Seasonal variation of the zooplankton vertical migration in the southern Yellow Sea described by acoustic method
基于声学方法的南黄海浮游动物垂直迁移季节变化研究

Data from acoustic current profiler deployed as mooring in four seasons are analyzed to study seasonal variation of the zooplankton vertical migration in the southern Yellow Sea. Volume backscattering strength measured with acoustic current profiler has dominant diel variation, which results from vertical migration of zooplankton. The vertical migration (downward at dawn and upward at dusk) occurs in all four seasons. However, the occurrence time of the vertical migration shows seasonal variation. The relationship between the migration occurrence time and the daylight is discussed based on the direct observation of radiative flux. It shows that the seasonal variation of the migration occurrence time is mainly affected by the daylight. All these are important for characterization of zooplankton vertical migration mechanism.