Jack Mackerels

Average length: (T. declivis) 35-50 cm; 30-40 cm (T. novaezelandiae). Average weight 850 gm. Blue, or green with faint brown bands above, silvery white below; small scales, and a row of rough scutes along the body. Both jack mackerels are widespread and common on the bottom, in midwater and occasionally at the surface, around most of New Zealand, especially the west coast of North Island (T. declivis) and the Bay of Plenty (T. novaezelandiae) to depths of 300 m; (T. declivis) is the more abundant species and is caught by trawl. T. novaezelandiae is caught by purse seine. Available all year round. A large resource species with estimated annual yield of perhaps 15,000-20,000 tonnes for (T. declivis) and 10,000-20,000 tonnes for (T. novaezelandiae).