Collaborative Research: Turbulence and Suspension Feeding - a New Approach using the Lobate Ctenophore Mnemiopsis Leidyi

合作研究：湍流和悬浮喂养——利用叶形栉水母 Mnemiopsis Leidyi 的新方法

• 批准号: 1061182
• 负责人: Sean Colin
• 金额: $ 19.04万
• 依托单位: Roger Williams University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-15 至 2015-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1061182&HistoricalAwards=false
• 关键词: Collaborative; Research; Turbulence; Suspension; Feeding

Prey selection, intake and, ultimately, the trophic impact of predators are determined by a succession of events that occur at the organismal level -- individual interactions among predators prey, and their environments. Furthermore, because the majority of predator-prey interactions occur in moving fluids, it is critical to observe and quantify predator-prey interactions within a hydrodynamic context. Successful predictions of trophic patterns in natural settings are limited by the ability to: 1) observe directly the effects of turbulence on feeding in pelagic organisms; 2) understand the mechanistic bases of animal-fluid interactions in turbulent environments; and 3) relate quantitative observations from still-water laboratory studies to nature. These limitations are pervasive in studies of trophic exchange within the larger scope of marine ecology. Recent technological advances, and the combined expertise of the Co-PIs, enables meaningful studies of the influence of turbulence on feeding by the notoriously invasive lobate ctenophore, Mnemiopsis leidyi. Mnemiopsis is a delicate gelatinous predator which uses a laminar feeding current to entrain and capture prey. Using a remarkably effective feeding strategy, zooplankton standing stocks and overall zooplankton biodiversity are reduced, and standing stocks of phytoplankton are increased via a trophic cascade. Like many suspension feeders, however, the feeding current produced by Mnemiopsis may be vulnerable to hydrodynamic disruption by ambient flows. In fact, turbulent events may change the behavior, distribution and prey selection of lobate ctenophores such as Mnemiopsis. This species is an ideal model organism to determine the mechanisms by which turbulence affects trophic exchange patterns of ecologically influential planktonic suspension feeders. Involving a combination of laboratory and in situ methods to quantify, at the organismal level, this study will determine effects of turbulent flows on the feeding mechanics and predator-prey interactions of Mnemiopsis. Understanding how these turbulent effects translate to the community level will be accomplished via in situ sampling techniques that relate natural turbulence levels to ingestion rates, prey selection and predatory impact of Mnemiopsis in the field. This approach extends beyond current laboratory and modeling studies, with the potential of establishing clear cause-and-effect relationships.Intellectual Merit: This research will: 1) directly quantify turbulent effects on in situ predator-prey interactions; 2) provide mechanistic understanding of key variables influencing the ecological impact of an important invasive marine species; and 3) develop a novel approach for studying small-scale physical-biological interactions both in the laboratory and in the field. Knowing how turbulence affects feeding in lobate ctenophores is valuable at the scale of the organism, as well as ecologically. The approach developed here also may be applied to a variety of other turbulence-dominated situations (e.g., mixing at fronts, animal-marine snow interactions) or to other organisms (other plankton, benthic-water column exchanges). In all cases, the outcomes depend upon small-scale physical-biological processes.Broader Impacts: Undergraduates (5), the graduate student, and the Co-PIs will work as a team in both the field and the laboratory, providing all participants with experience in every aspect of the research. The participation of underrepresented undergraduates will be facilitated through a program at Caltech (Freshmen Summer Institute Research Program) aimed at providing research opportunities to minority students from campuses across the nation. The Caltech Co-PI will continue his role as faculty advisor to this program. An invasive species that can dramatically affect the food chain within semi-enclosed bodies of water, Mnemiopsis leidyi is the focus of broad international interest. Remediation has been the subject of ongoing discussions (and experiments); therefore, results of this research will be communicated to the international scientific community in a timely fashion. In addition, contacts with media (e.g., PBS Shape of Life series, Fantastic Jellies exhibit at the New England Aquarium) involved in scientific education of the general public will be used to convey new findings.

捕食者的选择、摄入以及最终的营养影响是由生物体水平上发生的一系列事件决定的--捕食者、猎物及其环境之间的个体相互作用。 此外，由于大多数的捕食者-猎物的相互作用发生在移动的流体中，它是至关重要的，以观察和量化的捕食者-猎物的相互作用在流体动力学的背景下。 成功预测自然环境中的营养模式受到以下能力的限制：1）直接观察湍流对浮游生物摄食的影响; 2）了解湍流环境中动物-流体相互作用的机制基础; 3）将静水实验室研究的定量观察与自然联系起来。 这些局限性普遍存在于海洋生态学范围内的营养交换研究中。最近的技术进步，以及联合专业人员的专业知识，使有意义的研究的影响，湍流喂养臭名昭著的侵略性叶状栉水母，Mnemiopsis leidyi。 拟记忆虫是一种脆弱的凝胶状捕食者，它利用层流摄食流来携带和捕获猎物。 使用一个非常有效的喂养策略，浮游动物常备股票和整体浮游动物生物多样性减少，浮游植物常备股票通过营养级联增加。 然而，像许多悬浮饲养者一样，由拟记忆虫产生的饲养电流可能容易受到周围水流的水动力破坏。 事实上，动荡事件可能会改变的行为，分布和猎物选择的叶状栉水母，如Mnemiopsis。 该物种是一种理想的模式生物，以确定湍流影响生态影响的浮游悬浮饲养者的营养交换模式的机制。这项研究涉及实验室和原位方法相结合，在生物体水平上进行量化，将确定湍流对拟记忆鱼的进食机制和捕食者与猎物相互作用的影响。 了解这些动荡的影响如何转化为社会层面将通过原位采样技术，涉及自然湍流水平的摄食率，猎物的选择和掠食性影响的Mnemiopsis在外地完成。 这一方法超越了目前的实验室和模拟研究，具有建立明确的因果关系的潜力。智力优点：这项研究将：1）直接量化湍流对原位捕食者-猎物相互作用的影响; 2）提供影响重要入侵海洋物种生态影响的关键变量的机理理解;以及3）开发一种新的方法，用于在实验室和现场研究小规模的物理-生物相互作用。了解湍流如何影响叶状栉水母的进食，在生物体的规模和生态学上都是有价值的。 这里开发的方法也可以应用于各种其他服从主导的情况（例如，锋面混合、动物-海洋雪相互作用）或其他生物（其他浮游生物、底栖生物-水柱交换）。 更广泛的影响：本科生（5名）、研究生和合作PI将作为一个团队在现场和实验室工作，为所有参与者提供研究各个方面的经验。 代表性不足的本科生的参与将通过加州理工学院的一项计划（新生暑期研究计划）来促进，该计划旨在为来自全国各地校园的少数民族学生提供研究机会。 Caltech Co-PI将继续担任该计划的教师顾问。 作为一种入侵物种，它可以极大地影响半封闭水体中的食物链，莱氏拟线藓是国际上广泛关注的焦点。 补救一直是正在进行的讨论（和实验）的主题;因此，这项研究的结果将及时通报国际科学界。 此外，与媒体的接触（例如，公共广播公司的生命形态系列，神奇水母展览在新英格兰水族馆）参与科学教育的一般公众将被用来传达新的发现。