Global water ecosystems are confronted with increasing pressure, characterized by sustained deterioration of water quality and diminishing availability of water resources, which have emerged as critical constraints on regional sustainable development [...]

The Goreangab Reservoir was built in 1958 as part of the water reclamation plant to support the water supply in the Windhoek area, Namibia. It has not been used since 2002 due to deteriorated water quality. This work describes the occurrence of micropollutants in Goreangab Reservoir water and assesses the removal of a target steroid hormone micropollutant, 17β-estradiol (E2), with various emerging membrane processes. Results show that a variety of micropollutants exist in water, and many of them exceed the European guideline concentration values for surface water. While nanofiltration provides only moderate E2 removal (50 ± 9% for loose and 81 ± 4% for dense NF) from an initial concentration of 100 ng L-1, reactive photocatalytic membranes and a combination of ultrafiltration (UF) and adsorption by polymer-based spherical activated carbon (PBSAC) can remove 85-98% of E2, bringing the water quality closer to the target guideline (0.4 ng L-1). Water components such as organic matter, ions, and other micropollutants interfered with E2 removal to varying degrees, highlighting the requirement for pretreatment and process validation with real water. UF-PBSAC achieves good E2 removal at a comparatively low pressure, resulting in low energy consumption. The amount of energy required to apply light irradiation and voltage in photo- and electrocatalytic membrane systems is significant based on theoretical estimation.

Pasture cattle manure may not dominate the deterioration of water quality in pastoral lakes

Assessing source water reservoirs as pre-treatment units for simultaneous control of autochthonous and runoff pollution through artificial mixing and aeration technology.

Hydrological and water quality gradients shape the structure and network complexity of planktonic diatom community in river-lake confluence zones during flood regulation.

The risk of water quality impairment from agricultural runoff depends on nutrient source, transport, and bioavailability. Phosphorus (P) spirals between dissolved and particulate forms as it is transported with suspended sediment (SS) from agricultural fields, through the stream network, to receiving water bodies. This dynamic sorption-desorption influences bioavailability. We quantified P form and abundance in samples collected during surface-runoff events from a farm field in the East River Basin, Wisconsin and compared them to those in stream water collected from the East River. We sampled five events between late March 2022 and June 2023. During most events, P in surface runoff was mainly in dissolved form, with particulate P sorbed to fine clay, the most abundant particle fraction transported from the field, whereas P in stream water was mainly in particulate form and sorbed to silt, even though fine clay was the most abundant particle fraction in the stream during events. Overall capacity for P sorption to SS in the stream varied among events. Total P and SS concentrations were lower during summer baseflow conditions and smaller surface runoff events; however, what SS was present was more P enriched. This shift in P form from field to stream indicates a potential for sorbing dissolved P to SS during transport through the stream network, which changes the bioavailability of P exported downstream with less bioavailable P as dissolved P binds to SS.

This paper investigated the influence of the deterioration of water quality in processed potable water distributed to the public from the Lower Usuma Dam Water Treatment Plant (LUD-WTP) in Abuja, Nigeria. Laboratory results revealed that the physiochemical parameters of the water samples were within the guidelines set by the World Health Organization (WHO) and the Nigerian Standard for Drinking Water Quality (NSDWQ). However, analysis of the bacteriological content of the water samples collected from locations serviced by the LUD-WTP revealed the presence of E. coli, Enterobacter aerogenes, and Klebsiella. Through water age simulation, the water distribution system in Abuja is supply-driven rather than demand-driven, which leads to an intermittent supply of water in certain areas. To prevent this issue, recommended chlorine booster locations be implemented at community tanks to re-chlorinate the water before distribution to consumers, and future designs should consider potential urban expansion.

<p>Obtaining sufficient amount of water with acceptable quality is the main objective of water distribution networks, but it also brings a fundamental challenge. Risk assessment of water distribution networks is quite important due to the scarcity of data on water quality, quantity and infrastructure conditions and various factors that may change its operation. Deterioration of water quality, quantity and infrastructure, together with inadequate conditions, may lead to general failure of the system. Therefore, a decision support system should be developed to determine vulnerable and sensitive areas within the network. In this study, hydraulic modeling based on demand algorithm, Hardy Cross Algorithms and Analytical Hierarchy Process (AHP) and Geographic Information System (GIS) methods are proposed for the sustainable operation and management of water supply networks serving both drinking and irrigation water distribution systems in response to increasing population demands. In addition, in this study presented for wastewater treatment in Hilvan district of Şanlıurfa province, it is aimed to determine the water in the wastewater treatment distribution network in the most appropriate way according to the demand. Environmental factors include precipitation, land use, geology and geomorphology, and protected areas. Economic factors include slope, wastewater transfer systems and land values. The determined factors are divided into sub-criteria according to their suitability for wastewater treatment areas and the corresponding values ​​are assigned. It has been determined that the solution gives better results using algorithms.</p>

