A giant salamander species, commonly known as hellbenders, are the subject of a new research study out of Great Smoky Mountains National Park.
Hellbenders spend most of their life practically invisible. Their brown, textured skin helps them seamlessly blend with stream beds, and they often spend their time underneath the rocks. This, along with their 30-year life span, has made the species infamously difficult to quantify.
“One of the major conservation questions is: Are hellbenders reproducing in our streams?” said Jonathan Cox, wetlands biology technician for the park. “And it’s really hard to find that out because their lifespan is so long that you can have a hellbender detected in a stream for multiple decades, but it may be the same individual.”
Determining whether adult hellbenders are currently reproducing, and at what rate, will be critical for the conservation of the species. A proposal to list the eastern hellbender as endangered under the Endangered Species Act is receiving public comment until February 11.
In a two-year research project starting this summer, Amphibian and Reptile Conservancy researchers will combine cutting-edge technology and traditional survey techniques to determine the hellbender’s distribution in the Smokies. They’ll compare their results to baseline data gathered in the early 2000s.
Gathering data
While some data will be gathered by snorkeling, researchers are also developing a new technology that will increase the usefulness of the data.
This method, called environmental RNA, or eRNA for short, involves analyzing genetic material found in water samples from streams thought to contain hellbenders. The process is similar to eDNA, but eRNA goes a step further to show which genes are expressed. The results will help researchers determine whether there are larvae in the stream, which would show new population growth.
Scientists will also capture and analyze hellbender DNA to determine genetic lineage and discover whether populations are isolated, leading to genetic bottleneck and inbreeding.
If successful, this project will help inform NPS decisions about where and how to build river crossings for roads and trails. It will also help hellbender researchers create a more robust conservation and management plan for the population.
