Largemouth Bass Virus

Largemouth Bass Virus -- sounds like it could be the latest computer virus threatening to invade your hard drive, but it's not. It's a very real biological virus that infects a number of fish in the sunfish family but seems to be fatal only for the most popular game fish in the U.S., the Largemouth Bass.

Fortunately, not all bass infected with Largemouth Bass Virus (LMBV) develop the disease, and infected bass are symptom-free unless the disease is activated. A bass suffering from full-blown LMBV disease is likely to have trouble swimming and maintaining balance and may appear bloated. Currently, researchers are trying to determine what may be triggering the more than two dozen LMBV-related fish kills that have been reported since 1995 across the eastern half of the United States, including in Georgia and South Carolina.

Circumstantial evidence suggests that stressed bass -- such as those exposed to sustained warm water temperatures, very polluted waters, or frequent handling -- are more likely to develop and die from LMBV disease. It has not yet been determined how the virus is transmitted, but common sense measures can be taken to help prevent spreading it, such as cleaning boats and equipment with bleach between fishing trips, handling bass with care if practicing catch and release, and never releasing a fish caught in one water body into a different water body.

A LMBV-related fish kill is not necessarily detrimental to the long-term health of a fishery, although anglers may find their bass catches down, or the bass they catch downsized, for a year or two following the die-off. LMBV does not infect humans or other mammals, but all fish intended for human consumption should be thoroughly cooked. You should never eat a fish that was found dead or appeared to be ill or dying when caught, regardless of the cause, and should report the sighting of multiple dead or dying fish to your state wildlife agency. You can't fight Mother Nature, but you can be aware of the conditions in your lake, and be an advocate for good erosion and sediment control practices in your watershed.