what is phytoplankton
Photosynthetic (plant-like) constituent of plankton, mainly comprised of unicellular algae. Supplement. Plankton pertain to the small organisms that drift, float, or weakly swimming in aquatic habitats. Some of them may be capable of diel vertical migration but they, in general, flow with their surrounding currents. They may be classified according to their trophic level groups: (1) phytoplankton, (2) zooplankton, (3) bacterioplankton, and (4) mycoplankton. Phytoplankton are the photosynthetic constituent of the plankton. Most of them are algal groups such as diatoms, dinoflagellates and cyanobacteria.