The Road to Recovery

Hellbender populations have been declining since the 1970s. In most states within their range, hellbenders are listed as rare, threatened, or endangered. Since 2011, the Ozark Hellbender subspecies, C. a. bishopi, has been protected as a federally Endangered species with its population having declined to 600 individuals. The Missouri population of the Eastern Hellbender was listed as federally Endangered in 2019, while the eastern populations were found not warranted for listing. However, reports have shown Eastern Hellbenders have significantly declined or completely disappeared from many streams that they historically occupied. Although some Eastern Hellbender populations appear to be doing well, declines are indeed occurring in many locations throughout their range.

The declines of Eastern Hellbenders can largely be attributed to the degradation of stream quality, which is caused by the damming of rivers, water pollution, and siltation of streams. Dams eliminate free-flowing sections of rivers and produce low oxygen conditions on the river bottom. Toxic chemicals, such as untreated sewage and chemical runoff from lawns, fields, and parking lots pollute rivers and streams, impacting water quality and the health of hellbenders. Like other amphibians, hellbenders “breathe” through their permeable skin, so any toxic substance in the water can enter their bodies and cause them harm. Siltation is the buildup of sediment on the bottom of a stream. Excess sediment enters streams from various human disturbances to the soil, such as the removal of streamside vegetation, logging, poor forestry practices, and erosion from farms and housing developments. Siltation affects hellbender survival by burying the large rocks that hellbenders depend on for reproduction, suffocating their eggs, filling in hiding places of their young, and killing the crayfish and other invertebrates that they feed on.

Other threats to hellbenders include: collection pressure from the pet trade and people killing them. Anglers using live bait such as crayfish and worms may sometimes catch a hellbender. They will often cut the line or kill the hellbender. Another reason people may kill them is the unfortunate misbelief that they are poisonous, when they are in fact harmless.

Fortunately, several efforts are underway in Virginia to address these many threats in order to conserve and manage hellbender populations.

What the DGIF Has Done/Is Doing

The Virginia DGIF has taken the lead in Virginia on Eastern Hellbender conservation through multiple research studies, deployment of nest boxes, stream habitat restoration, and outreach and education.

Research

From 2012-2016, DGIF partially funded a partnership between the agency’s biologists and Virginia Tech researchers to assess hellbender populations in selected rivers in southwest Virginia that traversed a variety of habitats, including forests and agricultural landscapes. In this study, field researchers measure, weigh, and implant the captured hellbenders with a Passive Integrated Transponder (PIT) tag, which provides an identifying number unique to each specimen. Individuals that are recaptured are scanned to determine the presence of the PIT tag and reassessed.

In 2014 and 2015, DGIF partially funded another partnership; this time to collect Environmental DNA analysis (eDNA). In this project, DGIF biologists worked with Smithsonian National Zoological Park researchers and citizen scientists from the Virginia Master Naturalist Program (New River Chapter), and/or biology students from the University of Virginia-Wise and Southwest Virginia Community College.

Dr. Kim Terrell with the Smithsonian Institute and Dr. Bill Hopkins with Virginia Tech conducting eastern hellbender research in partnership with DGIF. Photo by J.D. Kleopfer/ DGIF.

This eDNA data is a relatively new approach to determining the presence/absence of aquatic vertebrates in targeted locations. Environmental DNA also is being investigated as a method for monitoring aquatic disease. In Georgia and Tennessee, eDNA analysis identified previously unknown hellbender populations that were later confirmed by conventional stream survey. The objectives of the DGIF eDNA collection were to 1) create a more comprehensive map of hellbender distribution in the state, 2) generate coarse estimates of abundance, 3) establish an eDNA sample archive as a long-term resource for wildlife management, and 4) engage private citizens in freshwater science and education.

Nest boxes

In 2019, the Virginia DGIF completed the testing of artificial shelters (nest boxes) and demonstrated their potential utility for hellbender research, monitoring, and conservation. From 2016-2020, partially funded by DGIF through a State Wildlife Grant, Virginia Tech researchers will deploy ~500 nest boxes at 12 different sites across 5 different streams. By refining this technique to be used effectively on a broad scale, nest boxes could help prevent population declines, promote population growth, and curtail listing of the species in Virginia.

A hellbender nest box resting in the bottom of the stream. The lid on top is used for monitoring. Photo by J.D. Kleopfer/ DGIF.

Equally important, these nest boxes can help identify the proximate factors that determine the fate of hellbender nests, arguably one of the most important unanswered questions about hellbender conservation.

A common characteristic of population declines across the species’ range is a strong demographic shift towards large, old individuals with few representatives in younger size/age classes. This shift suggests that reproductive failure and/or a lack of juveniles successfully joining the population may contribute to hellbender population declines. However, hellbender reproductive and juvenile ecology remain poorly understood, so filling in this knowledge gap with data obtained from nest boxes is critical for management of this species in Virginia and across its remaining range.

Restoration of Stream Habitats

The Virginia DGIF has completed and continues to work on numerous stream restoration projects that have improved water quality and benefited Eastern Hellbenders and numerous other aquatic species. These projects have included:

In 2016–2017, we worked with a partner and private landowner in Scott County, Virginia to restore 650 feet of Copper Creek stream channel and its surrounding habitats by addressing a severe erosion issue.

Currently working with partners to restore 3200 feet of steam habitat on the Middle Fork Holston River in Smyth County, Virginia at Chilhowie Town Park. We will also be working on establishing 1.5 acres of adjacent habitat to buffer the stream.

Currently working with partners and private landowners to restore nearly ¾ miles of stream channel on the North Fork Roanoke and its adjacent shoreline in Montgomery County, Virginia.

Outreach and Education

In order to educate the public on the plight of hellbenders, the Virginia DGIF produced an educational poster, this species profile, and a hellbender mascot, “Wally the Waterdog,” who hands out educational literature about Eastern Hellbenders at events.

Learn More About Our Work

Watch: Hellbender Research in Virginia (2015). This research partnership with Virginia Tech was partially funded by DGIF through a State Wildlife Grant.