Marine macroalgae in polar regions as natural sources for volatile organohalogens

Marine macroalgae species from the polar regions were investigated for thei r importance as natural sources of volatile halogenated compounds released into the biosphere. Several different halogenated C-1 to C-4 hydrocarbons w ere identified and their release rates determined. The compounds contained mainly bromine and iodine, and form was the dominant compound released. Alt hough an annual atmospheric input of approximately 10(8)-10(10) g bromine a nd 10(7)-10(8) g iodine was calculated from the release rates, marine macro algae are apparently nor the major source on a global scale, as the release is up to four orders of magnitude lower than a presumed annual flow from t he oceans. Despite this, macroalgae may be more important on a local scale due to their occurrence at a high biomass in the coastal regions. The prese nt paper gives an overview about studies done on the release of volatile ha locarbons by macroalgae from polar regions. Furthermore, the function of th ese compounds in the macroalgal metabolism is discussed.