Viruses in Marine Food Webs

最近的证据表明，病毒可能是非常重要的， 海洋食物网，一些估计表明它们是 负责大多数细菌的死亡率，并推动一个 营养循环的重要组成部分。 如果这些估计是 正确的，科学界将需要重新思考 我们的概念模型和性能的修改， 许多目前公认的现场测量的解释。 然而，迄今为止的证据仅来自少数样本， 方法和结果是在真实的需要验证之前， 可以放心接受。 本项目的目标 使用各种独立的方法从海洋中测量 样本：（1）病毒感染的细菌死亡率， 其他来源的细菌生长和死亡的背景 包括原生动物食草动物，和（2）率和机制， 哪些游离病毒被清除或摧毁。 没有已知 直接测量病毒诱导的细菌死亡率的方法 自然混合种群，因此将使用两种间接方法：（a） 电子显微镜下的领域人口含有成熟的 细胞内病毒，和（B）天然病毒群体大小变化 和现场样品中的去除或衰减速率。 率将 与细菌生长、放牧损失和 大小分级的总死亡率，试图收集一个 大型封闭样品的“源和汇”预算。 率和 病毒衰减和清除的机制将研究与 自然种群和培养的病毒。 这个项目包括 一些实验室工作，但主要是进行实地研究 在加州近海和近海环境中。 使用 多种方法，相互交叉验证， 增加对所得出的任何结论的信心。

Recent evidence suggest that viruses may be very important in marine food webs, with some estimates suggesting they are responsible for the majority of bacterial mortality, and driving a significant component of nutrient cycling. If these estimates are correct, the scientific community will need a major rethinking of our conceptual models and modification of the performance and interpretation of many currently-accepted field measurements. However, the evidence to date is only from a few samples, and the methods and results are in real need of verification before they can be accepted with confidence. The objectives of this project are to use a variety of independent methods to measure from marine samples: (1) mortality rates of bacteria from viral infection in the context of bacterial growth and mortality from other sources including protistan grazers, and (2) the rates and mechanisms by which free viruses are removed or destroy. There are no known direct means to measure virus-induced bacterial mortality in natural mixed population, so two indirect methods will be used: (a) electron microscopy of field populations containing mature intracellular viruses, and (b) native virus population size changes and removal or decay rates in field samples. Rates will be compared to estimates of bacterial growth, grazing losses, and size-fractionated total mortality in an attempt to assemble a "source and sink" budget for large enclosed samples. Rates and mechanisms of viral decay and removal will be studied with both natural populations and cultured viruses. This project includes some laboratory work, but primarily field studies to be performed in nearshore and offshore environments off California. The use of multiple methods, cross-verified with each other, should greatly increase the confidence in any conclusion that are reached.