Australian salmon (Arripis trutta): Population structure, reproduction, diet and composition of commercial and recreational catches. Final report to the Fisheries Research & Development Corporation for Project No. 2006/018 and 2008/056
Stewart, J., Hughes, J., McAllister, J., Lyle, J. and MacDonald, M., 2011. Australian salmon (Arripis trutta): Population structure, reproduction, diet and composition of commercial and recreational catches. Final report to the Fisheries Research & Development Corporation for Project No. 2006/018 and 2008/056. Industry & Investment NSW – Fisheries Final Report Series No. 129. Cronulla, NSW, Australia. 257 pp.
Management of eastern Australian salmon has been hampered by a lack of understanding of the species’ basic biology, life history, stock structure and fisheries. The research documented in this report addresses these information gaps for eastern Australian salmon across its distribution in south-eastern Australia. This information, which is synthesised into a model for cross-jurisdictional monitoring and assessment, is now available to fisheries managers nationally to use in the management of this species.
The new information on the diet and consumption rates of this species has addressed the concerns of various stakeholders (commercial fishers, recreational fishers, fisheries managers) in NSW that schools of salmon were having large negative impacts on the juveniles of their target species. The study concluded that the majority of the diet of Australian salmon consisted of small 'baitfish' species, mainly sardines, anchovies, scads and mackerel, which are resilient to relatively high rates of predation. Analysis of otolith chemistry, tagging data and fish morphometrics indicated that salmon in south-eastern Australia should be considered as a unit stock for management purposes.
Salmon grow rapidly and reach ~ 16 cm fork length (FL) after one year and ~ 27 cm FL after 2 years. Females grow slightly faster and larger than males after ~ 5 years of age. The largest fish sampled was 65 cm FL and was estimated to be 8 years old. The oldest fish sampled was estimated to be 12 years old and was 59 cm FL. Spawning occurs between October and March, and occurs earlier in more northern latitudes. Fish in spawning condition were recorded as far north as Coffs Harbour in NSW, some 740 km northwards of the previous northernmost observed spawning location. Spawning also occurs in Victoria and NSW waters; however no sexually mature fish have been sampled from Tasmanian waters.
In addition to the biology and life-history aspects of Australian salmon, this study examined the importance of Australian salmon to the aboriginal people of NSW. An outcome from this work should be better consultation and incorporation of aboriginal needs and interests in the management of this species.