LAKE ERIE
LAKE WIDE
MANAGEMENT
PLAN
Lake Erie Lake wide Management Plan (LaMP)
Technical Report Series
Impairment Assessment of Beneficial Uses:
Restrictions on Fish and Wildlife Consumption
Lauren Lambert
1998
Lake Erie LaMP Technical Report No. 2
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Technical Report 2
Restrictions on Fish And Wildlife Consumption
Prepared for the Lake Erie LaMP
Preliminary Beneficial Use Impairment Assessment
Lauren Lambert
July 1998
NOTE TO HI! READER:
This technical report was prepared as one component of Stage 1, or "Problem Definition,"
for the Lake Erie LaMP. This report provides detailed technical and background
information that provides the basis for the impairment conclusions recorded in the Lake
Erie LaMP Status Report.
This document has been extensively reviewed by the government agencies that are
partnering to produce the LaMP, outside experts, and the Lake Erie LaMP Public Forum,
a group of approximately of 80 citizen volunteers. This review was designed to answer
two questions:
• Is the document technically sound and defensible?
• Do the reviewers agree with the document conclusions and format?
In its present form, this report has been revised to address the comments received during
that review process, and there is consensus agreement with the impairment conclusions
presented.
2.1 Fish Consumption Restrictions
2.1.1 Listing Criteria
According to the International Joint Commission (IJC), fish consumption restriction
impairments occur when contaminant levels in fish exceed current standards, objectives or
guidelines, or when public health advisories are in effect for human consumption of fish or
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wildlife (IJC, 1989).
2.1.2 Scope of the Assessment
The geographic scope of the Lake Erie LaMP beneficial use impairment assessment
(BUIA) includes open lake waters, nearshore areas, river mouths and embayments, and
the lake effect zone of Lake Erie tributaries. The lake effect zone is defined as that zone
where the waters of the lake and tributary river are mixed. Detroit River impairments in
the Lake Erie LaMP will be evaluated on a case by case basis and will be included where
relevant to potential impacts in Lake Erie.
It is recognized that the reasons for Lake Erie sport fish consumption advisories and the
severity of some advisories, particularly those caused by mercury, has changed since the
1970s. However, this document does not address changes in advisories over time, nor
does it attempt to analyze what these changes tell us about improvement or lack of
improvement in the contaminant situation in the lake. The sole purpose of this assessment
it to identify impairments due to fish and wildlife consumption advisories in existence
today.
Current sport fish and wildlife consumption advisories and commercial fishing restrictions
are covered, as applicable, in this assessment. Fish consumption advisories are applicable
to sport fish and are recommended consumption levels to protect human health. The
choice of which fish to consume, how frequently, how much, and how to prepare the fish
for consumption remains the choice of the individual consumer. In contrast, commercial
fishermen are prohibited from catching certain species and size classes of fish when
contaminant levels are judged to be a risk to human health. These commercial fishing
restrictions are enforceable standards and are therefore mandatory.
Per the listing criteria, existing objectives and guidelines are also outlined in sections 2.1.4
and 2.2.2 and evaluated as they apply to impairment conclusions in sections 2.1.6 and
2.2.3.
2.1.3 Purpose of Sport Fish Consumption Advisories
According to a 1995 State of the Lakes Ecosystem Conference Report, there are a
number of pathways by which humans in the Great Lakes basin can be exposed to
persistent toxic contaminants. The major route of human exposure to PCBs, dioxins,
furans, organochlorine pesticides, and certain heavy metals is food consumption,
particularly consumption of contaminated fish (USEPA/EC, 1995) . People who
regularly eat sport fish, women of childbearing age, and children are particularly
susceptible to contaminants that build up over time (PADEP, 1996).
The purpose of sport fish consumption advisories is to protect human health by minimizing
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human exposure to chemical contaminants present in fish tissue. Sport fish consumption
advisories are issued as educational tools designed to assist sport fish consumers in
making consumption choices to protect their health. The goal is to: a) identify the
geographic locations where fish are affected, b) inform the fish consumer of fish
species/size classes that are known to be prone to contain higher levels of chemical
contaminants, c) offer recommendations on suggested frequency of consumption, and d)
provide recommendations on preparation and cooking techniques that reduce the risk of
exposure to toxic contaminants. The choice of which fish to consume, how frequently to
consume, and how to prepare remains with the individual.
The presence of mercury in fish has been of particular concern because it accumulates in
the tissue of the fish rather than the fat. Food preparation methods such as trimming fat
and skin, and broiling rather than frying do not reduce exposure to mercury. Therefore,
the only effective options to minimize exposure to mercury present in fish tissue are to
follow fish consumption advisories and to avoid eating the internal organs of the fish
(Mortimer, 1996).
2.1.4 Fish Consumption Advisory Criteria and Objectives
Bi-national Objectives
Two binational organizations have established objectives for fish consumption in the Great
Lakes, the International Joint Commission (IJC) and the Great Lakes Fishery Commission.
The IJC, through Annex 1 of the Great Lakes Water Quality Agreement (GLWQA),
developed specific objectives for concentrations of persistent toxics in fish flesh. A
number of these contaminant thresholds were chosen as objectives with the aim of
protecting human consumers of fish from the Great Lakes. These objectives are
summarized in table 2.1.
Table 2.1, GLWQA Objectives for Contaminant Levels in Great Lakes Fish Flesh (IJC,
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1988).
Chemical
CI.W Q.\ Object no
Aldrin/Dieldrin
Sum of concentrations of aldrin & dieldrin in edible portions of fish should not
exceed 0.3 microgram/gram (wet weight basis)
Endrin
Concentration in edible portion of fish should not exceed 0.3 microgram/gram
(wet weight basis)
Heptachlor/Heptachlor
epoxide
Sum of concentrations of heptachlor & heptachlor epoxide in edible portions of fish
should not exceed 0.3 microgram/gram (wet weight basis)
Lindane
Concentration in edible portions of fish should not exceed 0.3 microgram/gram
(wet weight basis)
Unspecified Organic
Compounds
For other organic contaminants, for which specific objectives have not been defined
(by GLWQA), but which can be demonstrated to be persistent and are likely to be
toxic, the concentrations of such compounds in water or aquatic organisms should
be substantially absent, i.e., less than detection levels as determined by the best
scientific methodology available.
In 1993, the IJC established an "Indicators for Evaluation" Task Force to identify
indicators to evaluate Great Lakes Water Quality Agreement Progress. In 1996 the IJC
Task Force identified 9 desired outcomes for the Great Lakes Basin Ecosystem. The first
desired outcome states: "Safe for Fishing: There shall be no restrictions on the human
consumption offish in the waters of the Great Lakes Basin Ecosystem resulting from
human inputs of persistent toxic substances" (IJC, 1996).
The Great Lakes Fishery Commission directed its Lake Committees to prepare fish
community objectives for each of the Great Lakes. Among the fish community objectives
developed by the Lake Erie Committee is the following: "Reduce contaminants in all fish
species to levels that require no advisory for human consumption and no detrimental
effect on fish-eating wildlife, fish behavior/productivity andfish reproduction" (emphasis
added, Lake Erie Fish Community Goals and Objectives, 1997).
Regional Advisory Protocol
In September 1993, a Great Lakes Sport Fish Advisory Task Force, composed of
representatives from public health, environmental or natural resource agencies from the
eight states bordering the Great Lakes (New York, Pennsylvania, Ohio, Michigan,
Indiana, Illinois, Wisconsin, and Minnesota), submitted a proposed protocol for a uniform
sport fish consumption advisory for the Great Lakes Basin to the Council of Great Lakes
Governors. Other participants have included the Canadian Province of Ontario, the
USEPA, and Native American organizations.
The foundation of the proposed protocol is the premise that the current Food and Drug
Administration (FDA) tolerances for market fish are not adequately protective of public
health, particularly for consumers of sport fish. Recent angler surveys have found that the
frequency of fish consumption among anglers far exceeds the frequencies assumed by the
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FDA when they established the tolerances. In addition, anglers tend to concentrate their
fishing in specific geographical locations which eliminates the nationwide contaminant
dilution factor assumed in FDA tolerance setting.
The Task Force chose to focus the advisory protocol on PCBs, the chemical contaminant
most frequently encountered in Great Lakes fish. The advisory uses a weight-of-evidence
derived individual health protection value (HPV) of 0.05ug/kg/day for PCB residue
ingested from fish tissue. The HPV is intended to encompass acceptable cancer and
reproductive/developmental risk. A risk analysis shows that this protection value is
reasonable and within the margins of exposure for no observed adverse effect levels
(NOAEL) for both laboratory animal and human effects (Great Lakes Sport Fish Advisory
Task Force, 1993).
Although not all Lake Erie jurisdictions have adopted the Task Force's specific proposed
guidance for establishing fish consumption advisories, all jurisdictions do include fish
cooking and cleaning guidelines very similar, if not identical, to those found in the 1993
Proposed Protocol for a Uniform Great Lakes Sport Fish Consumption Advisory. These
guidelines: a) emphasize the importance of removing fat prior to cooking and discarding
any fat drippings prior to consumption to reduce the risk of exposure to organochlorines;
b) point out which types of fish are more likely to accumulate contaminants; and c) point
out that mercury is found in the muscle and cannot be removed. Therefore, the amount of
fish eaten must be reduced to reduce exposure to mercury.
