Response of Microbial Community Structure and Protistan Grazing Pathways to Environmental Forcing in the Arabian Sea

9612509坎贝尔 阿拉伯海是世界海洋中一个动态非常大的区域，季风的季节性逆转很强。 在全球空间尺度联合方案的背景下，该区域很有意思，因为在相对恒定的热带光照下，海洋生产系统出现了“极端”现象-沿海涌升到开阔洋贫营养。 因此，它是一个天然的实验室，以测试物理强迫，食物链结构，地球化学循环和通量，以及碳埋藏在沉积物中的概念之间的联系。 该项目的总体目标是评估微型浮游动物作为细菌和浮游植物生产的消费者的作用，并有助于理解浮游生物群落结构、新生产和生物地球化学通量之间的关系及其对阿拉伯海物理强迫的响应。 该项目将在春季（4月）季风间和夏季（8月）西南季风季节进行，这两个季节的差异最明显。 通过流式细胞仪、显微镜和色素分析确定细菌和浮游植物的丰度、生物量和特定生长率，以确定它们随季节、深度和位置的变化。 将确定和量化占主导地位的微型浮游动物对皮科和微型浮游生物的食草动物，并将使用一套补充方法测量其放牧的影响，包括稀释，荧光标记猎物，尺寸分级和特定的代谢抑制剂。 这个项目的结果将有助于了解全球气候变化，这可能会影响盛行的强迫风，将改变浮游植物群落结构，并反过来如何在食物网结构的这些变化影响碳储存和出口从上层水柱。 ***

9612509 Campbell The Arabian Sea is an intensely dynamic region of the world's oceans driven by strong seasonal reversals in monsoon winds. The region is interesting in the context of the Joint Global spatial scales "extremes" in ocean production systems -coastal upwelling to open ocean oligotrophic -- under relatively constant tropical illumination. It is thus a natural laboratory to test conceptual linkages among physical forcing, food-wed structure, biogeochemical cycling and fluxes, and carbon burial in the sediments. The general goals of this project are to asses the roles of microzooplankton as consumers of bacterial and phytoplankton production and to contribute to nderstanding the relationships among plankton community structure, new production, and biogeochemical fluxes and their responses to physical forcing the Arabian Sea. The project is to be conducted during the spring (April) intermonsoon and summer (August) SW monsoon seasons, when the most dramatic differences should be evident. Abundance, biomass, and specific growth rates of bacteria and phytoplankton will be determined by flow cytometric, microscopic, and pigment analyses to determine their variations with season, depth and location. The dominant microzooplankton grazers on pico- and nanoplankton will be identified and quantified, and the impact of their grazing will be measured with a suite of complementary methods including dilution, fluorescently-labelled prey, size- fractionation, and specific metabolic inhibitors. Results of this project will contribute to understanding how global climate changes, which may affect prevailing forcing winds, will alter phytoplankton community structure and in turn how these changes in structure of the food web affect carbon storage and export from the upper water column. ***