The Study on Macrobenthos Community Structure in Jiaojiang Estuary

To evaluate the seasonal variation of species composition,dominant species,abundance,biomass and diversity of macrobenthos community and study the seasonal difference of macrobenthos community and its relationships with environment factors preliminarily,three cruise surveys were conducted in April(spring),July(summer) and October(autumn).A total of 60 species were collected and 48 species in summer is the highest.Mediomastus californiensis was the dominant species in every season.The highest seasonal average abundance and biomass were 187.11ind/m2 in summer and 69.82g/m2 in autumn.There was a significant difference in the Shannon-Wiener index and Margalef species richness of the macrobenthos between different seasons,but not in the Pielou's evenness index.Temperature,DO and SS in the bottom of sea water were the key environment factors affecting macrobenthos community.The results of cluster analysis and MDS showed that the distribution of macrobenthos had obvious environment and spatial heterogeneity,5 station groups were divided.