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This study presents a comprehensive dataset of hydrological information gathered from five key eastern basins in Jalisco, Mexico. The dataset encompasses approximately 50 limnological variables and phytoplankton counts specifically for one of these basins. Water‐quality data were collected by the State Water Commission of Jalisco, adhering to the methods outlined in the Official Mexican Norm 'NOM‐127'. Monthly samplings were conducted to assess environmental variables such as pH, temperature, oxygen, nutrients and heavy metals. Monitoring has been ongoing for three basins since 2009, while the remaining two basins have been monitored since 2015 and 2020. Phytoplankton data were obtained from monthly samples taken by the University of Guadalajara between 2014 and 2019 in Lake Cajititlán. The original data were cleaned and organized using tidy data principles, with codes accessible on GitHub. To facilitate data exploration and visualization, we developed a user‐friendly web application with the Shiny package in R. This application enables users to explore the dataset through summary statistics tables, time series plots and phytoplankton community analysis. The dataset is accessible on Zenodo. The presented data hold significance for environmental and water‐quality assessment and applications in machine learning, neural network models, community ecology and broader environmental research. Notably, the raw data, publicly accessible from the State Water Commission of Jalisco, have been previously utilized for these purposes. This dataset offers value due to its diverse limnological and phytoplankton variables, an extended time frame of availability, a curated and streamlined accessibility process and the inclusion of a web application for intuitive exploration and visualization. [ABSTRACT FROM AUTHOR]

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The present long-term (1993–2013) study was aimed at identifying the effects of global change on the environmental characteristics and the plankton community of the tropical, high-altitude Lake Alchichica, Puebla, Mexico. We found no statistically significant increasing trend in air temperature, but an increase from 2002 to 2013, and interannual variability in the meteorological variables. Accordingly, the water temperature rose from 1993 to 2003 and remained similar until 2013. Nonetheless, on a longer-term (1966-2018), longer than the period considered in the present study, air and water temperatures showed an increasing trend in the range considered indicative of climate change. The lake displayed a characteristic warm monomictic thermal pattern but exhibited interannual variability. The planktonic community composition and structure remained similar. The small chlorophytes (e.g., Monoraphidium minutum) dominated the phytoplankton abundance, while the large diatom Cyclotella alchichicana dominated the biomass. The calanoid copepod Leptodiaptomus garciai dominated both the zooplankton abundance and biomass. However, as the temperature increased the large-size phytoplankton (i.e., C. alchichicana) abundance and biomass increased, but the small-size phytoplankton abundance and biomass, as well as the adult copepod abundance and biomass, decreased. The increase in temperature could have favoured the large-size over the small-size phytoplankton. In addition, the temperature increase could have negatively affected the calanoid copepods in two different ways—direct association with the negative effects of higher temperatures on the physiology of the copepods, or indirect association with the negative effects of higher temperatures on the small-size phytoplankton, which diminish the copepods' food resource. [ABSTRACT FROM AUTHOR]

In the present study, the hydrochemical dynamic and the water quality of La Purísima reservoir, Central Mexico, have been determined. The reservoir presents total dissolved solids (TDSs) between 146 and 328 mg L−1 and water quality neutral to slightly alkaline (pH 7.0 to 8.7) during the dry season, whereas it becomes clearly alkaline (pH 8.1–9.9) in the rainy-warm season. Through its main tributaries, La Purísima reservoir has been receiving water affected by anthropic activities, such as mining, urbanization, and agriculture. La Purísima reservoir indicates water quality suitable for irrigation and aquatic lives, but unsuitable for drinking purposes. A geochemical evolution from the riverine to the lacustrine zone is evidenced by the complexation of several free ions: the higher saturation indexes; the lower toxic metal concentrations; and the lower trophic status, which ameliorate the water quality in the lacustrine zone. Trace elements co-precipitate and are adsorbed onto bottom sediments. During summer, high evaporation rates and atmospheric precipitation are found to decline the water quality. Cluster analyses reflect the geo-setting and different pollution levels: urban impact from the north coast, and agricultural activities from the east coast. The sensitivity of the lake to geochemical behavior can be used to understand the complex dissolved geochemical dynamics in a lake and the potential effects from long-term anthropic impact variability. The information about water quality of La Purísima reservoir may be useful to preserve the ecosystem and its biodiversity. [ABSTRACT FROM AUTHOR]

