By Jenny Neyman
What’s worse than being a frog — a major link in the food chain and a creature that’s acutely susceptible to deformations from exposure to contaminants or other changes in their environment?
Try being a biologist attempting to tease out definitive conclusions from studying them.
“It’s really hard to nail these things down. That’s what makes science challenging,” said Meg Perdue, a biologist specializing in environmental contaminants for the U.S. Fish and Wildlife Service.
She’s one of the researchers involved in continuing studies of amphibians on national refuges in Alaska, including the Kenai National Wildlife Refuge. The latest iteration of that monitoring project is a study focused specifically on the Kenai in an attempt to discern why, out of the five refuges monitored in the state, the Kenai is showing a higher incidence of frog deformations than any other.
“Out of the monitoring work, when we saw higher rates in Kenai, we focused a study trying to come up with correlations with the malformations,” Perdue said.
This program of amphibian monitoring is a nationwide effort dating back to the mid-1990s when a high number of amphibian deformations — specifically, frogs with extra limbs — was noticed on a refuge in Minnesota.
Frogs are considered a bellwether species, a sort of canary-in-the-coal-mine indicator of changes in an environment, because amphibians are very susceptible to contaminants and other changes in their ecology.
“They tend to bridge multiple environments and their developmental process is out in the environment, unlike mammals and birds that are more protected. Bird eggs at least have a hard shell, and mammals, their embryos are internalized, but frog eggs are just out there in the media and therefore have lot of exposure because of how permeable amphibians are in terms of that interface with the environment,” Perdue said. Continue reading