Commercial deep-sea mining by China of polymetallic nodules that contain copper, nickel and cobalt among other key minerals, can begin as early as 2030, according to the former head of the State Oceanic Administration.

"With the improvement in deep-sea technology, metal resources under the ocean can be explored and mined within 20 years," said Sun Zhihui.

Last year, China was among the first group of countries approved by the International Seabed Authority to look for polymetallic sulphide deposits, a recently discovered mineral source, in the Southwest Indian Ridge, a tectonic plate boundary on the bed of the Indian Ocean, he said, adding the country is applying to explore for cobalt in a new area in the Pacific Ocean.