Abundance, age structure, and spatial distribution of lake sturgeon, Acipenser fulvescens, in the St Clair System

Lake sturgeon population abundance, age structure, and spatial distributions in the St. Clair River and Lake were studied beginning in 1996. More than 900 fish were caught, tagged, and released. Recapture analysis indicates movement into southern Lake Huron, and puts population estimates at 45,506 for this area. Age structure suggests consistent recruitment in the 1970s and 1980s but low recruitment before 1973 and after 1995. An area of consistently high sturgeon density near the St. Clair River delta was identified. This river/lake system appears to support a large sturgeon population that aggregates in high densities in small areas. Further research is needed to identify the features that make such areas desirable, for future habitat restoration efforts.