Limnological Review

9 pages, 1570 KiB

Open AccessArticle

Antibiotic Resistance Genes Detection in Several Local Cyanobacteria Isolates

by Harith K. Buniya, Nuha A. Mohammed and Dhyauldeen Aftan Al-Hayani

Limnol. Rev. 2024, 24(4), 568-576; https://doi.org/10.3390/limnolrev24040033 - 23 Nov 2024

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Antibiotic resistance in cyanobacteria represents a global threat to public health. The widespread presence of cyanobacteria in aquatic environments exposes them to antibiotic contamination. Cyanobacteria are also in direct contact with pathogenic bacteria containing antibiotic-resistance genes (ARGs), which impart these characteristics to them. [...] Read more.

Antibiotic resistance in cyanobacteria represents a global threat to public health. The widespread presence of cyanobacteria in aquatic environments exposes them to antibiotic contamination. Cyanobacteria are also in direct contact with pathogenic bacteria containing antibiotic-resistance genes (ARGs), which impart these characteristics to them. This study aims to examine the presence of some ARGs in locally isolated cyanobacteria species, Spirulina laxa, Chroococcus minutes, Oscillatoria princeps, Oscillatoria proteus, Oscillatoria terebriformis, and Lyngbya epiphytica, and compare the presence of these genes in two pathogenic bacteria, Escherichia coli and Klebsiella pneumoniae. Ampicillin (Ap) and erythromycin (Em) resistance genes were detected in five algal samples. Meanwhile, Chloramphenicol (Cm) and gentamicin (Gm) resistance genes were apparent in only two species. Genes encoding resistance towards kanamycin (Km) and spectinomycin (Sp) were recorded in three specimens. It was also found that E. coli possessed resistance genes for four antibiotics, ampicillin (Ap), erythromycin (Em), gentamicin (Gm), and kanamycin (Km), whereas K. pneumoniae was resistant towards three antibiotics, ampicillin (Ap), gentamicin (Gm), and kanamycin (Km). The results show that there is a match in antibiotic-resistance genes in both cyanobacteria and pathogenic bacteria. Suggesting the possibility that cyanobacteria could acquire ARGs from the environment through horizontal gene transfer. Thus, freshwater cyanobacteria may play a significant role in the prevalence of ARGs in their environment. Full article

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11 pages, 2069 KiB

Open AccessArticle

Temporal and Spatial Dynamics of Carbon, Nitrogen, and Phosphorus in a Subtropical Urban River (Tamanduateí River, São Paulo, Brazil)

by Flávio H. B. Souza, Mariana Morilla, Beatriz Guedes-Pereira, Kauê Lemes and Ricardo H. Taniwaki

Limnol. Rev. 2024, 24(4), 557-567; https://doi.org/10.3390/limnolrev24040032 - 13 Nov 2024

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Abstract

Water quality in urban streams often reflects the broader environmental challenges posed by dense population centers, where pollution from untreated sewage and runoff can significantly degrade ecosystems. This study examines the spatial and temporal variations of carbon, nitrogen, and phosphorus concentrations in the [...] Read more.

Water quality in urban streams often reflects the broader environmental challenges posed by dense population centers, where pollution from untreated sewage and runoff can significantly degrade ecosystems. This study examines the spatial and temporal variations of carbon, nitrogen, and phosphorus concentrations in the Tamanduateí River, which runs through the Metropolitan Region of São Paulo, Brazil. Data were sourced from the annual reports of the Environmental Company of the State of São Paulo (CETESB) covering the period from 2011 to 2022. Between 2011 and 2017, carbon and phosphorus concentrations declined, likely due to sanitation improvements. However, since 2017, these concentrations have been rising again, indicating renewed pollution inputs, primarily from untreated sewage. Nitrogen levels remained consistently high, with elevated concentrations observed upstream, linked especially to domestic effluent discharges. The recent increase in phosphorus levels is also of concern. The absence of spatial variation in phosphorus suggests diffuse pollution from urban areas, while nitrogen decreases downstream, possibly due to biological assimilation. The study underscores the pressing need for enhanced sewage management. Drawing from the successful revitalization of the Cheonggyecheon stream in Seoul, implementing nature-based solutions and regular maintenance could effectively reduce nutrient pollution and improve water quality, facilitating the restoration of the Tamanduateí River. Full article

