WorldWideScience

Sample records for coastal water exchange

  1. Verification of mid-ocean ballast water exchange using naturally occurring coastal tracers

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Kathleen; Boehme, Jennifer; Coble, Paula; Cullen, Jay; Field, Paul; Moore, Willard; Perry, Elgin; Sherrell, Robert; Ruiz, Gregory

    2004-04-01

    We examined methods for verifying whether or not ships have performed mid-ocean ballast water exchange (BWE) on four commercial vessels operating in the Pacific and Atlantic Oceans. During BWE, a ship replaces the coastal water in its ballast tanks with water drawn from the open ocean, which is considered to harbor fewer organisms capable of establishing in coastal environments. We measured concentrations of several naturally occurring chemical tracers (salinity, six trace elements, colored dissolved organic matter fluorescence and radium isotopes) along ocean transects and in ballast tanks subjected to varying degrees of BWE (0-99%). Many coastal tracers showed significant concentration changes due to BWE, and our ability to detect differences between exchanged and unexchanged ballast tanks was greatest under multivariate analysis. An expanded dataset, which includes additional geographic regions, is now needed to test the generality of our results.

  2. Verification of mid-ocean ballast water exchange using naturally occurring coastal tracers

    International Nuclear Information System (INIS)

    Murphy, Kathleen; Boehme, Jennifer; Coble, Paula; Cullen, Jay; Field, Paul; Moore, Willard; Perry, Elgin; Sherrell, Robert; Ruiz, Gregory

    2004-01-01

    We examined methods for verifying whether or not ships have performed mid-ocean ballast water exchange (BWE) on four commercial vessels operating in the Pacific and Atlantic Oceans. During BWE, a ship replaces the coastal water in its ballast tanks with water drawn from the open ocean, which is considered to harbor fewer organisms capable of establishing in coastal environments. We measured concentrations of several naturally occurring chemical tracers (salinity, six trace elements, colored dissolved organic matter fluorescence and radium isotopes) along ocean transects and in ballast tanks subjected to varying degrees of BWE (0-99%). Many coastal tracers showed significant concentration changes due to BWE, and our ability to detect differences between exchanged and unexchanged ballast tanks was greatest under multivariate analysis. An expanded dataset, which includes additional geographic regions, is now needed to test the generality of our results

  3. Isotope Exchange: a Potential Mechanism Regulating the Natural and Anthropogenic Pb Isotope Budget in Coastal Waters

    Science.gov (United States)

    Chen, M.; Boyle, E. A.; Zurbrick, C.; Carrasco, G. G.; Switzer, A.; Zhao, N.

    2016-02-01

    Two independent studies on anthropogenic Pb and Pb isotopes in coastal corals from the northern Arabian Gulf and the Singapore Straits have shown an isotopic excursion where the main Pb sources discharging to the water move to more crustal-like values, indicating that the Pb in coastal waters might exchange isotopically with crustal particulates without propotional change in concentration. To investigate this issue, Pb isotope exchange is assessed through a closed-system exchange experiment using estuarine waters collected at the Johor River mouth (discharging to the Singapore Straits). During the experiment, a known amount of NBS-981 (206Pb/207Pb=1.093) was spiked into the unfiltered Johor water (dissolved 206Pb/207Pb = 1.199) and the changing isotopic composition of the dissolved Pb was monitored. Shortly after the spike addition, dissolved Pb exhibited 206Pb/207Pb=1.178, reflecting the influence of the spike. Within the following few days, the 206Pb/207Pb in the water increased to >1.190 with limited changes of the dissolved Pb concentration. The observations in closed-system experiment agree with the isotope difference between Singapore aerosol and seawater in our 2-year-long field observations. The kinetics of isotope exchange were assessed using a simple model, which reproduced >70% of the observed Pb isotope variance. Both the close-system experiment and field measurements imply that isotope exchange can be an important mechanism for regulating the Pb and Pb isotopes in coastal waters. Investigations on the distribution of Pb and Pb isotope in estuaries and coastal waters should further assess the role of isotope exchange in ocean Pb chemistry.

  4. Modeling Water Exchange and Contaminant Transport through a Baltic Coastal Region

    International Nuclear Information System (INIS)

    Engqvist, Anders; Doeoes, Kristofer; Andrejev, Oleg

    2006-01-01

    The water exchange of the Baltic coastal zone is characterized by its seasonally varying regimes. In the safety assessment of a potential repository for spent nuclear fuel, it is important to assess the consequences of a hypothetical leak of radionuclides through the seabed into a waterborne transport phase. In particular, estimates of the associated residence times in the near-shore coastal zone are of interest. There are several methods to quantify such measures, of which three are presented here. Using the coastal location of Forsmark (Sweden) as an example, methods based on passive tracers, particle trajectories, and the average age distribution of exogenous water parcels are compared for a representative one-year cycle. Tracer-based methods can simulate diffusivity more realistically than the other methods. Trajectory-based methods can handle Lagrangian dispersion processes due to advection but neglect diffusion on the sub-grid scale. The method based on the concept of average age (AvA) of exogenous water can include all such sources simultaneously not only boundary water bodies but also various (fresh)water discharges. Due to the inclusion of sub-grid diffusion this method gives a smoother measure of the water renewal. It is shown that backward in time trajectories and AvA-times are basically equipollent methods, yielding correlated results within the limits set by the diffusivity

  5. Use of a numerical simulation approach to improve the estimation of air-water exchange fluxes of polycyclic aromatic hydrocarbons in a coastal zone.

    Science.gov (United States)

    Lai, I-Chien; Lee, Chon-Lin; Ko, Fung-Chi; Lin, Ju-Chieh; Huang, Hu-Ching; Shiu, Ruei-Feng

    2017-07-15

    The air-water exchange is important for determining the transport, fate, and chemical loading of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere and in aquatic systems. Investigations of PAH air-water exchange are mostly based on observational data obtained using complicated field sampling processes. This study proposes a new approach to improve the estimation of long-term PAH air-water exchange fluxes by using a multivariate regression model to simulate hourly gaseous PAH concentrations. Model performance analysis and the benefits from this approach indicate its effectiveness at improving the flux estimations and at decreasing the field sampling difficulty. The proposed GIS mapping approach is useful for box model establishment and is tested for visualization of the spatiotemporal variations of air-water exchange fluxes in a coastal zone. The air-water exchange fluxes illustrated by contour maps suggest that the atmospheric PAHs might have greater impacts on offshore sites than on the coastal area in this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Variability in Benthic Exchange Rate, Depth, and Residence Time Beneath a Shallow Coastal Estuary

    Science.gov (United States)

    Russoniello, Christopher J.; Heiss, James W.; Michael, Holly A.

    2018-03-01

    Hydrodynamically driven benthic exchange of water between the water column and shallow seabed aquifer is a significant and dynamic component of coastal and estuarine fluid budgets. Associated exchange of solutes promotes ecologically important chemical reactions, so quantifying benthic exchange rates, depths, and residence times constrains coastal chemical cycling estimates. We present the first combined field, numerical, and analytical modeling investigation of wave-induced exchange. Temporal variability of exchange was calculated with data collected by instruments deployed in a shallow estuary for 11 days. Differential pressure sensors recorded pressure gradients across the seabed, and up- and down-looking ADCPs recorded currents and pressures to determine wave parameters, surface-water currents, and water depth. Wave-induced exchange was calculated (1) directly from differential pressure measurements, and indirectly with an analytical model based on wave parameters from (2) ADCP and (3) wind data. Wave-induced exchange from pressure measurements and ADCP-measured wave parameters matched well, but both exceeded wind-based values. Exchange induced by tidal pumping and current-bed form interaction—the other primary drivers in shallow coastal waters were calculated from tidal stage variation and ADCP-measured currents. Exchange from waves (mean = 20.0 cm/d; range = 1.75-92.3 cm/d) greatly exceeded exchange due to tides (mean = 3.7 cm/d) and current-bed form interaction (mean = 6.5 × 10-2 cm/d). Groundwater flow models showed aquifer properties affect wave-driven benthic exchange: residence time and depth increased and exchange rates decreased with increasing hydraulic diffusivity (ratio of aquifer permeability to compressibility). This new understanding of benthic exchange will help managers assess its control over chemical fluxes to marine systems.

  7. Epiphytic invertebrate patterns in coastal lakes along a gradient of salinity and water exchange with the sea

    Science.gov (United States)

    Obolewski, Krystian; Bąkowska, Martyna

    2017-10-01

    The species composition and abundance of epiphytic fauna inhabiting common reed (Phragmites australis (Cav.) Trin. ex Steud.) was performed in five coastal lakes in Słowiński National Park (southern Baltic coast in northern Poland). The lakes represent a salinity gradient (from freshwater to β-oligohaline waters) and four types of coastal lakes: (1) lagoon, L (Lake Łebsko, seawater enters it permanently); (2) coastal lake with periodically brackish water, CLB (Lake Gardno); (3) freshwater costal lake, CLF (Lake Smołdzińskie); and (4) coastal dune lakes, CLD (Dołgie Wielkie and Dołgie Małe). Using statistical ordination techniques, we found that the structure of epiphytic fauna (microinvertebrates and macroinvertebrates) is determined primarily by hydrological connectivity (water exchange) with the sea. Canonical Correspondence Analysis, coupled with variance partitioning, showed that hydrological connectivity accounted for 24% of the variation in the invertebrate community, followed by physico-chemical (19%) and trophic (8%) factors. Our results indicate that the assemblages of Ciliata-libera and Cnidaria are characteristic for L (β-oligohaline), Rotifera, Suctoria, Chaetogaster sp., Gastropoda and Trichoptera are characteristic for CLB (limnetic/β-oligohaline), but no taxonomic groups are characteristic for CLF and CLD (both limnetic). The index of multivariate dispersion showed a decreasing trend with the increasing lake isolation from the open sea, except for CLD. However, in terms of the structure of epiphytic fauna, Multi-Response Permutation Procedures showed that CLD significantly differed only from CLB. Our results suggest that the identified characteristic taxonomic groups of plant-associated macroinvertebrates have a high potential to be used as bioindicators of salinity and water exchange with the sea, due to their sensitivity to environmental stress.

  8. Variability in benthic exchange rate, depth, and residence time beneath a shallow coastal estuary

    Science.gov (United States)

    Russoniello, C. J.; Michael, H. A.; Heiss, J.

    2017-12-01

    Hydrodynamically-driven exchange of water between the water column and shallow seabed aquifer, benthic exchange, is a significant and dynamic component of coastal and estuarine fluid budgets, but wave-induced benthic exchange has not been measured in the field. Mixing between surface water and groundwater solutes promotes ecologically important chemical reactions, so quantifying benthic exchange rates, depths, and residence times, constrains estimates of coastal chemical cycling. In this study, we present the first field-based direct measurements of wave-induced exchange and compare it to exchange induced by the other primary drivers of exchange - tides, and currents. We deployed instruments in a shallow estuary to measure benthic exchange and temporal variability over an 11-day period. Differential pressure sensors recorded pressure gradients across the seabed, and up-and down-looking ADCPs recorded currents and pressures from which wave parameters, surface-water currents, and water depth were determined. Wave-induced exchange was calculated directly from 1) differential pressure measurements, and indirectly with an analytical solution based on wave parameters from 2) ADCP and 3) weather station data. Groundwater flow models were used to assess the effects of aquifer properties on benthic exchange depth and residence time. Benthic exchange driven by tidal pumping or current-bedform interaction was calculated from tidal stage variation and from ADCP-measured currents at the bed, respectively. Waves were the primary benthic exchange driver (average = 20.0 cm/d, maximum = 92.3 cm/d) during the measurement period. Benthic exchange due to tides (average = 3.7 cm/d) and current-bedform interaction (average = 6.5x10-2 cm/d) was much lower. Wave-induced exchange calculated from pressure measurements and ADCP-measured wave parameters matched well, but wind-based rates underestimated wave energy and exchange. Groundwater models showed that residence time and depth increased

  9. Water exchange estimates derived from forcing for the hydraulically coupled basins surrounding Aespoe island and adjacent coastal water

    International Nuclear Information System (INIS)

    Engqvist, A.

    1997-08-01

    A numerical model study based on representative physical forcing data (statistically averaged from approximately 10 years) has been performed of the Aespoe area, subdivided into five separate basins, interconnected by four straits and connected to the Baltic coast through three straits. The water exchange of the shallow Borholmsfjaerden, with comparatively small section areas of its straits, is dominated by the sea level variations while the baroclinic exchange components (estuarine and intermediary circulation) also contribute. The average transit retention time (averaged over the basin volume for a full year cycle) is found to be a little over 40 days for exogenous water (i.e. coastal water and freshwater combined); this measure of the water exchange is comparable to the combined average of an ensemble consisting of 157 similarly analyzed basins distributed along the Swedish east and west coasts. The exchange mechanisms and model assumptions are discussed. The consequences for the retention times by short- and long-term variations of the forcing is also analyzed. The standard deviation (SD) of the retention time during an average year (intra-annual variation) is greater than the SD between years (interannual variation) for all basins except Borholmsfjaerden for which these two measures are in parity. The range of the retention times that results from an extreme combination of forcing factor variation between years is found to be greater the farther a particular basin is located from the coast, measured as the minimal number of separating straits. The results of an earlier investigation are also reviewed

  10. Gas exchange rates measured using a dual-tracer (SF6 and3he) method in the coastal waters of Korea

    Science.gov (United States)

    Lee, Hyun-Woo; Lee, Kitack; Kaown, Duk-In

    2008-03-01

    Over a period of 5 days between August 12 and 17, 2005, we performed a gas exchange experiment using the dual tracer method in a tidal coastal ocean located off the southern coast of Korea. The gas exchange rate was determined from temporal changes in the ratio of3He to SF6 measured daily in the surface mixed layer. The measured gas exchange rate ( k CO 2), normalized to a Schmidt number of 600 for CO2 in fresh water at 20°C, was approximately 5.0 cm h-1 at a mean wind speed of 3.9 m s-1 during the study period. This value is significantly less than those obtained from floating chamber-based experiments performed previously in estuarine environments, but is similar in magnitude to values obtained using the dual tracer method in river and tidal coastal waters and values predicted on the basis of the relationship between the gas exchange rate and wind speed (Wanninkhof 1992), which is generally applicable to the open ocean. Our result is also consistent with the relationship of Raymond and Cole (2001), which was derived from experiments carried out in estuarine environments using222Rn and chlorofluorocarbons along with measurements undertaken in the Hudson River, Canada, using SF6 and3He. Our results indicate that tidal action in a microtidal region did not discernibly enhance the measured k CO 2 value.

