The only mammal that lives in Lake Baikal is nerpa or the Baikal seal. Till now it stays unknown how seals could appear in the lake, a very remote place, thousands kilometres from the ocean, traditional seal habitat. The main hypothesis is that seals went up along the Yenisey and the Angara rivers, reached the Baikal and settled there. Also there were fantastic versions considering possible the existence the underground channel between the Lena river and the lake, through which the migration could be done, but there is no scientific confirmation for it.

The ringed seal is a single fresh-water seal, attains a size lengthwise up to 1,5-1,7 metres and a weight of grown males up to 130-150 kg, the average weight is 50-60kg. It can dive on the depth of 200 metres, can be under water during 30min. and swim with a speed 20-25km/h. A life expectancy of the ringed seal is 50-56 years; it can give birth to a progeny in the age of 4-7 years. Seal cubs are born in February - April, in lairs on the ice of the Baikal. Small seals don’t look like their parents they have a white downy fur due to of which it became the object of a barbarous fur trade. While seal cubs live by maternal milk, they stay in their ice refuges and don’t dive in water. Unlike young animals the grown ringed seals pass their time fishing, a seal eats 3-5kg of fish daily, mainly Artic cisco and the Baikal oil fish. For making the life easy, some animals learnt to take out a fish from fishermen’s nets. To get out from the ice, a seal makes a hole which it cleans with the help of its powerful claws on front flippers, for getting a breath during the hunting. It is not necessary for a seal to crawl out from the ice it is enough just to stick out the snout to a small hole – airway which is also made by flippers. In summer the animal likes to bask on the offshore stones and place its shine sides under the sun. The Baikal seals are very careful when man’s brining near it dives quickly in water. But there is always a possibility to look after it, hiding behind a stone or settling down from the top of one cape. There are lots of the Baikal seals on the Ushkany Islands.There are lots of the Baikal seals near the Ushkany Islands, the eastern shore of Olkhon Island, and the Svyatoy Nos Peninsula. They are very rare to be met in the south of Lake Baikal.

Seals are being hunted because of their fur, meat, and fat that is considered by locals to be curative.

At present seal population of the Baikal is big enough and is not going to die out. However, seals, like the other representatives of the unique fauna of Lake Baikal, are to be treated carefully.