Community structure of zooplankton in adjacent area of Changjiang Estuary, China in summer 2016.

Based on the data of zooplankton samples from 27 stations in the offshore area of Changjiang Estuary in August 2016, we analyzed the community structure and diversity of zooplankton and examined the relationship between zooplankton community structure and environmental factors. A total of 108 species of zooplankton belonging to 12 groups in six phyla, together with 15 types of pelagic larvae and fish eggs were identified. The main groups were copepods, thaliacea, chaetognaths, cladocladus and medusae, with the average abundance being 273.9, 115.0, 67.1, 63.6 and 61.1 ind·m . The most dominant group of zooplankton was copepods (48 species), accounting for 44.4% of the total zooplankton abundance. Medusae ranked second with a total of 12 species, accounting for 11.1% of the total zooplankton abundance. Furthermore, the absolute dominant group was copepods, with the highest contribution to the zooplankton community (20.3%). According to the clustering results of environmental factors, the area could be divided into Changjiang diluted water and offshore water mass. The results of analysis of similarities showed that the difference of zooplankton community between the two regions was significant (the average diffe-rence was 4%), and the contribution to the difference was 20.3%, 18.0%, 14.1%, 13.4%, and 11.8% for copepod, thaliacea, cladocera, chaetognaths, and medusae, respectively.