Froggin' for fun, science

Posted: Monday, July 14, 2003

Jordan Stout, an environmental contaminants specialist from the Anchorage U.S. Fish and Wildlife Service field office, led a small but enthusiastic group of 11 volunteers in hip waders and rubber boots to a pond in Sterling this past weekend on an educational excursion in search of wood frogs.

"Mine has two legs," said one excited volunteer.

"Mine has all four," shouted another.

"It's not a contest," joked Stout.

The weekend outing was part of the Kenai Watershed Forum summer program series. Its goal was to keep the public informed about an ongoing research project focusing on malformed amphibians that is now in its fourth year.

Increased rates of malformations among amphibians and major declines to their populations have been the focus of global concern and attention since first discovered back in 1995.


This wood frog captured Saturday has an abnormality. It is missing an eye.

Photo by McNair Rivers

Although the problem is worldwide, it strikes close to home as well. In the Kenai Peninsula's own back yard the Kenai National Wildlife Refuge malformed frogs have been collected every year since the project began, with as many as 8 percent of the collected specimens having physical abnormalities. Two percent is the rate at which abnormalities are expected to occur.

Some of the anomalies from the frogs collected on the Kenai in the past have included missing hind legs, missing feet, partial hind legs, misshapen hind legs, club feet and missing eyes.

"Some people think of frogs as the canary in the coal mine," Stout said, referring to the fact that amphibians are good early indicators of environmental changes.

Studies such as Stout's are relevant to both the scientist and lay person, since frog health is closely linked to the health of the environment.

On Saturday's trip, Stout gave an introduction to the current malformed frog research, then showed the group how to find frogs, how to catch them and how to evaluate their stage of development.

Catching the froglets was tough for Isaiah Records, the group's youngest volunteer. The 3-year-old was barely visible in the tall grass that surrounded the pond, but the dense vegetation didn't stop him from having a good time.


Joe Connor and Peaches Talyor examine the net and hope they have collected some froglets.

Photo by McNair Rivers

"I like frogs," he said. "They're fun to catch."

The highlight of the day was a one-eyed frog collected by the group. There were many wrinkled noses and grimaces on the faces of volunteers as Stout held out the abnormal specimen so everyone could get a good look.

"I wasn't expecting to see a malformed one," said volunteer Michele Alexander.

Stout will have the specimen examined further for pathology. This can determine if an optic nerve is not present or undeveloped which would be a true malformation or if the eye was lost as the result of an injury which would make it a deformity.

"Now is a good time of year to attempt to collect froglets," said Stout. Froglets are frogs that only recently metamorphosed from the tadpole stage.

He attempts to collect 50 to 100 specimens in order to average a decent sample size, but this is often more difficult than it sounds.

"If you collect too early in the year, you get just tadpoles," he said.

This is no good since many of the malformations show up in the amphibians' legs, which haven't developed on tadpoles. Also, malformed specimens are X-rayed to glean more information, but since tadpoles' skeletons have not yet calcified, any malformations wouldn't show up on an X-ray.

As bad as collecting too early is collecting too late, because then you run the risk of not getting any, said Stout. This is because older frogs typically disperse away from the ponds as part of their natural seasonal cycle.

This means that froglets must be collected within a relatively narrow window of time. This is a challenging task because there are no certainties as to when this window will occur especially in years such as this when many species of flora and fauna are ahead of their natural schedules due to the mild winter.

Despite how challenging the research can be, Stout said it is still a luxury in Alaska compared to many other states. Alaska has six species of amphibians, but the wood frog is the only species of amphibian to occur with any regularity on the peninsula. This makes the work easier compared to states that have as many as a dozen or more frog species.

"The KNWR project is still in the first phase of the project, which is reconnaissance," said Stout. "The second phase will be to identify possible stressors and the third stage will be to determine a causal relationship.

"There is still no smoking gun as to the cause of the malformations."

There are many factors that can contribute to amphibians' malformations and deformities including: potential contaminant sources such as oil and gas development; industrial development near refuge boundaries; contamination associated with mining, pesticide application and transport through the atmosphere; exposure to environmental contaminants, ultraviolet radiation, disease agents and nutritional deficiencies; and injuries sustained from predators, he said.

Subscribe to Peninsula Clarion

Trending this week:


© 2018. All Rights Reserved. | Contact Us