Deformed frogs perplex scientists

July 26, 2005

JOEL DAVIDSON\Frontiersman reporter

BIG LAKE - Three weeks ago, longtime Big Lake resident Bud Beech was out mowing his grass. Surrounded by tiny ponds and marshlands that connect with Big Lake, Beech's yard teems with tiny Alaska wood frogs.

Moving the mower up and down the lawn, the frogs began jumping out of the way. It was nothing unusual until Beech caught sight of something strange.

"I looked down and saw one that didn't have any back legs," he recalled last week. "I thought I ran over it or something. I stopped to take a closer look and I couldn't find the crazy thing."

Then a few days later, a visiting friend noticed other frogs around the yard with missing legs and stump feet. Beech investigated the curiosity further and started picking up all kinds of malformed frogs.

"I picked up a dozen of them and three were missing the right rear leg," he said. Others limped along on shriveled hind legs or tiny nubs.

In nearly 50 years living near Big Lake, Beech has never seen anything like it before. State scientists, however, say sightings of deformed frogs are on the rise, both statewide and nationally.

"Deformities are starting to show up on the radar," said David Tessler, a Division of Wildlife Conservation non-game biologist with the Department of Alaska Fish and Game.

Since amphibians spend much of their life in water and breathe through their skin, they are often the first species to develop deformities when changes occur in their eco-system. Scientists are concerned that the recent frog reports could be early indicators of much broader environmental concerns.

Nationally, malformed amphibians - mostly frogs - have shown up in nearly every state and in more than 50 different species. Scientists from Vermont to New Mexico are tracking the phenomenon.

Tessler said wood frogs are the widely reported Alaskan amphibians to have deformities. Six native amphibian species live in the state: Three salamanders, one toad and two types of frogs. The wood frog, however, is the most widely distributed amphibian, with sightings that range from the Kenai Peninsula to the Brooks Range.

Last summer, about 50 scientists gathered in Juneau to discuss the problems facing Alaska's amphibians, which include a marked decline in toad and frog populations. The first-ever statewide conference on Alaska's amphibians brought together eight federal agencies, four state agencies and two nonprofit groups.

The goal was to coordinate research efforts, share information and develop standardized monitoring strategies to help explain what is happening to Alaska's amphibians.

"Not much research has been done on Alaskan amphibians," Tessler said. "We want to look at monitoring amphibians in a repeatable, scientifically justifiable way."

While individual reports of decreased populations and deformities abound, Tessler said precious little is actually documented in a way that would allow scientists to identify environmental trends.

"Until we really know, we can only speculate," he said. "We need documentation."

Any number of factors may contribute to amphibian deformities and population declines.

Tessler said the causes might stem from petrochemical or toxic pollution, temperature changes or fungal infections.

"We're talking about changes in the biosphere," he said. "It's not really clear."

This summer, a pilot program is under way to study amphibians in Southeast Alaska, where the highest concentration of Alaska's amphibians lives. The data will later be pooled to determine environmental trends.

Contact Joel Davidson at joel.davidson@frontiersman.com.