Mahananda River Research Articles

Environmental and human health risk associated with heavy metals in sediment of a tropical river in India

ABSTRACT Heavy metals persist in the sediment and can induce toxicological effects on living organisms. For analysing the risk of heavy metals, geochemical fractionation is beneficial. These geochemical fractions or speciations help to determine the heavy metals availability, mobility, toxicity, enrichment, and various risks. Here, we show how heavy metal contamination of sediment poses risks to both the ecosystem and human beings. We found significant Zn, Co and Cd contamination by analysing the geoaccumulation index. We also observed higher geoaccumulation index values for the pre-monsoon season than the post-monsoon one. Furthermore, pollution load index indicated gradual contamination of heavy metals in the sediments. This study's risk assessment and modified risk assessment codes showed low or no risk, but contamination factors indicated moderate to high risk. Our analysis of the effective range median mean quotient revealed some sampling stations as medium to high-priority sites. Similarly, probable effect level mean quotient designated some sampling stations as medium-low priority sites. We anticipated a moderate to significant mortality effect on the organisms from toxicity unit index values. Potential ecological risk index indicated a very high ecological risk on the Mahananda River. Furthermore, we predicted non-carcinogenic health hazards and carcinogenic health risks in the river's sediment.

Characterization of a hemolytic and antibiotic-resistant Pseudomonas aeruginosa strain S3 pathogenic to fish isolated from Mahananda River in India.

Virulent strain Pseudomonas aeruginosa isolated from Mahananda River exhibited the highest hemolytic activity and virulence factors and was pathogenic to fish as clinical signs of hemorrhagic spots, loss of scales, and fin erosions were found. S3 was cytotoxic to the human liver cell line (WRL-68) in the trypan blue dye exclusion assay. Genotype characterization using whole genome analysis showed that S3 was similar to P. aeruginosa PAO1. The draft genome sequence had an estimated length of 62,69,783 bp, a GC content of 66.3%, and contained 5916 coding sequences. Eight genes across the genome were predicted to be related to hemolysin action. Antibiotic resistance genes such as class C and class D beta-lactamases, fosA, APH, and catB were detected, along with the strong presence of multiple efflux system genes. This study shows that river water is contaminated by pathogenic P. aeruginosa harboring an array of virulence and antibiotic resistance genes which warrants periodic monitoring to prevent disease outbreaks.

Classifying the landscape units of the Mahananda River basin using hydrogeomorphic diversity model

Classifying the landscape units of the Mahananda River basin using hydrogeomorphic diversity model

A micro scale study of Mahananda river bank erosion and temporal Land use land cover scenario with special reference to natural forest in the foothills of Darjeeling Himalaya, West Bengal, India

Bank erosion is an inevitable vestige of past to evident fluvial dynamics in relation to its discharge and velocities and work-load in view of its load washed or unwashed. The central idea is best suited to study the case of River Mahananda alias Mahanadi within the Upper Mahananda River basin area having similar kind of attestation of facts. The present study needed extraction of satellite imageries of Landsat from USGS sites associated with its processing and ultimately to frame out the temporal scenes through NDVI technique to visualize if the forest cover is at all influenced by bank erosion or not or for specific scales whatever is the reality. The inference registered heavy scouring along the hugging banks with temporal avulsions and bed aggradation. The rates of change of foothill forest areas and variation of cultivable areas for a period of 30 years initiating from 1990 is addressed to study here.

Oxidative stress responses in Puntius sarana collected from some environmentally contaminated areas of River Mahananda, Malda, West Bengal.

