scholarly journals Organochlorine Pesticides and Polychlorinated Biphenyls in High Mountain Lakes, Mexico

Author(s):  
Liliana García-Solorio ◽  
Claudia Muro ◽  
Isaías De La Rosa ◽  
Omar Amador-Muñoz ◽  
Guadalupe Ponce-Vélez

Abstract Pollution levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the El Sol and the La Luna alpine lakes. The lakes are located in central Mexico, in the crater of the Nevado de Toluca volcano. The El Sol and the La Luna lakes are extremely relevant in Mexico and in the world because they are recognized as pristine regions and environmental reservoirs. Samples of atmospheric aerosol, sediment, plankton, and Tubifex tubifex were collected at three different sample locations for three years (2017, 2018, and 2019) at three different times of year, meaning that the weather conditions at the time of sampling were different. Pollutants were analysed by gas chromatography–mass spectrometry with negative chemical ionisation (GC-MS/NCI). Endosulfan was the most frequent and abundant pollutant, showing the highest peaks of all. Atmospheric aerosol revealed Σ2 = 45 pg/m3, including α and β, while sediment lakes displayed α, β and endosulfan sulphate as Σ3 = 1963 pg/g, whereas plankton and Tubifex tubifex showed Σ2 = 576 pg/g and 540 pg/g for α and β respectively. Results of endosulfan ratios (α/β) and (α-β/endosulfan sulphate) suggest that both fresh and old discharges continue to arrive at the lakesThis study shows for the first time the pollution levels of OCP and PCB in high mountain lakes in Mexico. These results that must be considered by policy makers to mitigate their use in the various productive activities of the region.

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 243
Author(s):  
Javier Alcocer ◽  
Luis A. Oseguera ◽  
Diana Ibarra-Morales ◽  
Elva Escobar ◽  
Lucero García-Cid

High-mountain lakes are among the most comparable ecosystems globally and recognized sentinels of global change. The present study pursued to identify how the benthic macroinvertebrates (BMI) communities of two tropical, high mountain lakes, El Sol and La Luna, Central Mexico, have been affected by global/regional environmental pressures. We compared the environmental characteristics and the BMI communities between 2000–2001 and 2017–2018. We identified three principal environmental changes (the air and water temperature increased, the lakes’ water level declined, and the pH augmented and became more variable), and four principal ecological changes in the BMI communities [a species richness reduction (7 to 4), a composition change, and a dominant species replacement all of them in Lake El Sol, a species richness increase (2 to 4) in Lake La Luna, and a drastic reduction in density (38% and 90%) and biomass (92%) in both lakes]. The air and water temperature increased 0.5 °C, and lakes water level declined 1.5 m, all suggesting an outcome of climate change. Contrarily to the expected acidification associated with acid precipitation, both lakes deacidified, and the annual pH fluctuation augmented. The causes of the deacidification and the deleterious impacts on the BMI communities remained to be identified.


2020 ◽  
Vol 42 (2) ◽  
pp. 105-118
Author(s):  
Javier Alcocer ◽  
Clara N Delgado ◽  
Ruben Sommaruga

Abstract We compared temporal changes in the concentration of photoprotective compounds (PCs) in zooplankton of two adjacent (600 m apart) tropical high mountain lakes, El Sol and La Luna. The lakes have the same geological origin, age and drainage basin. However, they differ in underwater light and UV penetration and in the presence of Oncorhynchus mykiss, only found in El Sol. Whereas Daphnia ambigua from the clear La Luna had carotenoids and melanin, in El Sol, the same species lacked pigmentation. The copepod Leptodiaptomus cuauhtemoci was only found in El Sol and relied on accumulation of MAAs and carotenoids. The maximum concentration of PCs was found over the period with highest incident ultraviolet radiation (UVR). Our data suggest that tropical species of zooplankton respond to UVR by accumulating PCs that are too different in relation to exposure to UVR. However, we cannot discard the possibility that the presence of fish in Lake El Sol influences also their phenotypical and behavioral responses. Overall, zooplankton exhibited an ample phenotypic plasticity in the type and concentrations of PCs in response to the high and variable doses of UVR prevailing in low-latitude lakes, similar to the zooplankton of their high-latitude counterparts.


2013 ◽  
Vol 84 (2) ◽  
pp. 387-397 ◽  
Author(s):  
Maria Vila-Costa ◽  
Albert Barberan ◽  
Jean-Christophe Auguet ◽  
Shalabh Sharma ◽  
Mary Ann Moran ◽  
...  

