There was once a time, not too long ago, when swaths of giant salamanders roamed the waterways of Appalachia. Growing up to two feet long, eastern hellbenders spent much of their lives at the bottom of rivers and streams along the Ohio River Basin, plodding along with their broad, paddle-like tails and stubby legs.
That time has long passed for many of the waterways the species once called home. Now, researchers, including at the Nashville Zoo, hope to save the few remaining wild hellbenders, which are struggling to keep a foothold amid climate change and human activity.
Researchers have watched populations decline significantly since the 1990s. Conservationists pressured the U.S. Fish and Wildlife Service in 2024 to propose the eastern hellbender as an endangered species throughout its range under the Endangered Species Act.
According to a lawsuit filed against the U.S. Fish and Wildlife Service by the Center for Biological Diversity, federal officials failed to meet a critical 2025 deadline for this proposal, preventing the species from becoming listed. The center has filed multiple other lawsuits against the U.S. Fish and Wildlife Service this year.
Hellbender conservation
Conservationists like Monte McGregor at Kentucky Fish and Wildlife have worked to restore the species through a process of catching, breeding, tagging and releasing groups of hellbenders around the region.
“It’s a large effort to look for hellbenders in different parts of the state,” McGregor said. “We asked fishermen for help with that. They catch them sometimes on fishing lines. When they catch them, we ask them to take pictures of them, send them to us, and tell us where they found them.”
Hellbenders are a vital part of regional ecosystems, and when populations decline, it signals a larger problem to researchers, McGregor said. The populations they’ve identified are in the eastern part of the state in areas like the Green River or Lake Cumberland.
Like other salamanders, hellbenders breathe through their skin and require highly oxygenated water to thrive in an environment. This makes the species sensitive to water pollutants that enter waterways through storm runoff.
“When you muddy up a river, you basically interfere with its ability to breathe a little bit, its ability to catch food, and also for the eggs to hatch and the young to survive,” McGregor said.
Efforts to conserve hellbenders extend well beyond Kentucky. Dale McGinnity is the senior curator of ectotherms at the Nashville Zoo, which has long worked to breed hellbenders with conservation in mind. In McGinnity’s opinion, the biggest factor impeding hellbender populations from fully repopulating is human alteration like land development and agriculture.
“[Agriculture] is probably the biggest change to most watersheds, and has the largest impact for most watersheds,” McGinnity said. “But also, cities and towns have stormwater runoff that picks up other things that can negatively impact a watershed.”
Silt and gravel that enter waterways through runoff heavily impact larvae. The sediment settles under rocks where hellbenders live most of their lives, leaving little room for macroinvertebrates that are key to their diet. It can take decades to see a species recover, even if conservation efforts are consistent, McGregor said.
Population imbalances
Environmental changes seen in many waterways have resulted in large die-offs of hellbenders, leaving a scattered, uneven balance of viable breeding adults.
“It could also be that the water quality has improved, but now there’s not enough of them to reproduce, so there aren’t many breeding populations left in the state,” McGregor said.
Those population imbalances appear in McGinnity’s conservation work with the zoo. He said that in most regional hellbender populations, the number of older individuals outweighs the number of juveniles.
“The real problem is in the larval stage because they have a different life history,” he said. “That’s why we’re not seeing recruitment or enough younger animals coming back into the population, so they’re just aging out, but very slowly.”
Through their conservation, juvenile populations raised in controlled settings and fed consistently with pinky mice survive the larval stage and thrive. The majority of populations in captivity can live for up to 30 years.
McGinnity said it’s important for conservationists and researchers to stress the severity of human impacts like land development and pollution and that these impacts can be prevented. Their hope is that education pushes people to take the necessary measures to reduce their impact by using erosion control measures on construction sites and taking precautions when spraying herbicides.
“A lot of people really don’t think about stormwater runoff and the impacts it has, like spraying herbicides anywhere near a body of water,” McGinnity said. “People give me grief because there are laws for it, but they’re not very well followed in many places.”
McGregor echoed McGinnity’s insistence that education is vital to the future survival of hellbenders. He hopes that with enough awareness and a bit of precaution, hellbenders can one day find renewed stability in the cool streams of Kentucky and beyond.
“The more people are familiar with what causes things to be rare and endangered, the better they will understand how we can correct those kinds of things to help maintain these species that we have and provide population for our next generation of people,” McGregor said.
This story was produced by the Appalachia + Mid-South Newsroom, a collaboration between West Virginia Public Broadcasting, WPLN and WUOT in Tennessee, LPM, WEKU, WKMS and WKU Public Radio in Kentucky, and NPR. Sign up for the weekly Porch Light newsletter here for news from around the region.
Copyright © 2026 WKU Public Radio
On Air - 90.3 WPLN-FM