Collaborative Research: Protistan Abundance, Diversity and Activity in the Deep-Sea and at Hydrothermal Vents

合作研究：深海和热液喷口的原生生物丰度、多样性和活动

• 批准号: 0550829
• 负责人: David Caron
• 金额: $ 40万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0550829&HistoricalAwards=false
• 关键词: Collaborative; Research; Protistan; Abundance; Diversity

Protistan assemblages are essential components of food webs in the vast majority of aquatic ecosystems that have been examined to date. Despite the pivotal roles that these organisms play in carbon fixation, energy utilization and elemental cycling in marine ecosystems, little information exists on the presence, abundance and activities of these species in the deep ocean in general, and in particular at and around hydrothermal vents. The latter environments should be particularly conducive to the growth of phagotrophic protists in the deep ocean because biomass is greatly elevated at these sites and organic carbon availability in these regions is largely mediated by archaeal and bacterial assemblages. This research project will address fundamental questions regarding the species diversity, abundances of specific taxa, and trophic activities of protists within the deep ocean including hydrothermal vent areas. Specifically, the PIs will determine whether deep-sea communities harbor endemic assemblages of protists, establish the identity of the protists associated with these environments that are trophically active, and document the protistan taxa that dominate these assemblages in situ. They will examine the diversity of the protistan assemblages in the deep-sea away from the vents and in the overlying water column, and in microenvironments in and around hydrothermal vents and associated with dominant macrofauna of vents. Traditional (microscopy) and molecular biological (18S rDNA) approaches will be used to characterize abundance and diversity. Observations of the ingestion of fluorescently labeled prey will be used to establish trophically active protists in situ. They will also employ 18S rDNA clone libraries, cultures and microscopy-based observations to target specific taxa for the application of fluorescent in situ hybridization (FISH) to link morphological identity to commonly occurring (and trophically active) phylotypes. A culture collection of deep-sea protists will be established to further characterize protistan diversity and also to provide specimens for baseline physiological measurements in the laboratory. Growth rates will be examined in the laboratory using cultured protists grown under temperatures, pressures and water chemistries representative of deep-sea environments. Hydrothermal vent research is an excellent vehicle for incorporation into education at all levels ranging from elementary through graduate level. The information resulting from this research will be incorporated into undergraduate and graduate courses by the PIs, and will be featured on the Caron Lab Homepage. The PIs and the postdoctoral investigator supported by this project will participate directly in an ongoing teacher education program (Centers for Ocean Science Education Excellence; COSEE-West) that will reach middle and high school students, most of whom are Hispanic, African-American or other ethnic minorities and most of whom are economically disadvantaged. This will be accomplished through existing teacher enhancement and student enrichment activities that will incorporate this research into a learning experience that will enhance student awareness of environmental science, microbiology and the natural world. This work will be the center feature for the internationally acclaimed Extreme 2000 outreach program for secondary schools which has, over the last 5 years, directly engaged over 180,000 students throughout the US and 9 foreign countries. Contributions from this project will educate the public at every level about the deepsea, and the importance of microbes in forming and maintaining the biosphere.

原生生物群落是迄今为止研究过的绝大多数水生生态系统中食物网的重要组成部分。尽管这些生物在海洋生态系统的固碳、能源利用和元素循环方面发挥着关键作用，但关于这些物种在一般深海、特别是在热液喷口及其周围的存在、丰度和活动的资料很少。后一种环境应特别有利于深海中食食性原生生物的生长，因为这些地点的生物量大大提高，这些地区的有机碳供应在很大程度上是由古细菌和细菌组合介导的。这一研究项目将探讨包括热液喷口地区在内的深海内物种多样性、特定分类群的丰度和原生生物的营养活动等基本问题。具体而言，PI将确定是否深海社区港口原生生物的地方性组合，建立与这些环境的原生生物的身份是营养活跃，并记录原生生物类群，占主导地位的这些组合在原地。他们将研究远离喷口的深海和上覆水柱中以及热液喷口内部和周围的微环境中与喷口主要大型动物有关的原生生物组合的多样性。传统的（显微镜）和分子生物学（18 S rDNA）的方法将用于表征丰度和多样性。观察荧光标记的猎物的摄入将被用来建立营养活性原生生物在原位。他们还将采用18 S rDNA克隆库，培养和显微镜观察，以靶向特定的分类群，用于荧光原位杂交（FISH）的应用，将形态特征与常见的（和营养活性的）真菌类型联系起来。将建立一个深海原生生物培养物收集库，以进一步确定原生生物多样性的特征，并为实验室进行基线生理测量提供标本。将在实验室中使用在深海环境的温度、压力和水化学代表性条件下培养的原生生物来检查生长率。 热液喷口研究是纳入从小学到研究生各级教育的极好工具。从这项研究中得到的信息将被PI纳入本科和研究生课程，并将在Caron Lab主页上显示。该项目支持的PI和博士后研究员将直接参与正在进行的教师教育计划（海洋科学教育卓越中心; COSEE-West），该计划将覆盖初中和高中学生，其中大多数是西班牙裔，非洲裔美国人或其他少数民族，其中大多数人经济上处于不利地位。这将通过现有的教师增强和学生丰富的活动，将这项研究纳入学习经验，将提高学生对环境科学，微生物学和自然世界的认识。这项工作将成为国际知名的Extreme 2000中学外展计划的中心特色，该计划在过去5年中直接吸引了美国和9个外国国家的超过180，000名学生。该项目的贡献将教育各级公众了解深海，以及微生物在形成和维持生物圈方面的重要性。