U.S. Federal
In September 1995, the U.S. Fish & Wildlife Service completed a Great Lakes Fishery
Resources Restoration Study. This study was conducted as a requirement of Section
2005 (a) of the Great Lakes Fish and Wildlife Restoration Act, P.L. 101-537. The study
concludes that "when viable and productive stocks of native and other desired fish species
are available, bald eagles successfully reproduce and inhabit shoreline, mink and otter once
again claim their habitat, chemical and other stress-induced deformities in fish and wildlife
are eliminated, and fish and wildlife can be consumed with little or no risk to human
health, then restoration goals for the Great Lakes Basin will have been met (emphasis
added, USFWS, 1995)."
Michigan
Michigan's fish consumption advisory program was initiated in 1970 with the discovery of
elevated mercury levels in fish from the St. Clair River, Lake St. Clair, the Detroit River,
and Lake Erie. As of 1996, the Michigan Department of Public Health (MDPH) has been
using the list of contaminants and associated trigger levels shown in Table 2.2 to establish
consumption advisories.
Table 2.2 Contaminant/Trigger Levels Used to Establish Fish Consumption Advisories For
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Michigan and
Vew York (MDPH, 1996; NYSDH, 1995-1996).
Chemical
Michigan
New York
Chlordane
0.3 ppm
0.3 ppm
DDT
5.0 ppm
5.0 ppm
Dieldrin
0.3 ppm
0.3 ppm
Dioxin
10.0 ppt (total TEQs are used for all
dioxins/furans)
10.0 ppt (total TEQs are used for all 2,3,7,8- chlorine
substituted dioxins and furans)
Endrin
0.3 ppm
0.3 ppm
Heptachlor
0.3 ppm
0.3 ppm (heptachlor/heptachlor epoxide)
Mercury
0.5 ppm (total mercury)*
1.0 ppm (total mercury) *
Mirex
0.1 ppm
0.1 ppm (mirex/photomirex)
PCB
2.0 ppm
2.0 ppm
Toxaphene
5.0 ppm
5.0 ppm
N/A = Not Applicable
ppm = parts per million
* For mercury, the FDA tolerance of 1.0 ppm is based on methyl mercury. New York and Michigan use total mercury
since fish contain mercury primarily in the methylated form.
For any of the organic contaminants (including PCBs, DDT, chlordane, dieldrin,
dioxin, and others), when between 11 and 49 percent of samples exceed a MDPH trigger
level, a "restrict consumption" advisory is issued. When 50 percent or more exceed a
trigger level, a "no consumption" advisory is issued. Attempts are made to provide size
specific advice wherever possible. For mercury, fish tissue mercury levels falling in the
range of 0.5 to 1.5 ppm are placed in the "restrict consumption" advisory category. Fish
tissue with mercury levels exceeding 1.5 ppm are placed in the "no consumption"
category. When data are too limited to judge the necessity for an advisory, but where
some indication of contamination exists, an advisory is usually not issued but additional
samples are requested (MDPH, 1996).
New York
In New York State, contamination of fish by mercury to levels in excess of FDA action
levels was discovered in late 1969 and early 1970. The first fish consumption advisories
were established in 1971 (NYSDEC, 1985). The New York State Department of Health
(NYSDH) uses the list of contaminants and associated trigger levels shown in Table 2.2 to
establish fish consumption advisories.
Ohio
The Ohio Department of Health (ODH) issues fish consumption advisories with input
from the Ohio Environmental Protection Agency (OEPA) and the Ohio Department of
Natural Resources (ODNR). Ohio uses a modified version of the protocol for a Uniform
Great Lakes Sport Fish Consumption Advisory to establish fish consumption advisories
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for PCBs, mercury, and lead. Use of this protocol is based on different criteria for each of
the three contaminants, as shown in Table 2.3. Table 2.4 details the levels of PCBs,
mercury and lead that govern the meal frequency advice for each advisory issued in Ohio.
Table 2.3 Criteria for Establishing Fish Consumption Advisories in Ohio for PCBs, Lead,
and Mercury (ODH, 1997)
PCBs
Mercury
I ,ead
Health Protection Value = 0.05 ug
PCB/kg/day
Reference Dose (RfD) = 0.1
ug/kg/day
Provisional Total Tolerable Daily
Intake (PTTD) = 6 ug lead/day
Average Meal = 227 grams/8
ounces (uncooked fish)
Average Meal = 227 grams/8
ounces (uncooked fish)
Average meal = 113.4 grams/4 ounces
(uncooked fish)
Representative target consumer is a
70 kg adult.
Representative target consumer is
a 70 kg adult.
Representative target consumer is a
child, 0-6 years in age.
Five advisory meal rates:
unrestricted (225/yr); 1/wk;
1/mo; 6/yr; none
Two advisory meal rates: 1/month
; none
Five advisory rates: unrestricted
(225/yr); 1/wk; 1/mo; 6/yr; none
Assume skinning/
trimming fat/ cooking
reduces PCB residues by 50%
from raw, skin-on fillet
Skinning/trimming fat/cooking
does not reduce mercury residues.
Skinning/trimming fat/cooking does
not reduce lead residues.
Pennsylvania
Fish tissue contaminant issues in Pennsylvania are addressed by an interagency workgroup
consisting of representatives of the Department of Health, the Fish and Boat Commission,
and the Department of Environmental Protection (PADEP, 1996). Monitoring of toxic
pollutants in Pennsylvania fish tissue began in 1976. This effort includes both special
studies and routine monitoring.
Pennsylvania is using the Proposed Uniform Great Lakes Fish Advisory Protocol for PCBs
in Lake Erie and the Presque Isle Bay Area of Concern (AOC). Table 2.4 details the
levels of PCBs that govern the meal frequency advice for each Lake Erie associated
advisory issued in Pennsylvania.
Ontario
The Ontario Ministry of Environment and Energy (OMEE) develops fish consumption
advisories for Ontario based on research and review of toxicological data. Health Canada
has established human "tolerable daily intakes" for an extensive list of contaminants. It is
then determined what proportion of the tolerable daily intake can come from each of the
environmental pathways (e.g. air, water, different types of food) including sport fish
consumption. It is assumed that the average-sized adult consumes 227 g (8 ounces) of
fish per meal (OMEE, 1995-1996). Specific levels of PCBs, dioxins, mercury, mirex,
DDT and toxaphene that govern meal frequency advice for Ontario are summarized in
Table 2.4.
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Table 2.4, Contaminant Levels in Raw Fish Fillets Related to Meal Advice Given for Ohio, Pennsylvania, and Ontario (Estenik,
OF.P.V 1006. Ohio Dcptii'inicni ofTTeiillli. 100/. Si\ arajall. P.YDTT.
006. TToudl. OMT.F.. 1005. Co\ uiul Yaillancouil. OMT7.
Type of Advisory
Chemical
Concentration lor ()hio
Concentration for ()nlario
Concentration lor Pennsylvania
DO NOT EAT
PCBs
> 1.900 ppm
> 4.0 ppm
> 1.90 ppm
Six Meals/Year
PCBs
1.001 - 1.900 ppm
N/A
1.1 - 1.9 ppm
One Meal/Month
PCBs
0.301 - 1.000 ppm
2.0- 4.0 ppm*
0.31 - 1.0 ppm
Two Meals/Month
PCBs
N/A
1.0 - 2.0 ppm
N/A
One Meal/Week
PCBs
0.051 - 0.300 ppm
0.50 - 1.0 ppm
0.06 - 0.30 ppm
Unrestricted
PCBs
0 - 0.050 ppm
<0.50 ppm *****
0-0.05 ppm
DO NOT EAT
Mercury**
> 1.00 ppm
> 1.5 ppm ****
N/A
One Meal/Month
Mercury**
0.201 - 1.00 ppm
N/A
N/A
Two Meals/Month
Mercury**
N/A
1.0 - 1.5 ppm
N/A
One Meal/Week
Mercury**
0.051- 0.200 ppm
0.5 - 1.0 ppm
N/A
Unrestricted
Mercury**
0 - 0.0500 ppm
<0.5 ppm*****
N/A
DO NOT EAT
Dioxins***
N/A
80.4 ppt
N/A
One Meal/Month
Dioxins***
N/A
40.2 - 80.4 ppt*
N/A
Two Meals/Month
Dioxins***
N/A
20.1 - 40.2 ppt
N/A
One Meal/Week
Dioxins***
N/A
10.1 -20.1 ppt
N/A
Unrestricted
Dioxins**
N/A
< 10.1 ppt *****
N/A
DO NOT EAT
Mirex/photomirex
N/A
> 0.56 ppm
N/A
One Meal/Month
Mirex/photomirex
N/A
0.28-0.56 ppm*
N/A
Two Meals/Month
Mirex/photomirex
N/A
0.14-0.28 ppm
N/A
One Meal /Week
Mirex/photomirex
N/A
0.07 -0.14 ppm
N/A
Unrestricted
Mirex/photomirex
N/A
<0.07 ppm *****
N/A
DO NOT EAT
DDT
N/A
5.0 ppm
N/A
DO NOT EAT
Toxaphene
N/A
>1.6 ppm
N/A
One Meal/Month
Toxaphene
N/A
0.8 - 1.6 ppm*
N/A
Two Meals/Month
Toxaphene
N/A
0.4 -0.8 ppm
N/A
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Type of Advisory
Chemical
Concentration lor ()hio
Concentration for ()nlario
Concentration lor Pennsylvania
One Meal/Week
Toxaphene
N/A
0.2 - 0.4 ppm
N/A
Unrestricted
Toxaphene
N/A
<0.2 ppm *****
N/A
One Meal/Month
Lead
0.373 - 1.069 ppm
N/A
N/A
One Meal/Week
Lead
0.087 - 0.372 ppm
N/A
N/A
Unrestricted
Lead
0 - 0.086 ppm
N/A
N/A
* Women of childbearing age and children under 15 in Ontario are advised not to consume fish in the one meal per month category.
