DNR installs barrier to invasive carp in Kandiyohi County

Feb. 3—WILLMAR

— We may have no more than a five-to-10 year window to act if we are to stop invasive carp from moving upstream in the Mississippi River and establishing reproducing populations in Minnesota waters.

That warning came from Christine Goepfert, with the

National Parks Conservation Association

and current chair of the

Stop Carp Coalition,

while speaking at the Minnesota Department of Natural Resources Round-table held Jan. 20 in Bloomington. "Once they start reproducing we are going to be in big trouble," she said. "Then we will be spending big money to just fish them out."

The invasive species, including bighead, grass, silver and black carp, pose threats to the state's fishing and recreational boating industries, she pointed out.

Money has been spent to develop a defense against the possibility of the invasive carp moving up the Minnesota River and its tributaries, including Hawk Creek, and into the waters of the Willmar area lakes and the Upper Mississippi River watershed.

This past year, the DNR installed a control structure in the large wetland connecting Ringo and Nest Lakes in Kandiyohi County. The location was identified years ago as a "breach site," according to Dave Coahran, fisheries supervisor with the DNR in Spicer. In regard to Hawk Creek, the Minnesota River watershed meets the Mississippi River watershed during high waters in this wetland.

If the day comes when the Minnesota River has a reproducing population of invasive carp, the carp could move upstream in Hawk Creek and infest the Willmar chain of lakes and other connected lakes in the watershed, including Eagle, Point, Long and Ringo. The breach in the Ringo-Nest Lake wetland would open the way for the invasive fish to reach Green Lake and the Crow River watershed, allowing the fish to reach the Upper Mississippi River above St. Anthony Falls, which is now a barrier to their upstream movement.

The structure in the Ringo and Nest Lake wetland consists of an earthen berm and a stainless steel culvert punctured with one-inch diameter holes that allows waters and small minnows to move through it, according to Coahran.

Invasive carp have been caught in the Minnesota River, although there is no evidence of a reproducing population. A bighead carp was caught just downstream of Granite Falls. Alarm bells sounded in 2017 when a bow fisher harvested a 61.7 pound, 47 1/2 inch bighead carp in a private gravel pit near Redwood Falls.

The structure installed between Ringo and Nest Lakes is the result of a "ground truthing" exercise by the DNR to identify similar, potential breaches where watersheds can join throughout the state. Jack Leuer, regional fisheries manager for the Minnesota DNR, pointed out at the Round-table that there are also locations where we purposely created connections between watersheds years ago.

Along with Hawk Creek, the Chippewa River is a potential route for invasive carp to reach the waters of Kandiyohi County and beyond. Coahran said the DNR took a good, hard look at the Granite Falls dam a few years ago. The dam is a barrier to native fish populations, but it will not stop invasive carp.

During spring flood levels, an overflow channel would allow the invasive carp to migrate upstream and reach the Chippewa River.

At the DNR Round-table, discussion focused on stopping the invasive carp from continuing their steady progress upstream in the Mississippi River. Lock and Dam 5, located in Winona County, is the preferred site. Peter Sorenson, University of Minnesota, originally urged the installation of a barrier there that would use sound, bubbles and strobe lights as a deterrent to the fish.

Whitney Clark,

Friends of the Mississippi River

, said it was chosen because it is the least likely of the locks to allow passage of the fish through its gates. The gates at this site are open just 2% percent of the year. The upstream pool is short, making it suitable for carp removal and unsuitable for carp reproduction, he added.

The site is also at the leading edge of the invasion. The DNR and other partners conduct periodic netting exercises and have radio-tagged carp as part of an effort to determine how many carp are in the Mississippi River above Iowa, but there remains much uncertainty. In the past two years, 250 or more invasive carp have been caught in Minnesota waters, according to information at the Round-table.

It was pointed out that the carp's upstream movement appears to increase during high-water years.

At the Round-table, presenters said that a coalition of groups is asking the state legislature to provide funding for the so-called "disco wall" for fish at Lock and Dam 5.

Groups are also urging the DNR to update its action plan for invasive carp. The current plan was adopted in 2014.

The DNR has not included a request for funding the Lock and Dam 5 barrier in its budget request to the Legislature, according to Dennis Anderson in a recent article in the Star Tribune. Speaking at the Round-table, Heidi Wolf, invasive species program director, said the DNR is examining the proposal along with a range of control methods. The DNR is also looking at how barriers can adversely affect native fish populations.

There is the possibility of adding a "selective" fish passageway for native fish at an auxiliary lock that is part of the Lock and Dam 5 complex, according to Clark. He noted that it may be possible to modify the gates to increase the water velocity to help prevent carp migration when they are open.

Brad Parsons, the DNR's fisheries manager, is chair of a board for the Mississippi Cooperative Resource Association, representing the 28 states in the Mississippi River basin. It is seeking continued federal funding for a wide spectrum of efforts to control the invasive carp, from barriers to removal. "This is an inter-jurisdictional problem," said Parsons, adding that the challenges posed by invasive carp definitely has the attention of Congress.

While river barriers are the focus of much of the current discussion, improving water quality and aquatic habitat and supporting the native fish populations are also critical to combating the invasive carp.

"I'd rather have one barrier lower on the river than a thousand barriers upstream," said Tyler Winter, director of a group known as

Native Fish for Tomorrow

, during the Roundtable discussion. Winter's group is lobbying the state legislature to provide more protection for Minnesota's native fish, such as bighead buffalo, which could compete with invasive carp and help keep their numbers in check.