Physicochemical Parameters Of Water Research Articles

Macrobenthic Assemblages and the Influence of Microhabitat in a High-Mountain Lake (Northwest Italy)

High-mountain lakes are freshwater ecosystems situated above the tree line which are known for their remote locations and limited accessibility. These ecosystems host simplified biotic communities primarily concentrated in the littoral zone and dominated by benthic macroinvertebrates that serve as bioindicators of environmental pressures. A two-year monitoring investigation was performed in July 2022 and July 2023 at Nero Lake (Cesana Torinese, Northwest Italy). Five sites along the lakeshore were selected for sampling physicochemical water parameters and macrobenthos. All collected data were analysed to compare trends across years and within specific sites. The results revealed that Nero Lake exhibited consistent macrobenthic communities across the two years studied, but significant differences were observed in its microhabitats. This suggests that substrate type and physicochemical water parameters strongly influence community composition. Chironomidae larvae and Mollusca were the dominant species, showing distinct associations with different substrates and environmental factors from one year to another. These findings contribute to our understanding of the intricate relationships between benthic macroinvertebrates and their environments, highlighting the necessity of detailed, small-scale assessments to comprehend ecosystem dynamics and develop effective conservation strategies.

Hematological and genotoxic biomarkers in a natural population of freshwater turtles Trachemys dorbigni (Duméril & Bibron, 1835) (Testudines: Emydidae) living in an urban area in Southern Brazil.

The present study aimed to report the morphometric and hematological indices and genotoxicity of a free-life population of D'Orbigny's slider turtles (Trachemys dorbigni) living in an urban area in Southern Brazil. For that, 16 specimens were randomly captured in an urban canal that receives irregular releases of wastewater. Biometrics and external visual changes were analyzed, such as turtle shell deformities, and the presence of parasites. Blood samples were collected to evaluate the hematological profile and the presence of micronuclei and other erythrocyte nuclear abnormalities as potential mutagenic and genotoxic effects. Water physicochemical parameters were also measured. Organisms with ectoparasites (31.25%) and small carapace deformations (56.25%) were observed, but maximum carapace length and weight were considered normal for the species according to the literature. The blood profile indicated low hemoglobin and hematocrit and a high number of total leukocytes, particularly eosinophils which characterize parasitic infections. A frequency of 0.12% for the micronucleus was considered basal, but the frequency of other erythrocyte abnormalities was evident, mainly of blebbed nuclei (63.79%), indicating chromosomal damage in the early stage. The results of this study suggest that natural populations of chelonian inhabiting urbanized areas are impacted by anthropogenic activities in the surrounding environment. Furthermore, it provides comprehensive data which can serve as a comparative model for environmental monitoring studies involving turtles.

Water physicochemical quality as driver of spatial and temporal patterns of microbial community composition in lake ecosystems

This study aimed at monitoring and management of the surface water and potentially pathogenic microbes of Lake Tonga (Algeria) with respect to. It characterized the main bacterial diversity patterns of Lake Tonga and predicted from water physicochemical parameters and water quality index (WQI) the distribution of bacterial species and the main indicator groups of faecal water contamination. Water samples were taken monthly at three sampling sites of different water depths. Several physicochemical parameters were measured; of which some were included in computing WQI to characterize the water quality of the lake. Counting, isolation and bacterial identification methods were used to characterize the existing aerobic heterotrophic bacteria. The composition of the microbial community of the waterbody of Lake Tonga included an abundant culturable bacterial flora belonging to several bacterial families and whose specific richness varied between water depths of the sites sampled. Species richness of the bacteria identified phenotypically varied between 7 and 11 per sample. The site with shallow water was the richest in bacterial species, compared to moderate and deep waters. The redundancy analysis showed the main physicochemical drivers of the microbial community composition. Our findings showed that high WQI scores indicated the water quality deterioration which triggered the increase in total load of faecal indicator bacterial groups. This study identified in Lake Tonga an important culturable aerobic bacterial flora whose specific richness and distribution varied spatially following the effects of water physicochemical parameters. Lake Tonga needs an integrated management plan to mitigate human disturbances declining water quality.

