Three environmental groups filed a friend of the court brief Friday, February 19, urging the U.S. Supreme Court to take up a Michigan lawsuit that aims for a long-term permanent solution to keep the destructive Asian carp from entering Lake Michigan through Chicago’s artificial navigational channels.

Filed by the Natural Resources Defense Council, the Alliance for the Great Lakes, and the National Wildlife Federation, the brief says the nation’s highest court is the proper venue for deciding a dispute that affects everyone who lives in a Great Lakes state.

“An issue of this magnitude and consequence for all of the Great Lakes states should land squarely in the Supreme Court,” said Lyman Welch, attorney and Alliance Water Quality Program manager. “We’re asking the court to intervene in an unprecedented crisis that, left unchecked, will impact the livelihoods of all who depend on a healthy Great Lakes.”

Built to divert Chicago's wastewater away from Lake Michigan and into the Illinois River, the city’s complex system of rivers and canals creates an aquatic superhighway for the jumbo-sized Asian carp and other invasives to travel between the Lake Michigan and Mississippi watersheds.

The environmental groups have called for a physical separation of the two watersheds – essentially returning them to their natural state – as the only permanent way to protect both basins.

“The permanent solution is not technology, but what we call ‘ecological separation’ -- or no movement of live organisms between the Great Lakes and the Mississippi River via the canals,” said Alliance President Joel Brammeier, who co-authored a study on the subject in 2008.

"Failure to shut down this invasive species superhighway poses a threat to all U.S. waters," said Marc Smith, policy manager with the National Wildlife Federation. "The Supreme Court has the power to force the state of Illinois and the U.S. Army Corps of Engineers to take all appropriate and necessary measures to permanently separate the Great Lakes from the Mississippi River. If nothing but the short-term halfmeasures that have been proposed by federal agencies are taken, economic and ecological devastation would only be a matter of time, and time is short."

The Supreme Court rejected Michigan’s request January 19 for

preliminary injunction to temporarily seal off two Chicago-area locks and waterways leading into Lake Michigan. The Supreme Court has not yet ruled on another Michigan request to reopen a nearly century-old case in which the high court allowed Chicago to divert its wastewater from Lake Michigan to the Illinois River, despite the protests of the other Great Lakes states.

The U.S.-Canadian International Joint Commission has commended the Alliance for leading the separation initiative.

Having already infested the Mississippi and Illinois Rivers, Asian carp DNA has been found in several places along the Chicago Waterway System as well as in Lake Michigan’s Calumet Harbor, just outside Chicago. The body of

single Asian carp was found about 20 miles south of the lake in December.

Known to batter boaters and even knock them into the water, Asian carp are voracious filter feeders that can grow to more than four feet long, weigh up to 100 pounds, and quickly dominate a body of water by gobbling up the same food that sustains native fish.