Swordfish

The swordfish stock in the Mediterranean is overfished but not subject to overfishing.This stock is managed and assessed by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Mediterranean swordfish have been fished for some time, but catches began to increase from the 1960s. They peaked at 20,000 tonnes in the 1980s, and have since fluctuated at around 14,000 tonnes. The last stock assessment was carried out in 2020, using data up to 2018.Biomass (B) has steadily declined since 1970, and dropped below the target level (Maximum Sustainable Yield, MSY) in the 1990s. In 2018, biomass was at its lowest level on record, at 72% of BMSY. There, it is in an overfished state and at increased risk of suffering reduced reproductive capacity.Fishing mortality (F) exceeded the target level in the 1980s and has generally fluctuated at high levels since. It decreased in 2013, and in 2018 was slightly below the target level at 93% of FMSY. Therefore, the stock is not subject to overfishing.Projections indicate that the stock will reach BMSY by 2028 with 60% probability if catches are 10,000 tonnes. There would be a higher probability at lower catch levels. However, this is assuming that recruitment of young swordfish into the stock stays at long term averages. Recruitment has been declining for the past 10 years, and catches of juveniles are too high. Swordfish younger than 4 years represent more than 70% of annual catches in terms of numbers of fish caught. These projections could therefore be too optimistic.The 2020 assessment employed different models and better catch and discard data than the 2016 one. It shows a much better stock status than in 2016, when the spawning biomass was estimated to be at just 12% of MSY, and F was 185% of FMSY.

A recovery plan came into force for this stock in 2017. It has successfully reduced catches, but there are still uncertainties in the catch data. Monitoring and enforcement needs to be improved, and juvenile catches need to be reduced. 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 measure is a 15-year recovery plan, running from 2017-2031. It aims to recover the stock to target levels (BMSY) with 60% probability by the end of the plan, and is currently on track to do so.Catch limits (Total Allowable Catches, TACs) were introduced in the plan in 2017, starting at 10,500 tonnes (including bycatch), and reducing by 3% each year to reach 9,017t in 2022. In 2020 it was projected that the stock would reach BMSY by 2028 with 60% probability if catches were 10,000 tonnes. The rebuilding plan therefore seems to be on track to achieve its target ahead of schedule. However, this is assuming that recruitment of young swordfish into the stock stays at long term averages, and it has been declining for the past 10 years. These projections could therefore be too optimistic. Actual catches have been reducing, and have stayed below the TACs. Average annual catch from 2016-2020 is around 9,440 tonnes. In 2020, the TAC was 9,583t and the catch was 7,665t. This is the lowest since the 1970s. The minimum catch size is 100cm or 10.2kg. Smaller swordfish can be caught if it is less than 5% of total catch for the vessel. This has reduced the number of undersize fish being landed, but observer data shows that it has increased the number of swordfish being discarded at sea by up to 600%. There is concern that most of the discarded swordfish (up to 88% based on studies in other areas) die after being released. 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. It is estimated that dead discards represented about 24% of catches in 2017-2018.Most Mediterranean swordfish are caught by longline. The mandatory level of observer coverage in Atlantic longline 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.Other management measures include a freeze on the number of vessels allowed to fish for swordfish to the average from 2013-2016. Fishing for swordfish is banned for 3 months, and to protect juvenile swordfish a simultaneous 2 month ban also applies to longliners targeting Mediterranean albacore. There is a limit on how many hooks longliners can set (2,500). Hooks must be larger than 7cm, and lines can be up to 55km. Sport fishing is limited to one fish per day. 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 Mediterranean are by longline. This method can have a bycatch of highly vulnerable species. Of greatest concern in the Mediterranean are the critically endangered Balearic shearwater and blue shark.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 5%, increasing to 10% in 2022. 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 and turtles are more easily attracted to the bait.In the Mediterranean, the main bycaught seabird species is the Cory’s shearwater. While the species is not threatened, bycatch could cause local depletion in some populations. Other species include the critically endangered Balearic shearwater. Studies indicate that at the current bycatch rate, the Balearic shearwater may be extinct in 60 years. The highest bycatch rates appear to be by demersal and/or small-scale longliners, rather than drifting or surface longliners targeting tuna and swordfish. However, data is insufficient to properly quantify impacts by the different gear types. To reduce seabird bycatch, ACAP (the Agreement on the Conservation of Albatrosses and Petrels) recommends the simultaneous use of weighted hooks, bird scaring lines and night setting; or hook-shielding or underwater bait setting devices. In the Mediterranean, no mitigation measures are mandatory. Given the critical status of the Balearic shearwater, the absence of mitigation measures in the longline fishery, and the poor observer coverage to monitor impact, this is of significant concern.Most shark, skate and ray bycatch in the Mediterranean is by longlining. Studies on drifting longline fisheries targeting swordfish and tuna across the Mediterranean have shown that sharks and rays represent about 6.2% by number and 13.5% by weight of the total catch. Most bycatches are of blue shark and shortfin mako, both listed as Critically Endangered in the Mediterranean. Numerous other endangered species are listed as bycatch in the area. Blue shark catches are so high in some areas that they may be considered as a target species rather than as bycatch. The bycatch rates and the status of blue shark in this area are of serious concern.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. 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 aimed at ending overfishing of this species.It is estimated that in the last 10 years, drifting longliners have been responsible for the bycatch of around 27,000 turtles in the Mediterranean, resulting in around 5,300 direct deaths and an unknown number of delayed deaths after being released. This is lower than bottom trawling (9,000 deaths) and set nets (16,000 deaths). Three species live in the Mediterranean: green (Endangered), loggerhead (Least Concern) and leatherback (Vulnerable). Loggerhead bycatch rates are particularly high in this area, although some data may indicate that populations are increasing. Bycatch rates appear to be declining owing to new technologies and and fishing strategies. Longliners are required to safely unhook and release alive turtles. Other scientifically recommended mitigation measures, such as using finfish bait and large circle hooks, are not mandated.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. A Spanish observer programme on Mediterranean longlining from 2000-2009 recorded only 52 interactions with marine mammals, mainly Risso's dolphins. The Mediterranean subpopulation of this species is Endangered.Drift nets were banned by the EU in 2002 and by ICCAT in the Mediterranean in 2003. This has helped to reduce fishing mortality of endangered, threatened and protected species. However, some fisheries are still known to employ them either illegally or through loopholes in the regulation.

