Capture method — Purse seine (FAD & Free School)
Capture area — Atlantic Ocean (FAO 21,27,31,34,41 and 47)
Stock area — Atlantic
Stock detail — All Areas
Updated: December 2019
Yellowfin and other tuna stocks in the Atlantic are assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). A new stock assessment was carried out in 2019. Although there are large uncertainties, it found that the stock was not overfished (B2018:BMSY = 1.17) or undergoing overfishing - although fishing mortality was close to the threshold (F2018:FMSY = 0.96). This is an improvement from the previous assessment, when the stock was in an overfished state, but this is not owing improved data in the model, not sock recovery. Biomass has continuously declined throughout the lifetime of the fishery, while fishing mortality has been increasing since the mid-2000s.
Projections indicate that catch levels at or below 120,000t (the estimated Maximum Sustainable Yield) would maintain healthy biomass through to 2033. However, and catches have exceeded 120,000 t every year since 2015 (2018 catch was 135,689t), and if this continues the stock will decline. If catches remain around 140,000 tonnes, there is only a 20% probability that the stock will be above BMSY and below FMSY by 2030. Given that this is also in excess of Total Allowable Catch (110,000t), existing conservation and management measures appear to be insufficient, and the scientific committee recommends that they be strengthened. The estimated MSY may be below what was achieved in past decades because overall selectivity has shifted to smaller fish. A multi-annual management programme has been in place for bigeye and yellowfin since 2012 and a closure and restrictions on the purse seine fishery exist off the west coast of Africa to reduce juvenile catches of bigeye and yellowfin, but this has had little impact so in 2019 the closure was extended to cover the whole convention area.
About 69% of the yellowfin catch is taken in purse seine fisheries, most setting on free schools, but with FAD sets increasing. FAD sets catch a greater amount of juvenile fish including yellowfin and bigeye tuna, the latter of which is significantly overfished. The proportion of bycatch of vulnerable species is relatively low in purse seine fisheries, (e.g.. less than 1.5% for sharks in the Atlantic), yet the overall catch is still significant (especially sharks) and better data collection is needed. The status of some sharks is in the area is unknown and some are overexploited. FADs can also entangle sharks and turtles, but FAD construction and overall management is improving. In 2019 it was agreed to increase observer coverage for large purse seiners targeting tropical tunas to 100% coverage year-round rather than just during the FAD closures, which is a positive improvement.
Commercial buyers should establish what measures the flag state relating to their source is taking to improve data collection, research, monitoring and management of their fisheries and specify the need to see ongoing, demonstrable improvements. Large buyers should consider supporting such improvements. MCS also advocates specifying the need for supplying vessels, in particular purse seiners, to register on the ISSF Proactive Vessel Register.
Some fleets are in Fishery Improvement Projects (FIPs) which are making progress on improving elements of the fishery. More info about these FIPs is available from fisheryprogress.org](https://fisheryprogress.org/directory).
Tuna belong to the family Scombridae. They are large, oceanic fish and are seasonally migratory, some making trans-oceanic journeys. Yellowfin are found throughout the world’s tropical and subtropical seas, except the Mediterranean. They often form large, size specific schools, frequently associated with dolphins or floating objects. Yellowfin is a large fast growing species, reaching maximum sizes of 240cm in length, 200kg in weight and an age of 8 years. They mature when 2 to 5 years old and mainly spawn in summer. Smaller fish are mainly limited to surface waters, while larger fish are found in surface and deeper waters, but rarely below 250m. Yellowfin has medium resilience to fishing.
Criterion score: 0 info
Yellowfin and other tuna stocks in the Atlantic are assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Yellowfin tuna have been exploited by three major gears (longline, bait boat and purse seine fisheries) and by many countries throughout its range.
A new stock assessment was carried out in 2019. Although there are large uncertainties, it found that the stock was not overfished (B2018:BMSY = 1.17) or undergoing overfishing - although fishing mortality was close to the threshold (F2018:FMSY = 0.96). This is an improvement from the previous assessment, when the stock was in an overfished state. It is important to note that this is not owing to stock recovery, but because of improved data in the model. Biomass has continuously declined throughout the lifetime of the fishery, including between 2014 and 2018, while fishing mortality has been increasing since the mid-2000s.
