Thursday, September 07, 2006

Having It Both Ways

Is not a good thing in this case.
Some species of male fish are acquiring female sexual characteristics at unusually high frequencies in the Potomac River and its tributaries, prompting concerns about pollutants that might be causing the problem. In some Potomac tributaries, including the Shenandoah River in Virginia, nearly all of the male smallmouth bass caught in a survey last year by the United States Geological Surveys were so-called intersex fish, producing immature eggs in their testes. In the Potomac itself, 7 of 13 largemouth bass exhibited female characteristics, including 3 that were producing eggs. Intersex fish were discovered in the Potomac rivershed in 2003 and have also been found in other parts of the country. But the frequency found by the surveys is much higher than what had been found elsewhere, said Vicki Blazer, a fish pathologist. Female fish caught in the survey did not develop any unusual sex traits, though fish of both sexes exhibited lesions and other problems related to pollution, said Ms. Blazer, who coordinated the survey. Smallmouth bass appear to be more susceptible to intersex development than largemouth bass, she said.

Smallmouth bass are great fighting fish. We have a great fishery, some say world class, but stuff like that puts me off. But it's great fun. Now, if I only had a boat.

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