Will Deep-sea Mining Yield an Underwater Gold Rush?

A mile beneath the ocean's waves waits a buried cache beyond any treasure hunter's wildest dreams: gold, copper, zinc, and other valuable minerals.

Scientists have known about the bounty for decades, but only recently has rising demand for such commodities sparked interest in actually surfacing it. The treasure doesn't lie in the holds of sunken ships, but in natural mineral deposits that a handful of companies are poised to begin mining sometime in the next one to five years.

The deposits aren't too hard to find—they're in seams spread along the seafloor, where natural hydrothermal vents eject rich concentrations of metals and minerals.

These underwater geysers spit out fluids with temperatures exceeding 600ºC. And when those fluids hit the icy seawater, minerals precipitate out, falling to the ocean floor.

The deposits can yield as much as ten times the desirable minerals as a seam that's mined on land.

While different vent systems contain varying concentrations of precious minerals, the deep sea contains enough mineable gold that there's nine pounds (four kilograms) of it for every person on Earth, according to the National Oceanic and Atmospheric Administration's (NOAA) National Ocean Service.

At today's gold prices, that's a volume worth more than $150 trillion.

Can an Industry Be Born?

But a fledgling deep-sea mining industry faces a host of challenges before it can claim the precious minerals, from the need for new mining technology and serious capital to the concerns of conservationists, fishers, and coastal residents.

The roadblocks are coming into view in the coastal waters of Papua New Guinea, where the seafloor contains copper, zinc, and gold deposits worth hundreds of millions of dollars and where one company, Nautilus Minerals, hopes to launch the world's first deep-sea mining operation.

more here: http://news.nationalgeographic.com/news/2013/13/130201-underwater-mining-gold-precious-metals-oceans-environment/