Tag: sexes

Fish Swimming in Hormones

  • Fish are putting up less of a fight on the line when caught - making them less fun for sport fishing. (Photo courtesy of the National Park Service)

A recent report from the US Geological
Survey confirms past findings that fish
are in trouble. Tanya Ott
reports the hormone estrogen is getting
into rivers and lakes and could reduce
fish populations:

Transcript

A recent report from the US Geological
Survey confirms past findings that fish
are in trouble. Tanya Ott
reports the hormone estrogen is getting
into rivers and lakes and could reduce
fish populations:

The fish have been turning up with lesions and intersexed –
meaning they have both male and female characteristics.

Rob Angus is a fish biologist at the University of Alabama at Birmingham.
He wasn’t involved in the USGS research, but has studied the problem for
more than a decade. The culprit?

“You’re a female? You excrete estrogens. Both natural estrogens,
the estrogenst that are in birth control pills, females that are
on estrogen replacement therapy. All of those end up in the
wastewater stream.”

Wastewater treatment plants clean up about 90 percent of the
estrogen, but the remaining ten percent is a problem.

Fish don’t reproduce as easily. And, for sport fishers, the fish
aren’t as much fun to catch. They don’t put up as much of a fight
on the line. That could affect the 75 billion dollars sport fishing industry.

For The Environment Report, I’m Tanya Ott.

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Water Pollution Feminizing Fish

  • Chemicals in the water are mixing up fish's gender (Photo courtesy of US Fish and Wildlife Service)

Scientists already know estrogen from things like ‘The Pill’ is getting into the water and causing reproductive problems for fish. Male fish are picking up female attributes. Some males are even growing eggs. Now a study finds there are other chemicals getting into water that might be messing with fish gender even more. Rebecca Williams reports:

Transcript

Scientists already know estrogen from things like ‘The Pill’ is getting into the water and causing reproductive problems for fish. Male fish are picking up female attributes. Some males are even growing eggs. Now a study finds there are other chemicals getting into water that might be messing with fish gender even more. Rebecca Williams reports:

This study’s found a group of chemicals that block the male hormone testosterone is getting into rivers.

Charles Tyler is the lead author of the paper in the journal Environmental Health Perspectives.

He says they don’t know exactly where these chemicals are coming from, but some medicines and pesticides can block testosterone. So, add that to the estrogen…

“And so it’s very likely they’re going to have interactive and additive effects, if you like, to induce a double whammy on the poor fish.”

Tyler says they don’t know if what’s happening in fish is also happening in people.

Human male fertility has been declining. But there might be other chemicals contributing to the problem.

And besides, there’s a difference. Fish can’t get away from these testosterone blocking chemicals or the estrogen in the water – they live and swim in them. So Tyler says they’re getting a much higher dose.

For The Environment Report, I’m Rebecca Williams.

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