29-pound carp pulled from Lake Pepin causes concern

A species of ecosystem-disrupting Asian carp has been found in Lake Pepin, the Minnesota Department of Natural Resources has confirmed.

Commercial fishermen reported that on Oct. 3 they caught a 29-pound bighead carp in the southeastern Minnesota lake, which consists of a miles-wide area of the Mississippi River near Frontenac, said Jay Rendall with the DNR's invasive species program.

Rendall said DNR officials learned of the sighting because the fishermen followed a state law that went into effect in August. Under that law, anglers who snag a bighead, silver or grass carp in Minnesota waters must report their catch to DNR officials.

The sighting is a bit unsettling because the voracious plankton-eating fish doesn't usually make it this far north, experts say. They are common in places such as Illinois, Missouri and Iowa and in the southern United States, but have not been spotted in Minnesota for nearly three years.

A bighead carp was spotted in Lake Pepin in 2004 and one was seen in the St. Croix River in 1996, the only two previous sightings in the state.

The bighead is a threat to native species such as paddlefish and sturgeon because "they have to eat continuously and can remove a food source" needed by other smaller fish, Rendell said. "Their presence can be an issue."

The bighead carp and other Asian species were introduced to U.S. waters nearly 30 years ago when they escaped from commercial fish farms in the South.

They've slowly migrated northward and have overtaken portions of the Illinois and Missouri rivers, but have not established a foothold in Minnesota -- yet.

The most recent sighting, DNR officials believe, is an isolated case of migrating this far north and not an indication that there is reproduction taking place in Minnesota waters. Still, Rendall said the DNR is trying to secure funding to build a barrier using electric currents, bio-acoustic sound and bubbles, and working on a prevention plan to keep invasive species out of the state.

Tim Harlow • 612-673-7768

Tim Harlow • harlow@startribune.com