West Virginia is a home among the hills not only to her people but to a rare species, the candy darter. After its home was invaded, it was listed as endangered under the Endangered Species Act. Where human activity has had devastating effects, a few caring people may have an even greater impact.
Researchers at West Virginia University teamed up with state and federal agencies to save the candy darter, a fish endemic to West Virginia and parts of Virginia, from extinction. Now, that team has been named the northeast region’s 2022 Recovery Champions by the U.S. Fish and Wildlife Service.
To save the species, Amy Welsh, conservation geneticist and Davis College of Agriculture, Natural Resources and Design professor of wildlife and fisheries resources, along with Brin Kessinger, Welsh’s former graduate assistant since deceased, found genetic markers differentiating the candy darter from the interlopers: the variegate darter.
In 1991, their tragic love affair was noticed by the National Parks Service: five fish didn’t quite look like they belonged to either species. The hybridization went unchecked until 2014, when Welsh’s genetic research into the candy darter began.
By then, hybridization already led to genetic swamping, meaning the variegate darter had essentially taken over. In 2016, there were a mere eight intact populations of candy darters remaining from the 35 there once were. The species was put on the Endangered Species List in 2018.
“What we’ve been doing in terms of recovery actions is taking pure candy darters that still remain in West Virginia and translocating them to places where the variegate darter is not," Welsh said. “And that's where the genetics come in. Prior to moving fish to the new location, I screen them to make sure that they are, indeed, pure candy darters."
Their efforts have had measurable success. The first observation of natural recruitment in a translocated population was in 2021, when young candy darters age and their risk of mortality is independent of the population’s size. The first successful captive propagation and stocking occurred in 2022, where candy darters were bred in captivity, increasing in numbers.
Welsh determines each fish’s ideal mate to ensure increased genetic diversity among the species. Going forward, she will continue to screen individuals and monitor the spread of hybridization indefinitely, keeping the pure candy darter populations untainted. Welsh and the conservation team plan to continue translocation efforts and hope to add to the eight burgeoning candy darter populations.
Alongside conservation efforts, research is necessary to guide future steps in saving the species. Welsh’s future research will focus on the reason for the candy darter’s decline when put in the aquatic boxing ring against the variegate darter.
“I would like to look at the genomics of the candy darter to figure out why it’s not doing as well as the variegate,” Welsh said. “I’m also interested in looking at the genomics of the variegate darter to find out where it came from and why it’s doing so well.”
Her main obstacle for future research and conservation of the candy darter is finding funding, but the candy darter’s obstacles are multifaceted. Aside from inconsistent restrictions on using variegate darters as live bait, the candy darter faces a more menacing foe: climate change.
"Candy darters do better in cold water whereas the non-native variegate darter does better in warm water, so that will be a challenge with climate change,” Welsh explained. “As the water temperatures continue to increase, it’s going to put the candy darter at a disadvantage and impede its recovery.”
Though the species’ listing as endangered helped spur organizations like the U.S. Fish and Wildlife Service to aid translocation efforts, the candy darter is still waiting on a formal recovery plan.
“A formal recovery plan includes more than what we’re doing. Sometimes that takes a while after listing. The U.S. Fish and Wildlife Service just recently designated critical habitat in 2021,” Welsh said, referring to the protection of specific areas that are essential to the conservation of a species.
Welsh and the team have been able to advance their conservation efforts and research without it.
"We got a jumpstart on this effort,” Welsh said. “There’s always a pretty big time lag between when a species is listed and when a recovery plan gets implemented. If we had waited that long for the candy darter’s recovery plan, it probably would have gone extinct -- at least in West Virginia.”
The team was informed of their prestigious recognition on May 19 of this year, the 50th anniversary year of the Endangered Species Act.
The team comprises Isaac Gibson of the West Virginia Division of Natural Resources (in memoriam), Kessinger (in memoriam), Stuart Welsh of the U.S. Geological Survey Cooperative Research Program, Nathaniel Owens of the West Virginia Division of Natural Resources, Jason Morgan of the West Virginia Department of Environmental Protection, Chad Landress of the U.S. Forest Service and Monongahela National Forest, and Andrew Phipps, John Moore and Craig Bockholt, all with the U.S. Fish and Wildlife Service.
They were nominated by Bockholt, manager of the White Sulphur Springs National Fish Hatchery.
The Davis College of Agriculture, Natural Resources and Design envisions a world sustainably fed, clothed and sheltered. To learn more about the Davis College, visit davis.wvu.edu. Keep up with the latest updates and news on Facebook, Twitter, Instagram and YouTube by following @WVUDavis.
-WVU-
ls/07/26/23
CONTACT: Leah Smith
Communications Specialist
Davis College of Agriculture, Natural Resources and Design
304-290-8680; lnestor2@mail.wvu.edu
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