The Effects of a Recurrent Coastal Plume on the Dynamics and Structure of the Lower Food Web in Lake Michigan

9817805 Lavrentyev研究将响应大湖海岸研究的机会公告（NSF 97-38）进行。这是来自12个学术和政府研究机构的研究人员之间的合作研究项目。这项研究是在美国国家科学基金会沿海海洋过程（CoOP）计划和美国国家海洋和大气管理局沿海海洋计划的支持下进行的。这个合作研究项目的重点是偶发事件对近岸-近海运输和随后的生态后果的重要性。本研究旨在1)确定控制五大湖沿海边缘生物、化学和地质物质跨边界（从近海到近海）运输的过程；2)开发和测试科学策略，以评估、量化和预测五大湖或选定沿海次区域的多种自然和人为压力的影响。在湖泊和沿海生态系统中，污染沉积物通过泥沙再悬浮过程与上覆水体存在紧密耦合。在密歇根湖的卫星观测显示了每年一次的近岸-近海运输，一个10公里宽的悬浮物质羽流沿着湖的南岸延伸了200多公里。初步证据表明，这一幕式事件可能是密歇根湖跨缘输沙的主要机制。这种类型的事件影响了生物地球化学重要物质（BIMS）的再循环、生态系统响应和五大湖的跨等深线运输。该计划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的运输和转化以及湖泊生态的影响。这部分研究的重点是在羽流形成之前、期间和之后的微生物食物网生物的结构和丰度；测量氮循环速率与群落和物种特定的浮游动物在羽流内部、边缘和外部的放牧速率有关。观察、实验和结果将与初级生产和浮游动物放牧实验以及其他营养和物理过程的研究相协调，以完成一个概念模型，并为拟议的生物/物理耦合模型提供数据。

9817805 Lavrentyev 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 twelve 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, research program focuses 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 structure and abundance of microbial food web organisms before, during, and after plume formation; measure Nitrogen cycling rates in relation to community and species-specific grazing rates of microzooplankton within, at the edge, and outside of the plume. Observations, experiments, and results will be coordinated with those from primary production and zooplankton grazing experiments and other studies of nutrient and physical processes to complete a conceptual model and provide data for the proposed coupled biological/physical model.