[patrick_g]

Gyro, Thanks for the offer, I'll PM you. Thanks for the explanation, it was interesting.

Another interesting, but newer, industry working renewable resources out of San Diego is Kelco. I have often watched their "mowing machine" cruising along the kelp beds along the west side of Point Loma. I was actually on board the kelp cutter vessel along side at their pier. It was interesting but not something I'd like to repeat due to the smell. There is collateral harvest of crabs which were living in the kelp. The seagulls flock to the boat to get the crabs and the whole assemblage stinks to high heaven.

Oh well, the algin produced by Kelco ends up in toothpaste, wiener skins, ice cream and oodles of other things I use/eat.

You mention that there are lots of different constituents in sea water but you didn't mention GOLD.

Seawater is variously measured as having gold in it ranging from 5 to 50 ppt (Parts Per Trillion)(Lucas 1985), with the average concentration at about 13 ppt. The gold is in a very dilute solution but is in the tons per cubic mile.

There is about 13.9 trillion pounds of seawater in a cubic nautical mile so roughly 1807 lbs of gold. I think I recall reading as a child in an encyclopedia that there was a ton of gold per cubic mile (statute) so that is rough agreement with the later data. The problem is how can you economically extract it.

Pat