Capture method — Longline
Capture area — Indian Ocean: Western (FAO 51), Eastern ( FAO 57)
Stock area — Indian Ocean
Stock detail — All Areas
Updated: November 2019
A new stock assessment of Indian Ocean albacore was carried out in 2019, using data up to 2017, but it has high uncertainty. The scientific committee strongly recommended carrying out an additional update in 2020, using the latest data and more recent information on biology. The assessment found that the stock was not overfished (Spawning stock, SB 2017, was 1.281 SBMSY), but was subject to significant overfishing (Fishing pressure, F 2017, is 1.346 FMSY). F is close to the limit reference point (1.4). Catch estimate for 2018 (41,603 tonnes) is above the estimated MSY (35,700t), as is the 2014-2018 average (38,030t). The scientific committee advises that catch reductions are required in order to prevent the biomass from declining to below MSY levels in the short term, due to low recent recruitment levels. If the 2018 catch level is maintained, there is an 83% probability of the stock dropping below SBMSY by 2020. Some countries in the IOTC do not report fishery data which is important for stock assessment and management. In 2018, the IOTC introduced a new measure aimed at improving reporting on direct and incidental catches, including prohibiting a country from retaining a species if they fail to report catches for that species. There are no specific management measures for Indian Ocean albacore tuna. No harvest control rule has been developed for the stock, although IOTC has set targets and thresholds for fishing effort and spawning stock biomass for all of the species it manages. Almost 100% of the catch is from pelagic longline fisheries and there is concern for bycatch of sharks, turtles and seabirds in these fisheries. It is likely that longline fleets are contributing to decline of these species. Observer coverage is relatively low at 5% for vessels over 24m and for vessels fishing on the High Seas. 20% coverage has been recommended in other longline fisheries.
Commercial buyers should establish what measures the flag state and fleet relating to their source is taking to reduce impacts to and improve reporting of interactions with vulnerable species. Large buyers should consider supporting such improvements.
Tuna belong to the family Scombridae. They are large, oceanic fish and are seasonally migratory, some making trans-oceanic journeys. Albacore are found throughout the world’s temperate, sub-tropical and tropical oceans, although they are less common in the tropics. They are found from the surface to a depth of 600m where they often form mixed schools with skipjack, yellowfin and bluefin tuna. They grow more slowly than skipjack and yellowfin tuna, reaching a maximum size of 140cm, 60kg in weight and maximum age of 10 years. Albacore mature when about 90cm length and 4-5 years old. Spawning normally occurs between January and July.
Criterion score: 0.5 info
Indian Ocean tuna stocks are managed by Indian Ocean Tuna Commission (IOTC). Prior to 1980 there were 20 years of moderate fishing, after which total catches of albacore tuna in the Indian Ocean more than doubled, peaking in 2001 at around 45,000 t. Between 1986 and 1991 the driftnet fishery was a responsible for a significant proportion (around 50% or more) of catches, with longlining dominating throughout the rest of the period. The impacts of piracy in the western Indian Ocean resulted in the displacement of a substantial portion of longline fishing effort into the traditional albacore fishing areas in the southern and eastern Indian Ocean, but in recent years there has been no clear pattern of fishing effort distribution in the Indian Ocean.
A new stock assessment was carried out in 2019, using data up to 2017, but it has high uncertainty. The scientific committee strongly recommended carrying out an additional update in 2020, when there will be more biological information, improved mortality estimates, and more recent catch and CPUE data. The assessment found that the stock was not overfished (Spawning stock, SB 2017, was 1.281 SBMSY), but was subject to significant overfishing (Fishing pressure, F 2017, is 1.346 FMSY). F is close to the limit reference point (1.4). Catch estimate for 2018 (41,603 tonnes) is some way above the estimated MSY (35,700t), as is the 2014-2018 average (38,030t). The scientific committee advises that catch reductions are required in order to prevent the biomass from declining to below MSY levels in the short term, due to low recent recruitment levels. Although there is considerable uncertainty in the projections, current catches are exceeding the estimated MSY level. If the 2018 catch level is maintained, there is an 83% probability of the stock dropping below SBMSY by 2020, although this is affected by recent very poor recruitment. Longer term projections looking ahead to 2027 are less affected by short-term recruitment fluctuations, but even then there is a 82% chance of the stock dropping below MSY.
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 achieve this, Intergovernmental Regional Fisheries Management Organisations (RFMOs) have been established; for this stock it is the Indian Ocean Tuna Commission (IOTC). There are five main tuna RFMOs worldwide and it is their responsibility to carry out data collection, scientific monitoring and management of these fisheries. 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. For this reason, it is important to choose tuna that has been caught by vessels that are well regulated by their flag state.
There are persistent failures by some countries to report to the commission annually, including reporting catch data, and other issues with lack of data and poor quality data persist. In 2018 IOTC introduced a new measure aimed at improving reporting on direct and incidental catches, including prohibiting a country from retaining a species if they fail to report catches for that species.
