Collaborative Research: Bloom Dynamics and Food Web Structure in the Ross Sea: Role of Microzooplankton in Controlling Production

合作研究：罗斯海的水华动力学和食物网结构：微型浮游动物在控制生产中的作用

• 批准号: 9315027
• 负责人: Evelyn Lessard
• 金额: $ 26万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9315027&HistoricalAwards=false
• 关键词: Collaborative; Research; Bloom; Dynamics; Food

9315027 Lessard The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. The focus of this proposal is the role of microzooplankton in controlling the production and fate of carbon during the two types of blooms. Objectives are: 1) to determine biomass, abundance, size and selected species composition of primary producer assemblages, 2) to determine similar features of nano- and microplanktonic heterotrophic assemblages, 3) to measure total community grazing on heterotrophic bacteria and phytoplankton, 4) to examine which grazers are the major herbivores and bacterivores, and 5) to measure the contribution of microzooplankton and mesozooplankton egesta, sinking of algal cells and colonies, and sinking of protozoan assemblages associated with detritus to the total carbon flux from the euphotic zone through 250 m depth. Water samples for abundance and biomass determinations will be taken and samples will be examined with epifluorescence microscopy. Grazing rates will be measured using the dilution grazing technique and the dual- isotope radiolabeling single cell method. Carbon fluxes will be determined on sinking material collected with particle interceptor traps at the base of the euphotic zone and two deeper depths, using microscopical analys is. An understanding of these processes and other fundamental processes studied by collaborating investigators will contribute to the understanding of the role of the Southern Ocean in present, past and predicted future sequestration of carbon, as well as in other global elemental cycles.

9315027 Lessard在极地海洋中浮游植物的生长季节很短，但很紧张。 有越来越多的证据表明，在许多南极栖息地中，最活跃的时期可能是本赛季早期的，这一时期尚未在先前的研究中强调。 该项目是一个跨学科计划的一部分，该计划重点介绍了南极春季浮游植物Bloom的动力学，南极，罗斯海。 整个程序将检验与冰融化发作后不久浮游植物开花有关的假设，控制春季浮游植物生长和生产力的机制，春季高生产率的含义和短期命运以及春季过渡到春季的过渡。 该提案的重点是Microzooplankton在两种类型的花朵中控制碳的产量和命运方面的作用。 目标是：1）确定主要生产者组合的生物量，丰度，大小和选定的物种组成，2）确定纳米和微量全膨胀的异育式组合的相似特征，3）衡量对异养细菌的全部社区覆盖的全部社区，以衡量哪些杂物和植物量的摄入量和5个gachazers和5） Microzooplankton和Mesozooplankton Egesta，藻类细胞和菌落的下沉，以及与碎屑相关的原生动物组合下沉到从兴奋区到250 m深度的总碳通量。 水样将进行丰度和生物量测定，并将使用落叶显微镜检查样品。 放牧速率将使用稀释放牧技术和双同位素放射性标记的单细胞法测量。 使用微观分析是，将确定碳通量在用颗粒拦截器陷阱中收集的下沉材料和两个更深的深度，使用微观分析。 对这些过程和协作研究人员研究的其他基本过程的理解将有助于理解南方海洋在当下，过去和预测碳以及其他全球元素周期中的未来隔离中的作用。