U.S. Fish & Wildlife Service | Southeast Region

Southeast Region

Two anglers fish for bass. U.S Fish & Wildlife Service Photo

U.S. Fish & Wildlife Service and Georgia Department of Natural Resources Staff conduct fish sampling. Photo by Norm Heil, USFWS

	WILD FISH HEALTH SURVEY PROVIDES CLUES TO LARGEMOUTH BASS VIRUS

FOR IMMEDIATE RELEASE #: R00-008

March 15, 2000

Contact: Tom MacKenzie 404/ 679-7291

Tom MacKenzie 404/ 679-7291

Within the last five years, Largemouth Bass Virus (LMBV) has caused fish kills in a dozen lakes in the southeast and Texas. To address this concern, B.A.S.S. Inc. sponsored a workshop with U.S. Fish and Wildlife Service fish health specialists from the Warm Springs Fish Health Center, along with state and federal fishery managers and fish health scientists from across the Southeast.

The workshop was held February 3rd in Savannah, Ga., to gather information, and implement a plan to deal with the impacts of LMBV on sportfish populations. Although the impacts of the virus are still uncertain, the scientists agreed that monitoring should continue across the United States to discover the full distribution of the virus, which affects only cold-blooded animals.

LMBV has occurred in 12 states: Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Missouri, Mississippi, North Carolina, South Carolina, Tennessee, and Texas. Fish kills caused by LMBV have occurred in several lakes: Santee-Cooper in South Carolina. (1995); Lake Eufaula, in Alabama and Georgia (1998); Greenwood Reservoir in South Carolina (1998); Sardis Reservoir in Mississippi (1998); Sam Rayburn in Texas (1998); Lake Fork and Lake Conroe in Texas (1999); Toledo Bend in Texas and Louisiana (1999); Table Rock Lake in Missouri and Arkansas (1999); Lake Ferguson and Tunica Cutoff in Mississippi (1999); and Atchafalaya Basin in Louisiana (1999). None of these lakes have had a subsequent fish kill.

"What causes the virus to turn into a deadly disease for largemouth bass is still a mystery,"said Sam D. Hamilton, Southeast Regional Director. Hamilton went on to say that all of the fish kills have occurred during warm weather, and stress caused by water pollution or from frequent handling by anglers may also be a factor.

The most important weapon needed to control or prevent fish diseases is knowledge. Currently, there is very little information about the relationship between presence of pathogens in wild fish and its likelihood of producing disease in either wild or hatchery-reared fish. Valuable stocks of fish are at risk because of our lack of knowledge about the distribution of pathogens and parasites in wild fish.

"We have been looking for the virus (LMBV) as part of the Wild Fish Health Survey," said Norm Heil, project leader at the Warm Springs Fish Health Center in Georgia. "Our findings have shed additional light on the distribution of LMBV and the species affected by the virus."

LMBV is one of many viruses included in the National Wild Fish Health Survey conducted by the U.S. Fish and Wildlife Service in the Southeast. The purpose of the survey is to determine the distribution of certain fish pathogens in the wild. A total of 446 largemouth bass (Micropterus salmoides) and related sunfish species from 44 sites in 8 southeastern states were surveyed for LMBV between October 1997 and November 1999. LMBV was found in apparently healthy fish captured by electrofishing, gill netting, or by chemical methods from 11 sites in 6 states.

"LMBV is not known to infect humans or warm-blooded animals," said Heil. ABut experts suggest any fish for consumption should be thoroughly cooked."

Sites where the virus was found include Georgia, Florida, North Carolina, South Carolina, Kentucky, and Louisiana. These sites represented the Chattahoochee-Flint system, Ochlockonee system, Wacissa River system, Tar-Neuse system, Santee-Cooper system, Tennessee River system, the Everglades, and the Atchafalaya River system.

The other 33 sites from Arkansas, Georgia, Florida, North Carolina, South Carolina, Kentucky, Mississippi, and Louisiana were negative for LMBV. A current review of data collected by other Fish Health Centers across the country involved with the Wild Fish Health Survey, demonstrated that LMBV has not been found outside of the Southeast.

Fish samples analyzed by U.S. Fish and Wildlife Service Warm Springs Fish Health Center revealed the LMBV in other bass and sunfish species, but has proven to be fatal only for largemouth bass. Other members of the sunfish family found infected with the virus include smallmouth bass, spotted bass, suwanee bass, bluegill, redear sunfish, white crappie, and black crappie. Amphibians, reptiles and other fish species also could be carriers of LMBV.

Anglers can help minimize the spread of LMBV virus and its activation into a lethal disease by doing the following:

$ Clean boats, trailers, and other equipment thoroughly between fishing trips to keep from transporting LMBV-- as well as other undesirable pathogens and organisms -- from one water body to another.
Do not move fish or fish parts from one body of water to another.
Do not release live bait into a fishery.
Handle bass as quickly and gently a possible if you intend to release them.
Stage tournaments during cooler weather, so fish caught will not be stressed.
Report dead or dying fish to state wildlife agencies.
Volunteer to help agencies collect bass for LMBV monitoring where appropriate.
Educate other anglers about LMBV

The National Wild Fish Health Survey was initiated in 1997 under the leadership of the U. S. Fish and Wildlife Service=s Regional Fish Health Centers, and in cooperation with stakeholders including States, Tribes, Universities, and the Aquaculture industry. The knowledge gained from this project will help protect threatened and endangered species, provide more options for better fish management, provide a national cohesive perspective for better fish health management, and develop standardized fish health and fish transport regulations that are scientifically defensible.

The U. S. Fish and Wildlife Service=s Regional Fish Health Centers have been mandated to establish and maintain a National Fish Disease Database. This database is to be a comprehensive survey of the health of wild fish populations throughout the United States. The data collected from the survey will be incorporated into a national wild fish health database available to all interested parties on the Internet. The National Wild Fish Health Survey depends on establishing productive partnerships. If any agency would like to participate in the survey, or would like more information concerning the National Wild Fish Health Survey, please visit the survey website at http://wildfishsurvey.fws.gov.

The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 93-million-acre National Wildlife Refuge System which encompasses more than 520 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 66 national fish hatcheries, 64 fish and wildlife management assistance offices, 64 Fishery Resource Offices and 78 ecological services field stations. The agency enforces Federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign governments with their conservation efforts. It also oversees the Federal Aid program that distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies.

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