States surrounding the Great Lakes have lost a lawsuit aimed at halting the spread of Asian carp. A US district court judge ruled that forcing the Army Corps of Engineers to cut off the lakes from the Mississippi River system was trumped by federal law, which required the Corps to keep connections navigable between the water bodies. The judge’s 46-page decision against Michigan, Wisconsin, Minnesota, Ohio and Pennsylvania said: “It is not the province of the courts to order parties to take action that would directly contravene statutory mandates and prohibitions.” The states wanted locks closed at the Chicago and Calumet river mouths, where they meet Lake Michigan, as well as permanent screens, grates and other measures to stop Asian carp spreading. They claimed the carp threatened a $7 billion fishing and tourism industry. David St Pierre, executive director of the Metropolitan Water Reclamation District of Greater Chicago, which was also named as a defendant, said: “Neither the MWRD or the Corps has the authority to close off the waterways in Chicago. We simply can’t do it. It would be illegal for us to take that action.” The judge has given the states until January 11 to try to replead their case in a way that doesn’t accuse the defendants of failing to do something that by law they’re required to do. Full story here.