. Phylogenetic development of melano-macrophage centers in fish. J Zool London
191:111-132. I
Agius, C. and Roberts, RJ. 1981. Effects of starvation on the melano-macrophage centers in fish J
FishBiol. 19:161-169. j
j
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. j
Blazer, V.S., J.W. Fournie, L.A. Courtney, J.K. Summers. 1993. Evaluation of piscine macrophage
aggregates as biomarkers of estuarine environmental degradation. Diseases of Aquatic Organisms
(submitted).
Boesch, D.F. and R. Rosenberg. 1981. Response to steess in marine benthib communities. Pages
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Chapman, P.M. 1988. Marine sediment toxicity tests. In: J.J. Lichtenberg,:F.A. Winter, C.I. Weber
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i
DiToro, D.M., J.D. Mahony, DJ. Hansen, KJ. Scott, A.R. Carlson, G.T. Apkley. 1991. Acid
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i
Ellis, A.E., Munro, A.L.S., and Roberts, RJ. 1976. Defense mechanisms in fish. I. A study of the
phagocytic system and the fate of intraperitoneally injected paniculate material in plaice
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Engle, V.D., J.K. Summers and G.R. Gaston. 1993. A benthic index of environmental condition of
Gulf of Mexico estuaries. Estuaries (in press)
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. ;
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Management5:55-68.
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Estuarine, Coastal and Shelf Science 12: 629-643.
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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
' NOS OMA 52. US Department of Commerce, National Oceanic and Atmospheric Administration,
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Lasserre and J.M. Martin, eds. Biogeochemical Processes at the Land-sea Boundary Elsevier, NY.
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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.
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Statistical Summary, EMAP-E Louisianian Province -1992 Page 82
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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 is 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 those described in
Appendix A 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 exists 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.
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=52) to a
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.1
-------
high for Mississippi of approximately 20 to
30% (N=9). 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=3), the
corresponding variance estimates are also small
(see Table A-l). The reduced variance and
95% confidence interval are due to the extreme
similarity of the collected data from the three
sites and the heavy weighting associated with a
single site. Therefore, estimates for
Mississippi showed uncertainties of 20 to 30%
while estimates for Alabama show uncertainties
of only 3 to 4%.
A.I.I BENTHIC INDEX
The construction of the benthic index is
described in Summers et al. (1993b) and Engle
et al. (1993). The cumulative distribution
function for the benthic index in Mississippi
and Texas are shown in Figures A-l and A-2.
About 27+26% of the estuarine sediments in
Mississippi contained benthic communities
similar to those observed at known
environmentally degraded sites (Fig. A-3). The
highest proportion of degraded benthic
communities within the Gulf states in 1992
were 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
BENTHIC INDEX
MISSISSIPPI 1992
Benthic Index
Figure A-l. Distribution of benthic index values in the estuarine resources of Mississippi (-) with 95% confidence intervals (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.2
-------
BENTHIC INDEX
TEXAS 1992
CtL
«C
J
a:
tu
o_
100
90
80
70
60
50
40
30
20
10
10
12
Benthic Index
Figure A-2. Distribution of benthic index values in the estnarine resources of Texas (-) with 95% confidence intervals (--)
BENTHIC INDEX
MISSISSIPPI 1992
INDEX 4-6
14±34*
INDEX < 4
27±26«
INDEX > 6
59±37x
BENTHIC INiDEX < 4.0
o
O£
UJ
Q-
TX
Figure A-3. Proportion of Mississippi estuarine resources with
benthic index values in selected categories.
Figure A-4. Proportion of Gulf states' estnarine resources with
benthic index values < 4.0 (bars represent 95% confidence intervals).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page A.3
-------
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
18±11% of the estuarine waters in Louisiana
produced one or fewer species in a single 10-
min trawl (Fig. A-7). Thirteen (±26) to
18±10% of the estuarine waters in Louisiana
and Mississippi were characterized by these
small numbers of species (Fig. A-8).
