Lerma-Chapala Basin Research Articles

Historical analysis of an imperiled fish species: environmental variables modeling, biotic interactions, extirpation, and current restricted-range.

Analyses of spatial and temporal patterns and interactions are important for determining the abiotic factors limiting populations and the impact from other species and different anthropogenic stressors that promote the extirpation of species. The fish Hubbsina turneri de Buen (1940) was studied as a model species in a historical context at varying locations. Originally distributed only in the Lerma-Chapala basin, the main lake complex in Mexico, this species has not been collected from Lake Cuitzeo (LC) and now is restricted to Lake Zacapu (LZ). At present, the Highland splitfin is classified as critically endangered. Historical information of LC and historical and current information from LZ were explored by applying cluster analysis and generalized additive mixed model (GAMM) to describe the biotic interactions among fish species and the relationship between density and environmental variables, respectively. The two lakes' contrasting abiotic/biotic characteristics provided elements to describe some species distribution limits in chemical ion gradients. Extirpation calendar dates were estimated using an optimal linear estimation method. Finally, a bibliographic review was conducted on the causes that promoted the extirpation and restriction of H. turneri and the prognosis for its reestablishment and conservation. Clusters showed the fishes relationship according to their distribution along the lakes. GAMM indicated that high H. turneri density is related to low hardness/fecal coliforms, medium depth/suspended solids, and high oxygen concentration. Estimated extirpation dates were between the years 2013 and 2018. The extirpation was linked to an abrupt drop in the LC volume, water quality degradation, increased biotic interactions within macrophytes habitats with native and introduced species, and fisheries bycatches. The current restricted range of H. turneri resulted from the draining of the larger lake, forcing the remaining populations to small spring-fed remnants. Recent samplings in LZ resulted in a low number of individuals. The integration of ecological interactions derived from statistical models, extirpation dates from nonparametric tests, and the exhaustive analysis of historical information can be applied to define the current situation of imperiled, ecologically relevant species, in different aquatic ecosystems. We are confident that this general framework is important for determining (1) the requirements and limitations of populations regarding abiotic variables, (2) biotic interactions (trophic and spatial) with native and introduced species, and (3) different anthropogenic stressors within and around the ecosystem. This knowledge will also allow understanding those aspects that contribute to the extirpation of populations and could help the restoration of the habitat and the reintroduction of extirpated species.

Metallophores production by bacteria isolated from heavy metal-contaminated soil and sediment at Lerma-Chapala Basin.

Environmental pollution as a result of heavy metals (HMs) is a worldwide problem and the implementation of eco-friendly remediation technologies is thus required. Metallophores, low molecular weight compounds, could have important biotechnological applications in the fields of agriculture, medicine, and bioremediation. This study aimed to isolate HM-resistant bacteria from soils and sediments of the Lerma-Chapala Basin and evaluated their abilities to produce metallophores and to promote plant growth. Bacteria from the Lerma-Chapala Basin produced metallophores for all the tested metal ions, presented a greater production of As3+ metallophores, and showed high HM resistance especially to Zn2+, As5+, and Ni2+. A total of 320 bacteria were isolated with 170 strains showing siderophores synthesis. Members of the Delftia and Pseudomonas genera showed above 92 percent siderophore units (psu) during siderophores production and hydroxamate proved to be the most common functional group among the analyzed siderophores. Our results provided evidence that Lerma-Chapala Basin bacteria and their metallophores could potentially be employed in bioremediation processes or may even have potential for applications in other biotechnological fields.

Heavy-metal resistance mechanisms developed by bacteria from Lerma-Chapala basin.

