The sea's irregular shape is formed by the large Kandalaksha, Onega, Dvina, and M.... sea speci

The sea's irregular shape is formed by the large Kandalaksha, Onega, Dvina, and Mezen gulfs. The largest islands in the sea are Solovetskiye, at the entrance to Onega Bay; Morzhovy, at the entrance to the Gorlo Strait; and Mudyuga, at the entrance to Dvina Bay. The White Sea is situated on a continental shelf whose present form appears as a land's-end depression on the slope of the ancient structural block known as the Baltic Shield. The sea's chief hollow is separated from the Barents Sea by a sill 130 feet deep, which restricts deepwater exchange between the two bodies of water. The White Sea contains more than 700 species of multicellular invertebrates, about 60 species of fish, and 5 species of marine mammals. The principal ports along the White Sea are Arkhangelsk, Belomorsk, Onega, Mezen, Kem, Kandalaksha, and Umba. sea speci