Cyanobacteria blooms have plagued western waters for a number of years, Each year agencies such as the Washington Department of Health close lakes because of the presences of the toxins these algae species produce. This year this trend has started early, for example the 73 acre lake in Anderson Lake State Park was posted as closed two weeks ago in early May. Generally this happens later in the year.
The strategies many groups use are reactive, treating algae blooms with EPA registered algaecides. Phoslock is a proactive strategy. This technology was developed by the Australian National Science Academy and has been used commercially throughout the world since 2000. The material is made up of two rare earth elements and is applied to the lake surface. As the material settles through the water column it binds and sequesters free reactive phosphorus. As it reaches the lake bottom, it forms a blanket a few millimeters thick that continues to grab and sequester phosphorus that mobilizes from the lake sediments. The phosphorus and Ploslock actually form a new compound that is insoluble and this technology deactivates phosphorus forever. Removing phosphorus reduces the carrying capacity of a lake to produce problem algae blooms. These single celled organisms need to obtain the nutrients they need from the water column. In addition. blue green algae or cyanobacteria thrive in waters with a high N to P ratio, removing phosphorus shifts the competitive advantage back toward beneficial green algae species and away from toxin producing blue-greens.
In many Western States, toxic algae blooms are prevalent. Washington State’s Department of Ecology has completed the first permit to apply this material to waters of the state. Aquatechnex biologists applied for this permit to support one of our clients in suburban Seattle. This lake system receives stormwater from the surrounding watershed and has been degrading each year because of high phosphorus levels. The application will be made in the coming weeks and we will post updates as this happens.