Denham, our penultimate destination
12 Aug 2012
We had a very busy day today doing nothing. Stocked up on a few essentials for the run to Denham where “isolation” is used as an excuse to hike prices, or so we are told by some locals. We are getting smart though, packed up the van this afternoon all but the power lead that belongs to the van park anyway, we will have a shower when we get there tomorrow which is always welcome anyway after a long day on the road.
Curiously the van park is nowhere near as full as it was last night, maybe there were a few ring ins due to the BBQ. As if the grey brigade could be that organised but they can smell a BBQ’d snag 50km away…
Northampton to Denham today, drove through acres of wildflowers (aka weeds) in full bloom in various shades of yellow white pink and even purple….. It was absolutely stunning and over the next few weeks will become even more stunning.
Stopped at Hamelin pool to observe the captive stromatolites there, in a word this is a mind blowing experience, I had only experienced this sort of sensation once before in my life and that was on a warm February morning in 1962 when I woke up and realised I had missed the last Coogee Tram and I’ll never see another and that’s what this place is like; these are one “family” of these things out of 2 on the planet. A stromatolite (literally, ‘layered rock’) is a solid structure created by single-celled microbes called cyanobacteria (blue-green algae). The cyanobacteria form colonies and trap sediment with their sticky surface coatings. The trapped sediment reacts to calcium carbonate in the water to form limestone. These limestone deposits build up very slowly – it can take a stromatolite 100 years to grow 5 cm. A 1m high stromatolite might be 2,000 years old!
Between 4,000 to 6,000 years ago a massive seagrass bank called the Fauré Sill began to block tidal flow into Hamelin Pool, causing the water to become extremely concentrated. The water in Hamelin Pool is twice as salty as water in the open ocean! Animals that would normally graze on algae, such as chitons and snails, cannot survive in these conditions. Around 3,000 years ago cyanobacteria started flourishing, forming stromatolites much as they did billions of years ago. More than 50 species of cyanobacteria live in Hamelin Pool.
Stromatolites look a cross between a cauliflower and a rock. However, unlike rocks they are actually alive – each stromatolite has a top surface layer teeming with living, active cyanobacteria. At least 3,000 million cyanobacteria can fit in 1 m2! Because cyanobacteria are plants, they photosynthesise their energy from the sun. A by-product of photosynthesis is oxygen, and if you look very carefully you may see the stromatolites gently ‘fizzing’ as tiny bubbles of oxygen are released by the cyanobacteria into the water. This is one reason these will avoid the Carbon Tax!
The size and shape of stromatolites are thought to be influenced by their immediate environment. Large mushroom-shaped stromatolites may form in places where tides and small waves approach from different directions. Loaf-shaped stromatolites are found in protected areas close to the shore. Because cyanobacteria need sunlight to photosynthesise, the stromatolites in Hamelin Pool do not form in water deeper than 4 m, where there is less light.
All I can say is this, I’m glad I saw them I would have loved to have jumped into the water and patted one and I’m really glad we did not have to drive over Km’s of rough dirt track to see them. Carol wants to see them again when we drive back to Kalbarri so taken was she with these living rocks. I’m thinking that there is enough blue green algae in Canberra’s lakes than maybe we should make them salty and grow some as a tourist attraction….
Then on to our penultimate destination Denham. Curiously driving through thick fog banks at 1:00 pm with bright sunshine and either side and temp around 26c. Denham is a busy little place with everything but the Visitor centre closed on Sunday, when tourists might really feel like a coffee and vanilla slice after the drive from where ever they have driven and “where ever” would be some considerable distance. No caravan sites anywhere in town but some available in the “Overflow’ areas, no water or power though but you pay for an unpowered site. Glad we booked!
The Shark Bay Van Park is quite ok, well for us at least as we have our own ablutions block on board. It’s also fully subscribed, we met some fellow travellers who wanted to stay on in Denham (for reasons kept secret) and they had to retreat to Hamelin Pool where there is no water but you do get 10ltrs of drinking water and the throaty burble of the generator lulls you to sleep at night.
Tomorrow we drive to the ultimate destination Monkey Mia to have discourse with the Dolphins, from there technically we are on our way home all be it the long way around.