Standardized CPUE for the autumn and winter-spring cohorts of neon flying squid based on Japanese driftnet surveys from 2001 to 2025

We standardized the catch per unit effort (CPUE) for the autumn and winter–spring cohorts of neon flying squid (Ommastrephes bartramii) using data from Japanese driftnet surveys conducted in the western North Pacific from 2001 to 2025. Captured individuals were separated into specific cohorts based on their mantle length. Generalized additive models (GAMs) were applied to standardize the CPUE by incorporating temporal (year and ten-day period), spatial (latitude and longitude), and environmental (sea surface temperature) variables. The standardized CPUE series generally tracked the nominal CPUE trends for both cohorts. These standardized indices can serve as a robust, fishery-independent abundance index for future stock assessments of this species.