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Sample records for hooghly-matla estuary india

  1. Assessing the potential ecological risk of Co, Cr, Cu, Fe and Zn in the sediments of Hooghly-Matla estuarine system, India.

    Science.gov (United States)

    Ghosh, Somdeep; Bakshi, Madhurima; Kumar, Alok; Ramanathan, A L; Biswas, Jayanta Kumar; Bhattacharyya, Subarna; Chaudhuri, Punarbasu; Shaheen, Sabry M; Rinklebe, Jörg

    2018-05-09

    Hooghly-Matla estuarine system along with the Sundarbans mangroves forms one of the most diverse and vulnerable ecosystems in the world. We have investigated the distribution of Co, Cr, Cu, Fe and Zn along with sediment properties at six locations [Shamshernagar (S1), Kumirmari (S2 and S3), Petuaghat (S4), Tapoban (S5) and Chemaguri (S6)] in the Hooghly estuary and reclaimed islands of the Sundarbans for assessing the degree of contamination and potential ecological risks. Enrichment factor values (0.9-21.6) show enrichment of Co, Cu and Zn in the intertidal sediments considering all sampling locations and depth profiles. Geo-accumulation index values irrespective of sampling locations and depth revealed that Co and Cu are under class II and class III level indicating a moderate contamination of sediments. The pollution load index was higher than unity (1.6-2.1), and Co and Cu were the major contributors to the sediment pollution followed by Zn, Cr and Fe with the minimum values at S1 and the maximum values at S5. The sediments of the Hooghly-Matla estuarine region (S4, S5 and S6) showed considerable ecological risks, when compared with effect range low/effect range median and threshold effect level/probable effect level values. The variation in the distribution of the studied elements may be due to variation in discharge pattern and exposure to industrial effluent and domestic sewage, storm water and agricultural run-off and fluvial dynamics of the region. The study illuminates the necessity for the proper management of vulnerable coastal estuarine ecosystem by stringent pollution control measures along with regular monitoring and checking program.

  2. Birds of Mahi River estuary, Gujarat, India

    Directory of Open Access Journals (Sweden)

    P.J. Pandya

    2010-06-01

    Full Text Available The Mahi river estuary is one of the major estuaries of Gujarat. This paper presents a comprehensive list of birds of the Mahi river estuary (nearly 50 km stretch and the adjacent banks/ravines and defines the avian diversity at three major estuarine gradations with a brief check of similarity and diversity within the three. The present observation is the outcome of a 3 year period from August 2006 to July 2009. A sum total of 118 species belonging to 42 families were reported and listed as on Upstream, Midstream, and Downstream of estuary. No significant difference was seen in the species richness at the three zones; a change in avian composition at upstream and downstream was notable.

  3. Heavy metals in Mindhola river estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Rokade, M.A; Mandalia, A

    The heavy metal concentrations are studied along the Mindhola river estuary. Surface and bottom water samples were collected using Niskin Sampler. The sediment samples were collected using a Van Veen grab. The heavy metal concentration is estimated...

  4. Suspended sediment fluxes in a tropical estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    AnilKumar, N.; DineshKumar, P.K.; Srinivas, K.

    Annual transport processes of suspended sediments in Beypore estuary - a tropical estuary along the south west coast of India - were investigated based on time series measurements within the system. It's observed that the sediment transport...

  5. Features at some significant estuaries of India

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattathiri, P.M.A.

    in the second and 162 in the third. Most of the studies on various aspects have been confined to very few of these, and that too, mostly to minor ones. Very little work has been carried out from many of the estuaries of the major rivers. An overview...

  6. Geochemical studies in the Godavari Estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Somayajulu, B.L.K.; Martin, J.M.; Eisma, D.; Thomas, A.J.; Borole, D.V.; Rao, K.S.

    are reported. The DOC and Fe concentrations are lower compared with those in other estuaries of the world and are below the average value reported for world rivers. Silicon behaves non-conservatively; its depletion which is most likely due to biological...

  7. Probable movement and mixing of contaminants in tidal estuaries - A field study in Kundalika Estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Sarma, R.V.; Zingde, M.D.

    The probable movement and mixing of contaminants within and through the Kundalika river estuary along the west coast of India are studied Neutrally buoyant biplane drogues, floats and dye were tracked at different stages of the tide to assess...

  8. Effects of hydrography on the distribution of bacteria and virus in Cochin Estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Parvathi, A; Jasna, V.; Jina, S.; Jayalakshmy, K.V.; Lallu, K.R.; Madhu, N.V.; Muraleedharan, K.R.; NaveenKumar, K.R.; Balachandran, K.K.

    The viral dynamics have rarely been investigated in estuarine environments of India. The present study brings out a first hand information on the distribution of virus and bacteria in an eutrophic estuary (Cochin, India). Thirteen stations were...

  9. Modelling of tidal hydrodynamics for a tropical ecosystem with implications for pollutant dispersion (Cochin Estuary, Southwest India)

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.; Reddy, G.S.; Revichandran, C.; Srinivas, K.; Vijayan, P.R.; Thottam, T.J.

    Tidal circulation in the Cochin Estuary, a moderately polluted estuary along the southwest coast of India, was studied using a 2D hydrodynamic model. The predicted tides and currents showed very good agreement with measured tides. Particle...

  10. Mixing and flushing time scales in the Azhikode Estuary, southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Revichandran, C.; Pylee, A.

    Flushing time scales of the Azhikode Estuary, Kerala, India showed pronounced dry season and wet season signals as well as large inter-annual variation. Cumulative flushing time of the estuary varies from 4.8 tide cycles in April to 1.22 tide cycles...

  11. Computation of dilution discharge and mean concentration of effluents in Beypore Estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Josanto, V.; Sankaranarayanan, V.N.

    Tide dominated Beypore estuary along the west coast of India was studied to estimate the mean flow available for diluting the conservative effluents based on the distribution of ambient salinity as a guide through one dimensional analysis...

  12. Speciation and behaviour of Cd, Pb and Cu in Zuari Estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    George, M.D.

    Dissolved labile and nonlabile forms of Cd, Pb and Cu in Zuari Estuary, Goa, India measured for a period of 14 months showed lowest concentrations during the SW monsoon (June-September) while maximum concentrations were observed during...

  13. Limno-tolerant bacteria govern nitrate concentration in Mandovi estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Divya, B.; Fernandes, S.O.; Sheelu, G.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

    The spatial and temporal abundances of limno-tolerant and halo-tolerant bacteria were investigated in the tide-dominated Mandovi estuary along the west coast of India. These investigations were carried out in relation to various environmental...

  14. Distribution of dissolved carbohydrates and uronic acids in a tropical estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Khodse, V.B.; Bhosle, N.B.; Matondkar, S.G.P.

    , concentrations of total dissolved carbohydrate (TCHO), dissolved polysaccharide (PCHO), dissolved monosaccharide (MCHO), and dissolved uronic acid (URA) were measured in the Mandovi estuary, west coast of India during the monsoon and premonsoon seasons...

  15. Temporal variability of macrofauna from a disturbed habitat in Zuari estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sivadas, S.; Ingole, B.S.; Nanajkar, M.

    of macrofaunal community from Mormugao Bay, Zuari estuary, (Goa) on the west coast of India was examined from 2003 to 2004 at seven stations. Environmental variability was assessed through physicochemical parameters of water and sediment. The changes...

  16. Influence of allochthonous input on autotrophiceheterotrophic switch-over in shallow waters of a tropical estuary (Cochin Estuary), India

    Digital Repository Service at National Institute of Oceanography (India)

    Thottathil, S.D.; Balachandran, K.K.; Gupta, G.V.M.; Madhu, N.V.; Nair, S.

    Bacterial productivity (BP) and respiration (BR) were examined in relation to primary productivity (PP) for the first time in a shallow tropical ecosystem (Cochin Estuary), India. The degree of dependence of BP (6.3 199.7 mu g C L sup(-1) d sup(-1...

  17. Tides in the Mandovi and Zuari estuaries, Goa, west coast of India

    Indian Academy of Sciences (India)

    Mandovi and Zuari are two estuaries located in Goa,west coast of India.Variation of water level in the estuaries was monitored for a month at 13 locations using tide-poles during March –April 2003.Analysis of this data has provided for the first time,characteristics of how tidal constituents vary in the narrow and shallow ...

  18. Fresh water influence on nutrient stoichiometry in a tropical estuary, Southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Martin, G.D.; Vijay, J.G.; Laluraj, C.M.; Madhu, N.V.; Joseph, T.; Nair, M.; Gupta, G.V.M.; Balachandran, K.K.

    et al.: Fresh water influence on nutrient stoichiometry in a tropical estuary, Southwest coast of India - 57 - APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 6(1): 57-64. http://www.ecology.uni-corvinus.hu ● ISSN 1589 1623  2008, Penkala Bt... estuary, Southwest coast of India - 58 - APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 6(1): 57-64. http://www.ecology.uni-corvinus.hu ● ISSN 1589 1623  2008, Penkala Bt., Budapest, Hungary natural and anthropogenic factors influencing the geochemistry...

  19. Seasonal stratification and property distributions in a tropical estuary (Cochin estuary, west coast, India)

    Digital Repository Service at National Institute of Oceanography (India)

    Shivaprasad, A.; Vinita, J.; Revichandran, C.; Reny, P.D.; Deepak, M.P.; Muraleedharan, K.R.; NaveenKumar, K.R.

    immune from extended hypoxia/anoxia and maintaining the health of the Cochin estuary. For the seasonally varying river flow in the estuary, salt intrusion receded with increasing river flow in monsoon and rebounded with decreasing river flow in dry season...

  20. Tides in the Mandovi and Zuari estuaries, Goa, west coast of India

    Indian Academy of Sciences (India)

    Indian Ocean, including the Arabian Sea. As a result, the windward side of the Ghats receives high precipitation due to the topographic effect. The rainfall along the central west coast of India is about 250 cm during June–September. The Mandovi and the Zuari are two estuaries that are located along the west coast, in Goa.

  1. Southwest monsoon influences the water quality and waste assimilative capacity in the Mandovi estuary (Goa state, India)

    Digital Repository Service at National Institute of Oceanography (India)

    VishnuRadhan, R.; Sagayadoss, J.; Seelan, E.; Vethamony, P.; Shirodkar, P.V.; Zainudin, Z.; Shirodkar, S.

    The monsoon-dominated Mandovi estuary is located in Goa state – a global tourist destination along the centralwest coast of India. In addition to factor analyses of water quality data, the water quality index (WQI), trophic state index (TSI...

  2. Evolution of Swarna estuary and its impact on braided islands and estuarine banks, Southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    AvinashKumar; Jayappa, K.S.; Vethamony, P.

    Qualitative and quantitative evolution of the Swarna estuary, Karnataka, India during the past 38 years (1967–2005), has been analysed by integrating the results of field surveys, satellite images, hydrodynamic modelling and topographic data in GIS...

  3. Spatio-temporal variation in δ13CDIC of a tropical eutrophic estuary (Cochin estuary, India) and adjacent Arabian Sea

    Science.gov (United States)

    Bhavya, P. S.; Kumar, Sanjeev; Gupta, G. V. M.; Sudharma, K. V.; Sudheesh, V.

    2018-02-01

    Carbon isotopic composition of dissolved inorganic carbon (δ13CDIC) in the Cochin estuary, a tropical eutrophic estuary along the southwest coast of India, and the adjacent coastal Arabian Sea was measured to understand spatio-temporal variability in sources and processes controlling inorganic carbon (C) dynamics in this estuarine-coastal system. δ13CDIC in the Cochin estuary showed wide variation during three different seasons (premonsoon: - 12.2 to - 3.26‰; monsoon: - 13.6 to - 5.69‰; and postmonsoon: - 6.34 to + 0.79‰). Detailed mixing curve approximation modeling along with relationships of δ13CDIC with dissolved oxygen and nutrients suggest dominant role of freshwater mixing and degassing of CO2 on DIC dynamics during wet seasons (premonsoon and monsoon). Excess CO2 brought in by rivers and in situ production due to respiration in the Cochin estuary result into one of the highest pCO2 observed in estuarine systems, leading to its degassing. During postmonsoon, a relatively dry period with high salinity, calcite precipitation was a major process with calcite saturation index > 1 at few locations. Relatively lower average surface values of δ13CDIC in the coastal Arabian Sea (premonsoon: + 0.95‰; monsoon: + 0.88‰; and postmonsoon: + 0.66‰) compared to the predicted open ocean value along with mixing curve modeling suggest dominance of respiration/organic matter (OM) degradation over primary productivity. Estuarine influence on coastal DIC dynamics was observed in nearshore region ( 10 km), whereas evidence of upwelling was found at farther locations.

  4. Flushing characteristics of Amba river estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Sarma, R.V.; Josanto, V.

    of 22 tidal cycles for neap, 6 to 7 tidal cycles for spring and dry weather flushing time of 45 tidal cycles for neap, 6 to 7 tidal cycles for spring based on modified tidal prism method indicated that the load retained in the estuary after infinite...

  5. Suspended sediment dynamics in Cochin estuary, West coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Vinita, J.; Revichandran, C.; Manoj, N.T.

    concentration (SSC) were conducted at spring and neap periods of wet and dry seasons. These data were complemented by measurements of tides, currents, vertical profiling of hydrography and turbidity at the main inlet of the estuary. The results showed that SSC...

  6. Reduced river discharge intensifies phytoplankton bloom in Godavari estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Acharyya, T.; Sarma, V.V.S.S.; Sridevi, B.; Venkataramana, V.; Bharathi, M.D.; Naidu, S.A.; Kumar, B.S.K.; Prasad, V.R.; Bandyopadhyay, D.; Reddy, N.P.C.; DileepKumar, M.

    et al., 2009; Sarma et al., 2011), behaviour of different 3 elements (Sarma et al., 1993) and heavy metals (Somayajulu et al., 1993).Virtually no systematic studies have been undertaken so far in these estuaries focussing on spatial and... their class specific marker pigment fucoxanthin (Jeffry et al., 1997; Mantoura and Llewellyn, 1983; Wright et al., 1991). To confirm the influence of SPM and flushing time on phytoplankton bloom a laboratory- based incubation experiment was conducted...

  7. Nutrients, hypoxia and mass fishkill events in Tapi estuary, India.

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; JiyalalRam, M.J.; Rokade, M.A.; Bharti, S.; Vishwasrao, C.; Majithiya, D.

    ecosystem (Villate et al. 2013). The flushing out of contaminants entering an estuary is further impacted due to impounding of water in dams, weirs and barrages for hydropower, navigation, aquaculture, diversion for urban water supply, agriculture, due...., 2008. Eutrophic waters, algal bloom and fish kill in fish farming areas in Bolinao, Pangasinan, Philippines. Marine Pollution Bulletin 57, 295–301 Sargaonkar, A., 2006. Estimation of land use specific runoff and pollutant concentration for Tapi...

  8. Distribution of mercury in a tropical estuary (India) situated near a chloro-alkali plant

    OpenAIRE

    Gouda, Rajashree; Panigrahy, R.C.

    1995-01-01

    The distribution of mercury in water, sediment and some biological samples of the Rushikulya estuary, east coast of India were assessed during Jan-Dec. 1989. Both the dissolved plus acid leachable mercury contents in water and the sediment mercury discerned conspicuous spatial and seasonal fluctuations. Adsorption on to the suspended particulates was found to be the most likely mechanism for removal of mercury from the water column. Exchange of mercury from sediments to water was observed at ...

  9. The impact of dredging on residence time in the Amba estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Velamala, S.N.; Thomas, J.; Bari, S.; Kachave, S.

    for the Musa estuary (Persian Gulf), Payandeh, Zaker and Niksokhan (2014) showed that the persistency of currents was a useful indicator for identifying areas of pollutant load accumulation. The RTs have also been studied by several authors (e.g. Luff....W.A Naqvi, Director, National Institute of Oceanography, India, for their constant encouragement and support during the work. Authors would also like to express their gratitude to Lisa V. Lucas, Geological Survey, US for her comments on this manuscript...

  10. Studies on fouling diatoms from the Zuari Estuary, Goa (west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Redekar, P.D.; Wagh, A.B.

    from offshore waters of Bombay High area using aluminium panels and recorded 58 species of fouling diatoms Of these Navicula Coscinodiscus Rhizosolenia and Chaetoceros were found to be common The dominance of Centrales over Pennales in water column... on fouling diatoms from the Zuari estuary, Goa (West coast of India) 119 Pangu (1993) used mild steel, aluminium, fiberglass and glass test panels and the immersion period of panels was long (1 month to 11 months) The fouling diatoms from Waghotana...

  11. Short-term variability of water quality and its implications on phytoplankton production in a tropical estuary (Cochin backwaters - India)

    Digital Repository Service at National Institute of Oceanography (India)

    Madhu, N.V.; Balachandran, K.K.; Martin, G.D.; Jyothibabu, R; Thottathil, S.D.; Nair, M.; Joseph, T.; Kusum, K.K.

    , C.A., Martin, G.D & Nair, K.K.C., (2006). Impact of fresh water influx on microzooplankton mediated food web in a tropical estuary (Cochin backwaters - India). Estuarine, Coastal and Shelf Science, 69, 505 - 518. Madhu. N.V., Jyothibabu, R..., Y., Wetzel, R.L., Anderson, I.C., 1999. Spatial and temporal characteristics of nutrient and phytoplankton dynamics in the York River Estuary, Virginia: analyses of long-term data. Estuaries 22, 260-275. Srinivas. K, Revichandran, C., Maheswaran...

  12. Tides in the Mandovi and Zuari estuaries, Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sundar, D; Shetye, S.R.

    , October 2005, pp. 493?503 ? Printed in India. 493 494 D Sundar and S R Shetye Figure 1. A map of the Mandovi and Zuari estuaries. The locations where water level observations were carried out are marked with a number in a circle. The name of the location... consecutive values. The amplitudes and phase lags were recomputed using a time series in which the time interval between two consecu- tive values was two hours. As the original data are 496 D Sundar and S R Shetye Figure 3. Observed sea level (cm) during...

  13. Impact of freshwater influx on microzooplankton mediated food web in a tropical estuary (Cochin backwaters - India)

    Digital Repository Service at National Institute of Oceanography (India)

    Jyothibabu, R; Madhu, N.V.; Jayalakshmi, K.V.; Balachandran, K.K.; Shiyas, C.C.; Martin, G.D.; Nair, K.K.C.

    -1 Impact of fresh water influx on microzooplankton mediated food web in a tropical estuary (Cochin backwaters - India) R. Jyothibabu A, B, N.V. Madhu A, K.V. Jayalakshmi A, K. K. Balachandran A, C. A. Shiyas A, G. D. Martin A and K. K. C. Nair A A... in the northeastern Atlantic Ocean. Deep Sea Research 40, 479 ? 493. Burkill, P. H., Leaky, R. J. G., Owens, N. J. P., and Mantoura, R. F. C., 1993b. Synechococcus and its importance to the microbial food web of the northwestern Indian Ocean, In: Biogeochemical...

  14. Biomarker pigment signatures in Cochin back water system - A tropical estuary south west coast of India

    Science.gov (United States)

    Aneeshkumar, N.; Sujatha, C. H.

    2012-03-01

    Sedimentary biomarker pigments around Cochin estuary situated in the southwest coast of India were determined by HPLC. Fucoxanthin, an indicator of diatom was observed to be the most abundant carotenoid pigment in the estuary. Dinoflagellate derived carotenoid pigment peridinin was confined in the southern part of estuary and zeaxanthin pigment indicative of cyanobacteria were more found in sites influenced by anthropogenic activities. One compound having close similarity to fucoxanthin was also detected. Alloxanthin (cryptophyceae), chl b (green algae), canthaxanthin, neoxanthin, lutein and peridinin isomer were also detected by spectra and corresponding algal class were identified. The highest concentration of chl a (11.01 μg g-1) found near to the anthropogenic affected area while the lowest chl a (0.65 μg g-1) was recorded in industrial area. Degradation products of chl a, such as pheophorbide and pheophytin were observed and principal mode of mechanism of degradation were derived. Higher pheopigments content than chl a, reflects a density trapping of dead cells and early degradation of phytopigments from grazing activities.

  15. Spatial and temporal distribution of metals in suspended particulate matter of the Kali estuary, India

    Science.gov (United States)

    Suja, S.; Kessarkar, Pratima M.; Fernandes, Lina L.; Kurian, Siby; Tomer, Arti

    2017-09-01

    Major (Al, Fe, Mn, Ti, Mg) and trace (Cu, Zn, Pb, Cr, Ni, Co, Zr, Rb, Sr, Ba, Li, Be, Sc, V, Ga, Nb, Mo, Sn, Sb, Cs, Hf, Ta, Bi, Th, U) elements and particulate organic carbon (POC) concentrations in surface suspended particulate matter (SPM) of the Kali estuary, (central west coast of India) were studied during the pre-monsoon, monsoon and post monsoon seasons to infer estuarine processes, source of SPM and Geoaccumulation Index (Igeo) assigned pollutionIgeo levels. Distribution of SPM indicates the presence of the estuarine turbidity maximum (ETM) during all three seasons near the river mouth and a second ETM during the post monsoon time in the upstream associated with salinities gradient. The SPM during the monsoon is finer grained (avg. 53 μm), characterized by uniformly low normalized elemental concentration, whereas the post and pre monsoon are characterized by high normalized elemental concentration with coarser grain size (avg. 202 μm and 173 μm respectively) with highest ratios in the upstream estuary. The elemental composition and principal component analysis for the upstream estuary SPM support more contribution from the upstream catchment area rocks during the monsoon season; there is additional contribution from the downstream catchment area during the pre and post monsoon period due to the tidal effect. The Kali estuarine SPM has higher Al, Fe, Mn, Ti, Mg, Ni, Co, Ba, Li and V with respect to Average World River SPM (WRSPM). Igeo values for the SPM indicate Kali Estuary to be severely enriched with Mn and moderately enriched with Cu, Zn, Ni, Co, U and Mo in the upstream estuary during pre and post monsoon seasons. Seasonal changes in salinity gradient (reduced freshwater flow due to closing of the dam gates), reduced velocity at meandering region of the estuary and POC of 1.6-2.3% resulted in co-precipitation of trace elements that were further fortified by flocculation and coagulation throughout the water column resulting in metal trapping in the

  16. Plankton food web and its seasonal dynamics in a large monsoonal estuary (Cochin backwaters, India)-significance of mesohaline region

    Digital Repository Service at National Institute of Oceanography (India)

    Sooria, P.M.; Jyothibabu, R; Anjusha, A.; Vineetha, G.; Vinita, J.; Lallu, K.R; Paul, M.; Jagadeesan, L.

    The paper presents the ecology and dynamics of plankton food web in the Cochin backwaters (CBW), the largest monsoonal estuary along the west coast of India. The data source is a time series measurement carried out in the CBW during the Spring...

  17. Differential impact of lytic viruses on prokaryotic morphopopulations in a tropical estuarine system (Cochin estuary, India).

    Science.gov (United States)

    Jasna, Vijayan; Pradeep Ram, Angia Sriram; Parvathi, Ammini; Sime-Ngando, Telesphore

    2018-01-01

    Our understanding on the importance of viral lysis in the functioning of tropical estuarine ecosystem is limited. This study examines viral infection of prokaryotes and subsequent lysis of cells belonging to different morphotypes across a salinity gradient in monsoon driven estuarine ecosystem (Cochin estuary, India). High standing stock of viruses and prokaryotes accompanied by lytic infection rates in the euryhaline/mesohaline region of the estuary suggests salinity to have an influential role in driving interactions between prokaryotes and viruses. High prokaryotic mortality rates, up to 42% of prokaryote population in the pre-monsoon season is further substantiated by a high virus to prokaryote ratio (VPR), suggesting that maintenance of a high number of viruses is dependent on the most active fraction of bacterioplankton. Although myoviruses were the dominant viral morphotype (mean = 43%) throughout the study period, there was significant variation among prokaryotic morphotypes susceptible to viral infection. Among them, the viral infected short rod prokaryote morphotype with lower burst estimates (mean = 18 viruses prokaryote-1) was dominant (35%) in the dry seasons whereas a substantial increase in cocci forms (30%) infected by viruses with high burst size (mean = 31 viruses prokaryote-1) was evident during the monsoon season. Such preferential infections of prokaryotic morphopopulations with respect to seasons can have a strong and variable impact on the carbon and energy flow in this tropical ecosystem.

  18. Heavy metal pollution exerts reduction/adaptation in the diversity and enzyme expression profile of heterotrophic bacteria in Cochin estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Jose, J.; Giridhar, R.; Anas, A; LokaBharathi, P.A; Nair, S.

    Over the past three decades heavy metal pollution has increased substantially in Cochin estuary, south west coast of India. The distribution, diversity and enzyme expression profile of culturable microbial population along a pollution gradient...

  19. Circulation and mixing process in Vasishta-Godavari estuary, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, A.R.S.; Murty, T.V.R.; Rao, M.M.M.; Rao, V.R.; Reddy, B.S.R.

    Circulation and Mixing Process in Vasishta-Godavari Estuary, have been studied by using estuarine classification model. Analysis of salinity, salt budget, diffusion coefficients and flushing times based on salinity data of Vasishta-Godavari estuary...

  20. Variability in stratification and flushing times of the Gautami-Godavari estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Sridevi, B.; Sarma, V.V.S.S.; Murty, T.V.R.; Sadhuram, Y.; Reddy, N.P.C.; Vijaykumar, K.; Raju, N.S.N.; JawaharKumar, CH.; Raju, Y.S.N.; Luis, R.; Kumar, M.D.; Prasad, K.V.S.R.

    –Godavari estuary (G–GE) during spring and neap tide periods covering entire spectrum of discharge over a distance of 36 km from the mouth. The bathymetry of the estuary was recently changed due to dredging of ~20 km of the estuary from the mouth for transportation...

  1. Investigating sea bed morphology of an estuary located in the western coast of India

    Science.gov (United States)

    Chowdhury, P.; Behera, M. R.; Ranjan, P.

    2016-02-01

    Estuaries and tidal inlets are complex natural systems. They form a vital ecosystem and host a plethora of diverse flora and fauna. The major problem associated with them is that they experience both climate effects and human interference in different spatial and temporal scales. The increasing threats of sea level variability and changes in the other ocean parameters like currents, waves, winds and tidal ranges may cause these inlets to behave differently. Mandovi - Zuari is one such complex inlet situated in the western coast of India. It is a major tourist attraction and a home to dense mangrove forest. It experiences mixed tides (mainly semi-diurnal in nature). Also the salinity of this region tends to change seasonally. The annual evolution in morphology of this region is of importance as the sediment transport in this area plays an important role in determining the beach morphology of the adjacent beaches. Tourism being the most important economic driver of this state, it is important to assess the possible changes in the beach morphology over the coming decades. A state-of-the-art process based model, Delft 3D, is used to calculate the annual sediment transport with a focus to understand the morphological evolution history of this inlet. In this regard a hydrodynamic analysis of the region is carried out by forcing a composite tide at the offshore boundary of the model domain to obtain the tidal levels and currents. The sea bed contours are obtained with the help of admiralty charts. For estimating the sediment transport, Van Rijn formula is used as found in the sediment module of Delft 3D. The morphological changes along the coast of Goa, India is estimated and the locations of accretion and erosion are identified.

  2. Response of phytoplankton to nutrient enrichment with high growth rates in a tropical monsoonal estuary - Zuari estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Mochemadkar, S.; Gauns, M.; Pratihary, A.K.; Thorat, B.R.; Roy, R.; Pai, I.K.; Naqvi, S.W.A.

    nitzschioides exhibited the ability to withstand hypoxic condition. [Keywords: Zuari estuary, Premonsoon, Nutrient uptake, Phytoplankton, Hypoxic] Introduction Phytoplanktons are responsible for nearly half of global primary production1. Diatoms... and fresh water inputs. Light and nutrients are the primary factors regulating phytoplankton growth4,5 followed by temperature and salinity6 . Major (macro) nutrients essential for plant growth are nitrogen, phosphorous and silicon7. Phytoplankton...

  3. Measurement of submarine groundwater discharge using diverse methods in Coleroon Estuary, Tamil Nadu, India

    Science.gov (United States)

    Prakash, R.; Srinivasamoorthy, K.; Gopinath, S.; Saravanan, K.

    2018-03-01

    Submarine groundwater discharge (SGD) is described as submarine inflow of fresh and brackish groundwater from land into the sea. The release of sewages from point and non-point source pollutants from industries, agricultural and domestic activities gets discharged through groundwater to ocean creating natural disparity like decreasing flora fauna and phytoplankton blooms. Hence, to quantify fluxes of SGD in coastal regions is important. Quantification of SGD was attempted in Coleroon estuary, India, using three dissimilar methods like water budget, Darcy law and manual seepage meter. Three seepage meters were installed at two prominent litho units (alluvium and fluvio marine) at a distance of (0-14.7 km) away from Bay of Bengal. The water budget and Darcy law-quantified submarine seepage at a rate of 6.9 × 106 and 3.2 × 103 to 308.3 × 103 m3 year-1, respectively, and the seepage meter quantified seepage rate of 0.7024 m h-1 at an average. Larger seepage variations were isolated from three different techniques and the seepage rates were found to be influenced by hydrogeological characteristics of the litho units and distance from the coast.

  4. Methane and nitrous oxide fluxes in the polluted Adyar River and estuary, SE India

    International Nuclear Information System (INIS)

    Nirmal Rajkumar, A.; Barnes, J.; Ramesh, R.; Purvaja, R.; Upstill-Goddard, R.C.

    2008-01-01

    We measured dissolved N 2 O, CH 4 , O 2 , NH 4 + , NO 3 - and NO 2 - on 7 transects along the polluted Adyar River-estuary, SE India and estimated N 2 O and CH 4 emissions using a gas exchange relation and a floating chamber. High NO 2 - implied some nitrification of a large anthropogenic NH 4 + pool. In the lower catchment CH 4 was maximal (6.3 ± 4.3 x 10 4 nM), exceeding the ebullition threshold, whereas strong undersaturation of N 2 O and O 2 implied intense denitrification. Emissions fluxes for the whole Adyar system ∼2.5 x 10 8 g CH 4 yr -1 and ∼2.4 x 10 6 g N 2 O yr -1 estimated with a gas exchange relation and ∼2 x 10 9 g CH 4 yr -1 derived with a floating chamber illustrate the importance of CH 4 ebullition. An equivalent CO 2 flux ∼1-10 x 10 10 g yr -1 derived using global warming potentials is equivalent to total Chennai motor vehicle CO 2 emissions in one month. Studies such as this may inform more effective waste management and future compliance with international emissions agreements

  5. Residual fluxes of water and nutrient transport through the main inlet of a tropical estuary, Cochin estuary, West Coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Vinita, J.; Lallu, K.R; Revichandran, C.; Muraleedharan, K.R; Jineesh, V.K.; Shivaprasad, A.

    of Oceanic Engineering, 25(4), 437-445. 13    Sooria, P.M., Jyothibabu, R., Anjusha, A., Vineetha, G., Vinita, J., Lallu, K. R., Paul, M., Jagadeesan, L., et al. (2015). Plankton food web and its seasonal dynamics in a large monsoonal estuary (Cochin... J., Lallu K.R., Muraleedharan K. R., Jineesh V.K., Shivaprasad A. Abstract Determining robust values for estuarine material fluxes has been a complex task and an interdisciplinary research challenge. With the advent of Acoustic Doppler...

  6. Macrobenthic communities of the Vellar Estuary in the Bay of Bengal in Tamil-Nadu in South India

    Science.gov (United States)

    Chertoprud, M. V.; Chertoprud, E. S.; Saravanakumar, A.; Thangaradjou, T.; Mazei, Yu. A.

    2013-03-01

    The macrobenthic fauna and communities of the Vellar Estuary located at the southeast cost of India (11°30' N, 79°45' E) and the adjacent marine and river habitats are described on the basis of original data (70 samples over 10 transects). The fauna consists of 115 macrobenthic species and 79 species in estuarine habitats. We described 14 types of macrobenthic communities with different compositions of the dominant species. The leading ecological factors of the distribution of the communities are the salinity, depth, and bottom type. The Vellar estuary consists of two longitudinal zones of macrobenthos. The polyhalinic area is populated by the marine species, but it is related not to a salinity decrease but to the protection from waves and silt on the bottom in this area. The polyhalinic communities are most abundant in terms of the biomass and species richness. The mesohalinic area is inhabited by brackish water species and communities with low abundance. The sublittoral estuarine area is dominated by filter-feeders—the bivalves Crassostrea madrasensis, Meretrix casta, Modiolus metcalfei, and Scapharca inaequivalves—and the littoral zone is dominated by the gastropods Cerithidea cingulata, some crabs, and polychaetes. The ecosystem function of the Vellar estuary can be defined as a filter for the fine organic particles transported by the river.

  7. Diurnal variation in zooplankton in the Zuari Estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Padmavati, G.; Goswami, S.C.; Vidya, P.S.

    Variations in zooplankton biomass and population density in relation to the prevailing hydrographical conditions were studied in Zuari Estuary, Goa. The physico-chemical parameters showed limited variations. Zooplankton biomass was relatively more...

  8. Sources, distribution and preservation of organic matter in a tropical estuary (Godavari, India)

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, M.S.; Naidu, S.A.; Subbaiah, Ch.V.; Gawade, L.; Sarma, V.V.S.S.; Reddy, N.P.C.

    the lower estuary, relatively low sediment OC was found in the former than the latter region, suggesting that strong influence of preservation conditions rather than surface biological production on OC accumulation in sediments. This is attributed to intense...

  9. Observed mixed standing-wave signatures in Cochin Estuary on the southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Srinivas, K.; Muraleedharan, K.R.; Thottam, T.J.

    Study of the characteristics of currents and water-level variations in the Cochin estuary reveals, for the first time, unique signatures of mixed standing-waves in the southern region. Analysis of the simultaneous water-level data generated...

  10. The nature and distribution of particulate matter in the Mandovi Estuary, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Kessarkar, P.M.; Rao, V.P.; Shynu, R.; Mehra, P.; Viegas, B.E.

    at the river- and sea-end stations, respectively. Smectite concentrations increase seawards with the increase in SPM content and are not influenced by salinity. Winddriven waves and currents and biogeochemical processes at the mouth of estuary likely play...

  11. Freshwater flushing time scales of the Vashishti Estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Sarma, R.V.; Zingde, M.D.

    method indicated that the load retained in the estuary after infinite number of tidal cycles was 44 to 54 times the load introduced per tidal cycles during premonsoon and 47 to 61 times during postmonsoon periods. Calculations on longitudinal diffusion...

  12. Uranium isotopes in rivers, estuaries and adjacent coastal sediments of western India: their weathering, transport and oceanic budget

    International Nuclear Information System (INIS)

    Borole, D.V.; Krishnaswami, S.; Somayajulu, B.L.K.

    1982-01-01

    The two major river systems on the west coast of India, Narbada and Tapti, their estuaries and the coastal Arabian sea sediments have been extensively studied for their uranium concentrations and 234 U/ 238 U activity ratios. The 238 U concentrations in the aqueous phase of these river systems exhibit a strong positive correlation with the sum of the major cations, and with the HCO 3 - ion contents. The abundance ratio of dissolved U to the sum of the major cations in these waters is similar to their ratio in typical crustal rocks. In the estuaries, both 238 U and its great-grand daughter 234 U behave conservatively beyond chlorosities 0.14 g/l. A review of the uranium isotope measurements in river waters yield a discharge weighted-average 238 U concentration of 0.22 μg/l with a 234 U/ 238 U activity ratio of 1.20 +-0.06. The residence time of uranium isotopes in the oceans estimated from the 238 U concentration and the 234 U/ 238 U A.R. of the rivers yield conflicting results; the material balance of uranium isotopes in the marine environment still remains a paradox. If the disparity between the results is real, then an additional 234 U flux of about 0.25 dpm/cm 2 .10 3 yr into the oceans is necessitated. (author)

  13. Distribution and behaviour of fluoride in Mandovi and Zuari estuaries, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    De; SenGupta, R.

    behaves conservatively during these 2 seasons. During the premonsoon, however, the F-Cl relationship is not linear but exponential of the type Y = abx which is curve concave to the fluoride-axis indicating that fluoride is lost in estuaries in this season...

  14. Wind-driven estuarine turbidity maxima in Mandovi Estuary, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Kessarkar, P.M.; Rao, V.P.; Shynu, R.; Ahmad, I.M.; Mehra, P.; Michael, G.S.; Sundar, D.

    Systematic studies on the suspended particulate matter (SPM) measured on a seasonal cycle in the Mandovi Estuary, Goa indicate that the average concentrations of SPM at the regular station are approx. 20mg/l, 5mg/l, 19mg/l and 5mg/l for June...

  15. Transport of dissolved nutrients and chlorophyll a in a tropical estuary, southwest coast of India.

    Digital Repository Service at National Institute of Oceanography (India)

    Lallu, K.R.; Fausia, K.H.; Vinita, J.; Balachandran, K.K.; NaveenKumar, K.R.; Rehitha, T.V.

    .Spring-neap tides.Chlorophyll a 2    Introduction Estuaries are the intermediate zones of land-sea interactions contributing significantly to the nutrient fluxes in to the ocean on varying time scales (Simpson et al. 2001). The nutrient delivery...

  16. Biological characteristics of the Vashishti Estuary, Maharashtra (west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Mustafa, S.; Mehta, P.; Govindan, K.; JiyalalRam, M.; Gajbhiye, S.N.

    The estuary and coastal nearshore regions sustained fairly high concentration of chlorophyll a (av. 3.1 mg/m sup(3)) and primary productivity (av. 89.9 mgC/m sup(3)/h). High rate of primary productivity wos observed in the estuarine segments...

  17. Does mining pollution affect foraminiferal distribution in Mandovi estuary, Goa, India?

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Nayak, G.N.; Naik, S.

    and 6.69 – 114.49 mg/l in 1990) in the estuary. This increased suspended load can be attributed to mining activities in the catchment area of Mandovi River along with its tributaries. Extraction of one tonne of iron ore generate about 1.5 to 4 tonnes...

  18. A comparative study on the internal dose due to Polonium-210 in the ecosystem of Athangarai estuary (Palk Strait) and Punnaikayal estuary (Gulf of Mannar), India

    International Nuclear Information System (INIS)

    Krishnamoorthy, R.; Ravikumar, S.; Shahul Hameed, P.

    2006-01-01

    The present study deals with Committed Effective Dose (CEO) due to 210 Po through the dietary intake of seafood from the Athangarai estuary and Punnaikayal estuary. The concentration of 210 Po was determined in selected species of estuarine organisms. It is found that the 210 Po dose due to the consumption of estuarine food varied from 49.9 to 552.1 μSv/y in Athangarai estuary and 148.0 to 406.9 μSv/y in Punnaikayal estuary. Concentration of 210 Po in the muscle of edible organisms in Athangarai estuary and Punnaikayal estuary ranged from 20.8 to 181.3 Bq/kg and 88.1 to 242.2 Bq/kg respectively. Higher 210 Po dose is expected via the consumption of fish Sandinella longiceps (552.1 μSv/y) in Athangarai estuary and Thyssa malabarica (406.9 μSv/y) in Punnaikayal estuary. In the present study higher level of 210 Po concentration was observed in Plankton feeding fish of both the estuary. (author)

  19. Physicochemical and biological factors controlling water column metabolism in Sundarbans estuary, India

    Science.gov (United States)

    2012-01-01

    Background Sundarbans is the single largest deltaic mangrove forest in the world, formed at estuarine phase of the Ganges - Brahmaputra river system. Primary productivity of marine and coastal phytoplankton contributes to 15% of global oceanic production. But unfortunately estuarine dynamics of tropical and subtropical estuaries have not yet received proper attention in spite of the fact that they experience considerable anthropogenic interventions and a baseline data is required for any future comparison. This study is an endeavor to this end to estimate the primary productivity (gross and net), community respiration and nitrification rates in different rivers and tidal creeks around Jharkhali island, a part of Sundarbans estuary surrounded by the mangrove forest during a period of three years starting from November’08 to October’11. Results Various physical and chemical parameters of water column like pH, temperature, conductivity, dissolved oxygen, turbidity, suspended particulate matter, secchi disc index, tidal fluctuation and tidal current velocity, standing crop and nutrients were measured along with water column productivity. Relationship of net water column productivity with algal biomass (standing crop), nutrient loading and turbidity were determined experimentally. Correlations of bacterial abundance with community respiration and nitrification rates were also explored. Annual integrated phytoplankton production rate of this tidal estuary was estimated to be 151.07 gC m-2 y-1. Gross primary productivity showed marked inter annual variation being lowest in monsoon and highest in postmonsoon period. Conclusion Average primary production was a function of nutrient loading and light penetration in the water column. High aquatic turbidity, conductivity and suspended particulate matter were the limiting factors to attenuate light penetration with negative influence on primary production. Community respiration and nitrification rates of the estuary were

  20. Physicochemical and biological factors controlling water column metabolism in Sundarbans estuary, India.

    Science.gov (United States)

    Chaudhuri, Kaberi; Manna, Suman; Sarma, Kakoli Sen; Naskar, Pankaj; Bhattacharyya, Somenath; Bhattacharyya, Maitree

    2012-10-19

    Sundarbans is the single largest deltaic mangrove forest in the world, formed at estuarine phase of the Ganges - Brahmaputra river system. Primary productivity of marine and coastal phytoplankton contributes to 15% of global oceanic production. But unfortunately estuarine dynamics of tropical and subtropical estuaries have not yet received proper attention in spite of the fact that they experience considerable anthropogenic interventions and a baseline data is required for any future comparison. This study is an endeavor to this end to estimate the primary productivity (gross and net), community respiration and nitrification rates in different rivers and tidal creeks around Jharkhali island, a part of Sundarbans estuary surrounded by the mangrove forest during a period of three years starting from November'08 to October'11. Various physical and chemical parameters of water column like pH, temperature, conductivity, dissolved oxygen, turbidity, suspended particulate matter, secchi disc index, tidal fluctuation and tidal current velocity, standing crop and nutrients were measured along with water column productivity. Relationship of net water column productivity with algal biomass (standing crop), nutrient loading and turbidity were determined experimentally. Correlations of bacterial abundance with community respiration and nitrification rates were also explored. Annual integrated phytoplankton production rate of this tidal estuary was estimated to be 151.07 gC m-2 y-1. Gross primary productivity showed marked inter annual variation being lowest in monsoon and highest in postmonsoon period. Average primary production was a function of nutrient loading and light penetration in the water column. High aquatic turbidity, conductivity and suspended particulate matter were the limiting factors to attenuate light penetration with negative influence on primary production. Community respiration and nitrification rates of the estuary were influenced by the bacterial abundance

  1. Sub-tidal water-level oscillations in the Mandovi estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Vijith, V.

    of rainfall associated with the ISM and its interannual and intraseasonal variability. With most of the rainfall occurring during the wet ISM, most of the runoff into the estuaries is also during the same season. There is virtually no runoff... water level computed using the pressure sensor versus that using the tide pole shows that the high-frequency scatter is larger for the tide-pole measurements. However, the low-pass filtered variability is virtually identical in the tide...

  2. High CO2 emissions from the tropical Godavari estuary (India) associated with monsoon river discharges

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Kumar, N.A.; Prasad, V.R.; Venkataramana, V.; Appalanaidu, S.; Sridevi, B.; Kumar, B.S.K.; Bharati, M.D.; Subbaiah, C.V.; Acharyya, T.; Rao, G.D.; Viswanadham, R.; Gawade, L.; Manjary, D.T.; Kumar, P.P.; Rajeev, K.; Reddy, N.P.C.; Sarma, V.V.; Kumar, M.D.; Sadhuram, Y.; Murty, T.V.R.

    ). Air-water flux of CO 2 was estimated following Wanninkhof (1992) using measured wind speed. 3. Results and discussion The dam controlled freshwater discharge into the Godavari estuary was maximal in August (Fig. 2a). There was virtually... bacterioplankton. Appl. Environ. Microbiol.52,1298-1303. Lewis, E., and D.W.R. Wallace (1998). Program developed for CO2 system calculations. ORNL/CDIAC-105. Carbon dioxide information analysis center, Oak Ridge National Laboratory, U.S. Department of Energy...

  3. Diagenesis and bioavailability of mercury in the contaminated sediments of Ulhas Estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Borole, D.V.; Rokade, M.A.; Zingde, M.D.

    ), and determining the retention of particle-bound elements in the sedimentary record (Shaw et al., 1990). Bioavailable metals are defined as metals in such a biologically available chemical state that they can be taken up by an organism and can react with its..., characterized by particular hydrodynamics and physical, 3 chemical and biological conditions. The estuary can be considered a natural chemical reactor in which material is constantly imported, transformed and exported. It is heavily affected by anthropogenic...

  4. Geospatial analysis of long-term morphological changes in Cochin estuary, SW coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Gopinath, G.; Manimurali, R.; Muraleedharan, K.R.

    are complex, where resource and management systems often confront with multiple conflicts. Estuarine functioning is case sensitive to changes in environmental factors and human interventions. Morphology of estuaries are generally characterized by the strong... for future. Synchronous environmental data would be useful in understanding the carrying capacity and problems and potentialities of fisheries, tourism and navigation. CONCLUSION In the discussion above, we examined the long period geospatial information...

  5. Massive production of heavy metals in the Ganga (Hooghly) River estuary, India: Global importance of solute-particle interaction and enhanced metal fluxes to the oceans

    Science.gov (United States)

    Samanta, Saumik; Dalai, Tarun K.

    2018-05-01

    The Ganga River System is a major contributor to the global sediment and water discharge to the oceans. The estuary of Ganga (Hooghly) River in India is under increasing influence of anthropogenic contributions via discharge of the industrial and urban effluents. Here we document, based on the investigation of water and suspended sediment samples collected during six periods over two years, that there is extensive production of heavy metals (Co, Ni and Cu) in the estuary such that the annual dissolved fluxes of metals from the Hooghly River are enhanced by up to 230-1770%. Furthermore, the estuarine dissolved metal fluxes, when normalized with water fluxes, are the highest among estuaries of the major rivers in the world. Our simultaneous data on the dissolved, suspended particulate and exchangeable phases allow us to identify the ion-exchange process (coupled adsorption and desorption) as the dominant contributor to the generation of heavy metals in the middle and lower estuary where the estimated anthropogenic contribution is negligible. The estimated contributions from the groundwater are also insufficient to explain the measured metal concentrations in the estuary. A strong positive correlation that is observed between the dissolved heavy metal fluxes and the suspended particulate matter (SPM) fluxes, after normalizing them with the water fluxes, for estuaries of the major global rivers imply that the solute-particle interaction is a globally significant process in the estuarine production of metals. Based on this correlation that is observed for major estuaries around the world, we demonstrate that the South Asian Rivers which supply only ∼9% of the global river water discharge but carry elevated SPM load, contribute a far more significant proportion (∼40 ± 2% Ni and 15 ± 1% Cu) to the global supply of the dissolved metals from the rivers.

  6. Morphometry and cell volumes of diatoms from a tropical estuary of India

    Digital Repository Service at National Institute of Oceanography (India)

    RaviKumar, M.S.; Ramaiah, N.; Tang, D.

    Cell volumes and per cell carbon contents of different diatoms (10 centric, 14 pennate and 1 dinoflagellate) collected from Dona Paula Bay in the central west coast of India have been analyzed. Morphometric information on the phytoplankton types...

  7. Dynamics of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Cochin estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Ramzi, A.;; Rahman, K.H.; Gireeshkumar, T.R.; Balachandran, K.K.; Jacob, C.; Chandramohanakumar, N

    - ters, Sediments, and Shrimps of Estero de Urias, an Estuary in Mexico, and Their Tox- icological Effects Scientific World Journal. Joseph, M.L., 2004. Status Report on Periyar River, Centre for Water Resource Develop- Parinos, C., Gogou, A., 2016... to particu- ent (Guzzella and De Marine Pollution Bulletin 114 (2017) 1081–1087 Contents lists available at ScienceDirect Marine Pollut l seincreases for the last four decades; so did concentrations of Cd, Zn, Hg and Pb (Mohan et al., 2012; Ranjitha...

  8. Eutrophication induced changes in benthic community structure of a flow-restricted tropical estuary (Cochin backwaters), India

    Digital Repository Service at National Institute of Oceanography (India)

    Martin, G.D.; Nisha, P.A.; Balachandran, K.K.; Madhu, N.V.; Nair, M.; Shaiju, P.; Joseph, T.; Srinivas, K.; Gupta, G.V.M.

    The influence of anthropogenic loading on the distribution of soft bottom benthic organisms of a tropical estuary (Cochin backwaters) was examined. The industrial activities were found to be high in the northern and central part of the estuary...

  9. Distribution, provenance and early diagenesis of major and trace metals in sediment cores from the Mandovi estuary, western India

    Digital Repository Service at National Institute of Oceanography (India)

    Prajith, A.; Rao, V.P.; Chakraborty, P.