This study investigated the impacts of climate change on smallholder dairy farming in Fiji through a mixed-methods approach, combining a survey of 242 farmers in Viti Levu’s Central Division with long-term meteorological and milk production data. Farmers were predominantly male (94.2%), aged over 54 years (73.1%), with low formal education (83.0% primary or secondary) and annual incomes below FJD 10,000 (43.4%), operating small farms (81.8% on 0.4–8.1 ha) with fewer than 20 milking cows (73.6%). Most farmers perceived rising daytime (70.2%) and nighttime (56.6%) temperatures and declining rainfall amounts and duration in both wet and dry seasons over the past 15 years. They reported substantial climate-induced impacts, including forage disappearance (73.6%), increased parasites and diseases (76.0%), reduced water availability (65.7%), and lower milk production (61.1%), compounded by potential inbreeding effects from disease control measures. Key adaptation challenges included pasture loss (64.9% high effect), deteriorated water quality (55.4%), and reduced milk yield (52.0%). Farmers primarily obtained climate information through peer networks (mean importance 4.5) and media (3.7), with limited input from research institutions or universities. Meteorological analysis (1970–2020) confirmed significant warming trends in maximum and minimum temperatures (Sen’s slope 0.01–0.04 °C/year at most stations), aligning with farmers’ perceptions, but revealed no significant long-term rainfall trends despite high interannual variability driven by ENSO. Tropical cyclones remained frequent, predominantly lower-intensity categories. National milk production declined significantly from 9.5 million liters in 2012 to 6 million liters in 2021, likely exacerbated by heat stress, rainfall variability, and socio-economic constraints. These findings highlight the vulnerability of Fiji’s smallholder dairy sector to climate change and underscore the urgent need for targeted adaptation strategies, including heat-tolerant breeds, resilient pastures, improved water management, enhanced extension services, and inclusive policies addressing demographic and economic barriers in rural area.

Chemical contaminants are increasingly detected in freshwater environments, yet the physiological and molecular responses of many non-model freshwater invertebrates to acute chemical stress remain poorly understood. In this study, we investigated the physiological and transcriptomic responses of the freshwater hydrozoan Craspedacusta sowerbii to two widespread aquatic pollutants: the antibiotic sulfamethoxazole (20 μM) and the heavy metal salt CdSO4 (10 μM). Morphological and behavioral observations showed that sulfamethoxazole exposure led to reduced motility and body shrinkage, whereas cadmium exposure caused rapid loss of movement and complete mortality within 24 h. RNA sequencing revealed distinct transcriptional response patterns to the two stressors. Sulfamethoxazole exposure primarily induced the up-regulation of genes associated with oxidative stress, apoptosis, immune responses, and signaling pathways, suggesting an active but limited stress-adaptation response. In contrast, cadmium exposure resulted in extensive down-regulation of genes involved in metabolic pathways, cell cycle regulation, fatty acid metabolism, and anti-aging processes, suggesting severe disruption of core metabolic processes. Comparative pathway analyses identified both shared stress-related responses and pollutant-specific transcriptional signatures, with cadmium exerting markedly stronger inhibitory effects at both physiological and molecular levels. These results reveal clear thresholds of stress tolerance and response failure in C. sowerbii under chemical pollution, and highlight its ecological sensitivity to water quality deterioration. Together, these findings provide mechanistic insight into acute pollutant-induced stress responses in a freshwater Cnidarian and offer a useful reference for understanding how freshwater invertebrates respond to short-term chemical disturbances.

