TRAVERSE CITY (AP) -- Scientists have published a paper defending their contention that DNA evidence shows Asian carp have gotten past an electric barrier designed to keep them out of the Great Lakes.

The paper is being released Wednesday by a journal called Conservation Letters.  It describes how biologists with the University of Notre Dame and The Nature Conservancy gathered more than 1,000 samples from waterways near Chicago.  Of those, 58 contained DNA from Asian carp and were taken beyond the barrier.

Scientists say it's unclear exactly how many Asian carp are in the waterways.

The DNA research has become a focal point in the debate over whether to close Chicago-area shipping locks to block the carp's path to Lake Michigan, which five states are seeking in a federal lawsuit.

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