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Australia's Albacore stocks in the South Pacific Ocean and Indian Ocean are both sustainable. The two biologically independent stocks are managed by separate international commissions as a resource shared by many countries including Australia.

Albacore in the Indian Ocean and South Pacific Ocean are considered to be two distinct biological stocks and are managed by separate regional fisheries management organisations. The single Indian Ocean stock falls under the jurisdiction of the Indian Ocean Tuna Commission (IOTC) while the South Pacific Ocean stock falls under the jurisdiction of the Western and Central Pacific Fisheries Commission (WCPFC) and the Inter American Tropical Tuna Commission (IATTC), separated at 130–150º West. These commissions are international organisations established to manage highly migratory fish species within their defined geographic ranges. 

Albacore are distributed globally but migrate within ocean basins in association with oceanic gyres. Given that the Indian Ocean contains only a single oceanic gyre, a single stock of Albacore has been assumed for the Indian Ocean assessments [Rice 2022]. This assumption is supported by recent genetics and otolith microchemistry research [Davies et al. 2020]. A separate genetic and morphometric study has also identified distinct stocks of Albacore in the southwest Indian Ocean and the southeast Atlantic Ocean [Nikolic et al. 2020]. 

In the Pacific Ocean, two distinct stocks of Albacore (North Pacific and South Pacific) are thought to exist, generally associated with the two oceanic gyres north and south of the equator [Nikolic et al. 2017]. There is some recent evidence for genetic structuring in the western and central south Pacific Ocean [Anderson et al. 2019], however Albacore in the South Pacific Ocean are still considered to be one stock.

Here, stock status is presented at the biological stock level for the two stocks fished by the Australian fisheries—Indian Ocean and South Pacific Ocean.

Indian Ocean

The Indian Ocean biological stock is fished by Australian fishers endorsed to fish in the Western Tuna and Billfish Fishery (Commonwealth), as well as by vessels from numerous other international jurisdictions.

The assessments undertaken by the Indian Ocean Tuna Commission take into account information from all jurisdictions, including the high seas. The most recent assessment [IOTC 2022] estimates that spawning biomass in 2020 was 36% (80% confidence interval 26–45%) of the assumed unfished level. This is above the Commonwealth limit reference point (LRP) of 20% of the unfished level. The biological stock is therefore not considered to be recruitment impaired. The assessment estimated that fishing mortality in 2020 was 68% (80% confidence interval 42–94%) of the level that would produce maximum sustainable yield (MSY). This level of fishing mortality is unlikely to cause the stock to become recruitment impaired.

On the basis of the evidence provided above, the Indian Ocean biological stock is classified as a sustainable stock.

South Pacific Ocean

The South Pacific Ocean biological stock is fished by Australian fishers endorsed to fish in the Eastern Tuna and Billfish Fishery (Commonwealth), as well as by vessels from other members of the Western and Central Pacific Fisheries Commission. 

The assessments undertaken for the Western and Central Pacific Fisheries Commission account for information from all jurisdictions. The most recent assessment [Castillo-Jordán et al. 2021] covers the entire Pacific Ocean south of the equator, while previous assessments did not include the eastern Pacific Ocean.

The recent (2016–2019) depletion levels estimated by the 2021 assessment are the lowest across the model time period. The median recent spawning biomass was 52% of the levels predicted to occur in the absence of fishing (80% confidence interval 41–57% across the grid of models used) [WCPFC 2021]. The recent depletion estimate (2016–2019) is above the Commonwealth limit reference point (LRP) of 20% of the unfished level. The current biological stock is, therefore, not considered to be recruitment impaired.  

Fishing mortality of adult South Pacific Albacore is estimated to have increased over most of the assessment period, with a record high in the last year of assessment (2019). The median 2016–2019 fishing mortality was 24% of the level that would produce MSY (80% confidence interval 15–37%). This level of fishing mortality is unlikely to cause the stock to become recruitment impaired. 

Further to these assessment results, stochastic projections that assume continued fishing at recent (2016–2019) levels show a steep and rapid future decline in biomass towards the 20% LRP in 2021, followed by an increase in biomass thereafter [WCPFC 2021]. However, more recent analysis suggests the magnitude of this projected decline is exaggerated [Scott et al. 2023].

On the basis of the evidence provided above, the South Pacific Ocean biological stock is classified as a sustainable stock. 

Albacore biology [Farley et al. 2012; Williams et al. 2012; Farley et al. 2014]

Distribution of reported commercial catch of Albacore in 2021

Commonwealth – Commercial (Catch). Catches reported for the Indian Ocean Tuna Commission and Western and Central Pacific Fisheries Commission are for 2021, the most recent year available.

Commonwealth – Recreational. The Australian Government does not manage recreational fishing in Commonwealth waters. Recreational fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters, under its management regulations.

Commonwealth – Indigenous. The Australian Government does not manage non-commercial Indigenous fishing in Commonwealth waters, with the exception of the Torres Strait. In general, non-commercial Indigenous fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters.