NEKTON SPECIES RICHNESS
LOUISIANA 1902
-i - r
4 fi a 10 12 H
NUMBER OF SPECIES (per travU
1B 2J>
Figaro A-5. Distribution of number offish species per trawl in the estuarine resources of Louisianan (-) with 95% confidence intervals (-).
NEKTON SPECIES RICHNESS
TEXAS 1892
-I-
6 8 10 12 H
NUMBER OF SPECIES (per trn»l)
It
18
figure A-6. Distribution of number of fish species per trawl in the estnarine resources of Texas (-) with 95% confidence intervals (-).
Statistical Summary, EMAP-E Louisianian Province -1992 Page A.4
-------
NEKTON SPECIES RICHNESS
LOUISIANA 1992
1 SPECIES
SPECIES
12111s
0 SPECIES
516 x
Figure A-7. Proportion of Louisiana estuarine resources with number
of fish species per trawl in selected categories.
NUMBER OF NEKTON
SPECIES =£ 1
50
FL AL MS LA TX
STATE
Figure A-8. Proportion of Gulf states' estuarine resources with
number of fish species per trawl £ 1 (bars represent 95% confidence
intervals).
MARINE DEBRIS
TX
Figure A-9. Proportion of Gulf steles' estuarine resources with marine
debris present in bottom segments (bars represent 95% confidence
intervals). ;
A.1.3 MARINE DEBRIS
i
i
The presence of marine debris is one of the
obvious indicators of estuarine "degradation"
from a human use perspective. Over 85% of
the estuarine sediments in Alabama contained
marine debris with about 7% of Florida and
10% 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
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.5
-------
WATER CLARITY
LOUISIANA 1692
0.0 0.1 02 03 0.4 0.5 0.6
o a o.s i o
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 (~).
tu
=
100
90
BO
70
BO
50
40
30
20-
10
PAR < 1 0%
FL
AL
MS
STATE
LA
TX
Figure A-ll. Proportion of Golf states' estuarine resources with
percent surface light reaching a depth of one meter < 10% (bars
represent 95% confidence intervals).
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 (24±12%) and Texas
(3±6%) (Fig. A-ll).
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 23±20%
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
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.6
-------
shown in Figures A-13 through A-16 for
Alabama, Mississippi, Louisiana and Texas and
ranged from 14±26% degraded estuarine area
in Mississippi to 86±3% in Alabama.
ECOLOGICAL CONDITIONS
FLORIDA 1992
lipalrid Uie
7±18«
Deprodtd Biology
Figure A-12. Proportion of estuarine resources having degraded
biology, impaired use, or both problems in Florida.
ECOLOGICAL CONDITIONS
MSSI9SIPPI1992
Dtgrodtd Blolog-
Ik 14±28«
Figure A-14. Proportion of estuarine resources having degraded
biology, impaired use, or both problems in Mississippi.
ECOLOGICAL CONDITIONS
ALABAMA 1992
lipolred Use
B6±J *
Undigrndid
H±3 i
ECOLOGICAL CONDITIONS
LOUISIANA 1992
Degraded Biology
1711OK
Inpalrid Un
12±13«
Both
!5±10«
Undejraded
56i13n
Figure A-13. Proportion of estuarine resources having degraded
biology, impaired use, or both problems in Alabama.
Figure A-15. Proportion of estuarine resources having degraded
biology, impaired use, or both problems in Louisiana.
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.7
-------
ECOLOGICAL CONDITIONS
TEXAS 1992
Degraded Biology
Inpalrid U*i
2±27i
Both
10±H*
Undograded
65i27*
Figure A-16. Proportion of cstuarine resources having degraded
biology, impaired use, or both problems 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.
The cumulative distribution function of bottom
dissolved oxygen in Florida estuaries is shown
in Figure A-17. All Gulf states experienced
100
oo
BO-
70
60
50
40
30-1
20
10
0
BOTTOM DISSOLVED OXYGEN
FLORIDA 1002
4 6
DISSOLVED OXYGEN (ppn)
10
12
Figure A-17. Distribution of instantaneous dissolved oxygen in bottom waters in the estuarine resources of Florida (-) with 95% confidence
intervals (--).
