Wednesday, February 11, 2015

Hellbenders and their conservation issues

A hellbender is a large salamander that is endemic to North America and has two distinct subspecies, the eastern hellbender, a salamander found throughout the eastern states, and the Ozark hellbender, which is found only in the Ozarks of northern Arkansas and southern Missouri. Hellbenders have existed for more than 65 million years, but sadly, they are now declining due to habitat destruction, poor water quality, predation, and invasive species.

State Wildlife Grants has helped these salamanders via securing hellbenders' futures. The Tennessee Wildlife Resources Agency and Tennessee Hellbender Recovery Partnership were presented with a State Wildlife Action Plan Partnership Award in March 2013 due to their leadership in conservation of eastern hellbenders, and their many efforts to prevent the subspecies becoming threatened.

The U.S Fish and Wildlife Service, in fall 2010, proposed listing both North American subspecies of hellbenders as federally endangered, due to declines in their populations since the 1990s. These two subspecies are North America's piece of the pie of giant salamanders, with only two other species in existence, the Chinese and Japanese giant salamanders. All giant salamanders are threatened by human activities, however.

While the eastern hellbender's federal status was being reviewed, the TWRA (Tennessee Wildlife Resources Agency) looked to see if it was really true that hellbenders were at great risk in Tennessee. At the time this was done, it was believed that the eastern hellbender was just as threatened as its cousin in the Ozark Mountains, but data was not available to support this. Other local hellbender experts were needed to help develop projects to firmly discern whether or not Endangered Species Act protection was needed. The experts used were Dr. Brian Miller, a professor working at Middle Tennessee State University, Dale McGinnity, the curator of reptiles and amphibians at the Nashville Zoo, and Dr. Michael Freake, a professor at Lee University. The copious amounts of knowledge, experience, and passion these experts had for hellbender conservation truly informed a number of TWRA projects that would soon produce the data needed to determine the eastern hellbender's federal status.

Surveying efforts helped show more of the picture of the hellbender's status in Tennessee. The salamander's distribution and abundance within the range it had historically declined severely over the last 20 years. Hellbenders in Middle Tennessee were only present in four Tennessee River tributaries, but they were not present in the Cumberland or Barrens Rivers systems, places where they were once abundant. Hellbenders were also missing in action from other streams that once had grand populations. Many of the populations of older animals had either no reproduction or the recruitment of young hellbenders. Genetic surveying of tissue samples from hellbenders in each river system differentiated two main populations:the Duck river system and Hiwassee river system populations. This knowledge would help guide future efforts to restock systems with hellbenders, to maintain genetic diversity.

In later years, new techniques were developed to restore hellbenders. McGinnity produced the first captive-bred eastern hellbenders, and he and Dr. Debra Miller at University of Tennessee, Knoxville produced sampling protocols for better understanding the impact of chytrid fungus and ranavirus on hellbenders, and both conditions were detected contributing to the eastern hellbender's decline. Furthermore, via conservation, improved techniques, and captive breeding, this ancient, beautiful salamander's life can be secured hopefully for years to come.

Reeves, Bill, Pfaffko, Mary. "Conserving the Eastern Hellbender in Tennessee" Tennessee Wildlife Resources Agency. 2014. (?)

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