** Women of childbearing age and children less than 6 years old in Ohio are
is the contaminant causing the advisory.
advised not to consume more than 1 meal per month when mercury
*** For toxicity equivalents of 2, 3, 7, 8 TCDD
**** Ontario has an advisory for mercury for subsistence fishermen. If the concentration of mercury is 0.2 ppm or higher, it is recommended that
subsistence fishermen do not eat the catch.
***** In Ontario, the unrestricted category was based on survey results that indicate the average sports fisherman eats no more than 8 meals of sport
fish per month.
N/A = Not Applicable;
ppm - parts per million; ppt = parts per trillion
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2.1.5 Status
There is a commercial fishing restriction due to PCBs on carp that are 32 cm or greater in
Ontario waters of Lake Erie (Hendzel, 1996). A summary of existing sport fish
consumption advisories, by jurisdiction and Lake Erie basin, is provided in Table 2.5.
In reviewing Table 2.5, it is important to keep the following points in mind.
• All fish species do not accumulate contaminants at the same rate due to differing
feeding habits, habitats, growth rates, and physiology. For example, when testing fish
for mercury in a specific area, the practice is initially to select those species which are
top predators, as they will usually indicate the highest mercury levels likely to be found.
In testing for organic contaminants such as PCBs and mirex, species with high fat
levels such as salmon, lake trout, smelt, and perch, are selected since organic chemicals
usually tend to accumulate in fatty tissue (OMEE, 1995-1996).
• Bottom feeders such as carp and channel catfish are often used as an indication of the
contaminant content of bottom sediments. Carp and channel catfish are also good
indicators of contaminant concentrations because they are fatty and long-lived.
• Certain subsets of overall fish consumers are at greater risk of adverse impacts due to
contaminant exposure. These groups are women of childbearing age, children under
15 years of age, certain cultural and immigrant groups, and subsistence anglers.
Certain cultural and/or immigrant groups include Great Lakes fish as a staple in their
diet and traditional food preparation may include eating the fat and organs. Initial
surveys show that certain cultural and immigrant groups may be eating up to 3 meals
per week of Great Lakes fish (Mortimer, 1996).
• Risk assessment methods are more widely used in establishing advisories, providing
more detailed information to the sport fish consumer than has been available in the
past. A list of the chemical parameters that each Lake Erie jurisdiction routinely
monitors in sport fish tissue is included in Appendix 2A.
• There are human contact advisories in effect for segments of the Ottawa and Black
Rivers that fall within AOC boundaries. In the case of the Black River, the reason
for the contact advisory is PAHs, whereas the reason for the fish consumption
advisories is PCBs. For the Ottawa River, both the fish consumption advisories and
the contact advisory are due to PCBs.
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Table 2.5 Summary of Lake Erie Related Sport Fish Consumption Advisories (MDPH, 1996; NYSDOH, 1996; ODH, 1997; ODNR,
1996; OMEE, 1995-1996; PADEP 1996) *
Location/Basin
Fish Species/Size Affected
Details of Advisory/Numbers of Meals
Suggested
Cause(s) of Advisory
/.. 1KE ERIE OI'EX /CI TERS
/.. 1 KE ERIE ORES /CI TERS
/.. 1 KE ERIE OREX /CI TERS
/.. 1 KE ERIE OI'EX /CI TERS
Lake Erie (all Michigan waters)/Western
Basin
Carp, channel catfish
DO NOT EAT
PCBs
Lake Erie (all Ohio waters)/Western and
Central Basins
All Species
For women of childbearing age and
children age 6 and under: One Meal Per
Week (52 meals/year)
This is a general precautionary
advisory which is in place for all Ohio
freshwaters. It has been issued to
avoid excess exposure to mercury
which is present at low background
levels in nearly all Ohio fish samples
tested.
Lake Erie (all Ohio waters)/Western and
Central Basins
Walleye, freshwater drum, chinook
salmon under 19"
One Meal Per Week (52 meals/year)
PCBs
Lake Erie (all Ohio waters)/Western and
Central Basins
Carp under 20", white perch,
steelhead trout, coho salmon,
chinook salmon 19" and over, small
mouth and white bass
One Meal Per Month (12 meals/year)
PCBs
Lake Erie (all Ohio waters)/Western and
Central Basins
Carp 20" and over, channel catfish,
lake trout
Six Meals Per year (1 meal 12 months)
PCBs
Lake Erie (all Pennsylvania
waters)/Central and Eastern Basins
Walleye under 23", freshwater drum
One Meal Per Week (52 meals/year)
PCBs, Chlordane
Lake Erie (all Pennsylvania
waters)/Central and Eastern Basins
Walleye over 23", coho salmon*
steelhead (rainbow trout)*,
smallmouth bass, white perch, white
bass, lake whitefish, carp under 20"
One Meal Per Month (12 meals/year)
PCBs
Lake Erie (all Pennsylvania
waters)/Central and Eastern Basins
Carp over 20", lake trout, channel
catfish
One Meal Every Two Months (6
meals/year)
PCBs
/.. 1KE ERIE OI'EX 11.1 TERS
/.. 1KIC ERIE OI'EX 11.1 TERS
/.. 1 KE ERIE OI'EX 11.1 TERS
/.. 1 Kl¦: ERIE OI'EX 11.1 TERS
12
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Location/Basin
Fish Species/Size Affected
Details of Advisory/Numbers of Meals
Suggested
Cause(s) of Advisory
Lake Erie (all New York waters)/Eastern
Basin
All Species
One Meal Per Week (52 meals/year)
This is a general precautionary
advisory which is in place for all New
York State freshwaters. It has been
issued to avoid excessive exposure to
contaminants which may be present
but have not yet been measured.
Lake Erie (Ontario Western Basin Waters)
Coho salmon (22-26"/55-65 cm),
small mouth bass (14-18735-45
cm), whitefish (22-26755-65 cm),
white bass (12-14730-35 cm, carp
(18-22745-55 cm), freshwater
drum (14-18735-45 cm)
Four Meals Per Month
PCBs
Lake Erie (Ontario Western Basin Waters)
White bass (14-18735-45 cm), carp
(22-30755-75 cm)
Two Meals Per Month
PCBs
Lake Erie (Ontario Western Basin Waters)
Channel catfish (12-22730-55 cm),
carp (>30"/>75 cm)
One Meal Per Month***
PCBs (both species); Dioxin
(catfish);
Lake Erie (Ontario Central Basin Waters)
White bass (14-18735-45 cm), carp
(18-26745-65 cm), channel catfish
(12-14730-35 cm)
Four Meals Per Month
PCBs
Lake Erie (Ontario Central Basin Waters)
Carp (26-30765-75 cm)
Two Meals Per Month
PCBs
Lake Erie (Ontario Central Basin Waters)
Channel catfish (14-22735-55 cm)
One Meal Per Month***
PCBs
Lake Erie (Ontario Eastern Basin Waters)
Coho salmon (26-30765-75 cm),
lake trout (22-26755-65 cm),
walleye (26-30765-75 cm), white
bass (14-18735-45 cm), channel
catfish (26" and above/65 cm and
above), freshwater drum (18-
22745-55 cm)
Four Meals Per Month
PCBs (Coho salmon, lake trout,
channel catfish)Mercury (walleye
and white bass, freshwater drum
fJ7'."N7m\ 11. [SIX TRIM T. [R1ES
IVKSTERX 11. [SIX TRIM T. [R1ES
IVKSTERX 11. [SIX TRIM T. [R1ES
IVKSTERX 11. [SIX TRIM T. [R1ES
Maumee Bay, Ohio**
Carp
Six Meals Per Year (1 meal 2 months)
PCBs
m-ximx />'. isix trim t. mu-:s
in-x/mx />'. isix trim t. iries
IVKSTERX 11. [SIX TRIM T. [R1ES
IVKSTERX 11. [SIX TRIM T. [R1ES
Maumee Bay, Ohio**
Channel catfish
DO NOT EAT
PCBs
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Location/Basin
Fish Species/Size Affected
Details of Advisory/Numbers of Meals
Suggested
Cause(s) of Advisory
Maumee River, Ohio, All Waters **
Carp, smallmouth bass
One Meal Per Month (12 meals/year)
PCBs (carp), mercury (smallmouth
bass)
Maumee River, Ohio, Waterville to the
Indiana Border**
Channel Catfish
One Meal Per Week (52 meals/year)
PCBs
Maumee River, Ohio, Mouth to
Waterville**
Freshwater Drum, Largemouth Bass
One Meal Per Week (52 meals/year)
PCBs
Maumee River, Ohio, Mouth to
Waterville**
Channel Catfish
DO NOT EAT
PCBs
Ottawa River, Ohio, from 1-475 N. of
Wildwood Preserve Toledo to Maumee Bay,
Lake Erie**
All species
DO NOT EAT
PCBs
Portage River, Ohio Turnpike to Lake
Erie**
Largemouth bass, smallmouth bass
One Meal Per Week (52 meals/year)
Lead, PCBs
Portage River, Ohio Turnpike to Lake
Erie**
Carp, channel catfish
One Meal Per Month (12 meals/year)
PCBs
Sandusky River, Ohio, All Waters**
Carp
One Meal Per Week (52 meals/year)
PCBs
Sandusky River, Ohio, All Waters**
Channel catfish, largemouth bass
One Meal Per Month (12 meals/year)
PCBs, mercury
Detroit River (MI advisory)
Carp
DO NOT EAT
PCBs
Detroit River (MI advisory)
Freshwater drum over 14"
One Meal Per Week (52
meals/year);Nursing mothers, pregnant
women, women who intend to have
children, and children under age 15, One
Meal Per Month (12 meals/year)
Mercury
Lower Detroit River (Ontario advisory)
