Parasitic gill lice found in Southwest Virginia trout

SMYTH COUNTY, Va. (WJHL) – Wildlife officials are asking for Southwest Virginia anglers’ help after finding concerning amounts of a parasite that can be harmful to fish.

According to a release and post from the Virginia Department of Wildlife Resources (VDWR), gill lice have been found on rainbow trout in Blue Springs Creek, which is located in Smyth and Wythe counties. The department is asking anyone who hooks one of these trout to help officials determine how widespread the parasites have become.

“Blue Springs Creek has a wild rainbow trout population, but gill lice were observed on wild trout as well as trout of hatchery origin,” the post reads.

The VDWR said the parasites are small and can have a serious impact on local fish populations.

“Gill lice are tiny, parasitic copepods, a type of zooplankton, that attach to a trout’s gills, mouth and fins,” the post states. “A minor gill lice infection can generally be tolerated, but a heavy infection can have a negative impact on a fish’s ability to breathe. The degree of impact to a trout population can depend on the level of infection and the presence of any other stressors such as high water temperature.”

Anyone who has recently eaten a trout from the area need not be concerned. Even though gill lice can be dangerous for the trout and are not pleasant to look at, they are safe to eat as long as the fish was cooked properly. However, anglers are urged to clean and dry their fishing equipment after each outing, particularly if the equipment will be used in multiple bodies of water.

Wildlife officials suspect the gill lice found in the region are a species known as Salmincola californiensis, which exclusively targets rainbow trout and related species. Samples of the gill lice have been sent to the U.S. Fish and Wildlife Service to be identified.

As of Thursday, the VDWR is working to determine if the infestation is only affecting Blue Springs Creek. Once the department knows how widespread the gill lice are, a plan will be created to limit the parasites’ range and reduce the impact on the trout. The exact origin of the infestation has not yet been determined.

Anglers can learn more about gill lice by visiting the department’s website. Anyone who catches a trout that has gill lice can report it by emailing fisheries@dwr.virginia.gov.