There are no specific management measures for Indian Ocean albacore tuna. No harvest control rule has been developed for the stock, although IOTC has set targets and thresholds for fishing effort and spawning stock biomass for all of the species it manages. Piracy in the southwest Indian Ocean has displaced considerable tuna fishing effort to traditional albacore fishing grounds in the southern and eastern Indian Ocean, which has presented challenges to limiting fishing effort on the albacore stock. In 2013, IOTC passed a resolution that management measures would be assessed and adopted for this stock and that these measures would ensure that fishing pressure is below FMSY and biomass is above SBMSY by 2020. The commission is not currently on track to meet this target. Although there is considerable uncertainty in the stock status and projections, current catches are exceeding the estimated MSY level (estimated MSY: 35,700t; 2014-2018 average catch: 38,030t). If the 2018 catch level is maintained, there is an 83% probability of the stock dropping below SBMSY by 2020, although this is affected by recent very poor recruitment. Longer term projections looking ahead to 2027 are less affected by short-term recruitment fluctuations, but even then there is a 82% chance of the stock dropping below MSY.
The main management measure for the stock was a freeze on capacity and tonnage to 2007 levels for vessels over 24m, or vessels under this length operating in international waters. This measure expired in 2018, and IOTC reverted to previous legislation which froze capacity and tonnage to 2003 levels. This legislation is very generic, applying across all fleets, and would be better replaced by spatial and temporal closures and quota allocation. There also appear to be concerns that the freeze has not been well enforced thus far.
Other IOTC conservation and management measures of note include:
A ban on the discarding of bigeye, yellowfin and skipjack tunas by purse seine vessels which from 2018 will extend to non target species such as other tunas and billfish.
A ban on the use of aircrafts and unmanned aerial vehicles as fishing aids, which significantly contribute to fishing effort by helping to detect fish.
A ban on surface or submerged artificial lights for the purpose of aggregating tuna and tuna-like species beyond territorial waters.
In 2012 IOTC banned the use of driftnets on the high seas. In 2022 this will be extended to the entire IOTC area (i.e. within countries’ EEZs as well).
5% regional observer coverage is required for all vessels over 24m and for vessels under 24m fishing outside of their Exclusive Economic Zone (EEZ). In 2019 a proposal was put forward to increase this to at last 20%, as 5% was considered to be insufficient. However, consensus on minimum coverage could not be reached.
To help address IUU, the IOTC maintains an active vessel register and an IUU Vessel List and prohibits transhipments for large scale vessels at sea unless they are pre-approved, monitored by an observer and the vessel uses a Vessel Monitoring System (VMS).
In 2016 IOTC introduced a number of resolutions to improve the poor compliance with existing management measures, e.g. observer coverage, catch and effort reporting, support for countries to implement measures.
Criterion score: 0.75 info
Almost 100% of albacore catches in the IOTC are made by drifting longlines. Several mitigation measures are in place (sharks, turtles, sea birds), but monitoring is deficient. Longlining targets large mature fish compared with purse seining, yet is associated with significant incidental capture and mortality of vulnerable sharks, turtles and sea birds.
A number of threatened seabirds can interact with longline fisheries in the Indian Ocean, including the critically endangered Amsterdam albatross (which lives on Amsterdam Island in the southern Indian Ocean), shy, black-browed, and wandering albatrosses. As with most tuna RFMOs, the IOTC requires two seabird bycatch mitigation measures from a list of three options (weighted branch line, bird scaring lines, and night setting), but recommended best practice is for these three measures to be applied simultaneously. Monitoring and reporting is deficient, and there has not been enough information available to fully review the effectiveness of the applied mitigation measures.
There is currently too little data to carry out stock assessments for shark species, so the scientific committee recommends better monitoring and a precautionary approach to their management. Full utilisation of sharks is required (i.e. no fin removal), unwanted sharks must be released live wherever possible and shark catches must be reported annually. Hooking mortality is apparently very high for bigeye and pelagic threshers, therefore the prohibition on retaining of any part of thresher sharks on-board and promoting live release of thresher shark may be largely ineffective for species conservation. In 2018 IOTC introduced a new measure on management of blue shark stocks, requiring better data collection on catches and discards and paving the way to consider additional management measures in 2021. Transshipment of oceanic whitetips and thresher sharks is prohibited. Countries must develop conservation and management measures for vulnerable shark species. A number of countries are currently incorporating a ban on the retention of oceanic whitetip sharks into national legislation in accordance with IOTC resolutions, but it is too early to evaluate the impact of this. In 2019 the first resolution for any ray species in the IOTC area of competence was brought in. It protects mobulid rays, which are declining across the Indian Ocean. Targeted fishing, retention, transhipping, landing, selling, or storage of mobulid rays is prohibited, with exceptions made for accidental catch by artisanal fishing until 2022.
