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What are cyanobacteria?

Cyanobacteria are micro-organisms which are half way between bacteria and algae. Like bacteria, cyanobacteria is microscopic. Like algae, it possesses pigments which permit photosynthesis (chlorophyll is responsible for the green colour).

It is important to note that cynanobacteria are not aquatic plants.

Cyanobacteria develop during the summer in shallow, tepid, calm and nutrient-rich waters (containing phosphorous and nitrogen).
Cyanobacteria are not always visible on the surface because they are frequently disseminated in the water column. Generally speaking, they become visible when they are bunched together in the same place. In this case, we can observe a blue-green colour in the water or on the surface. Eventually a green scum (or foam) forms on the surface of the water. While wind, waves and current tend to disperse them they may reappear. Bunches of cyanobacteris may sometimes be accompanied by disagreeable odours. 
The problem of bodies of water being affected by cyanobacteria exists throughout the world and that includes some lakes in the Eastern Townships including the Montérégie and Estrie sectors as well as elsewhere in Quebec.

Let us remember that cyanobacteria are at the origins of life and have been present on our planet for some 2.5 billion years. The problem is their too large numbers due to human activity which perturbs the natural balance.

There are more than 2000 species of cyanobacteria in existence of which some 300 have been identified in Quebec. Of these 300 species, about 50 can produce toxins which can provoke health problems.

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