(This article belongs to the Special Issue Carbon, Nutrients and Greenhouse Gases in Urban and Peri-Urban Ecosystems)

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14 pages, 1247 KiB

Open AccessArticle

Ecological Flow as a Water Stress Control Strategy: San Rodrigo River, Coahuila, Mexico

by María Concepción Martínez-Rodríguez, Diego Domínguez-Solís, Lorena Elizabeth Campos-Villegas, Zurizaday García-Sánchez and Miguel Alvarado-Cardona

Limnol. Rev. 2024, 24(4), 543-556; https://doi.org/10.3390/limnolrev24040031 - 13 Nov 2024

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Abstract

Ecological flow refers to the minimum amount of water that must be maintained in a body of water to protect and preserve aquatic ecosystems. This article aims to analyze the function of ecological flow to address the reproduction of the natural hydrological regime [...] Read more.

Ecological flow refers to the minimum amount of water that must be maintained in a body of water to protect and preserve aquatic ecosystems. This article aims to analyze the function of ecological flow to address the reproduction of the natural hydrological regime of the San Rodrigo River, Coahuila, Mexico. A quantitative methodology was used where the ecological flow was determined based on the Mexican Standard NMX-AA-159-SCFI-2012 considering the period from 1962 to 2016. The maximum data allows us to identify runoffs of low magnitude of 6.65–15.60, those with an average trend close to 500 Mm³, and floods of extraordinary volume (namely, those 844–1260 and 1670 Mm³) with a frequency of every 35 years. Likewise, the river marks drastic changes in the flow in certain years, ranging from 0.64 to 1260 Mm³, so that the rate of variation would possibly exceed several orders of magnitude scaled in an annual phase. In conclusion, this calculation indicates that the body of water may have the function of environmental conservation covered throughout the year, with the data suggesting that in the short term the river will recover part of the water that passed through its course and thus avoid its deterioration. Full article

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23 pages, 12666 KiB

Open AccessArticle

Assessment of Groundwater Quality in the Semi-Arid Environment: Implications of Climate Change

by Otman El Mountassir, Mohammed Bahir, Samir Hakimi, Turki kh. Faraj and Paula M. Carreira

Limnol. Rev. 2024, 24(4), 520-542; https://doi.org/10.3390/limnolrev24040030 - 11 Nov 2024

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Abstract

The hydrogeochemical properties and evolution of groundwater in the Essaouira syncline basin in northwestern Morocco were investigated in this study, with a total of 447 samples during different campaigns (April 2017, May 2018, March 2019, and July 2020). These samples were analyzed for [...] Read more.

The hydrogeochemical properties and evolution of groundwater in the Essaouira syncline basin in northwestern Morocco were investigated in this study, with a total of 447 samples during different campaigns (April 2017, May 2018, March 2019, and July 2020). These samples were analyzed for major ions and stable and radioactive water isotopes (δ²H, δ¹⁸O, and ³H). With decreasing rainfall from climate change in Morocco, it is crucial to assess the sustainability of groundwater reserves. This shortage leads to the degradation of water and soil quality. To ensure sustainable water management and preserve the environment in the study area, it is necessary to assess groundwater quality for drinking and irrigation, take precautions, and establish management plans. This study assessed groundwater quality using two water quality index methods (WQI and IWQI). Several natural processes control groundwater mineralization, including the dissolution of evaporite and carbonate minerals, cation exchange phenomena, evaporation, and seawater intrusion. According to the results obtained using the WQI method, all groundwater samples in the study area are generally of poor quality and must be treated before being used for domestic purposes. Based on the results obtained by the IWQI method, the samples are suitable for use as irrigation water, especially for plants resistant to high salinity concentrations. Stable isotope measurements (δ²H and δ¹⁸O) indicate that Atlantic precipitation continuously recharges the recharge areas of the Essaouira Basin. Thus, the low values of tritium (³H) in groundwater mean that the freshwater in the Essaouira Basin is ancient. Full article

