Subspecies
The populations living in different areas have evolved to separate subspecies, which are currently recognized as :
- Pusa hispida hispida: Arctic coasts of Europe, Russia, Canada and Alaska, including Novaya Zemlya, Spitsbergen, Greenland and Baffin Island.
- Pusa hispida ochotensis: Kamchatka, Okhotsk Sea and southward to 35°N, along the Japanese Pacific coast.
- Pusa hispida botnica (validity questionable): The Baltic Sea, especially in the Bothnian Bay where there is a large population, but there are also endangered populations in the Gulf of Finland, the Gulf of Riga and the Archipelago Sea.
- Pusa hispida ladogensis (Ladoga seal) Lake Ladoga
- Pusa hispida saimensis (Saimaa ringed seal). Lives only in Lake Saimaa in Finland and is one of the most threatened seals in the world with total population around 300 individuals.
The three last subspecies are isolated from the others, like the closely related Baikal seal and Caspian seal.
Read more about this topic: Ringed Seal