Test Results Show VHS Fish Disease Hasn't Spread

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Test results show VHS fish disease hasn’t spread
Weekly News Article Published: August 14, 2009 by the Central Office

Disease found in Green Bay in 2009 but no new waters
MADISON – Results are in from several dozen waters tested in 2009 for VHS fish disease and the news is good.

No new waters have been found with this year the deadly fish virus. VHS has also been ruled out as the cause of a large fish kill of carp in June on Chequamegon Bay on Lake Superior. The fish disease was detected in smallmouth bass from Green Bay], but the virus had previously been identified as being at that location.

VHS, or Viral Hemorrhagic Septicemia, is a deadly fish virus and an invasive species that has caused large fish kills in lakes Huron, St. Clair, Erie, Ontario, and the St. Lawrence River. It's not a threat to people who handle infected fish or want to eat their catch, but it can kill more than 25 fish species. It was first documented in Wisconsin in May 2007 in the Lake Winnebago system, and was also detected in June of that year, and in 2008, in fish from Green Bay and other parts of northern Lake Michigan.

“It appears that the efforts we’ve taken to contain the VHS fish disease are working,” said Department of Natural Resources Secretary Matt Frank “We’re very grateful for the cooperation we’ve gotten from people in protecting our waters.”

“Anglers, boaters, bait harvesters, fish farmers and our own fisheries management staff have done a great job in keeping this disease from spreading,” he says.

In 2009, the DNR conducted “surveillance” testing on more than two dozen waters to continue to assess the prevalence of VHS. In addition, four hatchery water supplies and all wild fish DNR uses for brood stock for its hatcheries were tested for VHS to make sure fish stocked from state fish hatcheries are VHS-free.

None of the fish or water supplies tested as part of these surveillance or hatchery programs were found to have VHS, according to Mike Staggs, DNR fisheries management director. “All clear,” he says.

The only positive VHS results in 2009 were in three smallmouth bass from Green Bay that were tested after anglers and DNR staff observed and reported skin lesions, one symptom of VHS.

The waters tested are popular and highly trafficked waters by anglers and boaters, increasing the chances of VHS being spread by the movement of water and live fish, Staggs says. Mendota Lake in Dane County, Geneva Lake in Walworth County, Castle Rock Lake in Juneau and Adams counties, and Butternut Lake in Price County were among those tested.

While fisheries officials are relieved no new waters tested positive for VHS, they say the results showed that the virus is still active in Wisconsin and that anglers need to remain vigilant in following rules to prevent the spread of VHS fish disease and other aquatic invasive species.

“VHS remains a serious fish health threat and there are other invasive species and fish diseases already in the Great Lakes that we want to keep out of Wisconsin and our inland lakes,” Staggs says.

National expert: VHS on the Move
In fact, Dr. Jim Winton, the nation’s leading expert on VHS fish disease on Aug. 12, 2009, briefed a Congressional committee on “VHS, a Deadly Fish Disease on the Move" and earlier this month told an audience at a national wildlife disease conference in Washington that VHS and other emerging diseases are affecting entire populations of North American fish and that the problem threatens to increase in the future with climate change and other stresses on aquatic ecosystems.

Winton, a fish disease specialist at the U.S. Geological Survey Western Fisheries Research Center in Seattle, said that recent studies in natural aquatic systems have shown that wild fish populations have suffered catastrophic losses after non-native diseases like VHS fish disease and whirling disease were first introduced into a water body.

In addition to being a cause of natural death, Winton said, such infectious and parasitic fish diseases can produce significantly greater mortality in altered habitats leading to population fluctuations, extinction of endangered fish, reduced overall health and increased susceptibility to predation.

More information about the VHS fish disease, the distribution and testing of VHS fish disease in Wisconsin can be found online.

FOR MORE INFORMATION CONTACT: Mike Staggs (608) 267-0796