When is ocean water most saline?

Ocean water is usually saltiest near the surface. High levels of evaporation at the surface cause a reduction in freshwater and thus create saltier water near the surface. This effect is most dominant in the warm tropical areas around the equator, thus these areas are saltier than in midlatitudes.

Since high salinity implies denser, and thus heavier, water, one might suspect that the saltiest water sinks to the bottom. However, temperature effects tend to dominate the vertical stratification.