SIGNIFICANCE OF SALINITY OF OCEAN

◇ The saline water freezes slowly in comparison to fresh water. It is known to all that pure water freezes at the temperature of 0°C freezing point. If the salinity of seawater becomes 35%o then it would freeze at the temperature of - 1.91°C. On the other hand, the boiling point of saline water (seawater) is higher than fresh water.

◇ Salinity and density of seawater are positively correlated i.e. the salinity of seawater increases its density because solutes (here salts) in water have greater atomic weight than the molecules of fresh water. This is why man is seldom drowned in the seawater with very high salinity.

◇ Evaporation is controlled by salinity of the oceans. In fact, solutes (salts) in water lowers the rate of evaporation in the oceans. Thus, more saline water is less evaporated than less saline water. It may be mentioned that evaporation also controls salinity of seawater. More evaporation reduces the volume of seawater and hence the concentration of salts increases (i.e seawater salinity increases).

◇ Spatial variation in seawater salinity becomes potent factor in the origin of ocean currents.

◇ The ocean salinity affects the marine organisms and plant community.