Water Ecosystem Research Articles

Spatiotemporal Variation of Water Use Efficiency and Its Responses to Climate Change in the Yellow River Basin from 1982 to 2018

The ecosystem water use efficiency (WUE) plays a critical role in many aspects of the global carbon cycle, water management, and ecological services. However, the response mechanisms and driving processes of WUE need to be further studied. This research was conducted based on Gross Primary Productivity (GPP), Evapotranspiration (ET), meteorological station data, and land use/cover data, and the methods of Ensemble Empirical Mode Decomposition (EEMD), trend variation analysis, the Mann–Kendall Significant Test (M-K test), and Partial Correlation Analysis (PCA) methods. Our study revealed the spatio-temporal trend of WUE and its influencing mechanism in the Yellow River Basin (YRB) and compared the differences in WUE change before and after the implementation of the Returned Farmland to Forestry and Grassland Project in 2000. The results show that (1) the WUE of the YRB showed a significant increase trend at a rate of 0.56 × 10−2 gC·kg−1·H2O·a−1 (p < 0.05) from 1982 to 2018. The area showing a significant increase in WUE (47.07%, Slope > 0, p < 0.05) was higher than the area with a significant decrease (14.64%, Slope < 0, p < 0.05). The region of significant increase in WUE in 2000–2018 (45.35%, Slope > 0, p < 0.05) was higher than that of 1982–2000 (8.23%, Slope > 0, p < 0.05), which was 37.12% higher in comparison. (2) Forest WUE (1.267 gC·kg−1·H2O) > Cropland WUE (0.972 gC·kg−1·H2O) > Grassland WUE (0.805 gC·kg−1·H2O) under different land cover types. Forest ecosystem WUE has the highest rate of increase (0.79 × 10−2 gC·kg−1·H2O·a−1) from 2000 to 2018. Forest ecosystem WUE increased by 0.082 gC·kg−1·H2O after 2000. (3) precipitation (37.98%, R > 0, p < 0.05) and SM (10.30%, R > 0, p < 0.05) are the main climatic factors affecting WUE in the YRB. A total of 70.39% of the WUE exhibited an increasing trend, which is mainly attributed to the simultaneous increase in GPP and ET, and the rate of increasing GPP is higher than the rate of increasing ET. This study could provide a scientific reference for policy decision-making on the terrestrial carbon cycle and biodiversity conservation.

Generation and Transmission of Antibiotic Resistance Genes in Livestock and Poultry Breeding Environments

The widespread presence of antibiotic resistance genes (ARGs) in livestock and poultry farming poses a significant threat to the ecological environment and public health. In this paper, the causes, transmission routes and environmental impacts of ARGs in livestock and poultry breeding environments are reviewed. ARGs spread in the environment through horizontal gene transfer (HGT), biological vectors, and airborne transmission, further exacerbating the problem of drug resistance. The presence of ARGs not only has a negative impact on soil and water ecosystems, but also poses a potential threat to human health through the food chain. This article discusses the current methods of detecting and controlling ARGs, and puts forward the focus and direction of future research, aiming to provide theoretical support for the formulation of effective prevention and control strategies to reduce the environmental and health risks caused by ARGs.This review identifies horizontal gene transfer as a critical mechanism in ARG propagation and proposes advanced detection techniques to curb environmental contamination, laying the groundwork for sustainable antibiotic usage in livestock.

Mitochondrial genome insights into the phylogenetics and biogeographic evolution of snow trout (Cyprinidae, Schizothorax) in the Tien Shan Mountains

