Lake Research Articles

Occurrence, bioaccumulation, and partitioning of phthalate acid esters in the third largest freshwater lake (Lake Taihu) in China

Phthalate acid esters (PAEs) are a category of plasticizers that are ubiquitous in freshwater environments attributable to extensive utilization. We collected water, suspended particulate matter (SPM), surface sediments, phytoplankton, and zooplankton from 23 sampling sites to investigate and complement the occurrence, bioaccumulation, and partitioning of five PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), and di (2-ethylhexyl) phthalate (DEHP) in the third largest freshwater lake (Lake Taihu) of China. PAEs were extracted using Soxhlet extraction and solid phase extraction, and determined by gas chromatography-mass spectrometry. The average concentrations of the five PAEs in the water column, SPM, sediments, phytoplankton, and zooplankton of Lake Taihu were 1.93±1.57μgL-1, 765±766μgg-1, 1.68±1.47μgg-1, 1358±1877μgg-1, and 72.7±134μgg-1, respectively. DBP and DEHP were the dominant PAE congeners in the five environment compartments. The logarithmic concentrations of DBP, BBP, and DEHP in the SPM were negatively correlated with the logarithmic content of the SPM. Biodilution significantly impacted the occurrence of PAEs in the plankton. Bioaccumulation of PAEs was found in the plankton with log BCF (bioconcentration factor) in the phytoplankton ranging from 1.78±0.86 to 4.13±1.23 and log BAF (bioaccumulation factor) in the zooplankton varying from -0.10±0.26 to 3.04±0.64. Biomagnification of the PAEs from phytoplankton to zooplankton was not observed. DMP, DEP, and BBP migrated from sediments to water. DBP was in dynamic equilibrium in the sediment-water system. DEHP transferred from water to sediments. Our results provide crucial complementary knowledge on bioaccumulation and transfer of PAEs in planktonic food web, and their partitioning in different compartments of waters.

Water depth alters the fate of estrone across the sediment–water interface in a typical inland lake

Water depth variation alters lake sediment environments, affecting the exchange of oxygen, trace elements, and nutrients at the sediment–water interface (SWI). However, there is still limited information on the in-situ fate of refractory emerging pollutants such as estrogenic compounds (ECs) at the SWI of different water depths in lakes. In this study, we integrated active sampling and diffusive gradients in thin film (DGT) technology to in-situ investigate the distribution, diffusion, and microbial responses of estrone (E1) at the SWI from the shallow-water zone (SZ), transition-water zone (TZ), and deep-water zone (DZ) in a typical inland lake of northern China. The surface sediment of the DZ accumulated most E1 (479.57 ± 194.90 ng/kg). In the vertical profile of the sediments, for SZ and TZ, E1 concentration in the sediment, porewater, and DGT fluctuated within a certain concentration range with increasing sediment depth. For the DZ, it exhibited a fluctuating and increasing trend with increasing depth. Dynamic migration analysis of E1 indicated partial resupply in each zone, and the resupply parameter R was 0.102 to 0.416 in the SZ, 0.111 to 0.384 in the TZ, and 0.084 to 0.374 in the DZ, respectively. The resupply capacity in the upper sediment layers (−1 to −4 cm) was higher for the TZ and DZ, whereas the SZ showed higher capacity in the lower layers (−5 to −9 cm). Based on the microbial sequencing results, Sulfuricurvum (typically present in microaerophilic and anoxic conditions) was predominant in the DZ (17.99 ± 15.4 %). Achromobacter (typical E1-degrading genus distributed in oxic environments) was more abundant in the SZ, which led to a higher E1 degradation potential in this zone. The results of this study shed light on the fate of E1 in the SWI of lakes at different water depths, facilitating a more precise control of estrogenic pollution in lake sediments.