Aquatic photosynthetic carbon pump driven by periodic temperature variations affects dissolved inorganic carbon and hydrochemical characteristics in a groundwater-fed reservoir

Under the influence of periodic temperature variations, biogeochemical cycling in water bodies is markedly affected by the periodic thermal stratification processes in subtropical reservoirs or lakes. In current studies, there is insufficient research on the influence and mechanism of dissolved inorganic carbon (DIC) distribution in karst carbon-rich groundwater-fed reservoirs under the coupled effects of thermal structure stratification and the biological carbon pump (BCP) effect. To address this issue, the Dalongdong (DLD) reservoir in the subtropical region of southern China was chosen as the site for long-term monitoring and research on relevant physicochemical parameters of water, DIC, and its stable carbon isotope (δ13CDIC), CO2 emission flux, as well as the reservoir's thermal stratification index. The results show that: (1) the DLD reservoir is a typical warm monomictic reservoir, which exhibits regular variations of mixing period-stratification period-mixing period on a yearly scale due to thermal structure changes; (2) DIC was consumed by aquatic photosynthetic organisms in the epilimnion during the stratification period, leading to a decrease in DIC concentration, partial pressure of CO2 (pCO2) and CO2 emission flux, and an increase in stable carbon isotope (δ13CDIC). During the mixing period, the trend was reversed; (3) During the thermal stratification, aquatic photosynthesis and water temperature were the primary factors controlling DIC variations in both the epilimnion and thermocline. Regarding the hypolimnion, calcite dissolution, organic matter decomposition, and water temperature were the dominant controlling factors. These results indicate that although carbon-rich karst groundwater provides a plentiful supply of DIC in the DLD reservoir, its availability is still influenced by variations in the reservoir's thermal structure and the metabolic processes of aquatic photosynthetic organisms. Therefore, to better estimate the regional carbon budget in a reservoir or lake, future studies should especially consider the combined effects of BCP and thermal structure variations on carbon variations.

Evaluation of Physicochemical and Microbiological Standards for Quality Packaged Drinking Water in Plastic Bags Produced by Three Companies in Korhogo in Northern Ivory Coast

Drinking water packaged in sachets is popular with the population of Korhogo in northern of Ivory Coast. The objective of this study is to evaluate the physicochemical and microbiological parameters of this water produced by three companies. Three packets of 40 sachets of water each were taken from each company and ten sachets of water were mixed to constitute the sample from each company. Physicochemical and microbiological analyzes were carried out according to ISO. Physicochemical parameters of water investigated were as follow: temperature (25.30±0.40 – 25.53±0.25), pH (7.37±0.06 – 7.67±0.23), bicarbonate (41±0.50 – 48.53±0.85 mg/L), chloride (4.34±0.03 - 8±0.43 mg/L), calcium (5.60±0.40 – 8.23±0.15 mg/L), magnesium (4.08±0.51 – 6.62±0.05 mg/L) and nitrates (0.59±0.02 – 0.83±0.03 mg/L). The results revealed that the physicochemical parameters of the water analyzed complied with WHO regulations. Concerning the microbiological parameters, results of the study are as follows: GAMs (22 °C) (6 – 113 CFU/mL), GAMs (37 °C) (6 – 89 CFU/mL), total coliforms (0 – 1100 CFU/100 mL), fecal coliforms (0 – 1100 CFU/mL), ASR (0 CFU/100 mL), S. aureus (190 – 310 CFU/100 mL) and streptococci fecal (0 – 3100 CFU/100 mL). These waters do not comply with the regulations and sample B is more loaded with microorganisms followed by sample C and finally A. However, no salmonella was identified in the samples analyzed. Consumption of this water exposes populations to health risks. It would be desirable to raise awareness among companies about hygiene conditions and employee training in order to reduce these risks.

Physicochemical and FT-IR analyses of some freshwater and inflow wastewater-treated effluents in the Eastern Cape Province of South Africa

