The move has transformed the energy business. About one-third of the world's oil and gas now comes from beneath the seabed, although some accidents and spills have caused extensive damage to the environment and been costly to clean up.
Despite the risks and technical challenges, the mining industry is about to do what oil and gas drillers have done. Buoyed by recent high prices of precious and base metals, leading mining and mineral-using economies are on the verge of opening a new frontier of deep-sea metals recovery.
Those involved in the hunt include companies from Canada, Australia, the United States, Japan, China, India and South Korea. One of their main targets is the Asia-Pacific rim where volcanic activity and tectonic plate movements create vast mineral and gas deposits on or just below the seabed.
Japan has calculated that in its waters alone, total recoverable metal and energy resources in sea floor deposits amount to at least ¥300 trillion.
Multi-metalic sulphide concentrations of gold, silver, copper and zinc in Japan's claimed exclusive economic zone, out as far as 200 nautical miles from the coast, were estimated to be worth ¥80 trillion in late 2008, when most commodity prices were depressed by the financial crisis.
Cobalt-rich crusts containing titanium, manganese, nickel and platinum as well as cobalt are valued at ¥100 trillion, while reserves of methanehydrate, icelike gas formations trapped in sediment on the seabed, are put at ¥120 trillion.
State-owned China Minmetals, the country's largest metals trader, is intensifying research and development into deep-sea mining. Noting that China relied heavily on costly raw-material imports, Minmetals president, Zhou Zhongshu, said in March that "this will push the country to go for deep-sea mining to explore (for) metals including copper, nickel, silver and gold."
No one has yet attempted full-scale commercial mining to exploit the trove of seabed mineral riches. But earlier this year, the Papua New Guinea government granted the world's first deep-sea mining lease to NautilusMinerals Inc, a Canadian-based firm backed by several multinational and Russian mining groups.
Nautilus is assembling a combination of proven technologies from different industries, among them mining, oil and gas, and dredging, to create what it says will be a cost-efficient system for deep-sea mining.
In 2013, it plans to start mining a high-grade copper-gold resource about 1,600 meters below the surface of the Bismarck Sea in Papua New Guinea waters.
The company says it will use remotely operated undersea vehicles and machines to cut ore from the sea floor and pump it up to a production support vessel on the surface as seawater slurry. The water will then be removed and the ore shipped to shore for smelting into ingots.
After investing about $400 million, Nautilus aims to produce ore at an annual rate of more than 1.3 million tons, containing approximately 80,000 tons of copper and up to 200,000 ounces of gold for a number of years before shifting its moveable production system to other nearby deposits it has found.
Multi-metallic sulphides are found around seabed hot springs emerging from volcanic vents. Seawater percolates down through the crust and reacts chemically with the rocks at very high temperatures, collecting metals as it does so.
When the hot vent water rises and mixes with the cold seawater on the ocean floor, the metals precipitate out to form concentrated deposits.
Exploiting these deposits in national waters is already controversial. After returning from a recent visit to Papua New Guinea, Australia's Greens party leader, Sen. Bob Brown, said he would seek a Senate inquire into the environmental impact of undersea mining.
Other critics say that the Asia-Pacific rim is being made a test bed for a potentially damaging new form of mining as technology races ahead of regulation.
Another Canadian-based company, DeepGreen Resources Inc., is seeking financial backing to mine a massive copper-nickel deposit in international waters in the Pacific Ocean between Hawaii and Mexico. The deposit lies 4,500 meters below the surface of the sea.
Meanwhile, China and India have filed applications with the United Nations International Seabed Authority (ISA) for high seas mining rights of the Indian Ocean. The ISA has regulatory authority over seabed mineral resources in international waters. Its mandate is to ensure that these resources are exploited in a way that is fair to all countries.
However, it has yet to spell out whether and to what extent conservation is part of the common heritage of mankind.
**Michael Richardson is a visiting senior research fellow at the Institute of Southeast Asian Studies in Singapore.
