The variations of salinity in different seas and oceans is affected by : The rate of evaporation. The amount of fresh water added by precipitation in the streams and icebergs. Mixing of the ocean waters. read more
An ocean's salinity is affected by water and air temperature, the volume of water that flows into it, its age and the chemical composition of surrounding geological formations. Because the effect of these factors varies over the area of an ocean, different levels are found within the ocean. read more
The influx of fresh water by river is another important factor which brings down the degree of salinity in ocean water. Rivers such as, the Congo, Niger, St. Lawrence, Ob and Amazon etc. carry a large supply of fresh water to the oceans in which they fall. read more
Factors affecting ocean salinity are: 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 fresh water flow from rivers, and in polar regions by the processes of freezing and thawing of ice. read more