    Major elements and trace metals were analyzed in four sediment cores recovered along a transect in the Mandovi estuary for their distribution, provenance and early diagenesis. The sediments were clayey silts in cores from the upper/lower estuary...

  10. Nursery life of the marine prawn, Metapenaeus dobsoni (Miers) in the Mandovi estuary, along Goa Coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.

    of the estuary. Seasonal variation in abundance was discernible. Initial growth occurred in the shallow region of the estuary bordered by mangroves and later in the deeper waters of the open estuary. Optimum attainable size in the estuarine environment was 50...

  11. A maritime archaeological exploration along the Narmada estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh

    few antiquities of protohistoric period also found including a chart blade, a carnelian bead (Figure 5) and splinder wheel. The second period is identified as medieval period and majority of pottery is comprised of back ware and main shape.... Law, B.C. 1967. Historical Geography of Ancient India. Paris: Societe Asiatique De Paris. McCrindle, J.W. 1885. Ancient India as described by Ptolemy. New Delhi: Today and Tomorrow’s Printers and Pub. Rao, S.R. 1962-63. Excavation at Rangpur...

  12. Influence of estuaries on shelf foraminiferal species

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.

    Dabhol-bhatkal stretch of the west coast of India is marked by a number of estuaries. Cavarotalia annectens is selected to monitor the influence of these estuaries on the inner shelf foraminiferal fauna. The percentage distribution of this species...

  13. Planktonic diatoms of the Zuari estuary, Goa (west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Redekar, P.D.; Wagh, A.B.

    composition in the coastal waters between Jaigarh and Rajapur along west coast of India. Mahasagar, 13(4) : 343-352. Qasim, S. Z. and R. Sengupta 1981. Environ- mental characteristics of the Mandovi- Zuari estuarine system in Goa. Estuarine Coastal Shelf...

  14. Organotins in the sediments of the Zuari estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Jadhav, S.; Bhosle, N.B.; Massanisso, P.; Morabito, R

    ., Jadhav, S., Harji, R., Sawant, S., Venket, K., Anil, A. C., 2004. Butyltins in water, biofilm and sediments of the west coast of India. Chemosphere 57, 897-907. Burton, E. D., Phillips, I. R., Hawker, D. W., 2004. Sorption and desorption behaviour... of tributyltin with natural sediments. Environmental Science & Technology 38, 6694 – 6700. Burton, E. D., Phillips, I. R., Hawker, D. W., 2005. In-situ partitioning of butyltin species in estuarine sediments. Chemosphere 59, 585 – 592. Burton, E. D., Phillips...

  15. REE in suspended particulate matter and sediment of the Zuari estuary and adjacent shelf, western India: Influence of mining and estuarine turbidity

    Digital Repository Service at National Institute of Oceanography (India)

    Shynu, R.; Rao, V.P.; Parthiban, G.; Balakrishnan, S.; Narvekar, T.; Kessarkar, P.M.

    in the development of ETM in the lower estuary (Rao et al., 2011). As a consequence bottom sediment may have been re-suspended, thereby increasing SPM and REE in the water column and mixed up with the sediment brought by the river. In other words, the REE.... Seminar Volume on Earth Resources for Goa’s Development. Geological Survey of India, pp. 1-13. Goldstein, S.J., Jacobsen, S.B., 1988. Rare earth elements in river waters. Earth Planetary Science Letters 89, 35-47. Govindaraju, K., 1994. Compilation...

  16. Heavy metal pollution exerts reduction/adaptation in the diversity and enzyme expression profile of heterotrophic bacteria in Cochin estuary, India

    Energy Technology Data Exchange (ETDEWEB)

    Jose, Jiya; Giridhar, Rajesh; Anas, Abdulaziz [National Institute of Oceanography (CSIR), Regional Centre, PB 1913, Cochin, Kerala 682018 (India); Loka Bharathi, P.A. [National Institute of Oceanography (CSIR), Dona Paula, Goa 403004 (India); Nair, Shanta, E-mail: shanta@nio.org [National Institute of Oceanography (CSIR), Dona Paula, Goa 403004 (India)

    2011-10-15

    Over the past three decades heavy metal pollution has increased substantially in Cochin estuary, south west coast of India. Here we studied the distribution, diversity and enzyme expression profile of culturable microbial population along a pollution gradient. The distribution of resistance against 5 mM concentration of Zn, Co, Ni and Cu was observed among 90-100% of bacterial isolates retrieved from highly polluted Eloor, whereas it was less than 40% in Vypin and Munambam. Similarly, there was a difference in the distribution and diversity of bacterial phyla with predominance of Proteobacteria in Eloor and Firmicutes in Munambam and Vypin. We observed that 75-100% of the organisms retrieved from Eloor had low levels of expression for hydrolytic enzyme. In conclusion, the heavy metal pollution in Cochin estuary brought in reduction/adaptation in the distribution, diversity and enzyme expression profile of bacteria, which may impart adverse impacts on ecosystem functioning. - Highlights: > Substantial proliferation of heavy metal pollution in Cochin estuary. > 90-100% of bacteria were resistant against heavy metals. > Proteobacteria dominated in the hot spot sites. > Low Enzyme expression profile among microorganisms in hot spot sites. - Heavy metal pollution exerts pressure on the diversity and enzyme expression profile of estuarine bacteria.

  17. Comparative efficacy of benthic biotic indices in assessing the Ecological Quality Status (EcoQS) of the stressed Ulhas estuary, India.

    Science.gov (United States)

    Mulik, Jyoti; Sukumaran, Soniya; Srinivas, Tatiparthi; Vijapure, Tejal

    2017-07-15

    Ecostatus of Ulhas estuary, one of the most polluted estuaries along the industrialized and urbanized northwest coast of India, was evaluated by six widely accepted benthic indices viz. H'(log 2 ), AMBI, M-AMBI, BENTIX, BOPA and BO2A to test their efficiency in a tropical setting. The mesohaline zone, which presented eutrophic conditions, was classified as 'bad' by all indices due to the azoic status. Despite significant correlations obtained between indices, there were discrepancies in the accurate level of EcoQS assigned to each station. AMBI was observed to be most efficient in indicating a clear spatial variability from a 'poor' to 'bad' ecological quality status in the middle and upstream zones to an improved status in the downstream region. Limitations of all indices are discussed in light of their suitability for assessing the estuarine environmental condition. The present results could provide a fillip to environmental improvement initiatives currently being undertaken in the estuary. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Distribution and sources of sedimentary organic matter in a tropical estuary, south west coast of India (Cochin estuary): A baseline study

    International Nuclear Information System (INIS)

    Gireeshkumar, T.R.; Deepulal, P.M.; Chandramohanakumar, N.

    2013-01-01

    Highlights: ► We report δ 13 C and δ 15 N values of sedimentary organic matter from the Cochin estuary. ► δ 13 C and δ 15 N values ranged from −27.5‰ to −21.7‰ and δ 15 N 3.1–6.7‰ respectively. ► Organic matter is found to be mixture terrestrial and marine derived materials. ► The δ 15 N values displayed a complex behavior in the study region. ► The fraction of terrestrial derived organic matter was estimated. -- Abstract: Surface sediments samples were collected from 9 stations of the Cochin estuary during the monsoon, post-monsoon and pre-monsoon seasons and were analyzed for grain size, total organic carbon (OC), total nitrogen (TN) and stable isotopic ratios of carbon (δ 13 C) and nitrogen (δ 15 N) to identify major sources of organic matter in surface sediments. Sediment grain size is found to be the key factor influencing the organic matter accumulation in surface sediments. The δ 13 C values ranges from −27.5‰ to −21.7‰ in surface sediments with a gradual increase from inner part of the estuary to the seaward side that suggest an increasing contribution of marine autogenous organic matter towards the seaward side. The δ 15 N value varies between 3.1‰ and 6.7‰ and it exhibits complex spatial and seasonal distributions in the study area. It is found that the dynamic cycling of nitrogen through various biogeochemical and organic matter degradation processes modifies the OC/TN ratios and δ 15 N to a considerable degree. The fraction of terrestrial organic matter in the total organic matter pool ranges from 13% to 74% in the surface sediments as estimated by δ 13 C based two end member mixing model

  19. Distribution and seasonal variation of trace metals in surface sediments of the Mandovi estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Alagarsamy, R.

    The concentration and distribution of selected trace metals in surface sediments of the Mandovi estuary were studied to determine the extent of anthropogenic inputs from mining activities and to estimate the effects of monsoon on geochemical...

  20. Suspended sediment dynamics on a seasonal scale in the Mandovi and Zuari estuaries, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Shynu, R.; Kessarkar, P.M.; Sundar, D.; Michael, G.S.; Narvekar, T.; Blossom, V.; Mehra, P.

    Suspended particulate matter (SPM) collected at regular stations from the Mandovi and Zuari estuaries indicates that the peaks of high SPM coincide with peaks of high rainfall and low salinity and also with peaks of moderate/low rainfall coupled...

  1. Dynamics of circulation and salt balance in the upper reaches of Periyar river estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Varma, P.U.; Pylee, A.; Sankaranarayanan, V.N.

    The Eulerian residual currents of the upper reaches of Periyar estuary (Kerala, India) were directed down the estuary throughout the water column during the monsoon season. During the summer months the residual flow was directed up the estuary...

  2. Environmental controls on the speciation and distribution of mercury in surface sediments of a tropical estuary, India

    International Nuclear Information System (INIS)

    Chakraborty, Parthasarathi; Babu, P.V. Raghunadh

    2015-01-01

    Highlights: • Physico-chemical parameters of water column control Hg speciation in sediments. • Sediments from the middle of the estuary were contaminated by Hg. • Concentrations of Hg were less during the monsoon and post monsoon period. • Salinity, pH of water column may change Hg speciation of the bottom sediments. • TOC in sediments control Hg partitioning in the system. - Abstract: Distribution and speciation of mercury (Hg) in the sediments from a tropical estuary (Godavari estuary) was influenced by the changing physico-chemical parameters of the overlying water column. The sediments from the upstream and downstream of the estuary were uncontaminated but the sediments from the middle of the estuary were contaminated by Hg. The concentrations of Hg became considerably less during the monsoon and post monsoon period. Total Hg concentrations and its speciation (at the middle of the estuary) were dependent on the salinity of the overlying water column. However, salinity had little or no effect on Hg association with organic phases in the sediments at downstream. Increasing pH of the overlying water column corresponded with an increase in the total Hg content in the sediments. Total organic carbon in the sediments played an important role in controlling Hg partitioning in the system. Uncomplexed Hg binding ligands were available in the sediments

  3. Pollution induced tidal variability in water quality of Mahim Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Sabnis, M.M.

    Variability of water quality due to release of wastewater in Mahim Estuary (Maharashtra, India) and associated nearshore waters is discussed. The mixing of low salinity contaminated estuary water with high salinity bay water was considerably...

  4. Temporal and spatial variability of trace metals in suspended matter of the Mandovi estuary, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shynu, R.; Rao, V.P.; Kessarkar, P.M.; Rao, T.G.

    of the estuary. SPM is consistently low at all stations during the post-monsoon. Trace metals (Cu, Ni, Zn, Cr, and Pb) show strong inter-relationships. They correlate well with Fe and Mn only during the monsoon. The concentrations of Cr, Cu, and Pb are high...

  5. Formation of anoxia and denitrification in the bottom waters of a tropical estuary, southwest coast of India.

    Digital Repository Service at National Institute of Oceanography (India)

    Martin, G.D.; Muraleedharan, K.R.; Vijay, J.G.; Rejomon, G.; Madhu, N.V.; Shivaprasad, A.; Haridevi, C.K.; Nair, M.; Balachandran, K.K.; Revichandran, C.; Jayalakshmy, K.V.; Chandramohanakumar, N.

    stratification coupled with low ventilation and presence of high organic matter have resulted in an anoxic condition (O sub(2)=0), 2-6 km away from barmouth of the estuary and leads to the formation of hydrogen sulphide. The reduction of nitrate and formation...

  6. Geochemical assessment of heavy metals pollution in surface sediments of Vellar and Coleroon estuaries, southeast coast of India.

    Science.gov (United States)

    Nethaji, S; Kalaivanan, R; Arya Viswam; Jayaprakash, M

    2017-02-15

    Surface sediments were collected from Vellar and Coleroon estuaries for determine sediment texture, calcium carbonate, organic matter and heavy metals. Pollution indices such as pollution load index (PLI), contamination factor (CF), enrichment factor (EF) and geo-accumulation index (I geo ) were done for this study to know the level of heavy metals pollution in the estuarine ecosystem. Pearson correlation matrix and factor were used to assess the relationship and source of heavy metals in the estuarine sediments. The results of PLI values reveal that the study area was polluted by all the heavy metals. The calculated values of CF and I geo followed the decreasing order Cu>Ni>Pb>Co>Cr>Zn>Mn>Fe and illustrate that Cu, Ni and Pb are contaminated due to anthropogenic sources in both estuaries. Correlation and factor analysis suggest that FeMn oxyhydroxides, organic matter and fine particles are responsible for high concentration of heavy metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Sources and fate of organic matter in suspended and bottom sediments of the Mandovi and Zuari estuaries, Western India

    Digital Repository Service at National Institute of Oceanography (India)

    Shynu, R; Rao, V.P.; Sarma, V.V.S.S.; Kessarkar, P.M.; ManiMurali, R

    in western India during wet and dry seasons, to characterize the sources of organic matter (OM) in these systems. Unlike major rivers, SPM concentrations increase seaward with a general trend of decreasing particulate organic carbon (POC) in these rivers...

  8. Occurrence and seasonal variation in distribution of fecal indicator bacteria in Tapi estuary along the West coast of India.

    Digital Repository Service at National Institute of Oceanography (India)

    Borade, S.; Dhawde, R.; Maloo, A.; Gajbhiye, S.N.; Dastager, S.G.

    rainfall runoff12-15. Seawaters along the Indian coasts are classified by Central Pollution Control Board of India (CPCB) as fit for commercial fishing, contact recreation and bathing activities when the FC is <100 CFU/mL. Whereas, the USEPA sets FC... limits of 200 CFU/mL natural waters for recreational purposes16. Indicator organisms are often used as a tool to identify the contaminant sources. Therefore, it is important to understand the potential and limitations of these indicator organisms...

  9. Distribution of hydro-biological parameters in coastal waters off Rushikulya Estuary, East Coast of India: a premonsoon case study.

    Science.gov (United States)

    Baliarsingh, S K; Srichandan, S; Naik, S; Sahu, K C; Lotliker, Aneesh A; Kumar, T S

    2013-08-15

    The hydro-biological parameters of coastal waters off Rushikulya estuary was investigated during premonsoon 2011. Important hydro-biological parameters such as water temperature, salinity, pH, DO, NO2, NO3, NH4, PO4, SiO4, TSM, Chl-a, phytoplankton and zooplankton were measured during the present study. Temperature established a strong positive correlation with salinity and pH during the present study. Chl-a found in positive relation with NO3, SiO, and TSM. Analysis of variance revealed significant monthly variation in pH, salinity and TSM. Significant station wise variation was observed in DO and most of the nutrients i.e., NO3, NH4, PO4, SiO4. A total of 119 species of phytoplankton were identified of which 84 species are of diatoms, 22 species of dinoflagellates, 7 species of green algae, 5 species of cyanobacteria (blue green algae) and 1 species of cocolithophore. Phytoplankton abundance varied between 25543 (Nos. L(-1)) and 36309 (Nos. L(-1)). Diatoms dominated the phytoplankton community followed by dinoflagellates in all the months. Diatoms contributed to 82-89% of the total phytoplankton population density whereas dinoflagellates contributed to 6-12%. The regression between Chl-a and phytoplankton abundance resulted with weak relation (R(2) = 0.042). Zooplankton fauna composed of 134 species of holoplankton and 20 types of meroplankton were encountered during the study period. Zooplankton population dominated by copepod during all months and accounted for 74 to 85% to the total zooplankton. The population density ranged from 6959 to 35869 Nos./10 m(3). Analysis of variance explained no significant variation in total zooplankton abundance and also for different groups of zooplankton.

  10. A study of the probable movement and mixing of contaminants in a tidal estuary

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Sarma, R.V.

    The probable movement and mixing of contaminants within and through the Amba river estuary, a tidal estuary along the westcoast of India are studied Neutrally buoyant bipelane drogues, floats and dye were tracked at different stages of the tide...

  11. Impact of maintenance dredging on macrobenthic community structure of a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Rehitha, T.V.; Ullas, N.; Vineetha, G.; Benny, P.Y.; Madhu, N.V.; Revichandran, C.

    This paper demonstrates the impact of maintenance dredging activities on the macrobenthic community structure of a tropical monsoonal estuary (Cochin estuary), located in the southwest coast of India for three consecutive years. The results...

  12. Maturation of the penaeid prawn Metapenaeus moyebi in Mandovi Estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Achuthankutty, C.T; Parulekar, A

    Metapenaeus moyebi contributed a good share of penaeid prawn population in the Mandovi Estuary of Goa, India throughout the year. Both males and females of this species with fully mature gonads were observed in the estuary, suggesting further...

  13. India.

    Science.gov (United States)

    1985-05-01

    In this discussion of India attention is directed to the following: the people; geography; history; government; political conditions; the economy; foreign relations (Pakistan and Bangladesh, China, and the Soviet Union); defense; and the relations between the US and India. In 1983 India's population was estimated at 746 million with an annual growth rate of 2.24%. The infant mortality rate was estimated at 116/1000 in 1984 with a life expectancy of 54.9 years. Although India occupies only 2.4% of the world's land area, it supports nearly 15% of the world's population. 2 major ethnic strains predominate in India: the Aryan in the north and the Dravidian in the south, although the lines between them are blurred. India dominates the South Asian subcontinent geographically. The people of India have had a continuous civilization since about 2500 B.C., when the inhabitants of the Indus River Valley developed an urban culture based on commerce, trade, and, to a lesser degree, agriculture. This civilization declined about 1500 B.C. and Aryan tribes originating in central Asia absorbed parts of its culture as they spread out over the South Asian subcontinent. During the next few centuries, India flourished under several successive empires. The 1st British outpost in South Asia was established in 1619 at Surat on the northwestern coast of India. The British gradually expanded their influence until, by the 1850s, they controlled almost the entire area of present-day India. Independence was attained on August 15, 1947, and India became a dominion within the Commonwealth of Nations with Jawaharlal Nehru as prime minister. According to its constitution, India is a "sovereign socialist secular democratic republic." Like the US, India has a federal form of government, but the central government in India has greater power in relation to its states, and government is patterned after the British parliamentary system. The Congress Party has ruled India since independence with the

  14. Detection of metal induced cytopathological alterations and DNA damage in the gills and hepatopancreas of green mussel Perna viridis from Ennore Estuary, Chennai, India

    International Nuclear Information System (INIS)

    Vasanthi, Lourduraj A.; Revathi, Peranandam; Babu Rajendran, Ramaswamy; Munuswamy, Natesan

    2017-01-01

    This study report the impact of heavy metals on cytopathology and DNA damage in the gills and hepatopancreas of Perna viridis collected from Ennore estuary and the Kovalam coastal waters. Principal Component Analysis (PCA) showed significant differences among all variables at the scale of plots. The ultrastructural alterations such as lack of microvilli, distorted mitochondria, electron dense particles and the presence of large mucous droplets were common in the gill and hepatopancreatic cells of mussels from Ennore estuary. However, the gill and hepatopancreatic cells of P. viridis from Kovalam revealed normal compartmentalization of cells. The percentage of tail DNA in the mussels from Ennore estuary was recorded as 12.44 and 10.14% in the gills and hepatopancreas respectively. Overall, it has been demonstrated that the Comet and cytopathological assays are useful biomarkers to assess the level of pollution and it provide reliable information on ecotoxicology and genotoxicology of coastal waters. - Highlights: • Bioaccumulation of heavy metals was studied in P. viridis from Ennore estuary. • Heavy metal accumulation leads to severe cellular and DNA damage. • Comet assay and cytopathology proved to be a biomarker in ecotoxicology. • The data justifies the need of remedial measures along Ennore Estuary.

  15. India

    International Nuclear Information System (INIS)

    Jones, R.W.

    1990-01-01

    Interest has grown recently in the issues of third tier or emerging nuclear suppliers. These are states that could export nuclear equipment, services, or technology but are outside the export control framework of the London Nuclear Supplier Group (NSG). The concern is that they may conduct nuclear trade without adequate safeguards, thus weakening the nonproliferation regime or even contributing to nuclear proliferation. The volume of nuclear sales by emerging suppliers is still minuscule, and it is unclear how far their export practices will diverge from the NSG framework. This case study of Indian nuclear supplier capability and practice is an effort to discern the type of path India is likely to adopt. This paper examines four aspects of India's nuclear activity for clues to India's potential role as an emerging nuclear supplier: foreign transactions; nuclear decision making; policy norms; and nuclear industrial capabilities

  16. Solar radiation and its penetration in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Qasim, S.Z.; Bhattathiri, P.M.A.; Abidi, S.A.H.

    The Cochin Backwater which is an estuarine area on the west coast of India receives maximum solar radiation from December to March and minimum from June to September. During the monsoon months the estuary becomes highly turbid as a result...

  17. Heavy metal accumulation in a flow restricted, tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.; Laluraj, C.M.; Nair, M.; Joseph, T.; Sheeba, P.; Venugopal, P.

    Levels of heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn), organic carbon content and textural characteristics in the surficial sediments of Cochin estuary (SW coast of India) and adjacent coast are presented. Anthropogenic inputs from...

  18. Bacterial contamination of mussels at Mahe estuary, Malabar coast

    Digital Repository Service at National Institute of Oceanography (India)

    Gore, P.S.; Raveendran, O.; Iyer, T.S.G.; Varma, P.R.G.; Sankaranarayanan, V.N.

    Mussel samples from the mussel bed and near-by market, beach sand, sediment and water from the Mahe Estuary, Kerala, India were analysed for the bacterial quality. Indicator bacteria such as Escherichia coli and faecal streptococci were isolated...

  19. Monitoring and assessment of mercury pollution in the vicinity of a chloralkali plant. III. Concentration and genotoxicity of mercury in the industrial effluent and contaminated water of Rushikulya estuary, India.

    Science.gov (United States)

    Panda, K K; Lenka, M; Panda, B B

    1992-01-01

    Aquatic mercury pollution of the Rushikulya estuary in the vicinity of the chloralkali plant at Ganjam, India was monitored over a period from October 1987 to May 1989. The concentrations of aquatic mercury in the water samples taken from the effluent channel and from different sites along the course of the estuary covering a distance of 2 km were periodically recorded and ranged from 0 to 0.5 mg/l. The bioconcentration and genotoxicity of aquatic mercury in the samples were assessed by the Allium micronucleus (MNC) assay. The frequency of cells with MNC was highly correlated not only with bioconcentrated mercury (root mercury) but also with the levels of aquatic mercury. The threshold assessment values such as effective concentration fifty (EC50) for root growth, lowest effective concentration tested (LECT), and highest ineffective concentration tested (HICT) for induction of MNC in Allium MNC assay for the present aquatic industrial mercury were determined to be 0.14, 0.06 and 0.02 mg/l, respectively.

  20. Characterization of Porteresia coarctata beds along the Goa coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Jagtap, T.G.; Bhosale, S.H.; Charulata, S.

    Porteresia coarctata, forms an important constituent in the plant succession leading to formation of mangrove communities along the estuaries in India. Major beds along the Mandovi estuary of Goa were monitored for their various ecological...

  1. Rare earth elements in suspended and bottom sediments of the Mandovi estuary,central west coast of India: Influence of mining

    Digital Repository Service at National Institute of Oceanography (India)

    Shynu, R.; Rao, V.P.; Kessarkar, P.M.; Rao, T.G.

    Rare earth elements (REEs) in the suspended particulate matter (SPM) of the Mandovi estuary indicated that the mean total-REEs and light REE to heavy REE ratios are lower than that of the average suspended sediment in World Rivers and Post...

  2. Dissolved inorganic carbon (DIC) and its δ13C in the Ganga (Hooghly) River estuary, India: Evidence of DIC generation via organic carbon degradation and carbonate dissolution

    Digital Repository Service at National Institute of Oceanography (India)

    Samanta, S.; Dalai, T.K.; Pattanaik, J.K.; Rai, S.K.; Mazumdar, A.

    to the oceans, which accounts for ca. 0.2% of the global river water flux. The results of this study suggest that estuaries in regions affected by tropical monsoon can be important in terms of their production of significant amounts of DIC and its delivery...

  3. Studies on mixing of the waters of different salinity gradients using Richardsons number and the suspended sediment distribution in the Beypore Estuary, south west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    AnilKumar, N.; Sankaranarayanan, V.N.; Josanto, V.

    of Richardsons number (log R sub(L)) shows high variation at river mouth section of the estuary (section-1) and at about 10 km upstream (section-2) during the postmonsoon period. During the premonsoon period there was no noticeable variation in log R sub...

  4. Seasonal effects on the air-water carbon dioxide exchange in the Hooghly estuary, NE coast of Bay of Bengal, India.

    Science.gov (United States)

    Mukhopadhyay, S K; Biswas, H; De, T K; Sen, S; Jana, T K

    2002-08-01

    Monthly variation of CO2 fugacity (fCO2) in surface water and related atmospheric exchanges were measured in the Hooghly estuary which is one of the most important estuaries, since it is fed by one of the world's largest rivers, the Ganges with a flow of 15,646 m3 s-1 (1.6% of the world's combined river flow). Carbon dioxide fluxes averaged over the entire estuary are in the range of -2.78 to 84.4 mmol m-2 d-1. This estuary acts as a sink for CO2 during monsoon months and seasonal variation of its flux is controlled by dilution of seawater by river water. Since the solubility of CO2 and the disassociation of carbonic acid in estuarine water are controlled by temperature and salinity, the observed variations of CO2 fluxes are compared with those predicted from seasonal changes in temperature, salinity and the ratio of gross primary production to community respiration using empirical equations with an explained variability of 55%.

  5. Cymothoa indica (Isopoda; Cymothoidae and Alitropus typus (Isopoda; Aegidae on freshwater fish Tilapia mossambica (Cichlidae in Vellar estuary, Southeast coast of India

    Directory of Open Access Journals (Sweden)

    G. Rameshkumar

    2010-09-01

    Full Text Available The study was carried out to establish the extent of double parasitation of two species of isopods Cymothoa indica and Alitropus typus on Tilapia mossambica. Cymothoa indica, a typical Indo-Pacific genus, and A. typus, a common crustacean parasite of fish in Southeast Asia, which feeds by sucking blood species, are reported by the first time in the freshwater fish Tilapia from Vellar estuary.

  6. River discharge as a major driving force on spatial and temporal variations in zooplankton biomass and community structure in the Godavari estuary India.

    Science.gov (United States)

    Venkataramana, V; Sarma, V V S S; Matta Reddy, Alavala

    2017-08-28

    Variability in horizontal zooplankton biomass distribution was investigated over 13 months in the Godavari estuary, along with physical (river discharge, temperature, salinity), chemical (nutrients, particulate organic matter), biological (phytoplankton biomass), and geological (suspended matter) properties to examine the influencing factors on their spatial and temporal variabilities. The entire estuary was filled with freshwater during peak discharge period and salinity near zero, increased to ~ 34 psu during dry period with relatively high nutrient levels during former than the latter period. Due to low flushing time ( 500 mg L -1 ) during peak discharge period, picoplankton (cyanophyceae) contributed significantly to the phytoplankton biomass (Chl-a) whereas microplankton and nanoplankton (bacillariophyceae, and chlorophyceae) during moderate and mostly microplankton during dry period. Zooplankton biomass was the lowest during peak discharge period and increased during moderate followed by dry period. The zooplankton abundance was controlled by dead organic matter during peak discharge period, while both phytoplankton biomass and dead organic matter during moderate discharge and mostly phytoplankton biomass during dry period. This study suggests that significant modification of physico-chemical properties by river discharge led to changes in phytoplankton composition and dead organic matter concentrations that alters biomass, abundance, and composition of zooplankton in the Godavari estuary.

  7. India.

    Science.gov (United States)

    1982-10-01

    This discussion of India focuses on the following: the history of the country's demographic situation; the government's overall approach to population problems; population data systems and development planning; institutional arrangements for the integration of population with development planning; the government's view of the importance of population policy in achieving development objectives; population size, growth and natural increase; morbidity and mortality; fertility; international migration; and spatial distribution. India's government views the population problem in the country as extremely serious particularly in relation to the alleviation of poverty. It was the 1st country to introduce a family planning program at the national level. Development plans have consistently treated the population situation as a priority issue. A relatively comprehensive system of data collection for demographic purposes has existed in India for a long time. The 1st census was conducted in 1872. The government has continually worked to maintain the integration of population concerns within overall development planning. The government regards population growth as an impediment to development and views the slow growth in per capita income as being due largely to the rapid population increase which continues to outpace the increases in the gross national product. The government perceives the current rate of population growth as unsatisfactory because it is too high. Mortality levels have dropped considerably, but the government still considers the situation with regard to mortality as unacceptable. In 1980 the UN estimated the infant mortality rate was 128.9 infant deaths/1000 live births for the 1975-80 period. The total fertility rate, as estimated by the UN, is reported to have dropped from 6.3 births per woman in 1960 to 6.0 in 1970 and 5.0 in 1980. The government has continuously indicated concern with fertility levels, perceiving the situation as unsatisfactory because its

  8. Impact of eutrophication on the occurrence of Trichodesmium in the Cochin backwaters, the largest estuary along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Martin, G.D.; Jyothibabu, R.; Madhu, N.V.; Balachandran, K.K.; Nair, M.; Muraleedharan, K.R.; Arun, P.K.; Haridevi, C.K.; Revichandran, C.

    fluxes at BATS. Deep Sea Research II, 48, 1609 – 1648. Joseph, P.S. (1974). Nutrient distribution in Cochin hrbour and its vicinity. Indian Journal of Marine Sciences, 3, 28-32. Joseph, S. (2005). Ecological and biochemical studies on cyanobacteria... environmental features of cochin backwaters a Tropical estuary. Proceedings of the Indian Academy of Science, 69, 336-348. Qasim, S.Z. (1970). Some characteristics of a Trichodesmium bloom in the Laccadives. Deep Sea Research, 17, 655-660. Qasim, S.Z. (2003...

  9. Estuary Data Mapper (EDM)

    Science.gov (United States)

    Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

  10. Climate Ready Estuaries

    Science.gov (United States)

    Information on climate change impacts to different estuary regions, tools and resources to monitor changes, and information to help managers develop adaptation plans for risk management of estuaries and coastal communities.

  11. Distribution of trace metals in surface seawater and zooplankton of the Bay of Bengal, off Rushikulya estuary, East Coast of India.

    Science.gov (United States)

    Srichandan, Suchismita; Panigrahy, R C; Baliarsingh, S K; Rao B, Srinivasa; Pati, Premalata; Sahu, Biraja K; Sahu, K C

    2016-10-15

    Concentrations of trace metals such as iron (Fe), copper (Cu), zinc (Zn), cobalt (Co), nickel (Ni), manganese (Mn), lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), vanadium (V), and selenium (Se) were determined in seawater and zooplankton from the surface waters off Rushikulya estuary, north-western Bay of Bengal. During the study period, the concentration of trace metals in seawater and zooplankton showed significant spatio-temporal variation. Cu and Co levels in seawater mostly remained non-detectable. Other elements were found at higher concentrations and exhibited marked variations. The rank order distribution of trace metals in terms of their average concentration in seawater was observed as Fe>Ni>Mn>Pb>As>Zn>Cr>V>Se>Cd while in zooplankton it was Fe>Mn>Cd>As>Pb>Ni>Cr>Zn>V>Se. The bioaccumulation factor (BAF) of Fe was highest followed by Zn and the lowest value was observed with Ni. Results of correlation analysis discerned positive affinity and good relationship among the majority of the trace metals, both in seawater and zooplankton suggesting their strong affinity and coexistence. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Distribution of trace metals in surface seawater and zooplankton of the Bay of Bengal, off Rushikulya estuary, East Coast of India

    International Nuclear Information System (INIS)

    Srichandan, Suchismita; Panigrahy, R.C.; Baliarsingh, S.K.; Srinivasa, Rao B.; Pati, Premalata; Sahu, Biraja K.; Sahu, K.C.

    2016-01-01

    Concentrations of trace metals such as iron (Fe), copper (Cu), zinc (Zn), cobalt (Co), nickel (Ni), manganese (Mn), lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), vanadium (V), and selenium (Se) were determined in seawater and zooplankton from the surface waters off Rushikulya estuary, north-western Bay of Bengal. During the study period, the concentration of trace metals in seawater and zooplankton showed significant spatio-temporal variation. Cu and Co levels in seawater mostly remained non-detectable. Other elements were found at higher concentrations and exhibited marked variations. The rank order distribution of trace metals in terms of their average concentration in seawater was observed as Fe > Ni > Mn > Pb > As > Zn > Cr > V > Se > Cd while in zooplankton it was Fe > Mn > Cd > As > Pb > Ni > Cr > Zn > V > Se. The bioaccumulation factor (BAF) of Fe was highest followed by Zn and the lowest value was observed with Ni. Results of correlation analysis discerned positive affinity and good relationship among the majority of the trace metals, both in seawater and zooplankton suggesting their strong affinity and coexistence. - Highlights: • First-hand report on trace metal concentration in zooplankton and seawater covering 2 years from this eco-sensitive region. • In seawater trace metals followed the rank order of Fe > Ni > Mn > Pb > As > Zn > Cr > V > Se > Cd. • In zooplankton the rank order was Fe > Mn > Cd > As > Pb > Ni > Cr > Zn > V > Se. • The bioaccumulation factor of Fe was highest followed by Zn. • Strong affinity, coexistence, and similar source of trace metals in the study area.

  13. Application of sequential leaching, risk indices and multivariate statistics to evaluate heavy metal contamination of estuarine sediments: Dhamara Estuary, East Coast of India.

    Science.gov (United States)

    Asa, Subas Chandra; Rath, Prasanta; Panda, Unmesh Chandra; Parhi, Pankaj Kumar; Bramha, Satyanarayan

    2013-08-01

    In the present study, concentration of some selected trace metals (Fe, Mn, Ni, Co, Pb, Zn, Cu, Cr and Cd) are measured in Brahmani, Baitarani river complex along with Dhamara estuary and its near shore. Chemical partitioning has been made to establish association of metals into different geochemical phases. The exchangeable fraction is having high environmental risk among non-lithogeneous phases due to greater potential for mobility into pore water. The metals with highest bio-availability being Cd, Zn and Cr. The metals like Mn, Zn, Cd and Cu represent an appreciable portion in carbonate phase. Fe-Mn oxides act as efficient scavenger for most of the metals playing a prime role in controlling their fate and transport. Among non-lithogeneous phases apart from reducible, Cr showed a significant enrichment in organic phase. Risk assessment code values indicate that all metals except Fe fall under medium-risk zone. In estuarine zone Cd, Zn, Pb and Cr are released to 32.43, 26.10, 21.81 and 20 %, respectively, indicating their significant bio-availability pose high ecological risk. A quantitative approach has been made through the use of different risk indices like enrichment factor, geo-accumulation index and pollution load index. Factor analysis indicates that in riverine zone, Fe-Mn oxides/hydroxides seem to play an important role in scavenging metals, in estuarine zone, organic precipitation and adsorption to the fine silt and clay particles while in coastal zone, co-precipitation with Fe could be the mechanism for the same. Canonical discriminant function indicates that it is highly successful in discriminating the groups as predicted.

  14. Heavy metals pollution influence the community structure of Cyanobacteria in nutrient rich tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Anas, A.; Jasmin, C.; Sheeba V.A.; Gireeshkumar, T.R; Nair, S.

    , Mn, Fe, Ni, Cu and Zn) on community structure of cyanobacteria in a nutrient rich tropical estuary, Cochin Estuary (CE), across the southwest coast of India. Dissolved heavy metals were higher in CE during dry season, with Zn as major pollutant...

  15. Destruction of timber panels by wood boring organisms in Mandovi estuary of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Wagh, A.B.; Anil, A.C.

    Destruction on mango wood (Mangifera indica Linn.) panels in the Mandovi Estuary of Goa, India at 5 different depths was studied for different seasons. The causative organisms were found to be Lyrodus pedicellatus Quatrefages and Martesia striata L...

  16. Heterotrophic utilization of extracellular products of phytoplankton in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Gomes, H.; Pant, A; Goes, J.I.; Parulekar, A

    Bacterial uptake of algal exudates has been estimated in a tropical estuary, Dona Paula, Goa, India, where the seasonal fluctuations in hydrographic and nutrient parameters as well as dissolved organic matter concentrations and phytoplankton species...

  17. A study on the zooplankton of the Burhabalanga Estuary, Orissa Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, Neelam; Chatterji, A.; Madhupratap, M.

    Annual variations in the zooplankton biomass and composition during 1991-92 were studied from the inshore, mouth and upstream regions of the Burhabalanga Estuary located in the Orissa Coast (India). Zooplankton biomass was maximum at all...

  18. Local Estuary Programs

    Science.gov (United States)

    This page provides information about Local Individual Estuary Programs including links to their NEP homepages, social media, Comprehensive Conservation and Management Plans, and state of the bay reports.

  19. Milwaukee Estuary AOC

    Science.gov (United States)

    The rivers in the Milwaukee estuary in Wisconsin drain into Lake Michigan. Wastewater treatment plants and combined sewer overflows contribute pollution which affects fish and wildlife and recreation.

  20. Organic carbon in the sediments of Mandovi estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Alagarsamy, R.

    Total organic carbon (TOC) in surficial sediments in Mandovi Estuary, Goa, India varies widely from 0.1 to 3% (av. 1.05%). Highest values of TOC (2.4-3%) lie close to the mouth region and indicate no definite trend in its variation in the estuarine...

  1. Macrobenthos of Vembanad estuary in relation to the deposition of degraded water fern Salvinia and other macrophytes

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalan, U.K.; Meenakshikunjamma, P.P.; Vengayil, D.T.

    Composition and seasonal abundance of macrobenthos in Vembanad estuary (India) seems to be influenced by the density of decaying macrophytes, especially the water fern Salvinia , deposited at the bottom of the estuary at the rate of 356.76 g/m super...

  2. Contribution of N2O emissions to the atmosphere from Indian monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, G.D.; Sarma, V.V.S.S.

    related to mean low concentration of DIN that led to low nitrification rates compared to world estuaries. Despite India ranking second in artificial fertilizers use, high flushing rates during the wet period reduce residence time leading to less...

  3. Penobscot Estuary (Maine) Monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's NEFSC collects fisheries data from the Penobscot Estuary using several types of fishing gear. The data is used to determine species presence, relative...

  4. About Estuary Data Mapper (EDM)

    Science.gov (United States)

    Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions.

  5. The Mandovi and Zuari estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; DileepKumar, M.; Shankar, D.

    of their extensive use for fisheries, agriculture, transportation, dumping of waste, etc. The two estuaries have since continued to attract scientific curiosity over the years, thanks in large measure to support from national and local funding agencies. As a... made so far to simulate them in numerical models, and characteristics of stratification and mixing. These are followed by chapters that examine the fun- damentals of biology and chemistry of the estuaries. A distinct characteristic of the estuaries...

  6. Ecology of estuaries

    International Nuclear Information System (INIS)

    Kennish, M.J.

    1992-01-01

    Ecology of Estuaries: Anthropogenic Effects represents the most definitive and comprehensive source of reference information available on the human impact on estuarine ecosystems. The book discusses both acute and insidious pollution problems plaguing these coastal ecotones. It also provides a detailed examination of the deleterious and pervasive effects of human activities on biotic communities and sensitive habitat areas in estuaries. Specific areas covered include organic loading, oil pollution, polynuclear aromatic hydrocarbons, chlorinated hydrocarbons, heavy metals, dredging and dredge-spoil disposal, radionuclides, as well as other contaminants and processes. The diverse components of these anthropogenic influences are assembled in an organized framework and presented in a clear and concise style that will facilitate their understanding

  7. Sediment Trapping in Estuaries

    Science.gov (United States)

    Burchard, Hans; Schuttelaars, Henk M.; Ralston, David K.

    2018-01-01

    Estuarine turbidity maxima (ETMs) are generated by a large suite of hydrodynamic and sediment dynamic processes, leading to longitudinal convergence of cross-sectionally integrated and tidally averaged transport of cohesive and noncohesive suspended particulate matter (SPM). The relative importance of these processes for SPM trapping varies substantially among estuaries depending on topography, fluvial and tidal forcing, and SPM composition. The high-frequency dynamics of ETMs are constrained by interactions with the low-frequency dynamics of the bottom pool of easily erodible sediments. Here, we use a transport decomposition to present processes that lead to convergent SPM transport, and review trapping mechanisms that lead to ETMs at the landward limit of the salt intrusion, in the freshwater zone, at topographic transitions, and by lateral processes within the cross section. We use model simulations of example estuaries to demonstrate the complex concurrence of ETM formation mechanisms. We also discuss how changes in SPM trapping mechanisms, often caused by direct human interference, can lead to the generation of hyperturbid estuaries.

  8. Speciation of iron and manganese in the sediments of Mandovi Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Jayakumar, D.A.; Rajendran, A.

    Several attempts have been made to study the distribution of iron and manganese in Mandovi Estuary, Goa, India. But this is the first report of its kind on the speciation of these metals in sediments from Indian waters. This study would be useful...

  9. Effect of mining rejects on the nutrient chemistry of Mandovi Estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.

    Nutrient chemistry in Mandovi Estuary, Goa, India during premonsoon in affected by the discharge of mining rejects. Concentrations of nitrate and phosphate, in general, show low levels in this season (nitate 0.3-3.3 mu M, phosphate 0.11-0.56 mu M...

  10. Determination of Cd, Pb and Cu in Mandovi estuary by differential pulse anodic stripping voltammetry

    Digital Repository Service at National Institute of Oceanography (India)

    George, M.D.; Sawkar, K.; Reddy, C.V.G.

    Dissolved labile and non-labile (organically associated) concentration of Cd, Pb and Cu in Mandovi Estuary, Goa, India have been measured for 1 y (February 1980 to January 1981). Percentage non-labile form varies from 0-50% of the total for Cd, from...

  11. FLORA OF MOLOCHNYI ESTUARY COASTS

    Directory of Open Access Journals (Sweden)

    Kolomiychuk V.P.

    2013-09-01

    Full Text Available Present-day characteristic of the coastal flora of Molochnyi eastury is given, that is one of the largest estuaries in Ukraine, the shores and waters of which in 2009 became a part of the Pryazov’ya National Nature Park. The analysis of the main parameters of the flora is made. Rare component of the estuary coastal flora is characterized, further steps to conserve the nature of Pryazov’ya are proposed.

  12. Estuary-wide genetic stock distribution and salmon habitat use, tidal-fluvial estuary - Columbia River Estuary Tidal Habitats

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the tidal-fluvial estuary study is to determine the estuary's contribution to the spatial structure and life history diversity of Columbia River salmon...

  13. 75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...

    Science.gov (United States)

    2010-06-21

    ... Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration Strategy; Request... interagency Estuary Habitat Restoration Council, is providing notice of the Council's intent to revise the ''Estuary Habitat Restoration Strategy'' and requesting public comments to guide its revision. DATES...

  14. Frequent Questions about Estuary Data Mapper (EDM)

    Science.gov (United States)

    Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

  15. Downloading and Installing Estuary Data Mapper (EDM)

    Science.gov (United States)

    Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

  16. SANCOR estuaries programme 1982-1986

    CSIR Research Space (South Africa)

    SANCOR

    1983-02-01

    Full Text Available , such research will also aid in the rational management of estuaries. Estuaries on which research should be concentrated are identified and guidelines are given for project proposals and reporting....

  17. Nutrients in some estuaries of Kerala

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, K.S.; Venugopal, P.; Remani, K.N.; Zacharias, D.; Unnithan, R.V.

    phosphate and ammonia were high at Kallai compared to other three estuaries. All the estuaries showed an increase in nitrate content during monsoon. Nitrite values were high in postmonsoon. Ammonia levels were generally high except at Korapuzha. Nutrient...

  18. Leven estuary project. Fisheries Department final report

    OpenAIRE

    Bayliss, B.D.

    1997-01-01

    This is the report on the Leven estuary project: Fisheries Department final report produced by the Environment Agency North West in 1997. This report contains information about Leven estuary, river Leven catchment, river Crake catchment and the Ulverston Discharges. The Leven estuary is characterised by being very shallow, and shares the extremely variable tides and currents that characterize the whole of Morecambe Bay. There was little detailed knowledge of the impact on the Leven estuary, a...

  19. Indian estuaries: Dynamics, ecosystems, and threats

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.

    the tide pulls the mixed water out of the estuary through its mouth. Different processes within an estuary contribute to mixing of the two waters, the important among these in the Mandovi estuary are: influence of the tide on the advective field within...

  20. Biogeochemical budgets for Tapi Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Bapardekar, M.V.; DeSousa, S.N.; Zingde, M.D.

    sup(-1) comes from the wastes. Chemical fertilizers are used in the basin at the rate of 113 kg.ha sup(-1). During the dry season the salinity in the estuary decreases progressively in the upstream direction form an average 32.53 psu at the mouth to 0...

  1. Food Webs in an Estuary.

    Science.gov (United States)

    Dunne, Barbara B.

    The Maryland Marine Science Education Project has produced a series of mini-units in marine science education for the junior high/middle school classroom. This unit focuses on food chains in an estuary. Although the unit specifically treats the Chesapeake Bay, it may be adapted for use with similar estuarine systems. In addition, the unit may be…

  2. Simulated Sampling of Estuary Plankton

    Science.gov (United States)

    Fortner, Rosanne W.; Jenkins, Deborah Bainer

    2009-01-01

    To find out about the microscopic life in the valuable estuary environment, it is usually necessary to be near the water. This dry lab offers an alternative, using authentic data and a simulation of plankton sampling. From the types of organisms found in the sample, middle school students can infer relationships in the biological and physical…

  3. In-stream PIT detection, estuary wetlands - Columbia River Estuary Tidal Habitats

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the tidal-fluvial estuary study is to determine the estuary's contribution to the spatial structure and life history diversity of Columbia River salmon...

  4. Salmon habitat use, tidal-fluvial estuary - Columbia River Estuary Tidal Habitats

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the tidal-fluvial estuary study is to determine the estuary's contribution to the spatial structure and life history diversity of Columbia River salmon...

  5. India Emerging

    International Development Research Centre (IDRC) Digital Library (Canada)

    Traditionally, India has had an extremely poor collection of direct taxes, not least due to ...... Economic Impact of Mobile in Bangladesh, Malaysia, Pakistan, Serbia, ...... in India owes its origin to Gandhian principles, philosophy and practices.

  6. Carbon dioxide emissions from Indian monsoonal estuaries

    Science.gov (United States)

    Sarma Vedula, VSS

    2012-07-01

    The oceans act as a net sink for atmospheric CO2, however, the role of coastal bodies on global CO2 fluxes remains unclear due to lack of data. The estimated absorption of CO2 from the continental shelves, with limited data, is 0.22 to 1.0 PgC/y, and of CO2 emission by estuaries to the atmosphere is 0.27 PgC/y. The estimates from the estuaries suffer from large uncertainties due to large variability and lack of systematic data collection. It is especially true for Southeast Asian estuaries as the biogeochemical cycling of material are different due to high atmospheric temperature, seasonality driven by monsoons, seasonal discharge etc. In order to quantify CO2 emissions from the Indian estuaries, samples were collected at 27 estuaries all along the Indian coast during discharge wet and dry periods. The emissions of CO2 to the atmosphere from Indian estuaries were 4-5 times higher during wet than dry period. The pCO2 ranged between ~300 and 18492 microatm which were within the range of world estuaries. The mean pCO2 and particulate organic carbon (POC) showed positive relation with rate of discharge suggesting availability of high quantities of organic matter that led to enhanced microbial decomposition. The annual CO2 fluxes from the Indian estuaries, together with dry period data available in the literature, amounts to 1.92 TgC which is >10 times less than that from the European estuaries. The low CO2 fluxes from the Indian estuaries are attributed to low flushing rates and less human settlements along the banks of the Indian estuaries.

  7. Estuaries of India: Making amends in a changing world

    Digital Repository Service at National Institute of Oceanography (India)

    Hoover, D.F.

    This short write up descibes the importance of estuarine ecosystems and the need to save it from the ill effects of anthropogenic factors. The issues like pollution caused by chemicals and overfishing are discussed in brief....

  8. Fluxes of nitrogen in Chaliyar River Estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Xavier, J.K.; Joseph, T.; Paimpillii, J.S.

    pool is from the organic -N. The net fluxes of inorganic nutrients in monsoon and post monsoon season are very large- with very small positive or negative fluxes for the pre-monsoon months. The average net fluxes are 4.97 to 9.61 mg m-2 s-1...

