Snow algae on snow slope
Base H - Signy Island Antarctica

  ©Copyright P. Ward - picture taken 1985 / 86

There are more than 300 species of algae that can live in such an environment as thick-walled cysts. A red species predominates over most of the bottom end of the Gourlay snow slope in this case though bluer and greener species can be seen towards the upper portion of the snow in this picture.

Protective pigments, usually carotenes, (the red in this case) are produced to reduce the quantities of visible and particularly of ultra violet light from damaging the other photosynthetic pigments. Such algae are usually found at high altitudes and/or latitudes where there is more uv light