Simulation Study on the Interannual Variation of the Transport and Distribution of Chub Mackerel (Scomber japonicus) Larvae and Juveniles Using Individual-Based Model

An individual-based model of Scomber japonicus in the East China Sea (ECS) was developed to simulate the effects of physical environment on the transport and distribution of eggs, larvae and juveniles of S. japonicus from 1978 to 2013. The results showed that there were interannual differences in the transport and distribution of eggs, larvae and juveniles of S. japonicus in the ECS due to different physical environments from 1978 to 2013, and this difference was extremely obvious in some specific years. The current in the drift path of eggs and juveniles controlled and affected the transport process and distribution characteristics. In April, the distribution of eggs and larvae was mainly controlled by the Taiwan Warm Current (TWC). The number of eggs and larvae transported into the northeastern waters of the ECS was positively correlated with the intensity of TWC. In May, it was mainly regulated by the TWC and the Tsushima Strait Warm Current (TSWC). In June, the number of larvae and juveniles entering the Tsushima Strait and the Pacific Ocean was determined by the TSWC. In general, in the years with high number of larvae and juveniles into the Tsushima Strait, the catch of 0-year-old S. japonicus was also higher. In addition, the number of larvae and juveniles entering the Tsushima Strait in El Niño years was less than that in La Niña years. In July, the transport was mainly controlled by the Kuroshio Current (KC), and the eddy within the KC strongly affected its distribution.