TRAVERSE CITY, Mich. (AP) -- Officials say DNA from Asian carp has been discovered in water samples collected from Lake Erie nearly a year ago.
It's the first time DNA from bighead and silver carp has turned up in Lake Erie. Three bighead carp were caught there between 1995 and 2000.
Researchers with the University of Notre Dame detected DNA from the invasive fish this week when examining more than 400 samples taken in August 2011.
Scientists are uncertain about whether carp DNA signals the presence of actual fish. Some say there could be other sources, such as feces from fish-eating birds. Still, the findings are unsettling because scientists have described Erie as the lake that could suffer the biggest harm from an Asian carp incursion.