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Integrating water and sediment analysis with land use brings significant results in understanding the transformations in the watershed and assessing anthropic actions. We assess water and sediment samples collected in four sites in a countryside urban-farming watershed landscape in Southern Brazil. We performed the land-use, physical–chemical, microbiological, potentially toxic element (Pb, Cd, Zn, Cu, Ni, and Cr), atrazine, 2.4-D, microbiological contamination analysis, and total organic carbon, nutrients, and granulometry. We also calculate the Water quality index, geoaccumulation index, enrichment factor, and ecological risk potential, with SQGs (TEL and PEL). Our results demonstrate that all the water samples of this study were contaminated with faecal and total coliforms, alerting the effectiveness of treatment at these plants. We found no significant concentrations of pesticides in the water. The concentration of metals in the sediment was in the order of Cu > Zn > Cr > Ni > Pb > Cd, with Igeo = 0–3 for Cu, Zn, and EF < 3 for Cu. The Cu concentration was eight times higher than TEL, Cr, and Cu above TEL at all sites. We found a strong positive correlation between atrazine, 2.4-D, Pb, and nutrients from agricultural activities and higher concentrations at the one site. The Zn, Cu, Ni, Cd, and Cr sources were plantations, forests, and domestic sewage discharges. The results corroborate with the proposition that complete assessments of watersheds including analyses of water, sediment, and land uses are necessary to understand the real effects of anthropic action on this ecosystem and diversity of this environmental. [ABSTRACT FROM AUTHOR]

This study aimed to compare the growth and survival of Crassostrea gigas spat at four sites (Sambaqui (SBQ), Paraíso das Ostras (PAR), Atlâtico Sul (ATL), and Cia das Ostras (CDO)) in Brazil. Batches of spat were reared in the summer and winter of 2018 and the summer of 2019 for two month periods. SBQ site had higher total particulate matter and particulate inorganic matter values than those observed at the other sites. The salinity at the PAR site was higher than that found at the other sites, but the temperature was lower. No differences in survival were observed among the sites in the summer or winter of 2018; however, in the summer of 2019, there were significant differences. Shell height was higher during warmer seasons than during winter. In conclusion, the SBQ and ATL sites were found to have better conditions for spat cultivation than the PAR and CDO sites. [ABSTRACT FROM AUTHOR]

This study presents a methodology to determine the appropriate location for effluent disposal in a low-flow river using numerical modelling, via a case study of a river located in Southern Brazil, considering disposal of landfill leachate with known characteristics. There are four key steps: 1) a principal component analysis (PCA) for a set of representative parameters; 2) a decision flowchart for proper water quality models; 3) a modified Water Quality Index (WQI) using the resulting concentrations and 4) simulation on 1D and 2D models and WQI calculation and evaluation. The PCA highlights eight relevant parameters: ammonia (NH3), chloride (Cl−), biochemical oxygen demand (BOD), total phosp horus, nitrite (NO2−), nitrate (NO3−), dissolved oxygen (DO) and total dissolved solids. Two models were considered suitable: HEC-RAS (1D) and SisBaHiA (2DH). After simulating the parameters in both models, a WQI was calculated for each location. Both HEC-RAS and SisBaHiA lead to the same effluent outfall location, showing that spatial discretisation does not affect the results. [ABSTRACT FROM AUTHOR]

The artificially created Lake Pampulha, within the metropolitan area of Belo Horizonte, Minas Gerais State, lacks detailed information about its freshwater mollusks, representing a challenge for the assessment and conservation of this ecosystem. In this study, conducted during June and August 2021, we collected specimens on four different occasions and at five sampling points around the lake, using different sampling equipment, such as a shovel and a scoop. During these collections, we identified, enumerated and measured 1538 species of mollusks and additionally examined the presence of trematode larvae. We identified twelve species of fresh water bivalves and gastropods: Biomphalaria straminea, Biomphalaria kuhniana, Biomphalaria occidentalis, Drepanotrema cimex, Pomacea maculata, Stenophysa marmorata, Physa acuta, Gundlachia ticaga, Melanoides tuberculata, Pseudosuccinea columella, Omalonyx matheroni and Corbicula largillierti. Echinostome and strigeocercaria types of larval trematodes were detected in B. straminea. Notably, some species of mollusks have not previously been recorded at Lake Pampulha. The analyses revealed differences in the composition and abundance of species, highlighting the higher number of mollusk species in areas more impacted by human actions. This study expands our understanding of mollusk diversity at Lake Pampulha, and provides valuable data for longitudinal comparisons of water quality and considerations of the conservation of native species. Furthermore, it highlights the importance of choosing appropriate sampling equipment, depending on the research objectives. The presence of invasive species of medical and veterinary relevance as intermediate hosts of parasites reinforces the need for efficient environmental protection strategies to preserve this artificial, aquatic environment widely used by the local population and by tourists. [ABSTRACT FROM AUTHOR]

Ecological quality evaluations using diatoms, which are accepted as one of the biological quality components have accelerated recently in different basins of Türkiye. Asi Basin which has a small catchment area within the borders of Türkiye, located near to Syrian border and is under the influence of a Mediterranean climate. This study aims to determine the water quality of the streams in this basin by using various diatom indices and to determine the environmental pressures affecting the diatom community structure. In this study, 21 rivers of the Asi Basin were sampled three times during 2019 to evaluate their ecological status by using 18 different diatom indices. A total of 157 diatom taxa were recorded in these rivers. Different environmental variables were also sampled combined with diatoms, and according to RDA, alkalinity (ALK), electrical conductivity (EC), total phosphorus (TP), and total nitrogen (TN) were determined as the most decisive pressures for the distribution of diatom assemblages. In terms of TN, Bayrak River (R7), while in terms of TP, Üçocak River (R12) have II. class water quality. The eight diatom indices showed significant correlations with TP (p < 0.01). The Trophic-Saprobic index (LOBO) showed the highest response to the TP (R2 = 0.63) and was consistent with the indicator species. This index was also compatible with the evaluation results made according to the water quality classes of the sites. LOBO index classified these rivers as high-good or poor-bad effectively in terms of TP. It was the first time that the LOBO which was developed to evaluate the surface freshwaters of Brazil has a high correlation with TP in a basin of Türkiye. [ABSTRACT FROM AUTHOR]

Biofloc technology (BFT) is an aquaculture technology that uses microbial communities to produce a balanced aquatic environment for fish and crustaceans. This study evaluated the global research trends and measured the performance of researchers, organizations or research centers, countries, and funding agencies participating in BFT research in the last decade. Scientific knowledge mapping was also performed to understand the social and conceptual structure of the research publications. The study was conducted based on journal article publications indexed in the Scopus database between 2013 and 2022. The analysis showed that BFT research was increasing steadily, with a total of 911 documents published in the past 10 years. Brazil, China, and India were the three most productive countries in the field. The most productive journals were Aquaculture, Aquaculture Research, and Aquaculture International. Regarding research topics, the largest share of documents was related to bioflocs and their technologies, followed by Litopenaeus vannamei, water quality, growth performance, shrimp, Nile tilapia, Oreochromis niloticus, etc. Co-authorship network analysis revealed that the largest cluster comprised researchers from Brazil, China, and India. Moreover, the study of societal attention revealed that the BFT research needs more public attention as the research was discussed and mentioned only a few social media platforms. However, the BFT research had significant readers on Mendeley. This study provides a comprehensive overview of the current state of BFT research and the research performance of scientific actors. It can serve as a valuable reference for researchers and policymakers. [ABSTRACT FROM AUTHOR]

