Fears mount over giant carp reaching Great Lakes

CHICAGO — Fears that giant, voracious species of carp will get into the Great Lakes and wipe out other fish have led to rising demands that the government close the waterway connecting the lakes to the Mississippi River — an unprecedented step that could disrupt the movement of millions of tons of iron ore, coal, grain and other goods.

The dispute could become an epic clash of competing interests: commerce, environmentalists and fishermen.

Michigan Gov. Jennifer Granholm and five environmental groups threatened on Wednesday to sue the U.S. Army Corps of Engineers to force it to temporarily shut three shipping locks near Chicago because of evidence that Asian carp may have breached the electrical barrier that is supposed to hold them back from the lakes.

The environmental groups went further than the governor and said the Great Lakes and the Mississippi should be permanently separated to avert what Granholm called "ecological disaster."

Col. Vincent Quarles, commander of the Corps' Chicago district, said the agency is considering all options but would not close the locks without first studying the possible effects.

Environmentalists fear that the fish, which consume up to 40 percent of their body weight daily in plankton, could starve out smaller and less-aggressive competitors and cause the collapse of the $7 billion-a-year Great Lakes sport and commercial fishing industry.

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 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.

The American Waterways Operators, a trade association representing the tug and barge industry, said closing the locks would lead to higher shipping costs because commodities would have to be sent overland via truck or train across Illinois before being put back onto vessels.

"The impact is going to be large," said Lynn Muench, the group's senior vice president for regional advocacy in St. Louis. "It could definitely impact day-to-day living."