A Biological Assessment and Response to a Missouri River Top-Widening Project

A river top-widening project on Lower Little Sioux Bend, named Deer Island, is located at river kilometers 1,079 to 1,083 in the upper portion of the channelized Missouri River along Nebraska’s eastern border.  Construction began in 2012 and was completed by fall of 2014.  At approximately 55 hectares, this project represents the largest channel widening project completed under the proposed restoration action to create shallow water habitat in the Missouri River.  From May 14^th to October 1^st in 2015, benthic trawls were deployed weekly to assess the fish diversity, relative abundance and distribution within these constructed habitats.  A total of 4,803 fish from 34 species were collected from 462 deployments.  An investigation of trends associated with the fish community and available habitat at the site in 2015 will be presented.  Further, an assessment of different modeled flow regimes from recorded physical measurements will produce habitat availability maps for individual fish species to determine how habitat availability changes as river discharge varies.