Present from the Ashburton River (Ref. 11885) in Western Australia to at least the Mary River and nearby Great Sandy Strait, or further south, in Queensland. Also Ref. 57343.

Stock structure: Probably distinct genetic stocks occur along the Gulf of Carpentaria and east coast of Queensland (Williams 1997).

Commercial fishery: Threadfin salmon are fished in the north of Western Australia, in the Northern Territory and in Queensland. In Western Australia they are fished all year from about 19°S northwards. In the Northern Territory, threadfin salmon comprise approximately 30% of the total landings of the barramundi fishery. Blue threadfin are taken in the mixed fish coastal gillnet fishery.

Blue threadfin form part of a multi-species fishery (which includes barramundi, Lates calcarifer) on the Queensland east coast from about Lloyd Bay southwards and in the Gulf of Carpentaria; although the landings vary between regions. On the central Queensland coast blue threadfin dominate net fishery catches; and from the Gulf of Carpentaria gillnet fishery between 1980 and 1987, blue threadfin averaged 5% by weight of total landings.

Threadfin salmon are important during the late dry season cooler months (about June to September), while barramundi tend to dominate the river catches at other times. On the east Queensland coast, blue threadfin are caught throughout the year, exhibiting greater catch rates during winter months (May to July) (Ref. 28736, 27247). In general, however, barramundi fishers target king threadfin, P. indicus, rather than blue threadfin because of their greater value. This targeting is facilitated by the mesh size permitted for gillnets. In other words, large mesh nets set for barramundi also gill king threadfin, but blue threadfin - being smaller - often pass through the nets.

Threadfin salmon are caught mainly by coastal set gillnets, but also by fixed tidal traps, beach seines and ring nets, over sandbanks offshore or onshore, or in the mouths of rivers on tidal mud flats.

In the southern Gulf of Carpentaria, blue threadfin enter the commercial fishery from about 40 cm FL when they are about 2 years of age.

Typically, threadfin salmon are marketed as fillets, either fresh and chilled on ice or frozen. They are shipped interstate or consumed locally. On the east Queensland coast south of Port Douglas and near Darwin in the Northern Territory, blue threadfin are often wholesaled as gilled and gutted whole fish, but in the Gulf of Carpentaria, the fishery is for fillets only. In the Northern Territory, threadfin salmon is used largely in the 'fish-and chips' trade.

Recreational fishery: Threadfin salmon are important sport fish. They are caught with rod-and-reel or handlines, from shore or boat. Live or very fresh baits of oily fish, prawns or crabs as well as lures are used. In Queensland, the fishery for blue threadfin is significant from about Port Douglas to Gladstone on the east coast, as well as in the Gulf of Carpentaria around the ports of Weipa and Karumba. Up to 1993, the recreational fishing record for a threadfin salmon was 13.6 kg from Queensland (Australian Anglers Association records).

Resource status: Better market acceptance of blue threadfin has produced a marked increase in the quantities of blue threadfin landed in Queensland. Up to 1993, threadfin salmon appeared to be fully exploited on the east coast but catches were increasing in the Gulf of Carpentaria as better prices were being offered. Catches declining on east coast after 1994 (Williams 1997).