Standardized CPUE of Pacific saury (Cololabis saira) caught by the Chinese Taipei stick-held dip net fishery up to 2020

The Pacific saury catch and effort data for the Chinese Taipei saury fishery in the Northwestern Pacific Ocean were collected from 2001-2020. Two alternative
approaches, generalized linear models (GLMs) and generalized additive models (GAMs), were used to standardize the catch per unit effort (CPUE) of Pacific saury, with an assumption of lognormal error distribution. In this study an updated version (incorporating 2020 data) of the previous year’s CPUE standardization data set derived from fishing logbooks was used. Most of the main explanatory variables and interaction terms used in the modeling analyses were statistically significant. The results derived from both approaches, GLMs and GAMs, were almost identical. Standardized CPUE of Pacific saury for the Chinese Taipei saury fishery in the Northwestern Pacific Ocean showed a general oscillating trend with a slight increase observed from 2001-2010, followed by a sharp increase through to 2014, a sharp decline until 2017, a dramatic increase in 2018, and then an abrupt decrease to 2020. We suggest using the standardized CPUE series derived from the GAM as basic input data in stock assessments.