  11. Surfactant control of air-sea gas exchange from North Sea coastal waters and the Atlantic Meridional Transect

    Science.gov (United States)

    Pereira, R.

    2016-02-01

    Suppression of gas transfer velocity (kw) by surfactants are well established, both in laboratory wind flumes and purposeful oceanic releases. However, the effects on kw of time and space varying concentrations of natural surfactant are inadequately studied. We have developed an automated gas exchange tank for simultaneous high precision measurement of kw in unmodified seawater samples. Here we present data from two studies along a coastal North Sea transect during 2012-2013 and the Atlantic Meridional Transect (AMT) 24 from September to November 2014. Measurements of surfactant activity (SA), CDOM absorbance and chlorophyll-a have enabled us to characterize the effects of variable amounts of natural surfactant on kw. North Sea coastal waters range in k660 (kw normalized to the value for CO2 in freshwater at 20oC) was 6.8-24.5 cm hr-1 (n=20), with the ranges of SA, total CDOM absorbance (200-450 nm) and chlorophyll-a measured in the surface microlayer (SML) of our seawater samples were 0.08-0.38 mg l-1 T-X-100, 0.13-4.7 and 0.09-1.54 µg l-1, respectively. The AMT k660 ranged from 7.0-23.9 cm hr-1 (n=22), with SA measured in the SML and subsurface water (SSW) of our seawater samples ranging from 0.15-1.08 mg l-1 T-X-100 and 0.07-0.43 mg l-1 T-X-100, respectively. Importantly, we found 12-45% (North Sea) and 1-43% (AMT) k660 suppression relative to Milli-Q water that relate to seasonal and spatial differences in SA. The North Sea demonstrated notable seasonal influences on k660 suppression that were related to CDOM absorbance and chlorophyll-a. The degree of k660 suppression was highest in summer consistent with k660 control by natural surfactant. The degree of k660 suppression decreased with distance offshore in the North Sea and displayed a strong relationship with SA (r2 = 0.51-0.64, p = 0.02, n = 20). The AMT demonstrated notable differences in k660 suppression between hemispheres and across the Longhurst Provinces but the overall relationship between k660

  12. Natural radium and radon tracers to quantify water exchange and movement in reservoirs

    Science.gov (United States)

    Smith, Christopher G.; Baskaran, Mark

    2011-01-01

    Radon and radium isotopes are routinely used to quantify exchange rates between different hydrologic reservoirs. Since their recognition as oceanic tracers in the 1960s, both radon and radium have been used to examine processes such as air-sea exchange, deep oceanic mixing, benthic inputs, and many others. Recently, the application of radon-222 and the radium-quartet (223,224,226,228Ra) as coastal tracers has seen a revelation with the growing interest in coastal groundwater dynamics. The enrichment of these isotopes in benthic fluids including groundwater makes both radium and radon ideal tracers of coastal benthic processes (e.g. submarine groundwater discharge). In this chapter we review traditional and recent advances in the application of radon and radium isotopes to understand mixing and exchange between various hydrologic reservoirs, specifically: (1) atmosphere and ocean, (2) deep and shallow oceanic water masses, (3) coastal groundwater/benthic pore waters and surface ocean, and (4) aquifer-lakes. While the isotopes themselves and their distribution in the environment provide qualitative information about the exchange processes, it is mixing/exchange and transport models for these isotopes that provide specific quantitative information about these processes. Brief introductions of these models and mixing parameters are provided for both historical and more recent studies.

  13. Chemical assessment of ballast water exchange compliance: Implementation in North America and New Zealand

    Directory of Open Access Journals (Sweden)

    Monaca eNoble

    2016-05-01

    Full Text Available Fluorescence by naturally occurring dissolved organic matter (FDOM is a sensitive indicator of ballast water source, with high FDOM in coastal ballast water decreasing typically dramatically when replaced by oceanic seawater during ballast water exchange. In this study, FDOM was measured in 92 ships arriving at Pacific ports on the US west coast and in New Zealand, and used to assess their compliance with ballast water regulations that required 95% replacement of port water to minimize invasive species risks. Fluorescence in many ships that reported ballast water exchange was significantly higher than is usual for oceanic seawater, and in several cases, significantly higher than in other ships with similar provenance and ballast water management. Pre-exchange source port conditions represented the largest source of uncertainty in the analysis, because residual coastal FDOM when highly fluorescent can significantly influence the fluorescence signature of exchanged ballast water. A meta-analysis comparing the intensities of FDOM in un-exchanged ballast tanks with calculated pre-exchange intensities assuming that ships all correctly implemented and reported ballast water exchange revealed notable discrepancies. Thus, the incidence of high-FDOM port waters was seven times lower in reality than would be expected on the basis of these calculations. The results suggest that a significant rate of reporting errors occur due to a combination of factors that may include inadequate ballast water exchange and unintentional or deliberate misreporting of ballast water management.

  14. Fate of major radionuclides in the liquid wastes released to coastal waters

    International Nuclear Information System (INIS)

    Bhat, I.S.; Verma, P.C.; Iyer, R.S.; Chandramouli, S.

    1980-01-01

    131 I, 134 Cs, 137 Cs and 60 Co have been reported as the major radionuclides in the low level liquid wastes released to coastal waters from atomic power stations. Silt absorption and desorption of the radionuclides were investigated. The exchangeability of the silt absorbed radionuclides and its dependence on particle size were also studied. More than 80% instantaneous absorpt;.on of 60 Co by suspended silt and less than 5% exchangeability of absorbed 60 Co were observed. Biological uptake of the radionuclides by the marine organisms present in sea waters was studied to evaluate radiation exposure pathways. A few benthic and crustacean organisms wnich are consumed by coastal population as fresh sea food, were observed to concentrate the radionuclides to a greater extent than other organisms. (H.K.)

  15. Hydrogeologic controls on chemical transport at Malibu Lagoon, CA: Implications for land to sea exchange in coastal lagoon systems

    Directory of Open Access Journals (Sweden)

    N. Dimova

    2017-06-01

    New hydrological insights for the region: Nearshore lagoons that are seasonally disconnected from the coastal ocean occupy about 10% of coastal areas worldwide. Lagoon systems often are poorly flushed and thus sensitive to nutrient over-enrichment that can lead to eutrophication, oxygen depletion, and/or pervasive algal blooms. This sensitivity is exacerbated in lagoons that are intermittently closed to surface water exchange with the sea and occur in populous coastal areas. Such estuarine systems are disconnected from the sea during most of the year by wave-built barriers, but during the rainy season these berms can breach, enabling direct water exchange. Using naturally-occurring 222Rn as groundwater tracer, we estimate that groundwater discharge to Malibu Lagoon during open berm conditions was one order of magnitude higher (21 ± 17 cm/day than during closed berm conditions (1.8 ± 1.4 cm/day. The SGD (submarine groundwater discharge into nearshore coastal waters at the SurferRider and Colony Malibu was 4.2 cm/day on average. The exported total dissolved nitrogen (TDN through the berm during closed berm was 1.6 × 10−3 mol/day, whereas during open berm (exported by the Creek was 3.5 × 103 mol/day. Although these evaluations are specific to the collection campaigns the 2009 and 2010 hydro years, these two distinct hydrologic scenarios play an important role in the seasonality and geochemical impact of land/sea exchange, and highlight the sensitivity of such systems to future impacts such as sea level rise and increasing coastal populations.

  16. Isotope exchange between natural and anthropogenic Pb in the coastal waters of Singapore: exchange experiment, Kd model, and implications for the interpretation of coastal 210Pb data

    Science.gov (United States)

    Boyle, E. A.; Chen, M.; Zurbrick, C.; Carrasco, G. G.

    2015-12-01

    Observations from annually-banded corals and seawater samples show that marine lead (Pb) in the coastal waters of Singapore has an isotopic composition that does not match that of the anthropogenic aerosols in this region, unlike what is seen in most parts of the open ocean. The 206Pb/207Pb composition of Singaporean marine Pb is 1.18-1.20 whereas the local aerosols are 1.14-1.16. In order to explore this discrepancy further, we collected a large volume water from the Johor River estuary (flowing from Malaysia to the northern border of Singapore), added a distinct isotope spike (NBS981, 206Pb/207Pb =1.093) to an unfiltered sample, and followed the dissolved isotope composition of the mixture during the following two months. The initial dissolved Pb concentration was 18.3 pmol/kg with 206Pb/207Pb of 1.200. "Total dissolvable" Pb released after acidification of the in the unfiltered sample was 373 pmol/kg with 206Pb/207Pb of 1.199, indicating that there is a large particulate Pb reservoir with an isotopic composition comparable to regional crustal natural Pb. The isotope spike should have brought the dissolved 206Pb/207Pb to 1.162, but less than a day after isotope spiking, the dissolved Pb had risen to 1.181 and continued a slow increase to 1.197 over the next two months. This experiment demonstrates that Johor estuary particulate matter contains a large reservoir of exchangeable Pb that will modify the isotopic composition of deposited aeolian aerosol anthropogenic Pb. We have modeled the evolution of Pb and Pb isotopes in this experiment with a single Kd -type model that assumes that there are two or three different Pb reservoirs with different exchange time constants. This observation has implications for isotope equilibrium between high Pb/210Pb continental particles and low Pb/210Pb ocean waters - what is merely isotope equilibration may appear to be 210Pb scavenging.

  17. Wind Stress Variability Observed Over Coastal Waters

    Science.gov (United States)

    Ortiz-Suslow, D. G.; Haus, B. K.; Laxague, N.; Williams, N. J.; Graber, H. C.

    2016-02-01

    The wind stress on the ocean surface generates waves, drives currents, and enhances gas exchange; and a significant amount of work has been done to characterize the air-sea momentum flux in terms of bulk oceanographic and atmospheric parameters. However, the majority of this work to develop operational algorithms has been focused on the deep ocean and the suitability of these methods in the coastal regime has not been evaluated. The findings from a two-part field campaign will be presented which highlight the divergence of nearshore wind stress observations from conventional, deep water results. The first set of data comes from a coastal region near a relatively small, natural tidal inlet. A high degree of spatial variability was observed in both the wind stress magnitude and direction, suggestive of coastal processes (e.g., depth-limited wave affects and horizontal current shear) modulating the momentum flux from the atmosphere to the ocean surface. These shallow-water processes are typically not accounted for in conventional parameterizations. Across the experimental domain and for a given wind speed, the stress magnitude was found to be nearly 2.5 times that predicted by conventional methods; also, a high propensity for stress steering off the mean azimuthal wind direction (up to ±70 degrees) was observed and linked to horizontal current gradients produced by the tidal inlet. The preliminary findings from a second data set taken in the vicinity of the macrotidal Columbia River Mouth will also be presented. Compared to the first data set, a similar degree of variability is observed here, but the processes responsible for this are present at a much larger scale. Specifically, the Columbia River Mouth observations were made in the presence of significant swell wave energy and during periods of very high estuarine discharge. The relative angle between the wind and swell direction is expected to be significant with regards to the observed momentum flux. Also, these

  18. Metabolism and Gaseous Exchanges in Two Coastal Lagoons from Rio de Janeiro with Distinct Limnological Characteristics

    OpenAIRE

    Sidinei M. Thomaz; Alex Enrich-Prast; José F. Gonçalves Jr.; Anderson M. dos Santos; Francisco A. Esteves

    2001-01-01

    The global metabolism and exchange of gases with the atmosphere were measured during a diel cycle in two tropical coastal lagoons, using the curves of carbon dioxide and dissolved oxygen. Heterotrophic metabolism (net CO2 production and net O2 consumption) was observed in a black water lagoon (Comprida), and autotrophic metabolism (net O2 production and net CO2 consumption) in a clear water lagoon (Imboassica). These differences were attributed to the limnological characteristics of both ecos...

  19. North American coastal carbon stocks and exchanges among the coupled ecosystems of tidal wetlands and estuaries

    Science.gov (United States)

    Windham-Myers, L.; Cai, W. J.

    2017-12-01

    The development of the 2nd State of the Carbon Cycle Report (SOCCR-2) has recognized a significant role of aquatic ecosystems, including coastal zones, in reconciling some of the gaps associated with the North American carbon (C) budget. Along with a large community of coauthors, we report major C stocks and fluxes for tidal wetlands and estuaries of Canada, Mexico and the United States. We find divergent patterns between these coupled ecosystems, with tidal wetlands largely serving as CO2 sinks (net autotrophic), and open-water estuaries largely serving as CO2 sources (net heterotrophic). We summarized measurements across 4 continental regions - East Coast, Gulf of Mexico, West Coast, and High Latitudes - to assess spatial variability and datagaps in our understanding of coastal C cycling. Subtracting estuarine outgassing of 10 ± 10 Tg C yr-1 from the tidal wetland uptake of 23 ± 10 Tg C yr-1 leaves a net uptake of the combined system of 13 ± 14 Tg C yr-1. High uncertainty for net atmospheric C exchange in this combined coastal system is further complicated by spatially and temporally dynamic boundaries, as well as terrestrial C sources. Tidal wetlands are among the most productive ecosystems on earth and are capable of continuously accumulating organic C in their sediments as a result of environmental conditions that inhibit organic matter decomposition. Estuaries have more interannual variability in C dynamics than those of tidal wetlands, reflecting the estuarine balance of exchanges with terrestrial watersheds, tidal wetlands, and the continental shelf. Whereas tidal, subtidal and estuarine maps are of limited accuracy at larger scales, North America likely represents less than 1/10 of global distributions of coastal wetland habitats. Coupled land-ocean C flux models are increasingly robust but lacking much of the data needed for parameterization and validation. Accurate boundary maps and synoptic monitoring data on air-water CO2 exchange may be developed

  20. Nutrient fluxes across sediment-water interface in Bohai Bay Coastal Zone, China.

    Science.gov (United States)

    Mu, Di; Yuan, Dekui; Feng, Huan; Xing, Fangwei; Teo, Fang Yenn; Li, Shuangzhao

    2017-01-30

    Sediment cores and overlying water samples were collected at four sites in Tianjin Coastal Zone, Bohai Bay, to investigate nutrient (N, P and Si) exchanges across the sediment-water interface. The exchange fluxes of each nutrient species were estimated based on the porewater profiles and laboratory incubation experiments. The results showed significant differences between the two methods, which implied that molecular diffusion alone was not the dominant process controlling nutrient exchanges at these sites. The impacts of redox conditions and bioturbation on the nutrient fluxes were confirmed by the laboratory incubation experiments. The results from this study showed that the nutrient fluxes measured directly from the incubation experiment were more reliable than that predicted from the porewater profiles. The possible impacts causing variations in the nutrient fluxes include sewage discharge and land reclamation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Assessing Near-surface Heat, Water Vapor and Carbon Dioxide Exchange Over a Coastal Salt-marsh

    Science.gov (United States)

    Bogoev, I.; O'Halloran, T. L.; LeMoine, J.

