I will review the present understanding of swimming plankton and their interaction with the hydrodynamic environment. I will present in detail a model of shear-triggered swimming that is objective in the sense of continuum mechanics, and that leads to zooplankton patchiness in the vertical. This patchiness occurs at depths that are determined, at least in part, by the hydrodynamics, as opposed to pure light preference levels. I will subsequently discuss the differences between shear triggered and acceleration triggered behaviour, in the context of a simple set up that is analogous to materials characterization in rheology. I will conclude with some speculation on future directions.

Marek Stastna, Justin Shaw.