Tracing sea oil slicks

Press, 21 August 1979, Page 16

Tracing sea oil slicks

From the “Economist,” London

About 500 oil slicks appear every year in the Baltic Sea and the bordering States are getting thoroughly sick of them. Most of the mess is caused not by accidents, but by the deliberate dumping of oily ballast or water used to wash out oil cargo tanks by captains at sea. Finland, the two Germanys, Poland, Russia and Sweden are jointly testing a scheme to catch the slickers and charge them for cleanup costs. If it works, the technique may be adopted internationally, under the a-spices of the United Nations maritime body, the Inter-Governmental Maritime Consultative Organisation (1.M.C.0). The aim is to link the slick with the ship. How? By putting a specific combination of small metal par-

tides — light alloys mad 4 of varying combinations of iron, nickel, silicon and chromium — into oil cargo tanks of ships when they are in port. If any oil is later dumped, a sample can be taken from the slick, the particles in it analysed, and the information then matched with a coded combination kept in a central register. Bingo, the slicker is identified. Sweden, which gets half of the Baltic slicks in its waters, came up with the idea — and tried it out in a limited national operation in 1975. That trial was successful enough to get the other Baltic countries to agree to the present experiment. Launched last month and due to end in December, the test run will cost about $450,000. About 210 different com-

binations of metal are being used in the particles of this experiment — enough to cover the ships involved in the short-haul coastal traffic responsible for most of the Baltic’s oil pollution problem. The Swedes say the number of combinations could be almost unlimited.

The data collected will go to a Swedish steering committee, which will report to 1.M.C.0. next year. 1.M.C.0. will decide where to go from there. If the technique is adopted officially, it will probably first be introduced in closed areas, such as the Baltic and the Mediterranean, where it would be easiest to operate. The Swedes see no reason why it could not be used round the world. Their experience is that it deters most would-be dumpers — and catches those not scared off.