Hello snesprogrammer and thank you for your question.
When I saw your question I thought the answer would be that sea water
contains only insignificant ammounts of precious metals, but no, there
is rather alot! (Although economocally, it might me expensive
extracting it) The average concentration of gold in the worlds oceans
is about 13 ppt, and spread geographically all over the oceans. See
below for further information.
Unfortunatley the following website is only available in the Google
cache, nevertheless, all the information is available on the first
"Seawater contains vast quantities of dissolved gold, perhaps as much
as 10 trillion dollars (US) worth, though in dilute concentrations.
Recent evidence suggests that much of the earths continental gold
deposits have biological origins. Certain bacteria are believed to
have been involved in the precipitation of gold out of dilute
hydrothermal solutions. A possible avenue for commercially viable gold
recovery from seawater might involve such a bacterium, or a
specifically engineered microbe."
"When considering only the data gathered since 1980, reported values
for the concentration of gold in seawater have ranged from 5 to 50 ppt
(Lucas 1985), with the average concentration at about 13 ppt. Some of
the highest concentrations recently reported have come from seawater
samples taken from the Bering Sea at 50 ppt"
"Lovley isn't encouraging. Although dissolved gold is found in all
water, even seawater, the use of these microbes to harvest gold does
not make economic sense, he said. "You couldn't use this process to
harvest the gold from the ocean. The cost in pumping the water would
be more than how much gold you could recover," he said. The gold
particles excreted by the microbes are so tiny it would take about a
million microbes to produce a gram of solid gold.
Nonetheless, the gold industry thinks the research is worth watching,
said Paul Bateman, executive director of The Gold Institute in
"The recent discovery of fabulous deposits of gold, silver, and other
precious metals in volcanic vents off the coast of Japan will
undoubtedly spark similar searches in other areas of the world's
Not currently available but worth keeping an eye on:
"Gold, Silver, and Uranium from Seas and Oceans: The Emerging Technology"
Thank you for your question, and if you need any clarification of my
answer, do not hesitate to ask.
Now where did I leave my extremophiles?
Very best regards
(To read more articles, click on my search strategy below)
Search strategy included:
"Gold, from the Seas OR sea OR Oceans OR ocean"
Request for Answer Clarification by
07 May 2004 15:17 PDT
Wow, the fluctuation in concentration is much larger than I would expect!
Being near Alaska is 10 x's greater than other areas... amazing.
Anyway, I was curious why you only checked on gold. It's not even the
most expensive of the precious metals. Can you check on platinum and
silver as well?
And as for the variation due to depth ... there just really isn't any?
A gold atom is pretty heavy compared to a water molecule, so I'd
expect there to be some. Hmm... but then again I think only the ions
are soluble, and water, being polar, should form "shells" of molecules
around ions ... since this would roughly move together, maybe it is
necessary to consider the weight of the whole average "gold-water
structure". If many molecules are involved, the difference in density
compared to salt water may be negligible. So after thinking that out,
I'm not really sure what to expect for variation due to depth.
Clarification of Answer by
10 May 2004 07:40 PDT
Hello again snesprogrammer,
The reason I focused on gold is because it seems that this is the
metal that has atracted most attention in terms of potential
extraction, but, before we get on to the subject of other metals (ie.
other than gold) I found this interesting statistic:
"ocean's gold content, estimated at $10,000,000 to $25,-000,000 per cubic mile."
Now some links to other sites discussing metals in seawater:
"Figure 10.2: Depth Profiles of Background Concentrations of Various
Metals in the Atlantic Ocean"
"Detailed composition of seawater at 3.5 salinity"
"Of the world's supply of magnesium, 60% comes from the sea, and so
does 70% of the bromine. There are vast amounts of dissolved minerals
in the world's seawater, including 10 million tons of gold and 4
billion tons of uranium, but the concentration is very low (one part
per billion or less). In the case of gold, no method has been devised
in which the cost of extraction does not exceed the value of the
recovered element. Japan, West Germany, and the United States have
expressed an interest in the extraction of uranium. Japan set up a
land-based test plant in 1986 to produce 10 kg (26 lb) of uranium from
seawater per year, but the operation has proved to be expensive, and
the Japanese are looking at methods to use wave energy to run the
system. (Some possible ways to harness wave energy are discussed in
I hope that additional information was useful to you.
Very best regards