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

周期性沿海羽流对密歇根湖下部食物网动力学和结构的影响

• 批准号: 9817805
• 负责人: Peter Lavrentyev
• 金额: $ 12.02万
• 依托单位: University of Akron
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9817805&HistoricalAwards=false
• 关键词: Effects; Recurrent; Coastal; Plume; Dynamics

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.

9817805 拉夫连季耶夫研究将根据五大湖沿海研究机会公告（NSF 97-38）进行。 这是来自十二个学术和政府研究机构的研究人员之间的合作研究项目。 该研究是在 NSF 沿海海洋过程 (CoOP) 计划和 NOAA 沿海海洋计划的支持下进行的。 该合作研究项目重点关注偶发事件对近岸-近海运输的重要性以及随后的生态后果。该研究旨在 1) 确定哪些过程控制五大湖沿岸边缘生物、化学和地质物质的跨界（近海到近海）运输，2) 制定和测试科学策略，以评估、量化和预测五大湖或选定的沿海次区域自然和人为多种压力的影响。通过沉积物再悬浮过程，湖泊和沿海生态系统中受污染沉积物与上覆水之间存在紧密耦合。密歇根湖的卫星观测表明，每年都会发生近岸-离岸运输现象，10 公里宽的悬浮物质羽流沿着该湖的南岸延伸 200 多公里。初步证据表明，这一偶发事件可能是密歇根湖跨缘沉积物输送的主要机制。 此类事件影响生物地球化学重要材料（BIMS）的回收、生态系统响应、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。这项全面的跨学科研究将实施综合观测计划和数值模拟工作，以识别、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 的运输和转变以及湖泊生态的影响。 该研究的这一部分重点关注羽流形成之前、期间和之后微生物食物网的结构和丰度；测量与羽流内部、边缘和外部微型浮游动物群落和物种特定放牧率相关的氮循环率。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研究相协调，以完成概念模型并为拟议的耦合生物/物理模型提供数据。