Why solving the Asian carp problem is so hard
Invasive Asian carp traveled up the Mississippi River to Lake Michigan, threatening the regional economy as well as the environment.
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Critics say that plan has no firm timeline and does not commit to permanent closure of the navigational locks to keep carp out.Skip to next paragraph
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"We think the court should take another look at our request to hit the pause button on the locks until the entire Great Lakes region is comfortable that an effective plan is in place to stop Asian carp," Michigan Attorney General Mike Cox said in a statement.
The federal plan argues against lock closure, saying 14.6 million tons of the Chicago area's petroleum, coal, road salt, cement, and iron travel through the lock. The canal generates $30 million a year in revenue, according to the American Waterways Operators, a trade association representing the tugboat, towboat, and barge industry.
But even if the locks are closed, Lake Michigan is still under threat from Chicago sewage.
The Chicago Sanitary and Ship Canal, which connects the lake to the Mississippi River, was built early last century to reverse the flow of Chicago wastewater, pushing it downstream from the lake.
Thomas Murphy, former editor of the Journal of Great Lakes Research, says closing the navigational locks would allow water to resume its historical flow. The problem, he says, would come when storms cause wastewater treatment plants to overflow. Without locks to release it, sewage would run into the lake.
Mr. Murphy estimates that 11 billion gallons of untreated sewage overflowed into Lake Michigan last year. "So it happens now," he says, "but it would happen much more frequently, although in smaller discharges, if the locks were closed."
Already, the carp are shaking up the fishing economies of small Illinois river towns downstate, where millions of carp are destroying local crappie, bass, and bullhead populations.
"You don't find [the native species] anymore," says Kurt Hettiger, chief aquarist at the John G. Shedd Aquarium in Chicago. "If [Asian carp] keep moving in and taking up the biomass in the river, they could totally replace the [other] fish."
If Asian carp infiltrate the Great Lakes, says Mr. Hettiger, they will have access to several Midwest river systems. "The potential is there for a lot of devastation."