Water Quality Variables Research Articles

Spatiotemporal variation of water quality in the context of suspended particulate matter in Laguna Mar Chiquita Lake, Argentina using ACOLITE

This study investigates seasonal variations in water quality at Laguna Mar Chiquita Lake, Argentina, by employing remote sensing techniques to analyze Suspended Particulate Matter (SPM) which offers valuable insights into the lake's environmental health. Landsat 8–9 OLI/TIRS data from 2014–2023 was utilized for spectral analysis of water quality, processed using ACOLITE software for accurate quantitative data. Results show SPM concentrations ranging from 0.823 to 44.172 mg/l, with significant seasonal variations. Higher SPM concentrations post-monsoon indicate increased anthropogenic influence, particularly in the northern area. Pollution from tourism and industrial activities is lower pre-monsoon but spikes post-monsoon and during monsoon, suggesting unfavorable conditions. Effective management and continuous monitoring are crucial for maintaining lake quality and ecosystem health.

Integrated cultivation of tambaqui (Colossoma macropomum) with coriander (Coriandrum sativum L.) grown at different plant density

The present study aimed to evaluate an aquaponic bioeconomic model integrating the cultivation of tambaqui (Colossoma macropomum) with coriander (Coriandrum sativum) at different densities of 32, 72, 128, and 512 cells m−2 for 19 days. The hydroponic bed was configured on a bench with a capacity of 100 L (1.62 m-long, 0.72 m-width, and 0.1 m-depth) and was coupled to a plastic tank with the fish. The coriander seeds were irrigated for four days until germination, when they were transferred to the hydroponic beds. Two hundred forty tambaqui juveniles (113.5 ± 0.15 g and 19.6 ± 0.20 cm) were distributed in 12 tanks (1000-L capacity) in aquaponic units, totaling 20 fish per unit. The fish were fed commercial feed (36% protein and 7% lipids), and water quality variables were monitored daily. At 5, 10, and 15 days after transplanting to the hydroponic bed, the leaf number (LN) and plant height (PH, in cm) of the coriander were determined. Additionally, total fresh mass (TFM, in g), leaf fresh mass (LFM, in g), root fresh mass (RFM, in g), total dry mass (TDM, in g), leaf dry mass (LDM, in g), root dry mass (RDM, in g), leaf length (LL, in cm), root length (RL, in cm), yield of total fresh mass (YTFM, in kg m−2), and the nutritional composition of macro and micronutrients were determined, as well as fish growth performance. A density of 512 cells m−2 reduced the electrical conductivity (0.097 ± 0.001 dS m−1) of the water. The pH, dissolved oxygen, and temperature did not differ significantly between the densities. The total ammonia nitrogen (28.81 ± 2.26 mg L−1) and nitrate (51.07 ± 0.81 mg L−1) concentrations were greater at a density of 32 cells m−2. At the end of the 19-day period, the fish growth indices did not significantly differ (p > 0.05) as a function of coriander cultivation density. Density significantly influenced coriander growth. All variables (PH with root, LL, RL, LFM, TFM, LDM, TDM, RFM, RDM, and YTFM) were significantly influenced (p < 0.05) as a function of cultivation density. YTFM (1.82 ± 0.45 kg m−2), PH (30.39 ± 0.61 cm), and LL (16.62 ± 0.53 cm) were significantly higher (p < 0.05) at a density of 512 cells m−2. RL was significantly higher (p < 0.05) at densities of 72 and 32 cells m−2, of the order of 15.98 ± 0.43 and 18.79 ± 1.01 cm, respectively. Boron was significantly greater at a density of 512 cells m−2 (39.70 ± 1.04 mg kg−1) than at 32 cells m−2 (29.93 ± 4.66 mg kg−1). Similarly, sodium was significantly more abundant at a density of 512 cells m−2 (5975.54 ± 783.82 mg kg−1) when compared to the densities of 128 and 72 cells m−2, which were 4179.97 ± 287.31 and 3760.60 ± 224.31 mg kg−1, respectively. Aquaponic production in the equatorial Amazon region accelerated, and the optimal density for coriander integrated with tambaqui without compromising plant growth performance was 128 cells m−2.

