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Washington Post, Monday, Sept. 30, 1996 A-1 In: Minnesota Lakes, an Alarming Mystery: Hundreds of Deformed Frogs Pose Environmental Warning

Note: This is a condensed version of the original article.

DULUTH, Minn, -- In lakes throughout Minnesota, hundreds of people are reporting thousands and thousands of frogs with significant deformities, ranging from extra legs to missing eyes. Wildlife biologists from EPA, the Minnesota Pollution Control Agency and universities have been unable to say conclusively what is causing the deformities, but many are concerned that the frogs are sentinels of environmental contamination.

EPA biologist Joe Tietge, from the Duluth laboratory, organized a conference of scientists to share recent findings. [presented here]

 The varieties of frogs most affected by deformities appear to be those that spend the most time in water. Some biologists speculate that parasitic infestations may be the root cause. Most, however, suspect a chemical pollutant, perhaps a pesticide. Other causes that have been proposed include viral or bacterial diseases, heavy metals, acidification, and increased ultraviolet exposure.

Tietge said EPA would continue researching the phenomenon. "If it turns out to be a chemical problem, then we'll have to do a risk evaluation for humans. After all, frogs are vertebrates and so are we."
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On Aug. 8, 1995, teacher Cindy Reinitz took a group of her middle-school students on a field trip to a farm in the town of Henderson in South-Central Minnesota. As they walked along, the kids started chasing frogs. Jeff Fish, a red-haired freckle-faced 13-year-old, caught the first one that didn't look right. "When I picked him up I saw that he was missing his right hind leg," said Jeff. "My first instinct was that a predator had bitten it off. But I looked him over for sores or scars and I didn't see any so I showed him to the teacher."

As Reinitz examined the amphibian, a girl brought over another frog, this one with a withered hind leg. Then another. All told that morning, the class caught 22 frogs, 11 of which had deformed hind legs. "I think the kids got kind of scared," said Reinitz. "They immediately started asking me what the cancer rate was in the area". Shaken, Reinitz alerted a local wildlife biologist and the frogs eventually were reported to the Minnesota Pollution Control Agency in St. Paul. It would be the first of many such reports the agency would receive in the coming months.

Deformed frogs have now been found at more than 100 sites in 54 of Minnesota's 87 counties, and researchers here believe they're everywhere in the state. Deformed frogs have also turned up across Wisconsin and in the St. Lawrence River Valey of Quebec.

A research team received an emergency grant of $123,000 from the Minnesota legislature to study the frog problem this past summer. The team, which could scarcely keep up with the reports pouring in from all over the state, found frogs with missing legs, extra legs, misshapen legs, paralyzed legs that stuck out from the body at odd places, legs that were webbed together with extra skin, legs that were fused to the body, legs that split into two half-way down. They also found frogs with missing eyes. One memorable specimen was a one- eyed frog that turned out to have the second eye growing inside its throat.

In the meantime, nobody knows what to tell people in Minnesota who want to know what all this might mean to them. Frogs serve as a "sentinel species" because many of their metabolic functions are similar to the same processes in humans. Early evidence points to something in the water where the frogs breed and develop. Their skin is permeable. What gets in the water can get into the frogs. Two theories are receiving the most scrutiny:

One is that the frogs have become infested with naturally occuring parasites. The other is that the water has become chemically contaminated. Judy Helgen, a research scientist and water quality expert with the Minnesota pollution agency who's led the investigation to date, said she believes the focus will eventually come down to chemicals of some kind. In the interim, the EPA will almost certainly get involved in the research which may take several years. Part of it is that you can only study the frogs for a limited amount of time each summer.

U.S. Department of the Interior
U.S. Geological Survey
Patuxent Wildlife Research Center
Laurel, MD, USA 20708-4038
http://www.pwrc.usgs.gov/naamp3/naamp3.html
Contact: Sam Droege, email: Sam_Droege@usgs.gov
Last Modified: June 2002