Search Results (20)

Unconfined coastal karst aquifers are highly susceptible to contamination from anthropogenic activities, particularly in regions lacking adequate wastewater treatment. Their open hydrological structure facilitates the input and dispersion of contaminants from both point and non-point sources. Furthermore, groundwater exerts a significant influence on coastal water quality through submarine discharge that could impact vulnerable ecosystems like seagrasses, mangroves, and coral reefs. Seasonal hydrological variability—especially between dry and rainy periods—affects contaminant transport, with increased groundwater flux potentially enhancing spatial dispersion. Additionally, the balance between the contributions from the coastal karst aquifer and the hydrodynamics of the coastal zone determines the extent and degree of salinization occurring at the interface between these two systems, which in turn influences aquifer water quality. This study presents a five-year dataset of metal and nutrient concentrations measured during dry and rainy seasons in surface waters (0.5 m depth) from 24 cenotes within the Ring of Cenotes (RC), Yucatán Peninsula, Mexico. The RC functions as a preferential groundwater flow path from inland to the coast via underwater conduits and submarine groundwater discharge (SGD), transporting contaminants present in groundwater into highly vulnerable coastal ecosystems. While most parameters remained below regulatory thresholds, concentrations of total Al, Cr, Pb, and N-NH₃ exceeded limits established by NOM-127-SSA1-2021 at several sites measured within the RC. Spatial heterogeneity was observed across seasons and years, driven by groundwater flux dynamics, land use, and individual sinkhole characteristics. Notably, N-NH₃ concentrations were higher during the dry season, particularly near agricultural and peri-urban zones. These findings underscore the need for mandatory wastewater treatment and integrated coastal karstic aquifer management to protect the region’s sole freshwater resource and the vulnerable ecosystems in the coastal area. Full article

In coastal regions, the interaction between freshwater and seawater creates a dynamic system in which the spatial distribution of salinity critically constrains the use of freshwater for human consumption. Although saline intrusion is a globally widespread phenomenon, its inland extent varies significantly with hydrological conditions, posing a persistent threat to groundwater quality and sustainability. This study aimed to characterize salinity distribution using an integrated karst-watershed approach, thereby enabling the identification of both lateral and vertical salinity gradients. The study area is in the northwestern Yucatan Peninsula. Available hydrogeological data were analyzed to determine aquifer type, soil texture, evidence of saline intrusion, seawater fraction, vadose zone thickness, and field measurements. These included sampling from 42 groundwater sites (open sinkholes and dug wells), which indicated a fringe zone approximately 5 km in size influenced by seawater interaction, in mangrove areas and in three key zones of salinity patterns: west of Mérida (Celestun and Chunchumil), and northern Yucatan (Sierra Papacal, Motul, San Felipe). Vertical Electrical Sounding (VES) and conductivity profiling in two piezometers indicated an apparent seawater influence. The interface was detected at a depth of 28 m in Celestun and 18 m in Chunchumil. These depths may serve as hydrogeological thresholds for freshwater abstraction. Results indicate that saltwater can extend several kilometers inland, a factor to consider when evaluating freshwater availability. This issue is particularly critical within the first 20 km from the coastline, where increasing tourism exerts substantial pressure on groundwater reserves. A coastal-to-inland salinity was identified, and an empirical equation was proposed to estimate the seawater fraction (fsea%) as a function of distance from the shoreline in the Cenote Ring trajectory. Vertically, a four-layer model was identified in this study through VES in the western watershed: an unsaturated zone approximately 2.6 m thick, a confined layer in the coastal Celestun profile about 9 m thick, a freshwater lens floating above a brackish layer between 8 and 25 m, and a saline interface at 37 m depth. The novelty of this study, in analyzing all karstic water surfaces together as a system, including the vadose zone and the aquifer, and considering the interactions with the surface, is highlighted by the strength of this approach. This analysis provides a better understanding and more precise insight into the integrated system than analyzing each component separately. These findings have significant implications for water resource management in karst regions such as Yucatan, underscoring the urgent need for sustainable groundwater management practices to address seawater intrusion. Full article

This study employs a thorough methodology to define water sustainability criteria for the development of new pig farms on the karst aquifer of Yucatan, Mexico. The integrated approach entails a field campaign to assess water quality from the aquifer (wells and cenotes) and effluents from designated pig farms to evaluate adherence to environmental regulations, alongside the utilisation of an extensive pig farm database that includes pig populations by the municipality in Yucatan. The water sustainability of pig farming in Yucatan was analysed by evaluating the nitrogen greywater footprint and water pollution levels for this municipality sector. The intensive pig farming practices in Yucatan significantly contribute to water contamination through nutrient runoff, namely nitrogen and phosphorus. Moreover, the breach of environmental regulations concerning pig farm effluents is demonstrated. This highlights the urgent need to regulate and monitor the expansion of new pig farms in Yucatan. Results introduce evidence-based criteria and their thresholds for achieving water sustainability in the pig sector at the municipal level (Pigs/ha = 1.0 and WPL < 1.1). This facilitated a concerted effort between national and state authorities to limit the proliferation of pig farms in order to safeguard the aquifer’s water quality. Full article

