Scientists in the UK claim to have developed a liquid that can replace the traditional methods of cleaning up the sea after an oil spill. Stephen Mudge, a marine scientist at the School of Ocean Sciences at the University of Wales, UK, and his team has found that biodiesel, a clear yellow liquid derived from vegetable oil, is very effective on the dreadful residue of oil spills: the black sludge-like substance. In the ship's tanks, crude oil is fluid, but in a spillage its volatile components quickly evaporate leaving a thick sludge that is washed ashore. When this sludge comes in contact with biodiesel it quickly reverts to a much more liquid and controllable state. As the tide come in, biodiesel's buoyancy lifts the sludge away from the sediments. The sea disperses the pollution naturally. "Biodiesel has the potential to be much efficient, quicker to apply and considerably cheaper. At present, beaches can be sterilised effectively by dispersants. But biodiesel can also preserve organisms," says Mudge ( London Press Service , July 27, 1999).