A Billion-Dollar Plan to Stop Carp From Invading the Great Lakes

Standing on a windy bridge over the Des Plaines River in Joliet, Illinois, Scott Whitney shows off a diagram of what he calls the gauntlet. Pictured is a half-mile-long underwater obstacle course for fish that runs upstream toward Lake Michigan. A curtain of turbulent bubbles is followed by a bank of speakers emitting ear-splitting noise, then a wall of electrified water and finally a navigation lock designed to flush downstream any organisms that make it that far. “It’s hell for the fish,” says Whitney, chief of the project management branch for the US Army Corps of Engineers’ Rock Island District. ...