Testing the turbulence avoidance hypothesis

检验避免湍流假设

• 批准号: 0928491
• 负责人: Jeannette Yen
• 金额: $ 44.58万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0928491&HistoricalAwards=false
• 关键词: Testing; turbulence; avoidance; hypothesis

This project will evaluate species-specific responses of copepods to turbulence via laboratory experiments and computer simulations. Field studies strongly suggest that oceanic turbulence affects the vertical position of copepods primarily by changing their behavior, and only secondarily by physically altering their position. The hypothesis to be tested is that fine-scale turbulence alters copepod behavior via directed movements and changes in swimming kinematics. The specially-designed laboratory apparatus enables comparison of plankton kinematic patterns in response to fine-scale turbulent flow features. The apparatus creates turbulent flows with dissipation rates, length scales, velocity scales, and fluctuating strain rate levels that are appropriate for zooplankton studies. Recent advances in 3D velocity measuring techniques make this an opportune time to quantify the flow field around frees-wimming zooplankton at high spatial and temporal resolution. To correlate specific behavior responses to specific instantaneous 3D flow patterns, the velocity field must be quantified in a 3D volume surrounding the animal. The experiments will facilitate a quantitative correlation between copepod behavior and hydrodynamic conditions and will provide new insight to the balance of biological versus physical forcing. Further, the rules of copepod response to a spatially-explicit physical environment will be entered into an individual-based model (IBM) to provide a context to assess the ecological significance of zooplankton behavior. The IBM simulations will test the influence of micro-scale behavior on fine-scale copepod distributions, and hence allow the turbulence-avoidance hypothesis question to be addressed: Do individual copepods react to fine-scale turbulent features with a species-specific response that results in a population distribution that does not overlap with the turbulent region?Collaborative interactions are essential to extending understanding of the biological, physical, and chemical processes that create and maintain fine-scale plankton distribution patterns. This interdisciplinary effort relies on combining expertise in fluid mechanics and biological oceanography to advance understanding of copepod ecology and sensory systems. This project will increase our understanding and ability to model the effects of turbulence on zooplankton distributions. Further, the data will be used by NOAA personnel towards developing long-term indices of secondary production as a function of wind-generated mixed-layer turbulence as part of NOAA's FATE (Fisheries And The Environment) program. Training will be provided for a graduate student in the specific areas of advanced laser measurement systems, copepod mechanosensory systems, and biological-physical interactions in the ocean. The student will experience a rich interdisciplinary research environment and develop skills to be a leader in her/his field. The project connects well with on-going educational efforts, in particular NSF IGERT and REU programs to educate in the area of aquatic chemical and hydromechanical signaling. Further, the investigators plan to work with staff members at the Georgia Aquarium and Zoo Atlanta to set up exhibits of invertebrate behavior and the role of underwater perception in mediating behavior.

该项目将通过实验室实验和计算机模拟评估copepods对湍流的特定物种反应。现场研究强烈表明，海洋湍流主要通过改变其行为，仅通过物理改变其位置来影响copepods的垂直位置。要测试的假设是，细数的湍流通过定向运动和游泳运动学的变化来改变copepod的行为。专门设计的实验室设备可以比较浮游生物运动模式，以响应细小的湍流特征。该设备以耗散速率，长度尺度，速度尺度以及适合浮游动物研究的应变速率水平创造湍流。 3D速度测量技术的最新进展使得这是在高空间和时间分辨率下量化射击浮游浮游生物周围流量场的适当时机。为了将特定的行为响应与特定的瞬时3D流动模式相关联，必须在动物周围的3D体积中量化速度场。该实验将促进Copepod行为与流体动力学条件之间的定量相关性，并将为生物学与物理强迫的平衡提供新的见解。此外，CopePod对空间说明的物理环境的响应规则将被输入基于个体的模型（IBM），以提供评估浮游动物行为的生态意义的上下文。 IBM模拟将测试微尺度行为对细尺度copepod分布的影响，因此允许避免湍流 - 避免湍流假设的假设问题：单个copepods是否会对精细尺度的湍流特征反应，并在物种特定的响应中与某种人群分布相关的物质分布与湍流相互作用，并且在湍流中不断依赖于湍流，并且是在湍流中的依据，并且是在湍流中的依据？细小的浮游生物分布模式。这项跨学科的工作依赖于将流体力学和生物海洋学方面的专业知识结合在一起，以提高人们对Copepod生态学和感觉系统的了解。该项目将提高我们的理解和对湍流对浮游动物分布的影响的影响。此外，NOAA人员将将数据用于开发二级生产的长期指数，这是风产生的混合层湍流的函数，作为NOAA命运（渔业与环境）计划的一部分。将为在海洋中高级激光测量系统，CopePod机械增强系统和生物学相互作用的特定领域的研究生提供培训。该学生将体验丰富的跨学科研究环境，并发展技能，成为其领域的领导者。该项目与正在进行的教育工作，尤其是NSF IGERT和REU计划有很好的联系，以在水生化学和水力力学信号领域进行教育。此外，调查人员计划与佐治亚水族馆和亚特兰大动物园的工作人员合作，以建立无脊椎动物行为的展览以及水下认知在中介行为中的作用。