Heavy-metal (HM) contamination is a huge environmental problem in many countries including Mexico. Currently, microorganisms with multiple heavy-metal resistance and/or plant-promoting characteristics have been widely used for bioremediation of HM-contaminated soils. The aim of the study was isolated bacteria with multiple heavy-metal resistance and to determinate the resistance mechanism developed by these organisms. A total of 138 aerobic bacteria were isolated from soil and sediments surrounding the Lerma-Chapala basin located in the boundary of the States of Michoacán and Jalisco states of Mexico. One hundred and eight strains showed at least 1 plant growth-promoting features. The Lerma-Chapala basin bacteria were also resistant to high concentrations of HMs including the metalloid arsenic. Sequence analysis of 16S RNA genes reveled that these bacteria were mainly affiliated to the phyla Proteobacteria (38%), Firmicutes (31%) and Actinobacteria (25%), covering 21 genera with Bacillus as the most abundant one. Among them, at least 27 putative novel species were detected in the genera Acinetobacter, Arthrobacter, Bacillus, Agrobacterium, Dyadobacter, Enterobacter, Exiguobacterium, Kluyvera, Micrococcus, Microbacterium and Psychrobacter. In addition, these bacteria developed various heavy-metal-resistance mechanisms, such as biosorption/bioaccumulation, immobilization and detoxification. Therefore, the bacteria isolated from soils and sediments of Lerma-Chapala basin could be used in bioremediation strategies.

Comparation of two climate methodologies on Lerma Chapala basin: moving mean and climate variability indices with RClimDex

The objective of this study is the comparation of two climate methodologies with the next variables, average maximum and minimum temperatures, and precipitation, said another way, it was calculated by two different methods, the moving mean and climate change indices with complements of R software (RClimDex and RhTest) on Lerma Chapala basin, which is located. The data were analyzed for representative periods of 30 years since 1960 to 2016, which, were collected from National Water Commission due to compiling with control qualify. Finally, the results will help for supporting international climate variability report and demonstrated that independently the methodology the results are similar, it means, the select variables showed modifications through the time that causing drier environments.

Presence and Distribution of Fluoride Ions in Groundwater for Human in a Semiconfined Volcanic Aquifer

Dental and emaciated fluorosis is derived from the chronic intake of fluoride ions (F−) by consumption of food, tooth products and drinking water from groundwater. Recent reports indicate that in some regions of Mexico, the incidence of fluorosis in temporary and permanent dentitions have increased in recent years. The purpose of the present investigation was to determine the presence and distribution of F− ions in semi-confined aquifers, located in the basins of Lerma-Chapala and Valley of México. Temperature (T), pH, electrical conductivity (EC) and alkalinity were determined in situ, in 27 groundwater wells. The hardness, chloride ions (Cl−), free chlorine (Cl2), total dissolved solids (TDS) and bicarbonates (HCO3−), were determined in the laboratory. The high content of bicarbonate ions (HCO3−) is associated with the alteration of silicates and the presence of chloride ions (Cl−) due to the anthropogenic activity. The highest value of fluoride ions (F−) (1.31 mg/L) was identified in a well of the Lerma-Chapala basin and in 25% of the samples (1.056 mg/L) of the Valley of México basin. The groundwater in the Lerma-Chapala basin is of the Ca-HCO3 type and the water in the Valley of Mexico basin is Na-HCO3 and Ca-HCO3. According to the Gibbs diagram, the water of the Toluca Valley aquifer is recharged by local meteoric precipitation and consequent the water-rock interaction occurs. The correlation analysis shows the significant relationship between F− and CE (R = 0.5933), F− and alkalinity (R = 0.6924), F− and HCO3− (R = 0.6924) and F− and TDS (R = 0.5933). The correlations confirm that the content of fluoride ions present in groundwater is associated with high concentrations of bicarbonate ions and the presence of sodium, due to a process of alteration of the silicates.

