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"It Isn't Easy Being Green," Kermit the Frog: Frogs, Part

© Kenneth Friedman

For several years, some of the scientists and others concerned with frogs and toads have been hopping about in shock. They're shocked because of widespread rumors and confirmed reports of horribly deformed frogs. The distribution of deformed frogs in Minnesota, for example, is so broad that scientists have a hard time finding wetlands without deformed frogs, according to Beth Silver of The Associated Press.

The deformed frogs aren't only in Minnesota. They're also in Wisconsin, South Dakota, California, Vermont, Quebec and elsewhere. Deformities, coupled with the scare about species that have disappeared altogether, has prompted scientists to expand monitoring and to create a national center for reporting amphibian deformities. If you haven't guessed, frogs and toads are amphibians. So are salamanders and newts.

In Minnesota, David M. Hoppe at the University of Minnesota says there has been an increase in deformities. He says that between 1975 and 1995 he handled thousands of frogs and saw only two with "microscopic" limb defects. But in 1996 he saw over 200 deformities in six species, including "missing limbs, missing portions of limbs, malformed limbs, extra limbs or limb portions, fusion of upper and lower legs, and missing eyes." Sounds like something from Fox Television's The X Files.

Hoppe thinks the frequency and geographic distribution of abnormalities indicate "a recent and rapidly developing phenomenon." At one site he found six species of frog and toad with deformities. The worst was the mink frog--most aquatic of the six--with 50 percent abnormalities. Hoppe believes that the cause is something that has "achieved higher concentration and/or wider distribution in recent years," and that "is most likely acting in the water where the anurans (frogs and toads) breed and their larvae develop." But he doesn't know what that something is.

Robert D. DuBois of Wisconsin's Department of Natural Resources confirms the increase in deformed frogs. He says that only two deformed frogs were reported in the 1970s but now they've been reported from 16 sites in 15 counties throughout the state. Although these reports were not substantiated, DuBois is concerned enough to believe that an information clearinghouse should be started. He also says that people should be taught where to report their discoveries of deformed frogs.

The causes of deformity could be climate change, pollution, natural factors or a combination of factors. Gerald T. Ankley of the U.S. Environmental Protection Agency doubts pesticides are at fault because deformed frogs and toads have been found on state forests, where there are no pesticides, as well as in wetlands affected by agriculture--the source of pesticides. Ankley suspects the well-documented increase in ultraviolet (UV) light associated with thinning of the ozone layer.