A decision could come within days on whether to temporarily close a vital Chicago area shipping waterway in an increasingly desperate bid to stop the invasive Asian carp from reaching the Great Lakes, an Obama administration adviser said Friday.
Cameron Davis, the Great Lakes adviser to the U.S. Environmental Protection Agency, told The Associated Press that discussions were under way about shutting the O'Brien Lock while crews poison part of the Chicago Sanitary and Ship Canal to kill the giant carp.
"It's going to happen soon," he said about a decision. "We're talking, best guess, within the next two or three days."
Before making a final decision, officials want to finish searching for Asian carp and conduct other tests along the canal to pinpoint where they might be located, Davis said. If officials do choose to close the lock, it would shut down immediately.
Authorities are trying to make sure the voracious carp don't reach Lake Michigan where they could starve out smaller, less aggressive competitors and cause the collapse of the $7 billion-a-year Great Lakes sport and commercial fishing industry.
But closing the lock could also disrupt the movement of millions of tons of iron ore, coal, grain, salts and other goods.
The American Waterways Operators, a trade group representing the tug and barge industry, said Friday that a safety zone set up by the U.S. Coast Guard to search for Asian carp near the O'Brien Lock already made it impassable for commercial vessels.
"De facto it is closed ... They're playing with words on this," said Lynn Muench, a senior vice president for the group. "Our vessels cannot go through to Lake Michigan. We cannot transit." She expected traffic to be restricted for up to eight days.
The closure of the locks, especially for any longer period of time, could result in sharply higher shipping costs because commodities would have to be sent overland by truck or train.
A sense of urgency among environmentalists rose on Thursday after officials said they found a single Asian carp during a fish-kill operation this week in another part of the canal. It was the closest that an actual fish has been found to Lake Michigan.
Last month, officials said they found DNA evidence that the carp may have breached an electrical barrier on the Chicago Sanitary and Ship Canal that is meant to hold back the fish from the lakes. Michigan Gov. Jennifer Granholm and five environmental groups have threatened to sue if the U.S. Army Corps of Engineers to force it to temporarily shut three locks near Chicago over fears the carp will creep into the Great Lakes.
The carp _ which can grow to 4 feet long and 100 pounds and are known for leaping out of the water when boats are near _ were imported by Southern fish farms in the 1970s but escaped into the Mississippi in large numbers during flooding in the 1990s and have been making their way northward ever since.
The Mississippi and the Great Lakes are connected by a complex, 250-mile network of rivers and canals engineered more than a century ago. It runs from Chicago, on the southern edge of Lake Michigan, to a spot on the Mississippi just north of St. Louis.
In the ongoing battle against the Asian carp, environmental officials began dumping poison Wednesday in a nearly six-mile stretch of the canal to kill off any Asian carp while the electrical barrier was turned off for maintenance. Work was expected to finish on Saturday.
Associated Press Writer John Flesher in Traverse City, Mich., contributed to this report.