    2017-12-01

    Coastal ecosystems play an important role in mitigating the effects of climate change by storing significant quantities of carbon. A growing number of studies suggest that vegetated estuarine habitats, specifically salt marshes, have high long-term rates of carbon sequestration, perhaps even higher than mature tropical and temperate forests. Large amounts of carbon, accumulated over thousands of years, are stored in the plant materials and sediment. Improved understanding of the factors that control energy and carbon exchange is needed to better guide restoration and conservation management practices. To that end, we recently established an observation system to study marsh-atmosphere interactions within the North Inlet-Winyah Bay National Estuarine Research Reserve. Near-surface fluxes of heat, water vapor (H2O) and carbon dioxide (CO2) were measured by an eddy-covariance system consisting of an aerodynamic open-path H2O / CO2 gas analyzer with a spatially integrated 3D sonic anemometer/thermometer (IRGASON). The IRGASON instrument provides co-located and highly synchronized, fast response H2O, CO2 and air- temperature measurements, which eliminates the need for spectral corrections associated with the separation between the sonic anemometer and the gas analyzer. This facilitates calculating the instantaneous CO2 molar mixing ratio relative to dry air. Fluxes computed from CO2 and H2O mixing ratios, which are conserved quantities, do not require post-processing corrections for air-density changes associated with temperature and water vapor fluctuations. These corrections are particularly important for CO2, because they could be even larger than the measured flux. Here we present the normalized frequency spectra of air temperature, water vapor and CO2, as well as their co-spectra with the co-located vertical wind. We also show mean daily cycles of sensible, latent and CO2 fluxes and analyze correlations with air/water temperature, wind speed and light availability.

  2. Dissolved organic carbon pools and export from the coastal ocean

    KAUST Repository

    Barrón, Cristina

    2015-10-21

    The distribution of dissolved organic carbon (DOC) concentration across coastal waters was characterized based on the compilation of 3510 individual estimates of DOC in coastal waters worldwide. We estimated the DOC concentration in the coastal waters that directly exchange with open ocean waters in two different ways, as the DOC concentration at the edge of the shelf break and as the DOC concentration in coastal waters with salinity close to the average salinity in the open ocean. Using these estimates of DOC concentration in the coastal waters that directly exchange with open ocean waters, the mean DOC concentration in the open ocean and the estimated volume of water annually exchanged between coastal and open ocean, we estimated a median ± SE (and average ± SE) global DOC export from coastal to open ocean waters ranging from 4.4 ± 1.0 Pg C yr−1 to 27.0 ± 1.8 Pg C yr−1 (7.0 ± 5.8 Pg C yr−1 to 29.0 ± 8.0 Pg C yr−1) depending on the global hydrological exchange. These values correspond to a median and mean median (and average) range between 14.7 ± 3.3 to 90.0 ± 6.0 (23.3 ± 19.3 to 96.7 ± 26.7) Gg C yr−1 per km of shelf break, which is consistent with the range between 1.4 to 66.1 Gg C yr−1 per km of shelf break of available regional estimates of DOC export. The estimated global DOC export from coastal to open ocean waters is also consistent with independent estimates of the net metabolic balance of the coastal ocean. The DOC export from the coastal to the open ocean is likely to be a sizeable flux and is likely to be an important term in the carbon budget of the open ocean, potentially providing an important subsidy to support heterotrophic activity in the open ocean.

  3. Dissolved organic carbon pools and export from the coastal ocean

    KAUST Repository

    Barró n, Cristina; Duarte, Carlos M.

    2015-01-01

    The distribution of dissolved organic carbon (DOC) concentration across coastal waters was characterized based on the compilation of 3510 individual estimates of DOC in coastal waters worldwide. We estimated the DOC concentration in the coastal waters that directly exchange with open ocean waters in two different ways, as the DOC concentration at the edge of the shelf break and as the DOC concentration in coastal waters with salinity close to the average salinity in the open ocean. Using these estimates of DOC concentration in the coastal waters that directly exchange with open ocean waters, the mean DOC concentration in the open ocean and the estimated volume of water annually exchanged between coastal and open ocean, we estimated a median ± SE (and average ± SE) global DOC export from coastal to open ocean waters ranging from 4.4 ± 1.0 Pg C yr−1 to 27.0 ± 1.8 Pg C yr−1 (7.0 ± 5.8 Pg C yr−1 to 29.0 ± 8.0 Pg C yr−1) depending on the global hydrological exchange. These values correspond to a median and mean median (and average) range between 14.7 ± 3.3 to 90.0 ± 6.0 (23.3 ± 19.3 to 96.7 ± 26.7) Gg C yr−1 per km of shelf break, which is consistent with the range between 1.4 to 66.1 Gg C yr−1 per km of shelf break of available regional estimates of DOC export. The estimated global DOC export from coastal to open ocean waters is also consistent with independent estimates of the net metabolic balance of the coastal ocean. The DOC export from the coastal to the open ocean is likely to be a sizeable flux and is likely to be an important term in the carbon budget of the open ocean, potentially providing an important subsidy to support heterotrophic activity in the open ocean.

  4. The "shallow-waterness" of the wave climate in European coastal regions

    Science.gov (United States)

    Håkon Christensen, Kai; Carrasco, Ana; Bidlot, Jean-Raymond; Breivik, Øyvind

    2017-07-01

    In contrast to deep water waves, shallow water waves are influenced by bottom topography, which has consequences for the propagation of wave energy as well as for the energy and momentum exchange between the waves and the mean flow. The ERA-Interim reanalysis is used to assess the fraction of wave energy associated with shallow water waves in coastal regions in Europe. We show maps of the distribution of this fraction as well as time series statistics from eight selected stations. There is a strong seasonal dependence and high values are typically associated with winter storms, indicating that shallow water wave effects can occasionally be important even in the deeper parts of the shelf seas otherwise dominated by deep water waves.

  5. Uranium from sea-water. Possibilities of recovery, exploiting slow coastal currents

    International Nuclear Information System (INIS)

    Bettinali, C.; Pantanetti, F.

    1976-01-01

    The authors analyse the interest in uranium recovery from sea-water within the framework of uranium world supply problems. The most reliable methods proposed for recovery are summarized and discussed, both from the chemical and the plant project points of view. Tides as a source of energy for water movement cannot be used in the Mediterranean and therefore only currents can be taken into account. The acceptable cost of an exchanger, in relation to the uranium price, is considered and related to known exchangers. The characteristics of exchanging elements are examined and the influence of the speed of sea currents discussed. The extractable uranium is a function of the exchange rate and of the speed of the flow inside the exchanging system; therefore it is quite clear that the current speed is not a prerequisite and that coastal currents around Italy are suitable. Exchanging elements built with sheets parallel to the flow, exchanging pans containing granular or fibrous exchangers have been considered. The main characteristics of a 1000 t/a plant are discussed considering different possibilities. The most acceptable seems to be the continuous extraction system. The parameters needed to calculate the dimensions of such a plant are given and the relation between the length and speed of the moving chain discussed. A rough economic evaluation of the plant cost - starting from known technologies - and of the final cost of the uranium oxide produced is made. (author)

  6. Coastal surface water suitability analysis for irrigation in Bangladesh

    Science.gov (United States)

    Mahtab, Mohammad Hossain; Zahid, Anwar

    2018-03-01

    Water with adequate quality and quantity is very important for irrigation to ensure the crop yields. Salinity is common problem in the coastal waters in Bangladesh. The intensity of salinity in the coastal zone in Bangladesh is not same. It fluctuates over the year. Sodium is another hazard which may hamper permeability and ultimately affects the fertility. It can reduce the crop yields. Although surface water is available in the coastal zone of Bangladesh, but its quality for irrigation needs to be monitored over the year. This paper will investigate the overall quality of coastal surface waters. Thirty-three water samples from different rivers were collected both in wet period (October-December) and in dry period (February-April). Different physical and chemical parameters are considered for investigation of the adequacy of water with respect to international irrigation water quality standards and Bangladesh standards. A comparison between the dry and wet period coastal surface water quality in Bangladesh will also be drawn here. The analysis shows that coastal surface water in Bangladesh is overall suitable for irrigation during wet period, while it needs treatment (which will increase the irrigation cost) for using for irrigation during dry period. Adaptation to this situation can improve the scenario. An integrated plan should be taken to increase the water storing capacity in the coastal area to harvest water during wet period.

  7. Spatial variation in sediment-water exchange of phosphorus in Florida Bay: AMP as a model organic compound.

    Science.gov (United States)

    Huang, Xiao-Lan; Zhang, Jia-Zhong

    2010-10-15

    Dissolved organic phosphorus (DOP) has been recognized as dominant components in total dissolved phosphorus (TDP) pools in many coastal waters, and its exchange between sediment and water is an important process in biogeochemical cycle of phosphorus. Adenosine monophosphate (AMP) was employed as a model DOP compound to simulate phosphorus exchange across sediment-water interface in Florida Bay. The sorption data from 40 stations were fitted to a modified Freundlich equation and provided a detailed spatial distribution both of the sediment's zero equilibrium phosphorus concentration (EPC(0-T)) and of the distribution coefficient (K(d-T)) with respect to TDP. The K(d-T) was found to be a function of the index of phosphorus saturation (IPS), a molar ratio of the surface reactive phosphorus to the surface reactive iron oxide content in the sediment, across the entire bay. However, the EPC(0-T) was found to correlate to the contents of phosphorus in the eastern bay only. Sediment in the western bay might act as a source of the phosphorus in the exchange process due to their high EPC(0-T) and low K(d-T), whereas sediments in the eastern bay might act as a sink because of their low EPC(0-T) and high K(d-T). These results strongly support the hypothesis that both phosphorus and iron species in calcareous marine sediments play a critical role in governing the sediment-water exchange of both phosphate and DOP in the coastal and estuarine ecosystems.

  8. Study on water quality around mangrove ecosystem for coastal rehabilitation

    Science.gov (United States)

    Guntur, G.; Sambah, A. B.; Arisandi, D. M.; Jauhari, A.; Jaziri, A. A.

    2018-01-01

    Coastal ecosystems are vulnerable to environmental degradation including the declining water quality in the coastal environment due to the influence of human activities where the river becomes one of the input channels. Some areas in the coastal regions of East Java directly facing the Madura Strait indicate having experienced the environmental degradation, especially regarding the water quality. This research was conducted in the coastal area of Probolinggo Regency, East Java, aiming to analyze the water quality as the basis for coastal rehabilitation planning. This study was carried out using survey and observation methods. Water quality measurement results were analyzed conforming to predetermined quality standards. The coastal area rehabilitation planning as a means to restore the degraded water quality parameters is presumably implemented through mangrove planting. Thus, the mangrove mapping was also devised in this research. Based on 40 sampling points, the results illustrate that according to the quality standard, the water quality in the study area is likely to be deteriorated. On account of the mapping analysis of mangrove distribution in the study area, the rehabilitation of the coastal zone can be done through planning the mangrove forest plantation. The recommended coastal area maintenance is a periodic water quality observation planning in the river region which is divided into three zones to monitor the impact of fluctuating changes in land use or human activities on the coastal water quality.

  9. MODIS Retrieval of Aerosol Optical Depth over Turbid Coastal Water

    Directory of Open Access Journals (Sweden)

    Yi Wang

    2017-06-01

    Full Text Available We present a new approach to retrieve Aerosol Optical Depth (AOD using the Moderate Resolution Imaging Spectroradiometer (MODIS over the turbid coastal water. This approach supplements the operational Dark Target (DT aerosol retrieval algorithm that currently does not conduct AOD retrieval in shallow waters that have visible sediments or sea-floor (i.e., Class 2 waters. Over the global coastal water regions in cloud-free conditions, coastal screening leads to ~20% unavailability of AOD retrievals. Here, we refine the MODIS DT algorithm by considering that water-leaving radiance at 2.1 μm to be negligible regardless of water turbidity, and therefore the 2.1 μm reflectance at the top of the atmosphere is sensitive to both change of fine-mode and coarse-mode AODs. By assuming that the aerosol single scattering properties over coastal turbid water are similar to those over the adjacent open-ocean pixels, the new algorithm can derive AOD over these shallow waters. The test algorithm yields ~18% more MODIS-AERONET collocated pairs for six AERONET stations in the coastal water regions. Furthermore, comparison of the new retrieval with these AERONET observations show that the new AOD retrievals have equivalent or better accuracy than those retrieved by the MODIS operational algorithm’s over coastal land and non-turbid coastal water product. Combining the new retrievals with the existing MODIS operational retrievals yields an overall improvement of AOD over those coastal water regions. Most importantly, this refinement extends the spatial and temporal coverage of MODIS AOD retrievals over the coastal regions where 60% of human population resides. This expanded coverage is crucial for better understanding of impact of anthropogenic aerosol particles on coastal air quality and climate.

