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

The proximity of many Pacific countries to seafood markets in Asia, the hig h value of species associated with coral reefs, and the increased demand fo r marine aquarium species, has prompted many nations in the region to inves tigate opportunities for coastal aquaculture. There are, however, several c onstraints to consider throughout much of the Pacific, including, transport problems, fragile ecosystems, lack of suitable sites, limited economies, a nd the effects of customary marine tenure on access to growout sites. To ov ercome these problems, coastal aquaculture in the Pacific will need to focu s either on species of high value, or those that yield non-perishable produ cts. Valuable industries have been established for pearl oysters, penaeid s hrimps, and the microalgae, Spirulina, in tropical Australia, the French te rritories and Hawaii, whereas enterprises for cultured giant clams, milkfis h (Chanos chanos) as tuna bait, the macroalgae, Eucheuma, and sponges are e merging in the small island developing states. Species demanded by the aqua rium trade, groupers for live reef fish markets, tropical abalone (Haliotid ae), mangrove crabs (Scylla spp.) and a variety of invertebrates as sources of bioactive compounds are promising new species for intensive farming. Aq uaculture technology is being applied to the restocking and stock enhanceme nt of valuable, sedentary species low in the food chain, and there are acti ve 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 th e potential benefits of increased aquaculture, restocking and stock enhance ment need to be balanced by the risks associated with culturing additional species, i.e. introduction of diseases, dilution of gene pools and increase d biological interactions with other species, and that sustainable aquacult ure, restocking and stock enhancement are most likely to be achieved with r esponsible application of technology and the use of indigenous species.