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(新冠肺炎)大流行对全球范围内的人类行为产生了重大影响，从商业和学校关闭到在家工作。其结果是，全球工作、教育、娱乐和其他日常活动的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了空气质量的改善。大气污染物(特别是氮、氮)的减少和污染物的沉积也必须影响营养循环，并影响陆地和水生生态系统的进程。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可能如何影响环境。为了更好地了解与大流行相关的环境变化，国家科学基金会的这个快速项目将侧重于沿海和河口水生生境的研究，众所周知，这些栖息地具有特别多的生物生产力和多样性。研究人员将通过对新冠肺炎关闭和重新开放期间美国东海岸一个城市河口的水样和卫星观测，测量关键的生物地球化学(营养物)和生态(浮游植物、细菌)指标。该项目还将培训博士后学者和研究生，包括那些来自科学领域代表性不足群体的博士后学者和研究生，同时提高对社会活动和沿海生态系统之间联系的了解。大气污染(特别是氮)浓度的持续下降，以及与新冠肺炎关闭相关的废水流出分布的变化，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型和相对于其他营养物质的化学计量比塑造浮游植物和细菌群落结构，城市河口营养物质数量、质量和来源分布的突然变化可能转化为微生物组合和生物地球化学过程的制度变化。这项研究的主要假设是，新冠肺炎大流行导致人类活动突然减少，将对沿海的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和可测量的影响。虽然这一假设广泛适用于世界各地的发达海岸线，但本研究将把重点放在长岛海湾(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)新冠肺炎的影响尤为严重；(Iv)纽约州和康涅狄格州是首批强制实施居家限制措施的州，导致周边社区大幅减少交通活动。这项研究涉及三个问题：1.最近人类活动的变化(空气质量的改善和废水输入的同时变化)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性质的变化有什么关系？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，并评估浮游植物和细菌组合的丰度和组成。这项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采样。卫星海洋彩色图像将被用于放大观测，从点测量到更大的生态系统。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.