OCE-RIG: Biological activity on particulate organic material in the coastal ocean

OCE-RIG：沿海海洋颗粒有机物质的生物活性

• 批准号: 1322950
• 负责人: Dana Hunt
• 金额: $ 10万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1322950&HistoricalAwards=false
• 关键词: OCE; RIG; Biological; activity; particulate

Overview: Marine microbial populations exhibit characteristic distributions both seasonally and across ocean basins. Using natural spatial and temporal variability, oceanographers have sought to identify the ecological variables that drive the abundance and activity of microbial groups. However, in addition to large scale resource gradients with distance and depth, there are numerous small scale microenvironments in the ocean where rates and processes are likely distinct from those in bulk seawater. Using an on-going time series, the investigator will examine seasonal changes in total and phylotype-specific biological activity in the particulate and freeliving phases. This project supports an early-career investigator working at the Pivers Island Coastal Observatory (PICO). The PICO time series has been sampled weekly (or more frequently) over the last two years to capture physical, chemical and biological variability in the coastal ocean. This time series enables the investigator to collaborate with a number of researchers and will serve as a long-term research focus. Intellectual merit: There is a growing interest in considering the contributions of microscale processes to total biological activity in the marine environment. Using size-fractionated seawater, this investigator will assess the changing contribution of particles to biological activity. Experiments will reveal the biogeochemical importance of particle-attached microbes to bulk biological processes and how they change over the course of a yearly cycle and in response to environmental perturbations (e.g. storms). The investigator will also compare the phylogeny and specific activity of particle-attached and free-living bacteria using 16S rRNA and rDNA libraries to identify which clades are responsible for these changes in total activity. In addition to categorizing clades as particle-attached or free-living, this investigator will examine the time series for transitions between particles and planktonic lifestyles at both coarse (16S rDNA) and fine scales (ITS) of phylogenetic resolution. This work will contribute to a more complete understanding of the role of particulate organic material as a distinct marine microenvironment and clarify its role in biogeochemistry. Broader impacts: The project directly involves a minority graduate student and several undergraduate students (from Duke, Marine Science Education Consortium Schools, and the REU program in marine science) in research activities. This work will also facilitate advancement of early career faculty in oceanography through development of a Preparing Oceanography Future Faculty (POFF) program to encourage women and underrepresented minorities to make the critical jump from graduate students and postdoctoral researchers to tenure-track faculty. POFF will provide motivated graduate students with a background in charting their careers to developing skills important for academic positions. After teaching the course, curricula, lesson plans and open source readings will be made publically available on a website to enable faculty to teach similar courses at other oceanography schools. To expand this outreach beyond academia, graduate students in the course will gain experience in mentoring by supervising middle school oceanography students in a science fair project, providing tours of the marine lab, and taking the eighth graders on a "research" cruise.

概述：海洋微生物种群具有季节性和跨海洋盆地的特征分布。利用自然的空间和时间变异性，海洋学家试图确定驱动微生物群体丰度和活动的生态变量。然而，除了随着距离和深度的大规模资源梯度外，海洋中还有许多小规模的微环境，其速率和过程可能与散装海水不同。使用持续的时间序列，研究者将检查颗粒和自由生活阶段总生物活性和特定类型生物活性的季节性变化。该项目支持在皮弗斯岛海岸观测站（皮科）工作的早期职业调查员。在过去两年中，皮科时间序列每周（或更频繁）进行采样，以捕获沿海海洋的物理、化学和生物变异性。这一时间序列使研究人员能够与一些研究人员合作，并将作为长期的研究重点。智力优点：人们越来越有兴趣考虑微型过程对海洋环境中总的生物活动的贡献。本研究员将使用粒度分级海水评估颗粒对生物活动的贡献的变化。实验将揭示颗粒附着的微生物对大量生物过程的生物地球化学重要性，以及它们如何在年度周期中变化并对环境扰动（例如风暴）作出反应。研究人员还将使用16S rRNA和rDNA文库比较颗粒附着和自由生活的细菌的繁殖和比活性，以确定哪些进化枝负责总活性的这些变化。除了分类为粒子附着或自由生活的分支，本研究员将检查颗粒和浮游生活方式之间的过渡的时间序列在两个粗（16S rDNA）和细尺度（ITS）的系统发育分辨率。这项工作将有助于更全面地了解颗粒有机物质作为一种独特的海洋微环境的作用，并澄清其在海洋地球化学中的作用。更广泛的影响：该项目直接涉及少数民族研究生和几个本科生（从杜克，海洋科学教育联盟学校，并在海洋科学REU计划）的研究活动。这项工作还将通过开发海洋学未来教师（POFF）计划，促进海洋学早期职业教师的发展，以鼓励妇女和代表性不足的少数民族从研究生和博士后研究人员到终身教职的关键飞跃。POFF将为积极进取的研究生提供规划职业生涯的背景，以发展对学术职位重要的技能。在教授这门课程后，课程、教案和开源读物将在一个网站上免费提供，使教师能够在其他海洋学学校教授类似的课程。为了将这一推广范围扩大到学术界之外，本课程的研究生将通过指导中学海洋学学生参加科学展览项目、提供海洋实验室的图尔斯参观以及带领八年级学生参加“研究”巡航来获得指导经验。