Invasive fish found in Illinois River

MORRIS, Ill. -- Two types of invasive fish have been found in the Illinois River near Morris, a federal spokesman said.

A round goby was caught last week in the Illinois River above the Dresden Island Lock and Dam east of Morris, said Gary Czypinski, a biologist with U.S. Fish & Wildlife Service. The Asian carp has traveled as far upstream from the Mississippi River as Joliet.

"You've got round gobies coming this way toward the Mississippi and Asian carp going that way toward Lake Michigan, and they're all meeting in Morris, or almost," Czypinski said.

Invasive fish concern biologists because often they are free of natural predators and compete with native fish for space, food and spawning sites, said Pam Thiel, project leader for USFWS's Fishery Resource Office in La Crosse, Wis.

There are four species of Asian carp -- the bighead, silver, grass and black carp. They are prolific and eat large quantities of vegetation and plankton, Thiel said.

"They consume so much of their total body weight per day, like 40 percent," said USFWS biologist Burr Fisher. "The worst case scenario is that the other fish will then die out and this will be all we have left."

Round gobies also reproduce quickly, spawning 300 to 500 eggs every 20 days.

The federal government monitors the Illinois River every year to check for new species, Czypinski said.

But scientists can't do anything about the fish that are already in the river. They can only try to educate the public on preventing the fish's spread, Czypinski said.

"It's really hard to eradicate or eliminate round gobies and Asian carp because you can't treat them with chemicals, as this will adversely affect the other fish species," said Elizabeth McCloskey, a biologist with the northern Indiana division of USFWS.

An experimental electrical barrier installed last year by USFWS in the Chicago Sanitary and Ship Canal near Romeoville might have been installed after the gobies were beyond that point, McCloskey said.

"They are hoping the barrier will keep the Asian carp out, but they don't know that for sure," she said. "The gobies are already past it, and we're just hoping now it won't be the huge population of them that they have upstream, that the Asian carp will get to the barrier and turn around instead of keeping on coming."