Environmental contaminant-induced aquatic pollution threatens the aquatic biota and causes oxidative stress in the aquatic organisms. Mahananda River, the lifeline of Malda district, West Bengal, India is presently experiencing environmental crisis due to increasing level of contaminants which deteriorate the water quality along with its biota. Puntius sarana is an economically important edible fish species in the River Mahananda that seems to be declining, owing to environmental pollution. Therefore, the present study aimed to investigate the health status of Puntius sarana by evaluating different oxidative stress biomarkers. The sampling sites were selected according to population density and possible anthropogenic activities around the River Mahananda. Significantly higher concentration of Zn2+ (p < 0.01), Cu2+ (p < 0.05) in different sampling sites has been observed, compared to the control site. Results of the water quality index and water pollution index confirmed the pollution status of different sampling sites. Significant decreases were observed in superoxide dismutase and catalase activity, compared to the control. The decreased values of reduced and oxidized glutathione ratio also indicate the increased oxidative stress of Puntius sarana. The principal component analysis showed that total hardness, calcium hardness, nitrate, manganese, zinc, copper, iron and arsenic were the main descriptors of the aquatic pollution. Therefore, findings of the present study demonstrate the ecotoxicological impacts of various anthropogenic activities which necessitates the need for continuous monitoring of the fresh water resources and its ecosystem from further contamination.

Bacterial Community Structure in Informal Solid Waste Dumping Site of Mahananda River Bank, West Bengal, India

Bacterial Community Structure in Informal Solid Waste Dumping Site of Mahananda River Bank, West Bengal, India

Impact of Sediment Quarrying on the Channel Morphology of the Upper Mahananda River, West Bengal, India

Impact of Sediment Quarrying on the Channel Morphology of the Upper Mahananda River, West Bengal, India

Assessment of urban river water quality using modified NSF water quality index model at Siliguri city, West Bengal, India

Rivers are the source of freshwater for any urban community and hence, monitoring of river water is an obligatory yet challenging task. This study was conducted in a subtropical urban river in India with the view of developing a quantitative approach to assess its water quality (WQ) status. For the purposes of this study, water samples were collected from five locations across the Mahananda River main streams encompassing both urbanised and non-urbanised parts of the Siliguri city during April to June of 2021 and collected samples were analysed for fourteen common WQ indicators: pH, Temperature, Conductivity, TDS, Turbidity, Total Hardness (TH), DO, BOD, COD, NO 3 − , PO 4 3− , Cl − , Fecal Coliform (FC) and E. coli for assessing water quality. In order to obtain WQ status, the present study utilised the modified national sanitation foundation (NSF) water quality index (WQI) model, whereas the crucial WQ indicators were identified using the principal components analysis (PCA) technique. All WQ indicators were considered to compute the NSF-WQI except water pH and TH. Most WQ indicators were breached the guideline values of the Bureau of Indian Standards (BIS) and Indian Standards (IS) for surface water. The modified NSF-WQI results revealed that the Mahananda River water quality was “good” to “medium” quality and the water is only suitable for limited purposes under certain conditions. The findings of this study provided evidence that the river WQ is heavily influenced by urban pressures because relatively “good” WQ was found at the sampling location of the outer part of the urban area. The results of this research could be effective in improving the Mahananda River's water quality and maintaining its complex ecosystem in order to ensure sustainable urban growth.

Use and perception of ecosystem services on an urban river: a case from lower Gangatic plain, Eastern India.

Rapid urbanisation and climate change have emerged as serious threats to ecosystem services (ES), and the deterioration of ES is affecting the quality of life. The research on ES was long performed from monetary perspectives and neglected evaluation of ES from social perspectives. This study proposes a social appraisal approach for evaluating urban river ES on Mahananda River in English Bazar Urban Agglomeration (EBUA), Eastern India, through the social perception and preference (SPP) approach. SPP approach was performed using the importance-performance analysis (IPA) model and satisfaction index (SI). Mann-Whitney U test, correlation analysis, and a median regression were performed to better understand the overall scenario on the perception and preference for ES. The findings of the study showed that (i) the stakeholder residing along the left bank of the river were highly dependent on provisioning ES; (ii) there was limited access to cultural ES provided by the river; (iii) the stakeholders residing along the left bank and slum stakeholders residing along the right bank of the river were more dependent on rive ES; (iv) relatively higher discrepancy was reported from recreation, aesthetic, and bio-diversity; (v) satisfaction level on ES was relatively low to the stakeholder residing along the left bank (50%); and (vi) as per improvement index (II), recreation, aesthetic value, bio-diversity, and purification of water must be prioritised to meet the societal needs. Thus, the study's findings can be very effective in implementing actions for sustainable holistic river ES management through the SPP approach.

