90Y/90Sr and 234Th/238U disequilibria: Using dual chronometers to measure the effect of invasive dreissenid mussels on particle dynamics in Lake Michigan.

90Y/90Sr 和 234Th/238U 不平衡：使用双计时器测量入侵的德莱森贻贝对密歇根湖粒子动力学的影响。

• 批准号: 1030558
• 负责人: James Waples
• 金额: $ 39.05万
• 依托单位: University of Wisconsin-Milwaukee
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1030558&HistoricalAwards=false
• 关键词: 90Y; 90Sr; 234Th; 238U; disequilibria

In this project, researchers at the University of Wisconsin at Milwaukee will continue their research into the fluxes, pathways and residence times of particles and their associated nutrients and energy in nearshore waters of Lake Michigan. Their overall objective is to further explore the use of dual fast process chronometers (90Y/90Sr) and 234Th/238U disequilibria) as tracers of rapid particle dynamics. In Lake Michigan, dreissenid mussels now dominate these nearshore dynamics and the project objectives, therefore, focus on this influence. There are three specific objectives: (1) Examine what effect the in situ benthic mussel population density has on in situ particle (nutrient) removal from the water column. (2) Examine what effect an in situ benthic mussel population has on in situ particle (nutrient) removal under seasonally changing thermal conditions. (3) Examine the residence time of mussel-filtered particles (in the form of feces and pseudo-feces) and the inventory of 90Y and 234Th on the nearshore non-depositional lake bed. Broader Impacts: Coastal zones are under increasing nutrient and toxic stress, and developing and improving techniques for tracking suspended materials on short time-scales will have broad applicability in both Great Lakes and marine biogeochemistry. Understanding the transport of contaminants is also relevant to the heightened concerns over water security, particularly in the Great Lakes from which nearly 40 million people draw drinking water. The utility of radionuclides as tracers for following and quantifying environmental processes is an expanding field, and novel radionuclide techniques have wide potential application in limnology, oceanography, ground water and surface water hydrology, and terrestrial-aquatic system coupling. These tools are an essential component of the environmental research toolbox. Relatively few laboratories in the Great Lakes region are capable of making radiometric measurements; improving this capability has regional importance.

在这个项目中，威斯康星大学密尔沃基分校的研究人员将继续研究密歇根湖近海水域的颗粒及其相关营养素和能源的通量，途径和住宿时间。 他们的总体目标是进一步探索双重快速过程中的天文钟（90Y/90SR）和234/238U不平衡）作为快速粒子动力学的示踪剂。在密歇根湖，德雷森尼德贻贝现在主导着这些近岸动态和项目目标，因此着重于这种影响。 有三个特定的目标：（1）检查原位底栖贻贝人口密度对原位粒子（营养）从水柱中取出的影响。 （2）检查在季节性变化的热条件下，原位底栖贻贝人群对原位颗粒（营养）去除的影响。 （3）检查贻贝过滤颗粒的停留时间（以粪便和伪feces的形式）以及近岸非沉积湖床上的90年代和第234位的库存。更广泛的影响：沿海地区的营养和有毒压力增加，并且在短时间内跟踪悬浮材料的发展和改进技术将在大湖区和海洋生物地球化学方面具有广泛的适用性。了解污染物的运输也与对水安全的更加担忧有关，尤其是在大湖区中，近4000万人抽水。放射性核素作为遵循和量化环境过程的示踪剂的实用性是一个扩展的领域，而新型的放射性核素技术在林格学，海洋学，地下水和地表水水文学以及陆层平衡系统中具有广泛的潜在应用。这些工具是环境研究工具箱的重要组成部分。 大湖区的实验室相对较少，能够进行辐射测量。提高此能力具有区域重要性。