Few appropriate management measures are in place. Management is not effective at controlling fishing pressure on this stock. Catch limits have been exceeded in every year since 2015, at levels that are expected to cause the stock to decline.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.Atlantic yellowfin tuna 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 controls on fishing gear.The TAC for yellowfin has been 110,000 tonnes since 2012. Scientific advice is that keeping catches at 120,000t or less is expected to maintain healthy stock status through to 2033. This indicates that catch limits are following scientific advice.However, catches have exceeded the TAC every year since 2015. Average catch from 2016-2020 is 140,000 tonnes, which is expected to cause the stock to decline. The scientific committee has suggested that existing conservation and management measures appear to be insufficient and need to be strengthened.Most yellowfin tuna catches are by purse seine nets, many of which use Fish Aggregating Devices (FADs). FADs are floating objects that attract tuna and other species, making it easier to set nets around them to catch them. Many juvenile fish are caught in these fisheries, which can have implications for future population growth. The recent average weight in European purse seine catches, which represent the majority of the landings, has declined to about half of the average weight of 1990, at least in part due to the use of FADs and the increased catches of small yellowfin.Consequently, a multi-annual management plan has been in place for bigeye and yellowfin since 2012, and eastern skipjack since 2015. It is mostly focussed on FAD management. Initially there was a 2-month FAD ban in an area where there are high concentrations of juveniles, and a 500 FAD limit per vessel for the rest of the year. This failed to reduce the mortality of juvenile bigeye and yellowfin tuna, so additional measures were added in 2019. The number of FADs per vessel was reduced to 300 for 2021 and 2022. The FAD ban was extended to the full convention area, lasting for 72 days in 2022 (January to mid-March). In 2021 the scientific committee advised that it was too soon to evaluate the impact of these changes. In 2021 the number of permitted support vessels, which help to increase the efficiency of purse seiners, was frozen.As well as the above measures, there is a ban on discarding skipjack, yellowfin and bigeye tuna, so that all fish caught must now be landed. There is also a tagging programme to improve stock assessments for tropical tunas and gauge effectiveness of management measures. This helped to improve the quality of the 2019 yellowfin assessment.Other management by ICCAT includes:A ban on drift nets by the EU in 2002 and by ICCAT in the Mediterranean in 2003.A list of vessels authorised to fish for this species, 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.A requirement for 100% observer coverage on large purse seiners targeting tropical tunas all year round. The requirement for longline is only 5%, increasing to 10% in 2022. Many fleets are not reaching this level. Scientific recommendations are 20% for accurate data. Work is underway to improve electronic monitoring. Vessel Monitoring Systems are required for all vessels over 24m.
