Ohio officials say they have found no trace of Asian carp, after a three-day sweep of western Lake Erie.
The search, which included netting and electroshock fishing, was prompted by tests from last month that had detected the DNA of two different species of Asian carp in six water samples taken from Maumee and Sandusky bays. According to The Columbus Dispatch, during the sweep, ten wildlife experts from the Ohio and Michigan sampled 58 sites in both bays. They say they found shad, common carp, and largemouth bass, but no Asian carp was found.
To explain the positive sample of DNA that was found, researchers say it could have come from fish mucus, excrement or scales that were floating in the water. The other possibility is that it could have come from the feces of a great blue heron that ate a juvenile carp in Indiana and then flew to Lake Erie.
DNA of Asian carp has shown up in several tests of Lake Calumet and other waterways around Chicago. This has led researchers to believe that the fish have somehow slipped past an electric barrier that is intended to keep them out of Lake Michigan. The discovery of a breeding population of Asian carp would be devastating for Lake Erie's $10-billion-a-year tourism industry. The fear is that the fish would quickly spread through the lake, out-competing native fish for food.