SGER: Southern and Coastal Extent of Picophytoplankton Populations in the South Pacific

海洋浮游植物中最丰富和最普遍的成员属于两个蓝藻属，聚球藻和原氯球菌属，这两个属加起来贡献了公海一半以上的初级生产力。这些属中的每一个在海洋蓝藻中形成了一个不同的微藻浮游植物分支，可以进一步细分为多个系统发育分支(称为遗传型或生态型)，其中一些具有明确的生理特征，可与其生态分布有关。然而，不同基因类型水平分布的边界还不完全清楚，南大西洋研究之间的差异需要进一步检查微藻浮游植物的分布，特别是原氯球菌种群的分布。2008年12月，在福克兰群岛附近从西经57度S 40度到西经55度S的巴塔哥尼亚陆架区域进行的一次研究巡航中，PI将能够研究浮游植物种群的南部范围以及沿陆架断裂锋面向东进入低营养水域的分布。在代表不同水域类型的站点，将采集样本用于浮游微藻种群的流式细胞仪分析，过滤后用于原氯球菌和聚球藻生态型的定量聚合酶链式反应分析，并将被超低温保存以用于使用高通量培养方法进行分离。该SGER项目将提供关于南方和沿海浮游微藻种群范围的新数据集，并可能解决以下问题：与十多年前最初观察到的情况相比，原氯球菌种群是否正在进一步向南延伸到更冷的水域。此外，它将使MS学生能够参与研究巡游并获得实地研究经验，提供用品和运输样品的资金，并提供MS学生津贴来分析样品。

The most abundant and ubiquitous members of the marine phytoplankton belong to two cyanobacterial genera, Synechococcus and Prochlorococcus, which together contribute more than half of the primary productivity in the open ocean. Each of these genera, which form a distinct picophytoplankton clade within the marine cyanobacteria, can be further subdivided into multiple phylogenetic clades (referred to as genotypes or ecotypes), some of which have clear physiological characteristics that can be related to their ecological distributions. However, the boundaries of the horizontal distributions of the various genotypes are not fully understood, and discrepancies between studies in the South Atlantic require further examination of the picophytoplankton distributions, particularly of the Prochlorococcus populations. In a research cruise during Dec 2008 to the Patagonia shelf region from ~40 deg S, 57deg W to ~53 deg S, 55 deg W near the Falkland Islands, the PI will be able to examine the southern extent of picophytoplankton populations as well as the distributions across the shelf break front going east into oligotrophic waters. At stations representing different water types, samples will be collected for flow cytometric analysis of picophytoplankton populations, will be filtered for later qPCR analysis of Prochlorococcus and Synechococcus ecotypes, and will be cryopreserved for isolations using high throughput culture methods.This SGER project will provide a new dataset of the southern and coastal extent of picophytoplankton populations, and possibly address the question of whetherProchlorococcus populations are extending further south into colder waters than initially observed more than a decade ago. Additionally, it will enable a MS student to participate in the research cruise and get experience with field research, provide funds for supplies and shipping samples, and provide a MS student stipend to analyze the samples.