Institute of Environmental Studies and Wetland Management

Salt Lake, India

Institute of Environmental Studies and Wetland Management

Salt Lake, India
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Bunting S.W.,University of Essex | Kundu N.,Institute of Environmental Studies and Wetland Management | Ahmed N.,University of Manitoba
Ocean and Coastal Management | Year: 2017

Shrimp-rice farming practices in the coastal areas of Bangladesh and West Bengal, India are reviewed. It is apparent that this integrated aquaculture-agriculture system is suited to environmental and hydrological conditions found in specific areas. Production strategies devised by farmers demonstrate that the diversified culture of shrimp with rice is technically feasible. Shrimp-rice agroecosystems exhibit several synergistic effects between systems components that result in efficient resource use and enhanced production, whilst avoiding negative environmental impacts. Integrated cropping enhances agrobiodiversity and reduces dependence on external inputs (agrochemicals, feed and fertiliser). Diversified shrimp-rice culture produces a valuable export crop, stimulating economic development and staple cereal, fish and vegetable crops that enhance human nutrition and food security. The contribution that diversified shrimp-rice agroecosystems make to social-ecological resilience is evaluated using the DPSIR (Driving forces, Pressures, State, Impacts, Responses) framework. Strengths, Weaknesses, Opportunities and Threats (SWOT) associated with prevailing practices are reviewed using the SWOT framework. We conclude, that with appropriate safeguards, diversified shrimp-rice agroecosystems could contribute to climate change adaptation and enhance production from land affected by salinization. Policy-support and practical action is needed to support and promote diversified shrimp-farming agroecosystems as they can contribute to social-ecological resilience in vulnerable coastal communities. © 2017 Elsevier Ltd


Grant
Agency: European Commission | Branch: FP7 | Program: CP-SICA | Phase: ENV.2007.4.1.4.2.;ENV.2007.2.1.4.3. | Award Amount: 1.91M | Year: 2009

Project partner will complete a detailed multidisciplinary situation analysis of highland aquatic resources, focused on values, livelihoods, conservation issues and wise-use options at five sites in Asia (Guangdong, China; Uttrakhand and West Bengal, India and northern and central Vietnam). Factors assessed will include biodiversity and ecosystem services, including provisioning, regulating, supporting and cultural services. Livelihood strategies of households dependent on ecosystem services derived from highland aquatic resources, in particular poor, food-insecure and vulnerable people, will be assessed within a sustainable livelihoods framework and opportunities to enhance such livelihoods assessed. Institutional features, including local, national and international policy and legislation, trajectories of change, stakeholder values associated with highland aquatic resources and areas of conflict will be assessed. Stakeholder participation will be critical to ensure new knowledge is accessible for collective decision-making and development of policies for the equitable use and conservation; methods and indicators for participatory monitoring and evaluation of ecosystem services and biodiversity will be developed. Action plans will then be formulated with stakeholders to: monitor the health of highland aquatic resources; develop and promote wise-use, and where necessary livelihoods diversification, to enhance poor livelihoods and conservation; integrate sustainable and wise-use, livelihoods diversification and conservation with watershed management priorities throughout the region. Action plans will be implemented by stakeholders at four sites displaying high biodiversity in Asia and the ecosystem, livelihoods and institutional impacts assessed through participatory monitoring and evaluation. Best practices aimed at conserving biodiversity and sustaining ecosystem services will be communicated to potential users to promote uptake and enhanced policy formulation.


Bishnu A.,Institute of Environmental Studies and Wetland Management | Chakraborty A.,Bidhan Chandra Krishi Viswavidyalaya | Chakrabarti K.,University of Calcutta | Saha T.,Institute of Environmental Studies and Wetland Management
Biology and Fertility of Soils | Year: 2012

Ethion, a highly persistent insecticide in soil, is extensively used in tea cultivation in the tropics. The studies on the environmental impact of ethion in tea soil ecosystems are scanty. Silty loam and sandy loam soils from tea fields of Dooars (Typic Uderthents) and Hill (Typic Dystrudepts), respectively, were investigated for the degradation and effect of ethion application on soil microbial and biochemical variables under controlled laboratory conditions. Ethion degraded faster in the Hill soil than in the Dooars soil. Higher temperature (30°C) aided in faster degradation due to the increased microbial activity in the soils. Ethion application at field rate (FR) had lower half-lives (70 days at 20°C and 42.3 days at 30°C for Dooars soil; 65.4 days at 20°C and 39 days at 30°C for Hill soil) than at ten times FR (10FR; 75.2 days at 20°C and 44.2 days at 30°C for Dooars soil; 70 days at 20°C and 41.8 days at 30°C for Hill soil). Soil microbial biomass carbon, ergosterol content, fluorescein diacetate hydrolyzing and β-glucosidase activities declined in all the treatment combinations up to day 60 for both FR and 10FR doses at 20°C, irrespective of the soil types. At 30°C, the decreasing trend was observed up to day 30 for both the soils. The toxicological effect of ethion on microbiological and biochemical parameters persisted till their corresponding half-lives. The microbial metabolic quotient and microbial respiration quotient were altered, but was short-lived, indicating ethion induced disturbances. The recovery of the depressive action at 10FR ethion spiking on the studied variables was of slightly longer duration than noticed at FR application, although the depressive effect was overcoming after the respective half-lives of ethion. The microbial and biochemical soil parameters were negatively correlated with application of ethion up to day 60 of incubation. © 2011 Springer-Verlag.


