PUBLIC TALK: The Thrombolites of Lake Clifton in Western Australia

Lake Clifton is well known for the largest array of living Thrombolites (a type of Microbialites similar to Stromatolites) in the southern hemisphere. They were first described in 1980s when the lake ranged in salinity between 7 and 35 ppt. Within the last 25 years the salinity in the lake has doubled with salinity levels recorded between 34 and 92ppt. This increase in salinity also coincides with an increase in nutrients.

In 2002, 2005, 2007 and 2010 there has been massive break down of thick microbial mats from the bottom of the lake and floating in the lake. In spring and summer the thrombolites are smothered with Cladophora – a sign of eutrophication. The microbial mats in the lake including those responsible for the growth of thrombolites have been investigated in conjunction with the environmental factors. The results indicate that the system is becoming eutrophic and hypersaline.

This presentation will provide a scientific background to what is occurring in Lake Clifton by tracing the origin of the floating algal mats and providing an explanation for the break up of the benthic algal mats. I will also attempt to address whether these current conditions are supporting thrombolite growth and what the likely out comes will be.

Jennifer Alexander is a research scientist with a scientific background in marine biology and environmental science. She has worked in a variety of fields and locations and has been conducting research at Lake Clifton since 2007 as part of her PhD.