EAR-PF: Current and future glacial controls on the rate of active microbial biogeochemical cycling in Arctic fjords

亚历山大医生B。Michaud已获得NSF博士后奖学金，在丹麦奥胡斯大学和纽约斯托尼布鲁克大学的地球微生物学中心开展研究和教育计划。 Michaud博士将研究北极峡湾在当前和未来气候条件下作为北极大陆架环境铁和锰的源或汇的作用。来自斯瓦尔巴特群岛（北冰洋的一个群岛，位于挪威和北极之间）峡湾的沉积物岩心将用于测量金属和硫酸盐还原速率，并分析水相和固相地球化学。这项调查将把活跃微生物种群的数据与北极峡湾沉积物中的地球化学速率联系起来，综合多个学科（地质微生物学、地球化学、冰川学、海洋学和地质学）。除了研究之外，Michaud博士还将根据北极地球化学和冰川学制定互动的、基于标准的地球和生命科学课程计划。本教案将在哈丁高中使用，这是蒙大拿州西南部的一所乡村学校，美国土著学生入学率很高。Michaud博士将通过Skype与学生互动。斯瓦尔巴群岛西部的峡湾是冰下环境和冰架环境之间地球化学活跃的界面。峡湾沉积物中微生物介导的Fe、Mn和S循环之间的速率和相互作用最终影响了出口到大陆架环境的金属浓度。通过RNA稳定同位素探针技术标记活性微生物，研究了增加有机碳输入对沉积物生物地球化学循环的影响。这些实验将使峡湾沉积物中铁、锰和硫的转化率与活性微生物种群联系起来。该调查将整合地球生物学和地球化学方法，以了解陆地冰下过程如何影响永久寒冷（5°C）海洋沉积物中的微生物群落。该奖项由国际科学工程办公室资助。

Dr. Alexander B. Michaud has been granted an NSF EAR Postdoctoral Fellowship to carry out research and education plans at the Center for Geomicrobiology at Aarhus University in Denmark and Stony Brook University in New York. Dr. Michaud will investigate the role of Arctic fjords as a source or sink of iron and manganese to the Arctic shelf environment under current and future climatic conditions. Sediment cores from the fjords of Svalbard (an archipelago in the Arctic Ocean, between Norway and the North Pole) will be used to measure rates of metal and sulfate reduction and to analyze aqueous and solid-phase geochemistry. The investigation will link data on active microbial populations with biogeochemical rates in Arctic fjord sediments, integrating multiple disciplines (geomicrobiology, geochemistry, glaciology, oceanography and geology). In addition to research, Dr. Michaud will develop interactive, standards-based Earth and life science lesson plans based on Arctic biogeochemistry and glaciology. This lesson plans will be used at Hardin High School, a rural school in southwestern Montana with high enrollment of Native American students. Dr. Michaud will interact with the students via Skype. The fjords of Western Svalbard are a biogeochemically active interface between the subglacial and shelf environments. The rates and interactions between microbially mediated Fe, Mn and S cycles within the fjord sediments ultimately influence the concentrations of metals exported to the shelf environment. The impact of increased organic carbon input to the sediments on biogeochemical cycles will be assessed by RNA stable isotope probing which labels the active microorganisms. These experiments will allow the rates of Fe, Mn and S transformations in fjord sediments to be linked with the active microbial populations. The investigation will integrate geobiological and geochemical methods to understand how terrestrial subglacial processes influence microbial communities in permanently cold (5°C) marine sediments. This award was supported with funding from the Office of International Science & Engineering.