Monitoring changes occurring in water bodies is a tool to make a sound decision on water quality management. This work investigates water quality parameters and metabolites in the Bloukrans, Buffalo, Swartkops and Tyhume Rivers in the Eastern Cape Province of South Africa. The water physicochemical parameters assessed include the dissolved oxygen, oxidation-reduction potentials, temperature, Hydrogen ion concentration, salinity, conductivity, turbidity and total dissolved solids measured with a pre-calibrated Hanna Multiparameter instrument on-site. Chemical oxygen demand, phosphate, chloride, ammonium, sulphate and nitrate ions were measured in the laboratory with a UVmini spectrophotometer. FT-IR analysis of extracted metabolites was done on a Perkin Elmer FT-IR spectrometer. The result shows that upstream river samples have lower COD values and below the detection level in some. The concentrations of phosphate, chloride, ammonium, sulphate and nitrate ions were above the recommended values in the wastewater effluents, midstream and downstream river samples. FT-IR peaks similar to vinylidene, saturated aliphatic aldehydes, aryl aldehydes, primary amines, hydantoin amides, halogen, and organofluorides were common in the wastewater effluent samples and the receiving rivers. Grahamstown treated wastewater effluents and its receiving Bloukrans River were distinguished with absorption peaks of urethane and aromatic aldehydes. Absorption peaks of sulphonyl halides were present only on the spectra of treated wastewater effluents of Alice and the receiving downstream Tyhume River. Multivariate analysis shows correlations between the water samples from different geographical locations and treated wastewater effluents. It is concluded that the quality of the rivers was very poor and more efforts are needed to make the treated wastewater conform to the acceptable standard for a sustainable aquatic ecosystem.

Influence of physicochemical parameters on the biodiversity indices of fresh water snails in selected rivers of Osun State, Nigeria

Studies have investigated the influence of environmental factors on distribution of vectors of parasites of public health importance but little is known on the role of these factors on the biodiversity indices of the vectors. This study is therefore set to assess the role of physicochemical parameters on biodiversity indices of fresh water snails. The study was carried out in three randomly selected communities across the three senatorial regions of Osun state namely Ere Ijesha, Ede and Erin-Osun. Through reports from community members, a mostly visited river from each community was selected. Three contact points with evident human water contact were identified for snail and water sampling. Morphological identification of snails was done. Physicochemical parameters of water were measured while snail biodiversity indices were determined using Shannon index, snail richness and abundance. Relationship between continuous variables was determined using Spearman’s correlation. There is a significant difference between pH values of Ere Ijesa and Erin Osun while Ede and Erin Osun also show a significant difference in their chloride concentration. A significant positive correlation was observed between pH and diversity (correlation coefficient (rho)= 0.64, P<0.05), pH and Bulinus abundance (rho= 0.68, P< 0.05), chloride and snail richness (rho= -0.65, P< 0.05), chloride and diversity (rho= -0.88, P< 0.01), BOD and snail richness (rho= -0.78, P < 0.05), BOD and diversity (rho= -0.64, P<0.05) COD and snail richness (rho= -0.61, P< 0.05). Ede had highest diversity index while Ere Ijesa had highest Bulinus abundance. Erin Osun was the least in terms of snail richness, diversity and Bulinus abundance. Snail diversity, snail richness and Bulinus abundance significantly differ across the sampling locations (P< 0.01). Physicochemical parameters such as pH, chloride content, BOD and COD have significant role to play in fresh water snail richness, snail diversity and Bulinus abundance.

Recent Issues and Challenges in the Study of Inland Waters

This paper addresses several important problems and methods related to studies of inland waters based on the existing scientific literature. The use of UAVs in freshwater monitoring is described, including recent contact and non-contact solutions. Due to a decline in biological diversity in many parts of the globe, the main threats are described together with a modern method for algae and cyanobacteria monitoring utilizing chlorophyll a fluorescence. Observed disturbances in the functioning of river biocenoses related to mine waters’ discharge, causing changes in the physico-chemical parameters of waters and sediments, give rise to the need to develop more accurate methods for the assessment of this phenomenon. Important problems occurring in the context of microplastic detection, including the lack of unification, standardization and repeatability of the methods used, were described. In conclusion, accurate results in the monitoring of water quality parameters of inland waters can be achieved by combining modern methods and using non-contact solutions.

Ichthyofaunal Diversity and Physico-chemical Analysis of Water in the Middle Stretch of Vembanad Lake, Kerala, India

The status of finfish and shellfish diversity and monthly variation in their distribution and abundance were investigated in the middle stretch of Vembanad Lake at 4 selected sites in Kerala. The study was carried out for a period of 7 months from December 2022 to June 2023. In total 31 species of finfishes and shellfishes belongs to 8 orders, 23 families and 29 genera were recorded from the study areas. Calculated values of Biodiversity indices were Shannon Weiner diversity index highest at Vaikom (3.4022), Simpson diversity index highest at Manakunnam (0.9538), Margalef’s richness index highest at Manakunnam (4.346) and Pielou’s evenness index was highest at Thaneermukkom (0.8573). Etroplus suratensis and Villorita cyprinoides were the most abundant species from all four study sites. Three species are under the category of threatened they are Oreochromis mossambicus, Horobagrus brachysoma and Hyporhampus xanthopterus. The result of the present study indicates that the Northern part of Thaneermukkom barrage is endowed with rich edible fish fauna. The physicochemical parameters of water were analyzed during the pre-monsoon and monsoon periods. Salinity was higher on the Northern side of the barrage. During the pre-monsoon period temperature, EC, TDS, alkalinity and salinity were high and during the monsoon period hardness, DO, BOD, Phosphate and Nitrate were high when compared with pre-monsoon but all are within the recommended limit.

