The ecological significance of sinking to planktonic bacteria.

Morphological and density measurements were made on planktonic bacteria from a subalpine lake. The observations were then used to predict in situ sinking rates from certain theoretical considerations. The predicted rates agreed well with observed sinking rates (on the order of 1 mm day-1). A simple analysis showed that sinking terms can be neglected in explaining distributions of unattached bacteria, except perhaps in relation to the presence of "bacterial plates."