Search for Fish Virus Intensifies: Popular Lakes Targeted in Effort to Contain Disease
By Lee Bergquist and Dan Egan, Milwaukee Journal Sentinel
May 15–The Department of Natural Resources intends to step up the hunt in other Wisconsin lakes for a deadly fish virus discovered in the Lake Winnebago system.
A DNR official said Monday that the agency will search for fish infected with the disease, especially in lakes and rivers that attract anglers from long distances.
Lakes in the Madison and Lake Geneva areas are likely targets, in addition to heightened surveillance already begun on Lake Michigan and the Mississippi River, said Mike Staggs, director of the DNR’s Bureau of Fisheries Management and Habitat Protection.
Beyond those lakes, which attract out-of-state anglers, their boats and, potentially, the hitchhiking virus in bait or a boat’s live well, the DNR is still mulling other locations.
Water bodies with unexplained fish kills also will be examined, Staggs said.
In addition, crews will be dispatched to selected lakes and rivers with electric shocking apparatus to test seemingly healthy fish, he said. The shocking equipment temporarily stuns fish so they can be gathered for study.
The DNR is also expected to use its emergency rulemaking powers to broaden restrictions on anglers, boaters and the commercial bait industry in the hope of slowing the disease, Staggs said.
Those rules are now in place for Lake Michigan, Lake Superior, the Mississippi River and their tributaries up to the first dam.
But the rest of state waters could be targeted when the Natural Resources Board holds a special meeting set tentatively for Thursday afternoon.
Staggs said the agency is not planning to impose additional restrictions on the 400 fishing tournaments that can attract anglers from out of state.
He said the DNR thinks restrictions should apply to all boaters and anglers.
Jobs are at stake
The state’s response is intended to protect the health of an important state resource that the DNR values at $2.3 billion and that supports 26,000 jobs.
“This is a gravely serious situation,” said George Meyer, former DNR secretary.
Meyer, now executive director of the Wisconsin Wildlife Federation, said the discovery of viral hemorrhagic septicemia could be more devastating than chronic wasting disease, which was discovered in 2002.
That’s because instead of affecting a single species such as deer, the virus is known to kill more than three dozen types of fish.
Also, the virus is transmitted by water — not blood or saliva as with chronic wasting disease, Meyer said.
The Lake Winnebago system, including the headwaters of the Fox and Wolf rivers, represents 22% of all the inland waters in the state, Meyer said.
Gary Whelan, fish production manager with the Michigan DNR, said nobody should expect the virus to wipe out entire populations. He said it might cause serious die-offs when certain species are weakened by harsh weather or inadequate food supplies, but it is “completely unrealistic” to expect entire populations to disappear.
But he said the virus is a problem that the Great Lakes — and now inland lakes such as Winnebago — are likely going to have to live with forever.
“The disease will never disappear,” he said. “It’s now a permanent part of our communities.”
The virus has been found in lakes Huron, St. Clair, Erie and Ontario, and in the St. Lawrence Seaway. But it has not been found in Lake Michigan — where officials expected to find it next — or Lake Superior.
Sturgeon at risk?
On Monday, DNR and state agriculture officials were meeting for the first time to consider their options after it was announced Saturday that the virus had been found in freshwater drum, or sheepshead, on Little Lake Butte des Morts.
The virus also is thought to have killed sheepshead on Lake Winnebago — home of North America’s largest self-sustaining population of lake sturgeon.
The list of fish species susceptible to the deadly virus is frighteningly long. But at this point it does not include the venerable sturgeon.
The bottom-feeding sturgeon is speared on the Winnebago chain through ice.
The federal government classifies 37 species as in danger of dying from the virus, and that includes such popular sport fish as chinook and coho salmon, rainbow trout, largemouth bass, walleye and yellow perch.
While there is no documentation of sturgeon falling prey to the virus that bleeds its victims to death, biologists are spooked nonetheless.
The DNR’s Staggs said his agency is not assuming that sturgeon are immune from infection.
“What it means is that no sturgeon have ever tested positive or died from the disease,” Staggs said.
Particularly worrisome is a mysterious sturgeon die-off on Lake Superior last year.
“We had reports late last summer or early fall of 15 dead adult sturgeon on the Minnesota shoreline north of Duluth,” said Sue Marcquenski, fish health specialist for the Wisconsin DNR. “Usually we never see dead adult sturgeon on the beach, let alone 15 of them.”
The fish were too decomposed to be tested for the virus, which was first discovered in Lake Ontario in 2005.
The strain of the virus that has infected the Great Lakes is a mutated version of one that has been documented on the Atlantic Coast.
Nobody knows how it made its way into the middle of the continent, but one popular theory is that it hitchhiked in the belly of an overseas freighter.
Natural fish migrations could be another pathway. So could shipments of baitfish.
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Copyright (c) 2007, Milwaukee Journal Sentinel
Distributed by McClatchy-Tribune Information Services.
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