Aquatechnex biologists often face management challenges on euptrophic lake systems we encounter. Increasingly, these nutrient rich lake systems shift to systems dominated by Blue Green Algae or Cyanobacteria. In addition to interfering with many of the beneficial uses of the lake, these organisms pose a severe threat to human health. In the short term, these organisms produce a number of toxins that can have an acute impact on water users. There are significant numbers of animal deaths reported each year from ingesting lake water during bloom conditions. In recent years the first human fatalities have been documented from the direct exposure. In addition, there are now long term impacts associated with these toxins (see http://aquatechnex.wordpress.com/2011/06/28/new-evidence-that-blue-green-algae-may-contribute-to-als-diseases/)
As algae are single celled organisms, they need key nutrients to be present at high levels in the water column in order to thrive. Phosphorus levels in the water column are key to this growth, high levels of phosphorus lead to conditions ripe for excessive algae blooms.
Phoslock is a new technology we discovered about one year ago. This technology was developed by the Australian Government’s National Science Academy as a lake restoration technology. We made contact with the group commercializing this system and we able to bring the technology to the United States. We began to integrate this into our programs in the Fall of 2010.
Phoslock is applied to the lake surface after a water quality sampling protocol helps us identify an application rate. As the material sinks through the water column, it grabs and bonds the free reactive phosphorus present in the water column. As it settles onto the lake sediments it also forms a layer that prevents phosphorus release from those sediments. By removing and locking phosphorus from the lake, the carrying capacity for algae goes down.
We have completed six applications in the Western United States and have monitored them extensively. In all cases, sampling shows that free reactive phosphorus levels drop to no detect within hours. In lakes without major phosphorus inputs, these levels have remained low since then. In one case where we are managing a lake that receives reclaimed water, we monitor the inputs and dose on a regular schedule based on loading.
We feel that this technology has an important role to play in the future of lake management. This technology shifts us from a reactive strategy to treat toxic algae when they occur to a proactive strategy that addresses the cause of the problem. For more information and case studies please email [email protected].