Structural characteristics and relative influencing factors of macrobenthos community in intertidal zone of Daya Bay

In recent years, the structure of macrobenthic community and ecological functions of intertidal zone in Daya Bay have changed significantly due to the influence of various factors such as anthropogenic disturbances. In order to understand the changing patterns of ecosystem functioning in the coastal waters of Daya Bay, we obtained the data on the macrobenthos and habitats in six intertidal sections (Three sands, two muds and one artificial shoreline) in summer (August) and autumn (November) of 2021, and analyzed their community structure characteristics and influencing factors. The results show that a total of 118 species were identified, including 82 species in summer and 64 species in autumn, among which molluscs had the largest quantity in both seasons followed by arthropods and annelids. The mean biomasses of the six sampling sections in two seasons were 589.36 and 188.22 g·m⁻², and the mean abundances were 356.39 and 1 010.3 ind·m⁻², respectively, with molluscs and arthropods accounting for a higher proportion. The results of cluster analysis and multidimensional scaling show that the macrobenthic fauna community in the survey areas displayed significant spatial differences. The macrobenthos in the intertidal zone of Daya Bay could be divided into three communities: sand facies, mud facies and artificial shoreline, among which the artificial shoreline community had the highest diversity index and best community stability. Distance-based redundancy analysis indicates that the structure of intertidal macrobenthic community was mainly affected by sediment type and anthropogenic disturbance.