Lake Baikal Holds 20% Fresh Water

The sheer volume of water in Siberia's Lake Baikal is difficult to comprehend, holding more fresh water than all of North America's Great Lakes combined. This immense reservoir exists because Baikal is not only the world's oldest lake, at an estimated 25-30 million years old, but also its deepest. It occupies a continental rift valley that is still actively widening, creating a chasm over a mile deep. This ongoing geological process is the secret to its incredible capacity, allowing it to collect snowmelt and river water over millennia in a basin of unparalleled size.

This ancient and isolated environment has also become a "Galapagos of Russia," a living laboratory for evolution. Over 80% of its thousands of animal species are found nowhere else on the planet. The most famous of these endemic creatures is the nerpa, the world's only exclusively freshwater seal, whose ancestors are believed to have traveled from the Arctic Ocean long ago. The lake's legendary clarity is maintained by another unique inhabitant: vast populations of tiny crustaceans that filter the water (Review), contributing to a one-of-a-kind ecosystem that is both massive in scale and delicate in its biological balance.