Xiphias gladius

Method of production — Caught at sea
Capture method — Longline
Capture area — Atlantic, South (FAO 41,47) and Central (FAO 31,34)
Stock area — South Atlantic
Stock detail — All Areas
Picture of Swordfish

Sustainability rating four info

Sustainability overview

Updated: December 2019 

Swordfish fisheries in the south Atlantic are assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). A new stock assessment was carried out in 2017 using data up to 2015 which indicated that the southern swordfish stock was in an overfished state (B2015 at 0.72BMSY) but overfishing was not occurring, although fishing mortality (F) was very close to Maximum Sustainable Yield (F2015 at 0.98FMSY). MSY is estimated to be 14,570 and the TAC (Total Allowable Catch) for 2014-2017 was 15,000 t, with individual catch limits assigned to each country. This reduces to 14,000 t for the years 2018-2021 in response to scientific advice that a TAC of 15,000 t has only a 26% probability of rebuilding the stock to within MSY reference levels by 2028, whereas a TAC of 14,000 t would increase this probability to 50%. Whilst the rebuilding plan and TAC are welcome measures, MCS believes a plan with greater than 50% probability of achieving recovery is needed.

Pelagic longlining in the Atlantic can be associated with significant bycatch of other billfish and vulnerable species such as sharks, turtles and seabirds. Whilst some mitigation measures are in place, their effectiveness has not been evaluated and better data collection & reporting is needed. Observer coverage is 5% on large longliners, increasing to 10% in 2022, but compliance has been mixed, and 20% coverage is recommended. 100% coverage is voluntarily applied in some countries.

Commercial buyers should establish what measures the flag state and fleet relating to their source is taking to reduce impacts to and improve reporting of interactions with vulnerable species. 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

Criterion score: 0.5 info

Stock Area

South Atlantic

Stock information

Swordfish fisheries in the south Atlantic are assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Atlantic swordfish have been targeted since harpoon fisheries began in the late 1800s. They are also taken as bycatch or opportunistically by fleets targeting tuna.

The latest stock assessment was carried out in 2017 using data up to 2015. It indicates that the southern swordfish stock biomass (B) is overfished (B2015 is at 0.72BMSY), and overfishing is not occurring, although fishing effort (F) is very close to Maximum Sustainable Yield (MSY) with the ratio of F2015 at 0.98FMSY. MSY is estimated to be 14,570 and the 2018 TAC is set at 14,000 (reduced from 15,000t in 2017). It is projected that catches at or below 14,000 t would rebuild the population to biomass levels that can produce MSY by 2028.

Catches of south Atlantic swordfish increased from an average of 1,700 t before 1980, to a peak of around 22,000 t in 1995. This was partly owing to fleets moving here from the north Atlantic and expansion of fishing by southern coastal communities. Catches have since reduced, partly owing to regulations and partly due to a shift to other oceans and target species. Provisional 2018 catch is 10,404 t, consistent with the 5 year average of 10,382 t.

Since 1991, very few fleets have reported dead discards for Atlantic swordfish stocks and the Scientific Committee has concerns that what has been reported is not necessarily representative of the fishery.


Criterion score: 0.5 info

Similar to most tuna stocks, swordfish range across and are accessed by numerous coastal states, making harmonised and effective management of these individual stocks very difficult. To try and address this, 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. This stock is managed and assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). 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. There remain large data deficiencies in most tuna and billfish fisheries, particularly with regards to fine scale spatial and temporal data for both target and especially for vulnerable bycatch species. For this reason, it is important to choose swordfish that has been caught by vessels that are well regulated by their flag state.

There are a number of Marine Stewardship Council (MSC) certified sustainable swordfish fisheries in Canada and the US which represent the best options.

The TAC (Total Allowable Catch) for 2014-2017 was 15,000 t, with individual catch limits assigned to each country. This reduced to 14,00 t for the years 2018-2021 in response to scientific advice that a TAC of 15,000 t has only a 26% probability of rebuilding the stock to within MSY reference levels by 2028, whereas a TAC of 14,000 t would increase this probability to 50%. The forecasts do not account for discards, which are underreported, quota carryover from year to the next and quota transfer between north and south Atlantic. Catches have not exceeded TACs since 2007.

For Atlantic swordfish (north and south):
Catching and landing swordfish of less than 25kg or 125cm is prohibited (although incidental catch of such fish is allowed as long as it doesn’t exceed 15% of total catch), or 15kg and 119cm with no incidental catch allowed and discards must be recorded. This has resulted in an estimated 10% reduction of landings of undersize north Atlantic swordfish, and south Atlantic undersize landings have remained stable, although the data are not reliable. Undersize fish hooked in longlines experience a high mortality (around 80%) and it is recommended that more complete data be gathered on fishing effort and size data over the entire Atlantic, taking into account effects on other species.
ICCAT maintains a list of vessels over 20m authorised to fish for these species, although other vessels may retain them as bycatch as long as the country sets limits on this and doesn’t exceed its quota.
Swordfish must be accompanied by Catch Documentation when being imported and exported.

Other management measures of note include:
There is a mandatory level of observer coverage of 5%, increasing to 2022. Compliance has been mixed, although some fleets are currently implementing voluntary observer programmes that cover 100% of fishing trips. Scientific committee recommendation is a minimum of 20% for accurate reporting of bycatch. Purse seine and longline vessels over 20m long are encouraged to increase their observer coverage from the required minimum. Vessel Monitoring Systems are required for all vessels over 24m.
In 2015 a working group was formed to look at ways to reduce juvenile catches of bigeye and yellowfin tuna caught in FAD fishing.
Drift nets are banned in the Mediterranean.
ICCAT maintains lists of vessels authorised to fish for tuna and tuna-like species in the ICCAT area, and those caught carrying out Illegal, Unreported or Unregulated activities.
At-sea transhipment is prohibited unless pre-authorised and the vessel has an observer on board.
In 2017 ICCAT banned the discarding of skipjack, yellowfin and bigeye.
In 2016 the Commission passed measures to strengthen and streamline its compliance assessment process and to develop a scheme of responses to non-compliance.

