RAPID: Hurricane Impact on Phytoplankton Community Dynamics and Metabolic Response

RAPID：飓风对浮游植物群落动态和代谢反应的影响

• 批准号: 1760620
• 负责人: Lisa Campbell
• 金额: $ 19.4万
• 依托单位: Texas A&M University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-11-01 至 2019-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1760620&HistoricalAwards=false
• 关键词: RAPID; Hurricane; Impact; Phytoplankton; Community

Hurricane Harvey is the strongest hurricane to hit the Texas coast in decades and the resulting tidal surges, flooding and terrestrial runoff have had a severe impact on the coastal ocean. The effects on the phytoplankton, the first link in the food chain, may be unprecedented. To determine how the phytoplankton community will respond to such drastic changes in salinity, nutrient inputs, and potential toxins, immediate and continuous sampling is the only way to fully capture the effects and to identify when conditions return to "normal". An automated, continuous phytoplankton imaging instrument that is deployed on the Texas coast records images of the phytoplankton and permits calculation of the abundance of different species. Together with molecular information on the genes that have been "turned on", or expressed, outcomes of this project will help determine the responses of individual types of phytoplankton. Extreme storms are expected to increase in frequency with future climate change, so the responses identified now will be valuable in predicting how such events will affect these primary producers, which in turn support most of the food webs in marine ecosystems, in the future.High temporal resolution observations from the Imaging FlowCytobot (IFCB) have revealed that hurricanes in the Gulf of Mexico cause drastic changes in the phytoplankton community structure. The objectives of this RAPID project are: 1) to characterize the dynamics of the phytoplankton species in relation to the environmental variables along the Texas coast; 2) to assess the short and long-term changes in the phytoplankton community; and 3) to identify the strategies of the phytoplankton community for resource acquisition. To accomplish these objectives, this project will utilize IFCB time series to follow phytoplankton community structure during the recovery period from Hurricane Harvey. In addition, two RAPID response cruises (in late September and early October) to sample at 5 sites along a transect from Galveston to Port Aransas, TX. At each station, CTD profiles and water samples from surface and the chlorophyll maximum will be collected for nutrients, carbonate chemistry, and RNA sequencing for metatranscriptomic analysis. Metatranscriptomics can provide an indication of the metabolic strategies employed and functional relationships within the plankton community in response to changes in the environment. The advantage of a metatranscriptomic approach is that the entire molecular response to the environment is captured. So, while the response of phytoplankton to increased nutrient inputs from floodwater runoff is targeted, the responses to other environmental stresses (toxics, hypoxia, acidification) are also captured. Analyses of this time series using multivariate statistical techniques, such as principal component analysis (PCA), and network analysis, a powerful technique for identifying potential interactions among taxa, will provide insights on the environmental factors and metabolic responses structuring the community during the aftermath of the hurricane.

哈维飓风是数十年来袭击德克萨斯海岸的最强烈的飓风，潮汐潮，洪水和地面径流对沿海海洋产生了严重影响。食物链中的第一个联系浮游植物的影响可能是前所未有的。为了确定浮游植物社区将如何应对盐度，营养输入和潜在毒素的这种急剧变化，即时和连续采样是完全捕获效果并确定何时恢复“正常”的唯一方法。一种部署在德克萨斯州海岸上的自动化，连续的浮游植物成像仪器记录了浮游植物的图像，并允许计算不同物种的丰度。以及有关已“打开”或表达的基因的分子信息，该项目的结果将有助于确定单个类型的浮游植物的反应。预计随着未来气候变化的频率，极端风暴将在预测这些主要生产者如何影响这些主要生产者方面有价值，这反过来支持海洋生态系统中的大多数食物网。 这个快速项目的目标是：1）表征浮游植物物种与德克萨斯海岸沿线的环境变量有关的动态； 2）评估浮游植物社区的短期和长期变化； 3）确定浮游植物社区的策略以获取资源。为了实现这些目标，该项目将利用IFCB时间序列在Harvey飓风期间遵循浮游植物社区结构。此外，从加尔维斯顿到德克萨斯州阿兰萨斯港的横除横梁的5个地点进行了两次快速响应巡航（在9月下旬和10月初）进行采样。在每个站点，将收集来自表面和叶绿素最大的CTD轮廓和水样，以进行营养，碳酸盐化学和RNA测序，以进行元文字分析。 Metatranscriptomics可以指示浮游生物社区中采用的代谢策略和功能关系，以应对环境的变化。元转录组方法的优点是捕获了对环境的整个分子反应。因此，尽管浮游植物对增加洪水径流的养分输入的反应是针对性的，但也捕获了对其他环境应力（有毒，缺氧，酸化）的反应。使用多元统计技术（例如主成分分析（PCA）和网络分析）对本时间序列进行分析，这是一种强大的技术，用于识别分类单元之间的潜在相互作用，将提供有关飓风后果期间社区的环境因素和代谢反应的见解。