Swordfish

Xiphias gladius

Method of production — Caught at sea
Capture method — Longline
Capture area — South West Pacific (FAO 71,77,81)
Stock area — South West Pacific
Stock detail

Certified fleets only


Certification

Marine Stewardship Council (MSC)


Picture of Swordfish

Sustainability rating two info

Sustainability overview

The last stock assessment for swordfish in the South West Pacific Ocean was carried out in 2017. This indicated that it is highly unlikely that the stock is an overfished state or experiencing overfishing. There is no Total Allowable Catch (TAC) set for this stock yet most participating countries have set national TACs for their components. Following scientific advice, countries must now limit the number of vessels fishing for swordfish south of 20 degrees South to the number in any one year between the period 2000-2005. In addition, they must limit the amount of swordfish caught south of 20 degrees South to the amount caught in any one year during the period 2000 -2006, and must not shift their fishing effort for swordfish to the area north of 20 degrees South as a result of this measure. Most 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 a review of coverage has been advised, and 20% has been recommended in similar fisheries elsewhere. This rating is specific to the Marine Stewardship Council (MSC) certified fleets. Measures in place to reduce bycatch and improved documentation and reporting enable this certified component of the longline fleet to score better.

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, northern hemisphere 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. In the South-West Pacific Ocean however, age at maturity is much later at about 10years for females (1-2yr for males).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

South West Pacific

Stock information

Swordfish in the South West Pacific Ocean (SWPO) are assessed and managed by the Western and Central Pacific Fisheries Commission (WCPFC). Historically, the majority of swordfish catches were bycatch from tuna-target fisheries (SWPO swordfish catches were around 2,500 t in the 1970s). SWPO swordfish biomass declined steeply from 1997 to 2010 and then stabilised, likely owing to increases in fishing effort during that period. Catches increased from to 5,000 in the 90s to 10,000 t in the early 2000s as targeted fisheries developed. The introduction of the Spanish longline fleet in 2004 significantly increased catches to around 15,000 t, and then to more than 20,000 t over the period 2011-2015. Total catches have been relatively stable in recent years, but regional increases have been significant, especially in the WCPFC area north of 20 degrees south. The provisional 2016 catch estimate declined from 2015, possibly due to a reduction in distant-water Asian fleet catches.

A new stock assessment was carried out in 2017 using data up to 2015 and is more certain than the 2013 assessment. Given that WCPFC has yet to formally agree a limit reference point for SWP swordfish, there are two methods for reporting stock status. It is highly likely that the stock is not in an overfished condition (0% probability), with the latest Spawning Biomass (SB) at more than 20% of unfished levels and the ratio of recent SB (2012-2015) to SBMSY at 1.58. It appears that the stock is not experiencing overfishing (32% probability of overfishing), with fishing mortality, F, at 0.86 FMSY.

Management

Criterion score: 0.25 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.

This particular fleet operating out of the east coast of Australia has been certified as a sustainable and well managed fishery by the Marine Stewardship Council (MSC) and represents the best option.

WCPFC is looking to establish harvest strategies for key fisheries and stocks but has not yet completed this work. There is no Total Allowable Catch (TAC) set for this stock yet most participating countries have set national TACs for their components. 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. WCPFC requires countries to limit the number of vessels fishing for swordfish in the south of 20 degrees South to the number in any one year between the period 2000-2005. In addition, they must limit the amount of swordfish caught south of 20 degrees South to the amount caught in any one year during the period 2000 -2006, and must not shift their fishing effort for swordfish to the area north of 20 degrees South to compensate. As well as maintaining these current restrictions for the area south of 20 degrees South, the scientific committee recommends management measures are developed for the area between the equator and 20 degrees South, from where half the total catches come, which contribute substantially to fishing mortality and spawning biomass depletion levels. Management measures that apply to directed tuna fisheries are expected to also benefit swordfish stocks yet the scientific committee has also supported reviewing the existing management measures for swordfish to prevent further increasing catches in this area.
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: 0.5 info

In the South-West Pacific Ocean, swordfish are mostly caught in mixed species pelagic longline fisheries off the coast of Australia and New Zealand and in the central South Pacific near the Cook Islands and French Polynesia, with smaller quantities taken in artisanal gill and fixed net fisheries. Pelagic longlining in the WCPO is associated with the incidental capture and mortality of vulnerable species including sharks, turtles, sea birds and other billfish.

This particular fleet is certified sustainable by the Marine Stewardship Council (MSC) and so is subject to greater monitoring and reporting requirements and needs to be able demonstrate implementation of various mitigation and monitoring measures in order to maintain its certification.

There is concern that some seabird species, notably albatrosses and petrels, are threatened with global extinction. Of critical concern is Antipodean wandering albatross, which is expanding foraging range into tuna fishery areas and has experienced a high and sustained rate of decline - it is now in New Zealand’s “Nationally Critical” conservation status category. High bycatch of seabirds, especially albatross, continue to be reported by some countries fishing south of 30 degrees South. The Commission for the Conservation of Antarctic Marine Living Resources advises that, together with illegal, unreported and unregulated fishing, the greatest threat to Southern Ocean seabirds is mortality in longline fisheries in waters adjacent to its Convention Area. 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.

References

Fishery Progress, 2017. Fishery Improvement Project Directory. Available at https://fisheryprogress.org/ [Accessed on 05.12.2017].

Takeuchi, Y., Pilling, G., Hampton, J., 2017. Stock assessment of swordfish (Xiphias gladius) in the Southwest Pacific Ocean, Document WCPFC-SC13-2017/SA-WP-13 for the Thirteenth Regular Session of the Scientific Committee of the Commission for the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean, 9 - 17 August 2017, Rarotonga, Cook Islands. 70 pp. Available at https://www.wcpfc.int/meetings/sc13 [Accessed on 27.11.2017]

WCPFC, 2017. Provisional outcomes document, WCPFC14-2017-outcomes, from the Western & Central Pacific Fisheries Commission Fourteenth Regular Session (As at 18 December 2017), 3-7 December 2017, Manila, Philippines. 15 pp. Available at https://www.wcpfc.int/meetings/wcpfc14 {Accessed on 18.12.2017]

WCPFC, 2017. Summary Report of the Thirteenth Regular Session of the Scientific Committee of the Commission for the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean, 9 - 17 August 2017, Rarotonga, Cook Islands. 281 pp. Available at https://www.wcpfc.int/meetings/sc13 [Accessed on 27.11.2017]

Williams, P., Terawasi, P., Reid, C., 2017. Overview of tuna fisheries in the Western and Central Pacific Ocean, including economic conditions - 2016, Document WCPFC-SC13-2017/GN-WP-01 for the Thirteenth Regular Session of the Scientific Committee of the Commission for the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean, 9 - 17 August 2017, Rarotonga, Cook Islands. 70 pp. Available at https://www.wcpfc.int/meetings/sc13 [Accessed on 27.11.2017]