Bighead and silver carp discovered in Pool 2 of Mississippi River
Commercial fishermen under contract by the Minnesota Department of Natural Resources netted two adult invasive carp in Pool 2 of the Mississippi River in the Cottage Grove area on Thursday, July 17.
One was a bighead carp that weighed approximately 40 pounds. The other was a silver carp – silver carp are the ones that leap from the water when disturbed – that weighed about 20 pounds.
Pool 2 is the portion of the Mississippi River above the dam at Hastings and extends upstream to the Ford Dam. Backwater lakes included are Baldwin Lake, River Lake, Spring Lake, Mooers Lake and Grey Cloud Slough.
Bighead and silver carp had not been found this far north in the Mississippi River. Until now, bighead carp had not been detected above the mouth of the St. Croix River near Prescott, Wis.; silver carp had not been detected above Pool 5A near Winona.
“The fish were caught as part of our invasive carp detection program,” said Brad Parsons, DNR regional fisheries manager. “This is disappointing but not entirely unexpected.” Parsons said while it’s unknown how long these fish were in Pool 2 it is known that invasive carp migrate upstream during high water conditions. “Such conditions existed for many weeks this year," he said.
Parsons said the discovery of these fish does not necessarily mean a breeding population of invasive carp exists within Pool 2. Still, he said both fish were females that contained eggs. “That’s concerning,” he said. “Invasive carp pose a threat to our native fisheries, water recreation and ecosystems.”
The DNR will continue its invasive carp sampling efforts next week in an effort to determine if more or smaller invasive carp are in the Grey Cloud Slough area. They will do this by setting additional gill nets and trap nets that are designed to catch smaller fish. The sampling nets used by commercial fisherman catch larger fish.
The DNR has been intensively sampling the Minnesota, St. Croix and Mississippi rivers for more than two years to assess the presence of all life stages of invasive carp. It is increasing sampling efforts in extreme southern Minnesota later this year (Pools 6 and 8).
Silver and bighead carp are two of four species of invasive carp threatening the Mississippi River and other native ecosystems. They can grow to 60 pounds, and they impact the base of the food chain by consuming large amounts of plankton that native fish also rely on.
Populations of bighead and silver carp are established in the Mississippi River and its tributaries downstream of Pool 16 in Iowa. Bighead carp have been found in Lake Pepin and the Mississippi and St. Croix rivers, and as far north as the mouth of the St. Croix in Prescott, Wis. But there is no indication bighead or silver carp are reproducing in the Minnesota waters of the Mississippi or St. Croix rivers.
The DNR continues to take a multi-pronged approach to managing Asian carp including:
- Monitoring for invasive carp by using targeted surveying and contracted commercial fishing.
- Partnering with the University of Minnesota’s Aquatic Invasive Species Research Center, which is researching ways to prevent the spread and to manage populations of invasive carp.
- Improvements to the Coon Rapids Dam to make it a better fish barrier.
This discovery of invasive carp highlights the importance of recently passed federal legislation that will close the Upper St. Anthony Falls Lock by June 2015.
The agency maintains that this is the best approach to keeping invasive carp out of the upper Mississippi River watershed. Gov. Mark Dayton has been a strong supporter of closing the lock.