300,000 seabirds dead. Only now can Europe count the cost of a sea of filth

At first, it looked like a clump of seaweed that had been dipped in tar. But when I turned it over, I saw it was a bird, a large bird, possibly a gannet, one wing outstretched as if in a final, despairing attempt to fly before it died.

At first, it looked like a clump of seaweed that had been dipped in tar. But when I turned it over, I saw it was a bird, a large bird, possibly a gannet, one wing outstretched as if in a final, despairing attempt to fly before it died.

Usually, this is a magical spot; there are miles of golden sand, booming surf, dunes, fringed by pine and cedar. But today the sands, as far as one can see, are criss-crossed with lines of oil, like a vast, tangled necklace of ebony. The Atlantic Ocean, when it retreated a few hours ago, etched the beach with man-created filth.

"People talk of a marée noire [a black tide]," said Annie Bernard, 40, who was kneeling to pick up the sticky beads of oil. "Here, we have had two black tides a day for the last four days. Tomorrow we will come and we will have to clean it again." Along the shore, a hundred ghostly figures in silver-grey overalls - local volunteers - knelt in the mist to collect, drop by glutinous drop the heavy heating oil spilt when the tanker Erika sank off southern Brittany three weeks ago.

The sand and rocks will be cleaned; the oyster farmers of the Atlantic coast - who were ordered yesterday to suspend sales - will be compensated. But the extraordinary bird life of the Western approaches may never recover. There has been, according to French ornithologists, an "unprecedented holocaust" of the open-sea species of birds - species already in decline.

More than 30,000 birds have been recovered, two-thirds of them dead. It is estimated that 10 birds die at sea for every one that washes, or struggles, ashore. In other words, something like 300,000 birds may have died - five times as many as in the much bigger Amoco Cadiz spill off Brittany in 1978.

The Erika, a Maltese- flagged vessel on hire to the French company Total-Fina, foundered on 12 December, just when seabirds gather in the greatest numbers off the west coast of France. Many of these birds - guillemots, gannets, puffins, kittiwakes, razorbills - spend the spring and summer off the coast of southern Britain and Ireland before migrating to the Bay of Biscay for the winter. Hundreds of the birds found dead have British identification rings.

Michel Métais , president of the Ligue pour la Protection des Oiseaux (LPO) - League for the Protection of Birds - said: "This is the worst single act of destruction of seabirds we have ever known in France, possibly the worst in Europe."

Further north, on the Vendée coast, south of the Loire estuary, the Erika's cargo came ashore in huge, treacly slabs. Large lumps look impressive on television but they are relatively easy to clear, with a spade or a tractor. The oil splattered over the beach at Saint-Clement-des-Baleines, on the Ile de Ré, tells a truer story of the calamitous scale of the pollution in the Bay of Biscay. The 10,000 tonnes of barely liquid oil spilt by the Erika has been broken up and blended with the sea by three weeks of tides and currents. It was given a final, destructive spin by the great Christmas gales, which also devastated the pine and cedar forests behind the dunes here.

The whole of the northern half of the Bay of Biscay - thousands of square miles of ocean - has become a whirlpool of pollution. Beaches have been polluted for 300 miles, from southern Brittany to the Ile d'Oléron, with smaller slicks arriving as far south as Spain.

Mr Métais explained: "Usually tanker spills happen close inshore and devastate a relatively small section of coastline. The Erika sank a long way offshore and the winds and currents took the spill out to sea and then back again. The birds which live far out to sea - guillemots especially, but also puffins and razorbills - have been massacred. Shore birds can always fly to another, cleaner piece of coastline. Birds of the open sea do not see the oil until it is too late. Anyway, the slick has been so scattered that they have nowhere safe and clean to go."

On the outskirts of La Rochelle, in a hastily converted, disused funeral parlour, 20 oil-stained gannets stared at me with disturbingly human, pale-blue eyes. More than 800 birds have been brought here to be medicated against oil poisoning, then fed and cleaned.

Fifteen rescue clinics have been set up by the LPO along the French coast. Other birds have been flown for treatment in Cornwall, Belgium and the Netherlands. More than half the birds in the La Rochelle "hospital" are guillemots, usually smart little penguin-like birds, with black and white feathers. Drenched in brown oil, they show no interest in the tiny fish dangled before their beaks. But they preen themselves constantly, ingesting still more life-threatening oil.

Miguel Neau, 23, a biologist and conscientious objector working with the LPO instead of doing military service, said: "So far, we are saving 90 per cent of the birds brought here. The crucial thing is not to stress them more. We feed them up first before we clean them with a special product - Nutriclean - which is generally used to wash the victims of serious burns.

"People say to us we are wasting our time, that thousands of people are dying in disasters all over the world. Why bother to save a few birds? But we don't think like that. To do nothing for these birds would be terrible."

On the beach at Saint Clement, the mainly young clean-up volunteers had been joined by Léon Massy, 78, president of the local tourist board. "This is breaking my back as well as my heart, but we are determined to clean up and we will," he said. "You tell the British tourists that the beaches here will be clean next month. By the summer, it will look as if nothing happened."

Will the bird life ever be the same again? Mr Métais said: "Past experience shows that the sea is a great cleanser. Yes, the beaches will be cleaned. Yes, shore life will recover over a number of years. But will the local populations of the most stricken birds recover? Personally I doubt it.

"It is going to be a very bad nesting season this spring in France and southern England for many species. Even those which survive may be too stressed to breed."

It costs up to £100 to clean each bird rescued from the beaches. The LPO is desperate for funds. Contributions can be made out to LPO-SOS Oiseaux Mazoutés, at BP263-17305 Rochefort, France.