Collaborative Research: EAGER: Particle-specific DNA sequencing to directly observe ecological mechanisms of the biological pump

合作研究：EAGER：颗粒特异性 DNA 测序，直接观察生物泵的生态机制

• 批准号: 1703422
• 负责人: Margaret Estapa
• 金额: $ 7.69万
• 依托单位: Skidmore College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-12-15 至 2018-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1703422&HistoricalAwards=false
• 关键词: Collaborative; Research; EAGER; Particle; specific

Carbon is fixed into organic matter by phytoplankton growing in the surface ocean, and is naturally sequestered in the ocean interior when particles and organisms sink: a process called the "biological pump." Because of its recognized influence on the global carbon cycle, ocean scientists have studied the biological pump for decades. However, we still do not have a sufficient understanding of the underlying processes to accurately quantify and predict carbon cycling. Much of this uncertainty stems from an inability to directly link specific plankton in the surface ocean with the types of particles sinking out of the surface ocean. To address this missing link in biological pump research, this work will directly observe how plankton are transported out of the surface ocean using novel, particle-specific observational approaches embedded within an interdisciplinary field program that will finely resolve upper ocean plankton groups and the resulting amount of sinking carbon across space and in time. The genetic identity of organisms within different types of sinking particles will be determined by sequencing the genetic contents of individually collected particles. This new application of a molecular method will definitively link surface plankton with sinking particles at five locations across the Pacific Ocean. This work has the potential to transform our understanding of the biological pump by identifying previously unknown links between surface ecosystems and sinking carbon particles. Because this work is embedded within an interdisciplinary field program, including biogeochemical modelers and remote sensing scientists, these data will feed directly into new models of the biological pump, improving our ability to quantify and predict carbon uptake by the ocean. This project will train 1 graduate student and at least 2 undergraduate researchers. Findings will be communicated to the non-scientific public through blogs, videos, and the public communication channels of participating institutions.Accurate prediction of the global carbon cycle requires an understanding of the specific processes that link surface plankton communities and sinking particulate carbon flux (export) out of the surface ocean, but current methodological paradigms in biological pump research do not directly observe these processes. This project will comprehensively determine who is exported from the surface ocean and how using new, particle-resolving optical and molecular techniques embedded within a sampling scheme that characterizes export events at high time and space resolution. The investigation suggests that different plankton types in the surface waters are transported out of the surface ocean by distinct export pathways, and that an understanding of these connections is critical knowledge for global carbon cycle modeling. If successful, this work has the potential to transform our conceptual understanding of the biological pump by directly identifying mechanisms that link surface plankton with particle export, without relying on bulk sampling schemes and large-scale correlation analysis. Particle export environments will be studied at five open ocean locations during a cruise from Hawaii to Seattle in January-February 2017. The surface plankton communities will be characterized by a combination of satellite observations, sensors attached to a free-drifting, continuously profiling WireWalker, an in situ holographic camera, microscopy, and by sequencing 18S and 16S rRNA gene fragments. Exported particles will simultaneously be captured by various specialized sediment traps and their characteristics will be directly related to their sources in the surface community by identifying the genetic contents of individual particle types. Individual particles will be isolated from gel layers and the 16S and 18S rRNA gene fragments will be amplified and sequenced. This work would, for the first time, combine molecular approaches with particle-specific observations to enable simultaneous identification of both which organisms are exported and the processes responsible for their export.

碳通过在地面海洋中生长的浮游植物固定在有机物中，当颗粒和生物沉没时，在海洋内部自然隔离：一种称为“生物泵”的过程。由于它对全球碳循环的公认影响，海洋科学家已经研究了几十年来研究生物泵。但是，我们仍然对基本过程没有足够的了解来准确量化和预测碳循环。这种不确定性的大部分源于无法将表面海洋中的特定浮游物与颗粒类型从表面海洋中沉没的类型联系起来。为了解决生物泵研究中的这种缺失的联系，这项工作将直接观察浮游生物如何使用嵌入在跨学科田间程序中的新型的，特定的粒子特异性观察方法将其运出地面海洋，该方法将精心解决上海浮游生物组以及在空间跨空间和时间上产生的水槽量的量。在不同类型的下沉颗粒中生物的遗传认同将通过对单独收集的颗粒的遗传含量进行测序来确定。这种新的分子方法的应用将定义地将表面浮游生物与太平洋五个位置的下沉颗粒联系起来。这项工作有可能通过识别表面生态系统和下沉碳颗粒之间的以前未知的联系来改变我们对生物泵的理解。由于这项工作嵌入了跨学科的现场计划中，包括生物地球化学建模者和遥感科学家，因此这些数据将直接进入生物泵的新模型中，从而提高了我们量化和预测海洋碳吸收的能力。该项目将培训1名研究生和至少2名本科研究人员。调查结果将通过博客，视频和参与机构的公共沟通渠道传达给非科学公众。准确地预测全球碳循环需要了解将表面浮游生物群落和颗粒碳纤维碳（Export）降低的特定过程，而不是直接观察到当前的生物泵研究中的生物学方法。该项目将全面确定谁是从地面海洋中导出的，以及如何使用嵌入在较高时间和空间分辨率出口事件的采样方案中的新的，分辨粒子的光学和分子技术。研究表明，地表水中的不同浮游生物类型通过不同的出口途径从地表海洋中运出，并且对这些连接的理解是全球碳循环建模的关键知识。如果成功的话，这项工作有可能通过直接识别将表面浮游物与粒子出口联系起来的机制来改变我们对生物泵的概念理解，而无需依赖批量抽样方案和大规模相关性分析。粒子出口环境将在2017年1月从夏威夷到西雅图的巡游中的五个开放海洋场所进行研究。表面浮游生物社区的特征是卫星观察结果的组合，卫星观测，传感器连接到自由散布的，连续的触发线 - 持续分析的线路，并在现场摄像机，显微摄像机，显微镜，Sequerne sequerne and sequern and sequern and sequencen and sequencencing 18s。出口颗粒将同时被各种专业的沉积物陷阱捕获，它们的特征将通过识别单个粒子类型的遗传含量来直接与表面社区中的来源相关。单个颗粒将从凝胶层中分离出来，将会放大和测序16S和18S rRNA基因片段。这项工作将首次将分子方法与粒子特异性观察结合在一起，以同时识别两者的出口和导致其出口的过程。