The upper layer has a salinity between 18‰ and 26‰ and the lower layer – separated by a strong halocline at around 15 meters – has a salinity between 32‰ and 34‰. The lower layer consists of inflowing seawater from the Skagerrak, with a salinity on level with most other coastal seawaters, while the upper layer consists of inflowing seawater from the Baltic Sea and has a much lower salinity, comparable to brackish water, but still a great deal higher than the rest of the Baltic sea.