Hydrological connectivity in tidal creek systems is a fundamental element of coastal wetland ecosystems, influencing the interactions among various key ecological factors within the wetlands. Understanding the mechanisms by which hydrological connectivity affects the functional feeding groups (FFGs) of macrobenthos is crucial for the restoration and maintenance of wetland ecosystems and biodiversity. This study focuses on a typical tidal creek system in the Yellow River Delta, where we investigated macrobenthos, environmental factors, and metal elements across different seasons in tidal creek areas. We employed multi-element fingerprint analysis, non-metric multidimensional scaling (NMDS) analysis, hierarchical cluster analysis (HCA), biological co-occurrence network analysis, and redundancy analysis (RDA) to explore the impact of hydrological connectivity on the ecological functions of tidal creek systems and the structure of macrobenthos FFGs. The results indicate that tidal creeks with greater differences in hydrological connectivity exhibit lower chemical connectivity. Scrapers had the highest abundance proportion in the tidal creek system, accounting for 40.9%. Gathering-collectors were identified as the key feeding functional group for maintaining the stability of biological communities. Areas with high hydrological connectivity showed strong synergistic effects and stability within the macrobenthos communities. The study further demonstrated that hydrological connectivity is a factor influencing the complexity of biological co-occurrence networks in typical tidal creeks. Sediment organic carbon, silicate, ammonia nitrogen, and metal element contents were identified as key factors affecting the structure of macrobenthos FFGs. Ecological function results suggest that high hydrological connectivity characteristics contribute to maintaining the productivity and stability of tidal creek systems.