  9. Spatial tidal asymmetry of Cochin estuary, West Coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Vinita, J.; Shivaprasad, A.; Manoj, N.T.; Revichandran, C.; Naveenkumar, K.R.; Jineesh, V.K.

    tidal amplitude and currents get attenuated towards upstream through frictional dissipation The results showed that the tidal momentum balance along the main axis of the channel was dominated by pressure gradient and friction The influence of advection...

  10. Trapping of sediment in tidal estuaries

    NARCIS (Netherlands)

    Chernetsky, A.

    2012-01-01

    An estuary is an ideal habitat for various aquatic species. At the same time, estuaries and adjacent rivers are used as fast navigation routes between the coastal and inland territories. The fast industrial development and the subsequent growth of cities and trade have led to large-scale

  11. Microplastic in three urban estuaries, China

    International Nuclear Information System (INIS)

    Zhao, Shiye; Zhu, Lixin; Li, Daoji

    2015-01-01

    Estuarine Microplastics (MPs) are limited to know globally. By filtering subsurface water through 330 μm nets, MPs in Jiaojiang, Oujiang Estuaries were quantified, as well as that in Minjiang Estuary responding to Typhoon Soulik. Polymer matrix was analyzed by Raman spectroscopy. MP (<5 mm) comprised more than 90% of total number plastics. The highest MPs density was found in Minjiang, following Jiaojiang and Oujiang. Fibers and granules were the primary shapes, with no pellets found. Colored MPs were the majority. The concentrations of suspended microplastics determine their bioavailability to low trophic organisms, and then possibly promoting the transfer of microplastic to higher trophic levels. Polypropylene and polyethylene were the prevalent types of MPs analyzed. Economic structures in urban estuaries influenced on MPs contamination levels. Typhoon didn't influence the suspended MP densities significantly. Our results provide basic information for better understanding suspended microplastics within urban estuaries and for managerial actions. - Highlights: • Suspended microplastic were investigated within three densely populated/developed urban estuaries, China. • Economical structures may contribute to the abundances of microplastic particles within the studied estuaries. • Typhoon Soulik didn't influence microplastic densities in the water column of Minjiang Estuary. • Microplastics (<5 mm in diameter) dominated more than 90% of the total plastic by number. - Suspended microplastics (MPs) levels were quantified within three urban estuaries, China. MPs densities were consistent with the urban economical structure, and that in Minjiang were unaffected by Typhoon.

  12. The Mntafufu and Mzamba River estuaries

    African Journals Online (AJOL)

    1989-03-14

    Mar 14, 1989 ... A survey of the fish fauna of Transkei estuaries. Part Four: The Mntafufu and Mzamba River estuaries. E.E. Plumstead • and J.F. Prinsloo. Department of Zoology, University of Transkei, Private Bag X1, Unitra, Umtata, Republic of Transkei. H.J. Schoonbee. Department of Zoology, Rand Afrikaans University, ...

  13. Collaborative Potential between National Estuary Programs ...

    Science.gov (United States)

    Estuaries are among the most productive ecosystems in the world, providing unique habitat for freshwater and marine species as well as valuable social and economic benefits. The wealth of ecosystem goods and services from estuaries has led to growth and development of human communities in adjacent areas and an increase in human activities that can adversely affect water quality and critical habitat. Managing for sustainable estuaries requires a balance of environmental concerns with community social and economic values. This has created an opportunity to leverage Environmental Protection Agency (EPA) scientific knowledge and tools with National Estuary Program (NEP) planning and management expertise to address environmental challenges in important estuarine ecosystems. The non-regulatory National Estuary Program (NEP) was outlined in the Clean Water Act to provide stakeholders an opportunity to monitor and manage ‘nationally significant’ estuaries. Currently there are 28 estuaries in the NEP, broadly distributed across the Atlantic, Pacific and Gulf Coasts, and in Puerto Rico. The local NEP management conferences must address a variety of environmental issues, from water quality and natural resources to coastal and watershed development. While the underlying objectives of each NEP are quite similar, each has unique landscapes, land uses, waterbodies, habitats, biological resources, economies and social culture. Consequently, the effects and severity of anthr

  14. Characterizing seston in the Penobscot River Estuary.

    Science.gov (United States)

    Meseck, Shannon L; Li, Yaqin; Sunila, Inke; Dixon, Mark; Clark, Paul; Lipsky, Christine; Stevens, Justin R; Music, Paul; Wikfors, Gary H

    2017-10-01

    The Penobscot River Estuary is an important system for diadromous fish in the Northeast United States of American (USA), in part because it is home to the largest remnant population of Atlantic salmon, Salmo salar, in the country. Little is known about the chemical and biological characteristics of seston in the Penobscot River Estuary. This study used estuarine transects to characterize the seston during the spring when river discharge is high and diadromous fish migration peaks in the Penobscot River Estuary. To characterize the seston, samples were taken in spring 2015 for phytoplankton identification, total suspended matter (TSM), percent organic TSM, chlorophyll a, particle size (2 μm-180 μm), particulate carbon and nitrogen concentrations, and stable carbon and nitrogen isotopes. The estuarine profiles indicate that TSM behaved non-conservatively with a net gain in the estuary. As phytoplankton constituted only 1/1000 of the particles, the non-conservative behavior of TSM observed in the estuary was most likely not attributable to phytoplankton. Particulate carbon and nitrogen ratios and stable isotope signals indicate a strong terrestrial, allochthonous signal. The seston in the Penobscot River Estuary was dominated by non-detrital particles. During a short, two-week time period, Heterosigma akashiwo, a phytoplankton species toxic to finfish, also was detected in the estuary. A limited number of fish samples, taken after the 2015 Penobscot River Estuary bloom of H. akashiwo, indicated frequent pathological gill damage. The composition of seston, along with ichthyotoxic algae, suggest the need for further research into possible effects upon resident and migratory fish in the Penobscot River Estuary. Published by Elsevier Ltd.

  15. CO2 emissions from a temperate drowned river valley estuary adjacent to an emerging megacity (Sydney Harbour)

    Science.gov (United States)

    Tanner, E. L.; Mulhearn, P. J.; Eyre, B. D.

    2017-06-01

    The Sydney Harbour Estuary is a large drowned river valley adjacent to Sydney, a large urban metropolis on track to become a megacity; estimated to reach a population of 10 million by 2100. Monthly underway surveys of surface water pCO2 were undertaken along the main channel and tributaries, from January to December 2013. pCO2 showed substantial spatio-temporal variability in the narrow high residence time upper and mid sections of the estuary, with values reaching a maximum of 5650 μatm in the upper reaches and as low as 173 μatm in the mid estuary section, dominated by respiration and photosynthesis respectively. The large lower estuary displayed less variability in pCO2 with values ranging from 343 to 544 μatm controlled mainly by tidal pumping and temperature. Air-water CO2 emissions reached a maximum of 181 mmol C m-2 d-1 during spring in the eutrophic upper estuary. After a summer high rainfall event nutrient-stimulated biological pumping promoted a large uptake of CO2 transitioning the Sydney Harbour Estuary into a CO2 sink with a maximum uptake of rate of -10.6 mmol C m-2 d-1 in the mid-section of the estuary. Annually the Sydney Harbour Estuary was heterotrophic and a weak source of CO2 with an air-water emission rate of 1.2-5 mmol C m-2 d-1 (0.4-1.8 mol C m-2 y-1) resulting in a total carbon emission of around 930 tonnes per annum. CO2 emissions (weighted m3 s-1 of discharge per km2 of estuary surface area) from Sydney Harbour were an order of magnitude lower than other temperate large tectonic deltas, lagoons and engineered systems of China, India, Taiwan and Europe but were similar to other natural drowned river valley systems in the USA. Discharge per unit area appears to be a good predictor of CO2 emissions from estuaries of a similar climate and geomorphic class.

  16. Climate Ready Estuaries Partner Projects Map

    Science.gov (United States)

    CRE partners with the National Estuary Program to develop climate change projects in coastal U.S. areas, such as bays and harbors; to develop adaptation action plans, identify climate impacts and indicators, and more. This map shows project locations.

  17. National Estuary Program Study Area Boundaries

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are 28 National Estuary Programs (NEPs) in the U.S.that implement habitat protection and restoration projects with their partners. This work takes place within...

  18. Mercury enrichment in sediments of Amba estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Rokade, M.A.; Zingde, M.D.

    of anthropogenic metal to the estuary. Geoaccumulation index and enrichment factor support Hg contamination of the estuarine sediment to a varying degree. Hg is not significantly correlated with TOC, Al, Fe and Mn in these sediments...

  19. Mercury in sediments of Ulhas estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Rokade, M.A.; Borole, D.V.; Zingde, M.D.

    Hg levels in water, suspended particulate matter and sediment of the Ulhas estuary are under considerable environmental stress due to the indiscriminate release of effluents from a variety of industries including chlor-alkali plants. Concentration...

  20. Benthic studies in south Gujarat estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Govindan, K.; Varshney, P.K.; Desai, B.N.

    Benthic biomass and faunal composition in relation to various environmental conditions of the four South Gujarat estuaries namely the Auranga, Ambika, Purna and Mindola were studied and compared. Mean population density of benthos in Auranga, Ambika...

  1. Estuaries.

    Science.gov (United States)

    Awkerman, Gary L.

    This publication is designed for use in standard science curricula to develop oceanologic manifestations of certain science topics. Included are teacher guides, student activities, and demonstrations designed to impart ocean understanding to high school students. When the student has completed this unit, he should be able to: (1) define an…

  2. Keurbooms Estuary floods and sedimentation

    Directory of Open Access Journals (Sweden)

    Eckart H. Schumann

    2015-11-01

    Full Text Available The Keurbooms Estuary at Plettenberg Bay lies on a wave-dominated, microtidal coast. It has a dune-topped sandy barrier, or barrier dune, almost 4 km long, with a narrow back-barrier lagoon connected to its source rivers, the Keurbooms and Bitou. The estuary exits to the sea through this barrier dune, and it is the geomorphology and mouth position in relation to floods, which is the subject of this paper. Measurements of rainfall, water level, waves and high- and low-tide water lines were used to analyse the mouth variability over the years 2006–2012. Two major floods occurred during this time, with the first in November 2007 eroding away more than 500 000 m3 of sediment. The new mouth was established at the Lookout Rocks limit – the first time since 1915. The second flood occurred in July 2012 and opened up a new mouth about 1 km to the north-east; high waves also affected the position of the breach. The mouth has a tendency to migrate southwards against the longshore drift, but at any stage this movement can be augmented or reversed. The effectiveness of floods in breaching a new mouth through the barrier dune depends on the flood size and the nature of the exit channel in the back-barrier lagoon. Other factors such as ocean waves, sea level, vegetative state of the dune and duration of the flood are also important and can determine where the breach occurs, and if the new mouth will dominate the old mouth.

  3. Bar dimensions and bar shapes in estuaries

    Science.gov (United States)

    Leuven, Jasper; Kleinhans, Maarten; Weisscher, Steven; van der Vegt, Maarten

    2016-04-01

    Estuaries cause fascinating patterns of dynamic channels and shoals. Intertidal sandbars are valuable habitats, whilst channels provide access to harbors. We still lack a full explanation and classification scheme for the shapes and dimensions of bar patterns in natural estuaries, in contrast with bars in rivers. Analytical physics-based models suggest that bar length in estuaries increases with flow velocity, tidal excursion length or estuary width, depending on which model. However, these hypotheses were never validated for lack of data and experiments. We present a large dataset and determine the controls on bar shape and dimensions in estuaries, spanning bar lengths from centimeters (experiments) to 10s of kilometers length. First, we visually identified and classified 190 bars, measured their dimensions (width, length, height) and local braiding index. Data on estuarine geometry and tidal characteristics were obtained from governmental databases and literature on case studies. We found that many complex bars can be seen as simple elongated bars partly cut by mutually evasive ebb- and flood-dominated channels. Data analysis shows that bar dimensions scale with estuary dimensions, in particular estuary width. Breaking up the complex bars in simple bars greatly reduced scatter. Analytical bar theory overpredicts bar dimensions by an order of magnitude in case of small estuarine systems. Likewise, braiding index depends on local width-to-depth ratio, as was previously found for river systems. Our results suggest that estuary dimensions determine the order of magnitude of bar dimensions, while tidal characteristics modify this. We will continue to model bars numerically and experimentally. Our dataset on tidal bars enables future studies on the sedimentary architecture of geologically complex tidal deposits and enables studying effects of man-induced perturbations such as dredging and dumping on bar and channel patterns and habitats.

  4. The Estuary Book: A Guide to Promoting Understanding and Regional Management of Maine's Estuaries and Embayments.

    Science.gov (United States)

    Ruffing, Jenny

    The objective of this document is to provide information about estuaries, the impact of uses on the environmental health of an estuary, and what communities and concerned individuals can do to manage and protect their local estuarine resources successfully. Much of the information presented here pertains to other embayments along the Maine coast…

  5. Diatom colonization on stainless steel panels in estuarine waters of Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Mitbavkar, S.; Anil, A.C.

    Temporal variations in diatom fouling was investigated at the Dona Paula Bay located at the mouth of the Zuari Estuary, Goa, India. Stainless steel panels admeasuring 15 x 10 cm were exposed to the environment every month for four consecutive days...

  6. Translating India

    CERN Document Server

    Kothari, Rita

    2014-01-01

    The cultural universe of urban, English-speaking middle class in India shows signs of growing inclusiveness as far as English is concerned. This phenomenon manifests itself in increasing forms of bilingualism (combination of English and one Indian language) in everyday forms of speech - advertisement jingles, bilingual movies, signboards, and of course conversations. It is also evident in the startling prominence of Indian Writing in English and somewhat less visibly, but steadily rising, activity of English translation from Indian languages. Since the eighties this has led to a frenetic activity around English translation in India's academic and literary circles. Kothari makes this very current phenomenon her chief concern in Translating India.   The study covers aspects such as the production, reception and marketability of English translation. Through an unusually multi-disciplinary approach, this study situates English translation in India amidst local and global debates on translation, representation an...

  7. Towards the classification of eutrophic condition in estuaries

    CSIR Research Space (South Africa)

    Lemley, DA

    2015-10-01

    Full Text Available Water quality and ecological integrity of estuaries closely reflect activities within the entire upstream catchment. Much emphasis has been placed on the response of estuaries to anthropogenic stressors through the use of monitoring programmes. Key...

  8. Benthos of Beypore and Korapuzha estuaries of North Kerala

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, K.S.; Sankaranarayanan, V.N.; Venugopal, P.

    The benthos from Beypore and Korapuzha estuaries were studied for one year. Environmental features, sediment characteristics and organic carbon content were estimated. Benthic density was high during monsoon and postmonsoon in both the estuaries...

  9. Variations of dissolved oxygen in Mandovi and Zuari estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.; SenGupta, R.

    During non-monsoon months the estuaries were well mixed showing uniform oxygen concentrations from surface to bottom. However, during monsoon months both the estuaries showed stratified conditions with surface water showing high oxygen concentration...

  10. Nutrient characterisation of river inflow into the estuaries of the ...

    African Journals Online (AJOL)

    Nutrient characterisation of river inflow into the estuaries of the Gouritz Water ... into the estuaries within the Gouritz Water Management Area (WMA) of South Africa. ... Long-term water quality monitoring data (dissolved inorganic nitrogen, i.e. ...

  11. Skagit IMW - Skagit River Estuary Intensively Monitored Watershed Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study evaluates system-level effects of several estuary restoration projects on juvenile Chinook salmon production in the Skagit River estuary. The monitoring...

  12. Origin and composition of particulate organic matter in a macrotidal turbid estuary: The Gironde Estuary, France

    Science.gov (United States)

    Savoye, Nicolas; David, Valérie; Morisseau, François; Etcheber, Henri; Abril, Gwenaël; Billy, Isabelle; Charlier, Karine; Oggian, Georges; Derriennic, Hervé; Sautour, Benoît

    2012-08-01

    At the interface between continent and ocean, estuaries receive particles, and especially particulate organic matter (POM) originating from these two reservoirs, but also produce POM, through autochthonous primary production. The origin and composition of surface POM in the Gironde Estuary (SW France) and the environmental forcing of its variability was investigated using the data set produced by the French Coastal Monitoring Network SOMLIT (Service d'Observation en Milieu LITtoral; monthly like sampling during years 2007-2009). This estuary is considered as a model of macrotidal turbid estuaries. Using elemental and isotopic composition of the POM, we estimated that, at the inner estuary space scale and inter-annual time scale, surface particulate organic carbon (POC) was composed of terrestrial POM originated from the turbidity maximum (96.4%; refractory POC) and flood events (1.6%; labile and refractory POC), and of riverine (0.1%), estuarine (0.8%) and marine (1.1%) phytoplankton, i.e. that POC was 98% and 2% of terrestrial and phytoplankton origin, respectively. However, there was a clear spatial gradient: the phytoplankton contribution increases from ca. 1% in the upper and middle estuary to 8.5% in the lower estuary, where light condition is more favourable to plankton growth. The low contribution of phytoplankton to the POC is a characteristic of the Gironde estuary and contrast with other large temperate estuaries. Statistical analysis indicates that salinity, river flow and SPM concentration, and thus associated hydro-dynamic and sedimentary processes, were the only environmental forcings to the composition of surface POC in this system, at intra- and inter-annual time scale. In contrast, temperature and nutrient concentrations, and thus associated processes, do not force this composition of POC. By combining POC fluxes entering the inner estuary (literature data), POC loss as dissolved organic carbon and CO2 and as sediment trapping within the inner

  13. Environmental flow assessments for transformed estuaries

    Science.gov (United States)

    Sun, Tao; Zhang, Heyue; Yang, Zhifeng; Yang, Wei

    2015-01-01

    Here, we propose an approach to environmental flow assessment that considers spatial pattern variations in potential habitats affected by river discharges and tidal currents in estuaries. The approach comprises four steps: identifying and simulating the distributions of critical environmental factors for habitats of typical species in an estuary; mapping of suitable habitats based on spatial distributions of the Habitat Suitability Index (HSI) and adopting the habitat aggregation index to understand fragmentation of potential suitable habitats; defining variations in water requirements for a certain species using trade-off analysis for different protection objectives; and recommending environmental flows in the estuary considering the compatibility and conflict of freshwater requirements for different species. This approach was tested using a case study in the Yellow River Estuary. Recommended environmental flows were determined by incorporating the requirements of four types of species into the assessments. Greater variability in freshwater inflows could be incorporated into the recommended environmental flows considering the adaptation of potential suitable habitats with variations in the flow regime. Environmental flow allocations should be conducted in conjunction with land use conflict management in estuaries. Based on the results presented here, the proposed approach offers flexible assessment of environmental flow for aquatic ecosystems that may be subject to future change.

  14. The Estuary Guide. Level 3: High School. Draft.

    Science.gov (United States)

    Alexander, Glen; And Others

    Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the high school level seeks to teach what estuaries are; provide opportunities to practice decision-making that affects estuaries; and encourage students to…

  15. Improving navigability on the Kromme River Estuary: A choice ...

    African Journals Online (AJOL)

    Navigation of estuaries is a vitally important aspect of boating recreation in South Africa and elsewhere. This paper uses a choice experiment to estimate recreation values of the Kromme River Estuary, a popular estuary along South Africa's east coast. This valuation methodology allows for the identification of preferred ...

  16. Estuary wader capacity following severe weather mortality

    International Nuclear Information System (INIS)

    Clark, J.A.; Baillie, S.R.; Clark, N.A.; Langston, R.H.W.

    1993-01-01

    The building of a tidal power barrage across an estuary may lead to substantial changes in its ecology. Many of Britain's estuaries hold internationally important numbers of waders. Careful consideration, therefore, needs to be given to the likely effects of tidal power barrages on wader populations. The opportunity for increased understanding of the mechanisms which govern wader populations was provided by a period of severe winter weather in 1991, which resulted in a substantial mortality of waders in eastern England. Such conditions are known to be stressful to birds and the study objectives were to investigate both the effects of and recovery from severe weather. (author)

  17. The relationship between sediment and plutonium budgets in a small macrotidal estuary: Esk Estuary, Cumbria, UK

    International Nuclear Information System (INIS)

    Kelly, M.; Emptage, M.; Mudge, S.; Bradshaw, K.; Hamilton-Taylor, J.

    1991-01-01

    During a spring tide, measurements were made of sediment and 239,240 Pu discharges through a cross-section of the Esk estuary. These indicated that over the full tidal cycle, the inner estuary had a net gain of ca. 18 t of sediment and ca. 85 MBq of particulate phase 239,240 Pu, and a probable net loss of ca. 1 to 2 MBq of solution phase 239,240 Pu. Each of these was the net result of large gross discharges of sediment and plutonium into and out of the estuary for which the sea was the main source, with eroded estuarine sediment providing an additional minor source of sediment, of particulate phase plutonium and, via desorption, of solution phase plutonium. A net input with each tide, of sediment and its associated radionuclides, is considered to be typical for the Esk estuary under the normal conditions of low river flows. (author)

  18. Establishing nursery estuary otolith geochemical tags for Sea Bass (Dicentrarchus labrax): Is temporal stability estuary dependent?

    Science.gov (United States)

    Ryan, Diarmuid; Wögerbauer, Ciara; Roche, William

    2016-12-01

    The ability to determine connectivity between juveniles in nursery estuaries and adult populations is an important tool for fisheries management. Otoliths of juvenile fish contain geochemical tags, which reflect the variation in estuarine elemental chemistry, and allow discrimination of their natal and/or nursery estuaries. These tags can be used to investigate connectivity patterns between juveniles and adults. However, inter-annual variability of geochemical tags may limit the accuracy of nursery origin determinations. Otolith elemental composition was used to assign a single cohort of 0-group sea bass Dicentrarchus labrax to their nursery estuary thus establishing an initial baseline for stocks in waters around Ireland. Using a standard LDFA model, high classification accuracies to nursery sites (80-88%) were obtained. Temporal stability of otolith geochemical tags was also investigated to assess if annual sampling is required for connectivity studies. Geochemical tag stability was found to be strongly estuary dependent.

  19. Estuary fish data - Juvenile salmon in migratory corridors of lower Columbia River estuary

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sampling juvenile salmon and associated fishes in open waters of the lower Columbia River estuary. Field work includes bi-weekly sampling during the spring...

  20. Radiological assessment of the Esk Estuary

    International Nuclear Information System (INIS)

    Howorth, J.M.; Barr, H.M.; Toole, J.; Strange, L.P.

    1993-01-01

    An assessment has been carried out of the radiological impact of artificial radionuclides in the Esk estuary in Cumbria, UK. Measurements were made of the distributions of 137 Cs, 239 + 240 Pu, and 241 Am in water, surface bed sediments and core profiles. The highest measured concentrations in surface sediments were 2.8 Bq g -1 of 137 Cs, 3.1 Bq g -1 of 239 + 240 Pu and 4.7 Bq g -1 of 241 Am. These values represent significant decreases from similar measurements made in 1970-1980. The measured behaviour of the actinides in low salinity water at the head of the estuary supports previous observations of actinide remobilisation from the bed. A model has been developed which simulates the long-term behaviour of radioactivity in the estuary. The model incorporates representations of tidal mixing, sediment transport, seasonal and long-term sediment accretion. The model also represents long-term build-up in salt marsh regions. The model gives good agreement with measured distributions of 137 Cs, but tends to underestimate actinide concentrations by factors of 2-3. Dose calculations show the importance of radionuclide uptake through livestock grazing sea-washed pasture alongside the estuary. 137 Cs and 241 Am are identified as the most important radionuclides considered in the assessment. (Author)

  1. Padilla Bay: The Estuary Guide. Level 2.

    Science.gov (United States)

    Friesem, Judy; Lynn, Valerie, Ed.

    Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the middle school level is designed for use with the on-site program developed by the Padilla Bay National Esturine Research Reserve (Washington). The guide…

  2. The environmental characteristics of the Ganga estuary

    Digital Repository Service at National Institute of Oceanography (India)

    SenGupta, R.; Murty, C.S.; Bhattathiri, P.M.A.

    This report presents physical, chemical and biological observations in the last 160 km stretch of river Ganga for period of 3 years. In the one-layer estuary the mixing is brought about by the horizontal gradient of the flow field closely associated...

  3. Restoration of the Golden Horn Estuary (Halic).

    Science.gov (United States)

    Coleman, Heather M; Kanat, Gurdal; Aydinol Turkdogan, F Ilter

    2009-12-01

    Restoration of the iconic Golden Horn Estuary in Istanbul, Turkey was a substantial political, logistical, ecological, and social challenge. Forty years of uncontrolled industrial and urban growth resulted in thick layers of anoxic sediment, toxic bacteria, strong hydrogen sulfide odor, and ecologically unlivable conditions. The major components of restoration, spanning two decades, have included (1) demolition and relocation of industries and homes along the shore, (2) creation of wastewater infrastructure, (3) removal of anoxic sludge from the estuary, (4) removal of a floating bridge that impeded circulation, and (5) creation of cultural and social facilities. Although Turkey is not known as an environmental leader in pollution control, the sum of these efforts was largely successful in revitalizing the area through dramatic water quality improvement. Consequently, the estuary is once again inhabitable for aquatic life as well as amenable to local resource users and foreign visitors, and Istanbul has regained a lost sense of cultural identity. This paper focuses on literature review and personal interviews to discuss the causes of degradation, solutions employed to rehabilitate the estuary, and subsequent physicochemical, ecological, and social changes.

  4. Estuaries and Tidal Marshes. Habitat Pac.

    Science.gov (United States)

    Fish and Wildlife Service (Dept. of Interior), Washington, DC.

    This educational packet consists of an overview, three lesson plans, student data sheets, and a poster. The overview examines estuaries and tidal or salt marshes by discussing the plants and animals in these habitats, marsh productivity, benefits and management of the habitats, historical aspects, and development and pollution. A glossary and list…

  5. Flushing characteristics of Mahim river estuary (Bombay)

    Digital Repository Service at National Institute of Oceanography (India)

    Sabnis, M.M; Zingde, M

    to the influence of wastewater. Flushing time of 19 tidal cycles was estimated by applying modified tidal prism method. After a large number of tidal cycles the estuary would retain 9.3x10 super(4) m super(3) of wastewater which was over 15% of the spring high tide...

  6. Influence of estuaries on shelf sediment texture

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, R.R.; Hashimi, N.H.

    on the coast. Offshore from regions where there are a large number of estuaries, the inner shelf sediments are fine grained (average mean size 5.02 phi, 0.03 mm), rich in organic matter ( 2%) and low in calcium carbonate ( 25%). In contrast, in regions...

  7. Carbon dioxide emissions from Indian monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Viswanadham, R.; Rao, G.D.; Prasad, V.R.; Kumar, B.S.K.; Naidu, S.A.; Kumar, N.A.; Rao, D.B.; Sridevi, T.; Krishna, M.S.; Reddy, N.P.C.; Sadhuram, Y.; Murty, T.V.R.

    estuaries. The mean pCO sub(2) and particulate organic carbon (POC) showed positive relation with rate of discharge suggesting availability of high quantities of organic matter that led to enhanced microbial decomposition. The annual CO sub(2) fluxes from...

  8. Hydrodynamics of the Bot river estuary revisited

    CSIR Research Space (South Africa)

    Van Niekerk, L

    2005-01-01

    Full Text Available For the past 20 years management of the Bot/Kleinmond estuarine system in the south-western Cape has been based on the premise that, barring intervention, the estuary was naturally evolving into a freshwater coastal lake. This paper presents...

  9. Sedimentation in a river dominated estuary

    CSIR Research Space (South Africa)

    Cooper, JAG

    1993-10-01

    Full Text Available The Mgeni Estuary on the wave dominated cast coast of South Africa occupies a narrow, bedrock confined, alluvial valley and is partially blocked at the coast by an elongate sandy barrier. Fluvial sediment extends to the barrier and marine depositon...

  10. Mouth Bar Formation in Yangtze River Estuary

    NARCIS (Netherlands)

    Wei, C.

    2002-01-01

    The periodic shifting of the bifurcation point of the North Channel and South Channel of the Yangtze river is very important in the estuary. The North Channel is bifurcated from the South Branch by cutting a channel through the submerged sandbanks. Once a bifurcation channel is formed, the

  11. India Emerging

    International Development Research Centre (IDRC) Digital Library (Canada)

    2017-12-13

    Dec 13, 2017 ... It is telling that in a famous paper authored by the Nobel Prize winner, Robert ..... Examples are the steam engine, railroad, electricity, electronics, the ...... According to Gartner's Senior Research Analyst 'India's domestic IT services .... in new areas such as engineering services and product development.

  12. India Emerging

    International Development Research Centre (IDRC) Digital Library (Canada)

    Here Veena Jha surveys the history of philanthropic giving in India going back to the ...... claim that ICTs produced benefits go beyond those pertaining to investors and owners. ...... Anti-migration policies include restricted access to public services by below poverty ...... Which medicines and vaccinations are not available?

  13. 76 FR 8345 - Endangered and Threatened Species; Recovery Plan Module for Columbia River Estuary Salmon and...

    Science.gov (United States)

    2011-02-14

    ... and Threatened Species; Recovery Plan Module for Columbia River Estuary Salmon and Steelhead AGENCY.... ACTION: Notice of availability; recovery plan module for Columbia River estuary salmon and steelhead... Plan Module for Salmon and Steelhead (Estuary Module). The Estuary Module addresses the estuary...

  14. Nutrient budgets for large Chinese estuaries

    Directory of Open Access Journals (Sweden)

    S. M. Liu

    2009-10-01

    Full Text Available Chinese rivers deliver about 5–10% of global freshwater input and 15–20% of the global continental sediment to the world ocean. We report the riverine fluxes and concentrations of major nutrients (nitrogen, phosphorus, and silicon in the rivers of the contiguous landmass of China and Korea in the northeast Asia. The rivers are generally enriched with dissolved inorganic nitrogen (DIN and depleted in dissolved inorganic phosphate (PO43− with very high DIN: PO43− concentration ratios. DIN, phosphorus, and silicon levels and loads in rivers are mainly affected by agriculture activities and urbanization, anthropogenic activities and adsorption on particulates, and rock types, climate and physical denudation intensity, respectively. Nutrient transports by rivers in the summer are 3–4 times higher than those in the winter with the exception of NH4+. The flux of NH4+ is rather constant throughout the year due to the anthropogenic sources such as the sewer discharge. As nutrient composition has changed in the rivers, ecosystems in estuaries and coastal sea have also changed in recent decades. Among the changes, a shift of limiting nutrients from phosphorus to nitrogen for phytoplankton production with urbanization is noticeable and in some areas silicon becomes the limiting nutrient for diatom productivity. A simple steady-state mass-balance box model was employed to assess nutrient budgets in the estuaries. The major Chinese estuaries export <15% of nitrogen, <6% of phosphorus required for phytoplankton production and ~4% of silicon required for diatom growth in the Chinese Seas (Bohai, Yellow Sea, East China Sea, South China Sea. This suggests that land-derived nutrients are largely confined to the immediate estuaries, and ecosystem in the coastal sea beyond the estuaries is mainly supported by other nutrient sources such as regeneration, open ocean and

  15. Historical changes in the Columbia River Estuary

    Science.gov (United States)

    Sherwood, Christopher R.; Jay, David A.; Bradford Harvey, R.; Hamilton, Peter; Simenstad, Charles A.

    Historical changes in the hydrology, sedimentology, and physical oceanography of the Columbia River Estuary have been evaluated with a combination of statistical, cartographic, and numerical-modelling techniques. Comparison of data digitized from US Coast and Geodetic Survey bathymetric surveys conducted in the periods 1867-1875, 1926-1937, and 1949-1958 reveals that large changes in the morphology of the estuary have been caused by navigational improvements (jetties, dredged channels, and pile dikes) and by the diking and filling of much of the wetland area. Lesser changes are attributable to natural shoaling and erosion. There has been roughly a 15% decrease in tidal prism and a net accumulation of about 68 × 10 6m 3 of sediment in the estuary. Large volumes of sediment have been eroded from the entrance region and deposited on the continental shelf and in the balance of the estuary, contributing to formation of new land. The bathymetric data indicate that, ignoring erosion at the entrance, 370 to 485 × 10 6m 3 of sediment has been deposited in the estuary since 1868 at an average rate of about 0.5 cm y -1, roughly 5 times the rate at which sea level has fallen locally since the turn of the century. Riverflow data indicate that the seasonal flow cycle of the Columbia River has been significantly altered by regulation and diversion of water for irrigation. The greatest changes have occurred in the last thirty years. Flow variability over periods greater than a month has been significantly damped and the net discharge has been slightly reduced. These changes in riverflow are too recent to be reflected in the available in the available bathymetric data. Results from a laterally averaged, multiple-channel, two-dimensional numerical flow model (described in HAMILTON, 1990) suggest that the changes in morphology and riverflow have reduced mixing, increased stratification, altered the response to fortnightly (neap-spring) changes in tidal forcing, and decreased the

  16. Plankton composition in two estuaries of the Konkan coast during premonsoon season

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Nair, S.R.S.; Devassy, V.P.; Nair, V.R.

    abundant at the mouth region. Zooplankton biomass was relatively high in the Kajvi Estuary and all the major groups occurred in high density throughout this estuary. In the Shastri Estuary, the zooplankton biomass was relatively lower and all the major...

  17. Fishes and fisheries in tropical estuaries: The last 10 years

    Science.gov (United States)

    Blaber, S. J. M.

    2013-12-01

    Since 2002 there has been an increase in knowledge of many aspects of the biology and ecology of tropical estuarine fishes, as well as significant changes to many estuarine fisheries. Analyses of literature databases (2002-2012) show that: of the c. 600 relevant papers, 52% are primarily related to ecology, 11% to conservation, 11% to anthropogenic and pollution effects on fishes, 9% to fisheries, 7% to aquaculture, 4% to study techniques, and 1% each to fish larvae, effects of fishing, taxonomy, climate change, evolution and genetics. In terms of geographic spread 17% are from North America, 15% from south Asia, 14% from the Caribbean, 13% from Australasia, 12% from Africa and 9% each from South America and SE Asia. Research papers came from 50 countries of which the dominant were USA (15%), India (12%), Australia (11%) and Brazil (7%). Increasing numbers of studies in West Africa, SE and South Asia and South America have increased basic knowledge of the ecology of estuarine fish faunas. Increases in understanding relate to: roles of salinity, turbidity and habitat diversity; connectivity between habitats; water flow; ecological drivers of spatial variability; scale dependent variation; thermal tolerances; movement patterns; food webs; larval adaptations; and the viability of areas heavily impacted by human activities. New reviews both challenge and support different aspects of the estuarine dependence paradigm - still perhaps one of the main research issues - and the protective function of estuaries and mangroves for juvenile fishes has received attention in relation to e.g. predation risks and fisheries. There have also been significant advances in the use of guilds and biodiversity models. Fishing pressures have continued unabated in most tropical estuaries and are summarised and management issues discussed. Understanding of the relationships between fisheries production and mangroves has advanced and significant differences have emerged between Indo

  18. Marine geology of the St. Lawrence Estuary

    Energy Technology Data Exchange (ETDEWEB)

    St-Onge, Guillaume [Canada Research Chair in Marine Geology, Institut des sciences de la mer de Rimouski (ISMER) and GEOTOP Research Center, 310 allee des Ursulines, Rimouski, Quebec, G5L 3A1 (Canada); Duchesne, Mathieu J [Geological Survey of Canada, Quebec Division, 490 de la Couronne, Quebec City, Quebec, G1K 9A9 (Canada); Lajeunesse, Patrick, E-mail: guillaume_st-onge@uqar.qc.ca [Departement de geographie and Centre d' etudes nordiques, Universite Laval, Quebec City, Quebec, G1V 0A6 (Canada)

    2011-05-15

    The St. Lawrence Estuary, Eastern Canada, contains a very thick (>450 m) Quaternary sedimentary sequence. The results from recently conducted geophysical surveys in conjunction with piston coring indicate that these sediments were deposited under very high sedimentation rates, sometimes as high as {approx}30 m/ka during the last deglaciation. Results also reveal evidence of large submarine landslides during the Holocene, changes in sedimentation rates and the significant role of submarine canyons and channels to transfer sediments from the coast to the deeper marine environment. Finally, this paper highlights the presence of more than 1900 pockmarks on the seafloor of the St. Lawrence Estuary and discusses their possible origins: active hydrocarbon seeps in the Laurentian Channel and biogenic gas seepage on the northwestern shoulder of the Laurentian Channel.

  19. Marine geology of the St. Lawrence Estuary

    International Nuclear Information System (INIS)

    St-Onge, Guillaume; Duchesne, Mathieu J; Lajeunesse, Patrick

    2011-01-01

    The St. Lawrence Estuary, Eastern Canada, contains a very thick (>450 m) Quaternary sedimentary sequence. The results from recently conducted geophysical surveys in conjunction with piston coring indicate that these sediments were deposited under very high sedimentation rates, sometimes as high as ∼30 m/ka during the last deglaciation. Results also reveal evidence of large submarine landslides during the Holocene, changes in sedimentation rates and the significant role of submarine canyons and channels to transfer sediments from the coast to the deeper marine environment. Finally, this paper highlights the presence of more than 1900 pockmarks on the seafloor of the St. Lawrence Estuary and discusses their possible origins: active hydrocarbon seeps in the Laurentian Channel and biogenic gas seepage on the northwestern shoulder of the Laurentian Channel.

  20. Deschutes estuary feasibility study: hydrodynamics and sediment transport modeling

    Science.gov (United States)

    George, Douglas A.; Gelfenbaum, Guy; Lesser, Giles; Stevens, Andrew W.

    2006-01-01

    Continual sediment accumulation in Capitol Lake since the damming of the Deschutes River in 1951 has altered the initial morphology of the basin. As part of the Deschutes River Estuary Feasibility Study (DEFS), the United States Geological Survey (USGS) was tasked to model how tidal and storm processes will influence the river, lake and lower Budd Inlet should estuary restoration occur. Understanding these mechanisms will assist in developing a scientifically sound assessment on the feasibility of restoring the estuary. The goals of the DEFS are as follows. - Increase understanding of the estuary alternative to the same level as managing the lake environment.

  1. Differences in the structure of copepod assemblages in four tropical estuaries: Importance of pollution and the estuary hydrodynamics.

    Science.gov (United States)

    Araujo, Adriana V; Dias, Cristina O; Bonecker, Sérgio L C

    2017-02-15

    We examined the relationship between pollution and structure of copepod assemblages in estuaries, using sampling standardization of salinity range to reduce the effects of "Estuarine Quality Paradox". Copepod assemblages were analyzed in four Southeast Brazilian estuaries with different water quality levels and different hydrodynamic characteristics. The pollution negatively impacted the descriptors of the assemblage structure. The distribution of structure of copepod assemblages also showed a main separation trend between the most polluted estuaries and those less polluted. Temperature was the main factor affecting the assemblage structuring in the four estuaries. This factor acted in synergism with the effects of pollution impact and physical characteristics of the estuaries on the structure of copepod assemblages, supporting the potential vulnerability of coastal environments due to nutrient enrichment associated with climate change. Our study demonstrated the importance of sampling standardization of the salinity range in estuaries for reliable analysis of pollution effects on biota. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Impact of climate change on Gironde estuary

    International Nuclear Information System (INIS)

    Laborie, Vanessya; Hissel, Francois; Sergent, Philippe

    2014-01-01

    Within the THESEUS European project, a simplified mathematical model for storm surge levels in the Bay of Biscay was adjusted on 10 events at Le Verdon using wind and pressure fields from CLM/SGA, so that the water levels at Le Verdon have the same statistic quantiles as observed tide records for the period [1960-2000]. A numerical model of the Gironde Estuary was used to evaluate future water levels at 6 locations of the estuary from Le Verdon to Bordeaux and to assess the changes in the quantiles of water levels during the 21. century using ONERC's pessimistic scenario for sea level rise (60 cm). The analysis of future storm surge levels shows a decrease in their quantiles at Le Verdon,, whereas there is an increase of the quantiles of total water levels. This increase is smaller than the sea level rise and gets even smaller as one enters farther upstream in the estuary. A series of flood maps for different return periods between 2 and 100 years and for four time periods ([1960-1999], [2010-2039], [2040-2069] and [2070-2099]) have been built for the region of Bordeaux. Quantiles of water levels in the flood plain have also been calculated. The impact of climate change on the evolution of flooded areas in the Gironde Estuary and on quantiles of water levels in the flood plain mainly depends on the sea level rise. Areas which are not currently flooded for low return periods will be inundated in 2100. The influence of river discharges and dike breaching should also be taken into account for more accurate results. (authors)

  3. Anthropogenic Carbon Pump in an Urbanized Estuary

    Science.gov (United States)

    Park, J. H.; Yoon, T. K.; Jin, H.; Begum, M. S.

    2015-12-01

    The importance of estuaries as a carbon source has been increasingly recognized over the recent decades. However, constraining sources of CO2 evasion from urbanized estuaries remains incomplete, particularly in densely populated river systems receiving high loads of organic carbon from anthropogenic sources. To account for major factors regulating carbon fluxes the tidal reach of the Han River estuary along the metropolitan Seoul, characterization of organic carbon in the main stem and major urban tributaries were combined with continuous, submersible sensor measurements of pCO2 at a mid-channel location over a year and continuous underway measurements using a submersible sensor and two equilibrator sytems across the estuarine section receiving urban streams. Single-site continuous measurements exhibited large seasonal and diurnal variations in pCO2, ranging from sub-ambient air levels to exceptionally high values approaching 10,000 ppm. Diurnal variations of pCO2 were pronounced in summer and had an inverse relationship with dissolved oxygen, pointing to a potential role of day-time algal consumption of CO2. Cruise measurements displayed sharp pCO2 pulses along the confluences of urban streams as compared with relatively low values along the upper estuary receiving low-CO2 outflows from upstream dams. Large downstream increases in pCO2, concurrent with increases in DOC concentrations and fluorescence intensities indicative of microbially processed organic components, imply a translocation and subsequent dilution of CO2 carried by urban streams and/or fast transformations of labile C during transit along downstream reaches. The unique combination of spatial and temporal continuous measurements of pCO2 provide insights on estuarine CO2 pulses that might have resulted from the interplay between high loads of CO2 and organic C of anthropogenic origin and their priming effects on estuarine microbial processing of terrigenous and algal organic matter.

  4. Impact of climate change on Gironde Estuary

    Science.gov (United States)

    Laborie, Vanessya; Hissel, François; Sergent, Philippe

    2014-05-01

    Within the THESEUS European project, a simplified mathematical model for storm surge levels in the Bay of Biscay was adjusted on 10 events at Le Verdon using wind and pressure fields from CLM/SGA, so that the water levels at Le Verdon have the same statistic quantiles as observed tide records for the period [1960-2000]. The analysis of future storm surge levels shows a decrease in their quantiles at Le Verdon, whereas there is an increase of the quantiles of total water levels. This increase is smaller than the sea level rise and gets even smaller as one enters farther upstream in the estuary. A numerical model of the Gironde Estuary was then used to evaluate future water levels at 6 locations of the estuary from Le Verdon to Bordeaux and to assess the changes in the quantiles of water levels during the XXIst century using ONERC's pessimistic scenario for sea level rise (60 cm). The model was fed by several data sources : wind fields at Royan and Mérignac interpolated from the grid of the European Climatolologic Model CLM/SGA, a tide signal at Le Verdon, the discharges of Garonne (at La Réole), the Dordogne (at Pessac) and Isle (at Libourne). A series of flood maps for different return periods between 2 and 100 years and for four time periods ([1960-1999], [2010-2039], [2040-2069] and [2070-2099]) have been built for the region of Bordeaux. Quantiles of water levels in the floodplain have also been calculated. The impact of climate change on the evolution of flooded areas in the Gironde Estuary and on quantiles of water levels in the floodplain mainly depends on the sea level rise. Areas which are not currently flooded for low return periods will be inundated in 2100. The influence of river discharges and dike breaching should also be taken into account for more accurate results.

  5. FDI Climate in India

    OpenAIRE

    Khandelwal, Varun

    2007-01-01

    ABSTRACT Since 1991, after the external payment crisis in India, there has been liberalization of various policies by the Government of India. Due to this there has been rapid surge of FDI inflows in India. The current investment climate has attracted many foreign investors to India in various sectors. India is considered as one of the favorable destination of FDI. However the country also suffers from few weaknesses and constraints in terms of policy and regulatory framework, which rest...

  6. Nutrient input through submarine groundwater discharge in two major Chinese estuaries: the Pearl River Estuary and the Changjiang River Estuary

    Science.gov (United States)

    Liu, Jianan; Du, Jinzhou; Wu, Ying; Liu, Sumei

    2018-04-01

    In this study, we used a 224Ra mass balance model to evaluate the importance of submarine groundwater discharge (SGD) for the budgets of biogenic elements in two major Chinese estuaries: the Pearl River Estuary (PRE) and the Changjiang River Estuary (CRE). The apparent water age in the PRE was estimated to be 4.8 ± 1.1 days in the dry season and 1.8 ± 0.6 days in the wet season using a physical model based on the tidal prism. In the dry season, the water age in the CRE was estimated to be 11.7 ± 3.0 days using the 224Ra/223Ra activities ratios apparent age model. By applying the 224Ra mass balance model, we obtained calculations of the SGD flow in the PRE of (4.5-10) × 108 m3 d-1 (0.23-0.50 m3 m-2 d-1) and (1.2-2.7) × 108 m3 d-1 (0.06-0.14 m3 m-2 d-1) in the dry season and wet season, respectively, and the estimated SGD flux was (4.6-11) × 109 m3 d-1 (0.18-0.45 m3 m-2 d-1) in the dry season of the CRE. In comparison with the nutrient fluxes from the rivers, the SGD-derived nutrient fluxes may play a vital role in controlling the nutrient budgets and stoichiometry in the study areas. The large amount of dissolved inorganic nitrogen and phosphorus fluxes together with high N: P ratios into the PRE and CRE would potentially contribute to eutrophication and the occurrence of red tides along the adjacent waters.

  7. Nutritional condition of fish larvae in South African estuaries: an ...

    African Journals Online (AJOL)

    Nutritional condition of fish larvae in South African estuaries: an appraisal of three biochemical methods. D Costalago, N Strydom, C Frost. Abstract. Estuaries are exposed to a number of threats and many South African estuarine systems are functionally and structurally altered. The extent to which fish are affected by these ...

  8. Columbia Estuary Ecosystem Restoration Program. 2012 Synthesis Memorandum

    Science.gov (United States)

    2013-01-01

    LCFRB Lower Columbia Fish Recovery Board LCRE lower Columbia River and estuary LCREP Lower Columbia River Estuary Partnership LWD large woody debris...hydraulic reconnections, channel creation, large woody debris [ LWD ] placement) have restored a total of 3152 acres since 2001. If land acquisition...fencing, invasive plant removal, native replanting. Mirror Lake 208 Culvert replaced with a bridge, riparian restoration, LWD enhancement, culvert

  9. Tillamook Estuary Case Study: Local Drivers Influencing Coastal Acidification

    Science.gov (United States)

    US EPA initiated a study in the Tillamook estuary and watershed focused on the impact of changes in watershed land use, ocean conditions, and weather on estuarine water quality and ecosystem goods and services production within the estuary. This project is a collaboration betwee...

  10. Management of Fishery Resources in Yangtze River Estuary

    OpenAIRE

    Li, Meiling; Huang, Shuolin

    2009-01-01

    We introduce the fish fauna composition and main commercial fishes in Yangtze River estuary. We also analyze the current situation of resources and environment in Yangtze River estuary as well as the influential factors. Finally, related countermeasures are put forward on how to protect and use the fishery resources in Yangtze River.

  11. Fish abundance and distribution in the Gamtoos estuary with notes ...

    African Journals Online (AJOL)

    favourably with other larger systems like the Sundays, Bashee and Kei estuaries. .... as well as the use of pesticides undoubtedly affects water quality in the ... Methods. Catch per unit effort (CPUE) of fish in the Gamtoos estuary was obtained ...

  12. Relation between tidal damping and wave celerity in estuaries

    NARCIS (Netherlands)

    Savenije, H.H.G.; Veling, E.J.M.

    2005-01-01

    Observations in estuaries indicate that an amplified tidal wave moves considerably faster than is indicated by the classical equation for wave propagation. Similarly, the celerity of propagation is lower if the tidal wave is damped. This phenomenon is clearly observed in the Schelde estuary (located

  13. Zooplankton community changes in Nhlabane estuary, South Africa ...

    African Journals Online (AJOL)

    made impacts since 1977, when the lake and estuary were separated by the construction of a barrage. More recent man-made events included the construction of temporary sand walls, mid-way along the estuary, to allow crossing of a mining ...

  14. Tidal exchange between a freshwater tidal marsh and an impacted estuary: the Scheldt estuary, Belgium

    NARCIS (Netherlands)

    van Damme, S.; Dehairs, F.; Tackx, M.; Beauchard, O.; Struyf, E.; Gribsholt, B.; van Cleemput, O.; Meire, P.

