SGER: Science-of-Opportunity Aboard Icebreaker Oden - Phytoplankton Global Change Experiments and Vitamin/Iron Co-Limitation in the Amundsen and Ross Seas

摘要这项探索性研究小额拨款(SGER)提案描述了与全球变化相关的实验研究，旨在充分利用一个独特的科学机会，在短时间内租用奥登号在麦克默多海湾进行破冰作业。我们的重点将是利用这个机会主义的研究平台，就南极边缘浮游植物群落的当前和未来控制提出两个问题。它们是：1.未来人为气候变化导致的南大洋二氧化碳、pH和铁有效性的预期变化将如何影响浮游植物物种组合、碳和营养生物地球化学以及再矿化过程？2.目前有机辅助因素(维生素)在限制或共同限制(与铁一起)南极边缘浮游植物的生长和生产中起什么作用？研究方法包括铁浓缩、二氧化碳浓度和温度变化的实验培养。第二组实验将检验维生素B12和铁之间的共同限制效应和B12摄取动力学。将与许多参与的美国和瑞典调查人员合作，确定浮游植物群落结构的变化，以及碳和养分循环。综合起来，这两个主要目标应该使我们能够对目前和未来对南极边缘浮游植物生长、生产力以及碳和营养生物地球化学的控制获得新的见解。特别是，在阿蒙森海的实验是一个独一无二的机会，可以了解这个鲜为人知的生态系统中的藻类动态和未来对气候变化的潜在反应，并将这些结果与更知名的罗斯海的结果进行比较。这项研究的一个重要成果将是与瑞典海洋科学界建立强有力的国际合作。其他更广泛的影响包括一名西班牙裔博士生参与邮轮工作和邮轮后分析，以及将结果整合到南加州大学卡塔琳娜实验室的研究生课程中。公众宣传将包括介绍全球变化对海洋的影响，受众从立法者和政策制定者到普通公众。

AbstractThis Small Grants for Exploratory Research (SGER) proposal describes global change-related experimental research designed to take full advantage of a unique science opportunity on short notice, the leasing of the Oden to conduct ice-breaking operations in McMurdo Sound. Our emphasis will be on using this opportunistic research platform to ask two questions about present day and future controls on Antarctic margin phytoplankton communities. These are: 1. How will expected alterations in pCO2, pH, and Fe availability in the Southern Ocean, due to future anthropogenic climate change affect phytoplankton species assemblages, carbon and nutrient biogeochemistry, and remineralization processes? 2. What is the current role of organic co-factors (vitamins) in limiting or co-limiting (along with iron ) phytoplankton growth and production in the Antarctic margin? The research approach includes experimental incubations with variation in iron enrichment, carbon dioxide concentration, and temperature. A second suite of experiments will examine co-limitation effects between vitamin B12 and Fe and B12 uptake kinetics. Changes in phytoplankton community structure, and carbon and nutrient cycling will be determined, in collaboration with many of the participating U.S. and Swedish investigators. Together, these two main objectives should allow us to obtain novel insights into the current and future controls on Antarctic margin phytoplankton growth, productivity, and carbon and nutrient biogeochemistry. In particular, the experiments in the Amundsen Sea represent a one-of-a-kind opportunity to understand algal dynamics and potential future responses to climate change in this little-studied ecosystem, and compare these results to those from the better-known Ross Sea. An important result of this study will be to build strong international collaborations with the Swedish marine science community. Additional broader impacts include participatin of an Hispanic Ph.D. student in cruise work and post-cruise analyses, and integration of results into graduate courses at the USC Catalina Lab facility. Public outreach will include presentations on global change impacts on the ocean targeted at audiences ranging from legislators and policymakers to the general public.