Collaborative Research: SOFeX: Mesoscale Iron fertilization Effects on Plankton Community Structure, Phytoplankton Growth and Zooplankton Grazing

合作研究：SOFeX：中尺度铁施肥对浮游生物群落结构、浮游植物生长和浮游动物放牧的影响

• 批准号: 0451771
• 负责人: Michael Landry
• 金额: $ 36.54万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0451771&HistoricalAwards=false
• 关键词: Collaborative; Research; SOFeX; Mesoscale; Iron

The Southern Ocean is a critical region for understanding the role of the oceans in global carbon cycling and its potential to regulate climate change. Besides being an area of high influx of atmospheric carbon and deep water formation, the persistently high concentrations of major nutrients in Antarctic circumpolar waters represent the largest pool of unrealized primary production potential in the oceans. This project is part of a larger effort to test the hypothesis that iron availability limits phytoplankton production and biomass accumulation, nutrient utilization and C02drawdown in the Southern Ocean. Drs. Landry, Chisholm and Bidigare, will contribute by investigating the effects of iron enrichment and silicate availability on the species composition and size structure of the plankton community and taxon-specific growth rates and fluorescence responses of the phytoplankton. Functional and taxonomic components of the plankton community from bacteria to mesozooplankton will be quantified by a combination of flow cytometry, taxon-specific pigments, video image-analysis microscopy and optical plankton counting. In addition, they will use dilution and gut fluorescence techniques to determine micro- and mesozooplankton contributions to grazing and to evaluate grazing as an alternate control mechanism preventing significant net growth of some or all of the phytoplankton populations. The research will bring a community perspective to the interpretation of these in situ fertilization experiments which is essential for a mechanistic understanding of the biological and geochemical responses.

南大洋是了解海洋在全球碳循环中的作用及其调节气候变化潜力的关键区域。南极环极地水域除了是大气碳大量流入和深水形成的地区外，主要营养物质浓度持续高，代表着海洋中未实现的最大的初级生产潜力库。该项目是检验铁可用性限制南大洋浮游植物生产和生物量积累、养分利用和二氧化碳减少这一假设的更大努力的一部分。 博士。 Landry、Chisholm 和 Bidigare 将通过研究铁富集和硅酸盐可用性对浮游生物群落的物种组成和大小结构以及浮游植物的分类单元特异性生长率和荧光响应的影响做出贡献。从细菌到中型浮游生物的浮游生物群落的功能和分类成分将通过流式细胞术、分类单元特异性色素、视频图像分析显微镜和光学浮游生物计数的组合来量化。此外，他们将使用稀释和肠道荧光技术来确定微型和中型浮游生物对放牧的贡献，并评估放牧作为防止部分或全部浮游植物种群显着净增长的替代控制机制。该研究将从社区的角度来解释这些原位受精实验，这对于理解生物和地球化学反应的机制至关重要。