a zone in which salinity changes rapidly.
In oceanography, a halocline is a subtype of chemocline caused by a strong, vertical salinity gradient within a body of water. Because salinity (in concert with temperature) affects the density of seawater, it can play a role in its vertical stratification. Increasing salinity by one kg/m3 results in an increase of seawater density of around 0.7 k...
vertical zone in the oceanic water column in which salinity changes rapidly with depth, located below the well-mixed, uniformly saline surface water ... [1 related articles]
A vertical salinity gradient in some layer of a body of water, which is appreciably greater than the gradients above and below it; also a layer in which such a gradient occurs. The principal haloclines in the ocean are either seasonal, due to fresh water inputs, or permanent. 
a zone in which salinity changes rapidly.
halocline 1. A vertical gradient in the saltiness of the ocean. 2. A salinity discontinuity; a zone of marked salinity gradient.
Depth zone within which salinity changes maximally 
In the oceans, a well-defined vertical gradient of salinity. 
Visible boundary between layers of water of different salinities. Appears as a barrier of mist.