Swordfish

Xiphias gladius

Method of production — Caught at sea
Capture method — Longline
Capture area — Pacific, North (FAO 61,67) and Central (FAO 71,77)
Stock area — Western & Central North Pacific
Stock detail — All Areas
Picture of Swordfish

Sustainability rating three info

Sustainability overview

Updated: December 2019 

The swordfish stock in the Western Central North Pacific Ocean is assessed by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) and managed by the Western and Central Pacific Fisheries Commission (WCPFC). The most recent stock assessment was carried out in 2018. It indicated that the stock did not appear to have been overfished or to be experiencing overfishing, although there are no agreed reference points. Maximum Sustainable Yield is estimated at 14,941t, and recent catches have averaged around 10,000 tonnes. There is no overall Total Allowable Catch (TAC) set for this stock, but the scientific committee have recommended that due to uncertainty in the assessment, there should be no increase in fishing mortality from 2007-2010 levels. In 2019, a new Harvest Strategy was proposed for Western Central North Pacific swordfish (north of 20 degrees N, within the WCPFC convention area). It requires further development and refinement, e.g. there is no target for biomass, but if fishing pressure is likely (more than 50% probability) to be exceeding the level associated with Maximum Sustainable Yield, measures will be implemented to reduce it to below FMSY as soon as possible. Management measures that apply to directed tuna fisheries are expected to also benefit swordfish stocks. Most of the catch is taken in pelagic longline fisheries which can be associated with significant bycatch of other billfish and vulnerable species such as sharks, turtles, birds. Whilst there are some mitigation measures in place to reduce the impact, monitoring and reporting of interactions is insufficient to evaluate the effectiveness of these measures. There is 5% observer coverage on large longliners, but 20% has been recommended.

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.

Biology

Swordfish is the only member of the family Xiphiidae. It is a highly migratory species, moving towards temperate or cold waters in summer to feed and returning to warmer waters to spawn. They are apex predators that feed opportunistically. Squids and fishes are major prey items. In the Atlantic, spawning takes place in spring in the southern Sargasso Sea. In the Pacific, spawning occurs during spring and summer, and in the Mediterranean between June-August. Usually solitary, it forms large schools during spawning. A fast growing fish, swordfish begin to mature at two years of age, when they are about 150 to 170 cm in length, and by age four all are mature. They can attain a maximum size of 4.5m and a weight of 650kg. Swordfish tolerate temperatures of about 5 to 27C, but their optimum range is about 18 to 22C, and larvae have been found only at temperatures exceeding 24C.

Stock information

Criterion score: 0 info

Stock Area

Western & Central North Pacific

Stock information

The swordfish stock in the Western Central North Pacific Ocean is assessed by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) and managed by the Western and Central Pacific Fisheries Commission (WCPFC). The most recent stock assessment was carried out in 2018. It indicated that the swordfish stock did not appear to be overfished or to be experiencing overfishing. There are no currently agreed upon reference points. Female spawning stock biomass (SSB) was estimated to be 87% above SSB MSY, and fishing mortality is around 45% below F MSY. Maximum Sustainable Yield is estimated at 14,941t. Catches have been variable but averaged around 13,000t between 1975 and 1999. They increased to around 14,300t between 2000 and 2009, and have been declining since 2010, averaging 10,160t between 2012 and 2016. Projections indicated that if current catches (2013-2015 average, around 10,000t) remained constant, both SSB and catches would increase through to 2026.

There are two swordfish stocks in the North Pacific: one is in the west (i.e. within the WCPFC convention area), and the other straddles the east and west north Pacific (within the Inter-American Tropical Tuna Commission convention area). The IATTC stock is not currently being assessed, and there is a recommendation that both of the northern stocks be assessed together by the ISC.

Management

Criterion score: 0.5 info

As with tuna, individual swordfish stocks range across and are accessed by numerous coastal states, making harmonised and effective management of these individual stocks very difficult. As a result, 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, including swordfish. Whilst the RFMOs, in this case the Western and Central Pacific Fisheries Commission (WCPFC), 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 so it is important to buy tuna and swordfish that has been caught in fisheries that are well regulated by their flag state.

The main countries reporting swordfish catches in this region are (in order): Japan, Taiwan, and the USA, with smaller catches from many Pacific coastal states.

There is no overall Total Allowable Catch (TAC) set for this stock. The WCPFC scientific committee have recommended that due to uncertainty in the assessment, there should be no increase in fishing mortality over current (2007 to 2010) levels. In 2019 a new Harvest Strategy was proposed for Western Central North Pacific swordfish (north of 20 degrees N, within the WCPFC convention area). It requires further development and refinement, e.g. the objective is no more specific than ‘to maintain the stock at levels capable of producing MSY’. The limit reference point for fishing pressure was set as FMSY, but no target for F was set, nor are there yet reference points for biomass. If there is a greater than 50% probability that F is exceeding FMSY, measures will be implemented to reduce it to below FMSY as soon as possible with greater than 50% probability. A stock assessment is intended to be carried out at least every 4 years.

To help address IUU, the WCPFC maintains an IUU Vessel List; and all transhipments at sea are to be documented and 100% observed as part of the regional observer programme.
The WCPFC requires 5% observer coverage for longline vessels over 20m.
In 2017, WCPFC introduced a Compliance Monitoring Scheme to assess and improve compliance with obligations, and penalise non-compliance.