Ponds built on land are the main production units for aquatic organisms and the characteristics of the base soil of these structures influence the quality of water and the aquatic ecosystem formed for production. The objective of this study is to verify the characteristics of fish farms' soils and address their importance for fish farming. The study was based on the collection of base soils for the construction of fish ponds in the city of Dourados - MS, Brazil. Particle size, pH, organic matter (OM), effective (t) and potential cation exchange capacity (T), base saturation (V%), and aluminum saturation (m%) were evaluated. There was a significant positive correlation between pH x V% (0.77) and V% x t (0.74). There were significant negative correlations between the chemical variables pH x m% (-0.87), V% x m% (-0.88) and physical variables with clay in relation to sand (-0.91) and silt (-0.83). The correlation results corroborated the clusters formed by the PCA analysis, which indicated the existence of three groups of variables considering the first two dimensions. A negative relationship of m% x pH and V% was evident. When performing the grouping of properties according to soil parameters, three groups formed. This shows that even properties built on soils of a same pattern, such as a floodplain site, may show differences in physical, chemical, and soil organic matter parameters. [ABSTRACT FROM AUTHOR]

The Law n° 14,026 from 15 July 2020, upgrades Brazil's new national sanitation framework. Whether this upgrade in the Law is not the market sequestering the Brazilian 'Blue and brown gold' had been pretty debated, however, we prefer to address two research questions: what water quality should we expect in Brazil's urban rivers? How should the management of urban rivers be planned? In this work, Porto Alegre city (South Brazil) was assessed, and the SDG 6.3.1, 6.3.2, and 6.5.1 were taken as a benchmarking tool. The main features approached suggested that: i. The new legislation may not guarantee good urban water quality; ii. The SDG 6.3.2 is essential to be determined at the municipal level; and iii. At the municipal/intra-urban level, IWRM and IUWM seem promising pathways to these desirable cities. The approach developed may provide a new perspective for urban water management. [ABSTRACT FROM AUTHOR]

Understanding the major drivers of runoff water quality in urban areas is important for sustainable water management. In this study, runoff water quality in a catchment in Colombia and another in Brazil was monitored and related to rain, and meteorological variables through correlation and principal component analysis. High correlations were found between event mean concentration of total suspended solids (TSS) and total phosphorus (TP), as well as with total Kjeldahl nitrogen (TKN) and total organic carbon (TOC). The results indicated that TSS and TP were related to sediment transport in the catchment, while NTK and TOC were derived from point sources (improper wastewater disposal). Rain depth, maximum specific discharge, air temperature, and solar radiation were the main factors explaining variability of water quality. These results contribute to a better understanding of local processes driving runoff water quality, and bring valuable insights for modelling and management of stormwater in urban catchments. [ABSTRACT FROM AUTHOR]

The potability of water, including underground sources, is constantly affected by human activities. To assess water quality and water security in rural and urban areas of southern Brazil, a quantitative, retrospective analysis of water samples collected monthly by the Brazilian health authorities (19,687 samples from 2013 to 2021) was performed. In rural areas, 5,979 water samples (77.54%) were found to be contaminated by coliform bacteria and 3,431 (44.50%) by Escherichia coli. In addition, 1,616 (20.95%) of the contaminated samples were significantly correlated with rainfall amount. In urban areas, 1,268 (10.95%) of the samples contained coliform bacteria and 293 (2.53%) of these samples contained E. coli, with the factor of rainfall associated with 1,081 samples (9.33%) with bacterial contamination. In terms of physicochemical parameters, turbidity exceeded the national standard (5 uT) in 448 (2.32%) samples and fluoride fell below the required level (0.8 mg/L) in 106 samples (0.54%). The presence of free residual chlorine (0.2–2.0 mg/L) was verified in 846 samples (14.38%) in rural areas and in 10,825 samples (56.13%) in urban areas. These results suggest a strong association between rainfall factors and physicochemical alterations, as well as the risk of greater microbial contamination of water for human consumption. [ABSTRACT FROM AUTHOR]

From distributed or semidistributed hydrological models, it is possible to identify where land use decisions can bring greater economic benefits in relation to water use. This study aimed to integrate simulations of a hydrological model varying the land use in four reforestation scenarios that influence the economic benefits of provision environmental services, including the user's alternatives as a key parameter and finally estimating the economic value of such benefits. The "avoided costs" method was used for economic valuation of flow regularization service and adequacy of water quality in the Piracicaba River basin, aiming to generate various economic instruments to support decision makers. The cost for water storage was estimated from the rising rain volume infiltrating the soil from the change in the dynamics of land use, whereas the cost of maintaining water quality was obtained from the variation between the effects of scenarios in nitrogen, phosphorus, and sediment loads. The valuation methodology allowed us to estimate the avoided costs, which will mainly contribute to application of economic instruments to manage water resources, directing land use decisions in hydrographic basins, guiding environmental impact assessment studies, and the definition of mitigation measures. [ABSTRACT FROM AUTHOR]

Plankton in rivers are good indicators of water quality and their study along the longitudinal axis allows for understanding the interactions between natural and anthropogenic variations and diversity at different spatial scales. We compared the taxonomic biodiversity of planktonic microcrustaceans in two sections of the Frades River Basin, Brazil. Water and microcrustaceans were sampled in August 2018, April 2019, July 2019, and October 2019 in the basin. We recorded 43 taxa as the regional diversity of microcrustaceans. Alpha diversity was statistically higher in the upper section of the basin. The analysis of indicator species showed that nine species were characteristic of the studied sections. The upper section was represented by Nicsmirnovius paggii, Acroperus tupinamba, Alonella dadayi, Alona guttata, and Microcyclops finitimus and characterized by higher dissolved oxygen, higher values of pH of water and lower nitrate and total coliforms concentrations. Diaphanosoma birgei, Alona sp., Grimaldina brazzai, and Ilyocryptus spinifer were characteristic of the lower sections of the basin, with the highest concentrations of nitrate and total coliforms. The microcrustaceans in the lower sections were limited by the gradient of environmental conditions, making local communities simpler (low species richness) and with few species probably adjusted to narrow ranges of environmental conditions. [ABSTRACT FROM AUTHOR]

The objective was to study the impacts of the implementation of fish farming projects (fish breeding), the quality of water effluents from these enterprises, in upland streams on properties in the municipalities of Manaus and Iranduba. We chose to monitor some physical-chemical attributes such as turbidity, dissolved oxygen, chlorophyll-a, ammonia, nitrite, nitrate and phosphorus because they are able to establish a relationship between fish farming and the loss of environmental quality of water. For this study, 16 sample units were analyzed, with two collection points each, upstream and downstream in the fish farming enterprises in uplands of continuous land (continuous flow), in two different periods in the year 2016 and 2017. The main variables studied in the analysis stage of an aquatic ecosystem, including fishing grounds, they can be: water temperature, pH, turbidity, concentration of nutrients (nitrite, nitrate and ammonia, total phosphorus), dissolved oxygen, chlorophyll. There was no significant difference in temperature, dissolved oxygen, ammonia and nitrate. There was a significant difference for the depth, turbidity and nitrite parameters. There was a significant difference for phosphorus and pH and no difference was observed for chlorophyll-a. The analyzed parameters were sufficient to demonstrate that the fish farming activity in Igarapé alters turbidity, nitrite and phosphorus and pH. Based on these parameters, better control of water quality in fish farming in Igarapé is suggested as water flow and better quality of the feed offered to fish. [ABSTRACT FROM AUTHOR]

