Hydrodynamic Simulation of Small, Passively-sinking Biological Objects

Abstract

SINKING velocity is an important ecological factor for many small biological objects such as pollen grains, airborne fruits and microplankton. Elaborate structures are often developed to increase drag and reduce sinking velocity, but their effectiveness cannot be directly investigated because of the difficulties involved in manipulation. The hydrodynamics of such small objects can be investigated, however, by using models of convenient size in highly viscous fluids. We have recently used this method in considering the feasibility of a planktonic mode of life for an extinct bivalve mollusc¹ and think the method should interest planktologists, palynologists and others who do not read palaeontological literature.