Production of competing water knowledge in the face of water crises: Revisiting the IWRM success story of the Lerma-Chapala Basin, Mexico

Integrated Water Resources Management (IWRM) is an approach that aims to change conventional water management. International agencies and organizations have promoted IWRM across the globe. The Lerma-Chapala Basin in Mexico is an archetypal case study on basin closure, where IWRM principles were said to have been applied in the early 2000s to help solve a serious water crisis. This paper analyses the controversies around socio-hydrological uncertainties that were raised during this and an earlier crisis of Lake Chapala, whose resolution defined the water management policies of the basin. We interviewed key stakeholders, analysed different hydrological models, and reviewed the most important literature assessing the case. Then, we analysed how stakeholders understood the functioning of the socio-hydrological system, and how that determined their perception of what the root causes of the crisis were, and ways to resolve it. We found that the modelling efforts by two stakeholders to understand the root causes of the crisis could not clarify important socio-hydrological uncertainties, which limited the scope of their conclusions. From the proposed responses, only those based on the existing institutional and regulatory framework were implemented. Our results question the assertion that IWRM principles of public participation, sound knowledge, and river basin institutions, actually changed the traditional water management paradigm. We conclude that economic and political interests, more than IWRM principles, influenced the decision-making process to solve the water crisis in the Lerma-Chapala basin.

Análisis del comportamiento de la evapotranspiración de referencia durante el periodo de lluvias en cinco estaciones meteorológicas de la cuenca Lerma-Chapala

Introduction: Estimating evapotranspiration of cultivated areas is commonly based on the calculation of reference evapotranspiration (ETo), and is essential in climatic and hydrological studies, as well as in projects related to water management in agriculture. Objectives: To evaluate ETo and analyze its behavior during the rainy season on a daily, monthly and seasonal basis. Methodology: Daily data series on temperature, radiation, atmospheric pressure, relative humidity and wind speed from five weather stations in the Lerma-Chapala basin were used. The ETo calculation was based on the application of the Penman-Monteith method. Results: ETo during the rainy season followed a decreasing pattern, characterized by being non-linear. At the beginning of the season, values higher than 6 mm∙day-1 were observed, and at the end they were lower than 2 mm∙day-1. Correlation analysis showed that ETo depends on relative humidity and radiation. Study limitations: The number of stations used was very low for the size of the basin because the network of automatic weather stations is still under development. Originality: There are very few studies focused on evapotranspiration variation as a function of elevation and meteorological variables, in addition to a specific analysis in the rainy season. Conclusions: The seasonal behavior of ETo shows important changes related to the behavior of relative humidity and radiation, which can have a significant impact on crop water needs.<

Epilithic diatom communities of selected streams from the Lerma-Chapala Basin, Central Mexico, with the description of two new species.

The Lerma-Chapala Basin, in Central Mexico, is geologically heterogeneous, climatically diverse and boasts high biodiversity, lying within two Biodiversity Hotspots, namely Mesoamerica and the Madrean Pine–Oak Woodlands. Epilithon and water samples were collected in the basin from 14 sampling sites three times each, two sampling campaigns during the rainy season and one in the dry season. A total of 274 infrageneric taxa in 48 genera were recorded. The taxonomic composition observed was dominated by taxa from the genera Nitzschia, Gomphonema, Pinnularia, Navicula, Sellaphora and Eunotia. About a third of the taxa found could not be identified to the species level. From those unidentified morphodemes, two are described as new species, namely Brachysira altepetlensis and Sellaphora queretana. Furthermore, Eolimna rhombica is transferred to Sellaphora. Canonical Correspondence Analysis (CCA) revealed that specific conductivity and pH were the main environmental factors driving the community composition observed. Three groups of samples were identified after the CCA: 1) characterized by acidic waters and low conductivity; 2) with circumneutral waters, low specific conductivity and high temperature and phosphorous concentrations; and 3) characterized by circumneutral waters, high conductivity and low nitrogen concentrations. The indicator value method (IndVal), based on the relative abundance and relative frequency of the most abundant taxa was calculated based on the groups observed in the CCA, identifying the characteristic taxa for each of the three groups.