    2009-01-01

    Tidal marsh exchange studies are relatively simple tools to investigate the interaction between tidal marshes and estuaries. They have mostly been confined to only a few elements and to saltwater or brackish systems. This study presents mass-balance results of an integrated one year campaign in a

  15. The importance of the river-estuary interface (REI) zone in estuaries

    African Journals Online (AJOL)

    drinie

    2002-07-03

    Jul 3, 2002 ... A multidisciplinary and multi-institutional research programme studied the influence of river flow rate on salinity distribution and response of the ... alia, the state of the mouth influences the extent of water exchange with the sea, vertical and ... The Kariega Estuary is a marine dominated system with very little.

  16. Nitrate levels modulate denitrification activity in tropical mangrove sediments (Goa, India)

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, S.O.; LokaBharathi, P.A.

    .M., & Bundrick, C.M. (1998). Potential sediment denitrification rates in estuaries of Northern Gulf of Mexico. Journal of environmental quality, 27(4), 859-868. Gruber, N., & Sarmiento, J.L. (1997). Global. Biogeochemical Cycles, 11, 235-266. Hahndel, R... of inorganic nitrogen in mangrove sediments (Terminos Lagoon, Mexico). Limnology and Oceanography, 41, 284-296. Sardessai, S. (1993). Dissolved, particulate and sedimentary humic acids in the mangroves and estuarine ecosystem of Goa, west coast of India...

  17. Conditions for tidal bore formation in convergent alluvial estuaries

    Science.gov (United States)

    Bonneton, Philippe; Filippini, Andrea Gilberto; Arpaia, Luca; Bonneton, Natalie; Ricchiuto, Mario

    2016-04-01

    Over the last decade there has been an increasing interest in tidal bore dynamics. However most studies have been focused on small-scale bore processes. The present paper describes the first quantitative study, at the estuary scale, of the conditions for tidal bore formation in convergent alluvial estuaries. When freshwater discharge and large-scale spatial variations of the estuary water depth can be neglected, tide propagation in such estuaries is controlled by three main dimensionless parameters: the nonlinearity parameter ε0 , the convergence ratio δ0 and the friction parameter ϕ0. In this paper we explore this dimensionless parameter space, in terms of tidal bore occurrence, from a database of 21 estuaries (8 tidal-bore estuaries and 13 non tidal-bore estuaries). The field data point out that tidal bores occur for convergence ratios close to the critical convergence δc. A new proposed definition of the friction parameter highlights a clear separation on the parameter plane (ϕ0,ε0) between tidal-bore estuaries and non tidal-bore estuaries. More specifically, we have established that tidal bores occur in convergent estuaries when the nonlinearity parameter is greater than a critical value, εc , which is an increasing function of the friction parameter ϕ0. This result has been confirmed by numerical simulations of the two-dimensional Saint Venant equations. The real-estuary observations and the numerical simulations also show that, contrary to what is generally assumed, tide amplification is not a necessary condition for tidal bore formation. The effect of freshwater discharge on tidal bore occurrence has been analyzed from the database acquired during three long-term campaigns carried out on the Gironde/Garonne estuary. We have shown that in the upper estuary the tidal bore intensity is mainly governed by the local dimensionless tide amplitude ε. The bore intensity is an increasing function of ε and this relationship does not depend on freshwater

  18. Greenhouse gas (N2O emission from Portuguese estuaries

    Directory of Open Access Journals (Sweden)

    Célia Gonçalves

    2014-07-01

    Tagus, Minho and Lima estuaries are source of N2O to the atmosphere. Particularly, in Lima estuary anthropogenic N input seems to play an important role on N2O emission. However, in a global perspective N2O attained emissions represent a reduced fraction (2O yr-1, Barnes and Upstill-Goddard, 2011. Values are comparable with those registered in some Portuguese estuaries and other European less eutrophic estuaries. However, it is known that higher N2O emissions in estuaries may occur during winter and spring (Sun et al., 2014. Thus, these systems may represent on an annual basis a larger source of N2O, which can only be clarified in future studies. Only a full comprehension of the global estuarine nitrogen cycle will provide an efficient basis of scientific knowledge for sustainably management of such ecosystems and ultimately reduce N2O emissions.

  19. Physicochemical and biological cycles in a tide dominated, nitrogen-polluted temperate estuary

    OpenAIRE

    Wafar, M.V.M.; Le Corre, P.; Birrien, J.L.

    1988-01-01

    Spatio-temporal variations in the physicochemical and biological parameters in the Morlaix estuary on the Brittany coast of France were studied. Hydrographically, the estuary can be classified into 3 segments: the upper estuary where stratification always persists, the lower estuary where vertical homogeneity is permanent, and a middle estuary where there is a regular oscillation of stratification and homogeneity during every tidal cycle, stratification being associated with slack waters and ...

  20. Environmental Flow for Sungai Johor Estuary

    Science.gov (United States)

    Adilah, A. Kadir; Zulkifli, Yusop; Zainura, Z. Noor; Bakhiah, Baharim N.

    2018-03-01

    Sungai Johor estuary is a vital water body in the south of Johor and greatly affects the water quality in the Johor Straits. In the development of the hydrodynamic and water quality models for Sungai Johor estuary, the Environmental Fluid Dynamics Code (EFDC) model was selected. In this application, the EFDC hydrodynamic model was configured to simulate time varying surface elevation, velocity, salinity, and water temperature. The EFDC water quality model was configured to simulate dissolved oxygen (DO), dissolved organic carbon (DOC), chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N), nitrate nitrogen (NO3-N), phosphate (PO4), and Chlorophyll a. The hydrodynamic and water quality model calibration was performed utilizing a set of site specific data acquired in January 2008. The simulated water temperature, salinity and DO showed good and fairly good agreement with observations. The calculated correlation coefficients between computed and observed temperature and salinity were lower compared with the water level. Sensitivity analysis was performed on hydrodynamic and water quality models input parameters to quantify their impact on modeling results such as water surface elevation, salinity and dissolved oxygen concentration. It is anticipated and recommended that the development of this model be continued to synthesize additional field data into the modeling process.

  1. Mercury distribution in Douro estuary (Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Ramalhosa, E. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Pereira, E. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal)]. E-mail: eduper@dq.ua.pt; Vale, C. [National Institute for Agronomy and Fishery Research, IPIMAR, Avenida Brasilia, 1449-006 Lisboa (Portugal); Valega, M. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Monterroso, P. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Duarte, A.C. [Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal)

    2005-11-15

    Determinations of dissolved reactive and total dissolved mercury, particulate and sedimentary mercury, dissolved organic carbon (DOC), particulate organic carbon (POC) and suspended particulate matter (SPM) have been made in the estuary of river Douro, in northern Portugal. The estuary was stratified by salinity along most of its length, it had low concentrations of SPM, typically <20 mg dm{sup -3}, and concentrations of DOC in the range <1.0-1.8 mg dm{sup -3}. The surface waters had a maximum dissolved concentration of reactive mercury of about 10 ng dm{sup -3}, whereas for the more saline bottom waters it was about 65 ng dm{sup -3}. The surface waters had maximum concentrations of total suspended particulate mercury of {approx}7 {mu}g g{sup -1} and the bottom waters were always <1 {mu}g g{sup -1}. Concentrations of mercury in sediments was low and in the range from 0.06 to 0.18 {mu}g g{sup -1}. The transport of mercury in surface waters was mainly associated with organic-rich particulate matter, while in bottom waters the dissolved phase transport of mercury is more important. Lower particulate organic matter, formation of chlorocomplexes in more saline waters and eventually the presence of colloids appear to explain the difference of mercury partitioning in Douro estuarine waters.

  2. Scavenging rate ecoassay: a potential indicator of estuary condition.

    Science.gov (United States)

    Porter, Augustine G; Scanes, Peter R

    2015-01-01

    Monitoring of estuary condition is essential due to the highly productive and often intensely impacted nature of these ecosystems. Assessment of the physico-chemical condition of estuaries is expensive and difficult due to naturally fluctuating water quality and biota. Assessing the vigour of ecosystem processes is an alternative method with potential to overcome much of the variability associated with physico-chemical measures. Indicators of estuary condition should have small spatial and temporal variability, have a predictable response to perturbation and be ecologically relevant. Here, we present tests of the first criterion, the spatio-temporal variability of a potential ecoassay measuring the rate of scavenging in estuaries. We hypothesised that the proposed scavenging ecoassay would not vary significantly among A) sites in an estuary, B) trips separated by weeks, or C) days in a trip. Because not all habitats are present in all estuaries, this test was undertaken in two habitats. When conducted over bare substrate there were occasional significant differences, but no discernible patterns, within levels of the experiment. When conducted over vegetated substrate, days within a trip did not vary significantly, but later trips experienced greater scavenging. This scavenging ecoassay shows potential as a tool for assessing the condition of estuarine ecosystems, and further exploration of this protocol is warranted by implementation in estuaries across a gradient of anthropogenic stress.

  3. Cyanobacteria and macroalgae in ecosystem of the Neva estuary

    Directory of Open Access Journals (Sweden)

    Nikulina V. N.

    2011-07-01

    Full Text Available The Baltic Sea and Neva estuary are plagued by coastal eutrophication. In order to estimate the scale of the problem, quantitative estimates of phytoplankton and macroalgal mats were determined in the Neva estuary. Long-term monitoring (1982–2009 of phytoplankton showed changes in its species composition and abundance. Summer phytoplankton biomass increased significantly in the 1990s, with concomitant changes in species composition, despite a decline of nutrients in the Neva estuary. The cyanobacteria Planktothrix agardhii became a dominant species. The summer biomass of phytoplankton reached a maximum of 5.2 ± 0.4 mg·L-1 in 2002–2004. Monitoring of macroalgal community in the coastal area of the Neva estuary from 2002 to 2009 showed the dominance of the filamentous green alga Cladophora glomerata in the phytobenthos. Average biomass of macroalgae in inner and outer estuary differed significantly at 132 ± 29 and 310 ± 67 g DW·m-2, respectively. This study showed, that fluctuations in macroalgal biomass reflected human influence on estuary, although it was less sensitive to human impact than the phytoplankton community. Thus qualitative and quantitative characteristics of phytoplankton and macroalgal blooms can indicate anthropogenic influence on the ecosystem, and help to better manage the Neva estuary.

  4. Waterfowl migration and distribution in North West estuaries. V. 1

    International Nuclear Information System (INIS)

    Clark, N.A.; Kirby, J.S.; Langston, R.H.W.; Donald, P.; Mawdesley, T.; Evans, J.

    1990-12-01

    Waterfowl populations may be affected by proposed tidal barrage across the Mersey. This study had three objectives:-(1) to evaluate the patterns of usage of the intertidal flats of the Mersey estuary by waders and wildfowl and to establish which are the preferred areas; (2) to identify the places of origin and movement patterns of the populations of waders and wildfowl that visit the Mersey Estuary; and (3) to evaluate evidence regarding the capacity of British estuaries to absorb waders and wildfowl populations which might be displaced by a Mersey Barrage. The text and tables and results only are presented in Volume 1. (author)

  5. India's Unfinished Telecom Tasks

    Indian Academy of Sciences (India)

    India's Telecom Story is now well known · Indian Operators become an enviable force · At the same time · India Amongst the Leaders · Unfinished Tasks as Operators · LightGSM ON: Innovation for Rural Area from Midas · Broadband Access Options for India · Broadband driven by DSL: still too slow · Is Wireless the answer?

  6. Salt Intrusion in the Tweed Estuary

    Science.gov (United States)

    Uncles, R. J.; Stephens, J. A.

    1996-09-01

    Results are presented from a 2-week field programme in the Tweed Estuary, U.K. Maximum values of the empirically based Estuarine Richardson Number, Ri E, occurred during neap tides, and minimum values occurred during spring tides. Estimated values of Ri Evaried between 0·3 and 2·3, suggesting the occurrence of partially mixed to stratified conditions, depending on tidal state and freshwater inflow. These relatively large values of Ri Ewere consistent with both observed strong salinity stratification and large salt fluxes due to vertical shear transport. Low values (0·5) values in the halocline. A velocity maximum occurred within the halocline during the early flood. Wave-like spatial oscillations of the halocline occurred on the ebb. The oscillation troughs were situated above deep holes located just down-estuary of the rail and old road bridges. There was an indication that the constricted flow between the bridges' arches resulted in enhanced mixing of near-surface waters and a thickening of the halocline. It is also possible that these wave-like structures were stationary, near-critical internal lee waves, triggered by the deep holes. Trapping of high-salinity waters occurred on the ebb. Saline pools were isolated within a deep hole or deeper section of bed by the falling halocline. When the salt wedge moved further down-estuary, the ' trapped ' waters were subjected to strongly ebbing, overlying freshwater, and were subsequently entrained and flushed. The salinity intrusion was a strong function of spring-neap tidal state and a weaker function of freshwater inflow. The estimated salinity intrusion varied from about 4·7 to 7·6 km during the fieldwork period. The strong dependence on tidal range followed from the comparable lengths of the tidal excursion and salinity intrusion. Long excursion lengths were also partly responsible for the short residence (or flushing) times and their strong dependence on spring-neap tidal state. For typical summer freshwater

  7. Evaluating Causes of Ecological Impairments in the Estuaries of Ukraine

    Science.gov (United States)

    Ukrainian estuaries have not undergone a systematic evaluation of the causes of ecological impairments caused by anthropogenic contamination. The objective of this evaluation is to use recently developed diagnostic tools to determine the causes of benthic ecological impairments. ...

  8. Fish and Salinity in the San Francisco Estuary

    Science.gov (United States)

    This page provides access to a set of time-series maps for six fishes that live in the SF Estuary. Maps were produced to strengthen best available science that inform actions needed to improve protection for aquatic life.

  9. Estuary 2100 Project, Phase 2: Building Partnerships for Resilient Watersheds

    Science.gov (United States)

    Information about the SFBWQP Estuary 2100 Project, Phase 2: Building Partnerships for Resilient Watersheds, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquat

  10. an ecophysiological study of the meiofauna of the swartkops estuary ...

    African Journals Online (AJOL)

    fauna in two exposed beaches in the Swartkops Estuary, near Port Elizabeth, were elucidated. PopUlation ... Variations of temperature and oxygen were found to be responsible for this pattern. ..... Apart from very low numbers of hermit crabs.

  11. Plutonium in Atlantic coastal estuaries in the southeastern United States

    International Nuclear Information System (INIS)

    Hayes, D.W.; LeRoy, J.H.; Cross, F.A.

    1975-01-01

    A survey was made to begin to provide baseline information on the Pu distribution of representative estuarine and coastal areas of the southeastern United States. Sediments and marsh grass (Spartina) were collected and analyzed from three locations within a tidal marsh. In three estuaries (Savannah, Neuse, and Newport), the suspended particulate matter (1 μm and greater) was filtered from waters with different salinities, and the plutonium content of the particulates determined. The Savannah River estuary, in addition to fallout Pu, has received up to 0.3 Ci of Pu from the Savannah River Plant (SRP) of the U. S. Energy Research and Development Administration. The SRP plutonium has a variable isotopic composition that can influence Pu isotopic ratios in the estuarine system. The other estuaries do not have nuclear installations upstream. Data are included on the content of 238 Pu, 239 Pu, and 240 Pu in sediments and marsh grass of the Savannah River estuary

  12. St. Louis River Estuary 2011 - 2013 Faucet snail location data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset consists of GPS coordinates for benthic invertebrate collections made in the St. Louis River Estuary in 2011 through 2013, and information on whether and...

  13. Comparative assessment of two agriculturally-influenced estuaries

    CSIR Research Space (South Africa)

    Lemley, DA

    2017-04-01

    Full Text Available This study compared the spatio-temporal dynamics in two agriculturally-influenced South African estuaries - Gamtoos and Sundays - to investigate how contrasting hydrological alterations influence physical, chemical and biological responses...

  14. Habitat Scale Mapping of Fisheries Ecosystem Service Values in Estuaries

    Directory of Open Access Journals (Sweden)

    Timothy G. O'Higgins

    2010-12-01

    Full Text Available Little is known about the variability of ecosystem service values at spatial scales most relevant to local decision makers. Competing definitions of ecosystem services, the paucity of ecological and economic information, and the lack of standardization in methodology are major obstacles to applying the ecosystem-services approach at the estuary scale. We present a standardized method that combines habitat maps and habitat-faunal associations to estimate ecosystem service values for recreational and commercial fisheries in estuaries. Three case studies in estuaries on the U.S. west coast (Yaquina Bay, Oregon, east coast (Lagoon Pond, Massachusetts, and the Gulf of Mexico (Weeks Bay, Alabama are presented to illustrate our method's rigor and limitations using available data. The resulting spatially explicit maps of fisheries ecosystem service values show within and between estuary variations in the value of estuarine habitat types that can be used to make better informed resource-management decisions.

  15. How the National Estuary Programs Address Environmental Issues

    Science.gov (United States)

    Estuaries face many challenges including, alteration of natural hydrologic flows, aquatic nuisance species, climate change, declines in fish and wildlife populations, habitat loss and degradation, nutrient loads, pathogens, stormwater and toxics.

  16. Short term variations in particulate matter in Mahi river estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Rokade, M.A.; Zingde, M.D.

    The particulate matter (PM) collected from Mahi River Estuary was analysed for organic carbon (POC), nitrogen (PON), and chlorophyll a (Chl a). The concentration of PM, POC, PON and Chl a showed short term variations. Average surface concentration...

  17. Time-dependence of salinity in monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Vijith, V.; Sundar, D.; Shetye, S.R.

    processes (diffusion, gravity current formation, impact of tidal asymmetries, etc.) is balanced by salinity-egress induced by runoff. Here we point out that the salinity field of the estuaries that are located on the coasts of the Indian subcontinent...

  18. Phytoplankton Diversity in the Cross River Estuary of Nigeria ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    This study was carried out to provide a concise set of structural based .... further growth of diatom in this zone due to rapid uptake of ... Table 1: Taxonomic listing and spatial distribution of phytoplankton species in Cross Rivers estuary. (+ =.

  19. Commercially important penaeid shrimp larvae in the estuaries of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.

    Larval stages of the penaeid shrimps, Metapenaeus dobsoni (Miers), M. affinis (Milne - Edwards) and Penaeus merguiensis De Man were mostly distributed at the lower reaches of Mandovi and Zuari estuaries. While larvae of M. dobsoni and M. affinis...

  20. Methane and nitrous oxide emissions from a subtropical estuary (the Brisbane River estuary, Australia)

    Energy Technology Data Exchange (ETDEWEB)

    Musenze, Ronald S.; Werner, Ursula [Advanced Water Management Centre (AWMC), the University of Queensland, Brisbane, Qld 4072 (Australia); Grinham, Alistair [Advanced Water Management Centre (AWMC), the University of Queensland, Brisbane, Qld 4072 (Australia); School of Civil Engineering, the University of Queensland, Brisbane, Qld 4072 (Australia); Udy, James [Healthy Waterways Ltd, P.O. Box 13086, George Street, Brisbane, Qld 4003 (Australia); Yuan, Zhiguo, E-mail: z.yuan@awmc.uq.edu.au [Advanced Water Management Centre (AWMC), the University of Queensland, Brisbane, Qld 4072 (Australia)

    2014-02-01

    Methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) are two key greenhouse gases. Their global atmospheric budgeting is, however, flout with challenges partly due to lack of adequate field studies determining the source strengths. Knowledge and data limitations exist for subtropical and tropical regions especially in the southern latitudes. Surface water methane and nitrous oxide concentrations were measured in a subtropical estuarine system in the southern latitudes in an extensive field study from 2010 to 2012 and water–air fluxes estimated using models considering the effects of both wind and flow induced turbulence. The estuary was found to be a strong net source of both CH{sub 4} and N{sub 2}O all-year-round. Dissolved N{sub 2}O concentrations ranged between 9.1 ± 0.4 to 45.3 ± 1.3 nM or 135 to 435% of atmospheric saturation level, while CH{sub 4} concentrations varied between 31.1 ± 3.7 to 578.4 ± 58.8 nM or 1210 to 26,430% of atmospheric saturation level. These results compare well with measurements from tropical estuarine systems. There was strong spatial variability with both CH{sub 4} and N{sub 2}O concentrations increasing upstream the estuary. Strong temporal variability was also observed but there were no clear seasonal patterns. The degree of N{sub 2}O saturation significantly increased with NO{sub x} concentrations (r{sup 2} = 0.55). The estimated water–air fluxes varied between 0.1 and 3.4 mg N{sub 2}O m{sup −2} d{sup −1} and 0.3 to 27.9 mg CH{sub 4} m{sup −2} d{sup −1}. Total emissions (CO{sub 2}-e) were N{sub 2}O (64%) dominated, highlighting the need for reduced nitrogen inputs into the estuary. Choice of the model(s) for estimation of the gas transfer velocity had a big bearing on the estimated total emissions. - Highlights: • The estuary is a strong source of atmospheric methane and nitrous oxide. • Emissions had strong spatial-temporal variability with unclear seasonal patterns. • Dissolved gas saturation comparable to that

  1. Methane and nitrous oxide emissions from a subtropical estuary (the Brisbane River estuary, Australia)

    International Nuclear Information System (INIS)

    Musenze, Ronald S.; Werner, Ursula; Grinham, Alistair; Udy, James; Yuan, Zhiguo

    2014-01-01

    Methane (CH 4 ) and nitrous oxide (N 2 O) are two key greenhouse gases. Their global atmospheric budgeting is, however, flout with challenges partly due to lack of adequate field studies determining the source strengths. Knowledge and data limitations exist for subtropical and tropical regions especially in the southern latitudes. Surface water methane and nitrous oxide concentrations were measured in a subtropical estuarine system in the southern latitudes in an extensive field study from 2010 to 2012 and water–air fluxes estimated using models considering the effects of both wind and flow induced turbulence. The estuary was found to be a strong net source of both CH 4 and N 2 O all-year-round. Dissolved N 2 O concentrations ranged between 9.1 ± 0.4 to 45.3 ± 1.3 nM or 135 to 435% of atmospheric saturation level, while CH 4 concentrations varied between 31.1 ± 3.7 to 578.4 ± 58.8 nM or 1210 to 26,430% of atmospheric saturation level. These results compare well with measurements from tropical estuarine systems. There was strong spatial variability with both CH 4 and N 2 O concentrations increasing upstream the estuary. Strong temporal variability was also observed but there were no clear seasonal patterns. The degree of N 2 O saturation significantly increased with NO x concentrations (r 2 = 0.55). The estimated water–air fluxes varied between 0.1 and 3.4 mg N 2 O m −2 d −1 and 0.3 to 27.9 mg CH 4 m −2 d −1 . Total emissions (CO 2 -e) were N 2 O (64%) dominated, highlighting the need for reduced nitrogen inputs into the estuary. Choice of the model(s) for estimation of the gas transfer velocity had a big bearing on the estimated total emissions. - Highlights: • The estuary is a strong source of atmospheric methane and nitrous oxide. • Emissions had strong spatial-temporal variability with unclear seasonal patterns. • Dissolved gas saturation comparable to that in tropical rivers and polluted estuaries. • Emissions are dominated by N2O, which

  2. Cladocerans (Branchiopoda) of a tropical estuary in Brazil

    OpenAIRE

    Paranaguá, M. N; Neumann-Leitão, S; Nogueira-Paranhos, J. D; Silva, T. A.; Matsumura-Tundisi, T.

    2005-01-01

    The study was conducted in the Capibaribe river estuary in Recife (Brazil) to assess the role played by cladocerans in a eutrophic environment. Samplings were carried out monthly at 4 fixed stations along the estuary from July 1987 to June 1988. Collections were made with a plankton net of 65 micrometers mesh size. Six cladocerans species were registered: Penilia avirostris, Diaphanosoma spinulosum, Chydorus barroisi, Ceriodaphnia rigaudi, Ilyocryptus spinifer, and Moina micrura. The most fre...

  3. Contamination and restoration of an estuary affected by phosphogypsum releases

    International Nuclear Information System (INIS)

    Villa, M.; Mosqueda, F.; Hurtado, S.; Mantero, J.; Manjon, G.; Perianez, R.; Vaca, F.; Garcia-Tenorio, R.

    2009-01-01

    The Huelva Estuary in Huelva, Spain, has been one of the most studied environmental compartments in the past years from the point of view of naturally occurring radioactive material (NORM) releases. It has been historically affected by waste releases, enriched in radionuclides from the U-decay series, from factories located in the area devoted to the production of phosphoric acid and phosphate fertilizers. Nevertheless, changes in national regulations forced a new waste management practice in 1998, prohibiting releases of phosphogypsum into the rivers. The input of natural radionuclides from phosphate factories to rivers was drastically reduced. Because of this there was a unique opportunity for the study of the response of a contaminated environmental compartment, specifically an estuary affected by tidal influences, after the cessation of the contaminant releases to, in this case, the Huelva Estuary (henceforth referred to as the Estuary). To investigate the environmental response to this new discharge regime, the specific activities of radionuclides 226 Ra and 210 Pb in water and sediment samples collected in four campaigns (from 1999 to 2005) were determined and compared with pre-1998 values. From this study it is possible to infer the most effective mechanisms of decontamination for the Estuary. Decontamination rates of 210 Pb and 226 Ra in the sediments and water have been calculated using exponential fittings and corresponding half-lives have been deduced from them. The cleaning half-life in the whole area of the Estuary is about 6 and 3.5 years for 226 Ra and 210 Pb respectively. The observed trend clearly shows that contamination of the Estuary by natural radionuclides is now decreasing and radioactive levels in waters and sediments are approaching the natural background references. This work attempts to evaluate whether it can be expected that the decontamination of the enhanced levels of natural radioactivity in the Estuary can be performed via natural

  4. Juvenile salmon usage of the Skeena River estuary.

    Science.gov (United States)

    Carr-Harris, Charmaine; Gottesfeld, Allen S; Moore, Jonathan W

    2015-01-01

    Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2-8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that

  5. Contamination and restoration of an estuary affected by phosphogypsum releases

    Energy Technology Data Exchange (ETDEWEB)

    Villa, M., E-mail: mvilla@us.es [Centro de Investigacion, Tecnologia e Innovacion, Universidad de Sevilla CITIUS, Av. Reina Mercedes 4B, E41012-Sevilla (Spain); Mosqueda, F. [Dpto. de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus de El Carmen, 21007-Huelva (Spain); Hurtado, S. [Centro de Investigacion, Tecnologia e Innovacion, Universidad de Sevilla CITIUS, Av. Reina Mercedes 4B, E41012-Sevilla (Spain); Mantero, J.; Manjon, G. [E. T. S. Arquitectura, Universidad de Sevilla, Departamento de Fisica Aplicada II, Av. Reina Mercedes, 2. 41012-Sevilla (Spain); Perianez, R. [E.U.I.T.A., Universidad de Sevilla, Departamento de Fisica Aplicada III, Carretera de Utrera, Km. 1, 41013 Sevilla (Spain); Vaca, F. [Dpto. de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus de El Carmen, 21007-Huelva (Spain); Garcia-Tenorio, R. [E. T. S. Arquitectura, Universidad de Sevilla, Departamento de Fisica Aplicada II, Av. Reina Mercedes, 2. 41012-Sevilla (Spain)

    2009-12-15

    The Huelva Estuary in Huelva, Spain, has been one of the most studied environmental compartments in the past years from the point of view of naturally occurring radioactive material (NORM) releases. It has been historically affected by waste releases, enriched in radionuclides from the U-decay series, from factories located in the area devoted to the production of phosphoric acid and phosphate fertilizers. Nevertheless, changes in national regulations forced a new waste management practice in 1998, prohibiting releases of phosphogypsum into the rivers. The input of natural radionuclides from phosphate factories to rivers was drastically reduced. Because of this there was a unique opportunity for the study of the response of a contaminated environmental compartment, specifically an estuary affected by tidal influences, after the cessation of the contaminant releases to, in this case, the Huelva Estuary (henceforth referred to as the Estuary). To investigate the environmental response to this new discharge regime, the specific activities of radionuclides {sup 226}Ra and {sup 210}Pb in water and sediment samples collected in four campaigns (from 1999 to 2005) were determined and compared with pre-1998 values. From this study it is possible to infer the most effective mechanisms of decontamination for the Estuary. Decontamination rates of {sup 210}Pb and {sup 226}Ra in the sediments and water have been calculated using exponential fittings and corresponding half-lives have been deduced from them. The cleaning half-life in the whole area of the Estuary is about 6 and 3.5 years for {sup 226}Ra and {sup 210}Pb respectively. The observed trend clearly shows that contamination of the Estuary by natural radionuclides is now decreasing and radioactive levels in waters and sediments are approaching the natural background references. This work attempts to evaluate whether it can be expected that the decontamination of the enhanced levels of natural radioactivity in the Estuary

  6. Continuous resistivity profiling data from the Corsica River Estuary, Maryland

    Science.gov (United States)

    Cross, V.A.; Bratton, J.F.; Worley, C.R.; Crusius, J.; Kroeger, K.D.

    2011-01-01

    Submarine groundwater discharge (SGD) into Maryland's Corsica River Estuary was investigated as part of a larger study to determine its importance in nutrient delivery to the Chesapeake Bay. The Corsica River Estuary represents a coastal lowland setting typical of much of the eastern bay. An interdisciplinary U.S. Geological Survey (USGS) science team conducted field operations in the lower estuary in April and May 2007. Resource managers are concerned about nutrients that are entering the estuary via SGD that may be contributing to eutrophication, harmful algal blooms, and fish kills. Techniques employed in the study included continuous resistivity profiling (CRP), piezometer sampling of submarine groundwater, and collection of a time series of radon tracer activity in surface water. A CRP system measures electrical resistivity of saturated subestuarine sediments to distinguish those bearing fresh water (high resistivity) from those with saline or brackish pore water (low resistivity). This report describes the collection and processing of CRP data and summarizes the results. Based on a grid of 67.6 kilometers of CRP data, low-salinity (high-resistivity) groundwater extended approximately 50-400 meters offshore from estuary shorelines at depths of 5 to >12 meters below the sediment surface, likely beneath a confining unit. A band of low-resistivity sediment detected along the axis of the estuary indicated the presence of a filled paleochannel containing brackish groundwater. The meandering paleochannel likely incised through the confining unit during periods of lower sea level, allowing the low-salinity groundwater plumes originating from land to mix with brackish subestuarine groundwater along the channel margins and to discharge. A better understanding of the spatial variability and geological controls of submarine groundwater flow beneath the Corsica River Estuary could lead to improved models and mitigation strategies for nutrient over-enrichment in the

  7. Hydro-morphological modelling of small, wave-dominated estuaries

    Science.gov (United States)

    Slinger, Jill H.

    2017-11-01

    Small, intermittently open or closed estuaries are characteristic of the coasts of South Africa, Australia, California, Mexico and many other areas of the world. However, modelling attention has tended to focus on big estuaries that drain large catchments and serve a wide diversity of interests e.g. agriculture, urban settlement, recreation, commercial fishing. In this study, the development of a simple, parametric, system dynamics model to simulate the opening and closure of the mouths of small, wave-dominated estuaries is reported. In the model, the estuary is conceived as a basin with a specific water volume to water level relationship, connected to the sea by a channel of fixed width, but variable sill height. Changes in the form of the basin are not treated in the model, while the dynamics of the mouth channel are central to the model. The magnitude and direction of the flow through the mouth determines whether erosion or deposition of sediment occurs in the mouth channel, influencing the sill height. The model is implemented on the Great Brak Estuary in South Africa and simulations reveal that the raised low water levels in the estuary during spring tide relative to neap tide, are occasioned by the constriction of the tidal flow through the shallow mouth. Freshwater inflows to the estuary are shown to be significant in determining the behaviour of the inlet mouth, a factor often ignored in studies on tidal inlets. Further it is the balance between freshwater inflows and wave events that determines the opening or closure of the mouth of a particular estuary.

  8. Functional diversity of fish in estuaries at a global extent

    OpenAIRE

    Rita P Vasconcelos; Sébastien Villéger; François Guilhaumon

    2015-01-01

    Biodiversity is currently viewed as a framework encompassing multiple facets of the variety of life, including taxonomic and functional aspects. Species richness and composition of fish assemblages in estuaries is defined by global to local processes acting on community colonization. The present study further investigates how biodiversity of fish assemblages varies among estuaries globally, by simultaneously analysing taxonomic and functional richness and diversity of assemblages. A comprehen...

  9. Sources, Ages, and Alteration of Organic Matter in Estuaries.

    Science.gov (United States)

    Canuel, Elizabeth A; Hardison, Amber K

    2016-01-01

    Understanding the processes influencing the sources and fate of organic matter (OM) in estuaries is important for quantifying the contributions of carbon from land and rivers to the global carbon budget of the coastal ocean. Estuaries are sites of high OM production and processing, and understanding biogeochemical processes within these regions is key to quantifying organic carbon (Corg) budgets at the land-ocean margin. These regions provide vital ecological services, including nutrient filtration and protection from floods and storm surge, and provide habitat and nursery areas for numerous commercially important species. Human activities have modified estuarine systems over time, resulting in changes in the production, respiration, burial, and export of Corg. Corg in estuaries is derived from aquatic, terrigenous, and anthropogenic sources, with each source exhibiting a spectrum of ages and lability. The complex source and age characteristics of Corg in estuaries complicate our ability to trace OM along the river-estuary-coastal ocean continuum. This review focuses on the application of organic biomarkers and compound-specific isotope analyses to estuarine environments and on how these tools have enhanced our ability to discern natural sources of OM, trace their incorporation into food webs, and enhance understanding of the fate of Corg within estuaries and their adjacent waters.

  10. Wind Wave Behavior in Fetch and Depth Limited Estuaries

    Science.gov (United States)

    Karimpour, Arash; Chen, Qin; Twilley, Robert R.

    2017-01-01

    Wetland dominated estuaries serve as one of the most productive natural ecosystems through their ecological, economic and cultural services, such as nursery grounds for fisheries, nutrient sequestration, and ecotourism. The ongoing deterioration of wetland ecosystems in many shallow estuaries raises concerns about the contributing erosive processes and their roles in restraining coastal restoration efforts. Given the combination of wetlands and shallow bays as landscape components that determine the function of estuaries, successful restoration strategies require knowledge of wind wave behavior in fetch and depth limited water as a critical design feature. We experimentally evaluate physics of wind wave growth in fetch and depth limited estuaries. We demonstrate that wave growth rate in shallow estuaries is a function of wind fetch to water depth ratio, which helps to develop a new set of parametric wave growth equations. We find that the final stage of wave growth in shallow estuaries can be presented by a product of water depth and wave number, whereby their product approaches 1.363 as either depth or wave energy increases. Suggested wave growth equations and their asymptotic constraints establish the magnitude of wave forces acting on wetland erosion that must be included in ecosystem restoration design.

  11. NEW DATA ABOUT MACROZOOBENTHOS OF BEYSUGSKY ESTUARY (SEA OF AZOV

    Directory of Open Access Journals (Sweden)

    N. I. Bulysheva

    2013-01-01

    Full Text Available Abstract. Aim. Beysugsky Estuary is one of the biggest estuaries of the Azov-Kuban’ lowland. Like the other water bodies in the South of Russia, this one is subject to strong anthropogenic load: detachment of the freshwater part for establishing the Beysug spawning area; regulation of the flow of the rivers feeding the estuary; destruction of the Yasenskaya spit and narrowing of the Bugaz mouth; disorganized tourism. The ongoing reformation of the ecosystem makes it necessary to carry out the analyses of the modern state of the biota of this water body and uncover reasons and regularities of its change.Location. Beysug Estuary of the Sea of Azov.Methods. Quantitative zoobenthos samples were taken with the Petersen dredger (sampling area 0,034 m2 from board of the inflatable “Zodiac” boat. Qualitative samples were taken in the coastal zone by hand and with the dredge. All the samples taken were washed through the bag made of mill sieve with mesh size 0,5 mm, and then were fixed in a plastic bucket by 4 % formaldehyde (quantitative samples or 70 % ethyl alcohol (qualitative samples. Taking and processing of samples were carried out in field and laboratory environment using common methods. 22 samples at 7 stations were taken in total.Results. Macrozoobenthos was presented by 14 invertebrate species. Estuarine fauna is the depleted version of the euryhaline one of the Sea of Azov with Holocene relic macrophyte-dwelling elements. Biodiversity and quantitative characters of the estuarine communities decrease from west to east. Pelophylic detritophages predominated in the benthic communities of the estuary. The results of this research are meant to be used for uncovering historical ways of forming of benthic fauna and clearing up the dependence of community structure on the seawater influence, freshwater flow, regulation of freshwater and seawater sources, nature of changing of faunas at salinization of estuaries connected with the sea and the

  12. Distribution and assessment of sediment toxicity in Tamaki Estuary, Auckland, New Zealand

    Science.gov (United States)

    Abrahim, G. M. S.; Parker, R. J.; Nichol, S. L.

    2007-07-01

    Heavy metal levels in surface sediments from Tamaki Estuary demonstrate significant up estuary increases in Cu, Pb, Zn, Cd and mud concentrations. Increased metal levels towards the head of the estuary are linked to local catchment sources reflecting the historical development, industrialisation and urbanisation of catchment areas surrounding the upper estuary. The relatively narrow constriction in the middle estuary (Panmure area), makes it susceptible to accumulation of upper estuary pollutants, since the constriction reduces circulation and extends the time required for fine waterborne sediments in the upper estuary to exchange with fresh coastal water. As a result fine fraction sediments trapped in the upper estuary facilitate capture and retention of pollutants at the head of the estuary. The increase in sandy mud poor sediments towards the mouth of the estuary is associated with generally low metal concentrations. The estuary’s geomorphic shape with a mid estuary constriction, sediment texture and mineralogy and catchment history are significant factors in understanding the overall spatial distribution of contaminants in the estuary. Bulk concentration values for Cu, Pb, Zn, and Cd in all the studied surface samples occur below ANZECC ISQG-H toxicity values. Cd and Cu concentrations are also below the ISQG-L toxicity levels for these elements. However, Pb and Zn concentrations do exceed the ISQG-L values in some of the surface bulk samples in the upper estuary proximal to long established sources of catchment pollution.

  13. Urban microbial ecology of a freshwater estuary of Lake Michigan.

    Science.gov (United States)

    Fisher, Jenny C; Newton, Ryan J; Dila, Deborah K; McLellan, Sandra L

    Freshwater estuaries throughout the Great Lakes region receive stormwater runoff and riverine inputs from heavily urbanized population centers. While human and animal feces contained in this runoff are often the focus of source tracking investigations, non-fecal bacterial loads from soil, aerosols, urban infrastructure, and other sources are also transported to estuaries and lakes. We quantified and characterized this non-fecal urban microbial component using bacterial 16S rRNA gene sequences from sewage, stormwater, rivers, harbor/estuary, and the lake surrounding Milwaukee, WI, USA. Bacterial communities from each of these environments had a distinctive composition, but some community members were shared among environments. We used a statistical biomarker discovery tool to identify the components of the microbial community that were most strongly associated with stormwater and sewage to describe an "urban microbial signature," and measured the presence and relative abundance of these organisms in the rivers, estuary, and lake. This urban signature increased in magnitude in the estuary and harbor with increasing rainfall levels, and was more apparent in lake samples with closest proximity to the Milwaukee estuary. The dominant bacterial taxa in the urban signature were Acinetobacter, Aeromonas , and Pseudomonas , which are organisms associated with pipe infrastructure and soil and not typically found in pelagic freshwater environments. These taxa were highly abundant in stormwater and sewage, but sewage also contained a high abundance of Arcobacter and Trichococcus that appeared in lower abundance in stormwater outfalls and in trace amounts in aquatic environments. Urban signature organisms comprised 1.7% of estuary and harbor communities under baseflow conditions, 3.5% after rain, and >10% after a combined sewer overflow. With predicted increases in urbanization across the Great Lakes, further alteration of freshwater communities is likely to occur with potential

  14. Urban microbial ecology of a freshwater estuary of Lake Michigan

    Directory of Open Access Journals (Sweden)

    Jenny C. Fisher

    2015-07-01

    Full Text Available Abstract Freshwater estuaries throughout the Great Lakes region receive stormwater runoff and riverine inputs from heavily urbanized population centers. While human and animal feces contained in this runoff are often the focus of source tracking investigations, non-fecal bacterial loads from soil, aerosols, urban infrastructure, and other sources are also transported to estuaries and lakes. We quantified and characterized this non-fecal urban microbial component using bacterial 16S rRNA gene sequences from sewage, stormwater, rivers, harbor/estuary, and the lake surrounding Milwaukee, WI, USA. Bacterial communities from each of these environments had a distinctive composition, but some community members were shared among environments. We used a statistical biomarker discovery tool to identify the components of the microbial community that were most strongly associated with stormwater and sewage to describe an “urban microbial signature,” and measured the presence and relative abundance of these organisms in the rivers, estuary, and lake. This urban signature increased in magnitude in the estuary and harbor with increasing rainfall levels, and was more apparent in lake samples with closest proximity to the Milwaukee estuary. The dominant bacterial taxa in the urban signature were Acinetobacter, Aeromonas, and Pseudomonas, which are organisms associated with pipe infrastructure and soil and not typically found in pelagic freshwater environments. These taxa were highly abundant in stormwater and sewage, but sewage also contained a high abundance of Arcobacter and Trichococcus that appeared in lower abundance in stormwater outfalls and in trace amounts in aquatic environments. Urban signature organisms comprised 1.7% of estuary and harbor communities under baseflow conditions, 3.5% after rain, and >10% after a combined sewer overflow. With predicted increases in urbanization across the Great Lakes, further alteration of freshwater communities is

  15. Urban microbial ecology of a freshwater estuary of Lake Michigan

    Science.gov (United States)

    Fisher, Jenny C.; Newton, Ryan J.; Dila, Deborah K.

    2015-01-01

    Freshwater estuaries throughout the Great Lakes region receive stormwater runoff and riverine inputs from heavily urbanized population centers. While human and animal feces contained in this runoff are often the focus of source tracking investigations, non-fecal bacterial loads from soil, aerosols, urban infrastructure, and other sources are also transported to estuaries and lakes. We quantified and characterized this non-fecal urban microbial component using bacterial 16S rRNA gene sequences from sewage, stormwater, rivers, harbor/estuary, and the lake surrounding Milwaukee, WI, USA. Bacterial communities from each of these environments had a distinctive composition, but some community members were shared among environments. We used a statistical biomarker discovery tool to identify the components of the microbial community that were most strongly associated with stormwater and sewage to describe an “urban microbial signature,” and measured the presence and relative abundance of these organisms in the rivers, estuary, and lake. This urban signature increased in magnitude in the estuary and harbor with increasing rainfall levels, and was more apparent in lake samples with closest proximity to the Milwaukee estuary. The dominant bacterial taxa in the urban signature were Acinetobacter, Aeromonas, and Pseudomonas, which are organisms associated with pipe infrastructure and soil and not typically found in pelagic freshwater environments. These taxa were highly abundant in stormwater and sewage, but sewage also contained a high abundance of Arcobacter and Trichococcus that appeared in lower abundance in stormwater outfalls and in trace amounts in aquatic environments. Urban signature organisms comprised 1.7% of estuary and harbor communities under baseflow conditions, 3.5% after rain, and >10% after a combined sewer overflow. With predicted increases in urbanization across the Great Lakes, further alteration of freshwater communities is likely to occur with

  16. Bacterial domination over Archaea in ammonia oxidation in a monsoon-driven tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Vipindas, P.V.; Anas, A.; Jasmin, C.; Lallu, K.R.; Fausia, K.H.; Balachandran, K.K.; Muraleedharan, K.R.; Nair, S.

    Autotrophic ammonia oxidizing microorganisms,which are responsible for the rate-limiting step of nitrification in most aquatic systems, have not been studied in tropical estuaries. Cochin estuary (CE) is one of the largest, productive, and monsoon...

  17. Picophytoplankton community in a tropical estuary: Detection of Prochlorococcus-like populations

    Digital Repository Service at National Institute of Oceanography (India)

    Mitbavkar, S.; Rajaneesh, K.M.; Anil, A.C.; Sundar, D.

    The influence of hydrography on the picophytoplankton (PP) abundance in estuaries was studied by sampling along a salinity gradient in an Indian estuary. Prochlorococcus-like cells were detected at salinities ranging from 0.06 to 35, which otherwise...

  18. Seasonal variations in abundance, biomass and grazing rates of microzooplankton in a tropical monsoonal estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Gauns, M.; Mochemadkar, S.; Patil, S.; Pratihary, A.K.; Naqvi, S.W.A.; Madhupratap, M.

    Seasonal abundance, composition and grazing rates of microzooplankton (20–200 µm) in the Zuari estuary were investigated to evaluate their importance in food web dynamics of a tropical monsoonal estuary. Average abundances of microzooplankton...

  19. A comparative study of Northern Ireland's estuaries based on the results of beam trawl fish surveys

    Science.gov (United States)

    Harrison, Trevor D.; Armour, Neil D.; McNeill, Michael T.; Moorehead, Peter W.

    2017-11-01

    The fish communities of Northern Ireland's estuaries were described and compared using data collected with a modified beam trawl over a six year period from 2009 to 2014. Multivariate analyses identified four estuary groups based on variations in their physico-chemical attributes. These groups broadly corresponded with the distribution and variation of estuary geomorphic types identified around the Irish coast. The dominant fish species captured were also among the main species reported in other North East Atlantic estuaries. A significant link between the estuary types and their fish communities was found; each estuary group contained a somewhat distinctive fish community. The fish communities also showed a significant relationship with the physico-chemical characteristics of the estuaries. Differences in fish species composition are attributed to habitat and environmental preferences of key estuary-associated species.

  20. West Coast Estuaries for Groundfish Essential Fish Habitat (EFH) Environmental Impact Statement

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — These data depict the boundaries of estuaries along the West Coast of the United States. The estuary boundaries are delineated according to the U.S. Fish and...