Snow trout (Schizothorax), endemic to the high-altitude freshwater systems of the Tibetan Plateau and the Tien Shan Mountains region, are key components of these ecosystems. This fish lineage may serve as an appropriate model to understand the evolution of biodiversity in the Tien Shan Mountain water ecosystems. However, research has been hindered by poorly understood phylogenetic relationships, unresolved taxonomic classifications, and ambiguous biogeographical histories, particularly in the underexplored western regions of the Tien Shan Mountains. Here, we analyzed three mitochondrial genomes assembled using the next-generation sequencing data of three snow trout species, S. eurystomus, S. fedtschenkoi, and Schizothorax sp., from the western Tien Shan Mountains. These genomes range from 16,584 to 16,592 bp in length and include 13 protein-coding genes (PCGs), 2 rRNAs, 22 tRNAs, and a control region. Our phylogenetic analyses suggest six snow trout from the Tien Shan Mountains region were divided into two distinct clades: clade I comprises S. fedtschenkoi, and Schizothorax sp., and clade II includes S. eurystomus, S. biddulphi, S. pseudoaksaiensis, and S. argentatus. We classified Schizothorax sp. as a valid independent species based on comprehensive phylogenetic trees and DNA barcode genetic distance. The dramatic uplift of the Tien Shan Mountains during the Late Miocene to the Pliocene, followed by periods of isolation on its eastern and western flanks, has driven extensive speciation, contributing to the rich diversity observed today. Notably, S. eurystomus spread westward along the Pamir-Tien Shan corridor, shaping the region’s current biogeographical distribution of snow trout species. Our findings not only clarify the evolutionary histories of snow trout in the Tien Shan Mountains but also advance our understanding of the mechanisms shaping the rich biodiversity.

Assessing the Impacts of Climatic and Water Management Scenarios in a Small Mountainous Greek River

The water resource management of transboundary mountainous river basins under climate change is expected to be challenging. In order to contribute to the better understanding of climate change effects on the water resources of the mountainous and transboundary Prespa Lakes basin, a hydrological model of the Agios Germanos River, one of the main rivers discharging to Great Prespa Lake, was developed, and two water management plans under two different climate scenarios were examined. Based on the results, the impact of climate change on surface water resources was evident in all climate change scenarios examined, even under the most favorable water abstraction practices. Nevertheless, sensible water management can moderate the impact of climate change by up to 10% in an optimistic scenario in both the near- and long-term, and by up to 6% and 1% for the near- and long-term, respectively, in a pessimistic scenario. Integrated water management practices that moderate the impact of climate change on the water ecosystem services should be prioritized. Nature-based approaches could provide solutions regarding climate change adaptation and mitigation. Transboundary cooperation, data exchange mechanisms, common policy frameworks, and monitoring, reporting, and evaluation systems, could reduce human and ecosystems’ vulnerabilities and improve the water security of the area.

The effects of teleconnections on water and carbon fluxes in the two South America’s largest biomes

Ecosystem services provided by terrestrial biomes, such as moisture recycling and carbon assimilation, are crucial components of the water, energy, and biogeochemical cycles. These biophysical processes are influenced by climate variability driven by distant ocean-atmosphere interactions, commonly referred to as teleconnections. This study aims to identify which teleconnections most significantly affect key biophysical processes in South America’s two largest biomes: The Amazon and Cerrado. Using 20 years of monthly data on Precipitation (P), Evapotranspiration (ET), Gross Primary Productivity (GPP), and Ecosystem Water Use Efficiency (EWUE), alongside data from six teleconnections (Antarctic Oscillation - AAO, Atlantic Multidecadal Oscillation - AMO, Oceanic Niño Index - ONI, Atlantic Meridional Mode - AMM, North Atlantic Oscillation - NAO, and Pacific Decadal Oscillation - PDO), we developed a multivariate linear model to assess the relative importance of each teleconnection. Additionally, time-lagged Spearman correlations were used to explore relationships between biophysical variables and teleconnections. Our findings indicate that the AMO exerts the strongest influence across all studied variables. Furthermore, ONI and AMM significantly impact precipitation in the northern Amazon, with a 3-month lag in ONI showing positive correlations with ET and GPP. In contrast, a 3-month lag in AMO negatively influences GPP in the southern Amazon and Cerrado, though positive correlations with EWUE were observed in the same region. These insights highlight the complex and regionally varied impacts of teleconnections on South America’s largest biomes.

Biotic factors shape the structure and dynamics of denitrifying communities within cyanobacterial aggregates.

