WASHINGTON (Legal Newsline)-The U.S. Supreme Court will consider on Friday a lawsuit filed by Michigan Attorney General Mike Cox to close some Chicago locks to prevent the massive Asian carp from invading the Great Lakes.

Cox, a Republican, has asked the nation's highest court to issue a preliminary injunction to close the locks in order to keep the invasive carp, which can weigh hundreds of pounds, from migrating into the Great Lakes, where they could ravage the regional fishing economy.

Last month, Cox sent a letter to the Army Corps of Engineers, the state of Illinois, and the Metropolitan Water Reclamation District of Greater Chicago asking that they take immediate action against the invasive carp species.

Attorneys general from Ohio, Wisconsin, Minnesota, New York, and the Canadian province of Ontario have filed amicus briefs in support of Cox's lawsuit, which the justices could rule on as soon as Friday.

Fighting the lawsuit is Illinois Attorney General Lisa Madigan, a Democrat. She has argued that closing the locks could harm the Chicago-area economy without guaranteeing that the carp would not reach the Great Lakes.

"Michigan offers no substantial evidence that the threatened injury is more than speculative at this time," Madigan wrote in a brief to the high court.

The White House too opposes closing the locks, saying in court papers that the move would disrupt commerce and endanger public safety since the closures would disrupt the U.S. Coast Guard activities in the area.

"In a host of ways, the federal government has demonstrated its commitment to protecting the Great Lakes from the expansion of Asian carp," U.S. Solicitor General Elena Kagan, who represents the Obama administration before the high court, said in a brief filed last week. "Nothing in federal law warrants second-guessing its expert judgment that the best information available today does not yet justify the dramatic steps Michigan demands."

For many years, the invasive bighead and silver carp have been migrating northward in the Mississippi and Illinois rivers, biologists say.

The case is being heard by the U.S. Supreme Court because legal disputes among states are adjudicated by the high court.

In seeking the preliminary injunction to close the locks, Cox reopened a 1966 U.S. Supreme Court case over the Chicago Sanitary and Ship Canal and the threats plaintiffs say it poses to the Great Lakes.

From Legal Newsline: Reach staff reporter Chris Rizo at chrisrizo@legalnewsline.com.