Review on the Indian Ocean albacore biological parameters for stock assessments (update)

IOTC will conduct stock assessments for ALB (albacore) in the WPTmP08 (July 25-29, 2022). Before the July assessment meeting, IOTC will take place the on-line “data preparatory meeting (April 13-15, 2022)” and will discuss input data for stock assessments. In this regard, I reviewed the updated information on the stock structure and seven biological parameters of ALB to be used for the stock assessments. Seven types of biological parameters are (1) sex ratio, (2) LW relation, (3) growth equation, (4) life span (plus group), (5) natural mortality, (6) fecundity and (7) maturity-at-age. In this review, I referred to parameters used in ICCAT, WCPFC, ISC and IOTC. Then plausible parameters for the ALB stock assessments are evaluated then suggested for both base case and sensitivity. As a result, the same stock structure and seven parameters used in the 2019 ALB stock assessments are suggested again as a base case to apply for the 2022 ALB stock assessments. We need to confirm this and also discuss options of sensitivities during this data preparatory meeting. Some future works to improve biological parameters are suggested.