On August 9, a U.S. Fish and Wildlife Service employee found an invasive Asian silver carp carcass on top of a concrete abutment just below Lock and Dam 5, nearly 20 miles farther north than the previous northernmost silver carp found in the Mississippi River.
Invasive Asian carp can quickly multiply, as has been seen in bodies of water to the south.
Although the silver carp found in the area appear to be loners, Nick Frohneauer, Minnesota Department of Natural Resources (DNR) invasive fish coordinator, noted that they appear to be trying to utilize their leaping abilities to overcome barriers to move farther north along the river.
There are four types of invasive Asian fish: the grass carp, bighead carp, silver carp, and black carp. Frohneauer noted the black carp has not been found in the area yet.
According to a DNR news release about the most recent discovery, a “fisheries biologist investigated, snagged the fish with a treble hook and reeled it up from the abutment, which was otherwise inaccessible.” The fish had been dead for at least a week hindering the ability to determine the carp’s weight, gender, and reproductive ability. The carcass measured 30 inches long.
Frohneauer noted that the DNR has yet to find evidence that the invasive carp have attempted to reproduce in the area, but that doesn’t mean the risk isn’t there. Asian carp affect the river in several ways. The carp, sometimes as big as 60 pounds, consume large amounts of plankton, which native fish rely on for food. If this part of the Mississippi River became highly populated with Asian carp, it would affect commerce and fishing in our fresh waters, and the leaping carp could create a danger for recreational water activities.
The DNR has multiple plans to control the Asian carp population. Currently the department is monitoring Asian carp through targeted surveying and contracted commercial fishing. According to Frohneauer, DNR staff and the University of Minnesota’s Aquatic Invasive Species Research Center are investigating ways to manage current carp populations and their spread throughout the region. The plan the DNR believes would be most helpful would necessitate closing the Upper St. Anthony Falls Lock, which would require approval by Congress, as it is run by the U.S. Army Corps of Engineers.
If people believe they have seen an invasive Asian carp, Frohneauer urges people to alert the DNR. “If you see one, take a picture; if you catch it or find a carcass, let us know,” he said. “Note the location where you saw it; be as specific as possible.”
To report an invasive Asian carp call (651) 259-5100.