High-altitude lakes are sensitive to modern and past climate changes. Given their low-water temperatures, alkalinity, and nutrient levels, small climatic differences can strongly affect their water chemistry, and/or biodiversity. In central Mexico, there are only two high-altitude lakes, and both are within the crater of the Nevado de Toluca volcano. Here, we present a paleolimnological record from one of these lakes: La Luna. Previous paleoenvironmental work showed that it was sensitive to the Little Ice Age (LIA) cooling. Our results show that sediment accumulation began ~6900 to 6100 cal. yr BP under periglacial conditions and that lake conditions were established ~6000 cal. yr BP. One tephra layer was dated to ~5600 cal. yr BP, with no evidence of more recent volcanic activity. The early stages of this lake (6000–4700 cal. yr BP) contained Cladocera and diatom assemblages with different species composition than modern assemblages. This early stage community structure was related to more mesic conditions and cooler winters inferred by the high abundance of planktonic Aulacoseira nivaloides and of Chydorus cf. sphaericus. The establishment of modern limnological conditions after 4700 cal. yr BP is inferred from Cladocera and diatom assemblages similar to recent samples. A reduction in A. nivaloides and low magnetic-susceptibility values suggest lower lakes levels, a trend consistent with lower available moisture in central Mexico after 4000 cal. yr BP. The rest of the sequence shows the impact of two cold periods, the first one around 3000 cal. yr BP, identified by a new increase in Chydorus cf. sphaericus. The second was the larger impact associated with the LIA (AD 1350–1910), and an increase in Cavinula pseudoscutiformis and Pinnularia microstauron suggesting an increase in lake water pH. Also, organic matter and photosynthetic pigments increased during this period showing an increase in nutrient levels and productivity. Finally, the coldest interval during the LIA (AD 1570–1890) is identified by an important reduction in arboreal pollen concentration which points to a wider environmental impact of this cold event. [ABSTRACT FROM AUTHOR]

Cladocera (Crustacea: Branchiopoda) quickly respond to changes in environmental conditions and their remains are usually found in large amounts in lacustrine sediments, which make them an important biological proxy in paleolimnological studies. Variations in species composition have been used to infer paleo-climate and paleo-environmental variables including lake depth, eutrophication, and deforestation. However, despite their advantages as bioindicators in the study of past conditions, they are underutilized in paleolimnological research in Central America due to limited knowledge about their diversity and the morphological differences between the subfossil remains of different taxa. In order to address this issue, we described and analyzed cladoceran remains from 56 waterbodies located in Mexico, Guatemala, El Salvador, and Honduras. Here, we provide a description of the remains from 10 different taxa that belong to the Sididae, Bosminidae, Daphniidae, Macrothricidae, and Ilyocryptidae families. [ABSTRACT FROM AUTHOR]

