Lake Thetis is on the outskirts of Cervantes, a three hour drive north of Perth, and is home to an assemblage of fascinating natural structures known as thrombolites.
These ancient structures – which date back 3.5 billion years – provide insights into what life was like at the dawn of time. There are found at just five locations throughout Western Australia.
Like the famous stromatolites of Hamelin Pool in Shark Bay, these rock-like structures scattered around the edge of the lake are built by micro-organisms too small for the human eye to see. Within the structures are living communities of diverse inhabitants with population densities of a mind-boggling 3,000 per square metre.
The thrombolite-building micro-organisms of Lake Thetis resemble the earliest forms of life on Earth. The discovery of modern examples helped scientists to understand the significance of micro-organisms in the environment and unravel the long history of life on Earth. Today living examples of these once completely dominant organisms are restricted to only a few places.
Visiting the remarkable thrombolites at the picturesque Lake Thetis is an opportunity not to be missed. An easy 1.5 kilometre walking loop around the lake provides opportunities to see and learn about these communities and the interesting environment that supports them. Interpretive signage provides information about the fossils, geology, flora, fauna and Indigenous culture. The first 300m of boardwalk, which passes the best examples of thrombolites in the lake, is universally accessible.
If you are feeling energetic and want to explore more of the region, a longer beach and bush walk trail is also available. The walk stretches between Thirsty Point and Hansen Bay with a detour into Lake Thetis. Visit during wildflower season and you will witness a stunning display of colour on your journey.
Ideally try and time your visit to be in the drier summer months for a better view of these extraordinary living fossils.
Source: Department of Biodiversity, Conservation and Attractions, and Australia’s Coral Coast.