Annual variation of copepod community in the Yangshan Port
洋山港浮游桡足类群落的周年变化特征

To understand the annual variation of the copepod community structure, abundance, dominant species and diversity in the Yangshan Port, samples were collected monthly from March 2009 to February 2010. The results showed that the dominant species were Limnoithona tetraspina, Acartia pacifica, Labidocera euchaeta, Paracalanus aculeatus, Acartia bifilosa, Microsetella norvegica, Paracalanus gracilis and Paracalanus parvus. The seasonal variation in the mean abundance was remarkable(F=2.11, P<0.05), and the order from high to low was spring (28.44 ind/L±19.16 ind/L), summer (18.60 ind/L±14.81 ind/L), winter (10.98 ind/L±3.65 ind/L), and autumn (10.57 ind/L±4.45 ind/L). The order of biomass from high to low was summer (12359.1 mg/L±18438.1 mg/L), autumn (7796.6 mg/L±1348.6 mg/L), winter (2944.8 mg/L±1680.9 mg/L), and spring (1401.0 mg/L±1057.3 mg/L). The copepod abundance showed single peak in one year, and the copepod biomass showed double peaks in one year. The results of multivariate analysis showed that the variation of dominant species made a great contribution to the variation of copepod community. Xiaoyang was the main shipping docks with bigger ship flux than Dayang. The copepod community had already showed difference between Dayang and Xiaoyang. The Shannon Weaver index of Xiaoyang was higher than that of Dayang both in spring and winter. But the Pielou index of Xiaoyang was higher than Dayang in spring, summer and winter.