The lampenflora in show caves and its treatment: an emerging ecological problem

Abstract

The artificial lighting of caves adapted for touristic visits, leads to the appearance and propagation of a complex community of phototrophic organisms known as "lampenflora". Formed mainly by algae and cyanobacteria, they produce the degradation of the colonized substrates and decrease the show value of the caves. This phenomenon became famous worldwide in the 1960s due to the damage caused to the paintings in the Lascaux Cave (France). Since then it has become an issue of serious concern to both managers of show caves and to the international scientific community. Over time, the problem has been approached following two complementary strategies: preventing colonization by the invading organisms or eliminating them once they have become established through the use of chemical products, mainly biocides and strong oxidants. This kind of treatment generates pollutant effluents that can move the problem from the walls of the caves to the groundwater. This paper presents a critical literature review of the problem and the proposed solutions, and emphasizes the need for further study of the optimal doses of treatment chemicals and to develop quantitative methods to determine their effectiveness. . The lampenflora in show caves and its treatment: an emerging ecological problem.

Lampenflora in a Show Cave in the Great Basin Is Distinct from Communities on Naturally Lit Rock Surfaces in Nearby Wild Caves

“…The presence of humans, even in caves, has a documented and substantial impact on the diversity of microbial communities, e.g., [6,9,15,20,52]. In Lehman Caves, the photosynthetic microbial communities around artificial lighting-cyanobacteria, diatoms, and algae-were distinct from communities sampled on rock walls near natural light in the wild caves (Table 2; Figures 2 and 5), suggesting the potential direct impact of human visitors on lampenflora communities.…”

“…Opportunistic lampenflora communities around artificial lighting in developed underground environments create novel ecological networks that otherwise would not exist [6][7][8][9]. Lampenflora communities also cause aesthetic changes, physical biodeterioration, e.g., increased porosity, exfoliation, and structural changes, and chemical biodeterioration (e.g., dissolution of speleothems, and alteration and precipitation of mineral mixtures) [10].…”

Safe and effective disinfection of show cave infrastructure in a time of COVID-19

“…In recommending these compounds for in-cave use, it should be noted that all disinfectants have the ability to negatively impact cave microbiota (Estévez et al, 2019). To limit the unnecessary introduction of these compounds into caves, the lowest concentration necessary to inactivate SARS-CoV-2 should be used (Table 1), as increased concentrations provide no additional antiviral activity, and in the case of alcohols, higher concentrations actually have reduced antiviral activity.…”

Present and Future Perspectives for Biocides and Antifouling Products for Stone-Built Cultural Heritage: Ionic Liquids as a Challenging Alternative

“…Some side effects, such as the possible diffusion of water into the substrate and/or the production of the organic debris of dead cells, which are readily used as a carbon source by other microorganisms (see above), have also been reported. UV irradiation, especially UV-C (λ 254 nm) will kill most indoor colonizing microorganisms and are especially used in natural caves and hypogea [12][13][14] and show caves [15]. They are easy to handle, but some preliminary tests need to be performed to establish the distance of lamps and duration of treatment.…”