Using eddy correlation to measure oxygen flux as an indicator of the health of aquatic systems

水向河流、湖泊沉积物和水生生物输送溶解气体（如氧气、O2）、营养物质和其他化学物质，并向它们施加水动力。通过生物和生物地球化学过程了解溶解氧的命运和转移对于理解水生生态系统的功能及其修复/恢复至关重要。涡流相关技术，测量最小湍流中的O2浓度，提供了O2通量的精确测量。使用涡流相关测量氧通量对于实现这些目标至关重要，但我现有的涡流相关系统（RTI于2007年资助）已经过时，无法修复。这限制了我实验室成员的研究机会。为了使我的实验室恢复这一基本能力，我请求支持购买一个替代的涡流相关系统。该系统使用光纤氧传感器测量O2，同时使用快速响应PAR光记录仪、多参数探空仪和声学多普勒电流分析器来测量涡流相关测量期间的环境条件。该系统使用基于光学的氧气传感器，与旧型号中使用的电化学传感器相比，该传感器更坚固，搅拌灵敏度更低。因此，新系统将大大提高我们研究水生环境中关键生物地球化学成分的命运和转移的能力。所提出的涡流相关系统是我的研究项目迫切需要的。没有它，我们就无法确定湖泊低氧水平（缺氧）的原因、濒危淡水贻贝物种的健康以及水生植被的生产力。此外，我们无法将我们的生态水文模型从实验室推进到现场。拟议的设备对我的NSERC发现研究项目至关重要，并将支持与省级和联邦机构的研究伙伴的重要合作。由于对水质下降（例如缺氧或低氧）的关注，以及恢复这些水生生态系统以为加拿大人提供经济和生态效益的要求，这些活动特别重要。

Water transports dissolved gases (e.g., oxygen; O2), nutrients, and other chemicals to and from river and lake sediments and aquatic organisms, as well as imparting hydrodynamic forces on them. Understanding the fate and transfer of dissolved O2 through biological and biogeochemical processes is essential to understanding the functioning of aquatic ecosystems as well as their remediation/recovery. The eddy correlation technique, which measures O2 concentration in the smallest turbulent, provides an accurate measurement of O2 flux. Measuring oxygen flux using eddy correlation is essential to achieve these goals, but my existing eddy correlation system (RTI funded in 2007) is obsolete and beyond repair. This has limited the research opportunities available to members of my lab.      To restore this essential capacity to my lab, I am requesting support to purchase a replacement eddy correlation system. The requested system uses a fibre--optic oxygen sensor to measure O2 along with a fast response PAR light logger, multiparameter sonde, and an acoustic Doppler current profiler to measure environmental conditions during eddy correlation measurements. The requested system uses optical--based oxygen sensors, which are more robust and less stirring sensitive than the electrochemical sensors used in older, now-obsolete models. Consequently, the new system will significantly advance our ability to examine the fate and transfer of a key biogeochemical constituent in aquatic environments.      The proposed eddy correlation system is urgently needed by my research program. Without it, we are unable to determine the causes of low oxygen levels (hypoxia) in lakes, the health of endangered freshwater mussel species, and the productivity of aquatic vegetation. Moreover, we are not able to advance our ecohydrological models from the laboratory to the field. The proposed equipment is essential to my NSERC Discovery research program and will support important collaborations with research partners in provincial and federal agencies. These activities are of particular importance because of concerns about declining water quality (e.g., hypoxia or low oxygen), and demands to restore these aquatic ecosystems to provide economic and ecological benefits to Canadians.