Two-stage meta-ensembling machine learning model for enhanced water quality forecasting

Accurate short-term forecasting of water quality variables (WQVs) such as dissolved oxygen (DO) and chlorophyll-a (Chl-a) is crucial for the effective management of aquatic resources. This study introduces a robust two-stage optimization-ensembling framework that integrates the Grey Wolf Optimizer (GWO) and the Non-dominated Sorting Genetic Algorithm II (NSGA-II) to enhance the forecasting capabilities of machine learning (ML) models. Focusing on Small Prespa Lake, Greece, we implemented an array of diverse ML techniques, including eXtreme Gradient Boosting (XGB), Gradient Boosting Regressor (GBR), Light Gradient-Boosting Machine (LightGBM), and Multilayer Perceptron (MLP). These models were fine-tuned using GWO to optimize their performance over critical WQVs predicted six hours in advance. Our methodology employed rigorous data preprocessing techniques, including lag time feature engineering and principal component analysis (PCA), to handle the high dimensionality of the dataset. Optimal lag times ranging from 6 to 24 hour were evaluated, with the 24-hour lag proving to be the most effective in utilizing historical data to enhance forecasting accuracy. The GWO not only facilitated hyperparameter tuning but also demonstrated a notable improvement (7.6%) in the Kling-Gupta Efficiency (KGE) over conventional randomized search methods. Subsequently, the NSGA-II was utilized for multi-objective optimization, constructing powerful model ensembles that outperformed the individual GWO-optimized models by up to a 7% in KGE. In comparision to a standard genetic algorithm-based ensemble, the NSGA-II ensemble demonstrated superior effectiveness in balancing solution quality. This innovative approach not only establishes a new benchmark in water quality forecasting but also contributes substantially to proactive environmental monitoring and management strategies.

Nitrogen removal pathways in lake restoration using microalgal-bacterial granular sludge: Unraveling influence of organics and carbon to nitrogen ratio

This study investigated the performance of microalgal-bacterial granular sludge (MBGS) in the restoration of Qingling Lake and Huangjia Lake, focusing on nitrogen removal under varying water quality conditions. Significant color changes in MBGS and differences in granule characteristics were observed, with Qingling Lake demonstrating superior removal efficiencies for ammonia nitrogen, nitrate nitrogen, and total nitrogen compared to Huangjia Lake. Stoichiometric analysis revealed that when the chemical oxygen demand (COD) and carbon-to-nitrogen (C/N) ratios were less than 20 mg/L and 20, respectively, assimilatory nitrate reduction was positively correlated with both, whereas denitrification was negatively correlated. Gene function analysis showed that Qingling Lake had a more active microbial community supporting efficient nitrogen metabolism. The findings highlighted the enormous potential of MBGS in lake restoration, demonstrating its ability to adapt to different COD concentrations and C/N ratios by altering its nitrogen removal pathways.

Intra-annual variability of urban effects on streamwater quality: An examination of watersheds in the Atlanta, Georgia USA region

There has been considerable research on urban impacts on streamwater quality, but studies have mostly ignored intra-annual variations in water-quality variables and thus seasonally-varying impacts. Therefore, this study uses daily water-quality data over eight years for 38 streams in the Atlanta, Georgia USA region and watershed-level, urbanization variables to assess month-specific impacts of urbanization on water quality. The water-quality variables were mean specific conductance, mean temperature, mean dissolved oxygen, median pH, and median turbidity. The watershed-level variables were population density, housing density, proportion of watershed that is high-intensity developed land, imperviousness, proportion of watershed that is urban land use, an urban-intensity index, and change in developed land. Both differences in water quality between urban, suburban, and exurban streams and correlations between water quality and the watershed-level variables were examined. During all months, urban streams had significantly higher specific conductance than suburban and exurban streams, and the urban intensity of a watershed was significantly positively correlated with specific conductance. Differences and correlations were intensified during winter and spring. For temperature and dissolved oxygen, only during non-winter months did urban streams have significantly higher temperatures and significantly lower dissolved oxygen as well as significant positive correlations between urban intensity and temperature and significant negative correlations between urban intensity and dissolved oxygen. Urban streams had the highest pH during all months, but none of the differences were significant. Significant correlations between pH and urban intensity were restricted generally to winter and spring months. Turbidity was highest for exurban watersheds and thus was not significantly positively correlated with urban intensity. Seasonal and stream-group differences in the weathering of concrete, use of road salts, solar heating of streams, urban surface temperatures, baseflow, and land-disturbance activities explain the water-quality findings. Most of the findings should be applicable to urban areas in humid subtropical climates within the Piedmont physiographic region.

