30 invasive carp caught in Mississippi near Winona, Minn., largest upstream haul

ST. PAUL -- The Minnesota Department of Natural Resources said Thursday that a commercial fishing crew caught 30 invasive carp in the Mississippi River Monday near Winona, Minn. — the largest number captured at one time so far upstream.

Invasive carp were brought to the southern United States in the 1970s to control algae in fish farms. They escaped and have advanced up the Mississippi ever since. They compete with native species and pose a threat to rivers and lakes. In 2020, 51 carp were captured just south of La Crosse, Wisconsin, downstream from Winona.

Individual invasive carp have been caught as far upstream as the Twin Cities metro. In 2017, an angler captured a massive bighead carp within the Minnesota River floodplain near Redwood Falls.

“While there is currently no ‘silver bullet’ to prevent or eliminate invasive carp, we will continue to use a combination of proven methods and the best available information to minimize risk by targeting and removing as many fish as possible,” Grace Loppnow, the DNR’s invasive fish coordinator, said in a statement.

Conservation officials say additional commercial fishing will take place in the Mississippi River this week, and a scheduled netting and capture operation will begin April 24.

That method uses a netting strategy that moves fish into cells with a combination of tactics that invasive carp hate: using boats that put an electric current in the water, and others outfitted with underwater speakers. Officials say native game fish aren't as bothered by the sound and prefer to hide.

The term invasive carp generally refers to four species — silver, bighead, black and grass carp. They’re large, voracious eaters that tend to crowd out and outcompete native fish species. Most of the fish caught this week near Winona were silver carp, which are known to leap out of the water, sometimes into boats.

Researchers at the University of Minnesota are testing and evaluating a deterrent system to stop the invasive fish from moving farther upstream.