Museum: CSIRO CA1251, from North West Cape to Darwin (Ref. 5978).

Present from Rottnest Island to Wollongong (Ref. 6390).

Stock structure: Australian spotted mackerel appear to form a single stock on eastern coast of Queensland (Ref. 30572). They undertake major seasonal migration along the east Queensland coast (Ref. 30572).

Commercial fishery: In Western Australia, spotted mackerel are fished north of approximately 28°S. Mackerel fishing is a major fishery on the North West Shelf. The fishery peaks in July and August, and weather conditions restrict fishing operations during the wet monsoon period (December-February) (Ref. 30203, 27266).

Taiwanese fleets fished for Scomberomorus species off northern Australia from 1974 to mid-1986 (Ref. 26279) and in the Gulf of Carpentaria until the fleet’s exclusion in 1978. The Taiwanese used drifting gillnets ranging in length from 8 km to more than 20 km (Ref. 26279). Australian Government regulations in 1986 limited the gillnet lengths to 2.5 km or less, effectively making the Taiwanese gillnet fishery uneconomic in Australian waters.

The Queensland fishery for mackerel is the State’s major offshore finfish fishery (Ref. 30220) and has been operating for at least 60 years (Ref. 30219). In 1989-90, its value was estimated at A$3.4 million, of which more than 66% was Spanish mackerel. The Queensland fishery extends from the southern Gulf of Carpentaria, through Torres Strait and along the east coast, although most fishing takes place from north of Cooktown to Mackay. Mackerel fishers operate mostly from the ports of Cairns, Townsville, Yeppoon, Mackay and Bundaberg. Mackerel are fished to approximately 30°S (Coffs Harbour) in New South Wales. The east coast fishery targets mackerel during the spring spawning season and the northward migration (Ref. 30194) and later in summer-early autumn in southern Queensland.

Catch rates vary depending on the time of day (early morning and evenings are preferred), moon phase, tides, water temperature, depth (Ref. 30221), sea floor temperatures (Ref. 30205), trolling speed and the fishers’ experience (Ref. 30221). The size of the fishing operation varies, from a mothership up to 16 m long operating several dories through smaller vessels without dories, to dinghies operating from island locations.

All Scomberomorus are susceptible to drifting gillnets. There are localised gillnet fisheries for small mackerel through almost their entire distribution in Australia, from approximately Shark Bay to northern New South Wales. Sharks form an important part of the catch in these fishing operations (Ref. 30205), and fishers target either shark or mackerel depending on availability and market demand. A small amount of mackerel is taken with offshore drifting gillnets by domestic fishers in north-eastern Queensland, where reasonable quantities of juvenile mackerel are also caught inshore.

Demersal otter trawlers targeting prawns in northern Australia may catch substantial quantities of mackerel either as bycatch or by line fishing. Some boats engaged primarily in other fisheries in northern waters switch to trolling mackerel when the fish are biting.

Wahoo (Acanthocybium solandri) (in north-eastern Australia) and shark mackerel (Grammatorcynus species) (in north-western Australia) are important bycatches of the mackerel troll fishery.

Mackerel are marketed frozen, fresh or chilled as gilled-and-gutted whole fish or trunks, and are retailed as fillets or cutlets. In Western Australia, the mackerel are gutted or put in chilled brine for gutting later the same day (Ref. 27266). In Queensland, some fish are filleted on the boats and stored on ice or frozen. Small local operations prepare smoked mackerel. Much of the Northern Territory product is trucked interstate, whereas Western Australian and Queensland product is sold both locally and interstate. Mackerel is in high market demand in Australia. It is a staple of the ‘fish-and-chips’ trade in Queensland.

Recreational fishery: In Queensland, line gear is used by recreational fishers.

Resource status: As of 1993, no studies on the resource status of mackerel had been conducted.

Ciguatera poisoning is associated with mackerel. A lipid-soluble toxin, similar to ciguatoxin, has been found in individual mackerel caught between 24°S and 26°S off Queensland (Ref. 168) and also in mackerel from the Gove Peninsula area, Northern Territory.

Also Ref. 1910, 2334, 9684.