A silver carp and a bighead carp were caught in a seine net by commercial fishermen March 1 in Pool 6 of the Mississippi River near Winona, according to the Minnesota Department of Natural Resources (DNR). Silver and bighead carp, members of the Asian carp family, are nonnative species that can cause serious ecological problems as they spread into new waters.
The silver carp caught last week, which weighed about 8 pounds, represents the farthest upstream discovery to date of the species, known for its tendency to leap from the water when startled.
“A silver carp discovery this far upstream is discouraging, but not surprising,” said Tim Schlagenhaft of the DNR’s Mississippi River Team at Lake City. “This is further evidence that Asian carp continue to move upstream in the Mississippi River.”
“We hope this galvanizes meaningful action to slow down the upriver movement of Asian carp while we figure out ways to control and deal with their impacts,” said Paul Labovitz, superintendent of the Mississippi National River & Recreation Area in the Twin Cities.
No established populations of bighead or silver carp are known in Minnesota. However, individual Asian carp have been caught by commercial fishermen in recent years. Three silver carp (two in pool 8 near La Crosse, one in pool 9) were caught between 2008 and 2011. One bighead carp was caught in the St. Croix River in 1996 and one in 2011. Between 2003-2009, six bighead carp were caught in the Mississippi River between Lake Pepin and the Iowa border.
Environmental DNA (eDNA) testing last year indicated the presence of silver carp in the Mississippi and St. Croix rivers in the Twin Cities area. However, searches by the DNR and commissioned commercial fishermen failed to turn up any sign of live Asian carp at that time.
Populations of bighead and silver carp are established in the Mississippi River and its tributaries downstream of pool 12 in Iowa.
Bighead carp can weigh up to 110 pounds and silver carp up to 60 pounds. They are voracious eaters, capable of consuming 5 to 20 percent of their body weight each day. They feed on algae and other microscopic organisms, often outcompeting native fish for food. Scientists believe Asian carp could severely disrupt the aquatic ecosystems of Minnesota waters.
Several grass carp were also caught in Pool 6 on March 1. Although grass carp are also a concern, they have been present in Minnesota waters for many years. Adult grass carp, which can weigh up to 70 pounds, can dramatically reduce aquatic vegetation.
More information about Asian carp is available on the DNR’s website.