Snow algae are algae that grow in semi-permanent to permanent snow or ice in the alpine or polar regions of the world. Their optimum growth temperatures are generally below 10 degrees Celsius . These algae have successfully adapted to their harsh environment through the development of a number of adaptive features which include pigments, polyols (sugar alcohols, e.g. glycerine), sugars and lipids (oils), mucilage sheaths, motile stages and spore formation.

Large blooms in the summer months can reach cell concentrations of 105 to 106 cells per mL. and colour whole snowbanks red, orange, green or grey depending on the species and habitat conditions. (More)

Source: Australian Antarctic Data Centre