Distribution of Age-0 Lake Sturgeon in the Lower Section of a Lake Michigan Tributary

Knowledge of spatial distribution and habitat use of juvenile lake sturgeon (Acipenser fulvescens) is critical for successful restoration of this threatened species. Juvenile lake sturgeon distribution was assessed in September-December 2009-2011 using gill nets in the lower section of the Kalamazoo River near Lake Michigan. Captured lake sturgeon were fitted with either a radio or ultrasonic tag to track movement. We used side-scan sonar and hydro-acoustics to map areas where juvenile lake sturgeon previously were captured. Ten age-0 lake sturgeon (1 wild and 9 hatchery reared) from the Kalamazoo River were fitted with transmitters and tracked until signals were unattainable. All age-0 lake sturgeon appeared to emigrate to Lake Michigan in September-November shortly after being tagged. Total residency time of juvenile lake sturgeon in the lower section of this river is unclear, but our preliminary results suggest age-0 individuals are not utilizing the lower section of this system for nursery habitat before migrating to Lake Michigan in late fall.