Wayne Hutchinson

Southern Bluefin Tuna Captive Breeding in Australia

Abstract The production of hatchery reared southern bluefin tuna (SBFT, Thunnus maccoyii) fingerlings is needed for further sustainable expansion of production from the Australian tuna aquaculture industry. Clean Seas Tuna Ltd (CST) has pioneered progress toward closing the SBFT life cycle in captivity since broodstock held in an onshore tank system first spawned in 2008. Since then, CST has collaborated with key Australian research agencies on a range of scientific programs supported by Australian Seafood Cooperative Research Centre (SfCRC). These investigations have developed a preliminary SBFT propagation husbandry protocol that has been implemented at CST Arno Bay hatchery in South Australia, including the techniques for broodstock management and induced spawning in the land-based facility, as well as larvae and juvenile fish rearing until the end of the nursery stage. Some major obstacles still remain unsolved for SBFT, such as unreliable egg supply from captive broodstock, low survival in late larval and early juvenile stages, sub-optimal weaning diets, cannibalism, wall collisions, and a high level of handling stress following transfer of fingerlings to ponds and sea cages. However, significant knowledge and hands-on experience toward closing the SBFT life cycle have been achieved.