Capture Information

Criterion score: 0.75 info

In the western central North Pacific, swordfish are mostly caught in mixed species longline fisheries, although there are some significant drift net and set net fisheries in Japan and USA. The largest catches are by Japan, Taiwan and the USA, with lesser amounts taken by a wide range of Pacific countries. Pelagic longlining is associated with the bycatch of vulnerable species including: shark, turtles, sea birds and other billfish. Various bycatch mitigation measures are available and required.

There is concern that some seabird species, notably albatrosses and petrels, are threatened with global extinction. Countries are expected to implement the International Plan of Action for Reducing Incidental Catches of Seabirds in Longline Fisheries (IPOA-Seabirds) and report back on this. South of 30 degrees South and north of 23 degrees North, longliners must use at least 2 mitigation measures. In the area between, longliners need only use 1. The simultaneous use of 3 measures (weighted branch lines, bird scaring lines and night setting) remains the best practice approach. Further research is being done on hook shielding devices, and countries are encouraged to develop and refine measures to mitigate seabird bycatch, including safe release of seabirds captured alive. Scientific advice is to review observer coverage rates (used to estimate total seabird interactions), which is not currently being done.

The five marine turtle species in the WCPFC Convention Area are threatened or critically endangered, and WCPFC does not hold sufficient information to quantify the severity of the threat posed by longline fisheries to sea turtle populations. Measures to mitigate turtle bycatch, from 2008, are: to safely recover and release captured turtles, for purse seiners to avoid encircling them, for longliners to carry cutters and dehookers for releasing them, and for shallow-set swordfish longliners to use circle hooks and whole finfish bait (some exemptions to the latter measure apply, e.g. if there is 10% observer coverage). Under this measure, less than 1% of Western and Central Pacific Ocean (WCPO) longline effort is subject to mitigation, even though approximately 20% of the WCPO longline effort consists of shallow sets. To improve current management measures, research into turtle bycatch mitigation is ongoing. Research includes, but is not limited to, the wider use in longline fisheries of large circle hooks and/or whole finfish for bait. Improvements in data collection on interactions with sea turtles are needed. Although interaction rates are higher in shallow-set longlines, mitigation for deep-set longlines would deliver greater reductions in total interactions because effort in deep-set longline fisheries is 4 times that of shallow sets. Similarly, introducing mitigation to deep-set longlines would deliver greater reductions in at-vessel mortality compared to shallow-sets, because sea turtles have a higher probability of asphyxiation in deep sets.

In 2016, catches of silky sharks in the longline fishery were around three times higher than in the purse seine fishery. Shark measures include: full utilisation of permissible sharks and retention of no more than 5% of fins to total shark weight, a prohibition to land silky and oceanic whitetip sharks, and a prohibition on the use of shark lines. The effectiveness of these measures are difficult to evaluate owing to lack of data. As of 2014, shark management plans are required where sharks are being targeted, although to date only 2 countries have developed them. There are measures to improve recording of manta and mobula rays discarded and released, and to treat these species as key shark species for assessment and research. In 2017 the scientific committee recommended guidelines for safe release of manta and mobulid rays, which were adopted by the WCPFC. The commission is also looking to develop guidelines for other rays and sharks, especially silky shark and oceanic whitetips, as well as develop stronger and more comprehensive management measures for sharks, but there is no stated deadline for this. It is recommended that target and limit reference points are established for pelagic sharks.

In general, the effectiveness of the above measures has not been evaluated. Monitoring is deficient and the reporting of interactions with vulnerable species is poor. The scientific committee has recommended a continuation of the work on purse seine bycatch estimates and extension of this work to producing estimates of bycatch in the longline fisheries for 2018, acknowledging the issues related to the 5% observer coverage in these fisheries.

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

ACAP, 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].

ISC, 2019. Report of the Nineteenth Meeting of the International Scientific Committee for Tuna and Tuna-Like Species in the North Pacific Ocean, 11-15 July 2019, Taipei City, Taiwan. Available at http://isc.fra.go.jp/pdf/ISC19/ISC19_PLENARY_Report_FINAL.pdf [Accessed on 29.11.2019].

WCPFC, 2019. Draft Summary Report of the Fifteenth Regular Session of the Northern Committee of the Commission for the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean, 3 - 6 September 2019, Oregon, USA. Available at https://www.wcpfc.int/system/files/0_NC15%20Summary%20Report%20-%20Distributed%20on%2011Sep2019%20%28Posted%20on%2001Nov2019%29.docx [Accessed on 29.11.2019].

WCPFC, 2019. Strengthening the management of south pacific broadbill swordfish (Xiphias Gladius). Document WCPFC16-2019-DP19 submitted by Australia to the Western and Central Pacific Fisheries Commission Sixteenth Regular Session, 5 - 11 December 2019, Port Moresby, Papua New Guinea. Available at https://www.wcpfc.int/node/44671 [Accessed on 05.12.2019].

WCPFC, 2019. Conservation and Management Measures of the Western and Central Pacific Fisheries Commission. Available at https://www.wcpfc.int/conservation-and-management-measures [Accessed on 05.12.2019].