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Collaborative Research: Control of Denitrification and Anammox in the Oxygen Deficient Waters of the Eastern Tropical North and South Pacific

合作研究：东部热带北太平洋和南太平洋缺氧水域反硝化和厌氧氨氧化的控制

基本信息

批准号：
1029316
负责人：
Allan Devol
金额：
$ 49.4万
依托单位：
University of Washington
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2010
资助国家：
美国
起止时间：
2010-09-15 至 2015-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1029316&HistoricalAwards=false
关键词：
Collaborative Research Control Denitrification Anammox

项目摘要

Fundamental question remain on how nitrogen (N) cycles in oxygen minimum zones (OMZs) and on the relative contribution of denitrification and anammox to the loss of fixed N. Recent work by scientists at the University of Washington and Princeton University showed the occurrence of anammox and denitrification in the OMZ of the Arabian Sea and indicated that denitrification dominated the fixed N removal in contrast to reports for the OMZ in the Eastern Tropical South Pacific (ESTP). The observed difference was attributed to the nature and timing of organic carbon supplied to the OMZ waters. In this project, the scientists propose to explain the limited observations of denitrifications in the OMZs by documenting that denitrification is linked to the flux of organic carbon from surface waters whereas anammox does not respond directly to organic C inputs but depends on the flux of soluble byproducts such as ammonium and nitrite released during the breakdown of organic matter. A field program involving two separate cruises, one to the ETSP and one to the Eastern Tropical North Pacific (ETNP) will be carried. These sites were selected because the ESTP is the most studied of the three major OMZs whereas the ETNP is the largest OMZ by volume and may be quantitatively the most important in terms of combined nitrogen removal. The experimental plan to attain their goals include the following: (1) use extensive spatial coverage as a substitute for high resolution temporal coverage to obtain many measurements of denitrification and anammox rates; (2) use manipulation experiments to investigate the response of denitrification and anammox rates to specific perturbations such as organic matter additions and transient oxygen perturbation; (3) use new tracer measurements to distinguish denitrification, dissimilatory nitrate reduction to ammonium and anammox in incubation experiments; (4) use DNA/RNA microarrays to investigate relationships between transformation rates and the denitrifier assemblage to resolve the role of particles in stimulation of denitrification rates; and (5) use high sensitivity oxygen probes to define the oxygen distribution and to follow oxygen dynamics at low levels in tracer incubation. In terms of the broader impacts, the University of Washington plans to contribute time on the R/V Thompson so that undergraduate students can participate in a cruise and learn about the methods and techniques involved in carrying out oceanographic research, especially those related to this study. One graduate student from the University of Washington and one postdoc, one graduate student and one undergraduate student from Princeton University would be supported and trained as part of this project.

氮在最小含氧区（OMZ）中的循环以及反硝化和厌氧氨氧化对固定氮损失的相对贡献仍然是一个基本问题。华盛顿大学和普林斯顿大学的科学家最近的研究表明，阿拉伯海OMZ中发生了厌氧氨氧化和反硝化作用，并表明反硝化作用主导了固定氮的去除，这与东热带南太平洋OMZ（ESTP）的报告相反。观察到的差异是由于有机碳的性质和时间提供给OMZ沃茨。在这个项目中，科学家们建议通过记录反硝化作用与地表沃茨的有机碳通量有关，而厌氧氨氧化反应不直接响应有机碳输入，而是取决于有机物分解过程中释放的可溶性副产物（如铵和亚硝酸盐）的通量来解释OMZ中对反硝化作用的有限观察。将进行一项实地方案，包括两次单独的巡航，一次前往ETSP，另一次前往东热带北太平洋（ETNP）。选择这些站点是因为ESTP是三个主要OMZ中研究最多的，而ETNP是按体积计最大的OMZ，并且在组合脱氮方面可能是定量上最重要的。为实现这一目标，本研究的实验方案包括：（1）利用大范围的空间覆盖代替高分辨率的时间覆盖，获得大量的反硝化和厌氧氨氧化速率的测量数据;（2）利用操作实验研究反硝化和厌氧氨氧化速率对特定扰动（如有机物添加和瞬时氧扰动）的响应;（3）利用新的示踪技术区分培养实验中的反硝化、异化硝酸盐还原为铵和厌氧氨氧化，（4）利用DNA/RNA微阵列技术研究转化率与反硝化菌组合之间的关系，以解决颗粒物在反硝化速率刺激中的作用;和（5）使用高灵敏度氧探针来确定氧分布并在示踪剂培养中以低水平跟踪氧动力学。就更广泛的影响而言，华盛顿大学计划在R/V Thompson上贡献时间，以便本科生可以参加巡航并了解进行海洋学研究所涉及的方法和技术，特别是与这项研究有关的方法和技术。华盛顿大学的一名研究生和普林斯顿大学的一名博士后、一名研究生和一名本科生将得到支助和培训，作为该项目的一部分。