The massive and rapid growth of cyanobacteria, especially of toxic species, is a huge problem. As a result, not only does the water quality deteriorate, but also the risk to the health and life of aquatic organisms, and above all to bathers, increases significantly. For this reason, reservoirs used for recreational and sports purposes can be closed if there is a cyanobacteria bloom, which can result in financial losses. What measures can be taken to prevent mass blooms of cyanobacteria? What solutions should you use when a bloom has occurred?
Cyanobacteria, despite having chlorophyll and the ability to oxygenate through photosynthesis, are neither plants nor algae. They are classified as prokaryotes in the kingdom of bacteria, which are characterized by the lack of a cell nucleus and cell organelles. Cyanobacteria are mostly self-feeding – they produce organic compounds through photosynthesis. Some species also have the ability to bind free nitrogen from the air, thanks to which they can develop even in an aquatic environment poor in nitrogen compounds. There are over 2,000 species of cyanobacteria in the world, the vast majority of which can cope well even in very unfavorable conditions, such as: poor lighting, poor oxygen conditions, or high pH value. They are most often found in freshwater, but they can also be found in seas, on glaciers, on tree bark, as well as in hot springs with temperatures of nearly 90° C. Cyanobacteria are present in all water reservoirs and this is completely normal. The problem begins when their number increases rapidly. Then cyanobacteria blooms which is the mass multiplication of cyanobacteria and simultaneous death of their cells; this is visible in the form of blue-green slimy material that accumulate under the water surface.