A proposal to close the St. Anthony Falls lock to prevent invasive carp from spreading into northern Minnesota waters has bipartisan support from state congressional lawmakers.
The bill proposed two weeks ago would require studying the possibility of closing the St. Anthony Falls lock to manage the threat of Asian carp traveling up the Mississippi River. The study would look at the economic and environmental impacts of closing the lock.
The lock is an enclosed chamber in a dam with gates at each end that is used for raising or lowering vessels from one level to another by gaining or releasing water.
Steve Hirsch, director of the Ecological Resources Management Team at the Minnesota Department of Natural Resources, said Asian carp could have a significant impact on Minnesota ecosystems.
“The carp could be a major competitor with native fish species,” he said. “This could have a large effect on native fish populations in Minnesota waters.”
Many southern states that have experienced invasive carp species have seen populations of their native fish species plummet, he said.
There is a very good chance of stopping invasive carp from dispersing into the upper Mississippi watershed if the St. Anthony Falls lock is closed, he said.
Supporters of the bill include Democratic congressional delegates Sens. Amy Klobuchar and Al Franken, Reps. Keith Ellison and Tim Walz and Republican Rep. Erik Paulsen.
Klobuchar is sponsoring the Senate bill, and Ellison is leading the House bill. Neither has had a hearing.
“The threat of the Asian carp has been well documented and we should prevent it from damaging our treasured waterways in Minnesota,” Ellison said in a statement.
“This bill is an important first step in combating this invasive species, and I’m proud that we’ve come together as a congressional delegation to take decisive action and to protect our environment and our economy,” he said.
Gov. Mark Dayton included $8 million for control of invasive species in his supplementary budget proposal introduced last week. He’s scheduled to meet with state lawmakers Wednesday to discuss invasive aquatic species.
In February, the U.S. Supreme Court rejected a request for a court order from Minnesota, Ohio, Michigan, Wisconsin and Pennsylvania that would close locks in Chicago waterways to protect the Great Lakes from invasive carp. The court has rejected the request twice before.
Dan Zielinski, a University research assistant at the St. Anthony Falls Laboratory, said the lock would affect the spread of Asian carp in northern waters.
“I think it’s a good idea because it prevents the Asian carp from traveling upstream,” he said.
There are multiple ways to prohibit invasive carp from traveling upstream, such as dams, electric barriers, acoustic barriers and bubble barriers, he said.
“Dams are probably the most effective way of stopping the carp from spreading up river,” he said. “They’re much more effective but they have a much greater environmental impact.”
Electrical barriers could be installed to halt the fish from spreading while waiting for congressional approval, Hirsch said.
Closing the lock is a concern for the shipping industries that depend on it, but Klobuchar told the Associated Press they used trucks instead of barges after the collapse of the Interstate 35W bridge in 2007.
Dams along rivers can restrict the movement of native fish species and can impact their populations, Zielinski said.
The lock was originally a large waterfall that acted as a natural barrier, he said, so many of the native fish species haven’t been severely affected by the dam and wouldn’t be impacted by the closing of the lock.
A silver and bighead carp — both classified as carp — were caught near Winona a couple weeks ago, Hirsch said. He said this catch was the farthest the silver carp has been caught upstream.
Silver carp eat plankton and compete with native organisms such as mussels, larval fishes and other fish, and the competition could result in fewer and smaller sport fish, according to the Minnesota DNR website.
Bighead carp can weigh up to 110 pounds and silver carp can weigh 60 pounds. When disturbed by boat motors or loud noises, silver carp jump up to 10 feet out of the water and could potentially injure boaters, according to the DNR.
Peter Sorensen, a professor who specializes in invasive species research at the University, has been working to bring an invasive species research center to campus.
Much of the research at the proposed research center would investigate the behavior of many invasive fish species and the development of repellents against Asian and common carp.
Hirsch said there’s still a lot of research that needs to be done on invasive carp species and their impacts in the northern waters of Minnesota or Great Lakes.
“Nobody really knows a lot about what would happen if the carp were to get up there,” he said.
“There’s a lot of guess work associated with it.”
—The Associated Press contributed to this report.