The view from the visitors’ centre at the southern edge of Doñana national park is striking, to say the least. From its plate-glass windows, you gaze – over a small lake ringed with bulrushes – at a group of tamarisk bushes covered with squawking, screeching birdlife. Cattle egrets, night herons, purple herons and glossy ibis have made their homes here, while in the foreground flamingos and spoonbills wade gracefully through the shallow, reed-filled water.
This an ornithologist’s dream: 200,000 hectares of salt marsh of unrivalled importance to the birdlife of western Europe. Dozens of Britain’s most loved migratory birds, including house martins, swallows, cuckoos and warblers, find precious rest here on their annual migrations from Africa.For good measure, Doñana, a UN World Heritage Site, is home to some of Europe’s rarest birds, including the Spanish imperial eagle, while its mammalian inhabitants include the highly endangered Iberian lynx.
It is a glorious, vibrant landscape. Yet it exists on a knife-edge, a point brought home dramatically 16 years ago last week when almost two billion gallons of contaminated, highly acidic water, mixed with arsenic, cadmium and other waste metals, surged into the park from a dam that had burst its bank at Los Frailes mine 45km to the north, near the little town of Aznalcóllar. A toxic tsunami of mine tailings poured down the Guadiamar river and over its banks, leaving a thick crust of metallic crud over a vast stretch of parkland.
More than 25,000 kilos of dead fish were collected in the aftermath and nearly 2,000 adult birds, chicks, eggs and nests killed or destroyed. Even worse, the contamination persisted and many birds gave birth to deformed or dead chicks for several years.
It was Spain’s worst environmental disaster and the clean-up cost €90m (£74m). Suddenly aware of Doñana’s status as the nation’s most important natural site, Spain decided to spend a further €360m, some of it EU money, on restoring the landscape which, in the 1950s and 60s, had been drained in places to create rice and cotton fields. Some of this farmland is now being returned to its original wetland state.
It has been a costly but encouraging process. Yet the fate of Doñana still hangs in the balance thanks to the increasing pressures of modern life. An example is provided by local farms which, in a bid to provide western Europe with out-of-season fruit, have laid out endless ribbons of plastic arches in which they grow strawberries all year round. Strawberries drink a lot, however, and that has led farmers to pump up ground water – in many cases, illegally – and so lower the park’s critically important water table.