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Subhajit Das

Bio: Subhajit Das is an academic researcher from University of Calcutta. The author has contributed to research in topics: Population & Mangrove. The author has an hindex of 9, co-authored 26 publications receiving 268 citations.

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Journal ArticleDOI
Tarun Kumar De1, M. De, Subhajit Das1, Raghab Ray1, P. B. Ghosh1 
TL;DR: The muscles of some important marine fishes collected in and around Hooghly estuarine coastal areas were analyzed for the heavy metals Cu, Zn, Ni, Cd, Cr and Pb and the toxic groups of metals showed higher variability than the essential metals.
Abstract: The muscles of some important marine fishes collected in and around Hooghly estuarine coastal areas were analyzed for the heavy metals Cu, Zn, Ni, Cd, Cr and Pb. The concentration range of Cu (16.22–47.97 ppm), Pb (12.40–19.96 ppm) and Zn (12.13–44.74 ppm) were recorded comparatively higher and were similar to that found in contaminated areas. On the other hand the ranges of Ni (2.20–3.69 ppm), Cr (0–3.89 ppm) and Cd (0.62–1.20 ppm) were almost equal to those carried out over a wide range of geographical areas. The degree of bioaccumulations was metal-specific as well as species-specific in nature. The toxic groups of metals (Pb and Cd) showed higher variability than the essential metals (Cu, Zn and Ni). The calculated intake value of metals (week−1 kg−1 body wt) varied from 14.88 to 27.60 of Pb, 0.87 to 1.68 of Cd, 0.0 to 5.45 of Cr, 22.70 to 137.16 of Cu, 3.08 to 5.17 of Ni and 16.98 to 62.60 of Zn through human consumption of these fishes and were compared with those of standard Provisional Tolerable Weekly Intake value (PTWI) per kg body weight as stipulated by WHO. The PTWICal values of Pb in some of the fishes recorded marginally excess values and may indicate a health risk through consumption of successive 7 days in a week.

61 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used a box model approach to assess the nitrogen budget in the Sundarban mangrove ecosystem, which acts as a sink for atmospheric nitrogen in terms of NOx, NH3, N2, and water column dissolved inorganic nitrogen.

56 citations

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TL;DR: In this article, seasonal fluctuations in the phytoplankton assemblage and the relationship between PHYTOPLankton abundance and key environmental parameters in a highly eutrophic system were reported.
Abstract: Human activities accelerate the input of plant nutrients sourced from agriculture, industrial waste, and sewage in the Hooghly River at the land ocean boundary of Indian Sunderban mangrove (21°32′–22°40′ N and 88°05′–89° E). This study reports seasonal fluctuations in the phytoplankton assemblage and the relationship between phytoplankton abundance and key environmental parameters in a highly eutrophic system. As far as seasonal perspective, the Hooghly estuarine system dominated by mangrove suffered complete change in terms of phytoplankton and other key parameters during monsoon compared to other times of the year. Diatoms were more abundant than dinoflagellates throughout all seasons with 58 species.

44 citations

Journal ArticleDOI
TL;DR: In the Sundarban Mangrove forest microbial activities are dominantly involved in both the mineralization and decomposition processes that regulate nutrient profile in soil of different depth.
Abstract: In the Sundarban Mangrove forest microbial activities are dominantly involved in both the mineralization and decomposition processes that regulate nutrient profile in soil of different depth. It was found that besides changing the water and soil quality, monsoonal cycle plays a crucial role in regulating microbial population distribution in the mangrove soil. Statistical analyses revealed that organic carbon was the most significant factor that regulated the total microbial population. The cellulose degrading bacteria, [mean value of CFU 14.32 × 10 6 (gm dry weight of soil) –1 ] was dominant throughout the year. The sulfate reducing bacteria showed an increasing trend along depth with a minimum value at the surface i.e. 6.113 × 10 6 (gm dry weight of soil) –1 and 12.312 × 10 6 (gm dry weight of soil) –1 at a depth of 60 cm. Intensification of monsoonal cycle could heavily affect microbe dominated soil biogeochemistry and subsequent change in the regional ecology of the Sundarban Mangrove Forest.

