Some of the Chicago DNA was found in Lake Calumet, where a live bighead carp was caught in 2010.

WSJ: Report: Asian carp may have reached Great Lakes

But the Jerde team's paper, published online Thursday by the Canadian Journal of Fisheries and Aquatic Sciences, argues that the likeliest explanation remains the presence of live Asian carp.

WSJ: Report: Asian carp may have reached Great Lakes

But while the government team acknowledges the presence of Asian carp genetic fingerprints, it disagrees that they necessarily signal the presence of live fish.

WSJ: Report: Asian carp may have reached Great Lakes