Current status of microencapsulated diets for aquaculture

The replacment of live foods by artificial diets in larval culture remains one of the major problems of commercial aquaculture because many systems are still dependent upon one or even two live food-chain links to provide adequate nutrition for larval molluscs, crustaceans, and fish. Recently it has been demonstrated that one, and in some cases, both live food-chain links may be successfully replaced by microencapsulated diets. The technology, which has reached pilot-scale production in at least one instance, now includes a wide range of coacervation and interfacial polymerization methods producing individual capsules ranging from 2 μm in diameter to capsule aggregates. These have been designed to function either as complete nutrient delivery systems or as feed supplements. In addition, by incorporation of specific nutrients into microcapsules, it is now possible to determine essential nutritional requirements for a wide range of aquatic larvae. The present paper reviews the progress in these fields and considers their likely consequences for aquaculture.