Oxygen Minimum Zone Variability and Ecosystem Responses in the Arabian Sea during the Last Glacial-interglacial Cycle:A Paired Paleogenomic and (Isotopic) Lipid Biomarker Approach

末次冰期-间冰期循环期间阿拉伯海的最低氧区变化和生态系统响应：配对古基因组和（同位素）脂质生物标记方法

• 批准号: 1357017
• 负责人: Marco Coolen
• 金额: $ 55万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1357017&HistoricalAwards=false
• 关键词: Oxygen; Minimum; Zone; Variability; Ecosystem

Available monitoring data suggest that mid-water oxygen depletion regions, or Oxygen Minimum Zones (OMZs), are expanding in the world's oceans in the context of global warming. As OMZs expand, marine ecosystems are expected to experience disturbances in the structure and dynamics of food webs and in the production of greenhouse gasses, with resulting feedbacks on the climate system. The northern Arabian Sea has an exceptionally widespread OMZ characterized by a strong seasonal variability of monsoonal upwelling and high algal primary productivity. Although sediment records from the region have been extensively studied to reconstruct causes, timing, and duration of OMZ extent since the last glacial-interglacial cycle, it remains entirely unknown how long-term changes in OMZ variability has impacted past ecosystems and food webs in the Arabian Sea. This research, conducted by a team of scientists from the Woods Hole Oceanographic Institution (WHOI), uses ultra-high-throughput sequencing of sedimentary ancient DNA signatures (i.e., the "paleome") to reconstruct past populations of marine organisms. Advanced bioinformatics and statistical tools will be used to identify species that were most strongly impacted by long-term fluctuations in OMZ strength during key climate intervals over the last 80,000 years. Parallel changes in climate and environmental conditions will be reconstructed using (molecular) geochemical techniques. For this project the research team will use a continuous, undisturbed and radiocarbon-dated sediment record that was recently obtained from the center of the OMZ on the continental slope northwest of the Indus Canyon.The high-resolution ancient DNA records will greatly help to refine past environmental and climate interpretations in the monsoon-impacted northeastern Arabian Sea area. This study will provide insights into how ecosystems will respond to long-term periods of OMZ conditions and how these ecosystems adapt after the return of a well-mixed and oxygenated water column. Bioinformatics and numerical modeling analyses will be carried out in collaboration with a researcher from the University of Glasgow in the United Kingdom. The project will provide educational opportunities for a graduate student enrolled in the MIT/WHOI joint program in oceanography and for two undergraduate students, who will be recruited through WHOI's Summer Student Fellowship and Minority Fellowship programs. In addition, results and bioinformatics approaches from this study will be implemented in a lecture during the popular annual course "Strategies and Techniques for Analyzing Microbial Population Structure (STAMPS)" at the Marine Biology Laboratory (MBL) in Woods Hole.

现有的监测数据表明，在全球变暖的背景下，世界海洋中的中层氧气枯竭区或氧气最低区（OMZs）正在扩大。随着海洋保护区的扩大，预计海洋生态系统将在食物网的结构和动态以及温室气体的产生方面受到干扰，并由此对气候系统产生反馈。阿拉伯海北部有一个异常广泛的海洋带，其特点是季风上升流的季节性变动性强，藻类初级生产力高。尽管已经对该地区的沉积物记录进行了广泛的研究，以重建自最后一次冰期-间冰期旋回以来OMZ范围的原因、时间和持续时间，但仍然完全不知道OMZ变异的长期变化如何影响阿拉伯海过去的生态系统和食物网。这项研究由伍兹霍尔海洋研究所（WHOI）的一组科学家进行，他们使用超高通量的沉积古代DNA特征测序（即“古生物组”）来重建过去的海洋生物种群。将使用先进的生物信息学和统计工具来确定在过去8万年的关键气候间隔中受OMZ强度长期波动影响最强烈的物种。气候和环境条件的平行变化将使用（分子）地球化学技术重建。在这个项目中，研究小组将使用最近从印度河峡谷西北大陆斜坡上的OMZ中心获得的连续的、未受干扰的、放射性碳定年的沉积物记录。高分辨率的古代DNA记录将极大地帮助改进过去受季风影响的阿拉伯海东北部地区的环境和气候解释。这项研究将深入了解生态系统如何对长期的OMZ条件做出反应，以及这些生态系统如何在混合良好和含氧的水柱返回后适应。生物信息学和数值模拟分析将与英国格拉斯哥大学的一名研究人员合作进行。该项目将为麻省理工学院/WHOI海洋学联合项目的一名研究生和两名本科生提供教育机会，他们将通过WHOI的暑期学生奖学金和少数民族奖学金项目招募。此外，本研究的结果和生物信息学方法将在伍兹霍尔海洋生物实验室（MBL）流行的年度课程“分析微生物种群结构（STAMPS）的策略和技术”的讲座中得到实施。