Swordfish

The swordfish stock in the North Atlantic Ocean is not overfished and not subject to overfishing.This stock is managed and assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). The last stock assessment was carried out in 2022, using data up to 2020. It is unclear when the next stock assessment will be.Atlantic swordfish has been caught in targeted fisheries since the 1950s. In the north, catches steadily increased to a peak of 20,000 tonnes in the 1980s. They then declined, and have averaged around 11,000t since the 2010s. However, 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 entire fishery.Biomass (B) of this stock continuously declined from the 1950s until stabilising at around target levels (Maximum Sustainable Yield, MSY) from 2003 onwards. In 2020, biomass was 108% of BMSY. Therefore, the stock is not in an overfished state.Fishing mortality (F) has been increasing since the 1950s, and exceeded MSY in the 1990s. It has since declined and has been below MSY since 2000. In 2020, F was 80% of FMSY. Therefore, the stock is not subject to overfishing.The 2022 stock assessment is an improvement on the 2017 one, in terms of including estimates of discards and understanding uncertainty. However, the status of the stock has remained the same.Catches at 13,200 tonnes (the current catch limit) are expected to allow the population to remain above BMSY and below FMSY with 60% probability. However, the Maximum Sustainable Yield is 12, 819t, so this is expected to cause a decline in biomass. If the 2021 catch level (9,700t) is maintained, the population is expected to remain above BMSY and below FMSY with more than 84% probability.

Management of North Atlantic swordfish seems to be maintaining the stock at sustainable levels, and catches stay within their limits. However, there are some uncertainties in the catch data, and monitoring and enforcement needs to be improved.Tuna, marlin, 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.This stock is managed and assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). The main management measures are a catch limit (Total Allowable Catch, TAC) and a minimum size limit. The aim of management is to keep the stock at target levels (BMSY) with greater than 50% probability. There is an interim lower reference point of 40% of BMSY, at which point additional measures should be implemented to reduce fishing pressure. The commission is working to develop Harvest Control Rules by 2023.The North Atlantic swordfish TAC for 2018-2023 is 13,200t, with individual catch limits assigned to each country. This was a reduction from the 2017 TAC of 13,700t, as scientific advice was that the 2017 level only had a 36% probability of maintaining the stock. The current TAC increases this probability to 60%. Management is therefore following scientific advice.Catches have stayed within the limits. The average from 2018-2021 is around 9,800t. However, for a number of years the scientific committee has raised concerns that countries are not reporting dead discards or live releases of swordfish, which means total fishing mortality is likely to be underestimated. This information is required, but not being provided. The mandatory level of observer coverage in the north and south Atlantic swordfish fisheries is low, at just 5%, rising to 10% in 2022. Many countries are not achieving this level. This is below the recommended minimum of 20%. Monitoring and enforcement therefore requires improvement.There is also a minimum catch size of 25kg or 125cm, with some exceptions. This has resulted in a reduction in landings of undersize north Atlantic swordfish, from 33% of the catch in 2000 to 23% in 2015. Undersize fish hooked in longlines experience a high mortality (around 80%). The lack of reporting on dead discards or live releases of swordfish mean that there is not enough data on the impact of the size limits. It is recommended that more complete data be gathered on fishing effort and size data over the entire Atlantic.In terms of enforcement and compliance with management measures: in 2016 ICCAT passed measures to strengthen and streamline its compliance assessment process and to develop a scheme of responses to non-compliance. There is also a list of vessels authorised to fish for tuna and tuna-like species in the ICCAT area, and a list of vessels caught carrying out Illegal, Unreported or Unregulated activities. At-sea transhipment is prohibited unless pre-authorised and the vessel has an observer on board. Vessel Monitoring Systems are required for all vessels over 24m, but smaller vessels are less well monitored. Swordfish must be accompanied by Catch Documentation when being imported and exported.

Almost all swordfish catches from the north Atlantic are by longline. While longlining is unlikely to have habitat impacts, it can have a bycatch of highly vulnerable species such as sharks, turtles, and seabirds.Monitoring and reporting of bycatch in fisheries managed by ICCAT is poor. Most data come from scientific observers on vessels. Scientific recommendations are that 20% of a fishery should be observed for accurate data. ICCAT only requires coverage of 10%. Many fleets are not reaching this level. This makes it difficult to assess the impact of these fisheries on vulnerable species.Longlining for swordfish and albacore tuna takes place closer to the surface than in other fisheries. This increases the bycatch risk, as animals such as seabirds are more easily attracted to the bait.There is a bycatch of loggerhead, leatherback and olive ridley turtles in longline and purse seine fisheries. According to the IUCN Red List, loggerhead turtles are endangered in the north east Atlantic and leatherbacks are endangered in the north west Atlantic. Observer data for all gears for the whole Atlantic for October 2021 - October 2022 indicates: 190 dead discards of turtles, 3,752 live discards and 69 discards of unknown status. Given the poor observer coverage, this is likely to be an underestimate of the total catch. Data on the impact of individual fisheries is not publicly available. Post-release mortality is 1-4%. Longliners are required to safely unhook and release alive turtles, and purse seiners must avoid encircling them. In 2023, ICCAT brought in additional measures that had been scientifically recommended and proven to be effective, which is to use either circle hooks or finfish bait, or other recommended measures. However, countries achieving 10% observer coverage can request an exemption from this.Seabirds are known to be vulnerable to bycatch in longline fisheries. Observer data for all gears for the whole Atlantic for October 2021 - October 2022 indicates: 1,376 dead discards of seabirds, 55 live discards and 64 discards of unknown status. Given the poor observer coverage, this is likely to be an underestimate of the total catch. Data on the impact of individual fisheries is not publicly available. Bycatch of seabirds is understood to be most problematic in the southern Atlantic. However, increasing evidence indicates that northern species are also at risk in some longline fisheries. For example, up to 1% of the global population of northern fulmars is killed annually in gillnet and longline fishing in the North Atlantic. A study comparing multiple gears in the Atlantic Iberian coast indicated that longlines had the highest seabird bycatch. Reliable bycatch data is needed to assess whether pelagic longlines in the North Atlantic are a concern for seabirds. The required mitigation measures do not follow recommended best practice by ACAP (the Agreement on the Conservation of Albatrosses and Petrels). ICCAT requires one or more measures from a set list of options, including weighted hooks, bird scaring lines and night setting, depending on location and target species. ACAP recommends the simultaneous use of all three, or hook-shielding or underwater bait setting devices. In the Mediterranean, all these mitigation measures are voluntary.Sharks are both bycaught and targeted in longline fisheries in the Atlantic. Bycatch species include the critically endangered scalloped hammerhead, silky shark, and the bigeye thresher, which is endangered in Europe and the Mediterranean. Observer data for all gears for the whole Atlantic for October 2021 - October 2022 indicates: 804 dead discards of sharks and 1,082 live discards. Data on the impact of individual fisheries is not publicly available. Given the poor observer coverage, this is likely to be an underestimate of the total catch. There are some mitigation measures, such as restrictions on finning, but no gear-specific measures. This is in spite of repeated recommendations from the scientific committee to use circle hooks, which have been shown to increase survival of shortfin mako, blue marlin and swordfish if accidentally caught. Circle hooks to prevent turtle bycatch are only required between 55 degrees N and 35 degrees S, which will not cover the full range of these species. 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. However, measures came into force in 2022 and 2023, aimed at ending overfishing of this species.There are no specific management measures to protect marine mammals, including cetaceans. ICCAT has not prioritised collecting data on mammal bycatch to date. More needs to be done to understand and reduce the impact of ICCAT fisheries on marine mammals.

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