Viral Abundance, Production and Diversity During the North Atlantic Spring Bloom (NASB 2005)

在2005年北大西洋春季水华期间(NASB 2005)，在国家科学基金会和欧洲联盟碳海洋项目的支持下，调查人员将解决二氧化碳水平和温度对藻类群落结构和生物地球化学的影响问题。尽管浮游植物在北大西洋春季水华期间变化很大，但没有关于这个群落与本地病毒种群之间相互作用的定量信息。研究人员将加入NASB 2005年的工作，并将1)在船上实验中检查病毒的丰度、产量和多样性，2)量化噬藻体和感染真核藻(藻导航病毒科)的主要病毒组，这些病毒通过以蓝藻或真核浮游植物为主的水域。在这项研究中收集的信息对于理解病毒在NASB 2005事件中的作用至关重要。研究人员还将研究系统营养状态和多样性的变化对病毒丰度、产量和多样性变化的影响。他们将与NASB 2005年的合作者合作，确定二氧化碳分压和温度的变化(基于2100年的预测条件)将如何影响病毒参数。他们的工作假设是，病毒的丰度、产量和多样性将随着系统营养状况、浮游植物种群多样性以及在模拟的全球气候变化条件下而变化。为了验证这些假设，定量聚合酶链式反应将与估计病毒丰度和产量的稀释方法相结合，与从研究地点收集的样本的透射电子显微镜分析以及对氰噬菌体和藻导航病毒科的特定靶标的高通量测序相结合。由此产生的信息将提供对该区域病毒多样性和活动的洞察，并向为NASB 2005项目生成的模型提供微生物食物网的病毒成分。该项目将包括对研究生和本科生研究助理的培训，以及促进EPSCoR(刺激竞争性研究的实验计划)机构的推广和多样化。三名研究生和四名本科生将得到支持，该项目的信息将直接纳入田纳西大学的课程、外展活动和网络传播。近年来，越来越明显的是，病毒在水生生物群落的结构和水生生物地球化学循环中发挥着重要作用。该项目将在一项实地实验中研究病毒的作用，该实验旨在模拟大气二氧化碳水平预计长期上升可能产生的影响，这将影响海洋化学。野外实验(NASB 2005)使用北大西洋春季浮游植物水华作为二氧化碳增加所导致的长期变化的代表。该项目将为NASB 2005项目提供必要的信息，以确定北大西洋的社区如何对下个世纪可能发生的气候变化作出反应。

During the North Atlantic spring bloom of 2005 (NASB 2005), investigators supported by the NSF and the European Union CarboOcean project will address questions about the impact of pCO2 levels and temperature on algal community structure and biogeochemistry. Although phytoplankton vary greatly during the North Atlantic spring bloom, no quantitative information is available on the interactions between this community and native viral populations. The investigators will join the NASB 2005 effort and will 1) examine viral abundance, production and diversity in shipboard experiments, and 2) quantify cyanophage and a major group of viruses infecting eukaryotic algae (the Phycodnaviridae) during transects through waters dominated by cyanobacteria or eukaryotic phytoplankton. The information collected during this study will be critical to understanding the role of viruses during the NASB 2005 event. The investigators will also examine the influence of changes in system trophic status and diversity on changes in virus abundance, production and diversity. They will work with NASB 2005 collaborators to determine how changes in pCO2 and temperature (based on predicted conditions in the year 2100) will impact virus parameters. Their working hypotheses are that viral abundance, production and diversity will vary with system trophic status, with phytoplankton population diversity, and during simulated global climate change conditions. To test these hypotheses, quantitative PCR will be combined with a dilution approach to estimating virus abundance and production, with TEM analysis of samples collected from study sites and with high throughput sequencing of cyanophage and Phycodnaviridae specific targets. The resulting information will provide insight into virus diversity and activity in the region as well as supply the viral component of the microbial food web to models generated for the NASB 2005 project. This project will include the training of graduate and undergraduate research assistants as well as the facilitation of outreach and diversification at an EPSCoR (Experimental Program to Stimulate Competitive Research) institution. Three graduate and four undergraduate students will be supported, and information from this program will be directly incorporated into courses, outreach events and web dissemination at the University of Tennessee. In recent years it has become increasingly evident that viruses play an important role in structuring the aquatic biological community, and in aquatic biogeochemical cycles. This project will examine the role of viruses during a field experiment designed to simulate the possible effects of a predicted long-term increase in atmospheric CO2 levels that would affect ocean chemistry. The field experiment (NASB 2005) uses the North Atlantic spring bloom of phytoplankton as a proxy for the longer-term changes that would result from CO2 increases. This project will provide essential information to the NASB 2005 project to determine how communities in the North Atlantic may react to the predicted changes in climate that may occur during the coming century.