Southern bluefin tuna
Introduction
Management of southern bluefin tuna in the Pacific is the responsibility of the Commission for Conservation of Southern Bluefin Tuna (CCSBT). New Zealand is a founding member of the CCSBT.
Between the 1960s to 80s Japanese longliners were catching thousands of tonnes of southern bluefin tuna every year from NZ waters. Most of that catch was taken prior to the establishment of the Exclusive Economic Zone (EEZ).
The CCSBT reviews the southern bluefin tuna stock periodically and adjusts the Global Total Allowable Catch based on the latest data. New Zealand is allocated a proportion of the Global TAC. In 2021 NZ’s allocation increased by 14 tonnes, to 1102 tonnes for the years 2021-2023 inclusive.
The Minister of Oceans and Fisheries has an obligation to manage all catch from NZ waters within the allocation from the CCSBT. A technical adjustment to the stock assessment has increased New Zealand’s allocation by 186 tonnes to 1288 tonnes for 3 years, from 2024 to 2026 inclusive.
On 13 December 2023 Fisheries New Zealand (FNZ) issued a discussion document proposing an increase the Total Allowable Catch (TAC) and in doing so, increase the overall recreational allowance by 35 tonnes.
The New Zealand Sport Fishing Council submitted in support of FNZ proposed increase to the TAC and adding 35 t to the recreational allowance. The Council also continues to promote the current daily bag limit and responsible fishing practices in the tuna fishery.
Biology
Southern bluefin tuna can live to 30 years old and reach a maximum size of around 190 cm and 140 kg by 20 years old. The recreational all tackle world record is 158 kg from the Bay of Plenty.
Most southern bluefin tuna are mature by the age of 12 years.
Stock status
For a long time the reported catch worldwide was around 14,000 tonnes. The CCSBT agreed to reduce global catches by 20% in 2010 to 2011, to 9,449 tonnes.
The Commission has since determined that the spawning stock biomass of southern bluefin tuna is on track to meet the international management target of 30% of the unfished spawning stock biomass by 2035, at current catch levels.
A technical adjustment to the stock assessment has increased New Zealand’s southern bluefin tuna allocation by 14 tonnes for the next few years, from 2021-23 inclusive.
Management controls
A Total Allowable Commercial Catch (TACC) applies to commercial harvest of southern bluefin tuna. The Minister sets aside an annual allowance to provide for recreational fishing in NZ waters.
In April 2019 the Minister of Fisheries introduced a recreational bag limit of one southern bluefin tuna per person, per day.
Thanks largely to the hard work by members of the Waihau Bay Sport Fishing Club and the patience of returning anglers, we now have weigh station data for a high proportion of landed recreational catch.
In 2018 the Waihau Bay Sport Fishing Club asked anglers to limit their landed catch to one southern bluefin tuna per boat, per day. This voluntary measure is being promoted by other NZSFC clubs and is now included in the LegaSea FishCare guide on best practice methods for handling tuna.
Management processes
TAC review Southern bluefin tuna, February 2024.
Landing review Southern bluefin tuna, March 2024.