Abalone ranching: a review on genetic considerations

Haliotis L. (abalone) is an economically important genus comprising approximately 14 species with commercial value. Unfortunately, due to habitat destruction, overfishing and illegal harvesting, this wild resource is being depleted to unrecoverable status worldwide. To supply the world demand, abalone are cultured in artificial hatchery environments. In the past few decades, attention has been paid to use these artificial environments to the benefit of the species by implementing abalone ranching or reseeding. This is done in an attempt to rebuild the collapsed populations and to prevent further declines in fished stocks. In various countries in which commercial production is in operation, this has been attempted with various levels of success. For ranching to be successful, various factors, however, need to be considered, one of the most important probably being the correct genetic management of such a ranching programme. Genetic management should include using broodstock that are representatives of natural populations, minimizing the effects of hatchery practices on the genetic make-up of the animals to be released and investigating the genetic impacts of this practice on wild populations. In this review, the genetic management and the effects if management is not implemented are discussed as well as the potential of molecular markers to be used as genetic tags in identifying hatchery-reared animals.