Every time you take a breath, thank a stromatolite. These microscopic cyanobacteria dominated in the earth's shallow seas 3.5 billion years ago (Sorry, Creationists, but that's the way it is!) and are responsible for putting oxygen into our atmosphere. Scientists believed that the stromatolites became extinct about 500 million years ago, but a large colony of these primative organisms is thriving today in Hamelin Pool in the Shark Bay World Heritage Site. They aren't much to look at, more like limestone rocks than living things, but when conditions are right you can see tiny bubbles of oxygen percolating to the surface. They are still doing their job after 3½ million millennia although more modern green plants have taken over the heavy lifting.
Shark Bay peninsula, nearly 1000 km north of Perth, juts into the Indian Ocean forming the western-most part of Australia. The turquoise water is fringed with white beaches of tiny shells, not sand, up to 25 feet deep in places. We watched from Eagle Bluff as dozens of lemon sharks cruised over the white bottom while dugongs grazed unseen on thousands of acres of seagrass farther offshore.
The sea breeze at our campsite in Denham is a boon for the kite surfers but isn't doing much to keep away the annoying flies. We may actually have to close up the van tonight, the first time in a week.