Evaluating the spatiotemporal variation of Ba River water quality in the agricultural and urban watershed in the highland of Vietnam.

The Ba River in Vietnam has been facing pollution due to waste generation from agricultural and urban areas. This study focuses on evaluating the spatiotemporal variations in river water quality based on physicochemical characteristics and pesticide parameters for different seasons in 2022-2023. The results indicate that the concentrations of most parameters in the rainy season were higher than those in the early-dry and dry seasons due to the non-point sources in agricultural areas. Notably, the analysis of pesticide residue in both the rainy and dry seasons revealed low levels of chlorpyrifos (ethyl), and deltamethrin was detected in the only rainy season. The results from the hierarchical cluster analysis and water quality index show that the water quality at Ben Mong, An Khe, and Ba River Bridges was classified as moderately to highly polluted. These areas should focus on regular water quality monitoring and appropriate pollution source management. PRACTITIONER POINTS: Agriculture activities strongly affected the water quality of the Highland Ba River of Vietnam. Chlorpyrifos and deltamethrin pesticides (0.0074-0.0218 μg/L) were detected in Ba River. Non-point pollution sources significantly influenced water quality in the Ba River. Variations in river water quality mainly depend on seasons and locations. Water quality index values in rainy seasons (26-88) are lower than that in dry season (37-92).

Influence of hydroclimatic conditions and anthropogenic activities on the water quality of a floodplain lake (Argentina) during a warm season.

Contamination of water bodies, associated with urbanization, agricultural, and industrial activities, is a serious environmental challenge, with particular concern about microbial pollution due to its public health implications. This study is aimed at evaluating the spatial and temporal variations in the microbiological and physicochemical quality of a floodplain lake used for recreational purposes, whose watershed has been disturbed by diverse anthropogenic activities. The results showed that, while the spatial variation of water quality principally depends on the basin characteristics, temporal variation of water quality depends on land uses, hydrological conditions, and climatic conditions. Rainfall and rising water level intensified the influence of land use on the water quality by increasing concentrations of Escherichia coli, thermotolerant coliforms, and organic matter and decreasing dissolved oxygen. Thus, the residents and tourists are potentially exposed to microbiological risks given that it exceeds the international standards suggested for recreational waters on some occasions. It would be advisable to improve routine bathing water monitoring and management to preserve the health of the inhabitants and limit the recreational use of the water body in the days following heavy rainfall as well as during the beginning of the increase in the hydrometric level.

Impact of soil and water quality on the sustainable management of mangrove-compatible brackishwater aquaculture practices in Indonesia

