Mystery slick kills hundreds of birds on Norfolk coast

The first casualties started arriving on the beaches three weeks ago, a tide of wretched creatures transformed from diving sea birds to listless feathered flesh by a thick coat of stinking fuel oil.

The first casualties started arriving on the beaches three weeks ago, a tide of wretched creatures transformed from diving sea birds to listless feathered flesh by a thick coat of stinking fuel oil.

By yesterday, the number of birds recovered from the mystery slick had reached 640, with more than 200 dead including protected species such as red throated divers and great crested grebes. This may sound like the havoc being wreaked in northern Spain by the sinking of the tanker Prestige but this disaster is happening in British waters along a 200-mile stretch of coast from Lincolnshire to Essex.

Research reveals that the slick floating off East Anglia is part of an estimated 400,000 tons of oil leaked little by little into the world's oceans by vessels of all sizes – equivalent to more than a dozen Prestige-scale disasters – every year.

Wildlife experts from the RSPCA who are treating the sick animals in East Anglia said the true number of birds affected by the oil was likely to be a 10 times the number found on the shore – representing some 6,400 oiled birds and about 2,000 dead.

Ian Robinson, the RSPCA's chief vet, said: "Many of the birds have been covered in so much oil or ingested so much they have to be put down on the spot. They could not survive."

The root of the problem is believed to be a pool of oil about 10 metres wide and stretching for five miles, which was spotted by the Maritime and Coastguard Agency on 21 November between Lowestoft and Great Yarmouth. A further two, smaller slicks have been spotted close to Southwold in Suffolk and Hunstanton in Norfolk. Environmentalists say the most likely cause of the spillage is from the tanks of a submerged wreck off the Belgian coast or a passing ship flushing out fuel, cargo or oil residue from bilge pumps.

Government figures show that there are more than 740 leaks of oil and chemicals from ships and oil rigs in British waters every year. In 2000, the latest year for which statistics are available, there were 27 incidents in which more than two tons of oil or fuel were dumped off the British coast. Most of them are what the industry calls "operational" pollution – illegal tank flushing rather than collisions or catastrophic structural failure such as that which led to the Prestige breaking up.

The problem is global. A study published last month by the American National Research Council found that, of the 413,000 tons of oil released into the sea annually by vessels from fishing boats to bulk carriers and supertankers, more than 75 per cent came from operational pollution.

Anti-pollution campaigners say that the small-scale clandestine dumping of oil and other toxic substances, often by vessels flying flags of convenience and seeking to avoid paying harbour fees for the safe disposal of their waste, is now one of the biggest sources of marine pollution.

* The nuclear power company British Energy is to be prosecuted for allegedly dumping radioactive waste into the sea from the Torness Nuclear Power Station. The company, which is in financial difficulty, has been accused of illegally discharging 60 cubic metres of contaminated water from the plant's laundry, sink and shower units into the sea off the East Lothian coast in October last year. The case will be heard next month.