  1. Nuclear India. Vol. II. [India's nuclear policy

    Energy Technology Data Exchange (ETDEWEB)

    Jain, J P

    1974-01-01

    The book contains 186 documents on India's nuclear policy covering a period from November 1948 to May 1974. It thus forms a comprehensive documentary account of India's nuclear policy. They include: texts of India's agreements for cooperation on the peaceful uses of atomic energy with the USA and Canada, the summary conclusions of India's atomic energy program for the decade 1970-80, the resolutions and amendments moved by India, the communications sent and the statements made by Indian representatives in various international forums--the conference of the IAEA statute, the Annual General Conference of the IAEA and its committees and the Board of Governors, the UN General Assembly and its First Committee, the conference of the Committee on Disarmaments etc. It also contains texts or extracts from the papers presented, statements made, and addresses and talks delivered by H. J. Bhabha, V. A. Sarabhai, H. N. Sethna and other eminent scientists at the international conferences on the peaceful uses of atomic energy, IAEA discussions on PNE, etc. Policy statements by India's Prime Ministers Nehru, Shastri and (Mrs.) Gandhi, and Foreign Ministers Chagla and Swaran Singh, made from time to time in the Lok Sabha and the Rajya Sabha--the two houses of the Indian parliaments--are also included. The sources of these documents are listed at the end. (MCB)

  2. Trophic flow structure of a neotropical estuary in northeastern Brazil and the comparison of ecosystem model indicators of estuaries

    Science.gov (United States)

    Lira, Alex; Angelini, Ronaldo; Le Loc'h, François; Ménard, Frédéric; Lacerda, Carlos; Frédou, Thierry; Lucena Frédou, Flávia

    2018-06-01

    We developed an Ecopath model for the Estuary of Sirinhaém River (SIR), a small-sized system surrounded by mangroves, subject to high impact, mainly by the sugar cane and other farming industries in order to describe the food web structure and trophic interactions. In addition, we compared our findings with those of 20 available Ecopath estuarine models for tropical, subtropical and temperate regions, aiming to synthesize the knowledge on trophic dynamics and provide a comprehensive analysis of the structures and functioning of estuaries. Our model consisted of 25 compartments and its indicators were within the expected range for estuarine areas around the world. The average trophic transfer efficiency for the entire system was 11.8%, similar to the theoretical value of 10%. The Keystone Index and MTI (Mixed Trophic Impact) analysis indicated that the snook (Centropomus undecimalis and Centropomus parallelus) and jack (Caranx latus and Caranx hippos) are considered as key resources in the system, revealing their high impact in the food web. Both groups have a high ecological and commercial relevance, despite the unregulated fisheries. As result of the comparison of ecosystem model indicators in estuaries, differences in the ecosystem structure from the low latitude zones (tropical estuaries) to the high latitude zones (temperate system) were noticed. The structure of temperate and sub-tropical estuaries is based on high flows of detritus and export, while tropical systems have high biomass, respiration and consumption rates. Higher values of System Omnivory Index (SOI) and Overhead (SO) were observed in the tropical and subtropical estuaries, denoting a more complex food chain. Globally, none of the estuarine models were classified as fully mature ecosystems, although the tropical ecosystems were considered more mature than the subtropical and temperate ecosystems. This study is an important contribution to the trophic modeling of estuaries, which may also help

  3. Riverbed Micromorphology of the Yangtze River Estuary, China

    Directory of Open Access Journals (Sweden)

    Shuaihu Wu

    2016-05-01

    Full Text Available Dunes are present in nearly all fluvial channels and are vital in understanding sediment transport, deposition, and flow conditions during floods of rivers and estuaries. This information is pertinent for helping developing management practices to reduce risks in river transportation and engineering. Although a few recent studies have investigated the micromorphology of a portion of the Yangtze River estuary in China, our understanding of dune development in this large estuary is incomplete. It is also poorly understood how the development and characteristics of these dunes have been associated with human activities in the upper reach of the Yangtze River and two large-scale engineering projects in the estuarine zone. This study analyzed the feature in micromorphology of the entire Yangtze River estuary bed over the past three years and assessed the morphological response of the dunes to recent human activities. In 2012, 2014, and 2015, multi-beam bathymetric measurements were conducted on the channel surface of the Yangtze River estuary. The images were analyzed to characterize the subaqueous dunes and detect their changes over time. Bottom sediment samples were collected for grain size analysis to assess the physical properties of the dunes. We found that dunes in the Yangtze River estuary can be classified in four major classes: very large dunes, large dunes, medium dunes, and small dunes. Large dunes were predominant, amounting to 51.5%. There was a large area of dunes developed in the middle and upper reaches of the Yangtze River estuary and in the Hengsha Passage. A small area of dunes was observed for the first time in the turbidity maximum zone of the Yangtze River estuary. These dunes varied from 0.12 to 3.12 m in height with a wide range of wavelength from 2.83 to 127.89 m, yielding a range in height to wavelength of 0.003–0.136. Sharp leeside slope angles suggest that the steep slopes of asymmetrical dunes in the middle and upper

  4. Dynamics of intertidal flats in the Loire estuary

    Science.gov (United States)

    Kervella, Stephane; Sottolichio, Aldo; Bertier, Christine

    2014-05-01

    Tidal flats form at the edges of many tidal estuaries, and are found in broad climatic regions. Their evolution plays a fundamental role in maintaining the morphodynamic equilibrium of an estuary. The Loire estuary is one of the largest macrotidal systems of the french atlantic coast. Since 200 years, its geometry has been drastically modified through channeling, deepening, embanking, infilling of secondary channels, etc. These works altered many intertidal areas. In the recent years, efforts for the rectification of the morphology have been made in order to restore the ecology of the estuary. In this context, it is crucial to better understand the dynamics of intertidal flats, still poorly understood in this estuary. The aim of this work is to analyse a series of original observations conducted for the first time in two intertidal flats of the central Lore estuary between 2008 and 2010. The tidal flats are situated in the northern bank, at 12 and 17 km upstream from the mouth respectively. Six Altus altimeters were deployed at two cross shore transects, measuring continuously and at a high-frequency bed altimetry and water level, providing information on tide and waves. At the semi-diurnal tidal scale, the surficial sediment of intertidal flats is permanently mobilized. Altimetry variations are low, and their amplitude varies as a function of tides and river flow. At the scale of several months, the sedimentation is controlled by the position of the turbidity maximum (and therefore by the river flow) and also by the tidal amplitude. During low river flow periods, altimetry variations are only due to tidal cycles. During decaying tides, suspended sediment settle mainly on the lower part of the tidal flats, forming fluid mud layers of several cm thick, which can consolidate rapidly; under rising tides, the increasing of tidal currents promotes erosion. During periods of high river flow, the turbidity maximum shifts to the lower estuary. The higher suspended sediment

  5. Silicon dynamics in the Oder estuary, Baltic Sea

    Science.gov (United States)

    Pastuszak, Marianna; Conley, Daniel J.; Humborg, Christoph; Witek, Zbigniew; Sitek, Stanisław

    2008-10-01

    Studies on dissolved silicate (DSi) and biogenic silica (BSi) dynamics were carried out in the Oder estuary, Baltic Sea in 2000-2005. The Oder estuary proved to be an important component of the Oder River-Baltic Sea continuum where very intensive seasonal DSi uptake during spring and autumn, but also BSi regeneration during summer take place. Owing to the regeneration process annual DSi patterns in the river and the estuary distinctly differed; the annual patterns of DSi in the estuary showed two maxima and two minima in contrast to one maximum- and one minimum-pattern in the Oder River. DSi concentrations in the river and in the estuary were highest in winter (200-250 μmol dm - 3 ) and lowest (often less than 1 μmol dm - 3 ) in spring, concomitant with diatom growth; such low values are known to be limiting for new diatom growth. Secondary DSi summer peaks at the estuary exit exceeded 100 μmol dm - 3 , and these maxima were followed by autumn minima coinciding with the autumn diatom bloom. Seasonal peaks in BSi concentrations (ca. 100 μmol dm - 3 ) occurred during the spring diatom bloom in the Oder River. Mass balance calculations of DSi and BSi showed that DSi + BSi import to the estuary over a two year period was 103.2 kt and that can be compared with the DSi export of 98.5 kt. The difference between these numbers gives room for ca. 2.5 kt BSi to be annually exported to the Baltic Sea. Sediment cores studies point to BSi annual accumulation on the level of 2.5 kt BSi. BSi import to the estuary is on the level of ca. 10.5 kt, thus ca. 5 kt of BSi is annually converted into the DSi, increasing the pool of DSi that leaves the system. BSi concentrations being ca. 2 times higher at the estuary entrance than at its exit remain in a good agreement with the DSi and BSi budgeting presented in the paper.

  6. Functional diversity of fish in estuaries at a global extent

    Directory of Open Access Journals (Sweden)

    Rita P Vasconcelos

    2015-10-01

    Full Text Available Biodiversity is currently viewed as a framework encompassing multiple facets of the variety of life, including taxonomic and functional aspects. Species richness and composition of fish assemblages in estuaries is defined by global to local processes acting on community colonization. The present study further investigates how biodiversity of fish assemblages varies among estuaries globally, by simultaneously analysing taxonomic and functional richness and diversity of assemblages. A comprehensive worldwide database was compiled on the fish assemblage composition and environmental characteristics of estuaries. In addition, functional attributes of the fish species were characterized such as body size, habitat use and trophic ecology. We investigated the relationship between taxonomic and functional aspects of biodiversity, i.e. the match or mismatch between the two. We also explored how functional diversity of fish assemblages varied among estuaries globally and related to environmental features of estuaries, i.e. historic and contemporary, global and local constraints. The results are explored in the context of ecosystem functioning and resilience, and outcomes relevant to assist in prioritizing conservation efforts are highlighted.

  7. 76 FR 23306 - Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Management...

    Science.gov (United States)

    2011-04-26

    ... Marine Mammals Incidental to Specified Activities; Russian River Estuary Management Activities AGENCY...) to incidentally harass, by Level B harassment only, three species of marine mammals during estuary... December 31, 2010; and Russian River Estuary Outlet Channel Adaptive Management Plan. NMFS' Environmental...

  8. 77 FR 24471 - Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Management...

    Science.gov (United States)

    2012-04-24

    ... Marine Mammals Incidental to Specified Activities; Russian River Estuary Management Activities AGENCY...) to incidentally harass, by Level B harassment only, three species of marine mammals during estuary... Estuary Outlet Channel Adaptive Management Plan; and Feasibility of Alternatives to the Goat Rock State...

  9. 33 CFR 165.1190 - Security Zone; San Francisco Bay, Oakland Estuary, Alameda, CA.

    Science.gov (United States)

    2010-07-01

    ..., Oakland Estuary, Alameda, CA. 165.1190 Section 165.1190 Navigation and Navigable Waters COAST GUARD... § 165.1190 Security Zone; San Francisco Bay, Oakland Estuary, Alameda, CA. (a) Location. The following area is a security zone: All navigable waters of the Oakland Estuary, California, from the surface to...

  10. 78 FR 68995 - Safety Zone: Vessel Removal From the Oakland Estuary, Alameda, CA

    Science.gov (United States)

    2013-11-18

    ...-AA00 Safety Zone: Vessel Removal From the Oakland Estuary, Alameda, CA AGENCY: Coast Guard, DHS. ACTION... waters of the Oakland Estuary just north of the Park Street Bridge in Alameda, CA in support of the Oakland Estuary Closure for the Vessel Removal Project on November 4, 2013 through November 22, 2013. This...

  11. 78 FR 46332 - Proposed Information Collection Request; Comment Request; National Estuary Program

    Science.gov (United States)

    2013-07-31

    ... Request; Comment Request; National Estuary Program AGENCY: Environmental Protection Agency (EPA). ACTION... request (ICR), ``National Estuary Program'' (EPA ICR No. 1500.08, OMB Control No. 2040-0138 to the Office... comments to OMB. Abstract: The National Estuary Program (NEP) involves collecting information from the...

  12. Eco-morphological problems in the Yangtze Estuary and the Western Scheldt

    NARCIS (Netherlands)

    De Vriend, H.J.; Wang, Z.B.; Ysebaert, T.; Herman, P.M.J.; Ding, P.X.

    2011-01-01

    This paper compares the Yangtze Estuary in China and the Western Scheldt Estuary in The Netherlands by their morphodynamic and ecological systems, their engineering works and estuarine management issues, and the major challenges in studying them. Physically speaking, the two estuaries are very

  13. 75 FR 2517 - Notice of Solicitation for Estuary Habitat Restoration Program

    Science.gov (United States)

    2010-01-15

    ..., wastewater treatment plant upgrades, combined sewer outfalls, and non-point source pollution projects such as... Estuary Restoration Act of 2000, Title I of the Estuaries and Clean Waters Act of 2000 (Pub. L. 106-457... with fresh water from land drainage.'' Estuary also includes the ``* * * near coastal waters and...

  14. Delaware Estuary situation reports. Emergency response: How do emergency management officials address disasters in the Delaware Estuary

    International Nuclear Information System (INIS)

    Sylves, R.T.

    1991-01-01

    From hurricanes and other natural threats to oil spills and other manmade emergencies, the Delaware Estuary has experienced a variety of disasters over the years. The toll that these events take on the estuary and those who live on its shores depends largely upon the degree of emergency preparedness, speed of response, and effectiveness of recovery operations. In Emergency Response: How Do Emergency Management Officials Address Disasters in the Delaware Estuary, the latest addition to its Delaware Estuary Situation Report series, the University of Delaware Sea Grant College Program defines emergency management; examines the roles that the Coast Guard, Army Corps of Engineers, and Environmental Protection Agency play in an emergency; and reviews how each of these federal agencies operated during an actual disaster--the 1985 Grand Eagle oil spill. The report was written by Dr. Richard T. Sylves, a professor of political science at the University of Delaware. Sylves has been studying emergency management for the past 15 years, with special emphasis on oil spill preparedness and response in the Mid-Atlantic Region. The Delaware Estuary Situation Report is 12 pages long and contains maps and photographs, as well as a detailed account of response and recovery operations undertaken during the Grand Eagle oil spill. A comparison of the 1985 Grand Eagle spill and the 1989 Presidente Rivera spill also is included

  15. Effects of heavy metal contamination on the macrobenthic fauna in estuaries: The case of the Seine estuary

    International Nuclear Information System (INIS)

    Dauvin, Jean-Claude

    2008-01-01

    Heavy metal contamination levels are generally higher in estuaries than in the open sea. Some estuaries, the Seine estuary for example, have particularly high pollution levels of metals, yet continue to support a very high benthic biomass and remain quite productive. Measurements of sediment contamination are highly variable due to diverse chemical analysis methods, sediments origin and sources of contaminants found in the estuaries. Salinity appears to be the principal factor controlling contaminant distribution in the sediment and the overlying and/or interstitial waters; it also affects the bioavailability of contaminants in estuarine sediments. Of course, the response to contaminants varies greatly among species and assemblages. Trace metals explain only a small part of the variation in benthic community structure. Some species, such as the shrimp Crangon crangon, appears vulnerable to metal pollution, while other species, such as Scrobicularia plana, are able to tolerate quite high levels of cadmium in their tissue. This paper demonstrates the wide variability of benthic responses to contamination, which is probably due to the high spatio-temporal heterogeneity of the estuary. To reduce the problems due the heterogeneity and variability observed to date in the available results, it will be necessary to encourage integrated estuarine studies, in which sedimentologists, chemists, and biologists work together on the same campaigns at the same sites

  16. Tritium in the Savannah River Estuary and adjacent marine waters

    International Nuclear Information System (INIS)

    Hayes, D.W.

    1978-01-01

    The tritium distribution in the Savannah River estuary and adjacent marine waters was measured to provide information on the dilution, mixing, and movement of Savannah River water in this region. The Savannah River marine region was chosen because the average tritium concentration in this river is 5 pCi/ml, whereas other rivers in the southeastern United States average less than 0.5 pCi/ml. The increased tritium concentration in the Savannah River is due to releases from the Savannah River Plant of the Department of Energy. Tritium measurements have proved particularly effective in estimating the flushing time of the Savannah River estuary (2.4 days) and in delineating the relative contribution to the water masses in Ossabaw and Port Royal Sounds from the River and from sea water. Ossabaw and Port Royal Sounds are located approximately 20 km south and north of the Savannah River estuary, respectively

  17. Waterfowl migration and distribution in North West estuaries. V. 2

    International Nuclear Information System (INIS)

    Clark, N.A.; Kirby, J.S.; Langston, R.H.W.; Donald, P.; Mawdesley, T.; Evans, J.

    1990-12-01

    Waterfowl populations may be affected by the proposed tidal barrage across the Mersey. A study was performed with three objectives: (1) to evaluate the patterns of usage of the intertidal flats of the Mersey estuary by waders and wildfowl and to establish which are the preferred areas; (2) to identify the places of origin and movement patterns of the populations of waders and wildfowl that visit the Mersey estuary; and (3) to evaluate evidence regarding the capacity of British estuaries to absorb waders and wildfowl populations which might be displaced by a Mersey Barrage. The text and tables of results of this study have already been presented in Volume 1. Volume 2 contains the figures describing the results (U.K)

  18. Tritium in the Savannah River estuary and adjacent marine waters

    International Nuclear Information System (INIS)

    Hayes, D.W.

    1979-01-01

    The tritium distribution in the Savannah River estuary and adjacent marine waters was measured to provide information on the dilution, mixing and movement of Savannah River water in this region. The Savannah River marine region was chosen because the average tritium concentration in this river is approximately 5 pCi/ml, whereas other rivers in the southeastern United States of America average less than 0.5 pCi/ml. The increased tritium concentration in the Savannah River is due to releases from the Savannah River Plant of the Department of Energy. Tritium measurements have proved particularly effective in estimating the flushing time of the Savannah River estuary (2.4 days) and in delineating the relative contribution to the water masses in Ossabaw and Port Royal Sounds from the river and from sea-water. Ossabaw and Port Royal Sounds are located approximately 20 km south and north of the Savannah River estuary respectively. (author)

  19. Does boat traffic cause displacement of fish in estuaries?

    Science.gov (United States)

    Becker, Alistair; Whitfield, Alan K; Cowley, Paul D; Järnegren, Johanna; Næsje, Tor F

    2013-10-15

    Estuaries are increasingly under threat from a variety of human impacts. Recreational and commercial boat traffic in urban areas may represent a significant disturbance to fish populations and have particularly adverse effects in spatially restricted systems such as estuaries. We examined the effects of passing boats on the abundance of different sized fish within the main navigation channel of an estuary using high resolution sonar (DIDSON). Both the smallest (100-300 mm) and largest (>501 mm) size classes had no change in their abundance following the passage of boats. However, a decrease in abundance of mid-sized fish (301-500 mm) occurred following the passage of boats. This displacement may be attributed to a number of factors including noise, bubbles and the rapidly approaching object of the boat itself. In highly urbanised estuarine systems, regular displacement by boat traffic has the potential to have major negative population level effects on fish assemblages. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Radium isotopes in the Orinoco estuary and Eastern Caribbean Sea

    International Nuclear Information System (INIS)

    Moore, W.S.; Todd, J.F.

    1993-01-01

    Radium isotopes provide a means of identifying the source of freshened waters in the ocean and determining the time elapsed since these waters were in the estuary. The authors present evidence that during April, waters from the Amazon mixing zone pass within 50 km of the mouth of the Orinoco River. These Amazon waters are characterized by a lower 228 Ra/ 226 Ra activity ratio (AR) than are waters from the Orinoco at similar salinities. During autumn, the increased discharge of the Orinoco displaces the freshened Amazon waters seaward, yet the two can be distinguished clearly. Within the Caribbean Sea, waters of Orinoco origin carry a characteristic radium signature including excess activities of 224 Ra. This isotope may be used to estimate the time elapsed since the waters were removed from contact with sediments. Current speeds based on 224 Ra dating ranged from 15 to 33 cm/s during April. The radium isotopes also provide an assessment of sediment mixing in the estuary. During low discharge (April), considerable mixing of older sediment by physical or biological processes or dredging maintained high activities of 228 Ra in the estuary and produced the highest 228 Ra/ 226 Ra AR's yet measured in any estuary. During high discharge (September), a large fraction of the 228 Ra was derived from desorption from fresh sediment rather than mixing of older sediments. Activities of 224 Ra were high in the estuary during both high and low discharge, indicating that considerable mixing of recently introduced sediment must occur during each period. During April, 224 Ra and 228 Ra activities in the water were about equal, indicating that most of the sediment being resuspended had been stored in the estuary long enough to reestablish radioactive equilibrium in the 232 Th decay series (i.e., 20 years). 19 refs., 11 figs., 3 tabs

  1. Modelling extreme climatic events in Guadalquivir Estuary ( Spain)

    Science.gov (United States)

    Delgado, Juan; Moreno-Navas, Juan; Pulido, Antoine; García-Lafuente, Juan; Calero Quesada, Maria C.; García, Rodrigo

    2017-04-01

    Extreme climatic events, such as heat waves and severe storms are predicted to increase in frequency and magnitude as a consequence of global warming but their socio-ecological effects are poorly understood, particularly in estuarine ecosystems. The Guadalquivir Estuary has been anthropologically modified several times, the original salt marshes have been transformed to grow rice and cotton and approximately one-fourth of the total surface of the estuary is now part of two protected areas, one of them is a UNESCO, MAB Biosphere Reserve. The climatic events are most likely to affect Europe in forthcoming decades and a further understanding how these climatic disturbances drive abrupt changes in the Guadalquivir estuary is needed. A barotropic model has been developed to study how severe storm events affects the estuary by conducting paired control and climate-events simulations. The changes in the local wind and atmospheric pressure conditions in the estuary have been studied in detail and several scenarios are obtained by running the model under control and real storm conditions. The model output has been validated with in situ water elevation and good agreement between modelled and real measurements have been obtained. Our preliminary results show that the model demonstrated the capability describe of the tide-surge levels in the estuary, opening the possibility to study the interaction between climatic events and the port operations and food production activities. The barotropic hydrodynamic model provide spatially explicit information on the key variables governing the tide dynamics of estuarine areas under severe climatic scenarios . The numerical model will be a powerful tool in future climate change mitigation and adaptation programs in a complex socio-ecological system.

  2. 76 FR 9709 - Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary

    Science.gov (United States)

    2011-02-22

    ... Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary AGENCY... the San Francisco Bay/ Sacramento-San Joaquin Delta Estuary (Bay Delta Estuary) in California. EPA is... programs to address recent significant declines in multiple aquatic species in the Bay Delta Estuary. EPA...

  3. The Myths of India.

    Science.gov (United States)

    Day, Frederick A.

    1988-01-01

    Stating that superficial stereotypes hinder the understanding of people and places, Day presents several well-known over-generalizations about India. Attempts to update readers about recent changes within the country while dispelling some popular myths. Discusses India's large population, poverty, economic growth, women's roles, and culture, along…

  4. African Journals Online: India

    African Journals Online (AJOL)

    African Journals Online: India. Home > African Journals Online: India. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access. Afghanistan ...

  5. HEALTH SCENARIO IN INDIA

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. HEALTH SCENARIO IN INDIA. Health Doctor / Hospital Infant expenditure 1000 beds / 1000 mortality / % GDP 1000. India 0.8 0.47 0.8 71. World 2.6 1.5 3.3 54. Developed 6.1 2.8 7.2 6 Countries.

  6. Hydropower development in India

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Praveen [Govt. of India, New Delhi (India). Ministry of New and Renewable Energy], E-mail: psaxena_98@yahoo.com; Kumar, Arun [Indian Institute of Technology Roorkee, Uttarakhand (India). Alternate Hydro Energy Centre], E-mail: aheciitr@gmail.com

    2011-04-15

    India is posed for large deployment of hydropower in present conducive policy and investment environment. Growing energy demand and concern for carbon emission is making hydropower development more favorable. The Government of India is ensuring a good performance of the new SHP stations by linking the incentives to the SHP developers with the performance of the station. (author)

  7. AREVA in India

    International Nuclear Information System (INIS)

    2008-01-01

    India is the sixth largest energy consumer in the world and its demand is rising rapidly. To support its economic growth, estimated to be 8% on average over the last three years and to ensure access to electricity for all, the country foresees massive investments in its power sector over the next five years. India is therefore an essential market for the AREVA Group, where its Transmission and Distribution division plays a leading role on the strategic grid modernization market. This document presents: 1 - the economic situation in India: Key figures, Growth, India's growing need for electricity, India's energy sources and policy: current mix, driving role of the State, the financial reorganization of the SEBs, the 'Mega-Power' projects, the electricity act, the rural electrification program, the Investments. 2 - Civil nuclear energy: a strong potential for development; 3 - India's transmission and distribution network: the power challenge of the transmission network, the efficiency challenge of the distribution network. 4 - AREVA T and D in India: AREVA T and D profile, Areva's presence in India, market share, T and D customers and flagship projects

  8. ADULT EDUCATION IN INDIA.

    Science.gov (United States)

    STYLER, W.E.

    AGAINST A BACKGROUND OF MASS ILLITERACY, POOR PAY AND STATUS OF TEACHERS, AND AN ALIEN EDUCATION PATTERN, THE STATE GOVERNMENTS OF INDIA HAVE PROVIDED SOCIAL EDUCATION FOR CITIZENSHIP AS WELL AS LITERACY. INDIVIDUAL AND GROUP METHODS HAVE BEEN USED, VIDYAPEETHS (RESIDENTIAL COLLEGES) AND EDUCATIONAL CENTERS HAVE BEEN SET UP, AND ALL INDIA RADIO…

  9. Optical Changes in a Eutrophic Estuary During Reduced Nutrient Loadings

    DEFF Research Database (Denmark)

    Pedersen, Troels Møller; Sand-Jensen, Kaj; Markager, Stiig

    2014-01-01

    Loss of water clarity is one of the consequences of coastal eutrophication. Efforts have therefore been made to reduce external nutrient loadings of coastal waters. This paper documents improvements to water clarity between 1985 and 2008–2009 at four stations in the microtidal estuary Roskilde...... to 74 % in 1985 to 78 to 85 % in 2008–2009. Overall, efforts to reduce nutrient loading and improve water clarity appeared to have had a larger impact on POM* than on Chl a and colored dissolved organic matter concentrations in the estuary, which can account for the decrease in the scatter...

  10. Impacts of pesticides in a Central California estuary.

    Science.gov (United States)

    Anderson, Brian; Phillips, Bryn; Hunt, John; Siegler, Katie; Voorhees, Jennifer; Smalling, Kelly; Kuivila, Kathy; Hamilton, Mary; Ranasinghe, J Ananda; Tjeerdema, Ron

    2014-03-01

    Recent and past studies have documented the prevalence of pyrethroid and organophosphate pesticides in urban and agricultural watersheds in California. While toxic concentrations of these pesticides have been found in freshwater systems, there has been little research into their impacts in marine receiving waters. Our study investigated pesticide impacts in the Santa Maria River estuary, which provides critical habitat to numerous aquatic, terrestrial, and avian species on the central California coast. Runoff from irrigated agriculture constitutes a significant portion of Santa Maria River flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in this watershed. Our study extended into the Santa Maria watershed coastal zone and measured pesticide concentrations throughout the estuary, including the water column and sediments. Biological effects were measured at the organism and community levels. Results of this study suggest the Santa Maria River estuary is impacted by current-use pesticides. The majority of water samples were highly toxic to invertebrates (Ceriodaphnia dubia and Hyalella azteca), and chemistry evidence suggests toxicity was associated with the organophosphate pesticide chlorpyrifos, pyrethroid pesticides, or mixtures of both classes of pesticides. A high percentage of sediment samples were also toxic in this estuary, and sediment toxicity occurred when mixtures of chlorpyrifos and pyrethroid pesticides exceeded established toxicity thresholds. Based on a Relative Benthic Index, Santa Maria estuary stations where benthic macroinvertebrate communities were assessed were degraded. Impacts in the Santa Maria River estuary were likely due to the proximity of this system to Orcutt Creek, the tributary which accounts for most of the flow to the lower Santa Maria River. Water and sediment samples from Orcutt Creek were highly toxic to invertebrates due to mixtures of the same pesticides measured

  11. Physical biological coupling in the Pearl River Estuary

    Science.gov (United States)

    Harrison, Paul J.; Yin, Kedong; Lee, J. H. W.; Gan, Jianping; Liu, Hongbin

    2008-07-01

    The Pearl River Estuary is a subtropical estuary and the second largest in China based on discharge volume from the Pearl River. Processes in the estuary vary spatially and temporally (wet vs dry season). In the dry season at the head of the estuary, hypoxic and nearly anoxic conditions occur and NH 4 reaches >600 μM, NO 3 is ˜300 μM and nitrite is ˜60 μM indicating that nitrification and denitrification may be important dry season processes in the region extending 40 km upstream of the Humen outlet. There are very few biological studies conducted in this upper section of the estuary in either the dry or wet seasons and hence there is a need for further research in this region of the river. In the wet season, the salinity wedge extends to the Hongqimen outlet and oxygen is low (35-80% saturation). Nitrate is ˜100 μM, silicate ˜140 μM; and phosphate is relatively low at ˜0.5 μM, yielding an N:P ratio up to ˜200:1 in summer. Nutrients decrease in the lower estuary and primary productivity may become potentially P-limited. Eutrophication is not as severe as one would expect from the nutrient inputs from the Pearl River and from Hong Kong's sewage discharge. This estuary shows a remarkable capacity to cope with excessive nutrients. Physical processes such as river discharge, tidal flushing, turbulent dispersion, wind-induced mixing, and estuarine circulation play an important role in controlling the production and accumulation of algal blooms and the potential occurrence of hypoxia. Superimposed on the physical processes of the estuary are the chemical and biological processes involved in the production of the bloom. For example, the 100N:1P ratio indicates that P potentially limits the amount of algal biomass (and potential biological oxygen demand) in summer. While extended periods of hypoxia are rare in Hong Kong waters, episodic events have been reported to occur during late summer due to factors such as low wind, high rainfall and river discharge which

  12. Nuclear policy for India

    International Nuclear Information System (INIS)

    Kaushik, B.M.

    1977-01-01

    Changes in India's nuclear policy from time to time are discussed. Though firmly wedded to the principle of peaceful uses of nuclear energy, India did not sign in 1965 the NPT as it discriminated between nuclear weapons powers and non-nuclear weapon powers as regards the safeguards. India wanted to keep open the option of conducting peaceful nuclear explosions (PNEs). In May 1974, India did conduct a PNE which, however, resulted into the stoppage of Canadian aid for India's nuclear power programme and created difficulties in obtaining enriched uranium for the Tarapur Atomic Power Station from the U.S.. The new Indian Government formed after the March 1977 general electtions has endorsed the earlier government's policy of opposing manufacture of nuclear weapons and has gone a step further by declearing 'If it (PNE) not necessary it should never be done'. (M.G.B.)

  13. Research, Monitoring, and Evaluation for the Federal Columbia River Estuary Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Diefenderfer, Heida L.; Ebberts, Blaine D.; Tortorici, Cathy; Yerxa, Tracey; Leary, J.; Skalski, John R.

    2008-02-05

    The purpose ofthis document is to describe research, monitoring, and evaluation (RME) for the Federal Columbia River Estuary Program. The intent of this RME effort is to provide data and information to evaluate progress toward meeting program goals and objectives and support decision-making in the Estuary Program. The goal of the Estuary Program is to understand, conserve, and restore the estuary ecosystem to improve the performance of listed salmonid populations. The Estuary Program has five general objectives, designed to fulfill the program goal, as follows. 1. Understand the primary stressors affecting ecosystem controlling factors, such as ocean conditions and invasive species. 2. Conserve and restore factors controlling ecosystem structures and processes, such as hydrodynamics and water quality. 3. Increase the quantity and quality of ecosystem structures, i.e., habitats, juvenile salmonids use during migration through the estuary. 4. Maintain the food web to benefit salmonid performance. 5. Improve salmonid performance in terms of life history diversity, foraging success, growth, and survival. The goal of estuary RME is to provide pertinent and timely research and monitoring information to planners, implementers, and managers of the Estuary Program. In conclusion, the estuary RME effort is designed to meet the research and monitoring needs of the estuary Program using an adaptive management process. Estuary RME's success and usefulness will depend on the actual conduct of adaptive management, as embodied in the objectives, implrementation, data, reporting, and synthesis, evaluation, and decision-making described herein.

  14. India's future: it's about jobs

    OpenAIRE

    Geoffrey N. Keim; Beth Anne Wilson

    2007-01-01

    Projections of sustained strong growth in India depend importantly on the utilization of the huge increase in India's working-age population projected over the next two decades. To date, however, India's economic growth has been concentrated in high-skill and capital-intensive sectors, and has not generated strong employment growth. In this paper, we highlight the tension between India's performance in output and employment, describe the characteristics of India's demographic dividend, and di...

  15. Intra-annual variability in nutrients in the Godavari estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Prasad, V.R.; Kumar, B.S.K.; Rajeev, K.; Devi, B.M.M.; Reddy, N.P.C.; Sarma, V.V.; DileepKumar, M.

    , and spectrofluorometrically measured (Suzuki and Ishimaru, 1990). The analytical precision for Chl a analysis was ±4%. All these analyses were completed within 12 hours of sampling at the shore-based laboratory set up at Yanam, on the bank of the river. Net community... s -1 ). There was virtually no discharge between January and May due to drying of the river in the upstream (Fig. 2b). The inter-annual variability in the October – November discharge was due to changes in the precipitation pattern in the upstream...

  16. Particle-associated bacterial dynamics in a tropical tidal plain (Zuari estuary, India)

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

    that the estuarine bacterial community undergoes physiologi- cal stress leading to reduced bacterial production (del Giorgio & Bouvier 2002), which was not observed at this station. However, during the pre-monsoon season, when the salinity values are the highest... to be significant. As PAB abundance and production formed a signifi- cant portion of the microbial biomass in the Zuari waters, the BCD would be expected to be high. The reported BGE from marine system ranged from <10 to 50% (Azam et al. 1983, del Giorgio et al...

  17. An account on the assemblage of fish larvae in Ponnani estuary, South India

    Directory of Open Access Journals (Sweden)

    Ranjeet Kutty

    2017-03-01

    Full Text Available Estuarine environments are one of the most dynamic aquatic ecosystems and serve many important functions in coastal waters. Larval fish dynamics contribute significantly to understanding the ecology of fish populations as they can indicate the spawning-stock biomass and recruitment in adult fish stocks. Initial development stages of fishes are particularly vulnerable and are influenced by physical and biological processes. Hence the present study was aimed to characterize ichthyoplankton assemblages, to evaluate environmental influence in its structure. Ponnani backwater fish larvae assemblages displayed a clear seasonal pattern presenting higher abundances and diversities during warmer months. Throughout the year there is a wide fluctuation in salinity, temperature and primary productivity in these backwaters enabling it to be classified under stressful environment for larval forms of certain economically important marine fishes.  A detailed analysis made to study the interaction of selected environmental parameters with ichthyofaunal diversity in Ponnani backwater provided a clear understanding on the influence of these variables on the distribution of marine fish larvae in the region. The results of the present analysis provided a model for the prediction of larval diversity from the prevailing environmental parameters.

  18. Morphological changes at Vellar estuary, India - Impact of the December 2004 tsunami

    Digital Repository Service at National Institute of Oceanography (India)

    Pari, Y.; Murthy, M.V.R.; Jayakumar, S.; Subramanian, B.R.; Ramachandran, S.

    collected during pre and post-tsunami periods through Real Time Kinematic GPS (for mapping coastal features and beach profiles) and Geographic Information System (GIS) couple. The tsunami with a wave height as high as 4m not only inundated the entire coastal...

  19. Diurnal variations in bacterial and viral production in Cochin estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Parvathi, A; Jasna, V.; Haridevi, C.K.; Jina, S.; Greeshma, M.; Breezy, J.; Nair, M.

    Microbes play a central role in the decomposition and remineralization of organic matter and recycling of nutrients in aquatic environments. In this study, we examined the influence of physical, chemical, and biological parameters on the rate...

  20. Effect of tropical rainfall in structuring the macrobenthic community of Mandovi estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gaonkar, U.V.; Sivadasa, S.K.; Ingole, B.S.

    of the dominant species. The variation in macrofaunal abundance was brought about by the recruitment and settling of re-suspended adults. It can be concluded that the macrofaunal structuring is influenced by temporal changes in the environment associated...

  1. Effect of freshwater influx on phytoplankton in the Mandovi estuary (Goa, India) during monsoon season: Chemotaxonomy

    Digital Repository Service at National Institute of Oceanography (India)

    Parab, S.G.; Matondkar, S.G.P.; Gomes, H.R.; Goes, J.I.

    for an increase in nitrate levels upto 26 mu M from less than 1 mu M during pre-monsoon and enhancement of chlorophyll a (chl a) as high as 14 mu g·L sup(-1) during the same period. The phytoplankton population was observed through both chemotaxonomy...

  2. Sedimentological characters of the mangrove ecosystem of Kali estuary, Karwar, west coast of India

    Directory of Open Access Journals (Sweden)

    V. Kumar

    2013-09-01

    Full Text Available Estuarine mangroves give natural support to the protection of the riverbanks, due to their accumulative nature. To study this effect, it is necessary to measure sedimentation rates under estuarine mangroves. Sediment plays an important role in the storage and release of nutrient into the water column, the mineralization of organic carbon deposits by various kinds of microbes. In association with other parameters, the sediment is responsible for the variations in densities of majority of benthic organisms. Regular monthly collections of bottom water and sediment were made for a period thirteen months from January 2008 and January 2009 at five different study sites using the motorized outrigger canoe. The present investigation encompassed collection of data pertaining to various aspects of sedimentology. Sediment temperature varied from 25.100c to 30.450c. The pH ranged between 6.18 to 8.30. Organic carbon Varied between 2.06 to 29.45%, moisture content varied from 20.10% to 41.88. Values of interstitial water content is varied between 1.60% to 30.95%. Wide variation in the percentage composition of sand (28.45% to 80.10%, silt (12.78% to 54.28%, and clay (3.66% to 33.63% was observed.

  3. Residual fluxes of salt and water in the Azhikode estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Pylee, A.; Varma, P.U.; Revichandran, C.

    hours at all stations and the data were analysed to provide estimates of the residual fluxes of water and salt. The interpolated data for the non-dimensional depth was used for computation of depth, tide and cross sectional averages. A net seaward flow...

  4. Spatiotemporal distribution in phytoplankton community with distinct salinity regimes along the Mandovi estuary, Goa, India.

    Digital Repository Service at National Institute of Oceanography (India)

    Pednekar, S.M.; Kerkar, V.; Matondkar, S.G.P.

    to 7 divisions were identified during the study period. The highest phytoplankton cell density (5.17 × 104 cells L–1) and biomass (7.68 mg m–3 chlorophyll a) were observed in the upper sections during the nonmonsoon...

  5. Influence of river discharge on plankton metabolic rates in the tropical monsoon driven Godavari estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Gupta, S.N.M.; Babu, P.V.R; Acharyya, T.; Harikrishnachari, N.; Vishnuvardhan, K.; Rao, N.S.; Reddy, N.P.C.; Sarma, V.V.; Sadhuram, Y.; Murty, T.V.R; Kumar, M.D.

    nutrient concentrations and high DIN:DIP ratios suggest possible external supply of nitrogen into the system. The mean photic zone productivity to respiration ratio (P:R) was 2.38 plus or minus 0.24 for the entire study period (September 2007-November 2008...

  6. Monsoonal impact on planktonic standing stock and abundance in a tropical estuary (Cochin backwaters - India)

    Digital Repository Service at National Institute of Oceanography (India)

    Madhu, N.V.; Jyothibabu, R; Balachandran, K.K.; Honey, U.K.; Martin, G.D.; Vijay, J.G.; Shiyas, C.A.; Gupta, G.V.M.; Achuthankutty, C.T.

    and post monsoon seasons, but became low during premonsoon season (<5). Hence, it is suggested that during the periods of fresh water dominance, the trophic food web of Cochin estuarine system is characterized by substantial amount of unconsumed carbon...

  7. Ambiguities in the classification of cochin estuary, West coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shivaprasad, A.; Vinita, J.; Revichandran, C.; Manoj, N.T.; Jayalakshmy, K.V.; Muraleedharan, K.R

    by monsoonal spells causing intense flushing. During the peak dry period, the runoff is less but steady providing a stable environment. River runoff is controlled by short term variations rather than long term variations. Using large comprehensive data sets...

  8. Observed variations in stratification and currents in the Zuari estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sundar, D.; Unnikrishnan, A.S.; Michael, G.S.; Kankonkar, A.; Nidheesh, A.G.; Subeesh, M.P.

    in stratification at different time scales (daily, spring–neap cycle and seasonal) are described. In the mixed tidal regime with semi-diurnal dominance, stratification at higher low water succeeding lower high water is more intense than that at lower low water...

  9. Temporal variations in dimethylsulphoniopropionate and dimethyl sulphide in the Zuari estuary, Goa (India)

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoy, D.M.; Patil, J.S.

    . F., & Wakeham, S. G. (1998). Temporal variability of dimethyl sulfide and dimethylsulfoniopropionate in the Sargasso Sea. DeepSeaRes.PartI, 45, 2085– 2104. DeSouza, M. P., & Yoch, D. C. (1996). Differential metabolism of dimethyl...) measurements and a procedure to predict sea surface DMS as a function of latitude, longitude, and month.GlobalBiogeochemicalCycles,13, 399–444. Kiene, R. P. (1990). Dimethyl sulfide production from dimethyl-sulfoniopropionate in coastal seawater samples...

  10. Intra- and inter-seasonal variability of nutrients in a tropical monsoonal estuary (Zuari, India).

    Digital Repository Service at National Institute of Oceanography (India)

    Anand, S.S.; Sardessai, S.; Muthukumar, C.; Mangalaa, K.R.; Sundar, D.; Parab, S.G.; DileepKumar, M.

    fixed location in the mid-estuarine zone and (b) longitudinal transect sampling from freshwater end to mouth during spring and neap tides of each month for about a year. Multivariate statistical analyses of oxygen and nutrients were carried out...

  11. Dichotomosiphon salina sp. nov. - a new marine algal form from Goa estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Jagtap, T.G.; Dhargalkar, V.K.

    A new species Dichotomosiphon salina sp. of family Vaucheriaceae has been reported from brackish water areas of Goa. The high salinity tolerance of 40 ppt and the variation in size as well as shape of the reproductive organs are the main...

  12. Influence of Saltwater Barrage on Tides, Salinity, and Chlorophyll a in Cochin Estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Shivaprasad, A.; Vinita, J.; Revichandran, C.; Manoj, N.T.; Srinivas, K.; Reny, P.D.; Ashwini, R.; Muraleedharan, K.R.

    . The analysis showed that the closure of the barrage caused amplification of tides in the immediate vicinity and up to 10 km farther downstream. When the barrage was closed, the northern region of the TB transformed from an ebb-dominant system into a flood...

  13. Tidally-modulated high frequency internal waves in Gautami-Godavari estuary, East coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sridevi, B.; Murty, T.V.R.; Sadhuram, Y.; Sarma, V.V.S.S.; Murty, V.S.N.; Prasad, K.V.S.R.

    At these modes, IW parameters viz., wave length (L), wave number (k), potential energy (PE), baroclinic potential energy (BPE) and phase speed (ci) and displacement function (n(z,t)) have been computed (with salinity and currents data) objectively...

  14. Tidal asymmetry in the Mandovi and Zuari estuaries, the West Coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Manoj, N.T.; Unnikrishnan, A.S.; Sundar, D.

    18 19 20 21 22 Table 1. Amplitudes (Amp), phases (Pha) and complex difference module (Diff) of tidal constituents in the Mandovi. The number in bracket... Mod Diff O 1 Amp 14.9 17 2.66 14.7 17 2.45 14.5 16.4 1.97 14.3 14.7 1.79 15 13.5 1.92 2.3 12.5 13.36 Pha 51.2 57.1 54.7 57.8 60.8 62.7 62.7 69.6 67.1 71.9 327.9 75.1 K 1 Amp 33.5 32.5 4.54 33.7 32.6 2.01 34.1 32.2 2.11 33.5 31.3 5.43 36.6 30...

  15. Elysia bangtawaensis Swennen (Nudibranch) from the mangrove habitat of Mandovi estuary, Goa (central west coast), India

    Digital Repository Service at National Institute of Oceanography (India)

    Jagtap, T.G.; Shenai-Tirodkar, P.S.; Savant, S.B.; Kulkarni, V.A.; Ansari, Z.A.

    with the duration of the pulverization period. The study reveals that a good amount of tungsten and cobalt get transferred into the sample during pulverization from the tungsten-carbide cup. The con- tamination of tungsten and cobalt from the pulverizing cup... (Table 2). The popu- lation declined from mid-January 2008. The present form of Elysia was con- fined to the mid-reaches of estuarine Figure 1. Geographical positions of sampling stations. Figure 2. Elysia bangtawaensis from various...

  16. The behaviour of aluminium in waters of the Mandovi estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Upadhyay, S.; SenGupta, R.

    over any biological or non-biological removal and/or supply through disso- lution/desorption processes involving suspended particles. Biological Si removal can be strongly seasonal and can vary with river flow/suspended solids con- centration... closely fol- lows the pattern of the September profile (Fig. 6b). During November and December the total Al con- centrations are approximately constant in the salinity range I 10 and then gradually increase with increas- ing salinity (Fig. 6b) closely...

  17. Recovery of an estuary in the southwest coast of India from tsunami impacts

    Digital Repository Service at National Institute of Oceanography (India)

    Laluraj, C.M.; Kesavadas, V.; Balachandran, K.K.; Gerson, V.J.; Martin, G.D.; Shaiju, P.; Revichandran, C.; Joseph, T.; Nair, M.

    ). The surface salinity gradually decreased from barmouth towards st. 2 and 3 during pre and posttsunami periods (20.5?35.8). But the tsunami erroded this gradient quickly, as the entire estuarine region was dominated by high saline water mass (34... and Madhupradhap, 1979; Sarala Devi et al., 1979, 1983, 1991; Sankaranarayanan et al., 1986; Dinesh Kumar et al., 1994; Balachandran, 2001.). In contrast, the homogenous water mass containing consistently high concentrations of these nutrients in the entire...

  18. Seasonal variability of physico-chemical characteristics of the Haldia channel of Hooghly estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Sarma, V.V.; Murty, T.V.R.; Rao, B.P.

    . In spite of high concentrations of nutrients, seasonal variation of these parameters attributed to the bio- logical intake and replenishment of nutrients coin- ciding with phytoplankton blooms showing their involvement in the biogeochemical cycle. High val...

  19. Salinity response to seasonal runoff in a complex estuarine system (Cochin estuary, west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Vinita, J.; Shivaprasad, A.; Revichandran, C.; Manoj, N.T.; Muraleedharan, K.R.; Jacob B

    of freshwater. However, during the period from January to April, the dependence of the salinity field on runoff was weakened by axial diffusivity. The salt transport was a balance between seaward flux induced by river runoff and tidally induced diffusive...

  20. Behaviour of boron, calcium and magnesium in Purna and Auranga estuaries (Gujarat), west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Narvekar, P.V.; Zingde, M.D.

    percentage of removal of B at low chlorinities indicated its rapid removal in the initial encounter of river water with seawater. On the contrary, Ca was preferentially added at low chlorinities. Addition decreased as the chlorinity increased and removal...

  1. Some aspects of circulation and mixing in lower reaches of Periyar estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Pylee, A.; Varma, P.U.; Revichandran, C.

    stream_size 4 stream_content_type text/plain stream_name Indian_J_Mar_Sci_19_32.pdf.txt stream_source_info Indian_J_Mar_Sci_19_32.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  2. Effects of bridge piers on a tropical estuary in Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Pathak, M.C.; Kotnala, K.L.; Prabaharan, N.

    . These types of changes can cause problems in river navigation. The results obtained may be useful for planning and designing of new bridge piers especially in view of the fact that the river is constantly used for barge transportation of iron ore...

  3. A model of nematode dynamics in the Westerschelde estuary

    NARCIS (Netherlands)

    Li, J.; Vincx, M.; Herman, P.M.J.

    1996-01-01

    We developed a time dynamic model to investigate the temporal dynamics of nematode community in the brackish zone of the Westerschelde Estuary. The biomass of four nematode feeding groups observed from March 1991 to February 1992 is used to calibrate the model. Using environmental data as the input,

  4. Sediment transport investigations in Hugli estuary using radiotracer technique

    International Nuclear Information System (INIS)

    Sharma, V.K.; Pant, H.J.; Kulkarni, U.P.; Pendharkar, A.S.; Chakraborty, Kalyan; Mukhopadhyay, Suman; Chaudhuri, Bikas

    2006-01-01

    This paper describes sediment transport investigations carried out at two different locations in Hugli estuary along the shipping channel leading to Haldia Dock Complex of the Kolkata Port Trust, Kolkata. The objectives of these investigations were to evaluate the suitability of the proposed dumping sites for optimizing the dredging operation and implementing the recommendations of the River Regulatory Measures, Kolkata Port Trust, Kolkata

  5. Water and suspended sediment dynamics in the Sungai Selangor estuary

    International Nuclear Information System (INIS)

    Abdul Kadir Ishak; Kamarudin Samuding; Nazrul Hizam Yusoff

    2000-01-01

    Observations of salinity, temperature, suspended sediment concentration (SSC) and tidal current velocity were made in the lower and along the longitudinal axis sungai Selangor estuary over near-spring cycles. The variations of these parameters at the measurement stations and along the channel are presented to illustrate the water and sediment dynamics in the estuary. The results shows that the Sungai Selangor estuary changes from a partially-mixed type during neaps to a well-mixed one during springs. promoted by stronger tidal energy during the higher tidal ranges. The strong neap density stratification is also promoted by the high river discharges during the measurement period maximum concentration of suspended sediment 2000 mg,'/) occurs during maximum current velocities both during flood and ebb. The maximum salinity was achieved during high water slack but the salt water was totally flushed out of estuary during low water springs. The longitudinal axis measurement indicates that a partially-developed zone of turbidity maximum with a sediment concentration over 1000 mg/l was observed at the limit of salt water intrusion in salinity range less than 1 ppt. Tidal pumping as oppose to the estuarine circulation is the more dominant factor in the maximum formation as the salt water is totally excluded at low water. (author)

  6. Thermodynamics of saline and fresh water mixing in estuaries

    Science.gov (United States)

    Zhang, Zhilin; Savenije, Hubert H. G.

    2018-03-01

    The mixing of saline and fresh water is a process of energy dissipation. The freshwater flow that enters an estuary from the river contains potential energy with respect to the saline ocean water. This potential energy is able to perform work. Looking from the ocean to the river, there is a gradual transition from saline to fresh water and an associated rise in the water level in accordance with the increase in potential energy. Alluvial estuaries are systems that are free to adjust dissipation processes to the energy sources that drive them, primarily the kinetic energy of the tide and the potential energy of the river flow and to a minor extent the energy in wind and waves. Mixing is the process that dissipates the potential energy of the fresh water. The maximum power (MP) concept assumes that this dissipation takes place at maximum power, whereby the different mixing mechanisms of the estuary jointly perform the work. In this paper, the power is maximized with respect to the dispersion coefficient that reflects the combined mixing processes. The resulting equation is an additional differential equation that can be solved in combination with the advection-dispersion equation, requiring only two boundary conditions for the salinity and the dispersion. The new equation has been confronted with 52 salinity distributions observed in 23 estuaries in different parts of the world and performs very well.