Statistical Summary, EMAP-E Louisianian Province 1992
Page A.8
-------
BOTTOM DISSOLVED
OXYGEN < 5 ppm
TX
Figure A-18. Proportion of Gulf states' estuarine resources with
instantaneous dissolved oxygen concentration < 5 ppm in bottom
waters (bars represent 95% confidence intervals).
BOTTOM DISSOLVED
OXYGEN < 2 ppm
FL
IX
Figure A-19. Proportion of Gulf states' estuarine resources with
instantaneous dissolved oxygen concentration < 5 ppm in bottom
waters (bars represent 95% confidence intervals).
DO conditions < 5 ppm but Alabama,
Mississippi and Florida predominated with
almost 23 to 92(±3 to 34)% of their resources
below this figure (Fig. A-18). All dissolved
concentrations < 2 ppm were primarily
observed in Mississippi and Florida (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. Continuous bottom DO
concentrations in Louisiana ranged from 0 to
12 ppm (Fig. A-20). Minimum dissolved
oxygen concentrations below 2 ppm were most
often observed in Mississippi (Fig. A-21).
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 ibxicity 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 (20±20%) and Texas
(13±17%) estuarine waters (Fig. A-23).
Statistical Summary, EMAP-E Louisianian Province - 1992
PageA.9
-------
BOTTOM DISSOLVED OXYGEN
MISSISSIPP11992
Ul
Qu
-i r
6 8
DISSOLVED OXYGEN (ppn)
10
12
14
Figure A-2G. Cumulative distribution of continuous dissolved oxygen in the cstuarine resources of Louisiana (-) with 95% confidence
Intervals (--)
MINIMUM D.O. < 2 ppm
100-
90-
80-
70-
1 so-
S 50-
£ 40-
O_
30-
20-
10-
0-
.
T 1
1 J
/
FL AL MS LA TX
STATE
figure A-21. Proportion of Gulf states' cstuarine resources with dissolved oxygen minima < 2 ppm in bottom waters (bars represent 95 %
confidence intervals).
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.10
-------
AMPELISCA - SEDIMENT TOXICITY
FLORIDA 1992
100
90
80
-c 70
L*J
^ eo
£ 50
LU
a.
30
20
10-
0-
10
20
40
50
60 70
« Surclval (Control-Corrected)
of Ampelisco obdi tn
Fignre A-22. Distribution of toxicity of estnarine sediments in Honda to amphipods (-) with 95% confidence intervals (-).
AMPELISCA MORTALITY > 20%
100
90
80
AL MS LA TX
FL
figure A-23. Proportion of Gulf states' estuarine sediments with toxicity to amphipods resulting in < 80% survival (bars represent 95%
contidence intervals). I r
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.11
-------
A.2.4 ALKANESAND
ISOPRENOroS
Alkanes and isoprenoids are contaminants
associated primarily with the petroleum
industry and uses of its products. The
continuous distribution function for total
alkanes and isoprenoids for Florida ranges
from 0 to 21,000 ppb (Fig. A-24). Total
alkane concentrations exceeding 7000 ppb in
sediments were located only in Florida
(16±18%), Louisiana (11±8%) and Texas
(7±13%) (Fig. A-25).
TOTAL ALKANES > 7000 ppb
50-f
FL
TX
Figure A-25. Proportion of Gulf states' estuarine sediments with total
alkanes concentrations > 7000 ppb (bars represent 95% confidence
intervals).
TOTAL ALIPHATIC HYDROCARBONS
FLORIDA 1992
6.9 12
TOTAL ALIPHATIC HYDROCARBONS {ppb x 1000}
21
-24. Distribution of total aliphatic hydrocarbons in estuarine sediments of Florida (-) «* 95% confidence Interval t-
Statistical Summary. EMAP-E Louisianian Province -1992
-------
A.2.5 POLYNUCLEAR AROMATIC
HYDROCARBONS
Forty three individual polynuclear aromatic
hydrocarbons (PAHs) were analyzed from
collected Louisianian Province sediments. The
distribution of total C3-fluorene is shown in
Fig. A-26 and ranges from 0.1 to 267 ppb/g
dwt in Louisiana. Total PAH concentrations
exceeding 4000 ppb (the concentration
resulting in ecological effects 10% of the time)
were found in sediments of small estuaries in
Florida (14±18%), Louisiana ( < 1±0%) and
Texas (7±13%) (Fig. A-27).
