Compilation and Summary of Shared Data for Operating Models of the Chub Mackerel in the Northwestern Pacific

As a lead of the OM Small Working Group, I compiled members’ data to be used for the development of operating models in the stock assessment of chub mackerel (Scomber japonicus). I firstly compensated catch-at-age and weight-at-age of China by making simple assumptions because they had missing values in a few years. I then merged the members’ data by using (weighted-)average for weight at age and maturity at age, because the figures were different among members. The four abundance indices of Japan have relatively long time series and clear tuning targets, whereas CPUEs from China and Russia have not associated with ages or growth stages. I distributed two kind of datasets (per-fleet data and the data merged into a single fleet) to the members, which will be used as an input of stock assessment model candidates. Simultaneously, it is important for us to review data quality, interpret large data discrepancies among members, and discuss ways for the data to be incorporated into the forthcoming formal stock assessment of chub mackerel in the Northwestern Pacific.