Franz Josef Land and snow bunting. Some ivory gulls, little auks and Brünnich's guillemots opt to spend the winter on the islands. The polar bear population of Franz Josef Land lies within the Barents Sea subpopulation, which also includes polar bears inhabiting Svalbard and the western coast of Novaya Zemlya. In 2004, the Barents Sea subpopulation was estimated at 2,650. There is also a population of Arctic fox, which typically have their territories near seabird habitats. Being declared as a marine mammal sanctuary, the island has rich biodiversity of rare marine mammals. Three species of seals habit the archipelago. Harp seal is the
Novaya Zemlya numbering 298, was removed to the mainland in 1957 before nuclear testing began. In 1943, during World War II, Novaya Zemlya briefly served as a secret seaplane base for Nazi Germany's "Kriegsmarine", to provide German surveillance of Allied shipping en route to Siberia. The seaplane base was established by U-255 and U-711, which were operating along the Northern coast of Soviet Russia as part of "13th U-boat Flotilla". Seaplane sorties were flown in August and September 1943. In the months following Hitler’s June 1941 invasion of the Soviet Union, the United States and Great Britain organized convoys of merchant ships