Walleye (22-26755-65 cm), channel
catfish (12-18730-45 cm), carp (14-
18735-45 cm)
Four Meals Per Month
PCBs (carp, channel
catfish)Mercury (walleye)
Lower Detroit River (Ontario advisory)
Carp (18-22745-55 cm)
One Meal Per Month***
PCBs
Lower Detroit River (Ontario advisory)
Carp (22-26755-65 cm)
DO NOT EAT
PCBs
a i:su:i<\ u isix trim t. irii:s
a i:sh:i<\ u isix trim t. irii:s
a i:sh:i<\ u isix trim t. irii:s
a i:sh:r\ r isix trim t. irii:s
River Raisin, Michigan, downstream from
Carp, white bass over 11"
DO NOT EAT
PCBs
14
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Location/Basin
Fish Species/Size Affected
Details of Advisory/Numbers of Meals
Suggested
Cause(s) of Advisory
Winchester Bridge
(i:\lKM. 11.ISIX Tin in T. IRIES
('EXTR.il. 11. ISIX TRIM T. IRIES
('EXTRA!. 11. ISIX TRIM T. IRIES
(¦EXTR.il. 11. ISIX TRIM T. IRIES
Black River, Ohio, from 31st Street Bridge,
Sheffield to Lake Erie**
Brown bullhead, freshwater drum
One Meal Per Week (52 meals year)
I'CBv
Black River, Ohio, from 31st Street Bridge,
Sheffield to Lake Erie**
Carp
One Meal Per Month (12 meals/year)
PCBs
Cuyahoga River, Ohio, Ohio Edison Dam
Pool to Lake Erie**
White sucker under 11",
One Meal Per Week (52 meals/year)
PCBs
Cuyahoga River, Ohio, Ohio Edison Dam
Pool to Lake Erie**
Carp, white sucker 11" and over,
largemouth bass
One Meal Per Month (12 meals/year)
PCBs (carp, white sucker), mercury
(largemouth bass)
Cuyahoga River, Ohio, Ohio Edison Dam
Pool to Lake Erie**
Brown and yellow bullhead
Six Meals Per Year (1 meal/2 months)
PCBs
Chagrin River, Ohio, All Waters**
Rock bass, smallmouth bass
One Meal Per Month (12 meals/year)
Mercury, Lead
Ashtabula River from 24th St. Bridge,
Ashtabula, Ohio to Lake Erie**
Smallmouth bass
One Meal Per Week (52 meals/year)
PCBs
Ashtabula River from 24th St. Bridge,
Ashtabula, Ohio to Lake Erie**
Largemouth bass, walleye
One Meal Per Month (12 meals/year)
Mercury, PCBs
Ashtabula River from 24th St. Bridge,
Ashtabula, Ohio to Lake Erie**
Channel catfish, carp
Six Meals Per Year (1 meal/2 months)
PCBs
Conneaut Creek, Ohio, All Waters**
Smallmouth bass
One Meal Per Month (12 meals/year)
Mercury
Rondeau Bay, Ontario
Large mouth bass (14-18735-45
cm), channel catfish (14-18735-45
cm), carp (18-26745-65 cm),
freshwater drum (14-18735-45 cm)
Four Meals Per Month
PCBs (Channel catfish,
carp)Mercury (Large mouth bass,
freshwater drum)
Rondeau Bay, Ontario
Cap (26-30765-75 cm)
Two Meals Per Month
PCBs
/•;. isterx ii. isix trim t. iries
/•;. isterx n. isix trim t. hues
/•;. ISTERX11. ISIX TRIM T. IRIES
/•;. ISTERX 11. ISIX TRIM T. IRIES
l'K-.i|ik- 1 .le |!:i\. IVmis\ l\ailia
Largemouth bass, walleye
One Meal Per Week (52 Meals Year)
PC I}n
/•;. isterx n. isix trim t. iries
/•;. ISTERX11. ISIX 7Rill! T. IRIES
/•;. ISTERX 11. ISIX TRIM T. IRIES
/•;. ISTERX 11. ISIX TRIM T. IRIES
Buffalo River/Harbor, New York
Carp (all consumers); all other fish
species (women of childbearing age,
infants and children under the age of
DO NOT EAT
PCBs
15
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Location/Basin
Fish Species/Size Affected
Details of Advisory/Numbers of Meals
Suggested
Cause(s) of Advisory
Long Point Bay, Ontario
15)
Coho salmon (22" and above/55 cm
and above), lake trout (22-26755-65
cm), walleye (26" and above/65 cm
and above), white bass (14-18735-
45 cm), white sucker (22-26755-65
cm), bowfin (18-26745-65 cm)
Four Meals Per Month
PCBs (Coho salmon, lake trout,
white bass)Mercury (walleye, white
sucker, bowfin)
Long Point Bay, Ontario
Carp (26-30765-75 cm), freshwater
drum (18-22745-55 cm)
Two Meals Per Month
PCBs (Carp)Mercury (Freshwater
drum)
Long Point Bay, Ontario
Freshwater drum (22-26755-65 cm)
DO NOT EAT
Mercury
* The Pennsylvania advisory states: "salmon and trout are migratory. They may be found seasonally in Presque Isle Bay or Lake Erie tributary streams. Trout,
salmon, and other fish that have lived in Lake Erie, whether caught in the lake or elsewhere should be treated as Lake Erie fish".
** Low background levels of mercury were found in nearly all fish tissue samples tested from various Ohio bodies of water. Therefore, women of childbearing age
and children 6 years and under are advised to eat not more than one meal per week of any species of fish from any Ohio body of water.
*** Women of childbearing age and children under 15 are advised not to consume fish in Ontario's one meal per month category.
16
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2.1.6 Summary of Fish Consumption Restriction Impairment Conclusions
Impairment to human consumption of Lake Erie fish is occurring. Fish consumption
restriction impairments occur when contaminant levels in fish exceed current standards,
objectives or guidelines, or public health advisories are in effect for human consumption of
fish or wildlife.
Public health advisories for human consumption of sport fish are in place for many
geographic locations within Lake Erie waters (see Table 2.5). The presence of
contaminants in Lake Erie, which are the basis for these advisories, exceed the Lake Erie
Committee (LEC) draft objective related to fish consumption advisories. The goal of this
objective is to "reduce contaminants in all fish species to levels that require no advisory
for human consumption. ..." Similarly, the presence of fish consumption advisories does
not meet the IJC objective of no restrictions on the human consumption of fish in waters
of the Great Lakes Basin Ecosystem.
A summary of Lake Erie/Lake Erie tributary fish consumption impairments and the
associated causes is included in Table 2.6. The species most commonly affected are carp,
channel catfish, and freshwater drum. The most common cause of a sport fish
consumption advisory/commercial catch restriction in Lake Erie, regardless of its severity,
is PCBs. The second most common cause of a sport fish consumption advisory is
mercury. Fish consumption advisories based on levels of lead, chlordane, and dioxins are
occurring in localized areas.
Bioaccumulation makes PCBs in fish especially hazardous to humans. Some PCBs in the
body retain biological activity after exposure stops. Bioaccumulated PCBs appear to be
more toxic than commercial PCBs and appear to be more persistent in the body. For
exposure through the food chain, risks can be higher than for other exposures
(U SEP A/U SDH&HS - AT SDR, 1996).
DO NOT EAT consumption advisories are in effect for certain species/size classes of
fish in Lake Erie, Maumee and Long Point Bays, the Maumee, Detroit, Raisin, and Rouge
River AOCs, and the Buffalo River/Harbor area. Human contact advisories are also in
effect for the segments of the Black and Ottawa Rivers that fall within AOC boundaries.
Human contact advisories are issued by the Ohio Department of Health and mean that it is
not safe to go into the waters in these areas.
17
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-------
Table 2.6, Summary of Sport Fish Consumption Advisories and Causes by Lake Erie Basin.
Location/Geographic Extent of Impairment
W. Basin Nearshore
W. Basin Offshore
C. Basin
Nearshore
C. Basin Offshore
E. Basin Nearshore
E. Basin
Offshore
Impaired.
Fish advisories for
Maumee. Portage.
Sandusky. Raisin.
Rouge. Detroit, and
()tla\\ a River
tributaries and
Maumee Bay.
Impaired
Fish advisories for
Lake 1 irie w aters of
all jurisdictions
bordering this basin.
Impaired.
Fish advisories for
Black, Cuyahoga,
Ashtabula. Chagrin
River and Conneaut
Creek tributaries
and Rondeau Bay.
Impaired.
Fish advisories for
Lake 1 irie w aters of
all jurisdictions
bordering this basin.
Impaired.
Fish advisories for
Presque Isle Bay,
Buffalo
River/I I arbor and
Long Point Bay.
Impaired.
Fish advisories for
Lake 1 irie w aters
of all jurisdictions
bordering this
basin.
Causes of Impairment - PCBs, mercury, lead, chlordane, and dioxins.
19
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2.1.7 Emerging Issues
An important issue related to potential routes of contaminant transfer to fish may be
emerging in Ohio nearshore waters of the central basin. Round goby populations, an
exotic species, have exploded within the last two years in the Grand River Harbor, Ohio
portion of the Lake Erie central basin (exclusive of the Grand River proper). Round
gobies feed principally on zebra mussels (approximately 80% of their diet) and compete
with sculpins and crayfish for habitat. Smallmouth bass primarily feed on sculpins and
crayfish, but with the abundance of round gobies in their feeding territory, smallmouth
bass are now preying on round gobies. This appears to have led to dramatic increases in
smallmouth bass populations in the Grand River Harbor nearshore area of Lake Erie.