A framework for automated supraglacial lake detection and depth retrieval in ICESat-2 photon data across the Greenland and Antarctic ice sheets

Abstract. Water depths of supraglacial lakes on the ice sheets are difficult to monitor continuously due the lakes' ephemeral nature and inaccessible locations. Supraglacial lakes have been linked to ice shelf collapse in Antarctica and accelerated flow of grounded ice in Greenland. However, the impact of supraglacial lakes on ice dynamics has not been quantified accurately enough to predict their contribution to future mass loss and sea level rise. This is largely because ice-sheet-wide assessments of meltwater volumes rely on models that are poorly constrained due to a lack of accurate depth measurements. Various recent case studies have demonstrated that accurate supraglacial lake depths can be obtained from NASA's Ice, Cloud and land Elevation Satellite (ICESat-2) ATL03 photon-level data product. ATL03 comprises hundreds of terabytes of unstructured point cloud data, which has made it challenging to use this bathymetric capability at scale. Here, we present two new algorithms – Flat Lake and Underlying Ice Detection (FLUID) and Surface Removal and Robust Fit (SuRRF) – which together provide a fully automated and scalable method for lake detection and along-track depth determination from ATL03 data and establish a framework for its large-scale implementation using distributed high-throughput computing. We report FLUID–SuRRF algorithm performance over two regions known to have significant surface melt – central West Greenland and the Amery Ice Shelf catchment in East Antarctica – during two melt seasons. FLUID–SuRRF reveals a total of 1249 ICESat-2 lake segments up to 25 m deep, with more water during higher-melt years. In the absence of ground-truth data, manual annotation of test data suggests that our method reliably detects melt lakes along ICESat-2's ground tracks whenever the lake bed is visible or partially visible and estimates water depths with a mean absolute error <0.27 m. These results imply that our proposed framework has the potential to generate a comprehensive data product of accurate meltwater depths across both ice sheets.

Increased mercury concentrations in walleye and yellow perch in lakes invaded by zebra mussels.

Zebra mussels (Dreissena polymorpha) are invasive species that alter ecosystems and food webs with the potential to affect aquatic mercury cycling and bioaccumulation in fishes, although the effect of zebra mussels on fish tissue mercury has not been tested in inland lakes. We assessed differences in fish tissue mercury concentrations and food webs in Minnesota lakes with and without zebra mussels while controlling for other lake and watershed characteristics. Mercury concentrations in adult walleye (Sander vitreus) and yellow perch (Perca flavescens) were 72 % and 157 % higher, respectively, in lakes containing zebra mussels compared to uninvaded lakes. Mercury in young of year (age-0) fish was also elevated, with mercury concentrations 97 % and 82 % higher in age-0 walleye and yellow perch, respectively, in zebra mussel lakes. Walleye mercury concentrations exceeded 0.22 ppm - a threshold triggering more restrictive human consumption advisories for sensitive populations - at a 23 % smaller size, and average-sized walleye (420 mm) exceeded this threshold at a rate of 77 % in invaded lakes, compared to 35 % in uninvaded lakes. Walleye and yellow perch relied more on littoral resources in lakes with zebra mussels but did not feed at meaningfully higher trophic levels. Increased fish tissue mercury in lakes invaded by zebra mussels have consequential implications for fisheries and human health.

Life-history of invasive common carp, Cyprinus carpio, within a natural lake (Groenvlei), South Africa

Common carp, Cyprinus carpio, is a global invasive species illegally introduced into the Groenvlei system, South Africa, in the 1990s for recreational angling. To manage this population effectively, basic information is needed on its biology including growth and reproduction. This study examined the growth trends of C. carpio using otolith growth zone deposition rates which were validated using a chemical mark–recapture experiment (n = 16). From a total of 140 C. carpio, length-at-age was best described using the Von Bertalanffy growth model for males and females. The average lengths-at-50% maturity were estimated at 314 mm F L (males) and 262 mm F L (females). Compared with other South African C. carpio populations, the Groenvlei population is relatively fast growing and long lived, with the oldest female aged 20 years and the oldest male aged 18 years, likely facilitated by relatively favourable environmental conditions at Groenvlei. Data from this study provide a baseline at the commencement of C. carpio management interventions at Groenvlei and an opportunity to monitor changes in population dynamics facilitated by these efforts.

