The Eastern hellbender (Cryptobranchus alleganiensis) is one of the largest salamanders of North America ranging along the Appalachians from Alabama to New York. In Alabama, this fully-aquatic salamander occupies clear, flowing streams of the Tennessee River system. Degradation of aquatic habitats from sedimentation, siltation, stream channelization, and impounding have affected populations, leading to suspected declines.
While the Eastern hellbender has been documented in Franklin, Colbert, Lauderdale, Limestone, Madison, and Morgan counties, the current status of the species is unknown. Surveys are underway to address this lack of information. Throughout its range, conservation efforts are in place to understand the status of this incredible salamander and the results from Alabama will aid in the overall conservation of the species.
In the past, the typical method to search for the Eastern hellbender was by wading and snorkeling in shallow streams and lifting large flat rocks. Hellbenders take refuge under rocks as do many other aquatic species. Care would be used in lifting the rocks to minimize habitat disturbance and to avoid injury to any hellbender present. A new technique integrating field and lab methods has been developed. This new method, environmental DNA (eDNA), can aid us in detecting the presence of Eastern hellbenders in streams in which they occur. Organisms interacting with their environment shed tissue, which contains DNA, and in the case of aquatic animals the DNA-containing cells and tissues become free-floating in the water. With the eDNA method, water samples are collected, filtered, and then screened to detect the presence of any Eastern hellbender DNA.
Throughout the range of the Eastern hellbender researchers are using standard sampling and eDNA techniques to assess the status of the species. In Alabama we are utilizing both methods as well, and since eDNA has been shown to be more sensitive to detecting the presence of the hellbender we expect to locate streams previously unknown to contain hellbenders.
