The significance of doliolid-microbial interactions: Do doliolids fundamentally alter the trophic structure and productivity of sub-tropical continental shelf food webs?

多利奥利德-微生物相互作用的意义：多利利德是否从根本上改变了亚热带大陆架食物网的营养结构和生产力？

• 批准号: 2023133
• 负责人: Marc Frischer
• 金额: $ 108万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2023133&HistoricalAwards=false
• 关键词: significance; doliolid; microbial; interactions; Do

Gelatinous zooplankton play crucial but poorly understood roles in food webs and element cycling in the world's oceans. This is especially true for smaller mucus-feeding gelatinous animals including the pelagic tunicates (salps, pyrosomes, larvaceans, and doliolids). Doliolids form massive blooms in particle and nutrient-rich waters of the world’s continental shelves, often exceeding 1,000 zooids m-3 and extending 100’s of km. These blooms are likely to alter the structure and function of marine food webs. When crustacean zooplankton (copepods) are the primary consumers of phytoplankton they nourish larger species such as fish, birds, and marine mammals. The investigators hypothesize that doliolid blooms, in contrast, enhance microbial loop processes leading to a lower efficiency of trophic transfer to larger consumers. In this project, the investigators examine the role that doliolids play in linking and modifying microbial loop and classical food web processes in subtropical continental shelf systems. In addition to the project’s focus on a central theme in biological oceanography, the results of this project are of broader interest. Specifically, gelatinous zooplankton remain a poorly resolved component of ecosystem models, and a better understanding of how these communities interact with microbial processes and are influenced by chemical and physical conditions will improve predictions of population- and ecosystem-level responses to the myriad of environmental stressors. The project supports a targeted effort to increase the representation of African Americans in the Ocean Sciences, provides experiential research opportunities to K-12 educators, supports 2 PhD students and several undergraduate students, and involves an investigator at the beginning of his academic career.The long-term goal of this project is to understand the ecological function of doliolids on subtropical continental shelves and their influence on microbial processes. In association with monthly oceanographic field expeditions on the mid-continental shelf at 31°N and two longer longitudinal expeditions complemented with experimental studies, the project investigates the relationship between doliolid abundance and life stage composition, their spatial relationships to marine snow aggregates and other zooplankton, water column microbial activity, bacterial production, and net system productivity. Utilizing a constellation of modern and classical approaches in microbial and zooplankton ecology, including deployment of an in situ zooplankton imaging system in the South Atlantic Bight, microbial metagenomics and transcriptomics, and stable isotope-based tracer experiments, these studies will allow the testing of three fundamental hypotheses. First, independent of total shelf productivity, the presence and abundance of doliolids is correlated with heterotrophy compared to periods when doliolids are not abundant. Second, doliolids predictably shape continental shelf microbial communities, activity, and function, and third, doliolids are detrital feeders benefiting nutritionally from the consumption of microbial enriched aggregated particles and fecal material - the pool to which they also contribute.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

胶质浮游动物在世界海洋的食物网和元素循环中起着至关重要但知之甚少的作用。这对于较小的粘液喂养的凝胶状动物尤其如此，包括远洋被囊动物（salps，pyrosomes，larvaceans和doliolids）。 在世界大陆架的颗粒和营养丰富的沃茨中，珊瑚虫形成大规模的水华，通常超过1,000个动物体m-3，延伸100公里。这些水华很可能改变海洋食物网的结构和功能。当甲壳类浮游动物（桡足类）是浮游植物的主要消费者时，它们滋养较大的物种，如鱼类，鸟类和海洋哺乳动物。 研究人员假设，相比之下，doliolid开花增强了微生物循环过程，导致向较大消费者转移营养的效率较低。 在这个项目中，研究人员研究了doliolids在连接和修改亚热带大陆架系统中的微生物循环和经典食物网过程中的作用。除了该项目侧重于生物海洋学的一个中心主题外，该项目的成果还具有更广泛的意义。具体而言，凝胶状浮游动物仍然是生态系统模型的一个解决不好的组成部分，更好地了解这些社区如何与微生物过程相互作用，并受到化学和物理条件的影响，将改善人口和生态系统层面的预测对无数环境压力的反应。 该项目支持有针对性的努力，以增加非洲裔美国人在海洋科学的代表性，提供经验研究的机会，K-12教育工作者，支持2名博士生和几名本科生，并涉及在他的学术生涯开始的调查员。长期-本计画的长期目标是了解亚热带大陆架上的珊瑚礁的生态功能及其对微生物过程的影响。该项目结合每月在31°N中部大陆架进行的海洋学实地考察和两次较长的纵向考察，并辅以实验研究，调查了硅砾丰度与生命阶段组成之间的关系、它们与海洋雪聚集体和其他浮游动物的空间关系、水柱微生物活动、细菌生产和净系统生产力。利用微生物和浮游动物生态学的一系列现代和经典方法，包括在南大西洋湾部署一个现场浮游动物成像系统、微生物宏基因组学和转录组学以及基于稳定同位素的示踪实验，这些研究将能够检验三个基本假设。首先，独立的总货架生产力，存在和丰富的doliolids与异养相比，doliolids不丰富的时期。第二，doliolids可预见地塑造大陆架微生物群落，活动和功能，第三，doliolids是碎屑饲养者，从微生物富集的聚集颗粒和粪便物质的消耗中获得营养-他们也有助于游泳池。这个奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

项目成果

In situ imaging across ecosystems to resolve the fine‐scale oceanographic drivers of a globally significant planktonic grazer

跨生态系统的原位成像，以解决全球重要浮游食草动物的精细海洋学驱动因素

• DOI: 10.1002/lno.12259
• 发表时间: 2022
• 期刊: Limnology and Oceanography
• 影响因子: 4.5
• 作者: Greer, Adam T.;Schmid, Moritz S.;Duffy, Patrick I.;Robinson, Kelly L.;Genung, Mark A.;Luo, Jessica Y.;Panaïotis, Thelma;Briseño‐Avena, Christian;Frischer, Marc E.;Sponaugle, Su
• 通讯作者: Sponaugle, Su

Selective feeding and linkages to the microbial food web by the doliolid Dolioletta gegenbauri

• DOI: 10.1002/lno.11740
• 发表时间: 2021-04
• 期刊: Limnology and Oceanography
• 影响因子: 4.5
• 作者: M. Frischer;L. Lamboley;T. Walters;J. Brandes;E. Arneson;L. E. Lacy;Natalia B. López-Figueroa;Á. Rodríguez‐Santiago;D. M. Gibson