Michigan and four other states on the lakes sued the federal government, asking for a temporary closing of the locks on the Calumet-Sag Channel and the Chicago River until a more permanent solution could be found to keep the carp from reaching Lake Michigan, the Chicago Tribune reported.
But a federal appeals court last year agreed with a federal judge that the carp, although an invasive species, did not appear to be an imminent threat, and that closing the locks might not be effective anyway.
Asian carp, native to China and with no known predators in the United States, have overwhelmed native fish populations in waters they reach, and pose a potential threat if they were to infiltrate the Great Lakes where the fishing industry is estimated at $7 billion annually, the report said.
Opponents of closing the locks have said that would harm the shipping industry.
The Tribune said it was the third time Michigan and supporters have sued the federal government to close the locks, without success.