Ladoga seal Ladoga seal The Ladoga ringed seal (; Pusa hispida ladogensis), is a freshwater subspecies of the ringed seal ("Pusa hispida") which are found entirely in Lake Ladoga in northwestern Russia. The subspecies evolved during the last ice age, about 11,000 years ago. As the glaciers retreated and water levels changed, the Baltic ringed seal (including Ladoga seals) was trapped in freshwater lakes and separated from the Arctic ringed seal. It is related to the even smaller population of Saimaa ringed seals in Lake Saimaa, a lake that flows into Ladoga through the Vuoksi River. The adult Ladoga seal grows to
Baltic Ice Lake small channel in the Strait of Øresund. The lake was higher than sea level (which itself was lower than the present-day sea level) by some tens of metres. Lake Ladoga was part of it. Emergence of the land then closed the channel through the Strait of Öresund. The lake rose until at about 11,200 BP it broke through a narrow corridor in the region of Mount Billingen in present-day south-west Sweden; this used to be described by Quaternary geologists as a massive, single tap of Niagara-like force but it is now considered more likely that it happened in several steps