GAINESVILLE, Fla. --- A farm irrigation canal would seem a healthier place for toads than a ditch by a supermarket parking lot.
But University of Florida scientists have found the opposite is true. In a study with wide implications for a longstanding debate over whether agricultural chemicals pose a threat to amphibians, UF zoologists have found that toads in suburban areas are less likely to suffer from reproductive system abnormalities than toads near farms where some had both testes and ovaries.
"As you increase agriculture," said Lou Guillette, a distinguished professor of zoology, "you have an increasing number of abnormalities."
Guillette is one of several UF authors of a paper on the research appearing in the online version of the journal Environmental Health Perspectives. The lead author is Krista McCoy, who did the work as part of her UF School of Natural Resources and the Environment dissertation.
Several past studies have suggested a link between herbicides commonly used in farming and sexual abnormalities in tadpoles and frogs. Such deformities may be responsible for declines in frogs documented in areas affected by agricultural contaminants, such as Sierra Nevada, Calif., McCoy said. Amphibians are declining worldwide and agricultural chemicals are considered to be one likely cause, she said. Others include pathogenic infections and habitat loss.
Past research has compared frogs collected from natural areas with those collected from agricultural areas. Other efforts have pointed to specific chemicals, including the herbicide Atrazine, as causing abnormalities. The UF study is the first peer-reviewed study to compare abnormalities in wild toads toads are a variety of frogs -- from heavily farmed areas with frogs from both partially farmed and completely suburban areas. In so doing, it highlights the difference between the impact of agriculture versus development.
"Our study is the firs
|Contact: Lou Guillette|
University of Florida