Preliminary standardized CPUE for the autumn cohort of neon flying squid caught by Japanese squid jigging fishery from 2007 to 2025 in the North Pacific

We standardized the catch per unit effort (CPUE) of the autumn cohort of neon flying squid (Ommastrephes bartramii), based on Japanese squid jigging fisheries in the North Pacific during the summer between 2007 and 2025. The cohort was defined as individuals caught in areas east of the 170°E longitude line. We used generalized additive models to standardize the nominal CPUE, incorporating temporal (year and month) and spatial (longitude and latitude) variables. The model with the lowest AIC value was selected as the best performing model. We found that the annual standardized CPUE derived from the best GAM showed a similar trend to the nominal CPUE. Although there is still room for improvement in cohort separation methods, this standardized CPUE can serve as a fishery-dependent abundance index in future stock assessments of this species.