TOTAL PAHs > 4000 ppb
50
FL All MS LA TX
Figure A-27. Proportion of Gulf states' estuarine sediments with total
PAH > 4000 ppb (based on 43 PAHs) (bars represent 95% confidence
intervals).
C3-FLUORENE
LOUISIANA 1992
CJ
o±
UJ
O.
80
120 150 180
C3-FLUORENE (ppb)
2+D
270
300
Figure A-26. Distribution of c3-fluorene in estuarine sediments of Louisiana (-) with 95% confidence intervals (--).
Statistical Summary, EMAP-E Louisianian Province - 1992
Page A.13
-------
A.2.6 POLYCHLORINATED
BIPHENYLS
Twenty polychlorinated biphenyl (PCB)
congeners were analyzed from the Louisianian
Province sediments. Concentrations of total
PCBs in Florida ranged from 2 to 14 ppb (Fig.
A-28). Given that the criterion for low-level
ecological effects are 400 ppb for total PCBs,
no PCB concentrations exceeded these criteria
in any of the Gulf states.
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 in shown in Fig. A-
29 ranging from 0 to 9 ppb. Most of the high
levels of TBT (> 5 ppb) were seen in Florida
estuaries (15±10%) while some sediments in
Texas (8±13%) and Louisiana (7±8%)
contained high levels of TBT (Fig. A-30).
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 of the Gulf states (Fig. A-31).
100-
90-
80
70-
60-
50-
40
30
20
10
0
TOTAL PCBs
FLORIDA 1992
i - 1 - 1 - -r - 1
10 15 20 25 30
TOTAL PCBs (ppb)
35
40
45
50
Figure A-28. Distribution of total PCBs in estuarine sediments of Florida (-) with 95% confidence intervals (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.14
-------
TRIBUTYLTIN
TEXAS 1992
LU
Q.
04.
I | i 1 I 1
10 15 20 25 30 35
TRIBUTYLTIN (ppti)
40
50
Figure A-29. Distribution of tributyltin in estuarine sediments of Texas (-) with 95% confidence internals (--).
TRIBUTYLTIN > 5 ppb
o
40-
30
20
10-
±U
AL
MS
STATE
LA
TX
TRIBUTYLTIN > 1 ppb
TX
Figure A-30. Proportion of Gulf states' estuarine sediments with Figure A-31. Proportion of Gnll?statos estuarine sediments with TBT
TBT > 5 ppb (bars represent 95% confidence intervals). > 1 ppb (bars represent 95% confidence intervals).
Statistical Summary, EMAE-E Louisianian Province -1992
Page A.15
-------
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. The cumulative distribution
function for dieldrin in Texas is shown in
Figure A-32. None of the pesticides exceeded
the 50% Long and Morgan criteria; however,
several pesticides exceeded the 10% criteria.
Dieldrin was found exceeding 0.02 ppb in 6 to
43% the estuarine sediments of Gulf States
(Fig. A-33).
DIELDRIN > ,02 ppb
FL
Figure A-33. Proportion of Gulf states' estnarine sediments with dieldrin
> 0.02 ppb (bars represent 95% confidence intervals).
DIELDRIN
TEXAS 1992
o
O2
0.0
0.2
0.4
0.6
DIELDRIN (ppb)
O.B
1.0
Figure A-32. Distribution of dieldrin in estuarine sediments of Texas (-) with 95% confidence intervals (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.16
-------
A.2.9 HEAVY METALS
Fifteen heavy metals were analyzed for the
sediments collected in 1992. Examining the
metal concentrations based on Long and
Morgan criteria, several heavy metals exceeded
the 10% criteria. The cumulative distribution
function of mercury in Texas sediments is
shown in Figure A-34. The proportion of
estuarine sediments in each of the Gulf states
that exceeded 0.15 ppm mercury (10%
criterion) is shown in Figure A-35. The
percentage of estuarine area in each state that
exceeded the 10% Long and Morgan criteria
for each analyzed metal are shown in Figures
A-36 to A-40.
