Lake Baikal is the deepest, and among the clearest of all lakes in the world. At more than 25 million years old, Baikal is also the world's oldest lake. Like Lake Tanganyika, Lake Baikal was formed as an ancient rift valley, having the typical long crescent shape with a surface area of 31,722 km 2, less than that of Lake Superior or Lake Victoria. Baikal is home to more than 1700 species of plants and animals, two thirds of which can be found nowhere else in the world and was declared a UNESCO World Heritage Site in It is also home to Buryat tribes who reside on the eastern side of Lake Baikal, rearing goats, camels, cattle and sheep, where the regional temperature varies from a minimum of 19 °C in winter to maximum of 14 °C in summer. Lake Baikal contains roughly 20% of the world's surface fresh water that is unfrozen and is located in the south of the Russian region of Siberia.
The lake is completely surrounded by mountains. The Baikal Mountains on the north shore and the taiga are technically protected as a national park. It contains 27 islands; the largest, Olkhon, is 72 km long and is the third-largest lake-bound island in the world. The lake is fed by as many as three hundred and thirty inflowing rivers. The main ones draining directly into Baikal are the Selenga River, the Barguzin River, the Upper Angara River, the Turka River, the Sarma River and the Snezhnaya River. It is drained through a single outlet, the Angara River.
Wildlife and vegetation Few other lakes can equal the extent of biodiversity present in Lake Baikal. Lake Baikal hosts 1085 species of plants and 1550 species and varieties of animals. More than 80% of the animals are endemic. Epischura baikalensis is endemic to Lake Baikal and the dominating zooplankton species there, making up 80 to 90 percent of total biomass. The Baikal Seal or nerpa found throughout Lake Baikal. It is one of only three entirely freshwater seal populations in the world, the other two being subspecies of Ringed Seal. Perhaps the most important local species is the omul, a smallish endemic salmonid. It is caught, smoked and then sold widely in markets around the lake.
Of particular note are the two species of golomyanka or Baikal oil fish. These long-finned, translucent fish normally live in depths of 200– 500 m and are the primary prey of the Baikal seal, representing the largest fish biomass in the lake. The Baikal grayling, a fast swimming salmonid, popular among anglers and the Baikal sturgeon, are both important endemic species with commercial value. The lake also hosts rich endemic fauna of invertebrates. Among them turbellarian worms, snails and amphipod crustaceans are particularly diverse.