The Baltic Sea is completely unique when compared to all the other seas found on planet Earth.

It is an inland sea, meaning that it is only connected to the oceans via a narrow waterway. Other European inland seas include the Mediterranean and the Black Sea. 

The Baltic Sea is uniquely shallow, which is why it contains a relatively small amount of water when compared to other seas. In addition, the bottom of the Baltic Sea does not contain layers of salt found in many other seas and oceans, which is why the Baltic has a very low salt concentration.

The Baltic Sea contains a large number of islands, especially in the archipelagos of Stockholm, Åland and Turku. The Gulf of Bothnia and the Gulf of Finland freeze over during the winter. In addition, the plants and animals of the Baltic Sea are vastly different from those found in other marine regions.

Areas of the Baltic Sea  The state of the Baltic Sea