Swordfish

Swordfish in the south west Pacific Ocean is not overfished and not subject to overfishing.This stock is assessed and managed by the Western and Central Pacific Fisheries Commission (WCPFC). Fishing for this stock began in the 1950s and catches increased to a peak in 2012 of around 11,000 tonnes. They have since declined to around 7,000t. The last stock assessment was carried out in 2021, using data up to 2019. The next assessment is expected in 2025. Spawning biomass (SB) is estimated to have gradually declined from the 1950s to the mid-1990s before rapidly declining to an overall low point in around 2010. Stock size in 2019 is close to this level, at 39% of unfished levels. However, it is thought to be around 3 times the level associated with Maximum Sustainable Yield (SB MSY). Therefore, the stock is not in an overfished state.Fishing mortality (F) is predicted to have increased gradually through the mid-1990s and sharply increased in the early-2000s. It appears to have stabilized at high levels in the last decade. However, it remains below the MSY level, at 47% of FMSY in 2019. Therefore, the stock is not subject to overfishing.There are no projections for the stock. The Maximum Sustainable Yield is estimated to be 9,543 tonnes, and catch in 2019 was around 7,700t.

Few appropriate management measures are in place for south west Pacific Ocean swordfish. Management measures only cover part of the fishery, and do not prevent overexploitation. 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 and managed by the Western and Central Pacific Fisheries Commission (WCPFC). Some stocks overlap with the 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.The main management measure for this stock is a freeze on fishing effort and catches to 2000-2006 levels. However, this only applies to an area south of 20 degrees S, which is only responsible for 42% of catches. This leaves half of the fishery effectively unmanaged. In addition, the measure does not include limits on the total fishing mortality on the stock, and so is insufficient to prevent overexploitation. Scientific recommendations are that these two issues be addressed. The Maximum Sustainable Yield is estimated to be 9,543 tonnes, and catch in 2019 was around 7,700t. It is unclear how this compares to 2000-2006 levels. The movement and aggregation behaviours of swordfish make it particularly vulnerable to local depletion. There may also be connectivity between the south western population and south eastern population. The south eastern population has no management and no stock assessment since 2011.Most swordfish is caught by longlining. Since 2011 only 5% observer coverage has been required on large longliners, considered by the scientific committee to be too low for accurate data: a minimum of 20% coverage is recommended. In addition, data recorded by longliners is considered inadequate for scientific purposes and minimum data standards must be identified and introduced.To help address IUU, the WCPFC maintains an IUU Vessel List, prohibits transhipments at sea between purse seiners (some exemptions apply) and requires all other transhipments to be documented and 100% observed as part of the regional observer programme. In 2017 a Compliance Monitoring Scheme was introduced to assess and improve compliance with obligations, and penalise non-compliance.

Most of the swordfish catches in the south west 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 poor, partly because there are not enough scientific observers on vessels. Observer coverage is only required to be 5%, and recommendations are for at least 20%. Some mitigation measures are in place, but they often don't follow scientific recommendations for best practice, and their effectiveness has not been evaluated.In 2020, an estimated 1.7 million sharks were caught as bycatch or had an interaction with WCPO fisheries. Of these, around 34,000 individuals were caught in FAD-free purse seines, 60,000 in FAD-associated purse seines, and 1.6 million by longlining. A proportion of these will have been released alive, however. Observer data indicates that there were 5,500 purse seine mortalities and 3,150 longline mortalities in 2020. As just 5% of the longline fleet is observed, this is a significant underestimate of total mortality. Bycatch species include bigeye thresher, shortfin mako, and silky. Of greatest concern is oceanic whitetip shark, which is in a severely overfished state and critically endangered. In the WCPO, it is at just 4% of unfished levels, although fishing pressure has been reduced and there are some signs of 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. Mobulid rays are also bycaught, but there is very little data on these species.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 are 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.The five marine turtle species in the WCPFC Convention Area (green, hawksbill, leatherback, loggerhead and olive ridley) are vulnerable, endangered, or critically endangered, and WCPFC does not have enough data to assess the threat posed by longline fisheries. Observer data indicates just 46 deaths from longlining in 2020. As just 5% of the longline fleet is observed, this is a significant underestimate of total mortality. There are some mitigation measures, including requirements for safe handling and release. 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 not mitigation requirements. 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.Data on seabird bycatch is not good enough to fully assess the impact of longlining in the WCPO, owing to the low observer coverage. Even the data that is recorded is thought to be a significant underestimate, due to lost, undetected bycatch However, modelling has estimated that between 13,000 and 19,000 seabirds were killed in western Pacific longline and purse seine fisheries from 2015 to 2018. Two thirds of the mortalities were by longline fisheries north of 20 degrees N, one quarter by longline fisheries south of 30 degrees S, and negligible amounts from purse seining. A small area east of Tasmania and south of 40 degrees S is estimated to account for around 60% of the longline seabird bycatch south of 30 degrees S and 15% of the total. Of critical concern is Antipodean wandering albatross, which is expanding its foraging range into tuna fishery areas and has experienced a high and sustained rate of decline - it is now in New Zealand's "Nationally Critical" conservation status category. Countries are expected to implement the International Plan of Action for Reducing Incidental Catches of Seabirds in Longline Fisheries (IPOA-Seabirds) and report back on this. The required longline mitigation measures do not follow recommended best practice by ACAP (the Agreement on the Conservation of Albatrosses and Petrels). WCPFC requires one or two measures (depending on location) from a set list of options, including weighted hooks, bird scaring lines and night setting. ACAP recommends the simultaneous use of all three, or hook-shielding or underwater bait setting devices. Further research is being done on hook shielding devices, and countries are encouraged to develop and refine measures to mitigate seabird bycatch, including safe release of seabirds captured alive. Scientific advice is to increase observer coverage and ensure compliance with existing regulations.Interactions between cetaceans and longliners have been recorded, with most resulting in the animal being released alive. Species include false killer whales, toothed whales and oceanic dolphins. They can be attracted by the fish caught on the line. These interactions are not well recorded and the scale of impact by longlining is unclear.

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