The authorities in Spain have found what they say is an ecologically sound way of dealing with the wooden boats taken from the thousands of illegal immigrants who try each year to reach the coast of Europe.

Coast-guards are planning to sink 18 of the boats, known as pateras, off the coast of the Spanish enclave of Ceuta, in North Africa, to create an artificial reef for marine wildlife.

Biologists, worried about damage being done to the region's ecosystem by overfishing, say the boats will create ideal conditions for lobsters and mussels, as well as pollack, grouper and mullet.

Spanish police have up to 300 of the boats, many of them piled on a beach visible from Morocco to act as a deterrant to would-be immigrants.

From the newsroom of the BBC World Service