The U.S. Fish and Wildlife Service (FWS) recently awarded a Competitive State Wildlife Grant (C-SWG) to the Southeastern Association of Fish and Wildlife Agencies (SEAFWA) to conduct research on the eastern hellbender (Cryptobranchus a. alleganiensis). This grant supports a critical need to identify and resolve conservation threats for this and many other species dwelling in high-quality watersheds throughout the Southeast.

Over the past three decades, amphibians have experienced the largest population declines of all vertebrate species, with nearly 30 percent of all known species in decline. Landscape alteration and destruction represent the largest threats to amphibian diversity worldwide, but amphibians are also vulnerable to other threats including emerging pathogens, such as amphibian chytrid fungus (Batrachochytrium dendrobatidis; Bd), salamander chytrid fungus (Batrachochytrium salamandrivorans; Bsal), and ranaviruses (Rv). Additionally, amphibians continue to be impacted by illegal collection. Many species that were once common have declined precipitously, and often data documenting the causes of these declines are lacking. This artifact is much exacerbated for stream-dwelling amphibians, because declines and their causes are often difficult to detect compared to pond-breeding and terrestrial amphibians.

The eastern hellbender is a large, fully aquatic salamander that inhabits cool, rocky, well-oxygenated rivers and streams within the Ohio, Tennessee, and Cumberland River drainages in the eastern United States. Disjunct populations of hellbenders also exist in Missouri and Arkansas ? the Ozark hellbender (Cryptobranchus a. bishopi) inhabits Ozark mountain streams. Populations of both hellbender subspecies have been greatly reduced throughout portions of the range where they were once common. Drastic declines have resulted in the federal listing of the Ozark hellbender as an endangered species and the inclusion of both eastern and Ozark hellbenders in Appendix III of the Convention on International Trade in Endangered Species of Wild Fauna. In addition, the eastern hellbender is currently considered as a candidate species for listing under the U.S. Endangered Species Act (ESA).

A lack of coordinated sampling efforts and difficulties associated with acquiring accurate population sizes have contributed to the lack of knowledge regarding the status of eastern hellbenders. In addition, little research has evaluated potential management strategies that will aid in the conservation and recovery of this species. With this in mind, the objectives of the research funded under the C-SWG program are:

• Evaluate the potential of using habitat improvements, including the installation of nest boxes, to mitigate losses of stream habitat due to stream-bank erosion and subsequent sedimentation.
• Confirm the presence or absence of historical eastern hellbender localities using manual and eDNA approaches.
• Monitor for prevalence of emerging amphibian pathogens, including Rv and two species of chytrid fungi (Bd and Bsal).
• Determine climatic vulnerability of eastern hellbenders and evaluate vulnerability of populations in the focal study region to climate change and other landscape stressors.


 

As the biological requirements of eastern hellbenders (e.g., cutaneous respiration, sensitivity to poor water quality) limit the distribution of this species to high-integrity stream environments, this species serves as an excellent indicator of environmental quality. This research will provide a timely evaluation of eastern hellbender population status throughout the study region and that can be used to leverage the conservation of high-quality watersheds that provide clean water for consumption and recreation. The overall goal of this multi-state endeavor is to identify primary conservation needs for eastern hellbenders and to complete the necessary management strategies for the long-term recovery of remaining populations to prevent federal listing under the ESA. (jg)