22nd Regular Session of the Scientific Committee

SC22 will review the outcomes of initial activities under Project 129, including progress on rapid ageing research and evaluation of sampling capacity and feasibility, and guide the next phase of the project, including the potential to scale up sampling efforts to support more robust and reliable stock assessments.

• The four-year Project 129, which commenced in 2026, aims to address a key limitation in tuna stock assessments by developing a sustained age-length data stream, given that current assessments rely heavily on size data and static growth assumptions due to limited historical otolith collections and the absence of systematic sampling, resulting in uncertainty and potential bias in estimating age structure and management quantities. The project seeks to increase the use of paired age-length data within assessment models to improve growth estimation and better capture spatial and temporal variability. In 2026, the project focuses on advancing rapid ageing methods using otolith morphometrics for yellowfin and bigeye tuna, and assessing the feasibility and requirements for implementing a structured age-length sampling program at a meaningful scale through engagement with CCMs, distant water fishing nations, and observer programs. These activities will inform whether sufficient support exists to progress to large-scale implementation.