Results are in for the first round of environmental DNA testing for invasive bighead and silver carp in tributaries of Lake Michigan. None of the 336 water samples collected in the Kalamazoo River, Spring Lake and Lake Macatawa tested positive for the genetic material (eDNA) of invasive carp.
The eDNA surveillance program – a collaborative effort between the Great Lakes states and the U.S. Fish and Wildlife Service – samples high-priority locations for the presence of bighead and silver carp genetic material. Results from additional monitoring efforts in Michigan will be available later this summer.
Since 2013, the DNR has coordinated with the USFWS to implement the eDNA surveillance program in Michigan’s major tributaries to all the Great Lakes except Lake Superior, because it has been deemed very low-risk for the introduction and establishment of invasive carp. Results of these surveys are available on the USFWS website FWS.gov.
Testing for eDNA involves collecting water samples throughout a river or lake and analyzing each sample for silver or bighead carp genetic material.
The 2019 sampling locations this year include Spring Lake and Lake Macatawa, both drowned river mouths of Lake Michigan. According to Kelly Baerwaldt, USFWS Region 3 Asian carp and eDNA coordinator, these lakes provide the type of habitat and food resources that invasive carp prefer and can hold eDNA longer than a high flowing river.
What if positive results are found?
In May, eDNA testing on Lake Calumet in Chicago, just 6 miles downstream of Lake Michigan, resulted in six positive detections – three each for silver carp and bighead carp.
In response to these findings, the USFWS and partners dispatched two crews to carry out intensive electrofishing in Lake Calumet for three days. No live silver or bighead carp were collected through this effort.
“A positive eDNA sample in Michigan’s waters would trigger a similar response,” said Seth Herbst, aquatic species and regulatory affairs unit manager with the DNR. “The state is prepared to implement a response appropriate to the indicated risk level. Response actions would include intensive monitoring to locate fish populations, and netting and electrofishing to capture and remove the invasive fish.”
It’s important to note that positive eDNA results don’t always mean live fish are present. Other sources, such as boats or angling equipment that have been in an area where invasive carp are established, also can deposit eDNA into uninfested water bodies.
What is Michigan doing to prevent invasive carp?
“Along with our participation in the eDNA surveillance program, we continue to be diligent with early detection efforts, such as conducting fish population surveys, increasing awareness among anglers, and maintaining an invasive carp reporting website for anglers to share any suspicious catches or observations that occur during their outings,” said Herbst.
Michigan’s management plan for invasive carp outlines the actions to be taken if invasive carp are found in Michigan’s waters.
The state of Michigan is a part of the Asian Carp Regional Coordinating Committee, which develops and supports the annual Asian Carp Action Plan, directing sampling and removal efforts and testing technologies to deter invasive carp movement.
Michigan continues to push the implementation of the U.S. Army Corps of Engineers’ plan to reconstruct the Brandon Road lock and dam near Joliet, Illinois, to install technologies to lessen the possibility of invasive carp entering Lake Michigan from the Mississippi River.
For more information about invasive carp and the threats they pose to Michigan’s waters, visit Michigan.gov/InvasiveCarp.