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14 pages, 2214 KiB

Open AccessArticle

Stable Isotope Analysis of Planktonic Lower Food Webs of Lakes Erie, Huron, Michigan and Superior

by John T. Lehman and Shelby Burgess

Limnol. Rev. 2024, 24(4), 506-519; https://doi.org/10.3390/limnolrev24040029 - 6 Nov 2024

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Abstract

Historical plankton samples from the St. Lawrence Great Lakes were subjected to taxon-specific ¹⁵N analysis to test the hypothesis that the changes recorded in zooplankton communities during the 21st Century are related to changes in the trophic positions of large-bodied carnivorous copepods. [...] Read more.

Historical plankton samples from the St. Lawrence Great Lakes were subjected to taxon-specific ¹⁵N analysis to test the hypothesis that the changes recorded in zooplankton communities during the 21st Century are related to changes in the trophic positions of large-bodied carnivorous copepods. Daphnia mendotae was used as the reference herbivore for trophic-level comparisons. The results were that Limnocalanus macrurus, Diaptomus (Leptodiaptomus) sicilis as well as the cladoceran Bythotrephes cederstroemi show evidence of elevated carnivory compared to data from the 20th Century. The large diaptomid Diaptomus (Leptodiaptomus) sicilis has a stable isotope signature that is significantly more carnivorous in Lake Superior than in Lakes Michigan and Huron by approximately one-half trophic level. Differences were found in 10 cases out of 15 for Limnocalanus (Huron, Michigan Superior), 6 cases out of 15 for Diaptomus (Huron, Michigan) and in 1 out of 1 for Senecella (Superior). We did not find evidence to support the theory that large-bodied calanoid copepods may have improved their representation in the food webs of the upper Great Lakes by shifting their trophic position downward. Instead, large-bodied Calanoida have increased their trophic positions in parallel with their increased relative abundance. More research is thus needed to explain the driving forces for changing food web dynamics in the Great Lakes. Full article

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15 pages, 9125 KiB

Open AccessArticle

Improvement of Phosphorus Removal from Wastewater Through Fermentation of Low-Concentrated Wastewater Sludge and Increased Production of Volatile Fatty Acids

by Elena Gogina, Nikolay Makisha, Igor Gulshin and Anna Reshetova

Limnol. Rev. 2024, 24(4), 491-505; https://doi.org/10.3390/limnolrev24040028 - 29 Oct 2024

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Abstract

This article presents the results of a two-stage study: the first stage involved assessing the dependence of the increase or decrease in the concentration of volatile fatty acids (VFAs) on external factors and then assessing the relationship between the VFA concentration in the [...] Read more.

This article presents the results of a two-stage study: the first stage involved assessing the dependence of the increase or decrease in the concentration of volatile fatty acids (VFAs) on external factors and then assessing the relationship between the VFA concentration in the supernatant after fermentation and the processing characteristics (temperature, mixing mode, alkalinity, pH, nitrogen and phosphorus content). The greatest increase in VFAs (content up to 285 mg/L in the supernatant) was achieved at a temperature in the range of 28 to 38 °C with constant mixing of the sludge. Based on the results of the second stage, a conclusion was made on the efficiency of using a particular substrate depending on the concentration of phosphorus phosphates in the incoming wastewater. The study results showed that 7.54 mg/L of phosphorus can be removed with a given probability (for activated sludge, raw sludge and wastewater). It is recommended to compensate for the excess of this concentration by dosing the acetic acid solution at a rate of 3800 meq/L of VFA per 1 mg/L of phosphorus phosphates. The literature does not contain any results of parallel studies of the operation of a controlled bioreactor with artificial external feeding and acidified VFA. The results of the study can be applied in planning sludge acidification systems in the technological scheme of wastewater treatment and sludge processing. Full article

