Sediment microbiota dynamics along PRE

River estuaries are dynamic and complex ecosystems influenced by various natural processes, including climatic fluctuations and anthropogenic activities. The Pearl River estuary (PRE), one of the largest in China, receives significant land-based pollutants due to its proximity to densely populated areas and urban development. This study aimed to characterize the composition, diversity, and distribution patterns of sediment microbial communities (Bacteria, Archaea, and Eukaryotes) and investigated the connection with environmental parameters within the PRE and adjacent shelf. Physicochemical conditions, such as oxygen levels, nitrogen compounds, and carbon content, were analyzed. The results showed that the microbial community structure was primarily influenced by site location and core depth, with differences in sediment properties like organic matter content and redox conditions. The different sites and core depths were characterized by specific microbial groups, in turn, linked to variations in specific chemical properties of the sediment, particularly C/N ratio and NH4+ concentration. Overall, this study underscores the critical role of microbial communities in shaping biogeochemical processes in estuarine environments and their sensitivity to environmental changes, providing valuable insights for managing and preserving the health of estuaries and coastal ecosystems.