Collaborative Research: Cyanobacteria, Nitrogen Cycling, and Export Production in the Laurentian Great Lakes

合作研究：劳伦森五大湖的蓝藻、氮循环和出口生产

• 批准号: 1948787
• 负责人: Silvia Newell
• 金额: $ 34.96万
• 依托单位: Wright State University
• 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: 2020-03-15 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1948787&HistoricalAwards=false
• 关键词: Collaborative; Research; Cyanobacteria; Nitrogen; Cycling

Collaborative Research: Cyanobacteria, Nitrogen Cycling, and Export Production in the Laurentian Great LakesThe Great Lakes hold about 20% of the freshwater on Earth and have been increasingly impacted by human activities in recent decades. Lake Erie suffers from large, annually recurring, toxic cyanobacterial blooms in summer, whereas Lake Superior experiences smaller, localized cyanobacterial blooms after storm events. Cyanobacterial blooms have harmful ecological, human health, and economic implications. These blooms are a global phenomenon, observed in lakes and oceans, and can lead to low oxygen conditions and the production of toxins, both of which can be harmful for ecosystems. Understanding how different types of cyanobacteria influence nutrient cycling remains a major knowledge gap. This project aims to provide a deeper understanding of the long-term state of the Great Lakes ecosystem. The research approach combines new and established methods. Project results and implications will be shared with local and regional water interests in partnership with the Pittsburgh Collaboratory for Water Research, Education, and Outreach, the Great Lakes Commission Harmful Algal Blooms Collaborative, and the Lake Erie Area Research Network. Education is a central part of this project and training opportunities target next generation of scientists, including postdoctoral, graduate, and undergraduate students. The students and postdoc will receive state-of-the-art training in the rapidly developing fields of biogeochemistry and geomicrobiology, while working with an interdisciplinary team of scientists.This study will examine nitrogen cycling, phytoplankton community composition, and the nitrogen isotopic composition of chloropigments in order to evaluate cyanobacterial productivity in the modern Laurentian Great Lakes as well as the historical record of cyanobacterial blooms over the past several hundred years. The nitrogen isotope composition of chloropigments is expected to provide a powerful new proxy for understanding primary productivity and the relative importance of cyanobacteria to export production and nitrogen cycling. This proxy would be valuable not only for management of modern systems but has important implications for increasing our understanding of the role of cyanobacteria throughout Earth history. This project would test this molecular isotopic proxy in contemporary aquatic ecosystems to assess its efficacy for: (1) determining the relative contributions of cyanobacteria vs eukaryotic algae (e.g., diatoms) to primary production; (2) evaluating export production of cyanobacterial productivity (including blooms); and (3) constraining historical cyanobacteria productivity in the sedimentary record. Comparison of a system characterized by eutrophication and seasonal cyanobacterial blooms (Lake Erie) with one characterized by picocyanobacteria productivity, but the near-absence of large-scale cyanobacterial blooms (Lake Superior), will provide information about the range of impacts that cyanobacteria can have on carbon and nitrogen cycling. Further information regarding nitrogen cycling will be derived from analysis of solid and dissolved nitrogen species throughout the annual cycle, as well as seasonal studies of sediment processes to measure associated sediment nitrogen removal rates through different processes.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.

合作研究：laurentian大湖区大湖区的蓝细菌，氮循环和出口产量占地球上约20％的淡水，并且最近几十年来受到人类活动的影响。伊利湖在夏季患有大型，每年反复发生的有毒蓝细菌盛开，而苏必利尔湖在暴风雨事件发生后经历了较小的局部蓝细菌盛开。蓝细菌的开花具有有害的生态，人类健康和经济影响。这些花朵是一种全球现象，在湖泊和海洋中观察到，可以导致低氧条件和毒素的产生，这两种情况都可能对生态系统有害。了解不同类型的蓝细菌如何影响营养循环仍然是一个主要的知识差距。该项目旨在更深入地了解大湖生态系统的长期状态。研究方法结合了新的和既定的方法。项目结果和含义将与地方和区域水利益共享，并与匹兹堡水研究，教育和外展合作，大湖委员会有害藻类合作社以及伊利湖地区研究网络。教育是该项目的核心部分，培训机会针对下一代科学家，包括博士后，研究生和本科生。学生和博士后将接受与科学家的跨学科团队合作的生物地球化学和地貌生物学迅速发展领域的最先进培训。这项研究将研究氮气环境，植物浮游生物，植物群社区组成，以及良好的同位素同位素群体的生产力，以使其在阶段的植物群体中的植物群体构成较高的植物群体，以使其对依赖的植物群体的质量构成构成。在过去的几百年中，随着蓝细菌的历史记录。预计叶绿素的氮同位素组成有望为理解一级生产力以及蓝细菌对出口产生和氮循环的相对重要性提供强大的新代理。该代理不仅对现代系统的管理很有价值，而且对我们对整个地球历史上蓝细菌的作用的理解具有重要意义。该项目将测试当代水生生态系统中的该分子同位素代理，以评估其功效：（1）确定氰基细菌与真核藻类（例如硅藻）对初级生产的相对贡献； （2）评估蓝细菌生产力的出口产生（包括开花）； （3）在沉积记录中限制历史蓝细菌的生产率。以富营养化和季节性蓝细菌盛开（伊利湖）为特征的系统的比较，其特征是以皮基氨基细菌的生产力，但大规模的蓝细菌盛开（苏必利尔湖）的差异将提供有关氰基细菌对碳细菌的影响范围的信息。 Further information regarding nitrogen cycling will be derived from analysis of solid and dissolved nitrogen species throughout the annual cycle, as well as seasonal studies of sediment processes to measure associated sediment nitrogen removal rates through different processes.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.