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Xiphias gladius

Method of production - Caught at sea
Capture method - Gill net,Fixed net
Capture area - South West and Central Pacific (FAO 71,77,81)
Stock area - South West 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 the least sustainable fish to eat and should be avoided. Click on the rating icon above to read more and on the alternatives tab below to find sustainable fish to eat.

Sustainability overview

Gill net fisheries for tuna and swordfish are largely unmanaged and are known to have bycatch of vulnerable species such as sharks and turtle. Monitoring and reporting is deficient in these local fisheries.


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
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 using data up to 2011 and indicated that there had been a relatively steep decline in biomass over the period between 1997 and 2011, corresponding with increased annual catches from approximately 2000t to 10,000t. 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 indicate that the stock is not in an overfished state, with spawning biomass ranging from 1.15 to 2.54Bmsy. Total recent catches have been relatively stable in recent years, but regional increases have been significant, especially in areas north off 20 degrees south.

The Australian government recently undertook additional research on age, growth and age validation for swordfish. One indication was that swordfish live longer and grow slower than previously estimated. There is consideration of splitting the stock into south-western and central-southern to resolve the uncertainties around reconciling the Hawaiian and Australian models. Recommendations will be taken on board for the next stock assessment in 2017.


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 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 Western and Central Pacific Fisheries Commission (WCPFC) and the Inter-American Tropical Tuna Commission (IATTC) in the east share this responsibility for this fishery. The main countries reporting swordfish catches in this region are: Japan, Spain, China, Taiwan and Korea with lesser amounts taken by Belize, Mexico, Chile, French Polynesia, Peru, Vanuatu, and the United States.

There is no Total Allowable Catch (TAC) set for this stock. As recent catches are nearly twice the estimated MSY, management measures to limit catches should be considered to ensure the sustainability of the stock in the long-term. Management measures that apply to directed tuna fisheries, in particular albacore and bigeye, are expected to also benefit swordfish stocks. For countries fishing in the WCPFC area, 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.

The IATTC & WCPFC require 5% observer coverage on longliners greater than 20m.

To help address IUU, the IATTC and 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-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

Froese, R. and D. Pauly. Editors. 2016. FishBase. Available at [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 [Accessed Nov 2016].

WCPFC, 2016. Conservation and management measures. Available at [Accessed Dec 2016].

WCPFC, 2016. Scientific committee meeting: summary report. Twelfth regular session. Bali, Indonesia, 3-11 August 2016. Available at [Accessed Dec 2016].

WCPFC, 2016. Thirteenth regular session of the commission. Denarau Island, Fiji 5-9 December 2016. Available at [Accessed Dec 2016].

WCPFC, 2013. Scientific committee: summary report. Ninth regular session. Pohnpei, Federated States of Micronesia, 6-14 August 2013. Available at [Accessed Dec 2016].

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