Lake Thetis is one of only a few
places in the world with living marine
stromatolites.
Living
stromatolites were prevalent 1-3 billion years ago on the shores of lakes and seas around the world and remarkably are still being formed today in just a small number of
places on earth.
Cervantes is one of several such sites in Western Australia where you can view them easily. Stomatolites grow as layers of sediment that has been trapped. These layers or mats slowly build on top of each other over many years with each Stromatolite formation only growing at a rate of 5 cm in 100 years! They need light so are limited to shallow water where the sunlight can penetrate.
Lake Thetis is just over 1km from the centre of
Cervantes (off the Hansen Bay
Lookout Rd). Lake Thetis has double the salinity of the sea. Here, the
stromatolites are easily accessible during the drier months when the water level is at its lowest. The best examples can be found at the south-western edge of the shoreline but they are brittle and visitors are asked to look, but don't touch.
There is a walkway all around the Lake and also a viewing platform. Please respect this area as it is very precious.
This is a free site and no camping is allowed. Please observe the signage and DO NOT WALK off the boardwalk.