Eutrophication caused by human activities has severely impacted freshwater ecosystems, leading to harmful cyanobacterial blooms that threaten water quality and ecosystem stability. During blooms, denitrification is a key process for nitrogen removal, which can occur both in the sediment and in the waterbody mediated by cyanobacterial aggregate (CA)-associated microorganisms. In this study, the structure, dynamics and assembly mechanisms of CA-associated nirK-, nirS-, and nosZ-encoding denitrifying communities were investigated in the eutrophic Lake Taihu across the bloom season. External environmental factors showed limited influence on denitrifying community structure, which were more strongly shaped by biotical factors. Network analysis revealed both monofunctional and multifunctional modules, with a small subset of linker OTUs playing a critical role in maintaining these multifunctional modules by mediating interactions among different functional communities. Biotic regulation was further demonstrated by coupling patterns among denitrifiers associated with specific microbial lineages, as well as niche partitioning driven by cyanobacterial composition. While the assembly of the total phycospheric communities was governed by stochastic processes, the denitrifying communities were predominantly shaped by homogeneous selection. These findings indicate biological processes, particularly synergistic relationships and autotroph-heterotroph interactions, were key drivers of the structure and dynamics of denitrifying communities within CAs. Moreover, the key taxa identified in this study may provide potential targets for regulating nitrogen cycling in the management of cyanobacterial blooms.

Facile synthesis of CQD/g-C3N4 as a highly effective metal-free photocatalyst for the degradation of carmoisine and indigo carmine dye

The development of extensive dye pollution in the water ecosystem seriously endangers the health of the living organism. For effectively eradicating dyecontaminants from water bodies, photocatalysis is consideredan effective, energy-consumption, inexpensive disinfection technique. As an alternative to conventional metal-based catalysts, heterogeneous metal-free photocatalysts are more sustainable and kinder to the environment. Here, we reported the simplehydrothermalchemical production of Carbon Quantum dots (CQD)-doped graphitic carbon nitride(GCN). Analytical instruments such as XRD, SEM, FE-SEM, HR-TEM, EDX, FT-IR, thesurface area of BET analysis, photoluminescence, and UV–vis spectroscopy, zeta potentialwere used to characterize the as-prepared CQD doped GCN (CDCN). The degradation studies reveal that the CDCN catalyst displays the highest rate of degradation performance than pure GCN. Within 60 min, it shows 96 % degradation toward indigo Carmine (IC) and 93 % decomposition towards carmoisine dye (CM). Significant e−/h+ separation, an increased surface area, and a high redox potential capacity to induce charge bears may all contribute to the CDCN catalyst’s enhanced photocatalytic degradation efficiency. The efficiency of the photocatalytic process was optimized by studying and altering many variables. These include Dye concentration, catalyst concentration, and variation of the pH solution were some of these. The nanocomposite exhibited excellent stability after three successive runs of the photocatalytic procedure. According to the kinetics analysis results indicate that the photocatalytic decomposition of Indigo Carmine (IC) and carmoisine (CM) dye follows pseudo-first-order kinetics. For better photodegradation performance, a potential photocatalytic method employing several pairs of electron-hole acceptor scavengershas been put forth. Based on the positionsof the band gap and the result of the characterization, a feasible mechanismpathway for charge carriers was also presented.

Emerging challenges in aquaculture: Current perspectives and human health implications

Aquaculture, the cultivation of aquatic organisms for human consumption, has become an essential contributor to global food security. However, it faces numerous challenges that threaten its sustainability and capacity to meet the growing demand for animal protein. This review investigates these challenges, with a particular focus on environmental degradation, public health risks, and ethical dilemmas posed by genetic interventions in fish breeding. Despite the promise of genetically modified organisms (GMOs) in enhancing fish production, their integration into aquaculture remains controversial due to potential risks and unresolved ethical questions. This study aims to provide a comprehensive understanding of these pressing issues and propose pathways for sustainable aquaculture development. With the global population increasing and the demand for animal protein intensifying, aquaculture holds great potential as a sustainable food source. However, its contribution to global protein demand remains minimal, projected to decline to as low as 4% in the coming decades. Furthermore, aquaculture’s environmental impact, including pollution of water bodies and ecosystem disruption, poses serious threats to biodiversity and public health. Addressing these challenges is critical for ensuring the long-term viability of aquaculture. By exploring the intersection of sustainability, ethics, and innovation, this review provides valuable insights for policymakers, industry stakeholders, and researchers seeking to advance sustainable aquaculture practices. This study aims to evaluate the current state of aquaculture and identify key challenges related to environmental sustainability, public health, and ethical considerations. It seeks to explore the potential of sustainable practices and genetic interventions to address these challenges while balancing the need for increased production and societal acceptance. The ultimate goal is to offer practical recommendations for fostering a resilient and ethical aquaculture industry capable of meeting future global food demands. Keywords: antibiotic resistance, aquaculture effluent, eutrophication, food safety, genetic engineering.

