West Coast Car Trip  2021  

 

Photographs and commentary: copyright Jonathan C Nevill,  2021, unless otherwise credited. Camera: Samsung Galaxy S7.
Dates: July  6 - 21, 2021.

 

Vivian cooked me a birthday cake!

 

RECIPE:

 

CAKE:

1 medium sized orange

200 g butter, melted

1.5 cups of self-raising flour

3 eggs, lightly beaten

1 cup castor sugar

 

Heat oven to 180 C

 

Wash and dry the orange, cut into quarters, and remove the seeds, then food processor until pulpy.

Transfer to a bowl, and stir in the melted butter, sugar, and flour, then mix in the eggs until smooth.

Pour into a baking tin and cook for 50 minutes.

 

SAUCE:

1 medium lemon and one small orange

1 cup of icing sugar

1 teaspoon of boiling water

 

Blend and pour over the cake

 

 

I was saddened to see a shop in Fremantle selling sea shells.

If you see a shop window like this, PLEASE don't buy. These beautiful shells are harvested live from reefs around the world. Like many reef animals, most have slow reproductive strategies. Harvesting them seriously degrades reef ecosystems, and is NOT sustainable.

 

 

Nambung National Park, north of Perth, is famous for its "pinnacles":

How did they form? The explanation is still being debated. To me they look like stalagmites, but of course they can't be... where is the cave ceiling?

 

 

The sand looks orange under cloud; yellow under sunlight.

 

 

 

 

 

Note the horizontal layering above.

 

 

Grasstrees: I love them! You seem them in many of WA's woodlands and shrublands.

 

 

In the image below, notice the "skirt" of dead leaves. This indicates that there has not been a fire in this area for many decades.

 

 

 

The landscape at Kalbarri National Park, like many of Western Australia's most scenic regions, has been created over many millions of years by rivers cutting down into a sandstone plateau.

The view from the Ross Graham Lookout.

 

I usually disapprove of skywalks, as they are so often unimpressive and over-sold.

But I have to say the Kalbarri Skywalk is impressive, not just for the skywalk but for the supporting visitors' centre, informative displays, and artwork.

I don't know who the project manager was, but, in concept, scale and execution, this is a model that similar places could well use as a guide. The whole project is a work of art.

 

Instead of a picture, why not have a work of art?

 

In this way, the WA Parks and Wildlife Service have created an informative and memorable place. It's special. 
It would have cost a lot of money, but it's well worth it.

 

 

 

 

 

 

 

The visitors' centre. Instead of concrete or brick steps: cut and polished local stone.

 

 

Above: colours at sunrise.

Below: just 30 minutes later.

 

 

 

The Shark Bay region lies north of Kalbarri and Geralton, and south of the city of Exmouth.

In 1984, I undertook the preparation of a report assessing the Shark Bay region against UNESCO World Heritage criteria.

This work was done in collaboration with Robert Lawrence, under a contract from the Australian Conservation Foundation.

We found that the region fully met four of the UNESCO criteria. 


Subsequently the Australian Government, in collaboration with the WA State Government, undertook their own assessment, reaching the same conclusion. 

UNESCO agreed to list the region in 1991. World Heritage values are now a key feature attracting visitors to the region.

 

In my view, the weakest part of current regional conservation management is the lack of substantial and effective no-take marine protected areas. 

Isolated coral outcrops within seagrass fields are a particularly vulnerable feature, and have not been effectively protected.

 

Photo: WA DBCA Parks and Wildlife Service

 

Tourists feed dolphins at Monkey Mia, under Parks and Wildlife Service supervision. As far as I know, this is the only place in Australia where tourists can feed wild dolphins.

Denham is the main town of Shark Bay, existing principally on tourist trade.

The shallow water east and west of Faure Island restrict water flows into the southerly pools.

 

There is an interesting feature on the west coast of Faure Island. A natural ridge has been augmented to create a fish trip. You can see this in the above image.  I presume this trap was constructed a long time ago, as it's under water, even at low tide (so in excess of 8000 years ago).  When I inspected the feature in 1984, I formed the opinion that the stones making up the fish trap were clearly laid by human hands. Since that time there has been considerable sand accretion, and now it's not so clear.

 

There must be many signs of aboriginal occupation of land which is now underwater. 

 

MAP of the SHARK BAY REGION

 

 

Shark Bay contains a great variety of arid and marine habitats - remarkably beautiful when viewed from the air. Photo: WA DBCA Parks and Wildlife Service.

 

The stromatolites of Hamelin Pool are of outstanding scientific interest.

Planet Earth formed about 4.6 billion years ago (that's before you were born). About 3.5 billion years ago, cyanobacteria (similar to algae) evolved, obtaining energy via photosynthesis. Clumped together, these microbes formed a variety of structures, but most commonly matts. They emitted oxygen as a waste product from their metabolism during daylight hours, just as plants do today.

