Very interesting. I think the Baltic is just the opposite...less salty than the Atlantic, because of less evaporation; more fresh water input. The Baltic is usually warm, if not buoyant.
With your comment Dennis, I googled an answer which described the geologic history
and likely future of the Mediterranean Sea.
....Even today, the Mediterranean is considerably saltier than the North Atlantic due to its near isolation by the Strait of Gibraltar and its high rate of evaporation....