Overall Atlantic catches declined by nearly half from their peak in 1990 (190,000t) to 109,000t in 2013, subsequently rising to an average of 140,000 tonnes from 2016-2018. 2018 catch was 135,689t, 75% of which was from the east Atlantic. Projections indicate that catch levels at or below 120,000t (the estimated Maximum Sustainable Yield) would maintain healthy biomass through to 2033. However, the most recent catch estimates suggest that overall catches have exceeded 120,000 t every year since 2015, and if this continues the stock will decline. If catches remain around 140,000 tonnes, there is only a 20% probability that the stock will be above BMSY and below FMSY by 2030. Given that this is also in excess of Total Allowable Catch (110,000t), existing conservation and management measures appear to be insufficient, and the scientific committee recommends that they be strengthened.
The majority of catches are from the east Atlantic purse seine fishery, about a third of which is on Fish Aggregating Devices (FADs). The scientific committee highlighted that increased catches of small yellowfin (and small bigeye, as they are caught together on FADs) will have negative effects on stock size and future harvest rates. Therefore, effective measures should be introduced to reduce fishing mortality on small yellowfin and bigeye tunas.
In the previous assessment, there were uncertainties in stock structure, natural mortality, and growth. As hoped, the ongoing Atlantic Ocean Tropical Tuna Tagging Programme (AOTTP) and Pacific yellowfin tagging studies were able to provide data to address a number of these uncertainties, highlighting the value of tagging programmes for managing tuna fisheries.
Criterion score: 0.75 info
Most tuna stocks range across and are accessed by numerous coastal states, making harmonised and effective management of these individual stocks very difficult. To try and address this, intergovernmental Regional Fisheries Management Organisations (RFMOs) have been established. There are five main tuna RFMOs worldwide and it is their responsibility to carry out data collection, scientific monitoring and management of these fisheries. This stock is managed and assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Whilst the RFMOs are responsible for the development of management and conservation measures, the degree to which they are implemented, monitored and enforced still varies significantly between coastal states. There remain large data deficiencies in most tuna and billfish fisheries, particularly with regards to fine scale spatial and temporal data for both target and especially for vulnerable bycatch species. For this reason, it is important to choose tuna that has been caught by vessels that are well regulated by their flag state.
The TAC (Total Allowable Catch) for yellowfin from 2012 onwards is 110,000 t, and keeping catches at 120,000t or less is expected to maintain healthy stock status through to 2033. However, in recent years the TAC has been exceeded by 17-37%, and if this level of fishing pressure is maintained the stock is projected to decline. In 2018 and again in 2019 the scientific committee suggested that existing conservation and management measures appeared to be insufficient and needed to be strengthened.
The following measures are in place for bigeye, skipjack and yellowfin:
There is a tagging programme to improve stock assessments for tropical tunas and gauge effectiveness of management measures for these species. This helped to improve the quality of the 2019 yellowfin assessment.
A multi-annual management programme has been in place for bigeye and yellowfin since 2012, and eastern skipjack since 2015. Fishing for these species using aggregation devices, including FADs, was prohibited from 1st January to 28th February in an area off the west African coast to reduce catches of juvenile bigeye and yellowfin, for the rest of the year vessels were limited to 500 FADs. This failed to reduce the mortality of juvenile bigeye and yellowfin tuna so in 2019, to address this, the number of FADs was reduced from 500 to 350 in 2020 and 300 in 2021. The FAD closure was extended to the full convention area, lasting 2 months in 2020 and 3 months in 2021.
Countries must have FAD Management Plans that improve understanding of FADs and limit their impacts on the ecosystem.
ICCAT maintains a list of vessels over 20m authorised to fish for these species, although other vessels may retain them as bycatch as long as the country sets limits on this and doesn’t exceed its quota.
Countries are encouraged to reduce discards.
