TRAVERSE CITY, Mich. (CBS) — Some Great Lakes States are putting pressure on the federal government to wall off the Chicago Sanitary and Ship Canal to stop the spread of Asian carp.

As WBBM Newsradio’s Nancy Harty reports, a federal appeals court ruled against the states last week.

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A letter signed by attorneys general from six of the eight Great Lakes states – Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin – is asking colleagues along the Mississippi River to encourage the U.S. Army Corps of Engineers to close the Sanitary and Ship Canal.

Illinois and Indiana were not included.

The group wants the Army Corps to speed up a study on how effective electric barriers along the canal are at keeping invasive species such as Asian carp and zebra mussels from traveling between the Great Lakes and the Mississippi.

In the letter, the officials also invited colleagues in 27 other 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.

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“We have Asian carp coming into Lake Michigan and zebra mussels moving out of the Great Lakes and into the heart of our country, both of which are like poison to the ecology of our waters,” Michigan Attorney General Bill Schuette said. “This is not just a Great Lakes issue. By working together, we hope to put pressure on the federal government to act before it’s too late.”

Last week, the 7th U.S. Circuit Court of Appeals in Chicago turned down a plea by five of the states for an order that the locks be closed immediately.

But the panel disagreed with a lower court’s conclusion that the states appeared to have little chance of succeeding in their lawsuit. Dow had acknowledged a carp invasion could harm the Great Lakes but said the states hadn’t shown it was likely or imminent. He said flooding and economic damage from closing the locks would do more damage to Chicago-area businesses and homeowners than “the more remote harm associated with the possibility” of Asian carp becoming established in the lakes.

Spokeswoman Jacqueline Tate said the Army Corps had not seen the attorneys generals’ letter and had no immediate comment. Officials with the Corps have said repeatedly they could not speed up the study because of the complex scientific and engineering issues involved. It’s examining dozens of potential aquatic pathways, not just the Chicago area.

For now, the Great Lakes remain untouched by the Asian carp menace. Testing earlier this year found carp DNA in Lake Calumet, but four days of intensive monitoring earlier this month turned up no trace of the voracious fish.

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