  10. An optical method to assess water clarity in coastal waters.

    Science.gov (United States)

    Kulshreshtha, Anuj; Shanmugam, Palanisamy

    2015-12-01

    Accurate estimation of water clarity in coastal regions is highly desired by various activities such as search and recovery operations, dredging and water quality monitoring. This study intends to develop a practical method for estimating water clarity based on a larger in situ dataset, which includes Secchi depth (Z sd ), turbidity, chlorophyll and optical properties from several field campaigns in turbid coastal waters. The Secchi depth parameter is found to closely vary with the concentration of suspended sediments, vertical diffuse attenuation coefficient K d (m(-1)) and beam attenuation coefficient c (m(-1)). The optical relationships obtained for the selected wavelengths (i.e. 520, 530 and 540 nm) exhibit an inverse relationship between Secchi depth and the length attenuation coefficient (1/(c + K d )). The variation in Secchi depth is expressed in terms of undetermined coupling coefficient which is composed of light penetration factor (expressed by z(1%)K d (λ)) and a correction factor (ξ) (essentially governed by turbidity of the water column). This method of estimating water clarity was validated using independent in situ data from turbid coastal waters, and its results were compared with those obtained from the existing methods. The statistical analysis of the measured and the estimated Z sd showed that the present method yields lower error when compared to the existing methods. The spatial structures of the measured and predicted Z sd are also highly consistent with in situ data, which indicates the potential of the present method for estimating the water clarity in turbid coastal and associated lagoon waters.

  11. The role of ocean tides on groundwater-surface water exchange in a mangrove-dominated estuary: Shark River Slough, Florida Coastal Everglades, USA

    Science.gov (United States)

    Smith, Christopher G.; Price, René M.; Swarzenski, Peter W.; Stalker, Jeremy C.

    2016-01-01

    Low-relief environments like the Florida Coastal Everglades (FCE) have complicated hydrologic systems where surface water and groundwater processes are intimately linked yet hard to separate. Fluid exchange within these lowhydraulic-gradient systems can occur across broad spatial and temporal scales, with variable contributions to material transport and transformation. Identifying and assessing the scales at which these processes operate is essential for accurate evaluations of how these systems contribute to global biogeochemical cycles. The distribution of 222Rn and 223,224,226Ra have complex spatial patterns along the Shark River Slough estuary (SRSE), Everglades, FL. High-resolution time-series measurements of 222Rn activity, salinity, and water level were used to quantify processes affecting radon fluxes out of the mangrove forest over a tidal cycle. Based on field data, tidal pumping through an extensive network of crab burrows in the lower FCE provides the best explanation for the high radon and fluid fluxes. Burrows are irrigated during rising tides when radon and other dissolved constituents are released from the mangrove soil. Flushing efficiency of the burrows—defined as the tidal volume divided by the volume of burrows— estimated for the creek drainage area vary seasonally from 25 (wet season) to 100 % (dry season) in this study. The tidal pumping of the mangrove forest soil acts as a significant vector for exchange between the forest and the estuary. Processes that enhance exchange of O2 and other materials across the sediment-water interface could have a profound impact on the environmental response to larger scale processes such as sea level rise and climate change. Compounding the material budgets of the SRSE are additional inputs from groundwater from the Biscayne Aquifer, which were identified using radium isotopes. Quantification of the deep groundwater component is not obtainable, but isotopic data suggest a more prevalent signal in the dry

  12. 226Ra and 228Ra tracer study on nutrient transport in east coastal waters of Hainan Island, China

    Directory of Open Access Journals (Sweden)

    Ni Su

    2011-06-01

    Full Text Available Material fluxes (e.g., nutrients from coastal waters to offshore areas play an important role in controlling the water quality of the adjacent sea areas not only by increasing nutrient concentration but also by changing nutrient structures. In this study, naturally occurring isotopes, 226Ra and 228Ra, were measured with the alpha spectrometry in the Wenjiao-Wenchang and Wanquan estuaries and adjacent sea areas along the east coast of Hainan Island. The excess 226Ra and 228Ra activities were observed by comparison with the values derived from the conservative mixing of freshwater and seawater end-members in both estuaries. Using a one-dimensional diffusion model, the horizontal eddy diffusion coefficient of 3.16 x 105 cm2/s, for nutrients diffusing from their sources, was derived from 228Ra activities. Consequently, the corresponding nutrient fluxes flowing into the coastal waters were assessed. The results can provide useful information for the study of the mixing and exchange processes of coastal waters as well as dissoluble pollutant transport in this sea area.

  13. Seasonal variations in 228Ra/226Ra ratio within coastal waters of the Sea of Japan: implications for water circulation patterns in coastal areas

    International Nuclear Information System (INIS)

    Inoue, M.; Tanaka, K.; Watanabe, S.; Kofuji, H.; Yamamoto, M.; Komura, K.

    2006-01-01

    In this study, low-background γ-spectrometry was used to determine the 228 Ra/ 226 Ra ratio of 131 coastal water samples from various environments around Honshu Island, Japan (mainly around Noto Peninsula) at 1-3 month intervals from April 2003 until September 2005. Spatial variation in 228 Ra/ 226 Ra ratios was also assessed by analyzing 34 coastal water samples from five areas within the Sea of Japan during May and June 2004. The 228 Ra/ 226 Ra ratio of coastal water from all sites around Noto Peninsula shows seasonal variation, with minimum values during summer ( 228 Ra/ 226 Ra = 0.7) and maximum values during autumn-winter ( 228 Ra/ 226 Ra = 1.7-2). This seasonal variation is similar to that recorded for coastal water between Tsushima Strait and Noto Peninsula. The measured lateral variation in 228 Ra/ 226 Ra ratios within coastal water between Tsushima Strait and Noto Peninsula is only minor (0.5-0.7; May-June 2004). Coastal waters from two other sites (Pacific shore and Tsugaru Strait, north Honshu) show no clear seasonal variation in 228 Ra/ 226 Ra ratio. These measured variations in 228 Ra/ 226 Ra ratio, especially the temporal variations, have important implications for seasonal changes in patterns of coastal water circulation within the Sea of Japan

  14. Hydrologic exchanges and baldcypress water use on deltaic hummocks, Louisiana, USA

    Science.gov (United States)

    Hsueh, Yu-Hsin; Chambers, Jim L.; Krauss, Ken W.; Allen, Scott T.; Keim, Richard F.

    2016-01-01

    Coastal forested hummocks support clusters of trees in the saltwater–freshwater transition zone. To examine how hummocks support trees in mesohaline sites that are beyond physiological limits of the trees, we used salinity and stable isotopes (2H and 18O) of water as tracers to understand water fluxes in hummocks and uptake by baldcypress (Taxodium distichum (L.) Rich.), which is the most abundant tree species in coastal freshwater forests of the southeastern U.S. Hummocks were always partially submerged and were completely submerged 1 to 8% of the time during the two studied growing seasons, in association with high water in the estuary. Salinity, δ18O, and δ2H varied more in the shallow open water than in groundwater. Surface water and shallow groundwater were similar to throughfall in isotopic composition, which suggested dominance by rainfall. Salinity of groundwater in hummocks increased with depth, was higher than in swales, and fluctuated little over time. Isotopic composition of xylem water in baldcypress was similar to the vadose zone and unlike other measured sources, indicating that trees preferentially use unsaturated hummock tops as refugia from higher salinity and saturated soil in swales and the lower portions of hummocks. Sustained upward gradients of salinity from groundwater to surface water and vadose water, and low variation in groundwater salinity and isotopic composition, suggested long residence time, limited exchange with surface water, and that the shallow subsurface of hummocks is characterized by episodic salinization and slow dilution.

  15. Seasonal characteristics of water exchange in Beibu Gulf based on a particle tracking model

    Science.gov (United States)

    Wang, L.; Pan, W.; Yan, X.

    2016-12-01

    A lagrangian particle tracking model coupled with a three-dimensional Marine Environmental Committee Ocean Model (MEC) is used to study the transport and seasonal characteristics of water exchange in Beibu Gulf. The hydrodynamic model (MEC), which is forced with the daily surface and lateral boundary fluxes, as well as tidal harmonics and monthly climatological river discharges, is applied to simulate the flow field in the gulf during 2014. Using these results, particle tracking method which includes tidal advection and random walk in the horizontal is used to determine the residence times of sub regions within the gulf in response of winter and summer wind forcing. The result shows water exchange processes in the gulf have a similar tendency with seasonal circulation structure. During the sourthwestly prevailing wind in summer, water particles are traped within the gulf that considerably increases the residence time of each sub region. On the contrary, the presence of strong northeastly prevailing wind in winter drives particles to move cyclonicly leading to shorter residence times and rather active water exchanges among sub regions. Similarly, particle tracking is applied to investigate the water transport in Beibu Gulf. As Qiongzhou Strait and the wide opening in the south of the gulf are two significant channels connecting with the open ocean, continuous particle releases are simulated to quantify the influence range and the pathways of these sources water flowing into Beibu Gulf. The results show that water particles originated from Qiongzhou Strait are moving westward due to the year-round strong westward flow transportation. Influencing range in the north of the Beibu Gulf is enlarged by winter northeastly wind, however, it is blocked to the Leizhou Peninsula coastal region by summer westly wind. In the south opening, water particles are transported northward into the gulf along Hainan Island and flushed from Vietnam coastal region to the ocean rapidly by

  16. Front-Eddy Influence on Water Column Properties, Phytoplankton Community Structure, and Cross-Shelf Exchange of Diatom Taxa in the Shelf-Slope Area off Concepción (˜36-37°S)

    Science.gov (United States)

    Morales, Carmen E.; Anabalón, Valeria; Bento, Joaquim P.; Hormazabal, Samuel; Cornejo, Marcela; Correa-Ramírez, Marco A.; Silva, Nelson

    2017-11-01

    In eastern boundary current systems (EBCSs), submesoscale to mesocale variability contributes to cross-shore exchanges of water properties, nutrients, and plankton. Data from a short-term summer survey and satellite time series (January-February 2014) were used to characterize submesoscale variability in oceanographic conditions and phytoplankton distribution across the coastal upwelling and coastal transition zones north of Punta Lavapié, and to explore cross-shelf exchanges of diatom taxa. A thermohaline front (FRN-1) flanked by a mesoscale anticyclonic intrathermocline eddy (ITE-1), or mode-water eddy, persisted during the time series and the survey was undertaken during a wind relaxation event. At the survey time, ITE-1 contributed to an onshore intrusion of warm oceanic waters (southern section) and an offshore advection of cold coastal waters (northern section), with the latter forming a cold, high chlorophyll-a filament. In situ phytoplankton and diatom biomasses were highest at the surface in FRN-1 and at the subsurface in ITE-1, whereas values in the coastal zone were lower and dominated by smaller cells. Diatom species typical of the coastal zone and species dominant in oceanic waters were both found in the FRN-1 and ITE-1 interaction area, suggesting that this mixture was the result of both offshore and onshore advection. Overall, front-eddy interactions in EBCSs could enhance cross-shelf exchanges of coastal and oceanic plankton, as well as sustain phytoplankton growth in the slope area through localized upward injections of nutrients in the frontal zone, combined with ITE-induced advection and vertical nutrient inputs to the surface layer.

  17. Physico-chemical and biological water quality of karachi coastal water

    International Nuclear Information System (INIS)

    Khalid, A.; Rahman, S.

    2009-01-01

    Physiochemical and biological techniques have been applied to investigate Karachi Coastal water pollution due to Layari and Malir rivers, which mainly carry Karachi Metropolitan domestic and industrial wastewater. In Manora channel, which receives domestic sewage through Layari river, pH and electrical conductivity (E.C.) of seawater were less in low tide conditions as compared to high tide condition, and except for Manora Lighthouse all sampling stations exhibit E.C. below normal values of seawater, indicating fair proportion of Layari river water mixing in seawater. Coliform contamination ranged from 156 - 542 per 100 ml ( high tide) and 132- 974 per 100 ml (low tide) with increased levels observed in sampling sites close to Layari river outfall zone. Along Southeast coast, a decrease in EC was recorded at Ghizri area and Ibrahim Haideri fish harbour in low tide which indicated Malir river water input. Coliform bacterial counts at these locations were also above WHO guidelines for seawater bathing. pH and electrical conductivity values of Northwest coastal water indicated that this coast is marginally polluted. The study revealed that Karachi Metropolitan domestic sewage and industrial effluents are main source of coastal water pollution. (author)

  18. Definition of water exchange zone between the Bohai Sea and Yellow Sea and the effect of winter gale on it

    Institute of Scientific and Technical Information of China (English)

    SONG Jun; GUO Junru; LI Jing; MU Lin; LIU Yulong; WANG Guosong; LI Yan; LI Huan

    2017-01-01

    The marine dynamic environment of the Bohai Sea and the Yellow Sea in the winter of 2006 is simulated by the Regional Ocean Modelling System (ROMS) marine numerical model. Using the simulated temperature and salinity, the water exchange zone between the Bohai Sea and Yellow Sea is defined through the Spectral Mixture Model (SMM). The influence of winter gales on the water exchange is also discussed. It is found that the Yellow Sea water masses in winter are distributed in a “tongue” shape in the Bohai Strait region, the water exchange zone presents a zonal distribution along the margin of the “tongue”, with a tendency of running from northwest to southeast, and the water exchange is intensified at the tip of the “tongue”. Besides, the coastal area in the northernmost Yellow Sea does not participate in the water exchange between the Bohai Sea and Yellow Sea. The result shows that the winter gale events play a role in enhancing the water exchange. It is specifically shown by the facts: the Yellow Sea warm current is enhanced to intrude the Bohai Sea by the gale process; the water exchange zone extends into the Bohai Sea; the water exchange belt in the southern part becomes wider; the mixture zone of river runoff with the Bohai Sea water upon its entry is enlarged and shifts northwards. Within two days after the gale process, the exchange zone retreats toward the Yellow Sea and the exchange zone resulted from the Huanghe River (Yellow River) runoff also shrinks back shoreward.

