Conservation Corner: March 20, 2000

Largemouth Bass Virus
by James L. Cummins

Over the past year, much talk has centered around the mysterious Largemouth Bass Virus (LMBV). Although it presents a multifaceted resource problem, not many facts have been presented.

LMBV is one of more than 100 naturally occurring viruses that affect fish, but not warm-blooded animals. The virus has been found only in largemouth bass. Although many scientists believe that the disease is stress-induced, they do not know how the virus is transmitted or how it is activated into disease. In addition, they know of no cure or preventative technique, as is commonly the case with most viruses.

LMBV has been found at various levels in largemouth bass collected from Bay Springs, Columbus, Enid, Ferguson, Sardis and Tunica Cut-off Lakes in Mississippi. Samples from seven other lakes across the state showed no LMBV, indicating that the virus is either absent or present at very low levels in these lakes. LMBV was first seen in Mississippi after significant number of largemouth bass were found dead at Sardis Lake in September 1998. The only other fish kill known to be caused by LMBV before that kill occurred in 1995 at Santee Cooper Reservoir in South Carolina. "LMBV is just another variable in the ecology of fish. Bass will adapt to it," said Dr. Larry Hanson, representing the College of Veterinary Medicine at Mississippi State University. Hanson recently attended a workshop of the Bass Anglers Sportsmen's Society's Conservation Department on the virus.

The best available information indicates that largemouth bass carrying the virus are safe to handle and eat. Anglers should take the following measures to help prevent the disease and reduce the likelihood of spreading LMBV, to include: (1) Reduce stress on bass by handling them gently and reducing the length of time they are held in live wells during tournaments or other outings; (2) Hold bass tournaments during cool weather; (3) Do not transfer fish from one body of water to another; (4) After dressing fish, don't discard the remains back into lakes or streams, and; (5) Wash and dry live wells between fishing trips.

Right now, the best thing anglers can do is to be aware of this problem and encourage others to use caution when handling and moving fish. The only known fish kills from LMBV occurred in hot weather and in lakes where a lot of bass fishing occurs. LMBV is a new phenomenon and there is much to be learned about the disease.

Research on largemouth bass recently collected by the Mississippi Department of Wildlife, Fisheries and Parks and the Mississippi Fish and Wildlife Foundation from Lake Ferguson is currently being conducted. The Southeastern Wildlife Disease Study Group in Athens, Georgia is also involved in the research.

James L. Cummins is Executive Director of the Mississippi Fish and Wildlife Foundation in Stoneville, Mississippi. Known as "Wildlife Mississippi," the Foundation is a non-profit, conservation organization founded to conserve, restore and enhance fish, wildlife and plant resources throughout Mississippi.