Assessment of Physicochemical Parameters in Selected Water Bodies in Laguna, Philippines

This study was aimed to examine the frequent variations in four selected physico-chemical parameters of surface water of two lakes in Laguna: Laguna de Bay in Calamba City and Sampaloc Lake in San Pablo City. Parameters such as conductivity, dissolved oxygen (DO), pH, and temperature were determined using in-situ water quality tester. The two lakes are both freshwater body, different data are collected and observed throughout the sampling. Due to various anthropogenic activities, the lakes are biotically affected. The water quality of the two important lakes in Laguna have been compared in different parameters like pH, DO, conductivity, water temperature and color. The result indicates that both lakes are within the standard (25-31°C) of DENR Administrative Order (DAO 2016-08 for Class C), but except for water temperature which exceeds the standard value (36.37°C mean values). The results support insights about the future effects of increased water temperature on fish management and the lake ecosystem for numerous aquatic purposes. This is also for the management and call on action for the residents and local government unit in said municipalities of Laguna especially after pandemic season.

Physico-chemical parameters, heavy-metals and soil particle distribution of Liverpool axis of Badagry Creek, Lagos, South-western Nigeria

Heavy metal pollution is a serious issue of concern worldwide because it can bioaccumulate in aquatic organisms and transferred through the food chain to harm humans. Information on the heavy metal pollution of aquatic ecosystems is essential to protect life. Therefore, this study was undertaken to determine the physico-chemical parameters of surface water, soil particle distribution (SPD) and heavy metals in two shellfish species in Liverpool axis of Badagry Creek, Lagos State, Nigeria. Twelve physico-chemical parameters and four heavy metals were studied using standard methods. The results showed that maximum temperature was 31.0±1.00˚0C; turbidity, 118.00±50.90NTU; dissolved oxygen (DO), 13.3±3.8mg/l; dissolved carbon dioxide (COD), 67.7±19.1mg/l; total hardness, 173.0±63.1mg/l; conductivity, 39.2±12.2μS/cm and chloride was 2.0±0.7mg/l. Water quality parameters showed significant spatial variations (p<0.05) among sample stations. Pearson’s correction matrices revealed high correlation of DO with nitrate (r = 0.61), total hardness (r=0.62) and COD (r=0.52) at p<0.05. The heavy metal concentrations (mg/kg) in the shellfishes, Callinectes pallidus and Farfantepenaeus notialis were: lead, 0.05±0.05 and 0.04±0.02; copper, 2.03±0.17 and 0.84±0.18; zinc, 3.51±0.44 and 1.99±0.2 and cadmium, 0.02±0.02 and 0.03±0.04 respectively. These levels were not above the WHO standards (for heavy metals in fish and shell fish). The sediment particle distribution (SPD) showed that Liverpool Jetty had 19.05% coarse sand and 43.91% fine sand, while Apapa Jetty had the highest amount of clay 45.29% in the environment. Heavy metals in shellfishes were above the WHO standards.

Prevalence, genetic diversity, and antimicrobial susceptibility of Vibrio spp. infected gilthead sea breams from coastal farms at Damietta, Egypt