It has been noted that smallmouth bass in Grand River Harbor have greater body burdens
of PCBs than smallmouth bass in other Ohio EPA Lake Erie fish tissue samples. Tissue
analysis of smallmouth bass from the Grand River Harbor areas has yielded the highest
concentrations of PCBs measured by the Ohio EPA for this species in Lake Erie waters.
The Grand River Harbor nearshore is relatively contaminant free, especially in comparison
to Ohio's four AOCs. Therefore, there is concern that the rate of PCB bioaccumulation, in
certain species which prey on round gobies, may increase in more contaminated areas
when round goby ranges expand (Thoma, 1996).
However, it is currently difficult to use the above-mentioned limited data to make
definitive statements about the implications of these findings. These higher contaminant
levels may be a result of late season sampling or the larger size of the fish examined to
date. Larger sized smallmouth bass are more frequently observed in this area. It should
also be noted that Ohio Department of Natural Resources monitoring of smallmouth bass
in offshore waters of the central basin near the Grand River Harbor indicates that
smallmouth are not currently consuming gobies in offshore waters (Ohio Sea Grant,
1996). Therefore, whatever dynamic is occurring between smallmouth and round gobies
is currently limited to the nearshore zone.
Further research is needed to determine the details of how and to what extent
contaminants are being transferred to smallmouth bass. This research needs to look at
PCBs and other contaminants and identify whether contaminants are approaching levels of
concern for human consumption.
Because most of the existing Lake Erie sport fish consumption advisories are based on the
presence of unacceptable levels of PCBs in fish tissues, there is the suggestion that once
the issue of PCB contamination is resolved, the resulting beneficial use impairment will be
eliminated. However, because of the analytical costs involved, most agencies only target
the contaminant currently responsible for consumption restrictions. Unfortunately, there is
likely to be a series of underlying contaminant restrictions, so that once the most
predominant chemical declines, the next one on the scale moves up the priority list. This
20
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issue will need attention, before fish consumption advisory restrictions are lifted (Estenik
and Whittle, 1996).
Research is underway to quantify the levels of microcystin present in fish tissue collected
in areas where the 1996 Microcystis bloom occurred. Microcystin is a potent liver toxin.
In addition to evaluating the effect of microcystin levels on fish health, the results of the
current research will identify whether microcystin is present in fish tissue at levels that
impact the health of human consumers (Culver, 1996).
2.2 Wildlife Consumption Restrictions
2.2.1 Listing Criteria
According to the International Joint Commission wildlife consumption restriction
impairments occur when contaminant levels in wildlife populations exceed current
standards, objectives, or guidelines, or public health advisories are in effect for human
consumption of wildlife (IJC, 1989).
2.2.2 Scope of the Assessment
The geographic scope of the Lake Erie LaMP beneficial use impairment assessment
(BUIA) includes open lake waters, nearshore areas, river mouths and embayments, and
the lake effect zone of Lake Erie tributaries. The lake effect zone is defined as that zone
where the waters of the lake and tributary river are mixed. Detroit River impairments in
the Lake Erie LaMP will be evaluated on a case by case basis and will be included where
relevant to potential impacts in Lake Erie.
2.2.3 Wildlife Consumption Restriction Criteria and Objectives
Wildlife contaminant level research in the Great Lakes has been extensive. However,
much of this research has focused on wildlife contaminant levels as they relate to wildlife
health, not human health. For example, in New York contaminant levels standards have
been established to protect the health of pisciverous wildlife (NYDEC, 1987). Recently,
the issue of contaminant levels as related to hormone mimics and endocrine disruptors in
all Great Lakes species has gained increasing attention. With this interest, there has been a
similar interest in contaminant levels in wildlife that are consumed by humans and the
potential associated human health impacts.
Existing criteria, objectives, and research results that pertain to contaminant levels in
wildlife consumed by humans is outlined below.
21
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U.S. Federal
In September 1995 the U.S. Fish & Wildlife Service completed a Great Lakes Fishery
Resources Study. This study was conducted as a requirement of Section 2005 (a) of the
Great Lakes Fish and Wildlife Restoration Act, P.L. 101-537. The study concludes that
"when viable and productive stocks of native and other desired fish species are available,
bald eagles successfully reproduce and inhabit shoreline, mink and otter once again claim
their habitat, chemical and other stress-induced deformities in fish and wildlife are
eliminated, andfish and wildlife can be consumed with little or no risk to human health,
then restoration goals for the Great Lakes Basin will have been met (emphasis added,
USFWS, 1995)."
Local Lake Erie Jurisdictions
With the exception of New York, none of the Lake Erie jurisdictions have established any
criteria for implementing wildlife consumption restrictions.
2.2.4 Wildlife Contaminant Level Studies
Canada and Michigan have done research to evaluate the potential need for wildlife
consumption advisories in game species of waterfowl. Ohio has research underway to
evaluate the potential need for consumption advisories for snapping turtles. Summaries of
these research efforts are provided below.
2.2.4.1 Canadian Wildlife Service Survey
In 1988 a national survey of contaminants in waterfowl and other game birds was
developed and initiated to address the question of whether or not birds harvested in
Canada, particularly Ontario and Quebec were safe to eat. See Appendix 2C for a map
showing the general boundaries of the areas surveyed.
The objectives of the study were:
1) To provide a comprehensive data base on contaminants in waterfowl to Health
Canada so that the risk to human health of eating those waterfowl may be
assessed, and so that consumption guidelines may be issued, if necessary.
2) To provide information to consumers on the levels of toxic chemical residues in
waterfowl, and to make recommendations for further work to complement the
information presently available.
The intensive survey for the province of Ontario occurred during 1990-91 and 602
specimens representing 19 species of waterfowl and one other harvested species were
22
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collected. Species chosen to be analyzed for contaminant residues were chosen to
represent the waterfowl most frequently shot by hunters. Collection of 10 birds per
species per location, representative of the hunted population, was requested in most
locations. Birds were collected during the regular fall hunting season, except in areas of
native hunting.
Since human health implications of consuming waterfowl were of primary concern, breast
muscle, as representative of the edible portion of waterfowl, was targeted for chemical
analysis. During sample preparation, all birds were examined for lead shot embedded in
the tissue and any fragments found were removed. Samples of breast muscle were
analyzed for moisture and lipid content, organochlorines, PCBs (both Arochlor 1254:1260
& congener specific basis), total mercury (Hg), Cadmium (Cd), Lead (Pb), arsenic (As)
and selenium (Se). Selected pools of samples were also analyzed for dioxins (PCDDs)
and furans (PCDFs). Samples were analyzed on a pooled basis (ideally 5-10 birds per
pool) for each species collected from each sampling site within a specified time period.
Therefore, the residue values are representative of the average value for the pool and there
is no estimate of variation among birds in the pool.
A summary of survey information for areas relevant to the Lake Erie LaMP is included in
Table 2.7.
Those species which feed at the top of the food chain contained the highest levels of
contaminants. The exception to this was lead, where elevated lead levels were measured
in a variety of species due to undetected fragments of lead shot left embedded in the flesh
after hunting and cleaning. Generally, however, the levels found were not unusual from a
wildlife health point of view. Many of the species hunted in eastern Canada, particularly in
Ontario and Quebec, are exposed to contaminants during overwintering or stop-over
periods in the Great Lakes (Braune, 1995).
Table 2.7, Waterfowl Species Sampled from the Lake Erie Basin Area of Ontario (Braune,
1995)
l.iiciiliiui
I5;ivin
N\ ;ilriTcn\ 1 T\ |>i-
^ rill' Siiinpk'd
Detroit River
Connecting Channel
Bufflehead, Mallard
1990
Rondeau
Central Basin
Mallard
1990
Rondeau Park
Central Basin
Canada Goose
1990
Long Point
Eastern Basin
Mallard, Greater Scaup, Lesser Scaup,
Black Duck
1988
Long Point
Eastern Basin
Bufflehead
1990
Lower Grand River
Eastern Basin
Mallard
1989
Lowbanks
Eastern Basin
Bufflehead, Greater Scaup
1990
Based on the 1988-92 data evaluated (plus some earlier data from 1985-86), Health
Canada concluded that, with the exception of Glaucous Gull breast muscle and/or eggs
23
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from Kuujjuarapik, Quebec, the contaminant levels reported in the various waterfowl
samples analyzed were either non-detectable or very low and would not be considered to
pose a hazard to the health of human consumers (Braune, 1995).
2.2.4.2 Canadian Organic Contaminants Study
Canadian research has been conducted regarding zebra mussels as a new food source for
ducks at Point Pelee, Long Point, Big Creek, the Detroit River and western Lake Erie
(Hamilton, 1994; Knapton, unpublished; Mazak, unpublished). The Detroit River/western
Lake Erie research is specifically looking at whether a zebra mussel diet may be
influencing levels of contaminant accumulation in ducks that eat them. Because humans
consume game duck from Lake Erie, the results of this research are reported here. The
results of this study are the first step in determining whether zebra mussels are changing
contaminant transfer patterns in a part of the Lake Erie food web that involves human
consumers.
The diets of six species of waterfowl (greater and lesser scaup, bufflehead, canvasback,
mallard and redhead) in the lower Great Lakes (Fighting Island, Detroit River, western
Lake Erie, and Big Creek) were evaluated. The study compared those species that
consume primarily zebra mussels with those that do not. Lesser and greater scaup from
Fighting Island had, on average, 85 and 67% zebra mussel diet content. Other taxa
consumed little (6%-bufflehead) or no (0%- canvasback, mallard, redhead) zebra mussels.
