Fish-Killing Virus Nears: Ugly Disease Seeping Inexorably Toward Lake Michigan

By Dan Egan, Milwaukee Journal Sentinel

Feb. 1–A nasty fish-killing virus recently discovered in the eastern Great Lakes is now poised to spill into Lake Michigan. State of Michigan officials announced last week that viral hemorrhagic septicemia, or VHS, has been confirmed in northern Lake Huron, only about 20 miles east of where it merges with Lake Michigan — an approximately 200-mile advance in its known range from just last fall. State fishery officials say it’s probably only a matter of time before the virus that bleeds its victims to death spills into our waters. VHS poses no threat to humans, but fishery experts fret that it could wreak havoc on the entire Great Lakes fishery, and the $4.5 billion commercial and recreational industry that it supports. Nobody knows how the disease made its way into the Great Lakes. It was first detected in Lake Ontario in 2005 and has subsequently been found in the St. Lawrence River, as well as Lakes Erie and St. Clair. Researchers now believe it has been in the Great Lakes at least since 2003. Scientists confirmed its presence in Lake Huron only after re-analyzing samples from fish collected during a 2005 survey. “It is the most serious fish disease problem that we’ve seen,” said Wisconsin fish health veterinarian Myron Kebus. Bill Horns, Great Lakes fisheries coordinator for the Wisconsin Department of Natural Resources, said it’s too early to say exactly how it might affect Lake Michigan’s popular but fragile recreational fishing industry, but the risk is real. “I don’t want to cry wolf or say the sky is falling, but we have to wonder if it is,” he said. Kelley Smith, chief of fisheries for the Michigan Department of Natural Resources, suspects that more surveys will net more bad news in terms of the actual range of the virus, particularly for Lake Michigan. “It’s going to get there sooner or later. If I had to risk a bet on this, I’d say it’s probably already there,” he said. “We just haven’t found it yet.” The disease has previously been found on the Atlantic and Pacific coasts, but the Great Lakes have been infected with a mutated version. What makes the Great Lakes strain particularly worrisome is its ability to attack so many different types of fish. The Lake Huron survey revealed it had infected salmon, whitefish and walleyes, and it previously had been blamed for large-scale die-offs of perch, musky and freshwater drum, among other species. The federal government has already implemented rigid restrictions on the movement of dozens of species of live fish out of the Great Lakes states in an attempt to slow the spread of the virus, but nobody at this point can stop it from moving in the wild. Veterinarian Kebus said the important thing now is to try to stop its spread beyond the Great Lakes. “I don’t think it’s inevitable that VHS will come to your fish farm, your hatchery or even your inland lake, if the right steps are taken,” he said. “But within the Great Lakes, there really aren’t any barriers we can put up, in terms of preventing movement.” Overseas freighters traveling up the St. Lawrence Seaway have been blamed for the majority of foreign species invasions in the Great Lakes during the past three decades. Some believe that is how this virus arrived in the lakes, though there are other possible pathways, including baitfish shipments. A RANGE OF VICTIMS Viral hemorrhagic septicemia has infected salmon, whitefish and walleyes, and it has been blamed for large-scale die-offs of perch, musky and freshwater drum, among other species. Buy a link here

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