Microzooplankton Grazing Interactions in the Central Equatorial Pacific

赤道中部太平洋微型浮游动物的放牧相互作用

• 批准号: 9022117
• 负责人: Michael Landry
• 金额: $ 36.58万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-15 至 1994-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9022117&HistoricalAwards=false
• 关键词: Microzooplankton; Grazing; Interactions; Central; Equatorial

The central equatorial Pacific is an extensive region of high nutrient upwelling, enhanced primary productivity, and elevated plankton concentrations that is of special interest to the Joint Global Ocean Flux Studies (JGOFS) because it may account for 20 to 50% of the estimated global rate of carbon export to the deep sea. The general goal of this research is to contribute to understanding the relationships among primary production, food- web structure, and biogeochemical cycling and fluxes in this region as a component of the JGOFS Equatorial Pacific Program. The research utilizes a complementary set of experimental approaches (fluorescently-labelled prey particles, metabolic inhibitors, and seawater dilution) and flow cytometry techniques to identify major microconsumer groups and to measure their grazing rates, behaviors, and community impacts at different temporal and spatial scales. Specifically, the research will 1) determine the distributions, abundances, and biomass of pico- and nanoplankton communities and their variations with depth and latitude on cross-equatorial transects, 2) identify and quantify the dominant microzooplankton grazers on pico- and nanoplankton communities, 3) determine the grazing impact of microzooplankton on component populations of bacteria, prochlorophytes, cyanobacteria, and algae as functions of depth, time of day, and trophic state, 4) evaluate the hypothesis that there is a general size relationship linking the rates of grazing impact on picoplankton populations, and test the hypotheses that the role of mixotrophy among planktonic flagellates will increase along environmental gradients from eutrophic (nutrient-rich) to oligotrophic (nutrient-poor) systems and at low light levels in the euphotic zone.

赤道中部太平洋是一个广阔的区域，具有高营养物上升流、增强的初级生产力和较高的浮游生物浓度，是全球海洋通量联合研究 (JGOFS) 特别感兴趣的区域，因为它可能占全球估计的深海碳输出率的 20% 至 50%。这项研究的总体目标是作为 JGOFS 赤道太平洋计划的一部分，帮助了解该地区初级生产、食物网结构以及生物地球化学循环和通量之间的关系。 该研究利用一套互补的实验方法（荧光标记的猎物颗粒、代谢抑制剂和海水稀释）和流式细胞术技术来识别主要的微型消费者群体，并测量他们在不同时间和空间尺度上的放牧率、行为和群落影响。具体来说，该研究将 1) 确定超小型浮游生物群落和纳米浮游生物群落的分布、丰度和生物量及其在跨赤道样带上随深度和纬度的变化，2) 识别和量化超小型浮游生物群落中占主导地位的微型浮游动物食草动物，3) 确定微型浮游动物对细菌组成种群的放牧影响， 原叶绿藻、蓝细菌和藻类作为深度、一天中的时间和营养状态的函数，4) 评估以下假设：存在一般大小关系，将放牧对超微型浮游生物种群的影响率联系起来，并检验浮游鞭毛虫中混合营养的作用将随着从富营养（营养丰富）到贫营养的环境梯度而增加的假设 （营养贫乏）系统和亮光区的低光照水平。