Standardized CPUE of Pacific saury (Cololabis saira) caught by the Chinese Taipei stick-held dip net fishery up to 2023

Catch and effort data of Pacific saury for the Chinese Taipei saury fishery in the Northwestern Pacific Ocean were collected from 2001-2023. Standardization of the catch per unit effort (CPUE) of saury was conducted using a generalized linear model (GLM) with two approaches: one used the 2001-2023 data (non-divided period approach) and the other divided the data into two periods (two-divided period approach). Most of the main explanatory variables and interaction terms used in the modeling analyses were statistically significant in both approaches. The exhibit trends of the standardized CPUEs derived from both approaches were uniform. The standardized CPUE from 2001 to 2011 exhibited an oscillation with a slight increase, followed by a sharp increase until 2014, a steep decline until 2017, a dramatic increase in 2018, a sharp decline until 2021, and a moderate rise from 2022 to 2023. We recommend using the standardized CPUE series from the two-divided period approach, which accounts for the impact of fishing efficiency changes from the significant replacement of old fishing vessels, as basic input data for stock assessments.