Østersøen

Østersøen is the Danish name for the Baltic Sea. It is a marginal sea of the Atlantic Ocean in Northern Europe, enclosed by the Scandinavian Peninsula, the mainland European continent, and the Danish islands. The Baltic Sea is connected to the Atlantic via the Danish Straits, which include the Øresund, the Great Belt, and the Little Belt. These straits are relatively shallow and narrow, influencing the water exchange between the Baltic and the Atlantic.

The Baltic Sea is characterized by its brackish water, meaning it has a lower salinity than typical ocean water. This is due to a combination of significant freshwater inflow from numerous rivers and limited exchange with the saltier North Sea. Its salinity varies, being lowest in the north and east and higher in the west, closer to the Danish Straits. The sea is also subject to seasonal ice cover, particularly in its northern parts during winter.

Several countries border the Baltic Sea, including Denmark, Sweden, Finland, Russia, Estonia, Latvia, Lithuania, Poland, and Germany. The region has a rich history of trade and cultural exchange, with numerous ports and coastal cities playing important roles. Environmental concerns, such as eutrophication and pollution, have been significant issues for the Baltic Sea for decades, leading to international cooperation efforts aimed at its protection and restoration.