The South China Sea (SCS) is a vital marine ecosystem, contributing ~10% of the global fish catch and providing employment for millions of livelihoods. However, increasing anthropogenic pressures—such as overfishing, pollution, and climate change—threaten its sustainability. Phytoplankton blooms, as key indicators of marine productivity, play a crucial role in the food web and are sensitive to environmental changes. In this study, we analysed the phenological characteristics of phytoplankton blooms in the SCS using data. We assessed the timing, intensity, and duration of blooms, focusing their variability across coastal and open sea regions. Preliminary results revealed significant spatial and temporal differences perhaps associated with physical processes. Furthermore, we examined the interannual variability of this the bloom events, in addition to the long-term changes in the phenological characteristics of phytoplankton bloom. Understanding these patterns is essential for sustainable fisheries management and marine conservation in the SCS. Our findings provide insights to inform policies aimed at preserving the region’s biodiversity and food security.

phytoplankton, South China Sea, phenological characteristics