Adelaide and WA Fever Tour 2014
Part 4 - WA Road Trip Pre-game (continued):
From the Pinnacles he visited Lake Thetis near Cervantes (and saw some unexpected Stromatalites)
and
and then refueled and headed north to Port Gregory, and into Kalbarri, where we eventually settled in well after dark at the Anchorage Motor Camp, had some cheese and crackers and cooked some very very tasty scotch fillet steak, potatoes and veges. All washed down with some excellent WA craft beers. And some scotch.
The next morning we had coffee, tea, meusli and toast and then headed off. Saw some Pelicans being fed at Kalbarri
and, some startling pink flowers:
Which really stood out amongst the harsh barren northern WA semi desert we were driving through...
...on the last stretch north to Shark Bay:
As the sign says this place is a World Heritage Area - and it really has to be seen to be believed. We had a day and a half there and could EASILY go back with a 4WD and a tent and spend two weeks there. The place it HUGE! From the turn off up to Denham it's about 150 kms, and that is just one narrow part of the whole place. If you ever get the chance to go to Shark Bay, do it. It rocked.
Hamelin Pool:
Hamelin Pool is HUGE. it is shown by the green part of this map:
http://www.sharkbay.org/assets/images/marine-zones-map-icon.jpg
But standing on the shore of it you can't see both sides of the inlet - it stretches from one horizon to the other.
The pool is very sahllow - averaging 1 to 1.5 metres deep. The entrance to the inlet is particularly shallow - there is a ridge that runs across it from one side to the other and there are thick patches of sea grass across the ridge. This restricts the water flow out of the pool. When the tide rises the water flows into the pool through the grass. The shallowness of the pool and the hot climate mean that the rates of evapotranspiration are very high. This results in no water flowing out of the pool - the evapotraspiration means the water level in the pool drops and the ridge and sea grass means it can't flow back out on the ebb tide. This results in a very high level of salinity in the pool 2 to 2.5 times normal sea water.
The first thing this means is it is perfect conditions for Stromatolites - one of the earliest known forms of life on Earth, which were responsible for oxygenating the planet back when it was a very saline and inhospitable place. The high salinity means that predators that would normally feed on the bacteria that form the Stromatolite colonies cannot survive, and the stromatolites thrive as a result/.
First stop was the stromatolites at Hamelin Pool:
Just next to the stromatolites was something almost equally incredible. The only animals who really thrive in the saline waters of Hamelin pool are small cockle species. Without predators able to survive in the saline waters of Hamelin Pool their numbers have EXPLODED. Around 20,000 of these cockles can be found in each cubic metre of the sea floor in Hamelin Pool.
Over time the dead shells have formed deposits in some places off 7 to 10 metres deep. The pressure of the weight of the shells on top result in the shells have formed a limestone that is known as Coquina.
This limestone used to be mined and buildings in the area are made out of blocks of coquina. The shell quarry is about a 700 metre walk from the stromatolites:
You can see here the blocks used to make a stairway and path:
Shell Beach:
Next stop was a few kilometres up the road at Shell Beach which (from Wikipedia) is a beach in the Shark Bay region of Western Australia, 45 kilometres south-east of Denham.
It covers a 110 km long stretch of coast along the L'Haridon Bight. It is one of only two beaches in the world made entirely from shells.
The beach was named "Shell Beach" because of the great abundance of the shells of the cockle species Fragum erugatum. The seawater in the L'Haridon Bight has a high salinity due to both the geomorphology and local climate of the area. This high salinity has allowed the cockle to proliferate unchecked, since its natural predators have not adapted well to this environment.
The shells typically reach a depth of 7 to 10 metres.
this is a handfull off the shells (there is no sand in any of these pictures, it is ALL shells)
The beach is HUGE
We went for a swim, and because of the salinity (over double normal sea water) you are very very bouyant. I was kneeling on the bottom with the water up to my chest. I tried to dive down and get my head down to the bottom, but could not do it. At about 1 foot under the surface my sinuses were screaming and burning and I could not get my head any deeper. And the water is CRYSTAL clear.
What an amazing place.
More to follow tomorrow.
