A genetic evaluation of stock enhancement of blue abalone Haliotis fulgens in Baja California, Mexico

Stock enhancement programs for Haliotis fulgens have been carried out for several years in Central Baja California to improve depleted populations, usually by the release of competent 5-day old larvae that are raised in hatcheries. In this study we analyzed the genetic diversity at two hatcheries and devised a method to monitor released abalone in the wild based on two microsatellite loci. The genetic diversity of the hatchery-reared abalone was high (mean Ho = 0.865, number of alleles per locus = 14) and comparable to that of the broodstock. The number of spawners that contributed genetically to the progeny was more than 80% of the total, indicating that management practices appear adequate to avoid significant reduction in genetic diversity. The presence of released larvae in the wild, assessed by recapture samplings 6, 12, and 18 months after release, was low, indicating that the stock enhancement strategy should be modified to release older juveniles that will have better survival. Low probability of identity (I = 1.7 × 10−4), estimated with the combination of the two microsatellites, indicates their potential for identification of individuals in the wild in stock enhancement programs.