CHICAGO (CBS) — Gov. Pat Quinn disagrees with the contention that the only way to block the Asian carp from the Great Lakes is to close the Chicago Sanitary and Ship Canal.

As WBBM Newsradio’s Bob Roberts reports, Quinn’s remarks come after attorneys general from six states – Wisconsin, Michigan, Minnesota, New York, Ohio and Pennsylvania – issued a letter asking colleagues along the Mississippi River to encourage the U.S. Army Corps of Engineers to close the Sanitary and Ship Canal.

LISTEN: WBBM Newsradio’s Bob Roberts reports

The attorneys general asked 27 additional states to join a lobbying campaign to separate the Great Lakes from the Mississippi River Basin, contending they have as much to lose as the Great Lakes do from migration of aquatic plants and animals that can do billions in economic damage and starve out native species.

But Quinn disagrees with the letter’s claims.

“They’ve gone to court and they’ve lost in court,” he said. “It’s something we understand. We want to keep the Asian carp out of Lake Michigan and out of the Great Lakes. We’re doing a Herculean job in that area and we will continue.”

The Army Corps of Engineers is studying the effectiveness of electronic barriers now in place. The study is not expected to be complete under 2015.

Although Asian carp DNA has been found in Lake Michigan, only one actual Asian carp has been found on the lake side of the electronic barriers to date, in Lake Calumet.

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