Some Lake Erie Samples Test Positive for Asian Carp

By CnAgri2012-07-18 19:52:39 Print

Federal and state wildlife officials working in conjunction with academic researchers announced six water samples taken from Sandusky and north Maumee bays tested positive for the presence of Asian carp environmental DNA in Michigan and Ohio waters.

The positive samples were among 417 taken from Lake Erie in August 2011, and more than 2,000 samples taken from the Great Lakes Basin since 2010. The Lake Erie batch was recently analyzed and test results were confirmed by eDNA researchers this week. The six positive samples represent less than 1.5 percent of the Lake Erie samples.

Four samples from Sandusky Bay, in Ohio waters, tested positive for bighead carp eDNA, while two samples from north Maumee Bay, in Michigan waters, were positive for silver carp eDNA.

In response to these findings, electro-shocking and netting began Friday in Sandusky Bay with no evidence of Asian carp found. However, additional testing and monitoring are planned by the Ohio and Michigan Departments of Natural Resources in conjunction with partner agencies.

The findings indicate the presence of genetic material left behind by the species, such as scales, excrement or mucous, but not the establishment of Asian carp in Lake Erie. Positive eDNA tests are regarded by the scientific community as an indicator of the species' recent presence, however, positive results can occur whether the organism was alive or dead.

While the eDNA findings suggest the possible presence of the invasive species, officials have no physical evidence the fish have migrated to the Great Lakes. Prior to 2003, three individual bighead carp were collected in Lake Erie. No additional observations have been reported during the past decade.

"The results from these water samples are certainly concerning, as this marks the first time Asian carp eDNA has been detected in water samples from Lake Erie, or any of the Michigan waters intensively surveyed for the presence of invasive carp," said Michigan DNR Fisheries Division Chief Jim Dexter. "Protecting the Great Lakes from the threat of Asian carp is critical to the health of our sport and commercial fisheries and to the quality of life in Michigan. We are actively engaged in Asian carp surveillance programs throughout the Great Lakes, including Lake St. Clair and Lake Erie, and the Department stands ready to take the necessary and appropriate actions to investigate and respond to these test results."

In response to the positive test results, officials from the Michigan and Ohio DNRs, the Michigan Department of Environmental Quality, the U.S. Fish and Wildlife Service, and White House Council on Environmental Quality are developing a plan of action in collaboration with the eDNA research team to obtain follow-up samples and test results as quickly as possible. Test results from future water samples will dictate the nature of further response methods.