Bizarre phenomenon of fish changing genders

Bizarre phenomenon of fish changing genders is happening all over the world: What's in the water?


(NaturalNews) What's going on in the Northland waters near Minnesota?
Well, scientists and other experts aren't quite sure - yet.

Not just one type but almost all kinds of fish, to include some of the most popular gaming fish like bass and walley, are changing.

What - wait. Changing?
Yes, and at least one local news team has been documenting these
changes since 2002, when concerns were first emerging. A decade later,
"scientists are beginning to call it a significant threat," the Northlands Newscenter reported in February.

"Walleye cakes, walleye bites, walleye sandwich...it's a popular delicacy in restaurants around the northland," the Newscenter said.
"It's also a multi-million dollar industry, attracting hundreds of
thousands of anglers to the Northland's beautiful lakes year round."

Feminization of male fish

While
many area residents and not a few visitors to the area take the
industry for granted in believing that the waters can be fished forever,
scientists have discovered a major threat to the abilities of many
kinds of fish to reproduce.

"Changes in, for example, the
external characteristics of males where they start to resemble females,"
Dr. Gary Ankley of the U.S. EPA Lab in Duluth, Minn., told the Newscenter.

Dr. Pat Schoff added, of the Natural Resources Research Institute at the University of Minnesota-Duluth: "The small mouth bass and large mouth are sensitive to fish feminization. We're seeing lots of symptoms in these species."

How can fish
actually change genders? Scientists aren't sure but they do know that
it is a frightening phenomenon that is happening all over the world.
Studies show thus far that a feminized male fish can suffer a
reproductive disability of at least 76 percent and more; the more
researchers look into this, the more they are finding fish that cannot reproduce at all.

The phenomenon has "actually caused some fish populations to go extinct," said Ankley.

Some of the leading scientific research examining the problem is taking place in Duluth, at UMD's NRRI, and also at an Environmental Protection Agency lab there. Scientists believe chemicals are behind the fish gender transformation.

"There's
only a few labs in the world that can do this very effectively when we
deal with these very potent chemicals," Ankley said. "There's a number
of chemicals that can act as what we call estrogens."

Scientists
and environmentalists note that there are literally thousands of
chemicals that make it into the nation's streams, rivers and other
waterways every day. They include medications, agricultural run-off and
other substances that carry very powerful estrogens scientists believe may be altering fish genders.

"We
can see everything from testicular tissue that is growing like an
ovary. Or some fish have one teste and one ovary," said Schoff.

"The male testes actually has eggs in it," Ankley added.

5,000-8,000 different medications could be altering environment

Researchers
know when they expose fish in the lab to such powerful estrogen
compounds they will see nearly complete transformations from one gender
to another, and that such transformation is dramatically harming fish
populations.

"There's lower rates of reproduction or even no reproduction," Dr. Schoff said.

Scientists
say they aren't sure what other substances and chemicals, besides
estrogen, might be contributing to the gender transformations in nature.

"It
turns out there are chemicals that can mimic natural estrogens and when
you expose males to these chemicals they can start to achieve these
female characteristics," Ankley said. "There's probably 5,000 to 8,000
different medications that are used and could enter the environment."

They say even substances as common as Ibuprofen might be contributing to the problem as well.

Source:-
http://www.naturalnews.com/039573_fish_gender_bender_chemicals.html