  19. The effects of precipitation, river discharge, land use and coastal circulation on water quality in coastal Maine.

    Science.gov (United States)

    Tilburg, Charles E; Jordan, Linda M; Carlson, Amy E; Zeeman, Stephan I; Yund, Philip O

    2015-07-01

    Faecal pollution in stormwater, wastewater and direct run-off can carry zoonotic pathogens to streams, rivers and the ocean, reduce water quality, and affect both recreational and commercial fishing areas of the coastal ocean. Typically, the closure of beaches and commercial fishing areas is governed by the testing for the presence of faecal bacteria, which requires an 18-24 h period for sample incubation. As water quality can change during this testing period, the need for accurate and timely predictions of coastal water quality has become acute. In this study, we: (i) examine the relationship between water quality, precipitation and river discharge at several locations within the Gulf of Maine, and (ii) use multiple linear regression models based on readily obtainable hydrometeorological measurements to predict water quality events at five coastal locations. Analysis of a 12 year dataset revealed that high river discharge and/or precipitation events can lead to reduced water quality; however, the use of only these two parameters to predict water quality can result in a number of errors. Analysis of a higher frequency, 2 year study using multiple linear regression models revealed that precipitation, salinity, river discharge, winds, seasonality and coastal circulation correlate with variations in water quality. Although there has been extensive development of regression models for freshwater, this is one of the first attempts to create a mechanistic model to predict water quality in coastal marine waters. Model performance is similar to that of efforts in other regions, which have incorporated models into water resource managers' decisions, indicating that the use of a mechanistic model in coastal Maine is feasible.

  20. Turn on, fade out - methane exchange in a coastal fen over a period of six years after rewetting

    Science.gov (United States)

    Jurasinski, Gerald; Glatzel, Stephan; Hahn, Juliane; Koch, Stefan; Koch, Marian; Koebsch, Franziska

    2016-04-01

    The rewetting of drained peatlands is widely regarded as an adequate measure for the mitigation of greenhouse gas emissions. Therefore, especially in NE Germany, many peatlands are being rewetted. Our knowledge about greenhouse gas exchange associated with rewetting is mainly based on short-term experiments or space-for-time substitutions. These approaches do not consider the transient character of ecosystem acclimatization to flooding by rewetting. Moreover data in this regard on coastal peatland ecosystems are sparse. Here, we present 7 years of data on CH4-exchange in a coastal fen after rewetting by flooding. On the site „Rodewiese", which is located within the NSG "Hütelmoor und Heiligensee" in the Northeast of Rostock, NE Germany, we have established a long term research observatory addressing atmospheric C-exchange. The site is part of the TERENO network. Since summer 2009 we determine CH4 fluxes with closed chambers distributed widely across the study site and CO2-exchange with eddy covariance as well as ancillary data on vegetation, hydrology, and biogeochemistry. This talk addresses the CH4-exchange over time whereas CO2-exchange data are presented by Koebsch et al. in the same session. Rewetting turned the site from a summer dry fen with mean annual water levels of around -0.08m into a shallow lake with water levels up to 0.60m. In the first year after flooding, we observed a substantial die-back of vegetation, especially in stands of Carex acutiformis. Flooding increased methane release rates to extremely high levels of up to 4.3 t ha-1 a-1 for sedge stands and 2.7 t ha-1 a-1 on average, which amounts to 75.6 t ha-1 a-1 in CO2-equivalents. Thereafter, the averaged annual CH4 emissions decreased asymptotically and where at an average of 0.5 t ha-1 a-1 (14 t ha-1 a-1 in CO2-equivalents) in 2015. Factoring in the NEE of the growing season (from Eddy measurements) suggests that the system may be slightly above neutral with respect to the greenhouse

  1. Wintertime dynamics in the coastal northeastern Adriatic Sea: the NAdEx 2015 experiment

    Directory of Open Access Journals (Sweden)

    I. Vilibić

    2018-03-01

    Full Text Available The paper investigates the wintertime dynamics of the coastal northeastern Adriatic Sea and is based on numerical modelling and in situ data collected through field campaigns executed during the winter and spring of 2015. The data were collected with a variety of instruments and platforms (acoustic Doppler current profilers, conductivity–temperature–depth probes, glider, profiling float and are accompanied by the atmosphere–ocean ALADIN/ROMS modelling system. The research focused on the dense-water formation (DWF, thermal changes, circulation, and water exchange between the coastal and open Adriatic. According to both observations and modelling results, dense waters are formed in the northeastern coastal Adriatic during cold bora outbreaks. However, the dense water formed in this coastal region has lower densities than the dense water formed in the open Adriatic due to lower salinities. Since the coastal area is deeper than the open Adriatic, the observations indicate (i balanced inward–outward exchange at the deep connecting channels of denser waters coming from the open Adriatic DWF site and less-dense waters coming from the coastal region and (ii outward flow of less-dense waters dominating in the intermediate and surface layers. The latter phenomenon was confirmed by the model, even if it significantly underestimates the currents and transports in the connecting channels. The median residence time of the coastal area is estimated to be approximately 20 days, indicating that the coastal area may be renewed relatively quickly by the open Adriatic waters. The data that were obtained represent a comprehensive marine dataset that can be used to calibrate atmospheric and oceanic numerical models and point to several interesting phenomena to be investigated in the future.

  2. Wintertime dynamics in the coastal northeastern Adriatic Sea: the NAdEx 2015 experiment

    Science.gov (United States)

    Vilibić, Ivica; Mihanović, Hrvoje; Janeković, Ivica; Denamiel, Cléa; Poulain, Pierre-Marie; Orlić, Mirko; Dunić, Natalija; Dadić, Vlado; Pasarić, Mira; Muslim, Stipe; Gerin, Riccardo; Matić, Frano; Šepić, Jadranka; Mauri, Elena; Kokkini, Zoi; Tudor, Martina; Kovač, Žarko; Džoić, Tomislav

    2018-03-01

    The paper investigates the wintertime dynamics of the coastal northeastern Adriatic Sea and is based on numerical modelling and in situ data collected through field campaigns executed during the winter and spring of 2015. The data were collected with a variety of instruments and platforms (acoustic Doppler current profilers, conductivity-temperature-depth probes, glider, profiling float) and are accompanied by the atmosphere-ocean ALADIN/ROMS modelling system. The research focused on the dense-water formation (DWF), thermal changes, circulation, and water exchange between the coastal and open Adriatic. According to both observations and modelling results, dense waters are formed in the northeastern coastal Adriatic during cold bora outbreaks. However, the dense water formed in this coastal region has lower densities than the dense water formed in the open Adriatic due to lower salinities. Since the coastal area is deeper than the open Adriatic, the observations indicate (i) balanced inward-outward exchange at the deep connecting channels of denser waters coming from the open Adriatic DWF site and less-dense waters coming from the coastal region and (ii) outward flow of less-dense waters dominating in the intermediate and surface layers. The latter phenomenon was confirmed by the model, even if it significantly underestimates the currents and transports in the connecting channels. The median residence time of the coastal area is estimated to be approximately 20 days, indicating that the coastal area may be renewed relatively quickly by the open Adriatic waters. The data that were obtained represent a comprehensive marine dataset that can be used to calibrate atmospheric and oceanic numerical models and point to several interesting phenomena to be investigated in the future.

  3. Isotopically exchangeable Al in coastal lowland acid sulfate soils

    Energy Technology Data Exchange (ETDEWEB)

    Yvanes-Giuliani, Yliane A.M. [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia); Centre Européen de Recherche et d' Enseignement des Géosciences de l' Environnement, Aix-Marseille Université, Aix en Provence (France); Fink, D. [Centre Européen de Recherche et d' Enseignement des Géosciences de l' Environnement, Aix-Marseille Université, Aix en Provence (France); Rose, J. [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Waite, T. David [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia); Collins, Richard N., E-mail: richard.collins@unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW 2052 (Australia)

    2016-01-15

    Periodic discharges of high concentrations of aluminium (Al) causing fish kills and other adverse effects occur worldwide in waterways affected by coastal lowland acid sulfate soils (CLASS). The exchangeability — a metal's ability to readily transfer between the soil solid- and solution-phases — of Al in these soils is therefore of particular importance as it has implications for metal transport, plant availability and toxicity to living organisms. In the present study, the concentrations of isotopically exchangeable Al (E values) were measured in 27 CLASS and compared with common salt extractions (i.e. KCl and CuCl{sub 2}) used to estimate exchangeable soil pools of Al. E values of Al were high in the soils, ranging from 357 to 3040 mg·kg{sup −1}. Exchangeable concentrations estimated using 1 M KCl were consistently lower than measured E values, although a reasonable correlation was obtained between the two values (E = 1.68 × Al{sub KCl}, r{sup 2} = 0.66, n = 25). The addition of a 0.2 M CuCl{sub 2} extraction step improved the 1:1 agreement between extractable and isotopically exchangeable Al concentrations, but lead to significant mobilisation of non-isotopically exchangeable Al in surficial ‘organic-rich’ CLASS having E values < 1000 mg·kg{sup −1}. It was concluded that currently used (i.e. 1 M KCl) methodology severely underestimates exchangeable Al and total actual acidity values in CLASS and should be corrected by a factor similar to the one determined here. - Highlights: • Isotopically exchangeable Al was compared to 1 M KCl or 0.2 M CuCl{sub 2} extractable Al. • 1 M KCl always underestimated isotopically exchangeable Al concentrations. • 0.2 M CuCl{sub 2} mobilised non-isotopically exchangeable Al • 1 M KCl values require correction of ~ 1.7 to reflect exchangeable Al concentrations.

  4. Diffusion of tritiated water in coastal areas

    International Nuclear Information System (INIS)

    Fukuda, M.; Kasai, A.; Imai, T.; Amano, H.; Yanase, N.

    1980-01-01

    The diffusion of tritiated water discharged by Japan Atomic Energy Research Institute at shore line has been investigated. In continuous discharge, the concentration of tritiated water in samples taken at a point downstream fluctuates largely. To reveal the cause, dye diffusion experiments were made in the coastal area. The shapes of dye cloud were photographed by a remote-control camera suspended from a captive balloon as color pictures. The movement of dye is so complex that a three-dimensional model must be employed to assess the diffusion in coastal areas

  5. Stable lead isotopes as a tracer in coastal waters

    International Nuclear Information System (INIS)

    Stukas, V.J.; Wong, C.S.

    1981-01-01

    The natural abundances of the stable isotopes of lead are used to identify natural and industrial sources of lead in the coastal waters of British Columbia, Canada. The 206 Pb/ 207 Pb ratios, used to characterize the lead source, had values of approx. 1.24 for coastal oceanic water, approx. 1.22 for fjord waters receiving lead from mine tailings, and approx. 1.163 for waters near urban centers. The lead concentration data are in agreement with presently accepted seawater values

  6. Radiative transfer modeling of upwelling light field in coastal waters

    International Nuclear Information System (INIS)

    Sundarabalan, Balasubramanian; Shanmugam, Palanisamy; Manjusha, Sadasivan

    2013-01-01

    Numerical simulations of the radiance distribution in coastal waters are a complex problem, but playing a growingly important role in optical oceanography and remote sensing applications. The present study attempts to modify the Inherent Optical Properties (IOPs) to allow the phase function to vary with depth, and the bottom boundary to take into account a sloping/irregular surface and the effective reflectance of the bottom material. It then uses the Hydrolight numerical model to compute Apparent Optical Properties (AOPs) for modified IOPs and bottom boundary conditions compared to the default values available in the standard Hydrolight model. The comparison of the profiles of upwelling radiance simulated with depth-dependent IOPs as well as modified bottom boundary conditions for realistic cases of coastal waters off Point Calimere of southern India shows a good match between the simulated and measured upwelling radiance profile data, whereas there is a significant drift between the upwelling radiances simulated from the standard Hydrolight model (with default values) and measured data. Further comparison for different solar zenith conditions at a coastal station indicates that the upwelling radiances simulated with the depth-dependent IOPs and modified bottom boundary conditions are in good agreement with the measured radiance profile data. This simulation captures significant changes in the upwelling radiance field influenced by the bottom boundary layer as well. These results clearly emphasize the importance of using realistic depth-dependent IOPs as well as bottom boundary conditions as input to Hydrolight in order to obtain more accurate AOPs in coastal waters. -- Highlights: ► RT model with depth-dependent IOPs and modified bottom boundary conditions provides accurate L u profiles in coastal waters. ► The modified phase function model will be useful for coastal waters. ► An inter-comparison with measured upwelling radiance gives merits of the

  7. The potential use of mussel farms in German coastal waters as an option to improve water quality

    DEFF Research Database (Denmark)

    Friedland, René; Maar, Marie

    Many German coastal waters like Szczecin (Oder) Lagoon or Bay of Greifswald are strongly used, heavily polluted by nutrients and at the same time a crucial supplier of ecosystem services. Although, nutrient loads have been decreased over the last decade, water quality of most coastal waters...... remained bad characterized by low macrophytes coverage and secchi depth caused by high phytoplankton densities and strong resuspension of sediments. Hence the Good Environmental Status claimed by EU`s Water Framework Directive will not be achieved in most coastal waters. Introducing mussel farming...... techniques is seen as an option to reduce the phytoplankton densities and to improve water transparency, e.g. in Kiel Bay a first farm using Mytilus edulis is running. Unfortunately, most German coastal waters have only low salinities causing a limited growth of Mytilus spp. or make it even impossible – like...

  8. Gradients in microbial methanol uptake: productive coastal upwelling waters to oligotrophic gyres in the Atlantic Ocean

    Science.gov (United States)

    Dixon, Joanna L; Sargeant, Stephanie; Nightingale, Philip D; Colin Murrell, J

    2013-01-01

    Methanol biogeochemistry and its importance as a carbon source in seawater is relatively unexplored. We report the first microbial methanol carbon assimilation rates (k) in productive coastal upwelling waters of up to 0.117±0.002 d−1 (∼10 nmol l−1 d−1). On average, coastal upwelling waters were 11 times greater than open ocean northern temperate (NT) waters, eight times greater than gyre waters and four times greater than equatorial upwelling (EU) waters; suggesting that all upwelling waters upon reaching the surface (⩽20 m), contain a microbial population that uses a relatively high amount of carbon (0.3–10 nmol l−1 d−1), derived from methanol, to support their growth. In open ocean Atlantic regions, microbial uptake of methanol into biomass was significantly lower, ranging between 0.04–0.68 nmol l−1 d−1. Microbes in the Mauritanian coastal upwelling used up to 57% of the total methanol for assimilation of the carbon into cells, compared with an average of 12% in the EU, and 1% in NT and gyre waters. Several methylotrophic bacterial species were identified from open ocean Atlantic waters using PCR amplification of mxaF encoding methanol dehydrogenase, the key enzyme in bacterial methanol oxidation. These included Methylophaga sp., Burkholderiales sp., Methylococcaceae sp., Ancylobacter aquaticus, Paracoccus denitrificans, Methylophilus methylotrophus, Methylobacterium oryzae, Hyphomicrobium sp. and Methylosulfonomonas methylovora. Statistically significant correlations for upwelling waters between methanol uptake into cells and both chlorophyll a concentrations and methanol oxidation rates suggest that remotely sensed chlorophyll a images, in these productive areas, could be used to derive total methanol biological loss rates, a useful tool for atmospheric and marine climatically active gas modellers, and air–sea exchange scientists. PMID:23178665

  9. 19 CFR 4.66b - Pollution of coastal and navigable waters.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Pollution of coastal and navigable waters. 4.66b... coastal and navigable waters. (a) If any Customs officer has reason to believe that any refuse matter is being or has been deposited in navigable waters or any tributary of any navigable waters in violation of...