Optical Sediment Trap for In Situ Monitoring of Sinking Marine Particles

The ocean’s biological carbon pump (BCP) comprises a set of physical and biological processes that impact how carbon is exchanged between the atmosphere, the land, and the ocean. Sinking particles, such as “marine snow,” are a key mechanism of the BCP, where the depth of remineralization of carbon from these particles governs the extent to which carbon releases back into the atmosphere or sequesters in the deep ocean (Siegel et al., 2021). In addition, this sinking flux is a key energy source for deep water and benthic ecosystems. Studying these particles remains challenging, however, making it difficult to quantify carbon flux on a global scale. Global climate change further decreases the predictability of oceanic carbon flux due to the indirect changes induced by warming, ecosystem shifts, and acidification. Other human-induced alterations of the ocean’s carbon cycle, such as proposed marine carbon dioxide removal (mCDR) techniques like ocean alkalinity enhancement or nutrient fertilization, stand to further complicate carbon quantification and the ability to establish a carbon flux baseline from which future measurements can be compared and contextualized.

Urban stormwater discharge contributes more micropollutants to surface water in humid regions of China: Comparison with treated wastewater.

Micropollutants have raised increasing concern due to their adverse effect on ecosystems and human health. So far, the effects of micropollutants in urban stormwater discharge on surface water quality or ecosystem health remains unclear. In this study, target and non-target screening methods were used to quantify and identify micropollutants in urban stormwater, wastewater, and surface water in humid regions of China. Results showed that the average concentration of micropollutants in surface waters in wet weather was 1.8 times that in dry weather. The cumulative concentrations of 143 micropollutants in samples from stormwater discharge were in the range of 490-1659 ng/L, which were comparable to or exceeded those from wastewater discharge. In terms of mass load in the studying area, stormwater discharges contained 10.8 kg of micropollutants in the month, a higher level compared to 4.58 kg in treated wastewater. Furthermore, the calculated risk quotients revealed medium to high ecological risk to aquatic organisms from substances such as telmisartan, irbesartan, 1,7-dimethylxanthine, and caffeine at ng/L concentrations, which are in typical levels in urban stormwater and surface waters in wet weathers. Our study reveals that urban stormwater discharge is an important pathway for micropollutants to surface waters, and urges for increased emphasis on, and reinforcement of, urban stormwater monitoring and control measures to minimize the transport of micropollutants to receiving waterbodies.

Tracing the trail of eroded fertile soils during a high intensity rainfall event: A fingerprinting study in war-torn tropical mountains

The depletion of fertile topsoil presents a critical challenge in tropical mountain agroecosystems. Impacts are intensified during heavy storm events that strip unprotected topsoils and pose risks to downstream water ecosystems. To better understand such dynamics, we investigated an agricultural mountainous catchment located on the Democratic Republic of the Congo shore of Lake Kivu. This area is characterised by weak governance systems exacerbated by protracted violent conflicts, which have prevented the application of remediation practices to address extensive land use changes, including deforestation and monoculture proliferation, notably banana plantations. Additionally, the spread of Banana Xanthomonas wilt (BXW) has further augmented land use impacts. Herein the complete diseased mat uprooting (CDMU) method employed to combat the disease has resulted in significant erosion and sediment export rates. Following the recovery of banana plantations from CDMU, sediment export rates continued to increase without a clear responsible party but more as a legacy of past and present land degradation activities and embedded soil erosion and connectivity process pathways. To analyse the impact of high-intensity storm events coupled with the aftermath of conflict instability and the effects of BXW on erosion dynamics, the sediment fingerprinting technique was implemented. We collected 60 sediment source samples across a 42km2 catchment, predominantly cultivated since the mid-20th century. Samples spanned four main land uses/land covers: seasonal crops, banana plantations, bare or degraded soil, and channel banks. Additionally, mixture/target samples were collected at the summit of six fluvial terraces located at different altitudes along the vertical profile of the river after a high-intensity storm event. These terraces serve as natural indicators of sediment accumulation under different flow intensities, with higher terraces representing sediment deposition during higher discharge. Furthermore, sediment samples were collected via a gravity core in delta deposits at the river's inflow into the lake, allowing us to identify the main sources contributing to fine sediment export to the lake. This methodology enabled us to assess how sediment provenance has changed in response to varying discharge levels while elucidating the primary sources responsible for fine sediment inputs to the lake and the subsequent water quality decrease. Our analysis indicates increased contributions occurred from channel banks and degraded areas as discharge increased. Despite steep channel banks and degraded soils being primary sediment sources on the terraces, agricultural and banana sources predominantly contributed to the fine sediments exported to the lake. These findings underscore the hazards of high-intensity storm events in these fragile ecosystems and highlight the role of current banana plantation and cropland management in degrading land and water quality. Understanding the primary factors driving land degradation and sediment export is crucial for preventing further ecosystem degradation and mitigating heightened instability in conflict-affected areas. This research suggests that remediation practices should be incentivised to create buffer structures in upslope agricultural areas and protect the fertile sediments from banana plantations from being exported to the lake if socio-cultural and economic hurdles to implementation can be overcome.

