TRAVERSE CITY, Mich. — A live Asian carp has been discovered in a Chicago waterway about nine miles from Lake Michigan — well beyond an electric barrier network designed to prevent the invasive fish that have infested the Mississippi River system from reaching the Great Lakes, officials said Friday.
The silver carp was 28 inches long and weighed about 8 pounds, officials with the Asian Carp Regional Coordinating Committee told The Associated Press. It was caught Thursday by a commercial fisherman under contract with the Illinois Department of Natural Resources about 2 miles below the below the T.J. O’Brien Lock and Dam in the Calumet River, on Chicago’s south side.
The location is the closest to the Great Lakes that a silver carp is known to have reached, said Charlie Wooley, Midwest deputy regional director for the U.S. Fish and Wildlife Service. Silver carp are among four types of Asian carp threatening to invade the lakes, where scientists say they could compete with native species, unravel aquatic food chains and devastate the region’s $7 billion fishing industry.
Even so, officials cautioned that the discovery doesn’t mean Asian carp populations have become established in the network of rivers and canals between the barriers and the Great Lakes, or in the lakes themselves. It’s more likely that the carp was a loner that somehow made its way into the Chicago area, Wooley said.
“This is concerning but it’s not a three-alarm fire right now and we don’t expect it to be,” he said in an interview.
The fish carcass is being sent to Southern Illinois University, where biologists will attempt to determine where it came from, said Kevin Irons, the state agency’s aquatic nuisance program manager. Under a plan developed years ago by the multi-agency coordinating committee, the find triggers two weeks of “intense” net fishing in the area where the silver carp was caught to look for others.
This is the second time a live Asian carp has been found beyond the three electric barriers clustered in the Chicago Sanitary and Ship Canal 37 miles downstream from Lake Michigan. The other was a bighead carp caught in Chicago’s Lake Calumet in 2010.
Bighead and silver carp are of special concern because of their voracious appetites for plankton — tiny plants and animals on which nearly all fish depend at some point in their live cycles. Silver carp are notorious for hurtling out of the water when startled, which can lead to bone-breaking collisions with people in motorboats.
The electric barrier system, operated by the U.S. Army Corps of Engineers, is intended to prevent fish from swimming between the Great Lakes and the Mississippi River system, which is infested with Asian carp. Federal officials say it does the job well, although a study has found that juvenile fish might get pulled through when caught in currents created by passing barges.
Members of Congress from some states in the Great Lakes region contend the electric barriers aren’t enough to safeguard the lakes. They have called for placing barriers in the Chicago-area waterway to seal off the lakes from the Mississippi watershed, a step opposed by Illinois lawmakers and shipping interests who say it would disrupt barge traffic on the busy waterway.
The Army Corps was scheduled to release an interim report in February on measures that could be taken to strengthen defenses against invasive fish at the Brandon Road Lock and Dam on the Des Plaines River in Joliet, Illinois, several miles downstream from the electric barriers. But the Trump administration has delayed making it public.
Lawmakers from Great Lakes states introduced bills this week that would order its release.
“The discovery of Asian Carp this close to Lake Michigan demonstrates how the window of opportunity to protect the Great Lakes is closing,” said Rep. Bill Huizenga, a Michigan Republican. “If Asian Carp are able to gain access and reproduce within the Great Lakes, the environmental and economic damage will be severe.”