Northern Albacore
MSE work for northern albacore began officially with Recommendation by ICCAT to establish harvest control rules for the North Atlantic albacore stock (Rec. 15-04). The development of the interim HCR at ICCAT was based on simulations conducted using a specifically designed (MSE) framework.
The software for the simulations was reviewed in 2018 (SCRS, 2019). The SCRS concluded that the advice provided was robust to a wide range of uncertainties. The ICCAT Commission adopted in 2017 the Recommendation by ICCAT on a harvest control rule for North Atlantic albacore supplementing the Multiannual Conservation and Management Programme, Rec. 16-06 (Rec. 17-04), which included an interim harvest control rule for North Atlantic albacore (Thunnus alalunga), representing the first harvest control rule adopted by ICCAT. The Commission reviewed the interim HCR in 2021 (Recommendation by ICCAT on conservation and management measures, including a Management Procedure and Exceptional Circumstances Protocol, for North Atlantic albacore (Rec. 21-04)) with a view to adopting a long-term management procedure. The Commission also adopted the Exceptional Circumstances protocol for North Atlantic albacore in 2021 (Rec. 21-04, Annex 2). The ICCAT Commission has since 2021 adopted the TAC recommendation for northern Atlantic albacore based on the Management Procedure that included the evaluation of the Exceptional Circumstance protocol every year by the SCRS.
Atlantic Bluefin Tuna
Atlantic bluefin tuna has complex dynamics involving two stocks (eastern and western) with long-distance movements and mixed-stock fisheries. MSE for Atlantic bluefin tuna was under development since at least 2014. After the substantial efforts by both the SCRS and the Commission, a Management Procedure (MP) was adopted in 2022 (Recommendation by ICCAT establishing a Management Procedure for Atlantic bluefin tuna to be used for both the western Atlantic and eastern Atlantic and Mediterranean management areas (Rec. 22-09)) and decided the TAC in 2023-2025 for both stocks as provided by the MP (Recommendation by ICCAT amending the Recommendation 21-08 establishing a Multi-annual Management Plan for bluefin tuna in the eastern Atlantic and the Mediterranean (Rec. 22-08) and Recommendation by ICCAT for a conservation and management plan for western Atlantic bluefin tuna (Rec. 22-10)). The final remaining task for full adoption of the MP is to agree on the Exceptional Circumstances protocol in 2023.
Detailed histories of BFT MSE activities can be found in the SCRS Reports and the Documents/Activity Reports of the ICCAT Atlantic-Wide Research Programme for Bluefin Tuna (GBYP). The Intersessional Meeting of Panel 2 in 2019 and the Resolution by ICCAT on development of initial management objectives for eastern and western bluefin tuna (Res. 18-03) provided guidance on initial operational management objectives. Since the SCRS adopted the Operating Models (OMs) at the Second Intersessional Meeting of the Bluefin Tuna Species Group in 2021, the SCRS focused on the development of Candidate MPs and interacted frequently with the Commission for the final adoption of the MP through intersessional meetings and so-called Ambassadors webinars that presented the MSE results to a wider community of stakeholders and decision makers. The SCRS evaluated the Exceptional Circumstances protocol in 2023 and will review the MP in 2026.
Northern Swordfish
Elements of MSE for northern swordfish have been explored at ICCAT for some time. Since the Intersessional Meeting of the Swordfish Species Group on MSE in 2018, the SCRS formally initiated the development of MSE, which included defining and conditioning Operating Models (OMs). Further refinement of OMs and testing of alternative Management Procedures has continued from 2019 to 2023. The SCRS presented to the Commission the proposed Management Procedure for northern Atlantic swordfish stock in 2023.
Southern Atlantic swordfish
While there is no formal MSE process in place for southern Atlantic swordfish, the SCRS is exploring some preliminary elements of MSE for this stock. These include analyses of Management Procedure performance from a limited number of management procedures.
Tropical Tunas
ICCAT has started developing MSEs for tropical tuna stocks in 2018. These included two processes: a) the Multi-Stocks Tropical Tunas MSE including bigeye tuna, yellowfin tuna, and eastern skipjack tuna MSE; and b) the Western Skipjack MSE. Since 2022, the ICCAT Commission and the SCRS have actively interacted on these MSEs through Panel 1 meetings and capacity building workshops.
Multi-stocks Tropical Tunas
Given the complexities of developing Operating Models (OMs) to capture the dynamics of a mixed, three-stock (Atlantic bigeye tuna, Atlantic yellowfin tuna, and eastern skipjack) purse seine fishery, the MSE for multi-stocks tropical tunas has had slow progress. Some preliminary work has been done on all MSE elements. These include some preliminary work on a simulation toolbox, Flbeia for multi-stock bio-economic impact assessment fisheries management strategies; Operating Model conditioning, observation error models, and Management Procedure development.
Western skipjack
The MSE work for the western Atlantic skipjack stock has advanced rapidly since 2022. In 2022, the Commission agreed on conceptual management objectives (Resolution by ICCAT on development of initial conceptual management objectives for western Atlantic skipjack (Res. 22-02)) for the western skipjack stock, and further revised them through the Intersessional Meeting of Panel 1 in 2023. In 2023 the SCRS completed the development of the OMs and provided refined candidate Management Procedures. The SCRS presented to the Commission the proposed Management Procedure for Western Skipjack in 2023.
Sharks
While there is no formal MSE process in place for sharks, closed-loop simulation techniques have been used to explore the consequences of different data and assessment model choices on management procedure performance for Northeast porbeagle shark. Given the current absence of time series of relative abundance for the stock, such analyses are important for exploring assessment and management options.