The Mankato Free Press
---- — Any hopes that invasive and voracious Asian carp have stayed out of Minnesota waters were dashed recently when the carcass of a more than 2-foot-long Asian carp was found atop a concrete dam on the Mississippi River near Winona.
The silver carp is the species of large carp people have seen on YouTube videos flying through the air by the hundreds when spooked by boats traveling on the rivers elsewhere in the country.
The discovery has accelerated pressure by Minnesota congressional members, including Tim Walz of Mankato, to have Congress order the closing of the Upper St. Anthony lock in downtown Minneapolis. Shutting down that lock would be the best — although not foolproof — way of blocking the carp from moving up the Mississippi and getting into other streams and lakes across northern Minnesota.
But the plan would do nothing to protect the state’s namesake river from being infested with the carp that not only pose risks of injury to boaters but can devastate other game fish habitat because of their voracious appetites. The mouth of the Minnesota River enters the Mississippi miles to the south of the St. Anothony lock, leaving the Minnesota River wide open to Asian carp that are making their way north.
While the carp carcass found in Winona is farther south of where the Minnesota enters the Mississippi, the discovery confirms the big fish are nearing, if not already in the Minnesota River.
Protecting the Minnesota River has, unfortunately, been all but ignored by state and national groups fighting to stop or at least slow the migration of Asian carp.
Attention on the St. Anthony lock is understandable. It’s a relatively easy spot to seal off the river and state residents are justly proud of the majestic Mississippi River and want to protect it from further damage by the carp. The fact the lock is in the midst of the Twin Cities also gives the effort much more political clout.
That doesn’t mean attention shouldn’t also be focused on protecting the Minnesota, which stretches from border to border, 335 miles across the state.
There is no solution for the Minnesota as simple as closing off a lock. But there are options that have been used with some success elsewhere, including creating a combination of bubble, light and electric barriers across the river. The barriers send electric currents and light, or create bubbles that have been shown to scare the carp back and keep them from moving upstream.
Such a system near the mouth of the Minnesota is not likely to be 100 percent effective. During floods and through other means, Asian carp are likely to eventually get into more streams and lakes in the state. But dramatically slowing their migration into the Minnesota River is necessary.
Congress and federal officials also should put more effort into containing the carp closer to their main source in states south of Minnesota.
Slowing their spread would limit the damage they cause and it would give researchers more time to develop other future strategies, including things such as finding ways to disrupt the reproductive cycles of the carp.
Minnesota elected officials and DNR leaders should be pressuring Congress to take a comprehensive approach to limiting the carp, not focusing entirely on one spot in the state.