Australia: The Land Where Time Began

A biography of the Australian continent 

Lake Clifton

Lake Clifton, a land-locked lagoon near the town of Mandurah, Western Australia, about 700 km south of Shark Bay, and about 100 km south of Perth, supports the second largest collection of stromatolites which occupy about 10 km on its eastern shore. It is a coastal lake about 21 km by 1 km wide, parallel to the coastline. It is shallow, the deepest parts being no more than 3 m deep. The water level varies throughout the year, rising after the winter rain then dropping in the dry summer months. When the water drops in summer, a reef is exposed near the northern end of the lake that is about 5 km long and about 30 m wide. Most of the stromatolites composing the reef are less than 50 cm across, though their diameters can be up to 1 m. The main organism involved in their building is the cyanobacterium Scytonema, a filamentous form. Groundwater seepage provides the carbonate and bicarbonate for use in the construction of the stromatolites, thus the location of the seep determines the location of the stromaolitic reef.

The lake has a diverse invertebrate fauna that includes isopods and amphipods (crustaceans), both grazers, that feed on the stromatolites. There are also molluscs that include the stromatolites in the diet. This existence of the stromatolites near the seep has been suggested as proof that if the balance is right between the grazers and the conditions for growth stromatolites can survive in the presence of grazers.

Sources & Further reading

1. Mary E. White, Earth Alive, From Microbes to a Living Planet, Rosenberg Publishing Pty. Ltd., 2003
2. Mary E White, Running Down, Water in a Changing Land, Kangaroo Press, 2000