The largest salamander in the U.S., known as the hellbender, seems to be in danger of disappearing completely, according to scientists. The Associated Press reports (via Fox News) that the hellbender salamander is starting to disappear from huge sections of the 16 states in which they live.

Hellbender Salamander

Hellbender habitats

The lizards are only found along rocky streams and rivers that are fast-flowing. They breathe almost entirely through their skin, which is important because they help scientists measure water quality. They are very sensitive to pollution and silt, according to researchers at Purdue University. Hellbenders can live up to 30 years in the wild, so if their numbers are declining, then it could mean that the quality of the water in the areas they once inhabited has deteriorated dramatically.

Currently the U.S. Fish and Wildlife Service is assessing the hellbender population to see if they should add it to the U.S. endangered species list. They are specifically look at the eastern hellbender, which is one of two subspecies. The other one is the Ozark hellbender, and it lives only in Arkansas and Missouri. It has been on the endangered species list since 2011 when a 75% decline in population was noted.

Hellbender salamanders are unique

The slimy amphibians have earned a bat rap and a number of bat nicknames, like devil dog and even snot otter. However, scientists say they are very unique and that there are no other animals like them in North America. They’re able to slide between rocks thanks to their flat heads and slimy coating. They have a tail that works like a rudder to guide them through strong currents and short fingers and legs so that they can grip rocks.

At this point, scientists don’t know why hellbenders are disappearing. In addition to concerns about pollution, they note that some dams have slowed the flow of some of the rivers they once inhabited. Also sediment runoff has increased along with development, filling up the areas in rocks where hellbenders once lived. In addition, a fungus that has decimated amphibian populations around the globe could be playing a role in their disappearance.

Scientists work to protect hellbenders

Researchers want landowners to plant grasses and trees on the banks of rivers to help improve the quality of the water. They are also taking care of some young hellbenders with the goal of releasing them out into the wild to give the population a boost. Currently the St. Louis Zoo has about 3,000 Ozark hellbenders that hatched from eggs. That’s more than double the number of the subspecies that’s believed to still be living in the wild.

Surveys of hellbender populations have found adult ones but very few young ones. In at least one case, researchers had to search for six hours before they could find a single one.