ABSTRACT
Altamira Cave (north of Spain) contains one of the world's most prominent Paleolithic rock art paintings, which are threatened by a massive microbial colonization of ceiling and walls. Previous studies revealed that exchange rates between the cave and the external atmosphere through the entrance door play a decisive role in the entry and transport of microorganisms (bacteria and fungi) and nutrients to the interior of the cave. A spatial-distributed sampling and measurement of carrier (CO2) and trace (CH4) gases and isotopic signal of CO2 (δ(13)C) inside the cave supports the existence of a second connection (active gas exchange processes) with the external atmosphere at or near the Well Hall, the innermost and deepest area of the cave. A parallel aerobiological study also showed that, in addition to the entrance door, there is another connection with the external atmosphere, which favors the transport and increases microorganism concentrations in the Well Hall. This double approach provides a more complete knowledge on cave ventilation and revealed the existence of unknown passageways in the cave, a fact that should be taken into account in future cave management.
Subject(s)
Caves/microbiology , Environmental Monitoring/methods , Gases/analysis , Bacteria/growth & development , Carbon Isotopes/analysis , Fungi/growth & development , Fungi/physiology , SpainABSTRACT
Different types of land use are usually present in the areas adjacent to many shallow karst cavities. Over time, the increasing amount of potentially harmful matter and energy, of mainly anthropic origin or influence, that reaches the interior of a shallow karst cavity can modify the hypogeal ecosystem and increase the risk of damage to the Palaeolithic rock art often preserved within the cavity. This study proposes a new Protected Area status based on the geological processes that control these matter and energy fluxes into the Altamira cave karst system. Analysis of the geological characteristics of the shallow karst system shows that direct and lateral infiltration, internal water circulation, ventilation, gas exchange and transmission of vibrations are the processes that control these matter and energy fluxes into the cave. This study applies a comprehensive methodological approach based on Geographic Information Systems (GIS) to establish the area of influence of each transfer process. The stratigraphic and structural characteristics of the interior of the cave were determined using 3D Laser Scanning topography combined with classical field work, data gathering, cartography and a porosity-permeability analysis of host rock samples. As a result, it was possible to determine the hydrogeological behavior of the cave. In addition, by mapping and modeling the surface parameters it was possible to identify the main features restricting hydrological behavior and hence direct and lateral infiltration into the cave. These surface parameters included the shape of the drainage network and a geomorphological and structural characterization via digital terrain models. Geological and geomorphological maps and models integrated into the GIS environment defined the areas involved in gas exchange and ventilation processes. Likewise, areas that could potentially transmit vibrations directly into the cave were identified. This study shows that it is possible to define a Protected Area by quantifying the area of influence related to each transfer process. The combined maximum area of influence of all the processes will result in the new Protected Area. This area will thus encompass all the processes that account for most of the matter and energy carried into the cave and will fulfill the criteria used to define the Protected Area. This methodology is based on the spatial quantification of processes and entities of geological origin and can therefore be applied to any shallow karst system that requires protection.
Subject(s)
Archaeology , Caves , Conservation of Natural Resources/methods , Geographic Information Systems , Environment , Models, Theoretical , SpainABSTRACT
Castañar de Ibor Cave (Spain) was discovered in 1967 and declared a Natural Monument in 1997. In 2003 the cave was opened to public visits. Despite of extensive control, on 26 August 2008 the cave walls and sediments appeared colonized by long, white fungal mycelia. This event was the result of an accidental input of detritus on the afternoon of 24 August 2008. We report here a fungal outbreak initiated by Mucor circinelloides and Fusarium solani and the methods used to control it.
Subject(s)
Environmental Monitoring , Fungi/growth & development , Geologic Sediments/microbiology , Chaetomium/growth & development , Chaetomium/isolation & purification , Cladosporium/growth & development , Cladosporium/isolation & purification , Fungi/classification , Fungi/isolation & purification , Fusarium/growth & development , Fusarium/isolation & purification , Geological Phenomena , Mucorales/growth & development , Mucorales/isolation & purification , Penicillium/growth & development , Penicillium/isolation & purificationABSTRACT
Bacteria thriving in underground systems, such as karsts, adapt to use a variety of nutrients. Most of these nutrients derive from superficial processes. This study shows that bacteria are able to differentially induce carbonate precipitation or dissolution depending on the availability of nutrients for growth. Different bacterial strains isolated from caves, representing the most common components of these microbial communities, were cultured with different carbon and nitrogen sources (e.g., acetate, glucose, peptone, humic acids) and induced changes in pH were measured during growth. Carbonate can either precipitate or dissolve during bacterial growth. The induction of carbonate precipitates or their dissolution as a function of consumption of specific carbon sources revealed the existence of an active nutrient cycling process in karsts and links nutrients and environmental conditions to the existence of a highly significant carbon sink in subterraneous environments.
