Friday 26 July 2013

Bigging up Baikal

We live in a rural community along way from a bus-stop in SE Ireland.  Our house is 300m from the County Road up a dirt track with a 1:10 slope. When we bought the property, we couldn't afford the whole farm and the top 10 hectares were bought by a local farmer.  He spent as much on the hire of diggers and dumper-trucks as he had actually buying the land.  The machinery was employed to make farming the land an economically viable proposition by grubbing up all the boundaries of a rattle of small, gorse covered, rocky fields and converting the whole 10 ha into 3 large green pastures for raising sheep.  The year after we moved in, the civil engineering works above us had finished; I'd put in a neighbourly day as part of a meitheal picking stones out of the incipient grassy field; a few tonnes of lime had been spread to sweeten the acid soil and a lot of pelleted fertiliser had been bought and spread to boost productivity.

A week later, there was the most tremendous Summer downpour, we had half-a-month's rain in a matter of hours and our lane was turned briefly into a raging torrent.  We have a picture somewhere of our two little girls standing in the lane with the flood not quite topping their gumboots. The lane finished up in a heap on the County Road.  My neighbour was rueful at the loss of all the bought stuff he'd put on the field and we resolved to sort out the drainage.  I told him that the capacity of reservoirs is measured in acre-feet and pointed out to him that 3cm of rain falling on a 3 ha field was 900 tons of water that, under the prevailing drainage arrangements, had nowhere to go but to rip the heart out of the lane that we shared.  It was a lesson for us all.

Lake Baikal is HUGE.  To us with euro-centric atlases, if it is shown at all, it looks like a small slash in the middle of Asia just north of Mongolia.  If it's a 19th century atlas, it will show as the reason for a jink in the Trans-Siberian Railway near Irkutsk.  But it contains so much water that if it leaked it would cover the whole 17m of Russia to the depth of one meter.  That's an enormous number of acre-feet.  It is the largest reservoir of unfrozen fresh water in the world, perhaps 20% of the accessible supply in the world.  Strangely enough, it has aboit a third surface area as Lake Superior, but that is a mere puddle compared to Baikal which is on average 700m deep.  Below the bottom of the water is 7000m of sediment, so Lake Baikal has been around for a long time.

So long indeed, that its unique ecological position has had time to generate nearly a 1000 "endemic" plant species growing in and around the Lake.  To put this is context, Ireland has a surface area nearly 4 times bigger than Lake Baikal but has only two endemic plant species: Fringed Rockcress Arabis brownii and Hart’s Saxifrage Saxifraga hartii, both of which are probably best considered sub-species of more widely distributed European species.  
There are also perhaps 1000 species of animal that are found nowhere else but the Lake, the most charismatic being the Lake Baikal Seal Pusa sibirica. How did it get there?  It's such a long way from the sea. But the health of the Lake depends much more on a far humbler creature, the copepod Epischura baikalensis which was only discovered/described 25 years ago but makes up at least 80% of the biomass in the water column making it the key element in the food-chain.

If our lane, indeed our whole farm got washed to oblivion by an even bigger flood, it wouldn't matter a damn to anyone but ourselves.  If Ireland was, like Atlantis or Lyonesse,  to sink beneath the waves tomorrow if would be bad for us (especially if we didn't have a boat at the bottom of the garden) but the planet would shrug and get on without a pause.  If Lake Baikal gets messed over it will be a serious loss for us all and for the planet. So we'd better start paying attention to what's happening there - both naturally and by human intervention. I've urged the Irish rather facetiously to know more about Ukraine and Belarus, but this call about Baikal is much more important. The Aral Sea, about 2000km further West, used to have a surface area of 68,000 - between 2 and 3 times broader than Lake Baikal, it has since shrunk to 17,000 of saline and polluted sludge.  That happened in the blink of a geological eye through 50 years of cunning economic and social-engineering plans by the Soviet government.

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