Soil-landform relationship and pedogenesis of flood plain soils of Mahananda sub-basin, Bihar

Alluvial flood plain soils are one of the major soil groups in northern Bihar and are highly heterogeneous as a result of the hydromorphic environment in which they are formed. Hence, the present investigation was carried out to understand the soil-landform relationship in Katihar district of Bihar. Five major landforms like old alluvial plains (1.97%), young alluvial plains (35.64%), meander plains (30.85%), flood plains (25.35%) and, char land and point (4.5%) were identified after visual interpretation of Sentinel-2 data in conjunction with survey of India toposheet and digital elevation model (SRT DEM). The detailed soil survey was carried out to understand the variability in the study area and 200 soil profiles were studied in different identified landforms. The soils of active alluvial plain (flood plain, char land and point bar) showed wide range of soil morphological properties with lithological discontinuities. Low chroma and value in soils of meander plain due to poor drainage conditions and high groundwater table showed gleying characteristics. The soils of young alluvial plain and active alluvial plain showed irregular distribution of clay content, cation exchange capacity (CEC) and organic carbon (OC). This study indicates that the soil-landform relationship in alluvial floodplains of Mahananda sub-basin partially followed due to mass movement of sediments from Himalayas, periodic flooding and deposition of alluvium during different fluvial cycles of Mahananda river and its tributaries. This was further confirmed by study on pedogenic indices of different landforms. The study on pedogenic indices in two selected sites (window area) away from the Mahananda river like fine sand/total sand, very fine sand/total sand, sand/silt, silt/clay, index of weathering and CEC/clay in the study area doesn't follow the trend in the flood plain as compared to nearly stable land. This may be due to the effect of shifting of river course and their tributaries in the selected two window areas across the different landforms. To overcome the above mentioned problems in soil-landform relationship in the study area, the identified landforms were further sub-divided based on the local factors like percentage of crop cover and moisture content. In revised landforms soil types present in each landform showed soil-landform relationship. Thus, the knowledge on soils in relation to landforms vis-a-vis soil properties and their pedogenesis is useful in understanding their potentials and problems for sustainable land use planning.

Assessment of bank erosion and its impact on land use and land cover dynamics of Mahananda River basin (Upper) in the Sub-Himalayan North Bengal, India

Bank erosion is the predominant character of River Mahananda in the Sub-Himalayan North Bengal. The present study aims to identify the bank erosion mechanism as well as the impact of river bank erosion on land use and land cover (LULC) dynamics of the study area. Survey of India (SOI) topographical map 78 B/5 (1975) and satellite imageries for the temporal year of 1991 and 2019 from USGS have been used for the study. For the assessment of bank erosion process Bank erosion hazard index (BEHI) model has been adopted here. The channel migration has been delineated by the superimposition of temporal bank lines extracted from the temporal satellite imageries. LULC analysis has been carried out through the supervised classification technique using remote sensing and GIS tools. Form the assessment of BEHI it can be visualized that the scores have been ranging from 30.75 to 44.30 which indicates high to very high vulnerable areas under fluvial erosion. The channel migration for the temporal period from 1991 to 2019 is ranging from 7.72 to 411.16 m along the studied reach which reflects the high erosion effectiveness. From LULC classes it has been assessed that settled or built-up areas have been increased and the water body is gradually decreased overall in the study area. The study resulted that the river bank erosion has its direct impact on land use of the studied area. In the study vulnerable sites to fluvial erosion have been delineated and unplanned land use can be managed through sustainable way.

Water Quality Assessment for Drinking and Irrigation Purposes in Mahananda River Basin of Bangladesh

Water Quality Assessment for Drinking and Irrigation Purposes in Mahananda River Basin of Bangladesh

Assessing the Status of Changing Channel Regimes of Balason and Mahananda River in the Sub-Himalayan West Bengal, India

