New species for coastal aquaculture in the tropical Pacific - constraints, prospects and considerations

Abstract

The proximity of many Pacific countries to seafood markets in Asia, the high value of species associated with coral reefs, and the increased demand for marine aquarium species, has prompted many nations in the region to investigate opportunities for coastal aquaculture. There are, however, several constraints to consider throughout much of the Pacific, including, transport problems, fragile ecosystems, lack of suitable sites, limited economies, and the effects of customary marine tenure on access to growout sites. To overcome these problems, coastal aquaculture in the Pacific will need to focus either on species of high value, or those that yield non-perishable products. Valuable industries have been established for pearl oysters, penaeid shrimps, and the microalgae, Spirulina, in tropical Australia, the French territories and Hawaii, whereas enterprises for cultured giant clams, milkfish (Chanos chanos) as tuna bait, the macroalgae, Eucheuma, and sponges are emerging in the small island developing states. Species demanded by the aquarium trade, groupers for live reef fish markets, tropical abalone (Haliotidae), mangrove crabs (Scylla spp.) and a variety of invertebrates as sources of bioactive compounds are promising new species for intensive farming. Aquaculture technology is being applied to the restocking and stock enhancement of valuable, sedentary species low in the food chain, and there are active programmes in several small island developing states to assess the scope for releasing cultured giant clams, trochus, green snail and sea cucumbers to replenish and enhance wild stocks. There is a growing awareness that the potential benefits of increased aquaculture, restocking and stock enhancement need to be balanced by the risks associated with culturing additional species, i.e. introduction of diseases, dilution of gene pools and increased biological interactions with other species, and that sustainable aquaculture, restocking and stock enhancement are most likely to be achieved with responsible application of technology and the use of indigenous species.