Pleistocene-Holocene Southern Ocean coccolithophore calcification and productivity

海洋浮游植物构成了远洋食物网和生态系统的基础。随着现代人为环境影响——包括富营养化、气候变化和海洋酸化——有证据表明，这一群体已经在经历生物地理范围的变化和群落结构的变化。在这里，我们试图调查一组关键的海洋浮游植物对快速环境变化的反应，特别是酸化，在南大洋。有关藻类产生碳酸钙（方解石）板状鳞片，这些鳞片在生时由细胞产生并围绕在细胞周围，但在死后会大量积聚在深海沉积物中。这些化石鳞片被称为球粒岩，可以用来重建数百万年来生活在海洋表面的物种的丰富性和多样性。球粒岩的化学成分也可以作为细胞过程和球粒岩形成时海洋表面环境条件的指示物。总之，我们建议利用不同物种产生的球石的大小和丰度的变化，以及细胞生长速度和环境的化学指标，来确定南大洋球石藻对近期海洋快速酸化间隔的响应，特别是那些与冰川气候间隔结束时大气二氧化碳浓度快速增加有关的反应。

Marine phytoplankton form the basis of pelagic food webs and ecosystems. With modern anthropogenic environmental impacts - including eutrophication, climate change and ocean acidification - there is evidence that this group is already experiencing biogeographic range shifts and changes to community structure. Here, we seek to investigate the response of a key group of marine phytoplankton to rapid environmental change, especially acidification, in the Southern Ocean. The alage concerned produce calcium carbonate (calcite) plate-like scales, which are produced by and surround the cell during life, but on death accumulate in great numbers in deep ocean sediments. These fossil scales, called coccoliths, can be used to reconstruct the abundance and diversity of species that were living in the surface ocean across millions of years. The chemistry of coccoliths can also be used as an indicator of cell processes and the conditions in the surface ocean environment at the time the coccoliths were formed. Together, we propose to use the variations in the size and abundances of coccoliths produced by different species, as well as chemical indicators of cell growth rates and environment, to determine the response of coccolithophore algae in the Southern Ocean to intervals of rapid ocean acidification in the recent past, specifically those associated with rapid increases in atmospheric carbon dioxide concentrations at the end of glacial climate intervals.