Mining adds to pollution fears

Concerns about large-scale marine pollution, fuelled by the Gulf of Mexico oil spill, are set to be heightened by a new development in exploitation of the oceans: deep-sea mining.

The Chinese government has just lodged the first application to mine for minerals under the seabed in international waters, in this case on a ridge in the Indian Ocean 1,700 metres (more than 5,000ft) below the surface.

The Chinese are hoping to recover valuable metals such as copper, nickel and cobalt