Small Critters--Big Effects

Phytoplankton are unicellular algae that use radiant energy to build organic molecules from dissolved CO. In their perspective, Morel and Antoine comment on how accurately the net primary productivity (NPP) of phytoplankton in the world ocean can now be estimated. New satellite sensors give accurate measurements of the phytoplankton biomass distribution, but the rate of production is less well known. A better estimate of NPP will require better knowledge of algal physiology and ecology.