NASHVILLE, Tenn. (WKRN) — Twenty-seven hellbenders were released into Middle Tennessee streams Monday and Tuesday.

A hellbender head start program began years ago to take the eggs from the wild and let the salamanders grow and be healthy in a conservation facility, per Dale McGinnity, Nashville Zoo Curator of Ectotherms.

“We have documented survival rates since we started releasing hellbenders in the summer of 2021. We are seeing increased success over time,” McGinnity said. “Hellbender populations in Middle Tennessee have been shown to have low genetic variation while also being genetically unique from all other populations. We are releasing hellbenders in different streams from which they were collected as eggs to properly increase gene diversity of individual historically connected sub populations.”

The release happens annually. The critters have surgery months before the release to have transmitters inserted so they can be tracked once released. “[We have] new information and more data on how hellbenders raised in a conservation facility move and utilize their environments over time. We have been able to document some interactions between the head start hellbenders and resident wild hellbenders,” McGinnity added.

Conservation for hellbenders is important because their numbers have been dwindling since the 1980s when they used to be abundant. McGinnity said these salamanders are significant.

“Hellbenders are very unique and not closely related to any other species in the New World.  They are important indicators of stream health and poor water quality is bad for everyone.  Hellbenders had a wide range in the eastern U.S.; however, they are becoming extremely rare and often extinct in most watersheds due to declines that were first documented in the early 1990s.”

It’s important for the hellbenders to be released where the water is clean and other wild hellbenders are present.

“We are only working in the few rivers or streams left that are fairly pristine and still contain hellbenders in Middle Tennessee. Before the 1980s, hellbenders were common in most of the area. All Middle Tennessee populations are declining at a fairly rapid rate which we believe is due to very low larval survivorship,” McGinnity said.