MERCURY > .15 ppm
50
40-
30-
LLJ
O
20-
10-
FL AL| MS LA
I
I STATE
TX
Figure A-35. Proportion of Gull'states' estuarine sediments with mercury
> 0.15 ppb (bars represent 95 %j confidence intervals).
MERCURY
TEXAS 1992
100
90
80
70
60
50-
40
30
20-
10-
0-
0
J
0.1
0.2 0.3
MERCURY (ppm}
0.4
0.5
Figure A-34. Distribution of mercury hi estuarine sediments of Texas (-) with 95% confidence intervals (--).
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.17
-------
% METALS > L&M 1 0% CRITERIA
FLORIDA 1992
100-
eo-
80-
-c 70'
Ul
^ 60-
z 50-
Ul
£ 40-
ui ^"
Q.
30-
20-
10-
0-
Ag As Cd Cr
Cu Pb Hg
METAL
Flgnre A-36. Proportion of Florida's estnarine sediments with heavy metals concentrations in excess of Long and Morgan 10% criteria
(ban represent 95% confidence intervals).
% METALS > L&M 10% CRITERIA
ALABAMA 1992
100
90
80
60-
x. 50
Ul
30
20
10
0
Ag As Cd Cr Cu Pb Hg Hi Sb Sn Zn
METAL
Figure A-37. Proportion of Alabama's estuarine sediments with heavy metals concentrations in excess of Long and Morgan 10% cr
There Is no error associated with these estimates because the estimates are heavily weighted by a single station.
Statistical Summary, EMAP-E Louisianian Province -1992
Page A.18
-------
% METALS > L&M 10% CRITERIA
100-
90-
80-
< 70~
UJ
'5 60-
£ 50-
UJ
£ 40-
CL.
30-
20-
10-
0-
1
1
MISSISSIPPI 1992
;
Ag As Cd Cr Cu Pb Hg Ni
METAL
Sb Sn In
Figure A -38. Proportion of Mississippi's estuarine sediments with heavy metals concentrations in exceiis of Long and Morgan 10% criteria
(bars represent 95% confidence intervals).
% METALS > L&M 1 0% CRITERIA
100-
90-
80-
^ 7°:
UJ
% 60-
z 50-
|t|i)
CJ
£ 40-
Q.
' 30-
20-
10-
0-
-
LOUISIANA 1992
Ag Ai Cd Cr Cu Pb Hg Ni
METAL
Sb Sn In
Figure A-39. Proportion of Louisiana's estuarine sediments with heavy metals concentrations in excess of Long and Morgan 10% criteria
(bars represent 95% confidence intervals). ,
Statistical Summary, EMAP-E Louisianian Province - 1992
Page A.19
-------
te
-<
*-
2:
C3
as
«T
a.
100-
90-
80-
60-
50-
40-
30-
20-
10-
0-
% METALS > L&M 10% CRITERIA
irms 1992
T T
I f j
I ill
1 1 1 1
Ag As Cd Cr Cu Pb Hg HI Sb 5n Zn
METAL
Figure A-40. Proportion of Texas' estaarine sediments with heavy metals concentrations in excess of Long and Morgan 10 % criteria (bars
represent 95% confidence intervals).