  10. Tidal Marsh Outwelling of Dissolved Organic Matter and Resulting Temporal Variability in Coastal Water Optical and Biogeochemical Properties

    Science.gov (United States)

    Tzortziou, Maria; Neale, Patrick J.; Megonigal, J. Patrick; Butterworth, Megan; Jaffe, Rudolf; Yamashita, Youhei

    2010-01-01

    Coastal wetlands are highly dynamic environments at the land-ocean interface where human activities, short-term physical forcings and intense episodic events result in high biological and chemical variability. Long being recognized as among the most productive ecosystems in the world, tidally-influenced coastal marshes are hot spots of biogeochemical transformation and exchange. High temporal resolution observations that we performed in several marsh-estuarine systems of the Chesapeake Bay revealed significant variability in water optical and biogeochemical characteristics at hourly time scales, associated with tidally-driven hydrology. Water in the tidal creek draining each marsh was sampled every hour during several semi-diurnal tidal cycles using ISCO automated samplers. Measurements showed that water leaving the marsh during ebbing tide was consistently enriched in dissolved organic carbon (DOC), frequently by more than a factor of two, compared to water entering the marsh during flooding tide. Estimates of DOC fluxes showed a net DOC export from the marsh to the estuary during seasons of both low and high biomass of marsh vegetation. Chlorophyll amounts were typically lower in the water draining the marsh, compared to that entering the marsh during flooding tide, suggesting that marshes act as transformers of particulate to dissolved organic matter. Moreover, detailed optical and compositional analyses demonstrated that marshes are important sources of optically and chemically distinctive, relatively complex, high molecular weight, aromatic-rich and highly colored dissolved organic compounds. Compared to adjacent estuarine waters, marsh-exported colored dissolved organic matter (CDOM) was characterized by considerably stronger absorption (more than a factor of three in some cases), larger DOC-specific absorption, lower exponential spectral slope, larger fluorescence signal, lower fluorescence per unit absorbance, and higher fluorescence at visible wavelengths

  11. Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift

    Science.gov (United States)

    Hahn, Juliane; Köhler, Stefan; Glatzel, Stephan; Jurasinski, Gerald

    2015-01-01

    Background Peatland restoration can have several objectives, for example re-establishing the natural habitat, supporting unique biodiversity attributes or re-initiating key biogeochemical processes, which can ultimately lead to a reduction in greenhouse gas (GHG) emissions. Every restoration measure, however, is itself a disturbance to the ecosystem. Methods Here, we examine an ecosystem shift in a coastal fen at the southern Baltic Sea which was rewetted by flooding. The analyses are based on one year of bi-weekly closed chamber measurements of methane fluxes gathered at spots located in different vegetation stands. During measurement campaigns, we recorded data on water levels, peat temperatures, and chemical properties of peat water. In addition we analyzed the first 20 cm of peat before and after flooding for dry bulk density (DBD), content of organic matter and total amounts of carbon (C), nitrogen (N), sulfur (S), and other nutrients. Results Rewetting turned the site from a summer dry fen into a shallow lake with water levels up to 0.60 m. We observed a substantial die-back of vegetation, especially in stands of sedges (Carex acutiformis Ehrh). Concentrations of total organic carbon and nitrogen in the peat water, as well as dry bulk density and concentrations of C, N and S in the peat increased. In the first year after rewetting, the average annual exchange of methane amounted to 0.26 ± 0.06 kg m-2. This is equivalent to a 190-times increase in methane compared to pre-flooding conditions. Highest methane fluxes occurred in sedge stands which suffered from the heaviest die-back. None of the recorded environmental variables showed consistent relationships with the amounts of methane exchanged. Conclusions Our results suggest that rewetting projects should be monitored not only with regard to vegetation development but also with respect to biogeochemical conditions. Further, high methane emissions that likely occur directly after rewetting by flooding should

  12. Carbon dynamics and CO2 air-sea exchanges in the eutrophied coastal waters of the Southern Bight of the North Sea: a modelling study

    Directory of Open Access Journals (Sweden)

    N. Gypens

    2004-01-01

    Full Text Available A description of the carbonate system has been incorporated in the MIRO biogeochemical model to investigate the contribution of diatom and Phaeocystis blooms to the seasonal dynamics of air-sea CO2 exchanges in the Eastern Channel and Southern Bight of the North Sea, with focus on the eutrophied Belgian coastal waters. For this application, the model was implemented in a simplified three-box representation of the hydrodynamics with the open ocean boundary box ‘Western English Channel’ (WCH and the ‘French Coastal Zone’ (FCZ and ‘Belgian Coastal Zone’ (BCZ boxes receiving carbon and nutrients from the rivers Seine and Scheldt, respectively. Results were obtained by running the model for the 1996–1999 period. The simulated partial pressures of CO2 (pCO2 were successfully compared with data recorded over the same period in the central BCZ at station 330 (51°26.05′ N; 002°48.50′ E. Budget calculations based on model simulations of carbon flow rates indicated for BCZ a low annual sink of atmospheric CO2 (−0.17 mol C m-2 y-1. On the opposite, surface water pCO2 in WCH was estimated to be at annual equilibrium with respect to atmospheric CO2. The relative contribution of biological, chemical and physical processes to the modelled seasonal variability of pCO2 in BCZ was further explored by running model scenarios with separate closures of biological activities and/or river inputs of carbon. The suppression of biological processes reversed direction of the CO2 flux in BCZ that became, on an annual scale, a significant source for atmospheric CO2 (+0.53 mol C m-2 y-1. Overall biological activity had a stronger influence on the modelled seasonal cycle of pCO2 than temperature. Especially Phaeocystis colonies which growth in spring were associated with an important sink of atmospheric CO2 that counteracted the temperature-driven increase of pCO2 at this period of the year. However, river inputs of organic and inorganic carbon were

  13. Atmospheric correction over coastal waters using multilayer neural networks

    Science.gov (United States)

    Fan, Y.; Li, W.; Charles, G.; Jamet, C.; Zibordi, G.; Schroeder, T.; Stamnes, K. H.

    2017-12-01

    Standard atmospheric correction (AC) algorithms work well in open ocean areas where the water inherent optical properties (IOPs) are correlated with pigmented particles. However, the IOPs of turbid coastal waters may independently vary with pigmented particles, suspended inorganic particles, and colored dissolved organic matter (CDOM). In turbid coastal waters standard AC algorithms often exhibit large inaccuracies that may lead to negative water-leaving radiances (Lw) or remote sensing reflectance (Rrs). We introduce a new atmospheric correction algorithm for coastal waters based on a multilayer neural network (MLNN) machine learning method. We use a coupled atmosphere-ocean radiative transfer model to simulate the Rayleigh-corrected radiance (Lrc) at the top of the atmosphere (TOA) and the Rrs just above the surface simultaneously, and train a MLNN to derive the aerosol optical depth (AOD) and Rrs directly from the TOA Lrc. The SeaDAS NIR algorithm, the SeaDAS NIR/SWIR algorithm, and the MODIS version of the Case 2 regional water - CoastColour (C2RCC) algorithm are included in the comparison with AERONET-OC measurements. The results show that the MLNN algorithm significantly improves retrieval of normalized Lw in blue bands (412 nm and 443 nm) and yields minor improvements in green and red bands. These results indicate that the MLNN algorithm is suitable for application in turbid coastal waters. Application of the MLNN algorithm to MODIS Aqua images in several coastal areas also shows that it is robust and resilient to contamination due to sunglint or adjacency effects of land and cloud edges. The MLNN algorithm is very fast once the neural network has been properly trained and is therefore suitable for operational use. A significant advantage of the MLNN algorithm is that it does not need SWIR bands, which implies significant cost reduction for dedicated OC missions. A recent effort has been made to extend the MLNN AC algorithm to extreme atmospheric conditions

  14. Quality Management of Lontar Village Coastal Waters, Banten

    Directory of Open Access Journals (Sweden)

    Ani Rahmawati

    2017-11-01

    Full Text Available The coastal waters of Lontar Village is located in Tirtayasa District, Banten. The coastal waters of Lontar Village is also used for fishing activities that become the livelihood of the surrounding community. Communities around the coast of Lontar village dispose of household waste directly into the waters so that the waters become dirty. The existence of these activities can cause the condition of the waters to decrease even can lead to contamination. Decrease in water conditions will affect the living biota inside. Waters quality can be determined by measuring physical, chemical, biological and heavy metal parameters. Physical parameters include brightness, turbidity, and temperature. Chemical parameters are salinity, pH, dissolved oxygen, nitrate, phosphate, BOD, TSS. The biological parameter is total coliform. The parameters of heavy metals are lead and copper. The purpose of this study is to analyze the quality of coastal waters of Lontar Village based on physical, chemical, biological and heavy metal parameters. The results showed that most of the parameters of water quality (physics, chemistry, biology and heavy metals are still in accordance with the value of water quality standards (Decree of the Minister of Environment No. 51 of 2004 only the value of lead metals exceeding the standard quality. It must be overcome so as not to disrupt the life of biota in the waters. Management that can be done is utilize aquatic biota that can absorb heavy metal content such as green shell (shell should not be consumed, reducing oil spilled from the activity of motor boats (giving box shelter under motor boat engines so that oil does not directly spill into the waters.

  15. Evaluation of Empirical and Machine Learning Algorithms for Estimation of Coastal Water Quality Parameters

    Directory of Open Access Journals (Sweden)

    Majid Nazeer

    2017-11-01

    Full Text Available Coastal waters are one of the most vulnerable resources that require effective monitoring programs. One of the key factors for effective coastal monitoring is the use of remote sensing technologies that significantly capture the spatiotemporal variability of coastal waters. Optical properties of coastal waters are strongly linked to components, such as colored dissolved organic matter (CDOM, chlorophyll-a (Chl-a, and suspended solids (SS concentrations, which are essential for the survival of a coastal ecosystem and usually independent of each other. Thus, developing effective remote sensing models to estimate these important water components based on optical properties of coastal waters is mandatory for a successful coastal monitoring program. This study attempted to evaluate the performance of empirical predictive models (EPM and neural networks (NN-based algorithms to estimate Chl-a and SS concentrations, in the coastal area of Hong Kong. Remotely-sensed data over a 13-year period was used to develop regional and local models to estimate Chl-a and SS over the entire Hong Kong waters and for each water class within the study area, respectively. The accuracy of regional models derived from EPM and NN in estimating Chl-a and SS was 83%, 93%, 78%, and 97%, respectively, whereas the accuracy of local models in estimating Chl-a and SS ranged from 60–94% and 81–94%, respectively. Both the regional and local NN models exhibited a higher performance than those models derived from empirical analysis. Thus, this study suggests using machine learning methods (i.e., NN for the more accurate and efficient routine monitoring of coastal water quality parameters (i.e., Chl-a and SS concentrations over the complex coastal area of Hong Kong and other similar coastal environments.

  16. Coastal Zone Hazards Related to Groundwater-Surface Water Interactions and Groundwater Flooding

    Science.gov (United States)

    Kontar, Y. A.; Ozorovich, Y. R.; Salokhiddinov, A. T.

    2009-12-01

    Worldwide, as many as half a million people have died in natural and man-made disasters since the turn of the 21st century (Wirtz, 2008). Further, natural and man-made hazards can lead to extreme financial losses (Elsner et al, 2009). Hazards, hydrological and geophysical risk analysis related to groundwater-surface water interactions and groundwater flooding have been to a large extent under-emphasized for coastal zone applications either due to economical limitations or underestimation of its significance. This is particularly true for tsunamis creating salt water intrusion to coastal aquifers, even though most tsunami hazard assessments have in the past relied on scenario or deterministic type models (Geist and Parsons, 2006), and to increasing mineralization of potable water because of intensive water diversions and also the abundance of highly toxic pollutants (mainly pesticides) in water, air and food, which contribute to the deterioration of the coastal population's health (Glantz, 2007). In the wake of pressing environmental and economic issues, it is of prime importance for the scientific community to shed light onto the great efforts by hydrologists and geophysicists to quantify conceptual uncertainties and to provide quality assurances of potential coastal zone hazard evaluation and prediction. This paper proposes consideration of two case studies which are important and significant for future development and essential for feasibility studies of hazards in the coastal zone. The territory of the Aral Sea Region in Central Asia is known as an ecological disaster coastal zone (Zavialov, 2005). It is now obvious that, in order to provide reasonable living conditions to the coastal zone population, it is first of all necessary to drastically improve the quality of the water dedicated to human needs. Due to their intensive pollution by industrial wastes and by drainage waters from irrigated fields, the Syr Darya and Amu Darya rivers can no longer be considered

  17. Land-margin ecosystem hydrologic data for the coastal Everglades, Florida, water years 1996-2012

    Science.gov (United States)

    Anderson, Gordon H.; Smith, Thomas J.; Balentine, Karen M.

