Estimates of Effective Number of Breeding Adults and Reproductive Success for White Sturgeon

AbstractAccurate estimates of the number of adults contributing to offspring (Ns), effective breeding number (Nb), and individual adult contributions to recruitment are required for recovery planning for endangered White Sturgeon Acipenser transmontanus populations, many of which are suffering from prolonged periods of recruitment failure. We show that genetic techniques can be used to characterize important features of White Sturgeon reproductive ecology in large rivers where census data are extremely difficult to obtain. We used 12 microsatellite loci and likelihood-based pedigree analysis to estimate Ns, Nb, number of kin groups (Nk), and individual reproductive success of White Sturgeon contributing to viable eggs and larvae collected in the upper Columbia River in each of 2 years. Estimated mean ±SD annual Ns was 121.5 ± 34.7, Nb was 86.5 ± 10.6, and Nk was 73.5 ± 17.3. Large variations in estimates of Ns, Nb, and Nk were observed between three spawning areas, in which one spawning site representing ...