States List:
Mississippi
New York
Ohio and Michigan
Washington
Texas
Florida
South Carolina
State of Mississippi - In 2000,
the State of Mississippi convened a Fish Advisory Task Force to
develop procedures regarding fish consumption advisories for organochlorine
compounds and other contaminants. Recommendations by the Task Force
to the Mississippi Departments of Environmental Quality and Health
were based on USEPA risk-based assessment guidelines, rather than
old FDA standards. Fish tissue data from the NAWQA Program in the
Mississippi Embayment played an important role in this change of
approach and new advisories because it demonstrated that elevated
organochlorine levels have persisted in fish in this part of the
country longer than anticipated by most managers. Concentrations
of total DDT collected from 30 of the 41 sites sampled in the Mississippi
Embayment exceeded guidelines established to protect wildlife. In
fact, fish collected in 1995 showed that
the highest concentrations of total DDT in fish tissue throughout
the entire Mississippi River drainage were in the Mississippi Embayment
study area. Streams demonstrating elevated levels in fish by
USGS, such as some in the Delta region in Mississippi, are included
in the preliminary state fish-consumption advisories, minimizing
necessary sampling by the State and, therefore, resulting in cost-effective
and timely management decisions.
State of New York - NAWQA findings
documented the occurrence of PCBs in the Mohawk River in the vicinity
of Utica and Little Falls, New York. These results contributed to
decisions by the New York State Department of Health to issue fish
consumption advisories on carp and selected game fishes, including
largemouth bass and tiger muskellunge.
Lake Erie Drainage, Ohio and Michigan
- NAWQA findings in the Lake
Erie-Lake Saint Clair Drainages show that certain organochlorine
contaminants were 10 to 100 times more concentrated in fish than
in the streambed sediments of streams and major rivers. DDT, chlordane,
dieldrin, PCBs, and the trace metal, mercury were the most frequently
detected contaminants in fish in these drainages. Fish-consumption
advisories are posted in the Lake Erie Drainage due to the prevalent
contamination by mercury and PCBs.
State of Washington - NAWQA scientists,
participating on a multi-agency team studying Lake Roosevelt, a
popular fishing area in Washington State, collected several species
of fish to evaluate mercury contamination. The results led to a
site-specific
health advisory for mercury by the Washington State Department of
Health, cautioning people about the consumption of walleye and
possible adverse health effects from mercury.
The Washington State Departments of Ecology and Health, along with
the Spokane Regional Health District, issued fish-consumption
advisories for rainbow trout and mountain whitefish caught in
the Spokane River from Upriver Dam, Washington, to the Idaho state
line because of elevated levels of PCBs and lead. The first advisory
was issued for lead in August 2000 following the release of NAWQA
information on lead and other heavy metals. A second advisory was
released in early 2001 for PCBs following a joint study by the State
and USGS that looked at PCB occurrence, as well as more detailed
surveys on the extent to which heavy metals spread downstream from
Idaho's historic mining activities.
In the Yakima River Basin, results of a NAWQA study revealed elevated
concentrations of the insecticide DDT in water, streambed sediment,
and fish tissue. These findings were a potential concern, especially
to the health of local Native Americans who rely on fish as a major
food source, and for fish-eating birds. The Washington State Department
of Health issued a statement on the health effects that may result
from consuming fish in the Yakima River Basin and conducted a
study on DDT in breast milk.
State of Texas - High levels of PCBs
detected in fish in the Donna Canal in south Texas in the early
1990s led to a ban on possession and consumption of fish. Subsequent
extensive sampling studies by the State of Texas continued to reveal
high levels in fish but no information on potential sources. The
Texas Natural Resource Conservation Commission approached the NAWQA
Program in 1998 and requested suspended-sediment chemistry and coring
methods to locate the PCB source. USGS sampling narrowed the potential
source to a 90-meter stretch along the approximately 4-mile long
Donna Canal. The State turned the results over to their Superfund
Program to begin the process of assessment and clean up.
For a period of four years following the discovery of high levels
of PCBs in fish tissue in the Donna Canal by the USEPA, the Texas
Natural Resource Conservation Commission, in cooperation with the
Texas Department of Health and Texas Parks and Wildlife Department,
conducted a series of investigations aimed at identifying the source
of PCB contamination in the Donna Canal and associated reservoirs.
Unfortunately, the subsequent (three) water, (two) fish and (three)
bottom sediment sampling efforts brought us no closer to finding
a source of the PCBs. Later (in 1998) after the first Superfund
Site Discovery and Assessment investigation yielded equally empty
results, we felt it was time to get help. Today, I am pleased to
say that, not only have we been able to narrow the potential source
of PCB contamination to an area of the canal approximately 90 meters
long, the suspended sediment sampling results from [USGS] studies
have enabled us to refocus our Superfund Site Discovery and Assessment
investigation efforts and I am confident that this project will
be in remediation mode by this Fall. Of course, the real benefactors
of your work are the people of the Rio Grande Valley who will have
one public health problem less to contend with (Roger Miranda,
Texas Natural Resource Conservation Commission, March 2001).
State of Florida - The USGS assessment
(Water
Quality in Southern Florida, 1996-98) indicates that mercury
has accumulated in game fish and other parts of the food web because
human influences and natural conditions in the Everglades region
enhance the methylation of mercury to its organic form, methylmercury.
The enrichment of methylmercury enhances mercury uptake by fish
and other biota. As a result, the Everglades ecosystem has one of
the highest ratios of methylmercury to total mercury in bottom sediment
in 21 NAWQA basins studied nationwide.
As the largest freshwater wetland in the continental US, and
one identified as being critically endangered by farming, drought,
development and drainage in its watershed, the Florida Everglades
has the misfortune to exhibit some of the highest concentrations
of mercury in its fish and wildlife
The contributions of the
USGS NAWQA Project team have been of vital importance to the [South
Florida Mercury Science] Program. The USGS has brought together
scientists of many disciplines and enabled the South Florida Mercury
Science Program to develop a deeper understanding of the scope,
scale, status and trends of mercury problems in Florida. This has
thereby greatly enhanced our ability to model and manage the factors
that contribute to this problem (Dr. Thomas Atkeson, Florida
Department of Environmental Protection, April 2001).
State of South Carolina - Concentrations
of mercury in clams and fish liver tissue from the Edisto River
were 24 and 8 times greater, respectively, than the South Carolina
action level for issuance of a fish-consumption advisory. The South
Carolina Department of Health and Environmental Control (2000) has
issued fish-consumption
advisories because of high levels of mercury in 49 rivers and
reservoirs in the Santee River Basin, including the Edisto River.
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