Fire events are increasing in frequency, duration, and severity worldwide. The combination of ash and uncovered land might increase the transportation of pollutants into the streams, potentially affecting the water supply systems. The intensifying fires in Brazil's Cerrado biome, responsible for 70% of the country's water supply, give rise to profound ecological, climatic, and socio-economic concerns that require urgent and effective mitigation strategies. However, little attention has been paid to the consequences of fire events on water resources in the region. In this study, the Fire Impact on Water Resources Index (FIWRI) is proposed and applied in six different water supply watersheds to analyse fire behaviour from 2003 to 2020 and its potential impact on inland water bodies. This is the first remote-sensing-based index for fire impact on water resources developed for the Brazilian territory, to support water management on a watershed scale and uses variables such as terrain slope, river proximity, and vegetation to classify fire events as having a low to high potential to contaminate water bodies. We observed that all six water supply watersheds suffered frequent fire events, with different FIWRI proportions, which ranged from High to Low FIWRI. The proposed index could be used in real-time fire monitoring alert systems in order to support water supply management. [ABSTRACT FROM AUTHOR]

Brazil, a country with a strong agricultural sector and holder of 12% of the planet's freshwater, has stood out worldwide in terms of pesticide consumption. These substances are among the main agricultural effluents, representing a risk to aquatic ecosystems. Ordinance No. 888 of 2021 of the Ministry of Health provides for the mandatory monitoring of pesticides in the water supplied to the Brazilian population, however, a small number of municipalities comply with the determination. In this sense, this study aims to propose a method for prioritizing crops, active ingredients, and times for monitoring pesticides in water sources. Data on the planted area with crops, their phenology, and plant health were used; the sale of pesticides and their physical and chemical parameters; and the climatic conditions of the state to propose the method. Coffee, sugarcane, corn, and banana were indicated as priority crops in the state of Espírito Santo. Of the 86 pesticides sold in the state, 54 were considered a priority for monitoring due to characteristics related to greater exposure, such as use, commercialization, favorable environmental dynamics, mostly during the rainy season of the year. There are statistically significant differences between the concentrations of pesticides found in the water in the priority and non-priority months, confirming the effectiveness of the method for setting priorities in pesticide monitoring. Thus, it is important to highlight the potential of the method to help states, municipalities, and regions to select, prioritize and monitor pesticides in their sources in a more assertive and adapted to local singularities. [ABSTRACT FROM AUTHOR]

Springs are important ecosystems in terms of environmental services and their quality has been degraded by various land uses. Aquatic insects are strongly affected by anthropogenic impacts. For this reason, researchers, use the taxonomic and functional structure of the Ephemeroptera, Plecoptera, and Trichoptera (EPT) assemblages for the evaluation of environmental quality of Neotropical springs in areas cultivated with eucalyptus. In this respect, we tested the hypothesis that taxa richness is lower in eucalyptus areas, and the taxonomic composition and functional diversity are different from those of forest areas. In order to verify this hypothesis, we used a pond net sampler to collect the substrate of 20 springs in Southeastern Brazil. Our results showed that in areas planted with eucalyptus, springs showed less richness of genera and a different EPT taxonomical composition compared to springs in forest areas. We also found that respiration and body size were the functional traits most influenced by abiotic variables in springs both in eucalyptus and forest areas. The reduced marginal vegetation and homogenization of the canopy in eucalyptus areas reduced the quality of the plant matter, altering the substrate composition and water quality of springs in those areas. [ABSTRACT FROM AUTHOR]

Spatial-temporal monitoring of the presence of pesticides and pharmaceuticals in water requires rigor in the choice of matrix to be analyzed. The use of matrices, isolated or combined, may better represent the real state of contamination. In this sense, the present work contrasted the effectiveness of using epilithic biofilms with active water sampling and with a passive sampler—POCIS. A watershed representative of South American agriculture was monitored. Nine sites with different rural anthropic pressures (natural forest, intensive use of pesticides, and animal waste), and urban areas without sewage treatment, were monitored. Water and epilithic biofilms were collected during periods of intensive pesticide and animal waste application. After the harvest of the spring/summer crop, a period of low agrochemical input, the presence of pesticides and pharmaceuticals was monitored using the POCIS and epilithic biofilms. The spot water sampling leads to underestimation of the level of contamination of water resources as it does not allow discrimination of different anthropic pressures in rural areas. The use of endogenous epilithic biofilms as a matrix for the analysis of pesticides and pharmaceuticals is a viable and highly recommended alternative to diagnose the health of water sources, especially if associated with the use of POCIS. [ABSTRACT FROM AUTHOR]

The rupture of the Córrego do Feijão iron mine Tailings Dam I killed at least 260 people and had major environmental and social impacts. We analyzed the chemical compounds dissolved in the surface water and the bottom sediments of Ferro-Carvão Creek, the watercourse directly affected by the disaster, and at points upstream and downstream of its confluence with Paraobeba River, the main watercourse of the region. We also analyzed samples of the released tailings and groundwater near the area directly affected. From an environmental geochemistry standpoint, the water analyses suggest that the water quality degradation was not as catastrophic as the human and material losses and damage to biota. The groundwater samples did not present disconformities according to the Brazilian Environmental Council (CONAMA). In fact, most of the surface water samples that exceeded the maximum allowed concentrations were upstream of the affected basin. This suggests that mining industry sources other than those associated with the disaster had damaged its water quality before the event. Thus, previous knowledge must be used to evaluate the real anthropic impact in events of this nature. It can also be an excellent tool to guide remediation in situations such as in the Córrego do Feijão Iron Mine disaster. [ABSTRACT FROM AUTHOR]

The current study aimed to investigate the ectoparasitic diversity and gill alterations in Hoplerythrinus unitaeniatus (Characiformes: Erythrinidae) and Cichlasoma bimaculatum (Perciformes: Cichlidae) and evaluate the microbiological and physicochemical quality of water samples deriving from a Quilombola zone in Maranhão State, Brazil. Water samples and 42 fish specimens, 21 H. unitaeniatus and 21 C. bimaculatum, were collected from a floodable environment. Water samples were subjected to physicochemical and microbiological analyses in the laboratory environment. Fish specimens were euthanized to collect and identify ectoparasites in animals' mucus, body surface, and gills, as well as to enable the histological analysis of the second right gill arch. The herein-identified ectoparasites have shown 30.95% prevalence and comprised three phyla: Platyhelminthes, Trematoda and Arthropoda. The herein-identified main histological changes comprised incomplete and complete fusion of several lamellae, lifting of respiratory epithelium, lamellar disorganization, lamellar epithelial hyperplasia, and blood sinus dilation. The herein calculated histological alteration index has shown that 23.80% of specimens presented mild-to-moderate tissue damage, 4.77% presented moderate-to-severe tissue changes, and 9.52% presented irreparable tissue damage. It was possible concluding that histological gill lesions identified in fish specimens analyzed may be adaptive responses to the affected environment and the incidence of ectoparasites. [ABSTRACT FROM AUTHOR]

Despite long-standing interest, the mechanisms driving aquatic macroinvertebrate drift in tropical streams remain poorly understood. Therefore, the objective of this study was to evaluate which environmental metrics drive macroinvertebrate drift in neotropical sky island streams. We evaluated whether altitude, the abundance of food resources, and variations in water quality influenced macroinvertebrate drift density, diversity, richness, and functional feeding groups. An hypothesis was developed to test whether increased altitude, lower food availability (particulate organic matter), and discharge would increase the density, taxonomic richness, and diversity of drifting invertebrates. Nine headwater stream sites were sampled in the rainy and dry seasons in the Espinhaço Meridional Mountain Range (EMMR) of southeast Brazil. Samples were collected using drift nets deployed from 5:00 p.m. to 8:00 p.m. The abundance of food resources was assessed through estimates of coarse (CPOM) and fine (FPOM) particulate organic matter, and primary producers. CPOM availability was an important explanatory variable for Gathering-Collectors and Scrapers, Altitude was important for Shredders and Predators, and Filtering-Collectors were linked to water discharge, suggesting that functional group drift masses were linked to different ecosystem components. Water temperature, conductivity, dissolved oxygen, current velocity, FPOM biomass and microbasin elevation range exerted little influence on macroinvertebrate drift. Regarding taxa composition, this study also found that Baetidae and Leptohyphidae (Ephemeroptera) and Chironomidae and Simuliidae (Diptera) were the most abundant groups drifting. [ABSTRACT FROM AUTHOR]

