Green abalone, pink abalone, and white abalone prefer southern climes, with each species occupying increasingly deeper waters, respectively, from Point Conception into Baja California. Red abalone, the largest species, occupies the broadest range, from tidal pools in Oregon to deep reefs as far south as Bahia Tortugas, Baja California. Abalone have separate sexes. To reproduce, they broadcast sperm and eggs into the sea, relying on high gamete densities for successful fertilization, a reproductive strategy requiring densely aggregated adults for success. The larvae are free-swimming for only a few days before settling to the bottom as juveniles.
Fecundity increases exponentially with size.
It was implemented through minimum harvest sizes, based on growth rates and size at maturity. Under this scheme, abalone were permitted to reproduce for the first few years of maturity and then were harvested. Closed seasons protected spawning aggregations. In northern California, an additional management measure protects more brood stock of red abalone, thus assuring a sustained fishery. Zoning use in this way separates commercial and sport fishing and protects a large spawning stock of big abalone.