Midge Paleo-Communities (Diptera Chironomidae) as Indicators of Flood Regime Variations in a High-Mountain Lake (Italian Western Alps): Implications for Global Change

Sediments of alpine lakes serve as crucial records that reveal the history of lacustrine basins, offering valuable insights into the effects of global changes. One significant effect is the variation in rainfall regimes, which can substantially influence nutrient loads and sedimentation rates in lacustrine ecosystems, thereby playing a pivotal role in shaping biotic communities. In this study, we analyze subfossil chironomid assemblages within a sediment core from an alpine lake (western Italian Alps) to investigate the effects of rainfall and flood regime variations over the past 1200 years. Sediment characterization results highlight changes in sediment textures and C/N ratio values, indicating phases of major material influx from the surrounding landscape into the lake basin. These influxes are likely associated with intense flooding events linked to heavy rainfall periods over time. Flooding events are reflected in changes in chironomid assemblages, which in our samples are primarily related to variations in sediment texture and nutrient loads from the surrounding landscape. Increased abundances of certain taxa (i.e., Brillia, Chaetocladius, Cricotopus, Psectrocladius, Cricotopus/Orthocladius Parorthocladius) may be linked to higher organic matter and vegetation inputs from the surrounding landscape. Biodiversity decreased during certain periods along the core profile due to intense flood regimes and extreme events. These results contribute to our understanding of alpine lake system dynamics, particularly those associated with intense flooding events, which are still understudied.

Assessment of Critical Environmental Risk Zones Around Wetlands in Colombo, Sri Lanka, Using Satellite Remote Sensing and Multi-criteria Decision Tools

Colombo, Sri Lanka’s commercial capital, is recognized as one of the first 18 global sites that were awarded the Ramsar Wetland City accreditation, and is a prime example of the intersection between urbanization and wetland conservation. Thus, this study aims to conduct an environmental risk assessment that can provide insights into the changes in biophysical properties driven by urbanization over the 2000–2020 period. The study used Geographical Information Systems and a remote sensing approach to assess critical environmental risk zones around urban freshwater lakes in the Colombo district of Sri Lanka, including Thalangama, an environmental protection area experiencing sub-urbanization. Satellite data (2000–2020) were employed, and spectral indices, including NDVI, NDBI, NDWI, NDMI, RVI and LST, were calculated. Intersecting areas with multiple risk factors were determined, and distances from these zones to lakes were calculated to generate spatially explicit risk maps using inverse distance weighting. The building density has consistently increased from 2000 to 2020 in all three sites, with ‘very high’ density areas expanding notably. NDVI reveals a gradual increase in ‘very high’ categories until 2015. Plant-water stress analysis shows significant water stress in 2015, and water body areas have decreased after 2010 in all the sites. Multi-criteria assessment identifies critical environmental risk zones around urban lakes, indicating high vulnerability to environmental damage and degradation. Overall, the study emphasizes the importance of leveraging data and risk analysis to inform decision-making processes in environmental management. By doing so, policymakers can enhance the effectiveness of conservation measures and promote the long-term sustainability of natural resources.

Studies on biodiversity of Nycticorax nycticorax- Linnaeus, 1758 at Manchar Lake, Sindh, Pakistan

The lake manchar is considered as one of the largest freshwater lakes in Pakistan, it’s located in district of Jamshoro. This wetland plays a substantial role in providing habitats to variety of resident and migratory birds. It provides shelter to the vast biodiversity that has daily and seasonal dependencies for all the life-support systems. Birds use this lake for drinking water, breeding, rearing young ones and social interactions. Meanwhile, birds play important role in balancing the ecosystem and food web of the ecosystem by conserving maintainable population levels of prey and predator species, and after death provide food to scavengers as well as decomposers. Birds are best pollinators, help in plant production through their services as pollinators or seed dispersers and increase forest growth, also help in environmental conservation. Considering the valuable role of wetlands and importance of avifaunal species in agriculture, food chains, ecosystem and pharmaceutics, a comprehensive study is carried out to evaluate diversity of socio-economically valuable avifaunal species at Manchar Lake. Monthly field surveys were conducted from January 2024 to October 2024, resulting in the collection of 80 specimens of Nycticorax nycticorax. Minor variation was recorded in body parameters including body weight, size of beak, body length, wingspan, limbs length, length of tail feathers, and width of web. Nycticorax nycticorax Weight of body 302±1.53 Length of beak 72± 1.20 Length of Wingspan 190±3.22 Length of limbs 787±140.5 Length of tail feathers 314±3.12 limbs Length of body 21.5±0.95. Nycticorax nycticorax was recorded to be the predatory bird, and their occurrence was abundant in the lake premises. The highest prevalence of recorded species occurred in January, February, and March, with the lowest richness observed in June and July. The study concluded that Manchar Lake is experiencing significant pollution due to runoff from agricultural fields, residential areas, and other sources. This pollution, combined with factors such as massive hunting, climatic changes, seasonal fluctuations, and decreasing food resources, has led to a decline in bird populations at the lake

Health risks of potentially toxic elements in Cyprinus carpio in the karst plateau lake, China.

