Life as plankton: When fluid mechanics really matters

Prof. Christophe Eloy, IRPHE Marseille Cambridge Fluids Network - fluids-related seminars 9 February 2023 12:30pm MR15, Centre for Mathematical Sciences, Wilberforce Road, Cambridge By definition, planktonic organisms drift with the water flows. But these millimetric organisms are not necessarily passive; many can swim and can sense the surrounding flow through mechanosensory hairs. But how useful can be flow sensing in a turbulent environment? To address this question, we show two examples of smart planktonic behavior: (1) we develop a model where plantkters choose a swimming direction as a function of the velocity gradient to "surf on turbulence" and move efficiently upwards; (2) we show how a plankter measuring the velocity gradient may track the position of a swimming target from its hydrodynamic signature.