RAPID: Coastal consequences of engineered water control systems: the role of freshwater discharges in Florida's ongoing harmful algal bloom crises

自2017年10月以来，佛罗里达州海湾沿着已有数百吨海洋生物因暴露于被称为“赤潮”的藻华而死亡。据信，这些水华的强度与奥基乔比湖（Lake Okeechobee）释放的淡水中的营养物质有关。奥基乔比湖是佛罗里达中南部的一个大型内陆湖，旨在防洪。然而，缺乏强有力的科学证据来支持赤潮和奥基乔比湖水释放之间的联系。该项目的目标是收集，分析和模拟水质数据之前和整个主要淡水释放。这些数据将提供深入了解淡水释放和藻类水华之间的因果关系。这项研究的结果将直接为全国最复杂的淡水防洪系统之一的管理提供信息，并支持解决赤潮造成的生态紧急情况的努力。拟议工作的中心目标是确定人类管理的淡水控制制度对沿海藻类大量繁殖的规模和持续时间的影响，并通过教育和外联活动向公众和决策者转让从这项研究中获得的知识。我们将使用跨学科，数据密集型，多尺度和综合的淡水海洋系统方法来研究奥基乔比湖释放和沿海Karenia brevis藻华之间的联系。这一努力需要迅速动员起来，收集有关通过运河连接到奥基乔比湖的卡鲁萨哈奇河和河口沿着营养物和藻类负荷的有针对性的数据。该项目有以下目标：（1）量化水柱条件（水化学和浮游植物群落）的空间变异性在西南部佛罗里达的淡水-海洋梯度在奥基乔比湖排放之前，期间和之后，在13个站点，（2）解释作为物理，化学和生物因素的函数的水柱条件的时空变异性。正在进行的赤潮和即将从奥基乔比湖淡水排放的组合创造了一个独特的环境，调查淡水排放和沿海藻类水华之间的因果关系。据我们所知，这项研究将是第一个耦合多尺度观测（即，该奖项反映了NSF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。

Several hundred tons of marine life have died along the Gulf shores of Florida since October 2017 from exposure to algal blooms known as a "red tide". The intensity of these blooms is believed to be related to nutrients in freshwater releases from Lake Okeechobee, a large inland lake in south-central Florida that is managed for flood prevention. However, strong scientific evidence to support the connection between the red tide and Lake Okeechobee water releases is lacking. The objective of this project is to collect, analyze, and model water quality data prior to and throughout major freshwater releases. These data will provide insight into cause-and-effect relationships between freshwater releases, and algal blooms. Findings from this study will directly inform management of one of the nation's most elaborate freshwater flood prevention systems, and support efforts to address the ecological emergency caused by red tide. The central goals of the proposed work are to define the effects of human-managed freshwater control regimes on the magnitude and duration of coastal algal blooms, and transfer knowledge gained from this study to the public and decision-makers through education and outreach activities. We will investigate connections between Lake Okeechobee releases and coastal algal blooms of the species Karenia brevis using an interdisciplinary, data-intensive, multi-scale, and integrated fresh-marine systems approach. This effort necessitates rapid mobilization to collect targeted data on nutrient and algal loads along the Caloosahatchee River and Estuary that connects to Lake Okeechobee via canals. The project has the following objectives: (1) quantify spatial variability in water column conditions (water chemistry and phytoplankton community) across 13 sites from a fresh-marine gradient in southwest Florida prior to, during, and after Lake Okeechobee discharges, and (2) explain spatiotemporal variability in water column conditions as a function of physical, chemical, and biological factors. The combination of an ongoing red tide and imminent freshwater discharges from Lake Okeechobee creates a unique setting for investigating causal relationships between freshwater discharges and coastal algal blooms. To our knowledge, this study will be the first to couple multi-scale observations (i.e., in situ point observations, continuous monitoring data, and satellite imagery products) to analyze connections between freshwater discharges and marine red tides.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.