This is a large surface species of temperate seas of Australia and New Zealand. It arrives in the Fiordland region around December and moves both east and west coasts mostly along the edge of the continental shelf.
Its food, while mostly other fishes, includes larger swimming crabs and shrimps. Saury are a commonly taken surface fish.
Its colour is blue-black above, greyish on the sides, and the finlets behind the dorsal and anal fins are bright yellow. This species is similar in general appearance to yellowfin tuna, which differs in having a pectoral fin reaching nearly to the second dorsal fin, a more slender appearance, and an angular outline of the cheek plate which is rounded in southern tuna. When in doubt, examine the liver. This is dark red in southern tuna, with several bluntly pointed lobes and the surface conspicuously streaked with dark parallel lines.
Names include bluefin and southern bluefin tuna. A greatly sought after, and valuable, commercial species, the only real recreational fishery for them is in the Fiordland area, where several boats have had success over the last couple of seasons. Although greatly reduced in numbers, there seems to have been a small resurgence in the population.
Most fish are taken on trolled lures although chunk fishing at night has been successful in the past.
- © Fairfax NZ News