Doliolid Blooms: What Are the Driving Variables? Investigations of Trophic Interactions

众所周知，亚热带海洋的浅海区域经历了远洋被囊动物水华的偶发性发生。然而，很少有人知道的过程，调节这些人口或其生态意义。根据零星的实地观察和相对少量的实验室研究，可以理解，理论上海樽纲，特别是珊瑚虫的开花可能特别重要，因为它们具有巨大而快速的无性繁殖能力。据报道，在世界上大多数大陆架上都有超过1 000个m-3的浮游生物大量繁殖。大量的doliolids有可能重组的营养结构的货架远洋生态系统限制桡足类生产通过消耗鸡蛋和分流初级生产的底栖生物和微生物循环通过粪便生产。虽然已经学到了很多东西，通过仔细的实验室研究，调查的过程中，管理的发展doliolid水华不能令人满意的模拟在实验室中，直到最近，方法来调查浮游动物，他们的猎物，和他们的捕食者之间的营养相互作用的关键方面在原地一直缺乏。在这个项目中，研究人员将进行一个基于实地的研究，其中经典的和经过验证的浮游动物生态学方法将与新的分子为基础的方法相结合，用于评估肠道内容物，以解决有关doliolid营养相互作用的几个基本问题，在夏季水华在南大西洋湾大陆架。该项目的两个方面可能被认为是潜在的变革。首先，它将是第一个系统地应用浮游动物分子肠道内容物原位分析方法，可能彻底改变浮游动物生态学领域。值得注意的是，科学界已明确指出，需要新的工具来调查浮游动物的营养过程，这是该领域的一个主要限制。第二，该项目将探讨一个范式转变假说，即doliolid水华不是由直接捕食，营养限制或平流海洋过程控制的，而是由不断变化的食物颗粒环境控制的。该研究集中在海洋浮游生物研究的不同领域内的一个中心主题，营养相互作用，因此将远远超出该项目的具体重点。在更广泛的程度上，这项研究将有助于弥合现代生物学中存在于分子、生物体和生态学之间的根本分歧。该项目的一个重要组成部分将涉及培训和增加STEM领域代表性不足的学生的代表性。将支持和培训一名研究生和三名本科生。通过与两所历史悠久的黑人大学建立良好的关系，这两所大学都有海洋科学课程（汉普顿大学和萨凡纳州立大学），调查人员将积极招收学生。此外，其中一名研究人员是汉普顿大学的年轻助理教授，该项目将为她提供机会，以推进她的研究生涯，改善汉普顿的研究基础设施，并增加学生对研究的接触。最后，该项目将利用与北欧研究人员建立的国际关系，这些研究人员积极从事类似的研究，但重点是浮游动物和其他凝胶状中上层物种。该项目还将支持美国海洋科学家参加即将于2009年在萨凡纳举办的分子营养相互作用II专题讨论会。

It is well known that neritic regions of subtropical oceans experience episodic occurrences of pelagic tunicate blooms. However, little is known regarding the processes that regulate these populations or their ecological significance. Based on sporadic field observations and a relatively small number of laboratory studies, it is understood that theoretically blooms of the Thaliacea, specifically the doliolids, may be particularly important because of their enormous and rapid asexual reproductive capacity. Blooms of over 1,000 zooids m-3 are reported from most of the world's continental shelves. Large blooms of doliolids have the potential of restructuring the trophic structure of shelf pelagic ecosystems by limiting copepod production via consumption of eggs and shunting primary production to the benthos and the microbial loop via fecal production. Although much has been learned via careful laboratory studies, investigation of the processes that govern the development of doliolid blooms cannot be satisfactorily simulated in the laboratory and, until recently, methods to investigate key aspects of trophic interactions between zooplankton, their prey, and their predators in situ have been lacking. In this project the investigators will conduct a field-based study in which classical and proven zooplankton ecology methods will be merged with new molecular based approaches for assessing gut contents to address several fundamental questions concerning doliolid trophic interactions during summer blooms on the South Atlantic Bight continental shelf.Two aspects of the project may be considered potentially transformative. First, it will be among the first to systematically apply zooplankton molecular gut content analytical methods in situ, potentially revolutionizing the field of zooplankton ecology. It is of note that the need for new tools to investigate zooplankton trophic processes has been clearly identified by the science community as a major limitation to the field. Second, the project will explore a paradigm shifting hypothesis that doliolid blooms are controlled not by direct predation, nutrient limitation, or advective oceanographic processes, but by a changing food particle environment.The research focuses on a central theme, trophic interactions, within the diverse field of marine plankton studies, and therefore will be of interest well beyond the specific focus of the project. To a broader degree, the study will serve to help bridge the fundamental divide in modern biology that exists between molecules, organisms, and ecology. An important component of the project will involve training and increasing representation of underrepresented students in STEM fields. One graduate student and three undergraduate students will be supported and trained. Through well established relationships with two Historically Black Universities, both of which have Marine Science programs (Hampton University and Savannah State University), the investigators will aggressively recruit students. Additionally, one of the investigators is a young assistant professor at Hampton University and this project will provide her opportunities to advance her research career, improve research infrastructure at Hampton, and increase student exposure to research. Finally, this project will take advantage of established International relationships with Nordic researchers who are actively engaged in similar research but focused on Appendicularians and other gelatinous pelagic species. The project will also support the participation of US marine scientists in the upcoming Molecular Trophic Interactions II symposium being organized in Savannah in 2009.