[Pharmwaste] Study suggests link between kills, intersex fish (Potomac River)

[Tenace, Laurie]

Study suggests link between kills, intersex fish
http://wvgazette.com/News/200906030813

Some of the same pollutants that apparently cause male fish in the Potomac
and Shenandoah rivers to exhibit female characteristics may also leave them
vulnerable to disease and large-scale fish kills, according to a new study. 

McLEAN, Va. -- McLEAN, Va.-- Some of the same pollutants that apparently
cause male fish in the Potomac and Shenandoah rivers to exhibit female
characteristics may also leave them vulnerable to disease and large-scale
fish kills, according to a new study.


The study points to a possible link between the occurrence of intersex fish
and fish kills in the rivers in recent years.


In the study from the U.S. Geological Survey by researcher Laura Robertson,
largemouth bass were injected with estrogen. Those fish were then found to
produce lower levels of a hormone called hepcidin that is believed to bolster
immune systems.


The study involved 24 fish, including control groups, that were monitored in
the survey's labs at Leetown, W.Va. It was published in the current edition
of Fish and Shellfish Immunology.


Previous studies have shown that intersex fish were susceptible to lesions
and other general illnesses, prompting Robertson's study.


Fish kills have plagued the Shenandoah and its tributaries since 2003. In
2005, up to 80 percent of the smallmouth bass and redbreast sunfish in the
river's South Fork died, and a similar kill occurred on the North Fork in
2004. Many of the dead fish exhibited intersex characteristics.


Intersex fish were first discovered in the Potomac in 2003. A 2008 study
found as many as 77 percent of male smallmouth bass in the South Branch of
the Potomac had started to produce eggs, with the highest percentages
adjacent to farming and population centers.


Many scientists suspect that pollutants, including certain household
detergents, and drugs like birth-control pills that make their way into the
water supply are the cause.


Legislation introduced in Congress would encourage state governments to
establish programs to recover unused prescription drugs from consumers to
prevent them going into landfills or being flushed down the toilet.


"Alarm bells go off when 80 percent of male bass in the Potomac River are
found to produce eggs,'' said Rep. Jim Moran, D-Va., a co-sponsor of the
legislation who is encouraging further study of the issue.


Laurie Tenace
Environmental Specialist
Waste Reduction Section
Florida Department of Environmental Protection
2600 Blair Stone Rd., MS 4555
Tallahassee FL 32399-2400
P: 850.245.8759
F: 850.245.8811
Laurie.Tenace at dep.state.fl.us 

Mercury: http://www.dep.state.fl.us/waste/categories/mercury/default.htm 

Unwanted Medicine:
http://www.dep.state.fl.us/waste/categories/medications/default.htm



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