Bruce Nelson was catching frogs for catfish bait last year when he realized something was horribly wrong: Some of the frogs had stumps for legs, and others had as many as four tangled hind legs.
“You see deformed things all the time in nature, but nothing like this,” Nelson said.
All across Minnesota, into neighboring Wisconsin, South Dakota, and even as far away as Quebec and Vermont, scientists and locals are seeing the same kind of grotesquely misshapen limbs, along with frogs with tails, missing or shrunken eyes, and smaller sex organs.
“It scares me,” said Judy Helgen, a research scientist with the Minnesota Pollution Control Agency. “I’m at different levels of getting a chill down my spine.”
Scientists aren’t sure what’s causing the deformities. The theories run the gamut from pesticides to parasites to radiation from ozone depletion, or some combination of factors.
What worries many around the state is whether humans are in danger, too.
“There’s a reasonable assumption that if there’s an external substance influencing amphibian development, it could influence human development,” said David Hoppe, who is on a state-financed team of scientists researching the problem.
So far, little has been discovered. The federal Environmental Protection Agency plans to do its own study.
Students from the Minnesota New Country School in Le Sueur, in the heart of the state’s farm country, first reported the deformed leopard frogs during a field trip to a wetland last year.
They reported their findings to the pollution control agency, then to state lawmakers, and finally went worldwide by putting their information and pictures of the frogs on the Internet.
“When somebody caught a frog without one leg,” 13-year-old Jack Bovee told a state House committee this year, “I thought, ‘Houston, we have a problem.”’
Cindy Reinitz, the teacher who has become known as “The Frog Lady” since her middle school students made the discovery, said there is at least once person with cancer in every household around the wetland. But scientists have made no direct link between the frog abnormalities and cancer.
The fact that the abnormalities are widespread suggests that the problem has more than one source, said Hoppe, a herpetologist from the University of Minnesota at Morris.