The White Sea, located on the northwest coast of Russia, is a semi-enclosed extension of the Arctic Ocean. It is one of four seas in the world named after a color. This body of water is almost entirely landlocked and falls completely under Russian sovereignty. Its environment distinguishes it from other arctic and subarctic marine areas.
Geographical and Physical Features
The White Sea is a southern inlet of the Barents Sea, bordered by the Kola Peninsula to the north, Karelia to the west, and the Kanin Peninsula to the northeast. The sea’s irregular shape is defined by four bays: Kandalaksha Gulf in the west, and Onega Bay, Dvina Bay, and Mezen Bay in the south and east.
With an average depth of only 60 meters, the White Sea is a relatively shallow body of water, though its deepest point in the Kandalaksha Gulf reaches 340 meters. The sea receives a substantial amount of freshwater from several large rivers, including the Northern Dvina, Mezen, and Onega. This riverine runoff, combined with low evaporation rates, results in surface water salinity levels of 24-26 parts per thousand, which is considerably lower than the adjacent Barents Sea.
The geography of the sea includes numerous islands, with the Solovetsky Archipelago being the most prominent. This group of six islands, formed of granite and gneiss, is situated at the entrance to Onega Bay. The islands feature a hilly landscape covered in pine and spruce forests.
Climate and Ice Conditions
The sea is named the “White Sea” because it is covered in ice and snow for more than half of the year. Its climate is a mix of polar and moderate continental, characterized by long, severe, and unpredictable winters.
The freezing process begins in October or November and the sea remains largely ice-covered until May or June. The average air temperature in February is around -15°C, but can fall to -40°C during cold snaps brought by Arctic anticyclones. The ice cover is mostly composed of floating ice, which is around 40 centimeters thick but can reach up to 1.5 meters in colder winters.
During the brief summer, surface water temperatures can warm to 15°C in the central part of the sea, while the northern sections remain cooler at 7–8°C due to water exchange with the colder, deeper layers. Below a depth of about 100 meters, the water temperature remains stable at approximately -1.4°C year-round. The summer air temperatures average between 8-12°C.
Unique Marine Ecosystem
The White Sea’s cold waters support a distinct marine ecosystem adapted to its harsh conditions. It is home to more than 700 species of invertebrates, around 60 species of fish, and several marine mammal species.
Beluga whales are one of the most notable marine mammals in the White Sea and are present year-round. Genetic data suggests that the White Sea beluga population is isolated from those in the Barents and Kara Seas. The sea also serves as a breeding ground for harp seals, which form large whelping colonies on the pack ice in the northern part of the sea each winter. Ringed seals are another common seal species found in the area.
The fish populations include commercially valuable species such as Atlantic herring, saffron cod, and Atlantic salmon. These fish, along with crustaceans and other organisms, form the basis of the food web that supports the larger marine mammals.
Economic and Historical Significance
The White Sea has long been an important center for Russian maritime activity. The port of Arkhangelsk, located on Dvina Bay, was established in 1584 and for centuries served as Russia’s primary hub for international trade. From the 15th to the early 18th centuries, it was the main trade route connecting Russia with the rest of Europe before the founding of St. Petersburg shifted trade routes to the Baltic Sea.
Today, the sea remains an important transportation corridor. The ports of Arkhangelsk, Belomorsk, and Kandalaksha facilitate the transport of goods like timber, oil, and minerals. Navigation is possible year-round with the use of icebreakers.
The White Sea–Baltic Canal, which opened in 1933, connects the White Sea with Lake Onega, which in turn links to the Baltic Sea via the Volga-Baltic Waterway. This 227-kilometer waterway shortens the shipping route between the Arctic and Baltic regions and primarily transports timber for local paper mills.