The Red Sea is one of the most saline bodies of water in the world, owing to high evaporation. Salinity ranges from between ~36 ‰ in the southern part because of the effect of the Gulf of Aden water and reaches 41 ‰ in the northern part, owing mainly to the Gulf of Suez water and the high evaporation. The average salinity is 40 ‰. (Average salinity for the world’s seawater is ~35 ‰ on the Practical Salinity Scale, or PPS; that translates to 3.5% actual dissolved salts.)
The salinity of the Red Sea is greater than the world average, approximately 4 percent. This is due to several factors:
- High rate of evaporation and very little precipitation.
- Lack of significant rivers or streams draining into the sea.
- Limited connection with the Indian Ocean, which has lower water salinity.