Bacterioplankton refers to the bacterial component of the plankton that drifts in the water column. The name comes from the Greek term, πλαγκτoν, meaning "wanderer" or "drifter", and bacterium, a word coined in the 19th century by Christian Gottfried Ehrenberg. They are found in both seawater and freshwater.

Most bacterioplankton (for instance, Bacillus and Nitrosomonas) obtain their energy through decomposition of other organisms, which largely renders them dependent on the phytoplankton for the production of dissolved organic matter as their main food source. A few species of bacterioplankton are capable of photosynthesis and chemosynthesis. Bacterio- and phytoplankton can regulate each others' numbers through mutual dependence and competition for resources such as phosphorus. They are preyed upon by protozoa and some cladocera, as well as phages.

See also

• Phytoplankton
• Zooplankton
• Pelagibacter

External links

• Typical Marine Bacterioplankton (http://www.mbari.org/rd/tigr/phylo.html)
• Marine Bacterioplankton Database (http://halia.hik.se/mbd/start.jsp)