WINONA, Minn. - The discovery of a carcass from a leaping Asian carp near Winona has state wildlife officials fearing that the invasive fish has the ability to bypass barriers set up to stop their migration.
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. It is 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 August 9 atop a concrete abutment just below Lock and Dam 5, about 20 miles further upstream than officials thought the invasive fish had reached.
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.
"We take this discovery very seriously," said Nick Frohnauer, the Invasive Fish Coordinator with the DNR. "Knowing where the carp front is important in determining how much time we have to combat them."
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 eating large amounts of plankton that native fish also rely on.
Populations of bighead and silver carp are already 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.
For more information on Asian carp in Minnesota, visit www.dnr.state.mn.us/asian-carp/index.html.
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