Oceanic systems are a central player in halogen biogeochemistry.
Halocarbon compounds are produced and consumed in the ocean and exchanged with the atmosphere. In the atmosphere, halocarbons can become involved in ozone-depleting chemistry. Oceanic concentrations of halocarbons influence fluxes to and from the atmosphere and those concentrations are the result of a balance of sources and sinks. Biological sources of halocarbons include algae and higher plants while bacterial degradation is the only known biological sink. The chemistry, and thus sea-air exchange, of these compounds is driven by biological processes which are themselves driven by a complex system of variables that include seasonal and spatial differences in physical and chemical oceanography.