Phytoplankton are microscopic, photosynthetic organisms inhabiting the sunlit (euphotic) layers of aquatic ecosystems, forming the base of most marine and freshwater food webs. Predominantly composed of cyanobacteria, diatoms, dinoflagellates, coccolithophores, and green algae, they fix inorganic carbon via oxygenic photosynthesis, driving primary production and biogeochemical cycling of carbon, nitrogen, phosphorus, silicon, and trace metals. Their biomass and productivity are tightly regulated by light availability, nutrient concentrations, temperature, and hydrodynamic mixing. Phytoplankton dynamics underpin global carbon export to the deep ocean via the biological pump and strongly influence atmospheric CO₂ levels and climate feedbacks.
Science never stops. Get notified about trending stories.