ABSTRACT Water quality is a stern issue in urban areas because it is indispensable for the sustenance of life. The present study aimed to determine the spatial trends with time in water quality attributed to transitioning anthropogenic land‐use/cover in a Himalayan city—Dehradun, India—through the Weighted Arithmetic Water Quality Index (WQI). A total of 36 samples from nine surface aquifers during four seasons were analyzed for physicochemical and biological water quality parameters and compared with standards prescribed by BIS—Bureau of Indian Standards and WHO—World Health Organization. The water quality categorization during the monsoon (good–moderate), post‐monsoon (poor–very poor), and the winter and premonsoon seasons (poor–unfit) reveals the temporal trends. Further, WQI values indicate that 25% of the water samples (urban) were in the very poor–unfit category, 52% in poor (semi‐urban), and 22.2% in good status (rural), with elevated values for Coliform bacteria at all locations. Unsustainable anthropogenic activities, namely, discharge of wastewater, indiscriminate dumping of solid waste, and fecal matter, are the main factors, which have negatively impacted the water quality of these rivulets. Land‐cover analyses from 2002 to 2023 observed an increase in settlement—urban built‐up (+7.5%), cultivated land (+7.5%), and barren land (+4.4%), whereas grassland (−8%), forest (−12%), and water bodies (−0.11%) decreased in terms of area coverage, with a slight decline in land surface temperature regimes attributed to the aerosol optical depth variations. The management of water resources (catchment basin conservation) in the Dehradun region is a major concern pertaining to urban land use planning and the mandate of Sustainable Development Goals (SDGs) 6 and 11.

Surface water quality in Dolisie (southwest of the Republic of Congo) is strongly impacted by human activities, particularly domestic wastewater discharge, agriculture, and livestock farming, leading to progressive degradation of water resources and posing risks to public health as well as domestic and agricultural uses. This study assessed water quality through analysis of physico-chemical and bacteriological parameters at several sites representative of domestic and agricultural areas. Physico-chemical analysis showed that pH ranged from 5.5 (Ninja Lake) to 9.9 (marsh near the Orthodox Church), with a mean of 6.58 ± 1.18. Water temperature varied from 25.36°C (upstream of the Loubomo River) to 28.5°C (Tahiti fish ponds), with an average of 26.83 ± 0.93°C. Electrical conductivity ranged from 115.66 to 315.33 µS/cm (mean 213.65 ± 73.18 µS/cm), while total dissolved solids (TDS) varied from 57 to 210.5 ppm (mean 112.52 ± 46.70 ppm). Three heavy metals were detected: cadmium (0.049–0.070 ppm, mean 0.057 ± 0.005 ppm), copper (0.0217–0.0509 ppm, mean 0.037 ± 0.010 ppm), and zinc (0.0004–0.00311 ppm, mean 0.004 ± 0.008 ppm). Microbiologically, total mesophilic aerobic flora (TMAF) ranged from 1,000 to 6,000 CFU/100mL (mean 3,333 ± 1,670), total coliforms from 69 to 193 CFU/100mL (mean 133 ± 43), and fecal coliforms from 32 to 102 CFU/100mL (mean 64 ± 21), exceeding WHO standards and indicating significant fecal contamination. Fecal streptococci ranged from 30 to 72 CFU/100mL, <i>Staphylococcus</i> spp. from 14 to 97 CFU/100mL, <i>Salmonella</i> from 40 to 110 CFU/100mL, <i>Shigella</i> from 19 to 77 CFU/100mL, and <i>Pseudomonas </i><i>aeruginosa</i> from 15 to 62 CFU/100mL. Correlation analyses revealed significant relationships: temperature correlated with total coliforms (r = 0.69) and fecal coliforms (r = 0.63), electrical conductivity correlated with TDS (r = 0.91), and several bacterial groups showed positive correlations among themselves. Principal component analysis associated the F1 axis (42.24% of variance) with microbiological parameters and the F2 axis (20.7%) with physico-chemical parameters. These findings reveal progressive deterioration of surface water quality in Dolisie and emphasize the urgent need for sustainable management measures, public awareness, and wastewater control to preserve water resources and protect public health.

Lake Anna is an important ecological and recreational body of water in Virginia but struggles with stream water and sediment quality impairments due to historical and modern anthropogenic activities. The overarching goal was to quantify potentially toxic elements (PTEs) (As, Cr, Cu, Pb, Ni, and Zn) and P pollution across nine subwatersheds and the outflow of Lake Anna to evaluate the role of exposed mine tailings, agriculture, and physicochemical properties on sourcing and transport. Phosphorus enrichment in stream waters and sediments was associated with DOM and Fe, but not agricultural land cover. Suspended sediment total annual P export (191Mg/year) was greater than dissolved P export (0.7Mg/year), but < 56% of the P was retained within Lake Anna. Stream water, suspended sediment, and bottom sediment Cr, Cu, Pb, and Zn concentrations at Contrary Creek subwatershed (CC) exceeded ecologically hazardous concentrations and was a major PTE source for the reservoir. Comparing total annual exports, Lake Anna was a net accumulator of PTEs and P. Exposed mine tailings at CC had ecologically hazardous concentrations of As, Pb, and Cu, but pine tree needle PTEs were not elevated, demonstrating limited bioavailability. Lastly, our column experiment using exposed mine tailings found an application rate of 9.2 tonnes/ha of lime and biochar could decrease the leaching of Pb and Zn and increase leachate pH but could not significantly reduce As or Cu. Additional research of subsurface transport pathways and mobility of legacy sediments is warranted to immobilize PTE transport.

