AK Press: Frog deformities may hold key to climate change

[Herp News]

KTUU (Anchorage, Alaska) 21 August 09 Frog deformities may hold key to climate change (Ashton Goodell)
Anchorage, Alaska: Biologists are testing the water to uncover why Alaska woodland frogs developed deformities.
They say climate change and water contamination has something to do with it, but the research is leaps and bounds behind the evolution.
U.S. Fish and Wildlife Service biologist Mari Reeves grew up a tomboy -- not afraid of anything slimy and always with one foot outdoors. Years later she never really gave up looking for frogs and figured out a way to cast a larger net.
Reeves studies the affects of climate change and water contamination on wetland animals. Frog populations are declining around the world and biologists worry the losses will force ecosystems to change too quickly.
Biologists found more and more abnormal frogs in Alaska and they say the levels can't be explained by evolution or natural progress -- only by human intervention.
"So normally you would expect to find between zero and 2 percent of the frogs you survey," Reeves said. "Say if you caught 100 you would expect to find two that were abnormal, but in a lot of areas of the Kenai National Wildlife Refuge and the Tetlin National Wildlife Refuge we found closer to 8 to 12 percent of these are abnormal."
Frog development depends on temperatures and scientists with Fish and Wildlife say rising global temperature affect how an egg develops into a tadpole and then into a frog.
Water quality also affects quality of life for wetland creatures.
"As frogs develop they do things like get rid of gills and develop lungs in that water, and they grow legs in the water exposed to whatever is happening in that water," Reeves said. "For those reasons we think of them as indicators of environmental quality."
Nine years ago biologists started testing frogs in five different wildlife refuges. In that time they found frogs living near human development were more likely to form abnormalities.
But correlation isn't causation. There are three reason scientists think the frog legs developed abnormally, and that's what they are researching now.
"The abundance of dragonfly larvae in the early season and chemical contaminants -- specifically metals -- another thing was temperature, higher temperatures being associated with more abnormalities," Reeves said.
Reeves and her researcher hypothesize that certain metals, like cooper, run off the road and into the wetlands. The animals that swim in these bogs take in those metals; it begins to affect signals to the brain and makes it harder for animals to detect predators.
In the case of frogs, their predators gain an advantage and bite off their legs.
"They don't smell the predators, so they don't they don't change their behavior, so they are getting hit at a much higher rate," Reeves said.
They test the water to measure temperature and acidity to see how contaminants and environmental factors influence frogs' development.
This is just a pilot study. The U.S. Fish and Wildlife Service wants to collect a larger sample from the Kenai National Wildlife Refuge to see which factor caused the deformities, but it is waiting on funding.
http://www.ktuu.com/global/story.asp?s=10973321