Milwaukee Journal Sentinel:
http://www.jsonline.com/story/index.aspx?id=585050
Fighting a fish killer
DNR to instill new rules to combat virus believed to be in Lake Michigan
By LEE BERGQUIST
lbergquist@journalsentinel.com
Posted: April 1, 2007
With state officials almost certain that a deadly fish virus is now lurking in the waters of Lake Michigan, a state agency is expected to approve emergency regulations Wednesday to control the spread of the disease.
Viral hemorrhagic septicemia was found in the eastern Great Lakes in 2005, but in January it was discovered only 15 miles east of the Mackinac Bridge in Lake Huron.
State Department of Natural Resources regulations are expected to go into effect by the end of the week and will affect boaters, anglers and the commercial bait industry.
Viral hemorrhagic septicemia is distinctive for its ability to infect many species, and it kills the fish by causing them to bleed to death, said Mike Staggs, director of the DNR's Bureau of Fisheries and Habitat Protection.
The virus poses no threat to humans.
But thousands of muskies, walleye, lake whitefish and other fish have died since 2005 in Lake Huron, Lake St. Clair, Lake Erie and Lake Ontario, Staggs said.
Other species such as chinook salmon, smallmouth bass, bluegill and northern pike have showed clinical signs of the disease but have not died off in large numbers, he said.
"It's almost certain it's in Lake Michigan now," Staggs said.
Tests run on fish
The DNR tested spawning salmon, brown trout, whitefish, bloater chubs and yellow perch from Lake Michigan and spawning lake trout from Lake Superior in 2006, but turned up nothing.
This spring, the DNR will test more fish in those lakes and test other waters where there are fish kills.
Staggs predicted that it may well be in Lake Superior, and in the Mississippi River by moving down the Chicago Sanitary & Ship Canal.
The DNR also doesn't believe the virus has made its way to Wisconsin's inland lakes. But officials are worried about the impact on the Great Lakes' $4.5 billion commercial and sports fishery.
Other states, the province of Ontario and the U.S. Department of Agriculture already have imposed restrictions on the movement of live fish in the region.
Rules will get review
Among the regulations that will be reviewed by the Wisconsin Natural Resources Board is a requirement that boaters must drain water from their craft immediately after leaving Lake Michigan, Lake Superior, the Mississippi River and portions of tributaries that reach dams that can't be breached by fish.
Anglers will be prohibited from using live bait purchased from outside Wisconsin, unless the bait is in compliance with federal health requirements.
The commercial bait industry also will be hit with new regulations and is already strengthening biosecurity standards.
Bait fish can be carriers of the virus.
Higher prices ahead?
For consumers, the changes could lead to higher prices and confusion at some bait shops, an industry representative said.
"It's probably the most sweeping thing to affect how our business is done," said David C. Gollon Jr., president of Gollon Bait & Fish Farm of Dodgeville.
The company sells bait from Wisconsin to the East Coast and will spend thousands of dollars at each fish-raising facility to meet higher standards.
Gollon said eggs of suckers are collected from Lake Michigan tributaries and grown as bait for larger fish like muskies and northerns. It will be hard to do that now.
"And this is only the start," Gollon said.
He was referring to the proliferation of invasive organisms that threaten to upend the health of the lakes. More than 180 non-native species currently inhabit the Great Lakes, and according to researchers, a new invader is discovered on average every six months.
Ballast tanks a culprit
Most invasive species are believed to enter the lakes through the ballast tanks of overseas freighters.
Michigan took steps to restrict ballast water discharges from oceangoing ships in a law that went into effect Jan. 1. But the shipping industry is challenging the law in federal court.
On March 23, the Lake Carriers' Association, representing most domestic vessels, announced a voluntary ballast water plan to help slow the spread of Viral hemorrhagic septicemia .
The latest invasive culprit is known to have killed large numbers of farmed rainbow trout in Europe in the 1930s. But in DNR documents, the agency said it wasn't until 1963 that scientists confirmed the disease was caused by a virus.
Infected fish transmit the virus through their urine and reproductive fluids that eventually cause blood vessels to weaken and hemorrhage, according to the DNR.
Some fish can develop antibodies. But over time antibodies can decline, and the fish can start secreting the virus again and create new cycles of infection.
Even after the virus leaves the fish, scientists have found that it can move through the water and infect other fish for 14 days.
Staggs said the virus has even been known to stay alive in frozen bait.
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