ABSTRACT
The increase in pollution by oil spills in the Baltic has lead to the Minister of Transport to set up a committee with the task to find methods for identifying ships responsible for oil spills.
A preliminary study of the oil transport situation in Sweden had shown that the fingerprint method for identification will be difficult to use. The study also showed that microparticles of plastic and metal as tags might be used. In most cases the oil spills in the Baltic are due to pumping out residues mixed with ballast. In the present paper the merits of different methods for tagging these residues, including the cost aspect, are treated as well as identification of recovered oil samples.
In a field experiment the oil residues in a tanker were tagged. Some of its tanks were tagged with plastic particles and some with metal particles. The tanks were treated in different ways for cleaning and the oil-water mixtures were then pumped out in the sea under controlled conditions. The different spills were kept inside an enclosure for a fortnight and samples were taken every day. In all analysed samples the tagged substance could be recovered and identified.
A plan for testing this method on a larger scale is under preparation.