"Whatever happened to the ‘deformed frogs’ problem?"
The ‘deformed frogs’ problem has not disappeared, even though it no longer makes the nightly news. Although the widespread occurrence of amphibian skeletal malformations has been considered an important environmental issue and researched extensively around the world, causes of these deformities in wild populations have been difficult to pinpoint.
One thing that scientists agree on is that deformities can result from multiple causes and that these causes vary from region to region. Scientists also believe that many of the causes are primarily due to, or exacerbated by, human activities. The major causes of malformations identified so far are chemical contaminants, parasites, and injuries from predators. At any given location, one or more of these factors could cause amphibian skeletal malformations as well as amphibian population declines. Additionally, the causes of malformations at one site may differ from those at another site.
Deformed frogs continue to be found across Minnesota and around the world, although rarely in huge outbreaks like that discovered in 1996 at Ney Pond in Le Sueur County, and other locations around Minnesota. Research continues to resolve uncertainties in the amphibian malformation phenomena and the U.S. Geological Survey continues to collect reports of amphibian malformations (www.nbii.gov/narcam/).