Southern Bluefin Tuna

Other names: southern tuna, bluefin tuna, SBT

name:Thunnys maccoyii

Minimum size:

Bag limit:
2 (southern bluefin, yellowfin, bigeye tuna combined)

Possession limit:
2 (southern bluefin, yellowfin, bigeye tuna combined)

Boat limit:
4 (only 2 over 1.5 metres)

Identifying features:
  The largest of the Tasmanian tunas, southern bluefin have a moderately long and muscular body with small scales covering skin.  They are bluish black in colour along the back and silvery white below.  Keels are present near the tail and are coloured yellow in juveniles and black in adults.  Looks similar to bigeye tuna (Thunnus obesus) but fishers experienced in catching SBT will be able to identify distinguish bigeye by the larger shape of the eye and the chubby form of the fish.  

Grows to:
Up to 2 metres and 220 kg.

A fast swimming tuna found in the open ocean, southern bluefin are highly migratory and may be found around Tasmania when the water temperature starts to cool, generally from March to June and spend winter in offshore waters.  Can be found in close to sea cliffs but generally found in waters from 40 metres depth.

Fishing information:
Southern bluefin tuna are actively targeted by game fishers off Tasmania’s east and south coasts during autumn and into winter.  Usually caught by trolling large lures.  In recent years, the stocks of SBT have declined to the point where catch limits have been placed upon the fishery in an attempt to allow the stocks to recover.

Responsible fishing tips:
Avoid long playing times by using heavier line.  Use a large de-hooker or pliers to remove hook.  Use barbless single hooks on lures.  Minimise interactions with seals and other wildlife.  Don’t dispose of fish frames around boat ramps.  If you catch a tagged tuna, please record the tag details and report to the Institute for Marine and Antarctic Research​.

If practising catch and release, keep tuna out of the water for the minimum time possible, cover their eyes and handle with wet hands or cloth.  Don’t use a gaff.  Larger tuna should be released without removing them from the water.  If photographing, hold horizontally, not unsupported by the tail.  

Tuna need to be correctly handled after capture to retain the best eating quality.  They should be killed using a brain spike, bled, then cleaned and chilled shortly after capture. Tuna has a high oil content, distinctive flavour and firm, dark flesh which lightens when cooked.  Cooking methods: bake, barbecue, foil bake, marinate, sashimi.  Cooked tuna steaks are often preferred by Tasmanian fishers.

Find out more on​ Southern Bluefin Tuna Code of Practice and Tuna Champions​

Fish illustration by Peter Gouldthorpe
Fish for the Future