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August 25, 2015

MADISON -- Ongoing surveillance efforts this summer found no new evidence of Asian carp in the Milwaukee and Fox rivers as part of work completed by the U.S. Fish and Wildlife Service in cooperation with the Wisconsin Department of Natural Resources.

USFWS biologists tested 160 water samples collected across three sampling dates in May and June for genetic evidence of silver and bighead carp. None of the samples tested positive for Asian carp DNA.

Bob Wakeman, DNR's aquatic invasive species program coordinator, said the testing represents an important tool in the ongoing effort to prevent the spread of silver and bighead carp into the Great Lakes. Asian carp pose significant ecological and economic threats to the Great Lakes region and its fishery because they eat voraciously and compete directly with valuable native fish for food.

"We certainly appreciate the U.S. Fish and Wildlife Service conducting this monitoring and giving us this good news," Wakeman said. "The continued negative results reinforce other findings that positive detections in 2013 near Sturgeon Bay and 2014 in the Fox River near Green Bay were likely from sources other than live fish."

The environmental DNA sampling approach used by the U.S. Fish and Wildlife Service is highly sensitive and can indicate the presence of a target species before traditional sampling techniques may. Early detection of new species aids in effective response efforts.

However, research suggests that small amounts of genetic material can be transported by sources including birds and boats, and even these trace amounts can be detected through the eDNA sampling protocol. As a result, biologists look for repeated detections over time to provide strong evidence of the presence of an unwanted species.

DNR and the USFWS will continue eDNA and traditional sampling efforts in future years to ensure that Asian carp do not become established in in the Great Lakes basin. In addition to the federal monitoring, DNR fisheries team members conduct a variety of netting, electroshocking and trawling operations in state waters as part of the ongoing monitoring effort and have not captured any Asian carp to date in any waters of the Lower Fox River, Green Bay or Lake Michigan.

Wakeman said anglers and other stakeholders from across the state play an important role in preventing the spread of aquatic invasive species, including Asian carp. To stop the spread of Asian carp, anglers are asked to review Asian carp identification materials, report any sightings of Asian carp and to dispose of unwanted live bait, including minnows, in the trash since small Asian carp look like many common bait species. These efforts will help prevent the establishment of Asian carp in the Great Lakes.

Photo identification tools and more information on Asian carp can be found by searching the DNR website,, for "Asian carp."

More information on environmental DNA testing is available from the Asian Carp Regional Coordinating Committee: Results of DNA monitoring from the Midwest region are posted here: (both links exit DNR).

FOR MORE INFORMATION CONTACT: Bob Wakeman, aquatic invasive species coordinator, 262-574-2149,; Jennifer Sereno, communications, 608-770-8084,

Last Revised: Tuesday, August 25, 2015

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