The relative distribution of non-aromatic hydrocarbons in the Baltic in September 1971

The relative distribution of the total non-aromatic (saturated and olefinic) hydrocarbons and of the total saturated hydrocarbons, was determined for the central Baltic in September, 1971. Only l litre of sample was required. The hydrocarbons were removed with liquid-liquid extraction, purified with liquid chromatography, and then determined by means of a micro-adsorption detector. Since hydrocarbons in nature are a very complicated mixture, it was impossible to determine their absolute concentration. The results therefore give the concentrations in respect to a standard, consisting of water extracted from the Kiel Bight.Even with this limitation one can see from the data that the hydrocarbons at that time of year originated largely in situ at the sediment-water interface, presumably synthesized by anaerobic bacteria. Low hydrocarbon values appeared in regions that would favor the presence of aerobic bacteria. A large amount of hydrocarbons was released by what was presumably a small plankton bloom, but there is reason to believe that they were relatively labile. The net result is that the dissolved hydrocarbons that enter into the sediment have most likely been produced at the sediment-water interface.