The sea which is rich in salt and when when winter season begins the water converts into salt crystals in which living organisms become dead or can not live any more. That is the reason this sea are known as dead "DEAD SEA".

The sea is called "dead" because its high salinity prevents macroscopic aquatic organisms, such as fish and aquatic plants, from living in it, though minuscule quantities of bacteria and microbial fungi are present. In times of flood, the salt content of the Dead Sea can drop from its usual 35% to 30% or lower.

                                                   SOURCE: GOOGLE