The Minnesota Department of Natural Resources implanted a small tracking device in a silver carp captured on the St. Croix River Tuesday, Sept. 10. This is the first time the DNR has tagged a silver carp, an invasive species that compete with native species for food.
The tagged silver carp will provide the DNR with valuable data on its movement and habits in the river system. The capture and tagging of the carp was a direct result of the tracking of a previously tagged bighead carp.
The DNR and a contracted commercial fishing business were tracking and attempting to net the tagged bighead carp Tuesday when they captured the silver carp two miles south of the Interstate 94 bridge over the St. Croix River.
“We expect this tagged silver carp to provide useful information about the species’ habits, as has been the case with the previously tagged bighead carp,” said DNR invasive fish coordinator Nick Frohnauer. “Since carp tend to congregate, we’re also hopeful that the tagged silver carp will lead us to any other individual invasive carp that may be in the area.”
The tagged bighead carp has led to four invasive carp discoveries this year and two last year.
High water means more invasive carp
More invasive carp than usual have been captured in 2019, likely because persistent high water in southern Minnesota, Iowa and Illinois created prolonged “open river” conditions, which allow fish to move up the Mississippi River unimpeded by locks and dams.
Open river conditions benefit native species like lake sturgeon and paddlefish, which often swim hundreds of miles in search of preferable habitat. Unfortunately, these conditions also allow other, non-native species to move upriver more easily.
Frohnauer noted that, while the DNR continues to be concerned about the potential impacts of invasive carp in Minnesota waters, individual adult fish captures do not indicate reproduction or an established population of invasive carp in the Mississippi River or elsewhere in the state.
Individual invasive carp have been caught as far upstream as Mississippi River Pool 2 near the Twin Cities (bighead, grass, and silver), the King Power Plant on the St. Croix River by Oak Park Heights (bighead), and just downstream of Granite Falls in the Minnesota River (bighead).
Invasive carp captures should be reported to the DNR. Call 651-587-2781 or email firstname.lastname@example.org. Take a photo and transport the carp to the nearest DNR fisheries office or make arrangements for it to be picked up by a DNR official.