Tuna, albacore

Thunnus alalunga

Method of production — Caught at sea
Capture method — Troll
Capture area — North Atlantic (FAO 21,27,31,34)
Stock area — North Atlantic
Stock detail

All Areas


Picture of Tuna, albacore

Sustainability rating one info

Sustainability overview

The most recent assessment of the stock was carried out in 2016 and indicated that the stock was not overfished (B2015 at 1.36BMSY) or subject to overfishing (Fishing mortality, F2014at 0.54FMSY). Preliminary 2016 catch was 30,141 t, higher than both the recent average (24,489 t) and the 2017-2018 Total Allowable Catch (TAC of 28,000 t), although it is below maximum sustainable yield (37,082 t). There is a Multi-Annual Plan in place for North Atlantic Albacore, which has the objective of maintaining the stock in a good state with at least 60% probability. Following a review and provision of advice by the scientific committee in 2017, the plan is now supported by a Harvest Control Rule with MSY-based targets and limits. The management plan includes a TAC in 2017 is 28,000 t, with individual catch limits assigned to each country. This increases to 33,600 t for 2018-2020. Since 1999, there has been a limit on the number of vessels in the fishery which appears to have reduced mortality. Approximately 21% of the albacore from the North Atlantic was caught in troll fisheries which are selective and rely on less amounts of bait than pole and line.

Biology

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 15 years. Albacore mature when about 90cm length and 4-5 years old. Spawning normally occurs between January and July.

Stock information

Criterion score: 0 info

Stock Area

North Atlantic

Stock information

Albacore stocks in the north Atlantic are assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Scientific studies on stocks in the North Atlantic, North Pacific and the Mediterranean, suggest that environmental variability may have a serious potential impact on albacore, affecting fisheries by changing the fishing grounds as well as productivity levels and potential MSY of the stocks. Those yet sufficiently unexplored aspects might explain recently observed changes in fisheries, such as the lack of availability of the resource in the Bay of Biscay in some years, or the apparent decline in the estimated recruitment which are demanding focussed research. Total reported landings steadily increased from 1930 to peak above 60,000 t in the early 1960s, declining afterwards, largely due to a reduction of fishing effort by the traditional surface (troll and bait boat) and longline fisheries. Some stabilization was observed in the 1990s, mainly due to increased effort and catch by new surface fisheries (driftnet and mid-water pair pelagic trawl), with a maximum catch in 2006 of 36,989 t and, since then, a generally decreasing trend of catch is observed in the North Atlantic. The historical minimum of around 15,000 t was recorded in 2009. The northern albacore stock is currently exploited mostly by surface fisheries targeting mainly immature and sub-adult fish (50 cm to 90 cm in length), but also by longline fisheries targeting immature and adult albacore (60 cm to 130 cm).

The most recent assessment of the stock was carried out in 2016 using data up to 2014. As with previous analyses, the model indicates that spawning stock biomass decreased between 1930 and the 1990s, and was in an overfished state in the 19080s and 1990s. It has had a recovery since then, and fishing mortality has decreased. While biomass, B, is estimated to be above Maximum Sustainable Yield (B2015/BMSY = 1.36), there are concerns that this might be overestimated. Fishing effort, F, is below (F2014/FMSY = 0.54). The probability of the stock currently not being overfished and not undergoing overfishing is 96.8%.

Preliminary 2016 catch was 30,141 t, higher than both the recent average (24,489 t) and the 2017-2018 Total Allowable Catch (28,000 t), although it is below Maximum Sustainable Yield (37,082 t). While projections have indicated that recent catch levels (between 25,000 t and 30,000 t) and the current TAC are likely sustainable, there are great uncertainties in this and the scientific committee has decided not to use them as the basis for any advice.

Management

Criterion score: 0.25 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.

There is a Multi-Annual Plan in place for North Atlantic Albacore, which has the objective of maintaining the stock in a good state with at least 60% probability. Following a review and provision of advice by the scientific committee in 2017, the plan is now supported by a Harvest Control Rule with MSY-based targets and limits. There is not enough fishery data to provide concrete advice on the expected effect of HCR or the TAC. The management plan includes the following measures:
The TAC (Total Allowable Catch) in 2017 is 28,000 t, with individual catch limits assigned to each country. This increases to 33,600 t for 2018-2020.
Since 1999, capacity has been limited to the average number of vessels from 1993-1995. The effect of this has not been evaluated but a general decrease of fishing mortality has been observed since its implementation.
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.

Other management measures of note include:
There is a mandatory level of observer coverage of 5%, which may not have been implemented by many fleets, although some fleets are currently implementing voluntary observer programmes that cover 100% of fishing trips. This is in spite of scientific committee recommendation of a minimum of 20% for accurate reporting of bycatch. Purse seine and longline vessels over 20m long are encouraged to increase their observer coverage from the required minimum. 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.

Capture Information

Criterion score: 0 info

Approximately 21% of the albacore from the North Atlantic is caught in troll surface fisheries. These fisheries are mainly EU fleets from Spain, with lesser catches from Ireland, France and Portugal in the Bay of Biscay, in the adjacent waters of the northeast Atlantic and in the vicinity of the Canary and Azores Islands in summer and autumn. The surface fisheries (troll and pole & line) generally target smaller (50 to 90cm FL) and younger fish, but are a very selective method of fishing and have minimal impact on bycatch species.

ICCAT aims to take an ecosystem-based and precautionary approach to fisheries management.

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). Sharks 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 can be caught and retained, but as of 2017 the country’s law must require a minimum length of 180cm for males and 210cm for females, otherwise, shortfin makos caught alive must be released unharmed. This is expected to prevent the stock’s currently poor state from worsening, and a rebuilding plan will be developed for 2019. In 2016 additional measures for blue shark were introduced, mainly focussed on improved data recording, with potential to introduce Harvest Control Rules. A catch limit of 39,102 t was also introduced in the north Atlantic (but none for the south Atlantic): if exceeded the commission has committed to reviewing the effectiveness of its blue shark management measures. Preliminary catch 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).

There is a mandatory level of observer coverage of 5%, which may not have been implemented by many fleets, in spite of scientific committee recommendation of a minimum of 20% for accurate reporting of bycatch. However, some fleets are currently implementing voluntary observer programmes that cover 100% of fishing trips.

References

ICCAT, 2017. Report of the Standing Committee on Research and Statistics (SCRS) of the International Commission for the Conservation of Atlantic Tunas, 2-6 October 2017, Madrid, Spain. 465 pp. Available at http://www.iccat.int/com2017 [Accessed on 27.11.2017].

ICCAT, 2017. Resolutions, Recommendations and other Decisions. Available at http://www.iccat.es/en/RecsRegs.asp [Accessed on 12.12.2017]

IPNLF, 2012. Ensuring sustainability of live bait fish, International Pole and Line Foundation, London, 57 pp.

ISSF, 2017. Status of the world fisheries for tuna: November 2017. ISSF Technical Report 2017-02A. International Seafood Sustainability Foundation, Washington, D.C., USA. 98 pp. Available at: https://iss-foundation.org/about-tuna/status-of-the-stocks/ [Accessed on 20.11.2017].