The determination of natural variation in physical habitat conditions and the establishment of least-disturbed reference standards is important for ecosystem conservation. Tropical regions hold most of the global freshwater diversity, nevertheless little is known about the natural conditions of their physical habitats. We calculated 255 physical habitat metrics for 31 stream sites in five protected areas of the Brazilian S~ao Francisco River basin to identify the most variable characteristics among tropical streams in least-disturbed areas. We performed principal components analyses (PCA) to find the most relevant metrics for ordination of streams in the following categories: water quality (2); substrate (7); fish shelter (6); riparian vegetation (9); and channel morphology (7). We used distance-based linear models (DISTLM) to test how much of the variation of these metrics could be explained by geographic position, average elevation, and average discharge of stream sites. The best statistically significant models explained 42% of substrate (33% geographic position; 9% average elevation), 26% of channel morphology (22% geographic position; 4% average discharge), 23% of water quality (14% geographic position; 9% average discharge), 17% of fish shelter (9% geographic position; 8% average elevation), and 14% of riparian vegetation (7% geographic position; 7% average elevation) variation. Thus, regional features (e.g. geology and climate) related to the geographic position are of greatest importance, followed by average elevation and discharge for determining physical habitat characteristics. Therefore, we suggest that reference sites should be set for tropical streams in the same regional landscape and with similar average elevation and discharge. [ABSTRACT FROM AUTHOR]

Sesame crops have large economic potential; however, the scarcity of good quality water in the Semiarid region of the Northeast of Brazil can affect production systems, which requires the search for cultivars that can better be adapted to the local conditions. In this context, the objective of this work was to evaluate the germination dynamics of sesame seed lots subjected to different electrical conductivities of the imbibition solution. The experiment was conducted at the Laboratory of Seeds and Seedling Analysis of the Federal University of Campina Grande, Pombal campus, Paraíba, Brazil. A completely randomized design was used, in an 8×6 factorial arrangement, corresponding to eight seed lots (BRS Seda; BRS Seda (S2); BRS G2 (S1); BRS G2 (S2); BRS G3 (S1); BRS G3 (S2); BRS G4 (S1) and BRS G4 (S2), where S1 and S2 represent the grown environments, saline (2.4 dS m-1) and non-saline, respectively; and six electrical conductivities of the imbibition solution (0.3; 1.2; 2.1; 3.0; 3.9; and 4.8 dS m-1), with four replications. The variables seed germination, vigor, germination speed index, mean time for germination, mean germination speed, and radicle length were evaluated. The sesame seeds are sensitive to salinity, regardless of the lot analyzed and their germination power decreases when they are subjected to high salt concentrations. [ABSTRACT FROM AUTHOR]

Water is an essential natural resource for maintaining life and its quality is influenced by the land use and occupation within a watershed. Furthermore, water quality has a direct impact on the health and well-being of a population. The present study aimed to carry out a macroscopic environmental analysis in shallow wells found in rural properties distributed in the states of Rio Grande do Sul and Santa Catarina, including the Uruguay River Basin. The evaluation period of the macroscopic parameters took place in April 2021. The physical characteristics of the water and the state of preservation of the shallow wells and their surroundings were visually evaluated in rural properties with predominant land use and occupation through dairy production, swine farming activity and seasonal crops (agricultural crops). As results obtained for the environmental macroscopic analysis, through the weighting of the characteristics observed in each parameter about the state of preservation of the shallow wells, it was verified that they presented different classifications, ranging from the Very Good class to the Poor, being possible to identify the main sources that cause negative impacts on the evaluated locations (state of vegetation, use by animals, protection of the area and proximity to residences). Therefore, rural producers were advised to carry out protection and care measures around these wells that presented lower classifications, Fair (38,10%) and Poor (19,09%) to improve the conditions and aspects that directly influence the quality of water for human consumption. [ABSTRACT FROM AUTHOR]

We developed the Trophic Diatom Index for Reservoirs (TDIR), the first index proposal for water trophic quality assessment of tropical reservoirs in Brazil. Furthermore, we applied four borrowed diatom indices to compare their performances with TDIR. The proposal development considered a calibration set from surface sediment diatoms (n = 113) from reservoirs ranging from ultraoligotrophic to hypereutrophic. Weighted averaging methods were applied to infer optimum (values) and tolerances for total phosphorous for each diatom species. Indicative values were categorized within the trophic classification for tropical reservoirs, and sensitivity values were classified according to the range of tolerances of diatom species. The TDIR index scores ranged from 1 (ultraoligotrophic) to 6 (hypereutrophic). The TDIR showed good performance for the trophic classification of reservoirs. In contrast, the borrowed diatom indices developed in subtropical rivers underestimated the water quality, whereas the diatom index developed for lakes in temperate regions overestimated the water quality of our reservoirs. Moreover, we calculated new records of indicative values, and some well-cited species had different optimum and tolerances values concerning other well-known studies. TDIR provides an applicable index and contributes as a reliable tool for assessing the water quality and ecological status of tropical reservoirs. [ABSTRACT FROM AUTHOR]

The aim of this study was to characterize the limnological parameters and analyse the biological effects of different ponds in a commercial fish farm in the Pará State, Brazil. One pond is designated for fingerling production (N) while the other is for fattening and termination (F). The other three ponds are named supply tanks, from which the water from the Parauapebas River is collected to fill N and F tanks. For the physical–chemical analysis, samples from N and F ponds were collected at a depth of 50 cm close to the water's outlets of the ponds, with the aid of a commercial kit for water analysis. Caenorhabditis elegans nematodes were used for water quality biomonitoring and exposed for 24 h to samples from all five tanks collected during three different days, being assessed through physiological endpoints. During the study, values of transparency and pH were higher in N, both with significant differences between the ponds. The other parameters did not show any differences among them in the different days and times analysed. The results showed that the water quality of N and F ponds is in accordance with the current legislation in the country. Despite being in accordance with legislation and with acceptable metal levels, samples caused toxicity to worms, which indicate that for fish production, a continuous supervision is essential for the success of the activity. Therefore, the limnological variables in relation to biomonitoring should be constantly assessed in fish farm enterprises in order to maintain a more efficient and sustainable productive system. [ABSTRACT FROM AUTHOR]

Summary: Protected areas (PAs) represent a powerful refuge for maintaining and safeguarding biodiversity. Generally, PAs are delineated to protect terrestrial taxa, providing incidental protection to the aquatic ecosystems within their borders. Here, we compare water quality within PAs and non-PAs in southern Brazil, encompassing remnants of the Atlantic Forest biome, to assess whether PAs serve as a buffer from external pressures for aquatic ecosystems within their boundaries. In addition to physicochemical and microbiological water parameters, we analysed 147 pesticide and 31 pharmaceutical compounds in water samples from 33 sites within and outside PAs. The water quality did not differ between PAs and non-PAs but indicated clear pollution from sewage discharges. We found 19 pesticides and five pharmaceuticals in streams within the study area. We detected pesticides in all sampling sites, with the herbicide 2,4-dichlorophenoxyacetic acid present in 91% of them. Our data show that PAs are insufficient means to mitigate the impacts stemming from their catchments, and the running water that reaches their domains already shows signs of anthropogenic interference, which may affect aquatic biodiversity. Protection and management measures require consideration of the whole watershed to protect freshwater habitats and biota. [ABSTRACT FROM AUTHOR]

