ANCIENT coral reefs containing rich bio-diversity in the north Atlantic are being threatened due to deep sea drilling by oil companies. Marine scientists are concerned that the oil industry is trying to exploit an area off northwest Scotland known as the Atlantic Frontier even before biological surveys are completed. British Petroleum of the UK is expected to start producing oil later this year. Scientists feel that this would impede their survey which is likely to take about two years. The Frontier contains a rare coldwater coral, Lophelia pertusa, which scientists believe could shelter as many fish and other species as tropical corals. The Scottish Association for Marine Science, based in Dunstaffnage, is carrying out a us $2.7-million study of the environmental impact of oil exploration in the Atlantic Frontier.