Marine mining: Underwater gold rush sparks fears of ocean catastrophe

The prospect of a race to the bottom of the ocean – a 21st-century high seas version of the Klondike gold rush – has alarmed scientists. The oceans, which make up 45% of the world’s surface, are already degraded by overfishing, industrial waste, plastic debris and climate change, which is altering their chemistry. Now comes a new extractive industry – and scientists say governments are not prepared.