(WFXR) — The Virginia Department of Wildlife Resources (DWR) is investigating reports of lesions found on smallmouth bass in the Jackson River. The fish have been caught in the past two weeks between Covington and Iron Gate.

One Eagle Rock guide says of the 100 or so smallmouth his clients have caught in the past week, roughly 40% have had some sort of lesion on them.

There could be a variety of causes for the lesions including pathogens, like a virus or bacteria; parasites; toxins; or it could be something else, like a predator. An exact cause will not be known until more investigation and testing are done.

The DWR plans to sample fish from the Jackson River over the next few days to see what can be found. Some fish will be collected and sent to a lab for analysis.

A smallmouth bass from the Jackson River with lesions on its gill flap and above its pectoral fin. (Photo courtesy: Rob England/Appalachian Bronzeback Adventures)

DWR officials were quick to respond. They were notified of the issue on Tuesday, June 14 and immediately launched an investigation. They say there is cause for concern, but no reason to panic.

There have been no reports of lesions in any other species.

Smallmouth bass are a highly targeted gamefish, and are one of the species at the heart of a multi-million dollar sport fishery on the Jackson River.

The Jackson also feeds the James River, where there has been concern over lagging smallmouth numbers in recent years.

The James is still considered a top smallmouth fishery, and the drop in numbers has been attributed to weak spawns.