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: 1061353
• 负责人: John Costello
• 金额: $ 22.28万
• 依托单位: Providence College
• 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=1061353&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.

猎物的选择、摄入以及最终捕食者的营养影响是由有机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，由于大多数捕食者与猎物的相互作用发生在移动的流体中，因此在流体动力学背景下观察和量化捕食者与猎物的相互作用至关重要。 自然环境中营养模式的成功预测受到以下能力的限制：1）直接观察湍流对中上层生物摄食的影响； 2）了解湍流环境中动物与液体相互作用的机制基础； 3）将静水实验室研究的定量观察结果与自然联系起来。 这些局限性在海洋生态学更大范围内的营养交换研究中普遍存在。最近的技术进步以及联合首席研究员的专业知识使得我们能够对湍流对臭名昭著的入侵性叶状栉水母 Mnemiopsis leidyi 摄食的影响进行有意义的研究。 Mnemiopsis 是一种精致的凝胶状捕食者，它利用层流进食流来夹带和捕获猎物。 使用非常有效的摄食策略，浮游动物的现有种群和整体浮游动物生物多样性减少，而浮游植物的现有种群通过营养级联增加。 然而，像许多悬浮喂食器一样，Mnemiopsis 产生的喂食流可能容易受到环境流动的水动力破坏。 事实上，湍流事件可能会改变叶状栉水母（例如栉水母）的行为、分布和猎物选择。 该物种是确定湍流影响具有生态影响的浮游悬浮饲养者的营养交换模式的机制的理想模型生物。这项研究将实验室和现场方法相结合，在生物体水平上进行量化，确定湍流对 Mnemiopsis 的摄食机制和捕食者与猎物相互作用的影响。 了解这些湍流效应如何转化为群落水平将通过原位采样技术来完成，该技术将自然湍流水平与田间 Mnemiopsis 的摄食率、猎物选择和捕食影响联系起来。 这种方法超越了当前的实验室和模型研究，有可能建立明确的因果关系。智力价值：这项研究将：1）直接量化湍流对原位捕食者与猎物相互作用的影响； 2）提供对影响重要入侵海洋物种生态影响的关键变量的机制理解； 3）开发一种在实验室和现场研究小规模物理生物相互作用的新方法。了解湍流如何影响叶状栉水母的摄食对于生物体规模以及生态而言都很有价值。 这里开发的方法也可以应用于各种其他湍流主导的情况（例如，锋面混合、动物与海洋雪相互作用）或其他生物（其他浮游生物、底栖水柱交换）。 在所有情况下，结果都取决于小规模的物理生物过程。 更广泛的影响：本科生 (5)、研究生和联合 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。 加州理工学院的一个项目（新生暑期学院研究项目）将促进代表性不足的本科生的参与，该项目旨在为全国各地校园的少数族裔学生提供研究机会。 加州理工学院联合首席研究员将继续担任该项目的教员顾问。 莱德细纹藻 (Mnemiopsis leidyi) 是一种能够极大影响半封闭水体中食物链的入侵物种，是国际社会广泛关注的焦点。 补救措施一直是持续讨论（和实验）的主题；因此，这项研究的结果将及时向国际科学界通报。 此外，与参与公众科学教育的媒体（例如 PBS Shape of Life 系列、新英格兰水族馆的神奇果冻展览）的联系将用于传达新发现。