海洋酸化对海洋生态系统特别是钙化生物构成威胁。颗石藻作为主要的钙化浮游生物，在海洋碳循环过程中具有重要作用。了解海洋酸化对颗石藻钙化作用的影响是预测海洋生态系统变化的基础。通过分析南海不同海区3个沉积物柱状样中颗石形态大小和重量变化，揭示末次冰期以来不同大气CO2条件下颗石藻钙化作用的变化规律。结合对南海表层沉积物和现代海水中颗石藻的分析，综合研究在颗石藻生长、沉降、保存过程中环境因素对颗石形态大小和重量的影响，寻求颗石藻钙化作用对海洋环境和气候变化的响应，重点在于对海洋酸化和海洋碳酸盐系统变化的反应，找寻海洋酸化过程的潜在替代性指标。

Ocean acidification has been identified as a threat to marine ecosystem especially calcified organisms. Coccolithophores as the primary calcifying phytoplankton group play an important role in marine carbon cycle. To understand the impact of ocean acidification on coccolithophore calcification is the foundation for predicting marine ecosystem change in future. By analyzing the morphologic size and weight of coccoliths in three sediment cores in the South China Sea, the purpose of this project is to study the response of coccolithophore calcification to different CO2 condition since the last glaciation. Combined with the study on the coccolithophores in surface sediments and modern water column in the South China Sea, it is to investigate the environmental effect on coccolith size and weight during coccolithophore living, sedimentation and preservation. We will explore the relationship between coccolithophore calcification and environmental parameters, especially the response to ocean acidification and ocean carbon system change. This would be helpful in seeking potential index of ocean acidification.