The present investigation was made to characterize spatial and temporal variations in soil properties and to evaluate possible differences that could be dependent on the tannery effluent discharges, municipal sewage discharges, vegetation cover, soil settlement rate, crop rotation, etc. Soil total organic matter (TOM), cations like, Sodium (Na), Ammonium (NH 4), Potassium (K), Calcium (Ca) and Magnesium (Mg) contents in the bank soils and bottom sediments were recorded from seven different characteristic sites in East Kolkata wetland ecosystem, a Ramsar site (Ramsar site No. 1208). The profile maps were constructed by geostatistical methods to describe the spatial distribution as well as temporal variations of all the factors to identify the influences of composite wastewaters. The work was initiated to identify causes and consequences of the waste dumping in the concerned region for the past hundred years and thereby to suggest necessary precautionary measures to prevent further loss of soil quality.
Tannery wastewater in the East Calcutta Wetlands (a Ramsar site of West Bengal; number 1208) exerts adverse effects on commercial fish production and subsequently affects humans. The present study was conducted to investigate acute and chronic toxicity of tannery effluent on a fish biosystem by examining oxidative stress enzyme expression in different organs including liver, gills, and muscle following exposure. Phosphatases, both alkaline phosphatase and acid phosphatase, and antioxidant superoxide dismutase and catalase enzyme activities were determined in guppy fish (Poecilia reticulata) exposed to sublethal concentrations of composite tannery effluent. Data demonstrated that tannery effluent was capable of interfering with metabolic processes of fish by altering stress enzyme activities in fish organs, resulting in cellular injury. Data suggest that elevated activities of stress enzymes in fish upon exposure to environmental pollutants may serve as important biomarkers for oxidative stress.
Fish grown in the East CalcuttaWetland (ECW) areas in West Bengal, India amass waste elements within their body through nutritional uptake and accumulation. The present investigation had been carried out to study the extent of accumulation of di¡erent waste elements in tissues of Indian major carps (IMCs) commonly cultured in composite industrial wastewaterfed ¢shponds in ECW, India. Energy-dispersive X-ray £uorescence spectrometric studies were used to estimate metals like chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn) and lead (Pb) in water and sediment of ¢shponds, and in ¢sh tissues (gill, liver and muscle) of three economically important IMCs, rohu (Labeo rohita), katla (Catla catla) and mrigel (Cirrhinus mrigala), collected from contaminated and control sites. It is evident from the study that mainly liver is the site of maximum accumulation of the elements, while gill, in most cases, is the site of least metal accumulation in the three IMC species studied. Principal component analysis reveals that Fe and Cr were in the ¢rst component and thereby must be having a major in£uence in trace metals uptake and bioaccumulation. Tissue-speci¢c and species-speci¢c patterns of metal concentration and partitioning were apparent from our present study.
The municipal sewage of Calcutta city together with industrial effluents traversed the East Calcutta Wetlands (ECW) (Ramsar Site No. 1208) for nearly a century. The composite wastewater at the ECW, was used for pisciculture and agriculture after natural stabilization. Such uses have always been thought to be a source of contamination to biota and humans. Some water-borne pollutants generate reactive oxygen species including superoxide radical anion (O 2À .), hydrogen peroxide (H 2 O 2 ), and hydroxyl radical (.OH), which are highly reactive and potentially deleterious to biological systems. The present study was initiated to examine the antioxidant activities against oxidative stress during different seasons in body fluids of two zooplankters, Moina micrura and Mesocyclops leuckarti thriving in wastewater-fed ponds of ECW. Results showed significantly higher electrical conductivity, chloride and metal (Cr, Cu, and Pb) concentrations in contaminated wastewater-fed pond (CP) at ECW compared to the uncontaminated village pond (UP). Zooplanktons thriving in CP displayed significantly higher superoxide dismutase and catalase activities at all seasons compared to those in UP. Seasonal variations in antioxidant activities were found to be in agreement with variations in limnochemical factors. Hence, antioxidant activity was used as a biomarker against oxidative damage in plankters surviving under pollutant stress.
Avifauna of shola and semi-evergreen forest patches belonging to three different sanctuaries and National Parks in the southern part of Western Ghat range of Tamil Nadu and Kerala was studied. Altogether 36 species from 17 families were recorded. One globally threatened species (A1), two restricted range species (A2) and one Palearctic-Asian migrant species have been recorded from forest edges during the relatively short study period. The highest population density of 47.59 ind./ha at Varagaliar Shola was followed by 43.69 ind./ha at Anapaddy, 27.53 ind./ha at Karian Shola, and 23.25 ind./ha at Punnumalai Shola. As Punnumalai Shola is least disturbed by human activity it got the highest number of avian families (15) and was followed by Karian Shola (9) and Vargaliar Shola and Anapaddy-8 in both cases. Punnumalai Shola having varied bird families showed lower dominance (0.075) and higher evenness value (0.957). In contrast, the edge of semi-evergreen forest at Anapaddy, although very much disturbed by various human activities, showed almost comparable diversity value (2.890) to that of Punnumalai Shola (2.913). More open canopy and much vegetational intergradations at the ecotone of semi-evergreen biotope inherently shelter avian community of high diversity. Conversely, the edges of Karian Shola and Varagaliar Shola having much anthropogenic interferences and with edges showing much lower intergradations of vegetations, exhibited a low avian diversity.
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