Poultry farming has expanded to regions with adverse weather conditions such as the semiarid region of northeastern region of Brazil. The objective of this study was: 1) to evaluate the thermo-acoustic environment of two laying poultry sheds, with different covering material, measuring the variables: minimum, average, median and maximum temperature of the internal surface of the coverings; instantaneous noise level; temperature, relative humidity and average air speed; ETI - Equivalent temperature index; 2) to analyze the quality of the animals' drinking water, measuring the variables: temperature and electrical conductivity; and 3) to estimate the sensible heat losses of the animals. The commercial warehouses evaluated were built identically, in the Californian model, with metal frame porches and equipped with fans and an internal misting system. The portable digital equipment used in data collection were: photothermal camera, anemometer, thermo-hygrometer, decibel meter and conductivity meter. Data collection was carried out in the afternoon at seven different points along the length of the sheds. The air velocity, minimum, average and median temperature of the internal surface of the tiles showed a significant difference between treatments (sheds). Furthermore, all the temperatures of the internal surface of the galvanized steel roof tiles showed a significant difference between the south-facing face and the north-facing face. The other variables showed no significant difference. [ABSTRACT FROM AUTHOR]

The main objective of this work was the development and evaluation of usage of a new water quality index (WQI) that linked the information of the parameters that compose it and the practicality of calculation to the current legislation in Brazil. For this, 30 water monitoring stations were selected, in the hydrographic unit of Upper Iguaçu-Parana-Brazil. Three methods of WQIs calculation were applied: National Sanitation Foundation- NSF (WQINSF), Bascaran (WQIb), and the new method proposed called Bascaran-CONAMA (WQIc). The calculation of the WQIc was adapted based on the WQIb and had its parameters based on Brazilian legislation (CONAMA 357). Statistical analysis at a significance level of 1% was performed in the comparison of the three indexes, by monitoring station and seasonal periods. It was verified that the results obtained through the calculation of the new index proposed had a greater coherence with the Brazilian scenario. Keywords: Brazilian Water Quality Index; Water Pollution; Watersheds Monitoring. [ABSTRACT FROM AUTHOR]

Rainwater can be harvested from different roofs of rural buildings, which can be stored for multipurpose depending on its quality. This technical note describes rainwater quality collected directly from the atmosphere and after passing through four types of roofs that are: French ceramic (roof1/Agronomy school building), fiber cement (roof2/farm machinery shed), or French ceramic (roof3/sheep housing), and French ceramic (roof4-swine housing) located inside Agroveterinary School Campus (CAV/UDESC) in Lages, Santa Catarina state, Brazil. The parameters analyzed were pH, color, turbidity, dissolved oxygen, total coliforms, and thermotolerant coliforms. Results showed that pH "in natura" rainwater was variable and below 7.0 with an average of 6.02. However, after passing through the roof, there was an increase in the pH (average) to 6.34 (roof1), 6.90 (roof2), 7.14 (roof3) and 6.50 (roof4). The rainwater also presented variations in the parameters of turbidity, dissolved oxygen, and coliforms after passing through roofs. Thus, the rainwater can potentially be used for non-potable purposes, being then advised of their use without treatment for cleaning of nearby environments of these rural buildings, as well as the irrigation of trees and ornamental plants, among others. [ABSTRACT FROM AUTHOR]

The main objective of this research is to analyse the unique aspects of a karstic system. The River Formoso watershed presents an unbalanced social-nature relationship because of the use of its drainage and its scenic beauty is threatened because of increased turbidity and other signs of pollution. This work analyses and classifies the surface waters in the area according to the Brazilian Environmental Council recommendations (physicochemical parameters and flow velocity were analysed from 36 collection points). The results indicate that waters arriving in this karstic system show chemical concentrations of calcium, magnesium, and carbonate, which account for high conductivity, alkalinity, and low turbidity. However, there is evidence of contamination from monocultures, cattle farms, and urban areas). The results of this research can be useful in three main ways: understanding aspects that influence the water quality of a karst area; understanding the environmental impacts related to the anthropic use of water in the study area; and assisting in the territorial planning strategies of this area - which features important environmental, touristic, economic, and social values for the state of Mato Grosso do Sul, Brazil. [ABSTRACT FROM AUTHOR]

• The Volumetric Idleness Coefficient allows to identify the less idle reservoir. • The Volumetric Overflow Coefficient allows to identify minimum overflow scenarios. • The optimal reservoir volume can be associated with minimum values of VOC or VIC. In Brazil, the existing regional disparity in water availability makes it essential to search for alternative solutions that guarantee the supply complies with water quality parameters, affordable cost and adaptation to local conditions and needs. Rainwater may satisfy these requirements. The existence, however, of numerous methods for sizing the reservoir of the system adds some subjectivity to the calculation of the storage volume and can lead to the determination of a storage value that does not meet the project's needs. In this context, this work aims to propose two coefficients, the Volumetric Idleness Coefficient (VIC) and the Volumetric Overflow Coefficient (VOC), which can be used as criteria for determining optimal volumes of reservoirs for rainwater storage. To this end, we considered three reservoir sizing methodologies, already existing in the literature, in different scenarios of catchment area and demand, with data from daily rainfall series of 37 years throughout the Brazilian territory. Additionally, an algorithm in Python was developed to obtain the values of these coefficients for the selected reservoir sizing methods for any point in Brazil, considering different scenarios of catchment area and demand. Results showed that the rainfall characteristics influence the values obtained for VIC and VOC, especially when the reservoirs are sized by a method that considers a water balance. Furthermore, an increase in demand in the catchment area causes a decrease in the values of both coefficients. Both coefficients presented in this article can be applied as reservoir sizing criteria through the comparative analysis between different sizing methods within a scenario since the method that allows a minimum coefficient is associated with an optimal reservoir volume, either for the project that aims to maximize the use of the useful storage volume (VIC) or maximize the use of the volume of water captured by the system (VOC). [ABSTRACT FROM AUTHOR]

• Terrestrial ecosystems perform functions directly related to the availability and quality of water resources. • This study presents a simple way to carry out watershed ecosystems services assessments. • We apply an InVEST model and map algebra to create a comprehensive importance index for hydrological services provision. • The environmental systems were ranked based on their performance in terms of eco-hydrological functions. Hydrologic services describe the way terrestrial ecosystems affect freshwater resources. This study employed an ecosystem-based approach and spatial models to assess the significance of ecosystems in providing hydrological services in a Watershed in southern Brazil. The environmental systems and hydrological services were characterized and evaluated for the significance weights assignment by expert opinion dynamics. Spatial and tabular data generated were applied in an ecosystem services model (InVEST-Integrated Valuation of Ecosystem Services and Trade-offs) for a relative importance analysis. Map algebra was performed to integrate relative importance with runoff values, resulting in an importance index (II), which enabled the identification of the most important ecosystems for the hydrological services provision. Among the environmental systems, riparian forests (0.2457), forests (0.2455), wetlands (0.2332), and fields with livestock (0.2291) demonstrated the highest II values. Ranking environmental systems and their vegetation cover based on their performance in terms of eco-hydrological functions and hydrological services has the potential to support management actions on land use in the pursue of sustainability regarding water resources use. [ABSTRACT FROM AUTHOR]