    2014-01-01

    , as a response for a more interdisciplinary science approach to understanding the coastal Everglades ecological system, the SOFL-GCC hydrology project was integrated into the “Dynamics of Land-Margin Ecosystems: Historical Change, Hydrology, Vegetation, Sediment, and Climate” study (Smith and others, 2002). Data from the ongoing study has been useful in providing an empirical hydrologic baseline for the greater Everglades ecosystem restoration science and management needs. The hydrology network consisted of 13 hydrologic gaging stations installed in the southwestern coastal region of Everglades National Park along three transects: Shark River (Shark or SH) transect, Lostmans River (Lostmans or LO) transect, and Chatham River (Chatham or CH) transect (fig. 1). There were five paired surface-water/groundwater gaging stations on the Shark transect (SH1, SH2, SH3, SH4, and SH5) and one stage gaging station (BSC) in the Big Sable Creek; four paired surface-water/groundwater gaging stations on the Lostmans transect (LO1, LO2, LO3, and LO4); and three paired surface-water/groundwater gaging stations on the Chatham transect (CH1, CH2, and CH3). Both surface-water and groundwater levels, salinities, and temperatures were monitored at the paired gaging stations. Rainfall was recorded at marsh and open canopy gaging stations. This report details the study introduction, method, and description of data collected, which are accessible through the final instantaneous hydrologic dataset stored in the USGS South Florida Information Access (SOFIA) South Florida Hydrology Database website, http://sofia.usgs.gov/exchange/sfl_hydro_data/location.html#brdlandmargin.

  18. Water exchange of Oeregrundsgrepen. A baroclinic 3D-model study

    Energy Technology Data Exchange (ETDEWEB)

    Engqvist, A. [A and l Engqvist Konsult HB, Vaxholm (Sweden); Andrejev, O. [Finnish Inst. of Marine Research, Helsinki (Finland)

    1999-04-01

    Hypothetically transport of radionuclides from the SFR repository for low and medium active wastes could be mediated by natural water circulation within receiving coastal basins. In this context a basic equation, free surface 3D-model has been used to compute the water exchange of the Oeregrundsgrepen bay-like area for a representative full year cycle. This has been achieved in two steps in order to provide coherent densimetric and sea level elevation boundary data relative to the adjacent Baltic coastal water. Weather data from 1992 were chosen. The focus is placed entirely on water exchange aspects with no consideration of what the water parcels may contain. Earlier model and measurement programs have also been reviewed. The first phase consisted of running a 3D-model encompassing the entire Baltic Sea. This model resolves the Baltic horizontally in five by five nautical miles (5x5). This model was driven by gridded (approx. 20x20) synoptic weather data with geostrophic wind and the varying density and sea level elevation on the Kattegat border. Freshwater discharge from the major rivers along the Baltic coastline was also taken into account. Initial data prior to December 1991 have been assessed from the available, but relatively scarce, salinity and temperature profile measurements in the Baltic. The time step was 2 hours. The relevant boundary data in the vicinity of the Oeregrundsgrepen area were saved after one full-year cycle of simulation. The second phase consisted of running a local model over the Oeregrundsgrepen with a higher horizontal grid resolution consisting of a 0.1x0.1 grid. This model was driven by the same weather data, combined with the saved densimetric and sea level elevation boundary data that were produced by the Baltic model with the coarser grid. This procedure applies both for the wide northern and the narrow southern interface. The transference of boundary data necessitated development of an appropriate interpolation scheme. This

  19. Water exchange of Oeregrundsgrepen. A baroclinic 3D-model study

    International Nuclear Information System (INIS)

    Engqvist, A.; Andrejev, O.

    1999-04-01

    Hypothetically transport of radionuclides from the SFR repository for low and medium active wastes could be mediated by natural water circulation within receiving coastal basins. In this context a basic equation, free surface 3D-model has been used to compute the water exchange of the Oeregrundsgrepen bay-like area for a representative full year cycle. This has been achieved in two steps in order to provide coherent densimetric and sea level elevation boundary data relative to the adjacent Baltic coastal water. Weather data from 1992 were chosen. The focus is placed entirely on water exchange aspects with no consideration of what the water parcels may contain. Earlier model and measurement programs have also been reviewed. The first phase consisted of running a 3D-model encompassing the entire Baltic Sea. This model resolves the Baltic horizontally in five by five nautical miles (5x5). This model was driven by gridded (approx. 20x20) synoptic weather data with geostrophic wind and the varying density and sea level elevation on the Kattegat border. Freshwater discharge from the major rivers along the Baltic coastline was also taken into account. Initial data prior to December 1991 have been assessed from the available, but relatively scarce, salinity and temperature profile measurements in the Baltic. The time step was 2 hours. The relevant boundary data in the vicinity of the Oeregrundsgrepen area were saved after one full-year cycle of simulation. The second phase consisted of running a local model over the Oeregrundsgrepen with a higher horizontal grid resolution consisting of a 0.1x0.1 grid. This model was driven by the same weather data, combined with the saved densimetric and sea level elevation boundary data that were produced by the Baltic model with the coarser grid. This procedure applies both for the wide northern and the narrow southern interface. The transference of boundary data necessitated development of an appropriate interpolation scheme. This

  20. Accuracy assessment of satellite Ocean colour products in coastal waters.

    Science.gov (United States)

    Tilstone, G.; Lotliker, A.; Groom, S.

    2012-04-01

    The use of Ocean Colour Remote Sensing to monitor phytoplankton blooms in coastal waters is hampered by the absorption and scattering from substances in the water that vary independently of phytoplankton. In this paper we compare different ocean colour algorithms available for SeaWiFS, MODIS and MERIS with in situ observations of Remote Sensing Reflectance, Chlorophyll-a (Chla), Total Suspended Material and Coloured Dissolved Organic Material in coastal waters of the Arabian Sea, Bay of Bengal, North Sea and Western English Channel, which have contrasting inherent optical properties. We demonstrate a clustering method on specific-Inherent Optical Properties (sIOP) that gives accurate water quality products from MERIS data (HYDROPT) and also test the recently developed ESA CoastColour MERIS products. We found that for coastal waters of the Bay of Bengal, OC5 gave the most accurate Chla, for the Arabian Sea GSM and OC3M Chla were more accurate and for the North Sea and Western English Channel, MERIS HYDROPT were more accurate than standard algorithms. The reasons for these differences will be discussed. A Chla time series from 2002-2011 will be presented to illustrate differences in algorithms between coastal regions and inter- and intra-annual variability in phytoplankton blooms

  1. Cation Exchange Water Softeners

    Science.gov (United States)

    WaterSense released a notice of intent to develop a specification for cation exchange water softeners. The program has made the decision not to move forward with a spec at this time, but is making this information available.

  2. Groundwater–Surface Water Exchange

    DEFF Research Database (Denmark)

    Karan, Sachin

    The exchange of groundwater-surface water has been invetigated in the western part of Denmark. Holtum AA provides the framework for all the performed investigations. Several methods are used, primarily eld based measurements ombined with numerical models to achieve insight to the governing...... processes of interaction between groundwater and surface water. By using heat as a tracer it has been possible to use temperature directly as calibrationtargets in a groundwater and heat transport model. Thus, it is possible to use heat investigate the change in groundwater discharge in dynamic conditions...... by using simple temperature devices along a stream to delineate the areas of interest in regard to GW{SW exchange. Thus, at several locations in a stream a temperature data logger was placed in the water column and right at the streambed-water interface. By looking at the correlation of streambed...

  3. Water permeation through anion exchange membranes

    Science.gov (United States)

    Luo, Xiaoyan; Wright, Andrew; Weissbach, Thomas; Holdcroft, Steven

    2018-01-01

    An understanding of water permeation through solid polymer electrolyte (SPE) membranes is crucial to offset the unbalanced water activity within SPE fuel cells. We examine water permeation through an emerging class of anion exchange membranes, hexamethyl-p-terphenyl poly (dimethylbenzimidazolium) (HMT-PMBI), and compare it against series of membrane thickness for a commercial anion exchange membrane (AEM), Fumapem® FAA-3, and a series of proton exchange membranes, Nafion®. The HMT-PMBI membrane is found to possess higher water permeabilities than Fumapem® FAA-3 and comparable permeability than Nafion (H+). By measuring water permeation through membranes of different thicknesses, we are able to decouple, for the first time, internal and interfacial water permeation resistances through anion exchange membranes. Permeation resistances on liquid/membrane interface is found to be negligible compared to that for vapor/membrane for both series of AEMs. Correspondingly, the resistance of liquid water permeation is found to be one order of magnitude smaller compared to that of vapor water permeation. HMT-PMBI possesses larger effective internal water permeation coefficient than both Fumapem® FAA-3 and Nafion® membranes (60 and 18% larger, respectively). In contrast, the effective interfacial permeation coefficient of HMT-PMBI is found to be similar to Fumapem® (±5%) but smaller than Nafion®(H+) (by 14%).

  4. Nitrogen Cycling in Permeable Sediments: Process-based Models for Streams and the Coastal Ocean

    OpenAIRE

    Azizian, Morvarid

    2017-01-01

    Bioavailable forms of nitrogen, such as nitrate, are necessary for aquatic ecosystem productivity. Excess nitrate in aquatic systems, however, can adversely affect ecosystems and degrade both surface water and groundwater. Some of this excess nitrate can be removed in the sediments that line the bottom of rivers and coastal waters, through the exchange of water between surface water and groundwater (known as hyporheic exchange).Several process-based models have been proposed for estimating ni...

  5. Toward a better guard of coastal water safety—Microbial distribution in coastal water and their facile detection

    International Nuclear Information System (INIS)

    Xie, Yunxuan; Qiu, Ning; Wang, Guangyi

    2017-01-01

    Prosperous development in marine-based tourism has raised increasing concerns over the sanitary quality of coastal waters with potential microbial contamination. The World Health Organization has set stringent standards over a list of pathogenic microorganisms posing potential threats to people with frequent coastal water exposure and has asked for efficient detection procedures for pathogen facile identification. Inspection of survey events regarding the occurrence of marine pathogens in recreational beaches in recent years has reinforced the need for the development of a rapid identification procedure. In this review, we examine the possibility of recruiting uniform molecular assays to identify different marine pathogens and the feasibility of appropriate biomarkers, including enterochelin biosynthetic genes, for general toxicity assays. The focus is not only on bacterial pathogens but also on other groups of infectious pathogens. The ultimate goal is the development of a handy method to more efficiently and rapidly detect marine pathogens. - Highlights: • Culture-based approaches and molecular approaches can be used to describe pathogenic microbial distribution in coastal area. • Beach sand is a hidden habitat for pathogenic microorganisms. • qPCR is an efficient detection technique to identify pathogenic microbes and their potential pathogenicity. • Enterochelin synthase gene can be used as single molecular biomarker for multiple pathogen identification.

  6. Retrieval of aerosol properties and water-leaving reflectance from multi-angular polarimetric measurements over coastal waters.

    Science.gov (United States)

    Gao, Meng; Zhai, Peng-Wang; Franz, Bryan; Hu, Yongxiang; Knobelspiesse, Kirk; Werdell, P Jeremy; Ibrahim, Amir; Xu, Feng; Cairns, Brian

    2018-04-02

    Ocean color remote sensing is an important tool to monitor water quality and biogeochemical conditions of ocean. Atmospheric correction, which obtains water-leaving radiance from the total radiance measured by satellite-borne or airborne sensors, remains a challenging task for coastal waters due to the complex optical properties of aerosols and ocean waters. In this paper, we report a research algorithm on aerosol and ocean color retrieval with emphasis on coastal waters, which uses coupled atmosphere and ocean radiative transfer model to fit polarized radiance measurements at multiple viewing angles and multiple wavelengths. Ocean optical properties are characterized by a generalized bio-optical model with direct accounting for the absorption and scattering of phytoplankton, colored dissolved organic matter (CDOM) and non-algal particles (NAP). Our retrieval algorithm can accurately determine the water-leaving radiance and aerosol properties for coastal waters, and may be used to improve the atmospheric correction when apply to a hyperspectral ocean color instrument.

  7. Sediment and toxic contaminant transport modeling in coastal waters

    International Nuclear Information System (INIS)

    Onishi, Yasuo; Mayer, D.W.; Argo, R.S.

    1982-01-01

    Models are presented to estimate the migration of toxic contaminants in coastal waters. Ocean current is simulated by the vertically-averaged, finite element, two-demensional model known as CAFE-I with the Galerkin weighted residual technique. The refraction of locally generated waves or swells is simulated by the wave refraction model, LO3D. Using computed current, depth, and wave characteristics, the finite element model, FETRA, simulated sediment and contaminant transport in coastal waters, estuaries and rivers. Prior to the application of these models to the Irish Sea and other coastal waters, the finite element model, FETRA, was tested to demonstrate its ability to simulate sediment and contaminant interaction, and the mechanism governing the transport, deposition, and resuspension of contaminated sediment. Several simple equations such as the unsteady, advection-diffusion equation, the equation for noncohesive-sediment load due to wind-induced waves in offshore and surf zones, and the equation for sediment-radionuclide transport simulation were solved during the preliminary testing of the model. (Kato, T.)

  8. Hydrogen-water isotopic exchange process

    International Nuclear Information System (INIS)

    Cheung, H.

    1984-01-01

    The objects of this invention are achieved by a dual temperature isotopic exchange process employing hydrogen-water exchange with water passing in a closed recirculation loop between a catalyst-containing cold tower and the upper portion of a catalyst-containing hot tower, with feed water being introduced to the lower portion of the hot tower and being maintained out of contact with the water recirculating in the closed loop. Undue retarding of catalyst activity during deuterium concentration can thus be avoided. The cold tower and the upper portion of the hot tower can be operated with relatively expensive catalyst material of higher catalyst activity, while the lower portion of the hot tower can be operated with a relatively less expensive, more rugged catalyst material of lesser catalyst activity. The feed water stream, being restricted solely to the lower portion of the hot tower, requires minimal pretreatment for the removal of potential catalyst contaminants. The catalyst materials are desirably coated with a hydrophobic treating material so as to be substantially inaccessible to liquid water, thereby retarding catalyst fouling while being accessible to the gas for enhancing isotopic exchange between hydrogen gas and water vapor. A portion of the water of the closed loop can be passed to a humidification zone to heat and humidify the circulating hydrogen gas and then returned to the closed loop

  9. Wading through Perceptions: Understanding Human Perceptions of Water Quality in Coastal Waters

    Science.gov (United States)

    Water quality perceptions influence people’s preferences for visiting coastal areas and willingness to participate in activities on or near the water. They also influence people’s social values for a waterbody, sense of place, support for protection of a waterbody, an...

