CAREER: Experimentally Testing the Role of Sympagic Algae in Sea-ice Environments using a Laboratory Scale Ice-tank.

南极沿海沃茨的海冰塑造了海洋表面沃茨和底部的生态系统，这些环境依赖于生活在海冰中的藻类的生产力。由于海冰的形成和融化在不同年份之间以及作为对气候变化的一种反应，变化很大，因此必须更好地了解海冰与藻类的相互作用，并为全球气候模型提供更好的数据。该项目将通过使用冰槽进行实验来测量海冰中浮游植物的生长和细胞特性，从而实现这些目标。实验室实验将根据以前在南极半岛沿海沃茨的观测结果，提供可模拟的现实条件。拟议工作的科学重要性与国家科学基金会的目标相一致，即了解海冰生物地球化学的生物和化学特性及其与季节性海冰动态和气候的反馈。该项目的发现将引起广泛的科学界的兴趣，包括海洋学家，生物学家，化学家，生态系统和海洋建模者。为了解决海冰微生物数据的缺乏限制了我们准确预测未来南极气候的能力，首席研究员将开发南极科学辅修课程，以培养具有环境观点的未来科学家，并为未来的美国劳动力提供地球和生物科学方面的强大科学背景。目前缺乏数据来了解海冰观测模式的基本过程质量及其与海冰微生物群落的相互作用。该项目将提供对南极海冰形成和融化的季节性周期中共生藻类的初级生产和生理学的机械理解。虽然海冰是南极沿海生态系统的核心，但人们对海冰如何影响海冰藻类以及海冰藻类如何影响海冰藻类知之甚少。该项目专注于第一年的海冰，每年形成和融化，创造独特和非常动态的栖息地。该研究将由4个主要目标构成：1）不同的藻类物种如何适应海冰条件的季节性变化，2）测量初级生产力的不同方法（二氧化碳下降，氧气生产和可变荧光）在海冰中的相关性，并不同于海水测量，3）共生藻类如何影响海冰的物理结构，（4）冰融过程中共生藻类对有机质循环的贡献。由于气候变化导致海冰的预期变化，这项研究具有独特的优势，可以提供短期和季节性过程所需的数据。这项研究的结果将有助于完善南极和北极生态系统中藻类生产的模型，迄今为止，海冰及其生物地球化学的数据在地球系统模型中往往表现不佳。该项目还将为研究生和本科生提供教育，并为中学生开发课堂课程提供材料。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Sea ice in Antarctic coastal waters shape ecosystems, both in the surface waters and at the bottom of the ocean, environments that depend on algae living in sea ice for their productivity. With high variability in sea ice formation and melt between years and as a response to climate change, it is of importance to obtain better understanding of the interaction of sea ice with algae, as well as provide better data for global climate models. This project will accomplish those goals by measuring phytoplankton growth and cellular properties in sea ice with experiments performed using an ice tank. Laboratory experiments will be based on previous observations in the Antarctic Peninsula coastal waters, providing realistic conditions to emulate. The scientific importance of the proposed work aligns with the National Science Foundation goals to understand the biological and chemical properties of sea ice bio-geo-chemistry and its feedbacks with seasonal sea ice dynamics and climate. The finding from this project will be of interest to a broad scientific community, including oceanographers, biologists, chemists, and ecosystem and ocean modelers. To address the scarcity of data on sea ice microbes that limits our ability to predict future Antarctic climate with accuracy, the principal investigator will develop an Antarctic Science Minor in order to train future scientists with an environmental perspective and prepare the future US workforce with a strong scientific background on Earth and Biological Sciences.There is a paucity of data to understand the processes underlying observed patters in sea ice quality and their interaction with the sea-ice microbial community. This project will provide a mechanistic understanding of primary production and physiology of sympagic algae over the seasonal cycle of formation and melt of Antarctic sea ice. Although sea ice is central to the Antarctic coastal ecosystems, little is known of how they affect, and are in turn affected, by sea-ice algae. This project concentrates on first-year sea ice, forming and melting each year, creating unique and very dynamic habitats. The study will be structured by 4 main objectives: 1) how different algal species adapt to the seasonal changes in sea ice conditions, 2) how different methods to measure primary production (carbon dioxide drawdown, oxygen production and variable fluorescence) relate in sea ice and differ from sea water measurements, 3) how sympagic algae influence the physical structure of sea ice, 4) how sympagic algae contribute to organic matter cycling during ice melt. Due to expected changes in sea ice due to climate change, this study is uniquely positioned to provide needed data on short-term and seasonal processes. Results from this study will be useful to refine models of algal production in Antarctic and Arctic ecosystems, data not available to date as sea ice and its biogeochemistry are often poorly represented in earth system models. This project will also provide education for graduate and undergraduate students as well as material to develop class curriculum for middle-school students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.