Contaminated water may be hurting many species of popular fish in the United States. A virus is showing up in more lakes across the North, and that worries the anglers and the businesses that count on a multibillion-dollar sport-fishing industry.
The virus is viral hemorrhagic septicemia, or VHS. It causes fish to hemorrhage, often leaving red blotches on their skin. Despite many warnings over the past few years, humans may be helping to spread the disease by inadvertently moving contaminated fish, bait or boat water. The virus has killed some fish in most of the Great Lakes, a lake in upstate New York, and most recently a few inland lakes in Michigan and Wisconsin.
One of them is Lake Winnebago, Wisconsin's largest lake — 30 miles long and a favorite destination for dedicated anglers like Ron Thompson.
"I hunt, fish and play the guitar, and I'm a Christian," Thompson says. "And, I think, besides God, fishing is probably my biggest pastime."
Now, Thompson also is a devoted follower of emergency rules implemented in Wisconsin to try to stop the spread of the virus. He says his bait comes from trusted sources, he drains water from his boat at the landing, and he doesn't transfer fish into other bodies of water.
But, clearly, not everyone is doing that. Some fishermen, including John Panik, question the protocol.
"This stuff got into the Great Lakes, and now it's gotten into here. I mean, if you're talking microscopic organism, there's always going to be some water remaining in your boat. It's going to be impossible to keep these things sanitary," Panik says.
But Wisconsin game wardens are trying to enforce the rules.
Warden supervisor Todd Sheller examines boats and questions anglers as they pull into a landing along a river that flows into Lake Winnebago. Sheller says he's especially concerned about those who come to the area from many miles away.
"People travel up from Illinois and go back to Illinois, come from all over the state, fish walleyes — it's a great walleye fishery — and then go back to their lakes. That's the people we need to get the message out to, is that transient boater and fisherman," Sheller says.
As the virus spreads, tourism officials are expressing concern. Wisconsin bait shops report that business is suffering in virus-afflicted areas. Several months ago, the USDA put limits on the movement of fish from the Great Lakes region.
Agriculture Department fish pathologist Jill Roland says no cure for VHS is on the horizon. She says the best hope for the long-term is that fish will build immunity to VHS — "they've seen the virus, they develop some kind of an immunity, and they produce off-spring that hopefully ... will become more and more resistant."
But if that doesn't happen, the disease could become a tipping point in the battle to keep invasive species out of inland waters. Some scientists believe the virus first infiltrated the Great Lakes by way of ballast water from ocean ships that travel along the St. Lawrence Seaway.
A coalition of 90 environmental and sport-fishing groups is calling for such ships to be barred from the Great Lakes until federal regulators can make them sterilize their ballast water. Shipping companies and port directors are fighting that proposal.
Chuck Quirmbach reports for Wisconsin Public Radio.