Elevated potentially toxic elements (PTEs) in aquatic products could threaten the health of ordinary consumers. Levels of chromium (Cr), arsenic (As), lead (Pb), and mercury (Hg) in Cyprinus carpio in karst plateau freshwater Lake, Caohai Lake, China were quantified using inductively coupled plasma mass spectrometry (ICP-MS) and evaluated using a risk method with Monte Carlo simulation. Levelsof Cr, As, Pb, and Hg in muscle tissue were substantially lower than those in viscera. The maximum concentration of muscle-bound Cr, As, Pb, and Hg were less than the standard references set by Chinese Food Codex (GB 2762-2022). The levels of Cr, As, Pb, and Hg in muscle tissue were independent of fish weight and length. The hazard index of all investigated elements in muscle tissue wereless than one for adults and children, whereas the target hazard quotients of muscle-bound PTEs for children were higher than those for adults. Results indicated that exposure duration was the largest contributor to the hazard quotient of Cr, As, and Hg, whereas the concentration of Pb in muscle was the most sensitive factor affecting the variation in hazard quotient of Pb. There is no risk related to the normal intake of muscle-bound Cr, Pb, As and Hg with the consumption of Cyprinus carpio. A better definition of the probability distribution for exposure duration and PTEs concentration could result in a more accurate hazard quotient. © 2024 Society of Chemical Industry.

Interactive Effects of Anthropogenic Stressors on the Temporal Changes in the Size Spectrum of Lake Fish Communities

ABSTRACTThe size spectrum represents a powerful approach for quantifying the effects of environmental changes from individuals to communities in aquatic ecosystems. However, our understanding of its temporal stability in freshwater ecosystems is still limited. In the present study, we used a size spectrum approach to investigate the responses of 126 lake fish communities to changes in the intensity of three common anthropogenic stressors (i.e., global warming, nutrient loading and biological invasions) in French natural lakes and reservoirs over an average 5‐year time period. Using a backward selection on a full model including all possible effects of stressors on the size spectrum slope, we demonstrated that (i) increasing summer temperature shifted fish abundance towards the largest size classes, resulting in a flatter size spectrum slope and (ii) nutrient loading and biological invasions were associated with a shift towards smaller size classes in natural lakes, while the opposite effect was observed in reservoirs. In addition, these two stressors interacted in determining changes in the size structure of fish communities, complicating what the size spectrum can reveal about changes in stressor intensity during monitoring programs. All predictors accounted for a limited part of the observed changes in size spectra, and further investigations are needed to fully apprehend the interplay between natural and human‐induced drivers of the temporal changes in size spectra in contrasting environmental conditions.

Phylogenomics of novel clones of Aeromonas veronii recovered from a freshwater lake reveals unique biosynthetic gene clusters.

Lakes and other aquatic ecosystems can harbor harmful bacteria that can make people sick and resist antibiotics, posing a significant global health risk. In this study, we investigated Aeromonas veronii, a Gram-negative bacteria found in Lake Wilcox in Ontario. We used various techniques, including whole-genome sequencing (WGS), to analyze the bacteria and found that many of the isolates had the potential to cause human disease. We also discovered significant genetic diversity among the isolates, indicating that the lake may be a reservoir for multiple human pathogenic strains. All isolates carried genes that confer resistance to antibiotics, and some virulence genes were associated with human pathogenic isolates. This study highlights the importance of monitoring aquatic ecosystems for harmful bacteria to better understand their evolution, potential for human pathogenicity, and the ecological roles of their genetic elements. This knowledge can inform strategies for preventing the spread of antibiotic-resistant bacteria and protecting public health.

