The Supreme Court has turned down a second request to immediately close shipping locks to prevent invasive Asian carp from infesting the Great Lakes.
The court on Monday refused a renewed request by Michigan to issue a preliminary injunction that would order the locks closed. The justices turned down the original request in January.
Scientists fear that if they reach the lakes, they could disrupt the food chain and endanger the $7 billion fishery.
The biggest Asian carp can weigh 100 pounds and consume up to 40 percent of their body weight daily in plankton, the base of the food chain for Great Lakes fish.