Update on LMBV (Largemouth Bass Virus)
Galen Jons, Fisheries Biologist

Last fall we told you about the "Largemouth Bass Virus", also known as LMBV. This virus, first isolated in the Santee-Cooper Reservoir system of South Carolina, was discovered in Texas in 1998. It has been responsible for a fish kill in each of four Texas lakes (Sam Rayburn, Toledo Bend, Conroe and Fork). Fish kills have primarily involved adult largemouth bass, but have not significantly hurt the long-term fisheries where they have occurred. No fish kills have occurred following the initial kills in these reservoirs.

Since the LMBV was discovered only recently, little is known about its distribution. Consequently, the TPWD has tested fish from 49 lakes across every major drainage in the state in an effort to determine the extent of the virus in Texas. Of those 49, the virus has been found in fourteen lakes. Additionally, the virus was found in five other lakes tested in 1999, for a total of 19 positives out of 54 tested. It has also been found in two Texas hatcheries, indicating fish raised in those hatcheries can only be stocked in lakes known to carry the virus.

In last fall's article, we promised to keep you posted of the test results as they apply to our area. Five lakes in the Big Country area were tested. These include lakes O.H. Ivie, Brownwood, Ft. Phantom Hill, Possum Kingdom and Hubbard Creek. Sixty fish were tested in each lake, and the virus has shown up in two fish in Hubbard Creek Lake and in two fish in Possum Kingdom Lake. This translates to a 3.3% prevalence of the virus in the bass population of those two lakes.


It is important to remember that this virus is relatively harmless. More largemouth bass are killed every year by many other causes; however, the virus has received much attention due to its recent discovery and its affects on the most popular gamefish in the U.S.

The virus does not infect any warm-blooded animals, including humans. Infected fish are safe to eat, but should be thoroughly cooked regardless. There is no easy way to tell if a fish is infected, since many healthy fish carry the virus without ever getting the disease. However, dead and dying fish should be avoided as a food fish regardless of their cause of death.

The virus appears to manifest itself into disease only in stressed fish. Some origins of stress include unusually warm water temperature, falling or very low water levels and handling by anglers. Following are some tips to help anglers in reducing the spread of LMBV.

1) Clean boats, trailers and other equipment thoroughly between fishing trips.
2) Do not move fish parts from one body of water to another, and do not release live bait into a fishery.
3) Handle bass as quickly and gently as possible if you intend to release them.
4) Stage tournaments during cooler weather, so fish caught will not be so stressed.
5) Report dead or dying fish to the TPWD.
6) Educate other anglers about LMBV.






Texas Parks and Wildlife Dept.
5325 N. 3rd
Abilene, TX 79603
(915) 692-0921

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