Asian carp are on the move.
The carcass of a silver carp was discovered recently on a dam abutment near Lock and Dam 5, the farthest upstream one has been found, the Minnesota Department of Natural Resources announced Thursday.
The fish is known for leaping only when it’s disturbed, so the discovery suggests that the carp are aggressively working to move up the Mississippi River.
“Finding this carp on the sill of the dam suggests that it was attempting to jump over it,” said Nick Frohnauer, DNR invasive fish coordinator, in a statement. “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 on the concrete abutment, about 20 miles further upstream of the previous discovery of a a silver carp, according to the DNR.
A DNR fisheries biologist 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, the DNR said.
Officials at all levels of government have worried for years about the fish moving up the Mississippi, and the fact that the species has made an appearance just more than 100 miles south of Lock and Dam 1 in St. Paul has stoked new concerns.
Minnesota’s U.S. senators, Amy Klobuchar and Al Franken, teamed up earlier this year on new legislation to help stop the spread of Asian carp. The bill would create a coordinated federal response and enable the federal government to work more effectively with state and local entities on technical assistance and projects. Several federal agencies have been working to combat Asian carp, but none has been designated as the lead agency to coordinate with state and local partners.
The state has considered a project to build an electric barrier at Lock and Dam 1 to stop the carp, but there hasn’t been significant motion on the project. And it’s not clear that it’s effective: Carp and carp DNA have been found on the other side of barriers in other waterways.
The DNR continues to argue that the best plan is to close the Upper St. Anthony Falls Lock in Minneapolis, though there has not been significant motion on that project, either, which would require approval from both Congress and buy-in from the U.S. Army Corps of Engineers.
Silver carp are one of four species of invasive Asian carp threatening the Mississippi River and other 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, according to Thursday’s DNR release. Populations of bighead and silver carp are established in the Mississippi River and its tributaries downstream of Pool 16 in Iowa.
The DNR said it plans to continue monitoring for Asian carp using both surveying methods and collaborating with commercial fishermen on the river. It has also teamed up with with the University of Minnesota Aquatic Invasive Species Research Center to study new ways of stopping the carp.