An Individual-based model (IBM) for studying the blue mackerel larval transport in East China Sea (ECS), for the first time, is developed based on Ichthyop model. Coastal and Regional Ocean Community model (CROCO), a typical hydrodynamic model, is configured as well to provide Ichthyop with the physical variables (e.g. temperature, salinity, current). Effects of physical environments (current and temperature), spawning ground/depth/time and diel vertical migration (DVM) on aspects of the early life stage of blue mackerel, including connectivity between spawning ground and nursery area, temperature-dependent mortality, transportation and dispersal distance, are discussed in detail for the first time based on IBM. Two transport scenarios are considered in our simulations: (1) passive Lagrangian transport and (2) DVM. The experimental results show that the transport of the blue mackerel in ECS is principally controlled by the Kuroshio Current (KC) and Tsushima Warm Current (TSWC). Most of the larvae that affected by TSWC are mainly remained in ECS stock, while those controlled by KC are generally confined in the Pacific stock. In passive Lagrangian transport, the larvae from the largest spawning ground do not only remain in ECS stock but also drift to the Pacific stock in February. In travelling to the Pacific stock, the larvae will experience a long-distance trip and may spread away from the suitable growth area, which is not conducive to their survival. Whereas in DVM scenario, cases with different vertical migration mechanisms all have shorter dispersal distances comparing to the first scenario, the long-distance movement is significantly reduced during the simulating period, particularly in February. DVM tends to prevent the larvae entering the Pacific stock from the largest spawning ground in ECS, thus could increase the recruitment and survival for ECS stock.

基于Ichthyop模型，首次建立了一个基于个体的模型（IBM），用于研究东海蓝鲭鱼的幼体运输（ECS）。还配置了沿海和区域海洋群落模型（CROCO），这是一种典型的水动力模型，可以为鱼鳞提供物理变量（例如温度，盐度，电流）。物理环境（电流和温度），产卵场/深度/时间和介电迁移（DVM）对鲭鱼早期生命期各个方面的影响，包括产卵场与苗圃区域之间的连通性，与温度相关的死亡率，运输和扩散距离，是首次基于IBM进行详细讨论。在我们的模拟中考虑了两种传输方案：（1）无源拉格朗日传输和（2）DVM。实验结果表明，在ECS中蓝鲭鱼的运输主要受黑潮（KC）和对马暖流（TSWC）的控制。受TSWC影响的大多数幼虫主要保留在ECS种群中，而由KC控制的幼虫通常局限于太平洋种群。在被动拉格朗日运输中，来自最大产卵场的幼虫不仅保留在ECS种群中，而且在2月流向太平洋种群。在前往太平洋种群时，幼虫将经历一次长途旅行，并可能从适当的生长区域扩散开，这不利于它们的生存。相对于第一种情况，在DVM情况下，具有不同垂直迁移机制的情况都具有较短的分散距离，在模拟期间，特别是2月，长途运动明显减少。DVM倾向于防止幼虫从ECS最大的产卵场进入太平洋种群，因此可以增加ECS种群的募集和生存。