Red-throat emperors are distributed between the Houtman Abrolhos and Sydney Harbour; also Norfolk Island (Ref. 6390). They are reportedly absent from the Gulf of Carpentaria and Queensland waters north of Cooktown (Ref. 27260). Recorded from Shark Bay (Ref. 115274). They are most abundant from the Houtman Abrolhos to North West Cape and on the Great Barrier Reef from near Townsville to the Capricorn-Bunker Reefs group (Ref. 6390).

Including Lord Howe I. (Ref. 8879, 75154).

Commercial fishery: Emperors in general are caught by handlines, rod-and-line, traps and demersal otter trawling - mainly stern trawling but also semi-pelagic trawling in the Northern Territory.

Emperors are trawled off northwestern and northern Australia. From 1970 (Ref. 28206, 28207) until 1991, Taiwanese and later Thai and Chinese fleets operated pair trawlers and stern trawlers on the North West Shelf and northern Australia. Emperors and butterfly bream (Nemipteridae) dominated catches on the North West Shelf for the 10 years from 1980 (Ref. 27275), peaking at a retained catch of 2200 t of emperor in 1982. Emperors were far less abundant in retained catches in the Timor and Arafura seas for the same period. The trawlers worked in depths between 30 m and 120 m, and concentrated on waters between 115° and 120°E (Ref. 28206).

Domestic fishing interest in trawling in northern Australia commenced in 1985 and increased after 1988 (Ref. 28207). It is focused on grounds on the North West Shelf, the Arafura Sea and in the northern region of the Gulf of Carpentaria (Ref. 28207), and has a large seasonal component caused by prawn trawlers converted to fish trawling during the closed seasons of the Northern Prawn Fishery (Ref. 28207, 27275).

Trap fishing began on the North West Shelf in 1984 (Ref. 28206, 27266). Fishing is carried out on hard-bottom areas to the west or inshore from main areas worked in the past by Taiwanese pair trawlers. It first concentrated on the Monte Bello-Barrow Island area mainly near the coastal towns of Onslow, Port Hedland and Point Samson (Ref. 27266, 28209). The main area for trapping is now north of Broome.

Fish traps used in Western Australia are mostly circular ('O' traps) and are baited usually with pilchards (Sardinops neopilchardus).

Red-throat emperors are targeted by handline fishers on the west coast. A small quantity of emperors are also taken by dropline.

Red-throat emperors are caught in the North West Shelf Trap and Line Fishery, second only to spangled emperors (L. nebulosus) in abundance (Ref. 27266).

Red-throat emperors are the third largest component of the Queensland East Coast Reef Line Fishery and comprise 14% of the catch or more than 500 t annually (Ref. 27263). On the Great Barrier Reef this species comprises more than 90% of the emperor catch. Catches of red-throat emperors are highest between August and October. They peak in the waters off Mackay, and are largely confined to waters between Cardwell and Shoalwater Bay, with small catches as far south as Maryborough.

Spangled and red-throat emperors are the only emperors of significance on the Great Barrier Reef although red-spot emperors (L. lentjan) are caught in fish traps on the outer slopes of mid-shelf reefs (Ref. 27260). Red-throat emperors are caught with rod-and-line or handlines, baited usually with pilchards. Commercial vessels operate with 2-4 tender boats which anchor over coral 'bombies' to fish. Bottom fishing in Great Barrier Reef shallow lagoons at night catches mainly spangled emperors, and red-throat emperors are caught both in the daytime and at night. There is also a handline fishery for red-throat emperors in Norfolk Island waters. Best catches are taken in summer months between November and February (Ref. 6061).

Most fish from the North West Shelf fishery are sent to Perth as whole, chilled fish. Some are gutted and brined before freezing.

Recreational fishery: Red-throat emperors are 1 of the major target species by anglers on the Great Barrier Reef and the Queensland east coast. Emperors are caught with either fresh baits or whole or cut fish, crabs, prawns and squid, and tackle ranges from handlines to casting rigs. The largest emperor recorded by the Australian Anglers Association was 9.6 kg. from Queensland.

Resource status: Emperors comprised 47% of demersal fish in retained catches taken by Russian survey vessels on the North West Shelf between 1962 and 1973. Emperors and sea perch (Lutjanidae) comprised 40-60% by weight in 1962 but the amount dropped to about 10% in 1983 (Ref. 28206) (the emperor component of the total catch fell from 27.9% in 1967 to 5.4% in 1983 (Ref. 28006). This reduction in yield can partly be attributed to the removal of large epibenthos from the sea floor by the action of trawlers and to over-fishing these groups in the mixed species trawl fishery (Ref. 28206, 28207). The size composition also changed, with emperors (probably blue-spotted emperors) larger than 0.6 kg disappearing from the catch after 8 months of fishing (Ref. 28006). By 1986, the catch per unit of effort for emperors had declined by 65% from a peak in 1973. Whereas the abundance of emperors has continued to decline in trawled areas, the catch rate has increased since 1986 due to concentration of fishing effort on emperors (L. choerorynchus) by Taiwanese fleets (Ref. 28207).

As of 1993, there have been no studies on the resource status of emperors on the Great Barrier Reef and inshore areas of northern Australia. Although there have been reports of declining numbers of red-throat emperors on the Great Barrier Reef (Ref. 27260), information from fishing clubs along the coast fom Cairns to Bundaberg do not suggest a decline. Similarly, there is no information on the resource status of emperors in Western Australian fisheries.

Museum: CSIRO CA980 (Ref. 5978). Also Ref. 2334, 3111.