Treasures from the deep
Mining companies are exploring underwater volcanic vents, hoping to extract metals such as gold and copper. Victoria Gill looks at the technical, environmental and political hurdles
Although it’s not a new idea, mining from the seabed is controversial, both environmentally and commercially. In the 1970s and 80s, several of the world’s largest mining companies, including Kenecott, Inco and Pruesag Hughes, along with government agencies, invested in programmes to mine polymetallic manganese nodules from the sea floor. For the most part, the rush of interest ended in failure as collecting these tiny but metal-rich lumps, formed over millions of years by the precipitation of metals from seawater, proved unprofitable. This expensive failure led most of the mining industry to stick to dry land. But interest has been rekindled by the discovery of rich mineral deposits around hydrothermal vents.