I did some back of the envelope calculations, there is 1 gram in 100 million metric tons of seawater [0] and there is an estimated 1.3x10^18 metric tons of seaw

I did some back of the envelope calculations, there is 1 gram in 100 million metric tons of seawater [0] and there is an estimated 1.3x10^18 metric tons of seawater on earth [1] then the total amount of gold in ocean is about 13,500,000,000 grams of gold