Sea salt is made by evaporating sea water, but this is not straight-forward.Between 100% and 50% first the calcium carbonate (Ca CO3= limestone) precipitates out, which is chalk and not desirable.So, saltwater fish drink water copiously while excreting excess salts through their gills.Freshwater fish do the opposite by not drinking but excreting copious amounts of urine while losing little of their body salts.
Shallow coastal areas are 2.6-3.0% saline and estuaries 0-3%.
one ends up with almost 0, suggesting that the above values are about right.
During the Challenger Expedition of the 1870s, it was discovered that the ratios between elements is nearly constant although salinity (the amount of H2O) may vary.
The Navy has been working on this project since 2005.
The new test of the gun broke the Navy’s previous 10-megajoule record for railgun firing set in 2008.
This world map shows how the salinity of the oceans changes slightly from around 32ppt (3.2%) to 40ppt (4.0%).