- TORONTO -- Canadian researchers
studying wildlife on the Great Lakes have found sexual abnormalities in
male snapping turtles, with penis size diminished and some males able to
produce egg yolk protein, a capability normally found only in females.
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- The research, conducted by biologists with the Canadian
Wildlife Service of Environment Canada, is part of a growing body of international
evidence indicating that many species are suffering from exposure to so-called
gender-bending chemicals, industrial pollutants that have been found to
mimic sex hormones.
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- These changes so far have been observed most in fish,
but researchers have noted genital abnormalities in other species ranging
from Florida panthers to alligators.
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- The turtles with abnormal penis size were found in Ontario:
in the Detroit River near Windsor, the St. Clair River near Sarnia, and
the harbour of Wheatley, a small fishing community on Lake Erie. All three
sites are pollution hot spots.
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- Snapping turtles in cleaner environments, such as Algonquin
Park and in a marsh near Midland, Ont., lacked the abnormalities.
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- The turtles that produced egg yolk protein were found
around Wheatley. That protein is normally "only produced by females
when they're laying eggs," said Kim Fernie, a biologist with the wildlife
service, who was part of the team conducting the research. "You would
not expect to find it in a male turtle."
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- Additional work by the scientists on herring gulls discovered
the egg protein in some male birds along the Detroit River.
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- Female reproductive characteristics in male turtles and
birds are a sign of contact with chemicals that act like female sex hormones.
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- More than 50 synthetic compounds have been found to affect
hormone systems, among them dioxins, polychlorinated biphenyls, pesticides
and some plastics.
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- Sarnia has Canada's largest concentration of petrochemical
plants; the Windsor-Detroit area is heavily industrialized. Wheatley is
in an agricultural area.
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- Young turtles showed other biological abnormalities,
such as impaired thyroid function, at all three sites.
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- Researchers say they don't know yet which compounds caused
the developments they observed.
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- "As this is relatively new, we don't know what is
causing that yet," said Laird Shutt, a toxicologist with the wildlife
service who conducted the research on the gulls.
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- Ms. Fernie said her results are preliminary, and she
has done more field work trying to verify the extent of the turtle abnormalities.
But the newer samples are being analyzed, and results are not expected
until next year because of laboratory backlogs at Environment Canada's
testing facilities.
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- "We did find these changes in the first year, but
is that going to be consistent over multiple years or not, I don't know
at this point," she said.
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- Environment Canada has issued a summary of the research
on its website but has not publicized the findings.
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- Mr. Shutt said the levels of egg yolk protein he observed
in male birds were not high enough to affect their chances of survival.
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- However, environmentalists said the research is worrisome
because chemicals powerful enough to affect hormones are a potential health
threat.
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- "As soon as you're disrupting hormone systems, there
is a chance of cancer; there is a chance of other diseases," said
Bailey Mylleville, a spokesman for Great Lakes United, an environmental
group based in Buffalo.
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- In the turtle research, Ms. Fernie said she calculated
penis size by measuring the distance between the reptile's shell and anus,
and from that made an estimate of penis length.
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- She would not say how much the organs were reduced in
size. Taking actual penis measurements would have required killing the
turtles and opening up their shells.
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- The research also found excessive production of some
liver enzymes in young snapping turtles and adult herring gulls from the
Detroit River area.
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- They said high production of the enzymes occurs when
animals are exposed to dioxin-like substances.
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- At Wheatley, the researchers were unable to find any
signs of reproductive activity by the snapping turtles.
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- Along the St. Clair River, scientists found less hatching
success than at the non-polluted sites.
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- Gulls from the Detroit River showed impaired immune systems.
There were also high numbers of dead gull embryos in nests along the Detroit
River and in western Lake Erie, compared to cleaner sites, and a single
male bird with what the Environment Canada research summary called a "significantly
feminized reproductive tract."
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