Roles of Heterotrophic Bacteria and Protists in the Arctic Ocean Carbon Cycle

异养细菌和原生生物在北冰洋碳循环中的作用

• 批准号: 9400218
• 负责人: Barry Sherr
• 金额: $ 25.23万
• 依托单位: Oregon State University
• 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: 1994-05-01 至 1996-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9400218&HistoricalAwards=false
• 关键词: Roles; Heterotrophic; Bacteria; Protists; Arctic

9400218 Sherr Research supported by this grant is under the auspices of the Arctic Systems Science (ARCSS) Global Change Research Program and is jointly sponsored by the Division of Ocean Sciences and the Office of Polar Programs. The research will be centered around a unique and intensive, multidisciplinary research expedition to parts of the Arctic Ocean that have never been extensively studied. The 1994 U.S./Canada Arctic Ocean Section is a collaborative effort with Canada that will involve approximately 60 scientists on a Canadian and a U.S. icebreaker during summer 1994. NSF-funded projects will focus on hydrography, biology, paleo-, and sea-ice studies. Data collected will be amongst the first ever from several regions of the Arctic Ocean and will be highly relevant to improving our understanding of how the Arctic is an indicator of changing global climate conditions and how it affects the physical, chemical, and biological features of the more temperate oceans and regions. This collaborative research effort between investigators at Oregon State University and the University of Delaware represents a critical component of the AOS biology program. Research will measure microzooplankton abundances, biomass, and size distributions, together with estimates of their grazing on phytoplankton and other zooplankton. Work will focus on heterotrophic bacteria and protists in the water column and sea ice of the Arctic Ocean. Present information is sparse on the abundance and activity of these microbes and about their influence on primary production. The investigators will quantify the distribution of numbers, biomass, and productivity of bacteria and compare these parameters to the in situ concentrations of labile organic substrates (dissolved free + combined amino acids and sugars); quantify the abundance, size frequency distribution, and biomass of phagotrophic protists in the nano- and microplankton size classes; and measure the grazing impact of protists on bacteria and on algal cells . Incubation experiments will also be performed where substrate concentrations and temperatures are varied to ascertain the effect on heterotrophic bacterial growth. Understanding these processes will help resolve role heterotrophic and autotrophic microbes' influence on the Arctic carbon cycle. ***

9400218 Sherr研究项目由北极系统科学（ARCSS）全球变化研究项目资助，由海洋科学部和极地项目办公室联合主办。研究将围绕一个独特的和密集的，多学科的研究考察北冰洋的部分，从未被广泛研究过。1994年美国/加拿大北冰洋科是与加拿大的一项合作努力，1994年夏季将有大约60名科学家乘坐加拿大和美国的破冰船。nsf资助的项目将集中于水文、生物学、古和海冰研究。从北冰洋几个地区收集的数据将是有史以来的首批数据之一，这些数据将与提高我们对北极如何成为全球气候条件变化的一个指标，以及它如何影响温带海洋和地区的物理、化学和生物特征的理解高度相关。俄勒冈州立大学和特拉华大学的研究人员之间的合作研究是AOS生物学项目的重要组成部分。研究将测量微型浮游动物的丰度、生物量和大小分布，以及它们对浮游植物和其他浮游动物的摄食估计。工作重点是北冰洋水柱和海冰中的异养细菌和原生生物。目前关于这些微生物的丰度和活性以及它们对初级生产的影响的信息很少。研究人员将量化细菌数量、生物量和生产力的分布，并将这些参数与不稳定有机底物（溶解的游离+结合的氨基酸和糖）的原位浓度进行比较；量化纳米级和微型浮游生物中吞噬原生生物的丰度、大小频率分布和生物量；并测量原生生物对细菌和藻类细胞的放牧影响。还将在改变底物浓度和温度的情况下进行培养实验，以确定对异养细菌生长的影响。了解这些过程将有助于解决异养和自养微生物对北极碳循环的影响。＊＊＊