Commercial fishermen net 51 invasive Asian carp
Spot near La Crosse yields biggest catch to date
Commercial fishermen netted 51 Asian carp last weekend in the Mississippi River near La Crosse and Trempealeau, the largest catch of the invasive fish to date in Wisconsin or Minnesota waters.
The Asian carp, which included 40 silver carp and 11 grass carp, were collected by commercial fishermen using seines to target buffalo and common carp.
“The location where these fish were caught is commonly netted because of concentrations of commercially valuable fish,” Ben Larson of the Minnesota Department of Natural Resources said in a statement released Friday. “This is the largest congregation of invasive carp we’ve seen this far upstream.”
The haul heightened fears the destructive fish could be reproducing in the region.
“Obviously we have a great concern about it,” said Marc Schultz of the La Crosse County Conservation Alliance. “Does this represent an invasion that will never be turned back? Or is it a bunch of fish that made it up here but won’t be able to spawn? Either way, it’s very worrying.”
Asian carp, including bighead, silver and grass, are aquatic invasive species that have been spreading north through the Mississippi River system since escaping in the 1970s from fish farms in Arkansas.
The filter-feeding fish remove plankton from the water and damage the ecosystem for native fish and other animals. In areas of the Illinois and Kentucky rivers that are heavily infested with Asian carp, native fish populations have declined significantly.
Fisheries personnel with state and federal agencies have been monitoring waters of the Upper Midwest for signs of the invasive fish.
While no Asian carp have been found in Lake Michigan or Lake Superior, the invasive species have been spreading for nearly 25 years in inland waters along Wisconsin’s western border.
The first detection was a bighead carp found in 1996 near the confluence of the St. Croix and Mississippi rivers in Pierce County, according to Wisconsin DNR records.
In 2019 a silver carp captured in the St. Croix River in northwestern Wisconsin was fitted with a tag and released by Minnesota DNR researchers. The fish’s movements are being studied in an effort to learn more about its habitat preferences and perhaps assist with removal efforts of the invasive species.
To date, authorities have not documented any successful spawning of Asian carp in Wisconsin or Minnesota waters.
Previous catches of Asian carp in the Upper Mississippi and Wisconsin rivers have been mostly of individual fish or a few fish at a time, said Bob Wakeman, statewide aquatic invasive species coordinator for the Wisconsin DNR.
However, the catch of 51 Asian carp in one weekend ratcheted up fears over the potential for successful natural reproduction of the invasive fish in the region.
High water in 2019, coupled with decisions to open dam gates on the Mississippi to facilitate water flow, could have led to more of the carp moving upstream, Wakeman said.
The commercial fishermen contacted the Minnesota DNR after the catches.
Minnesota DNR personnel identified 39 silver carp and 11 grass carp caught in Pool 8 of the Mississippi, just south of La Crosse, and one silver carp caught in Pool 6, about 20 miles farther upstream.
All of the recovered invasive carp were transferred to the U.S. Fish and Wildlife Service to determine their age, size and gender. Tests will also attempt to determine if any of the fish spawned in the past.
In response to the catch of the 51 Asian carp, authorities and commercial fishing operators plan to conduct increased monitoring and a large-scale netting effort, according to Heidi Wolf, Minnesota DNR invasive species unit supervisor.
“This robust response will provide additional information about the population while removing any other invasive carp they happen to catch,” Wolf said.
It is illegal to transport live Asian carp in the U.S.
If an Asian carp is caught by an angler or other member of the public, authorities ask that it be killed and kept and reported to the local DNR office.