Sarkar S.,Institute of Environmental Studies and Wetland Management | Ghosh P.B.,Institute of Environmental Studies and Wetland Management | Sil A.K.,University of Calcutta | Saha T.,Institute of Environmental Studies and Wetland Management
Environmental Earth Sciences | Year: 2011

The sediments of the raw sewage-fed fishpond system at East Kolkata Wetland (EKW) were analyzed for heavy metal content in a comprehensive way. Various indices of contamination like enrichment factor (EF), geo-chemical index (Igeo), modified degree of contamination (mDC), and pollution load index (PLI) were assessed. In all cases, instead of literature values, the metal concentrations of less contaminated sites, separated by the statistical approach of the hierarchical cluster analysis, were used as baseline values. In the present study, about 70% of the pond sediments are found uncontaminated, 5% display low degree of contamination and 25% are designated as moderate degree of contamination. Both the EF and Igeo indices highlighted that the metals lead (Pb), cadmium (Cd), and chromium (Cr) are responsible for the contamination while there is little anthropogenic input in cases of Cu, Zn, and Ni. Most of the ponds situated near the main sewage flowing canals as well as the main traffic highway and close to the solid waste dumping areas recorded higher degree of metal contamination as evident from spatial variation of mDC and PLI indices in the study area. Indices comparison study clearly indicates that although these are calculated using different methods, these may or may not produce the same indices values and hence the values should neither be compared nor be averaged. But all the above indices are directly related to a common term contamination factor (CF). Classification of contamination levels based on these CF values is found to be similar and this classification is only valid up to the level of high degree of contamination. Thus, the use of any one of these indices is sufficient to classify the degree of contamination of an area. However, to evaluate the contamination per metal, both Igeo and EF are effective while, to assess the composite effect of all the metals, PLI is preferable to mDC. © 2010 Springer-Verlag.


Ghosh S.,University of Calcutta | Chatterjee T.,Institute of Environmental Studies and Wetland Management | Saha T.,Institute of Environmental Studies and Wetland Management | Mukherjee A.,University of Calcutta
Nucleus (India) | Year: 2012

The study deals with the genotoxicity of soil samples collected from locations near a thermal power plant in the eastern parts of India. The metal content in the soil samples collected near the thermal power plant, fly ash pond and ash dumping sites were higher than the control sample. Physicochemical parameters such as pH, bulk density, water holding capacity and soil texture did not show much difference between the reference soil and the contaminated soils. Comet assay was carried in pot experiments utilizing Allium bulbs. The results of DNA damage as a reference to the genotoxicity of the soil were positive and could be correlated to the presence of the toxic metal content. The damage was high in the sites located near the ash pond and the ash dumping sites. The root growth was also inhibited in the fly ash contaminated soils. The bioassay data in combination with the physico-chemical analyses will be useful in the management and disposal practices of fly ash and can be undertaken to minimize the adverse impact on agricultural land. © Archana Sharma Foundation of Calcutta 2012.


Bhattacharyya S.,Institute of Environmental Studies and Wetland Management | Pethick J.,The World Bank | Sarma K.S.,Institute of Environmental Studies and Wetland Management
Water Policy | Year: 2013

Tidal estuaries constrained by embankments in the Sundarbans have failed to respond to a >1 m sea level rise over the past 100 years since their construction. This paper shows that this has led to a disequilibrium morphology leading to channel erosion that has undermined embankments, causing mass failure, breaching and subsequent flooding during surge events. Predicted future sea level rise will exacerbate this trend and managed realignment of embankments will be needed to accommodate it. Management practices have, however, modified this underlying process of erosion. The increasing practice of severing tributary channels from the main channel using flap sluices to create freshwater storage ponds has, in many cases, reduced tidal flow in the main channels so that they are not only accreting rather than eroding, but capable of accommodating future sea level rise without erosion. In contrast, the rapid spread of salt water aquaculture in the Sundarbans, flooding previous paddy land, has led to an increase in tidal discharge and accelerated erosion of the embankments in estuary channels conveying water to the ponds. This paper concludes that existing management practices may have a more significant impact on flooding in the Sundarban than the predicted sea level rise due to global warming. © IWA Publishing 2013.


