Characteristics of macrobenthic community structure in the intertidal zone of four mangrove reserves in Hainan Island

To characterize the community dynamics of macrobenthic fauna across four designated mangrove reserves on Hainan Island, a systematic survey was conducted in August 2024, involving 69 sampling stations throughout the reserves. This investigation identified 118 macrobenthic species, classified into 6 phyla, 8 classes, 15 orders, 44 families, and 74 genera. Species richness exhibited a clear hierarchical gradient among the reserves in the order: Xinying Bay Reserve > Qinglan Port Reserve > Dongzhai Port Reserve > Xinying Wetland Park. Significant differences in macrobenthic density were also evident, following the trend: Xinying Bay Reserve > Dongzhai Port Reserve > Xinying Wetland Park > Qinglan Port Reserve. Bray-Curtis cluster analysis in conjunction with non-metric multidimensional scaling (nMDS) revealed that the macrobenthic communities across the four reserves could be categorized into three distinct subcommunities: Xinying Wetland Park and Xinying Bay shared similar community structures and clustered together to form one community, while Dongzhai Port and Qinglan Port reserves each formed separate clusters. Analyses of the abundance-biomass comparison (ABC) curves and diversity indices indicated that the macrobenthic communities in all four mangrove reserves remained ecologically intact, demonstrating minimal anthropogenic disturbance and maintaining optimal ecological health.