Asian Carp Threaten Great Lakes

Dec. 2, 2009— -- Environmental officials in Illinois plan to dump a toxic chemical into a stretch of the Chicago Sanitary and Ship Canal Wednesday night hoping to keep Lake Michigan safe from a species of massive and voracious fish called Asian carp.

The fish, which can grow to 4 feet long and weigh 100 pounds, are known for their ability to leap up to 8 feet out of the water as motor boats speed by, injuring fishermen. Scientists fear that the fish, which can eat the equivalent of 40 percent of their body weight every day, could damage the ecosystem of the Great Lakes, which is the largest body of fresh water in the world.

For now, officials say there's nothing to do but kill them.

"We are all very concerned about the threat Asian carp pose to the Great Lakes," said Stacey Solano, spokeswoman for the Illinois Department of Natural Resources.

Officials said the carp are closing in on Lake Michigan, and that's why they plan to poison a 5.7-mile channel south of Chicago to keep the carp from passing an electric barrier that would normally hold them back. Officials will spread a fish toxin called rotenone near Lockport, Ill., hoping to kill the carp. Rotenone kills fish by disrupting their ability to metabolize oxygen.

"The U.S. Army Corps of Engineers needs to take their barrier down for routine maintenance, and to ensure that no carp are able to reach the barrier, we are taking this action to rotenone the canal," Solano told ABC News.

The Army Corps of Engineers built the electric barrier 25 miles from Lake Michigan back in 2002 to protect the waters.

Environmental organizations say the carp need to be kept from crowding other species out of the Great Lakes. The fish, which make up the largest percentage of biomass in some Midwest rivers, have traveled along the Mississippi for nearly two decades. Some conservation groups say all Illinois locks and gateways leading to Lake Michigan ought to be closed.

"If we want our kids and grandkids to know anything remotely like the Great Lakes we have today, we have to stop the carp. The carp will change the lakes permanently," said Jen Nalbone, director of invasion for Great Lakes United. Her group says Asian carp have had a devastating effect on the Mississippi -- and must be stopped from doing the same thing to the Great Lakes.