WALLAND, Tenn. (AP) — A University of Tennessee student is catching and testing water snakes for viruses that have killed a large amount of frogs and salamanders around the world.
Stephen Nelson, who is a senior majoring in wildlife and fisheries management, has spent the last two years testing northern water snakes for ranavirus, which is actually a group of viruses. The Knoxville News Sentinel (http://bit.ly/OMZux8) reports his project is the first to test all North American snakes for ranavirus.
The virus was linked in the 1980s to large-scale amphibian deaths, but recently has been found in box turtles, including those at the Oak Ridge Arboretum. Especially with the disease's jump to turtles, which are reptiles, biologists are trying to find out how it spreads.
During a recent trip to Little River in Blount County, Nelson caught a northern water snake with the help a couple of local teenagers who told him they had just seen one disappear under a rock.
Nelson waded into the water, gently raised the rock and found a 24-inch specimen with alternating bands of reddish-brown and gray. Nelson says researchers are trying to figure out how the ranavirus can be present in ditches and other places that stay dry part of the year and should be virus-free.
"We figure something is bringing the virus back to these ponds whenever they fill up," Nelson said. "Water snakes can travel in between bodies of water. They could be the host."
It's not even known if northern water snakes carry the disease, but studies show that hellbenders do — and small hellbenders are part of the snake's diet. After catching the snakes, Nelson swabs them and takes the samples to a UT lab where they are tested for ranavirus. The project will end in the fall when the northern water snakes start hibernating.
So far, he has caught 17 northern water snakes on the Little River; he hopes to get 30.
"They're elusive," Nelson said. "They're bad about diving in the water and getting away. I've had to grab them as they swim down rapids."
Information from: The Knoxville News Sentinel, http://www.knoxnews.com