应用全息图像技术和模式识别研究桡足类浮游动物摄食行为与海洋物理因子的耦合关系

We are going to conduct an experimental study to find how copepods control their movements and positions under various flow conditions. We choose two species of copepods, Calanus sinicus and Paracalanus parvus as target zooplankton. They are widely distributed at Chinese Huanghai and Bohai area and are both important for marine ecosystem. But we are lack of knowledge of their swimming behavior and responses to the change of environment at the scale of hundreds of their body length. This scale is the critical link between tiny zooplanktons and huge scale physical oceanographic phenomenon, such as current and tides. We identify several key parameters that dominant, which are gradient fields of velocity, salty, temperature and food. Such patterned distributions will be calibrated and used as background for zooplankton behavior observation study. The small-scale turbulence which is statistically homogeneous and isotropic is another model of real marine environment that we used. The relationship we find from is the key to understand the meso-scale distribution of zooplankton. We will build up flow facilities to generate such designed flow conditions which permit simultaneous detailed observations of plankton behavior and flow. The flow field will be evaluated by PIV technology (Particle Image Velocimetry). The target zooplankton will be exposed to those flow conditions whose parameters will match those found in East China Sea. The characteristics of swimming behaviour affected by various factors will be identified and analyzed. We are able to acquire three-dimension (3D) trajectories of each zooplankton by digital holographic imaging technology. Copepod kinematics can be quantified via several measures, including transport speed, net-to-gross displacement ratio, number of escape events. The complex morphology of 3D trajectories will be further analyzed and compared by their fractal characteristics. Thus we will quantified the interactions between environment factors and target zooplankton. The contribution of this study addresses on quantified methodology for ocean biology research. The flow facilities and technology, as well as algorithm developed are ready for more applications.

申请项目人选用中华哲水蚤(Calanus sinicus)和小拟哲水蚤(Paracalanus parvus)这两种代表性的桡足类优势种浮游动物为研究对象。通过室内可控实验定量研究浮游动物的运动与摄食行为。探索这些特征行为与浮游动物发育形态、雌雄差异及种间差异等生物因子的对应关系。更进一步，定量研究上述行为在成体阶段时受海洋物理过程中关键物理因子的调制，包括代表性水动力学因子以及受水动力因子影响的温、盐梯度和饵料藻类分布等物理因子。应用高速数字全息图像技术和模式分析，在可控的流场环境中实现对生物体行为的定量观测和比较分析。这些结果对解读海洋观测结果，完善和检验浮游动物种群动力模型具有重要的意义。有助于发现和建设适宜饵料浮游动物生长的水动力学环境参数，对精培育系统的设计有指导意义。本研究所建立的海洋流动及物理因子的实验室模拟，以及时空高分辨率的三维观测技术可以推广到其他生物行为的定量测量。

浮游生物是海洋生态重要组成部分。浮游生物的分布既代表了环境因素对浮游生物生消的调制，也包含了浮游动物的选择性，即被动特别是主动运动的结果。因此对浮游动物行为的定量观测和分析是浮游生物行为生态学的一个重要方面，也是目前制约其发展的一个主要因素。本研究选用中华哲水蚤（Calanus sinicus）和小拟哲水蚤（Paracalanus parvus）为代表性桡足类优势种目标动物，以其个体/群体的行为为主要观测和分析对象。通过研发实验观测技术探索目标动物定量的运动和行为规律。以此建立评估观测方法和参数体系以推广到其他种属的研究。应用该定量观测分析技术，进一步研究目标动物行为模式受到生物因素（种属、雌雄、发育形态）和环境因素（盐度、饵料密度、流动结构等）的影响。. 主要研究内容分为三个方面：即观测技术建设——建立浮游动物行为测量和分析技术；环境模拟设备建设——建立海洋典型流动环境的实验室模拟，研究物理因子影响浮游动物行为。生物因子影响行为研究——衡量浮游动物生物性因子对行为的影响；..经过四年研究，受基金直接支持或引领下，共计建设了六大类半永久性实验设备（包括层流水槽、湍流水箱等）；研发了十台套积木式光学图像测量系统，可以在采样频率、分辨率、测量体积、观测视角等方面进行组合。能够根据目标动物的行为特征和典型时空尺度，分别实现浮游动物的运动学和动力学观测（包括个体/群体）、流场测量、流固耦合测量等涉及生物学、机械运动分析、环境、流体力学以及测量与识别方面的交叉研究。基本建设成功一个能开展浮游生物行为生态学研究的独立实验室。在研内容包括：.1.从行为学角度对评估种群、雌雄、成长等生物因子所产生的差异。.2.评估目标浮游动物行为与流动结构的相关性，为饵料动物密集培养环境的设计提供有效参数。.3.评估真实流场下浮游动物摄食策略和能量平衡，为生态模型提供参数。.4.评估浮游动物对工程的影响，例如影响近壁区传热传质效率。.5.行为学参数在环境污染探测中更敏感高效。为提高准确度，评估目标动物反应阈值。