The Antarctic marine ecosystem contains low concentrations of a range of hydrocarbons, overwhelmingly biogenic in origin. The low natural levels of hydrocarbons and the small amount of local human activity make the Antarctic marine ecosystem suitable as a yardstick against which future global pollution by hydrocarbons can be assessed. At present, contamination is very low and difficult to resolve against the background. Local pollution is restricted to a very few events. A systematic programme with a clear definition of the natural background is proposed to monitor both global and local pollution.