World's deepest lake crippled by putrid algae, poaching and pollution

Lake Baikal in Siberia holds one fifth of the world's unfrozen fresh water, but its precious fish stocks are disappearing

Lake Baikal is undergoing its gravest crisis in recent history, experts say, as the government bans the catching of a signature fish that has lived in the world's deepest lake for centuries but is now under threat.

Holding one-fifth of the world's unfrozen fresh water, Baikal in Russia's Siberia is a natural wonder of "exceptional value to evolutionary science" meriting its listing as a world heritage site by Unesco.