Lake - Torrens Lake
Torrens Lake is an impounded section of the Torrens River, a meandering river running through the centre of the city of Adelaide in the Australian State of South Australia. The lake was treated with 50 tonnes of Phoslock in March 2007 and a further 12 tonnes of Phoslock in February 2008. The purpose of the treatments was to reduce the potential for the development of blue green algal blooms that might have threatened scheduled events of the “Adelaide Festival”, a major festival held in the city during February and March. Blue green algal blooms had resulted in the closure of the lake to recreational use in seven of the ten years prior to the Phoslock application.
The results from the 2007 application indicate that Phoslock appeared to have significantly altered the nutrient availability within Torrens Lake, with Phoslock having created and retained a barrier at or near the sediment water interface in four out of the six tested sites seven months after the treatment.
The 2008 Phoslock application provided evidence of a decrease in total algal biomass and cyanbacterial abundance in the water column soon after application. Sediment analysis suggests that the Phoslock treatment reduced the release of bio-available phosphorus, however a redistribution of lanthanum within the lake also occurred after the treatment, possibly due to scouring and drift. As the lake forms part of a river system, applications of Phoslock at critical times in each summer may be required for effective results. No adverse effects of the application on aquatic fauna were measured after either application.
The results from both applications summarized in the downloadable reports.