Australian salmon

What it is

This streamlined fish has a long, slender body with dark bluish-green backs and silvery white bellies. Juveniles display golden bars on their flanks that break into large spots as they mature. Distinctive features include vivid yellow pectoral fins and blackish margins on the tail and dorsal fin. A bony ridge with serrations sits beneath the eye in young individuals, smoothing out in adults. It reaches up to 89 centimetres in length and weighs nearly 10 kilograms. Despite names like salmon or trout, it belongs to the family Arripidae, not Salmonidae.

Where it lives

The species inhabits the southwestern Pacific Ocean, primarily in the Tasman Sea and Bass Strait. In Australia, its range extends from Moreton Bay in Queensland down to western Victoria and northern Tasmania, with rare sightings near Kangaroo Island. Populations also exist around Lord Howe and Norfolk Islands. In New Zealand, it is found around most coasts but is more common north of Kaikōura on the South Island. Groups also live near the Chatham and Kermadec Islands. They frequent littoral waters, estuaries, and exposed coastal areas.

How it lives

These carnivorous fish are highly visual predators that form large schools. Adults feed mainly on small schooling baitfish like pilchards, sprats, and anchovies. Juveniles in sheltered bays eat crustaceans and polychaetes. Studies suggest a dietary shift since the late twentieth century from krill and squid to baitfish, likely due to warming waters from the East Australian Current extending southward. Seals, dolphins, and sharks prey on them. Their feeding behaviour pushes small fish to the surface, aiding seabirds like the white-fronted tern, which often feeds alongside them.

Breeding and life cycle

Spawning occurs in the surf zone between Lakes Entrance in Victoria and Bermagui in New South Wales. This activity takes place during late spring and summer. Individuals reach sexual maturity at around four years of age, having grown to approximately 39 centimetres in length. The species can live for up to 26 years. Migratory patterns allow them to travel thousands of kilometres, with adults congregating in large groups off oceanic beaches while juveniles remain in smaller schools in protected estuaries.

Fish and people

Māori people have long valued this fish, known as kahawai, as a traditional food source. Tribes migrated to river mouths in summer to catch swarming schools using specialised hooks with iridescent pāua shell. Early European settlers initially disliked the flesh, describing it as dry and coarse. However, it has become one of the most caught recreational fish in New Zealand, prized by anglers using light tackle or fly fishing. Commercial fisheries use purse seines, though much of the catch serves as pet food or bait due to lower consumer demand for the meat.

Status and threats

Fisheries New Zealand manages the stock to maintain populations at roughly 52 per cent of pre-commercial levels. In 2019, the population remained well above this target. The species faces no immediate extinction threat mentioned in the provided text. Its changing diet serves as a biological indicator of oceanic warming trends. While commercial landings occur in southern Australia and New Zealand, the fish is not considered endangered. Conservation efforts focus on sustainable harvest limits rather than emergency protection measures.

Relatives and look-alikes

It is one of four extant species in the genus Arripis. It is often confused with Arripis truttacea, but can be distinguished by gill raker counts: this species has 33–40 rakers compared to 25–31 in A. truttacea. It also differs from Arripis xylabion by having a larger tail. Although called salmon or trout in common language, it is not related to true salmons or trouts of the family Salmonidae. It belongs to the order Scombriformes.

Questions people ask about Australian salmon

Good reading and sources

• Arripis trutta on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data