The latest weapon in the fight against Asian carp doesn’t look much like a weapon at all: It’s a 13-mile concrete and steel mesh fence that splits the narrow divide between the Des Plaines River and the Chicago Sanitary and Ship Canal as they meander through the southwest suburbs.
The $7 million project, paid for from the federal Great Lakes Restoration Fund, is a relatively low-tech solution to keep the dreaded carp from breaching the low-lying strip of land between the river and the shipping canal during heavy rains.
It may look simple, but state and federal officials say this fence in Illinois and a similar one recently erected in Indiana are vital to the national effort to keep the invasive species out of the Great Lakes.
“This was absolutely critical,” said John Rogner, assistant director of the Illinois Department of Natural Resources. “We knew that during high flood events that Asian carp, if they’re in the river, could easily span the gap and get into the Sanitary and Ship Canal.”
A native of China with no known predators in the U.S., Asian carp have overwhelmed native fish populations by out-competing them for food in a 30-year migration up the Mississippi and Illinois rivers. Many fear the carp could soon enter the Great Lakes, jeopardizing its estimated $7 billion a year commercial and recreational fishing industry.
With a bill in Congress and a verdict soon expected in a divisive court case aimed at closing Chicago-area shipping locks to halt the northward migration of the fish, officials say the fence is a reminder that the daily battle against carp continues unabated.
“We just keep using every tool that we have to try and make sure they don’t come any closer and to eradicate them eventually,” said U.S. Rep. Judy Biggert, R-Ill.
Though it’s unclear how many Asian carp exist in the Des Plaines River, the winding tributary connects to the Illinois River where Asian carp are known to be abundant. The fence is designed to work in partnership with a more sophisticated carp weapon — the underwater electrical barriers installed a decade ago in the shipping canal near Romeoville.