Status of research in stock enhancement and sea ranching

Abstract

The growing human population and increasing food demand have put pressure on coastal environments and fisheries resources. Overfishing and destruction of coastal habitats have resulted in depletion of coastal resources, and have threatened the viability of the fishing industry. Efforts are being made to protect the coastal habitats, to restore the populations of aquatic organisms and to create new fishing opportunities. Fisheries management that has been in place for a fairly long time requires reorientation to meet new challenges (Liao, 1999; Chua, 2001). In recent years, stock enhancement and sea ranching have been recognized for their potential of increasing and sustaining coastal fisheries (Oshima, 1984; Bartley, 1999; Liao, 1999, 2002). Stocking has been attempted at some level in over 25 countries worldwide (Bartley, 1999) with more than 100 species of aquatic organisms (fish, crustaceans, molluscs and other invertebrates) (Liao, 1999; Fushimi, 2001). Varying results have been obtained and problems identified. A well-planned enhancement or ranching project will aspire either to recapturing releases or to promoting inter-breeding between released and wild populations so that an enhanced self-sustaining population is produced (Cross, 1999). Because many marine enhancement and ranching projects worldwide are still in the experimental or pilot stages (Bartley, 1999) sufficient data is not available to answer a growing number of questions that are being raised. The purpose of this chapter is to provide a review of the status of research and developments on stock enhancement and sea ranching of aquatic animals.