Manipulations of adult density and juvenile habitat quality in northern abalone stock restoration

Wild abalone populations throughout the world have declined dramatically over the past 40 years due primarily to market demands for the mollusc's edible foot. Northern abalone (Haliotis kamtschatkana), the only abalone species occurring in British Columbia (B.C.), is widely thought to be threatened by potential population collapse as a result of low adult densities that impair reproductive potential. This study examined the hypothesis that the abundance of wild northern abalone populations are below a critical density required for successful reproduction and assessed two techniques that may aid the 'recovery' of northern abalone in B.C.; In the first study, I created dense aggregations of mature abalone during the reproductive period to test whether abalone preferred high density spawning aggregations that theoretically enhance reproductive potential.; In the second study, I installed artificial habitats that provided standardized surrogate habitat for juvenile abalone and surveyed surrounding natural habitats to determine an index of juvenile abalone abundance. (Abstract shortened by UMI.)...