BackgroundVibriosis is one of the most serious bacterial diseases and causes high morbidity and mortality among cultured sea breams. This study was undertaken to track the surveillance of Vibrio infection and its correlation to environmental factors. A total of 115 gilthead sea breams were collected seasonally from a private earthen pond fish farm in the Shatta area of Damietta, Egypt from September 2022 to July 2023. Physicochemical parameters of water were analyzed, and heavy metal levels were measured. The fish samples were subjected to clinical, bacteriological, Enterobacterial Repetitive Intergenic Consensus (ERIC) fingerprinting, and hematoxylin and Eosin histopathological staining.ResultsThe results revealed significant variations in the water quality parameters over different seasons, in addition to an increase in heavy metals. Naturally infected fish showed external signs and postmortem lesions that were relevant to bacterial infection. Two dominant Vibrio subspecies of bacteria were identified: V. alginolyticus (205 isolates) and V. fluvialis (87 isolates). PCR confirmed the presence of V. alginolyticus using the species-specific primer collagenase at 737 bp. The highest prevalence of V. alginolyticus was detected during the summer season (57.72%), and the lowest prevalence was observed in autumn (39.75%). The correlation analysis revealed a positive relationship between V. alginolyticus and water temperature (r = 0.69). On the other hand, V. fluvialis showed a high prevalence during the autumn season (25.30%) and the lowest prevalence during the summer season (10.56%), where it was negatively correlated with water temperatures (r =—0.03). ERIC fingerprinting showed genetic variation within the Vibrio isolates. Antimicrobial susceptibility testing revealed sensitivity to ciprofloxacin and doxycycline, and resistance to amoxicillin and erythromycin. The multiple antibiotic resistance (MAR) index values for V. alginolyticus and V. fluvialis ranged from 0.3 to 0.7, with a multi-drug resistance pattern to at least three antibiotics. Histopathological alterations in the affected tissues revealed marked hemorrhage, vascular congestion, and hemosiderosis infiltration.ConclusionThis study provides insights into the potential propagation of waterborne diseases and antibiotic resistance in the environment. Ensuring that the environment does not serve as a reservoir for virulent and contagious Vibrio species is a critical concern for regional aquaculture industries. Therefore, we recommend implementing environmental context-specific monitoring and surveillance tools for microbial resistance.

Impacts of water physicochemical parameters on schistosomiasis vector snail distributional-abundance and infectivity rate in South-Eastern Nigeria.

Schistosomiasis, an NTD, poses public health problems for rural communities. The parameters controlling its intermediate hosts are scarcely studied. 24 human-water contacts were sampled for 12 months to understand the impacts of water parameters on the vector. Sampling was done by monthly handpicking of the snail vector with a net to analyze the water parameters (temperature, dissolved oxygen, conductivity, depth, and rainfall). 546 snails recovered from the water sites showed that Bulinus globosus had the highest occurrence (50.5%), followed by Lanistes varicus (27.7%), and Bulinus truncatus species (3.7%). Ohaukwu LGA recorded the highest occurrence of freshwater snails at 55.3%, while Amovu stream had the highest number of snails with an overall abundance of 35.9%. May had the highest cercariae shedding at 26%, followed by June at 20%. No shedding occurred in September, November, December, and January. The infectivity rate of freshwater snails collected showed a significant difference based on the month (X2=6590.079, p- value=0.006). The study reveals that water physicochemical parameters significantly influence the abundance of intermediate snail hosts, with all parameters positively correlated except for temperature, conductivity, and TDS. This poses a significant public health threat due to vector snails' presence.

Human Health Risk Assessment of Some Trace Metals through Fish Consumption from Qua Iboe River, Oruk Anam, Nigeria

Food consumption is an important route of human exposure to organic chemicals. To assess the health risks associated with these chemicals due to fish consumption, the levels of trace metals (Cd, Cr, Ni, Cu, V, Pb and Sn) in water and fish from Qua Iboe River were assessed using atomic absorption spectrometry (ASS). Physicochemical parameters in water were determined using standard methods. The levels of physicochemical parameters in water were within permissible limits set by World Health Organisation (WHO). The levels of trace metals in water samples varied from one sampling location to another and ranged from 0.01± 0.01 to 0.10 ±0.00mg/L in wet season and from 0.01± 0.01 to 0.08± 0.01 mg/L in dry season. In fish, the levels ranged from 0.01± 0.01 to 0.61 0.01 mg/kg in wet season and from 0.02± 0.01 to 0.51± 0.01mg/kg in dry season. Results of physicochemical parameters showed variations across the sampling locations and seasons. Human health risk of trace metals contamination due to consumption of the fish revealed that hazard quotient (HQ) values were all less than unity (HQ <1). It therefore means that there is no health risk implication for consumers of commercial fish from the river. From the results, routine monitoring of these metals in studied river is strongly recommended to check escalation. Riverine communities should be educated by government on danger associated with indiscriminate disposal of wastes into aquatic environment.