Assessment of Surface Runoff Vulnerability to Climate Change in the Lerma-Chapala Basin, Mexico

AbstractThe Intergovernmental Panel on Climate Change (IPCC) suggests that vulnerability to climate change depends on three main factors: exposure, sensitivity, and adaptive capacity. Each factor was evaluated in a hydrologic context; for instance, exposure was interpreted as a change in surface runoff. Factors were combined using a geographic information system (GIS), and an overall methodology was proposed to map hydrologic vulnerability. The Lerma-Chapala basin was selected as a case study since the largest water body in Mexico is located at its outlet. The long-term rate of change in surface runoff was estimated considering the variation in future precipitation from 23 atmosphere–ocean general circulation models (AOGCMs) and by using the reliability ensemble averaging (REA) method. Two climate change scenarios from an IPCC special report on emissions scenarios and three time horizons (2030, 2050, and 2100) were chosen. Results showed a decrease in surface runoff of up to 29% (A1B-2100) in the northern...

Validación de dos índices biológicos de integridad (IBI) en la subcuenca del río Angulo en el centro de México

Efforts to halt freshwater ecosystem degradation in central Mexico can benefit from using bio-monitoring tools that reflect the condition of their biotic integrity. We analyzed the applicability of two fish-based indices of biotic integrity using data from lotic and lentic systems in the Angulo River subbasin (Lerma-Chapala basin). Both independent data from our own collections during two consecutive years, and existing information detailing the ecological attributes of each species, were used to calculate indices of biological integrity for 16 sites in lotic and lentic habitats. We assessed environmental quality by combining independent evaluations water and habitat quality for each site. We found sites with poor, regular and good biotic integrity. Our study did not find sites with good environmental quality. Fish-based IBI scores were strongly and significantly correlated with scores from independent environmental assessment techniques. IBI scores were adequate at representing environmental conditions in most study sites. These results expand the area where a lotic system fish-based IBI can be used, and constitute an initial validation of a lentic system fish-based IBI. Our results suggest that these bio-monitoring tools can be used in future conservation efforts in freshwater ecosystems in the Middle Lerma Basin.

Capturing the waters: the hydraulic mission in the Lerma–Chapala Basin, Mexico (1876–1976)

The hydraulic mission of the Mexican federal government, embodied in its hydraulic bureaucracy (hydrocracy), led to the centralization of water development and the creation of water overexploitation in the Lerma–Chapala Basin between 1876 and 1976. In the late nineteenth century, the federal government began asserting its control over water, both to promote commercial agriculture and to arbitrate in water allocation conflicts between large landowners. The centralization of water development accelerated after the Mexican Revolution (1910–1920) and continued until the 1970s. These 50 years witnessed a large increase in the irrigated area in the Lerma–Chapala Basin, intertwined with the formation and expansion of a strong hydrocracy with a keen sense of its hydraulic mission. This led to the creation of water overexploitation in the basin, through the construction of dams and irrigation systems, and modifications to Lake Chapala. This article argues that this was not an unforeseen side effect, but the deliberate intent of the hydrocrats working in the basin.

Negotiating Surface Water Allocations to Achieve a Soft Landing in the Closed Lerma-Chapala Basin, Mexico

The Lerma-Chapala basin exemplifies the challenges posed by basin closure, where surface water allocation mechanisms, lack of environmental flows and access to water are critical issues. Underlying these issues is a need for accurate water accounting that is transparent and publicly available. This paper describes basin closure in the Lerma-Chapala basin, and focuses on negotiation processes surrounding surface water allocation mechanisms. Although significant attempts have been made to achieve a ‘soft landing’, the basin is still faced with water over-exploitation, environmental degradation, and a complicated transition from centralized water management to one in which states and water users have a larger say.

