Phototrophic picoplankton: An overview from marine and freshwater ecosystems

Algal picoplankton are a ubiquitous component of the microbial plankton communities of both marine and freshwater ecosystems. They contribute significantly to the total biomass of phytoplankton communities, and in oligotrophic oceans and lakes can be responsible for up to 80–90% of the total daily or annual carbon production. As part of the “microbial loop,” they are thought to be grazed by flagellates, ciliates, rotifers, copepods, and other metazoans, and contribute to the flow of energy to higher trophic levels. This presentation highlights their discovery, distribution, physiology, production, and contribution to pelagic food webs in marine and freshwater systems.