What are the factors that affect the salinity of seawater?

The factors that affect the salinity of seawater are mentioned below: 

• The salinity of water in the surface layer of oceans depend mainly on evaporation and precipitation. 
• Surface salinity is greatly influenced in coastal regions by the freshwater flow from rivers, and in polar regions by the processes of freezing and thawing of ice. 
• Wind also influences the salinity of an area by transferring water to other areas. 
• The ocean currents contribute to the salinity variations. Salinity, temperature and density of water are interrelated. Hence, any change in the temperature or density influences the salinity of water in an area.

Further Reading:

• Horizontal And Vertical Distribution Of Salinity
• Salinity Of Ocean Water