Japanese longline CPUE for yellowfin tuna in the Indian Ocean standardized by generalized linear model which includes cluster analysis

Japanese longline CPUE for yellowfin tuna in the Indian Ocean (area specific) was standardized for 1975-2020 by GLM based using the method in the new CPUE collaborative analysis. Cluster analysis was conducted before standardization, and cluster number was used for main effect as well as year, quarter, vessel ID and five degree latitude/longitude blodks. Basically, standardized CPUEs showed similar trends among areas. CPUEs continuously decreased from 1970s to around mid 2010s, and those showed slight increasing grend after that. Trend of CPUEs was similar to those in the previous studies.