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.

异养原生生物是全球海洋浮游植物 50% 初级生产的主要消费者。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能量向更高营养级的转移方面发挥着关键作用。该项目的目的是开发一种新颖的饱和方法来量化海洋中吞噬性原生生物对浮游植物的摄食率。作为概念验证，本研究将重点确定微型浮游植物的放牧率。这种最小尺寸的浮游植物通常在海洋初级生产中占主导地位，占沿海水域年初级生产的 50%。 了解放牧对于了解浮游生物群落如何发挥作用和应对环境变化至关重要，具有重要的社会效益，可以更准确地预测全球渔业的未来以及影响气候的海洋与大气之间的相互作用。该项目结合了本科生在研究环境和生物海洋学方面的体验式教育，并将成为为研究生、教职员工和商业实体设计的高级水流课程的一个特色。公众对科学的参与将通过科学咖啡馆的演讲和毕格罗实验室全年举办的一系列开放日活动进行。该项目背后的动机是，执行和解释当前海洋中原生生物食草性实验测量的挑战限制了我们对这个关键过程的理解。本方法的基础是用替代猎物使食草动物饱和，从而释放对自然猎物的放牧压力。对自然猎物由此增加的生长速率的测量提供了放牧速率的值。该项目涉及使用模型捕食者-猎物组合培养物进行实验室实验，以选择合适的替代猎物并测试该方法的基本理论假设。然后，该信息将用于为天然浮游生物群落的实验设计提供信息。这些实验的目的是测试饱和方法的有效性，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经过彻底测试的生物海洋学新方法，并提供最佳设置程序的建议以及对影响结果不确定性的因素的评估。饱和方法比以前的方法具有潜在的优势。它适合通过流式细胞术进行分析，从而实现高通量和精确测量，避免对天然海水和微生物群落的操作，并提供有关浮游植物群落的特定组成部分的生长和放牧信息。

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.