Habitat Constraints in Epikarstic Waters of an Iberian Peninsula Cave System

14 páginas, 6 figuras, 11 tables et al..The epikarstic waters of a restricted sector of the Ojo Guareña cave (north Iberian Peninsula) were investigated to characterize the physico-chemical variation in an annual cycle, to improve the scarce knowledge of the aquatic cave fauna on the Iberian Peninsula, to look for distribution patterns of species per habitat along the annual cycle, and to search for the environmental basis (either physico- or hydro-geochemical) that could explain species distribution in the epikarst. The habitats studied included all puddles and gours present in the sector selected making a total of 51 chemical and 42 biological samples for the entire cycle. The waters show no appreciable contaminationand exhibit small chemical variations throughout the year which are patently affected by external weather conditions. The 53 taxa found belong to ten higher taxonomic groups (Oligochaeta, Turbellaria, Mollusca, Copepoda, Ostracoda, Isopoda, Bathynellacea, Tardigrada, Acarina and Cnidaria), and consist mainly of crustacea with a total of 27 species. Fourteen species were stygobionts (belonging to ten genera), nine of which are new to science and ten of which are endemic. Cave pools that appeared to be more stable in terms of water volume and mineralization, had a lower pCO2 and were carbonate oversaturated, harboured the greatest number of taxa. It is these pools that can maintain strictly cave dwelling species. Pools with lower levels of mineralization and greater water volume fluctuations had a lower diversity of fauna and in general lacked stygobiotic species.Projects PASCALIS EVK2-CT-2001-00121; Convenio Junta de Castilla y León-CSIC (2002-2004) and BTE2002-04492-C02-02.Peer reviewe

High radon levels in subterranean environments: monitoring and technical criteria to ensure human safety (case of Castañar cave, Spain)

Castañar cave contains the highest radon gas (222Rn) concentration in Spain with an annual average of 31.9 kBq m−3. Seasonal variations with summer minimums and maximum values in fall were recorded. The reduction of air-filled porosity of soil and rock by condensation or rainfalls hides the radon exchange by gas diffusion, determining this seasonal stair-step pattern of the radon activity concentration in underground air. The effective total dose and the maximum hours permitted have been evaluated for the guides and public safety with a highly detailed radon measurement along 2011 and 2012. A network of 12 passive detectors (kodalphas) has been installed, as well as, two radon continuous monitoring in the most interesting geological sites of the subterranean environment.A follow up of the recommended time (max. 50 min) inside the underground environment has been analysed since the reopen to public visitors for not surpassing the legal maximum effective dose for tourists and guides. Results shown that public visitors would receive in fall a 12.1% of the total effective dose permitted per visit, whereas in summer it is reduced to 8.6%, while the cave guide received a total effective dose of 6.41 mSv in four months.The spatial radon maps allow defining the most suitable touristic paths according to the radon concentration distribution and therefore, appropriate fall and summer touristic paths are recommended.This research was funded by the Regional Government of Extremadura (Spain) through EAFRD Axis 2 “Improving the environment and the countryside” and the Spanish Ministry of Economy and Competitiveness through project CGL2013-43324R and the programme Torres Quevedo (PTQ 13-06296 and PTQ 12-05601).A.F-C is funded by an IEF Marie Curie Action (FP7/2007–2013) under REA grant agreement n° 624204Peer reviewe

