About 10-15,000 metric tons of gold dissolved in the ocean if calculations roughly correct.

Despite recent advances in desalination and gold extraction from solution, it is still not worth it to mine the brine.

But it is always good to think logically, critically and do your own research.

" all the gold in the world is 171,300 tonnes" (human accumulated)

https://www.bbc.com/news/magazine-21969100

“1 gram of gold for every 100 million tonnes of sea water.”

https://www.atlasobscura.com/articles/gold-ocean-sea-hoax-science-water-boom-rush-treasure

hydrosphere is 1.4×1018 long tons

https://en.wikipedia.org/wiki/Ocean#:~:text=Further%20information%3A%20Seawater%20The%20total%20mass%20of%20the,almost%20all%20of%20which%20is%20in%20the%20ocean.

cheaper desalination possibly in conjunction with nuclear power plant cooling (think STNP)

https://phys.org/news/2020-06-unorthodox-desalination-method-global.html

recycling gold now easier

https://arstechnica.com/science/2020/06/new-polymer-easily-captures-gold-extracted-from-e-waste/