CHICAGO (CN) - States bordering the Great Lakes cannot compel closure of the Chicago River's locks to prevent the migration of the invasive Asian carp, the 7th Circuit ruled.
"Meddling with Mother Nature is not always a good idea, as the ongoing saga of the Asian carp illustrates," Judge Diane Wood wrote for a three-judge panel Monday.
Fish farmers in southern states imported
Asian carp from China in the 1970s to help clean vegetation at the bottom commercial ponds. The fish can grow up to 100 pounds, is extremely good at jumping and eats several times its weight in food per day.
Now that it is well established in the Mississippi River and its tributaries, the U.S. Fish and Wildlife Service has labeled Asian carp as highly injurious to native ecosystems.
Three years ago in this case, the 7th Circuit denied
the states bordering the Great Lakes an injunction to close the locks of the Chicago River to prevent the fish's migration.
"In light of the active regulatory efforts that are ongoing, we conclude that an interim injunction would only get in the way," Wood wrote in 2011, noting that "there is a powerful array of expert federal and state actors that are engaged in a monumental effort to stop invasive carp from entering the Great Lakes."
The court ruled against the states again on Monday.
"We find once again that the states have not alleged facts showing that the Corps and the District are operating the CAWS [Chicago Area Waterway System] in a manner that is likely to allow the Asian carp to reach Lake Michigan," Wood said.
To prevent the carp's spread, the corps has already adopted several measures, such as the installation of barriers between the Des Plaines Rive and Chicago Sanitary and Ship Canal, which would prevent carp from washing between them during floods. It has also introduced three electric barriers operating at maximum-safe strength and installed two additional screens at Chicago-area sluice gates.
When one of the barriers was shut down for maintenance in 2009, the Illinois Department of Natural Resources dumped
2,200 gallons of the toxin rotenone into the canal.
Though workers found only one Asian Carp among tens of thousands of poisoned fish, there have been several sightings of the fish beyond
the electric barriers.
"Even on the assumption (favorable to the states) that the carp are advancing toward the CAWS and will establish a sustainable population if they reach Lake Michigan, none of the present allegations tends to show that the Corps's current method of operating the CAWS will permit the Asian carp to pass," Wood said. "To the contrary, the allegations tend to show that the Corps is taking its stewardship over the CAWS and the carp problem seriously."
Wood was careful to note, however, that the states are free to revive their claims if new facts develop showing that the corps has been lax in its duty to protect the Great Lakes
"It is the defendants' apparent diligence, rather than their claimed helplessness, that is key to our holding today," the opinion concludes.