Capture Information

Criterion score: 0.75 info

The largest proportion of the Atlantic catches (97%) is made using surface-drifting longline, which is associated with the bycatch of vulnerable species, including sharks, sea turtles and seabirds. In the South Atlantic catches are primarily taken by (in order): Spain, Brazil, and Japan, but is captured in smaller quantities by various other gears in subsistence fisheries, such as gill nets off the coast of Africa.

ICCAT aims to take an ecosystem-based and precautionary approach to fisheries management. In order to protect juvenile swordfish, a closure period applies to longline vessels targeting Mediterranean albacore from 1 October to 30 November each year.

For sharks: Countries are required to develop and submit National Plans of Action for the conservation and management of sharks. Sharks must be fully utilised (e.g. no removal of fins); must be released wherever possible (if not being directly targeted); and countries must try to minimise bycatch of sharks (although no gear-specific measures are identified). Catching silky sharks, hammerheads, oceanic whitetips, and bigeye threshers is prohibited, and catching other thresher species is discouraged. Shortfin mako, which is heavily overfished, can be caught and retained if over 180cm for males and 210cm for females, otherwise, they must be released unharmed. An updated assessment in 2019 indicated that shortfin mako is unlikely to recover to healthy levels until 2070, unless size restrictions combined with a fixed Total Allowable Catch were introduced. The maximum catch that would allow recovery by 2070 with a reasonable probability (60%) was 300 tonnes. Regardless of management measures, the stock will continue to decline until 2035. However, in 2019 ICCAT failed to reach agreement on measures to protect this species. Catch limits are now in place for both northern (39,102t as of 2016) and southern (28,923t as of 2016) blue sharks, with the northern TAC being allocated out to countries - a first for ICCAT shark stocks. If exceeded, the commission has committed to reviewing the effectiveness of its blue shark management measures (although preliminary catch of northern blue shark in 2016 was 42,117 t). Porbeagle is overfished throughout the Atlantic, significantly so in the northwest, and for the north Atlantic overall it is predicted to take at least 30 years to recover if there was zero fishing mortality. The main porbeagle-directed fisheries (EU, Uruguay and Canada) have closed, and ICCAT have a recommendation to release live porbeagle unharmed, but it is still caught incidentally and discarded, and also landed by other fleets. Currently there is not enough data to properly assess the status of many pelagic sharks (no assessments have been carried out for the Mediterranean).

For seabirds: There are particular concerns over the status of albatross and petrels. South of 20 degrees South, vessels must use bird-scaring lines. Swordfish vessels are exempt from this if they fish at night and weight their hooks. South of 25 degrees South, vessels must use 2 of the three measures (bird-scarers, night fishing or weighted hooks). In the Mediterranean, these measures are voluntary. However, recommended best practice is to use all three of the aforementioned measures for all longline vessels.

For turtles: Longliners must carry equipment and have training to enable them to safely release turtles that have been caught. Countries are required to research and trial circle hooks for longliners. The scientific committee recommends that longliners targeting swordfish and sharks must use either large circle hooks or finfish bait as mitigation, but as of 2019 this has still not been implemented.

Observer coverage was increased in 2019 (see Management) but is still inadequate for purse seiners targeting species other than tropical tunas, and all longliners.


Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.

Anchovy, anchovies
Arctic char
Herring or sild
Salmon, Atlantic (Farmed)
Salmon, Chum, Keta, Calico or Dog salmon
Salmon, Pink, Spring , humpback
Salmon, Sockeye , Red Salmon, Bluebacks, Redfish
Trout, Rainbow
Tuna, albacore
Tuna, skipjack
Tuna, yellowfin


EC, 2019. European Commission Press: Good news for tuna and blue sharks, 29.11.2019. Available at https://ec.europa.eu/fisheries/press/good-news-tuna-and-blue-sharks_en [Accessed on 09.12.2019].

ICCAT, 2019. Report of the Standing Committee on Research and Statistics (SCRS) of the International Commission for the Conservation of Atlantic Tunas, 30 September - 4 October 2019, Madrid, Spain. 459 pp. Available at https://www.iccat.int/Documents/Meetings/Docs/2019/REPORTS/2019_SCRS_ENG.pdf [Accessed on 09.12.2019].

ISSF, 2019. International Seafood Sustainability Foundation Blog: ICCAT Moves to Protect Atlantic Bigeye and Close Gaps in Monitoring and Data Collection, 4 December 2019. Available at https://iss-foundation.org/iccat-moves-to-protect-atlantic-bigeye-and-close-gaps-in-monitoring-and-data-collection/ [Accessed on 09.12.2019].

ISSF, 2019. Status of the world fisheries for tuna. Oct. 2019. ISSF Technical Report 2019-12. International Seafood Sustainability Foundation, Washington, D.C., USA. Available at https://iss-foundation.org/knowledge-tools/technical-and-meeting-reports/download-info/issf-2019-12-status-of-the-world-fisheries-for-tuna-october-2019/ [Accessed on 26.11.2019].

ICCAT, 2018. Resolutions, Recommendations and other Decisions. Available at http://www.iccat.es/en/RecsRegs.asp [Accessed on 11.12.2018].

IPNLF, 2012. Ensuring sustainability of live bait fish, International Pole and Line Foundation, London, 57 pp.