The status of all turtle species in the Indian Ocean is concerning. The scientific committee advises that maintaining or increasing fishing effort in the Indian Ocean without appropriate mitigation measures in place will likely result in further declines in biomass, and recommends that appropriate mechanisms are developed to ensure compliance with data collection and reporting requirements. Turtles must be released wherever possible and countries are requested to research other mitigation techniques. Longliners must carry cutters or de-hookers to aid with this but gear modification, such as circle hooks, is not required.
Interactions with all vulnerable non-target species should be recorded. Several countries have failed to implement national plans of action (NPOAs) for sharks, seabirds and turtles as required (although the shark plan is not binding in India as they have objected to the measure). In 2019, of the 34 members of IOTC, 16 countries had completed national plans of action (NPOAs) for sharks, 7 for seabirds and 11 for turtles. Click here to see which countries had and had not fully implemented NPOAs.
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
ReferencesACAP, 2019. ACAP Review and Best Practice Advice for Reducing the Impact of Pelagic Longline Fisheries on Seabirds, Reviewed at the Eleventh Meeting of the Advisory Committee of the Agreement on the Conservation of Albatrosses and Petrels, 13 - 17 May 2019, Florianopolis, Brazil. Available at https://www.acap.aq/en/bycatch-mitigation/mitigation-advice/3498-acap-2019-review-and-best-practice-advice-for-reducing-the-impact-of-pelagic-longline-fisheries-on-seabirds/file [Accessed on 29.11.2019].
Dias, M. P., Martin. R., Pearmain, E., J., Burfield, I. J., Small, C., Phillips, R. A., Yates, O., Lascelles, B., Garcia Borboroglu, P. and Croxall, J. P., 2019. Threats to seabirds: A global assessment. Biol. Cons. 237, pp 525-537. https://doi.org/10.1016/j.biocon.2019.06.033 [Accessed on 29.11.2019].
IOTC, 2017. Report of the 13th Working Party on Ecosystems and Bycatch, IOTC-2017-WPEB13-R, for the Indian Ocean Tuna Commission, 4-8 September 2017, San Sebastian, Spain. 124pp. Available at http://www.iotc.org/meetings/13th-working-party-ecosystems-and-bycatch-wpeb13 [Accessed 21.11.2017].
IOTC, 2018. Report of the 22nd Session of the Indian Ocean Tuna Commission, IOTC-2018-S22-R[E]. 21-25 May 2018, Bangkok, Thailand, 144pp. Available at https://iotc.org/documents/report-22nd-session-indian-ocean-tuna-commission [Accessed on 28.11.2019].
IOTC, 2019. Report for the 23rd session of the Indian Ocean Tuna Commission, IOTC-2019-S23-R_rev1[E], 17-21 June 2019, Hyderabad, India. Available at https://iotc.org/sites/default/files/documents/2019/10/IOTC-2019-S23-RE_Rev1_FINAL.pdf [Accessed on 26.11.2019].
IOTC, 2019. Report of the Seventh Session of the IOTC Working Party on Temperate Tunas: Assessment Meeting. IOTC-2019-WPTmT07(AS)-R[E]. 23-27 July 2019, Shizuoka, Japan. 37pp. Available at https://iotc.org/documents/WPTmT/702/R_E [Accessed on 27.11.2019].
IOTC, 2019. Status of development and implementation of national plans of action for seabirds and sharks, and implementation of the FAO guidelines to reduce marine turtle mortality in fishing operations. Paper IOTC-2019-SC22-06[E] presented to the 22nd Indian Ocean Tuna Commission Scientific Committee, 2-6 December 2019, Karachi, Pakistan. 11pp. Available at https://iotc.org/documents/SC/22/06E [Accessed on 27.11.2019].
IOTC, 2019. On a regional observer scheme. Paper IOTC-2019-S23-PropJ[E] submitted by the European Union to the 23rd session of the Indian Ocean Tuna Commission, 17-21 June 2019, Hyderabad, India. 5pp. Available at https://iotc.org/documents/regional-observer-scheme-eu [Accessed on 27.11.2019].
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].
IOTC, 2019. Draft: Status of the Indian Ocean albacore (ALB: Thunnus alalunga) resource. Paper IOTC-2019-SC22-ES01 presented to the 22nd Indian Ocean Tuna Commission Scientific Committee, 2-6 December 2019, Karachi, Pakistan. 4pp. Available at https://iotc.org/documents/SC/22/ES01 [Accessed on 28.11.2019.].
Zhu, J. and Toshihide, K., 2019. Uncertainties in the 2019 stock assessment for Indian Ocean albacore tuna and suggestions of further researches in 2020 for improving the assessment and providing management advice. Paper IOTC-2019-SC22-13 presented to the 22nd Indian Ocean Tuna Commission Scientific Committee, 2-6 December 2019, Karachi, Pakistan. 5pp. Available at https://iotc.org/documents/SC/22/13 [Accessed on 27.11.2019.].