The East China Sea (ESC) is a highly productive continental shelf sea, however, the important ecosystem services it provides are under pressure from environmental and climate change. A better understanding of the interplay between ecosystems and ecosystem stressors will enable more efficient management of ecosystem services. Our approach is to develop new modelling tools that will deliver an improved understanding of the interactions among the components of the pelagic ecosystem. We developed simulations through a 1D physical-biogeochemical coupled model: GOTM-FABM-ERSEM that considered phytoplankton, zooplankton, bacteria, particulate matter and nutrients as state variables. Model results indicate that phytoplankton characteristics are driven by temperature, light, feeding pressure and nutrient availability, with two clear productive periods in spring and autumn. The maximum chlorophyll-a occurs in summer with a peak of 5.3 mg C m-3 along with high temperature and stable stratification of water column. In addition, phytoplankton show cyclic variability influenced by season, light and tides. The timing of zooplankton and bacteria is similar to that of phytoplankton, though with a 3-day lag in spring, related to the trophic level in the ecosystem; respective biomasses reach highest values of 150 mg C m-3 and 39 mg C m-3 in the spring. Zooplankton also exhibits two productivity peaks through a year where as bacteria are present year round.