CAREER: Quantifying wave-driven mixing and mass transport dynamics within coastal ecosystems

职业：量化沿海生态系统内波浪驱动的混合和质量传输动力学

• 批准号: 1151314
• 负责人: Matthew Reidenbach
• 金额: $ 53.14万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1151314&HistoricalAwards=false
• 关键词: CAREER; Quantifying; wave; driven; mixing

Seagrass ecosystems comprise highly productive regions of the coastal ocean that have declined dramatically in abundance over the past several decades. While losses can be attributed to a variety of factors, including ocean warming and disease, the primary threat appears to be from anthropogenic changes to water quality. The proposed research will be composed of measurements to determine large-scale circulation and micro-scale fluid processes impacting sediment suspension and oxygen fluxes surrounding seagrass communities with the aim of understanding how hydrodynamic processes, and in particular wave-action, may ultimately impact pollutant and particulate transport and benthic respiration. Although previous studies have focused on hydrodynamics of seagrasses, information on how wave-dominated flows impact particulate and dissolved chemical transport within these seagrass ecosystems, and to adjacent coastal environments, is sorely lacking. Research within tropical seagrass ecosystems will be carried out at two sites along the Atlantic coast of Panama, one a disturbed and the other a relatively pristine system. Temperate seagrass research will be conducted along the Virginia, USA coast at the Virginia Coast Reserve-Long Term Ecological Research (VCR-LTER) station, where there are ongoing efforts to reestablish a viable seagrass community within the coastal bays.The intellectual merit of the proposed research resides in establishing a better understanding of flow and turbulent mixing processes within wave-dominated environments and how local and large-scale hydrodynamics affect the ecology of seagrass communities. In doing so, this research will help advance our knowledge of (1) how the physical structure of seagrass beds alter the retention and dispersion of sediments within coastal ecosystems, (2) how wave-dominated flow over and through benthic plant structures alters the flux of oxygen across the sediment-water interface, and (3) how alterations to these environments, through changes in seagrass cover, land use and eutrophication, affect micro- and macro-scale chemical and particulate transport. Integral to this work will be the development of new instruments and techniques to quantify mixing and mass transport in wave-dominated environments that can also be applied broadly to many other coastal ecosystems.The broader impact of this research resides in its contribution to understanding hydrodynamic-biological interactions within important yet vulnerable marine ecosystems. Within Virginia, measurements will quantify the impact of seagrasses on wave attenuation and sediment resuspension to determine the extent to which seagrass expansion has altered the bay from a net erosional environment to one that promotes deposition of suspended sediment, thereby reducing light attenuation and creating a positive feedback for seagrass growth. Hydrodynamic and chemical flux measurements in healthy and degraded seagrass beds in Panama, combined with analysis of historical changes to on-shore mangrove and off-shore coral reef cover, will determine the impact of land-use and eutrophication on ecosystem processes. The education plan for this project includes in-depth classroom, field and laboratory research experiences for high school to graduate-level students. Collaboration with the VCR-LTER Schoolyard program will involve high school students and teachers in the monitoring of water quality in local harbors and coastal bays, which directly integrates with the proposed research. International outreach, through a University of Virginia/Panama initiative, will include developing and teaching an interdisciplinary course in Panama that brings together U.S. and Panamanian students to study environmental policy and marine conservation. Student progress in both the Virginia high school and Panama courses will be monitored through use of a Web-based Interactive Science and Engineering (WISE) learning tool. WISE is an online science-learning environment that provides for real-time collaboration and assessment of student's understanding of core concepts. An online curriculum will be developed for marine sciences where students will input and analyze their data, compare and contrast findings from U.S. and Panamanian seagrass communities, and learn about the benefits of and threats to coastal ecosystems.

海草生态系统包括沿海海洋的高生产力区域，这些区域在过去几十年中数量急剧减少。虽然损失可以归因于各种因素，包括海洋变暖和疾病，但主要威胁似乎来自人为变化对水质的影响。拟议的研究将包括确定影响海草群落周围沉积物悬浮和氧气通量的大尺度循环和微尺度流体过程的测量，目的是了解水动力过程，特别是波浪作用，最终可能如何影响污染物和颗粒传输以及海底呼吸。尽管以前的研究侧重于海草的水动力学，但关于海浪主导的水流如何影响这些海草生态系统内的颗粒和溶解化学物质的运输以及向邻近沿海环境的运输的信息严重缺乏。热带海草生态系统的研究将在巴拿马大西洋沿岸的两个地点进行，一个是受干扰的系统，另一个是相对原始的系统。温带海草研究将在美国弗吉尼亚州海岸保护区-长期生态研究(VCR-LTER)站进行，在那里正在努力重建沿海海湾内可行的海草群落。拟议研究的学术价值在于更好地理解波浪主导环境中的流动和湍流混合过程，以及局部和大规模水动力学如何影响海草群落的生态。通过这样做，这项研究将有助于增进我们对以下方面的了解：(1)海草床的物理结构如何改变沿海生态系统内沉积物的滞留和扩散；(2)底栖植物结构上方并通过底栖植物结构的波浪主导水流如何改变沉积物-水界面的氧通量；以及(3)这些环境的变化如何通过海草覆盖、土地利用和富营养化的变化，影响微观和宏观尺度的化学和颗粒输送。这项工作的一个组成部分是开发新的工具和技术来量化波浪控制环境中的混合和质量传输，这些工具和技术也可广泛应用于许多其他沿海生态系统。这项研究的更广泛影响在于它有助于了解重要但脆弱的海洋生态系统内的水动力-生物相互作用。在弗吉尼亚州，测量将量化海草对波浪衰减和沉积物再悬浮的影响，以确定海草扩张在多大程度上将海湾从净侵蚀环境改变为促进悬浮沉积物沉积的环境，从而减少光衰减并为海草生长创造积极的反馈。测量巴拿马健康和退化的海草床的水动力和化学通量，结合对近岸红树林和近海珊瑚礁覆盖的历史变化的分析，将确定土地利用和富营养化对生态系统过程的影响。该项目的教育计划包括为高中到研究生水平的学生提供深入的课堂、实地和实验室研究经验。与VCR-LTER校园方案的合作将使高中生和教师参与监测当地港口和沿海海湾的水质，这直接与拟议的研究相结合。通过弗吉尼亚大学/巴拿马倡议的国际拓展，将包括在巴拿马开发和教授一门跨学科课程，将美国和巴拿马的学生聚集在一起学习环境政策和海洋保护。学生在弗吉尼亚高中和巴拿马课程的进度将通过使用基于网络的交互式科学与工程(WISE)学习工具进行监控。WISE是一个在线科学学习环境，提供实时协作和评估学生对核心概念的理解。将为海洋科学开发一个在线课程，学生将在其中输入和分析他们的数据，比较和对比美国和巴拿马海草群落的研究结果，并了解沿海生态系统的好处和威胁。