Baltic Sea

The Baltic Sea is found in Northern Europe and forms part of the Atlantic Ocean.

The Baltic Sea is surrounded by Germany, Poland, Russia, Lithuania, Latvia, Estonia, Finland and Sweden, and Denmark.

It spans a total area of 377,000 square kilometers and includes the Bay of Bothnia, the Bay of Gdańsk, the Gulf of Bothnia, the Gulf of Finland, and the Gulf of Riga.

Baltic Sea Facts for Kids

  • The Baltic Sea’s water volume is about 21,700 cubic kilometers.
  • The average depth of the Baltic Sea is 55 meters, and the maximum extent reaches 459 meters below the sea’s surface.
  • The shore length of the Baltic is around 8,000 kilometers (that’s the length of 16,000 Olympic-sized swimming pools next to each other).
  • Since 1720, the Baltic has entirely frozen over 20 times. The most recent case was in 1987.
  • During the 18th Century, the Baltic was under the ruling power of Russia and Prussia.
  • Part of World War I was fought in the Baltic Sea.
  • Germany reclaimed the southern and most of the eastern shores of the Baltic during World War II when they occupied Poland and most of the Baltic states.
  • The Baltic Sea is mainly used for commercial fishing, which has been a long-standing tradition amongst the surrounding countries. Fish species that are caught from the Baltic Sea include cod, herring, and sprat. 85% of the total fish caught are herring and sprat.
  • The Baltic Sea also has amber deposits, mostly found in the southern shores at the borders of Russia, Poland, and Lithuania. Amber mining has been done here since the 12th century.
  • Additionally, the Baltic is a popular site for shipbuilding. There are numerous shipyards around the Baltic, the largest of which include: Gdańsk in Gdynia; Szczecin in Poland; Kiel in Germany; Saint Petersburg in Russia; Karlskrona and Malmö in Sweden; Helsinki in Finland; Liepāia in Latvia and Klaipėda in Lithuania.
  • The Baltic Sea has a salinity much lower than that of ocean water. This is a result of many freshwater streams running into it. This makes the Baltic a brackish inland sea. Brackish refers to water that has more salt than freshwater, but less than ocean water.
  • The Baltic receives salty water from the North Sea very infrequently- roughly once every ten years. The White Sea Canal is an artificial waterway that connects the Baltic Sea to the White Sea, while the Kiel Canal connects the Baltic to the North Sea at the German Bight.


There is a combination of both freshwater and marine species that call the Baltic Sea their home. Freshwater species include pike, roach, perch, and whitefish. Marine fish include herring, cod, hake, plaice, sculpin, shorthorn, stickleback, flounder, and turbot.

Harbor porpoises and Atlantic white-sided dolphins, both critically endangered species also live in the Baltic.

Other species that have been spotted in the Baltic include white-colored porpoises, minke whales, beluga whales, beaked whales, orcas, and bottlenose dolphins.

Economic Value

The Baltic Sea acts as the main trade route for exporting petroleum from Russia. Although, this does pose a significant concern about oil leaks by other nations.

The Baltic is also home to the Great Belt Bridge and the Øresund Bridge-Tunnel which link Sweden and Denmark, providing a railroad and highway between the two nations as well as an undersea tunnel allowing for large ships to navigate in and out of the Baltic easily. There are also many ferries for cargo and passengers across the sea making transport easy between countries.

1. What are the two main commercial activities in the Baltic Sea?
2. What type of water does the Baltic Sea have?
3. Which species in the Baltic are critically endangered?

1. Fishing and Amber-mining
2. Brackish water
3. Harbour porpoises and Atlantic white-sided dolphins