The structure of macrobenthic community in Pearl River Estuary

The macrobenthic communities of estuaries are often indicative of important community traits, such as the environmental pollution a community may experience. To better understand the structure of Pearl River Estuary’s macrobenthic community, macrobenthic species were identified based on investigations car-ried out from November 2014 to August 2015, and biodiversity analyses were performed. More specifically, biodiversity index calculations, cluster analysis, and nMDS (non-metric MDS) analysis were performed used PRIMER 6.0 software. While 52 macrobenthic species were identified in the Pearl River estuary, the dominant species in this study area were Potamocorbula laevis, Glaucomya chinensis, Potamocorbula ustulata and Dendroneris pinnaticirrus. The annual mean density of macrobenthos in the Pearl River Estuary was 269.3 ind./m² and the annual mean biomass was 129.61 g/m². The mean values of richness index (D), evenness index (J’) and Shannon-Wiener diversity index (H’) of 12 samplings were 1.81 ± 1.38, 0.50 ± 0.27 and 1.60 ± 1.13, respectively. The results showed a range of environmental quality from clean to severe pollution, in which only P01 section indicated clean environmental quality in autumn and winter. Cluster and nMDS results revealed that low community similarity were observed among P01 section and P02 together with P03 sections, potentially due to the geographical distribution factors. Additionally, the P02 section and P03 section gathered crosswise with higher community similarity. Our results suggested the combination of environmental factors with physical and chemical sediment factors were significantly correlated with the distribution characteristics of communities. Also to note, water salinity and pH can help explain the biod-iversity distribution pattern of the microbenthic community in the Pearl River Estuary.