陆架边缘海的浮游生物群落是不同生态类型浮游生物群落（近岸群落、远洋暖水群落、远洋冷水群落）交错和淡水影响的结果，因此研究不同生态类型群落的扩散和交错特征和机理具有重要意义。砂壳纤毛虫是微型浮游动物的重要类群，分类特征明显，生活史简单，对环境变化反应敏感，是浮游生物群落研究的模式生物。本项目拟在四个季节调查渤海、黄海、东海和南海北部砂壳纤毛虫各个种属的分布区域，判定不同生态类型砂壳纤毛虫群落及其核心区和前锋区，刻画群落的扩散特征，探索群落扩散的机制（物理输送过程的强弱、限制各种属扩散的环境因子）。由两个群落的核心区和前锋区的重叠情况得出群落的交错特征。项目还探讨主要河流（黄河、长江、珠江）淡水输入的影响和砂壳纤毛虫生态功能（壳开口直径）变化。本项目将不同类型浮游生物群落作为整体进行研究，为不同海区和季节微食物网结构的变化提供基础资料，为预测全球变化对陆架边缘海浮游生态系统的影响提供理论依据。

Marginal seas are important area of primary production and fishery production. Plankton community in marginal sea is resulted from the convergence and mixing of different biogeographical type communities (neritic community, warm water community, cool water community). Freshwater discharge also has important influence on the neritic community. Therefore, study on the spread and mixing characteristics and mechanism of converging plankton communities is the key in understanding the plankton dynamics in marginal seas. Tintinnid is an important component of microzooplankton. With lorica as taxonomic character, simple life history and rapid response to environmental change, tintinnids is a good example of plankton community research. This project will collect tintinnd community samples in four seasons in the China marginal sea (Bohai Sea, Yellow Sea, East China Sea and northern South China Sea). Distribution area of abundant species and genera in every season will be used to identify the core area and pioneer area of different biogeographical type communities. The spread characteristics of different communities will be compared according to the comparative position of core area and pioneer area. The mixing will be depicted as the overlap among core area and pioneer area of converging communities. Influence of freshwater discharge on neritic tintinnid community will be studied in large river estuaries (Yellow River, Yangtze River and Pearl River). Tintinnid functional change in the process of community mixing is evaluated according to the variation of lorica oral diameter (LOD). Different biogeographical type tintinnids community is studied as a life unit, which is a new research angel. This project constitute a data base for the study of spatial and temporal variation of microbial food web structure. It is also theoretically helpful in the prediction of global change influence on plankton ecosystem in the marginal sea.