  7. Water Quality Drivers in 11 Gulf of Mexico Estuaries

    Directory of Open Access Journals (Sweden)

    Matthew J. McCarthy

    2018-02-01

    Full Text Available Coastal water-quality is both a primary driver and also a consequence of coastal ecosystem health. Turbidity, a measure of dissolved and particulate water-quality matter, is a proxy for water quality, and varies on daily to interannual periods. Turbidity is influenced by a variety of factors, including algal particles, colored dissolved organic matter, and suspended sediments. Identifying which factors drive trends and extreme events in turbidity in an estuary helps environmental managers and decision makers plan for and mitigate against water-quality issues. Efforts to do so on large spatial scales have been hampered due to limitations of turbidity data, including coarse and irregular temporal resolution and poor spatial coverage. We addressed these issues by deriving a proxy for turbidity using ocean color satellite products for 11 Gulf of Mexico estuaries from 2000 to 2014 on weekly, monthly, seasonal, and annual time-steps. Drivers were identified using Akaike’s Information Criterion and multiple regressions to model turbidity against precipitation, wind speed, U and V wind vectors, river discharge, water level, and El Nino Southern Oscillation and North Atlantic Oscillation climate indices. Turbidity variability was best explained by wind speed across estuaries for both time-series and extreme turbidity events, although more dynamic patterns were found between estuaries over various time steps.

  8. Phytoplankton/protozoan dynamics in the Nyara Estuary, a small ...

    African Journals Online (AJOL)

    Phytoplankton/protozoan dynamics in the Nyara Estuary, a small temporarily open system in the Eastern Cape (South Africa) ... freshwater inflow, the Nyara is best described as a predominantly low nutrient, low phytoplankton biomass, stratified system, dominated by the microbial food-web and possibly fed by detritus.

  9. Benthic deversity in the Rhine-Meuse estuary

    NARCIS (Netherlands)

    Wolff, W.J.

    1974-01-01

    The benthic diversity of the Rhine-Meuse estuary has been investigated by means of three diversity indices: the Shannon-Weaver information function, an index obtained by SANDERS' rarefaction method and the number of the species per sample. Succession proved to be a very important factor in the

  10. Salt Intrusion, Tides and Mixing in Multi-channel Estuaries

    NARCIS (Netherlands)

    Nguyen, A.D.

    2008-01-01

    Multi-channel estuaries, such as the Mekong Delta in Vietnam and the Scheldt in the Netherlands, have characteristics of both the river and the sea, forming a unique environment influenced by tidal movements of the sea and freshwater flow of the river. This study addresses a number of knowledge gaps

  11. Contaminants of emerging concern in a large temperate estuary.

    Science.gov (United States)

    Meador, James P; Yeh, Andrew; Young, Graham; Gallagher, Evan P

    2016-06-01

    This study was designed to assess the occurrence and concentrations of a broad range of contaminants of emerging concern (CECs) from three local estuaries within a large estuarine ecosystem. In addition to effluent from two wastewater treatment plants (WWTP), we sampled water and whole-body juvenile Chinook salmon (Oncorhynchus tshawytscha) and Pacific staghorn sculpin (Leptocottus armatus) in estuaries receiving effluent. We analyzed these matrices for 150 compounds, which included pharmaceuticals, personal care products (PPCPs), and several industrial compounds. Collectively, we detected 81 analytes in effluent, 25 analytes in estuary water, and 42 analytes in fish tissue. A number of compounds, including sertraline, triclosan, estrone, fluoxetine, metformin, and nonylphenol were detected in water and tissue at concentrations that may cause adverse effects in fish. Interestingly, 29 CEC analytes were detected in effluent and fish tissue, but not in estuarine waters, indicating a high potential for bioaccumulation for these compounds. Although concentrations of most detected analytes were present at relatively low concentrations, our analysis revealed that overall CEC inputs to each estuary amount to several kilograms of these compounds per day. This study is unique because we report on CEC concentrations in estuarine waters and whole-body fish, which are both uncommon in the literature. A noteworthy finding was the preferential bioaccumulation of CECs in free-ranging juvenile Chinook salmon relative to staghorn sculpin, a benthic species with relatively high site fidelity. Published by Elsevier Ltd.

  12. Aspects of the ecology of meiofauna in Mngazana estuary, Transkei

    African Journals Online (AJOL)

    of Mngazana estuary were monitored over a period of 15 months from April 1977 .... Salinity was measured at 5 and 15 cm in the sandy area by withd rawing a few ... marina roots and a large number of fiddler crabs (Uca pugilator). The beach ...

  13. Environmental features and macrofauna of Kahana Estuary, Oahu, Hawaii

    Science.gov (United States)

    Maciolek, J.A.; Timbol, A.S.

    1981-01-01

    Lack of ecological information on Hawaiian estuaries prompted an intensive 2-year study of a small (5.7 ha) stream-mouth estuary on windward Oahu. Water quality and macrofauna were sampled weekly at seven stations. The water mass was strongly stratified vertically except during freshets. Average values for water column temperature and bottom salinity were 23.2°C and 12‰ at the head to 28.3°C and 28‰ at the mouth. Dissolved oxygen saturation in the water column varied from about 50% at night to 140% in the afternoon. Usually, bottom waters were 3–6°C warmer than surface waters and sometimes showed severe oxygen depletion.Macrofauna, collected primarily by seining, consisted mainly of decapod crustaceans (four species of crabs, seven species of shrimps) and fishes (24 species). Other typical estuarine taxons (mollusks, barnacles, polychaetes) were scarce or absent. Diversity increased seaward from 14 species near the estuary head to 29 species near the mouth. Three species of crustaceans and six of fishes were captured at all stations. Most abundant were the native prawn, Macrobrachium grandimanus, and mullet, Mugil cephalus. Perennially resident adults occurred among crustaceans and gobioid fishes; most other fishes were present as juveniles and sporadic adults. Comparisons with other data suggest that more than 50 species of native fishes may occur in Hawaiian estuaries, and that estuarine macrofaunal diversity on oceanic islands is much lower than on continents at similar latitudes.

  14. ECOLOGICAL CONDITION OF THE ESTUARIES OF OREGON AND WASHINGTON

    Science.gov (United States)

    Estuaries are bodies of water that receive freshwater and sediment from rivers and saltwater from the oceans. They are transition zones between the fresh water of a river and the salty environment of the sea. This interaction produces a unique environment that supports wildlife...

  15. Moveable flood barriers in the Rhine-Meuse estuary

    NARCIS (Netherlands)

    Rijcken, T.; Kok, M.

    2011-01-01

    It is possible to reduce flood risk in estuaries without having to drastically modify the river banks by levees or to block shipping routes and ecological flows by dams. ‘Storm surge barriers’ close off a river mouth at times of high sea water levels, but keep the river open during calmer times.

  16. Seasonal variation of the salinity in the Zuari estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Murty, C.S.

    The annual salt budget of the Zuari is examined. The characteristics of the estuary differ markedly from the low run off season during November - May to the heavy run off period of the southwest monsoon from June to October. During November - May...

  17. An assessment of tidal energy potential. The Lima estuary

    Energy Technology Data Exchange (ETDEWEB)

    Trigo-Teixeira, A. [Department of Civil Engineering and Architecture, Instituto Superior Tecnico, Lisbon Technical University, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Rebordao, I. [WW Consulting Engineers, Laveiras, Caxias 2760-032 (Portugal)

    2009-07-01

    A hydrodynamic model was set up for the Lima estuary (Portugal) and a preliminary assessment of the strength of tidal currents to produce tidal energy was made. To calibrate the model results were compared with measured data, and the model tuned to reproduce water levels and currents in several locations within the estuary. The data was acquired with ADCPs, during a field campaign that was planed to cover a spring-neap tide cycle, in October 2006. The Advanced Circulation Model - ADCIRC was forced with the most important harmonic constituents present in the ocean tide signal. Upstream, in the river boundary, the discharge was taken from hydrographs. The wetting and drying tool was also applied and a detailed bathymetry was considered, since there are areas in the domain where salt marshes occur, drying out at low tide. The tidal currents potential were assessed for a scenario of tidal forcing only, without any river discharge. The lower estuary is occupied by the port infrastructure and navigation channels which conflicts with any kind of equipment installation. Values of the currents and water depths given by the model indicate that some places in the main channel of the middle estuary, might be interesting to install micro turbines in the future, depending on the evolution of the requirements of this technology.

  18. Field observations of hypersaline runoff through a shallow estuary

    Science.gov (United States)

    Hosseini, Seyed Taleb; Siadatmousavi, Seyed Mostafa

    2018-03-01

    This study investigates a rare situation at the Mond River Estuary in the Persian Gulf, in which the classical estuarine density gradient coincides with hypersaline runoff entering from saline soils upstream of the estuary after severe precipitation. This builds a unique estuarine setting, where two salt water masses, one originating from the coastal ocean and the other being discharged from upstream confine a range of almost freshwater in the middle of estuary. This "freshwater lens estuary" (FLE) situation includes two saltwater sources with opposing senses of estuarine circulation. Therefore, the tidal damping by the strong river flood can occur, especially during neap tide when high Unsteadiness number (∼0.04) signified ebb oriented condition which was induced by straining residual lateral circulation near the FLE mouth. Transition from well-mixed to weak strain induced periodic stratification regimes indicated the importance of the spring-neap tidal variations. Close to the mouth, a 13.66-day periodic tidal asymmetry from the triad K1-O1-M2 (ebb-dominance during spring tide and flood-dominance in neap tide) was overcome by higher harmonics.

  19. Initial growth of phytoplankton in turbid estuaries: a simple model

    NARCIS (Netherlands)

    de Swart, H.E.; Schuttelaars, H.; Talke, S.A.

    2009-01-01

    An idealised model is presented and analysed to gain more fundamental understanding about the dynamics of phytoplankton blooms in well-mixed, suspended sediment dominated estuaries. The model describes the behaviour of subtidal currents, suspended sediments, nutrients and phytoplankton in a channel

  20. On Internal Waves in a Density-Stratified Estuary

    NARCIS (Netherlands)

    Kranenburg, C.

    1991-01-01

    In this article some field observations, made in recent years, of internal wave motions in a density-stratified estuary are presented, In order to facilitate the appreciation of the results, and to make some quantitative comparisons, the relevant theory is also summarized. Furthermore, the origins

  1. Salt intrusion study in Cochin estuary - Using empirical models

    Digital Repository Service at National Institute of Oceanography (India)

    Jacob, B.; Revichandran, C.; NaveenKumar, K.R.

    been applied to the Cochin estuary in the present study to identify the most suitable model for predicting the salt intrusion length. Comparison of the obtained results indicate that the model of Van der Burgh (1972) is the most suitable empirical model...

  2. Environmental studies of the Ambika and associated river estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Narvekar, P.V.; Sharma, P.; Sabnis, M.M.

    loads quantified. High sea water influx, strong currents and small low tide volume rendered the estuaries well mixed with excellent flushing characteristics. The fraction of freshwater method gave a flushing time of 2.5 and 5.8 tidal cycles in October...

  3. Physico-chemical investigations in Auranga river estuary (Gujarat)

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Sharma, P.; Sabnis, M.M.

    currents. The flushing time calculated (2.7-4.1 tidal cycles) by applying the fraction of fresh water method was at least three times higher than computed on the basis of the tidal prism method. The load retained in the estuary under continuous flow...

  4. The zooplankton of Mgazana, a mangrove estuary in Transkei

    African Journals Online (AJOL)

    continent. The estuary is in an excellent state of preservation and all three species of mangrove trees which occur south of K.osi Bay (260 54' S) are recorded here (Avicennia marina, Bruguieria gymnorhiza .... of Heron Island a shallow ford or drift occurs where depth may be less than 0,25 m at low tide. Above the island the ...

  5. Maturation of Metapenaeus moyebi (Kishinouye) in Goa estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Achuthankutty, C.T; Parulekar, A

    An assessment of the stake net fishery in the Mandovi and Zuari estuaries of Goa revealed that Metapenaeus moyebi, a penaeid prawn hitherto rarely recorded in Indian waters, formed a good percentage of the estuarine prawn fishery of Goa. At one...

  6. Temporal and spatial variations in hydrographic conditions of Mandovi estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Varma, K.K.; Rao, L.V.G.; Cherian, T.

    Nine stations over a stretch of 21 km of Periyar river estuary were sampled during January to December 1981. Particulate matter varied from 3-253 mg.1 super(1) at the surface and 24.8-257mg.1 super(1) at the bottom. Particulate organic carbon ranged...

  7. Identification and characterisation of Thiobacilli spp. from Chaliyar Estuary - Malabar

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, O.; Kumaran, S.; Sankaranarayanan, V.N.

    Thiobacilli spp. occurring in surface and bottom water and sediment from seven stations in the Chaliyar Estuary, for a period of one year, were isolated and cultured. A total of 231 sample of water and sediments were analysed of which 77 gave...

  8. Clinical trials in India.

    Science.gov (United States)

    Maiti, Rituparna; M, Raghavendra

    2007-07-01

    The concept of outsourcing for the development and global studies on new drugs has become widely accepted in the pharmaceutical industry due to its cost and uncertainty. India is going to be the most preferred location for contract pharma research and development due to its huge treatment naïve population, human resources, technical skills, adoption/amendment/implementation of rules/laws by regulatory authorities, and changing economic environment. But still 'miles to go' to fulfill the pre-requisites to ensure India's success. In spite of all the pitfalls, the country is ambitious and optimist to attract multinational pharmaceutical companies to conduct their clinical trials in India.

  9. Gross Nitrogen Mineralization in Surface Sediments of the Yangtze Estuary

    Science.gov (United States)

    Liu, Min; Li, Xiaofei; Yin, Guoyu; Zheng, Yanling; Deng, Fengyu

    2016-01-01

    Nitrogen mineralization is a key biogeochemical process transforming organic nitrogen to inorganic nitrogen in estuarine and coastal sediments. Although sedimentary nitrogen mineralization is an important internal driver for aquatic eutrophication, few studies have investigated sedimentary nitrogen mineralization in these environments. Sediment-slurry incubation experiments combined with 15N isotope dilution technique were conducted to quantify the potential rates of nitrogen mineralization in surface sediments of the Yangtze Estuary. The gross nitrogen mineralization (GNM) rates ranged from 0.02 to 5.13 mg N kg-1 d-1 in surface sediments of the study area. The GNM rates were generally higher in summer than in winter, and the relative high rates were detected mainly at sites near the north branch and frontal edge of this estuary. The spatial and temporal distributions of GNM rates were observed to depend largely on temperature, salinity, sedimentary organic carbon and nitrogen contents, and extracellular enzyme (urease and L-glutaminase) activities. The total mineralized nitrogen in the sediments of the Yangtze Estuary was estimated to be about 6.17 × 105 t N yr-1, and approximately 37% of it was retained in the estuary. Assuming the retained mineralized nitrogen is totally released from the sediments into the water column, which contributed 12–15% of total dissolved inorganic nitrogen (DIN) sources in this study area. This result indicated that the mineralization process is a significant internal nitrogen source for the overlying water of the Yangtze Estuary, and thus may contribute to the estuarine and coastal eutrophication. PMID:26991904

  10. Comparison of nitrifier activity versus growth in the scheldt estuary - a turbid, tidal estuary in northern Europe

    NARCIS (Netherlands)

    Andersson, M.G.I.; Brion, N.; Middelburg, J.J.

    2006-01-01

    Nitrifier activity and growth were measured in the Scheldt estuary over a salinity gradient. Measurements were made during all 4 seasons using 15N enriched ammonium and 14C labeled carbon incorporation. Established conversion ratios are often used to convert the growth of nitrifiers (measured as the

  11. Rapid growth within India

    International Nuclear Information System (INIS)

    Hayes, D.

    2000-01-01

    The Indian government has published (in Hydrocarbon Vision 2025) its ideas for a long term strategy for its oil industry which is currently growing at an unprecedented rate. Increasing domestic production and investment in oil exploration and production overseas figure strongly in the plan. At present, India has a refining surplus but with an annual growth of 8-10%, this will disappear in the next 2-3 years. The report recommends that India should maintain 90% self-sufficiency in refining. The report sees development of the domestic oil industry as globally competitive and helping safeguard India's assets. The capability of India's refineries, current upgrading, the newer refineries and plans for new projects are all mentioned

  12. India's nuclear program

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    India made an early commitment to being as self-sufficient as possible in nuclear energy and has largely achieved that goal. The country operates eight nuclear reactors with a total capacity of 1,304 MWe, and it remains committed to an aggressive growth plan for its nuclear industry, with six reactors currently under construction, and as many as twelve more planned. India also operates several heavy water production facilities, fabrication facilities, reprocessing works, and uranium mines and mills. Due to India's decision not to sign the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), the country has had to develop nearly all of its nuclear industry and infrastructure domestically. Overall, India's nuclear power program is self-contained and well integrated, with plans to expand to provide up to ten percent of the country's electrical generating capacity

  13. Energy India 'dependence

    International Nuclear Information System (INIS)

    Cygler, C.

    2007-01-01

    India has an economic growth between 8 to 10 % by year. To become a great country of the twenty first century and to stop poverty it is necessary to keep this growth but the growth of India is dependant of its ability to supply electric power necessary to increase the industrial production. The country has to multiply by four its energy production. The electric production comes from thermal power plants for 65%, 26% from hydroelectric power plants, 6% from renewable energy sources and 3% from nuclear energy. Between solar energy ( India has three hundred solar days by years) and nuclear energy using thorium that can be increased India has to choose an energy policy to answer its energy demand and independence need. (N.C.)

  14. IDRC in India

    International Development Research Centre (IDRC) Digital Library (Canada)

    challenges facing India. The Centre's past support ... are tackling some pressing problems in wireless ... policymakers improve workers' earnings and working ... since 1974. Many of the telecentre managers that IDRC helps to train are women.

  15. Women Scientists in India

    Indian Academy of Sciences (India)

    participate in large numbers not just in learning ... earlier reports and give a summary of the situation .... noting best practices and recommendations that ..... service. This certainly has helped women working in organizations. In fact India has ...

  16. PRESENT STATUS IN INDIA

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. PRESENT STATUS IN INDIA. FIXED LINES – 36 MILLION. MOBILE CONNECTIONS – 14 MILLION. TELEDENSITY APPROXIMATELY 5. INTERNET CONNECTIONS – 5 MILLION. INTERNET USERS NEARLY – 25 MILLION.

  17. IDRC in India

    International Development Research Centre (IDRC) Digital Library (Canada)

    India has experienced impressive economic growth over the ... and those still living in poverty is widening. ... IDRC supports research to improve women's security, access to justice, and economic ... viction rates for offenders remain low. This.

  18. Effects of environmental and water quality parameters on the functioning of copepod assemblages in tropical estuaries

    Science.gov (United States)

    Araujo, Adriana V.; Dias, Cristina O.; Bonecker, Sérgio L. C.

    2017-07-01

    We examined changes in the functioning of copepod assemblages with increasing pollution in estuaries, using sampling standardization of the salinity range to enable comparisons. Copepod assemblages were analyzed in four southeast Brazilian estuaries with different water quality levels and hydrodynamic characteristics over two years. We obtained mesozooplankton samples together with environmental and water quality parameters in the estuaries, every two months under predetermined salinities ranging from 15 to 25. The values of parameters, except species size, associated with the functioning of the copepod assemblages (biomass, productivity, and turnover rate) did not differ among estuaries. However, in the more polluted estuaries, the biomass and productivity of copepod assemblages of mesozooplankton were negatively correlated with concentration of pollution indicator parameters. Conversely, in the less polluted estuaries some degree of enrichment still seems to increase the system biomass and productivity, as these parameters were inversely related to indicators of improved water quality. The pollution level of estuaries distorted the relationship between temperature and the efficiency of converting energy to organic matter. In the less polluted estuaries, the relationship between turnover rate and temperature was over 70%, while in the most polluted estuaries, this relationship was only approximately 50%. Our results demonstrated that the functioning of assemblages in the estuaries was affected differently by increasing pollution depending on the water quality level of the system. Thus, investigating the functioning of assemblages can be a useful tool for the analysis of estuarine conditions.

  19. India : the new China?

    Energy Technology Data Exchange (ETDEWEB)

    Nanavaty, K. [Reliance Industries Ltd., Mumbai (India). Cracker and Polymer Div.

    2006-07-01

    India is emerging as a strong force in the global economy. The population of China is 1.2 times that of India, and its gross domestic product is 2.5 times that of India. However, analyses of per capita gross domestic product (GDP) indicate that if India continues its rate of growth, its' consumption and production will reach China's current levels in less than 15 years. This represents a significant investment opportunity in basic industry, particularly since a growing middle class will ensure a boom in consumer products consumption. This presentation compared India and China, in terms of economic approaches and challenges for India. Implications for the petrochemical industry were also discussed with reference to Reliance Industries Ltd. and its full integration in the value chain with petroleum refining. Reliance Industries Ltd. claims that India's captive utilities and labour productivity provide the company with conversion costs that are among the lowest in the industry. In terms of agriculture, India is one of the largest producers of agricultural commodities in the world and is well supported by varying agro-climates and fertile land. This presentation also included an agro-commodities yield comparison for rice, wheat and cereal. The Indian manufacturing industry is also competitive, focusing on cutting cost, increasing productivity and innovation. It was noted that although China has the advantage of a well established infrastructure on a global and domestic scale as well as job opportunities and quick policy implementation, it has lax labour laws, poor pollution laws and a challenging banking system. In contrast, India has the entrepreneurial advantage as well as global scale information technology, a globally competitive manufacturing industry, an independent regulatory framework and world class capital markets and banking system. India's challenge lies in its lack of a world-class infrastructure, complicated tax structure and slow

  20. Gestational surrogacy in India

    OpenAIRE

    Rozée , Virginie; Unisa , Sayeed; De La Rochebrochard , Elise

    2016-01-01

    International audience; While gestational surrogacy is illegal in France, it is authorized in other countries, such as India. Drawing upon a study of Indian surrogates, Indian and foreign intended parents pursuing surro­gacy, as well as physicians, lawyers and Indian clinic and agency managers, Virginie Rozée, Sayeed Unisa and Elise de La Rochebrochard describe how surrogacy services are organized in India and examine the expectations and rationales of the protagonists.

  1. India's Downstream Petroleum Sector

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This study provides a holistic examination of pricing and investment dynamics in India's downstream petroleum sector. It analyses the current pricing practices, highlights the tremendous fiscal cost of current pricing and regulatory arrangements, and examines the sectoral investment dynamics. It also looks at potential paths towards market-based reform along which the Indian government may move, while at the same time protecting energy market access for India's large poor population.

  2. Circulation and suspended particulate matter transport in a tidally dominated estuary: caravelas estuary, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Augusto França Schettini

    2010-03-01

    Full Text Available The circulation and transport of suspended particulate matter in the Caravelas Estuary are assessed. Nearly-synoptic hourly hydrographic, current (ADCP velocity and volume transport and suspended particulate matter data were collected during a full semidiurnal spring tide, on the two transects Boca do Tomba and Barra Velha and on longitudinal sections at low and high tide. On the first transect the peak ebb currents (-1.5 ms-1 were almost twice as strong as those of the wider and shallow Barra Velha inlet (-0.80 ms-1 and the peak flood currents were 0.75 and 0.60 ms-1, respectively. Due to the strong tidal currents both inlets had weak vertical salinity stratification and were classified with the Stratification-circulation Diagram as Type 2a (partially mixed-weakly stratified and Type 1a (well mixed. Volume transports were very close, ranging from -3,500 to 3,100 m³s-1 at the ebb and flood, respectively, with a residual -630 m³s-1. The concentration of the suspended particulate matter was closely related to the tidal variation and decreased landwards from 50 mg.L-1 at the estuary mouth, to 10 mg.L-1 at distances of 9 and 16 km for the low and high tide experiments, respectively. The total residual SPM transport was out of the estuary at rates of -18 tons per tidal cycle.A circulação e o transporte de material particulado em suspensão no Estuário de Caravelas são pesquisados. Dados quase-sinóticos hidrográficos, de correntes (velocidade e transporte de volume com ADCP e de material particulado em suspensão, foram medidos em intervalos horários durante um ciclo semidiurno de maré de sizígia, em duas seções transversais na Boca do Tomba e na Barra Velha e também em seções longitudinais na baixa-mar e na preamar. Na primeira transversal as correntes máximas de vazante (-1,50 m s-1 foram quase duas vezes mais intensas do que na seção transversal mais larga e rasa Barra Velha, (-0,80 m s-1 e as maiores velocidades das correntes de

  3. History of Nuclear India

    Science.gov (United States)

    Chaturvedi, Ram

    2000-04-01

    India emerged as a free and democratic country in 1947, and entered into the nuclear age in 1948 by establishing the Atomic Energy Commission (AEC), with Homi Bhabha as the chairman. Later on the Department of Atomic Energy (DAE) was created under the Office of the Prime Minister Jawahar Lal Nehru. Initially the AEC and DAE received international cooperation, and by 1963 India had two research reactors and four nuclear power reactors. In spite of the humiliating defeat in the border war by China in 1962 and China's nuclear testing in 1964, India continued to adhere to the peaceful uses of nuclear energy. On May 18, 1974 India performed a 15 kt Peaceful Nuclear Explosion (PNE). The western powers considered it nuclear weapons proliferation and cut off all financial and technical help, even for the production of nuclear power. However, India used existing infrastructure to build nuclear power reactors and exploded both fission and fusion devices on May 11 and 13, 1998. The international community viewed the later activity as a serious road block for the Non-Proliferation Treaty and the Comprehensive Test Ban Treaty; both deemed essential to stop the spread of nuclear weapons. India considers these treaties favoring nuclear states and is prepared to sign if genuine nuclear disarmament is included as an integral part of these treaties.

  4. India's nuclear security

    International Nuclear Information System (INIS)

    Thomas, Raju G.C.; Gupta, Amit

    2000-01-01

    The nuclear weapons and ballistic missile tests conducted by India and Pakistan in the late 1990s substantially altered the security environment, both in the region and globally. Examining the complexities, and dynamics of this new strategic context, this timely and significant book examines the claim of many Indian strategists that stability in the region is better served under conditions of declared-rather than covertly developed-nuclear weapons. Bringing together original essays by a diverse group of scholars, this volume discusses a number of important issues such as: the political considerations that caused India and Pakistan to go nuclear; the type of nuclear doctrine that is likely to emerge and its implications for the safety of nuclear weapons, the potential for an arms race in the region, and the likelihood of war; the political and economic consequences for India after Pokhran-II and the impact of economic sanctions; the technological ramifications of the nuclear program on India's defence science scenario; the impact of these tests on the future of India's relationship with the United States, the main bulwark against nuclear weapons proliferation, also, the changed role that India sees for itself in international fora; the possible arms control measures that might succeed in stabilizing the South Asian nuclear rivalry. This insightful, comprehensive and topical volume is a must-read for all those in the fields of political science, international relations, strategic affairs, conflict/peace studies, economics, and policy studies

  5. Why Do Some Estuaries Close: A Model of Estuary Entrance Morphodynamics.

    Science.gov (United States)

    McSweeney, S. L.; Kennedy, D. M.; Rutherfurd, I.

    2014-12-01

    Intermittently Closed/Open Coastal Lakes/Lagoons (ICOLLs) are a form of wave-dominated, microtidal estuary that experience periodic closure in times of low river flow. ICOLL entrance morphodynamics are complex due to the interaction between wave, tidal and fluvial processes. Managers invest substantial funds to artificially open ICOLLs as they flood surrounding property and infrastructure, and have poor water quality. Existing studies examine broad scale processes but do not identify the main drivers of entrance condition. In this research, the changes in entrance geomorphology were surveyed before and after artificial entrance openings in three ICOLLs in Victoria, Australia. Changes in morphology were related to continuous measures of sediment volume, water level, tide and wave energy. A six-stage quantitative phase model of entrance geomorphology and hydrodynamics is presented to illustrate the spatio-temporal variability in ICOLL entrance morphodynamics. Phases include: breakout; channel expansion with rapid outflow; open with tidal exchange; initial berm rebuilding with tidal attenuation; partial berm recovery with rising water levels; closed with perched water levels. Entrance breakout initiates incision of a pilot channel to the ocean, whereby basin water levels then decline and channel expansion as the headcut migrates landwards. Peak outflow velocities of 5 m/s-3 were recorded and channel dimensions increased over 6 hrs to 3.5 m deep and 140 m wide. When tidal, a clear semi-diurnal signal is superimposed upon an otherwise stable water level. Deep-water wave energy was transferred 1.8 km upstream of the rivermouth with bores present in the basin. Berm rebuilding occurred by littoral drift and cross-shore transport once outflow ceased and microscale bedform features, particularly antidunes, contributed to sediment progradation. Phase duration is dependant on how high the estuary was perched above mean sea level, tidal prism extent, and onshore sediment supply

  6. Research, Monitoring, and Evaluation for the Federal Columbia River Estuary Program.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Diefenderfer, Heida L. (Pacific Northwest National Laboratory)

    2008-02-20

    The purpose of this document is to describe research, monitoring, and evaluation (RME) for the Federal Columbia River Estuary Program, hereafter called 'the Estuary Program'. The intent of this RME effort is to provide data and information to evaluate progress toward meeting program goals and objectives and support decision making in the Estuary Program. The goal of the Estuary Program is to understand, conserve, and restore the estuary ecosystem to improve the performance of listed salmonid populations. The Estuary Program has five general objectives, designed to fulfill the program goal, as follows: (1) Understand the primary stressors affecting ecosystem controlling factors, such as ocean conditions and invasive species. (2) Conserve and restore factors controlling ecosystem structures and processes, such as hydrodynamics and water quality. (3) Increase the quantity and quality of ecosystem structures, i.e., habitats, juvenile salmonids use during migration through the estuary. (4) Maintain the food web to benefit salmonid performance. (5) Improve salmonid performance in terms of life history diversity, foraging success, growth, and survival. The goal of estuary RME is to provide pertinent and timely research and monitoring information to planners, implementers, and managers of the Estuary Program. The goal leads to three primary management questions pertaining to the main focus of the Estuary Program: estuary habitat conservation and restoration. (1) Are the estuary habitat actions achieving the expected biological and environmental performance targets? (2) Are the offsite habitat actions in the estuary improving juvenile salmonid performance and which actions are most effective at addressing the limiting factors preventing achievement of habitat, fish, or wildlife performance objectives? (3) What are the limiting factors or threats in the estuary/ocean preventing the achievement of desired habitat or fish performance objectives? Performance measures

  7. Estuary-ocean connectivity: fast physics, slow biology.

    Science.gov (United States)

    Raimonet, Mélanie; Cloern, James E

    2017-06-01

    Estuaries are connected to both land and ocean so their physical, chemical, and biological dynamics are influenced by climate patterns over watersheds and ocean basins. We explored climate-driven oceanic variability as a source of estuarine variability by comparing monthly time series of temperature and chlorophyll-a inside San Francisco Bay with those in adjacent shelf waters of the California Current System (CCS) that are strongly responsive to wind-driven upwelling. Monthly temperature fluctuations inside and outside the Bay were synchronous, but their correlations weakened with distance from the ocean. These results illustrate how variability of coastal water temperature (and associated properties such as nitrate and oxygen) propagates into estuaries through fast water exchanges that dissipate along the estuary. Unexpectedly, there was no correlation between monthly chlorophyll-a variability inside and outside the Bay. However, at the annual scale Bay chlorophyll-a was significantly correlated with the Spring Transition Index (STI) that sets biological production supporting fish recruitment in the CCS. Wind forcing of the CCS shifted in the late 1990s when the STI advanced 40 days. This shift was followed, with lags of 1-3 years, by 3- to 19-fold increased abundances of five ocean-produced demersal fish and crustaceans and 2.5-fold increase of summer chlorophyll-a in the Bay. These changes reflect a slow biological process of estuary-ocean connectivity operating through the immigration of fish and crustaceans that prey on bivalves, reduce their grazing pressure, and allow phytoplankton biomass to build. We identified clear signals of climate-mediated oceanic variability in this estuary and discovered that the response patterns vary with the process of connectivity and the timescale of ocean variability. This result has important implications for managing nutrient inputs to estuaries connected to upwelling systems, and for assessing their responses to changing

  8. Heavy Metallic Element Distribution in Cisadane River Estuary's Water and Sediment

    Directory of Open Access Journals (Sweden)

    M. Taufik Kaisupy

    2006-04-01

    Full Text Available Observation of heavy metallic elements in Cisadane River Estuary has been done in July and November 2005. The results show that heavy metallic elements content in seawater is lower and still below the treshold value stated by government for fisheries. There was an indication of heavy metallic elements on sediment. Distribution of Pb on July and of Cu on November 2005 were found higher near the coast and decrease towards the sea, and commonly were found in front of estuary such as Cisadane, Muara Saban and Tanjung Pasir. High Pb and Zn distributions on November 2005 were found only in front of Cisadane estuary. Cd distribution of Cisadane estuary was constant at all station but did not show any correlation with the distance of station and estuary. The Cd content on July and November 2005 is lower than 0,001 ppm. Generally, heavy metallic elements content have a uniform distribution at all stations inspite of its distance to estuary.

  9. An analytical solution for tidal propagation in the Yangtze Estuary, China

    Directory of Open Access Journals (Sweden)

    E. F. Zhang

    2012-09-01

    Full Text Available An analytical model for tidal dynamics has been applied to the Yangtze Estuary for the first time, to describe the tidal propagation in this large and typically branched estuary with three-order branches and four outlets to the sea. This study shows that the analytical model developed for a single-channel estuary can also accurately describe the tidal dynamics in a branched estuary, particularly in the downstream part. Within the same estuary system, the North Branch and the South Branches have a distinct tidal behaviour: the former being amplified demonstrating a marine character and the latter being damped with a riverine character. The satisfactory results for the South Channel and the South Branch using both separate and combined topographies confirm that the branched estuary system functions as an entity. To further test these results, it is suggested to collect more accurate and dense bathymetric and tidal information.

  10. Rare earth elements mobility processes in an AMD-affected estuary: Huelva Estuary (SW Spain).

    Science.gov (United States)

    Lecomte, K L; Sarmiento, A M; Borrego, J; Nieto, J M

    2017-08-15

    Huelva Estuary is a transition zone where REE-rich acidic waters interact with saline-alkaline seawater. This mixing process influences the geochemical and mineralogical characteristics of particulate and dissolved fractions. The Tinto River has >11,000μgL -1 dissolved REE (pH=1.66), whereas seawater only reaches 8.75·10 -2 μgL -1 dissolved REE (pH=7.87). REE-normalized patterns in "pH<6 solutions" are parallel and show similarities, diminishing their concentration as pH increases. Sequential extraction performed on the generated precipitates of mixed solutions indicates that most REE are associated to the residual phase. In a second order, REE are associated with soluble salts at pH3 and 3.5 whereas in sediments generated at pH4 and 5, they are distributed in salts (1° extraction), poorly crystallized Fe-bearing minerals (schwertmannite, 3° extraction) and well crystallized Fe-bearing minerals (goethite - hematite, 4° extraction). Finally, precipitated REE are highest at pH6 newly formed minerals with a release to solution in higher pH. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Petroleum hydrocarbon concentrations in eight mollusc species along Tamilnadu coast, Bay of Bengal, India.

    Science.gov (United States)

    Veerasingam, S; Venkatachalapathy, R; Sudhakar, S; Raja, P; Rajeswari, V

    2011-01-01

    Eight mollusc species and sediment samples collected from three different stations along Tamilnadu coast, Bay of Bengal, India were analysed for the levels of petroleum hydrocarbons to elucidate the status of the petroleum residues in mollusc meant for human consumption. The concentrations of petroleum hydrocarbons in sediments along Tamilnadu coast varied from 5.04-25.5 microg/g dw (dry weight). High concentration of petroleum hydrocarbons in the sediment of Uppanar estuary (25.5 +/- 1.45 microg/g dw) was perhaps land and marine based anthropogenic sources of this region. The petroleum hydrocarbon residues in eight mollusc species collected from Uppanar, Vellar and Coleroon estuaries varied between 2.44-6.04 microg/g ww (wet weight). Although the concentration of petroleum hydrocarbons in sediment of the Uppanar region was markedly higher than the background, the petroleum hydrocarbon residues in mollusc collected from Uppanar estuary did not suggest bioaccumulation. The results signified that industrial growth has affected the aquatic environments and regular monitoring will help to adopt stringent pollution control measures for better management of the aquatic region.

  12. Diet and trophic organization of the fish assemblage from the Mamanguape River Estuary, Brazil

    OpenAIRE

    Medeiros, Aline Paiva Morais de; Xavier, Josias Henrique de Amorim; Rosa, Ierecê Maria de Lucena

    2017-01-01

    ABSTRACT The present work aims to characterize a fish assemblage from a northeastern Brazilian estuary according to its diet and trophic organization along the estuarine-reef gradient. Sampling was performed at the Mamanguape Estuary, and fishes were collected using three types of nets at seventeen sites, grouped into four regions according to salinity range: reefs and the lower, middle, and upper estuary. The most abundant species were Atherinella brasiliensis, Mugil curema, and Sphoeroides ...

  13. Linking behavior, physiology, and survival of Atlantic Salmon smolts during estuary migration

    Science.gov (United States)

    Stich, Daniel S.; Zydlewski, Gayle B.; Kocik, John F.; Zydlewski, Joseph D.

    2015-01-01

    Decreased marine survival is identified as a component driver of continued declines of Atlantic Salmon Salmo salar. However, estimates of marine mortality often incorporate loss incurred during estuary migration that may be mechanistically distinct from factors affecting marine mortality. We examined movements and survival of 941 smolts (141 wild and 800 hatchery-reared fish) released in freshwater during passage through the Penobscot River estuary, Maine, from 2005 to 2013. We related trends in estuary arrival date, movement rate, and survival to fish characteristics, migratory history, and environmental conditions in the estuary. Fish that experienced the warmest thermal history arrived in the estuary 8 d earlier than those experiencing the coolest thermal history during development. Estuary arrival date was 10 d later for fish experiencing high flow than for fish experiencing low flow. Fish released furthest upstream arrived in the estuary 3 d later than those stocked further downstream but moved 0.5 km/h faster through the estuary. Temporally, movement rate and survival in the estuary both peaked in mid-May. Spatially, movement rate and survival both decreased from freshwater to the ocean. Wild smolts arrived in the estuary later than hatchery fish, but we observed no change in movement rate or survival attributable to rearing history. Fish with the highest gill Na+, K+-ATPase activity incurred 25% lower mortality through the estuary than fish with the lowest gill Na+, K+-ATPase activity. Smolt survival decreased (by up to 40%) with the increasing number of dams passed (ranging from two to nine) during freshwater migration. These results underscore the importance of physiological preparedness on performance and the delayed, indirect effects of dams on survival of Atlantic Salmon smolts during estuary migration, ultimately affecting marine survival estimates.

  14. The Coastal Dynamics of Heterogeneous Sedimentary Environments: Numerical Modeling of Hydrodynamics and Mass Transport in Estuaries

    Science.gov (United States)

    2010-08-12

    Medina, et al. (2006). "The Prestige oil spill in Cantabria (Bay of Biscay). Part I: Operational forecasting system for quick response, risk assessment...estuaries (Kostoglidis, Pattiaratchi et al. 2005), macrotidal estuaries (Yang, Eisma et al. 2000), and estuaries with fringing mangrove swamps...the Atchafalaya Bay system (Cobb, Keen et al. 2008), and Patos Lagoon, Brazil . The model current fields used in the Papua New Guinea study (Keen, Ko

  15. Salt Plug Formation Caused by Decreased River Discharge in a Multi-channel Estuary

    OpenAIRE

    Shaha, Dinesh Chandra; Cho, Yang-Ki

    2016-01-01

    Freshwater input to estuaries may be greatly altered by the river barrages required to meet human needs for drinking water and irrigation and prevent salt water intrusion. Prior studies have examined the salt plugs associated with evaporation and salt outwelling from tidal salt flats in single-channel estuaries. In this work, we discovered a new type of salt plug formation in the multi-channel Pasur River Estuary (PRE) caused by decreasing river discharges resulting from an upstream barrage. ...

  16. The Caloosahatchee River Estuary: a monitoring partnership between Federal, State, and local governments, 2007-13

    Science.gov (United States)

    Patino, Eduardo

    2014-01-01

    The tidal Caloosahatchee River and downstream estuaries have substantial environmental, recreational, and economic value for southwest Florida residents and visitors. Modifications to the Caloosahatchee River watershed have altered the predevelopment hydrology, thereby threatening the environmental health of estuaries in the area. Hydrologic monitoring of the freshwater contributions from tributaries to the tidal Caloosahatchee River and its estuaries is necessary to adequately describe the total freshwater inflow and constituent loads to the delicate estuarine system.

  17. Multibiomarker assessment of three Brazilian estuaries using oysters as bioindicators

    International Nuclear Information System (INIS)

    Valdez Domingos, F.X.; Azevedo, M.; Silva, M.D.; Randi, M.A.F.; Freire, C.A.; Silva de Assis, H.C.; Oliveira Ribeiro, C.A.

    2007-01-01

    Oysters have been largely employed as bioindicators of environmental quality in biomonitoring studies. Crassostrea rhizophorae was selected to evaluate the health status of three estuarine areas impacted by anthropogenic activities along the Brazilian coast, in three estuarine complexes, ranging in latitude from 7 to 25 deg. S. In each estuary three sites were sampled in Winter and in Summer: a site considered as reference, and two sites next to contamination sources. Condition index was similar at all sites and estuaries, with the highest values found for Itamaraca oysters in Summer. Necrosis, hyperplasia, mucocyte hypertrophy and fusion of ordinary filaments were the main histopathological lesions observed. Muscle cholinesterase activity was overall similar, but with a strong seasonal effect. Inhibition or activation of branchial total ATPase and Na,K-ATPase activities at the contaminated sites was observed. The health status of these estuarine areas is quite similar, and the combined use of biomarkers is recommended

  18. Thermal impact assessment of multi power plant operations on estuaries

    International Nuclear Information System (INIS)

    Eraslan, A.H.; Kim, K.H.; Harris, J.L.

    1977-01-01

    The assessment of the thermal impact of multi power plant operations on large estuaries requires careful consideration of the problems associated with: re-entrainment, re-circulation, thermal interaction, delay in the attainment of thermal equilibrium state, and uncertainty in specifying open boundaries and open boundary conditions of the regions, which are critically important in the analysis of the thermal conditions in receiving water bodies with tidal dominated, periodically reversing flow conditions. The results of an extensive study in the Hudson River at Indian Point, 42 miles upstream of the ocean end at the Battery, concluded that the tidal-transient, multi-dimensional discrete-element (UTA) thermal transport models (ESTONE, FLOTWO, TMPTWO computer codes) and the near-field far-field zone-matching methodology can be employed with a high degree of reliability in the assessment of the thermal impact of multi power plant operations on tidal dominated estuaries

  19. Desorption of Ba and 226Ra from river-borne sediments in the Hudson estuary

    International Nuclear Information System (INIS)

    Li, Y.-H.

    1979-01-01

    The pronounced desorption of Ba and 226 Ra from river-borne sediments in the Hudson estuary can be explained quantitatively by the drastic decrease in the distribution coefficients of both elements from a fresh to a salty water medium. The desorption in estuaries can augment, at least, the total global river fluxes of dissolved Ba and 226 Ra by one and nine times, respectively. The desorption flux of 226 Ra from estuaries accounts for 17-43% of the total 226 Ra flux from coastal sediments. Two mass balance models depicting mixing and adsorption-desorption processes in estuaries are discussed. (Auth.)

  20. India's nuclear spin-off

    International Nuclear Information System (INIS)

    Kaul, Ravi.

    1974-01-01

    After examining world-wide reactions of the foreign governments and news media to the India's peaceful nuclear experiment (PNE) in the Rajasthan Desert on 18 May 1974, development of nuclear technology in India is assessed and its economic advantages are described. Implications of the Non-Proliferation Treaty are explained. Psychological impact of India's PNE on India's neighbours and superpowers and associated political problems in context of proliferation of nuclear weapons are discussed in detail. (M.G.B.)

  1. Technical vocational education in India

    OpenAIRE

    溝上, 智恵子

    1999-01-01

    In India, several efforts have been made for the development of skilled manpower during the last twenty years since the launch of formal technical vocational education at school. A huge education infrastructure has developed in India. However, 45~50 percent of the population of India is still illiterate. To solve the mismatch between education and employment, a revolution in education is really needed. Additionally, there is a need for a system of National Vocational Qualifications in India a...

  2. Fiscal Discipline in India

    Directory of Open Access Journals (Sweden)

    Sanhita SUCHARITA

    2011-07-01

    Full Text Available The present study broadly attempts to analyze the role of Fiscal Responsibility and Budget Management Act in restoring fiscal balance in India. It analyses the need for fiscal rules and constraints in India. The study aims at finding out the major factor behind rising fiscal imbalance in India and to examine whether there is an electoral motive towards high fiscal deficit to GDP ratio or not. It also analyzes the effectiveness of various measures undertaken at the central and state level to inculcate fiscal discipline in the fiscal management. The study also makes an attempt to do a critical in depth reviews of the Fiscal Responsibility and Budget Management Act and make an attempt at examining effectiveness and suitability of FRBM Act through a quantitative analysis. It also makes an attempt to suggest improvements in the fiscal monitoring mechanism in India. We employ Ordinary Least Square (OLS method to examine the impact of Fiscal Responsibility and Budget Management Act on fiscal deficit in India using the data for the period 1980-81 to 2008-09. The regression results indicates that FRBM Act does not have a significant effect on the Gross Fiscal Deficit (GFD to GDP ratio where as GDP (at factor cost growth rate has a significant negative effect on the GFD to GDP ratio.

  3. Venereology in India

    Directory of Open Access Journals (Sweden)

    Devinder Mohan Thappa

    2011-01-01

    Full Text Available Venereology-the study of venereal diseases or more recently, the sexually transmitted infections (STI includes a variety of pathogens namely viruses, bacteria, fungi and protozoa for which the common factor is the mode of transmission and acquisition: Sexual relations between human beings. Medical and other historians have often suggested that well-known diseases such as syphilis, gonorrhea, chancroid and lymphogranuloma venereum have existed since earliest times. However, it is difficult to identify modern disease entities based on written historical record. Studying the origin of STIs helps us to learn the political, economic and moral conditions that led to the disease. Effective management of STI rests on three pillars of diagnosis, prevention and treatment. For most of past 50 years in India, the diagnostic pillar has been the least well-supported. Until well into present century, diagnosis of STI in India was clinical. Treatment of STIs in India followed the methods used in England. Of course in the 19th century, in many parts of the world, only a few had access to modern methods of treatment; in India, there was extensive use of Ayurvedic treatment with traditional medicines. This article thus gives just an overview and evolution of venereology in India with regard to venereal diseases (now more often known as STIs/disease, control measures, academic, association and journal development and finally future perspective.

  4. Water Quality Drivers in 11 Gulf of Mexico Estuaries

    OpenAIRE

    Matthew J. McCarthy; Daniel B. Otis; Pablo Méndez-Lázaro; Frank E. Muller-Karger

    2018-01-01

    Coastal water-quality is both a primary driver and also a consequence of coastal ecosystem health. Turbidity, a measure of dissolved and particulate water-quality matter, is a proxy for water quality, and varies on daily to interannual periods. Turbidity is influenced by a variety of factors, including algal particles, colored dissolved organic matter, and suspended sediments. Identifying which factors drive trends and extreme events in turbidity in an estuary helps environmental managers and...

  5. The recreational value of river inflows into South African estuaries ...

    African Journals Online (AJOL)

    For the 37 estimates deemed reliable (but not necessarily valid), the average of the predicted median values of river inflow into estuaries was calculated to be 3.4 c/m3 (South African cents, ZAR) and standard deviation 3.84 c/m3. The average of the predicted mean values was calculated to be 7.4 c/m3 and the standard ...

  6. Effects of Prevailing Winds on Turbidity of a Shallow Estuary

    OpenAIRE

    Cho, Hyun Jung

    2007-01-01

    Estuarine waters are generally more turbid than lakes or marine waters due to greater algal mass and continual re-suspension of sediments. The varying effects of diurnal and seasonal prevailing winds on the turbidity condition of a wind-dominated estuary were investigated by spatial and statistical analyses of wind direction, water level, turbidity, chlorophyll a, and PAR (Photosynthetically Active Radiation) collected in Lake Pontchartrain, Louisiana, USA. The prolonged prevailing winds were...

  7. Phosphorus fractionation distribution in Guapimirim estuary: SE Brazil.

    Science.gov (United States)

    Vicente, Michel Arthur Faria; de Melo, Gustavo Vaz; Baptista Neto, José Antonio; de Oliveira, Allan Sandes

    2016-01-01

    The Guapimirim estuary is the main tributary of Guanabara bay and is located in the northeast portion. Although it is protected, this estuary has been experiencing strong anthropogenic pressure, which has led to changes in the natural characteristics. Large amounts of sewage are dumped into the bay through tributaries, thereby changing the water and bottom sediment quality. One of the main elements of sewage is phosphorus. Despite its importance to life, a high concentration of this nutrient in the environment can result in eutrophication. This work describes the phosphorus distribution in its different fractions in the bottom sediment at 16 stations located in the main channel of the Guapimirim estuary. These results are correlated with data on grain size, organic matter and calcium carbonate content in the bottom sediment and with physicochemical parameters of the bottom water. The grain size decreases toward the mouth of the estuary, whereas the organic matter and carbonate content increase. The salinity increases significantly at 3.5 km upstream from the mouth, where there is also a notable increase in fine sediments; the same site is the mean position of the salinity front. The temperature and pH increase in the same direction. The Pinorg-total ranges between 3.18 and 7.13 µmol g(-1), increasing toward the mouth. The same trend is observed for the other phosphorus fractions P-Ca, P-Fe and P-f.a., which range from 0.68 to 1.91, 0.79 to 1.71 and 0.03 to 0.93 µmol g(-1), respectively. The P-Ca and P-Fe fractions are the most representative in the Pinorg-total, occurring at 26.3 and 26.0 %, respectively.