Rapid infrastructural development, triggered by the economic policies implemented in 1991, subsequently modified the river channel planform of the Terai region of northern West Bengal, India, through perceptible channel fragmentation, excessive in-channel sediment mining and rampant landuse alterations of the floodplains. In this context, this study has attempted to assess the impacts of anthropogenic interventions on fluvial regime of the lower reaches of Balason and Mahananda River of the sub-Himalayan region over the last 30 years by adopting a combined methodological framework of remote sensing and field survey. Results showed that initially the naturally vegetated areas had converted into crop land and grass land, tea plantation or bare land, and afterwards, the majority of it had been converted into built-ups. Besides, a noticeable amount of channel narrowing was directly proportionate to unrestricted sediment mining and embanking of the river channels, evidenced between 1987 and 2017. Comparison of measured multi-temporal channel width along with cross-profiles showed remarkable channel narrowing (18.8 m/year) as well as significant bed lowering (3.15 m). Studies reveal that the rivers have started showing signs of losing their existing equilibrium condition and if that happens then that will lead to the sinking of the ground water table, decreasing flood occurrence interval, destabilization of existing infrastructures associated with rivers, and destruction of river ecology. In order to restore the state of socio-hydrological as well as eco-hydrological amenities of these rivers, certain recommendations have also been made towards promoting the wise use of riverine resources by the local communities and policy makers.

Human health risk assessment of heavy metals in major carp (Labeo rohita) of Mahananda river in Northern India

Human health risk assessment of heavy metals in major carp (Labeo rohita) of Mahananda river in Northern India

Water quality assessment of a tropical river using water quality index (WQI), multivariate statistical techniques and GIS

Mahananda River is an important river in India and Bangladesh, as the people of both the countries use the water extensively, without sufficient and reliable information about water qualities and pollution status. The purpose of this study is to evaluate the water quality of the river and to analyse the suitability for drinking, agricultural and industrial uses. This is why this study on the Mahananda River is extremely important for the region. For this study, samples from fourteen sampling stations were collected in pre-monsoon and post-monsoon seasons in 2016 and water quality index (WQI), agriculture and industry-related indices were computed. WQI values designated two sampling stations out of fourteen sampling stations as ‘very bad’ category and another two sampling stations as ‘bad’ category. The pH values of some sampling stations slightly exceeded the upper permissible limit. USSL diagram analysis classified two samples of pre-monsoon season in C2S1 category which indicates a medium salinity and low sodium water. Magnesium hazard values of four sampling stations are above 50% suggesting not suitable for irrigation. However, some indices like sodium per cent, residual sodium carbonate and residual sodium bicarbonate, Kelly’s index, permeability index and potential salinity allow the water for use in irrigation purposes. Langelier Saturation Index and aggressive index values designate the water as moderately aggressive or non-aggressive. Ryznar Stability Index values designate the water as ‘aggressive’ or ‘very aggressive’ indicating unsuitability for industrial uses. Sampling stations S-1, S-2, S-8 and S-14 need special attention.

Health risk assessment and spatial variations of dissolved heavy metals and metalloids in a tropical river basin system

Abstract River water is too much vulnerable to pollution as it is exposed to a large number of pollutants through natural and anthropogenic activities. Mahananda River is an important river in West Bengal and Bangladesh without having prominent research information about its water quality and pollution status and is likely to be under the threat of pollution by practical experience. The study was conducted to identify the dissolved heavy metals and metalloids in the water and their concentrations; to analyse metal(loid) pollution status through Nemerow index (Pn) and heavy metal pollution index (HPI); to evaluate the non-carcinogenic human health hazards by hazard index (HI) and to anticipate the incremental lifetime cancer risk (ILCR) by index analysis. For this purpose 54 samples were collected from 27 sampling stations in pre-monsoon and post-monsoon seasons. Eleven metal(loid)s (Mn, Cr, Fe, Cu, Zn, Ni, Co, As, Cd, Pb and Hg) were tested and identified with concentrations considerably below from their regulatory standards indicating safe for drinking purpose. Pearson’s correlation analysis and principal component analysis (PCA) reveal the sources of these metal(loid)s as both geogenic and anthropogenic. HPI and HEI analysis permit the water as suitable for use but Pn index designates one sampling station as heavily polluted and a few stations as slightly polluted in pre-monsoon. HIAdult analysis reveals that seven sampling stations in pre-monsoon and two sampling stations in post-monsoon exceeded the limiting value (HI ≤ 1) of hazards. HIChild values were found greater than one (>1) at six sampling stations in the pre-monsoon season. ILCR analysis predicts that 15 sampling stations (55.55%) in pre-monsoon and six sampling stations in post-monsoon have crossed the cancer risk limiting value (ILCR > 1.0 × 10−4). As the study area does not possess any heavy industries, the metal(loid) pollution occurs mainly from heavily populated municipal zones like Siliguri, Barsoi and Malda town. The pre-monsoon values of different indices are greater than the post-monsoon ones because of the low quantity of water available and flow rate that increase the concentrations of metal(loid)s in river water. Moreover, some pollutants are washed out with heavy water during monsoon season. These municipalities need sustainable management planning.

