Phytoplankton-nutrient interactions in the upper ocean

上层海洋浮游植物与营养物的相互作用

• 批准号: 288269-2011
• 负责人: Varela, Diana
• 金额: $ 2.04万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571379
• 关键词: Phytoplankton; nutrient; interactions; upper; ocean

The ocean covers about 71% of the earth's surface and strongly affects global climate. Floating unicellular algae (phytoplankton) play a critical role in modifying the earth's climate by changing the carbon balance of the ocean, which have a direct impact on atmospheric carbon dioxide concentrations. These photosynthetic organisms take up nutrients (e.g. carbon, nitrogen, silicon, phosphorus) through photosynthesis and return them back to seawater after death and decomposition, thereby controlling the level of carbon dioxide in the ocean and atmosphere. Phytoplankton physiology can also affect nutrient transfer along marine food webs with consequences for the survival of fish and marine mammals. High-latitude oceans are experiencing the most dramatic climatic variations due to global warming. Predicted changes (e.g. in sea ice cover, circulation patterns, water column stratification, temperature, dissolved carbon dioxide, nutrient supply) will impact marine ecosystem structure and function by affecting phytoplankton productivity at the base of the biological system. Therefore, it is critical to evaluate phytoplankton responses to ocean warming and acidification in subarctic and arctic seas. This research program examines the links between phytoplankton physiology and nutrient cycling in the ocean. Studies will be conducted in the laboratory and on oceanographic research cruises to the subarctic Northeastern Pacific and western Arctic Oceans, and utilize interdisciplinary techniques. Specifically, I will advance my research by studying (1) biogenic silica production and silicon isotopes, (2) the balance between planktonic calcification and photosynthesis, and (3) phytoplankton elemental composition. I will explore the sensitivity of nutrient acquisition in marine phytoplankton to nutrient limitation and changing environmental conditions. Results will shed new light on the factors affecting the productivity of marine phytoplankton, and improve our understanding of present and past nutrient cycles, carbon export and food web dynamics in high-latitude marine waters.

海洋覆盖了地球表面约71%的面积，强烈影响全球气候。漂浮的单细胞藻类（浮游植物）通过改变海洋的碳平衡，在改变地球气候方面发挥着关键作用，这对大气二氧化碳浓度有直接影响。这些光合生物通过光合作用吸收营养物质（如碳、氮、硅、磷），并在死亡和分解后将其返回到海水中，从而控制海洋和大气中二氧化碳的水平。浮游植物的生理学也会影响海洋食物网中的营养物质转移，从而对鱼类和海洋哺乳动物的生存产生影响。 由于全球变暖，高纬度海洋正在经历最剧烈的气候变化。预测的变化（例如海冰覆盖、环流模式、水柱分层、温度、溶解二氧化碳、养分供应）将通过影响生物系统基础上的浮游植物生产力来影响海洋生态系统的结构和功能。因此，评估浮游植物对亚北极和北冰洋海洋变暖和酸化的反应至关重要。 该研究计划研究海洋中浮游植物生理学和营养循环之间的联系。研究将在实验室和前往亚北极东北太平洋和北冰洋西部的海洋学研究巡航中进行，并利用跨学科技术。 具体来说，我将通过研究（1）生物二氧化硅的产生和硅同位素，（2）浮游钙化和光合作用之间的平衡，以及（3）浮游植物元素组成来推进我的研究。 我将探讨海洋浮游植物的养分获取对养分限制和环境条件变化的敏感性。研究结果将为影响海洋浮游植物生产力的因素提供新的线索，并提高我们对高纬度海洋水域当前和过去的营养循环、碳输出和食物网动态的理解。