Health of the Potomac River Watershed:
High Rate of Tumors in Catfish from the Anacostia River in
The final report
on a 2000-2001 tumor survey of brown bullheads in the Anacostia
now available. The report, entitled "Tumor prevalence and
biomarkers of exposure and response in brown bullheads (Ameiurus
nebulosus) from the Anacostia River, Washington, D.C. and
Tuckahoe River, Maryland." is available through the
Service's Chesapeake Bay Field Office. Contact Info.
A U.S. Fish and Wildlife Service survey of the tidal Potomac
River watershed found that brown bullhead (Ameiurus nebulosus),
a species of catfish, collected from the Anacostia River
Washington, DC had high rates of both liver and skin tumors.
Tumor rates in freshwater
and saltwater fish have been used as an indicator of pollution.
It is believed that tumors are
caused by exposure to cancer causing-chemicals in sediments.
Brown bullheads feed on worms and other invertebrates on
river bottom and bury themselves in the mud during winter.
Because toxic chemicals often accumulate in sediments, pollution
problems are frequently observed in bottom-dwelling species.
A fish consumption advisory, issued in 1995 for the District
of Columbia's portion of the Anacostia and Potomac Rivers,
already urges the public not to eat catfish, carp and eels
from those areas.
Click on image for
of the fish collected from the Anacostia River near the
CSX Railroad Bridge in the spring and 60% of those
collected in the fall had liver tumors. In addition, a record
68% of the fish collected
location near a combined sewer outfall were found to have
liver tumors."These are comparable
to the highest reported liver tumor rates in studies conducted
in the Great Lakes, where rates above 9% indicate contamination" reports
lead author, Fred Pinkney, an Environmental Contaminants
biologist with the Service's Chesapeake Bay Field Office.
The survey found that the liver tumor rate in Neabsco Creek,
a Virginia tributary of the Potomac located about 25 miles
down river from Washington, DC was also high (17%). Neabsco
Creek borders the Featherstone National Wildlife Refuge, managed
by the Service.
Tests on fish
and sediments suggest that exposure to polynuclear aromatic
hydrocarbons (PAHs), identified as carcinogens in
laboratory tests, may be responsible for the tumors. PAHs
are found in petroleum, coal, and other fossil fuels. The
most toxic forms of PAHs are formed from burning these fuels.
PAHs enter rivers through runoff from roads and storm sewers,
through spills, and from the atmosphere. The recently released
report reveales that high concentrations
of polycyclic aromatic compound-DNA adducts were found in
both age >3 and age 1-2 Anacostia bullheads.
Surveys such as this may affect the issuance of fish consumption
advisories. For example, as a result of the tumor research
done in the Great Lakes, a consumption advisory was issued.
These advisories inform the public that high concentrations
of chemical contaminants have been found in local fish and
wildlife and include recommendations to limit or avoid consumption
of certain fish and wildlife species from specific waterbodies
or waterbody types.
The survey report recommends using tumor surveys to monitor
areas of the Chesapeake Bay with contaminated sediments. Such
studies could be conducted before and after the source of
the contaminants is controlled or cleaned up to determine
the efforts success. Studies in a tributary of Lake Erie showed
that tumor rates decreased following closure of an industrial
plant that was the major PAH source. The brown bullhead survey
is part of a larger effort involving the Service, other federal
agencies and local groups to identify the sources of pollutants
in the Anacostia river, determine their effects on fish and
wildlife and recommend appropriate cleanup measures.
Fred Pinkney 410 573-4519
Pinkney, A.E., J.C. Harshbarger, E.B. May, and W.L. Reichert. 2002. Tumor
prevalence and biomarkers of exposure and response in brown bullheads (Ameiurus
nebulosus) from the Anacostia River, Washington, D.C. and Tuckahoe River,
US Fish and Wildlife Service, Chesapeake
Bay Field Office.