Indications of a changing winter through the lens of lake mixing in Earth’s largest freshwater system

Abstract Global surface freshwater primarily resides in lakes, with the overwhelming majority found in Earth’s largest lakes, thus understanding potential climate change effects in these large lakes is critical. In dimictic lakes, climate change has extended the duration of summer thermal stratification and reduced the length of the ice season. These changes are relatively straightforward to evaluate in smaller, inland lakes. However in large lakes, such as the North American Great Lakes, temporally intermittent and spatially heterogeneous ice cover, and spatial thermal heterogeneity limit the utility of simple ice on-off or mixing classifications; therefore, assessing how climate change is impacting winter conditions in large lakes is challenging. Here, we use in-situ and satellite-derived surface water temperature observations from the North American Great Lakes to overcome these limitations and show that warming air temperatures are driving reductions in the number of winter days, collectively those with either ice cover or inverse thermal stratification, in favor of increases in isothermal conditions for the period 1995 to 2023. We find that on average the Great Lakes are experiencing a loss of 14 winter days per decade. Our results demonstrate how climate change has yielded disproportionate changes in the annual thermal cycle and mixing conditions of Earth’s largest freshwater system and signals the potential for fundamental ecosystem shifts due to a loss of winter.

Uncovering the Anthropogenic Influences on Water Quality: A Case of Lake Victoria Shores, Entebbe, Uganda

Lakes serve as vital ecosystems, providing freshwater resources and habitats for diverse species. However, human activities, particularly around lakeshores, have led to significant environmental degradation, including heavy metal contamination. Lake Victoria, the second-largest freshwater lake globally, has been severely impacted by pollution from industrial, agricultural, and urban sources. This research aims at examining the influence of the anthropogenic activities on the water quality of Lake Victoria. Specifically, the study tried to determine the activities undertaken at the Lake shores of Lake Victoria; determined the physico-chemical parameters of the water from the shores and the heavy metal concentration in the water samples obtained from the shores of Lake Victoria. This study utilized a cross-sectional and experimental research designs to assess water quality and anthropogenic influences around Lake Victoria. A total of 150 residents from selected communities were surveyed using a semi-structured questionnaire to gather demographic information, perceptions of water quality and the activities carried out within the shores of Lake Victoria. Water samples were collected from multiple sites along the lake shores for analysis of heavy metals using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Water quality parameters were determined In-situ using a multi-parameter water testing kit and Hanna instrument. Results showed that the anthropogenic activities that could have contributed to water degradation include: fishing, transport, agriculture and construction among others. Apart from pH which was outside the permissible limits, all the other water parameters were within the WHO permissible limits. Considering the heavy metal concentration, all the sampled sites apart from one inlet, had the concentrations above the WHO permissible levels an indication of significant heavy metal contamination in the Lake Victoria shores. These findings highlight the urgent need for targeted pollution control measures and regular monitoring to mitigate further environmental degradation. Effective interventions, including stricter regulations and sustainable land use practices within the Victoria shores are essential for safeguarding the lake's ecosystem and the health of surrounding communities.

Occurrence, characterization, and ecological risk analysis of petroleum hydrocarbons in water and sediments following large-scale field simulated oil spills at the experimental lakes area, Northwestern Ontario, Canada

This study assessed the impact of on-site field-simulated oil spills at the International Institute for Sustainable Development-Experimental Lakes Area (IISD-ELA) on a freshwater boreal lake. Low total petroleum hydrocarbons (TPH) values were obtained in water and sediments from the locations without direct oil loading across the 6-year monitoring program. Biogenic n-alkanes and pyrogenic polycyclic aromatic hydrocarbons (PAHs) were predominant pre- and post-spill. No petroleum biomarkers were detected in the water, but trace levels appeared in a few sediments. Most TPH and PAH levels were within acceptable limits set by the Canadian Council of Ministers of the Environment (CCME) and Ontario regulations, though some PAHs exceeded guidelines. However, the frequency of exceedances did not change significantly before and after the spill. These results suggest that the spilled oil was contained effectively during the experiment period, and the environment recovered to near-background levels afterward with appropriate precautions and remediation operations.

