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产区域，在过去几十年里，这些区域的丰度急剧下降。虽然损失可归因于各种因素，包括海洋变暖和海洋疾病，但主要威胁似乎来自人为对水质的改变。拟议的研究将由测量组成，以确定影响海草群落周围沉积物悬浮物和氧通量的大尺度循环和微尺度流体过程，目的是了解水动力过程，特别是波浪作用，如何最终影响污染物和颗粒运输以及底栖生物呼吸。虽然以前的研究主要集中在海草的流体动力学上，但关于波浪主导的流动如何影响这些海草生态系统中颗粒和溶解化学物质的运输以及邻近沿海环境的信息非常缺乏。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，另一个是相对原始的系统。温带海草研究将沿着美国弗吉尼亚海岸在弗吉尼亚海岸保护区-长期生态研究站进行，在那里正在努力在沿海海湾内重建一个可行的海草群落。所提出的研究的智力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，以及局部和大规模的水动力学如何影响海草群落的生态。在此过程中，本研究将有助于提高我们对以下方面的认识：(1)海草床的物理结构如何改变沿海生态系统中沉积物的保留和分散；(2)波浪主导的水流如何通过底栖植物结构改变沉积物-水界面的氧通量；(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运输。这项工作的组成部分将是开发新的仪器和技术，以量化波浪主导环境中的混合和质量运输，这也可以广泛应用于许多其他沿海生态系统。这项研究的广泛影响在于它对理解重要但脆弱的海洋生态系统中水动力-生物相互作用的贡献。在弗吉尼亚，测量将量化海草对波浪衰减和沉积物再悬浮的影响，以确定海草扩张将海湾从净侵蚀环境改变为促进悬浮沉积物沉积的程度，从而减少光衰减并为海草生长创造积极的反馈。在巴拿马健康和退化的海草床上进行的水动力和化学通量测量，结合对岸上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。该项目的教学计划包括为高中至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校园项目的合作将让高中学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(University of Virginia) /巴拿马的一项倡议开展的国际拓展活动将包括在巴拿马开设和教授一门跨学科课程，让美国和巴拿马的学生共同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学习进度将通过使用基于网络的交互式科学与工程（WISE）学习工具进行监测。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，学生将输入和分析他们的数据，比较和对比来自美国和巴拿马海草群落的发现，并了解沿海生态系统的好处和威胁。