The Yucatan Peninsula (YP) presents heterogeneous environments in a karstic landscape that has been formed from permeable sedimentary rocks dating from the Cretaceous period. Its aquifers now face significant pressure from tourism, agriculture, soil use changes and population growth. Aquifer delimitation typically relies on environmental and socioeconomic criteria, overlooking the subterranean fauna. Stygobiotic crustaceans are highly diverse in the YP’s subterranean karstic systems, expressing adaptations to extreme environments while often also displaying the primitive morphology of evolutionary relics. With distributions restricted to specific environments, they are potential markers of water reserves. A literature review recovered records of 75 species of crustaceans from 132 subterranean systems in the YP, together with geomorphological, hydrological, hydrogeochemical and historical precipitation data. Fourteen UPGMA clusters were informative for mapping species composition, whereby the “Ring of Cenotes”, “Caribbean Cave” and “Cozumel Island” regions were delineated as consolidated aquifers. These aquifers are distinguished by abiotic factors as well: freshwater species dominate the Ring of Cenotes, while marine-affinity species characterize the Caribbean Cave and Cozumel Island aquifers. Stygobiotic crustaceans, being linked to geologically ancient water reserves and having a restricted distribution, offer a complementary tool for aquifer delimitation. Their presence suggests long-term and stable water availability. The use of these unique organisms for integrative aquifer delimitation can provide a way to improve the monitoring networks of regional aquifers. Full article

Biodiversity patterns provide insights into the conservation value of ecosystems and also aid in an understanding of some research priorities. This research paper presents an exhaustive inventory of crustaceans and fish species from the Yucatan Peninsula’s epicontinental, underground, and anchialine aquatic systems. Using records spanning from 1936 to 2024, this study analyzed over 2600 entries across 670 aquatic systems, including cenotes, flooded cave lakes, springs, and wetlands. A total of 329 species were recorded, comprising 117 fish and 212 crustacean species. The richness and endemism of these species were assessed through a completeness analysis, utilizing non-parametric models (Chao 2, Jackknife 1, Bootstrap) to estimate potential species richness. Notably, the region exhibits high endemism, especially among crustaceans, with up to 50 species and 2 endemic families being unique to the Yucatan Peninsula. This study underscores the importance of the eastern YP for crustaceans and the central YP for fish, highlighting areas critical for conservation. These findings emphasize the need for further exploration, as the diversity of aquatic species remains incompletely understood. This comprehensive synthesis aims to inform future conservation strategies, environmental management, and regional planning efforts, particularly highlighting the vulnerability of these unique aquatic systems to environmental degradation. Full article

“El Aerolito” is the most biodiverse cenote cave globally, home to Poecilia velifera and Gambusia yucatana. However, their trophic niches and interactions remain undescribed. A total of 53 P. velifera and 38 G. yucatana were analyzed for stable isotopes, along with water samples for chlorophyll, silicates, and physical–chemical parameters. Data were collected during the norths, rainy, and dry seasons in the year 2023. Isotopic niches were calculated, and a PCA analysis was used to assess environmental factors. P. velifera showed δ¹³C values of −25.4‰, −25.7‰, and −24.5‰, whereas G. yucatana exhibited −24.8‰, −24.0‰, and −24.2‰ across seasons. Niche size varied, with the largest during the norths and smallest during the rainy season, indicating seasonality. PCA linked environmental parameters (e.g., temperature and dissolved oxygen) to resource availability, suggesting niche shifts due to rainfall. Mangroves and insects contributed to the isotopic signals, with shifts observed during the dry and rainy seasons. The highest water parameter values occurred during the dry and rainy seasons, while the lowest was during the norths. The system, nutrient-poor and lacking chlorophyll production, relies on external sources. The study concludes that isotopic niches are dynamic and seasonally influenced by abiotic factors, especially rainfall. Full article

