One of the seven Underwater Wonders of the World, Lake Baikal is located in Southern Siberia in Russia. It is often called as the Blue Eye of Siberia and also the “Sacred Lake”. This lake is considered to be the oldest lake on earth. Also this is the deepest lake on earth and also the largest freshwater lake in the world by volume which holds around 20 percent of the total fresh water on the earth.
Lake Baikal is more biologically diverse than other lakes because of the circulation of the oxygen rich water from the surface to the depths of the lake. The aquatic life constitutes around 1500 animal species and 1000 plant species out of which two thirds are endemic and would not be found anywhere else.
In winters, a three feet thick layer of ice covers the entire lake. However underneath, the water is warmed up by the geological vent that is present at a depth of 1,350 feet, which facilitates the life of fish, sponges, snails, etc that live in the pitch dark environment at that depth. However in summers, the ice melts and the organisms come up again from the great depths and once again flourish in the water.