The mining of minerals from the deep ocean floor looks closer to becoming a reality after years of research as the first commercial exploration progresses, though the technology is far from proven.
Nautilus Minerals, a Canadian company, is the closest of several companies in the sector to go into production, and it expects to be producing gold and copper by 2009.
Following scientific studies, Nautilus has exploration licenses for high-grade copper, gold, zinc and silver deposits in the Pacific off Papua New Guinea. The final bureaucratic hurdle to obtaining mining licenses will be the Papua New Guinea government's approval of its environmental study, due to be submitted next year.
However, Nautilus - the first company to begin commercial sea bed exploration - faces extreme technical challenges. The deposits are more than a mile below sea level, and its remote-controlled submarines haven't been proved capable of mining the planned volumes.
"We are yet to understand how they (Nautilus) plan to commercially exploit resources on the sea floor and using new technology ... you can almost guarantee it's going to cost them more than they expect," said David Coates, analyst at brokerage firm Ambrian.
Nautilus' budget for exploration in 2007 is $20 million. The company has cash reserves of $270 million, which it expects to fund its activities to 2009.
The company began investigating deep sea mining in 1997, when production started to become feasible due to advances in deep sea oil and gas technology.
Mining giants including Anglo American PLC, Teck Cominco Ltd. and Barrick Gold Corp. have invested in Nautilus, owning stakes of 6.4 percent, 5.8 percent and 3.7 percent respectively.
Denver-based Newmont Mining Corp., the world's second-largest gold producer, has invested $4 million in a 10.8 percent stake in Neptune Minerals, a U.K. company that hopes to be trial mining in New Zealand's waters by 2010.
"Should they mature and develop, we are in a strong position to acquire a larger part of the venture," said Newmont spokesman Omar Jabara.
Blue Water Metals, an Australian company planning to list on the Toronto exchange later this year, also hopes to cash in on seabed mining in the Western Pacific.
The mineral deposits, known as sea floor massive sulfides, or SMS deposits, form when metal-rich water is discharged from sea floor vents. The metals precipitate as they enter the near-freezing water and form a mound or "chimney," which is full of minerals with little waste rock. The mounds form in clusters above deep fractures in the earth's crust.
Scientists have discovered approximately 150 sites in oceans around the world so far, said Professor Steve Scott from the Department of Geology at the University of Toronto.
"The best deposits appear to be in the Western Pacific ... although how big they might be, we don't know," said Scott, who with Dr. Ray Binns of Australia's Commonwealth Scientific and Industrial Research Organization, discovered Nautilus' flagship Solwara 1 site off Papua New Guinea.
Initially, companies are focusing on areas convenient to processing plants, with relatively calm waters and deposits at reasonable depths.
Companies have identified deposits offshore Papua New Guinea, Vanuatu, Japan and New Zealand. However, the countries haven't issued mining licenses yet.
The extraction technology comes from the offshore diamond mining, oil and gas, and dredging industries. Undersea diamond mining has taken place since the 1950s, but in shallower waters.
The rock containing the minerals is crushed before a remote-controlled submarine vacuums the minerals from the sea floor through a pipe to the surface.
The problem is that the soft and porous structure of the ore means that as the rock is crushed, the minerals are easily dispersed in the water.
Still, Nautilus predicts that one remotely operated submarine could mine 150,000 tons of copper and 350,000 ounces of gold per year. It hasn't yet been able to demonstrate this.
To ward off skepticism, the companies planning deep-sea mining point to the offshore oil and gas industry, which was unthinkable 50 years ago, but now provides around one-third of production.
Chris Yeats of Australia's CSIRO believes the public's attitude that oceans are sacrosanct will have to change. "None of the technology issues are insurmountable and the untapped resources on the sea floor are too economically attractive not to be mined," Yeats said.