Zebra mussel was the primary food source of lesser scaup (100%), greater scaup (97%),
and bufflehead {12%) in western Lake Erie.
A representative group of low- (pentachlorobenzene [QCB], poly chlorinated biphenyl
[PCB] #28), mid- (PCBs # 105, 153) and high- (PCBs # 194, 206) Kow compounds were
examined in liver tissues for each group of waterfowl. In each case, mussel-consumers
had elevated concentrations of these compounds relative to individuals that avoided zebra
mussels. Among zebra mussel consumer species, all six compounds, except QCB were
present in significantly higher concentrations in lake individuals.
Appendix 2D contains a summary comparison of contaminant level results from this study
and others. Results from this study indicate that concentrations of most contaminants
biomagnify in waterfowl that consume zebra mussels as a primary food source.
Consequently, zebra mussels may serve as both an energy source and conduit for transfer
of persistent organic contaminants to higher trophic levels in the Great Lakes. However, it
is not clear whether consumption of zebra mussel portends adverse reproductive effects in
Great Lakes waterfowl (Mazak, 1995).
2.2.4.3 Michigan Waterfowl Survey
Michigan hunter surveys have indicated that the amount of wild duck meat consumed per
24
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person per year is similar to the amount of Michigan fish consumed per person per year.
Therefore, the Michigan Department of Health (MPDH) used their 1992 fish consumption
advisory trigger levels for contaminants (see Table 2.8) to evaluate risks to hunters eating
wild duck meat. (It should be noted that 1992 and 1996 consumption advisory trigger
levels are identical). Based upon the results of a 1989 survey of 754 Michigan hunters,
mallards comprise 50% of the ducks harvested and Canada geese make up 99% of all
geese harvested (Michigan DNR, 1993).
Table 2.8,1992 MPDH Fish Consumption Advisory Trigger Levels (MDNR, 1993)
(hemic nl
MPDH Advisory Tn
-------
contaminated dredge spoils at the Pointe Mouillee confined disposal facility (MDNR,
1993).
2.2.4.4 New York Contaminants Study
The New York State Department of Health (NYSDH) provides the following advice to
those considering eating snapping turtles or waterfowl from New York.
Snapping turtles retain contaminants in their fat, liver, eggs and, to a lesser extent, muscle.
If you choose to consume snapping turtles, you can reduce your exposure by carefully
trimming away all fat and discarding the fat, liver and eggs prior to cooking the meat or
preparing soup (to reduce exposure). Women of childbearing age, infants and children
under the age of 15 should avoid eating snapping turtles or soups made with their meat.
The contaminant of concern for this advisory is PCBs.
Mergansers are the most heavily contaminated waterfowl species and should not be eaten.
Other waterfowl should be skinned and all fat removed before cooking; stuffing should be
discarded after cooking; limit eating to two meals per month. Monitoring data indicate
that wood ducks and Canada geese are less contaminated than other waterfowl species
and diving ducks are more contaminated than dabbling ducks. The contaminants of
concern for this advisory are PCBs, mirex, chlordane, and DDT (NYSDH, 1995-1996).
2.2.4.5 Ohio Contaminants Studies
Ohio does not currently have any wildlife consumption advisories. Two research projects
are underway that will look at contaminant levels in certain wildlife species as related to
human consumption. One study is looking at the levels of microcystin present in Lake
Erie mallards that died in 1996. The other study is looking at contaminant levels in Lake
Erie snapping turtles as related to human consumption.
Microcystis blooms occurred in the western basin of Lake Erie in the late summer and
early fall of 1995 and 1996. Besides the aesthetic impact of the alga bloom on Lake Erie,
there is also concern about Microcystis' tendency under certain conditions, to produce
microcystin. Microcystin is a potent hepatic (liver) toxin. At elevated concentrations,
microcystin is suspected to cause bird and fish kills as well as severe gastrointestinal
problems in humans (Ohio Lake Erie Office, 1995). Since microcystins are normally
confined within the cyanobacterial cells, and do not enter the water until lysis or cell death,
the relationship between the age and condition of a bloom and the public health
consequences is particularly important (Carmichael, 1992).
Because the Microcystis blooms occurred so recently and were not expected, it is not yet
known if any aquatic organism mortality due to microcystins occurred in 1995 or 1996.
Eleven mallards were collected from Microcystis bloom areas during 1996. These
mallards were all very sick with severe diarrhea. The stomachs from each duck were
26
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examined to see if they contained microcystin. None was detected, presumably due to the
severe diarrhea which preceded the stomach analysis. Liver tissue from each duck is
currently under analysis to see if the tissue contains microcystin and if, so, what level of
microcystin. This data will be used to determine if microcystin levels in ducks are high
enough to be a health issue for human consumers (Culver, 1996).
The snapping turtle, Chelydra serpentina, accumulates organochlorines mainly in its fat,
liver and eggs, due to the high lipid content of these tissues (EC, 1991). Because
snapping turtles are long-lived (up to 50 years) and omnivorous, they are considered good
indicators of contaminant levels in the environment over time (Estenik and Fisher, 1996).
Because turtles eat plants, as well as fish, a portion of their diet is directly representative
of the contaminant levels in the area where they feed (Estenik, 1996).
A research project titled "Turtles as Environmental Monitors of Priority Pollutants and
Significance to Human Consumers," is underway in Ohio. The study is intended to test
the general hypothesis that contaminant concentrations in snapping turtles reflect
concentrations in environmental media and can be used to predict exposure and possible
effects in other organisms. Specific study objectives are: 1) to analyze PCB and dioxin
levels in fat and blood of field-collected snapping turtles. Turtles will be obtained from
sites with varying degrees of known contaminants so that it can be determined whether
concentrations in turtle tissue are reflective of environmental exposure; 2) to measure
levels of key reproductive hormones in exposed and control turtles in order to correlate
level of contamination with potential reproductive impairment; 3) to measure contaminant
loads in turtle eggs; 4) to quantify PCB exposure and identify effect as total Arochlor
versus specific congeners; 5) to evaluate blood concentrations of PCBs and dioxins as
predictors of organ distribution of contaminants; and 6) if, as expected, the contaminant
levels in turtles are high, the risk to human consumers will be verified in a follow-up study
by measuring PCB and dioxin levels in blood samples of humans who eat snapping turtles
(Fisher, 1996).
2.2.4.6 Ontario Contaminants Studies
Ontario is unique among the Lake Erie jurisdictions in having snapping turtle harvesting
data. In 1982 the annual harvest of snapping turtles in Ontario was 5,000 to 8,333
turtles. Biological supply companies commercial fish buyers, pet wholesalers and retailers,
and fish markets were surveyed to determine the principle buyers of turtles, their sources
of supply, and information on retail and wholesale prices. 1982 data showed that the
major markets for wholesaling turtles as food items were the larger fish markets in the
U.S. including Detroit, Chicago, and New York city. Data from 1982 also indicated the
need for regulation of turtle harvesting to protect the turtles during the nesting season,
which lasts from late May until the end of June (Lovisek, 1982).
Ontario has also studied contaminant levels in common snapping turtle eggs in the lower
27
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Great Lakes-St. Lawrence River Basin in the early to late 1980s. Two of the Canadian
sites studied are on Lake Erie — Big Creek National Wildlife Area, and Rondeau
Provincial Park near the marsh at Point aux Pins.
The focus of these studies was on the use of snapping turtle eggs as an indicator of
contaminant levels in wetland habitats rather than on the potential impacts to humans of
consuming the eggs. However, this data will be relevant, from a historical standpoint,
when the results of the Ohio study become available, and is therefore reported here.
Contaminant levels in snapping turtle eggs from the Canadian sample sites is included in
Tables 2.9 through 2.11 in Appendix 2B (Struger, et. al., 1993).
2.2.5 Wildlife Consumption Restriction Impairment Conclusions
Although contaminant level studies in Great Lakes wildlife are extensive, the amount of
information available regarding the human health impacts of consuming Lake Erie wildlife
is limited, but growing. This fact makes it difficult to reach a definitive conclusion
regarding the significance and extent of wildlife consumption problems in Lake Erie. An
additional confounding factor in the analysis of wildlife contaminant levels versus fish
contaminant levels, is their broader range. Whereas the fish environment is exclusively
aquatic and usually limited to the Lake Erie basin, wildlife, particularly migratory
waterfowl, can pick up contaminants quite distant from Lake Erie. In the case of snapping
turtles, although their range is much more limited than waterfowl, the range of the fish that
they eat can be quite large, making it difficult to pinpoint the origin of the contaminants
they ingest.
Many of the wildlife contaminant level studies have been related to waterfowl, suggesting
that further research may be needed into contaminant levels in other wildlife consumed by
humans. In addition, the reasons for the studies varied. For example, the study of Lake
Erie ducks that eat zebra mussels looked at contaminant bioaccumulation in liver tissue
(which is not normally consumed by humans) and potential associated reproductive effects
in the waterfowl. However, since humans consume greater and lesser scaup and
bufflehead, the results of this study may indicate the need for monitoring of the levels of
contaminants in breast tissue for these species. This is particularly needed since zebra
mussels are relatively new to Lake Erie and their impact on contaminant transfer up the
food chain is not yet well understood.
Despite the above-mentioned limitations to our knowledge, some wildlife consumption
impairment conclusions can be drawn for Lake Erie. Lake Erie contaminant level studies
conducted to date show the following.
Waterfowl in Michigan and Ontario have not shown levels that would require issuance of
human consumption advisories in or near Lake Erie.