An issue that affects the effectiveness of water pricing policies is consumer misperception, which implies that households decide their water consumption based on poor/inaccurate information about the marginal price. We use household survey data on bill and quality perception in Brazil to analyze this problem and its drivers. Once we control for the selection bias caused by survey respondents voluntarily providing their bill, we find evidence of Bill misperception. Apart from the informational and socioeconomic drivers usually considered in the literature, perceived water quality is a relevant factor in misperception. • Water service providers use prices to manage demand; however, consumers commonly misperceive how much they pay for water. • In Brazil, bill misperception is more common among those who perceive their tap water as having poor quality. • Bill awareness can be increased among customers by improving and communicating water quality and educating about tariffs. [ABSTRACT FROM AUTHOR]

This article presents the QDA-System (Sistema Qualidade da Água, from Portuguese), a system developed to monitor the quality of surface waters in Brazilian hydroelectric reservoirs using satellite images and cloud computing services. The development requirements of the QDA-System considered its use for operational monitoring purposes, with all processing steps automated, and a user-friendly interface to access and query the data generated automatically by the system. A pilot application of the QDA-System was customized and implemented for monitoring the Foz do Chapecó hydroelectric reservoir located in southern Brazil. For the pilot application, the QDA-System was customized to estimate nine water quality parameters,: five were estimated directly from Sentinel-2 multispectral images and four were estimated indirectly. We expect that in the near future the QDA-System can be replicated to monitor other Brazilian reservoirs, bringing benefits and cost reduction related to water quality monitoring, not only for the sector of hydroelectric generation but for other sectors that also need similar monitoring, such as sanitation and aquaculture production. [ABSTRACT FROM AUTHOR]

Aims: To evaluate the physicochemical and microbiological quality of dialysis water and dialysate samples from haemodialysis centres. Methods and Results: Samples were fortnightly collected from three haemodialysis centres in Bauru City, Brazil, between July 2017 and June 2018, at the stages of post‐reverse osmosis, reuse and dialysate. Analyses included determination of conductivity, fluoride, nitrate and sulphate; test for total coliform bacteria; count of heterotrophic bacteria; count and identification of non‐fermenting gram‐negative bacilli (NFGNB); drug susceptibility test; biofilm formation capacity; and genetic similarity among some isolated NFGNB. Of the analysed samples, only 4/72 (5.6%) had conductivity values ≥10 mS/cm, 4/216 (1.9%) presented total coliforms and 1/216 (0.5%) had heterotrophic bacteria count >100 CFU/ml. NFGNB were isolated from 99/216 (45.8%) samples, and the major identified micro‐organisms included Herbaspirillum aquaticum/huttiense, Brevundimonas aurantiaca, Cupriavidus metallidurans, Pseudomonas aeruginosa and Ralstonia insidiosa. Isolates of P. aeruginosa and Burkholderia cepacia complex were sensitive to most antimicrobials and, together with isolates of Ralstonia insidiosa and Ralstonia pickettii, showed strong biofilm formation capacity. Some isolates expressed the same electrophoretic profile on pulsed‐field gel electrophoresis, indicating the persistence of bacterial clones in the systems over time. Conclusions: NFGNB were observed in several dialysis water and dialysate samples from all investigated centres, which may represent a risk to the health of patients. Significance and Impact of the Study: Regular inclusion of actions for NFGNB control and monitoring in haemodialysis fluids are suggested for greater safety of the dialytic process. [ABSTRACT FROM AUTHOR]

Trait-based classifications can efficiently capture species' responses to environmental gradients and their impacts on ecosystem functioning. Thus, the clustering of phytoplankton species into functional groups can improve the understanding of their relationships with the environment and help to predict their response to environmental changes. Accordingly, this study aimed to create habitat templates of Reynolds phytoplankton functional groups (RFGs) in tropical drinking water reservoirs to describe, explain, and predict their occurrence and formation of blooms. We analyzed the structure of RFGs in 10 tropical reservoirs, in humid and semiarid regions of Brazil, and defined their relationships with 10 environmental variables. We designated the habitat template based on niche differentiation, thresholds for the occurrences and bloom formation, cluster analyses, and generalized additive models. We identified 136 species, assembled in 20 RFGs. Six groups of habitat templates were recognized based on environmental conditions and dominant RFGs, usually represented by bloom-forming species of cyanobacteria, dinoflagellates, green algae, and diatoms. The functional groups D, X1, and P presented the most restrictive occurrences, while RFGs M and SN displayed the widest, occurring in almost all sets of conditions. Moreover, salinity was the best predictor of RFGs' biomass (higher R2), followed by depth, soluble reactive phosphorus, irradiance, water transparency, and dissolved inorganic nitrogen. Our approach improves the understanding of how RFGs interact with environmental gradients in tropical reservoirs, helping water managers to adopt sustainable practices to control algal blooms, based on predictions of the future state of dominance. [ABSTRACT FROM AUTHOR]

In recent years, several environmental pollutants have been monitored in surface waters and sediments. However, few studies apply multivariate statistics to identify the main components and correlate them temporally and spatially. In this sense, the present study sought to monitor the quality of water and sediments in the Rio Marrecas/Brazil, through the analysis of physicochemical parameters and trace elements, as well as to identifying sources of contamination, using multivariate statistics. For this purpose, sampling was carried out in nine locations for a period of 12 months. The Total Reflection X-ray Fluorescence (TXRF) technique was used to quantify the 15 elements identified in water and sediment samples. Through multivariate statistical analyses, the most significant elements, their correlations and possible pollutant sources were defined, and the pollution index (HPI) and assessment index (HEI) of heavy metals were applied. The parameters pH and BOD5 do not comply with Brazilian legislation. Based on PCA and Spearman correlation, there was strong evidence of contamination of the water naturally, composed of the elements Ti, V, Mn, Fe, and of anthropogenic origin composed of the elements Ca, Ni, Cu, Zn. These findings provide insights to determine the impacts of heavy metals on human health and the environment. [ABSTRACT FROM AUTHOR]

The Paciência river estuary (PRE) is an Amazonian estuary with relevant socio-economic importance; however, it is undergoing a continuous anthropogenic pressure such as the input of untreated domestic effluents. Hence, the phytoplankton community and trophic indices were analysed during three seasons in 2017 to assess the water quality and understand the degree of human influence in a macrotidal estuary. The trophic state of the PRE was determined by applying the trophic state index (TSI), trophic index, and Karydis trophic index, and ecological status by diversity metrics (diversity, evenness, richness, and dominance). Multivariate analysis indicated that TSI and dominance index were the most sensitive indices to changes in environmental conditions. The precipitation regime characterised the estuary in two different trophic scenarios. PRE was hypereutrophic in the dry season and mesotrophic in the rainy/transitional seasons based on the TSI. A high dominance index was recorded in the dry season with blooms of Thalassiosira rotula, reflecting an ecological disturbance. A higher phytoplankton diversity was recorded in the rainy/transitional seasons, indicating a tendency toward a lower stressed ecosystem. Therefore, understanding the trophic state variability in tropical estuaries and its response to changes in phytoplankton ecology is essential to support the management of coastal ecosystems. [ABSTRACT FROM AUTHOR]

