Papers by Bhaskar Deb BHattacharya
Marine pollution bulletin, Jan 15, 2015
Little knowledge is available about the potential impact of commercial silver nanoparticles (Ag-N... more Little knowledge is available about the potential impact of commercial silver nanoparticles (Ag-NPs) on estuarine microbial communities. The Hugli river estuary, India, is susceptible to heavy metals pollution through boat traffic, and there is the potential for Ag-NP exposure via effluent discharged from ongoing municipal and industrial activities located in close proximity. This study investigated the effects of commercial Ag-NPs on native microbial communities in estuarine sediments collected from five stations, using terminal restriction fragment length polymorphism (T-RFLP) technique. An increase in the number of bacteria in consortium in sediments was observed following exposure to Ag-NPs. In general microbial communities may be resistant in estuarine systems to the antimicrobial effects of commercial Ag-NPs, but key microorganisms, such as Pelobacter propionicus, disappeared following exposure to Ag-NPs. In conclusion, the T-RFLP analysis indicated that Ag-NPs have the potent...
Bulletin of Environmental Contamination and Toxicology, 2008
This is a preliminary report on total mercury (T Hg) in core sediments (\63 lm particle size) of ... more This is a preliminary report on total mercury (T Hg) in core sediments (\63 lm particle size) of Sunderban mangrove wetland, northeastern part of the Bay of Bengal, India. Cold vapor atomic absorption spectrometry (CVAAS) was used for T Hg determination. The concentration varies from 9.8 to 535.1 ppb (ngg-1). Results revealed variations over premonsoon and postmonsoon month at different core depth, as well as in studied three sampling stations, located at the site of three rivers: Hugli River (S 1), Matla River (S 2) and Bidyadhari River (S 3). Elevated concentration of T Hg in subsurface layer (4-8 cm) of the core at S 2 is attributed to remobilization of mercury from deeper sediment (32-36 cm). Positive correlation is present between total Hg and clay content. Based on index of geoaccumulation (I geo) and Effects-Range Low (ER-L) value (150 ppb) it is considered that the sediments are till now unpolluted. As a consequence, there is less chance of ecotoxicological risk to organisms living in studied sediments. Two statistical methods were applied to determine T Hg anomalies. Box plot method showed one extreme and three outliers in S 1 at postmonsoon season. Two extremes were found at S 2 at 4-8 and at 32-36 cm in premonsoon period. In S 3 there was no anomaly by box plot method. MAD method was more sensitive than box plot method and T Hg anomaly was detected at 12-16 cm in S 3 during postmonsoon season. The data reported are useful baselines for T Hg in Sunderban mangrove wetland, India and would be of help in future sediment quality studies.
th May, 2009. The Aila incident not only caused stupendous changes in the physicochemical charact... more th May, 2009. The Aila incident not only caused stupendous changes in the physicochemical characteristics of the water but also left direct impact on the mesozooplankton biomass. A sharp increment in water turbidity, chemical oxygen demand (COD), phytopigment chlorophyll b (chl b) and micronutrients (nitrate, phosphate and silicate) were noticed during post-Aila period with a corresponding decrease of water transparency and phytopigments chl a and chl c. Reduction of zooplankton biomass, density and species diversity was also pronounced during post-Aila period. An absolute dominance of two copepod species of diverse feeding guilds, namely, Bestiolina similis (herbivore) and Oithona brevicornis (carnivore) was the most interesting feature observed during post-Aila period. The meroplanktons such as nauplius, zoea and ichthyoplanktons which constituted the most dominant forms (~31 % of total mesozooplankton) during pre-Aila period, were completely absent in post-Aila stage.
Bulletin of Environmental Contamination and Toxicology, 2010
Bioaccumulation of trace metals in four softbottom polychaetes along with the host sediments was ... more Bioaccumulation of trace metals in four softbottom polychaetes along with the host sediments was recorded from the intertidal regions of Indian Sundarban mangrove wetland. The enrichment of Mn (maximum 730 mg kg-1) and Zn (maximum 320 mg kg-1) was recorded for all the polychaetes followed by Cr, Cu, As, Co, Ni and Pb, showing sharp variations between the species. However, concentrations of Sn and Hg were very low with small variations between the species. An overall high bioconcentration factor (BCF) was recorded in the capitellid worm Mastobranchus indicus. The results of the investigation indicate the possibility of developing a standard test protocol for bioaccumulation by polychaetous annelids.