  8. Hydrographic and chemical observations in the Sierra Leone River estuary

    International Nuclear Information System (INIS)

    Koske, P.H.; Weiler, K.

    1979-01-01

    Hydrographic and chemical observations in the Sierra Leone River estuary are reported, a West-African river in the tropics. Because of the typical change between rainy season in the sommer months and dry season in winter time the research work has been adapted to these semi-annual changes. The collected data and results are given and discussed under this aspect of the seasonal fluctuations. (orig.) [de

  9. Suspended matter and heavy metal content of the Elbe Estuary

    International Nuclear Information System (INIS)

    Vollbrecht, K.

    1980-01-01

    (1) In the River Elbe estuary there is a turbidity zone which is closely bound to the region of brackish waters. Its suspended matter content changes strongly with the tidal rhythm. Suspended matter and river bed sediments influence each other by exchanging their particles. Owing to that mechanism, the heavy metal ions bound or taken up by the suspended matter (sorption) enter the sediments. To obtain an estimation of the estuary's ability to cope with ( self purify ) a strong burden of industrial wastes, it is neccessary to take into consideration the absorbing capacity of both the mean suspension load and the sediments. (2) The concentration of nearly all heavy metal ions investigated in the suspension load decreases remarkably at the very beginning of the turbid zone already, in the Hamburg region. It indicates that the binding process are going on very rapidly and that the metal ion absorbing capacity of the Elbe estuary still requires only the first few miles of this self purification system. The results gained indicate that the suspended matter in Hamburg waters could bind or take up more heavy metal ions than are discharged into this area. (3) The concentration of most ions bound to the suspension material correlates very well with the grain size distribution of the (anorganic) particles. The concentration values decrease along the estuary and lead to a continuous transition to the values of the open sea. Cu, Ni and Cd appear to be captured preferably by organic suspended matter. This behaviour, however, is solely restricted to the turbid zone. In the open sea, after oxidation of the binding organic material, Cu and Ni correspond to the anorganic grain size distribution. (orig./HP) [de

  10. Trace elements distribution in bottom sediments from Amazon River estuary

    International Nuclear Information System (INIS)

    Lara, L.B.L.S.; Nadai Fernandes, E. de; Oliveira, H. de; Bacchi, M.A.

    1994-01-01

    The Amazon River discharges into a dynamic marine environment where there have been many interactive processes affecting dissolved and particulate solids, either those settling on the shelf or reaching the ocean. Trace elemental concentration, especially of the rare earth elements, have been determined by neutron activation analysis in sixty bottom sediment samples of the Amazon River estuary, providing information for the spatial and temporal variation study of those elements. (author). 16 refs, 6 figs, 3 tabs

  11. The physico-chemical characteristics of Imo River Estuary in ...

    African Journals Online (AJOL)

    Sampling was done monthly at fishing grounds in the estuary designated upper, middle and lower course, respectively. Mean water temperature was 26.2°C; transparency, 58.66cm and salinity, 12.66‰. Total dissolved solids, total suspended solids, and total solids had means of 7.91mg/l, 11.91 and 19.82mg/l, respectively.

  12. Characteristics of Wind Generated Waves in the Delaware Estuary

    Science.gov (United States)

    Chen, J. L.; Ralston, D. K.; Geyer, W. R.; Chant, R. J.; Sommerfield, C. K.

    2016-02-01

    Coastal marshes provide important services for human uses such as fishery industry, recreation, ports and marine operations. Bombay Hook Wildlife Refuge, located along the western shore of the Delaware Estuary, has experienced substantial loss of salt marsh in recent decades. To evaluate the importance of different mechanisms which cause observed shoreline retreat, wave gauges were deployed along the dredged navigation channel and shoreline in the Delaware Estuary. A coupled wave and circulation modeling system (SWAN/ROMS) based on the most recent bathymetry (last updated 2013) is validated with waves observed during both calm and energetic conditions in November 2015. Simulation results based on different model parameterizations of whitecapping, bottom friction and the wind input source are compared. The tendency of observed wave steepness is more similar to a revised whitecapping source term [Westhuysen, 2007] than the default in SWAN model. Both model results and field data show that the generation/dissipation of waves in the Delaware estuary is determined by the local wind speed and channel depth. Whitecapping-induced energy dissipation is dominant in the channel, while dissipation due to bottom friction and depth-induced breaking become important on lateral shoals. To characterize the effects of wind fetch on waves in estuaries more generally, simulations with an idealized domain and varying wind conditions are compared and the results are expressed in terms of non-dimensional parameters. The simulations based on a 10m-depth uniform idealized channel show that the dissipation of waves is mainly controlled by whitecapping in all wind conditions. Under strong wind conditions (wind speed >10m/s) the effect of bottom friction becomes important so the simulated wave heights are no longer linearly correlated with wind speed.

  13. Renewable Energy Education in India

    Science.gov (United States)

    Bajpai, Shrish; Kidwai, Naimur Rahman

    2017-01-01

    The issue of renewable energy sources that have great potential to give solutions to the longstanding energy problems of India has been considered. It has been stated that renewable energy sources are an important part of India's plan to increase energy security and provide new generation with ample job opportunities. India's plans to move towards…

  14. Large wood in the Snowy River estuary, Australia

    Science.gov (United States)

    Hinwood, Jon B.; McLean, Errol J.

    2017-02-01

    In this paper we report on 8 years of data collection and interpretation of large wood in the Snowy River estuary in southeastern Australia, providing quantitative data on the amount, sources, transport, decay, and geomorphic actions. No prior census data for an estuary is known to the authors despite their environmental and economic importance and the significant differences between a fluvial channel and an estuarine channel. Southeastern Australian estuaries contain a significant quantity of large wood that is derived from many sources, including river flood flows, local bank erosion, and anthropogenic sources. Wind and tide are shown to be as important as river flow in transporting and stranding large wood. Tidal action facilitates trapping of large wood on intertidal bars and shoals; but channels are wider and generally deeper, so log jams are less likely than in rivers. Estuarine large wood contributes to localised scour and accretion and hence to the modification of estuarine habitat, but in the study area it did not have large-scale impacts on the hydraulic gradients nor the geomorphology.

  15. Major hydrogeochemical processes in an Acid Mine Drainage affected estuary

    International Nuclear Information System (INIS)

    Asta, Maria P.; Calleja, Maria Ll.; Pérez-López, Rafael; Auqué, Luis F.

    2015-01-01

    Highlights: • Mixing of acid riverine water with alkaline seawater was studied in an estuary. • Combination of data and geochemical tools allowed modeling the water mixing. • The main geochemical processes were identified and for the first time quantified. • Water chemistry is the result of mixing, dissolution-precipitation and sorption. • Main reactions: gypsum and calcite dissolution and Al and Fe solids precipitation. - Abstract: This study provides geochemical data with the aim of identifying and quantifying the main processes occurring in an Acid Mine Drainage (AMD) affected estuary. With that purpose, water samples of the Huelva estuary were collected during a tidal half-cycle and ion–ion plots and geochemical modeling were performed to obtain a general conceptual model. Modeling results indicated that the main processes responsible for the hydrochemical evolution of the waters are: (i) the mixing of acid fluvial water with alkaline ocean water; (ii) precipitation of Fe oxyhydroxysulfates (schwertmannite) and hydroxides (ferrihydrite); (iii) precipitation of Al hydroxysulfates (jurbanite) and hydroxides (amorphous Al(OH) 3 ); (iv) dissolution of calcite; and (v) dissolution of gypsum. All these processes, thermodynamically feasible in the light of their calculated saturation states, were quantified by mass-balance calculations and validated by reaction-path calculations. In addition, sorption processes were deduced by the non-conservative behavior of some elements (e.g., Cu and Zn)

  16. Parameterization of mixing by secondary circulation in estuaries

    Science.gov (United States)

    Basdurak, N. B.; Huguenard, K. D.; Valle-Levinson, A.; Li, M.; Chant, R. J.

    2017-07-01

    Eddy viscosity parameterizations that depend on a gradient Richardson number Ri have been most pertinent to the open ocean. Parameterizations applicable to stratified coastal regions typically require implementation of a numerical model. Two novel parameterizations of the vertical eddy viscosity, based on Ri, are proposed here for coastal waters. One turbulence closure considers temporal changes in stratification and bottom stress and is coined the "regular fit." The alternative approach, named the "lateral fit," incorporates variability of lateral flows that are prevalent in estuaries. The two turbulence parameterization schemes are tested using data from a Self-Contained Autonomous Microstructure Profiler (SCAMP) and an Acoustic Doppler Current Profiler (ADCP) collected in the James River Estuary. The "regular fit" compares favorably to SCAMP-derived vertical eddy viscosity values but only at relatively small values of gradient Ri. On the other hand, the "lateral fit" succeeds at describing the lateral variability of eddy viscosity over a wide range of Ri. The modifications proposed to Ri-dependent eddy viscosity parameterizations allow applicability to stratified coastal regions, particularly in wide estuaries, without requiring implementation of a numerical model.

  17. Is India the Exception?

    DEFF Research Database (Denmark)

    Nielsen, Klaus; Storm, Rasmus K.

    India is still the extreme under-achiever in international sport competitions. Whereas in China high growth rates have been accompanied by a huge improvement in its ranking in international sport events a similar impact of extraordinary growth rates is seemingly totally absent in the case of India....... Is India an exception? Several econometric studies have shown that income per capita is a significant variable explaining elite sport results such as results in the Olympic Games. From this stylized fact follows the hypothesis that 'above/below average' growth rates lead to relative improvements...... between growth in GNP per capita and growth in medal points (no. 1: five points, no. 2: three points, no.3: two points) in Olympic Summer Games. The findings show no correlation and in a few calculations a very weak correlation. Among the countries behaving in accordance with the hypothesis in the most...

  18. Nuclear power in India

    International Nuclear Information System (INIS)

    Bose, D.K.

    1980-01-01

    India has now nine years of experience with her in nuclear power generation. The system has been acclaimed on various grounds by the authority concerned with its organization in the country. The present paper intends to examine critically the claim for economic superiority of the nuclear power over the thermal power which is asserted often by the spokesmen for the former. Information about the cost of nuclear power that is available to researchers in India is very meagre. Whatever appears in official publications is hardly adequate for working out reasonable estimates for scrutiny. One is therefore left to depend on the public statements made by dignitaries from time to time to form an idea about the economics of nuclear power. Due to gaps in information we are constrained to rely on the foreign literature and make careful guesses about possible costs applicable to India

  19. Ecosystem degradation in India

    International Nuclear Information System (INIS)

    Sinha, B.N.

    1990-01-01

    Environmental and ecosystem studies have assumed greater relevance in the last decade of the twentieth century than even before. The urban settlements are becoming over-crowded and industries are increasingly polluting the air, water and sound in our larger metropolises. Degradation of different types of ecosystem are discussed in this book, Ecosystem Degradation in India. The book has been divided into seven chapters: Introduction, Coastal and Delta Ecosystem, River Basin Ecosystem, Mountain Ecosystem, Forest Ecosystem, Urban Ecosystem and the last chapter deals with the Environmental Problems and Planning. In the introduction the environmental and ecosystem degradation problems in India is highlighted as a whole while in other chapters mostly case studies by experts who know their respective terrain very intimately are included. The case study papers cover most part of India and deal with local problems, stretching from east coast to west coast and from Kashmir to Kanyakumari. (author)

  20. Evolution of mid-Atlantic coastal and back-barrier estuary environments in response to a hurricane: Implications for barrier-estuary connectivity

    Science.gov (United States)

    Miselis, Jennifer L.; Andrews, Brian D.; Nicholson, Robert S.; Defne, Zafer; Ganju, Neil K.; Navoy, Anthony S.

    2016-01-01

    Assessments of coupled barrier island-estuary storm response are rare. Hurricane Sandy made landfall during an investigation in Barnegat Bay-Little Egg Harbor estuary that included water quality monitoring, geomorphologic characterization, and numerical modeling; this provided an opportunity to characterize the storm response of the barrier island-estuary system. Barrier island morphologic response was characterized by significant changes in shoreline position, dune elevation, and beach volume; morphologic changes within the estuary were less dramatic with a net gain of only 200,000 m3 of sediment. When observed, estuarine deposition was adjacent to the back-barrier shoreline or collocated with maximum estuary depths. Estuarine sedimentologic changes correlated well with bed shear stresses derived from numerically simulated storm conditions, suggesting that change is linked to winnowing from elevated storm-related wave-current interactions rather than deposition. Rapid storm-related changes in estuarine water level, turbidity, and salinity were coincident with minima in island and estuarine widths, which may have influenced the location of two barrier island breaches. Barrier-estuary connectivity, or the transport of sediment from barrier island to estuary, was influenced by barrier island land use and width. Coupled assessments like this one provide critical information about storm-related coastal and estuarine sediment transport that may not be evident from investigations that consider only one component of the coastal system.

  1. From Hair in India to Hair India.

    Science.gov (United States)

    Trüeb, Ralph M

    2017-01-01

    In all cultures, human hair and hairdo have been a powerful metaphor. Tracing back the importance and significance of human hair to the dawn of civilization on the Indian subcontinent, we find that all the Vedic gods are depicted as having uncut hair in mythological stories as well as in legendary pictures. The same is true of the Hindu avatars, and the epic heroes of the Ramayana, and the Mahabharata. Finally, there are a number of hair peculiarities in India pertinent to the creed and religious practices of the Hindu, the Jain, and the Sikh. Shiva Nataraja is a depiction of the Hindu God Shiva as the cosmic dancer who performs his divine dance as creator, preserver, and destroyer of the universe and conveys the Indian conception of the never-ending cycle of time. The same principle manifests in the hair cycle, in which perpetual cycles of growth, regression, and resting underly the growth and shedding of hair. Finally, The Hair Research Society of India was founded as a nonprofit organisation dedicated to research and education in the science of hair. Notably, the HRSI reached milestones in the journey of academic pursuit with the launch of the International Journal of Trichology, and with the establishment of the Hair India conference. Ultimately, the society aims at saving the public from being taken for a ride by quackery, and at creating the awareness that the science of hair represents a subspecialty of Dermatology. In analogy again, the dwarf on which the Nataraja dances represents the demon of egotism, and thus symbolizes Shiva's, respectively, the HRSI's victory over ignorance.

  2. Is India the Exception?

    DEFF Research Database (Denmark)

    Nielsen, Klaus; Storm, Rasmus K.

    2013-01-01

    in international sport events a similar impact of extraordinary growth rates has been almost totally absent in the case of India. Is India an exception? Several econometric studies have shown that income per capita is a significant variable explaining elite sport results such as results in the Olympic Games. From...... in the sports of the Olympic Summer Games. The findings show only a very weak correlation, if any at all. However, a detailed analysis of country evidence shows interesting trends and details. The paper concludes with tentative explanations for the findings including the contradictory country evidence....

  3. PV opportunities in India

    Science.gov (United States)

    Stone, Jack L.; Ullal, Harin S.

    1996-01-01

    The growing middle class in India, coupled with a need for electricity to provide basic services to the masses, provides an opportunity to deploy photovoltaic systems in cost-effective applications ranging from grid-connected to isolated location requirements. This need is being satisfied by aggressive government programs, the availability of funds from agencies such as the World Bank, and the desire of Indian industries to form joint ventures for in-country manufacturing. The relaxed restrictions on doing business in India makes today's opportunities timely indeed.

  4. Energies in India

    International Nuclear Information System (INIS)

    Gama, Michel

    2013-01-01

    Based on information gathered during a mission in India, and also from reports and local newspapers and magazines, the author gives an overview of the energy issue in India: population, energy consumption, greenhouse gas emissions, electricity consumption, economic activities and life conditions, biomass production, potential for solar energy production, hydraulic energy production and operators, situation regarding coal, oil and natural gas as primary energies, situation of the nuclear industry and sector (international agreements and cooperation, reactor fleet, research centres). A table indicates the level and percentage of the different produced and imported consumed primary and final energies

  5. India's African Engagement

    DEFF Research Database (Denmark)

    Kragelund, Peter

    was addressed. This kicked off a quest among donor agencies, think tanks and researchers alike to identify and establish the doings of these ‘emerging’ donors. To date, however, China has received most attention while the doings of other donors like India, Brazil and South Africa have remained virtually......The exceptionally fast growth of big economies like China and India has resulted in a new-found interest in the economic and political consequences of this growth for the developed economies. Recently, traditional donors’ concern that ‘emerging’ donors were re-emerging on the development scene...

  6. Urology in ancient India

    Directory of Open Access Journals (Sweden)

    Sakti Das

    2007-01-01

    Full Text Available The practice of medical and surgical measures in the management of urological ailments prevailed in ancient India from the Vedic era around 3000 BC. Subsequently in the Samhita period, the two stalwarts - Charaka in medicine and Susruta in surgery elevated the art of medicine in India to unprecedented heights. Their elaboration of the etiopathological hypothesis and the medical and surgical treatments of various urological disorders of unparalleled ingenuity still remain valid to some extent in our contemporary understanding. The new generation of accomplished Indian urologists should humbly venerate the legacy of the illustrious pioneers in urology of our motherland.

  7. India's energy needs

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, N. B.

    1980-03-15

    Only a small portion (15%) of India's commerical energy requirements is imported, but this import accounts for nearly 75% of total imports. Noncommercial energy (firewood, agricultural waste, cow dung) will still have an important role in the future. The major thrust of India's energy policy should be to ensure that energy will not be a constraint to economic growth, and to increase the per capita energy consumption. In the future, hydroelectric and nuclear power will become increasingly important. Solar energy will also be utilized. (DLC)

  8. Variation in tidal wetland plant diversity and composition within and among coastal estuaries: assessing the relative importance of environmental gradients

    Science.gov (United States)

    Question: Does wetland plant composition vary more by estuarine type (differentiated by the degree of riverine versus oceanic influence) or habitat type within estuaries (defined by US National Wetlands Inventory [NWI] marsh classes)? Location: Oregon estuaries: Netarts Bay, ...

  9. Size Matters: The Contribution of Mega-Infauna to the Food Webs and Ecosystem Services of an Oregon Estuary

    Science.gov (United States)

    Large-bodied, invertebrates are common to infaunal communities of NE Pacific estuaries (e.g., bivalves, polychaetes, burrowing shrimps), but their contribution to the ecological structure, function and ecosystem services of most estuaries has been poorly characterized because the...

  10. Estuaries of the northeastern United States: Habitat and land use signatures

    Science.gov (United States)

    Roman, C.T.; Jaworski, N.; Short, F.T.; Findlay, S.; Warren, R.S.

    2000-01-01

    Geographic signatures are physical, chemical, biotic, and human-induced characteristics or processes that help define similar or unique features of estuaries along latitudinal or geographic gradients. Geomorphologically, estuaries of the northeastern U.S., from the Hudson River estuary and northward along the Gulf of Maine shoreline, are highly diverse because of a complex bedrock geology and glacial history. Back-barrier estuaries and lagoons occur within the northeast region, but the dominant type is the drowned-river valley, often with rocky shores. Tidal range and mean depth of northeast estuaries are generally greater when compared to estuaries of the more southern U.S. Atlantic coast and Gulf of Mexico. Because of small estuarine drainage basins, low riverine flows, a bedrock substrate, and dense forest cover, sediment loads in northeast estuaries are generally quite low and water clarity is high. Tidal marshes, seagrass meadows, intertidal mudflats, and rocky shores represent major habitat types that fringe northeast estuaries, supporting commercially-important fauna, forage nekton and benthos, and coastal bird communities, while also serving as links between deeper estuarine waters and habitats through detritus-based pathways. Regarding land use and water quality trends, portions of the northeast have a history of over a century of intense urbanization as reflected in increased total nitrogen and total phosphorus loadings to estuaries, with wastewater treatment facilities and atmospheric deposition being major sources. Agricultural inputs are relatively minor throughout the northeast, with relative importance increasing for coastal plain estuaries. Identifying geographic signatures provides an objective means for comparing the structure function, and processes of estuaries along latitudinal gradients.

  11. Hydrobiological characteristics of Shark River estuary, Everglades National Park, Florida

    Science.gov (United States)

    McPherson, B.F.

    1970-01-01

    Water quality in the Shark River estuary was strongly influenced by seasonal patterns of rainfall, water level and temperature. During the rainy season (summer and early fall) the salinity in the 20-mile long estuary ranged from that of fresh water to half that of sea water while concentrations of dissolved oxygen were low, 2-5 milligrams per liter (mg/l) presumably because, among other factors, microbial activity and respiration were accelerated by high temperatures (30-33 degrees C). During the dry season (late fall through spring) the salinity ranged from 18 grams per liter (g/l) in the headwaters to 36 g/l at the Gulf during a dry year such as 1967 and from 1 to 25 g/l during a wet year such as 1969. Concentrations of dissolved oxygen increased from 2-3 mg/l in the summer of 1967 to 4-7 mg/l in the winter of 1968, and temperature decreased from an average of about 30 degrees C in summer to 20 degrees C in winter. Water level declined 5 to 10 decimeters in the headwaters during the dry season, and salinity and tidal action increased. Large amounts of submerged vegetation died in some headwater creeks at the end of the dry season, presumably killed by salinities above 3 g/l. The decaying organic matter and the decrease in photosynthesis resulted in low dissolved oxygen (1-2 mg/l). Fish died at this time probably as a result of the low dissolved oxygen. Trace elements, heavy metals and insecticides occurred in the waters of the estuary in concentrations below those indicated as harmful for aquatic life by current standards established by the Federal Water Pollution Control Administration (1968). The insecticides detected were concentrated in sediment and in various organisms. The patterns of distribution of planktonic and small nektonic animals in the estuary were related to salinity. Copepods (Arcatia tonsa, Labidocera aestiva, Pseudodiaptomus coronatus), cumaceans (Cyclaspis sp.), chaetognaths (Sagitta hispida), bay anchovies (Anchoa mitchilli), and scaled

  12. The dynamics of a frictionally-dominated Amazonian estuary

    Directory of Open Access Journals (Sweden)

    Nils Edvin Asp

    2012-09-01

    Full Text Available The hydrodynamics, morphology and sedimentology of the Taperaçu estuary were investigated. This is one of several estuaries located within the largest mangrove fringe in the world, bordering the Amazon region, subject to a macrotidal regime and regionally atypical negligible fresh water supply. The results reveal widespread sand banks that occupy the central portion of the estuarine cross-section. Well-sorted very fine sandy sediments of marine origin prevail. Shorter flood phases, with substantially higher current velocities, were observed in the upper sector of Taperaçu, as expected for a shallow, friction-dominated estuary. However, ebb domination can be expected for estuaries with large associated mangrove areas and substantial estuarine infilling, both of which situations occur on the Taperaçu. The tidal asymmetry favoring flood currents could be the result of the absence of an effective fluvial discharge. Furthermore, it was observed that the Taperaçu is connected by tidal creeks to the neighboring Caeté estuary, allowing a stronger flux during the flood and intensifying the higher flood currents. As a whole, the results have shown a complex interaction of morphological aspects (friction, fluvial drainage, connections with neighbor estuaries, infilling and large storage area in determining hydrodynamic patterns, thus improving the understanding of Amazon estuaries.A hidrodinâmica, morfologia e sedimentologia do estuário do Taperaçu foram investigadas. Este é um entre vários estuários do litoral amazônico que integram a maior extensão contínua de manguezais do mundo, apresentando uma descarga de água doce muito reduzida, atípica para a região. Os resultados revelam grandes bancos arenosos que ocupam em grande parte a porção central do estuário. Areias muito finas e bem selecionadas de origem marinha prevalecem. Fases de enchente mais curtas, com velocidades de corrente substancialmente mais altas, são observadas na por

  13. of Manipur, India

    Indian Academy of Sciences (India)

    This is the first record of perissodactyl footprints from the Lower Oligocene of India and the first evidence of mammals in the. Barail Group of the age. Remarkable is the occurrence in a marginal marine setting, whereas other known perissodactyl footprints from the Eocene–Oligocene in particular from North America, Europe.

  14. Reisverslag India 2009

    NARCIS (Netherlands)

    Velthuijsen, Hugo

    2009-01-01

    Verslag van een bezoek in mei 2009 aan India als onderdeel van een delegatie van KPN. In een week werden bezoeken gebracht aan 7 IT leveranciers van KPN, 3 universiteiten en waren er gesprekken met diverse andere partijen. Daarbij zijn de steden Mumbai, Pune, Bangalore en Chennai aangedaan. Dit

  15. Healthcare biotechnology in India.

    Science.gov (United States)

    Srivastava, L M

    2005-01-01

    Biotechnology in India has made great progress in the development of infrastructure, manpower, research and development and manufacturing of biological reagents, biodiagnostics, biotherapeutics, therapeutic and, prophylactic vaccines and biodevices. Many of these indigenous biological reagents, biodiagnostics, therapeutic and prophylactic vaccines and biodevices have been commercialized. Commercially when biotechnology revenue has reached $25 billions in the U.S. alone in 2000 excluding the revenues of biotech companies that were acquired by pharmaceutical companies, India has yet to register a measurable success. The conservative nature and craze of the Indian Industry for marketing imported biotechnology products, lack of Government support, almost non-existing national healthcare system and lack of trained managers for marketing biological and new products seem to be the important factors responsible for poor economic development of biotechnology in India. With the liberalization of Indian economy, more and more imported biotechnology products will enter into the Indian market. The conditions of internal development of biotechnology are not likely to improve in the near future and it is destined to grow only very slowly. Even today biotechnology in India may be called to be in its infancy.

  16. Pursuing Mathematics in India

    Indian Academy of Sciences (India)

    Admin

    2012-09-07

    Sep 7, 2012 ... of public–private partnership in research and education in India. The Institute receives major private funding, side by side with substantial .... We are writing this to say that students who fail to do well in Mathematics Olympiad have no reason to get disheartened and to think that they are not good enough to ...

  17. CAPTURED India Country Evaluation

    NARCIS (Netherlands)

    O'Donoghue, R.; Brouwers, J.H.A.M.

    2012-01-01

    This report provides the findings of the India Country Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the End Evaluation has assessed that results are commendable. I-AIM was able to design an approach in which health

  18. Women's Work in India.

    Science.gov (United States)

    Devi, D. Radha; Ravindran, M.

    1983-01-01

    The proportion of women in paid employment in India is very low, and working women tend to be concentrated in low-wage, low-status, unskilled jobs, especially in agriculture. Even for the few women working in the modern sector, discrimination is pervasive, and change seems unlikely to occur soon. (IS)

  19. Natural gas in India

    International Nuclear Information System (INIS)

    Lefevre, Thierry; Todoc, Jessie L.

    1999-11-01

    Contains Executive Summary and Chapters on: Country background; Overview of the energy sector; Natural gas supply; Natural gas infrastructure; Natural gas infrastructure; Natural gas demand; Outlook-government policy reform and industry development, and Appendices on Global and regional energy and gas trends; Overview of India's investment policy, incentives and regulation; The ENRON Dabhol power project. (Author)

  20. Healthcare biotechnology in India

    OpenAIRE

    Srivastava, L. M.

    2005-01-01

    Biotechnology in India has made great progress in the development of infrastructure, manpower, research and development and manufacturing of biological reagents, biodiagnostics, biotherapeutics, therapeutic and, prophylactic vaccines and biodevices. Many of these indigenous biological reagents, biodiagnostics, therapeutic and prophylactic vaccines and biodevices have been commercialized. Commercially when biotechnology revenue has reached $25 billions in the U.S. alone in 2000 excluding the r...

  1. Cotton trends in India

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Cotton trends in India. A crop of significant economic importance, valued at over Rs. 15000 Crs. Provides income to 60 million people. Crucial raw material for Rs 83000 Crores textile industry out of which Rs 45754 crores is exports. Approx. 20 Million acres of cotton provides ...

  2. Muslim education in India

    Directory of Open Access Journals (Sweden)

    Beata Pietkiewicz-Pareek

    2015-11-01

    Full Text Available Madrasa education is a very important part of the History of Muslim education and Islamic studies in India. As many as 25 per cent of Muslim children in the 6-14 year age group have either never attended school or have dropped out, so madrasa school is the only choice for them.

  3. 78 FR 1246 - Otay River Estuary Restoration Project; South San Diego Bay Unit and Sweetwater Marsh Unit of the...

    Science.gov (United States)

    2013-01-08

    ...-FF08RSDC00] Otay River Estuary Restoration Project; South San Diego Bay Unit and Sweetwater Marsh Unit of the... scoping with regard to the environmental impact statement (EIS) for the proposed Otay River Estuary... one of the following methods. Email: [email protected] . Please include ``Otay Estuary NOI'' in the...

  4. 76 FR 70480 - Otay River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National...

    Science.gov (United States)

    2011-11-14

    ... River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National Wildlife...), intend to prepare an environmental impact statement (EIS) for the proposed Otay River Estuary Restoration... any one of the following methods. Email: [email protected] . Please include ``Otay Estuary NOI'' in the...

  5. AIDS in India.

    Science.gov (United States)

    Shreedhar, J

    1995-01-01

    A major HIV epidemic is underway in India, home to 900 million people and the world's second largest population. The director-general of the Indian Council of Medical Research expects India by the year 2000 to be the country with the largest number of HIV infections, with some experts predicting 5 million people to be infected with HIV in India by the year 2000. Others predict 30-55 million to be infected. Although HIV is increasingly spreading to typically low-risk group populations, it is the female sex workers and their clients, long distance truck drivers, men who have sex with men, blood transfusion donors and recipients, and IV drug users throughout the country who are both the reservoirs of HIV and vectors of transmission to the general population. For example, 52% of sex workers in Bombay in 1994 were found to be infected with HIV. Studies indicate that India's long-distance truck drivers average 200 sexual encounters per year; at any given time, 70% of them have STDs. Preliminary surveys estimate that almost 33% are infected with HIV. HIV seroprevalence among truckers in Madras requesting HIV testing because they have STDs increased from almost 60% in 1993 to 91% in 1995. Moreover, the illegal status of homosexuality in India has created an underground culture in which HIV and STDs are rampant; one 1995 study in the Sangli district of Maharashtra found 50% of men who have sex with men to be infected with HIV. Half of India's blood for transfusion is drawn from commercial donors. A Bombay study, however, found 86% of such donors screened in 1992 to be HIV-seropositive and not all blood banks comply with mandatory screening laws. As widespread HIV infection evolves into a multitude of AIDS cases, India's health care system and economy will be heavily taxed, and the number of tuberculosis (TB) cases greatly increased. More than half the population carries the TB bacillus. The government by 1992 had drafted a national prevention and control plan and formed the

  6. India's population in transition.

    Science.gov (United States)

    Visaria, L; Visaria, P

    1995-10-01

    This demographic profile of India addresses fertility, family planning, and economic issues. India is described as a country shifting from economic policies of self-reliance to active involvement in international trade. Wealth has increased, particularly at higher educational levels, yet 25% still live below the official poverty line and almost 66% of Indian women are illiterate. The government program in family planning, which was instituted during the early 1950s, did not change the rate of natural increase, which remained stable at 2.2% over the past 30 years. 1993 marked the first time the growth rate decline to under 2%. The growth rate in 1995 was 1.9%. The total population is expected double in 36 years. Only Nigeria, Pakistan, and Bangladesh had a higher growth rate and higher fertility in 1995. India is geographically diverse (with the northern Himalayan mountain zone, the central alluvial plains, the western desert region, and the southern peninsula with forest, mountains, and plains). There are regional differences in the fertility rates, which range from replacement level in Kerala and Goa to 5.5 children in Uttar Pradesh. Fertility is expected to decline throughout India due to the slower pace of childbearing among women over the age of 35 years, the increase in contraceptive use, and increases in marriage age. Increased educational levels in India and its state variations are related to lower fertility. Literacy campaigns are considered to be effective means of increasing the educational levels of women. Urbanization is not expected to markedly affect fertility levels. Urban population, which is concentrated in a few large cities, remains a small proportion of total population. Greater shifts are evident in the transition from agriculture to other wage labor. Fertility is expected to decline as women's share of labor force activity increases. The major determinant of fertility decline in India is use of family planning, which has improved in access

  7. Dissolved organic matter (DOM) export to a temperate estuary: Seasonal variations and implications of land use

    DEFF Research Database (Denmark)

    Stedmon, C. A.; Markager, S.; Søndergaard, M.

    2006-01-01

    Inputs of dissolved carbon, nitrogen, and phosphorus were assessed for an estuary and its catchment (Horsens, Denmark). Seasonal patterns in the concentrations of DOM in the freshwater supply to the estuary differed depending on the soil and drainage characteristics of the area. In streams draini...

  8. Colored dissolved organic matter in shallow estuaries: the effect of source on quantification

    OpenAIRE

    W. K. Oestreich; N. K. Ganju; J. W. Pohlman; S. E. Suttles

    2015-01-01

    Light availability is of primary importance to the ecological function of shallow estuaries. For example, benthic primary production by submerged aquatic vegetation is contingent upon light penetration to the seabed. A major component that attenuates light in estuaries is colored dissolved organic matter (CDOM). CDOM is often measured via a proxy, fluorescing dissolved organic matter (fDOM...

  9. Modelling the transverse distribution of velocity and suspended sediment in tidal estuaries

    NARCIS (Netherlands)

    Huijts, K.M.H.

    2011-01-01

    An estuary is a semi-enclosed coastal body of water which has a free connection with the open sea and within which sea water is measurably diluted with fresh water derived from land drainage. Examples are the Western Scheldt River Estuary and the Chesapeake Bay. Within these environments complex

  10. The benthic regeneration of N and P in the Great Brak estuary ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the flux of inorganic nutrients (NH4 +, TOxN [NO3 - + NO2 -], SRP) as well as total N and P across the sediment–water interface in the estuary. There have been very few studies on nutrient cycling and benthic pelagic coupling in South African estuaries. This study showed that the ...

  11. Mapping ecosystem services in a Great Lakes estuary supports local decision-making

    Science.gov (United States)

    Estuaries of the Laurentian Great Lakes provide a concentrated supply of ecosystem goods and services from which humans benefit. As long-term centers of human activity, most estuaries of the Great Lakes and have a legacy of chemical contamination, degraded habitats, and non-point...

  12. Concentration and Distribution of Hydrophobic Organic Contaminants and Metals in the Estuaries of Ukraine

    Science.gov (United States)

    In this baseline study of Ukrainian estuaries, sediments and organisms from the Dnieper and Boh estuaries and Danube Delta on the mainland, Sevastopol and Balaklava Bays on the Crimean Peninsula, and coastal Black Sea along the Crimean Peninsula were collected in 2006. Contamina...

  13. Biogeochemistry of the MAximum TURbidity Zone of Estuaries (MATURE): some conclusions

    NARCIS (Netherlands)

    Herman, P.M.J.; Heip, C.H.R.

    1999-01-01

    In this paper, we give a short overview of the activities and main results of the MAximum TURbidity Zone of Estuaries (MATURE) project. Three estuaries (Elbe, Schelde and Gironde) have been sampled intensively during a joint 1-week campaign in both 1993 and 1994. We introduce the publicly available

  14. Benthic macrofaunal dynamics and environmental stress across a salt wedge Mediterranean estuary.

    Science.gov (United States)

    Nebra, Alfonso; Alcaraz, Carles; Caiola, Nuno; Muñoz-Camarillo, Gloria; Ibáñez, Carles

    2016-06-01

    The spatial distribution of benthic macroinvertebrate community in relation to environmental factors was studied along the Ebro Estuary (NE Iberian Peninsula), a salt wedge Mediterranean estuary. Both ordination methods and generalized additive models were performed to identify the different benthic assemblages and their relationship to abiotic factors. Our results showed a strong relationship between macrofaunal assemblages and the predominant environmental gradients (e.g. salinity); thus revealing spatial differences in their structure and composition. Two different stretches were identified, namely the upper (UE) and the lower Ebro Estuary (LE). UE showed riverine characteristics and hence was colonized by a freshwater community; whereas LE was influenced by marine intrusion and sustained a complex marine-origin community. However, within each stretch, water and sediment characteristics played an important role in explaining species composition differences among sampling stations. Moreover, outcomes suggested a total species replacement pattern, instead of the nestedness pattern usually associated with well-mixed temperate estuaries. The sharp species turnover together with the estuarine stratification point out that the Ebro Estuary is working, in terms of ecological boundaries, under an ecotone model. Finally, despite obvious differences with well mixed estuaries (i.e. lack of tidal influence, stratification and species turnover), the Ebro Estuary shares important ecological attributes with well-mixed temperate estuaries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Microbial Community Structure in Relation to Water Quality in a Eutrophic Gulf of Mexico Estuary

    Science.gov (United States)

    Weeks Bay is a shallow, microtidal, eutrophic sub-estuary of Mobile Bay, AL. High watershed nutrient inputs to the estuary contribute to a eutrophic condition characterized by frequent summertime diel-cycling hypoxia and dissolved oxygen (DO) oversaturation. Spatial and seasonal ...

  16. Salt intrusion in multi-channel estuaries: a case study in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    A. D. Nguyen

    2006-01-01

    Full Text Available There is a well-tested theory for the computation of salt intrusion in alluvial estuaries that is fully analytical and predictive. The theory uses analytical equations to predict the mixing behaviour of the estuary based on measurable quantities, such as channel topography, river discharge and tidal characteristics. It applies to single-channel topographies and estuaries that demonstrate moderate tidal damping. The Mekong delta is a multi-channel estuary where the tide is damped due to a relatively strong river discharge (in the order of 2000 m3/s, even during the dry season. As a result the Mekong is a strongly riverine estuary. This paper aims to test if the theory can be applied to such a riverine multi-channel estuary, and to see if possible adjustments or generalisations need to be made. The paper presents salt intrusion measurements that were done by moving boat in 2005, to which the salt intrusion model was calibrated. The theory has been expanded to cater for tidal damping. Subsequently the model has been validated with observations made at fixed locations over the years 1998 and 1999. Finally it has been tested whether the Mekong calibration fits the overall predictive equations derived in other estuaries. The test has been successful and led to a slight adjustment of the predictive equation to cater for estuaries that experience a sloping bottom.

  17. Nitrous oxide in the Schelde estuary: production by nitrification and emission to the atmosphere

    NARCIS (Netherlands)

    De Wilde, H.; De Bie, M.J.M.

    2000-01-01

    Concentrations of nitrous oxide (N2O), oxygen, nitrate, and ammonium, as well as nitrification activity were determined along the salinity gradient of the Schelde Estuary, Northwest Europe, in October 1993, March 1994, and July 1996, The entire estuary was always supersaturated with N2O.

  18. A law & economics approach to the study of integrated management regimes of estuaries

    NARCIS (Netherlands)

    van de Griendt, W.E.

    2004-01-01

    In this paper it is proposed to analyse legal regimes for integrated management of estuaries with the help of institutional legal theory and the Schlager & Ostrom framework for types of ownership. Estuaries are highly valued and valuable and therefore need protection. The problem is that they

  19. Vitamin B@d12@@ concentrations in Mandovi and Zuari estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    De; Rajendran, A.

    Bioassay method using @iCyclotella nana@@ (clone 13) was employed for the estimation of Vitamin B@d12@@ in Mandovi and Zuari estuaries. At the mouth of the Mandovi estuary, B@d12@@ concentration varied between 0.38 and 7.0 ng/l in surface water...

  20. Application of remote sensing techniques to study the distribution of mangroves along the estuaries of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Wafar, S.; Jagtap, T.G.

    Aerial photographs were used to study the distribution of mangroves in the estuaries of Goa during 1978-79. The total area covered by 7 estuaries in Goa including the major Mandovi - Zuari estuarine complex, is approximately 12,000 ha of which...

  1. DistributiOl1 of fishes in the MhlaIlga estuary in relation to food ...

    African Journals Online (AJOL)

    The Mhlanga estuary (29°42'S; 31°06'E) is fed by a river. 28 km in length .... All animals were washed ... fishes were captured in the lower reaches, 1 320 (63 320 g) in the middle ..... inhabiting an open estuary, those marine species resident in.

  2. How many people use the Three Bays estuary system for recreation?

    Science.gov (United States)

    Little is known about recreational use on estuaries like Three Bays, MA. We are testing a practical approach to quantify recreational use of the Three Bays estuary system so we can better understand how many people are affected by changes in environmental quality. This involves c...

  3. Residual estuarine circulation in the Mandovi, a monsoonal estuary: A three-dimensional model study

    Digital Repository Service at National Institute of Oceanography (India)

    Vijith, V.; Shetye, S.R.; Baetens, K.; Luyten, P.; Michael, G.S.

    -dependence is forced by the Indian Summer Monsoon (ISM) and hence the estuary is referred to as a monsoonal estuary. In this paper, we use a three-dimensional, open source, hydrodynamic, numerical model to reproduce the observed annual salinity field in the Mandovi. We...

  4. Water pollution in estuaries and coastal zones. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The bibliography contains citations concerning the studies of water pollution in estuaries and coastal zones. Citations examine the development, management, and protection of estuary and coastal resources. Topics include pollution sources, environmental monitoring, water chemistry, eutrophication, models, land use, government policy, and laws and regulations. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  5. An analytical solution for tidal propagation in the Yangtze Estuary, China

    NARCIS (Netherlands)

    Zhang, E.F.; Savenije, H.H.G.; Chen, S.L.; Mao, X.H.

    2012-01-01

    An analytical model for tidal dynamics has been applied to the Yangtze Estuary for the first time, to describe the tidal propagation in this large and typically branched estuary with three-order branches and four outlets to the sea. This study shows that the analytical model developed for a

  6. Potential Climate-Induced Runoff Changes and Associated Uncertainty in Four Pacific Northwest Estuaries

    Science.gov (United States)

    As part of a larger investigation into potential impacts of climate change on estuarine habitats in the Pacific Northwest (PNW), we estimated changes in freshwater inputs into four estuaries. These were the Coquille River estuary, the South Slough of Coos Bay, and the Yaquina Bay...

  7. 76 FR 55673 - Vulnerability Assessments in Support of the Climate Ready Estuaries Program: A Novel Approach...

    Science.gov (United States)

    2011-09-08

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9460-8; Docket ID No. EPA-HQ-ORD-2011-0485] Vulnerability... titled, Vulnerability Assessments in Support of the Climate Ready Estuaries Program: A Novel Approach...) and Vulnerability Assessments in Support of the Climate Ready Estuaries Program: A Novel Approach...

  8. Migration dynamics of clupeoids in the Schelde estuary: a stable isotope approach

    DEFF Research Database (Denmark)

    Guelinckx, J.; Maes, J.; De Brabandere, Loreto

    2006-01-01

    Large numbers of young of the year herring (Clupea harengus L.) and sprat (Sprattus sprattus (L.)) typically enter and remain within North Sea estuaries during the winter months. The main purpose of this study was to examine their migration dynamics between the North Sea and the Schelde estuary u...... is concluded the results support the hypothesis that migration to estuarine nurseries is individually based....

  9. Transport of fallout and reactor radionuclides in the drainage basin of the Hudson River estuary

    International Nuclear Information System (INIS)

    Simpson, H.J.; Linsalata, P.; Olsen, C.R.

    1982-01-01

    The transport and fate of Strontium 90, Cesium 137 and Plutonium 239, 240 in the Hudson River Estuary is discussed. Rates of radionuclide deposition and accumulation over time and space are calculated for the Hudson River watershed, estuary, and continental shelf offshore. 37 references, 7 figures, 15 tables

  10. A preliminary fish survey of the estuaries on the southeast coast of ...

    African Journals Online (AJOL)

    2016-01-01

    Jan 1, 2016 ... ABSTRACT. A basic ichthyofaunal and physico-chemical survey of estuaries on the southeast coast of South Africa from Kayser's Beach to Kei Mouth was undertaken during September and October 1996. Twenty-eight (28) estuaries have been identified along this stretch of coastline, and these were ...

  11. Submarine groundwater discharge and nutrient addition to the coastal zone of the Godavari estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Rengarajan, R.; Sarma, V.V.S.S.

    .8 d during November 2011. Knowing the water age, the distribution of radium in the estuary, and the radium isotopic composition of groundwater enabled us to calculate SGD fluxes to the estuary. These fluxes (in units of 106 m3 d...

  12. Modeling Diel Oxygen Dynamics and Ecosystem Metabolism in a Shallow, Eutrophic Estuary

    Science.gov (United States)

    Weeks Bay is a shallow eutrophic estuary that exhibits frequent summertime diel-cycling hypoxia and periods of dissolved oxygen (DO) oversaturation during the day. Diel DO dynamics in shallow estuaries like Weeks Bay are complex, and may be influenced by wind forcing, vertical an...

  13. Dominance of cyanobacterial and cryptophytic assemblage correlated to CDOM at heavy metal contamination sites of Gujarat, India.

    Science.gov (United States)

    Patidar, Shailesh Kumar; Chokshi, Kaumeel; George, Basil; Bhattacharya, Sourish; Mishra, Sandhya

    2015-01-01

    Industrial clusters of Gujarat, India, generate high quantity of effluents which are received by aquatic bodies such as estuary and coastal water. In the present study, microalgal assemblage, heavy metals, and physico-chemical variables were studied from different habitats. Principal component analysis revealed that biovolume of cyanobacterial and cryptophytic community positively correlated with the heavy metal concentration (Hg, As, Zn, Fe, Mo, Ni, and Co) and chromophoric dissolved organic matter (CDOM) under hypoxic environment. Green algae and diatoms dominated at comparatively lower nitrate concentration which was positively associated with Pb and Mn.

  14. Revealing monsoonal variability of the last 2,500 years over India using sedimentological and foraminiferal proxies

    Digital Repository Service at National Institute of Oceanography (India)

    Khare, N.; Nigam, R.; Hashimi, N.H.

    for interpreting the physical environment. Therefore, the interrelation between sediment characteristic (such as ratios of sand–silt–clay) and physical environment are most advantageous (Creager 1963). The relative size of the clas- tic sediment largely depends... in the Araniar River estuary, Chingleput district, Tamil Nadu State. J Geol Soc India 24:106–110 Sahu BK (1964) Depositional mechanism for the size analysis of clas- tic sediments. J Sediment Petrol 34:73–83 Schilman A, Ayalon M, Bar-Matthews M, Kagan EJ, Almogi...

  15. Female feticide in India.

    Science.gov (United States)

    Ahmad, Nehaluddin

    2010-01-01

    Women are murdered all over the world. But in India a most brutal form of killing females takes place regularly, even before they have the opportunity to be born. Female feticide--the selective abortion of female fetuses--is killing upwards of one million females in India annually with far-ranging and tragic consequences. In some areas, the sex ratio of females to males has dropped to less than 8000:1000. Females not only face inequality in this culture, they are even denied the right to be born. Why do so many families selectively abort baby daughters? In a word: economics. Aborting female fetuses is both practical and socially acceptable in India. Female feticide is driven by many factors, but primarily by the prospect of having to pay a dowry to the future bridegroom of a daughter. While sons offer security to their families in old age and can perform the rites for the souls of deceased parents and ancestors, daughters are perceived as a social and economic burden. Prenatal sex detection technologies have been misused, allowing the selective abortions of female offspring to proliferate. Legally, however, female feticide is a penal offence. Although female infanticide has long been committed in India, feticide is a relatively new practice, emerging concurrently with the advent of technological advancements in prenatal sex determination on a large scale in the 1990s. While abortion is legal in India, it is a crime to abort a pregnancy solely because the fetus is female. Strict laws and penalties are in place for violators. These laws, however, have not stemmed the tide of this abhorrent practice. This article will discuss the socio-legal conundrum female feticide presents, as well as the consequences of having too few women in Indian society.

  16. Turning the Tide: Estuaries Shaped by Channel-Shoal Interactions, Eco-engineers and Inherited Landscapes

    Science.gov (United States)

    Kleinhans, M. G.; Braat, L.; Leuven, J.; Baar, A. W.; van der Vegt, M.; Van Maarseveen, M. C. G.; Markies, H.; Roosendaal, C.; van Eijk, A.