Análisis geoambiental en medios hipogeos

8 páginas, 1 figura. Ed. Miguel Ángel Rogerio Candelera y Cesáreo Sáiz Jiménez. Primera Reunión de la Red de Ciencia y Tecnología para la Conservación del Patrimonio (Madrid, 28-29 de junio de 2011).Los coordinadores de los dos grupos de trabajo localizados actualmente en dos instituciones independientes (CSIC, Universidad de Alicante) se iniciaron científica y profesionalmente en el equipo de investigación de Geología - Geoquímica - Microclima aplicados a la Conservación del Patrimonio que se formó bajo la dirección de Manuel Hoyos Gómez a principios de la década de los 90. En el campo de la Conservación del Patrimonio, las investigaciones de ese grupo se centraron especialmente en la protección del arte rupestre y actualmente se enfocan al estudio integrado de ambientes subterráneos (cuevas, catacumbas,túneles, etc.) y de los procesos de deterioro del patrimonio que albergan. Los proyectos en los que los dos grupos trabajan abitualmente en estrecha relación incluyen datos de los parámetros climáticos y microclimáticos que caracterizan los sitios de estudio, de las características mineralógicas, geoquímicas y petrofísicas de los soportes y de las aguas de infiltración, y de los aspectos geomicrobiológicos de la interacción entre microoorganismos y los diferentes sustratos existentes (rocas, materiales de construcción, espeleotemas, etc.).Peer reviewe

Geochemical Fingerprinting of Rising Deep Endogenous Gases in an Active Hypogenic Karst System

The hydrothermal caves linked to active faulting can potentially harbour subterranean atmospheres with a distinctive gaseous composition with deep endogenous gases, such as carbon dioxide (CO2) and methane (CH4). In this study, we provide insight into the sourcing, mixing, and biogeochemical processes involved in the dynamic of deep endogenous gas formation in an exceptionally dynamic hypogenic karst system (Vapour Cave, southern Spain) associated with active faulting. The cave environment is characterized by a prevailing combination of rising warm air with large CO2 outgassing (>1%) and highly diluted CH4 with an endogenous origin. The δ13CCO2 data, which ranges from −4.5 to −7.5‰, point to a mantle-rooted CO2 that is likely generated by the thermal decarbonation of underlying marine carbonates, combined with degassing from CO2-rich groundwater. A pooled analysis of δ13CCO2 data from exterior, cave, and soil indicates that the upwelling of geogenic CO2 has a clear influence on soil air, which further suggests a potential for the release of CO2 along fractured carbonates. CH4 molar fractions and their δD and δ13C values (ranging from −77 to −48‰ and from −52 to −30‰, respectively) suggest that the methane reaching Vapour Cave is the remnant of a larger source of CH4, which was likely generated by microbial reduction of carbonates. This CH4 has been affected by a postgenetic microbial oxidation, such that the gas samples have changed in both molecular and isotopic composition after formation and during migration through the cave environment. Yet, in the deepest cave locations (i.e., 30m below the surface), measured concentration values of deep endogenous CH4 are higher than in atmospheric with lighter δ13C values with respect to those found in the local atmosphere, which indicates that Vapour Cave may occasionally act as a net source of CH4 to the open atmosphere

Patrimonio geológico: valorización y utilización funcional

The geological heritage has usually undergone legislative or conceptual developments. A new strategy is here proposed, which intends to change the ordinary point of view towards a horizontal model, including a bigger participation of social and economic agents of a region. A change in information, education and participation processes apears necessary. Such change should be based on a deeper analysis of the geological reality related to the results of European program targets as well as on a more structured view of the places of geological interest

Deterioration of an Etruscan tomb by bacteria from the order Rhizobiales

7 páginas, 4 figuras, 29 referencias.The Etruscan civilisation originated in the Villanovan Iron Age in the ninth century BC and was absorbed by Rome in the first century BC. Etruscan tombs, many of which are subterranean, are one of the best representations of this culture. The principal importance of these tombs, however, lies in the wall paintings and in the tradition of rich burial, which was unique in the Mediterranean Basin, with the exception of Egypt. Relatively little information is available concerning the biodeterioration of Etruscan tombs, which is caused by a colonisation that covers the paintings with white, circular to irregular aggregates of bacteria or biofilms that tend to connect each other. Thus, these colonisations sometimes cover extensive surfaces. Here we show that the colonisation of paintings in Tomba del Colle is primarily due to bacteria of the order Rhizobiales (Alphaproteobacteria), which were likely influenced by the neighbouring rhizosphere community and the availability of nutrients from root exudates.This work was funded through the projects CGL2010-17183, 201030E011 and Consolider 2007-00058. M.D.H. was supported by a JAE Research Fellowship from CSIC, and S.C. was supported by a Juan de la Cierva contract.Peer reviewe