ACAP, 2021. ACAP Review of mitigation measures and Best Practice Advice for Reducing the Impact of Pelagic Longline Fisheries on Seabirds. Reviewed at the Twelfth Meeting of the Advisory Committee Virtual meeting, 31 August – 2 September 2021. Available at https://www.acap.aq/resources/bycatch-mitigation/mitigation-advice/3956-acap-2021-pelagic-longlines-mitigation-review-bpa/file [Accessed on 09.12.2021].ACCOBAMS, 2019. Review of bycatch rates of cetaceans in the Mediterranean and the Black Sea. ACCOBAMS-MOP7/2019/Doc 29. Seventh Meeting of the Parties to ACCOBAMS, 5-8 November 2019. Istanbul, Republic of Turkey. Available at https://accobams.org/wp-content/uploads/2019/04/MOP7.Doc29_Review-cetaceans-bycatch.pdf [Accessed on 23.12.2021].Anon., 2021. Advances on the collaborative work to assess sea turtle bycatch in pelagic longline and purse seine fleets (Atlantic and Indian oceans and Mediterranean Sea). SCRS/2021/076. Collect. Vol. Sci. Pap. ICCAT, 78(4): 155-166. Available at https://www.iccat.int/Documents/CVSP/CV078_2021/n_4/CV078040156.pdf [Accessed on 16.12.2021].Biton-Porsmoguer, S. & Lloret, J. 2018. Potentially unsustainable fisheries of a critically-endangered pelagic shark species: the case of the blue shark (Prionace glauca) in the Western Mediterranean Sea. Cybium, 42(3): 299–302. https://www.researchgate.net/profile/Sebastian-Porsmoguer/publication/323453937_Potentially_unsustainable_fisheries_of_a_critically-endangered_pelagic_shark_species_The_case_of_the_blue_shark_Prionace_glauca_in_the_Western_Mediterranean_Sea/links/5bc594bc458515f7d9bf4b76/Potentially-unsustainable-fisheries-of-a-critically-endangered-pelagic-shark-species-The-case-of-the-blue-shark-Prionace-glauca-in-the-Western-Mediterranean-Sea.pdf.Carpentieri, P., Nastasi, A., Sessa, M. & Srour, A., eds. 2021. Incidental catch of vulnerable species in Mediterranean and Black Sea fisheries - A review. General Fisheries Commission for the Mediterranean. Studies and Reviews. No. 101. Rome, FAO. Last updated 2/07/2021. https://doi.org/10.4060/cb5405en.Casale, C., Broderick, A.C., Camiñas, J.A., Cardona, L., Carreras, C., Demetropoulos, A., Fuller, W.J., Godley, B.J., Hochscheid, S., Kaska, Y., Lazar, B., Margaritoulis, D., Panagopoulou, A., Rees, A.F., Tomás, J., and Türkozan, O., 2018. Mediterranean sea turtles: current knowledge and priorities for conservation and research. Endang. Species Res. 36, pp. 229-267 https://doi.org/10.3354/esr00901.Genovart, M., Manuel Arcos, J., Alvarez, D., McMinn, M., Meier, R., Wynn, R.B., Guilford, T. and Oro, D., 2016. Demography of the critically endangered Balearic shearwater: the impact of fisheries and time to extinction. Journal of Applied Ecology: 53, pp. 1158–1168. https://doi.org/10.1111/1365-2664.12622.ICCAT, 2020. 5.3 SWO-MED – Mediterranean swordfish. From 2020 SCRS Advice to the Commission, September 2020, Madrid, Spain. 362pp. Available at https://www.iccat.int/Documents/SCRS/ExecSum/SWO_MED_ENG.pdf [Accessed on 23.12.2021].ICCAT, 2021. 2021 SCRS Report: Panel 4-Swordfish, Billfishes, Sharks, Small tunas. Presented to the 27th Regular Meeting of the Commission. 15-23 November 2021, Online. Available at https://www.iccat.int/com2021/presentations/SCRS_Chair_2021_PA4_Presentation.pdf [Accessed on 16.12.2021].ICCAT, 2021. 2021 Secretariat Report on Research and Statistics. PLE-105 presented to the 27th Regular Meeting of the Commission. 15-23 November 2021, Online. Available at https://www.iccat.int/com2021/ENG/PLE_105_ENG.pdf [Accessed on 15.12.2021].ICCAT, 2021. Report of the Standing Committee on Research and Statistics (SCRS), 27 September - 2 October 2021, Online. Available at https://www.iccat.int/Documents/Meetings/Docs/2021/REPORTS/2021_SCRS_ENG.pdf [Accessed on 14.12.2021].ICCAT, 2021. Resolutions, Recommendations and other Decisions. Available at https://www.iccat.int/en/RecRes.asp [Accessed on 16.12.2021].IUCN, 2021. The IUCN Red List of Threatened Species. Available at https://www.iucnredlist.org/ [Accessed on 23.12.2021].