Swordfish

Swordfish in the north Pacific Ocean is not overfished and not subject to overfishing.This stock is assessed by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) and managed by the Western and Central Pacific Fisheries Commission (WCPFC) and the Inter American Tropical Tuna Commission (IATTC). Previous stock assessments, the most recent being 2018, covered swordfish in the western and central North Pacific only. A new stock assessment was published in 2023 using data from 1975-2021. It covers the whole of the North Pacific, including both WCPFC and IATTC convention areas. It is not clear when the next stock assessment will be carried out.Based on the new assessment, catches of this stock averaged around 14,000 tonnes between 1975 and 1990, with a peak in 1998 at 18,000t. They have since declined to average around 11,000t.No reference points have been established for this stock by either the IATTC or WCPFC, so the assessment has used MSY-based reference points.The spawning stock biomass (SSB) increased from 28,205t in 2016 to 35,179t in 2020. In 2021, SSB was 35,778t, which is 218% of the level associated with Maximum Sustainable Yield, SSB MSY (16,388t). Therefore, the stock is not in an overfished state.Fishing mortality (F) has been declining since 2001. It was around 0.09 in each year between 2019 and 2021, equating to 49% of FMSY (0.18). F has been below FMSY since the beginning of the assessment period. Therefore, the stock is not subject to overfishing.The catch associated with Maximum Sustainable Yield is estimated to be 14,924t. Catches have been below this, averaging 10,653t between 2019 and 2021. Projections indicate that if current catches remain constant, SSB will decrease slightly to around 31,000t but remain above MSY.This stock status is similar to previous assessments. For the northwest stock in 2018 SSB, was 187% of SSB MSY and F was 55% of FMSY. Maximum Sustainable Yield was estimated at 14,941t. For the northeast, there has been no recent stock assessment, but it was considered by IATTC to be "probably not overfished and overfishing is most likely not occurring".

Few appropriate management measures are in place for north Pacific Ocean swordfish. There is no management plan and no catch limits. Observer coverage, which is important for ensuring accurate data on catch and bycatch, is too low.Tuna and swordfish are highly migratory species, found on the high seas and in numerous countries' waters. This makes harmonised and effective management challenging. Regional Fisheries Management Organisations (RFMOs) are responsible for monitoring and managing these stocks on behalf of the countries that access them. However, the degree to which management is implemented, monitored and enforced by each country varies significantly. It is important that commercial buyers choose swordfish that has been caught by vessels that are well regulated by their flag state.This stock is assessed by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) and managed by the Western and Central Pacific Fisheries Commission (WCPFC) and Inter-American Tropical Tuna Commission (IATTC). The IATTC and WCPFC endeavour to work together to promote compatibility between their respective conservation and management measures across the Pacific, but this is not always achieved. In previous years, swordfish in the north Pacific was treated as two stocks - east and west. In 2023, following a tagging programme to better understand stock structure, a new assessment was released that covers the whole north Pacific. This is the first time that the north eastern portion of the stock has been assessed since 2007 and is an important improvement in monitoring the fishery.There are few management measures in place for swordfish in the north Pacific, and no catch limits or harvest strategy. Management measures that apply to tuna fisheries, in particular albacore and bigeye, are expected to also benefit swordfish stocks. Catches overall have been declining while catch per unit effort has been increasing. However, while there are currently no concerns for stock status, there is little in place to prevent future overexploitation. Scientific recommendations are that both RFMOs work together to adopt reference points for fishery management.In the WCPFC area, the first specific management measure for north Pacific swordfish came into force in 2023 (CMM 2022-02). It applies to any fisheries north of 20N in the WCPFC zone that catch more than 200t of North Pacific swordfish annually. Effort by these fisheries should be limited to average levels from 2008-2010. It is too early to assess what impact this has had on the fishery. However, catches and effort in 2020-2022 have been below 2008-2010 levels. The 2023 stock assessment indicates that a substantial proportion of the catch comes from south of 20N, where there are no swordfish management measures.There are no stock-specific management measures in the IATTC area. Catches sharply declined from 2019-2021, along with effort, so there is not currently concern for fishing pressure. However, as noted above, the lack of management means there is no protection for this stock.Most swordfish is caught by longlining. Only 5% observer coverage is required on large longliners, considered too low for accurate data: a minimum of 20% coverage is recommended. In addition, data recorded by longliners in the IATTC area is considered inadequate for scientific purposes and minimum data standards must be identified and introduced.To help address illegal, unregulated and unreported fishing, WCPFC and IATTC maintain an IUU Vessel List; a register of authorised large longliners; and prohibit transhipments at sea for large purse seiners, and most other transhipments must be documented and observed as part of the regional observer programme. Countries are required to report annually on monitoring, control and compliance of management measures. However, improvements are needed on compliance processes in both RFMOs.

