Fresh or smoked fish for breakfast?
After three days on the train our first chance for a serious change of diet.
Suddenly the view opens up and there on our right lies Lake Baikal. Today its waters are a deep steely grey and ice fringes the shore-line. To our left are the granite (basalt?) cliffs that had to be dynamited back in 1901 to cut a way through for the railway.
The lake conceals a massive rift created as one tectonic plate drifts north-west and the one we are on drifts south-east. We don’t notice this movement as its only 6mm / year, but over twenty to twenty five million years this drift has created the largest fresh water lake on our planet.
Lake Baikal holds 20% of the worlds freshwater, as much as all five of America’s Great Lakes combined. It is also the planet’s deepest lake at 1635 meters and sediments going down several more kilometers. Lake Baikal has the richest biodiversity of any freshwater lake with over 1,000 endemic species of animals and plants packed into its 640 km by 30-60 km size.
And Lake Baikal has the worlds only freshwater seal. These seals might have evolved from arctic ringed seals left behind when the arctic ocean receded some millions of years ago, but nobody knows for sure.
We’re off to visit a research centre to find out more about the exotic life found here, but before that we’re going to eat some of it! The omul’ (Coregonus autimnalis) is a local smoked fish delicacy, and if you are lucky you can also eat it fresh. It thrives in the cold, clear, generally clean conditions found in Lake Baikal, so clean apparently that a friend, Iana, who was brought up in Irkutsk drank water straight from the lake when her family camped on its shores.
We hope to buy some fish when we stop at the next station, Mysovaya, the first on the shores of Baikal.
On a more serious note, Lake Baikal is responding strongly to climate change, according to recent analyses of water temperature and ice cover.* The climate of the Baikal region is becoming warmer and wetter, particularly in winter. As the climate changes, ice cover and transparency, water temperature, wind dynamics and mixing, and nutrient levels will change.
The ice-cover is vital to the seals because they give birth on the ice while microscopic crevices in the winter ice act as home to diatoms that are the base of the lakes ecosystem, so changes in ice cover will alter the food-web, perhaps catastrophically. We’ll hear first hand about this when we visit the research centre.
* Climate Change and the World’s “Sacred Sea”—Lake Baikal, Siberia
MARIANNE V. MOORE, STEPHANIE E. HAMPTON, LYUBOV R. IZMEST’EVA, EUGENE A. SILOW, EKATERINA V. PESHKOVA, AND BORIS K. PAVLOV
www.biosciencemag.org May 2009 / Vol. 59 No. 5