A scientific report says at least some Asian carp probably have reached the Great Lakes, but there's still time to stop them from becoming established.

The paper released Thursday was written by scientists with the University of Notre Dame, The Nature Conservancy and Central Michigan University. It summarizes findings from a two-year search for the carp in and around the Great Lakes.

The scientists took 58 water samples that contained Asian carp DNA in waterways near Chicago. Six samples taken from Lake Erie also yielded positive hits.

Lead author Chris Jerde of Notre Dame says the likeliest explanation is that the DNA came from live carp, some of which may be in Lake Michigan.

The U.S. Army Corps of Engineers says the DNA could have come from other sources.