Community structure and variation of zooplankton in the Northern Yellow Sea

The community structure of zooplankton was monitored and analyzed in the Northern Yellow Sea( NYS,121°30' ~ 124°00'、 37°30' ~ 40°00') in four seasons from 2011 to 2012. A total of 63 species belonging to 12 classes( excluding zooplankton larva and juveniles,fish eggs and fish larvae) were identified. Warm-temperate and eurythermal species constituted the majority of zooplankton in the Northern Yellow Sea and a small number of cold-temperate and subtropical species were found. Macro-zooplankton Calanus sinicus and Sagitta crassa,Meso-zooplankton Paracalanus parvus and Oithona similis were the dominant species in four seasons in the NYS. Compared with the same period of 1959,warm water species increased in autumn and winter; the average abundance of both C. sinicus and S. crassa,the dominant species of the four seasons,increased significantly and the abundance of C. sinicus increased more significantly than that of S. crassa. Our study indicated that the community structure of zooplankton has changed significantly in the past 50 years in the NYS. This research is of scientific interest for community succession and biodiversity protection of zooplankton in warm-temperate sea of China.