Metagenomic Analysis of Sediment Bacterial Diversity and Composition in Natural Lakes and Artificial Waterpoints of Tabuk Region in King Salman Bin Abdulaziz Royal Natural Reserve, Saudi Arabia

The Tabuk region is located in the northern part of Saudi Arabia, and it has an area of 117,000 km2 between longitudes 26° N and 29° N and latitudes 34° E and 38° E. King Salman Bin Abdulaziz Royal Natural Reserve (KSRNR) is the largest natural reserve in Saudi Arabia and covers about 130,700 km2. It represents a new tourist attraction area in the Tabuk region. Human activities around the lake may lead to changes in water quality, with subsequent changes in microenvironment components, including microbial diversity. The current study was designed to assess possible changes in bacterial communities of the water sediment at some natural lakes and artificial waterpoints of KSRNR. Water samples were collected from ten different locations within KSRNR: W1, W2, W3 (at the border of the royal reserve); W4, W5, W6, W7 (at the middle); and W8, W9, and W10 (artificial waterpoints). The total DNA of the samples was extracted and subjected to 16S rRNA sequencing and metagenomic analysis; also, the environmental parameters (temperature and humidity) were recorded for all locations. Metagenomic sequencing yielded a total of 24,696 operational taxonomic units (OTUs), which were subsequently annotated to 193 phyla, 215 classes, 445 orders, 947 families, and 3960 genera. At the phylum level, Pseudomonadota dominated the microbial communities across all samples. At the class level, Gammaproteobacteria, Clostridia, Alphaproteobacteria, Bacilli, and Betaproteobacteria were the most prevalent. The dominant families included Enterobacteriaceae, Pseudomonadaceae, Clostridiaceae, Comamonadaceae, and Moraxellaceae. At the genus level, Pseudomonas, Clostridium, Acinetobacter, Paenibacillus, and Acidovorax exhibited the highest relative abundances. The most abundant species were Hungatella xylanolytica, Pseudescherichia vulneris, Pseudorhizobium tarimense, Paenibacillus sp. Yn15, and Enterobacter sp. Sa187. The observed species richness revealed substantial heterogeneity across samples using species richness estimators, Chao1 and ACE, indicating particularly high diversity in samples W3, W5, and W6. Current study results help in recognizing the structure of bacterial communities at the Tubaiq area in relation to their surroundings for planning for environmental protection and future restoration of affected ecosystems. The findings highlight the dominance of various bacterial phyla, classes, families, and genera, with remarkable species richness in some areas. These results underscore the influence of human activities on microbial diversity, as well as the significance of monitoring and conserving the reserve’s natural ecosystems.

Seasonal assessment of biomarkers in Channa punctata from Tampara Lake, Odisha, India and toxicity of thorium nitrate on fish

Tampara Lake, a freshwater lake in the Chatrapur beach placer deposits of Ganjam, Odisha, India is a well-known tourist attraction. Multiple factors seem to disturb the aquatic life of Tampara Lake, especially fish. Chatrapur beach placers are rich in various heavy minerals including monazite, an ore of thorium, that emits high background radiations and can affect the biota. Run-offs from the monazite mining sites on the beach placers are also presumed to be carried to the lake. Thus, tourism, local transportation, fishing activities, presence of heavy minerals and mining run-offs appear to disrupt the lake's ecosystem. The present work assessed the protein and lipid concentrations in the liver and muscle, nuclear abnormalities in the peripheral blood erythrocytes and histopathology of gills, liver, kidney, intestine and stomach of Channa punctata from Tampara Lake in summer, winter and rainy seasons. The study also documented the effects of thorium nitrate, a byproduct of monazite ore processing, on Channa punctata of non-monazite areas. Channa punctata from the Tampara lake had significantly lower protein and lipid content in the liver and muscle, nuclear deformities and micronuclei in the erythrocytes and deformities in the gill, kidney, liver, stomach and intestine relative to the fish from the non-monazite areas. Seasonal alterations were observed in the protein and lipid content of muscle and liver, gill and kidney structure. Fish from the non-monazite areas treated with sub-lethal concentrations of thorium nitrate showed a dose-dependent response in the protein and lipid content of liver and muscle, erythrocyte nuclear abnormalities and histopathological aberrations. The present study provides evidence that Channa punctata from Tampara Lake have relatively low nutritional value compared to fish from undisturbed non-monazite areas and are probably distressed by the water contamination due to the presence of heavy minerals and anthropogenic interventions.

