Study and remediation of environmental problems caused due to the growth of algae in speleothems of calcareous caves adapted for tourism- a case of success in Spain

Caves, mainly those located on calcareous rocks are one of the best examples of geological heritage around the world. Their care and preservation should be a priority for the authorities dealing with the environment and culture. In addition to the dryness and discoloration wrought about by algae and bacteria in the speleothems, huge amounts of visitor traffic to the caves pose an additional burden, which is harmful to the conservation of the calcareous structures present inside the caves.

This article is a compendium of the results and the on-going studies under the Rehabilitation Project of Ortigosa de Cameros system caves. This project deals with the assessment and clean-up of exogenous algal communities that have deteriorated the speleothems in the tourist caves located in the municipality of Ortigosa de Cameros [Spain].In order to choose an appropriate cleaning agent for the speleothems, a bibliographic review was conducted. Several methods of remedying including the use of mechanical as well as chemical methods have been discussed.

After selecting the agent of choice for the clean-up of the speleothems, laboratory and in situ tests were performed using the same. Based on the results of these initial studies, the same methodology was applied to all areas affected by the "lampenflora". Care was taken that the selected methodology did not cause any damage to the fauna that inhabits these caves and nor did it leave a perceptible trace. An economical and environmental friendly method is still required to eliminate the algal mat that covers the speleothems of many caves adapted for tourist visits, in order to preserve our subterranean geological heritage throughout the world.