ABSTRACT
All forms of aquatic life rely on the surrounding fluid for the transport of resources and the products of metabolic activity. The processes that affect the transport of material to and from the surface of an organism include molecular and turbulent diffusion. However, since the viscosity of water is about 55 times that of air, the scales at which these processes occur are different and may represent considerable constraints to aquatic organisms. Transport processes in aquatic environments are considered for both pelagic (i.e., those in the water column) and benthic organisms (i.e., those at the bottom). The relevant issues related to mass transfer to and from benthic plants and animals are considered in detail.
