A federal appeals panel today rejected the request of five Great Lakes states to close Chicago-area shipping locks. But the panel warned that if ongoing efforts to stop the advance of Asian carp stop or slow down the issue could be revisited.
The ruling by the three-judge panel of the 7th U.S. Circuit Court of Appeals follows a district court decision in December that concluded the invasive species did not appear to be an imminent threat and closing the locks might not keep them from reaching Lake Michigan anyway.
Locking gates were built into the Calumet-Sag Channel and the Chicago River to limit the amount of water releasing out of Lake Michigan when engineers reversed the flow of the Chicago River at the turn of the century.
The U.S. Army Corp of Engineers and the Metropolitan Water Reclamation District control the locks to limit flooding during heavy rains and to allow cargo ships and boats to pass.
In July 2010, Michigan, Minnesota, Ohio, Pennsylvania and Wisconsin sued the federal government to force a temporary closure of the locks until other carp-control methods could be put in place. Critics, however, alleged that the effort was “politically motivated” and could devastate the regional shipping industry and put residents who live in flood-prone areas at risk.
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, jeopardizing the Great Lakes’ estimated $7 billion annual commercial and recreational fishing industry.
Although the 7th Circuit of Appeals upheld the lower court’s ruling, it disagreed with U.S. District Judge Robert M. Dow’s opinion that the “plaintiffs cannot establish a showing of irreparable harm.”
“We are less sanguine about the prospects of keeping the carp at bay,” the panel wrote. “If the invasion comes to pass, there is little doubt that the harm to the plaintiff states would be irreparable.”