On the 5th of February, Russian researchers announced they had finally managed to make contact with Lake Vostok’s body of water. It’s no exaggeration for me to say I’ve been waiting half my lifetime for this. Ever since finding out about Vostok in 2000, I’ve been fascinated by the challenges and mystery associated with what is effectively another planet on the surface of ours. Lake Vostok is a fresh water lake 4km beneath the Antarctic surface. It’s believed to have formed through a mixture of glacial ice melting caused by the earths warmth and the extreme pressure from the weight of ice above. The most startling thing about the lake, however, it’s magnitude – it’s about the same size as Wales.
For the last 14 million years, the world has been evolving with (largely) the same selective pressures, and, most importantly, with the potential for biological exchange between different habitats. Obviously, this exchange is often dependent on geography – hence why Australia has some strange animals not seen elsewhere, but even in Australia you have things like wind, rain, sun, seasons etc. The “general” macro-environmental selective pressures are the same. In the oceans you don’t have this geographical separation – a fish can swim from the Pacific to the Atlantic, and can swim from the sea bed to the surface. Whether or not the modern day versions of the species we see actually make this kind of migration is another (somewhat irrelevant) question, but the fact it’s possible has a lot of implications for how those water-dwelling creatures have evolved. Lakes are a little different, but typically big lakes are connected to other lakes and the oceans by rivers. They are still part of this “surface” habitat, which has sun, changing water levels, the impact of land animals and birds, seasons, wind, etc.
Lake Vostoc has neither the same selective pressures, nor biological exchange. There has probably (I’m always uneasy with absolutes) been no biological exchange for 14 million years with the outside world. On top of that, it is an environment so foreign compared with anywhere else on the planet. There’s no light, so the food chain must be based on chemosynthetic organisms (as opposed to photosynthetic ones – plants and algae). The water is cold, estimated at -3 degrees Centigrade, but kept liquid by the lakes high pressure. There are no seasons, no lake “surface” as the lake’s interface is either rock or ice, although there are small tides. Finally, the level of oxygen and nitrogen in the lake is 50 times higher than in normal freshwater lakes.
Needless to say, it’s quite a unique environment.
You might well assume there’ll be nothing down there, and any life found would be highly inactive to try and conserve the minimal energy it has access to. Those as widely optimistic as myself would disagree. When scientists explored similar, but much smaller caves that had been sealed off from the rest of the world in Romania, they found over thirty new species, where the largest were related to the size of their environment (i.e. they could still move around freely). These species were highly active, and to some extent resembled modern insects but had many features that were totally novel. Granted, these caves were open air (as opposed to water), but water provides a more stable environment for growth and evolution. Even if there is no “large” life (I’m hoping for mermaids, but that’s probably too much to ask for) the micro-organisms that exist could be truly extraordinary.
In a lake the size of Lake Ontario, but twice as deep in places, the possibility of new species, and even new ecosystems within the lake is truly incredible. More excitingly, for the biochemist in me, is the potential for totally new routes of evolution – new systems for energy generation, new skeletal formation to deal with the pressure, new circulatory systems to take advantage of the high oxygen concentration. Who knows – while carbon is readily available on the surface through photosynthetic fixation, in water this is very much not the case – perhaps an ecosystem where sulfur, nitrogen or even oxygen are it’s principle “biological” component exists?
The main risk is that in the process of entering the lake to “have a look around” (at 4km below the surface, this is a bit of an engineering feat) we contaminate the lake. The various parties involved (Russian, American and British teams are all drilling) have been careful to try and avoid this, but in what may be an ecosystem radically different from our own, it seems to me that assessing what would be a contaminant is an impossible task – surely anything represents a contaminant.
Whatever the case, the next stage is to recover water, which is expected towards the end of 2012. Still more waiting, but hopefully, something truly fascinating will be at the end of the wait.