Probing the in situ activities of marine microbes in marine oxygen minimum zones

溶解氧浓度是海洋中一个重要的组织原则。在过去的50年里，由于气候变化和农场和城市废物径流的增加，氧气最低带（OMZs）已经扩大。目前，8%的海洋被认为是缺氧的。在某些沿海地区，极度缺氧会产生“死亡区”，大量破坏海洋渔业和食物网结构。与OMZ形成和膨胀相关的微生物群落代谢变化改变了海洋中的营养和能量流动模式，包括二氧化碳、甲烷和一氧化二氮等温室气体的产生和消耗。了解微生物如何与海洋缺氧相互作用并作出反应，使我们了解了形成海洋食物网的组织原则，并定义了微生物如何协同工作，并与环境一起推动气候变化时期的营养和能量循环。在此，我们要求为一种名为PPS的原位采样仪器提供基础设施资金，该仪器将能够以最小的扰动和高时间和空间分辨率从Saanich Inlet缺氧水柱中收集微生物生物量。这种形式的采样将提供更准确的基因表达描述，可以与各种营养和能量循环的过程速率测量相关联。由此产生的数据集将使我们了解海洋表层微生物群落代谢，并为样本收集提供培训和实践标准，指导全球海洋表层微生物群落科学家的同行工作。

Dissolved oxygen concentration is a critical organizing principle in the ocean. Over the past 50 years oxygen minimum zones (OMZs) have expanded due to climate change and increased waste run-off from our farms and cities. At present 8% of the ocean is considered oxygen-starved. In certain coastal areas extreme oxygen-starvation produces "dead zones" decimating marine fisheries and destroying food web structure. Changes in microbial community metabolism associated with OMZ formation and expansion alter nutrient and energy flow patterns in the ocean, including production and consumption of greenhouse gases such as carbon dioxide, methane and nitrous oxide. Knowing how microorganisms interact with and respond to ocean oxygen starvation teaches us about the organizing principles that shape ocean food webs and define how microorganisms work together and with their environment to drive nutrient and energy cycles in a time of climate change. Here we request infrastructure funding for an in situ sampling instrument called the PPS that will enable collection of microbial biomass from the oxygen-starved water column of Saanich Inlet with minimal perturbation and high temporal and spatial resolution. This form of sampling will provide more accurate depictions of gene expression that can be correlated with process rate measurements for a wide variety of nutrient and energy cycles. Resulting datasets will inform our understanding of microbial community metabolism in OMZs and provide a training and practice standard for sample collection guiding the peer efforts of scientists working in OMZs throughout the global ocean.