Southern Bluefin Tuna (SBT), Thunnus maccoyii, are as magnificent in the ocean as they are on the plate.
SBT are migratory fish, crossing the Pacific, Atlantic and Indian Ocean within their annual migration. As a result, their habitat that ranges widely across the southern hemisphere including territorial seas of Australia, New Zealand and South Africa.
Every year between September and April, adult SBT (aged 11-12 years) migrate from southern feeding areas to their single identified spawning ground in the waters south of Indonesia. It is not known whether all mature fish spawn every year, every few years or only once in their lifetime. The larvae and juvenile fish are swept south by the Leeuwin current along the Western Australian coastline, and reach the Great Australian Bight as 1 to 2 year olds. At this point, depending on a range of factors SBT either push west into the Indian Ocean or east into the Great Australian Bight.
Southern Bluefin Tuna are generally long lived, with some fish living greater than 40 years. At maturity SBT can be up to 2 metres in length and weigh greater than 200kg. The age of maturity is a matter of debate; however, is generally agreed to be between 8 and 12 years of age.
SBT are incredible predators of the ocean. They are able to accelerate at twice the rate of a Ferrari and have the capacity to swim long distances at speeds which are illegal on most urban roads. The constant physical action creates an enormous demand for energy and a need to eat large quantities of food. Luckily, SBT are opportunistic feeders meaning they prey on a large variety of food including crustaceans, cephlapods and small pelagic fish.