Agricultural runoff is a major source of water quality impairments and is prevalent in areas where agricultural operations focus on maintaining global food security. To alleviate downstream impacts, best management practices are used to cultivate food systems and enhance soil nutrient cycling. When runoff events do occur, tracing the impairments often involves complex and costly methods to determine analyte concentrations and forecast mitigation techniques. Fluorescent dissolved organic matter (fDOM) is an innovative approach to understanding parent source materials and carbon signatures from runoff. Fluorescence and absorbance indices can distinguish intensities of the carbon molecular weight, biological activity, and humification that can trace the environmental availability of carbon sources. Comprehensive data sets can be combined using parallel factor analysis (PARAFAC) to determine parent source components. Integrating these analyses can provide real-time high-frequency data to empower policymakers and land managers to make informed decisions aimed at reducing the environmental degradation associated with modern intensive agriculture.

Springs are a critical source of freshwater in India, particularly in the Himalayan and sub-Himalayan regions, the Western Ghats, and parts of central and northeastern India, where they support drinking water, agriculture, and local ecosystems. In recent decades, the quality of spring water across the country has deteriorated significantly due to a combination of natural processes and increasing anthropogenic pressures. This review synthesizes available literature on the status and trends of spring water quality deterioration in India, with emphasis on key physicochemical and microbiological indicators. Major drivers of degradation include land-use change, deforestation, unplanned urbanization, agricultural runoff, improper waste disposal, sewage intrusion, and overexploitation of groundwater, compounded by climate-induced variability in rainfall and recharge patterns. Studies report elevated levels of nutrients, fluoride, iron, nitrates, heavy metals, and microbial contamination in several spring systems, often exceeding Bureau of Indian Standards (BIS) limits for drinking water. The consequences of declining spring water quality for public health, rural livelihoods, and spring-dependent ecosystems are increasingly evident. The review underscores the need for regular monitoring, spring-shed based management, community-led conservation initiatives, and policy integration to safeguard spring water resources. Strengthening scientific research and governance frameworks is essential to ensure the long-term sustainability and safety of spring water supplies in India.

Epidemiology and immunoprophylaxis of lactococcosis in European Sea bass (Dicentrarchus labrax): A comprehensive study from Egyptian Aquaculture.

Unveiling ecological risks of organophosphorus pesticides at environmental levels: Cyanobacterial bloom stimulation and toxin accumulation.

A staged and layered approach to restoring turbid nearshore coral reefs.

An alternative to in vivo/in vitro toxicity testing: Consensus-based prediction for toxicity assessment and prioritisation of diverse chemicals in Japanese eel to safeguard aquatic and public health.

Many populations of the weatherfish ( Misgurnus fossilis L.) in north-western Europe have experienced significant declines since the end of the Second World War. These declines have been largely attributed to changes in land use practices, such as agricultural intensification and urban development, as well as a deterioration in water quality across their natural habitats. Several of the remaining weatherfish populations are currently characterized by poor conservation status. Decades of habitat fragmentation have resulted in reduced genetic diversity, increased levels of inbreeding, and the presence of phantom populations—small, isolated groups that are demographically unstable and genetically unsustainable in the long term. Although traditional approaches to aquatic restoration—such as habitat enhancement, water quality improvement, and the removal of migration barriers—remain essential and should be prioritized, they are often insufficient to recover genetically depleted populations. To support the recovery of these populations, a targeted breeding program was developed, funded by LIFE B4B, for the weatherfish. This involved introducing genetic material from populations with high genetic diversity into extant, inbred populations. Over recent years, the protocol for artificial reproduction has been gradually optimised, resulting in a stable and scalable production of large numbers of juvenile weatherfish. In parallel, a release program for this endangered species was implemented in Flanders. Thousands of farmed young-of-the-year individuals were introduced at eight sites within the species’ historical range. Additionally, as part of a complementary reintroduction strategy, tens of thousands of juvenile fish (2–4 weeks old, 10–20 mm in length) were released into carefully selected river sectors. Recent monitoring at one of the release sites revealed encouraging results, with high survival rates and numerous juveniles originating from natural recruitment. While it is still too early to declare the project a definitive success, the re-establishment of natural reproduction represents a critical first milestone. Ongoing genetic analyses will be necessary to assess the extent of admixture between the introduced genetic lines and the resident populations (Suppl. material 1).