Why is the water near the Volga River outlet less salty than other parts of the Caspian Sea?

The water near the Volga River outlet is significantly less salty than the rest of the Caspian Sea because of the massive volume of freshwater the river discharges into the northern part of the sea.12

While the average salinity of the Caspian Sea is approximately 12.8 parts per thousand, the influx from the Volga—which, along with other major rivers, accounts for the vast majority of all river water entering the sea—dilutes the concentration of salts near its delta to as low as 1 part per thousand. In contrast, other areas of the sea, such as the Kara-Bogaz-Gol, experience extremely high salinity levels due to intense evaporation.123