Investigating the larval culture requirements of Southern Bluefin Tuna, Thunnus maccoyii, for aquaculture in Australia

The closed life-cycle production of Southern bluefin tuna (SBT) (Thunnus maccoyii) is under investigation in Australia, with the first spawning of fertilized eggs from captive broodstock occurring in 2008 at Clean Seas Tuna Ltd (CST), South Australia. Establishment of a sustainable aquaculture industry, not dependent on wild caught juvenile SBT, is the primary goal of CST and the Australian Seafood Cooperative Research Centre (CRC) supported collaborative research projects. Wild-caught broodstock are maintained in a land-based facility at Amo Bay in South Australia, with environmental control and active research to manage reproduction and facilitate annual spawning. Recent larval rearing activity has addressed critical mortality events, including surface mortality in newly hatched larvae, sinking and death on the tank bottom in the live feed stage, cannibalism, weaning, and wall collisions. These are known bottlenecks in the hatchery production of other bluefin tuna species, initially identified through research in Japan (Kumai, 1997; Sawada et al., 2005; Masuma et al., 2011; Ishibashi et al., 2012; Kurata et al., 2012). The SBT research is an internationally collaborative effort, involving four international partners, eight Australian organisations and larval rearing in five hatchery sites from 2008 to 2012. This paper presents a summary of recent research and future directions.