Explanation:

Baltic Sea, North Sea, Gulf of California, Red Sea

The salinity of the Baltic Sea east of 13°E ranges between 13 g/kg at the bottom in the central Baltic Sea and 2 g/kg at the surface in the Bothnian Bay . The Baltic Sea salinity is driven by freshwater supply due to river runoff and net precipitation and the exchange with saline water from the North Sea.

The salinity averages between 34 and 35 grams per litre (129 and 132 g/US gal) of water. The salinity has the highest variability where there is fresh water inflow, such as at the Rhine and Elbe estuaries, the Baltic Sea exit and along the coast of Norway.

The mean annual ranges of salinity of the Sea of Cortez are between 3.5 and 3.58% at the surface. Furthermore, the salinity of the water of the northern gulf is generally higher than the central and southern faunal regions due to the increased amount of evaporation that occurs in that region.

Areas of the Baltic Sea may have salinity values depressed to 10 psu or less. Increased salinity by evaporation is accentuated where isolation of the water occurs. This effect is found in the Red Sea, where the surface salinity rises to 41 psu.