Organochlorine Pollutants and Stable Isotopes in Resident and Migrant Passerine Birds from Northwest Michoacán, Mexico

Although concentrations of organochlorine compounds (OCs) in birds from most of the United States and Canada have decreased over the last 30 years, there is still concern that migrant birds might be exposed to elevated concentrations of OCs during migration in Latin America. The Lerma-Chapala Basin in west-central Mexico is an important migration corridor and wintering area for many species. The objectives of this study were to assess if resident and migrant birds wintering in western Michoacán, Mexico accumulated elevated concentrations of OCs during fall and spring and to determine if the stable isotopes delta(15)N, delta(13)C, and deltaD could be used to predict burdens and origins of DDE accumulation. Resident and migrant passerine insectivorous birds were collected during fall and spring (2001-2002) in northwest Michoacán, near Chapala Lake, Mexico. The carcasses were analyzed for OCs and tail feathers were analyzed for stable isotopes delta(15)N, delta(13)C, and deltaD. The OCs detected in more than 50% of the samples were: oxychlordane (79%), p,p'-DDE (100%), p,p'-DDT (57%), and total PCBs (100%). p,p'-DDE was the OC detected at the highest concentrations, whereas residues of other OCs were near or below detection limits. Overall, there were no significant differences in concentrations of OCs between seasons or between resident and migrant birds. Concentrations of DDE and oxychlordane were somewhat higher in migrant and resident birds during spring than in fall; however, concentrations were significantly different only for oxychlordane. Two resident birds collected in fall and spring had DDE residues >10 microg/g wet weight in carcass. There were no significant differences in delta(13)C and delta(15)N values among species, between seasons, or between migrant and resident birds. However, deltaD values were clearly different between species and helped differentiate migrant from resident birds. deltaD values also were negatively and significantly correlated with DDE concentrations in carcass. Birds with more depleted deltaD values in feathers tended to have higher DDE concentrations than those with less depleted deltaD values, suggesting a potential latitudinal accumulation of DDE. Overall, our results suggest that during fall and spring, there is not a significant buildup of persistent OCs in migrant and resident passerine insectivorous birds in northwest Michoacán, Mexico.

Water Resources Management in the Lerma–Chapala Basin, Mexico: A Case Study

Water resources have become an increasingly important topic of discussion in natural resources and environmental management courses. To address the need for more critical thinking in the classroom and to provide an active learning experience for undergraduate students, we present a case study based on water competition and manage- ment in the Lerma-Chapala basin of Mexico. This case was designed to promote critical thinking and enhance learning in undergraduate students through their engagement in a relevant contemporary management issue. We discuss the value of a case-study approach for natural resource and environmental courses, as well as approaches to using this case study in the classroom. The case study contains background information and stakeholder profiles relevant to the issue of water management in the Lerma-Chapala basin. It also provides sample discussion questions to help inspire higher-level think- ing among students.

Construyendo puentes entre la política ambiental y la política de tratamiento de aguas en la cuenca Lerma-Chapala

El desarrollo sostenible de una nación no reconoce divisiones entre la importancia de los factores económicos, ecológicos, sociales, políticos y culturales; sin embargo, una revisión analítica de política hidráulica y ambiental en México hace patente la existencia de un abismo. Existen divergencias entre dos políticas sectoriales que debieran ser, por definición, convergentes. Para demostrar dicho abismo, en este artículo se examina la política hidráulica en materia de aguas residuales desde la teoría neoinstitucional, considerando la cuenca Lerma-Chapala como caso de estudio. Aquí se argumenta que es posible fortalecer la política hidráulica en materia de tratamiento de aguas residuales mediante el diseño de instituciones cooperativas robustas para la gestión integrada de la cuenca Lerma-Chapala. Esto contribuirá (aunque no garantizará) a la construcción de puentes entre dos políticas tradicionalmente desintegradas.

The Politics of Regional Water Management: The Case of Guanajuato, Mexico

This article examines water politics in Guanajuato. Focusing on the social construction of risk, it is argued that the region is vulnerable to water shortages due to political competition. State officials have promoted economic activity and demographic growth without concern for the area’s water supply. State and national water authorities compete over political power within the Lerma-Chapala Basin Council, the organization responsible for water management in the area. Moreover, representatives of the five states that make up the council attempt to maximize their own water supplies rather than guarantee the maintenance of the r egion’s aquifers.

