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Swordfish

Xiphias gladius

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

The last stock assessments (2010) undertaken for swordfish in both the Eastern Pacific and Central West Pacific indicated that these fisheries were healthy. Recent catches suggest that this is still the case. Bycatch of vulnerable species such as birds, sharks and turtles is of concern in these pelagic longline fisheries. Buy swordfish from fisheries that are well regulated by their flag state to ensure that bycatch mitigation devices are being employed and monitored. Harpooning is very selective capture method and is a more sustainable option yet accounts for a small proportion of the catch.

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

Stock area
Western & Central North Pacific

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Stock information
Swordfish stocks in the western and central North Pacific Ocean are managed by the Western and Central Pacific Fisheries Commission (WCPFC) and assessed by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC). The last stock assessment was carried out in 2010 and, despite uncertainties in the assessment, indicated that the stock was not likely overfished nor being subject to overfishing. Updated projections using data up to 2012 suggest that this is still the case, with spawning biomass estimated to be 41% above Bmsy and fishing mortality estimated to be about 54% below Fmsy. It has been noted though that a new assessment is required and is scheduled for 2014.

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. 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 (In order): Chinese-Taipei, Japan, USA, Korea and to a lesser extent Mexico. Swordfish in the North Pacific even ranges between jurisdictions of the RFMOs (between the east and the west), which makes harmonised management even more difficult. The Western and Central Pacific Fisheries Commission (WCPFC) and the Inter-American Tropical Tuna Commission (IATTC) in the east share this responsibility for this fishery.

There is no Total Allowable Catch (TAC) set for this stock yet WCPFC participating coastal states are expected to have set TACs which are not to exceed the maximum level reported in any one year between 2001 and 2006. Management measures that apply to directed tuna fisheries are expected to also benefit swordfish stocks.

Longliners over 20m in length are required to use at least 2 prescribed seabird mitigation measures (eg tori line, dyed bait, weighted branch line, night setting, underwater setting chute); vessels are to carry line cutters and de-hookers to promptly release turtles or to foster to recovery any sick or comatose turtles captured; and permissible sharks are to be fully utilized and no more than 5% of fins to total shark weight can be retained. Monitoring of these measures is deficient.

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.

There is 5% observer coverage for vessels over 20m.

Capture information

In the North Pacific Ocean (NPO), 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 have been taken by Japan for more than five decades. Since about 1990, however, the combined catches of other nations (Chinese-Taipei, Mexico, Korea and USA) have approached the Japanese tonnage in several years. Longlining is a less fuel intensive method of fishing; however, pelagic longline fisheries for swordfish are associated with high levels of bycatch of vulnerable species including: shark, turtles, sea birds and other billfish.

Read more about capture methods


References
WCPFC, 2013. Scientific committee ninth regular session: summary report. 6-14 August 2013, Pohnpei, Federated States of Micronesia. Avaiilable at http://www.wcpfc.int/meetings/9th-regular-session-scientific-committee [Last accessed Jan 2014].
ISC, 2009. Report of the billfish working group workshop.19-26 May, 2009. Busan, Korea, USA.
ISC, 2013. Billfish working group: Swordfish (Xiphias gladius) - North Pacific. Available at http://isc.ac.affrc.go.jp/working_groups/billfish_swordfish.html [Accessed Jan 2013].
IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. . [Accessed December 2013].

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