EAGER: A Saturation Approach to Microzooplankton Grazing Rate Determination

EAGER：微型浮游动物吃草率测定的饱和方法

• 批准号: 1738061
• 负责人: Stephen Archer
• 金额: $ 29.74万
• 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: 2017
• 资助国家: 美国
• 起止时间: 2017-05-15 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1738061&HistoricalAwards=false
• 关键词: EAGER; Saturation; Approach; Microzooplankton; Grazing

Heterotrophic protists are the dominant consumers of the 50% of global primary production by phytoplankton in the oceans. Hence, they play a key role in influencing ocean biogeochemistry, the composition of microbial communities, and transfer of energy to higher trophic levels. The aim of the project is to develop a novel saturation approach to quantify the rates of grazing on phytoplankton by phagotrophic protists in the ocean. As a proof-of-concept, this study will focus on determining grazing rates on picophytoplankton. This smallest size-class of phytoplankton often dominates oceanic primary production and can contribute up to 50% of annual primary production in coastal waters. Understanding grazing is of critical importance to understanding how planktonic communities function and respond to environmental change has the important societal benefit of potentially more accurately predicting the future of global fisheries and interactions between ocean and atmosphere that influence our climate. The project incorporates experiential education of undergraduates in the research environment and biological oceanography and will be a feature of an Advanced Aquatic Flow Courses designed for graduate students, faculty members and commercial entities. Public engagement in the science will be through Cafe Scientifique presentations and the series of Open House events that occur at Bigelow Laboratory through the year.The motivation behind this project is that challenges in performing and interpreting current experimental measurements of herbivory by protists in the ocean constrain our understanding of this key process. The basis of the present approach is saturation of the grazers with a surrogate prey, resulting in release of grazing pressure on the natural prey. Measurement of the resulting increased growth rate of the natural prey provides a value for the rate of grazing. The project involves laboratory experiments using cultures of model predator-prey combinations to select suitable surrogate prey and test the underlying theoretical assumptions of the approach. This information will then be used to inform the design of experiments on natural planktonic communities. The objectives of these experiments are to test the efficacy of the saturation approach and to compare results to traditional experimental approaches run in parallel. This research will introduce a new approach to biological oceanography that will have been thoroughly tested, with recommendations for optimum set-up procedures and an assessment of the factors that influence uncertainty in the results. The saturation approach has potential advantages over previous methods. It lends itself to analysis by flow cytometry allowing high throughput and accurate measurements, avoids manipulation of the natural seawater and microbial communities, and provides growth and grazing information on defined components of the phytoplankton community.

异养生物是浮游植物在海洋中全球初级产量50％的主要消费者。因此，它们在影响海洋生物地球化学，微生物群落的组成以及将能量转移到更高营养水平方面起着关键作用。该项目的目的是开发一种新型的饱和方法，以量化海洋中吞噬营养性生物对浮游植物的放牧速率。作为概念验证，这项研究将着重于确定皮基蓬兰克顿的放牧率。这种最小的植物浮游生物通常会占主导地位的海洋初级生产，并且可以贡献高达沿海水域年初级生产的50％。 理解放牧对于理解浮游社区如何运作和对环境变化的作用至关重要，这具有重要的社会利益，即可能更准确地预测全球渔业的未来以及影响我们气候的海洋与气氛之间的相互作用。该项目纳入了研究环境和生物海洋学中的本科生的体验式教育，并将成为为研究生，教职员工和商业实体设计的先进水上流动课程的特征。公众参与科学将是通过Cafe Scientifique演讲以及一年中Bigelow Laboratory发生的一系列开放式事件。该项目的动机是，在海洋中，Putorment执行和解释当前的草食主义者对草食的实验测量的挑战限制了我们对这一关键过程的理解。本方法的基础是用替代猎物的放牧者饱和，从而释放了自然猎物的放牧压力。自然猎物的生长增长速率的测量为放牧率提供了价值。该项目涉及实验室实验，使用模型捕食者捕食组合的培养物选择合适的替代猎物并测试该方法的基本理论假设。然后，这些信息将用于告知有关自然浮游社区实验的设计。这些实验的目标是测试饱和方法的功效，并将结果与​​并行运行的传统实验方法进行比较。这项研究将引入一种新的生物海洋学方法，该方法将经过彻底测试，并建议对最佳设置程序进行建议，并评估影响结果不确定性的因素。饱和方法比以前的方法具有潜在的优势。它通过流式细胞仪进行分析，可以允许高通量和准确的测量，避免对天然海水和微生物群落操纵，并在浮游植物群落的定义组件上提供生长和放牧信息。

项目成果

Saturation Approach to Determine Grazing Mortality in Picoeukaryote and Synechococcus Populations

饱和法测定微微核生物和聚球藻种群的放牧死亡率

• DOI: 10.3389/fmars.2022.844620
• 发表时间: 2022
• 期刊: Frontiers in Marine Science
• 影响因子: 3.7
• 作者: Archer, Stephen D.;Lubelczyk, Laura C.;Kunes, Moriah;McPhee, Kathryn;Dawydiak, Walter;Staiger, Michael;Posman, Kevin M.;Poulton, Nicole J.
• 通讯作者: Poulton, Nicole J.