Research, Surveys and Data Management

Nature Conservation 4/2008 — 19. 8. 2008 — Research, Surveys and Data Management

Microbial Contamination at the Opona/Curtain in the Zbrašov Aragonite Caves

na Oponě ve Zbrašovských aragonitových jeskyních

authors: Milan Geršl, Dana Hanuláková, Barbora Šimečková

The Zbrašov Aragonite Caves are the only show caves of hydrothermal original with unique karst ornaments in the Czech Republic.

Among others, they include a continuous aragonite sheet on the formation called The Opona/Curtain where since the 1980s, undesirable contamination and colour changes in aragonite crystals have been observed there. In the 1990s, using electron microscope, the contamination was identified as textile fibres released from visitors´ clothes, being at the same time food resource for microscopic fungi incl. moulds which have also found there. In 2000-2003, a detailed mineralogical analysis of the Opona and a study on effects of hydrogen peroxide solution in water on ara-gonite were carried out. The optimal concentration of the solution was also defined. In 2004, an experimental spraying was applied at a selected site of the Opona. Since 2005, overall application with repeated sampling and monitoring has been performed. At the same time, research on red and brown pigments found on the aragonite ornaments which can be a by-product of metabolism in the micro-organisms has been also implemented. The continuing remedial measures and research have been supervised by microbiologists and environmental geologists. The main aim is to preserve the extraordinary valuable karst ornaments: there is no analogy worldwide.