The widespread degradation of mangroves has been attributed to their conversion into other land uses and purposes, most notably their destruction to construct extensive brackishwater aquaculture ponds. This study investigated the relationship between environmental factors and management alternatives for an integrated mangrove-aquaculture system in Derawan Island District, Berau Regency, East Kalimantan Province, Indonesia. The study collected a total of 56 soil and water samples from around 50 ha to assess environmental limiting factors for integrated mangrove-brackishwater aquaculture management. The measured soil quality variables included field pH (pHF), pH of hydrogen peroxide extract (pHFOX), peroxide oxidizable sulfur (SPOS), pyrite (FeS2), organic matter (OM), nitrogen-total (N-TOT), iron (Fe), and aluminum (Al). Water quality variables included salinity, temperature, pH, dissolved oxygen (DO), different forms of nitrogen (NH3–ammonia, NO3–nitrate, and NO2–nitrite), phosphate (PO4), Fe, and total organic matter (TOM). The study employed a hydrological restoration approach to suggest a mangrove-friendly aquaculture pond design and layout. The study generally showed that Acid Sulfate Soils (ASS) significantly restricted the existing mixed-mangrove aquaculture pond management by negatively impacting water quality. This study highlights that, given the characteristics of ASS-affected aquaculture ponds, reducing pond size for shrimp culture (mangrove-to-pond ratio of 80% and 20%) will simplify managing ASS environmental limiting factors through cost-effective remediation techniques and a Balanced Fertilization Strategy (BFS). The reduced shrimp pond size will also provide direct opportunities for mangrove restoration and allow effective hydrological restoration. The economic benefit of the proposed pond design and management model focuses on diversifying production units which include shrimp aquaculture ponds, milkfish or tilapia culture in the peripheral canals of the mangrove compartment, juvenile shrimp production, and periodic harvest from the primary pond canal. The study findings are particularly applicable to ponds that have already been built in ASS to improve productivity in addition to supporting the mangrove rehabilitation program. Converting mangrove and ASS-affected land is not advisable for constructing new aquaculture ponds.

High-capacity adsorption of organic dyes using separable pullulan gel encapsulated with PDA-modified ZIF-8

In this investigation, a hydrogel adsorbent featuring remarkable efficiency in dye adsorption was successfully synthesized by the integration of natural polysaccharide (pullulan) and nanoparticles (ZIF-8@PDA). The prepared natural polysaccharide nanocomposite hydrogels not only exhibit superior mechanical strength and biocompatibility, but also demonstrate adeptness in the removal of dye pollutants. The dye removal capacities were 615.4 mg/g for malachite green (MG) and 525.8 mg/g for Congo red (CR), respectively. Notably, the adsorption process exhibits minimal susceptibility to variations in water quality and the presence of co-existing ions. The pH-responsive surface charge conversion capability of the adsorbent renders it recyclable, maintaining a dye adsorption performance exceeding 88 % even after 5 cycles of repeated usage. Overall, these environmentally friendly natural polysaccharide nanocomposite hydrogels hold potential for addressing complex wastewater treatment challenges and long-term use.

Case study: Nutrients distribution and assessment of the current trophic status of Plastiras lake in Thessaly (central Greece) after tropical storm Daniel

Based on the interactions of three water quality variables, chlorophyll-a (Chl-a), secchi depth (SD – water transparency) and total phosphorus (TP), this study was aimed to assess the trophic state of Plastiras Lake through the modified method of Carlson's trophic state index (CTSI). Eutrophication is one of the most serious problems for water quality and CTSI is an important index for monitoring water quality status and eutrophication assessment. The classification scale for Trophic State Index (TSI) fluctuates from 0 to 100 and the results of this study showed that the mean TSI for Chl-a was 42.95, for SD was 45.50 and for TP was 75.15. The overall CTSI finally was 54.53. These show that Plastiras Lake is presently classified as mesotrophic to eutrophic which reflects the current levels of nutrients in the lake.

Linking sediment geochemistry with catchment processes, internal phosphorus loading and lake water quality

Research in the field of sediment geochemistry suggests potential linkages between catchment processes (land use), internal phosphorus (P) loading and lake water quality, but evidence is still poorly quantified due to a limited amount of data. Here we address the issues based on a comprehensive data set from 27 lakes in southern Finland. Specifically, we aimed at: 1) elucidating factors behind spatial variations in sediment geochemistry; 2) assessing the impact of diagenetic transformation on sediment P regeneration across lakes based on the changes in the vertical distribution of sediment components; 3) exploring the role of the sediment P forms in internal P loading (IL), and 4) determining the impact of IL on lake water quality. The relationship between sediment P concentration and field area percentage (FA%) was statistically significant in (mainly eutrophic) lakes with catchments that included more than 10 % of fields. We found that sediment iron-bound P (Fe-P) increased with increasing FA%, which agrees with the high expected losses from the cultivated areas. Additionally, populated areas increased the pool of sediment Fe-P. Internal P loading was significantly positively related to both sediment Fe-P and sediment organic P (Org-P). However, Org-P was not significant (as the third predictor) in models that had a trophic state variable as the first predictor and Fe-P as the second predictor. Further, the vertical profiles of sediment components indicated a role of diagenetic transformations in the long-term sediment P release, especially in lakes with deeper maximum depth and longer water residence time. Finally, IL was significantly positively correlated to water quality variables including phytoplankton biomass, its proportion of cyanobacteria, chlorophyll a concentration and trophic state index. Our findings suggest that reduction of P losses from the field and populated areas will decrease internal P loads and increase water quality through a reduced pool of Fe-P.

