Aconcagua

Environmental risk assessments strategies that account for the complexity of exposures are needed in order to evaluate the toxic pressure of emerging chemicals, which also provide suggestions for risk mitigation and management, if necessary. Currently, most studies on the co-occurrence and environmental impacts of chemicals of emerging concern (CECs) are conducted in countries of the Global North, leaving massive knowledge gaps in countries of the Global South. In this study, we implement a multi-scenario risk assessment strategy to improve the assessment of both the exposure and hazard components in the chemical risk assessment process...

Two new species of Haplopappus (Asteraceae) from central Chile are described in this article. Haplopappuscolliguayensis sp. nov. is restricted to La Chapa hill, Colliguay, Valparaíso Region, and is most similar to H.undulatus but differs from the latter in its stem indumentum, leaf shape and margin, and synflorescence arrangement. Haplopappusteillieri sp. nov . has been recorded from four high-Andean localities in the Choapa, Petorca, Rocín and Aconcagua river basins, and is most similar to H.punctatus but differs from the latter in its leaf length and margin, number of peduncles per twig, width of outer phyllaries, number of ray florets per capitulum, and achene dimensions...

Chemical pollution caused by synthetic organic chemicals at low concentrations in the environment poses a growing threat to the ecological status of aquatic ecosystems. These chemicals are regularly released into surface waters through both treated and untreated effluents from wastewater treatment plants (WWTPs), agricultural runoff, and industrial discharges. Consequently, they accumulate in surface waters, distribute amongst environmental compartments according to their physicochemical properties, and cause adverse effects on aquatic organisms...

This study summarises six years of spatio-temporal patterns of the discarded demersal community fauna recorded by onboard scientific observer program for both artisanal and industrial crustacean fisheries between 2014 and 2019, from mesophotic to aphotic depths (96 to 650 m) along the southern Humboldt Current System (28-38°S). In this period, one cold and two warm climatic events were observed during the austral summer 2014, 2015-2016 (ENSO Godzilla), and 2016-2017 (coastal ENSO), respectively. Satellite information showed that Chlorophyll-a concentration varied seasonally and latitudinally, associated with upwelling centres, while equatorial wind stress decreased southward of 36°S...

Chromosomal rearrangements can directly influence population differentiation and speciation. The Liolaemus monticola complex in Chile is a unique model consisting of several chromosome races arranged in a latitudinal sequence of increasing karyotype complexity from south to north. Here, we compared chromosomal and mitochondrial cytochrome b data from 15 localities across the northern geographic distribution of L. monticola. We expanded the distribution of the previously described Multiple Fissions race (re-described as MF2), in the Coastal range between the Aconcagua River and the Petorca River, and described a new Multiple Fissions 1 (MF1) race in the Andean range...

Basking and retreat sites constitute a key resource in the habitat of any ectotherm. Identifying the elements that are used and modelling the microhabitat selection of species is crucial for assessing the impact of anthropogenic disturbances at the population level and, therefore, focusing on conservation efforts. We investigated how structural attributes of the microhabitat and biotic factors influence the probability of basking and retreat sites use by Phymaturus palluma, a rock-dwelling and viviparous lizard endemic to the Central Andes of Argentina...

The Mountain-Block Recharge (MBR), also referred to as the hidden recharge, consists of groundwater inflows from the mountain block into adjacent alluvial aquifers. This is a significant recharge process in arid environments, but frequently discarded since it is imperceptible from the ground surface. In fault-controlled Mountain Front Zones (MFZs), the hydrogeological limit between the mountain-block and adjacent alluvial basins is complex and, consequently, the groundwater flow-paths reflect that setting. To cope with the typical low density of boreholes in MFZs hindering a proper assessment of MBR, a combined geoelectrical-gravity approach was proposed to decipher groundwater flow-paths in fault-controlled MFZs...

Fascioliasis is a zoonotic disease caused by liver flukes transmitted by freshwater lymnaeid snails. Donkey and horse reservoir roles have been highlighted in human endemic areas. Liver fluke infection in mules has received very limited research. Their role in disease transmission, epidemiological importance and Fasciola hepatica pathogenicity are studied for the first time. Prevalence was 39.5% in 81 mules from Aconcagua, and 24.4% in 127 from Uspallata, in high-altitude areas of Mendoza province, Argentina...

OBJECTIVE: to compare mountaineers with and without asymptomatic sleep apnea (OSA) before the ascent and to study high altitude-related sleep disorders, its interaction with metabolic, neuroendocrine and immunological components. MATERIAL AND METHODS: During an expedition to Mount Aconcagua, researchers assessed the respiratory polygraphy (RP), clinical condition and inflammatory parameters, and rhythm of cortisol secretion in mountaineers sleeping at different altitude camps...

Mountain protected areas provide a range of ecosystem services including conserving biodiversity, while often providing recreation and tourism opportunities. Unfortunately, tourists and pack animals used to transport equipment can damage sensitive alpine vegetation particularly when they leave trails. This study assessed the impacts of disturbance from off trail use on alpine vegetation in a popular park in the Andes. The effect of different levels of disturbance as well as abiotic factors on alpine steppe vegetation was assessed using generalized linear models and ordinations in 91 plots (20 m2 ) in the popular Horcones Valley that is used to access remote areas in Aconcagua Provincial Park in Argentina...