Majumdar S.S.,Institute of Environmental Studies and Wetland Management | Das S.K.,Indian Association for The Cultivation of Science | Chakravarty R.,Indian Association for The Cultivation of Science | Saha T.,Institute of Environmental Studies and Wetland Management | And 2 more authors.
Desalination | Year: 2010

Removal of lead from its aqueous solutions by adsorption on different biomasses was studied. Mucor rouxii biomass (MRB) had been found to be the most efficient in this respect and removed more than 90% of lead from its aqueous solution. Adsorption of lead by the biomass was dependent on pH and temperature. Maximum sorption was noted at the pH range of 5.0-6.0 and an increase in temperature above 30 °C resulted in the decrease in adsorption indicating the exothermic nature of the process. The adsorption process was very fast initially, and around 70% of the total adsorption was completed within the first 10min. The process is found to follow the pseudo second order rate kinetics throughout the period. Langmuir isotherm model fitted well to describe the isotherm data. Scanning electron micrographs showed homogeneous accumulation of lead ions on the surface of the biomass. From the FTIR study, involvement of various functional groups like amine, carboxyl, phosphate, etc. for the binding of lead ions was evident. Blocking of these functional groups indicated major involvement of phosphate group for metal ions binding. Lead ions could be desorbed from the loaded biomass with elution with 0.1M hydrochloric acid. © 2009 Elsevier B.V.


Manna S.,Institute of Environmental Studies and Wetland Management | Chaudhuri K.,Institute of Environmental Studies and Wetland Management | Bhattacharyya S.,Institute of Environmental Studies and Wetland Management | Bhattacharyya M.,University of Calcutta
Saline Systems | Year: 2010

Background: Sundarbans is the largest chunk of mangrove forest and only tiger mangrove land in the world. Compared to the rich species diversity and uniqueness, very few studies have so far been conducted here, mainly due to its inaccessibility. This study explores water quality, density of biomass, species diversity, phytoplankton abundance and bacterial population of a tidal creek in Sunderban estuary during the post and pre monsoon period of 2008-09.Results: Phytoplankton community was observed to be dominated by diatoms (Biacillariophyceae) followed by Pyrrophyceae (Dinoflagellates) and Chlorophyceae. A total of 46 taxa belonging to 6 groups were recorded. Other algal groups were Cyanophyceae, Euglenophyceae and Chrysophyceae. Species diversity was highest in summer (March) and lowest in winter season (November) in all the sample stations indicating its close correlation with ambient temperature. Species evenness was fairly high in all five stations throughout the study period. Present study indicated that dissolved oxygen, nutrients and turbidity are the limiting factors for the phytoplankton biomass. The estuary was in eutrophic condition (Chlorophyll-a ≥10 μg/L) in winter. During the month of May phytoplankton biomass declined and at high salinity level (21.2PSU) new phytoplankton species take over, which are definitely better resilient to the high saline environment. Bio-indicator species like Polykrikos schwartzil, Dinophysis norvegica and Prorocentrum concavum points to moderately polluted water quality of the estuary.Conclusion: Eutrophication as well as presence of toxic Dinoflagellates and Cyanophyceae in the tidal creek of Sundarban estuary definitely revealed the deteriorated status of the water quality. The structure and function of the mangrove food web is unique, driven by both marine and terrestrial components. But little attention has been paid so far to the adaptive responses of mangrove biota to the various disturbances, and now our work unfolds the fact that marine status of Sundarban estuary is highly threatened which in turn will affect the ecology of the mangrove. This study indicates that ecosystem dynamics of the world heritage site Sundarban may facilitate bioinvasion putting a question mark on the sustainability of mangroves. © 2010 Manna et al; licensee BioMed Central Ltd.


PubMed | University of Calcutta and Institute of Environmental Studies and Wetland Management
Type: | Journal: Chemosphere | Year: 2016

At East Kolkata Wetlands, though the domestic city sewage is purified very rapidly, the mechanisms of treatment remains inadequately explored. In this context, the present study investigated nitrogen dynamics of the single pond treatment systems during purification and explored its potential role in sewage treatment. For this purpose the concentrations of different forms of nitrogen present both in water and soil at different time points of purification were measured. The organic nitrogen content decreased sharply, in the early phase, with an increase in ammonium concentration. Notably the reduction in organic nitrogen was significantly higher than the increase in NH


PubMed | Institute of Environmental Studies and Wetland Management
Type: Journal Article | Journal: Environmental monitoring and assessment | Year: 2016

The present investigation was intended to assess the seawater quality of Digha (India) in the northwestern coast of the Bay of Bengal. Digha is a meso-tidal coastal plain located between two major estuarine systems, i.e. Subarnarekha and Hooghly located respectively on the western and eastern sides of the West Bengal along the northeast coast of India. The sampling was made at nine stations at various distances. Significant seasonal variations in environmental parameters and nutrients were observed during the study period. Analyses of physicochemical characteristics of the study area indicated that the level of dissolved oxygen (DO), biological oxygen demand (BOD), total dissolved solid (TDS) and nutrients is within the permissible limit. The results clearly revealed that, though sewage discharge takes place in the coastal waters, the quality of the water was not affected. It may be due to the large quantity of estuarine water input from the Hooghly estuarine system that have enhanced dilution of discharged sewage in Digha coastal waters. Strong tidal activities, wave dynamics and coastal current further dilute the effluent water in the study area, resulting to the minimised sewage effect on coastal ecosystem. Further studies on the heavy metal concentration and benthic diversity can be assessed to understand the health of the ecosystem.

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