19 citations

Journal ArticleDOI
TL;DR: In this article, the seasonal and spatial fluctuation of the culturable microbial population collected from different zones in the sediment of the Sunderban mangrove forest was documented, and the abundances of microbes, in decreasing order, studied from different regions were nitrifying bacteria (mean value of CFU 1.125 ± 0.359 × 106 (g dry weight of sediment)−1), phosphorous solubilizing bacteria (PSB), free living nitrogen fixing bacteria (NFG), and sulfur reducing bacteria (SRB) [mean value CFU 0.356
Abstract: This is the first documentation of seasonal and spatial fluctuation of the culturable microbial population collected from different zones in the sediment of the Sunderban mangrove forest. The population of cellulose degrading bacteria, [mean value of CFU 6.189 ± 1.025 × 106 (g dry weight of sediment)−1] was found to be maximum during post monsoon in the deep forest region, whereas, the fungal population [mean value of CFU 3.424 ± 0.886 × 106 (g dry weight of sediment)−1] was found to be maximum during pre-monsoon in the rooted region. The abundances of microbes, in decreasing order, studied from different zones are nitrifying bacteria [mean value of CFU 1.125 ± 0.359 × 106 (g dry weight of sediment)−1], phosphorous solubilizing bacteria (PSB) [mean value of CFU 0.805 ± 0.322 × 106 (g dry weight of sediment)−1], free living nitrogen fixing bacteria [mean value of CFU 0.417 ± 0.120 × 106 (g dry weight of sediment)−1] and sulfur reducing bacteria (SRB) [mean value of CFU 0.356 ± 0.125 × 106 (g dry weight of ...

18 citations


Cited by
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Journal ArticleDOI
TL;DR: It was showed that, Zn was the most and Cd was the least accumulated metal in the studied fish muscles, and there was no possible health risk to consumers due to intake of studied fishes under the current consumption rate.

386 citations

Journal ArticleDOI
TL;DR: There is growing evidence that P activators can promote the release of phosphate from soil and, hence, have potential for mitigating the impending global P crisis.

336 citations

Journal ArticleDOI
TL;DR: In this paper, a comprehensive and critical rather than encyclopaedic summary of the data of environmental chemistry is presented, focusing on air, water, rocks and soils; the cycling of C, N, H, O2 and S in the biosphere are covered in 1 chapter and the elemental Other CABI sites are discussed.
Abstract: All chapters of the previous edition [see HbA 37, 2103] have been completely rewritten to cover the rapid increase in research in this area. The number of literature citations have been reduced by referring to recent review articles and the book aims at a comprehensive and critical rather than encyclopaedic summary of the data of environmental chemistry. The 1st 4 chapters deal with air, water, rocks and soils; the cycling of C, N, H, O2 and S in the biosphere are covered in 1 chapter and the elemental Other CABI sites 

289 citations

Journal ArticleDOI
TL;DR: Although some metals concentrations exceed the limits set by the European regulation, the estimated weekly intake was below the Provisional Tolerable Weekly Intake established by theEuropean Food and Safety Authority, and the Target Hazard Quotient values indicate that there is no carcinogenic risk for humans.
Abstract: Cadmium, lead, mercury and chromium concentrations in fish muscle tissue taken from various Sicilian areas were detected. Fish caught in Siracusa, nearby a petrochemical industrial area, were more contaminated by cadmium, lead and chromium (respectively 0.366, 0.32, 0.72 μg/g) than those from the other sites. In the Sicily Channel, we found the highest bioaccumulation of mercury (0.31 μg/g). Although some metals concentrations exceed the limits set by the European regulation, the estimated weekly intake was below the Provisional Tolerable Weekly Intake established by the European Food and Safety Authority, and the Target Hazard Quotient values indicate that there is no carcinogenic risk for humans.

232 citations