Construction crews began installing massive steel gates at the Coon Rapids Dam as part of a $16 million upgrade to prevent Asian carp from spreading to the upper Mississippi watershed, the Star Tribune reports.
The gates will replace older, less effective rubber tube gates.
The goal is to install five gates on the Anoka County side of the dam by Dec. 1. Four more barriers on the Hennepin County side would be installed in the spring, the Star Tribune said.
ABC Newspapers says the Legislature approved funding for the rehabilitation project in the 2011 bonding bill.
About 130 miles southeast, a silver carp carcass was found near Winona -- the farthest north the invasive species has been spotted in the Mississippi River. The DNR suspects the invasive fish was attempting to leap over Lock and Dam 5.
"We can control them," Duane Chapman, a fisheries expert who works for the U.S. Geological Survey's Environmental Research Center in Columbia, Mo., said at a speaking engagement in St. Paul earlier this month, according to MinnPost.
MinnPost reports promising research on invasive species control methods is underway, including an option that would involve carp-killing chemical "toxicants" that are relatively harmless to other fish.
Chapman says improvements to Mississippi River dams have proved effective in slowing the aquatic invaders' upstream migration.