Analysis of Residential Well Water Quality Around People's Gold Mines in the Tourist Area of Dusun Selindungan

The Sekotong area has natural charm and potential mining. This area is one of the preferred destinations for visits by local and foreign tourists. However, apart from that, the Sekotong area is also famous as a community gold mining area. Mining activities carried out still use traditional methods, which are very far from environmentally friendly principles, so they can have impacts, including causing a decrease in the quality of residential well water. This research was conducted to determine the water quality of residential wells around community gold mining in the tourist area of Dusun Selindungan Eleven well water samples were taken using a purposive sampling method based on the distance of the well to the source of gold mining waste disposal and are still used by residents to meet their daily needs. Physical, chemical and biological water quality parameters of water samples were investigated in the laboratory, except temperature and pH were measured directly in the field. Data for each water quality variable was analyzed to determine the pollution index. The results show that DO, TDS, content of phosphate, E. Coli bacteria and total coliforms in well water from the study area generally exceed quality standardsWell water in an area that is a different distance from the people's gold mining waste disposal site has each been contaminated with manganese and mercury, although it is still below quality standards.

Spatio-Temporal Variability of Water Quality in the Middle Danube—The Influence of Air Temperature and Discharge

Large watercourses are characterised by significant spatial and temporal changes in water quality due to both natural and anthropogenic impacts. The paper analyses changes in the Danube’s spatial and seasonal water quality in its middle part at five monitoring stations for the period 2018–2022. Examined water quality parameters include oxygen saturation (Os), ammonium (N-NH4), pH, 5-day biochemical oxygen demand (BOD), nitrate nitrogen (N-NO3), orthophosphates (P-PO4), suspended solids (SS), electrical conductivity (EC), and water temperature (WT). Furthermore, the analysis took into account the influence of two additional factors: air temperature (AT) and discharge (D). Throughout the entire period under study, all parameters were characterised by low concentration values, which met the environmental objective of good ecological status. The use of multivariate statistical methods allowed for the identification of EC, N-NH4, WT, Os, SS, and N-NO3 as determining the greatest spatio-seasonal variability of water quality in a selected section of the Danube. Regression models determined WT, EC and nitrogen nitrate changes as depending on AT, flow, and exposure time. Knowing models not only gives a better understanding of the dynamics of changes in water quality in the stretch of the Danube under study but potentially allows the prediction of these parameters based on easily measurable environmental variables.

Interactive impact of landscape composition and configuration on river water quality under different spatial and seasonal scales

Currently, the comprehensive effect of the landscape pattern on river water quality has been widely studied. However, the interactive influences of landscape type, namely composition (COM) and configuration (CON) on water quality variations, as well as the specific landscape driving types affecting water quality variations under different spatial and seasonal scales remain unclear. To further improve the effectiveness of landscape planning and water quality protection, this study collected monthly water samples from the Fengyu River Watershed in southwestern China from 2018 to 2021, the Biota-Environment Matching Analysis (Bioenv) was used to identify key metrics representing landscape COM and CON, respectively. Then, the multiple regression (MLR) and redundancy analysis (RDA) were used to explore the relationship between these landscape metrics and water quality. In addition, this study used a variation partitioning analysis (VPA) to quantify the interactive and independent influence of landscape COM and CON on water quality. Results revealed that construction land and the Shannon's diversity index (SHDI) were the key metrics of landscape COM and CON, respectively, for predicting water pollution concentrations. The interactive contribution was particularly sensitive to seasonal changes in riparian buffer areas (27.66 % to 48.73 %), while it remained relatively stable at the sub-watershed scale (38.22 % to 40.51 %). Moreover, landscape CON had a higher independent contribution to variations on water quality across most spatio-temporal scales. Overall, identifying and managing key landscape type and consequential metrics, matching with the spatio-temporal scale, holds promise for enhancing water quality conservation. Furthermore, this study provides valuable insights into the identification and selection of core landscape metrics.

