A plan to close the Upper St. Anthony Falls lock in a desperate effort to halt the advance of Asian carp is swimming its way through Congress, the Star Tribune reports.
Legislation aimed at stopping the jumping invasive species cleared a key hurdle Thursday when a House panel attached a plan to close the lock to a broader national spending measure that lawmakers are expected to approve.
The proposal is controversial. Closing a lock is extremely rare. But many environmentalists and outdoors enthusiasts are lauding the plan, while river industry groups, notably shippers, are strongly opposed. Critics say the plan won't do much to stop the leaping fish.
Closing the lock near the Stone Arch Bridge in downtown Minneapolis would be a dramatic step, acknowledges Rep. Rick Nolan, D-Minn., who is working with Rep. Keith Ellison, D-Minn., to move the plan through the Capitol. “We’re not sure if this will work, but we sure feel like we have to try to do something,” Nolan told the Star Tribune.
Debate around the issue is complex, and there are numerous sides. There is much at stake, state officials say, including the state's thriving $11 billion tourism industry. Visitors flock to Minnesota to enjoy its streams and lakes, and state officials have watched with horror as the silver carp have largely ruined water recreation on rivers south of Minnesota.
The silver carp is believed to have been first brought into the U.S. in 1973 when a private fish farmer imported silver carp into Arkansas, according to the USGS.
Silver carp are a species of invasive Asian carp that can grow to 60 pounds, and conservation officials say the fish gobble up plankton that native fish eat, according to the DNR. Here's more info on the silver carp from the DNR, and a report from earlier this spring that says DNA tests suggest little evidence that the fish is in the Mississippi or St. Croix rivers.
The fish are known for their tremendous leaping ability, and conservationists are anxiously watching the species jump their way northward up rivers and spread into new waters – threatening to crowd out Minnesota's beloved walleye and other sport fish. Officials fear that left unchecked the fish could spread to lakes such as Itasca, Mille Lacs, Bemidji, and other Mississippi River tributaries.
In August, the carcass of a single 30-inch silver carp attracted a lot of attention near Winona – the furthest north the invasive species has been seen in the Mississippi River.
"Upper St. Anthony Falls Lock and Dam and Lock and Dam No.1 are two of the highest dams on the upper Mississippi River, at 49 feet tall and 36 feet tall, respectively. The only way carp can get past them is to swim through the locks when they open to pass a boat. This is because the distance between the water above and below the dam is far enough apart that a carp can't jump over the dam, even during floods. Therefore, minimizing lock use will limit the opportunity for Asian carp to travel farther north on the Mississippi."