Coon Rapids Dam more important than ever for carp strategy, says DNR commissioner

Stouter fish barrier still much in need

by T.W. Budig
ECM Capitol Reporter
Minnesota Department of Natural Resources (DNR) Commissioner Tom Landwehr indicated a full-throttle approach to upgrading the Coon Rapids Dam into a stouter fish barrier should not be eased because of the discovery of silver Asian carp DNA in water samples taken above the dam.
“This is not the time to take our foot off the gas,” Landwehr said, speaking to reporters in a teleconference on Thursday, Dec. 8.
Landwehr, DNR and federal Asian carp experts were reacting to new DNA test results from water samples taken recently above and below the Coon Rapids Dam indicating the presence of the silver Asian carp nearby in the river.

The results of DNA water testing suggest that silver Asian carp, perhaps the most notorious of Asian carp because of their habit of leaping into the air, may be in the Mississippi River above the Coon Rapids Dam. The carp are pictured in waters in another state. (Photo from DNR website)

These are carp known for their habit of leaping into the air when disturbed.
Earlier test results this year indicated the presence of silver Asian carp downstream in the Mississippi River near the Ford Dam in St. Paul.
Nineteen of the 48 water samples tested positive for Asian carp DNA at the Coon Rapids Dam, with three of the 19 positive hits coming from samples taken above the dam.
The century-old dam is now more important than ever, Landwehr said.
Tim Schlagenhaft, who is heading up the DNR’s Asian carp response efforts, said the presence of Asian carp above the Coon Rapids Dam — commercial fishermen will be dispatched to the Mississippi River near the dam to attempt to pull a live Asian carp to the surface — means Central Minnesota is now open to the invasive species.
Asian carp could enter both the Crow and Rum rivers by swimming upstream in the Mississippi, he noted. The dam on the Rum River in downtown Anoka is not considered a sound fish barrier, and Asian carp could reach Mille Lacs Lake via the Rum, he explained.
The carp can move quickly under the right conditions, Schlagenhaft said.
But if Asian carp are present in Minnesota rivers, DNR officials believe the populations are still small.
A number of fish barriers exist on the Mississippi River upriver from the Coon Rapids Dam, Schlagenhaft noted. These include dams at St. Cloud and Little Falls.
Officials are currently examining the possibility of conducting more Asian carp DNA water sample testing from sites upriver from the Coon Rapids Dam and on its tributaries such as the Rum River.
Indeed, the DNR is also considering taking water samples on tributaries of the St. Croix River, another river where water samples have tested positive for Asian carp.
Additional water samples have been taken both above and below the St. Croix Dam at Saint Croix Falls, Wis., and the results should be out soon, Schlagenhaft said.
DNR officials are curious whether the samples taken above the St. Croix Dam, which, like the Coon Rapids Dam is considered a good fish barrier, will also yield positive results.
That test results came back positive from above the Coon Rapids Dam is something of a “head scratcher,” said a DNR spokesman.
Experts are cautious about overreacting to the test results — some theories suggest positive Asian carp DNA test results in Illinois waters could be less caused by the presence of Asian carp than the use of fertilizers containing their ground remains.
But DNR officials stress the importance of trying to keep ahead of invading Asian carp. Asian carp DNA water test results are too important to be ignored, they argue.
The Mississippi River is not the only avenue for Asian carp to spread throughout Minnesota. The Minnesota River and the Red River in western Minnesota, Schlagenhaft said, can connect during periods of high water.
He recently said preventing Asian carp from going up the Minnesota River would be difficult, and that Minnesotans may have to be satisfied more with Asian carp control in that river than prevention.
Lawmakers have slotted some $16 million towards upgrading the Coon Rapids Dam into a stouter fish barrier.
Although actual construction is not expected to begin on the dam until 2013, Landwehr said steps such as adjusting water levels at the dam are being considered to more immediately address the Asian carp threat.
Democratic Gov. Mark Dayton will hold his third Asian carp summit on Dec. 20 to further discuss the state’s proposed actions.
DNR officials said the positive Asian carp DNA test results from above the Coon Rapids Dam do not markedly change the state’s Asian carp response strategy.

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