Southern bluefin tuna
What to check for
Location
Southern Ocean
Technical location
Atlantic, Antarctic, Indian Ocean, Antarctic and Southern, Pacific, Antarctic, All areas, All areas, All areas
Caught by
Hook & line (longline), Hook & line (pole & line), Net (purse seine on aggregating devices or free-schooling fish)
Rating summary
Southern bluefin tuna is listed as Endangered on the IUCN Red List and therefore is a Fish to Avoid.Rating last updated January 2024
Technical consultation summary
Southern bluefin tuna is listed as Endangered on the IUCN Red List and therefore is a default red rating. It is still in a heavily overfished state, but a rebuilding plan seems to have been effective and the stock is gradually recovering. The last stock assessment was carried out in 2023 using data up to 2022, and the next one is expected in 2026. In 2023, the stock was thought to be at 23% of unfished levels, and 85% of levels associated with Maximum Sustainable Yield (MSY). The Marine Conservation Society considers 20% of unfished levels to be equivalent to Blim. This means that the increases in abundance have led to the stock raising above Blim, however the stock is still at an increased risk of suffering reduced reproductive capacity. Catch in 2022 was 17,138 tonnes. This was equivalent to 46% of the level associated with MSY (F/Fmsy = 0.46). The stock is therefore not subject to overfishing. The stock has been successfully rebuilt to its interim target, which was 20% of unfished levels by 2035. The new objective is now to reach a level associated with MSY, which is 30% of unfished levels, by 2035. Stock projections indicate that SBT is on track to meet this target. The Total Allowable Catch (TAC) has been increased from 17,647 tonnes per year in 2021- 2023 to 20,647 tonnes per year for 2024 – 2026. Observer coverage is too low and there are some compliance concerns in this fishery. The CCSBT aims for 10% of coverage of each gear type, but in 2021 and 2022, this target was not met. Scientific recommendations are for a minimum of 20%, and therefore current observer coverage is inadequate. In this fishery there are significant concerns about the bycatch of endangered seabirds. Most catches are by longline. Estimates indicate that, on average, at least 5,000 birds were killed by SBT longliners each year from 2017-2020. The SBT fishery has more overlap with albatrosses than any other tuna fishery, covering 22 albatross species as well as 7 petrel species. This includes endangered and critically endangered species such as the Tristan albatross and sooty albatross, whose declines are thought to be owing to longline fishing. There are some mitigation measures to reduce bycatch, but compliance is too low. In addition, mitigation does not follow recommended best practice by ACAP (the Agreement on the Conservation of Albatrosses and Petrels).