Increased harvests on FADs may have negative consequences for adult yellowfin and bigeye tuna, as well as other by-catch species. The increasing use of fish aggregation devices (FADs) in skipjack fisheries since the early 1990s has changed the species composition of free schools. It is noted that, in fact, free schools of mixed species were considerably more common prior to the introduction of FADs. Furthermore, the association with FADs may also have an impact on the biology (growth rate, plumpness of the fish) and on the ecology (distances, movement orientation) of skipjack and yellowfin (the “ecological trap” concept). To increase long term sustainable yield, the scientific committee continues to recommend that effective measures be found to reduce FAD-related and other fishing mortality of small yellowfin tuna.
Other management measures of note include:
In 2019 ICCAT increased observer coverage: large purse seiners targeting tropical tunas must have 100% coverage year round rather than just during the FAD closures, and longline coverage will increase from 5% to 10% in 2022. However, the 5% coverage was not well complied with or enforced by some fleets (although others exceeded it), and even this increase falls short of recommendations for a minimum of 20% for accurate reporting of bycatch. However, standards for electronic monitoring are to be developed by 2021. Purse seine and longline vessels over 20m long are encouraged to increase their observer coverage from the required minimum, and some have. Vessel Monitoring Systems are required for all vessels over 24m.
In 2015 a working group was formed to look at ways to reduce juvenile catches of bigeye and yellowfin tuna caught in FAD fishing.
Drift nets are banned in the Mediterranean.
ICCAT maintains lists of vessels authorised to fish for tuna and tuna-like species in the ICCAT area, and those caught carrying out Illegal, Unreported or Unregulated activities.
At-sea transhipment is prohibited unless pre-authorised and the vessel has an observer on board.
In 2017 ICCAT banned the discarding of skipjack, yellowfin and bigeye.
In 2016 the Commission passed measures to strengthen and streamline its compliance assessment process and to develop a scheme of responses to non-compliance.
Criterion score: 0.75 info
Purse seiners accessing Atlantic yellowfin fisheries are mainly from the EU in the East Atlantic, and Venezuela in the West. They caught around 91,000 tonnes of yellowfin in 2018. The majority of catches are still made on free schooling fish (about 48% of total yellowfin catch), but the use of Fish Aggregation Devices (FADs) is increasing (21% of total catch). Purse seining is commonly an industrial scale fishery used to catch tuna destined for canneries. These fisheries target smaller fish that aggregate close to the surface, whereas longliners target larger fish that inhabit deeper waters. Many juvenile fish are often caught in purse seine fisheries, mainly skipjack, yellowfin and bigeye. When a high proportion of young fish are removed from a population, the potential maximum catch from a fishery is reduced. The recent average weight in European purse seine catches, which represent the majority of the landings, has declined to about half of the average weight of 1990, at least in part due to the use of FADs and the increased catches of small yellowfin. A decline in average weight and size is also evident in eastern tropical bait boat catches, although longline catches have not seen the same trend. The ICCAT Scientific Committee continues to recommend that effective measures be found to reduce FAD-related and other fishing mortality of small yellowfin and bigeye.
Purse seining is also associated with bycatch of species such as sharks, turtles and marine mammals, although less so than longlining. Whilst bycatch may comprise a small proportion of the total catch, the high volume of tuna that is caught means that it can still be significant for these vulnerable species. FAD-associated purse seining encounters higher bycatch rates compared with sets on free-schools, and higher proportions of juvenile tuna. The widespread use of FADs is of concern due to the unknown impacts such gear might have on natural species composition of tuna schools, migratory patterns, growth rates and predation rates of affected pelagic species. Poorly designed FADs can also entangle animals.
ICCAT aims to take an ecosystem-based and precautionary approach to fisheries management. In order to minimize the ecological impact of FADs, in particular the entanglement of sharks, turtles and other non-targeted species, and the release of synthetic persistent marine debris, countries must use non-entangling FADs and phase out non-biodegradable FADs. Countries must have FAD Management Plans that improve understanding of FADs and limit their impacts on the ecosystem.
