SC-DNR Confirmed Whirling Disease in Pickens and Greenville Counties

The S.C. Department of Natural Resources has documented the presence of whirling disease for the first time in four streams sampled recently in Pickens and Greenville counties. This represents the first positive diagnosis of the whirling disease pathogen in South Carolina trout streams.

Whirling disease can cause 90 percent or greater mortality of young rainbow trout and can have serious impacts to wild and hatchery trout populations. The disease is caused by a microscopic parasite which damages cartilage and skeletal tissue in trout, causing diseased fish to swim in a “whirling” motion.

A recent fish health inspection at Walhalla State Fish Hatchery in Oconee County was negative for whirling disease and other new exotic pathogens. SCDNR has conducted surveillance for exotic trout pathogens in wild trout populations and at Walhalla State Fish Hatchery for decades.

Much of this work was conducted in partnership with the U.S. Fish and Wildlife Service’s Wild Fish Health Project, operated out of their fish disease lab in Warm Springs, GA. For more information on whirling disease in South Carolina, visit https://www.dnr.sc.gov/whirling.html.