ADAPTation of COCCOlithophore communities to environmental change in the Southern Ocean (ADAPT-COCCO)

南大洋的海洋群落极易受到人为环境变化的影响。地表水变暖和酸化已经对构成南大洋海洋食物网基础的浮游生物群落产生了影响。浮游生物的生产力也影响到南大洋吸收大气中二氧化碳的能力。由于南大洋的一些区域将在下个世纪经历海洋酸化率最高的一些地区，必须为这一具有全球重要性的海洋环境设计基于证据的战略。单细胞浮游球藻是南大洋钙化浮游植物的主要群体。作为海洋钙化剂，它们将受到海洋酸化导致的表层海洋碳酸盐离子浓度降低的影响。尽管卫星估计表明，最近南大洋大片海域的钙化速度有所下降，但对于未来海洋酸化是否会促进或降低球石生物体的钙化速度，仍存在争议。该项目将侧重于不同的晚第四纪时间片，并通过使用扫描电子显微镜(用于球石组合)、球石识别的自动化系统SYRACO-(用于球石质量估计)和有机地球化学(用于[CO2(AQ)]估计)来解决这一科学问题。这项提议的结果将有助于测试[CO32-]和温度控制对球藻生物体发生的限制，并将为监测21世纪南大洋浮游植物群落的变化提供一个关键的基线数据集。

The marine communities of the Southern Ocean are extremely vulnerable to anthropogenic environmental change. Warming and acidification of surface waters are already impacting the plankton communities that form the basis of Southern Ocean marine food webs. The productivity of the plankton also influences the ability of the Southern Ocean to absorb carbon dioxide from the atmosphere. With regions of the Southern Ocean set to experience some of the highest rates of ocean acidification over the coming century, it is imperative to design evidence-based strategies for this marine environment of global importance.Single-celled coccolithophore algae are the dominant group of calcifying phytoplankton in the Southern Ocean. As marine calcifyers they will be impacted by reduced surface ocean carbonate ion concentrations as a result of ocean acidification. Although satellite estimations suggest that calcification rates have recently decreased in broad areas of the Southern Ocean, there is still controversy about whether ocean acidification will promote or reduce coccolithophore calcification rates in the future. This project will address this scientific question focusing on different late Quaternary time slices and by using scanning electron microscopy (for coccolithophore assemblages), an automated system of coccolith recognition -SYRACO- (for coccolith mass estimates) and organic geochemistry (for [CO2(aq)] estimates). The findings from this proposal will help to test the limits of [CO32-] and temperature controls on coccolithophore occurrences and will provide a key baseline dataset for monitoring 21st Century changes in Southern Ocean phytoplankton communities.