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 al (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 Louisianmn Province -1992
Page A.20
-------
Parameter Florida Alabama
:S 16 3
Estuarine Condition 23(20) 86(3)
Biotic Condition
Benthic Index i6(18) 0(Q)
Abundance < 10 I4(ig) 6(4)
* Species < 2 7(13) 0(0)
# Species < 5 i6(18) fi(4)
Fish
Abundance < 5 22(22) 0(0)
Abundance < 10 35(24) 0(0)
# Species < 1 7(14) 0(Q)
# Species < 2 0(0) 0(0)
Fish Pathology < 1(0) 84(0)
Fish Contaminants1
Shrimp
All > FDA Limits 0(0) 0(0)
Croaker
All >,FDA Limits 0(0) 0(0)
Marine Catfish
Hg > FDA Limits 0(0) 0(0)
Others > FDA Limits 0(0) 0(0)
Bottom DO2 < 2 ppm 7(14) 0(0)
Bottom DO2 < 5 ppm 23(27) 92(3)
Minimum DO < 2 ppm 7(14) 0(0)
Sediment Toxicity 20(20) 0(0)
j Percentage based on sample size rather than estuarine area
Instantaneous dissolved oxygen measurements
Mississippi
9
14(26)
14(26)
0(0)
0(0)
0(0)
13(26)
40(37)
0(0)
13(26)
27(33)
0(0)
0(0)
0(0)
0(0)
26(34)
26(34)
26(34)
0(0)
Louisiana
52
44(13)
| 32(13)
7(7)
3(4)
12(9)
25(12)
37(14)
5(6)
18(10)
23(11)
0(0)
0(0)
1(1)
0(0)
2(5)
18(11)
5(6)
| 8(7)
Texas
20
35(27)
33(27)
31(18)
24(13)
46(23)
14(17)
27(21)
<1(1)
<1(1)
49(30)
0(0)
0(0)
0(0)
0(0)
<1(1)
16(18)
<1(1)
13(17)
Statistical Summary. EMAP-E Louisianian Province -1992
Page A.21
-------
amncter
N
Abiotic Condition
Marine Debris3
Water Qarity
PAR < 10%
PAR < 25%
Silt-Clay Content
<20%
>80%
Alkancs
Total > 7000 ppb
PAHs
Total > 4000 ppb
PCBs
Total > 200 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 > 33 ppm
Cd > 5 ppm
Cr > 80 ppm
Cu > 70 ppm
Hg > .15 ppm
Ni > 30 ppm
Pb > 35 ppm
Sb>2ppm
So > 3 ppm
Zn > 120 ppm
Tributyltin
TBT > 1 ppb
TBT > 5 ppb
3 Estimate based on
Florida
16
7
0(0)
39(21)
45(24)
9(14)
16(18)
14(18)
0(0)
0(0)
32(16)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
7(13)
0(0)
0(0)
7(13)
7(13)
0(0)
7(13)
0(0)
39(21)
15(10)
presence-absence so 95%
Alabama
3
86
0(0)
8(3)
8(3)
84(0)
0(0)
0(0)
0(0)
0(0)
6(4)
0(0)
0(0)
84(0)
0(0)
0(0)
0(0)
0(0)
84(0)
0(0)
0(0)
84(0)
0(0)
0(0)
84(0)
84(0)
84(0)
0(0)
confidence intervals
Mississippi
9
0
0(0)
34(33)
26(34)
26(33)
0(0)
0(0)
0(0)
0(0)
26(33)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
13(26)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
0(0)
13(26)
0(0)
are not calculated.
Louisiana
52
3
24(12)
50(14)
7(7)
39(14)
11(8)
<1(0)
0(0)
15(10)
42(14)
5(6)
<1(0)
0(0)
<1(1)
0(0)
0(0)
0(0)
0(0) --
0(0)
< 1(0)
16(10)
0(0)
0(0)
9(7)
13(9)
53(14)
7(8)
Texas
20
10
3(6)
40(13)
17(19)
27(21)
7(13)
7(13)
0(0)
2(3)
43(22)
8(13)
1(2)
1(1)
1(3)
0(0)
0(0)
0(0)
0(0)
0(0)
7(13)
0(0)
7(13)
7(13)
16(18)
15(18)
31(26)
8(13)
Tabfc MfanA) Estimates of the proportion of the individual Gulf states experiencing the listed parameters and their
anoclatod 95% confidence intervals in parentheoes (N = number of sampling sites).
Statistical Summary. EMAP-E Louisianian Province -1992
Page A.22
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