Experts are stepping up a search for places where the invasive Asian carp might slip from the Mississippi River watershed into the Great Lakes.

In the fight to keep the dreaded carp out of the lakes, most of the attention has focused on a Chicago shipping canal and nearby waters that offer a pathway to Lake Michigan.

But the Army Corps of Engineers has identified 18 other locations from Minnesota to New York that offer at least a medium risk of letting species migrate from one drainage basin to the other.

Of those, the biggest danger zone is a wetland complex near Fort Wayne, Ind., that could enable the carp to reach the Maumee River and then Lake Erie.

Other possible pathways include wetlands, streams and man-made ditches and canals.