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Swordfish

Xiphias gladius

Method of production - Caught at sea
Capture method - Gill or fixed net
Capture area - South West Pacific (FAO 71,77,81)
Stock area - South West Pacific
Stock detail - All Areas
Certification -
Fish type - Oily fish

Sustainability rating Under assessment


Sustainability overview

We are reviewing this specific listing at the moment. Please contact MCS if you or your organisation would like further information about this listing.

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

Stock area
South West Pacific

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Stock information
Swordfish in the South West Pacific Ocean (SWPO) are assessed and managed by the Western and Central Pacific Fisheries Commission (WCPFC). The latest stock assessment was carried out in 2013 and indicated that there has been a relatively steep decline in biomass over the period between 1997 and 2011, corresponding with reductions in Catch Per Unit Effort (CPUE) and landed fish sizes. Estimates of stock size are highly uncertain as a result of high variation in assumed growth and maturity and mortality at age schedules between Australian and Hawaiian data sets. As a result, the ranges of current spawning biomass and fishing mortality with regards to Maximum Sustainable Yield (MSY) models differ, depending on whether the Australian or Hawaiian schedules are used. Assuming the Hawaiian schedule produces estimates between 0.40 to 0.70Fmsy (not being overfished)while, assuming the Australian schedule produces estimates that are between 1.06 to 1.77Fmsy (stock being overfished). However, both schedules indicated that the stock is not in an overfished state, with spawning biomass ranging from 1.15 to 2.54Bmsy.

In 2014, the Australian government agreed to undertake additional research on age, growth and age validation for swordfish and it is expected that project will also provide a description of any unresolved uncertainties and an indication of the stock status implications in the context of the 2013 stock assessment.

Management

As for 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 that has been caught in fisheries that are well regulated by their flag state. The dominant countries reporting swordfish catches in the region are Japan, Australia, New Zealand, China and Spain.

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. They also recommend developing management measures between the equator and 20°S as this region now represent the largest component of the catch. Management measures that apply to directed tuna fisheries are expected to also benefit swordfish stocks.

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 vessels over 20m.

Capture information

In the South-West Pacific Ocean, swordfish are mostly caught in mixed species longline fisheries off the coast of Australia and New Zealand and in the central South Pacific near the Cook Islands and French Polynesia. Much smaller quantities of swordfish are taken in artisanal gill or fixed net fisheries. These operations are associated with relatively high levels of bycatch of vulnerable species such as sharks and endangered turtles. Monitoring is deficient in these artisanal fisheries.

Read more about capture methods


References
Froese, R. and Pauly, D. Editors, 2013. FishBase. World Wide Web electronic publication. Available at www.fishbase.org [Accessed Nov 2013].

ISC, 2014. North Pacific swordfish (Xiphias gladius) stock assessment in 2014. Report of the billfish working group. 16 to 22 July, Taipei. Available at http://isc.ac.affrc.go.jp/pdf/ISC14pdf/Annex%209%20-%20NP%20Swordfish%20Stock%20Assessment%20(1)_2014.pdf [Accessed Dec 2014].

IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. . [Accessed December 2013].

WCPFC, 2014. Scientific committee tenth regular session: summary report. 6 to 14 August 2014. Majuro, Republic of the Marshall Islands. Available at https://www.wcpfc.int/system/files/SC10%20-%20final_posted_1.docx [Last accessed Jan 2015].

WCPFC, 2013. Stock assessment of swordfish (Xiphias gladius) in the southwest pacific ocean. Scientific committee ninth regular session. 6 to14 August, 2013. Pohnpei, Federated States of Micronesia. vaiilable at http://www.wcpfc.int/system/files/SA-WP-05-SWO-Assessment.pdf [Last accessed Jan 2014].

WCPFC, 2012. Eighth regular session: spatial dynamics of swordfish in the South Pacific Ocean inferred from tagging data. 7-15 August 2012. Busan, Republic of Korea. Available at http://www.iotc.org/files/proceedings/2012/wpb/IOTC-2012-WPB10-INF05.pdf [Accessed Jan 2013].

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