Asian Carp DNA Found in Mississippi River at Coon Rapids Dam

Asian carp are in the Mississippi, just miles north of Mendota Heights and the Mississippi's juncture with the Minnesota River.

That's the word Thursday from the Minnesota Department of Natural Resources in a surprise announcement that samples taken around the Coon Rapids Dam were positive for Asian carp DNA.

No one has seen the dreaded invasive fish in the area yet, and there is a chance that the DNA got into the dam area some other way.

But the tests suggest that Coon Rapids dam, seen as a , has already been breached.

“The one positive is that the tests continue to indicate that the silver carp population remains small, leaving us a window of opportunity to contain and control their movement," said Rep. Rick Hansen (D-District 39A) in a statement released Friday. "Minnesotans understand the severity of this issue and the damage these invasive species could cause to our important waterways and vibrant tourism industry."

Scientists sampled the river in 48 locations around the dam in September. Of 29 samples below the dam, 16 tested positive for silver carp, an Asian carp species, known for leaping out of the water as they migrate upstream.

Even more alarming: Three of the 19 samples taken above the dam tested positive.

Silver carp eat huge quantities of algae and other organisms, leaving little for native fish, according to the DNR. They could quickly upset ecosystems in the Mississippi River and its tributaries.

Gov. Dayton has set a third Asian Carp Summit meeting for Dec. 20.  experts said the Coon Rapids dam could function as a backup fish barrier to the locks and dams at St. Anthony Falls in Minneapolis. But seasonal ice jams at Coon Rapids likely will change water levels enough to make it possible for the jumping carp to get past the dam.

Tim Schlagenhaft, Mississippi River manager for the DNR, said in an interview Thursday that there could be explanations other than migration for the presence of DNA from Asian carp mucous and excrement. Birds or boats could be transporting the fish, Schlagenhaft said, though "it's not likely."

But positive tests upstream from the Coon Rapids dam suggests that positive tests downstream will continue. "DNA would be drifting down," Schlagenhaft said.

"Science requires replication and analysis. We’ve had reports and plans on this issue for years now; we need to use the best available information to make decisions," said Hansen. "It’s time to get to work implementing steps to contain this problem. Since the DNR did not anticipate these results we need to also immediately test other waterways where we assume the carp are not present."

Editor's Note: This post was updated 2 p.m. Dec. 9 to include comments released by Rick Hansen, who represents Mendota Heights in the Minnesota House of Representatives.