Tropical cyclones are increasingly affecting the estuarine communities. Impacts of category-5 tro... more Tropical cyclones are increasingly affecting the estuarine communities. Impacts of category-5 tropical cyclone Amphan (landfall on 20 May 2020 near Ganges estuary mouth) on the copepod community of Muriganga section of Ganges estuary was studied by sampling the copepod assemblages before (February to December 2019), shortly after (31 May to 12 June 2020) and post (September to November 2020) cyclone. Hypothesis was shortly after Amphan a relatively homogenous community consists of a few estuarine specialist copepods would succeed but within months that community would be replaced by a heterogenous one but those estuarine specialists would continue their dominance. Shortly after Amphan, species richness declined but the recovery process completed within months led by herbivorous Paracalanus parvus, omnivorous Bestiolina similis, Acartia spinicauda, Acartiella tortaniformis, and carnivorous Oithona brevicornis. Spatial homogeneity of the community that prevailed in Muriganga in pre-Am...
Copepods are considered as indicators of ecological stresses of estuaries. Spatial-temporal chang... more Copepods are considered as indicators of ecological stresses of estuaries. Spatial-temporal changes of diversity, abundance, and dominance of the copepod community of India's Ganges River estuary were hypothesised to result from abiotic fluctuations, seasonal change and the COVID-19 lockdown which possibly affected the habitat. This hypothesis was studied by sampling the estuary on different occasions between February 2019 and October 2020. Salinity and pH showed significant temporal variability but not significant spatial variability. Water temperature showed no significant spatial-temporal variability. Salinity showed significant negative relationships with diversity and abundance of the copepod community. After the COVID-19 lockdown (between unlock phase 1 to 5), nutrient status of the estuary did not show significant temporal variation. The copepod community mostly comprised calanoids except for the cyclopoids Oithona spp. Relative abundances of Pseudodiaptomus binghami, Euc...
Continental Shelf Research, 2016
The influence of Kuroshio water on temporal distribution and copepod diversity was investigated i... more The influence of Kuroshio water on temporal distribution and copepod diversity was investigated in the Lanyang River estuary (LRE), the longest river in northeast Taiwan, to assess secondary productivity. Zooplankton samples were collected bimonthly from the surface waters (0-2 m) of the estuary during cruises in 2006. Hydrological parameters indicated that the water in the LRE was an admixture of the Lanyang River water and seawater. Among the different genera, 47 copepod species (including 10 species that were identified only to the generic level) belonging to 28 genera, 16 families, and 4 orders were identified. The abundance and proportion of copepods to the total zooplankton counts range from 0 to 3683.42 (304.97 692.7 individuals m À 3) and from 0 to 100 (55.09 734.84%) respectively. The copepod community structure revealed a distinct seasonal succession and showed significant differences among the sampling cruises (po0.05, One-way ANOVA). The 5 most abundant species were Parvocalanus crassirostris (relative abundance [RA]: 50.93%), Pseudodiaptomus serricaudatus (RA: 16.85%), Euterpina acutifrons (RA: 7.34%), Cyclops vicinus (RA: 4.82%), and Microcyclops tricolor (RA: 3.15%). The abundance, species number, indices of richness, evenness, and copepod diversity varied significantly (p o0.05, Oneway ANOVA) for all the cruises. Pearson correlation analysis results demonstrated that salinity was positively correlated with the copepod species number (r¼0.637), total copepod abundance (r¼0.456), and Shannon-Wiener diversity index (r¼ 0.375) with a 1% level of significance. By contrast, the evenness index was negatively correlated with salinity (r¼ À0.375, p¼0.01), indicating that copepod diversity in the LRE was influenced mainly by seawater. The Kuroshio Current played a major role in transporting and distributing warm-water copepods to its affected area. Copepod species assemblages showed seasonal succession and varied drastically with tidal change. The latter registered high abundance, and the presence of the highest number of species was correlated with intruding seawater.
Marine Pollution Bulletin, 2015
The study first illustrates a comprehensive account of large-scale changes in water quality chara... more The study first illustrates a comprehensive account of large-scale changes in water quality characteristics and plankton community structure due to occurrence of Annual Gangasagar Festival (AGF) at Sagar Island, western part of Indian Sundarban megadelta for 3-year duration (2012-2014; n=36). About 1 million pilgrims across India converge to take their holy bath at the confluence of Hooghly estuary and Bay of Bengal during January each year. This mass scale bathing results negative impact on water quality due to high turbidity (14.02 ± 2.34 NTU) coupled with low chlorophyll a (1.02 ± 0.21 mg m(-3)) and dissolved oxygen (3.94 ± 1.1 mg l(-1)). A marked decrease in abundance (from 4140 to 2997 cells l(-1)) and diversity (H'=2.72-1.33) of phytoplankton and microzooplankton tintinnids (from 450 to 328 ind l(-1); H'=4.31-2.21) was recorded. The festival acts as multiple stressors modifying natural functions of the delta. Sound and sustainable management strategies are to be adopted to maintain the protection-usage equilibrium.