Collective action for water harvesting irrigation in the Lerma-Chapala Basin, Mexico

Water and watersheds are difficult to separate for management purposes. Providing irrigation as a supplement to rainfall for crop production requires considerable collective action at the watershed level to mobilize labor and other resources, as well as to make decisions and implement the distribution of benefits. Small-scale water harvesting irrigation systems in Mexico have endured for centuries. They now face considerable challenges with changes in the ejido property rights over land and water, the growing importance of alternative sources of livelihoods, and increasing scarcity and competition for water within the river basins.

Phosphates in Lake Chapala, Mexico

AbstractLake Chapala, the most important lake in Mexico, has suffered from cultural eutrophication problems for many years, manifested by the growth of aquatic vegetation and an increase in primary productivity. It was found that about 70% of the total phosphorus entering Lake Chapala is orthophosphate, thus increasing the biological availability of nutrients in the lake. In addition, the hydrologic imbalance in the lake, caused by the over‐use of water resources along the Lerma–Chapala basin, has significantly increased the hydraulic residence time of the inflow waters, thus increasing the effects of the added phosphorus, and creating conditions that increase the lake’s eutrophication status.The shallow characteristics of the lake and the action of the wind forces produce rapid changes in water quality, especially in the distribution of phosphate. The focus of this paper is on the development of a historical orthophosphate balance in Lake Chapala, quantifying the main point and non‐point sources that contribute to the enhancement of this nutrient in the lake. The estimation of the amount of phosphate in the lake can be used to determine appropriate management practices to reduce the phosphate loads on the lake.

Selenium in municipal wells in the Irapuato City — spectrofluorimetric determination with 2,3-diaminonaphthalene

Abstract A chromatographic procedure with spectrofluorimetric detection (λ = 257 nm, λ = 548 nm) is proposed in this work for Se determination in well water after formation of a piazselenol compound. The low detection limit obtained (15 ng·l-1 ) enabled minimisation of the sample size and, consequently, smaller amounts of reagents were needed. Selenium content was confirmed using standard reference material. The proposed procedure was applied for the determination of Se in municipal wells in Irapuato city (Lerma-Chapala basin) and the obtained results showed that 52.5% of the analysed wells contained amounts higher than the limit 10 μg·l-1 of selenium as recommended by the World Health Organisation for drinking water. The high selenium levels were found only in the wells of the city of Irapuato (concentration range 12 – 223 μg l-1 ), not in the wells in other cities of the State of Guanajuato. No contamination by other trace elements (arsenic, cadmium, chromium, iron, manganese, lead) was found in Irapuato wells.

Towards a New Water Management Practice: Experiences and Proposals from Guanajuato State for a Participatory and Decentralized Water Management Structure in Mexico

Per-capita water availability is relatively high in Mexico (about 5000 m 3 per year). Nevertheless, water demand is concentrated in some critical zones, where scarcity and pollution are causing growing conflicts between water users and authorities. The Lerma-Chapala basin is one of those critical regions. The recent demands to preserve Chapala lake have added an explosive ingredient to the historical importance of its mining and agricultural production, its industrial and commercial development and its relevance as a communications link due to its location in the geographical centre of Mexico. In Guanajuato state, located right in the middle of the basin, water availability per capita does not even reach 1000 m 3 per year, with the resulting pressure coming from water users in dispute over a resource that is becoming each day more scarce, polluted and over-exploited. For this reason the state government implemented a programme oriented to the building of a participatory management structure, together with the consolidation of the technical, managerial, financial and social capacity of local organizations, based on a new paradigm of real decentralization, to which government brings the necessary support, in a subsidiary form, for the social participation structures to become the central actors in the achievement of a sustainable method of using water. Cultural change is the basis of this effort. This vision of water management has implied leaving behind the established one, in which decentralization programmes are constrained to the transfer of predefined programmes and their financial resources, according to rules and supervisory bodies coordinated from Mexico City.