Estimating the national fishing mortality of southern bluefin tuna Thunnus maccoyii from Australia’s recreational fishing sector

Southern Bluefin Tuna (SBT) Thunnus maccoyii (Castelnau) comprises a single, highly migratory stock that is managed internationally by the Commission for the Conservation of Southern Bluefin Tuna (CCSBT). CCSBT members are expected to provide estimates of all sources of fishing mortality within their allocation, including commercial and recreational catch and any additional mortality associated with discarded or released catch. In the absence of a national registration system for the SBT recreational fishery, which would provide a comprehensive sampling frame, an ensemble of off-site and on-site survey methods was used across five state jurisdictions to provide the first species-specific national assessment of a recreational fishery in Australia. The national harvest of SBT for the 12 months from December 2018 to November 2019 by the recreational sector was 270 t (239–301 t: 95% CL). This survey has resulted in the first official recognition of a catch set aside to the recreational sector for an Australian Commonwealth managed fishery with 5% per cent of the CCSBT allocation to Australia now set aside for the sector.