As a charity MCS relies on your generous support

Donate

MCS Home

Good Fish Guide

return to search Return to search results

 

Click to enlarge

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 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 and best avoided.

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

View map areas

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.

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.

The next full stock assessment is not scheduled until 2017.

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) 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 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, 2015. FishBase. Available at www.fishbase.org [Accessed Dec 2015].

Return to top Return to top

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

Enewsletter

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