As a charity MCS relies on your generous support


MCS Home

Good Fish Guide

return to search Return to search results


Click to enlarge


Xiphias gladius

Method of production - Caught at sea
Capture method - Longline
Capture area - North East Pacific (FAO 77,87)
Stock area - North 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 a good choice of sustainable fish to eat and should be only eaten very occasionally. 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 assessment for swordfish in the Eastern Pacific Ocean was undertaken in 2014. This revealed that whilst the population is at healthy levels, the fishing mortality has increased in recent years and is now likely above longterm sustainable levels. The 2012 catch of 9,910t was a historical record and nearly twice the estimated Maximum Sustainable Yield (MSY). Swordfish in the region is primarily taken in mixed longline fisheries operated by Japan, Spain, China, Taiwan and Korea with lesser amounts taken by Belize, Mexico, Chile, French Polynesia, Peru, Vanuatu, and the United States. A small proportion is caught in harpoon fisheries which are very selective. Bycatch of vulnerable species including seabirds, sharks and turtles remains of concern in the pelagic longline fisheries, and whilst there are measure to reduce this, monitoring and reporting is deficient in many fisheries. 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 is taking to improve these deficiencies and specify the need for ongoing and demonstrable improvements. Large buyers should consider supporting such improvements.


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
North East Pacific

View map areas

Stock information
Swordfish stocks in the northern East Pacific Ocean are managed by both the Inter-American Tropical Tuna Commission (IATTC) and 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). In recent years, catches of swordfish in the region have reached a historic peak and have averaged approximately 9,700t between 2010 and 2012. The last stock assessment was carried out in 2014 and revealed that Maximum Sustainable Yield (MSY) was approximately 5,490t - considerably less than recent catches. Whilst the assessment indicated that the biomass is in a healthy state (Spawning Biomass, SB, at 1.87SBmsy), the recently observed fishing mortality, F, is too high in the long term (F at 1.11Fmsy proxy) and overfishing is likely occurring.


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) Japan, Taiwan and the USA with smaller catches from many Pacific coastal states.

There is no Total Allowable Catch (TAC) set for this stock yet WCPFC participating coastal states are expected to have set national 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.

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 northern East Pacific Ocean, swordfish are mostly caught in mixed species longline fisheries. The largest catches have been taken by Japan for more than five decades, yet since the 90s, Spain, Korea, Taiwan and China have significantly increased their catches. These five countries are now responsible for 90% of the total catch which has recently peaked at 9,700t. Longlining is associated with the bycaught vulnerable species including sharks, seabirds, and turtles.

To address this, both the IATTC and the WCPFC require: that longliners north of 30degrees north and over 20m in length use at least two prescribed seabird mitigation measures (e.g. tori line, dyed bait, weighted branch line, night setting, underwater setting chute); for vessels to carry line cutters and de-hookers to promptly release turtles or to foster to recovery any sick or comatose turtles captured; permissible sharks are to be fully utilized and no more than 5% of fins to total shark weight can be retained with a prohibition to land oceanic whitetip; and countries to develop national plans of action to address the bycatch of sharks, turtles and seabirds. The WCPFC also prohibits the landing of silky and has recently prohibited the use of wire leaders and lines running directly off the longline floats or drop lines - known as shark lines. For fisheries specifically targeting sharks, WCPFC countries are also required to develop management plans in 2015, demonstrating how they intend to avoid or reduce catches of highly depleted shark species.

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

Froese, R. and Pauly, D. Editors, 2015. FishBase. Available at [Accessed Dec 2015].

Return to top Return to top

Sign up to get the latest marine information from the Marine Conservation Society


Sign up to get all the latest marine related news from MCS

The UK charity for the protection of our seas, shores and wildlife.

Read more about MCS

The MCS website uses 'Cookies' to enhance your web experience. Please read our data and cookie policy.
If you do not wish to use cookies please read how to disable cookies. Don't show this message again