Protecting Lake Michigan

Battle against Asian carp off to a promising start

Jim Lynch / The Detroit News

After introducing thousands of gallons of toxin into the Chicago Sanitary and Ship Canal and monitoring results for a day, biologists recovered one Asian carp Thursday in a canal leading to Lake Michigan, the nearest the destructive species has come to the Great Lakes, Illinois environmental officials said.

Illinois and federal officials began pumping the toxin rotenone into a section of the canal Wednesday evening in an attempt to kill any of the carp that may have passed north of electrical barriers designed to stop them. The application was necessary for maintenance work on the barrier this week.

U.S. Fish and Wildlife Service officials found the 22-inch immature specimen among tens of thousands of dead fish, from gizzard shad to drum, identified in a fish kill operation in the Chicago Sanitary and Ship Canal, about 40 miles from Lake Michigan, said John Rogner, assistant director of the Illinois Department of Natural Resources.

"Asian carp are indeed knocking on the door of the Great Lakes," Rogner said. "This is the closest to Lake Michigan that an actual Asian carp body has been found."

After being introduced to the United States in the 1970s, Asian carp have been making their way through the Mississippi River system. They can grow to 4 and 5 feet , weigh as much as 100 pounds and eat 40 percent of their body weight daily. Their voracious appetite could devastate a $7 billion-a-year fishing industry, officials fear.

It likely will be days before officials have a clear idea of what they've learned from this week's project. Phil Moy, a researcher with the University of Wisconsin Sea Grant Institute and co-chairman of the Dispersal Barrier Advisory Council, said Asian carp may not have risen to the surface yet.

"Because of their size, we expect them to sink during the first 24 hours or so and then begin to rise as their bodies decompose," Moy said.

It's unlikely the steps taken this week will quell the concerns. Michigan Gov. Jennifer Granholm was among those calling for more action. That could include closing off all the waterways leading from where the Asian carp is established.

Associated Press contributed.