Standardized CPUE of Chub mackerel (Scomber japonicus) caught by the China’s lighting purse seine fishery up to 2022

Catch per unit fishing effort (CPUE) standardization is an important approach to obtaining accurate indices of resource abundance by removing the influence of external factors. Chub mackerel (Scomber japonicas) is an economically important small pelagic fish inhabiting the Northwest Pacific Ocean. Most of the Chub mackerel catch is harvested by the lighting purse seine fishery in China. In this paper, we standardized CPUE of Chub mackerel using generalized linear model (GLM) and generalized additive model (GAM). Four groups of independent variables were considered in the CPUE standardization: spatial variables (latitude and longitude), temporal variables (year and month), fishery variables (vessel length and proportion of chub mackerel) and environmental variables (SST and Chla). The model selections of GLM and GAM were based on the Bayesian information criterion (BIC). From the results, Higher Spearman’s correlation and lower mean squared error (MSE) were observed by GAM. Therefore, we prefer to choose the best GAM model to estimate standardized CPUE of Chub mackerel fishery.