Collaborative Research: Dispersal and Life History Dynamics in Benthic Foraminifera

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。扩散和连通是已知的支撑海洋人口和社区健康和稳定的基本过程。有效的分散和招募有助于从各种环境扰动中恢复，并使人口和社区能够对各种时间尺度上的环境变化作出反应。这个项目将研究底栖有孔虫的扩散、连通性和生活史动力学的关键方面，底栖有孔虫是一组定义明确的原生生物，几乎在所有海洋环境中都有丰富和多样化。有孔虫在很大程度上是异养的，在碳循环中很重要，对环境条件很敏感，它们丰富的化石记录为我们提供了从历史到深层的过程。扩散和连通的模式还没有被很好地理解，特别是在这一类的底栖生物中。然而，最近的研究表明，深海环境中的连接模式非常广泛，但至少一个沿海有孔虫属的密切相关物种之间的扩散能力不同。该项目的主要目标是描述沿海至半深海底栖有孔虫的扩散模式和能力，并将这些模式与它们的生活史动态、对不同环境条件的反应能力以及在其他广泛分布的形态物种中是否存在隐蔽的系统型所反映的种群连接程度联系起来。PIS利用美国东北部沿海到半深海的研究地点和佐治亚州(美国东南部)的沿海地点，并将使用跨学科方法对有孔虫繁殖体(来自本地和远程来源的沉积物中存在的幼体)进行实验操作；形态、荧光和精细结构技术；以及分子遗传学。该项目将：(1)确定垂直于海岸带的扩散程度，从岸上到离岸地点，以及从近岸到岸上的相反方向；(2)确定海岸带内(即与海岸平行)的扩散是否如许多关于“世界性”潮间带物种的报告所暗示的那样，发生远距离的扩散(即，在相邻的沿海省份之间)，或者扩散是否一般受到区域的限制。(3)确定选定底栖有孔虫的扩散与其生活史动态之间的关系；以及(4)评估在不同环境条件下从单个繁殖体库中生长的成体有孔虫组合的多样性，从而洞察每个地点繁殖体库的环境适应性，从而对环境变化做出反应。更广泛的影响：该项目将有助于更全面地了解海洋系统中的扩散过程、生活史动态和连通性。这些结果将进一步解决微生物扩散的普遍性和适度地方性模型之间的争论，为真核微生物和大型生物之间的扩散模式提供额外的比较，并有助于我们理解环境扰动和变化导致的群落水平的变化。在教育方面，该项目将包括格鲁吉亚大学研究生和本科生的参与，包括来自代表性不足群体的学生。该项目还将为一名或多名科学教育专业的本科生或研究生提供参与研究邮轮的机会。这样的机会扩大了未来教师的教育基础和经验。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)." Dispersal and connectivity are fundamental processes known to underpin the health and stability of marine populations and communities. Effective dispersal and recruitment facilitate recovery from a variety of environmental perturbations and allow populations and communities to respond to environmental change operating over a range of temporal scales. This project will study to examine key aspects of dispersal, connectivity, and life history dynamics in benthic foraminifera, a well-defined group of protists that are abundant and diverse in nearly all marine settings. Foraminifera are largely heterotrophic, important in carbon cycling, sensitive to environmental conditions, and their rich fossil record provides insight into processes functioning over the span of historical to deep time. Dispersal and connectivity patterns are not well understood, particularly in benthic representatives of this group. Recent studies, however, suggest very broad connectivity patterns in deep-sea settings yet different dispersal capabilities among closely related species of at least one coastal foraminiferal genus. The overarching goal of this project is to characterize the dispersal patterns and capabilities of coastal to bathyal benthic foraminifera and to relate these patterns to their life history dynamics, ability to respond to different environmental conditions, and the extent of population connectivity as reflected by the presence or absence of cryptic phylotypes in otherwise broadly distributed morphospecies. The PIs utilize coastal to bathyal study sites off the Northeastern US and coastal sites in Georgia (SE US) and will use interdisciplinary methodology for experimental manipulation of the foraminiferal propagule bank (juveniles present in sediments derived from both local and distant sources); morphological, epifluorescence and fine structural techniques; and molecular genetics. This project will: (1) Determine the extent of dispersal perpendicular to the coastal zone, both from onshore-to offshore sites, and in the opposite offshore-to-onshore direction; (2) Determine whether dispersal within the coastal zone (i.e., parallel to the coast) occurs over long distances (i.e., between adjacent coastal provinces), as implied by numerous reports of "cosmopolitan" intertidal species, or whether dispersal is generally limited by region. (3) Determine the relationship between dispersal in selected benthic foraminifera and their life history dynamics; and (4) Assess the diversity of adult foraminiferal assemblages that can be grown from a single propagule bank under different environmental conditions, thus providing insight into the environmental adaptability of the propagule bank at each of the sites and hence the ability to respond to environmental change. Broader Impacts: This project will contribute to a more comprehensive understanding of the processes of dispersal, life history dynamics, and connectivity in marine systems. Results would further resolve the debate between the ubiquity and moderate endemicity models of microbial dispersal, provide additional comparisons of dispersal patterns between eukaryotic microbes and macro-organisms, and contribute to our understanding of community-level modifications that result from environmental perturbations and change. In terms of education, this project will include participation by graduate and undergraduate students from the University of Georgia, including students from under-represented groups. The project will also provide the opportunity to participate in the research cruise for one or more undergraduates or graduate students majoring in science education. Such opportunities expand the educational base and experiences of future teachers.