The present research was carried out in stands of Scots pine and black pine, pure or mixed with deciduous trees, installed on degraded lands from the Curvature Subcarpathian area, Romania, in a representative network of permanent research plots and followed the analysis of the structural diversity and stability indicators of these stands at different ages and in different conditions of degraded lands. The relationships between the quantitative variables with reference to the structure were established by analyzing the significance of the Pearson correlation coefficient (r) and also including datasets of slenderness indexes, which were classed into three domains of vulnerability to abiotic factors (like wind and snow). The compositional diversity of pine stands (pure or mixed with deciduous ones) is different in relation to age and is correlated with the structural diversity. The obtained correlation coefficients (r Pearson) express very strong and significant relationships between biometric parameters (h x Dbh, h x Lc%, Dc x Dbh, and Lc% x Dbh) of the structural diversity (r = 0.800–0.930), which is important for the analysis of the stability and vulnerability of pine forests. The strong correlation between the analyzed variables expresses a weak vulnerability to the action of harmful abiotic factors and the increase in the stability and resilience of the studied stands, especially of over 50 years old. In the old pine stands, the low-vulnerability domain (I < 0.80) is the best represented one, with an average of 64.01% from the total number of trees. At this age, trees with DBH > 22 cm fall into the low-vulnerability category. The explanation is that the stands were affected in their youth by the action of snow and wind, which, combined with the silvotechnical works performed, led to their compositional and structural diversification and increased stability. The young (<45 years) and pure-pine stands with higher consistency (>0.8) and even-aged structure are the most vulnerable to abiotic factors due to the fact that a large number of trees are passing gradually into the higher cenotic classes. Full article

In this work, electrical resistivity tomography was carried out together with physical hydrogeology techniques to evaluate the karst aquifer in the northwest region of the Yucatán Peninsula in a study area near the western edge of the Ring of Cenotes of the Chicxulub Crater. In addition, based on a systematic compilation of open-access data of water levels reported for the peninsular aquifer, maps of groundwater isolines and groundwater flows were generated using IDW interpolation, Empirical Bayesian Kriging, and the Flow Net method. From these results, a shallow aquifer is observed, with the presence of heterogeneities such as possible dissolution conduits and/or flooded caverns, approximately 20 m below ground level, formed by the dissolution processes of limestone rocks. On a regional scale, the geomorphological influence of the Ring of Cenotes on groundwater flows was observed. In general, the flow directions observed from these maps coincide with those conceptualized for this region of the peninsular aquifer. Nevertheless, some differences were observed depending on the interpolation method used. Our results contribute to hydrogeological studies carried out in the periphery of this ring, where the vulnerability of the aquifer to anthropogenic contamination has been highlighted due to the intrinsic features of the karst environment. Full article

Plants of arid regions have adapted to harsh environments during the long span of their evolution and have developed a set of features necessary for their survival in water-limited conditions. Artemisia frigida Willd. (Asteraceae) is a widely distributed species possessing significant cenotic value in steppe ecosystems due to its high frequency and abundance. This study examines different patterns of formation of essential oil composition in A. frigida plants under the influence of heterogeneous factors, including climate and its integral characteristics (HTC, C_extr, SPEI and others). The work is based on the results of our research conducted in Russia (Republic of Buryatia, Irkutsk region), Mongolia, and China, from 1998 to 2021. A total of 32 constant compounds have been identified in the essential oil of A. frigida throughout its habitat range in Eurasia, from Kazakhstan to Qinghai Province, China. Among them, camphor, 1,8-cineol and bornyl acetate are the dominant components, contained in 93–95% of the samples. Among the sesquiterpenoids, germacrene D is the dominant component in 67% of the samples. The largest variability within the composition of the essential oils of A. frigida is associated with significant differences in the climatic parameters when plants grow in high-altitude and extrazonal conditions. Full article

Through the execution of scientific innovations, “smart materials” are shaping the future of technology by interacting and responding to changes in our environment. To make this a successful reality, proper component selection, synthesis procedures, and functional active agents must converge in practical and resource-efficient procedures to lay the foundations for a profitable and sustainable industry. Here we show how the reaction time, temperature, and surface stabilizer concentration impact the most promising functional properties in a cotton-based fabric coated with silver nanoparticles (AgNPs@cotton), i.e., the thermal and bactericidal response. The coating quality was characterized and linked to the selected synthesis parameters and correlated by a parallel description of “proof of concept” experiments for the differential heat transfer (conversion and dissipation properties) and the bactericidal response tested against reference bacteria and natural bacterial populations (from a beach, cenote, and swamp of the Yucatan Peninsula). The quantification of functional responses allowed us to establish the relationship between (i) the size and shape of the AgNPs, (ii) the collective response of their agglomerates, and (iii) the thermal barrier role of a surface modifier as PVP. The procedures and evaluations in this work enable a spectrum of synthesis coordinates that facilitate the formulation of application-modulated fabrics, with grounded examples reflected in “smart packaging”, “smart clothing”, and “smart dressing”. Full article

