Eye witness

九月 11, 1998

Millions of birds are beginning their annual migration from Northern Europe to their wintering grounds in the Mediterranean and Africa.

The journey is tough enough at the best of times, especially for this year's young birds which are heading southwards for the first time.

But the ordeal has been made immeasurably worse because of the effects of a pollution incident 40 miles north of the Coto Do$ana, one of the world's most sensitive environmental sites, on the Atlantic coast of Spain.

Last April a containment dam at a pyrites mine in Andalucia burst, discharging an estimated five million cubic metres of acidic sludge containing heavy metals into the Guediamar river, which in turn joins the Guadalquivir in the Coto Do$ana.

The reserve is recognised as a Unesco biosphere reserve, a wetland of international importance, and a Natural World Heritage site, while the company involved in the spill is a Swedish-Canadian multinational, so the case for an international research effort is strong. There are at least two broad areas in which academics could be involved - monitoring bird populations and the clean-up.

But despite the early intervention of the Royal Society for the Protection of Birds and Sociedad Espa$ola de Ornitol"gica, its Spanish partner organisation through BirdLife International, neither its officers nor Christopher Perrins, director of the Edward Grey Institute of Ornithology at Oxford University, are aware of any British academic involvement. Monitoring of bird populations is being left to the SEO.

Professor Perrins said: "Many migrants will be moving through the Do$ana soon and the heavy autumn rains will wash the polluted sludge all over the place."

The Coto Do$ana has an international reputation not only for the numbers of migrating birds that use it as a staging post or winter there, but for its number of endangered species - marbled teal, purple gallinule and white-headed duck.

Long-term research into endangered species, contamination of water draining into the park, and regeneration of its water system have been coordinated by Miguel Ferrer Baena, director of the Seville-based Do$ana Biological Station, which is a part of the state-funded Consejo Superior de Investigaciones Cientificas.

Immediately after the spillage Cesar Nombela Cano, president of CSIC, mobilised the council's resources at the disposal of the environment ministry and coordinated analyses of tissue and blood samples from the affected areas by several Spanish university laboratories.

Scientists from the Institute of Terrestrial Ecology in the UK found evidence that heavy metals have been absorbed into the lush vegetation, which forms a vital food for many waterfowl. Levels of up to 100 times the normal levels of heavy metals were found in samples of rushes and reedmace from affected areas. Scientists predict a progressive build-up of toxic metals throughout the food chain with a risk to the thousands of wildfowl that winter in the marshes. Without a coordinated approach by national and regional governments, which will unlock vital European Union funds, the clean up is predicted to last for a further 20 months but the consequences for the region's wildlife may be felt for 20 years.

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