RAPID: Collaborative Research: Understanding linkages between nutrient quality and phytoplankton assemblage responses to COVID-19 stay-at-home orders in an urban, estuarine system

除了健康和安全问题外，全球冠状病毒（COVID-19）大流行对全球人类行为产生了重大影响，从企业和学校关闭到居家令。因此，为工作、教育、娱乐和其他日常活动而进行的全球旅行出现了前所未有的急剧下降。化石燃料消耗和污染排放的相关下降导致空气质量得到改善。大气污染物（特别是氮）的减少和污染物的沉积也一定在影响养分循环，影响陆地和水生生态系统过程。这种情况创造了一个全新的、大规模的“人类实验”，研究社会经济行为和流动模式的突然变化如何影响环境。为了更好地了解与大流行相关的环境变化，NSF RAPID项目将重点研究沿海和河口水生栖息地，这些栖息地已知具有特别的生物生产力和多样性。研究人员将在2019冠状病毒病关闭和重新开放期间，利用美国东海岸城市河口的水样和卫星观测，测量关键的生物地球化学（营养）和生态（浮游植物、细菌）指标。该项目还将培养博士后学者和研究生，包括那些来自科学界代表性不足群体的学者和研究生，同时加强对社会活动与沿海生态系统之间联系的理解。大气污染（特别是氮）浓度急剧下降，从而沉积，再加上与COVID-19关闭相关的废水排放分布的变化，预计将影响邻近沿海水域的生物地球化学和生态。由于主要的n形态和相对于其他营养物质的化学计量比决定了浮游植物和细菌群落结构，因此城市河口中营养物质数量、质量和来源分布的突然变化可能导致微生物组合和生物地球化学过程的变化。本研究的总体假设是，COVID-19大流行导致的人类活动突然减少将对沿海生物地球化学和物理水质参数以及浮游植物和细菌组合产生相当大且可测量的影响。虽然这一假设广泛适用于全球发达的海岸线，但本研究将重点关注长岛海峡（LIS），因为它(i)与大纽约市（NYC）大都市区接壤，特别是纽约州和康涅狄格州（CT）之间的通勤走廊，（ii）高度城市化，（iii）受COVID-19的打击尤其严重，（iv）纽约州和康涅狄格州是首批强制实施居家限制的州之一。导致周边社区的交通活动大幅减少。该研究解决了三个问题：1。最近人类活动的变化（空气质量的改善和废水输入的同步变化）是否与关键生物地球化学指标（C、N、P、Si）和化学计量比的变化有关？2. 浮游植物和细菌组合的相应反应是什么？3. 这些变化与生物光学特性的变化有什么关系？为了及时回答这些生态系统规模的问题，该团队将测量关键的水质和生物地球化学参数，以及评估浮游植物和细菌组合的丰度和组成。工作将利用区域水和空气质量监测以及LIS过去和正在进行的水取样。卫星海洋彩色图像将用于将观测从点测量扩大到更大的生态系统。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。

In addition to health and safety concerns, the global coronavirus (COVID-19) pandemic has had significant impacts on human behavior worldwide, from business and school closures to stay-at-home orders. As a consequence there have been unprecedented and precipitous drops in global travel for work, education, recreation, and other daily activities. The associated declines in fossil fuel consumption and pollution emissions have resulted in improved air quality. Reductions in atmospheric contaminants (particularly nitrogen, N) and deposition of pollutants must also be influencing nutrient cycling and impacting terrestrial and aquatic ecosystem processes. The situation has created a completely novel and large-scale "human experiment" in how sudden changes in socio-economic behavior and mobility patterns may influence the environment. To better understand environmental changes associated with the pandemic, this NSF RAPID project will focus on studies of coastal and estuary aquatic habitats, which are known to be particularly biologically productive and diverse. Researchers will measure key biogeochemical (nutrient) and ecological (phytoplankton, bacteria) metrics using water sampling and satellite observations of an urban estuary on the east coast of the US over the COVID-19 shutdown and reopening periods. This project will also train postdoctoral scholars and graduate students, including those from underrepresented groups in science, while enhancing the understanding of connections between societal activity and coastal ecosystems.Steep declines in the concentration, thus deposition, of atmospheric pollution (particularly N), combined with shifts in wastewater effluent distribution associated with the COVID-19 shut-down are expected to influence the biogeochemistry and ecology of adjacent coastal waters. Since the dominant N-form, and stoichiometric ratios relative to other nutrients, shape phytoplankton and bacterial community structure, sudden changes in nutrient amounts, quality, and source distribution in an urban estuary could translate to regime shifts in microbial assemblages and biogeochemical processes. The overarching hypothesis of this study is that the sudden decline in human activity due to the COVID-19 pandemic will exert considerable and measurable effects on coastal biogeochemical and physical water quality parameters as well as phytoplankton and bacterial assemblages. While this hypothesis is broadly applicable to developed coastlines worldwide, this study will focus on Long Island Sound (LIS) because it (i) borders the greater New York City (NYC) metropolitan area, specifically the commuting corridor between NY and Connecticut (CT), (ii) is heavily urbanized, (iii) was especially hard-hit by COVID-19, and (iv) NY and CT were among the first states to mandate stay-at-home restrictions, leading to surrounding communities drastically downscaling transportation activity. The research addresses three questions: 1. Have recent changes in human activity (improved air quality and concurrent changes in wastewater inputs) been associated with shifts in key biogeochemical metrics (C, N, P, Si) and stoichiometric ratios? 2. What are the corresponding responses of phytoplankton and bacterial assemblages? 3. How do these changes relate to shifts in bio-optical properties? To answer these timely ecosystem-scale questions, the team will measure key water quality and biogeochemical parameters, as well as evaluate the abundances and composition of phytoplankton and bacterial assemblages. Work will leverage regional water and air quality monitoring and past and ongoing water sampling in LIS. Satellite ocean color imagery will be used to scale-up observations from point measurements to the larger ecosystem.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.