Cyanobacteria as Dominant Mediator of Altitudinal Gradient Effects on Phytoplankton Community Diversity in Freshwater Ecosystems: Evidences from the Freshwater Lakes along the Hu Line

Cyanobacteria as Dominant Mediator of Altitudinal Gradient Effects on Phytoplankton Community Diversity in Freshwater Ecosystems: Evidences from the Freshwater Lakes along the Hu Line

Microplastics and their interaction with microorganisms in Bosten Lake water

Microplastic pollution in inland freshwater lakes, formed from melting ice, atmospheric precipitation, and groundwater, remains under-researched. This study examines microplastic (MPS) presence and distribution in Bosten Lake and their interaction with microorganisms. We employed a Confocal Raman spectrometer to identify MPS types and 16S rRNA high-throughput sequencing to analyze microbial diversity and composition. In May, the lake's average microplastic concentration was 108.20 particles per liter (PCS/L), decreasing to 21.67 PCS/L by October. Transparent and yellow fibrous microplastics, predominantly 0.2–0.5 mm in size, were most common. Key microplastics in May included PEEK (27%), PMMA (25%), and PET (9%), while October saw a prevalence of PET (35%), PS (13%), and PA (9%). Higher microplastic concentrations correlated with reduced microbial diversity. In May, the high microplastic concentration group (MH) showed increased Planctomycetota, while in October, Patescibacteria and Bacteroidota rose significantly in the high plastic group (OH), known for microplastic degradation. MH also had a higher abundance of Cryptomycota compared to OH. Functional analysis indicated that MH had more genes related to bisphenol, benzene, and chlorine compounds, whereas OH had genes linked to methane, nitrogen, and organic matter degradation. Microplastic concentrations peaked near the lake inlet and tourist areas, affecting microbial quantity, diversity, structure, and function. This research enhances our understanding of MPS distribution and environmental microbial shifts in similar settings, providing essential data for environmental management strategies at Bosten Lake.

Prevalence of human Schistosoma mansoni infection in endemic regions (2010–2024): a systematic review and meta-analysis

Schistosoma mansoni infection poses a substantial public health challenge globally, and the World Health Organization (WHO) aims for the elimination of schistosomiasis by 2030. This study aimed to assess the current prevalence of human S.mansoni infection in endemic regions worldwide between 2010 and2024. We conducted a comprehensive search in PubMed/Medline and Scopus databases as well as other public sources from 1 January 2010 to 15 July 2024. Population-based studies reporting the prevalence of S.mansoni infection were eligible. We undertook a random-effects meta-analysis to estimate pooled prevalences with 95% confidence intervals (CIs) in WHO-defined regions and assessed potential risk factors associated with S.mansoni infection. The protocol for this study was registered on PROSPERO (CRD42023438455). We identified a total of 542 eligible studies involving 1,163,866 individuals who had been tested for S.mansoni infection in 38 countries. The overall, pooled global prevalence of S.mansoni infection in endemic region was 14.8% (95% CI, 13.5%-16.1%). The pooled prevalences (95% CI) in specific regions were: 15.3% (13.9-16.8%) in sub-Saharan Africa, 12.4% (8.9-16.4%) in South America and 9.5% (5.4-14.6%) in the Eastern Mediterranean region. There was a 52.6% decrease in prevalence of S.mansoni infection and a 37% decrease in high-intensity infection for studies conducted between 2010 and 2014 compared to those conducted between 2020 and 2023. The present analysis revealed that factors including male gender, bathing or swimming in natural water bodies, crossing rivers or lakes, and engaging in water irrigation activities such as fishing, working in rice paddies or maintaining irrigation canals were significantly associated with S.mansoni infection. The findings of this investigation revealed that, despite a decline in prevalence and high-intensity infection, 7-12% of people in endemic regions, notably in sub-Saharan Africa, remained affected by schistosomiasis mansoni between 2020 and 2024. This study provides data of relevance to policymakers to support efforts to eliminate this disease. This study received no funding.

Seasonal Development of Cyanobacteria and Microcystin Production in a Shallow Freshwater Lake (North-Eastern, Algeria)Seasonal Development of Cyanobacteria and Microcystin Production in a Shallow Freshwater Lake (North-Eastern, Algeria)

Seasonal Development of Cyanobacteria and Microcystin Production in a Shallow Freshwater Lake (North-Eastern, Algeria)Seasonal Development of Cyanobacteria and Microcystin Production in a Shallow Freshwater Lake (North-Eastern, Algeria)