Many marine organisms can survive only within a particular salinity range, which makes salinity a notable factor in determining the types of potentially commercial organisms found in the gulf. The mean annual ranges of salinity of the Sea of Cortez are between 3.5 and 3.58% at the surface. Furthermore, the salinity of the water of the northern gulf is generally higher than the central and southern faunal regions due to the increased amount of evaporation that occurs in that region.
