Microbiology and distribution of hydrocarbons in the marine surface oil film

The amount of carbon tetrachloride soluble material varied in the suiface film or at 1 m depth across the northern part of the Irish Sea, as did the concentration of the aromatics taken as a measure of oil pollution. Considerable differences in both concentration and composition were detected over short distances both vertically and horizontally. GLC signatures indicated that possibly both biogenic and anthropo­ genic hydrocarbons were present. There was no clear seasonal pattern, and frontal influences were not unequivocally detected when the western Irish Sea front was firmly established. The bacterial variation showed the expected greater concentration in the suiface film on most occasions. The front as expected had no discernible effect on the number of bacteria. Inorganic nitrogen was markedly increased in the suiface film as compared with the bulk water but appears to have had little effect on the rate of hydrocarbon degradation.