WASHINGTON (Legal Newsline)-The White House has expressed opposition to Michigan Attorney General Mike Cox's effort to close down the Chicago locks connecting the Mississippi River and Lake Michigan.

Cox has asked the nation's high court for a preliminary injunction to force the closure of some Chicago-area locks connecting Illinois waterways to Lake Michigan to keep Asian carp from invading the Great Lakes.

U.S. Solicitor General Elena Kagan, who represents the Obama administration before the high court, on Tuesday said the plan would impede commerce and compromise public safety by interrupting U.S. Coast Guard activities.

"In a host of ways, the federal government has demonstrated its commitment to protecting the Great Lakes from the expansion of Asian carp," Kagan said in court papers. "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."

Illinois Attorney General Lisa Madigan has filed papers expressing her opposition to Cox's lawsuit, saying the Michigan attorney general has failed to show that it will suffer "irreparable harm" if the locks are not closed.

"First, Michigan offers no substantial evidence that the threatened injury is more than speculative at this time," Madigan wrote.

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

Cox and a group of other attorneys general from neighboring states have said in court briefs that if the invasive species is allowed to migrate into the Great Lakes it 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.

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.

Ohio, Wisconsin, Minnesota, New York, and the Canadian province of Ontario have filed amicus briefs in support of Cox's lawsuit.

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