California Sea Grant College Program

Over the past three decades, we have witnessed dramatic declines of abalone stocks along the southern California coast. What was once an important fisheries resource (commercial and recreational) has completely disappeared and there is now a moratorium on all abalone harvesting in the region (California Department of Fish and Game 2002). Populations of white, red, black, pink and green abalone have all been impacted; the former species, Haliotis sorenseni, has become the first marine invertebrate to be listed as an endangered species. Both anthropogenic (overexploitation and habitat destruction) and natural (disease and predation) processes have contributed to the decline in abalone abundance. Attempts to develop effective conservation and recovery strategies for abalone require understanding many aspects of the biology of these species. The primary question is: can reproduction in remnant populations provide the recruits necessary for recovery of abalone populations that have gone locally extinct? Two factors are important in answering this question. First, there is the question of fertilization success in low abundance populations of broadcast spawning invertebrates; can males and females locate one another and successfully produce fertilized eggs? The second issue regards the level of "connectivity" of abalone populations; can success in one part of the species range provide a natural reseeding in other parts of the range? This project used population genetic methods to address the latter question.