[Pharmwaste] More 'Intersex Fish' found in the Potomac,
and Hermaphrodite fish provoke concern about pollution
dldebiasi at deq.virginia.gov
Thu Sep 7 15:52:05 EDT 2006
More 'Intersex Fish' Found in Potomac
By MATTHEW BARAKAT
The Associated Press
Wednesday, September 6, 2006; 11:19 PM
McLEAN, Va. -- Some species of male fish in the Potomac River and its
tributaries are developing female sexual traits at a frequency higher
than scientists have seen before, raising concerns about pollutants in a
waterway that provides drinking water for millions of people.
The so-called "intersex fish," which produce immature eggs in their
testes, were discovered in the Potomac rivershed in 2003 and have also
been found in other parts of the country.
But the frequency that the U.S. Geological Surveys found last year is
much higher than what has been found elsewhere, said fish pathologist
In some Potomac tributaries, nearly all of the male smallmouth bass
caught in last year's survey were the abnormal fish. In the Potomac
itself, seven of 13 largemouth bass exhibited female characteristics,
including three that were producing eggs.
Although the frequency discovered was surprisingly high, Blazer
cautioned that the sample size was relatively small, with about 10 male
and 10 female fish taken from each of eight locations in Maryland,
Virginia and the District of Columbia.
Researchers were reluctant to remove large numbers of bass from the
rivers because of conservation concerns, she said.
Female fish caught in the survey did not develop any unusual sex traits,
though fish of both sexes exhibited lesions and other pollution-related
problems, said Blazer, who coordinated the survey.
Smallmouth bass appear to be more susceptible to intersex development
than largemouth bass, Blazer said.
Blazer said researchers are still waiting on data that would help them
determine the water quality at the time the fish were caught, but
preliminary data taken from the Potomac found a variety of chemical
It is not exactly clear what is causing the changes, though it is likely
a combination of pollutants, scientists say.
Certain chemicals and pesticides are believed to stimulate estrogen
production. Also, estrogen from birth control pills and human waste can
make its way from sewage treatment plants to the waterways.
The Environmental Protection Agency has been studying the issue of
so-called "endocrine disruptors" since 1996, but currently does not
issue guidelines to water treatment plants for allowable levels of
Jeanne Bailey, a spokeswoman for Fairfax Water, said the findings are a
The water authority, which draws from the Potomac and Occoquan rivers to
provide service to roughly 1.5 million people, is working with USGS and
other agencies to research and develop ways to improve water treatment
to eliminate potentially harmful compounds.
The water treatments used by Fairfax Water, including ozone and
activated charcoal, have been shown to reduce levels of estrogenic
compounds, she said.
Bailey cautioned against drawing dire conclusions about the impact on
human health. She said, "Fish are a great indicator of the health of our
waters, but they are not a great indicator of what may translate to
Hermaphrodite fish provoke concern about pollution
D.C.'s drinking water okay, city officials say
For those of you who enjoy water from the tap, you may want to consider
switching to Dasani.
The United States Geological Survey announced that a large number of
intersex fish have been found in the Potomac River. The upstream parts
of the river provide water to Washington and parts of Virginia.
photo by Michael Keller 80 percent of the tested male sea bass were
producing immature eggs, according to the survey. Some scientists are
concerned that these biological irregularities are due to the
contamination of the river by chemicals called endocrine disruptors.
Intersex fish were first discovered in 2003 in the Chesapeake Bay, which
is fed by the Potomac. The gender benders have also been found in the
water off the San Diego coast.
Despite concerns about a possible threat to the District's drinking
water, Thomas Jacobus, general manager of the Washington Aqueduct,
insisted that the city's tap water is completely safe for human
"Our water meets all regulatory standards," Jacobus said. "There is no
indication that people should not drink the water."
Jacobus acknowledged, however, that these chemicals could possibly be
harmful if their levels rise. He blamed the presence of the endocrine
disruptors on medications that reach the sewer system through careless
He said that there is a lack of guidelines for these chemicals, since
the Environmental Protection Agency has not created regulations for the
chemicals despite having extensively researched the issue since 1996.
Dale Kemery, media contact for the EPA's Office of Water, said that the
Agency is waiting for more scientific investigations before declaring a
"Essentially, this is fairly deep science on a molecular level," Kemery
said. "It takes a long time to find the facts and the effects on
Some believe that the mere existence of these hormonally altered fish
signifies a problem. Glen O'Gilvie, President of the Earth Conservation
Corps, an environmental advocacy group based in Southeast D.C., lamented
this finding as a sign of the damage that people have done to the area
He also said that he worried the pollution of the Potomac River will
spill into the Anacostia River, which his organization closely monitors.
The state of the Anacostia River has also been the subject of concern,
since neighborhoods near the river have suffered high rates of chronic
"This will have negative effects on us as people as we fish these rivers
and eat these fish," O'Gilvie said.
In addition to the possible physical aspects, O'Gilvie is concerned
about the psychological effect that these modified fish will have on
"Folks feel discomfort living by a polluted river," O'Gilvie said.
"There will be a mental effect. It's bad for the area."
Deborah L. DeBiasi
Email: dldebiasi at deq.virginia.gov
WEB site address: www.deq.virginia.gov
Virginia Department of Environmental Quality
Office of Water Permit Programs
Industrial Pretreatment/Toxics Management Program
Mail: P.O. Box 10009, Richmond, VA 23240-0009
Location: 629 E. Main Street, Richmond, VA 23219
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