Talk by Marek Stastna (DAM Colloquium)

Title: Mathematical models of swimming zoo-plankton

Abstract: Natural bodies of water such as lakes or the coastal ocean are really a soup of tiny organisms.  Plankton, or wanderers of the sea, is a catchall term for an incredible range of lifeforms that exist in what is to us a completely alien environment.  Over the past two decades a great deal of work has gone into theoretical descriptions of plankton locomotion.  In this talk I will review the range of scales, and the relevant physics on those scales, for plankton, and introduce a larger member of the plankton family, Euphasia Pacifica.  I will spend some time on the oceanographic setting which these “little shrimps” inhabit, and then introduce a rational model of their swimming that we have developed to explain why Euphasia Pacifica are often observed in thin layers.  This will be followed by a discussion of swimming triggers, that has the twin goals of providing an experimental method of testing what triggers swimming and exploring some of the mathematical nonlinearity in even the simplest of these models.  I will conclude with some thoughts on moving to include more complex stratified hydrodynamics into plankton modeling.  I will aim to make all material self-contained, and no hydrodynamics or plankton modeling background is assumed.