Dynamics of Autotrophic Picoplankton in Marine and Freshwater Ecosystems

Abstract

Small unicellular algae in the size range of picoplankton (0.2–2.0 µm; Sieburth et al., 1978) are ubiquitous components of pelagic ecosystems. They contribute substantially to both phytoplankton biomass and production in marine and freshwater ecosystems. In the early 1950s, Rhode found up to 11,600 cells/ml of minute green algae (size 1–2 µm or less) in oligotrophic subarctic Lake Katter-jaure (Rhode, 1955). Abundances of those “µ-algae” ranging from 1000 to 10,000 per ml were also common in the winter plankton of other lakes around Abisko, Sweden (Rhode, 1955).