This paper reports on the algal growth-limiting nutrients of five lakes located on Mexico's Mesa Central - a topic poorly known in the regional limnology of Mexico. The five case studies involved three contiguous watersheds of Michoacán State and provided a trophic state variation from mesotrophic to hypereutrophic; the case studies included Lakes Zirahuén, Pátzcuaro, Teremendo, Cuitzeo and the Cointzio Reservoir. The fieldwork involved the collection of physical and chemical data (including nutrients) from each case study during the dry and rainy seasons of 2010. Additionally, water samples (1 L) were obtained and filtered (0.45 µm) in the laboratory to keep the nutrient content available for bioassays. The chemical analyses suggested a phosphorus (P) limitation in the Cointzio Reservoir, Lake Teremendo and Lake Zirahuén relative to an N:P>16:1. There was a nitrogen (N) limitation at three sampling stations of Lake Pátzcuaro, with an N:P<16:1. As result of the bioassays conducted in July 2012, the Cointzio Reservoir and Lake Teremendo appeared to be P-limited and Lake Pátzcuaro appeared to be N-limited at three sampling stations. Lake Zirahuén showed seasonal variation, with an N limitation during the dry season and a P limitation during the wet season. Those cases with similar results from both methods confirmed the limiting nutrient identification. Lake Cuitzeo, Lake Zirahuén (dry season), and the shallowest sampling station in Lake Pátzcuaro produced unclear results because of divergent outcomes. In terms of the algal growth potential, the Cointzio Reservoir remained unaltered from one season to the next. However, for most of the lakes (with the exception of Lake Pátzcuaro sites 2 and 4), the rainy season provided a dilution effect. Effective lake management depends on a clear recognition of such elements that are in control of the aquatic productivity. In the area of Michoacán, both N and P may act as limiting nutrients. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the amount and quality of water in the Magdalena-Eslava river system and to propose alternatives for sustainable water use. The system is the last urban river in the vicinity of Mexico City that supplies surface water to the urban area. Historical flow data were analyzed (1973–2010), along with the physicochemical and bacteriological attributes, documenting the evolution of these variables over the course of five years (2008–2012) in both dry and rainy seasons. The analyses show that the flow regime has been significantly altered. The physicochemical variables show significant differences between the natural area, where the river originates, and the urban area, where the river receives untreated wastewater. Nutrient and conductivity concentrations in the river were equivalent to domestic wastewater. Fecal pollution indicators and various pathogens were present in elevated densities, demonstrating a threat to the population living near the river. Estimates of the value of the water lost as a result of mixing clean and contaminated water are presented. This urban river should be rehabilitated as a sustainability practice, and if possible, these efforts should be replicated in other areas. Because of the public health issues and in view of the population exposure where the river flows through the city, the river should be improved aesthetically and should be treated to allow its ecosystem services to recover. This river represents an iconic case for Mexico City because it connects the natural and urban areas in a socio-ecological system that can potentially provide clean water for human consumption. Contaminated water could be treated and reused for irrigation in one of the green areas of the city. Wastewater treatment plants and the operation of the existing purification plants are urgent priorities that could lead to better, more sustainable water use practices in Mexico City. [ABSTRACT FROM AUTHOR]

A new species ofAcanthocyclopsis decribed from an Ecological Reserve in Mexico City.Acanthocyclops eduardoisp. nov. was assigned as a member of theAcanthocyclops vernalis–robustuscomplex and it differs from its congeners by a combination of characters including 17 segmented antennules, the ornamentation of spinules on the ventral and dorsal surface of caudal ramus, a short dorsal seta (0.47–0.56), an elongated third segment of endopodite of fourth leg (length/width 3.10–3.80) and, the length/width ratio of caudal ramus ranging from 4.30 to 4.35. The male ofA. eduardoisp. nov. shows a unique ornamentation pattern on the coxal plate of the fourth leg. The new species resembles other species such asAcanthocyclops marceloi,Acanthocyclops caesariatus,Acanthocyclops brevispinosus,Acanthocyclops trajaniandAcanthocyclops einslei.The number of species of the genus in the Mexican Plateau is increased so the diversity of the genus in this biogeographic province may be underestimated and deserves further study.http://www.zoobank.org/urn:lsid:zoobank.org:pub:32A9F42E-5C7F-4149-920E-E14A91C719FD [ABSTRACT FROM AUTHOR]

