Habitat Use of Shovelnose Sturgeon Scaphirhynchus Platorynchus in the Lower Mississippi River

The habitat requirements of shovelnose sturgeon populations are unknown for the lower Mississippi River. Active acoustic telemetry was used to measure temporal variation in habitat use of shovelnose sturgeon and preference for depth, surface current velocity, and riverbed rugosity and slope by the population and within sandbar microhabitats. Shovelnose sturgeon occupied habitats differently throughout the year; and, within habitats, areas of moderate depth and surface current velocity and smooth riverbed were preferred. Within sandbars, environmental conditions did not differ from the surrounding environment, yet frequent aggregations of individuals in the lower portion of sandbars often in close proximity suggest habitat preference at a scale greater than the 5 ha measured. Results of this study provide information on seasonal habitat use patterns and methods that can be applied to a long-term dataset to identify the habitat requirements of shovelnose sturgeon