Marine Pollution Bulletin, 2014
Mesozooplankton (Body size 20-200 lm) along with the surface water were collected from coastal re... more Mesozooplankton (Body size 20-200 lm) along with the surface water were collected from coastal regions of Sundarban, northeastern part of Bay of Bengal considering three seasons, namely premonsoon, monsoon and postmonsoon. Samples were analyzed for community structure and the dominant copepod species were further analyzed for trace metal concentration. In total, 50 copepods were identified (22 families and 43 genera). The dominant mesozooplankton species included 9 copepods and an epipelagic chaetognath, exhibited both spatial and seasonal variations. Metal concentration exhibited considerable inter-specific variations for the copepods and the mean concentrations were: Fe, 1350.2-51118.3 lg/g; Al, 647.2-73019.1 lg/g; Ni, 32.4-110.3 lg/g; Mn, 122.8-1066.5 lg/g; Pb, 0.04-97.5 lg/g; Pb, 10.6-97.5 lg/g; Cd, 4.2-21.6 lg/g; Cu, 17.4-145.1 lg/g; Zn, 225.7-1670.9 lg/g; Cr, 21.7-194.3 lg/g; Co, 1.32-111.1 lg/g. Metal concentrations showed the following order: Sagitta bedoti > Coryceas danae > Oithona sp. > Eucalanus subcrassus > Labidocera euchaeta > Paracalanus parvus > Acartiella tortaniformis > Acartia spinicauda > Pseudocalanus serricaudatus.
The general concern for arsenic in the marine environment is associated with its wide distributio... more The general concern for arsenic in the marine environment is associated with its wide distribution and potential toxicity. In the present work, concentrations and chemical speciation of arsenic were characterized in sediments and representative biota from the Indian Sundarban, the largest continuous mangrove tract formed at the mouth of the Hugli (Ganges) River estuary, northeastern part of the Bay of Bengal. Analyzed organisms included both shellfish (Macoma birmanica, Sanguinolaria acuminata and Meretrix meretrix) and finfish (Liza parsia, Liza tade, Harpodon nehereus and Eleutheronema tetradactylum). Arsenic concentrations in sediments did not exceed 4 μg g(-1) dry weight with the contribution of inorganic molecules (arsenate and arsenite) ranging from 61.7 to 81.3%. Total As (TAs) concentrations varied from less than 2 to 16 μg g(-1) in tissues of bivalves; the more elevated As accumulation was observed in gills and the mantle probably due to ion exchange properties of the mucous layer covering these organs, whereas adductor muscle and the podium showed limited values. Distribution of various arsenic compounds followed a quite similar trend in bivalve tissues; arsenobetaine (AsB) was the most dominant form followed by compounds such as dimethylarsinate (DMA), trimethyl arsine-oxide (TMAO), tetramethyl arsonium (TETRA) and arsenocholine (AsC), while inorganic arsenic (IAs) represented a minor constituent (0.2 to 6.9%). Among the fish, detritivorous/herbivorous species (L. parsia and L. tade) exhibited TAs concentrations of 10.8 and 9.71 μg g(-1) dry wt with a prevalence of AsB (52-67%) and TETRA (26-35%); higher concentrations of TAs were measured in the two carnivorous species (20.62 and 19.67 μg g(-1) dry wt, in H. nehereus and E. tetradactylum respectively) mostly as AsB (63.3-72.3%) and AsC (17.5-28.6%). The obtained results can be considered as baseline levels for arsenic in the investigated area, confirming the predominance of organoarsenicals in marine organisms compared to more toxic inorganic compounds. Considering the ecological importance of this ecosystem and the increasing anthropogenic impact, the distribution of arsenic through the food chain should be continuously monitored, using organisms of different feeding guilds as indicators.
Zeitschrift für Geomorphologie, 2012
... vary widely in size from boulders to fine sand, the miner-al compositions of which are derive... more ... vary widely in size from boulders to fine sand, the miner-al compositions of which are derived from the metamorphic and sedimentary ... at different locations were carried out using GPS, common surveying instruments and topographical map 1:100,000 sheet Ivanić Grad, issued ...
