The future of mining (or how Aquaman got the bling)

National Geographic:  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...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 USD 150 trillion."

Hmmm USD 150 trillion in gold sounds like a lot.  Assuming a current price of USD 1667 per troy oz. that would mean the underseas supply would be nearly 90 BB troy oz.  In 2011 the world production of Gold was 2,700,000 kgs or 86 MM troy oz.  So the underseas supply is equivalent to 1000+ years of current production...call me skeptical.  I wonder if we applied the concept of proven reserves (see below) to underseas minerals what sort of estimates we would get?  I assume there exists a substantial quantity of underseas minerals which could not be recovered at a any reasonable cost.

Definition of Proven Reserves from Wikipedia
"Proven reserves, also called proved reserves, measured reserves, 1P, and Reserves, are business or political terms regarding fossil fuel energy sources. (see prove: usage). They are defined as a "Quantity of energy sources estimated with reasonable certainty, from the analysis of geologic and engineering data, to be recoverable from well established or known reservoirs with the existing equipment and under the existing operating conditions."[1] These terms relate to common fossil fuel reserves such as oil reserves (see main article), natural gas reserves, or coal reserves.  Operating conditions includes operational break-even price, regulatory and contractual approvals, of which without these items cannot be classified as proven and are usually classified into probable. Price changes therefore can have a large impact on classification of proven reserves. Regulatory and contractual conditions may change, and also affect proven reserves amount."