Asian carp continue their spread

Fish found closer to Lake Michigan than previously thought possible

Associated Press

TRAVERSE CITY, Mich. — A live Asian carp has been discovered in a Chicago waterway about 9 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.

The silver carp was 28 inches long and weighed about 8 pounds, officials with the multi-state Asian Carp Regional Coordinating Committee said. It was caught by a commercial fisherman under contract with the Illinois Department of Natural Resources about 2 miles below the T.J. O’Brien Lock and Dam in the Calumet River, onChicago’s south side.

The location is 34 miles closer to Lake Michigan than silver carp previously were known to have reached, said Charlie Wooley, Midwest deputy regional director for theU.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 the discovery doesn’t mean Asian carp have become established in the rivers and canals between the barriers and the Great Lakes, orin the lakes themselves.

It’s more likely the carp was a loner that somehow made its way into the Chicagoarea, Wooley said.

“Thisis concerning but it’s not a three-alarm fire right now and we don’t expect it to be,” he said.

The fish carcass was sent to Southern Illinois University for necrospy, said Kevin Irons, the state agency’s aquatic nuisance program manager. Biologists there examined its inner-ear bones for chemicals that are characteristic of particular waterways to learn where it had been,he said.

Under a plan developed by the multi-agency coordinating committee, the find triggered two weeks of “intense” searching for additional Asian carp. Crews used nets and electric stunning devices to comb the area where the silver carp was found, plus other sections of the Chicagoarea waterways and Lake Michigan’sCalumet Harbor.

The catch marked the second time a live Asian carp was found beyond three electric barriers clustered in the Chicago Sanitary and Ship Canal 37 miles from Lake Michigan. The other was a bighead carp caught in Chicago’sLake Calumet in 2010.

Bighead and silver carp are of special concern becauseof their voracious appetites for zooplankton, the tiny THIS WEEK: Control of invasive species entering the Great Lakes should be a national priority. • Yes • No LAST WEEK: plants and animals on which nearly all fish depend at some point in life. Silver carp are notorious for hurtling out of the water when startled, which can lead to bonebreaking collisions with peoplein motorboats.

The electric barrier system, operated by the U.S. Army Corps of Engineers, is intended to prevent fish from swimming between the the Mississippi River watershed and the Great Lakes. Federal officials say it performs well, although a study has found that juvenile fish might get pulled through when caught inbarge currents.

Members of Congress from some states in the Great Lakes region contend the electric barriers aren’t enough.

They want permanent impediments in the Chicagoarea waterways to physically separate the lakes from the Mississippi system, a step opposed by Illinois lawmakers who say it would disrupt shipping.

The Army Corps of Engineers has an internal plan to strengthen defenses against invasive fish at a choke point several miles downstream from the electric barriers. The costly plan would requirefederal approval.

Environmental groups said the Trump administration was delaying implementationof a permanent fix.

One thing agreed upon is that the invasive fish are coming.

“The discovery of Asian carp this close to Lake Michigan demonstrates how the window of opportunity to protect the Great Lakes is closing,” said U.S. Rep. Bill Huizenga, a Michigan Republican.

The silver carp was the first detected in the water past the barriers, Wooley said.

Still, the main front for adult bighead and silver carp remains well downstream and is being thinned by continuous fishing, reducing the odds that enough will reach the lake to establish breeding populations, he said.