Frog deformities caused by parasites, not pesticides.

ASSOCIATED PRESS ^ | May. 06, 2002 | JEFF BARNARD

[grundle]

http://www.duluthsuperior.com/mld/duluthtribune/news/nation/3206507.htm

Posted on Mon, May. 06, 2002

Study reports parasitic worms cause frog deformities

BY JEFF BARNARD

ASSOCIATED PRESS

GRANTS PASS, Ore. -- After slogging through 101 ponds and wetlands in five western states, scientists on the trail of a mysterious outbreak of deformities in frogs have settled on a microscopic parasitic flatworm as the prime suspect.

Linked with existing laboratory studies showing that the trematode known as Ribeiroia ondatrae can cause the frogs to sprout extra legs, the new field work closes the loop by showing a direct correlation between the prevalence of the parasite and the number of deformed frogs, scientists said.

"There's still work to do, but this nails it,'' said Stan Sessions, associate professor of biology at Hartwick College in Oneonta, N.Y., who did not take part in the study, but has been working on the mystery since 1990.

The study was published in the May issue of Ecological Monographs, the journal of the Ecological Society of America.

Since the late 1980s, scientists have been concerned about catastrophic declines in populations of frogs, toads, salamanders and other amphibian species, particularly in Australia, South America, Central America and high-altitude regions of the American West.

In the 1990s, reports started popping up around the United States of large numbers of deformed frogs. Scientists suspected pesticides, ultraviolet light and trematodes as causes.

The reason the deformities are becoming more common appears to be a chain reaction related to human changes to ecosystems, especially fertilizer and cow manure washing into the ponds, said Andrew Blaustein, professor of zoology at Oregon State University and one of the study's authors.

"We think the fertilizer is causing more algae,'' Blaustein said. "More algae means more snails to eat the algae. More snails means more parasites (because they live in the snails). More parasites means more malformed frogs.''

Pieter Johnson, a graduate student at the University of Wisconsin and senior author of the study, said more surveys need to be done in the Midwest and East, where frog deformities are also prevalent, to conclusively put the blame on trematodes.

But the work already done showed 80 percent of the ponds with more than 5 percent malformations in one or more species of amphibians were built to water cattle, he said.

The researchers tested water samples for pesticides, but found no statistical link to the prevalence of malformations. They did not directly test for ultraviolet light levels, other than to note the elevations of the sites. The Environmental Protection Agency has shown UV radiation can induce deformities in laboratory tests.

[jwalburg]

No. I've been told by an animal rights activist
that it is demand for milk and meat by people, especially
people with large families, that cause there to BE
so many cows in the first place.

[tracer]

It's true, ya know. The bovines sense the demand and then breed accordingly... 8~)

[Carry_Okie]

This story is guaranteed not to make the front pages of the major media. Probably will be buried in Page B23 of the Saturday editions.

Naaah, they just need to clean it up a little bit. How's this for a headline:

Agricultural Runoff Causes Frog Deformities

Now which NGO is going to sue under the Clean Water Act Section 303(d)? My bet is on NRDC.

[Diddle E. Squat]

Good point. Never underestimate the cunning of professional liars.