Viruses in Pack Ice Communities of the Ross Sea, Antarctica

南极洲罗斯海冰盖群落中的P.I.Marcia Ging OPP97-25136病毒南大洋海冰藻类群落的初级生产力是重要的。在低纬度地区，放牧和病毒溶解等过程被认为控制了藻类种群，但关于冰群落内放牧的数据很少，也没有关于冰藻病毒的数据。冰群落应该是研究真核藻类和原生动物种群病毒控制的绝佳场所，因为种群可以达到高密度，而且许多栖息地在一年中的部分时间几乎关闭。这项研究将使用单个真核藻类和原生动物细胞的透射电子显微镜(TEM)以及水样的光学显微镜和TEM来评估罗斯海各种浮冰群落中的病毒感染和病毒种群。目的是(1)确定冰群落中藻类和原生动物细胞内病毒的出现程度并估计感染细胞的百分比，(2)将细胞内病毒出现的程度与海冰群落的演替阶段联系起来，(3)评估冰群落向上层传播病毒的潜力，(4)确定海冰原生浮游动物摄取类病毒颗粒的程度，(5)将冰群落的这些特征与冰正下方海水中浮游植物和原生浮游动物的特征进行比较；(6)描述和量化冰群落间隙水和冰正下方海水中游离病毒样颗粒的尺寸结构。因此，研究将有助于理解海冰群落生态，并将使真核藻类和原生动物的病毒能够纳入南极的碳流模型。

Abstract P.I. Marcia Gowing OPP97-25136 Viruses in Pack Ice Communities of the Ross Sea, Antarctica Primary productivity of sea ice algal communities in the Southern Ocean is significant. In lower latitudes, processes such as grazing and lysis by viruses are thought to control algal populations, but there are few data on grazing within ice communities and no data on viruses of ice algae. Ice communities should be excellent sites for studying viral control of populations of eukaryotic algae and protozoans because populations can reach high densitites and many habitats are nearly closed for parts of the year. This study will use transmission electron microscopy (TEM) of individual eukaryotic algal and protozoan cells and light microscopy and TEM of water samples to assess viral infections and viral populations in a variety of pack ice communities from the Ross Sea. The objectives are (1) to determine the extent of the occurrence of viruses within cells of algae and protozoans in ice communities and to estimate the percentage of infected cells, (2) to relate the extent of the occurrence of viruses within cells to the stages of succession of sea ice communities (3) to assess the potential for ice communities to seed viruses to the pelagial, (4) to determine the extent of ingestion of virus- like particles by sea ice protozooplankton, (5) to compare these features of ice communities to those of phytoplankton and protozooplankton assemblages in the seawater directly under the ice and (6) to describe and quantify the size structure of the free virus-like particles in the intersitital water of ice communities and in the seawater directly under the ice. Thus study will contribute to the understanding of sea ice community ecology and will allow incorporation of viruses of eukaryotic algae and protozoans into models of carbon flow for the Antarctic.