Most swordfish catches in the north Pacific Ocean are by longlining. While longlining is unlikely to have habitat impacts, it can have a bycatch of highly vulnerable and endangered species, including sharks, turtles, and seabirds.Data on bycatch in longline fisheries is very poor because there are not enough scientific observers on vessels. Observer coverage is only required to be 5%, and scientific recommendations are for at least 20%. Both WCPFC and IATTC report that the 5% target is not currently being achieved, and the situation has been exacerbated by ongoing Covid impacts. In 2022, coverage in the WCPFC area was 4%. WCPFC scientists advise that observer coverage has been particularly poor in the northwest Pacific, and for all WCPFC bycatch data, trends are more reliable than magnitudes.In the WCPFC and IATTC areas, there are regulations for sharks and rays, turtles, seabirds and cetaceans. Most highlight the need for better data. Some bycatch mitigation measures are in place, but they often don't follow scientific recommendations for best practice, and their effectiveness has not been evaluated.Longlining for swordfish and albacore tuna usually happens in shallower waters than other tuna species, making it more accessible to species such as seabirds and increasing the risk of bycatch.Sharks are both bycaught and targeted in longline fisheries in the Pacific. In the western Pacific in 2021, an estimated 1.1 million sharks were caught as bycatch. In the eastern Pacific in 2021, over 9,000 tonnes of sharks were caught by longlining, including targeted blue shark. IATTC reports that almost all interactions resulted in mortalities. In both areas, bycatch species include bigeye thresher, shortfin mako, and silky shark. There are also some catches of the critically endangered oceanic whitetip and scalloped hammerhead, and the endangered pelagic thresher and mako species. A WCPFC stock assessment of oceanic whitetip in 2019 indicated it is at just 4% of unfished levels, although fishing pressure has been reduced and there were very slight signs of recent recovery. The greatest impact on this species is bycatch from longline fisheries, with lesser impacts from purse seining. Further catch mitigation and improved handling and release practices are required. Mobula rays, which includes a number of endangered species, are also bycaught.There are some mitigation measures, including restrictions on finning, a ban on landing silkies and oceanic whitetips, and restrictions on the use of shark lines (which increase bycatch in longlining). The effectiveness of these measures is difficult to evaluate owing to lack of data. As of 2014, shark management plans are required where sharks are being targeted, although few countries have developed them.Seabird bycatch is also a concern. Albatrosses and petrels are attracted to the baited hooks on longlines. There were at least 340 seabird deaths from EPO longlining in 2021, which is a minimum estimate given the significant data gaps. Species include the white-chinned petrel, wandering albatross, and black-browed albatross. In the WCPO, modelling has estimated that between 13,000 and 19,000 seabirds were killed annually in longline and purse seine fisheries from 2015 to 2018. Two thirds of the mortalities were by longline fisheries north of 20 degrees N.The required mitigation measures do not follow recommended best practice by ACAP (the Agreement on the Conservation of Albatrosses and Petrels). IATTC and WCPFC require one or more measures (depending on location) from a set list of options, including weighted branch lines, bird scaring lines and night setting. ACAP recommends the simultaneous use of all three, or hook-shielding or underwater bait setting devices.The five marine turtle species in the Pacific (green, hawksbill, leatherback, loggerhead and olive ridley) are vulnerable, endangered, or critically endangered. A 2023 review estimated that turtles represented 0.1% of WCPFC longline catch from 2003-2019, and around 13,000 individuals in 2021. Around 15% of turtle catches were loggerhead, which can be found in the north Pacific and therefore overlaps with this swordfish fishery. 52% were olive ridley and 13% green, both of which are more commonly found in the tropics. NOAA lists the North Pacific loggerhead population as endangered, with fisheries bycatch being the primary threat. IATTC does not have enough data to assess longline turtle bycatch in the east Pacific, although it reports that new rules in 2019 may lead to better data availability. Only 8 turtle deaths were reported in 2021, which is not representative of impacts.There are some mitigation measures, including requirements for safe handling and release. In the west, shallow-set swordfish longliners, used for swordfish and albacore, must use circle hooks and whole finfish bait (with some exemptions), but this covers less than 1% of WCPO longline effort, even though approximately 20% of the WCPO longline effort consists of shallow sets. The remaining 80% of longlining, which is deeper-set, has no mitigation requirements. In the east, shallow longliners must use circle hooks or finfish bait. Turtle interaction rates are thought to be higher in shallow-set longlines, but mortality rates are higher in deeper sets because sea turtles have a higher probability of asphyxiation.Interactions between marine mammals and longliners have been recorded, but data is very poor They can be attracted by the fish caught on the line. Species have included false killer whales and other cetaceans. A 2023 review estimated that mammals represented 0.01% of WCPFC longline catch from 2003-2019, and around 1,500 individuals in 2021. IATTC does not have enough data to assess longline mammal bycatch in the east Pacific. There were 11 reported deaths in 2021, which is a minimum estimate, given the data gaps.