Despite the large amounts of freshwater available in Brazil, the deterioration of surface water can represent a risk of waterborne disease for national and international tourists. The main goal of this study was to assess the quality of drinking water in the triple border region of Brazil before and after being treated in water treatment plants (WTPs) and in Municipal Early Childhood Education Centers (MECECs), in terms of parasitological, microbiological, and physical–chemical aspects. Different water samples were monitored: raw water (RW), treated water (TW), and tap water from the MECECs, giving 60 samples in total, to investigate the presence of Giardia and Cryptosporidium, microbiological indicators, Pseudomonas aeruginosa, and antimicrobial resistance profiles using conventional microbiological assays and parasitological, immunological, and molecular techniques. The results obtained were compared with the reference values recommended by the legislation of drinking water in Brazil. For the first time, contamination by Cryptosporidium and Giardia was demonstrated in RW used to supply WTPs, in TW of Foz do Iguaçu, and in water destined for consumption by children. A total of 52 bacterial isolates were obtained, with high percentages of multidrug resistance to antibiotics, including a carbapenem-resistant profile, highlighting the need to improve quality control standards. [ABSTRACT FROM AUTHOR]

This study tests if rainfall regime and estuary hydrodynamics affect ecological picocyanobacterial patterns. We statistically related rainfall with picocyanobacteria (flow cytometry) and water quality data from a seven-year-long survey of Guanabara Bay (GB). The quality of GB's water varies spatially, depending on pollution hotspots, tidal influence, and water circulation patterns. It also varies seasonally, depending on the rainfall regime. Our results showed that rainfall regularly makes water quality and microbiology of the inner estuarine regions more like the tributaries' environment. We found that phycocyanin-rich and phycoerythrin-rich picocyanobacterial abundances are associated with riverine and marine waters, respectively. Besides affecting GB's water quality, rainfall governs its picocyanobacterial distribution and ecology. Thus, climate changes may influence the balance of the picocyanobacterial groups in tropical estuaries. Furthermore, the omnipresence of picocyanobacterial groups found in GB, such as Synechococcus and Cyanobium, highlights their ecological role in tropical estuaries, as seen in the open ocean. [ABSTRACT FROM AUTHOR]

This study assessed the occurrence of five antibiotics, three hormones, caffeine, and long and short-chain perfluoroalkyl and polyfluoroalkyl substances (PFASs) in surface water and feedstuff samples obtained from aquaculture cages in Três Marias reservoir in Brazil. This is the first work to evaluate the presence of PFAS in surface water used for aquaculture in Brazil. Solid-phase extraction and low temperature partitioning extraction followed by liquid chromatography coupled to mass spectrometry (LC-MS) were performed to process and analyze surface water samples and feedstuff, respectively. The ecotoxicological risk quotient was calculated for target compounds detected in water. Ciprofloxacin and caffeine were detected in all surface water samples. Pharmaceutical drugs ranged from 0.7 ng L−1 (trimethoprim) to 389.2 ng L −1 (β-estradiol). Estrone (10.24 ng g−1) and β-estradiol (66.20 ng g−1) were also found in feedstuff. Four PFASs (PFOA, PFDoA, PFTeDA, and PFBS) were detected (9.40–15.2 μg L−1) at levels higher than reported in studies conducted worldwide. Ecotoxicological risk assessment indicated high risks for caffeine and PFOA, PFDoA, and PFTeDA with RQ values from 10 to 103. These findings reveal risks to biodiversity, ecosystem integrity and human health considering possible intake of these contaminants by fish consumption due to potential bioaccumulation of these substances. Hence, it is critical to conduct more studies in this direction in Brazil and other low and middle-low-income countries. [Display omitted] • Ciprofloxacin and caffeine were found in all water samples at 3.3–296.4 ng L−1. • Caffeine exhibited a substantial ecological risk to Green algae. • Detected PFAS in surface water pose cumulative risk to aquatic organisms. • PFTeDA (PFAS) poses high ecological risk for all samples and taxonomic groups. • Low ecotoxicological risk was detected for four emerging contaminants. [ABSTRACT FROM AUTHOR]

[Display omitted] Artisanal cheese from Serra Geral, Minas Gerais, Brazil, stands out for its cultural asset and socio-economic relevance. However, standards of identity and quality and the peculiar terroir associated with the edaphoclimatic conditions have not been established. Therefore, the production flow diagram and the physico-chemical and microbiological quality of the raw milk, pingo (natural starter culture), production benches, water and fresh cheese were investigated for the first time. In addition, lactic acid bacteria (LAB) from cheese and its production environment were identified by MALDI-TOF. For that, 12 cheese making facilities were selected. The raw milk and pingo showed adequate physico-chemical characteristics for cheesemaking; however, high microbial counts were found. In the water, total and thermotolerant coliforms were also identified. The fresh cheeses were classified as 'high moisture and fat' and 'soft mass'. Most physico-chemical parameters were satisfactory; however, there were high counts of total coliforms, Staphylococcus spp. and coagulase-positive staphylococci. There were high counts of LAB in the raw milk, pingo , bench surface and fresh cheese. A total of 84 microbial biotypes from MRS agar were isolated. Lactococcus lactis was the predominant LAB, followed by Lactococcus garvieae. Leuconostoc mesenteroides (benches), Leuconostoc pseudomesenteroides (fresh cheese), and Enterococcus faecium (pingo) were identified sporadically. These results indicate the risks to public health associated with the consumption of the fresh cheese, and measures to improve its safety are needed. [ABSTRACT FROM AUTHOR]

The São Francisco River is the fourth largest river in Latin America, and particularly important since it crosses the Brazilian semi-arid region. During the 1960s–90s, a series of dams for hydropower were built in cascade, changing drastically the flow regime. To evaluate the influence of changes in the flow on hydrodynamic processes and saline intrusion in the estuary, a three-dimensional hydrodynamic model was applied to the system. The model was calibrated and validated from hydrodynamic data collected in the estuary. The simulated scenarios of river discharges were Q min , Q 10 , Q 80 and Q max (corresponding to 600, 5000, 1200, and 12,000 m3.s−1, respectively), determined from historical river discharge observations. There was an increase in the mixing and a decrease in the river contribution after the installation of dams. The average salinity in the estuarine domain ranged from 0.7 g.kg−1 for intermediate pre-dam discharge to 15.6 g.kg−1 in the lowest discharges after the dam installations. The results of the simulations were used to establish an exponential relationship between fluvial discharge and saline intrusion, which can be used by management agencies to optimize the water quality in catchments for human consumption. [Display omitted] • São Francisco River is the fourth largest river in Latin America. • Reduced river contribution after the installation of dams increased mixing. • An exponential relationship between fluvial discharge and saline intrusion is observed. • Average salinity in the estuary increased by a factor of ∼20 due to flow regulation. • Results are important for the correct water use management. [ABSTRACT FROM AUTHOR]

Low impact development (LID) practices contribute to the reduction of flooding and improvement of water quality. Water crises may be a result of water scarcity and flooding due to climatic changes and the increase of impervious areas, and thus, stormwater harvesting becomes a sustainable alternative solution for relative water problems. The performance of a bioretention system with the submerged zone (SZ) and unsaturated zone (USZ) was evaluated as an alternative for stormwater harvesting. The study was carried out on a laboratory scale, using a bioretention box to simulate the processes that occur in a real system and in the field. The system was efficient in removing TP (68.5% and 76.5%), COD (71.6% and 56.9%), and NO2 (28% and 16.6%) in USZ and SZ events, respectively. NH3 removal (31%) occurred only at SZ events. NO3 was exported at all events tested but at values below the Brazilian CONAMA Resolution 357/2005 on the quality of water bodies for supply. The bioretention effluent showed relatively high values of turbidity; however, the pH parameter presented good values in all experiments (>6.5 and <7.5), and E. coli only in some cases presented satisfactory values to meet the Brazilian Standard for Rainwater Usage for nonpotable purposes (<200 MPN/100 mL). In general, both configurations provide different improvements for stormwater to support sustainable water resources management. This study presents a comparison between bioretention systems with and without SZ as an initial proposal for the improvement in bioretention systems in Brazil; however, more experiments must be monitored, and new improvements should be tested for reaching restrictive water reuse purposes. [ABSTRACT FROM AUTHOR]

