AP/Milwaukee Journal-Sentinel, November 5 1998 Researcher suggests link between deformed frogs, chemicals Researcher suggests link between deformed frogs, chemicals ST. PAUL, Minn. (AP)

Deformed frogs may be linked to the use of agricultural chemicals, a Canadian researcher suggests.

"From an epidemiological perspective, it’s quite obvious that there is a problem in sites subject to pesticides," said Martin Ouellet of McGill University in Montreal. He has examined almost 30,000 frogs along a 150-mile stretch of the St. Lawrence River Valley during the past seven years.

Ouellet has noted the association between deformed frogs and agricultural chemicals in previous years. But until this year he was not convinced he had seen enough evidence to establish a strong link. "It’s not just a s mall-scale problem here now," he said. "It’s everywhere, everywhere there’s an association with pesticides." Scientists internationally have reported a sharp decline in the numbers of frogs, toads and salamanders in many locations. Numerous explanations have been proposed, including water pollution and increased ultraviolet radiation from the sun because of a thinning ozone layer around the Earth.

Deformed frogs were noticed first by schoolchildren in 1995 as they studied a farm pond near Henderson, about 55 miles southwest of Minneapolis. Finding the deformities’ cause is important because scientists believe amphibians may be an early barometer of environmental problems. Minnesota state scientists hope Ouellet’s new information will aid their studies on frog deformities. "Depending on how his data fall out, it could add to what we’re thinking of doing in designing experiments for next year," said Judy Helgen, wetlands biologist at the Minnesota Pollution Control Agency. Ouellet said his latest findings include research on about 30 ponds and wetlands in the St. Lawrence River Valley, mostly on private property. The ponds near land with no recent pesticide use-including abandoned farmland and land used mainly for grazing-contained frog populations with less than 2 percent deformities. But ponds near land being farmed and subject to a variety of pesticides, insecticides and fungicides held frog populations with an average of about 20 percent deformities, he said. Numbers were even higher in some areas. In one pond, all the frogs from three species had deformities.

At some study sites, Ouellet said, he noticed empty pesticide containers discarded in or near the ponds, and at one location he found a farmer burning the plastic containers. Ouellet said most of the "frog" deformities were in the hind limbs and affected many of the species that have also shown deformities in Minnesota, Vermont and other states. The results have not been published in a scientific journal, but Helgen planned to discuss them with Ouellet and about 40 other scientists at a conference in San Diego.