New insights into the structure, microbial diversity and ecology of yellow biofilms in a Paleolithic rock art cave (Pindal Cave, Asturias, Spain)

In the absence of sunlight, caves harbor a great diversity of microbial colonies to extensive biofilms with different sizes and colors visible to the naked eye. One of the most widespread and visible types of biofilm are those with yellow hues that can constitute a serious problem for the conservation of cultural heritage in many caves, such as Pindal Cave (Asturias, Spain). This cave, declared a World Heritage Site by UNESCO for its Paleolithic parietal art, shows a high degree of development of yellow biofilms that represents a real threat to the conservation of painted and engraved figures. This study aims to: 1) identify the microbial structures and the most characteristic taxa composing the yellow biofilms, 2) seek the linked microbiome reservoir primarily contributing to their growth; 3) seed light on the driving vectors that contribute to their formation and determine the subsequent proliferation and spatial distribution. To achieve this goal, we used amplicon-based massive sequencing, in combination with other techniques such as microscopy, in situ hybridization and environmental monitoring, to compare the microbial communities of yellow biofilms with those of drip waters, cave sediments and exterior soil. The results revealed microbial structures related to the phylum Actinomycetota and the most characteristic bacteria in yellow biofilms, represented by the genera wb1-P19, Crossiella, Nitrospira, and Arenimonas. Our findings suggest that sediments serve as potential reservoirs and colonization sites for these bacteria that can develop into biofilms under favorable environmental and substrate conditions, with a particular affinity for speleothems and rugged-surfaced rocks found in condensation-prone areas. This study presents an exhaustive study of microbial communities of yellow biofilms in a cave, which could be used as a procedure for the identification of similar biofilms in other caves and to design effective conservation strategies in caves with valuable cultural heritage.This research was supported by the Spanish Ministry of Science and Innovation through project PID2019-110603RB-I00 and the collaboration of PID2020-114978GB-I00 project, MCIN/AEI/FEDER, UE/10.13039/501100011033. This is a contribution from CSIC Interdisciplinary Thematic Platform Open Heritage: Research and Society (PTI-PAIS)

Detection of human-induced environmental disturbances in a show cave

Purpose: We investigated the effects of human-induced disruption in a subterranean stable environment containing valuable Palaeolithic paintings and engravings (Ardales Cave, Southern Spain) using a double analytical approach. Methods: An environmental monitoring system was installed in the cave to record temperature, relative humidity, carbon dioxide (CO2) and radon (222Rn) concentrations in air. In the same stations, an aerobiological sampling was conducted to quantify the level of airborne microorganisms. Results: The combination of different methods allowed us to detect the extent of human-induced changes, confirming that these can be very hazardous in certain cave areas that should be apparently outside the scope of human disturbances, either by their remoteness to the visitor entrance or by being briefly visited. Conclusions: The detection of evident anomalies in the environmental parameters and airborne microorganism concentration in the cave area housing the high density of paintings and engravings helps to control human disturbances and supports the direct application of this double approach for cave management purposes.Peer Reviewe

Die Wettbewerbsfähigkeit der arabischen Mittelmeerländer im internationalen Vergleich

6 p.- Papers presented at the International Workshop "The Conservation of Subterranean Cultural Heritage", held 25-27 March 2014, in Seville, Spain.Paranhos constitutes one of the main water galleries excavated in the granite substratum of Porto City (Portugal) to gather the groundwater for public use during the past five centuries. This gallery is a Subterranean Cultural Heritage site with a potential use for underground geotourism under safe conditions. An environmental monitoring programme has been conducte in the site comprising rapid multi-parameters. This programme has allowed the identification of urban-induced causes of contamination of the aquifer and internal tunnel atmosphere (waste-water and gas leakage). This study has also comprised the determination of effective radioactive dose in different sectors of the tunnel for potential visitors based on 222Rn studies.Financiado con el Proyecto (HAR-2010-11432-E) Red de Ciencia y Tecnología para la Conservación del Patrimonio CulturalPeer reviewe