Minnesota DNR Removing Invasive Carp From Mississippi River Get our free mobile app St Paul (KROC AM News) - The latest effort to rid the Mississippi River of an unwanted fish is being concentrated in a section that includes southeast Minnesota. The Minnesota Department of Natural Resources is the lead agency in the state/federal effort that has the official name of “Modified Unified Method.” Deborah Rose The MUM method uses block nets to create compartments or “cells” from which the fish can be driven. The USGS then uses electrofishing boats and boats outfitted with underwater speakers to herd carp from each cell. When a cell is cleared, another net is used to close the cell and prevent the fish from returning. This process is repeated one cell at a time, gradually reducing the area available to the carp and concentrating the fish into a harvest removal area, where a large commercial seine will be used to draw out the congregated fish. Native fish do not seem to respond in the same way as the invasive carp, preferring to hide, rather than run, from the sound stimulus.