For sharks: Countries are required to develop and submit National Plans of Action for the conservation and management of sharks. Sharks must be fully utilised (e.g. no removal of fins); must be released wherever possible (if not being directly targeted); and countries must try to minimise bycatch of sharks (although no gear-specific measures are identified). 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 if over 180cm for males and 210cm for females, otherwise, they must be released unharmed. An updated assessment in 2019 indicated that shortfin mako is unlikely to recover to healthy levels until 2070, unless size restrictions combined with a fixed Total Allowable Catch were introduced. The maximum catch that would allow recovery by 2070 with a reasonable probability (60%) was 300 tonnes. Regardless of management measures, the stock will continue to decline until 2035. However, in 2019 ICCAT failed to reach agreement on measures to protect this species. Catch limits are now in place for both northern (39,102t as of 2016) and southern (28,923t as of 2016) blue sharks, with the northern TAC being allocated out to countries - a first for ICCAT shark stocks. If exceeded, the commission has committed to reviewing the effectiveness of its blue shark management measures (although preliminary catch of northern blue shark in 2016 was 42,117 t). Porbeagle is overfished throughout the Atlantic, significantly so in the northwest, and for the north Atlantic overall it is predicted to take at least 30 years to recover if there was zero fishing mortality. The main porbeagle-directed fisheries (EU, Uruguay and Canada) have closed, and ICCAT have a recommendation to release live porbeagle unharmed, but it is still caught incidentally and discarded, and also landed by other fleets. Currently there is not enough data to properly assess the status of many pelagic sharks (no assessments have been carried out for the Mediterranean) and more work is needed to understand the effects of entanglement in FADs.
For turtles: Purse seiners must avoid encircling turtles and release them when they do so.
Observer coverage was increased in 2019 (see Management) but is still inadequate for purse seiners targeting species other than tropical tunas, and all longliners.
Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.Anchovy, anchovies
Herring or sild
Salmon, Atlantic (Farmed)
Salmon, Chum, Keta, Calico or Dog salmon
Salmon, Pink, Spring , humpback
Salmon, Sockeye , Red Salmon, Bluebacks, Redfish
ReferencesEC, 2019. European Commission Press: Good news for tuna and blue sharks, 29.11.2019. Available at https://ec.europa.eu/fisheries/press/good-news-tuna-and-blue-sharks_en [Accessed on 09.12.2019].
ICCAT, 2019. Report of the 2019 ICCAT yellowfin tuna stock assessment meeting, 8-16 July 2019, Grand-Bassam, Cote d'Ivoire. Available at https://www.iccat.int/Documents/SCRS/DetRep/YFT_SA_ENG.pdf [Accessed on 09.12.2019].
ICCAT, 2019. Report of the Standing Committee on Research and Statistics (SCRS) of the International Commission for the Conservation of Atlantic Tunas, 30 September - 4 October 2019, Madrid, Spain. 459 pp. Available at https://www.iccat.int/Documents/Meetings/Docs/2019/REPORTS/2019_SCRS_ENG.pdf [Accessed on 09.12.2019].
ISSF, 2019. International Seafood Sustainability Foundation Blog: ICCAT Moves to Protect Atlantic Bigeye and Close Gaps in Monitoring and Data Collection, 4 December 2019. Available at https://iss-foundation.org/iccat-moves-to-protect-atlantic-bigeye-and-close-gaps-in-monitoring-and-data-collection/ [Accessed on 09.12.2019].
ISSF, 2019. Status of the world fisheries for tuna. Oct. 2019. ISSF Technical Report 2019-12. International Seafood Sustainability Foundation, Washington, D.C., USA. Available at https://iss-foundation.org/knowledge-tools/technical-and-meeting-reports/download-info/issf-2019-12-status-of-the-world-fisheries-for-tuna-october-2019/ [Accessed on 26.11.2019].
ICCAT, 2018. Resolutions, Recommendations and other Decisions. Available at http://www.iccat.es/en/RecsRegs.asp [Accessed on 11.12.2018].
IPNLF, 2012. Ensuring sustainability of live bait fish, International Pole and Line Foundation, London, 57 pp.
Restrepo, V., Dagorn, L., Itano D., Justel-Rubio A., Forget F. and Moreno, G., 2017. A summary of bycatch issues and ISSF mitigation initiatives to-date in purse seine fisheries, with emphasis on FADs. ISSF Technical Report 2017-06. International Seafood Sustainability Foundation, Washington, D.C., USA.