Dissolved Oxygen

Parameter governing most of biological processes in aquatic ecosystems. The concentration of dissolved oxygen is the result of the following physical, chemical and biological factors: exchanges at the air-ocean interface; dissemination and mixing in the water body; use in chemical oxidation reactions (natural or anthropogenic); use by aquatic organisms for breathing (which includes bacterial degradation of organic matter in a broad sense) and for nitrification; in situ production by photosynthesis.