Genetic Diversity and Population Structure Analyses of Threatened Amblyceps mangois from Sub-Himalayan West Bengal, India Through Rapd and ISSR Fingerprinting

Abstract Amblyceps mangois or the “Indian torrent catfish” is a tropical, freshwater, hill-stream species that has ornamental-commercial value and has been included within the “Endangered” category in the list of threatened freshwater fishes of India. A total fourteen populations from the Terai and Dooars region of northern West Bengal, India were analyzed to study the genetic architecture of this species with the help of RAPD and ISSR markers. The observed number of alleles (S), Nei’s gene diversity (H) and Shannon’s information index (H´ or I) showed the highest values in the Teesta river system and the lowest values in the Mahananda river system. The UPGMA-based dendrogram and PCoA, based on RAPD and ISSR fingerprints, showed that the Mahananda and the Teesta river populations formed a group distinct from the remaining Jaldhaka river population. We further considered the fourteen riverine populations into nine groups according to the continuity of the water flow for SHE analysis. It was found that the three components, i.e. the pattern of diversity (H´), richness (S) and evenness (E), have varied and fluctuated across all fourteen populations from higher to lower altitude as the river flows downstream. AMOVA, PhiPT and genetic hierarchical analyses showed that a distinct hierarchical structure is present in Amblyceps populations in the study region. Low levels of genetic diversity/variation and genetic hierarchical structure with high genetic divergence were found in the present study as an indicator of the recent picture of threatened status of this species. This study is the initial attempt to characterize and evaluate the genetic architecture of the species from this region and there is a scope to manage the evolutionary significant units (ESU) for conservation purpose.

Draft Genome Sequence of a Novel Bacterium, Pseudomonas sp. Strain MR 02, Capable of Pyomelanin Production, Isolated from the Mahananda River at Siliguri, West Bengal, India.

ABSTRACTThe draft genome sequence of a novel strain, Pseudomonas sp. MR 02, a pyomelanin-producing bacterium isolated from the Mahananda River at Siliguri, West Bengal, India, is reported here. This strain has a genome size of 5.94 Mb, with an overall G+C content of 62.6%. The draft genome reports 5,799 genes (mean gene length, 923 bp), among which 5,503 are protein-coding genes, including the genes required for the catabolism of tyrosine or phenylalanine for the characteristic production of homogentisic acid (HGA). Excess HGA, on excretion, auto-oxidizes and polymerizes to form pyomelanin.

Fish Faunal Biodiversity in Mahananda River of Malda District, West Bengal, India

Fish Faunal Biodiversity in Mahananda River of Malda District, West Bengal, India

Seasonal variation and community structure of fishes in the Mahananda River with special reference to conservation issues

This study was carried out in the Mahananda River from January to December 2013 with a view to determining the seasonal variation and community structure of fishes along with some conservation issues. Monthly sampling was carried out using traditional fishing gears and fishes were identified based on morphometric and meristic characters. A total of 4082 individuals of native fish species were captured, analyzed and classified into 62 species belonging to 46 genera, 25 families and 9 orders. Cypriniformes and Siluriformes were the dominant fish orders represented by 19 species each and the most abundant family was Cyprinidae (14 species). In addition to indigenous individuals, 9 individuals of 2 exotic fish species (Hypophthalmichthys molitrix and Pangasius hypophthalmus) were also recorded. Among three sampling sites, S-1 was the most diversified in terms of not only the number of individual fish but also the number of species present represented by mean (±SE) individuals of 151.50±25.22 and species of 25.58±3.91. Three distinct fish groups of fish families were revealed from the cluster analysis of similarity. To improve the situation, control of illegal fishing gears, establishment of sanctuaries and legal protection for threatened species are recommended.