28
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Public health advisories for human consumption of snapping turtles and waterfowl are in
place for New York waters of Lake Erie. This is an impairment to human consumption of
these wildlife species. The contaminants causing these advisories are PCBs, mirex,
chlordane, and DDTs.
The Great Lakes Fishery Restoration Study (GLFRS) contains the following objective
related to wildlife consumption advisories, "restoration goals for the Great Lakes Basin
will have been met when wildlife can be consumed with little or no risk to human health."
No concrete definition for "little or no risk" to human health has been developed.
Information to date suggests that unacceptable human health risks related to human
consumption of wildlife only exist in New York waters of Lake Erie. However, research
underway on mallards and snapping turtles may show otherwise. Therefore, the Lake Erie
LaMP process has not reached a conclusion regarding whether the GLFRS objective has
been met.
2.2.6 Monitoring Needs
The state of our knowledge regarding contaminant levels in Lake Erie wildlife as related
to human consumption is much less advanced than it is for sport fish. Therefore, it is
recommended that, at a minimum, the Lake Erie LaMP process support, sponsor, and/or
coordinate monitoring of contaminant levels in muskrat, snapping turtles, and the breast
tissue of waterfowl that eat zebra mussels, in the areas within the geographic scope of the
LaMP. The focus of this contaminant level monitoring should be on identifying
contaminant levels in tissue eaten by humans to determine if consumption advisories are
needed. In particular, it is recommended that the results of research currently underway in
Ohio (and any similar projects), when available, be used to reevaluate the status of wildlife
consumption restrictions in Lake Erie.
2.3 References
1. Ashtabula Remedial Action Plan. 1991. Stage 1 Report.
2. Burch, Kelvin. 1996. Personal Communication. Pennsylvania Department of
Environmental Protection.
3. Braune, Birgit. October, 1995. Survey of Contaminants in Waterfowl.
Unpublished manuscript. Canadian Wildlife Service, National Wildlife Research
Centre.
4. Carmichael, Wayne. 1992. A Status Report on Planktonic Cyanobacteria (Blue-
Green Algae) and Their Toxins. EPA/600/R-92/079. Wright State University,
Department of Biological Sciences.
29
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5. Cox, Chuck and Vaillancourt, Andre. February, 1996. Personal communication.
Ontario Ministry of Environment & Energy, Sport Fish Contaminant Monitoring
Program.
6. Culver, D.A. 1996. Personal communication. The Ohio State University,
Department of Zoology.
7. Environment Canada. 1991. Toxic Chemicals in the Great Lakes and Associated
Effects, Volume 1, Contaminant Levels and Trends.
8. Estenik, John. 1996. Personal communication. Ohio Environmental Protection
Agency, Division of Surface Water.
9. Fisher, Susan W. 1996. Turtles as Environmental Monitors of Priority Pollutants and
Significance to Human Consumers. Research Proposal.
10. Great Lakes Fish Advisory Task Force. September, 1993. Protocol for a Uniform
Great Lakes Sport Fish Consumption Advisory.
11. Hendzel, Marilyn. 1996. Personal communication. Department of Fisheries and
Oceans, Inspection Branch.
12. Hamilton, D.J. and C.D. Ankney. 1994. Consumption of Zebra Mussels
Dreissenapolymorpha by Diving Ducks in Lakes Erie and St. Clair. Wildfowl 45:
159-166.
13. Howell, Todd. September, 1995. Personal communication referencing OASIS
(Ontario Accessible Standards Information System). Ontario Ministry of
Environment and Energy, Environmental Monitoring & Reporting Branch.
14. IJC. 1996. Indicators Will Help to Evaluate Progress Under the Great Lakes
Water Quality Agreement. Focus on International Joint Commission Activities.
15. IJC. 1989. Proposed Li sting/Deli sting Criteria for Great Lakes Areas of Concern.
Focus on International Joint Commission Activities. Volume 14, Issue 1, insert.
16. IJC. 1988. Revised Great Lakes Water Quality Agreement of 1978.
17. Knapton, R.W. Occurrence of a Novel and Abundant prey item, the Zebra Mussel
(Dreissena polymorpha) in Diets of Aythya and Bucephala Diving Ducks at Long
Point, Lake Erie, Ontario. Canadian Journal of Zoology (submitted).
18. Lake Erie Committee. 1997. Lake Erie Fish Community Goals and Objectives.
30
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Page 20.
19. Letterhos, Julie. 1996. Personal communication. Ohio Environmental Protection
Agency, Division of Surface Water, Lake Erie Unit.
20. Mazak, Edward John. 1995. Organic Contaminants in Lower Great Lakes'
Waterfowl in Relation to Diet, with Particular Reference to Dreissena polvmorpha.
A Thesis submitted to the Faculty of Graduate Studies and Research, Department
of Biological Sciences, University of Windsor, Ontario. Abstract.
21. Michigan Department of Public Health. 1996. Summary of Revisions To the
Michigan Sport Fish Consumption Advisory. Division of Health Risk Assessment.
22. Michigan Department of Natural Resources, Wildlife Division. 1993. Wildlife
Contaminant Monitoring Program, Annual Report.
23. Mortimer, Joyce. February, 1996. Personal communication. Health Canada,
Great Lakes 2000 Program.
24. New York State Department of Environmental Conservation. October, 1985.
Final Environmental Impact Statement for Policy on Contaminants in Fish. p. 1.
25. New York State Department of Environmental Conservation. 1987. Niagara
River Biota Contamination Project: Fish Flesh Criteria for Piscivorous Wildlife.
26. New York State Department of Health. 1995-1996. Health Advisory, Chemicals
in Sportfish and Game.
27. Ohio Department of Health. 1997. Ohio Fish Consumption Fact Sheet.
28. Ohio Department of Natural Resources. 1995-1996. Ohio Fishing Regulations.
Division of Wildlife.
29. Ohio Environmental Protection Agency. 1994. Ohio Fish Contaminant
Monitoring Program. Volume 2, Ohio Water Resource Inventory.
30. Ohio Sea Grant. June, 1996. Exotic Species Update #40. Twine Line. p. 5.
31. Ontario Ministry of Environment & Energy. 1995-1996. Guide to Eating Ontario
Sport Fish.
32. Pennsylvania Department of Environmental Protection. 1991. Rationale for Fish
Tissue Sampling and Rotation Water Quality Network (WQN) and Additional
31
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Sampling.
33. Pennsylvania Department of Environmental Protection. 1994. 305(b) Report.
34. Pennsylvania Department of Environmental Protection. 1996.
35. Sivarajah. 1996. Personal communication. Pennsylvania Department of Health,
Division of Environmental Health Assessment.
36. Struger, John, et. al. 1993. Environmental Contaminants in Eggs of the Common
Snapping Turtle (Chelydra serpentina serpentina) from the Great Lakes-St.
Lawrence River Basin of Ontario, Canada (1981, 1984). J. Great Lakes Res.
19(4):681-694.
37. Sweet, Bob. 1996. Personal communication. Michigan Department of
Environmental Quality.
38. Thoma, Roger. 1996. Personal communication. Ohio Environmental Protection
Agency, Division of Surface Water.
39. USEPA/USDH&HS-ASTSDR. 1996. Public Health Implications of PCB
Exposures, p. 6.
40. USEPA/Environment Canada. 1995. State of the Great Lakes, p. 26.
41. USFWS. September, 1995. Great Lakes Fishery Resources Restoration Study.
42. Vandermeer, Paul. 1996. Personal Communication. Ohio Environmental
Protection Agency, Division of Surface Water.
43. Vidra, Andy. 1995. Status of Research Activities in the Black River Area of
Concern. Black River Remedial Action Plan Coordinating Committee, pp. 2-3.
44. Whittle, D. M. 1996. Personal communication. Environment Canada.
32
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Appendix 2A
Routine Chemical Parameters Monitored
in Lake Erie Fish, by Jurisdiction
33
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Michigan
(Source: Sweet, 1996)
Hexachlorobenzene gamma-BHC (Lindane)
Aldrin Dieldrin
4,4'-DDE 4,4'-DDD
4,4'-DDT Heptachlor Epoxide
Mercury Oxychlordane
gamma-Chl ordane trans-Nonachlor
alpha-Chlordane cis-Nonachlor
Octochlorostyrene Hexachlorostyrene
Heptachlorostyrene Pentachlorostyrene
Heptachlor Terphenyl
Toxaphene Mirex
PBB (FF-1, BP-6) PCBs (Alochlors 1242, 1248, 1254, & 1260)
Other chemical parameters are analyzed for on a site specific basis in Michigan.
