Abundance and Distribution Estimation for Chub Mackerel and Blue mackerel in the Northwest Pacific Based on Scientific Research Surveys

This document tends to provide some information based on fishery independent survey in the convention area for Chub mackerel and its bycatch species, Blue mackerel. Based on the Chinese survey data during 2021~2023, the results of this study indicating that there are obvious temporal and spatial variations for the catch and abundance of mackerels. The catch, density and relative biomass estimates were much lower in 2022 and 2023 than those in 2021. Generally, the catch of BM is covering about 17% of mackerels catch in 2023. This document provides preliminary but important information for understanding the population dynamics of Chub mackerel in the high sea, with some uncertainties due to data only covering limit years and area.