This study presents limnological and morphological characteristics, physical and chemical properties of waters, and geochemistry of surface sediments for 63 aquatic ecosystems located on the karst Yucatán Peninsula and surrounding areas of Belize and the Guatemalan highlands and eastern lowlands. Our principal goal was to classify the aquatic systems based on their water variables. A principal component analysis (PCA) of the surface water chemistry data showed that a large fraction of the variance (29%) in water chemistry is explained by conductivity and major ion concentrations. The broad conductivity range, from 168 to 55,300 μS cm reflects saline water intrusion affecting coastal aquatic environments, and the steep NW-S precipitation gradient, from ~450 to >3,200 mm year. Coastal waterbodies Celestún and Laguna Rosada displayed the highest conductivities. Minimum surface water temperatures of 21.6°C were measured in highland lakes, and warmest temperatures, up to 31.7°C, were recorded in the lowland waterbodies. Most lakes showed thermal stratification during the sampling period, with the exception of some shallow (<10 m) systems. Lakes Chichancanab, Milagros, and Bacalar displayed sulfate-rich waters. Waters of sinkholes had relatively high conductivities (<3,670 μS cm) and a broad range of δO values (−4.1 to +3.8‰). Ca, HCO, and SO dominated the waters of the lowland lakes, whereas Na was the dominant cation in highland lakes. Coastal aquatic ecosystems were dominated by Na and Cl. Cluster analysis based on surface water variables classified aquatic environments of the lowlands and highlands into three groups: (1) lowland lakes, ponds, wetlands, and coastal waterbodies (2) highland lakes, and (3) sinkholes and rivers. A broad trophic state gradient was recorded, ranging from the eutrophic Lake Amatitlán and the Timul sinkhole to oligotrophic Laguna Ayarza, with the highest water transparency (11.4 m). We used major and trace elements in surface sediments to assess pollution of waterbodies. Lakes Amatitlán, Atescatempa, El Rosario, Cayucón, Chacan-Lara, La Misteriosa, rivers Subín and Río Dulce, the wetland Jamolún, and the sinkhole Petén de Monos showed evidence of pollution and urban development. Their surface sediments displayed high concentrations of As, Cu, Fe, Ni, Pb, Se, Zn, and Zr, which suggest moderate to strong pollution. [ABSTRACT FROM AUTHOR]

The article presents information on a study which described the two new species of the freshwater cyclopoid copepod genus Acanthocyclops Kiefer from ponds located in Aguascalientes, Central Mexico. Acanthocyclops caesariatus specie has a unique combination of characters including 17 segmented antennules and a strongly hairy inner margin and dorsal and ventral surfaces of the caudal rami. The Acanthocyclops marceloi specie has a relatively weak pilose pattern on the inner margin of the caudal rami and are covered with spinules arranged in symmetrical patches ventrally and irregularly on the dorsal surface.

The present work reviews our current understanding of the limnology of Lake Zirahuén and extends this knowledge through an analysis of the phytoplankton, illustrating phenomena that typify monomictic tropical lakes. The analysis reinforces the postulate that atelomixis determines the variation in phytoplankton composition of deep tropical lakes with a monomictic mixing regime. Similarly, it is proposed that an incomplete or partial atelomixis, generating a highly dynamic mixing layer, is a force that possibly drives the selection of algal groups, like the Desmidiaceae, with a high surface area to volume ratio. These organisms, characteristic of tropical lakes, though found in the deep epilimnetic layer, receive sufficient irradiance to support their high photosynthetic rate; their high population density survive thanks to a constant supply of nutrients. Lake Zirahuén is a particularly relevant case for Mexico, since the low calcium concentration and the trophic level of the lake provide an explanation for the otherwise uncommon presence of desmids in other Mexican lakes, even in lakes that exhibit atelomictic phenomena. [ABSTRACT FROM AUTHOR]

