Impact of Episodic Transport and Resuspension on Coastal Phytoplankton Processes: A Case Study of Lake Michigan Recurrent Coastal Plume

将根据五大湖海岸研究机会(NSF 97-38)的公告进行研究。这是一个由来自十个学术和政府研究机构的研究人员合作的研究项目。这项研究是在NSF海岸海洋过程(COOP)计划和NOAA海岸海洋计划的赞助下进行的。这项为期5年的合作研究计划将侧重于偶发事件对近岸-近海运输和随后的生态后果的重要性。这项研究旨在1)确定控制五大湖沿海边缘生物、化学和地质材料跨边界(近岸到近海)运输的过程，以及2)制定和测试科学战略，以评估、量化和预测五大湖或选定的沿海分区域自然和人为多重压力的影响。在湖泊和沿海生态系统中，通过沉积物再悬浮的过程，污染沉积物和上覆水之间存在着紧密的耦合。对密歇根湖的卫星观测表明，每年都会出现近岸-近海运输的反复事件，一股10公里宽的再悬浮物质羽状物沿着密歇根湖南岸延伸超过200公里。初步证据表明，这一阶段性事件可能是密歇根湖跨界泥沙运移的主要机制。这类事件影响到五大湖生物地球化学重要物质(BIMS)的再循环、生态系统反应、跨等深线运输。该方案的结果将适用于许多沿海地区的类似事件。这项综合的跨学科研究将实施综合观测计划和数值模拟工作，以确定、量化和开发冬春季再悬浮事件的预测工具，并评估该事件对BIMS的运输和转化以及对湖泊生态的影响。该研究的这一部分侧重于了解在五大湖内的间歇性物理强迫事件期间控制浮游植物和群落结构的生态生理机制。对细胞、物种、群体和群落过程的测量，结合最先进的生物光学仪器，将允许对特定分类单元和群落对不同物理强迫因素的反应进行独特的全面检查。这项工作还将进一步开发、评估和改进密歇根湖目前的生物光学生产模型，并协助开发淡水遥感算法。

Research will be undertaken in response to an Announcement of Opportunity (NSF 97-38)for Coastal Studies in the Great Lakes. This is a collaborative research project between investigators from ten academic and government research institutions. The research is being conducted under the auspices of the NSF Coastal Ocean Processes (CoOP) program and the NOAA Coastal Ocean Program. This collaborative, 5-year research program will focus on the importance of episodic events on nearshore-offshore transport and subsequent ecological consequences. The study seeks to 1) determine what processes control the cross- margin (inshore to offshore) transport of biological, chemical, and geological materials in the coastal margins of the Great Lakes, and to 2) develop and test scientific strategies for assessing, quantifying, and predicting the impacts of multiple stresses both natural and anthropogenic, in the Great Lakes or selected coastal sub-regions. A tight coupling between contaminated sediments and overlying water exists in lakes and coastal ecosystems through the process of sediment resuspension. Satellite observations in Lake Michigan illustrate an annually recurrent episode of nearshore-offshore transport, a 10 km wide plume of resuspended material extending over 200 km along the southern shores of the lake. Preliminary evidence indicates that this episodic event may be the major mechanism for cross-margin sediment transport in Lake Michigan. This type of event impacts recycling of biogeochemically important materials (BIMS), ecosystem responses, cross-isobath transport in the Great Lakes. The program results will be applicable to similar events in many coastal areas. This comprehensive, interdisciplinary study will implement an integrated observational program and numerical modeling effort to identify, quantify, and develop prediction tools for the winter-spring resuspension event and to assess the impact of this event on the transport and transformation of BIMS and on lake ecology. This component of the study focuses on understanding of ecophysiological mechanisms controlling phytoplankton and community structure during episodic, physical forcing events within the Great Lakes. The measurement of cellular, species, group, and community processes coupled with state- of-the-art, bio-optical instrumentation will allow for a unique comprehensive examination of the taxon-specific and community responses to distinct physical forcing factors. Work will also further develop, evaluate, and improve the current bio-optical production model for Lake Michigan and assist in efforts to develop fresh water remote-sensing algorithms.