Gold in Seawater

Seawater does contain gold, but at an extremely low concentration—on the order of parts per trillion. NOAA cites an estimate of about 1 g of gold per 100 million metric tons of water in the Atlantic and North Pacific, or roughly 0.01 ng/L. That is a million times lower than 0.01 mg/L. There is currently no cost-effective way to extract dissolved gold from the ocean.