WASHINGTON (Reuters) - The U.S. Supreme Court on Monday rejected a legal request by Michigan aimed at keeping voracious Asian carp out of the Great Lakes where they are considered a threat to fisheries.
Two species of Asian carp -- the Bighead and Silver carp, which can grow to five feet in length and weigh 100 pounds (45 kg) -- are seen as a danger to the lakes' $7 billion fisheries.
Scientists fear they would consume plankton and other small life forms, crowding out other fish species.
The action marked Michigan's third Supreme Court setback this year. In January and in March, the justices rejected separate state requests for an order to close two Chicago-area waterway locks and for other steps that would keep the carp out of the lakes.
Asian carp were imported into the United States to eat algae in ponds but the fish escaped into the wild and have been reproducing in the Mississippi River and its tributaries since the 1970s.
In the latest request, Michigan had sought to reopen Supreme Court cases that dated back to the 1920s and involved the Chicago-area waterway system and how much water can be diverted from Lake Michigan.
Michigan had sought to reopen the litigation by arguing the Chicago-area waterways now serve as a conduit for the carp to pass into Lake Michigan, threatening ecological and economic havoc to the Great Lakes.
Michigan also had requested that the federal government, the state of Illinois and Chicago's sewer authority take steps to stop the carp migration into Lake Michigan.
Solicitor General Elena Kagan, representing the federal government, opposed Michigan's request. She said the carp issue was unrelated to the decades-old cases.
Instead of trying to reopen the Supreme Court cases, the proper forum for Michigan would be to bring a lawsuit before a federal judge, she said.
(Reporting by James Vicini; Editing by Eric Walsh)