Commercial catch of Albacore - note confidential catch not shown

1. Anderson, G, Hampton, J, Smith, N and Rico, C 2019, Indications of strong adaptive population genetic structure in albacore tuna (Thunnus alalunga) in the southwest and central Pacific Ocean. Ecology and Evolution, 9:10354–10364.
2. Castillo-Jordán, C, Hampton, J, Ducharme-Barth, N, Xu, H, Vidal, T, Williams, P., Scott, F, Pilling, G and Hamer, P 2021, Stock assessment of South Pacific albacore tuna, working paper WCPFC-SC17-2021/SAWP-02 Rev 2, WCPFC Scientific Committee 17th regular session, online meeting, 11 to 19 August 2021.
3. Davies, C, Marsac, F, Murua, H, Fraile, I, Fahmi, Z, Farley, J, Grewe, P, Proctor, C, Clear, N, Eveson, P, Lansdell, M, Aulich, J, Feutry, P, Cooper, S, Foster, S, Rodríguez-Ezpeleta, N, Artetxe-Arrate, I, Krug, I, Mendibil, I, Agostino, L, Labonne, M, Nikolic, N, Darnaude, A, Arnaud-Haond, S, Devloo-Delva, F, Rougeux, C, Parker, D, Diaz-Arce, N, Wudiano, Ruchimat, T, Satria, F, Lestari, P, Taufik, M, Priatna, A and Zamroni, A 2020, Study of population structure of IOTC species and sharks of interest in the Indian Ocean using genetics and microchemistry: 2020 final report to IOTC, final report submitted to the Indian Ocean Tuna Commission, Victoria, Seychelles.
4. Farley, JH, Hoyle, SD, Eveson, JP, Williams, AJ, Davies, CR and Nicol SJ 2014, Maturity ogives for South Pacific albacore tuna (Thunnus alalunga) that account for spatial and seasonal variation in the distributions of mature and immature fish, PLoS ONE 9(1): e83017 10.1371/journal.pone.0083017.
5. Farley, JH, Williams, AJ, Davies, CR, Clear, NP, Eveson, PJ, Hoyle, SD and Nicol, SJ 2012, Population biology of albacore tuna in the Australian region, FRDC Project No. 2009/012 final report, CSIRO Marine and Atmospheric Research, Hobart.
6. Indian Ocean Tuna Commission 2022, Report of the twenty-fifth session of the IOTC Scientific Committee, Seychelles, 5-9 December 2022.
7. Larcombe, J, Blake, S, Patterson, H and Dylewski, M 2022, Eastern Tuna and Billfish Fishery, in Patterson, H, Bromhead, D, Galeano, D, Larcombe, J, Timmiss, T, Woodhams, J and Curtotti, R (eds), Fishery status reports 2022, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.
8. Nikolic, N, Montes, I, Lalire, M, Puech, A, Bodin, N, Arnaud-Haond, S, Kerwath, S, Corse, E, Gaspar, P, Hollanda, S, Bourjea, J, West, W and Bonhommeau, S 2020, Connectivity and population structure of albacore tuna across southeast Atlantic and southwest Indian Oceans inferred from multidisciplinary methodology. Scientific Reports, 10:15657, doi:10.1038/s41598-020-72369-w.
9. Nikolic, N, Morandeau, G, Hoarau, L, West, W, Arrizabalaga, H, Hoyle, S, Nicol, SJ, Bourjea, J, Puech, A, Farley, J, Williams, AJ and Fonteneau A 2017, Review of albacore tuna, Thunnus alalunga, biology, fisheries and management. Reviews in Fish Biology and Fisheries, 27(4): 775–810.
10. Patterson, H, Bromhead, D and Dylewski, M 2023, Western Tuna and Billfish Fishery, in Butler, I, Patterson, H, Bromhead, D, Galeano, D, Timmiss, T, Woodhams, J and Curtotti, R (eds), Fishery status reports 2023, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.
11. Rice, J 2022, Stock assessment of albacore tuna in the Indian Ocean using Stock Synthesis, working paper IOTC-2022-WPTmT08-09, Indian Ocean Tuna Commission 8th Working Party on Temperate Tunas, Virtual Meeting, 25-29 July 2022.
12. Scott, R, Yao, N, Scott, F, Natadra, R, Hoyle, S, Hamer, P, Hampton, J and Pilling, G 2023, Factors contributing to recent and projected declines in south Pacific albacore stock status, WCPFC Scientific Committee Nineteenth Regular Session, WCPFC-SC19-2023/MI-IP-08, Palau.
13. Western and Central Pacific Fisheries Commission 2021, Commission for the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean: Seventeenth Regular Session of the Scientific Committee - Summary Report, electronic meeting, 11-19 August 2021.
14. Williams, AJ, Farley, JH, Hoyle, SD, Davies, CR and Nicol SJ 2012, Spatial and sex-specific variation in growth of albacore tuna (Thunnus alalunga) across the South Pacific Ocean, PLoS ONE 7(6): e39318, doi:10.1371/journal.pone.0039318.