Subject(s)
Bacteria/growth & development , Acetates/metabolism , Actinobacteria/growth & development , Actinobacteria/metabolism , Ammonium Chloride/metabolism , Bacillus/growth & development , Bacillus/metabolism , Bacteria/isolation & purification , Bacteria/metabolism , Bioreactors , Carbon/metabolism , Carbonates/metabolism , Culture Media , Glucose/metabolism , Humic Substances , Hydrogen-Ion Concentration , Nitrates/metabolism , Peptones/metabolism , Proteobacteria/growth & development , Proteobacteria/metabolism , Spain , Staphylococcus/growth & development , Staphylococcus/metabolismABSTRACT
In the last few years, the microbial colonisation of mural paintings in ancient monuments has been attracting the attention of microbiologists and conservators. The genus Rubrobacter is commonly found in biodeteriorated monuments, where it has been reported to cause rosy discolouration. However, to date, only three species of this genus have been isolated, all from thermophilic environments. In this paper, we studied three monuments: the Servilia and Postumio tombs in the Roman Necropolis of Carmona (Spain), and Vilar de Frades church (Portugal), in search of Rubrobacter strains. In all cases, biodeterioration and the formation of efflorescences were observed, and five Rubrobacter strains were isolated. These isolates showed different physiology and migration in denaturing gradient gel electrophoresis, suggesting they might represent new species within this genus. The isolates reproduced some biodeterioration processes in the laboratory and revealed their biomediation in crystal formation.
Subject(s)
Actinobacteria/genetics , Actinobacteria/isolation & purification , Architecture , Funeral Rites/history , Roman World , Actinobacteria/classification , DNA Primers , DNA, Bacterial/isolation & purification , History, Ancient , Phylogeny , RNA, Bacterial/genetics , RNA, Bacterial/isolation & purification , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 16S/isolation & purificationABSTRACT
In the last decades, damages on building materials and mural paintings were observed in Roman catacombs. The damages were due to extensive formation of biofilms induced by artificial illumination and humidity. Microenvironmental data (temperature, CO(2) concentration, humidity, and atmospheric pressure) clearly showed the negative influence of visitors. Increasing heat, light and water vapour condensation into corridors and cubicles favoured biofilm development. The composition of biofilms was different and depended mainly on distance to illumination sources and humidity, thus denoting the influence of light on the growth of phototrophic microorganisms in the catacombs. In addition, biofilm distribution was governed by the type of material to be colonised. This study shows that countermeasures are needed to prevent deterioration of hypogean environments.
Subject(s)
Bacteria/isolation & purification , Construction Materials/microbiology , Cyanobacteria/isolation & purification , Bacteria/classification , Bacteria/genetics , Biofilms/classification , Construction Materials/analysis , Cyanobacteria/classification , Cyanobacteria/genetics , Facility Design and Construction , Humans , Humidity , Lighting , Microclimate , Microscopy, Electron, Scanning , Porosity , RNA, Bacterial/analysis , RNA, Ribosomal, 16S/analysis , Rome , Sequence Analysis, RNA , TravelABSTRACT
In this work, we present the values of radon concentration, measured by continuous monitoring during a complete annual cycle in the Polychromes Hall of Altamira Cave in order to undertake more precise calculations of annual effective dose for guides and visitors in tourist caves. The (222)Rn levels monitored inside the cave ranges from 186 Bq m(-3) to 7120 Bq m(-3), with an annual average of 3562 Bq m(-3). In order to more accurately estimate effective dose we use three scenarios with different equilibrium factors (F=0.5, 0.7 and 1.0) together with different dose conversion factors proposed in the literature. Neither effective dose exceeds international recommendations. Moreover, with an automatic radon monitoring system the time remaining to reach the maximum annual dose recommended could be automatically updated.
Subject(s)
Air Pollutants, Radioactive/analysis , Occupational Exposure/analysis , Radon/analysis , Air Pollutants, Radioactive/standards , Humans , Radiation Dosage , Radiation Monitoring , Radiation Protection/standards , Radon/standards , Spain , Time FactorsABSTRACT
In order to study the wall corrosion processes induced by visitors in the Altamira Cave (northern Spain), a multidisciplinary study was conducted in the cave. For a period of 1 year, a microclimate monitoring system, measuring the temperature, relative humidity, CO2 and 222Rn concentrations was operated. Host rock samples were collected as well as indoor and outdoor atmospheric particulate matter. These data are used for a quantitative assessment of the wall corrosion processes. The presence of visitors was found to enhance the corrosion processes up to 78 times in comparison with the natural processes. Outdoor air pollution did not have a significant affect.