Geomorphic classification framework for assessing reproductive ecology of Scaphirhynchus albus (pallid sturgeon), Fort Peck segment, Upper Missouri River, Montana and North Dakota

Abstract

First posted October 11, 2023 For additional information, contact: Director, Columbia Environmental Research CenterU.S. Geological Survey4200 New Haven RoadColumbia, MO 65201Contact Pubs Warehouse The segment of the Upper Missouri River between Fort Peck Dam and the headwaters of Lake Sakakawea is home to a population of the endangered Scaphirhynchus albus (pallid sturgeon). Lack of population growth (recruitment failure) has been attributed to inadequate dispersal distance of larvae between spawning locations and the headwaters of Lake Sakakawea, where conventional wisdom holds that anoxic water-quality conditions are lethal to larval sturgeon. River-management objectives to recover pallid sturgeon in this segment therefore focus on increasing available drift distance, decreasing drift rate, increasing larval development rate, or a combination of these objectives. Understanding of channel morphological conditions along this about 400-kilometer segment may provide insight into upstream spawning habitat potential (where sturgeon likely spawn) and into geomorphic factors that may contribute to flow complexity, hence drift rate. This report documents a continuous geomorphic classification of the Fort Peck segment of the Upper Missouri River using remotely sensed datasets to provide contextual information about spatial variations potentially affecting pallid sturgeon reproductive ecology.