Just out of Cervantes, some 200 kms north of Perth, we visit Lake Thetis a small inland salt water lake - there is a lovely board walk that we can wander along for about 1.5 kms and it is a bright morning with no one around. We have come to see the stromatolites here by the edge of the lake - what I hear you say ??
In the famous words of Mr Portokalos of my Big Fat Greek Wedding - everything comes from Greek, so stroma= layer and lithos = stone. Layers of stone except these ones are living.
These are living fossils created by cyanobacteria - blue green algae. These are micro organisms which are known to have existed some 3.5 billion years ago - that is a very long time ago. How they know they are that old is that they found traces of the blue green algae in fossils in the Pilbara. The cyanobacteria trap sediments with mucous to form enormous mats of rock-like structures called stromatolites. At first glance these don’t even seem to be living. Each structure is actually a very slow growing microbial colony that may grow less than 1mm per year.
Why these strange microbial mats are important is that they are one of the first ecosystems that are known to have produced oxygen into the atmosphere- necessary to sustain life as we know it today.
So while seemingly inert and really not the world's greatest lookers these " things" are amazing and useful at the same time. They are the simplest forms to use photosynthesis to provide food and oxygen.
They exist in two places in Western Australia - Lake Thetis and Hamelin Pools close to Shark Bay.
They are World Heritage Listed Marine Parks.
The stromatolites at Hamelin Pools some 800 kms north of this Lake are even more spectacular though not everyone might share this enthousiasm at a bunch of strange looking stones. But don't we always need to go a little deeper then the surface to find what lies beneath!
Hamelin Pool stromatolites. These crustier ones may be the oldies in the colony !
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