Marine Pollution Bulletin, 2012
This study reports the first evidence of the quantification of two dominant perfluorinated compou... more This study reports the first evidence of the quantification of two dominant perfluorinated compounds (PFCs), namely perfluorooctanesulfate (PFOS) and perfluorooctannoate (PFOA), in surface sediment samples (0-5 cm; n = 13) from the Ganges (Hugli) River including Sundarban wetland, India using HPLC-MS/ MS. The concentrations of PFOA exhibited a wide range of concentrations from <0.5 to 14.09 ng/g dry wt, whereas the concentration of PFOS was always below the detection limit of <0.5 ng/g dry wt. A consistent enrichment of PFOA was recorded in all the five sites of Sundarban (mean value 11.61 ± 1.86) whereas it was of moderate concentration or below the detection level in the seven sites along with the lower stretch of the Ganges (Hugli) River estuary (mean value 5.96 ng/g dry wt ± 5.36). Wastewater and untreated effluents are likely the major causes of accumulation of PFCs in sediments. The present paper could be used as baseline study to assess future monitoring programs of the ecosystem.
Journal of Cleaner Production, 2015
The work first documents detailed account of the seasonal variations of total dissolved trace met... more The work first documents detailed account of the seasonal variations of total dissolved trace metals in the coastal regions of Sundarban mangrove wetland (a UNESCO World Heritage Site) using a graphitefurnace atomic absorption spectrophotometer. Considering all three different seasons (premonsoon, monsoon and postmonsoon), the average concentrations and relative variability of the metals exhibited the following sequential order: Mn (223 mg l À1 ; 261.50 mg l À1) > Cr (39.30 mg l À1 ; 32.08 mg l À1) > Zn (57.25 mg l À1 ; 59.78 mg l À1) > Ni (36.23 mg l À1 ; 43.28 mg l À1) > Cu (33.88 mg l À1 ; 48.85 mg l À1) > Pb (14.76 mg l À1 ; 19.76 mg l À1)> Co (20.73 mg l À1 ; 25.18 mg l À1) > Cd (5.53 mg l À1 ; 5.68 mg l À1). Concentrations of Cu (maximum 48.85 mg l À1) exceeded the WHO recommended value. The results of the carcinogenic risks for the metals revealed that dermal absorption (CDI dermal) of Cr, Pb and Cd might be a matter of concern. Chromium is significantly correlated with majority of the metals indicating their identical behaviour during transport in this coastal environment. Results of canonical correspondence analyses (CCA) confirmed that two study sites in Sundarban, namely Canning and Dhamakhali, clustered at about 85% similarity loading as they suffer from huge load of domestic sewage effluents discharged from the megacity Calcutta resulting maximum concentrations of majority of the trace metals.
Environmental Geochemistry and Health, 2012
This paper documents the concentration of total arsenic and individual arsenic species in four so... more This paper documents the concentration of total arsenic and individual arsenic species in four soft-bottom benthic polychaetes (Perenereis cultifera, Ganganereis sootai, Lumbrinereis notocirrata and Dendronereis arborifera) along with host sediments from Sundarban mangrove wetland, India. An additional six sites were considered exclusively for surface sediments for this purpose. Polychaetes were collected along with the host sediments and measured for their total arsenic using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Arsenic concentrations in polychaete body tissues varied greatly, suggesting speciesspecific characteristics and inherent peculiarities in arsenic metabolism. Arsenic was generally present in polychaetes as arsenate (As V ranges from 0.16-0.50 mg kg-1) or arsenite (As III ranges from 0.10-0.41 mg kg-1) (30 to 53% as inorganic As) and dimethylarsinic acid (DMA V ; <1 to 25%). Arsenobetaine (AB; <16%), and PO 4-arsenoriboside (8 to 48%) were also detected as minor constituents, whilst monomethylarsonic acid (MA V) was not detected in any of the polychaetes. The highest total As (14.7 mg kg-1 dry wt) was observed in the polychaete D. arborifera collected from the vicinity of a sewage outfall in which the majority of As was present as an uncharacterized compound (10.3 mg kg-1 dry wt) eluted prior to AB. Host sediments ranged from 2.5 to 10.4 mg kg-1 total As. This work supports the importance of speciation analysis of As, because of the ubiquitous occurrence of this metalloid in the environment, and its variable toxicity depending on chemical form. It is also the first work to report the composition of As species in polychaetes from the Indian Sundarban wetlands.
