OCE-PRF: Integrating high-throughput plankton imaging and DNA meta-barcoding to elucidate the prevalence and oceanographic determinants of diatom parasitism

硅藻是一种藻类，在支持沿海社区赖以获取食物和其他资源的多产的海洋食物网和渔业方面发挥着巨大的作用。由寄生浮游生物引起的硅藻“流行病”有时已被观察到，并可能对海洋食物网产生重大影响。然而，传统上用于观察硅藻寄生的困难和耗时的方法限制了我们了解这些事件的普遍性以及促进感染的环境条件的能力。该项目将利用浮游生物成像和DNA测序方面的最新技术进步，开发有效的方法，从而能够持续观察沿海海洋大片地区的硅藻寄生情况。这些方法将应用于经济上重要的美国东北陆架生态系统内现有的DNA序列和浮游生物图像数据集，以确定硅藻寄生在该生态系统中的重要性。这项工作将通过在沿海海洋中产生硅藻寄生的基础知识来推进科学和生物海洋学领域。这将使预测海洋生态系统变化以应对气候变化的工作得到改进，从而促进国家沿海社区的繁荣、福利和安全。该项目还将通过为两名本科生提供有偿的沉浸式研究体验，扩大海洋科学的参与范围，并为他们提供额外的机会，参加科学会议并展示他们的工作，并为科学出版物做出贡献。一个早期的博士后研究人员将获得宝贵的专业经验，设计和实施研究和战略指导计划，旨在公平招聘和支持两名本科研究人员的职业发展。具体来说，该项目将整合大型DNA元条形码和浮游生物成像数据集，以开发一种通用的、高通量的方法来推断和验证硅藻宿主与真核纳米寄生虫之间的相互作用，并随后估计特定宿主-寄生虫对的感染流行程度。这种方法将适用于其他水生生态系统，并有可能适用于研究浮游生物之间其他类型的相互作用。此外，它将有助于优化DNA元条形码分析、浮游生物成像和其他复杂的、观测的、生物海洋学数据集，并加速它们在解决新的科学问题方面的应用。将这种方法应用于美国东北部大陆架上广泛的图像和DNA元条形码数据集，将能够定量人群特异性和聚集的社区水平硅藻感染流行情况，并揭示感染事件的流行情况和时空分布。然后，将种群特异性和社区聚集性感染动态与物理、化学和生物海洋学过程联系起来，开始解开种群特异性生理生态位和假设的社区水平强迫在控制硅藻-寄生虫相互作用方面的相对重要性，从局部和事件尺度到区域和季节或更长尺度。总体而言，本项目将建立一个将硅藻寄生纳入预测远洋食物网模型的框架，并协助预测人为气候变化对海洋生态系统结构和功能的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Diatoms, a group of algae, play an outsized role in supporting the productive marine food webs and fisheries that coastal communities rely on for food and other resources. Diatom “epidemics” caused by parasitic plankton have been observed at times and likely have major impacts on marine food webs. However, the difficult and time-consuming methods traditionally used to observe diatom parasitism have limited our ability to understand how common these events are as well as the environmental conditions that promote infection. This project will leverage recent technological advances in plankton imaging and DNA sequencing to develop efficient approaches that will enable sustained observations of diatom parasitism across large areas of the coastal ocean. These approaches will be applied to existing DNA sequence and plankton image data sets within the economically important Northeast U.S. Shelf ecosystem to determine the importance of diatom parasitism in this ecosystem. This work will advance science and the field of biological oceanography by generating foundational knowledge of diatom parasitism in the coastal ocean. This will enable improvements in efforts to forecast changes in marine ecosystems in response to climate change, thus advancing the prosperity, welfare, and security of the nation’s coastal communities. This project will also broaden participation in ocean science by providing paid, immersive research experiences for two undergraduate students with additional opportunities to attend and present their work at scientific conferences and to contribute to scientific publications. An early-career postdoctoral researcher will gain invaluable professional experience designing and implementing both the research and a strategic mentorship plan targeted toward equitably recruiting and supporting the career advancement of the two undergraduate researchers. Specifically, this project will integrate large DNA meta-barcoding and plankton imaging data sets to develop a generic, high-throughput approach to infer and validate interactions between diatom hosts and eukaryotic nano-parasites, and subsequently estimate infection prevalence for specific host-parasite pairs. This approach will be applicable to other aquatic ecosystems and will have the potential to be adapted to the study of other types of interactions amongst the plankton. Further, it will contribute to ongoing efforts to optimize analysis of DNA meta-barcoding, plankton imaging, and other complex, observational, biological oceanographic data sets, and accelerate their use in addressing novel scientific questions. Application of this approach to extensive image and DNA meta-barcoding data sets available on the Northeast U.S. Shelf will enable quantitation of population-specific and aggregated community-level diatom infection prevalence and reveal the prevalence and spatiotemporal distribution of infection events. Population-specific and community-aggregated infection dynamics will then be related to physical, chemical, and biological oceanographic processes to begin to disentangle the relative importance of population-specific physiological niches and hypothesized community-level forcings in governing diatom-parasite interactions from local and event scales to regional and seasonal or longer scales. Overall, this project will establish a framework for integrating diatom parasitism into predictive pelagic food web models and assist in forecasting the impacts of anthropogenic climate change on the structure and function of marine ecosystems.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.