SCDNR stocks first federally endangered freshwater mussels grown in hatchery

September 21, 2023

Media contact: Stephen Fastenau, Office of External Affairs, 803-240-4385, FastenauS@dnr.sc.gov.

This month, the S.C. Department of Natural Resources released into the wild on U.S. Forest Service property the first group of Carolina Heelsplitters raised by agency biologists.

These rare freshwater mussels are federally endangered and found only in the Carolinas, with as few as 200 individuals left in the wild.

While SCDNR has worked with the U.S. Fish and Wildlife Service on previous stocking efforts, these were the first Heelsplitters produced by SCDNR to be released into the wild since beginning its freshwater mussel program in 2018.

Eight Carolina Heelsplitter mussels were stocked in a small creek near the border of Edgefield and McCormick counties Sept. 8. This first group of mussels was produced at Cohen Campbell Fish Hatchery in West Columbia after SCDNR received its first federal permit in 2022.

The program’s biologists recently moved into a larger facility at the fish hatchery that will allow for many more mussels to be produced in future years, with more than 2,000 currently in culture.

Growing freshwater mussels is a complicated process. Freshwater mussels use a fish host to disperse their young like grass seeds taking a ride on your jeans. To grow mussels in a hatchery, biologists must first collect female mussels holding larvae in the wild. After extracting the larvae, biologists expose the larvae to host fish held in tanks on the hatchery. Biologists then collect the tiny juveniles from these tanks after the larvae develop into filter feeding juvenile mussels that fall off their hosts naturally within a month.

Once the mussels are large enough, biologists attach a numbered tag to each shell and a special tracking tag to be able to locate and monitor the stocked population.

Carolina Heelsplitters live in freshwater streams along the slate belt, a geological rock formation running from Lancaster County to Edgefield County.

The mussels’ habitat is believed to be threatened by ongoing land development and other sources of pollution. Stocking hatchery-produced animals will help to keep these populations on the landscape to reproduce on their own when their habitat stabilizes.

Carolina Heelsplitters and other freshwater mussels help establish the foundation of ecosystems and are vital for water quality. These animals are natural filters and help keep our water clean.

"If you care about water quality, you should care about freshwater mussels," said Morgan Kern, mussel program coordinator for SCDNR. "We have a less stable ecosystem without them present."