The white sturgeon (Acipenser transmontanus) population in the Upper Columbia River, Canada, has been undergoing recruitment failure for several decades. Uncertainty exists regarding white sturgeon reproductive ecology including the number of adults annually contributing offspring and accuracy of estimating the duration of spawning activity. The effects of temperature on white sturgeon larval development were examined to improve estimates of fertilization dates for wild caught larvae and number of spawning days. Molecular techniques allowed for the examination of levels of recruitment to the egg or larval stage and/or reproductive success of adult fish. Microsatellite loci (N=12) and likelihood-based pedigree analysis were used to quantify the number of spawning adults (N), effective breeding number (Nb) and individual reproductive success from eggs and larvae collected in each of two consecutive years. Genetically derived estimates of numbers of spawning adults (N) were concordant with empirical estimates of the number of annual available breeders (Nc) based on sex ratios and maturation stages of adults. Results are fundamental to our understanding of white sturgeon spawning strategies and can be applied to revise ongoing recovery strategies (e.g. conservation aquaculture programs).
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