....to stay away from the Herring family's favorite waterway.



'Toxic stew' of chemicals causing male fish to carry eggs in testes

Intersex fish, found across the US, result from a mix of drugs that
mimic natural hormones, say scientists


More than 80% of the male bass fish in Washington's major river are now
exhibiting female traits such as egg production because of a "toxic
stew" of pollutants, scientists and campaigners reported yesterday.

Intersex fish probably result from drugs, such as the contraceptive
pill, and other chemicals being flushed into the water and have been
found right across the US.

The Potomac Conservancy, which focuses on Washington DC's river, called
for new research to determine what was causing male smallmouth bass to
carry immature eggs in their testes. "We have not been able to identify
one particular chemical or one particular source," said Vicki Blazer, a
fish biologist with the US geological survey. "We are still trying to
get a handle on what chemicals are important."

But she said early evidence pointed to a mix of chemicals – commonly
used at home as well as those used in large-scale farming operations –
causing the deformities. The suspect chemicals mimic natural hormones
and disrupt the endocrine system, with young fish being particularly
susceptible.

The chemicals could include birth control pills and other drugs,
toiletries especially those with fragrances, products such as tissues
treated with antibacterial agents, or goods treated with flame
retardants that find their way into waste water. However, Blazer also
pointed to runoff from fertilisers and pesticides from agricultural areas.

About 5 million people live in the greater Washington area, and 90% of
them get their drinking water from the Potomac.

There is evidence that the anomaly is not confined to the Potomac, one
of the largest rivers on America's Atlantic coast.

A report last year by the US geological survey found intersex fish in a
third of 111 sites tested around the country. Of the 16 fish species
studied, the condition was most common in smallmouth and largemouth bass
and among males, although researchers also discovered the occasional
female fish with male characteristics. The researchers studied sites
along some of America's greatest rivers from the Mississippi to the Rio
Grande.

"We need to get these toxins out of our river water," said Hedrick
Belin, the president of the Potomac Conservancy. The campaign group
called for $3m (£1.9m) in research over three years on endocrine
disrupters on their effects on fish. It also called on the authorities
to involve pharmaceutical companies in the safe disposal of drugs, and
to invest in technology that can filter out endocrine disrupting compounds.