Spatial and temporal distribution of physicochemical parameters of water in Gorgan Bay (the southeast of the Caspian Sea - Iran): Fundamentals for the monitoring of the Caspian Sea coastal areas

Gorgan Bay as a main part of the Miankaleh (a natural biosphere reserve registered by UNESCO) is one of the richest ecological area in the West Asia and very important internationally recognized refuge for the wildlife. To date, multi physicochemical parameters have not been examined on a large scale. To fill this knowledge gap, the present study aimed to explore the seasonal and spatial variability of water quality parameters of the bay. The results showed that except for depth and transparency, there are significant variations in most parameters across the four seasons. The patterns of these changes in the bay vary, as evidenced by a comparison of the distribution maps of the various factors throughout the year. Notably, alkalinity declined from east to west, reaching its highest levels at important entry points such as the Qarasu River, Bandar-Gaz, and the pier. TDS, on the other hand, increased westward, reaching its highest concentration in the shallow western regions. Maximum depth (310 cm) and transparency (250 cm) were observed in the central bay. While the pH was higher in deeper areas, the distribution of PO4 was more uniform. With lower levels in the east (salinity = 0.40 ‰) and higher levels in the west (salinity = 28.9 ‰), the salinity showed a coherent gradient. Agricultural land use in the basin of the bay and fluxes of nutrients and sediments of the rivers entering the bay has significant contribution to the bay pollution situation. These results will serve as a guide for improving our understanding of the Gorgan Bay ecosystem. They also have implications for informed conservation and management plans adapted to the specifics of this special region within the Caspian Sea.

Assessment of surface and groundwater quality in Tikamgarh city, Madhya Pradesh, India

Surface water and groundwater are primary resources for communities living in arid and semi-arid regions. The expansion of industrial and agricultural practices has raised pressure on natural resources. Water quality assessment provides valuable information about potential of resources for intended uses. The correlation study was carried out on the physicochemical parameters of surface water and groundwater in the Tikamgarh city. The physicochemical parameters, such as pH, total dissolved solids (TDS), total hardness (TH), calcium (Ca2+), magnesium (Mg2+), total alkalinity (TA), sulphate (SO42-), fluoride (F-), iron (Fe), nitrate (NO3-), chloride (Cl-) and turbidity were analysed to determine correlation between parameters. The grab sampling technique was adopted to collect water samples from selected dug wells and reservoirs. The results of physicochemical parameters were fitted in the correlation coefficient equation to predict probable values of different parameters for selected locations. Results of the correlation study showed that calcium and TH are strongly correlated, followed by TH with chloride. However, Ca2+, TH, Cl-, TA, TDS, SO42-, and iron show a high correlation. The findings show that water quality can be managed by controlling TH and TDS concentrations through conventional and non-conventional treatment methods.

Limnological Studies Related to Physico-Chemical Parameters of Nizamsagar Reservoir, Kamareddy District, Telangana, India

The Nizamsagar Reservoir is one of the oldest irrigation projects in India, constructed across the Manjeera River, a tributary of the Godavari River. The present study aimed to analyse15 different water parameters of Nizamsagar Reservoir from June 2021 to May 2022 from two different locations. Standard methods were used for the analysis of various physico-chemical parameters, and correlation coefficients were calculated to determine the relationships between different types of physico-chemical parameters by using MS Excel software. All the physico-chemical parameters of reservoir water are within the permissible limits according to the standard methods of APHA and AWWA.

Ecological degradation of a fragile semi-arid wetland and the implications in its microbial community: The case study of Las Tablas de Daimiel National Park (Spain)

