Program(s) in charge: Stock Assessment Program
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- Develop sampling designs for estimating well-level and trip-level catch composition to be used in the IVL enhanced port-sampling program in 2023-2024.
- At the 98th Meeting of the IATTC, the Commission established an IVL program for bigeye tuna catches (Resolution C-21-04), which is to include a special portsampling program (“IVL enhanced port-sampling program”) for trips considered to have caught a significant amount of bigeye tuna.
- To implement the IVL enhanced port-sampling program, the sampling protocol of this program needs to be tailored to estimation of well-level and trip-level catch composition.
- The sampling protocol of the current IATTC port-sampling program is not appropriate for this task because it was designed for estimation of fleet-level catch composition and was based on results of studies conducted prior to the expansion of the fishery on fish-aggregating devices in the 1990s.
- Given this, as outlined in SAC-13 INF-E, an IVL pilot study is planned for the second half of 2022 to: 1) collect extensive well sampling data for a simulation study to test sampling designs for well-level and trip-level catch composition estimation; and, 2) field-test the best sampling designs from (1) to identify and mitigate any logistical issues in advance of the initiation of the IVL enhance port-sampling program in 2023.
- Relevance for management
- Development of sampling designs for estimation of catch composition for individual vessel trips is essential to the success of the IVL enhanced port-sampling program and to the IVL Program, more generally.
- 6 months
- Workplan and status
- July – October 2022: collect extensive well sampling data and conduct a simulation study to test sampling designs.
- November – December 2022: Field-test sampling designs developed in the simulation study, to identify and mitigate any logistical issues.
- External collaborators
- Government of Ecuador (4 samplers to be provided in-kind)
- Reports for the SAC and the Commission; publications in peer-reviewed journals.