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25 pages, 9855 KiB

Open AccessArticle

Assessing the Impact of Environmental Conditions on Reflectance Values in Inland Waters Using Multispectral UAS Imagery

by Daniel Henrique Carneiro Salim, Gabriela Rabelo Andrade, Alexandre Flávio Assunção, Pedro Henrique de Menezes Cosme, Gabriel Pereira and Camila C. Amorim

Limnol. Rev. 2024, 24(4), 466-490; https://doi.org/10.3390/limnolrev24040027 - 29 Oct 2024

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Abstract

This study investigates the impact of environmental conditions on reflectance values obtained from multispectral Unmanned Aerial System (UAS) imagery in inland waters, focusing on sun glint, cloud glint, wind-generated waves, and cloud shading projections. Conducted in two reservoirs with differing water qualities, UAS [...] Read more.

This study investigates the impact of environmental conditions on reflectance values obtained from multispectral Unmanned Aerial System (UAS) imagery in inland waters, focusing on sun glint, cloud glint, wind-generated waves, and cloud shading projections. Conducted in two reservoirs with differing water qualities, UAS platforms equipped with MicaSense Altum and DJI Phantom 4 Multispectral sensors were used to collect multispectral images. The results show that sun glint significantly increases reflectance variability as solar elevation rises, particularly beyond 54°, compromising data quality. Optimal flight operations should occur within a solar elevation angle range of 25° to 47° to minimize these effects. Cloud shading introduces complex variability, reducing median reflectance. Wind-generated waves enhance sun glint, increasing variability across all spectral bands, while cloud glints amplify reflectance non-uniformly, leading to inconsistent data variability. These findings underscore the need for precise correction techniques and strategic UAS deployment to mitigate environmental interferences. This study offers valuable insights for improving UAS-based monitoring and guiding future research in diverse aquatic environments. Full article

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16 pages, 7236 KiB

Open AccessArticle

Reconstructing the Relative Ice-Flow Chronology South of Lake Mistassini in Canada from New Ice-Flow Indicator Mapping

by Mohamed El Amrani, Khadija Diani, Mohamed Hafedh Hamza, Mohamed Elhag, Said Courba, Afaf Amine, Moulay Ahmed Ben Driss, Lahcen Ousaid, Nabil Mdiker, Youssef Hahou and Larbi Boudad

Limnol. Rev. 2024, 24(4), 450-465; https://doi.org/10.3390/limnolrev24040026 - 16 Oct 2024

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Abstract

Understanding paleo-ice flow chronology is essential for reconstructing past ice mass dynamics, interpreting the current landscape, and identifying the sources of Quaternary sediments in deglaciated regions. A recent systematic mapping of striated bedrock and streamlined landforms south of Lake Mistassini in Canada reveals [...] Read more.

Understanding paleo-ice flow chronology is essential for reconstructing past ice mass dynamics, interpreting the current landscape, and identifying the sources of Quaternary sediments in deglaciated regions. A recent systematic mapping of striated bedrock and streamlined landforms south of Lake Mistassini in Canada reveals a complex sequence of five ice flows. The earliest flow was directed to the southeast (SE) and originated from a NE-SW ice divide located northwest of Lake Mistassini at the Last Glacial Maximum. A progressive clockwise rotation of this ice divide, likely triggered during the early deglaciation, appears to have generated ice flows toward the south–southeast (SSE) and then toward the south (S). During the later stages of deglaciation, the flow originated from the Québec–Labrador Dome, initially toward the south–southwest (SSW) and then toward the southwest (SW). This study presents new data on ice flows south of Lake Mistassini and shows that the southward and south–southeastward ice events occurred before the late stage of deglaciation. This interpretation contradicts some previous studies and will contribute to the discussion on the dynamics of the Laurentide Ice Sheet in the Mistassini area and support mineral exploration efforts in the region. Full article

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13 pages, 2023 KiB

Open AccessArticle

Dam Impact on Fish Assemblages Associated with Macrophytes in Natural and Regulated Floodplains of Pandeiros River Basin

by Ivo Gavião Prado, Marcela Alves de Souza, Flávia Freitas Coelho and Paulo Santos Pompeu

Limnol. Rev. 2024, 24(4), 437-449; https://doi.org/10.3390/limnolrev24040025 - 14 Oct 2024

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Abstract

The impacts of hydropower plants and their reservoirs on floodplains can potentially create new environmental filters and reduce the exchange of organisms and access to habitats. In this study, we aimed to compare the fish assemblage associated with aquatic macrophytes between floodplain lakes [...] Read more.

