Scientists have turned up more genetic evidence of Asian carp above an electric barrier designed to keep them from invading the Great Lakes.
The U.S. Army Corps of Engineers this week reported that nine water samples taken in May and June from Chicago-area waterways contained DNA from silver carp, one of two Asian species threatening to enter the lakes after migrating northward in the Mississippi River and its tributaries.
Hundreds of other samples had no carp DNA. But environmentalists say the latest findings show the electric barrier isn't enough to protect the Great Lakes. They want to sever the link between the lakes and the Mississippi basin near Chicago.
The federal government's Asian carp program coordinator said Thursday there's no evidence the fish are getting through the barrier.