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：
1029951
负责人：
Bess Ward
金额：
$ 63.71万
依托单位：
Princeton University
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 2014-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1029951&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.

基本问题仍然是氮 (N) 在最低氧区 (OMZ) 中如何循环以及反硝化和厌氧氨氧化对固定氮损失的相对贡献。华盛顿大学和普林斯顿大学的科学家最近的研究表明厌氧氨氧化的发生阿拉伯海 OMZ 中的反硝化作用，表明反硝化作用主导了固定氮去除，与热带南太平洋东部 (ESTP) OMZ 的报告相反。观察到的差异归因于供应到 OMZ 水域的有机碳的性质和时间。在该项目中，科学家们建议通过记录反硝化与地表水中有机碳的通量有关，而厌氧氨氧化不直接对有机碳输入做出反应，而是取决于可溶性副产品的通量，来解释 OMZ 中反硝化的有限观察结果。例如有机物分解过程中释放的铵和亚硝酸盐。将开展一项实地计划，涉及两次独立的巡航，一次前往 ETSP，另一次前往东部热带北太平洋 (ETNP)。选择这些地点是因为 ESTP 是三个主要 OMZ 中研究最多的，而 ETNP 是体积最大的 OMZ，并且在组合脱氮方面可能在数量上是最重要的。实现其目标的实验计划包括以下内容：（1）使用广泛的空间覆盖范围代替高分辨率的时间覆盖范围，以获得反硝化和厌氧氨氧化速率的许多测量结果；（2）利用操纵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) 在孵化实验中使用新的示踪剂测量来区分反硝化、异化硝酸盐还原成铵和厌氧氨氧化； (4)利用DNA/RNA微阵列研究转化率与反硝化菌组合之间的关系，以解析颗粒在刺激反硝化率中的作用； (5) 使用高灵敏度氧探针来定义氧分布并跟踪示踪剂孵育中低水平的氧动态。就更广泛的影响而言，华盛顿大学计划在汤普森号R/V上贡献时间，以便本科生可以参加巡航并了解开展海洋学研究所涉及的方法和技术，特别是与本研究相关的方法和技术。作为该项目的一部分，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持和培训。