The Role of Protozoan Zooplankton in Plankton Community Structure, Composition and Fate in the Equatorial Pacific

该项目是美国联合全球海洋 赤道太平洋中部通量研究（JGOFS）。 几 在这一地区的观察结果与一些人的看法相矛盾。 我们传统的营养状态概念， 浮游生物群落结构与垂直分布的关系 通量 高氮浓度和供应率，通常 与富营养化条件相关，与相对 低叶绿素，初级生产力，和“新生产”- 这是贫营养沃茨的特征。 更小的皮科- 和微型浮游生物细胞支配浮游植物（Chavez，et.al. 然而，由于生物沉积作用， 与初级生产力相关。高通量率是 通常认为与大细胞有关，例如 硅藻，下沉出表面沃茨或被消耗 更大的细胞，粪便颗粒生产浮游动物。 这些 明显的矛盾表明， 浮游植物的大小结构，原生动物与后生动物的放牧， 以及它们与物质垂直通量的关系 表面层没有完全理解。 本项目将通过测量 向光微型浮游生物的丰度和生物量， 光养和异养微型浮游生物， 原生动物在地表水，放牧的影响， 原生浮游动物的生长速率。 我们的研究将采用经过验证的， 最先进的彩色图像分析， 荧光显微镜描述大小，营养和 浮游生物的分类结构。 结果将用于 确定原生动物浮游动物在耦合的作用， 颗粒物的生产、消费和出口 赤道中部表面沃茨中的有机物 太平洋是如此

This project constitutes a portion of U.S. joint global ocean flux study (JGOFS) of the central equatorial Pacific. Several observations have been made in this region which contradict some of our conventional concepts of trophic status and the relationship between plankton community structure and vertical flux. High nitrogen concentrations and supply rates, usually associated with eutrophic conditions, co-exist with relatively low chlorophyll, primary productivity, and "new production" - which are characteristics of oligotrophic waters. Smaller pico- and nanoplankton cells dominate the phytoplankton (Chavez, et.al. in press), yet significant rates of biogenic sedimentation occur and is correlated with primary production. High flux rates are usually thought to be associated with large cells, such as diatoms, sinking out of surface waters or being consumed by larger cells, fecal pellet-producing metazooplankton. These apparent contradictions indicate that the consequences of phytoplankton size structure, protozoan versus metazoan grazing, and their relationship to vertical flux of material out of the surface layer are not fully understood. This project will examine these contradictions by measuring the abundances and biomass of the phototropic picoplankton, phototrophic and heterotrophic nanoplankton, and phagotrophic protozoans in the surface water, and the grazing impact and growth rates of protozooplankton. We study will employ proven, state-of-the-art color image analysis combined with epifluorescence microscopy to describe the size, trophic and taxonomic structure of the plankton. Results will be used to determine the role of protozoan zooplankton in the coupling of production, consumption and export of particulate of particulate organic matter in the surface waters of the central equatorial Pacific.