New York
(Source: Skinner, 1996)
Arochlor 1248/1242 Arochlor 1254/1260
DDE DDT
DDD Hexachlorobenzene
Mirex Photomirex
Transnonachlor cis-chlordane
trans-chlordane Oxychlordane
Dieldrin Mercury
Moisture Lipid content
Ohio
(Source: Paul Vandermeer, Ohio EPA, Division of Surface Water, 1994)
Aldrin Benzene Hexachloride (BHC)
alpha-BHC beta-BHC
delta-BHC gamma-BHC (Lindane)
Cadmium 4-4' DDT, 4-4' DDE, 4-4' DDD
34
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Ohio (continued)
Dieldrin Endosulfan I
Endosulfan II Endosulfan Sulfate
Endrin Heptachlor
Heptachlor Epoxide Hexachlorobenzene (HCB)
Lead Mercury
Methoxychlor Mirex
Chlordane (isomers and breakdown products including alpha, gamma and oxychlordane,
cis-nonachlor, and trans-nonachlor)
PCBs (Arochlor 1060, 1221, 1232, 1242, 1248, 1254, 1260)
Ontario
(Source: OMEE, 1995-1996)
The chemicals for which Ontario fish are analyzed vary by species and location. Fish may
be analyzed for one or more of the following:
Mercury PCBs
Mirex Pesticides
Dioxins Furans
Chlorinated Phenols Chlorinated Benzenes
Polynuclear aromatic hydrocarbons (PAHs)
Pennsylvania
(Source: PADEP, 1991)
PCBs DDT
Aldrin Dieldrin
Endrin Mercury
Cadmium Chromium
Copper Lead
Chlordane
35
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Appendix 2B
Summary of Organochlorine Residues in Snapping Turtle Eggs
Big Creek National Wildlife Area
and
Rondeau Provincial Park
Ontario, Canada
36
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Table 2.9, Absolute and Mean Concentrations (mg/kg wet weight) and Coefficient of Variation (CV) of Organochlorine Residues in Snapping Turtle Eggs 1981 and 1984 (from Struger et al., 1993).
Sample
Ratio of
Total PCBs
DDE
Mirex
HCB
Dieldrin
Oxy-
Cis-
Trans-
Hcptachlor
B-HCB
Percentage
Location
PCB 1254
chlordanc
chlordanc
Nonachlor
Epoxide
Lipid
to1260
Big Creek Nal'l.
0.6500
0.306
0.070
0.005
0.003
0.010
0.010
0.005
0.005
0.010
ND
67.0
\\ ildlile Area-
0.9901
0.465
0.040
0.005
0.003
0.010
0.020
0.005
0.005
ND
0.040
6.4
0 090S
0.479
0.080
0.005
0.002
0.020
0.020
ND
ND
ND
ND
7.7
W. WZWJ
2.702
0.225
0.020
0.006
0.030
0.050
0.005
0.005
0.005
ND
7.2
0.7502
1.076
0.070
0.010
0.004
0.020
0.020
0.005
ND
ND
ND
7.2
0.2902
1.006
0.097
0.0098
0.004
0.018
0.024
0.004
0.003
0.003
0.008
0.140
CV% 88.3
CV % 67.4
CV % 64.8
CV % 37.7
CV % 41.6
CV % 56.5
CV % 50.0
CV % 81.6
CV % 133.3
CV % 200.0
CV% 88.3
Kondeau
4.300
2.021
0.080
0.010
0.004
0.020
0.030
0.005
0.005
0.010
0.010
4.8
Pnmncial Park
0.350
0.164
0.010
ND
ND
0.005
0.005
ND
ND
ND
0.010
4.8
2.840
1.335
0.070
0.005
0.005
0.010
0.005
0.010
0.005
0.005
0.010
6.3
2.630
1.236
0.030
0.005
0.004
0.010
0.020
0.005
0.010
0.005
0.020
4.1
1.510
0.710
0.020
0.005
0.002
0.010
0.010
0.005
0.005
0.005
0.020
4.7
2.326
1.093
0.042
0.005
0.003
0.011
0.014
0.005
0.005
0.005
0.014
CV % 57.1
CV % 57.1
CV % 66.3
CV % 63.2
CV % 59.6
CV % 44.5
CV % 69.3
CV % 63.2
CV % 63.2
CV % 63.2
CV% 63.2
CV % 35.0
* Eggs were collected in 1981,4 clutches were sampled, 5 eggs were collected per clutch.
** Eggs were collected in 1984, 5 clutches were sampled, 10 eggs were collected per clutch.
37
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Table 2.10, Mean Organochlorine Concentrations (PPB, wet weight+/-standard deviation) in Snapping Turtle
Eggs from Big Creek Marsh, 1986 (EC, 1991)
Number of Clutches*
Hcxachloro benzene
alpha-Chlordane
p,p-DDE
Total PCBs**
5
3.1+/-1.5B***
2.1+/-0.8B***
69.8+/-9.9 A***
689.9+/-124.3 B***
* Five eggs were collected from each clutch, pooled and analyzed for residues.
** Total PCBs = sum concentrations of PCB congeners found in eggs.
*** Letters refer to significant differences between sites for each year.
Table 2.11, Mean Organochlorine Concentrations (PPB, wet weight) in Snapping Turtle Eggs from Lake Erie
Populations, 1988 and 1989 (EC, 1991)
Sample Locations
Number of Clutches*
p,p-DDE
Mirex
PCBs**
Big Creek Marsh
7
43.9+/-28.0D***
1.4+/-0.68 C***
754+/-486D***
Rondeau Provincial Park
7
36.9+7-24.4 D***
1.9+/-1.3 C***
1420+/-910 C***
* Five eggs were collected from each clutch, pooled and analyzed for residues.
** PCB concentrations are based on Aroclor 1254/1260 1:1 mixture.
*** Letters refer to significant differences between sites for each year.
39
-------
Appendix 2C
Areas of Waterfowl Contaminant Level Sampling In Ontario
40
-------
M ^ & hi
jS rf V
.Jules'
Ontario
VA.'ri-
¦Pfr tKvq -d
Qrtt&rid
-------
Appendix 2D
Comparison of Waterfowl Contaminant Levels
42
-------
From:Mazak, Edward John. 1995. Organic Contaminants in Lower Great Lakes' Waterfowl in Relation to Diet, with Particular Reference to Dreissena
polvmorpha. a Thesis Submitted to the Faculty of Graduate Studies and Research, Department of Biological Sciences, University of Windsor, Ontario.
Table 2.12 Comparison of Contaminant Level Results from This Study and Others. All values given in g/kg wet weight with mean in parenthesis. * Taken
from Gebauer and Weseloh (1993).
REFERENCE & LOCATION
OF STUDY
WATERFOWL
SPECIES/TISSUE
HCB
T-
NONACHLOR
DDE
OXYCHLORDANE
DIELDRIN
PCBS
This Siudv
Middle Sister Island, Ontario
bufflehead/liver
1.4-2.9 (1.8)
1.3-2.7 (2.3)
10.7-32.6
(21.0)
0.68-1.7 (1.0)
147-308
(237)
Middle Sister Island, Ontario
greater scaup/liver
0.35-3.4 (1.6)
0.38-1.1 (0.66)
7.6-71.5
(22.7)
0.54-7.8 (3.3)
7.3-26.9
(16.2)
120-487
(241)
Middle Sister Island, Ontario
lesser scaup/liver
0.55-1.7 (1.1)
0.45-1.7 (0.83)
5.5-32.5
(13.6)
0.41-3.1 (1.1)
4.4-11.4
(7.9)
38.7-241
(133)
Fighting Island, Detroit River,
Ontario
bufflehead/liver
0.54-1.7 (1.1)
0.25-0.55 (0.39)
1.3-8.3 (5.2)
0.58-1.1 (0.80)
2.6-5.9 (4.6)
9.5-47.6
(26.1)
Fighting Island, Detroit River,
Ontario
greater scaup/liver
0.24-0.81
(0.48)
0.06-0.07 (0.07)
0.51-0.84
(0.70)
0.13-0.22 (0.16)
0.51-1.1
(0.60)
5.6-7.3 (6.6)
Fighting Island, Detroit River,
Ontario
lesser scaup/liver
0.35-0.61
(0.45)
0.05-0.06 (0.06)
0.19-1.6
(0.76)
0.05-0.33 (0.18)
0.30-0.94
(0.65)
2.4-20.9 (8.2)
Dobos cl al. 1991'
Thunder Bay CDF, Ontario
domestic
mallards/muscle
2.6-12.3
Foley 1992
Statewide, New York
mallard/muscle
(3.1)
ND-190
(20)
(15.0)
(5.9)
ND-300 (80)
bufflehead/muscle
(7.7)
ND-70 (20)
(34.9)
(26.4)
ND-600
(150)
scaup/muscle
(5.9)
ND-30 (20)
(19.9)
(17.3)
ND-500
(130)
Kirn cl al. 1984
Statewide New York
mallard/liver
(24)
(520)
bufflehead/liver
(5)
(75)
greater scaup/liver
(43)
(1,200)
Miles and Ohlcndorl 1993
San Francisco Bay, California
canvasback/carcass
(13)
(386)
(11)
(17)
(1,079)
REFERENCE & LOCATION
WATERFOWL
HCB
T-
DDE
OXYCHLORDANE
DIELDRIN
PCBS
43
-------
OF STUDY
SPECIES/TISSUE
NONACHLOR
I It-bi 11 ii al. 1990*
Walpole Island, Ontario
non migratory
mallards and
redheads/liver
(20.0-29.6)
Smilli el al. 198.7 "
Detroit River, Ontario
lesser and greater
scaup,
goldeneye/whole
carcass
330-1,700
81-330
480-1,300
7,800-11,000
Swill el al. 1993
Niagara River, New York
common
goldeneye/muscle
0.0-0.0 (0.0)
0.0-0.0 (0.0)
10-20 (20)
0.0-0.0 (0.0)
0.0-0.0 (0.0)
70-120 (90)
common
goldeneye/fat
10-40 (20)
10-40 (20)
630-970
(780)
30-90 (60)
100-200
(140)
2,470-4,830
(3,450)
\\ >li 1' >
St. Clair River, Ontario
mallard, goldeneye,
common
merganser/muscle
10-276
1-26
21-398
2-22
2-54
225-2,855
Weseloli el al. 1992*
Windemere Basin, Ontario
pekin ducks/liver
2-18
4-14
27-132
8-139
25-73
1,214-7,555
Walpole Island, Ontario
pekin ducks/liver
21-48
1-2
8-11
ND-1
2-10
34-214
44
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