We investigated taxonomic and endemic richness, patterns of spatial distribution, cenotic and spatial diversification, and chorological and life form spectra of montane coniferous forests in the central part of the Balkan Peninsula. We collected information on 1435 taxa (1351 at the level of species and 84 subspecies) with 65,289 species-occurrence data, published in 1930 original plots with a total area of about 215 ha in the analysis. All statistical analyses (univariate and multivariate) were performed on binary matrices prepared for different levels of analysis. Our main results showed that the montane coniferous forests of the central Balkan Peninsula represent very species-rich vegetation. At the same time, the high proportion of endemics indicated that the montane coniferous forests of the central Balkan Peninsula differ significantly from Central European and boreal forests of a similar type. Furthermore, we found that there were regional differences in the species composition of the coniferous forests of the Balkan Peninsula, and that the primary centers of floristic richness are located in the area of the central and continental Dinarides. This latter finding suggested that the true centers of the richness of European coniferous forests are located south of the Limestone Alps—Western Dinarides—Carpathian Foothills line in Romania, which used to be considered the center of the richness of the coniferous forests in Europe. Full article

In a relatively short timescale (less than 50 years), urbanization has caused many anthropogenic disturbances that have affected ecosystem health and, directly or indirectly, quality of life for the local human population. Global disturbances, such as climate change, can also have a substantial, overarching impact on ecosystems. In this scenario, natural disturbances, previously considered an integral part of ecosystem dynamics, can now cause irreversible change to the state of ecosystems, and at the same time, negatively impact social and economic systems. The objective of this study was to identify ecosystem disturbances at a site of interest to recommend strategies to improve coastal zone management. We chose the Mexican Caribbean as a case study, because its biological and cultural complexity render it an interesting location from a coastal management point of view. The PRISMA framework was used to conduct a systematic literature review to identify the ecosystem disturbances that affect this area, as well as the main causes and consequences of these disturbances. Additionally, we discuss how disturbances and their impacts, as screened through PRISMA, can be incorporated into a coastal zone management framework. Results need to consider the limitations associated with using this technique e.g., the degree of impact from a current disturbance may vary from that reported in an earlier publication. Despite its limitations, we believe that this methodology proves useful for identifying key ecosystem disturbances and their consequences, providing a useful tool for identifying appropriate actions to inform coastal zone management plans. Full article

While recent changes in treatment have reduced the lethality of idiopathic chronic diarrhea (ICD), this condition remains one of the most common causes of rhesus macaque deaths in non-human primate research centers. We compared the viromes in fecal swabs from 52 animals with late stage ICD and 41 healthy animals. Viral metagenomics targeting virus-like particles was used to identify viruses fecally shed by each animal. Five viruses belonging to the Picornaviridae, one to the Caliciviridae, one to the Parvoviridae, and one to the Adenoviridae families were identified. The fraction of reads matching each viral species was then used to estimate and compare viral loads in ICD cases versus healthy controls. None of the viruses detected in fecal swabs were strongly associated with ICD. Full article

The Mexican Caribbean is part of the Mesoamerican Barrier Reef System, considered the second largest reef system globally. This system, as well as inland aquatic ecosystems, are at risk of contamination due to the intensive use of sunscreen by the tourists who visit the Riviera Maya each year. At present, the regulation and management of sunscreens are inconsistent, with most policies and legislation focused on the protected marine areas with little current focus on inland aquatic ecosystems. An estimated 229.76 tons of sunscreen are used annually, with residues putting the health of the marine and freshwater aquatic ecosystems and residents at risk. Groundwater is used recreationally (e.g., tourists swimming in sinkholes or cenotes) and as household drinking water. To understand the environmental impacts of sunscreen use and the management implications, a mixed-methods study was carried out, combining survey and interview data on how tourists use sunscreen and their perceptions of discharge of sunscreens into the water, with analysis of regional, national and international policies and legislation. Our findings of touristic behaviors, gaps in current legislation, and the pollution implications of different sunscreen types provide useful information for future decision-making and the creation of stronger environmental regulations. Full article

We present 52 new geographic location records for the peracarid crustacean Antromysis cenotensis Creaser, 1936, endemic in cenotes of the Yucatan Peninsula, Mexico. This species is currently considered threatened and, therefore, is protected by Mexican law. These results arise from several expeditions carried out between 2017 and 2020 in 75 locations within the cenote-ring, the interior, and coastal plains of the peninsula. A comprehensive literature review provided 84 geographic location records since the species was described in 1936. A map with 136 geographic location records that better describe the current species distribution is also included. With this information, plus some notes on the ecology of the species, a comprehensive literature and data review, and a brief analysis regarding the possible factors associated with the confirmed absence of the species in some locations in the state of Yucatan, we provide a brief and condensed summary of the actual knowledge on this particular species. The data in Darwin Core format can be retrieved in Zenodo. Full article