Hellbender

The Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) is one of only two completely aquatic salamanders found in the state of Ohio.  Within the state it has historically been found in nearly all of the major systems draining into the Ohio River.

Previous surveys conducted during the drought years of the mid-1980s and in 2000 resulted in the capture of 112 individuals from 15 waterways, more than 50% of the total number of documented Hellbender occurrences in the state at the time.  At the conclusion of these initial surveys, the species was listed as endangered by the Ohio Division of Wildlife.

A follow-up survey (2006-2010) included mark-recapture, examination of the prevalence of the amphibian chytrid fungus (Bd) on Hellbenders and in Hellbender habitat, and assessments of habitat quality.

A total of 1487 person-hours spent searching resulted in 89 observations of 79 individual Hellbenders in 11 Ohio waterways.  The number of Hellbenders captured per person-hour searching had declined by nearly 82% in the waterways where they were previously documented, with no Hellbenders detected in seven of the 15 (47%) waterways.

Hellbenders were found in four waterways where they were not previously detected or where surveys were not previously performed.  In seven of the 11 (64%) waterways, no individuals <45 cm were encountered, and together with the low relative abundance, these populations do not appear to be viable.  The lack of successful recruitment of young into populations appears to be the mechanism of Hellbender decline in both Ohio and elsewhere throughout the species’ range.

In order to maintain viable populations of the Hellbender in Ohio, four recommendations were made at the conclusion of the statewide assessment:
1) Support conservation efforts in areas where viable populations currently exist;
2) Increase the use of existing conservation programs to protect Hellbender habitat;
3) Investigate the feasibility of a repatriation/augmentation program for Hellbenders in Ohio; and,
4) Continue to conduct mark-recapture surveys to monitor populations, collect demographic and growth data, and provide on-the-ground outreach and early detection of potential threats.

From Surveys to Implementation
More is known about the status of Hellbenders in Ohio than any other state, with the exception of Missouri.  Due to the widespread decline of Hellbenders in the state, action must be taken now to prevent their extirpation.

The Ohio Hellbender Partnership consists of representatives of the Ohio Division of Wildlife, the US Fish and Wildlife Service, several Ohio Zoos (Columbus Zoo, the Wilds, Toledo Zoo, Akron Zoo), the Ohio EPA, local soil and water conservation districts, and college/university researchers and students.  We have been meeting regularly since the completion of statewide surveys to discuss strategies for reversing the decline of the Hellbender in Ohio.

In conjunction with the Ohio Division of Wildlife and the Ohio Hellbender Partnership, I was the lead author on the Division’s “Eastern Hellbender Ohio Conservation Plan.”  This plan outlines strategies and methods for the conservation and recovery of the Eastern Hellbender in Ohio from 2012-2017.  Included in this document are summaries of the historic and current status of the species in the state, as well as recovery goals and objectives.  From the plan:
“The goal of hellbender conservation activities in Ohio is to restore hellbender populations to a point where they are no longer in danger of becoming extirpated and can be removed from the list of state endangered species.  This goal will be reached when multiple viable (self-sustaining) populations are established in at least six watersheds.”

To reach this goal, the Ohio Hellbender Partnership has embarked on a captive head-starting and repatriation program to return Hellbenders to areas where they have been extirpated.  In September 2011, Eastern Hellbender eggs were collected from an Ohio stream and transported to the Columbus Zoo and Aquarium for captive-rearing and eventual release back into the wild.  This was only the second time a Hellbender nest had been found in the state.

In 2012 and 2013, 3- and 4-year old hellbenders collected as eggs from a nest in neighboring West Virginia and reared at the Columbus Zoo became the first Hellbenders to be released as part of the head-staring program.  The released individuals underwent exhaustive medical screenings to ensure the released animals would not transmit exotic pathogens. Each Hellbender was also implanted with a radiotelemetry device so that their fate could be tracked until the following spring.

The head-starting program has grown rapidly since our modest beginnings in 2012. Today, Hellbenders are being reared in biosecure facilities at the Columbus Zoo, Toledo Zoo, and Penta Career Center.  As of 2020, we have successfully collected eggs from 35 Ohio Hellbender nests, and reared and released 1,524 young Hellbenders (mostly 3-yr old) back into 26 sites in 10 watersheds.

Just as important, the partnership is working to protect and restore vital Hellbender habitat in the state.  Siltation of waterways is likely the greatest threat to Ohio’s Hellbenders, and may be responsible for the lack of recruitment that appears to be so widespread.  Excess sediment entering waterways is largely the result of the loss of forested riparian corridors, but can also come from agriculture, development, mine drainage, and roads.

To read more about our conservation efforts and the 2014 releases, read this story from the Toledo Zoo’s newsletter (part 1part 2).