The effect of multi‐year vs single‐year stocking on lake sturgeon ( A cipenser fulvescens R afinesque, 1817) genetic diversity

Summary Many lake sturgeon ( A cipenser fulvescens R afinesque, 1817) populations in the G reat L akes have not recovered from previous threats, whereby stocking can increase population abundances. Stocking in O neida L ake, N ew Y ork used two approaches: single‐year stocking using sturgeon from the D es P rairies R iver and multi‐year stocking using sturgeon from the S t. L awrence R iver. Stocked A . fulvescens were sampled and assigned to their corresponding stocking strategy based on age. Samples were analyzed at 12 microsatellite loci to evaluate how a single year of stocking (N = 273) and multiple years of stocking (N = 100) affected genetic diversity and effective population size ( N e ). Single‐year stocking resulted in lower genetic diversity, likely due to a small number of parents. Multi‐year stocking retained most of the genetic diversity of the source population, compensating for the few parents available in a single year. Although multi‐year stocking resulted in a higher N e , the N e : N ratio was lower (0.34) compared to single‐year stocking (0.65), likely due to unequal sex ratios and family size variance across years. It is recommended that stocking of L ake S turgeon take place over several years. However, consistent numbers need to be stocked each year and family size should be equalized across cohorts in order to maximize N e .