US Salamander Disappearances Puzzling Scientists

North America's largest salamander - also the third largest salamander in the world - is disappearing, and scientists are trying to figure out the reasoning behind it, the Associated Press reported.

Hellbenders, as they're called, which can grow two or more feet long, are vanishing from large parts of the 16 states they inhabit. Scientists believe the disappearance could reflect a plunge in the quality of the swift-flowing, rocky rivers and streams they are found in.

"These are animals that live up to 30 years in the wild, so if you have populations declining, that alerts us that there could be a problem with the water quality," Rod Williams, a Purdue University associate professor of herpetology who's tracked Indiana's hellbenders for nearly a decade, told the Associated Press (AP).

Hellbenders, also commonly dubbed snot otters and devil dogs, can be found in a number of states, including New York, Missouri, Arkansas, Indiana, Virginia and North Carolina. The Ozark hellbender, found only in Missouri and Arkansas, was added to the federal endangered species list in 2011 after their numbers dropped approximately 75 percent.

The US Fish and Wildlife Service (USFWS) is currently deciding if the eastern hellbender should also be added to the list.

"There's nothing else like them in North America," said federal biologist Jeromy Applegate, who's leading the eastern hellbender assessment, according to AP.

Because of their long lifespan, researchers at first did not recognize how rapidly their populations were declining. Even in areas that recently were thought to have healthy, stable hellbender populations, have plummeted, according to the USFWS.

Scientists suspect that water contamination could be the culprit, but dams have tamed some of the fast currents they prefer while sediment runoff from development has filled up the rocky nooks young hellbenders use for shelter, the AP reported. A fungus blamed for amphibian declines worldwide may also be a factor.

To combat their waning numbers, researchers encourage landowners to plant trees and grasses along rivers to improve the water quality. They're also raising young hellbenders to be released into the wild to bolster the population.