Asian Carp May Have Breached Electronic Barrier

(ABC News)

Asian carp may have breached an electronic barrier designed to prevent the giant invaders from upsetting the ecosystem in the Great Lakes and jeopardizing a $7 billion sport fishery, officials said Friday.

Scientists recently collected 32 DNA samples of Asian carp between the barrier and Lake Michigan in waterways south of Chicago, although the fish have yet to be spotted in the area, said Maj. Gen. John Peabody of the U.S. Army Corps of Engineers.

If the feared bighead and silver carp have got through the $9 million barrier, the only remaining obstacle between the carp and Lake Michigan is a navigational lock on the Calumet River. Some DNA was found as close as 1 mile south of the lock and 8 miles south of the lake.

Still, federal officials insisted a Great Lakes invasion was not inevitable.

"We're going to keep throwing everything we possibly can at them to keep them out," said Cameron Davis, senior Great Lakes adviser to Lisa Jackson, head of the Environmental Protection Agency.

Asian carp escaped from Southern fish farms into the Mississippi River during 1990s flooding and have been migrating northward since.

The monstrous creatures can exceed 4 feet long and 100 pounds. They consume up to 40 percent of their body weight daily in plankton, starving out smaller and less aggressive competitors.

Aside from decimating species prized by anglers and commercial fishers, Asian carp are known to leap from the water at the sound of passing motors and sometimes collide with boaters.

It is not known how the carp would fare in the chilly Great Lakes, which are different ecosystems than rivers, Davis said.

A worst-case scenario envisions them spreading "like a cancer cell," he said, eventually dominating a fishery already damaged by zebra mussels, sea lamprey and other exotic pests.

In 2002, the Army Corps placed an electronic device on the Chicago Sanitary and Ship Canal, a man-made waterway south of the city that forms part of a linkage between the Mississippi and Lake Michigan.