Diversity ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 42
Author(s):  
Estela Cuna ◽  
Javier Alcocer ◽  
Martha Gaytán ◽  
Margarita Caballero

Lakes El Sol and La Luna, inside the crater of the Nevado de Toluca volcano, Central Mexico, are the only two perennial high mountain lakes [HML] in the country. HML are considered among the most comparable ecosystems worldwide. These lakes are “extreme” environments with diluted, oligotrophic, and cold waters exposed to high UV radiation doses. In this paper, we document the phytoplankton species inhabiting these two extreme tropical ecosystems. The phytoplankton diversity of Lakes El Sol and La Luna is low compared to the global phytoplankton diversity from other Mexican inland waters. Nonetheless, the phytoplankton diversity turned out to be high compared to other HML worldwide, both temperate and tropical. The phytoplankton community in Lake El Sol was formed by 92 morphospecies and in Lake La Luna by 63; in both, the most diverse groups were Bacillariophyceae and Chlorophyceae. All species found in Lake La Luna were present in Lake El Sol, but 29 species present in Lake El Sol were absent in Lake La Luna. Nevertheless, 57% of the most frequent and abundant taxa in Lake El Sol were rare in La Luna, and 47% of the most frequent and abundant taxa in Lake La Luna were rare in Lake El Sol. Associated with their shallowness and polymictic thermal pattern, 87.5% of the Bacillariophyceae morphospecies are tychoplantonic, while the remaining 12.5% are truly planktonic. Dominant taxa were Chlorophyceae in Lake El Sol and Cyanobacteria in Lake La Luna. The most extreme conditions of Lake La Luna (ultraoligotrophy, very low pH, high ultraviolet radiation) most likely explained the differences in the dominant species composition and lower species richness compared to Lake El Sol. Herein, we provide for the first time a taxonomic list of the phytoplankton community of Lakes El Sol and La Luna. This information constitutes a baseline needed to use these HML as sentinels of global and climate change.


2014 ◽  
Vol 73 (3) ◽  
Author(s):  
Renata Trevisan ◽  
Marco Picarella ◽  
Frank B. Dazzo ◽  
Stefano Bona ◽  
Giuseppe Morabito ◽  
...  

2001 ◽  
Vol 1 ◽  
pp. 609-611 ◽  
Author(s):  
Joan O. Grimalt ◽  
Pilar Fernandez ◽  
Rosa M. Vilanova

High mountain areas have recently been observed to be polluted by organochlorine compounds (OC) despite their isolation. These persistent pollutants arrive at these remote regions through atmospheric transport. However, the mechanisms involving the accumulation of these compounds from the atmospheric pool to the lacustrine systems still need to be elucidated. These mechanisms must be related to the processes involving the transfer of these pollutant from low to high latitudes[1] as described in the global distillation effect[2].


2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Jordi Catalan ◽  
John C. Donato Rondón

<p>High mountain lakes are extreme freshwater ecosystems and excellent sentinels of current global change. They are likely among the most comparable ecosystems across the world. The largest contrast occurs between lakes in temperate and tropical areas. The main difference arises from the seasonal patterns of heat exchange and the external loadings (carbon, phosphorus, metals). The consequence is a water column structure based on temperature, in temperate lakes, and oxygen, in tropical lakes. This essential difference implies that, in tropical lakes, one can expect a more sustained productivity throughout the year; a higher nutrient internal loading based on the mineralization of external organic matter; higher nitrification-denitrification potential related to the oxyclines; and a higher metal mobilization due to the permanently reduced bottom layer. Quantifying and linking these and other biogeochemical pathways to particular groups of organisms is in the current agenda of high-mountain limnology. The intrinsic difficulties of the taxonomic study of many of the organisms inhabiting these systems can be now overcome with the use of molecular techniques. These techniques will not only provide a much less ambiguous taxonomic knowledge of the microscopic world, but also will unveil new biogeochemical pathways that are difficult to measure chemically and will solve biogeographical puzzles of the distribution of some macroscopic organism, tracing the relationship with other areas. Daily variability and vertical gradients in the tropics are the main factors of phytoplankton species turnover in tropical lakes; whereas seasonality is the main driver in temperate communities. The study of phytoplankton in high-mountain lakes only makes sense in an integrated view of the microscopic ecosystem. A large part of the plankton biomass is in heterotrophic, and mixotrophic organisms and prokaryotes compete for dissolved resources with eukaryotic autotrophs. In fact, high-mountain lake systems are excellent model ecosystems for applying an investigation linking airshed to sediments functional views. Additionally, the study of the mountain lakes districts as functional metacommunity units may reveal key differences in the distribution of organisms of limited (slow) dispersal. We propose that limnological studies at tropical and temperate high mountain lakes should adhere to a common general paradigm. In which biogeochemical processes are framed by the airshed-to-sediment continuum concept and the biogeographical processes in the functional lake district concept. The solid understanding of the fundamental limnological processes will facilitate stronger contributions to the assessment of the impacts of the on-going global change in remote areas.</p>


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