In the latest sign that invasive Asian carp are penetrating Minnesota waters, a silver carp and a big-head carp were netted by commercial fishermen last week in the Mississippi River near Winona, state conservation officials said Monday.

The catch represents the farthest upstream discovery yet of the flying carp, known for leaping from the water when startled. The silver carp, which was caught March 1, weighed 8 pounds.

"A silver carp discovery this far upstream is discouraging, but not surprising," said Tim Schlagenhaft of the Minnesota Department of Natural Resources' (DNR). "This is further evidence that Asian carp continue to move upstream in the Mississippi River."

No established populations of big-head or silver carp are known in Minnesota. However, individual specimens have been caught by commercial fishermen in recent years, including three silver carp near La Crosse, Wis., between 2008 and 2011. One big-head carp was caught in the St. Croix River in 1996 and another in 2011. Between 2003 and 2009, six big-head carp were caught in the Mississippi River between Lake Pepin and the Iowa border.

Water sampling by the DNR last year found DNA evidence of silver carp in the Mississippi and St. Croix rivers as far north as the Twin Cities area, causing state naturalists and Gov. Mark Dayton to accelerate the state's search for a solution. However, searches by the DNR and commissioned commercial fishermen failed to turn up any sign of live Asian carp at that time.

Asian carp can consume 5 to 20 percent of their body weight each day, often out-competing native fish for food and disrupting the aquatic ecosystems that support more desirable fish and plants. Big-head carp can weigh up to 110 pounds and silver carp up to 60 pounds.

Paul Walsh • 612-673-4482