BROMOFORM IN THE NANSEN BASIN IN THE ARCTIC-OCEAN

Bromoform (CHBr3) has been measured throughout the water column on a transect across the Nansen Basin in the Arctic Ocean. The work was carried out on board the German R/V "Polarstern" in the summer of 1987. The analytical technique incorporated the extraction of the water samples with pentane and capillary gas chromatography with electron capture detection. Surface water concentrations varied from 7 ng l-1 in the southern part of the basin to 3 ng l-1 at the northernmost station. Bottom water concentrations in the interior of the basin were consistently around 0.7 to 0.9 ng l-1. The sources of bromoform in the environment are known to be largely natural, for example releases from marine algae. The results obtained in this investigation indicate that pelagic, as well as benthic algae, are capable of producing bromoform. The results also suggest that there is a flux of bromoform from the water to the atmosphere in the Arctic Ocean, possibly in the order of 10(6) kg year-1, and that marine algae thus are a significant source of atmospheric bromine in the Arctic.