The carcass of a silver carp – the kind that leaps from the water when disturbed – was found recently on a dam abutment just north of Winona, the furthest upstream a silver carp has been discovered in the Mississippi River, according to the Minnesota Department of Natural Resources (DNR).
“Finding this carp on the sill of the dam suggests that it was attempting to jump over it; it wasn’t just leaping due to a disturbance,” said Nick Frohnauer, DNR invasive fish coordinator. “That confirms our assumption that silver carp may use their leaping ability to attempt to overcome barriers.”
A worker with the U.S. Fish and Wildlife Service first noticed the fish on Aug. 9. The fish was atop a concrete abutment just below Lock and Dam 5, about 20 miles further upstream of the previously northernmost instance of a silver carp. The dam is about 110 miles south of Lock and Dam 1 in St. Paul.
A DNR fisheries biologist investigated, snagged the fish with a treble hook and reeled it up from the abutment, which was otherwise inaccessible. Because the carp had been dead for at least a week, weight, gender and reproductive ability could not be determined, but the carcass measured about 30 inches long.
Silver carp are one of four species of invasive Asian carp threatening the Mississippi River and other native ecosystems. They can grow to 60 pounds, and they impact the base of the food chain by consuming large amounts of plankton that native fish also rely on. Populations of bighead and silver carp are established in the Mississippi River and its tributaries downstream of Pool 16 in Iowa. Bighead carp have been found in Lake Pepin and the Mississippi and St. Croix rivers, and as far north as the mouth of the St. Croix in Prescott, Wis. But there is no indication bighead or silver carp are reproducing in the Minnesota waters of the Mississippi or St. Croix rivers.
The DNR continues to take a multi-pronged approach to managing Asian carp including:
- Monitoring for Asian carp by using targeted surveying and contracted commercial fishing.
- Partnering with the University of Minnesota’s Aquatic Invasive Species Research Center, which is researching ways to prevent the spread and to manage populations of Asian carp.
- Contracting on the design and approval of an electric barrier using new “sweeping” electrical technology at Lock and Dam 1 in St. Paul.
- Improvements to the Coon Rapids Dam to make it a better fish barrier.
The agency maintains that the best approach to keeping Asian carp out of the upper Mississippi River watershed is to close the Upper St. Anthony Falls Lock. The lock is administered by the U.S. Army Corps of Engineers, and it would require an act of Congress to close the lock.
Find more information on Asian carp in Minnesota.