Blue-green algae (cyanobacteria) are bacterial organisms that have some of the characteristics of bacteria and some of algae. They are present in almost all aquatic ecosystems in Australia, including rivers, lakes and estuaries.
Under certain environmental conditions, blue-green algae concentrations in water can rapidly increase and form visible blooms or scums.
Water affected by blue-green algae may be unsuitable for drinking, recreational activities such as swimming and fishing, and agricultural uses. Some species of blue-green algae produce toxins that are harmful to humans and animals when they are eaten, inhaled or contact the skin.