Water samples collected this summer from the Maumee Bay and River have tested positive for Asian carp environmental DNA, the Michigan Department of Natural Resources said Monday. The search for Asian carp in Lake Erie has been conducted by the Ohio and Michigan Departments of Natural Resources and U.S. Fish and Wildlife Service. Although no live Asian carp have been found during the recent tests in those bodies of water, which are part of or feed into Lake Erie, the continuing presence of positive test results is perplexing. Test results in those areas also were positive for Asian carp environmental DNA in 2011.
Traces of Asian carp environmental DNA, which can include mucous, scales and other fish remnants, is not proof that live fish were in the tested waters.
The announcement follows positive results from water sampling conducted in the Sandusky Bay and River during about the same period in late July and early August.
"Our field crews were out on the water numerous times over the last couple of months, using multiple gear types, and they found no live Asian carp," U.S. Fish and Wildlife Service Midwest Deputy Regional Director Charlie Wooley said in a news release. "We are still trying to pull back the curtain on what the source is for these positive DNA samples."
This month, Todd Kalish, Lake Erie basin coordinator and acting Lake Michigan basin coordinator for the state Department of Natural Resources, said officials would likely develop a plan to gather representative samples from live bait shipments to determine whether Asian carp or their DNA could be slipping into Lake Erie or its tributaries through bait shop purchases.