These Regulations amend the Sea-Fisheries (Common Fisheries Policy) (Bluefin Tuna) Regulations 2016 to implement further measures for the protection of Bluefin Tuna (Thunnus Thynnus) adopted by the European Union as a contracting party to The International Commission for the Conservation of Atlantic Tunas. The multiannual recovery plan for bluefin tuna in the eastern Atlantic and Mediterranean is implemented by Council Regulation (EC) No. 2016/1627 (the Bluefin Tuna Regulation) as amended by Regulation (EU) 2019/833 of the European Parliament and of the Council. A master shall ensure that by-catches of bluefin tuna are retained until the level of 5% of total catches is reached, and a master shall ensure the level of by-catches of bluefin tuna shall not exceed 5% of the total catches on board at the end of each fishing trip.