METHYL HALIDES FROM ANTARCTIC MACROALGAE

Various species of Antarctic macroalgae have been found to produce and release methyl halides at mean values of 34.7 pmol g(-1) waw (wet alg al weight) d(-1) (methyl chloride), 1.98 pmol g(-1) waw d(-1) (methyl bromide) and 1.68 pmol g(-1) waw d(-1) (methyl iodide) into the seawat er. Compared to temperate macroalgae, Antarctic macroalgae showed an a pproximately 10 to 50-fold lower release of these compounds. Due to th e lower release and the restriction to the Antarctic region, Antarctic macroalgae may play a minor role in the global production of methyl h alide, but have to be considered as biogenic contributors for methyl h alides to the halocarbon budget in the Antarctic environment. Addition al, investigated bromoform release, brominating activity and dimethyls ulfoniopropionate (DMSP) concentrations detected in Antarctic macroalg ae showed no correlation with methyl halides release rates. Therefore, a formation different to suggested enzymic pathways or origin from DM SP reacting with halides can be assumed.