Chile as a major international Cu producer faces serious soil contamination issues in mining areas. Currently Chile does not have any specific law governing the maximum permissible concentrations of metals in soils to protect ecosystems and human health. Chile heavily relies on the use of environmental laws of 14 foreign countries; the choice of the country depends on the similarity of its environmental conditions with those in Chile. In this study, we used an online database to compare the similarity of Chilean rocks to those in foreign countries...

In Central Chile, the increment of withdrawals together with drought conditions has exposed the poor understanding of the regional hydrogeological system. In this study, we addressed the Western Andean Front hydrogeology by hydrogeochemical and water stable isotope analyses of 23 springs, 10 boreholes, 5 rain-collectors and 5 leaching-rocks samples at Aconcagua Basin. From the upstream to the downstream parts of the Western Andean Front, most groundwater is HCO3 -Ca and results from the dissolution of anorthite, labradorite and other silicate minerals...

Social media images are a novel source of data to assess how people view and value the environment. Access to these images is often free, the volume and spread of images is expanding rapidly and hence they are an increasingly valuable source of data complementing and expanding on other data. Recently, coding images has been used to assess sociocultural values relating to ecosystem services including those provided by national parks. To further explore the use of social media images, including for remote environments, we analysed the content of images posted to Flickr by people visiting a national park that contains the highest mountain in the southern hemisphere, Mt...

Acinetobacter radioresistens strain DD78 (= CCUG 69565) is a soil hydrocarbon-degrading and biosurfactant-producing bacterium isolated from chronically crude oil-polluted soil of the Aconcagua River mouth in Chile. The 3.25-Mb A. radioresistens DD78 genome (41.8% GC content) was completely sequenced, with 4 replicons, 2,970 coding sequences, and 77 tRNAs.

Stable isotopes and geochemical proxies (TOC/TN and Chla/TOC) in sediments can be used to distinguish organic matter sources (anthropogenic, terrestrial, or marine). This study aims to characterize organic matter (OM) in superficial sediments from three sectors of central Chile (33°S) that are highly influenced by urban and industrial development. Our results show that a substantial fraction of these OM in Quintero Bay is anthropogenic, from industrial and domestic wastewater sources. In contrast, a mixture of terrestrial and anthropogenic OM dominates the isotopic signal of surface sediments from Concón, derived from non-point industrial and agriculture sources associated with the Aconcagua River basin, while Ritoque exhibited a mixture of different OM sources...

Introduction: Mountaineers exposed to hypobaric hypoxia (HH) show high-altitude periodic breathing (PB). Objective: To analyze high-altitude PB during the ascent of Mount Aconcagua (Argentina). Materials and Methods: Descriptive study in healthy volunteers using respiratory polygraphy (RP) at different altitudes. Results: We studied 8 andinist, mean age: 36 years old (25-51), body mass index (BMI) of 23.6 (20.9-28.7) and 22...

Managing protected areas effectively requires information about patterns of visitor use, but these data are often limited. We explore how geotagged photos on Flickr, a popular photo-sharing social-media site, can generate hotspot maps and distribution models of temporal and spatial patterns of use in two mountain-protected areas of high conservation value. In Aconcagua Provincial Park (Argentina), two routes to the summit of Aconcagua were used in summer, but most visitors stayed close to the main road, using formal and informal walking trails and the Visitor Centre, while in winter, there was very limited visitation...

The estuaries of the Aconcagua and Maipo Rivers of central Chile are receptors of residues that contain metals from anthropic activities including agriculture, mining and smelters, which have different levels in the two basins. This study postulates that the exposition to metals is different in the two estuaries and that their sediments contain bioavailable chemical agents that produce oxidative stress. The aim of the study was to evaluate the effect of estuarine sediments on the polychaete Perinereis gualpensis using oxidative stress biomarkers and to determine the metal concentrations in sediments and their accumulation in P...

Steier, Joerg, Nic Cade, Ben Walker, John Moxham, and Caroline Jolley. Observational study of neural respiratory drive during sleep at high altitude. High Alt Med Biol. 18:242-248, 2017. AIMS: Ventilation at altitude changes due to altered levels of pO2 , pCO2 and the effect on blood pH. Nocturnal ventilation is particularly exposed to these changes. We hypothesized that an increasing neural respiratory drive (NRD) is associated with the severity of sleep-disordered breathing at altitude...

When visitors are not constrained to remain on formal trails, informal trail networks can develop and damage plant communities in protected areas. These networks can form in areas with low growing vegetation, where formal trails are limited, where there is limited regulation and where vegetation is slow to recover once disturbed. To demonstrate the extent of impacts from unregulated recreational use, we assessed damage to alpine vegetation by hikers and pack animals in the highest protected area in the southern Hemisphere: Aconcagua Park, in the Andes...