Anthropogenic Drivers of Spatial Trends in Groundwater Quality in the Upper Athi River Basin of Kenya, East Africa

Rapid urbanization and population growth in the upper Athi River basin in Kenya have increased the strain on the sub catchments water supply and sanitation situation. Due to increasing demand, inadequate supply of drinking water and lack of sanitation facilities, people in the sub-catchment are increasingly reliant on groundwater as a primary or supplementary water source. However, the use of on-site wastewater systems and agricultural pollution, mainly from runoff containing fertilizers, pesticides, herbicides, and faeces, pose a threat to groundwater in the sub catchment. Subsequently, the current study was conducted in the Thiririka sub catchment, Kiambu County, Kenya, to determine the safety of groundwater sources and to examine the factors influencing groundwater quality in the catchment area. This study assessed the influence of anthropogenic activities on the physical, chemical, and bacteriological quality of groundwater in the Upper Athi River basin of Kenya between April and June 2022. Twenty variables were analyzed and compared with water quality standards to determine hydro chemical characteristics, evidence of contamination, and suitability of groundwater. Shallow wells (SW) had higher concentrations of major ions and key parameters than boreholes (BH), such as alkalinity (7%), turbidity (96%), nitrates (92%), sulfates (48%), phosphates (93%), chlorides (77%), potassium (84%), sodium (30%) and fecal coliforms (99%) significant at p &amp;lt; 0.01. Concentrations of eleven water quality variables however were comparable in both systems. Farming, animal husbandry, and pit latrines were negatively but significantly correlated with the water quality of SW explaining substantial amounts of variation (≤ 45%) in concentrations of water quality variables. Ionic and coliform levels increased with decreasing distance and vice versa. IDW interpolation maps were generated in ArcGIS software to determine the spatial variability of groundwater quality in the basin. Anthropogenic activities such as pit latrines and animal husbandry impaired the quality of groundwater which in most cases was not potable.

Exploring the nexus between water quality and land use/land cover change in an urban watershed in Uruguay: a machine learning approach.

The expansion of urban areas contributes to the growth of impervious surfaces, leading to increased pollution and altering the configuration, composition, and context of land covers. This study employed machine learning methods (partial least square regressor and the Shapley Additive exPlanations) to explore the intricate relationships between urban expansion, land cover changes, and water quality in a watershed with a park and lake. To address this, we first evaluated the spatio-temporal variation of some physicochemical and microbiological water quality variables, generated yearly land cover maps of the basin adopting several machine learning classifiers, and computed the most suitable landscape metrics that better represent the land cover. The main results highlighted the importance of spatial arrangement and the size of the contributing watershed on water quality. Compact urban forms appeared to mitigate the impact on pollutants. This research provides valuable insights into the intricate relationship between landscape characteristics and water quality dynamics, informing targeted watershed management strategies aimed at mitigating pollution and ensuring the health and resilience of aquatic ecosystems.

