Biologically- induced Mixing of Stratified Waters by Swimming Zooplankton

水生生物的游动与速度波动和流体混合的产生有关。这种生物产生的流动不仅对生物本身很重要，通过影响营养摄取，捕食者-猎物相互作用，以及对水动力和化学信号的感知，一个正在进行的科学辩论也涉及它们对盆地尺度上垂直质量和热量传输的重要性。在这个项目中，我们将量化与密度分层水域中游动的浮游动物相关的流体输送。虽然浮游动物属于水生生态系统中最小的活动生物，但由于它们的密度很高，而且许多浮游动物种类都进行垂直迁移，因此它们对生物混合的贡献预计是重要的。利用体积粒子图像测速法表征流场，结合激光诱导荧光法测量标量输运和通量，我们将在一系列实验室实验中量化由个体、相互作用的生物群体和垂直迁移的浮游动物引起的生物诱导混合。

Swimming of aquatic organisms is associated with the generation of velocity fluctuations and fluid mixing. Such biologically-generated flows are not only important for the organisms itself, by affecting nutrient uptake, predator-prey interactions, and the perception of hydrodynamic and chemical signals, an ongoing scientific debate also concerns their importance for the vertical mass and heat transport on basin-scales. In this project we will quantify the fluid transport associated with swimming zooplankton in density-stratified waters. Although zooplankton belongs to the smallest motile organisms in aquatic ecosystems, their contribution to biomixing are expected to be important because they occur in high densities and many zooplankton species perform a diel vertical migration. Using volumetric particle image velocimetry for characterizing the flow field, in combination with laser-induced fluorescence for measuring scalar transport and fluxes, we will quantify the biologically-induced mixing due to individuals, groups of interacting organisms, and vertically migrating zooplankton, in a series of laboratory experiments.