20100519 illinois carp 18
A worker from Illinois Marine Towing keeps watch from the deck of the Windy City as it pushes a barge into downtown in Chicago, Ill. - 

by Tony Arnold

Good old-fashion nets haven't stopped the fish. Neither have electrical barriers submerged in water. So today -- for the second time -- the Illinois Department of Natural Resources will dump chemicals into an Illinois river that should kill all fish in a 2-mile stretch.

"We need this important information to find out what the population is and how big of a problem it may or may not be," says Chris McCloud, a spokesman for the department.

The worry is the carp will take over Lake Michigan -- and beyond. The fish has caused a battle between Illinois and other Great Lakes states that fear the carp would ruin the region's roughly $7 billion sport fishing industry.

Joy Yearout is with Michigan's Attorney General office. She says today's chemical dump doesn't go far enough.

"It's good, but it's not comprehensive. There are so many more basic, short-term steps that we could be taking to address Asian carp," says Yearout.

Michigan's attorney general has tried to force Illinois to close waterways leading into Lake Michigan. But Chicago business groups say if that happens -- it would halt billions of dollars of goods now shipped on the waterways.