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Swordfish

Xiphias gladius

Method of production - Caught at sea
Capture method - Longline
Capture area - South and Eastern Central Pacific (FAO 77,87,81)
Stock area - South East Pacific
Stock detail - All Areas
Certification -
Fish type - Oily fish

Sustainability rating Click for explaination of rating

This fish, caught by the methods and in the area listed above, is not the most sustainable choice of fish to eat. Click on the rating icon above to read more and on the alternatives tab below to find more sustainable fish to eat.


Sustainability overview

Swordfish in this region are both targeted for and landed as valuable bycatch in directed tuna fisheries. To a lesser extent they are also taken in artisanal net and harpoon fisheries off the coast of South America. The last stock assessment, updated in 2011 indicated that stocks were in a healthy state and were being harvested sustainably. Bycatch of vulnerable species such as birds, sharks and turtles is of concern in both the pelagic longline fisheries and net fisheries. Various measures are available and required to be used to reduce bycatch in the longline fisheries yet monitoring is deficient and their effectiveness is yet to be evaluated. Harpooning is very selective capture method and is a more sustainable option yet accounts for a small proportion of the catch.

Buy swordfish from fisheries that are well regulated by their flag state to ensure that bycatch mitigation devices are being employed and monitored. Commercial buyers in particular should establish what measures the flag state and or fleet is taking to improve deficiencies in reporting interactions with vulnerable species and specify the need for ongoing and demonstrable improvements. Large buyers should consider supporting such improvements. Much smaller quantities are taken in artisanal harpoon and gill net fisheries off the coast of South America. Pelagic gill nets are associated with high levels of bycatch of shark, birds, other billfish and endangered marine turtles. There are few effective measures to prevent mortality of these animals caught in these nets and the reporting of such incidents is very poor.

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 South-East Pacific Ocean (SEPO), spawning takes place in summer months. Usually solitary, it forms large schools during spawning. A fast growing fish, swordfish in the SEPO mature at 2-3 years of age, when they 115-120cm (males) and 165-175cm (females).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 East Pacific

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Stock information
The South-east Pacific swordfish stock is managed by both the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCPFC). The most recent stock assessment was updated in 2011, and indicated that the stock was not experiencing overfishing and was not overfished. Results indicated that the spawning biomass had decreased to a low of about 43,000 t in 1993 and had been increasing since, reaching about 135,000 t in 2010t. At the same time as this increase, the annual catch by all fisheries was maintained at an average 12,000t during the 10 year period ending in 2010. Spawning biomass was estimated to be at 50% above the carrying capacity, and substantially above the level which is expected to produce catch at the level of Maximum Sustainable Yield (1.45SBmsy). Catches have increased in the last few years towards the estimated MSY of 25,000 t. It is not clear whether this is due to increased abundance of swordfish or increased effort directed toward that species.

A new stock assessment is needed to gain a better understanding of current stock status.

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. In this case, it is shared between the Inter-American Tropical Tuna Commission (IATTC) and the Western Central Pacific Fisheries Commission (WCPFC). 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. The main countries reporting swordfish catches in this region are Chile, Japan and Spain.

There is no Total Allowable Catch (TAC) set for this stock. Management measures that apply to directed tuna fisheries are expected to also benefit swordfish stocks.

The IATTC and WCPFC requires 5% observer coverage on longliners greater than 20m.

To help address IUU, the IATTC & WCPFC maintain an IUU Vessel List; maintains a register of authorised fishing vessels; and prohibits transhipments at sea for most vessels (Some exemptions apply) and requires most other transhipments to be documented and observed as part of the regional observer programme.

Capture information

In the South-east Pacific Ocean, swordfish are mostly caught in mixed species longline fisheries by Chilean, Japanese and Spanish fleets.

Pelagic longlining for tuna and billfish is associated the bycatch of vulnerable sharks, seabirds and marine turtles. To address this, both the IATTC and the WCPFC require a number of mitigation measures. Longliners must use one or more of the following, depending on vessel size and fishing location: weighted branch lines, night setting, tori lines, side setting with a bird curtain and weighted branch lines, blue-dyed bait; deep setting line shooter; management of offal discharge. WCPFC is beginning a project in 2017 to estimate seabird mortality. WCPFC Scientific Committee research in 2016 into sea turtle mitigation in longline fisheries found that interaction rates are lower when large circle hooks are used, higher at hooks closest to floats and higher when squid baits are used. Current measures relating to turtles include: the use of circle hooks for shallow set gear to reduce turtle capture, along with the requirement to carry line cutters and de-hookers and to promptly release turtles or to foster to recovery any sick or comatose turtles captured. 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 countries to develop national plans of action to address the bycatch of sharks, turtles and seabirds. WCPFC prohibits the use of wire leaders and lines running directly off the longline floats or drop lines - known as shark lines; and for fisheries specifically targeting sharks, WCPFC countries are required to develop management plans, demonstrating how they intend to avoid or reduce catches of highly depleted shark species. In 2016 IATTC adopted a resolution to prohibit retention, transshipment, landing or storing of silky sharks caught by purse seine vessels. They also introduced stricter monitoring and reporting of catches of shark species. Data on the effectiveness of the WCPFC ban on shark finning is very limited. In 2016, WCPFC adopted 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.

Monitoring and reporting of interactions with vulnerable species is deficient in many fisheries however, and the effectiveness of these various measures has not been evaluated. The IATTC and WCPFC both require 5% observer coverage on longliners greater than 20m.

Read more about capture methods


References
Froese, R. and D. Pauly. Editors. 2016. FishBase. Available at www.fishbase.org [Accessed Dec 2016].

IATTC, 2016. Active IATTC and AIDCP resolutions and recommendations. Available at http://www.iattc.org/ResolutionsActiveENG.htm [Accessed Dec 2016].

IATTC, 2016. Fishery status report no. 14: tunas, billfishes and other pelagic species in the Eastern Pacific Ocean in 2015. La Jolla, California, 2016. Available at https://www.iattc.org/PDFFiles2/FisheryStatusReports/FisheryStatusReport14.pdf [Accessed Dec 2016].

ISC, 2016. Report of the sixteenth meeting of the international scientific committee for tuna and tuna-like species in the North Pacific Ocean: plenary session. Sapporo, Hokkaido, Japan, 13-18 July 2016. Available at http://isc.fra.go.jp/reports/isc/isc16_reports.html [Accessed Dec 2016].

ISSF, 2016. Status of the world fisheries for tuna: Management of tuna stocks and fisheries, 2016. ISSF Technical Report 2016-14.International Seafood Sustainability Foundation, Washington, D.C., USA. Available at http://iss-foundation.org/downloads/13305/ [Accessed Nov 2016].

WCPFC, 2016. Conservation and management measures. Available at https://www.wcpfc.int/conservation-and-management-measures [Accessed Dec 2016].

WCPFC, 2016. Scientific committee meeting: summary report. Twelfth regular session. Bali, Indonesia, 3-11 August 2016. Available at https://www.wcpfc.int/meetings/sc12 [Accessed Dec 2016].

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