Fish Virus Feeds Fears It Will Spread to Mississippi River
Saturday, July 19, 2008
CHICAGO -- A deadly fish virus has been found for the first time in southern Lake Michigan and an inland Ohio reservoir, spurring fears of major fish kills and the virus's possible migration to the Mississippi River.
The Illinois Department of Natural Resources invoked emergency fishing regulations June 30 to stop the spread of viral hemorrhagic septicemia (VHS), often described as "fish Ebola," which was found in round gobies and rock bass tested at a marina near the Wisconsin border in early June.
A few days earlier, the virus was detected in round gobies and yellow perch just outside Milwaukee. And weeks earlier, muskellunge in the Clear Fork Reservoir north of Columbus, Ohio, tested positive for the virus. That was the first time the virus was found in a waterway outside of the Great Lakes basin.
The virus attacks saltwater fish off the coasts of Europe, Japan and North America. It was first found in the Great Lakes in 2005. Officials say it was probably transported in the ballast water of the oceangoing freighters that enter the lakes through the St. Lawrence Seaway.
In 2005 and 2006, VHS caused major fish kills in Lake Ontario, Lake Huron, Lake Erie and Lake St. Clair, and it was found in northern Lake Michigan. State and federal officials, however, took immediate steps -- such as banning the transporting of fish and bait among lakes, and requiring the cleaning of boats and fishing equipment -- that limited the spread of the virus in 2007.
But this year's virus detection in Wisconsin, Illinois and Ohio are of particular concern, as the virus was never before seen in those areas and all are routes to the Mississippi River, through the Chicago Sanitary and Ship Canal and the Ohio River. Officials worry that if VHS finds its way into the Mississippi, it will be carried by fish to other rivers and to hatcheries throughout the Midwest and much of the South.
"We're holding our breath, because we could see an outbreak," said Marc Gaden, Great Lakes Fishery Commission legislative liaison.
States have implemented their own rules in addition to federal regulations.
"Guys will go and fish Lake Michigan, and within a week they will be on another big lake," said Steve Robillard, Illinois Department of Natural Resources fisheries biologist. "There's the chance of it getting in there and affecting walleye fisheries or other game fish."
VHS, which has no effect on human health, causes a fish's eyes, skin and gills to hemorrhage. The virus is spread through bodily fluids and can survive in the water for several weeks without a host.
"It ranges from disgusting bloody fish with their eyes popped out to fish with no signs of infection," Gaden said. "Fish swim around, they are in proximity to each other in lakes, just like a kid at a day-care center is more likely to get sick than a kid at home."
The Great Lakes variety of the virus appears to have come from the Atlantic Ocean.