Will vegetation restoration affect the supply-demand relationship of water yield in an arid and semi-arid watershed?

Natural processes, combined with human activities, determine the inherent quality of regional water supply and demand. However, the interaction between artificial vegetation restoration and water supply-demand dynamics remains insufficiently understood, particularly in arid and semi-arid regions. This study focuses on the Jinghe River Basin (JRB) in the central Loess Plateau, aiming to investigate the changes in supply and demand of ecosystem water yield services and analyze factors affecting the water supply-demand relationship during the vegetation restoration, using the InVEST model, scenario analysis, and the Geodetector. The key findings are as follows: (1) Water shortages in the basin are concentrated in the southern and northern areas, while the southwestern and central areas exhibit water surpluses. Between 2000 and 2020, the water supply showed a first decline and then increase trend, whereas water demand exhibited an opposite trend, with 2009 and 2013 as turning points, respectively. These changes mitigated the basin's water scarcity. (2) Assuming constant meteorological factors and fixed water use indicators, water supply in the vegetation restoration areas decreased by 47.4 million m3, but water demand decreased by 89 million m3, indicating that vegetation restoration did not threaten human water availability. (3) Water supply is primarily influenced by meteorological factors, while water demand and the water supply-demand ratio (WSDR) are mainly driven by socio-economic factors. The influence of precipitation on water yield (q=0.69) outweighs that of land use (q=0.14), indicating that the reduction in water yield due to vegetation restoration is offset by the increased precipitation. This study provides insights into the spatiotemporal dynamics of water yield services and the relationship between vegetation restoration and water supply-demand in the arid and semi-arid regions.

Changes in Water and Carbon Fluxes in the USA Southern Great Plains Grassland Due to Evergreen Forest Encroachment

The southern Great Plains (SGP) grassland of the United States has been largely encroached by evergreen forest in recent decades. The response of the grassland water and carbon cycles to the encroachment is not clear yet. Given so, this study quantified the changes in gross primary production (GPP), evapotranspiration (ET), and ecosystem water use efficiency (EWUE) between grassland pixels with evergreen forest encroachment and neighboring pure grassland pixels (500 m). We also assessed the spatial variation of the changes in relation to precipitation (mm), air temperature (°C), and evergreen forest coverage (%). These analyses were repeated, respectively for the years of 2004, 2008, 2016, and 2019 as robustness check. Results suggest that across the 4 years, 62–72% of encroached grassland pixels exhibit higher annual GPP, 67–74% exhibit higher annual ET, whereas 65–71% exhibit lower annual EWUE. The change ratio of ET is positively correlated with that of GPP but negatively correlated with that of EWUE. Additionally, the spatial variation in the change ratios of annual GPP and ET can be explained to a certain degree by the encroachment amount. These results further clarify the response of water and carbon cycles to evergreen forest encroachment in the SGP grassland.

Enhanced productivity and evapotranspiration dominated by woody plant encroachment-induced vegetation greening in boreal wetland ecosystems

