Collaborative Research: Testing Linkages Between Plankton Community Structure and Export of C, Po, and Th in the Sub-Arctic NE Pacific: Field and Lab Studies

合作研究：测试亚北极东北太平洋浮游生物群落结构与 C、Po 和 Th 输出之间的联系：现场和实验室研究

• 批准号: 1303270
• 负责人: Michael Lomas
• 金额: $ 2.64万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1303270&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; Linkages; Between

In this project, an interdisciplinary research team from CUNY Queens College, University of Rhode Island and the Bermuda Institute of Ocean Sciences will investigate and directly test hypotheses on ecosystem processes that link variability in plankton community structure to particle production, export, and POC-Po210-Th234 interactions in the upper sub-arctic NE Pacific Ocean. They will use field and lab studies, and a combination of geochemical (Po210, Th234 tracers) and biological (primary production, sediment traps, plankton community structure) techniques that will lead to an improved understanding of these important and complex upper ocean processes, which have wide applicability to the interpretation of current and recent results (e.g., VERTIGO, MEDFLUX, HOT, BATS). An important focus will be on the natural radionuclide Po210, which is bioaccumulated in the marine environment, and which recent studies indicate has promise and utility as a tracer of carbon export. This study is designed to refine our understanding of the mechanisms that control variability in export fluxes of Po210, Th234, and POC from the upper water column, rather than using these radionuclide disequilibria to exclusively estimate POC export fluxes. Specifically the team will investigate the relationships between POC, Po210, 210Pb, and Th234 associated with specific types and size-fractions of sinking particles in the field, and then use controlled laboratory studies to test hypotheses and interpret the field data. This will improve our understanding and provide a valuable comparison of Po210 and Th234 as particle tracers. The research is guided by the following two key questions: 1) How variable is the partitioning of POC, Po210, and Th234 between suspended and settling particles and the dissolved pool in response to seasonal variability in the euphotic zone plankton community? 2) How do rates of mobilization and decomposition of POC, Po210, and Th234 vary with the packaging and export of materials produced by the planktonic community in the surface ocean under low and high flux conditions? Field work will be conducted at the Ocean Station Papa (OSP) time series site, during low and high flux seasons when export is dominated by salps (February), copepods (May), and phytodetritus (August). This well-studied high-nutrient/low-chlorophyll site provides a wealth of necessary supporting data and logistical infrastructure. One of the most exciting outcomes from this proposal would be an experimental and field demonstration of strong and consistent relationships between planktonic food webs and the rates of C, Po210, and Th234 packaging, sinking, and remineralization. This study will illuminate the role of euphotic zone ecosystem processes in predicting the eventual fate of export flux in the mesopelagic. The project is expected to yield information that could be used to guide future use of radionuclide tracers, including mechanistic justifications for which tracer to use, when and where to use each tracer, as well as insight into which particulate C fraction Po210 and Th234 are tracing. Broader Impacts: This project is relevant to several national and international research programs. These include; GEOTRACES, whose focus is the global-ocean distribution of trace elements and isotopes in seawater; and IMBER, whose focus in on the functioning of ocean ecosystems. It will also build upon the results of earlier process studies at OSP including SUPER (Subarctic Pacific Ecosystem Research), VERTEX (VERTical EXchange) and the Canadian JGOFS study. The participating institutions will make provision for graduate and/or undergraduate student involvement in all aspects of the research.

在这个项目中，来自CUNY皇后学院，罗德岛大学和百慕大海洋科学研究所的一个跨学科研究团队将调查并直接检验有关将浮游生物社区结构中的变异性与粒子生产，出口，POC-PO210-TH234相互作用的生态系统过程的假设，这些过程将上下层级的PAC-ub-arctic ne artcipic ne artcipic seecome互动。他们将使用现场和实验室研究，以及地球化学（PO210，TH234示踪剂）和生物学（初级生产，沉积物陷阱，浮游生物社区结构）技术的结合，这些技术将对这些重要而复杂的上海过程有了深刻的了解，这些过程对当前和最新结果的解释具有广泛的适用性（例如，Vertigo，Medflux，hotflux，hott，bats，bats，bats）。一个重要的重点将放在天然放射性核素PO210上，该核素PO210在海洋环境中被生物累积，最近的研究表明，这是有望和效用作为碳出口的示踪剂。这项研究旨在完善我们对控制上水柱中PO210，TH234和POC出口通量变异性的机制的理解，而不是使用这些放射性核素不平衡来独家估计POC出口通量。具体而言，团队将研究与特定类型和域中沉没粒子的特定类型和大小相关的POC，PO210、210pb和Th234之间的关系，然后使用受控的实验室研究来检验假设并解释现场数据。这将提高我们的理解，并提供对PO210和TH234作为粒子示踪剂的宝贵比较。这项研究以以下两个关键问题为指导：1）POC，PO210和TH234在悬浮和沉降颗粒之间的分区以及溶解的池的分配方式有多可变，以响应浮游区浮游生物社区的季节性变异性吗？ 2）POC，PO210和TH234的动员和分解速率如何随着浮游生物群落在低和高通量条件下在地面海洋中浮游生物社区产生的材料的包装和出口而变化？现场工作将在海洋站爸爸（OSP）时间序列地点进行，在出口季节的低和高通量季节，当时出口量为salps（2月），copepods（5月）和植物菌（8月）。这个经过良好研究的高营养/低氯植物位点提供了大量必要的支持数据和后勤基础架构。该提案中最令人兴奋的结果之一是实验性和现场演示，表明浮游食物网与C，PO210和TH234包装，下沉和回想矿产之间的牢固和一致的关系。这项研究将阐明一个肿区生态系统过程在预测中质质量中出口通量的最终命运方面的作用。预计该项目将产生可用于指导放射性核素示踪剂的未来使用的信息，包括用于使用哪种示踪剂，何时何地使用每个示踪剂的机械辩护，以及洞察颗粒C分数PO210和TH234的信息。更广泛的影响：该项目与几个国家和国际研究计划有关。这些包括； Geotraces，其重点是海水中痕量元素和同位素的全球分布；和Imber，他们专注于海洋生态系统的功能。它还将基于OSP早期过程研究的结果，包括超级（亚北极太平洋生态系统研究），顶点（垂直交换）和加拿大JGOFS研究。参与的机构将为研究生和/或本科生参与研究的各个方面提供准备。