Lithophytic algae: A major threat to the karst formation of show caves

Depending on the intensity, quality and duration of the illumination, necessary for viewing show caves, conditions conducive for algal growth are created. Although algae are the major component of this flora, ferns and mosses have also been recorded. Little is known of the algae, except that they are considered a nuisance in terms of discoloration and damage to the karst formations. The occurrence and possible control of the algal flora has been studied in the Cango Caves, one of the most important touristic sites in South Africa. The algal flora is sparse in species diversity and primitive forms are present. They have particular physiological adaptations and using micro-oxygen liberation and fluorescence measurements, their photosynthetic characteristics were established. Environmentally friendly control measures were investigated and a solution for their control is proposed.