Alfonsino age and growth

This project will contribute to the 2026 assessment and build on the work undertaken by Krusic-Golub K. and Robertson S.G. (2020), Brouwer et al. (2020), and Brouwer et al. (2021) to develop growth and maturity curves for alfonsino (Beryx splendens) in the Western and Eastern stocks of the Southern Indian Ocean, using otoliths collected and held by the Cook Islands and Japan. The results from the bomb radiocarbon ageing project (SER2022-BYS2) and the 2024 development of a new ageing protocol should be used.
The development of this project is dependent upon the completion of the alfonsino ageing protocol project (ALF-2024-01).
Objectives:
1. Select 20 otoliths for each 5 cm length bin for both male and female fishes caught at each of the Western and Eastern stocks (about 400 otoliths in total).
2. If otolith weight proves to be a useful tool to estimate age a larger sample can be processed using otolith weight to estimate age.
3. Develop sex separated and combined sex growth curves for alfonsino for both stocks and combined area SIOFA growth curves.
4. Use the biological sampling to develop maturity curves in both areas.
5. Provide growth curve parameters suitable for use in a stock assessment for the stocks.