Las Tablas de Daimiel National Park (TDNP, Iberian Peninsula) is a semi-arid wetland of international significance for waterfowl and serves as a migratory route for various bird species. However, TDNP presents strong anthropization and fluctuating water levels, making it a highly fragile ecosystem. Water physico-chemical parameters and microbial diversity of the three domains (Bacteria-Archaea- Eukarya) were analysed in Zone A and Zone B of the wetland (a total of eight stations) during spring and summer, aiming to determine how seasonal changes influence the water quality, trophic status and ultimately, the microbial community composition. Additionally, Photosynthetically Active Radiation (PAR) was used to determine the trophic status instead of transparency using Secchi disk, setting the threshold to 20–40 μmol/sm2 for benthic vegetation growth. In spring, both zones of the wetland were considered eutrophic, and physico-chemical parameters as well as microbial diversity were similar to other wetlands, with most abundant bacteria affiliated to Actinobacteriota, Cyanobacteria, Bacteroidota, Gammaproteobacteria and Verrumicrobiota. Methane-related taxa like Methanosarcinales and photosynthetic Chlorophyta were respectively the most representative archaeal and eukaryotic groups. In summer, phytoplankton bloom led by an unclassified Cyanobacteria and mainly alga Hydrodictyon was observed in Zone A, resulting in an increase of turbidity, pH, phosphorus, nitrogen, chlorophyll-a and phycocyanin indicating the change to hypertrophic state. Microbial community composition was geographical and seasonal shaped within the wetland as response to changes in trophic status. Archaeal diversity decreases and methane-related species increase due to sediment disturbance driven by fish activity, wind, and substantial water depth reduction. Zone B in summer suffers less seasonal changes, maintaining the eutrophic state and still detecting macrophyte growth in some stations.This study provides a new understanding of the interdomain microbial adaptation following the ecological evolution of the wetland, which is crucial to knowing these systems that are ecological niches with high environmental value.

The predictive model of hydrobiological diversity in the Asana-Tumilaca basin, Peru based on water physicochemical parameters and sediment metal content

The hydrobiological diversity in the basin depends on biotic and abiotic factors. A predictive model of hydrobiological diversity for periphyton and macrobenthos was developed through multiple linear regression analysis (MLRA) based on the physicochemical parameters of water (PPW) and metal content in sediments (MCS) from eight monitoring stations in the Asana-Tumilaca Basin during the dry and wet seasons. The electrical conductivity presented values between 47.9 and 3617 μS/cm, showing the highest value in the Capillune River due to the influence of geothermal waters. According to Piper's diagram, the water in the basin had a composition of calcium sulfate and calcium bicarbonate-sulfate. According to the Wilcox diagram, the water was found to be between good and very good quality, except for in the Capillune River. The Shannon–Wiener diversity indices (H′) were 2.62 and 2.88 for periphyton, and 2.10 and 2.44 for macrobenthos, indicating moderate diversity; for the Pielou's evenness index (J′), they were 0.68 and 0.70 for periphyton, and 0.68 and 0.59 for macrobenthos, indicating similar equity, in the dry and wet seasons, respectively, for both indices. In the model there were three cases, where the first two cases only worked with PPW or MCS, and case 3 worked with PPW and MCS. For case 3, the predicted values for H′ and J′ of periphyton and macrobenthos concerning those observed presented correlation coefficients of 0.7437 and 0.6523 for periphyton and 0.9321 and 0.8570 for macrobenthos, respectively, which were better than those of cases 1 and 2. In addition, principal component analysis revealed that the As, Pb, and Zn contents in the sediments negatively influenced the diversity, uniformity, and richness of the macrobenthos. In contrast, Cu and Cr had positive impacts because of the adaptation processes.

Water Quality Assessment and Heavy Metal Levels in Mudskipper (Periophthalmus Papilio), Sediments and Water of Mangrove Swamps, Rivers State, Nigeria

A study was conducted to determine the physicochemical parameters of surface water and heavy metal concentrations in the mudskipper (Periophthalmus papilio) fish, sediments, and water collected from the Ikpukulu, Kalio, and Ogoloma swamps of Okrika Local Government Area, Rivers State, Nigeria and analysed using standard methods. All samples were collected for six months from three stations in 2023. The results indicate that pH and temperature values were significantly lower across stations in terms of physicochemical properties than standards. However, there was a significant increase in electrical conductivity, total dissolved solids, and salinity. Ikpukulu had the highest EC (1917 uS/cm), while Kalio had the highest salinity (333.3 ppm). All stations had significant decreases in dissolved oxygen (DO) and biological oxygen demand (BOD), with Ogoloma having the lowest values (DO: 3.2 mg/L, BOD: 2.9 mg/L). Copper and chromium levels were significantly higher than the standards in all stations, while cadmium levels were not significantly different from those in the standards. As compared with the standards, copper levels in water samples were considerably higher, especially in Ogoloma (2.03 mg/kg). Ogoloma had a higher concentration of chromium. Cadmium levels decreased significantly at all stations for the mudskipper (P. papilio). The copper levels in Ogoloma and the chromium levels in Ikpukulu were significantly higher than those in standards. The results of the study suggest an increase in heavy metal concentrations in the mangrove swamp region, emphasising the need for proactive measures to mitigate activities that may adversely affect the aquatic ecosystem and the communities that depend on it.