plankter

Plankton (singular plankter) are any organisms that live in the water column and are incapable of swimming against a current.

The study of plankton is termed planktology and a planktonic individual is referred to as a plankter.

The arrival of cool, formerly deep water associated with internal bores into warm, shallower waters corresponds with drastic increases in phytoplankton and zooplankton concentrations and changes in plankter species abundances.