Source: Patterson, H, Larcombe, J, Woodhams, J and Curtotti, R 2020, Fishery status reports 2020, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra. CC BY 4.0.
The fishery continues to be managed in accordance with the Southern Bluefin Tuna Fishery Management Plan 1995. It is managed through a system of output controls in the form of individually transferable quotas, which are allocated as SFRs under the management plan. The performance criteria detailed in the management plan were all met in 2019-20.
The Commission for the Conservation of Southern Bluefin Tuna sets an annual global total allowable catch. From the global total allowable catch national allocations are provided to all members. Prior to the commencement of the fishing season (1 December to 30 November), AFMA determines a total allowable catch of southern bluefin tuna for the domestic fishery based upon Australia’s national allocation.
The Southern Bluefin Tuna Fishery is an approved wildlife trade operation for the purposes of Parts 13 and 13A of the Environment Protection and Biodiversity Conservation Act 1999 until 11 November 2022.
Analysis of Performance
Performance – quota setting
The domestic total allowable catch for the 2019–20 Southern Bluefin Tuna fishing season was 6,165 tonnes. When undercatch from the previous season is added the effective total allowable catch becomes 6,283 tonnes.
The AFMA Commission set the 2019–20 total allowable catch after accepting an undertaking from the Australian Southern Bluefin Tuna Industry Association to voluntarily set aside 250 tonnes of the quota to account for other sources of mortality, including that from recreational fishing.
The total catch in the fishery, for the 2019–20 fishing season, was 6,324 tonnes. This exceeded the effective total allowable catch by approximately 41 tonnes. Australia committed to reducing the total allowable catch for the following season by the same amount.
Concession holders in the ranching sector of the fishery took approximately 88 per cent of the catch. The remaining catch was taken by longline vessels working primarily off the New South Wales south coast.
During 2019-20, the Department of Agriculture, Water and the Environment contracted a major survey to quantify recreational fishing catch of Southern Bluefin Tuna so that arrangements could be made to account for that catch against Australia’s national allocation. The survey found that approximately 270 tonnes were caught by recreational fishers in December 2018 – November 2019. In response, the Australian Government has determined that 5 per cent of Australia’s national allocation will be set aside to cover recreational catch in the future and AFMA is now implementing that decision.
Performance – status of fish stocks
The Commission for the Conservation of Southern Bluefin Tuna management procedure specifies that a full quantitative stock assessment should be undertaken every three years. The 2017 stock assessment suggested that the stock remains at a low state, estimated to be 13 per cent of the initial spawning stock biomass, and below the level to produce maximum sustainable yield.
The 2019 Commission for the Conservation of Southern Bluefin Tuna Extended Scientific Committee meeting advised that the 2019 reconditioned operating models suggest that the spawning stock biomass in 2018 was 17 per cent of the initial biomass (15-21 per cent), up from an historic low of 5 per cent in 2009. A full stock assessment will be undertaken in 2020.
Internationally, the management procedure is considered a success in that it has been instrumental in addressing the previous sharp decline in the stock and facilitating recovery towards agreed targets.
Performance – economic returns
The majority of the southern bluefin tuna total allowable catch continues to be taken by the purse seine sector in South Australia, for subsequent grow out by the ranching sector. Historically the purse seine catch was taken in the Great Australian Bight south of Ceduna. However, in recent years the majority of the catch has been taken in areas to the east of Kangaroo Island. As these areas are closer to the aquaculture zone in Port Lincoln, the time the fish spend in the tow cage before transfer to farms has been reduced.
The amount of fish taken by longliners on the east coast depends primarily on access to available quota from the ranching sector and the seasonal availability of fish, but was also heavily influenced in mid-2020 by extremely high freight costs and decreased international demand as a result of COVID-19. In the 2018–19 fishing season 783 tonnes was caught compared to 1,034 tonnes in the previous season.
A management procedure is a pre-agreed set of rules that can specify changes to the total allowable catch based on updated monitoring data. In 2011 the Commission for the Conservation of Southern Bluefin Tuna adopted a management procedure to guide its global total allowable catch setting. The current management procedure is tuned to a 70 per cent probability of rebuilding the stock to the interim rebuilding target reference point of 20 per cent of the original spawning stock biomass by 2035.
The Commission for the Conservation of Southern Bluefin Tuna has agreed a new management procedure to guide the setting of total allowable catches from 2021. The new management procedure is tuned to rebuilding the stock to a target reference point of 30 per cent of the original spawning stock biomass by 2035, an increase over the original 20 per cent biomass.