Permeable pavements have been the subject of numerous studies in recent decades. The possibility of dissipating stormwater more smoothly and generating numerous benefits to the environment and users makes the use of permeable pavements an excellent possibility of integration into sustainable and resilient water management systems in cities. In Brazil, numerous studies on the quantity and quality of infiltrated water, permeability of the coating, clogging, environmental burden, and feasibility, among other characteristics, have been researched. Within this theme, the Federal University of Santa Catarina (UFSC) has contributed with ten papers in the research of permeable pavements in the last six years, which address various topics about the effectiveness and applicability of permeable pavements. This paper reviews the studies conducted at UFSC on permeable pavements and discusses the different results within the main issues found. In general, the selected documents addressed seven themes in the studies: potential for potable water savings, clogging, quantity and quality of the water infiltrated into the pavement, Life Cycle Assessment (LCA) and its variants, and hydraulic and structural design details. More specifically, many selected papers assess the potential use of stormwater harvested through permeable pavements in non-potable uses of buildings. The possibility of aligning the benefits of green infrastructure with the rational use of water expands the advantages of the system and can help prevent future water scarcity, as well as reduce the environmental impacts of paving. [ABSTRACT FROM AUTHOR]

Santos and São Vicente Estuarine Complex (SSEC) is a densely populated coastal area that houses the main port in Latin America and the most prominent Brazilian industrial complex. Irregular occupations in preservation areas result in a disorderly increase in population, with negative social and environmental impacts. We evaluated the average annual growth of 74 slums occurring in this area and variations in water quality from 2005 to 2018. We monitor the growth of the occupied areas and estimate their respective populations. The average annual population growth was over 6% per year (p.a.). Invasions of new areas and verticalisation of already occupied areas represent 85% of the growth seen. The monthly polluting loads exceeded 450 tonnes or 2,086,000 m3, compromising the waters and local and regional public health. We strongly recommend re-urbanising the area using the resource savings caused by water loss to reduce the risks of ecosystem degradation, damage to health and disease spread. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the influence of shrimp farming on the phytoplankton community of a nearby shrimp estuary in Northeastern Brazil during a single cultivation cycle. Samples were collected from shrimp ponds and the estuary to analyse water quality variables, ecological indices and phytoplankton assemblages in both areas. Significant differences between sampling sites and over time were found for all variables. Phytoplankton density, orthophosphate and chlorophyll a content were lower in the estuary than in the ponds and were in accordance with Brazilian environmental law. Cyanophyta was abundant in the estuary and dominant in the shrimp ponds. Moreover, a significant positive correlation was found between Cyanophyta and orthophosphate. Thus, the influence of shrimp farming on the phytoplankton community was minimal or nil in the nearby estuary, as lower cell densities, a lower quantity of nutrients (especially orthophosphate) and better ecological health were found in the estuary than in the shrimp farm ponds. These findings contribute to a better understanding of the ecological balance in water bodies adjacent to aquaculture areas. Further studies should address the influence of wastewater from other aquaculture activities on the equilibrium of aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Secchi Disk Depth (Z sd) is one of the widely used water quality measurements. Controlled by variations in Optically Active Constituents, it is a key index of overall water quality. In-situ measurements of Z sd lacks spatiotemporal coverage which could be solved using remote sensing data, such as from the Sentinel-2/MSI. However, inland waters have highly variable optical properties, and that is still a challenge for the state-of-art algorithms of Z sd retrieval. One of the most promising approaches for dealing with this challenge is the use of Machine Learning methods. Moreover, predicting Z sd for large areas using high-resolution remote sensing imagery requires a high computational effort, which could be solved using Cloud-Computing platforms. Therefore, this study evaluates the use of Machine Learning (Random Forest, Extreme Gradient Boosting, and Support Vector Machines) and Semi-Analytical algorithms (SAA) for Z sd retrieval focused on Sentinel-2 imageries available in the Google Earth Engine platform to assess the clarity of the Brazilian inland waters. Machine Learning methods were calibrated and validated using a comprehensive dataset (N = 1492) collected in the last 20 years in Brazil. The results were compared with semi-analytical approaches. After evaluation with in-situ data, the best algorithm was implemented in the Google Earth Engine platform to generate Z sd maps. The calibration with in-situ data demonstrated that the Machine Learning methods outperform the SAA, with the Random Forest presenting the best results (errors lower than 22%). The results showed that when SAA were applied to the environment in which they were calibrated, the results were closer to that of machine learning methods, indicating that SAA could also be used for Z sd retrieval. The application of Random Forest to the Sentinel-2 atmospherically corrected imagery had errors of 28%, demonstrating the feasibility of the algorithm and atmospheric correction methods for predicting Z sd. [ABSTRACT FROM AUTHOR]

A great challenge for water managers and stakeholders is the maintenance and improvement of basin sustainability, tackling the ever-increasing threats and impacts. Some catchments, such as the Paranoá River basin (Central Brazil), are facing rapid urbanization, with increasing water demand and water quality impacts that threaten their sustainability. To assess this, two basin indices, the Watershed Sustainability Index (WSI) and the Water Resources System Dynamics (WRSD), were applied to the Paranoá basin in the period between 2015 and 2018. Off-the-shelf data and tailored surveys were used as information sources. The basin WRSD and WSI scores were 0.33 and 0.60, respectively, corresponding to a medium level of hydrologic and integrated sustainability. The WSI bottlenecks were the high unit water demand in the basin, and the incipient management responses with respect to the basin's environment, livelihood, and policy indicators. For the WRSD index, high water demand was the limiting sustainability factor. Adaptation measures to improve basin sustainability include effective water demand management and the establishment of new protected areas in the catchment. [ABSTRACT FROM AUTHOR]

This work aimed to analyse the water quality and identify the fungal diversity present in the skin and gills of tambatinga fish from the environmental protection area of the western lowlands of Maranhão, Brazil. The physicochemical parameters of water were analysed and microbiological tests were carried out to identify the most probable number of total coliforms and Escherichia coli. Forty tambatinga specimens were collected. In addition, skin and gill fragments were removed for fungi isolation in culture medium (BDA). Physicochemical and microbiological parameters of water, fish biometry and fungal diversity of fish in the dry and rainy periods were analysed. Results showed significant differences in the total length (TC) and weight (P) of fish in the dry and rainy periods. Microbiological data showed that the water of the four fish farms analysed in both periods are within the limits established by the National Environment Council (CONAMA) of Brazil and within limits established in complementary literature. Regarding the physicochemical parameters of water, only conductivity (F (1, 14) = 8.611; p = 0.011) and temperature had considerable differences (F (1, 14) = 11.037; p = 0.005). There was prevalence of yeasts (33%) and fungi of the genus Fusarium sp. (26%), Penicillium sp. (21%) and Aspegillus sp. (20%). The analysis of fungal diversity showed associations for sex, Aspegillus sp. (X2 = 19,600; DF = 1; p = 0,001) and the dry season, Penicillium sp. (X2 = 8,120; DF = 1; p = 0,004) and Fusarium sp. (X2 = 21.583; GL = 1; p = 0.001). It is concluded, therefore, that the harvests are within the established by the legislation of the National Environment Council—CONAMA in Brazil and complementary literature. However, it is necessary to evaluate the presence of possible mycotoxins in cultivated fish, since the most prevalent fungal species are considered to be mycotoxigenic fungi and are widely disseminated in the environment. [ABSTRACT FROM AUTHOR]