Water quality and unseen health outcomes: A cross-sectional study on arsenic contamination, subclinical disease and psychosocial distress in Bangladesh

Health risks from water quality pose a major threat to billions of people globally. Most microbial contaminants have short subclinical periods, compared to chemical contaminants that can take years to manifest, which can translate to less attention in the policy sphere. Complex water quality issues in Bangladesh, including arsenic contamination, offer an ideal case study to highlight the wide-ranging health and social impacts of perceived and invisible contaminants. This paper presents a cross-sectional study where two tools are explored for understanding the less visible health impacts of water contamination: (1) measuring subclinical disease via nail arsenic measurements (n = 899) to better ascertain chronic exposure; and (2) understanding the relationship between water quality and psychosocial distress (n = 876), for men and women across three sites with varying water quality issues. Applying generalised linear regression models, subclinical arsenic showed strong positive correlation with water arsenic, while the relationship between severity of psychosocial distress and water arsenic was modified by perceived risk from arsenic. Subclinical disease was much more prevalent than what current exposure through drinking water would indicate, with 65.3% of participants having nail arsenic levels above the 1 μg/g cut-off for unexposed individuals (spanning across sites with average water arsenic as low as 2.51 μg/L and as high as 379 μg/L). Further demonstrating the breadth of unseen outcomes of water contamination, uncertainty was the most commonly expressed component of distress, followed by worry, fear, suffering, and lack of choice. The presence of psychosocial distress underscores how experiences of contaminated water go beyond physiological illnesses, while the use of subclinical biomarkers can shift the understanding of disease and provide a useful way of leveraging policy change by pinpointing exactly where and by whom intervention is needed.

Do protected areas enhance surface water quality across the Brazilian Amazon?

Protected Areas (PAs) are pivotal instruments in natural resource conservation and maintaining or enhancing ecosystem services, including hydrological functions. In the Amazon, the impact of PAs on the quality of river waters remains largely overlooked. Therefore, this study aims to evaluate whether Environmental Protected Areas (EPAs) and Indigenous Lands (ILs) efficiently protect the quality of surface waters in the Brazilian Amazon. Water quality variables from river gauge stations distributed across the lowlands Amazon are analyzed according to baseline river hydrogeochemistry classification, both inside and outside PAs. This study found that whitewater and clearwater rivers coursing within EPAs and ILs show lower turbidity and electrical conductivity compared to those outside PAs, likely due to the buffering effect of dense forest cover within protected landscapes. Moreover, data indicate that protected areas enhance the water quality from upstream unprotected landscapes in the Brazilian Amazon. These results highlight the need to further invest on effective mechanisms of water resource conservation across lowland tropical regions, and particularly in the Earth’s largest watershed.

When beer is safer than water: Beer availability and mortality from waterborne illnesses

We investigate the impact of beer on mortality during the Industrial Revolution in 18th century England. Due to the brewing process, beer represented an improvement over available water sources during this period prior to the widespread understanding of the link between water quality and human health. Using a wide range of identification strategies to derive measures of beer scarcity driven by tax increases, weather events, and soil quality, we show that beer scarcity was associated with higher mortality, especially in the summer months when mortality was more likely to be driven by waterborne illnesses related to contaminated drinking water. We also leverage variation in inherent water quality across parishes using two proxies for water quality to show that beer scarcity resulted in greater deaths in areas with worse water quality. Together, the evidence indicates that beer had a major impact on human health during this important period in economic development.

Effects of log booms on physical habitat, water quality, and benthic invertebrates in the lower Fraser River and estuary

To facilitate the movement and processing of timber in some regions of the Pacific Northwest, logs are tied together to form large rectangular rafts (often called “booms”) which are transported and stored in aquatic environments. In the lower Fraser River, British Columbia, some reaches have &gt;50% of shoreline with adjacent log booms, yet our understanding of the effects of log booms on habitats and biota is very limited. We compared sites that have never had log booms to nearby ones with active boom storage occurring to examine differences in environmental characteristics. In contrast to reference sites, nearly all active sites had compacted sediments and little vegetation coverage, likely caused by logs “grounding” onto benthic environments due to tidally influenced water level changes. Total benthic invertebrate abundance was higher at reference sites which had relatively more Amphipoda and Trichoperta, but fewer Haplotaxida, compared to active sites whose compacted and more detrital-laden sediments should favour haplotaxids. Water quality variables generally did not differ between reference and active sites. Grounding of log booms and contact with the below substrate is in contradiction of best management practices and has clear effects on the physical habitat and biota of the area underneath booming sites.