ABSTRACT Woody plant encroachment (WPE), a global phenomenon documented across various biomes and continents, has the potential to significantly impact ecosystem carbon and water cycling. However, the impacts of WPE on carbon and water cycling in wetland ecosystems of middle and high latitudes are still lacking. In this study, the interannual and seasonal impacts of WPE on gross primary production (GPP) and evapotranspiration (ET), as well as their underlying mechanisms, within boreal wetland ecosystems located in middle-high latitude regions, were examined using remote sensing datasets spanning the period 2001–2016. Our results demonstrated that WPE enhanced annual GPP, ET, Normalized Difference Vegetation Index (NDVI), and solar-induced chlorophyll fluorescence (SIF) in boreal wetlands with impacts increasing over time. The multi-year average GPP and ET in fully encroached wetland ecosystems were approximately 31% and 3% higher, respectively, compared to pure wetland ecosystems. Prominent increases in wetland GPP occurred during the early growing season, while an exacerbation of ET was observed during the peak growing season. The impacts of WPE on wetland GPP and ET were predominantly attributed to increased vegetation greenness followed by secondary contributions from climate change. Climate change not only directly influenced the responses of GPP and ET to WPE but also exerted indirect effects by regulating vegetation greenness and the degree of encroachment. Our findings offer valuable insights into the understanding of the interaction between WPE and climate change, highlighting the importance of considering WPE effects and their drivers for accurate predictions of carbon and water cycles, as well as atmosphere–biosphere feedbacks in boreal wetlands.

Assessing the Effects of Microplastics on Freshwater Fish

Microplastics are formed through the breakdown of engineering products in consumer goods and large plastic products. These anthropogenic pollutants accumulate globally in both marine and freshwater ecosystems. Nowadays, people use personal care products a lot, and microplastics formed through the decomposition of the packaging of these products spread to the land and water ecosystems, and many living things come into contact with them. Studies have made the presence of microplastics in body parts such as the gastrointestinal tract and stomach, especially in marine and freshwater fish. It can cause physical harm in fish such as internal organ and tissue damage, immune system damage, accumulation, obstruction and damage in the gastrointestinal tract. Increasing evidence shows that a wide range of fish species are susceptible to microplastic ingestion. Already to many criteria such as overfishing, habitat loss, and the increasing number of invasive fish, the negative effects of microplastics will cause fish populations to decrease and some species to become extinct. It is known that plastic pollution, especially about increasing plastic production, poses a great threat to humans, aquatic creatures, and the global environment. Therefore, to draw attention to the danger of microplastics, in this study, the conducted research was examined, the effects of microplastics were reviewed, and the study results were evaluated. In this study, all articles searching microplastics and the amount of microplastics in freshwater fish were systematically examined. 25 studies were found that included the criteria we were looking for, and in these studies, the presence of microplastics was detected in a total of 100 fish species.

Wastewater management by using effective phytoremediator duckweed

Water pollution and the increasing discharge of untreated wastewater into natural water bodies are intensifying the pressure on aquatic environments. Sustainable and eco-friendly methods are essential for restoring water quality and mitigating pollution. One such approach is water phytoremediation, which involves the use of aquatic plants to remove pollutants from water bodies and ecosystems. This study explored the removal of contaminants from municipal wastewater using floating aquatic plants such as Lemna minor, which have proven highly effective for phytoremediation due to their low cost, high pollutant uptake capacity, minimal generation of chemical and biological sludge, ease of transport, adaptability to diverse climatic conditions, and rapid reproduction rates. Notable findings from the research include reductions in chemical oxygen demand (COD) by 82.2%, biological oxygen demand (BOD) by 84.3%, phosphates by 63.8%, ammonium nitrogen by 75.4%, and nitrates by 79.1% for Lemna minor. Maximum plant growth occurred during the experiment at pH levels between 7 and 8. The study demonstrated that large-scale remediation could be effectively achieved using Lemna minor as a phytoremediation agent within 17 days. This method offers a cost-effective, efficient tertiary treatment for heavily polluted wastewater. Additionally, it can serve as an independent treatment solution when integrated with preliminary wastewater treatment systems in smaller communities.

Evaluation of the Impact of Tourism on Environmental Sustainability at the Situ Bagendit Tourist Destination

This research evaluates the impact of tourism on environmental sustainability at Situ Bagendit, a natural tourist destination in Garut Regency, West Java. The increase in tourist numbers has led to both positive and negative environmental impacts, such as water pollution, waste accumulation, and ecosystem degradation. The mixed-methods approach used in this study involved field observations, interviews with local stakeholders, and surveys with tourists and residents. The findings indicate significant challenges, including pollution from motorized boats and inadequate waste management, but also highlight increased community awareness and sustainable initiatives. The study recommends improvements in environmental regulations, waste management systems, and educational programs for tourists.

