The Saimaa ringed seal (Pusa hispida saimensis, Finnish: Saimaannorppa) is a subspecies of ringed seal (Pusa hispida). They are among the most endangered seals in the world, having a total population of only about 400 individuals. The only existing population of these seals is found in Lake Saimaa, Finland (hence the name). They have lived in complete isolation from other ringed seal species for around 9,500 years and have diverged into a morphologically and ecologically different subspecies of ringed seal. The population is descended from ringed seals that were separated from the rest when the land rose after the last ice age. This seal, along with the Ladoga seal and the Baikal seal, is one of the few living freshwater seals.