Microbial ecology at cabled seafloor observatories

维多利亚大学运营的金星和海王星电缆天文台为海洋生物如何对其环境变化做出反应的时间序列研究提供了前所未有的机会。我的研究计划将率先使用这些观测站来研究海洋微生物的生态。一系列研究项目将开发一个观察站工具箱，其中包括对生态系统功能重要的微生物过程进行直接和间接研究的途径和方法协议。我们将研究环境因素如何影响微生物控制氮的生物有效性、为热液喷口生物生产食物以及分解沉积物中的有机碎片的方式。直接研究将量化微生物现存量变化、群落结构和代谢过程与环境变量的关系。间接研究将侧重于生物扰动的动力学，这是影响微生物生长和新陈代谢的关键物理变量。将在Juan de Fuca山脊奋进号热液喷口主场的海王星观测站开展两个项目。一个远程启动的水样采样器将收集喷口流体样本，用于研究海底地下环境中与流体化学有关的微生物反硝化作用。第二个热液项目将使用遥控相机研究宏观微生物垫生长与流体排放和动物群放牧活动有关的动态。在位于大陆边缘的巴克利峡谷的海王星遗址，将使用照相机和微型剖面传感器来调查大型动物对表层沉积物的生物扰动与季节栖息地变量的关系。在沿海的Saanich Inlet，在金星天文台未来的水柱剖面仪工具包的现场，我们将研究光区的微生物硝化作用，强调以前观察到的硝化作用两个连续步骤(氨氧化和亚硝酸盐氧化)的不平衡及其与潮汐混合的关系。这项工作还将为2012年安装在金星剖面仪上的自动微生物基因分析仪做实验准备。

The VENUS and NEPTUNE cabled observatories operated by the University of Victoria offer unprecedented opportunities for the time series study of how marine organisms respond to changes in their environment. My research program will pioneer the use of these observatories to study the ecology of marine microorganisms. A series of research projects will develop an observatory toolbox of approaches and methodological protocols for the direct and indirect study of microbial processes that are important to ecosystem function. We will study how environmental factors influence the way in which microbes control the bioavailability of nitrogen, produce food for hydrothermal vent organisms and decompose organic debris in sediments. Direct studies will quantify microbial standing stock variations, community structure and metabolic processes, in relation to environmental variables. Indirect studies will focus on the dynamics of bioturbation, a key physical variable that influences microbial growth and metabolism. Two projects will be undertaken at the NEPTUNE observatory site in the Main Endeavour hydrothermal vent field on the Juan de Fuca Ridge. A remotely-activated water sampler will collect vent fluid samples for a study of microbial denitrification in the subsurface environment below the seafloor, in relation to fluid chemistry. The second hydrothermal project will use remote-controlled cameras to study the dynamics of macroscopic microbial mat growth in relation to fluid discharge and faunal grazing activity. At the NEPTUNE site in Barkley Canyon, on the continental margin, cameras and micro-profiling sensors will be used to investigate the relationship of bioturbation of surface sediments by the macrofauna, to seasonal habitat variables. In coastal Saanich Inlet, at the site of the VENUS observatory's future water column profiler instrument package, we will study microbial nitrification in the photic zone, emphasizing a previously observed imbalance in the two successive steps in nitrification (ammonium oxidation and nitrite oxidation) and its relationship to tidal mixing. This work will also serve to prepare experiments for an automated microbial gene analyzer to be installed on the VENUS profiler in 2012.