Production of active chlorine and sodium hypochlorite in a closed electrolyser

Today, in the conditions of warfare, there is constant local pollution of the environment due to the use of explosives, fires, spillage of fuel and lubricants, etc. Every day, the danger increases when the water drainage systems of various enterprises are damaged, such as mining enterprises, facilities of the energy, metallurgy, chemical, petrochemical industries, sludge storage facilities for highly toxic waste. Next to this, there is a growing problem of highly efficient purification of water, primarily drinking water. As a result of the destruction of the Kakhovsky reservoir in 2023, the problem of disposal of mine waters, which are characterized by a high level of mineralization, a significant content of iron, manganese and other toxicants, has sharply worsened. In this case, there are no water resources for diluting mine waters before their discharge. Despite a significant number of developments in the field of water quality control and water purification technologies, a number of problems in this direction remain unresolved. Existing technologies are ineffective when the levels of mineralization and water hardness are exceeded. We are talking about the southern regions of our country and Donbas. In Mykolaiv, after the aggressor reduced the water intake on the Dnieper, the centralized water supply system supplies brackish water from the estuary. It is known that concentrated salt solutions, which are formed and are still present next to the problems described above, are practically not processed. In most cases, they are dumped into the surface reservoirs of the surrounding natural environment, which significantly worsens the state of water ecosystems of Ukraine. The situation is worsened by the fact that a significant part of mine water suitable for use, due to the problem of disposal of concentrates, is not used, but is discharged into the environment after dilution, or even without dilution and purification, since there is simply no resource for dilution in today's realities. That is why, the problem of processing concentrates of baromembrane purification with obtaining secondary useful products was the aim of the research of this work.

Assessing Temperature Change Impact in the Wake of Ongoing Land Use Change: A Case Study at Lake Dianshan

Climate change exerts both direct and indirect influences on the eutrophication of surface water ecosystems in various ways. This study aimed to evaluate the impact of temperature fluctuations on trophic levels through various interdisciplinary coupling analysis methods after land use change, which including water and sediment sample analysis, hydraulic model, remote sensing, and historic data analysis. For the historical analysis, six satellite images of Lake Dianshan were examined to assess algal bloom occurrences and the coverage of Eichhornia crassipes from 2013 to 2023. The correlation between trophic indicators and temperature was analyzed using statistical methods. For the monthly analysis, a total of 27 sediment samples and 54 water samples collected from Lake Dianshan were assessed to determine how seasonal temperature variations influence eutrophication status. The trophic indicators have higher concentration at inlet sampling sites compared to outlet sites, which validated the potential external pollution source. The trophic level of Lake Dianshan is influenced not only by climate change but also significantly by urban human activities. The management of eutrophication has substantially improved the water quality of Lake Dianshan over the past few decades. Furthermore, increasing temperatures demonstrate a positive correlation with the proliferation of cyanobacteria, particularly in urban areas.

Dynamic Modelling Analysis of <i>Vibrio </i>sp. and Plankton Abundance in Intensive Shrimp Pond

Vibrio sp. and plankton are important microorganisms in shrimp pond ecosystems. The research aims to predict the dynamics of Vibrio sp. and plankton abundance in intensive shrimp pond ecosystems based on causal model analysis. The research method used is an ex-pose facto causal design concept with quantitative descriptive data analysis using causal dynamic modeling. The results showed the water quality in the pond has a high correlation, except Vibrio sp. and alkalinity. In the pond ecosystem 24 genus of plankton from 6 classes. Chlorella sp. is the dominant plankton genus with an abundance of 1.00E+05-4.00E+05 cells/ml. Vibrio sp. abundance in ponds ranged from 1.38E+03 - 1.31E+05 CFU/ml. Based on the results of dynamic modelling, the growth pattern of Vibrio sp. lasted for 30 weeks which was divided into 4 growth phases. The conclusion of this study is that Vibrio sp. will dynamically experience a pure growth rate for 30 weeks with details of the initial growth phase (1-7 weeks), logarithmic growth phase (8-14 weeks), exponential phase (15-21 weeks), and growth declination phase (22-30 weeks). The growth phase of Vibrio sp. has a high degree of similarity to the growth pattern of plankton in the pond water ecosystem correlatively. The novelty of this research lies in the discovery of an estimation model for the abundance of Vibrio sp. and plankton during the shrimp farming cycle. This finding can serve as a fundamental reference for farmers to optimize feeding processes and conduct regular siphoning during the peak abundance of Vibrio sp. and plankton.