The amount of gold in seawater is incredibly small, and it is not economically feasible to extract it. According to estimates, the total amount of gold dissolved in the oceans is about 20 million tons. However, the average concentration is only about 0.0000005 parts per million, which is about 13 billionths of an ounce per ton of seawater. This means that to extract one ounce of gold, you would need to process about 20 million tons of seawater.
There have been several attempts throughout history to extract gold from seawater, but none have been successful on a large scale. One of the main challenges is the low concentration of gold in seawater. Additionally, the extraction process would require a large amount of energy, making it not cost-effective.
There are a few companies that claim to be able to extract gold from seawater, but their methods are not widely accepted in the scientific community and there is little evidence to support their claims.
In conclusion, while there is a small amount of gold in seawater, it is not currently economically feasible to extract it on a large scale. The amount of gold dissolved in the oceans is small and the extraction process is energy-intensive, making it not cost-effective.