The impacts of hydropower plants and their reservoirs on floodplains can potentially create new environmental filters and reduce the exchange of organisms and access to habitats. In this study, we aimed to compare the fish assemblage associated with aquatic macrophytes between floodplain lakes under natural conditions and a regulated floodplain lake in the Environmental Protection Area of Rio Pandeiros, Brazil. We tested the hypothesis that in the regulated floodplain lake, there would be a lower richness and a greater of abundance of macrophytes and fish than is natural. We also verified the influence of the seasons, macrophyte bank richness, and biomass on the fish assemblage abundance. The fish assemblages differed between the regulated and natural floodplains due to the higher richness and abundance of fish in the natural floodplains. The presence of non-native and generalist species in the regulated floodplain influenced the dissimilarity between the floodplains. Migratory species have been found only in natural floodplains. Fish abundance was negatively related to macrophyte richness on the regulated lake. There was a lower fish abundance and macrophyte richness in the regulated lake. There was no evidence that macrophyte biomass affected the abundance and richness of fishes. Our results confirm that the Pandeiros small hydroelectric dam affects the fishes’ assemblage and the macrophyte community, since the regulated floodplain lake has a lower richness and abundance of fish. The regulated floodplain lake is connected to a reservoir created by a small hydroelectric dam, which will be removed in the coming years. The removal of this dam might change these dynamics, and this must be evaluated when the change is implemented. Full article

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31 pages, 643 KiB

Open AccessReview

Unveiling the Hydrochemical and Ecotoxicological Insights of Copper and Zinc: Impacts, Mechanisms, and Effective Remediation Approaches

by Halina Falfushynska, Kamila Lewicka and Piotr Rychter

Limnol. Rev. 2024, 24(4), 406-436; https://doi.org/10.3390/limnolrev24040024 - 12 Oct 2024

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Abstract

Water pollution is a pressing global issue significantly affecting ecosystem health, biodiversity, and human well-being. While numerous studies have concentrated on toxic metals like cadmium, lead, and mercury, essential metals such as copper and zinc often receive less attention. This review focuses on [...] Read more.

Water pollution is a pressing global issue significantly affecting ecosystem health, biodiversity, and human well-being. While numerous studies have concentrated on toxic metals like cadmium, lead, and mercury, essential metals such as copper and zinc often receive less attention. This review focuses on the distribution and occurrence of copper and zinc in surface water, their accumulation in freshwater organisms, and potential strategies for mitigating the environmental pressure caused by these metals. Zinc concentrations in uncontaminated freshwater usually range from 3 to 12 μg∙L⁻¹ and form low-bioavailable hydroxo-complexes that are especially stable in weak alkaline water. The zinc concentration trend globally is Europe > Africa > Asia > South America > North America. Conversely, copper concentrations vary from 0.2 to 5.5 µg∙L⁻¹, with the order being Asia > Africa > South America > North America > Europe. Humic substances are the likely predominant ligands for copper in these environments. The accumulation of copper and especially zinc in freshwater animals may not be a reliable indicator of metal pollution due to potential metabolic regulation. Bioremediation approaches, including phytoremediation and biosorption using plants and microorganisms, show promise in addressing water contamination. Future research should emphasize advanced bioremediation methods, emission reduction strategies, and refined modeling techniques to predict pollution trends and evaluate remediation effectiveness. Full article

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Limnol. Rev., Volume 24, Issue 4 (December 2024) – 10 articles

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