The purpose of this study was to characterize five crater lakes in Los Tuxtlas, Mexico, on the basis of morphological, physical, chemical, and biological features. A bathymetric map of each lake was obtained and morphometric parameters were calculated. Physical and chemical parameters (temperature, transparency, nutrients, pH, conductivity, cations) and chlorophyll a were measured for three periods: the cold season (January), the dry season (May), and the rainy season (October) of 2000. The trophic state of each lake was determined using Carlson's indices for transparency and chlorophyll a. The lakes studied have the morphometric characteristics of maar-type volcanic lakes. Majahual, Chalchoapan, and Manantiales are the deepest lakes with elliptical basins and are classified as warm monomictic systems; Verde and Mogo are shallow lakes with conic basins and are warm polymictic. Majahual and Chalchoapan had an anoxic hypolimnion, while at Manantiales a metalimnetic oxygen maximum was measured. Sodium was the dominant cation in the five lakes, while bicarbonate was the dominant anion. Nutrient and chlorophyll a concentrations, transparency, and trophic indices suggest that Chalchoapan, Verde, and Mogo are eutrophic lakes with tendencies toward hypereutrophy; Manantiales and Majahual, in contrast, can be classified as mesotrophic lakes. The trophic state of lakes was indirectly related to deforestation and to the use of agricultural fertilizer in Los Tuxtlas as well as to certain morphometric characteristics. [ABSTRACT FROM AUTHOR]

The karstic nature of the Yucatan Peninsula allows the formation of natural sink-holes from the dissolution of calcareous rock. These systems are almost the only epigean source of fresh water available in this region. In spite of their biological importance, little is known about the morphometric and limnologic characteristics of these karstic systems. The authors measured limnological variables in eight cenotes in central Quintana Roo, Mexico. Zooplankton biomass and chlorophyll a were also measured. Important short-term changes were observed in nutrients, biomass, and chlorophyll a. Results indicate the existence of sharp differences between these karstic systems and non-karstic ones, but are similar to previous data from other karstic systems of Mexico and other parts of the world. Understanding of these fragile tropical systems is in the initial phase.

Abstract The environmental characteristics and degree of pollution of a jagüey (a small, shallow tropical water-body) in Mexico were identified by means of an environmental impact matrix. Jagüeys are important as their main sources of water are the subsurface water-table and rainfall, however, they have not been studied because of their small size. A flow diagram was designed to incorporate the main climatic, geological and hydrological environmental factors, as well as physico-chemical data on sediment and water qualities, and biological, technostructural and socioeconomic aspects. The resulting index of –90 in the environmental impact matrix indicates a severe negative impact on jagüeys from the input of allochtonous nutrients because of their small depth, limited circulation and the high rate of evaporation. The jagüeys studied appear in a state of hypertrophy and senility, despite geological youth. [ABSTRACT FROM AUTHOR]

The article discusses macroalgae as biomonitors of heavy metal availability in coastal lagoons from the subtropical Pacific of Mexico. Despite the fact that a relatively rich algal flora exists along the broad range of coastal environments in Mexico their viability as biomonitors of trace metals has not been studied. Macroalgae have been known to concentrate heavy metals to levels several times those found in the surrounding waters. This is due to their accumulation of metals by active and passive processes responding essentially to metals present in solution.

A limnological survey was conducted in three water bodies from the tropical rain forest region of southeast Veracruz, Mexico, in order torecognize their morphometric characteristics and to define their mixing patterns. These were: a temporary pond, Laguna del Zacatal (A = 7.64 ha, z{sub}m = 13.0 m); and two permanent lakes, Laguna Escondida (A = 18.26 ha, z{sub}m{end} = 32.5 m) and Lago de Catemaco (A = 7254 ha, z{sub}m{end} = 22.0 m). Both El Zacatal and La Escondida are warmmonomictic, whereas Lago de Catemaco is polymictic. Our results support the hypothesis that most tropical lakes are prone to winter overturn. Dissolved oxygen showed large variation, from almost constant epilimnetic saturation in all three lakes to hypolimetic anoxia in Laguna Escondida. Differences in mixing betwden lakes are determined by the joint influence of morphometry, rainfall and wind. [ABSTRACT FROM AUTHOR]