Movements & Habitat Use of Juvenile Lake Sturgeon in the North Channel of the St. Clai River

Abstract: Juvenile sturgeon Acipenser fulvescens between the ages of 3-7 years were studied to determine movement patterns and habitat usage in the North Channel of the St. Clair River. Nine juveniles were implanted with ultrasonic transmitters and tracked in the summer seasons of 2005 and 2006. Telemetry data and Geographic Information Software were used to determine habitat preferences. All fish tracked showed a large degree of site fidelity, with an overall home range area between 0.8km² and 10.8km². Juvenile lake sturgeon habitat selection was strongly related to depth, and they were found over 95% of the time in depths that exceeded 9m. Sturgeon appeared to occupy deeper habitats compared to what was available; sturgeon were most commonly found in depths between 12 and 18m (44% of occupied locations), however the most frequently available habitat was between 9-12m (32% of all available locations). Many sturgeon had a high degree of home range overlap, and overlap was significantly higher in areas that contained gravel bottom substrate without zebra mussels. Juvenile home range was also smaller in areas that contained gravel substrate than in areas with appreciable zebra mussel coverage, indicating that more food might be available in areas that contain gravel substrate. A significant negative correlation was found between the amount of zebra mussel cover and depth, meaning greater depths had lower zebra mussel coverage. These data suggest that sturgeon chose deeper sections of the North Channel because of a lack of zebra mussels and greater amounts of other types of invertebrates that served as food.Master of Science (MS)School of Natural Resources and EnvironmentUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/50471/1/THESIS_Final_Draft_4_16_2007.pd