The features of the Baltic Sea make it unique
The Baltic Sea is the youngest in the world. It is surrounded by continents on almost every side and the connection to the sea is both narrow and shallow. Every year, the surface of the Baltic Sea is at least partially covered by ice. Compared to many other seas, the Baltic Sea is low in salinity and quite shallow. These features make it a globally unique marine area.
The water in the Baltic Sea is brackish with low salinity. The salinity is low because the Baltic Sea is only connected to the ocean by narrow straits, in addition to which a significant number of rivers discharge their waters into the sea. The low salinity has a significant impact on the Baltic Sea’s biota. Consequently, the Baltic Sea is home to a unique mix of marine and freshwater species.
As the Baltic Sea is shallow and geologically diverse, it offers a wide range of habitats for organisms: sheltered bays and coves, open rocky shores, continuously shifting sand bottoms and rocky reefs rising up to the water surface. Land uplift is constantly changing the shapes and depth ratios of the coasts. Land uplift has created unique habitats along the coasts of the northern Baltic Sea: lagoons about to lose their connection to the sea, or flads, which turn into gloe-lakes over time.
