Feared Asian carp may be near US Great Lakes

There are signs the Asian carp may have breached barriers designed to keep the prolific fish out of the Great Lakes, which could spell ecological disaster for the vital source of fresh water, authorities said on Friday.

Concentrations of DNA discovered by Notre Dame University researchers may indicate the presence of bighead and silver carp upstream from two electrical barriers designed to bottle up the invasive fish.

Environmentalists say that if the fish reach the Great Lakes, about 20 miles (32 km) from the barriers, they would quickly destroy the lakes' $4.5 billion fishery by consuming other fish and their food sources. Only Lake Superior among the five lakes may be too cold for the carp, which can reproduce rapidly and reach 100 pounds (45 kg).

The Great Lakes are the world's largest body of surface fresh water and are relied on by 30 million people in the United States and Canada for drinking water and recreation.

"This is devastating news," Andy Buchsbaum of the National Wildlife Federation said of the discovery of carp DNA in the Cal-Sag channel 8 miles (13 km) from Lake Michigan.

"We have to hope that there aren't enough population of fish to reproduce and create an epidemic of Asian carp in the lakes," he said.

The barriers are on the Chicago Sanitary Ship Canal, which is fed by several waterways that flow away from Lake Michigan. The canal is connected by various rivers to the Mississippi River.

Two electrical barriers constructed in recent years in the canal near Chicago were designed to shock the carp and keep them out of the lake.

The DNA could be from carp feces or eggs carried by ship and barge traffic, but it could indicate the carp have breached the barriers, Buchsbaum said.