Ecotoxicology, 2009
The paper presents the first document to identify the enrichment pattern of acid leachable trace ... more The paper presents the first document to identify the enrichment pattern of acid leachable trace metals (ALTMs) such as Fe, Mn, Cr, Cu, Ni, Pb, Cd, Co, Mo, Ag, As and Ba and their relationship with sediment quality parameters (pH, organic carbon, carbonates and texture) in core sediments (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;63 microm particle size) from Indian Sunderban mangrove wetland, formed at the estuarine phase of the river Hugli (Ganges). Textural analysis reveals an overall predominance of mud. The results indicate that the change in pH values causes coagulation and precipitation of ALTMs. Fe and Mn have fairly close distribution patterns of enrichment in surface layers which might be ascribed to early diagnetic processes. The most prominent feature of ALTMs is the enrichment of Fe, Mn, Cr, Cu, Ni, Pb, and Ba in the surface-subsurface layers in the sediment cores, which is mainly attributed to the intense industrial and agricultural activities as well as drainage of untreated domestic sewage to this coastal region. The ALTMs also indicate their association with organic carbon and Fe-Mn oxyhydroxides. The enrichment is well--supported by the correlation, grouping and clustering of ALTMs in statistical analyses. Anthropogenic Factor values indicated ALTMs enrichment for all trace metals due to intense anthropogenic activities. Overall higher values of ALTMs in sediments in comparison to other Indian coastal regions indicate that they are mainly due to the uncontrolled anthropogenic activities in this mangrove estuarine complex. Statistical analyses suggest that five ALTMs (Cu, Pb, As, Mo, Ba) are attached to the organic particles and the clustering of elements separately also indicates that they are from external source. The result of the present study suggests the need for a regular monitoring program which will help to improve the quality of this potential wetland.
CLEAN - Soil, Air, Water, 2013
An intense monospecies bloom of the centric diatom Hemidiscus hardmannianus (Greville) Mann. (Bac... more An intense monospecies bloom of the centric diatom Hemidiscus hardmannianus (Greville) Mann. (Bacillariophyceae) occurred in the coastal waters of Sundarban mangrove wetland, India on 22 July, 2010. The species was abruptly flourished (mean density 8.86 Â 10 6 cells/L) resulting intense green coloration of water. The greatest impoverishment of diversity and density of phytoplankton, micro-and mesozooplankton community was observed during the bloom. The phytoplankton community showed an extreme reduction in diversity (12 species to one) and sharp decrease in standing stock (12.84 Â 10 3 to 8.86 Â 10 6 cells/L) during this period. The late bloom condition coincided with sudden and huge arrival of a clupoid fish Hilsa ilisha which forms the most potential fisheries in Sundarban deltaic region. An attempt has been made to correlate the satellite remote sensing-derived information to the bloom conditions. The MODIS-Aqua derived chlorophyll and TMI satellite derived sea surface temperature and wind speed maps have been interpreted.
Chemosphere, 2008
The aim of this paper was to obtain the first screen ing eco tox i co log i cal risk eval u a tio... more The aim of this paper was to obtain the first screen ing eco tox i co log i cal risk eval u a tion in the Sun der ban wet lands, the larg est pro grad ing delta in the estu a rine phase of the River Gan ges. The char ac ter iza tion of expo sure was con ducted by means of an exten sive sur vey of sev eral per sis tent organic pol lu tants (PAHs, PCBs, DDTs, PBDEs, HCHs, HCB) mea sured in seven core sed i ments from the Sun der ban wet lands, obtaining a data set with more than 2200 anal y ses. The pol lu tant effects were assessed by the use of three dif fer ent sed i ment qual ity guide lines (SQGs) pre vi ously devel oped in the lit er a ture to eval u ate tox ic ity induced in sed i ment-dwell ing organ isms. The three dif fer ent approaches cho sen for risk assess ment of the Sun der ban were the con sen sus SQGs obtained by TEC (thresh old effect con cen tra tion), PEC (proba ble effect con cen tra tion) and EEC (extreme effect con cen tra tion), the thresh old/prob a ble effect level (TEL/PEL) approach and, finally, the ERL-ERM guide lines, includ ing the m-ERM-Q (mean ERM quo tient). The eval u a tion of the tox ic ity induced by a mix ture of the tar get pol lu tants indi cated the impor tance of c-HCH con tam i na tion in the Sun der ban sed i ments despite the very low con cen tra tions mea sured in core sed i ments. A dif fer ent sen si tiv ity for tox ic ity assess ment due to qual ity guide lines was obtained, as the con sen sus SQGs based on TEC were less con ser va tive and pro tec tive than the TEL and ERL approaches, while the use of m-ERM-Q seems to be the most pow er ful tool to pre dict the tox ic ity related to a con tami nant mix ture.
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Papers by Bhaskar Deb BHattacharya