Albacore tuna

Albacore tuna in the south Atlantic Ocean is not overfished and not subject to overfishing.This stock is managed and assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Atlantic albacore have been caught in targeted fisheries since the 1950s. In the south, catches peaked at 40,000 tonnes in 1987 and again in 2001. They have since declined to around 15,000t. The last stock assessment was carried out in 2020, using data up to 2018. The next assessment is expected in 2023.Biomass (B) of the stock steadily declined from the 1960s to drop just below target levels (Maximum Sustainable Yield, MSY) in the mid-2000s. It has since improved and has been above BMSY since 2009. In the 2020 assessment it is estimated to be 158% of BMSY. Therefore, the stock is not in an overfished state.Fishing Mortality (F) increased to above sustainable levels in the 1980s, peaked in 2001 and then declined. It has been below the target level (FMSY) since 2003 and in the 2020 assessment was estimated to be 40% of FMSY. Therefore, the stock is not subject to overfishing.Both biomass and fishing pressure are at levels last seen in the 1980s. The probability of the stock not being overfished and not undergoing overfishing is 99.4%. Catches around the MSY level of 27,000t will keep the stock from being overfished or subject to overfishing through to 2033 with 90% probability. The catch limit is set to 24,000t. Provisional catch in 2020 was around 18,000t, and the 2016-2020 average is around 15,700t.Much about the reproductive biology of Atlantic albacore is still poorly known, which undermines the advice of the scientific committee as this is critical for the stock assessment currently being used. A research program is underway to increase biological knowledge to improve the quality of scientific advice and reduce the uncertainty associated with it.

Management of the southern Atlantic albacore stock appears to be keeping it in a healthy state. However, observer coverage in most fisheries targeting albacore is too low and needs to be improved.Tuna, marlin, and swordfish are highly migratory species, found on the high seas and in numerous countries' waters. This makes harmonised and effective management challenging. Regional Fisheries Management Organisations (RFMOs) are responsible for monitoring and managing these stocks on behalf of the countries that access them. However, the degree to which management is implemented, monitored and enforced by each country varies significantly.This stock is managed and assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). There is no Harvest Control Rule for this fishery. The main management measure is a catch limit (Total Allowable Catch, TAC).The south Atlantic albacore TAC for 2017-2022 is 24,000t, with individual catch limits assigned to each country. This increases to 28,000t for 2023-2026. Catches of up to 28,000t are expected to keep the stock from being overfished or subject to overfishing through to 2033 with 83% probability. Since the late 1990s, catch limits have been set for this stock in line with the best estimates for Maximum Sustainable Yield. Management therefore appears to be following scientific advice.Catches have generally stayed within the limits. Provisional catch in 2020 was around 18,000t, and the 2016-2020 average is around 15,700t. In 2016, countries were required to immediately improve their catch reporting systems to ensure accurate and validated catch and effort data for southern albacore. Most albacore is caught by longline. The mandatory level of observer coverage in Atlantic longline fisheries is low, at just 5%, rising to 10% in 2022. Many countries are not achieving this level. This is below the recommended minimum of 20%. Monitoring and enforcement therefore requires improvement.In terms of enforcement and compliance with management measures: in 2016 ICCAT passed measures to strengthen and streamline its compliance assessment process and to develop a scheme of responses to non-compliance. There is also a list of vessels authorised to fish for tuna and tuna-like species in the ICCAT area, and a list of vessels caught carrying out Illegal, Unreported or Unregulated activities. At-sea transhipment is prohibited unless pre-authorised and the vessel has an observer on board. Vessel Monitoring Systems are required for all vessels over 24m, but smaller vessels are less well monitored.

Albacore in the south Atlantic are mainly caught by longlining. While longlining is unlikely to have habitat impacts, it can have a bycatch of highly vulnerable species such as sharks, turtles, and seabirds.Around 80% of south Atlantic albacore catches are by surface-drifting longline. Monitoring and reporting of bycatch in fisheries managed by ICCAT is poor. Most data comes from scientific observers on vessels. Scientific recommendations are that 20% of a fishery should be observed for accurate data. ICCAT only requires coverage of 5%, increasing to 10% in 2022. Many fleets are not reaching this level. This makes it difficult to assess the impact of these fisheries on vulnerable species.There is a bycatch of loggerhead, leatherback and olive ridley turtles in longline and purse seine fisheries. According to the IUCN Red List, loggerhead turtles are endangered in the north east Atlantic and leatherbacks are endangered in the north west Atlantic and critically endangered in the southwest Atlantic. Observer data for 2020 indicates 20 dead discards of turtles, 1,308 live discards and 20 discards of unknown status. Given the poor observer coverage, this is likely to be an underestimate of the total catch. Post-release mortality is 1-4%. Longliners are required to safely unhook and release alive turtles, and purse seiners must avoid encircling them. Other scientifically recommended mitigation measures, such as using finfish bait and large circle hooks, are not mandated.Albatrosses and large petrels are amongst the most threatened groups of birds in the world, due in a large part to the impacts of bycatch in longline fisheries. In the Atlantic Ocean, bycatch of seabirds is most problematic in waters south of 25°S, which coincides with the greatest densities of albatrosses and large petrels. Observer data for 2020 indicates 195 dead discards of seabirds, 21 live discards and 2 discards of unknown status. Species recorded included the wandering albatross, the endangered sooty albatross, and the black-browed albatross. Given the poor observer coverage, this is likely to be an underestimate of the total catch. A recent assessment estimated that approximately 30,000-40,000 seabirds were killed by longlining in the Southern Hemisphere (including south Atlantic) between 2012 and 2016. The required mitigation measures do not follow recommended best practice by ACAP (the Agreement on the Conservation of Albatrosses and Petrels). ICCAT requires one or more measures from a set list of options, including weighted hooks, bird scaring lines and night setting, depending on location and target species. ACAP recommends the simultaneous use of all three, or hook-shielding or underwater bait setting devices.Sharks are both bycaught and targeted in longline fisheries in the Atlantic. Bycatch species include the critically endangered scalloped hammerhead, silky shark, and the bigeye thresher, which is endangered in Europe and the Mediterranean. Observer data for 2020 indicates 1,098 dead discards of sharks and 1,109 live discards. Given the poor observer coverage, this is likely to be an underestimate of the total catch. There are some mitigation measures, such as restrictions on finning, but no gear-specific measures. This is in spite of repeated recommendations from the scientific committee to use circle hooks, which have been shown to increase survival of shortfin mako, blue marlin and swordfish if accidentally caught. Catching silky sharks, hammerheads, oceanic whitetips, and bigeye threshers is prohibited, and catching other thresher species is discouraged. Shortfin mako, which is heavily overfished, can be caught and retained. However, measures are came into force in 2022 to end overfishing of this species.There are no specific management measures to protect marine mammals, including cetaceans. ICCAT has not prioritised collecting data on mammal bycatch to date. More needs to be done to understand and reduce the impact of ICCAT fisheries on marine mammals.