As cyanobacteria proliferated across the planet, they changed the composition of the atmosphere. Once oxygen levels reached around 20%, this set the scene for the evolution of more complex air-breathing organisms. Organisms also evolved to take advantage of cyanobacteria as a food source. Gastropods are one such group, with their mobility enabling them to graze cyanobacteria matts. Bivalves evolved to use a diet of water-borne algae and bacteria. Cyanobacteria, which had evolved with no competitors and no predators, were now under attack; and their populations and range started to contract.

 

Fast forward to today. Hamelin Pool, lying to the immediate south east of Faure Island, is a hyper-saline sea within Shark Bay. At its northern edge, an extensive sand/seagrass bank developed, called Faure Sill, visible in the image two above. 

 

This shallow bank restricts the movement of fresh sea water into Hamelin Pool. In the hot, windy climate of Shark Bay, water evaporates from the Pool, leaving salt behind.

Over the last 6,000 - 8,000 years (the Pool did not exist in earlier times as the sea level was lower) the Pool became hypersaline. Cyanobacteria, adapted to highly saline conditions, continue to flourish in the southern areas of highest salinity, forming matts and circular clumps. No gastropods have adapted to these salinity levels, so the cyanobacteria have no predators, just like it was billions of years ago. If they could read evolutionary history, they would feel happy and privileged! As water-borne sediment settles into the matts, another layer of cyanobacteria grow on top, then the process is repeated. Eventually columns form in some conditions, over hundreds or thousands of years, made up of cyanobacteria and sediment. These columns are the stromatolites. This has happened in a few other hyper-saline environments, notably in Africa and Central America. Although gastropods have not been able to adapt to this hostile environment (thus allowing the stromatolites to form) one bivalve, a fragum cockle (Fragum eragatum), has adapted. As for the cyanobacteria, without competitors or predators, Hamelin Pool is cockle paradise, and a particular kind of soft limestone, called coquina, forms where banks of cockle shells pile up over time, driven by wind and waves - just like sand dunes. The action of rain (slightly acidic with carbonic acid) serves to dissolve and re-precipitate calcium carbonate, dissolving and binding the shells together, forming coquina.

 

A viewing platform has been constructed at the south end of Hamelin Pool, to allow tourists to see the stromatolites without damaging either the stromatolites or the nearby matts.

 

 

The southern shores of Hamelin Pool: billions of cockle shells create a 'beach'. Photo: Brian W Scheller.

 

 

Upper piece: cockle shells clump together, driven by waves and wind.

Below piece: the same stuff, after 1000 years of sunshine, very slightly acidic rain, and wind. The cockle shells have been transformed into limestone.

 

Coquina is 'half way' between wind-blown cockle shells, and limestone.

A wall constructed of coquina blocks, which can be readily cut with a normal wood saw. Walls such as this one need to be protected from rain. The blocks are not particularly strong, but they have good heat insulation qualities.

 

Why do stromatolites form in some places, and algal matts in other locations?  If you know, please send me an email. 

Hamelin Pool stromatolites at low tide. Photo: M Alton.

 

 

 

 

 

 

The larger, darker columns at the back of this image are presumable older formations.

 

Stromatolite photos: Jonathan Nevill 1984.

Current management restrictions do not allow swimmers or snorkelers within 300m of the shores of Hamelin Pool. 
These controls are to protect fragile and globally-significant features and ecosystems.

 

 

The landscape just south of Hamelin Pool: stony and arid. Telegraph poles, obsolete decades ago, still perform a useful function.

 

 

 There are plenty of wildflowers in late winter and early spring. My visit was during a wet year.

 

 

Farther north, termites build impressive structures. I suppose they are the principal herbivores here.

 

 

The small town of Carnarvon definitely has a tropical feel about it.

 

 

A Carnarvon car park. It's unusual to see a vehicle which is NOT a four-wheel drive.

 

If you were to take a random sample of 20 vehicles on WA's North West Highway, my count (July 2021) suggests that one would be a campervan, one would be a commercial truck (probably a three-carriage road train) while the remaining 18 would be recreational 4WDs. These 4WDs would mostly be towing either a caravan, a boat or a camping trailer.

 

Coral Bay, just north of Carnarvon, is a small town, almost entirely based on tourism.

These photos were taken just 200m off a sandy beach.

 

 

 

 

 

 

After an unexpected knee injury, I turned around and headed back to Perth.

 

An early morning rainbow in the western sky, just south of Shark Bay. It lasted only a few minutes.

 

 

Below: roof-top campers are popular. First image: the Lighthouse car park at Geralton. Second image: the camping area at the Billabong Roadhouse.

 

 

 

 

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