    2015-12-01

    Estuaries exhibit correlations between inlet dimensions, tidal prism and intertidal area, but to what extent estuary planform shape and shoal patterns resulted from biomorphological processes or from inherited conditions such as coastal plain and drowned valley dimensions remains unclear. We explore the hypothesis that mud flats and vegetation as a self-formed lateral confinement have effects analogous to that of river floodplain on braided versus meandering river patterns. Here we use the Delft3D numerical model and a novel tidal flume setup, the Metronome, to create estuaries from idealized initial conditions, with and without mud supply at the fluvial boundary. Experimental mud was simulated by crushed nutshell. Both the numerical and experimental estuaries were narrower with increasing mud, and had a lower degree of channel braiding. The experimental estuaries developed meanders at the river boundary with floodplain developing on the pointbar whereas cohesionless cases were more dynamic.

  17. Metal toxicity characterization factors for marine ecosystems: considering the importance of the estuary for freshwater emissions

    DEFF Research Database (Denmark)

    Dong, Yan; Rosenbaum, Ralph K.; Hauschild, Michael Zwicky

    2017-01-01

    The study develops site-dependent characterization factors (CFs) for marine ecotoxicity of metals emitted to freshwater, taking their passage of the estuary into account. To serve life cycle assessment (LCA) studies where emission location is often unknown, site-generic marine CFs were developed...... with an estuary removal process to calculate FF. BF and EF were taken from Dong et al. Environ Sci Technol 50:269–278 (2016). Site-generic marine CFs were derived from site-dependent marine CFs. Different averaging principles were tested, and the approach representing estuary discharge rate was identified...... between both methods. Accounting for estuary removal particularly influences marine ecotoxicity CFs for emission to freshwater of metals that have a strong tendency to complex-bind to particles. It indicates the importance of including estuary in the characterization modelling when dealing with those...

  18. Sedimentary fabrics of the macrotidal, mud-dominated, inner estuary to fluvio-tidal transition zone, Petitcodiac River estuary, New Brunswick, Canada

    Science.gov (United States)

    Shchepetkina, Alina; Gingras, Murray K.; Zonneveld, John-Paul; Pemberton, S. George

    2016-03-01

    The study provides a detailed description of mud-dominated sedimentary fabrics and their application for the rock record within the inner estuary to the fluvial zone of the Petitcodiac River estuary, New Brunswick, Canada. Sedimentological characteristics and facies distributions of the clay- and silt-rich deposits are reported. The inner estuary is characterized by thick accumulations of interbedded silt and silty clay on intertidal banks that flank the tidally influenced channel. The most common sedimentary structures observed are parallel and wavy lamination, small-scale soft-sediment deformation with microfaults, and clay and silt current ripples. The tidal channel contains sandy silt and clayey silt with planar lamination, massive and convolute bedding. The fluvio-tidal transition zone is represented by interbedded trough cross-stratified sand and gravel beds with planar laminated to massive silty mud. The riverine, non-tidal reach of the estuary is characterized by massive, planar tabular and trough cross-stratified gravel-bed deposits. The absence of bioturbation within the inner estuary to the fluvio-tidal transition zone can be explained by the following factors: low water salinities (0-5 ppt), amplified tide and current speeds, and high concentrations of flocculated material in the water body. Notably, downstream in the middle and outer estuary, bioturbation is seasonally pervasive: in those locales the sedimentary conditions are similar, but salinity is higher. In this study, the sedimentological (i.e., grain size, bedding characters, sedimentary structures) differences between the tidal estuary and the fluvial setting are substantial, and those changes occur over only a few hundred meters. This suggests that the widely used concept of an extensive fluvio-tidal transition zone and its depositional character may not be a geographically significant component of fluvial or estuary deposits, which can go unnoticed in the study of the ancient rocks.

  19. Effects of mud supply on large-scale estuary morphology and development over centuries to millennia

    Directory of Open Access Journals (Sweden)

    L. Braat

    2017-10-01

    Full Text Available Alluvial river estuaries consist largely of sand but are typically flanked by mudflats and salt marshes. The analogy with meandering rivers that are kept narrower than braided rivers by cohesive floodplain formation raises the question of how large-scale estuarine morphology and the late Holocene development of estuaries are affected by cohesive sediment. In this study we combine sand and mud transport processes and study their interaction effects on morphologically modelled estuaries on centennial to millennial timescales. The numerical modelling package Delft3D was applied in 2-DH starting from an idealised convergent estuary. The mixed sediment was modelled with an active layer and storage module with fluxes predicted by the Partheniades–Krone relations for mud and Engelund–Hansen for sand. The model was subjected to a range of idealised boundary conditions of tidal range, river discharge, waves and mud input. The model results show that mud is predominantly stored in mudflats on the side of the estuary. Marine mud supply only influences the mouth of the estuary, whereas fluvial mud is distributed along the whole estuary. Coastal waves stir up mud and remove the tendency to form muddy coastlines and the formation of mudflats in the downstream part of the estuary. Widening continues in estuaries with only sand, while mud supply leads to a narrower constant width and reduced channel and bar dynamics. This self-confinement eventually leads to a dynamic equilibrium in which lateral channel migration and mudflat expansion are balanced on average. However, for higher mud concentrations, higher discharge and low tidal amplitude, the estuary narrows and fills to become a tidal delta.

  20. Oil spill response planning on the Columbia river estuary

    International Nuclear Information System (INIS)

    Christopherson, S.K.; Slyman, P.M.

    1993-01-01

    The Columbia River Estuary lies along the Washington-Oregon state boundary on the west coast of the United States. The entire area is environmentally very sensitive with numerous large, shallow bays, exposed mud flats, wetland areas, and central channels having maximum currents of three to four knots. These features make the area very difficult to protect from an oil spill. Spill response is further complicated because of the many different state, federal, and local jurisdictions with mandated responsibilities in oil spill response and environmental protection. Under the leadership of the US Coast Guard Marine Safety Office in Portland, Oregon, a steering group was established to guide the development of a response plan for the Columbia River Estuary. A concerted effort was made to include representatives from response organizations, natural resource agencies, and resource users from federal, state, and local governments, and commercial sectors in the planning process. The first draft of an operational response plan was completed the summer of 1992 through a combination of technical workshops, field trips, and small working groups meeting with local communities. The Columbia River Estuary Response Plan prioritizes areas to protect; identifies specific response strategies for protecting these areas; and outlines the Iogistics needed to implement these strategies, including equipment needs, the location of staging areas, and the identification of pre-designed command posts. The local spill response cooperative and oil transportation industry are using the plan to coordinate the purchase of response equipment and the staging of this equipment at numerous locations along the river. The key to success is ensuring that all the groups responding to an event participate in the planning process together. This process has worked well and will serve as a model for response planning for other areas along the Columbia River and coastal areas of Washington and Oregon

  1. Aggregate Settling Velocities in San Francisco Estuary Margins

    Science.gov (United States)

    Allen, R. M.; Stacey, M. T.; Variano, E. A.

    2015-12-01

    One way that humans impact aquatic ecosystems is by adding nutrients and contaminants, which can propagate up the food web and cause blooms and die-offs, respectively. Often, these chemicals are attached to fine sediments, and thus where sediments go, so do these anthropogenic influences. Vertical motion of sediments is important for sinking and burial, and also for indirect effects on horizontal transport. The dynamics of sinking sediment (often in aggregates) are complex, thus we need field data to test and validate existing models. San Francisco Bay is well studied and is often used as a test case for new measurement and model techniques (Barnard et al. 2013). Settling velocities for aggregates vary between 4*10-5 to 1.6*10-2 m/s along the estuary backbone (Manning and Schoellhamer 2013). Model results from South San Francisco Bay shoals suggest two populations of settling particles, one fast (ws of 9 to 5.8*10-4 m/s) and one slow (ws of Brand et al. 2015). While the open waters of San Francisco Bay and other estuaries are well studied and modeled, sediment and contaminants often originate from the margin regions, and the margins remain poorly characterized. We conducted a 24 hour field experiment in a channel slough of South San Francisco Bay, and measured settling velocity, turbulence and flow, and suspended sediment concentration. At this margin location, we found average settling velocities of 4-5*10-5 m/s, and saw settling velocities decrease with decreasing suspended sediment concentration. These results are consistent with, though at the low end of, those seen along the estuary center, and they suggest that the two population model that has been successful along the shoals may also apply in the margins.

  2. Oil spill trajectory analysis for the Calcasieu Estuary

    International Nuclear Information System (INIS)

    Meselhe, E.A.; Barker, C.H.; Hodges, M.

    2001-01-01

    A three-dimensional hydrodynamic model (H3D) was used to determine how oil spills might travel and spread within the Calcasieu River Estuary which has heavy oil traffic. The Calcasieu River is located in the southwest corner of the State of Louisiana and houses valuable wetlands that provide both commercial and recreational fishing and wildlife value to the area. These wetlands also filter water and protect Louisiana's coast areas from hurricane storm surges. An oil spill would damage areas of marshes that would have devastating effects on the entire ecological system within the estuary. A Trajectory Analysis Planner (TAP) H3D computer model is under development by the Hazardous Materials Response Division of the National Oceanic and Atmospheric Administration (NOAA). TAP is a statistical planning tool that randomly samples historical hydrodynamic, hydrology and climatological data, to build up a database with biological and cleanup resource information. TAP can be used to predict which sites within the estuarine system will be most susceptible to oil spills of varying magnitudes, materials and locations. TAP can also estimate the time available for mitigation and remedial actions before the spill can impact the site. Hydrodynamics in the Calcasieu estuary is a combination of processes such as saltwater intrusion and response to water level fluctuations at an open boundary, as well as lake dynamics. H3D provides the three components of velocity, plus scalar quantities such as water levels, temperature and salinity distribution on a Cartesian three-dimensional grid. TAP was tested for spills of kerosene, non-weathering oil, crude oil, and gasoline and was able to perform reliable spill trajectory analysis. 12 refs., 9 figs

  3. Identifying resuspended sediment in an estuary using the 228Th/232Th activity ratio: the fate of lagoon sediment in the Bega River estuary, Australia

    International Nuclear Information System (INIS)

    Hancock, G.J.

    2000-01-01

    Thorium-series nuclides ( 228 Th and 232 Th) have been used to identify resuspended sediment in the Bega River estuary, south-eastern Australia. A non-conservative increase in concentration of suspended sediment of water in the vicinity of mid-estuary back-flow lagoons was associated with a decrease in the 228 Th/ 232 Th activity ratio (AR) of the suspended sediment. The lagoon sediment is characterized by a low estuarine 228 Th/ 232 Th signature, distinguishing it from freshwater suspended sediment recently delivered to the estuary, and identifying it as the likely source of the additional suspended sediment. Sediment-core 210 TPb profiles show that the lagoons are accumulating sediment, presumably during high river-flow events. However this study indicates that during intervening periods of low flow, 40% of sediment deposited in the lagoons is subsequently resuspended and exported to the lower estuary, and possibly to the ocean. The utility of the 228 Th/ 232 Th AR to quantify sediment resuspension in estuaries is likely to be estuary-dependent, and is controlled by the extent of scavenging of dissolved 228 Th by suspended particles. Copyright (2000) CSIRO Publishing

  4. CO2 supersaturation and net heterotrophy in a tropical estuary (Cochin, India): Influence of anthropogenic effect - Carbon dynamics in tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, G.V.M.; Thottathil, S.D.; Balachandran, K.K.; Madhu, N.V.; Madeswaran, P.; Nair, S.

    of pCO sub(2) (up to 6000 mu atm) and CO sub(2) effluxes (up to 274 mmolC m sup(-2) d sup(-1)) especially during monsoon. A first-order estimate of the carbon mass balance shows that net production of dissolved inorganic carbon is an order of magnitude...

  5. Distribution and sources of aliphatic hydrocarbons and fatty acids in surface sediments of a tropical estuary south west coast of India (Cochin estuary)

    Digital Repository Service at National Institute of Oceanography (India)

    Gireeshkumar, T.R.; Deepulal, P.M.; Chandramohanakumar, N.

    acid biomarkers and stable isotopes. Estuarine, Coastal and Shelf Science, 70, 271–286. Andrews, J. E., Greenaway, A. M., & Dennis, P. F. (1998). Combined carbon isotope and C/N ratios as indictors of source and fate of organic matter in a poorly.... (1997). Even n- alkane predominances on the Amazon Shelf and a Northeast Pacific Hydrothermal System. Naturwissenschaften, 84, 415–420. Fang, J., Kato, C., Sato, T., Chan, O., & McKay, D. (2004). Biosynthesis and dietary uptake of polyunsaturated fatty...

  6. Distribution pattern of benthic invertebrates in Danish estuaries

    DEFF Research Database (Denmark)

    Kristensen, Erik; Delefosse, Matthieu; Quintana, Cintia Organo

    2013-01-01

    distribution of 9 dominating benthic invertebrate species from two study areas, the estuaries Odense Fjord and Roskilde Fjord, Denmark. The slope (b) obtained fromthe power relationship of sample variance (s2) versusmean (μ) appears to be species-specific and independent of location and time. It ranges from...... factors such as behavior and intraspecific interactions. Thus, at the examined spatial scale, the more intense intraspecific interactions (e.g. territoriality) cause less aggregated distribution patterns among large- than small-bodied invertebrates. The species-specific interactions seem sufficiently...

  7. The herbicide Glyphosate affects nitrification in the Elbe estuary, Germany

    Science.gov (United States)

    Sanders, Tina; Lassen, Stephan

    2015-04-01

    The Elbe River is one of the biggest European rivers discharging into the North Sea. It also transports high amounts of nutrients and pollutants like pesticides. Important source regions of both nutrients and pollutants are located within the river catchment, which is dominated by agricultural land-use. From these agricultural soils, pesticides can be carried via the river and estuary into the North Sea. Glyphosate (N-(phosphonomethyl) glycine) is the most commonly used herbicide worldwide and mainly used to regulate unwanted plant growth and for the expedition of crop ripening. In Germany, ~ 6000 tons of glyphosate are applied yearly in agriculture and private use. Glyphosate is degradable by microorganisms and has a half-life in water of 35 to 60 days. This herbicide specifically inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), an enzyme that catalyzes the biosynthesis of essential aromatic amino acids in plants, fungi, and bacteria. Nitrifying bacteria, which play an important role in the internal nitrogen cycling in the Elbe estuary, also possess this enzyme. The aim of our study was to quantify the concentration of glyphosate in water and sediment samples of the Elbe to get an overview about relevant environmental levels and to assess the impact of glyphosate on inhibition of nitrifying activities. To quantify the effect of glyphosate on nitrification activity, natural samples as well as pure cultures of Nitrosomonas europea (strain Nm50) were incubated with different concentrations of glyphosate over a period of some weeks. The nitrifying activity was determined according to changes of the nitrite and nitrate concentration as well as the cell number. Glyphosate was detectable in water and sediment samples in the Elbe estuary with up to 5 ppb mainly in the Port of Hamburg region. In both incubation experiments an inhibiting effect of glyphosate on nitrification could be shown. The incubated natural water sample was affected by a glyphosate

  8. Application of microwave radiometers for wetlands and estuaries monitoring

    International Nuclear Information System (INIS)

    Shutko, A.; Haldin, A.; Novichikhin, E.

    1997-01-01

    This paper presents the examples of experimental data obtained with airborne microwave radiometers used for monitoring of wetlands and estuaries located in coastal environments. The international team of researchers has successfully worked in Russia, Ukraine and USA. The data presented relate to a period of time between 1990 and 1995. They have been collected in Odessa Region, Black Sea coast, Ukraine, in Regions of Pittsville and Winfield, Maryland, USA, and in Region of St. Marks, Florida, USA. The parameters discussed are a soil moisture, depth to a shallow water table, vegetation index, salinity of water surface

  9. Microplastics in sediments of the Changjiang Estuary, China.

    Science.gov (United States)

    Peng, Guyu; Zhu, Bangshang; Yang, Dongqi; Su, Lei; Shi, Huahong; Li, Daoji

    2017-06-01

    Microplastics are plastics that measure less than 5 mm in diameter. They enter the marine environment as primary sources directly from industrial uses, as well as secondary sources resulting from the degradation of large plastic debris. To improve the knowledge of microplastic pollution in China, we investigated samples from 53 estuarine sediment locations collected with a box corer within the Changjiang Estuary. Microplastics (studies using the same quantification method. The identification of microplastics raises the awareness of microplastic pollution from drainage systems. The prevalence of microplastic pollution calls for monitoring microplastics at a national scale on a regular basis. Copyright © 2016. Published by Elsevier Ltd.

  10. Traditional grains boost nutrition in rural India

    International Development Research Centre (IDRC) Digital Library (Canada)

    India, particularly among vulnerable women and children. The research ... This approach will improve the quality of life for farmers, and is part of a long-term solution to rural poverty in India. ... Traditional grains boost nutrition in rural India.

  11. India dokfilmide paremik jõuab taaralinna

    Index Scriptorium Estoniae

    2007-01-01

    Tartus täna algavatest India dokumentaalfilmide päevadest, mida korraldavad Maailmafilmi festival, Eesti Rahva Muuseum ja organisatsioon Films For Freedom India. Lisatud nimekiri "India dokfilmi päevad"

  12. WATER: EMERGING CHALLENGE FOR INDIA'S BRIGHTEST A ...

    Indian Academy of Sciences (India)

    T. N. Narasimhan

    2009-08-25

    Aug 25, 2009 ... of science, technology, and management will lead the way. • Justifiably so. Alumni of ... INDIA'S WATER CRISIS. • Water availability in India is ... developments stress India's already stressed water systems. • Economy drives ...

  13. [History of acupuncture in India].

    Science.gov (United States)

    Bai, Xinghua

    India and China are both featured with ancient civilization. During the communication between the two countries, the communication from Indian culture, especially Buddhism, to China was predominant, while communication from Chinese culture to India was rare. So it was with medical communication until the end of 1950s when acupuncture was introduced to India. In this article, the medical communication between India and China as well as the introduction of acupuncture to India were discussed, and the resulting phenomenon was analyzed. The introduction of acupuncture to India proved personnel exchange was not necessary to acupuncture communication, and several invisible factors, such as language, religion and culture tradition might be the reasons for foreign nations to accept acupuncture. Therefore, these factors should be valued in the future international communication of acupuncture.

  14. Exploring Emerging India - Eight Essays

    OpenAIRE

    Müller-Brandeck-Bocquet, Gisela; Gieg, Philipp; Lowinger, Timo; Gsänger, Matthias; Becker, Michael; Kundu, Amitabh; Valerian, Rodrigues; S, Shaji; Schömbucher-Kusterer, Elisabeth; Biswas, Aparajita

    2015-01-01

    India's economic rise since the 1990s has been followed by a more prominent global role for the country. Despite economic setbacks in recent years and huge domestic challenges like poverty, caste issues, and gender inequality, India today is almost universally characterised as an “emerging power”. At the same time, the country continues to show an enormous diversity. Thus, exploring emerging India can surely not be confined to economic analysis only. Instead, it is vital to take current devel...

  15. Hemovigilance Program-India

    Directory of Open Access Journals (Sweden)

    Akanksha Bisht

    2013-01-01

    Full Text Available A centralized hemovigilance program to assure patient safety and to promote public health has been launched for the first time in India on Dec 10, 2012 in 60 medical colleges in the first phase along with a well-structured program for monitoring adverse reactions associated with blood transfusion and blood product administration. National Institute of Biologicals (NIB will be the National Coordinating Centre for Hemovigilance. This program will be implemented under overall ambit of Pharmacovigilance Program of India (PvPI, which is being coordinated by Indian Pharmacopoeia Commission (IPC. All medical colleges of the country will be enrolled in this program by the year 2016 in order to have a National Centre of Excellence for Hemovigilance at NIB, which will act as a global knowledge platform.

  16. Fighting corrosion in India

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopalan, K S; Rangaswamy, N S

    1979-03-01

    A survey covers the cost of corrosion in India; methods of preventing corrosion in industrial plants; some case histories, including the prevention of corrosion in pipes through which fuels are pumped to storage and the stress-corrosion cracking of evaporators in fertilizer plants; estimates of the increase in demand in 1979-89 for anticorrosion products and processes developed by the Central Electrochemical Research Institute (CECRI) at Karaikudi, India; industries that may face corrosion problems requiring assistance from CECRI, including the light and heavy engineering structural, and transport industries and the chemical industry; and some areas identified for major efforts, including the establishment of a Corrosion Advisory Board with regional centers and the expansion of the Tropical Corrosion Testing Station at Mandapam Camp, Tamil Nadu.

  17. Oil in India

    Energy Technology Data Exchange (ETDEWEB)

    Diab, E.; Raimbault, C. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France)

    1995-12-01

    India is a country that is rich in energy resources. Concerning oil, proven reserves are already abundant, but there are some who think that a very large potential remains to be discovered, since the country is one of the least thoroughly explored in the world. The recent opening up of energy industries to private and foreign capital should speed up the development of exploration, refining and petrochemicals. However, even if numerous projects were to be approved by the Government, actually carrying them out does not always ensure because of conditions that are not always judged to be attractive by potential investors. Despite all this, there are some who think that India will be a power equal to if not greater than China and one that is already upholding the comparison with the Southeast Asian dragons. (authors). 8 refs., 15 figs., 6 tabs.

  18. Current status of emerging hypoxia in a eutrophic estuary: The lower reach of the Pearl River Estuary, China

    Science.gov (United States)

    Qian, Wei; Gan, Jianping; Liu, Jinwen; He, Biyan; Lu, Zhongming; Guo, Xianghui; Wang, Deli; Guo, Liguo; Huang, Tao; Dai, Minhan

    2018-05-01

    We examine the current status of dissolved oxygen (DO) and its trend over the past 25 years in the lower Pearl River Estuary, a large eutrophic estuary located in Southern China and surrounded by large cities including Hong Kong, Shenzhen and Guangzhou. Monthly cruises conducted from April 2010 to March 2011 clearly show that DO depletion began to emerge in the bottom layer of the lower estuary off Hong Kong in June, and became fully developed in July and August when oxygen-deficient water occupied ∼1000 km2 before gradually becoming re-oxygenated in September and October. The development of the low oxygen zone was closely coupled with phytoplankton blooms in the surface water, which was supersaturated with respect to DO suggesting the importance of autochthonous organic matter in fueling bottom DO consumption after settling through the pycnocline. Long-term monitoring data collected in the study area adjacent to Hong Kong by the Hong Kong Environmental Protection Department showed a decreasing trend of ∼2 ± 0.9 μmol kg-1 yr-1 in the annual minimum DO concentration in bottom water over the past 25 years. Associated with the decrease in DO was an increase in the annual maximum surface concentration of dissolved inorganic nitrogen (DIN) at a rate of ∼1.4 ± 0.3 μmol kg-1 yr-1, suggesting again that eutrophication is the most plausible driver of oxygen deficiency in this region. Therefore, our monthly cruises, along with the decadal monitoring data, reveal a large low oxygen zone, likely developing into a large hypoxic zone driven primarily by anthropogenic eutrophication. This new development suggests environmental stressors such as eutrophication may have a cascading effect, with important and expensive consequences for the regional environment.

  19. Effects of Nitrogen Availability and Form on Phytoplankton Growth in a Eutrophied Estuary (Neuse River Estuary, NC, USA)

    Science.gov (United States)

    Paerl, Hans W.; Wetz, Michael S.

    2016-01-01

    Nitrogen availability and form are important controls on estuarine phytoplankton growth. This study experimentally determined the influence of urea and nitrate additions on phytoplankton growth throughout the growing season (March 2012, June 2011, August 2011) in a temperate, eutrophied estuary (Neuse River Estuary, North Carolina, USA). Photopigments (chlorophyll a and diagnostic photopigments: peridinin, fucoxanthin, alloxanthin, zeaxanthin, chlorophyll b) and microscopy-based cell counts were used as indicators of phytoplankton growth. In March, the phytoplankton community was dominated by Gyrodinium instriatum and only fucoxanthin-based growth rates were stimulated by nitrogen addition. The limited response to nitrogen suggests other factors may control phytoplankton growth and community composition in early spring. In June, inorganic nitrogen concentrations were low and stimulatory effects of both nitrogen forms were observed for chlorophyll a- and diagnostic photopigment-based growth rates. In contrast, cell counts showed that only cryptophyte and dinoflagellate (Heterocapsa rotundata) growth were stimulated. Responses of other photopigments may have been due to an increase in pigment per cell or growth of plankton too small to be counted with the microscopic methods used. Despite high nitrate concentrations in August, growth rates were elevated in response to urea and/or nitrate addition for all photopigments except peridinin. However, this response was not observed in cell counts, again suggesting that pigment-based growth responses may not always be indicative of a true community and/or taxa-specific growth response. This highlights the need to employ targeted microscopy-based cell enumeration concurrent with pigment-based technology to facilitate a more complete understanding of phytoplankton dynamics in estuarine systems. These results are consistent with previous studies showing the seasonal importance of nitrogen availability in estuaries, and also

  20. Development of an estuarine assessment scheme for the management of a highly urbanised catchment/estuary system, Sydney estuary, Australia.

    Science.gov (United States)

    Birch, G F; Gunns, T J; Chapman, D; Harrison, D

    2016-05-01

    As coastal populations increase, considerable pressures are exerted on estuarine environments. Recently, there has been a trend towards the development and use of estuarine assessment schemes as a decision support tool in the management of these environments. These schemes offer a method by which complex environmental data is converted into a readily understandable and communicable format for informed decision making and effective distribution of limited management resources. Reliability and effectiveness of these schemes are often limited due to a complex assessment framework, poor data management and use of ineffective environmental indicators. The current scheme aims to improve reliability in the reporting of estuarine condition by including a concise assessment framework, employing high-value indicators and, in a unique approach, employing fuzzy logic in indicator evaluation. Using Sydney estuary as a case study, each of the 15 sub-catchment/sub-estuary systems were assessed using the current scheme. Results identified that poor sediment quality was a significant issue in Blackwattle/Rozelle Bay, Iron Cove and Hen and Chicken Bay while poor water quality was of particular concern in Duck River, Homebush Bay and the Parramatta River. Overall results of the assessment scheme were used to prioritise the management of each sub-catchment/sub-estuary assessed with Blackwattle/Rozelle Bay, Homebush Bay, Iron Cove and Duck River considered to be in need of a high priority management response. A report card format, using letter grades, was employed to convey the results of the assessment in a readily understood manner to estuarine managers and members of the public. Letter grades also provide benchmarking and performance monitoring ability, allowing estuarine managers to set improvement targets and assesses the effectiveness of management strategies. The current assessment scheme provides an effective, integrated and consistent assessment of estuarine health and

  1. Effects of Nitrogen Availability and Form on Phytoplankton Growth in a Eutrophied Estuary (Neuse River Estuary, NC, USA).

    Science.gov (United States)

    Cira, Emily K; Paerl, Hans W; Wetz, Michael S

    2016-01-01

    Nitrogen availability and form are important controls on estuarine phytoplankton growth. This study experimentally determined the influence of urea and nitrate additions on phytoplankton growth throughout the growing season (March 2012, June 2011, August 2011) in a temperate, eutrophied estuary (Neuse River Estuary, North Carolina, USA). Photopigments (chlorophyll a and diagnostic photopigments: peridinin, fucoxanthin, alloxanthin, zeaxanthin, chlorophyll b) and microscopy-based cell counts were used as indicators of phytoplankton growth. In March, the phytoplankton community was dominated by Gyrodinium instriatum and only fucoxanthin-based growth rates were stimulated by nitrogen addition. The limited response to nitrogen suggests other factors may control phytoplankton growth and community composition in early spring. In June, inorganic nitrogen concentrations were low and stimulatory effects of both nitrogen forms were observed for chlorophyll a- and diagnostic photopigment-based growth rates. In contrast, cell counts showed that only cryptophyte and dinoflagellate (Heterocapsa rotundata) growth were stimulated. Responses of other photopigments may have been due to an increase in pigment per cell or growth of plankton too small to be counted with the microscopic methods used. Despite high nitrate concentrations in August, growth rates were elevated in response to urea and/or nitrate addition for all photopigments except peridinin. However, this response was not observed in cell counts, again suggesting that pigment-based growth responses may not always be indicative of a true community and/or taxa-specific growth response. This highlights the need to employ targeted microscopy-based cell enumeration concurrent with pigment-based technology to facilitate a more complete understanding of phytoplankton dynamics in estuarine systems. These results are consistent with previous studies showing the seasonal importance of nitrogen availability in estuaries, and also

  2. Biogas energy in India

    Energy Technology Data Exchange (ETDEWEB)

    Moulik, T K

    1982-01-01

    A socio-economic study of India's biogas energy program, a response to the oil crisis of the 1970's, reviews the impact of promoting large-scale community biogas plants as a way to reach the lowest income groups. A case study draws on the experiences of the community plant in Gujarat village, and explores the program's secondary benefits and impacts on life styles. 15 references, 5 figures, 37 tables. (DCK)

  3. Medical tourism in India.

    Science.gov (United States)

    Gupta, Vijay; Das, Poonam

    2012-06-01

    The term 'medical tourism' is under debate because health care is a serious business and rarely do patients combine the two. India is uniquely placed by virtue of its skilled manpower, common language, diverse medical conditions that doctors deal with, the volume of patients, and a large nonresident Indian population overseas. Medical tourism requires dedicated services to alleviate the anxiety of foreign patients. These include translation, currency conversion, travel, visa, posttreatment care system,and accommodation of patient relatives during and after treatment.

  4. OUTSOURCING TO INDIA

    OpenAIRE

    Sancheti, Mayur

    2007-01-01

    Topic selected by me for dissertation is of outsourcing to India. Outsourcing is generally done from countries like United Kingdom and United States. I have discussed each and every aspect which is related to Outsourcing in detail. Outsourcing is gaining more and more attention because it enables organizations to cut the cost and improve efficiency of work which results in to overall increase in profitability and competitiveness of the organization. I tried to cove what is Outsourcing, w...

  5. Military Strategy Of India

    Directory of Open Access Journals (Sweden)

    M. S. Zaitsev

    2017-01-01

    Full Text Available The article analyzes the evolution of military strategy of the Republic of India and key factors that influences its development. New Delhi keeps an eye on the balance of power in South Asia to create favorable conditions for its economic and social development, yet the remaining threats and new challenges still undermine the security and stability in India. The ambitions of China aspiring to power in Asia-Pacific region, combined with its immense military build-up and territorial disputes, cause disturbance in New Delhi. The remaining tensions between India and Pakistan also cause often border skirmishes and medium-scale conflicts. Close relations between China and Pakistan, labeled as “all-weather friendship”, are a source of major concern for India. The fact that both Beijing and Islamabad wield nuclear weapons means that without effective mechanisms of nuclear deterrence any military conflict may turn into a full-scale nuclear war. Terrorist activities and insurgency in the Indian state of Jammu and Kashmir and in the North-Eastern regions of the country, along with maritime piracy and illicit drug trafficking contribute to the complicated nature of the challenges to the Indian security. Indian military strategy is considered as a combination of the army doctrine, maritime doctrine and nuclear doctrine. The Indian political and military leadership wants to meet the challenges of changing geopolitical environment and thus continuously adapts its strategy. However, there is still a gap between theory and practice: Indian armed forces lack the capacity to implement the declared goals because of bulky bureaucratic system, outdated military equipment and insufficient level of command and control. The government needs to mobilize political will and administrative resources to upgrade its defense sector to counter its security threats and challenges.

  6. India's misconceived family plan.

    Science.gov (United States)

    Jacobson, J L

    1991-01-01

    India's goal of reducing the national birth rate by 50% by the year 2000 is destined to failure in the absence of attention to poverty, social inequality, and women's subordination--the factors that serve to perpetuate high fertility. There is a need to shift the emphasis of the population control effort from the obligation of individual women to curtail childbearing to the provision of the resources required for poor women to meet their basic needs. Female children are less likely to be educated or taken for medical care than their male counterparts and receive a lower proportion of the family's food supply. This discrimination stems, in large part, from parents' view that daughters will not be able to remunerate their families in later life for such investments. The myth of female nonproductivity that leads to the biased allocation of family resources overlooks the contribution of adult women's unpaid domestic labor and household production. Although government statistics state that women comprise 46% of India's agricultural labor force (and up to 90% of rural women participate in this sector on some basis), women have been excluded systematically from agricultural development schemes such as irrigation projects, credit, and mechanization. In the field of family planning, the Government's virtually exclusive focus on sterilization has excluded younger women who are not ready to terminate childbearing but would like methods such as condoms, diaphragms, IUDs, and oral contraceptives to space births. More general maternal-child health services are out of reach of the majority of poor rural women due to long distances that must be travelled to clinics India's birth rate could be reduced by 25% by 2000 just by filling the demand for quality voluntary family planning services. Without a sustained political commitment to improve the status of women in India, however, such gains will not be sustainable.

  7. Energy planning in India

    International Nuclear Information System (INIS)

    Venu, S.

    1982-01-01

    A review is presented of India's planning for energy requirements in coal, oil, gas and nuclear power and in the fields of solar energy and the extension of forest areas to provide firewood. Coal and natural gas supplies will be increased to reduce oil demand. There will be an accelerated programme of development of bio-gas, an exploration of solar energy potential and extensive afforestation to provide additional energy sources. (author)

  8. Energy for rural India

    International Nuclear Information System (INIS)

    Urban, Frauke; Benders, Rene M.J.; Moll, Henri C.

    2009-01-01

    About 72 million households in rural India do not have access to electricity and rely primarily on traditional biofuels. This research investigates how rural electrification could be achieved in India using different energy sources and what the effects for climate change mitigation could be. We use the Regional Energy Model (REM) to develop scenarios for rural electrification for the period 2005-2030 and to assess the effects on greenhouse gas emissions, primary energy use and costs. We compare the business-as-usual scenario (BAU) with different electrification scenarios based on electricity from renewable energy, diesel and the grid. Our results indicate that diesel systems tend to have the highest CO 2 emissions, followed by grid systems. Rural electrification with primarily renewable energy-based end-uses could save up to 99% of total CO 2 emissions and 35% of primary energy use in 2030 compared to BAU. Our research indicates that electrification with decentralised diesel systems is likely to be the most expensive option. Rural electrification with renewable energy tends to be the most cost-effective option when end-uses are predominantly based on renewable energy, but turns out to be more costly than grid extensions when electric end-use devices are predominantly used. This research therefore elaborates whether renewable energy is a viable option for rural electrification and climate change mitigation in rural India and gives policy recommendations.

  9. Medicine in South India

    Science.gov (United States)

    McHenry, Malcolm M.

    1978-01-01

    A three-month sabbatical allowed a superficial overview of Indian medical history and practice. As in Western nations, cost is a major determinant of health care delivery in India; poverty and fiscal shortages, however, deny care to many. The education of Indian physicians is similar to that in Western nations and a high level of clinical competence is seen. However, physician compensation is woefully low by Western standards. India possesses its own indigenous medical systems, purported to be the oldest in the world and predating Hippocrates by several millenia. Most Indians are cared for by native practitioners whose medical techniques are intricately related to the Hindu and Islamic religions. Many of their herbal medicines have been assimilated into contemporary Western practice. Diseases unknown to us except by textbooks are commonly seen and effectively treated. On the other hand, Western diseases such as coronary arteriosclerosis are not uncommon in a land of massive overpopulation and malnutrition. The humbling aspect of this experience is the realization that medical practice dating back several millenia can be made more modern and carried out competently by contemporary physicians. A Western physician working in India finds an unparalleled variety of disease in a totally different medical-religious environment allowing him to reorganize his priorities and to rediscover himself in the world within which he lives. PMID:716392

  10. Medicine in South India.

    Science.gov (United States)

    McHenry, M M

    1978-10-01

    A three-month sabbatical allowed a superficial overview of Indian medical history and practice. As in Western nations, cost is a major determinant of health care delivery in India; poverty and fiscal shortages, however, deny care to many. The education of Indian physicians is similar to that in Western nations and a high level of clinical competence is seen. However, physician compensation is woefully low by Western standards. India possesses its own indigenous medical systems, purported to be the oldest in the world and predating Hippocrates by several millenia. Most Indians are cared for by native practitioners whose medical techniques are intricately related to the Hindu and Islamic religions. Many of their herbal medicines have been assimilated into contemporary Western practice. Diseases unknown to us except by textbooks are commonly seen and effectively treated. On the other hand, Western diseases such as coronary arteriosclerosis are not uncommon in a land of massive overpopulation and malnutrition. The humbling aspect of this experience is the realization that medical practice dating back several millenia can be made more modern and carried out competently by contemporary physicians. A Western physician working in India finds an unparalleled variety of disease in a totally different medical-religious environment allowing him to reorganize his priorities and to rediscover himself in the world within which he lives.

  11. India's draft nuclear doctrine

    International Nuclear Information System (INIS)

    Kapur, A.

    2000-01-01

    India's draft nuclear doctrine and its nuclear and missile testing are a response to recent international, regional and domestic developments. Nehru's policy of nuclear disarmament, non-discriminatory international arrangements and unilateral restraint has been overturned in favour of self-reliant security and negotiated nuclear restraints. The draft nuclear doctrine is aimed at transparency and formalization of existing capacities. It is anchored in the United Nations Charter, based on the legitimacy of self-defence and espouses minimum nuclear deterrence. After the launching of Pokhran II, the debate in India has been settled on weaponization and deployment. The doctrine is not country-specific with respect to threat perceptions, but the author posits that the long-term focus is on China and the short-term on Pakistan. The doctrine emphasizes civilian command and control. India's decision to test incurred diplomatic and other economic costs, but afforded new opportunities for the country to assert itself militarily and politically in Asia and in the world. There were no diplomatic costs in issuing the draft nuclear doctrine, but the author estimates the economic costs of a full-blown (triad) Indian nuclear deterrent. (author)

  12. Environmental flow assessments in estuaries related to preference of phytoplankton

    Science.gov (United States)

    Yang, Z. F.; Sun, T.; Zhao, R.

    2014-01-01

    We developed an approach to assess environmental flows in estuaries related to preference of phytoplankton considering the complex relationship between hydrological modification and biomass in ecosystems. As a first step, a relationship was established between biomass requirements for organisms of primary and higher nutritional levels based on the principle of nutritional energy flow of ecosystem. Then, diagnostic pigments were employed to represent phytoplankton community biomass, which indicated competition between two groups of phytoplankton in the biochemistry process. Considering empirical relationships between diagnostic pigments and critical environmental factors, responses of biomass to river discharges were established based on a convection-diffusion model by simulating distributions of critical environmental factors under action of river discharges and tide currents. Consequently, environmental flows could be recommended for different requirements of fish biomass. In the case study in the Yellow River estuary, May and October were identified as critical months for fish reproduction and growth during dry years. Artificial hydrological regulation strategies should carefully consider the temporal variations of natural flow regime, especially for a high-amplitude flood pulse, which may cause negative effects on phytoplankton groups and higher organism biomass.

  13. Mathematical simulation of sediment and radionuclide transport in estuaries

    International Nuclear Information System (INIS)

    Onishi, Y.; Trent, D.S.

    1982-11-01

    The finite element model LFESCOT (Flow, Energy, Salinity, Sediment and Contaminant Transport Model) was synthesized under this study to simulate radionuclide transport in estuaries to obtain accurate radionuclide distributions which are affected by these factors: time variance, three-dimensional flow, temperature, salinity, and sediments. Because sediment transport and radionuclide adsorption/desorption depend strongly on sizes or types of sediments, FLESCOT simulates sediment and a sediment-sorbed radionuclide for the total of three sediment-size fractions (or sediment types) of both cohesive and noncohesive sediments. It also calculates changes of estuarine bed conditions, including bed elevation changes due to sediment erosion/deposition, and three-dimensional distributions of three bed sediment sizes and sediment-sorbed radionuclides within the bed. Although the model was synthesized for radionuclide transport, it is general enough to also handle other contaminants such as heavy metals, pesticides, or toxic chemicals. The model was checked for its capability for flow, water surface elevation change, salinity, sediment and radionuclide transport under various simple conditions first, confirming the general validity of the model's computational schemes. These tests also revealed that FLESCOT can use large aspect ratios of computational cells, which are necessary in handling long estuarine study areas. After these simple tests, FLESCOT was applied to the Hudson River estuary between Chelsea and the mouth of the river to examine how well the model can predict radionuclide transport through simulating tidally influenced three-dimensional flow, salinity, sediment and radionuclide movements with their interactions

  14. Natural radioactivity assessment of surface sediments in the Yangtze Estuary

    International Nuclear Information System (INIS)

    Wang, Jinlong; Du, Jinzhou; Bi, Qianqian

    2017-01-01

    The activities of the natural radionuclides ( 238 U, 232 Th, 226 Ra and 40 K) of the surface sediments in the Yangtze Estuary were determined and used to evaluate radiation hazards in the study area. The of activities of 238 U, 232 Th, 226 Ra and 40 K ranges from 14.1 to 62.3, 26.1 to 71.9, 13.7 to 52.3, and 392 to 898 Bq kg −1 , respectively, which were comparable to values of other regions in China. The activities of 232 Th, 40 K and 226 Ra were clearly different from the global recommended values. The radium equivalent activity was less than the recommended limit of 370 Bq kg −1 ; therefore, the sediment in this area can be safely used for reclamation. The external hazard index values were less than one. The average absorbed gamma dose rate and annual effective dose equivalent values were slightly greater than the world average value. 226 Ra/ 238 U and 232 Th/ 238 U ratios could potentially be applied for tracing sediment source. - Highlights: • The natural radioactivity of surface sediments in the Yangtze Estuary was observed. • The radiological hazards of the sediments are insignificant in this study area. • The ratios of natural radionuclides can potentially be applied for sediment source.

  15. Effects of Prevailing Winds on Turbidity of a Shallow Estuary

    Directory of Open Access Journals (Sweden)

    Hyun Jung Cho

    2007-06-01

    Full Text Available Estuarine waters are generally more turbid than lakes or marine waters due to greater algal mass and continual re-suspension of sediments. The varying effects of diurnal and seasonal prevailing winds on the turbidity condition of a wind-dominated estuary were investigated by spatial and statistical analyses of wind direction, water level, turbidity, chlorophyll a, and PAR (Photosynthetically Active Radiation collected in Lake Pontchartrain, Louisiana, USA. The prolonged prevailing winds were responsible for the long-term, large-scale turbidity pattern of the estuary, whereas the short-term changes in wind direction had differential effects on turbidity and water level in varying locations. There were temporal and spatial changes in the relationship between vertical light attenuation coefficient (Kd and turbidity, which indicate difference in phytoplankton and color also affect Kd. This study demonstrates that the effect of wind on turbidity and water level on different shores can be identified through system-specific analyses of turbidity patterns.

  16. Major hydrogeochemical processes in an acid mine drainage affected estuary.

    Science.gov (United States)

    Asta, Maria P; Calleja, Maria Ll; Pérez-López, Rafael; Auqué, Luis F

    2015-02-15

    This study provides geochemical data with the aim of identifying and quantifying the main processes occurring in an Acid Mine Drainage (AMD) affected estuary. With that purpose, water samples of the Huelva estuary were collected during a tidal half-cycle and ion-ion plots and geochemical modeling were performed to obtain a general conceptual model. Modeling results indicated that the main processes responsible for the hydrochemical evolution of the waters are: (i) the mixing of acid fluvial water with alkaline ocean water; (ii) precipitation of Fe oxyhydroxysulfates (schwertmannite) and hydroxides (ferrihydrite); (iii) precipitation of Al hydroxysulfates (jurbanite) and hydroxides (amorphous Al(OH)3); (iv) dissolution of calcite; and (v) dissolution of gypsum. All these processes, thermodynamically feasible in the light of their calculated saturation states, were quantified by mass-balance calculations and validated by reaction-path calculations. In addition, sorption processes were deduced by the non-conservative behavior of some elements (e.g., Cu and Zn). Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Uranium export from a sandy beach subterranean estuary in Australia

    Science.gov (United States)

    Sanders, Christian J.; Santos, Isaac R.; Sadat-Noori, Mahmood; Maher, Damien T.; Holloway, Ceylena; Schnetger, Bernhard; Brumsack, Hans-J.

    2017-11-01

    Few studies exist on the contribution of subterranean estuaries (STEs) to the oceanic uranium (U) budget. Here, we estimate the dissolved U fluxes out of a quartz sand STE located on the east coast of Australia. Our results indicate that the advective flow of seawater in permeable sands enhances cycling of U in the STE. Dissolved U concentrations ranged from 25 nM in the STE to an effective zero salinity end-member of 3.8 nM in the surface estuary. The dissolved U (salinity corrected) concentrations were positively correlated to Fe (r2 = 0.49 p based on shallow saline groundwater exchange pathways and 0.4 μmol U m-2 day-1 based on deep fresh submarine groundwater discharge (SGD). Uranium's behavior in STEs is diverse and site specific. Out of the seven investigations available here and in the literature, three suggested a SGD-derived U source to the coastal ocean, while four suggested a U sink within STEs removing seawater U. Therefore, it remains unclear whether SGD is a source or sink of U to the ocean and additional investigations in contrasting settings are required to resolve the global contribution of SGD to the marine U cycle.

  18. Distribution ofVibrio cholerae in two Florida estuaries.

    Science.gov (United States)

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-04-01

    The distribution ofVibrio cholerae was examined in 2 Florida estuaries, Apalachicola and Tampa Bay.Vibrio cholerae serotype non-01 was the most abundant serotype, being isolated from 45% of the oyster samples, 30% of the sediments, 50% of the waters, and 75% of the blue crabs.Vibrio cholerae serotype 01 was isolated from only one oyster sample. Strong linear correlations betweenV. cholerae and temperature, salinity, or the other physical/chemical parameters measured,Escherichia coli, or fecal coliforms were not observed, but a range of temperatures and salinities appeared relevant to the distribution of the organism. The organism was present in the highest concentrations when salinities were 10‰-25‰ and temperatures were 20‡C-35‡C.In vitro growth curves of 95V. cholerae environmental isolates further supported that 10‰-25‰ was an ideal salinity range for the organisms. The results suggest thatV. cholerae is a widely distributed organism in the nutrient-rich warm waters of the Gulf Coast estuaries.

  19. Understanding the fate of iron in a modern temperate estuary: Leirarvogur, Iceland

    International Nuclear Information System (INIS)

    Byrne, Gemma M.; Worden, Richard H.; Hodgson, David M.; Polya, David A.; Lythgoe, Paul R.; Barrie, Craig D.; Boyce, Adrian J.

    2011-01-01

    Highlights: → Fluvial Fe (aq) and Fe (total) concentrations drop upon mixing with seawater in estuaries. → The majority of Fe in estuaries is lost in the bay-head delta. → Our results suggest that the bay-head delta is a key location in Fe-mineral formation. → Isotopic variation in estuarine waters may play a role in the formation of Fe-minerals. - Abstract: Fluvial dissolved Fe concentrations decrease upon mixing with seawater, resulting in the formation of Fe-floccules. However, a clear understanding of the fate of these floccules has yet to be established. Assessing how tidal processes affect the formation of Fe-colloids in the Leirarvogur estuary, SW Iceland, is an important step in understanding the formation and potential deposition of estuarine Fe-rich minerals within this estuarine system. The Leirarvogur estuary drains predominately Fe-rich basalt, increasing the likelihood of detecting changes in Fe-phases. Fluvial waters and local lake waters that drain into the estuary were compared and the effects of seasonal changes were considered, in an attempt to understand how varying end-members and external factors play a role in Fe-rich mineral formation. Aqueous and colloidal Fe concentrations were found to be greater towards the head of the Leirarvogur estuary, suggesting that potential Fe-rich minerals and complexes are forming at sites of fluvial input. Increasing suspended colloidal Fe towards the estuary mouth suggests that Fe-colloids are readily transported seaward.

  20. Assessment of heavy metals bioavailability and toxicity toward Vibrio fischeri in sediment of the Huelva estuary.

    Science.gov (United States)

    Rosado, Daniel; Usero, José; Morillo, José

    2016-06-01

    Relationship between toxicity and bioavailable metals in sediments from the Huelva estuary and its littoral of influence was analyzed. Toxicity was assessed with Microtox® bioassay using a marine luminescent bacterium: Vibrio fischeri. Bioavailable metals were considered as both, acid extractable fraction of BCR procedure and the sum of exchangeable and bound to carbonates fractions of Tessier sequential extraction. A bioavailable metals index was calculated to integrate results in a single figure. Toxicity and bioavailable metals showed a similar pattern. Higher levels were found in the estuary than in the littoral (140 TU/g). In Huelva estuary, highest levels were found in the Tinto estuary (5725 TU/g), followed by the Odiel estuary (5100 TU/g) and the Padre Santo Canal (2500 TU/g). Results in this area were well over than those in nearby estuaries. Furthermore, they are similar to or even higher than those in other polluted sediments around the world. Bioavailable metal index showed a stronger correlation with acid extractable fraction of BCR (R(2) = 0.704) than that for the sum of exchangeable and bound to carbonates fractions of Tessier (R(2) = 0.661). These results suggest that bioavailable metals are an important source of sediment toxicity in the Huelva estuary and its littoral of influence, an area with one of the highest mortality risks of Spain. Copyright © 2016 Elsevier Ltd. All rights reserved.