Tuna, skipjack

Euthynnus pelamis, Katsuwonus pelamis

Method of production — Caught at sea
Capture method — Pole & line
Capture area — Atlantic, Western (FAO 21,31,41)
Stock area — West Atlantic
Stock detail — All Areas
Picture of Tuna, skipjack

Sustainability rating two info

Sustainability overview

Updated: December 2019 

Skipjack stocks are difficult to assess. Smaller sub-units of stocks are being considered here and it is expected that the five year Atlantic Tropical Tuna Tagging Programme (AOTTP), may improve understanding of skipjack stock structures and movement patterns. The latest stock assessment for the west Atlantic was undertaken in 2014. Results suggest that it is unlikely that the stock is overfished (probably close to 1.3Bmsy) or being subject to overfishing (probably close to 0.7Fmsy). Maximum Sustainable Yield (MSY) was estimated to be around 30,000-32,000t and recent catches are below this. Preliminary catch for 2018 was 22,837t. Recent catches have been marginally lower than the historical average of around 27,000t, with 2015-2018 average at 22,300t. There is concern regarding the under-reporting of skipjack catches in the Atlantic. The scientific committee recommends that the catch and effort levels do not exceed the maximum sustainable yield. There are no specific management measures for skipjack in the ICCAT area, but ICCAT measures designed for yellowfin and bigeye are likely to impact skipjack.

Approximately 83% of the skipjack in the West Atlantic is caught in pole and line surface fisheries which are selective yet rely on large amounts of live bait fish. Whilst the scale of this is unlikely to overexploit stocks of these species, it could have implications for local availability.

Commercial buyers should establish what measures the flag state or fleet 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.

Biology

Tuna belong to the family Scombridae. They are large, oceanic fish and are seasonally migratory, some making trans-oceanic journeys. Skipjack tuna are found throughout the world’s tropical and warm temperate waters. During the day they school on the surface (often with birds, drifting objects, sharks, whales etc.) but at night can descend to depths of 260m. Skipjack tuna are a very fast growing species, maturing at 2 to 3 years old (40cm in length) and living for up to 12 years. They can grow up to 100cm and 34 kg in weight, but are rarely found larger than 80cm and 10kg. They spawn all year round and have a medium to high resilience to fishing.

Stock information

Criterion score: 0 info

Stock Area

West Atlantic

Stock information

There are two skipjack stocks in the Atlantic - one in the east and one in the west. Both are assessed and managed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). In all the oceans, traditional stock assessment models are difficult to apply to skipjack because of their particular biological and fishery characteristics. In order to overcome these difficulties, several assessment methods have been applied to the two stocks of Atlantic skipjack. Smaller sub-units of stocks are being considered and it is expected that the five year Atlantic Tropical Tuna Tagging Programme (AOTTP) may improve understanding of skipjack stock structures and movement patterns.

The last stock assessments for east and west Atlantic skipjack were carried out in 2014 using data up to 2013. For western skipjack, it is unlikely that the stock is overfished (SB is probably close to 1.3Bmsy) nor being subject to overfishing (F is probably close to 0.7Fmsy). Maximum Sustainable Yield (MSY) was estimated to be around 30,000-32,000t. Preliminary catch for 2018 was 22,837t. Recent catches have been marginally lower than the historical average of around 27,000t, with 2015-2018 average at 22,300t.

In the West Atlantic the major fishery is the Brazilian bait boat fishery, followed by the Venezuelan purse seine fleet. West Atlantic annual catches have been relatively stable over the last 20 years, following the historic record of 40,272 t in 1985.

Management

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.

A component of the Brazilian pole and line fleet was assessed for Marine Stewardship Council certification in 2019, but was not successful owing to poor reporting and management structures in place in Brazil.

The scientific committee recommends that the catch and effort levels do not exceed the maximum sustainable yield (30,000-32,000t) and recent catches have been below this level (around 22,300t). Increasing harvests and fishing effort for skipjack could lead to involuntary consequences for other species that are caught in combination with skipjack in certain fisheries (particularly juveniles of yellowfin and bigeye). There is concern regarding uncertainties which the underreporting of skipjack catches may have on the perception of the state of the stocks.

There are no specific management measures for skipjack in the West Atlantic, but ICCAT measures designed for yellowfin and bigeye are likely to impact skipjack. Other Atlantic wide measures include: A maximum of 500 purse seine FADs to be active at any one time and countries must have FAD Management Plans that improve understanding of FADs and limit their impacts on the ecosystem. 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.
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.
Performance indicators and evaluations of the projected impact of current management measures are expected in 2017, with adjustments to management following in 2018.
Countries are encouraged to reduce discards.
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.
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.

Capture Information

Criterion score: 0.25 info

In the West Atlantic the major fishery is the Brazilian pole and line fishery (accounting for 83% of catches), followed by the Venezuelan purse seine fleet (7%). Pole and line fishing is labour intensive, but is very selective and has the least impact on bycatch species. Substantial amounts of bait fish are used in these fisheries though and a better understanding of the impact to these stocks is needed. The average weight (3 to 4.5kg) of skipjack caught in the Western Atlantic is higher than in the East (2 to 2.5kg). This is primarily because the pole and line fleet targets larger fish than FAD associated purse seining.

Sardines are the major baitfish species in the Brazilian skipjack pole and line fishery, which is responsible for only a small proportion (less than 5%) of the total catch of Brazilian sardines. The fishery for sardines collapsed in the 1990s owing to excess fishing pressure and adverse environmental conditions. As of 2012, management measures in place for the live bait sardine fishery were: a closed season, closed areas, a requirement for tuna vessels to catch their own bait, and restrictions on fishing close to the beach. There is a recognized need to reduce overall sardine fishing effort, especially during periods of low sardine abundance, but primarily by the targeted purse seine fishery.

Alternatives

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
Arctic char
Herring or sild
Mackerel
Salmon, Atlantic (Farmed)
Salmon, Chum, Keta, Calico or Dog salmon
Salmon, Pink, Spring , humpback
Salmon, Sockeye , Red Salmon, Bluebacks, Redfish
Swordfish
Trout, Rainbow
Tuna, albacore
Tuna, skipjack
Tuna, yellowfin

References

EC, 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].

Gillett, R., 2012. Report of the 2012 ISSF Workshop: The Management of Tuna Baitfisheries: The Results of a Global Study. ISSF Technical Report 2012-08. International Seafood Sustainability Foundation, Washington, D.C., USA. Available at https://iss-foundation.org/knowledge-tools/reports/technical-reports/download-info/issf-technical-report-2012-09-the-management-of-tuna-baitfisheries-the-results-of-a-global-study/ [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.