Collaborative Proposal: Site Survey and Initial Characterization of North Pond: Microbiology, Biogeochemistry, Seismic Profiles

合作提案：北池塘的现场调查和初步表征：微生物学、生物地球化学、地震剖面

• 批准号: 0728381
• 负责人: Katrina Edwards
• 金额: --
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0728381&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Site; Survey; Initial

Microbial cells occur in shallow and deep sediments throughout the world's oceans. These cells constitute a major portion of the Earth's prokaryotic biomass and their activity catalyzes the decomposition of buried organic matter. Similarly, microorganisms colonize the ocean crust, leading to the oxidative alteration of young ridge flank basalts. Despite their cosmopolitan abundance, the diversity, habitat, and dispersal pathways of these organisms are poorly defined. Little is known regarding their functional genes and the metabolic activities that allow these prokaryotes to grow and survive in the young crustal environment. North Pond is an isolated northeast-trending sediment pond on the western flank of the Mid-Atlantic Ridge (MAR) at 22deg45'N and 46deg05'W; it is surrounded and underlain by young (7 Ma), porous mid-ocean ridge basalt, and it is isolated from the sediment cover of the Atlantic abyssal basins and outer ridge flanks. This setting provides a "natural laboratory" for examining subsurface microbial community dispersal pathways, occurrence, and colonization patterns. In particular studies can differentiate bacteria and archaea from the deep-sea water column, deep subsurface sediments, and ridge flank basalt. Current deep subsurface microbiology focuses on the question "What kind of microbial life is there, and why?" while avoiding its necessary complement "How did it get there?" This study will accomplish that goal with a vision toward establishing a microbial observatory at North Pond as part of future IODP campaigns. By tracing physical and chemical "signatures" in North Pond sediments, the research will constrain fluid transport pathways and flow rates, and these will be correlated to site-specific microbial composition, key metabolic gene repertoire, and biogeochemical activity of subsurface microbial communities. This research focuses on detailed mapping of the sediment-basement interface of North Pond, by coupling heat flow, seismic information, and pore fluid chemistry data to microbial sampling of the sediments. The goals are two-fold: 1) to conduct a comprehensive site survey of North Pond that includes constraining the hydrology in preparation for our upcoming IODP cruise to North Pond, and 2) to perform a survey of near-surface microbial communities in conjunction with the biogeochemical characteristics and flow paths of their sediment environment. This site survey cruise will permit necessary refinement in shipboard and shore-based methodology and sample handling in preparation of our IODP cruise. Broader Impacts. The biogeochemical activities, composition and temporal and spatial dynamics of marine subsurface communities are an emerging central topic in marine sciences and geomicrobiology. The researchers plan to integrate the findings directly into ongoing undergraduate and graduate student education at their institutions through integration of materials in coursework, and the direct involvement of an REU student. The researchers will engage the broader public via the JOI distinguished Speaker series. Finally, this site survey is part of a much larger vision to develop North Pond into an internationally coordinated benchmark study in subsurface microbiology (i.e., a microbial observatory).

微生物细胞发生在世界海洋中的浅层和深层沉积物中。这些细胞构成了地球原核生物生物量的主要部分，它们的活性催化了埋入有机物的分解。同样，微生物在海壳中定居，导致年轻山脊侧面玄武岩的氧化改变。尽管具有国际化的丰富性，但这些生物的多样性，栖息地和分散途径的定义很差。关于它们的功能基因和代谢活性，允许这些原核生物在年轻的地壳环境中生长和生存知之甚少。北部池塘是一个孤立的东北趋势沉积物池塘，位于22deg45'n和46deg05'w的中大西洋山脊（3月）的西侧；它被杨（7 mA），多孔的中山脊玄武岩包围和延伸，并与大西洋深渊盆地和外脊侧面的沉积物盖中隔离。该设置提供了一个“自然实验室”，用于检查地下微生物社区的分散途径，发生和殖民模式。特别是研究可以将细菌和古细菌与深海水柱，深面沉积物和山脊侧玄武岩区分开。当前的深面微生物学重点是“有哪种微生物生活，为什么？”避免了必要的补充“它是如何到达那里的？”这项研究将实现这一目标，以在未来的IODP运动中建立在北池塘建立微生物天文台的愿景。通过追踪北部池塘沉积物中的物理和化学“特征”，该研究将限制流体的传输途径和流速，并且这些将与特定地点的微生物组成，关键代谢基因库以及地下微生物群落的生物地球化学活性相关。这项研究的重点是通过将热流，地震信息和孔流体化学数据耦合到沉积物的微生物采样来详细映射北池塘的沉积物底座界面。目标是两个方面：1）对北池塘进行全面的现场调查，其中包括将水文学限制为准备我们即将进行的iodp巡航到北池塘，以及2）对近地表微生物群落进行调查，并结合使用。其沉积物环境的生物地球化学特征和流道。该网站调查巡游将允许在船上和基于海岸的方法和样品处理中进行必要的细化，以准备我们的IODP巡航。更广泛的影响。海洋地下社区的生物地球化学活动，组成以及时间和空间动力学是海洋科学和地球生物学中的一个新兴中心话题。研究人员计划通过将材料的整合在课程中和REU学生的直接参与中，将发现直接纳入其机构正在进行的本科生和研究生教育。研究人员将通过JOI杰出的演讲者系列与更广泛​​的公众吸引。最后，这项现场调查是将北池发展发展为地下微生物学（即微生物天文台）的国际协调基准研究的更大愿景的一部分。