ALKANES IN SEAWATER IN THE VICINITY OF THE BUCCANEER OILFIELD

Concentrations of alkanes in 76 water samples collected within 30 km of the Buccaneer oilfield between June, 1976, and March, 1977, were found to be as high as 43 ppb. It appears that petroleum alkanes discharged from the production platforms float at the air/sea interface and are dispersed. Further studies are required to determine their rates of dispersion and to investigate whether oxidation, metabolism, and other processes have a significant role in the removal of petroleum from the region of this oilfield. It seems likely that discharge from the production platforms of hydrocarbon-producing bacteria, or a nutrient which supports such bacteria, is responsible for the presence of bacterial hydrocarbons in bottom water samples down-current of the oilfield. BARBIER et al. (1973) found alkane concentrations of 2-28 ppb in the eastern Atlantic Ocean. A concentration maximum at C27 to C30 indicated that these compounds derived from phytoplankton (BLUMER 1970). Levels of alkanes ranging from 0 to 75 ppb were found by ILIFFE and CALDER (1974) in the Gulf of Mexico and the Caribbean Sea. Most of these were C15 to C20 alkanes of petroleum origin, but others in the range C21 to C36 were observed. BROWN and HUFFMAN (1976) have reported that the mean concentration of alkanes at several locations in the Atlantic, Arctic, and Indian Oceans, the Mediterranean Sea, and the Persian Gulf is 4 ppb. It was concluded that most of the compounds were petroleum-derived. Our data, by comparison with other reports in the literature, indicate that oil production in the Buccaneer field does not afford significant levels of alkanes in the surrounding seawater. © 1979 Springer-Verlag New York Inc.