World's deepest Lake Baikal dying mysteriously

Over the past several years, a major international tourist attraction, has been crippled by a series of detrimental phenomena, some of which remain a mystery to scientists.

Representational image

Moscow: Lake Baikal, the world's deepest lake is undergoing its gravest crisis in recent history, as the government has banned the catching of a signature fish that has lived in the lake for centuries.

Over the past several years, the lake, a major international tourist attraction, has been crippled by a series of detrimental phenomena, some of which remain a mystery to scientists.

They include the disappearance of the omul fish, rapid growth of putrid algae and the death of endemic species of sponges across its vast 3.2 million-hectare (7.9 million-acre) area.

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.

Baikal's high biodiversity includes over 3,600 plant and animal species, most of which are endemic to the lake.

Starting in October, the government introduced a ban on all commercial fishing of omul, a species of the salmon family only found in Baikal, fearing "irreversible consequences for its population", the Russian fisheries agency told AFP.

"The total biomass of omul in Baikal has more than halved since 15 years ago" from 25 million tonnes to just 10 million, the agency said.

Local fishery biologist Anatoly Mamontov said the decrease is likely caused by uncontrollable fish poaching, with extra pressure coming from the climate.

"Baikal water stock is tied to climate," he said. "Now there is a drought, rivers grow shallow, there are less nutrients. Baikal's surface heats up and omul does not like warm water."