  10. Hydrology and water budget for a forested atlantic coastal plain watershed, South Carolina

    Science.gov (United States)

    Scott V. Harder; Devendra M Amatya; Callahan Timothy J.; Carl C. Trettin; Hakkila Jon

    2007-01-01

    Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

  11. Hyrdology and water budget for a forested atlantic coastal plain watershed, South Carolina

    Science.gov (United States)

    Scott V. Harder; Devendra M. Amatya; Timothy J. Callahan; Carl C. Trettin; Jon Hakkila

    2007-01-01

    Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

  12. Estimating total alkalinity for coastal ocean acidification monitoring at regional to continental scales in Australian coastal waters

    KAUST Repository

    Baldry, Kimberlee; Hardman-Mountford, Nick; Greenwood, Jim

    2017-01-01

    Owing to a lack of resources, tools, and knowledge, the natural variability and distribution of Total Alkalinity (TA) has been poorly characterised in coastal waters globally, yet variability is known to be high in coastal regions due to the complex interactions of oceanographic, biotic, and terrestrially-influenced processes. This is a particularly challenging task for the vast Australian coastline, however, it is also this vastness that demands attention in the face of ocean acidification (OA). Australian coastal waters have high biodiversity and endemism, and are home to large areas of coral reef, including the Great Barrier Reef, the largest coral reef system in the world. Ocean acidification threatens calcifying marine organisms by hindering calcification rates, threatening the structural integrity of coral reefs and other ecosystems. Tracking the progression of OA in different coastal regions requires accurate knowledge of the variability in TA. Thus, estimation methods that can capture this variability at synoptic scales are needed. Multiple linear regression is a promising approach in this regard. Here, we compare a range of both simple and multiple linear regression models to the estimation of coastal TA from a range of variables, including salinity, temperature, chlorophyll-a concentration and nitrate concentration. We find that regionally parameterised models capture local variability better than more general coastal or open ocean parameterised models. The strongest contribution to model improvement came through incorporating temperature as an input variable as well as salinity. Further improvements were achieved through the incorporation of either nitrate or chlorophyll-a, with the combination of temperature, salinity, and nitrate constituting the minimum model in most cases. These results provide an approach that can be applied to satellite Earth observation and autonomous in situ platforms to improve synoptic scale estimation of TA in coastal waters.

  13. Estimating total alkalinity for coastal ocean acidification monitoring at regional to continental scales in Australian coastal waters

    KAUST Repository

    Baldry, Kimberlee

    2017-06-01

    Owing to a lack of resources, tools, and knowledge, the natural variability and distribution of Total Alkalinity (TA) has been poorly characterised in coastal waters globally, yet variability is known to be high in coastal regions due to the complex interactions of oceanographic, biotic, and terrestrially-influenced processes. This is a particularly challenging task for the vast Australian coastline, however, it is also this vastness that demands attention in the face of ocean acidification (OA). Australian coastal waters have high biodiversity and endemism, and are home to large areas of coral reef, including the Great Barrier Reef, the largest coral reef system in the world. Ocean acidification threatens calcifying marine organisms by hindering calcification rates, threatening the structural integrity of coral reefs and other ecosystems. Tracking the progression of OA in different coastal regions requires accurate knowledge of the variability in TA. Thus, estimation methods that can capture this variability at synoptic scales are needed. Multiple linear regression is a promising approach in this regard. Here, we compare a range of both simple and multiple linear regression models to the estimation of coastal TA from a range of variables, including salinity, temperature, chlorophyll-a concentration and nitrate concentration. We find that regionally parameterised models capture local variability better than more general coastal or open ocean parameterised models. The strongest contribution to model improvement came through incorporating temperature as an input variable as well as salinity. Further improvements were achieved through the incorporation of either nitrate or chlorophyll-a, with the combination of temperature, salinity, and nitrate constituting the minimum model in most cases. These results provide an approach that can be applied to satellite Earth observation and autonomous in situ platforms to improve synoptic scale estimation of TA in coastal waters.

  14. The change in the primary production of Danish coastal waters

    International Nuclear Information System (INIS)

    Edelvang, K.; Erichsen, A.; Gustavson, K.; Bundgaard, K.; Dahl-Madsen, K.I.

    2001-01-01

    The background for this study is the development of the 'Farvandsmodel' for the NOVA-2003 programme and the nationally founded research project DECO (Danish Environmental Monitoring of Coastal Waters), which focuses on the use of remote sensing for the monitoring of Danish Coastal waters. Danish national programmes for the monitoring of the marine ecosystem are a relatively new activity, which has grown during the last 20 years. The HAV90 research programme amassed important information to be included in future environmental efforts such as the NOVA-2003 programme, aimed at monitoring the Danish coastal waters. The following is a selection of the topics mentioned in the NOVA-2003 programme (NOVA-2003, 2000) especially relevant to this study: 1) Hydrography. 2) Concentration and spatial distribution of nutrients. 3) Water and nutrient fluxes. 4) Oxygen depletion. As part of this programme, a 3D hydrographic model describing currents and fluxes in Danish waters has been designed by DHI Water and Environment for the Danish Ministry of Energy and Environment. The model is called the 'Farvandsmodel', which is the collective Danish name of this regional 3D hydrodynamic model and its associated database for storage and dissemination of model results and field measurements. The model is planned to be in operation until 2004. It has a great potential within hydrographic modelling in Danish waters, as it is capable of running 5-day prognoses for currents, water levels and stratification. The model is also able to calculate the sensitivity of the present system to changes in various input parameters. In this way the model may be used as a tool for testing the sensitivity of Danish coastal waters to the impact of the green house effects. The nationally funded research programme, DECO (1997-2000), aims to investigate the use of remote sensing for monitoring Danish coastal waters. To support this research, a eutrophication module (EU) was set up for the 'Farvandsmodel'. The

  15. A whole plant approach to evaluate the water use of mediterranean maquis species in a coastal dune ecosystem

    Science.gov (United States)

    Mereu, S.; Salvatori, E.; Fusaro, L.; Gerosa, G.; Muys, B.; Manes, F.

    2009-02-01

    An integrated approach has been used to analyse the water relations of three Mediterranean species, A. unedo L., Q. ilex L. and P. latifolia L. co-occurring in a coastal dune ecosystem. The approach considered leaf level gas exchange, sap flow measurements and structural adaptations between 15 May and 31 July 2007, and was necessary to capture the different response of the three species to the same environment. The complexity of the response was proportional to the complexity of the system, characterized by a sandy soil with a low water retention capacity and the presence of a water table. The latter did not completely prevent the development of a drought response, and species differences in this responses have been partially attributed to a different root distribution. Sap flow of A. unedo decreased rapidly in response to the decline of Soil Water Content, while that of Q. ilex decreased only moderately. Midday leaf water potential of P. latifolia and A. unedo was between 2.2 and 2.7 MPa through the measuring period, while in Q. ilex it reached a value of 3.4 MPa at the end of the season. A. unedo was the only species to decrease the leaf area to sapwood area ratio from 23.9±1.2 (May) to 15.2±1.5 (July), as a response to drought. A. unedo also underwent an almost stepwise loss on hydraulic conductivity, such a loss didn't occur for Q. ilex, while P. latifolia was able to slightly increase hydraulic conductivity, showing how different plant compartments coordinate differently between species as a response to drought. Such different coordination affects the gas exchange between vegetation and the atmosphere, and has implications for the response of the Mediterranean coastal dune ecosystems to climate change.

  16. Sediment and toxic contaminant transport modeling in coastal waters

    International Nuclear Information System (INIS)

    Onishi, Y.; Mayer, D.W.; Argo, R.S.

    1982-02-01

    A hydrodynamic model, CAFE-I, a wave refraction model, LO3D, and a sediment and contaminant transport model, FETRA, were selected as tools for evaluating exposure levels of radionuclides, heavy metals, and other toxic chemicals in coastal waters. Prior to the application of these models to the Irish Sea and other coastal waters, the finite element model, FETRA, was tested to demonstrate its ability to simulate sediment and contaminant interactions (e.g., adsorption and desorption), and the mechanisms governing the transport, deposition, and resuspension of contaminated sediments

  17. Application of Hyperspectral Remote Sensing Techniques to Evaluate Water Quality in Turbid Coastal Waters of South Carolina.

    Science.gov (United States)

    Ali, K. A.; Ryan, K.

    2014-12-01

    Coastal and inland waters represent a diverse set of resources that support natural habitat and provide valuable ecosystem services to the human population. Conventional techniques to monitor water quality using in situ sensors and laboratory analysis of water samples can be very time- and cost-intensive. Alternatively, remote sensing techniques offer better spatial coverage and temporal resolution to accurately characterize the dynamic and unique water quality parameters. Existing remote sensing ocean color products, such as the water quality proxy chlorophyll-a, are based on ocean derived bio-optical models that are primarily calibrated in Case 1 type waters. These traditional models fail to work when applied in turbid (Case 2 type), coastal waters due to spectral interference from other associated color producing agents such as colored dissolved organic matter and suspended sediments. In this work, we introduce a novel technique for the predictive modeling of chlorophyll-a using a multivariate-based approach applied to in situ hyperspectral radiometric data collected from the coastal waters of Long Bay, South Carolina. This method uses a partial least-squares regression model to identify prominent wavelengths that are more sensitive to chlorophyll-a relative to other associated color-producing agents. The new model was able to explain 80% of the observed chlorophyll-a variability in Long Bay with RMSE = 2.03 μg/L. This approach capitalizes on the spectral advantage gained from current and future hyperspectral sensors, thus providing a more robust predicting model. This enhanced mode of water quality monitoring in marine environments will provide insight to point-sources and problem areas that may contribute to a decline in water quality. The utility of this tool is in its versatility to a diverse set of coastal waters and its use by coastal and fisheries managers with regard to recreation, regulation, economic and public health purposes.

  18. Imbalance in Groundwater-Surface Water Interactions and its Relationship to the Coastal Zone Hazards

    Science.gov (United States)

    Kontar, Y. A.; Ozorovich, Y. R.; Salokhiddinov, A. T.

    2011-12-01

    We report here some efforts and results in studying the imbalance in groundwater-surface water interactions and processes of groundwater-surface water interactions and groundwater flooding creating hazards in the coastal zones. Hazards, hydrological and geophysical risk analysis related to imbalance in groundwater-surface water interactions and groundwater flooding have been to a large extent under-emphasized for coastal zone applications either due to economical limitations or underestimation of significance of imbalance in groundwater-surface water interactions. This is particularly true for tsunamis creating salt water intrusion to coastal aquifers, even though most tsunami hazard assessments have in the past relied on scenario or deterministic type models, and to increasing mineralization of potable water because of intensive water diversions and also the abundance of highly toxic pollutants (mainly pesticides) in water, air and food, which contribute to the deterioration of the coastal population's health. In the wake of pressing environmental and economic issues, it is of prime importance for the scientific community to shed light onto the great efforts by hydrologists and geophysicists to quantify conceptual uncertainties and to provide quality assurances of potential coastal zone hazard evaluation and prediction under conditions of imbalance in groundwater-surface water interactions. This paper proposes consideration of two case studies which are important and significant for future understanding of a concept of imbalance in groundwater-surface water interactions and development and essential for feasibility studies of hazards in the coastal zone. The territory of the Aral Sea Region in Central Asia is known as an ecological disaster coastal zone. It is now obvious that, in order to provide reasonable living conditions to the coastal zone population, it is first of all necessary to drastically improve the quality of the water dedicated to human needs. Due

  19. Intertidal zones as carbon dioxide sources to coastal oceans

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; George, M.D.; Rajagopal, M.D.

    To understand the factors controlling carbon dioxide (CO sub(2)) exchanges near land-sea boundary diurnal observations have been made twice on CO sub(2) in the air and water in a coastal region. The results suggest that CO sub(2) enrichment...

  20. Exchange of polycyclic aromatic hydrocarbons across the air-water interface in the Bohai and Yellow Seas

    Science.gov (United States)

    Chen, Yingjun; Lin, Tian; Tang, Jianhui; Xie, Zhiyong; Tian, Chongguo; Li, Jun; Zhang, Gan

    2016-09-01

    In this study, air and surface seawater samples collected from the Bohai (BS) and Yellow Seas (YS) in May 2012 were determined exchange of PAHs, especially of low-molecular-weight (LMW) PAHs (three- and four-ring PAHs) at the air-water interface. Net volatilization fluxes of LMW PAHs were 266-1454 ng/m2/d and decreased with distance from the coast, indicating that these PAHs transported from coastal runoff were potential contributors to the atmosphere in the BS and YS. Moreover, LMW PAHs were enriched in the dissolved phase compared with those in the particulate phase in the water column, possibly suggesting that the volatilized LMW PAHs were directly derived from wastewater discharge or petroleum pollution rather than released from contaminated sediments. The air-sea exchange fluxes of the three-ring PAHs were 2- to 20-fold higher than their atmospheric deposition fluxes in the BS and YS. The input to and output from the water reached equilibrium for four-ring PAHs. Differently, five- and six-ring PAHs were introduced into the marine environment primarily through dry and wet deposition, indicating that the water column was still a sink of these PAHs from the surrounding atmosphere.

  1. Coastal groundwater exchange on a small Pacific atoll island: Roi Namur, Republic of the Marshall Islands

    Science.gov (United States)

    Oberle, Ferdinand K. J.; Swarzenski, Peter W.; Storlazzi, Curt

    2017-04-01

    Atoll islands, most of which only average 1-2 meters above today's sea level, provide a tremendous natural laboratory in which to study and better understand the intensifying impacts of high rates of sea-level rise on tropical reef-lined islands globally due to their unique geologic structure and limited water supply. Groundwater resources of atolls are typically minimal due to the low elevation and small surface area of the islands and are also subject to recurring droughts, and more frequent, storm-driven seawater overwash events. Although groundwater is the principal means of freshwater storage on atoll islands and is a major factor in determining the overall sustainability of island communities, hydrological data on how an aquifer will response to changes in sea-level rise or storm-driven overwash remain limited. We here present high-resolution time series hydrogeological and geochemical data to determine the role of the atoll's carbonate geology, land use, and atmospheric and oceanographic forcing in driving coastal groundwater exchange on the island of Roi Namur on Kwajalein Atoll in the Republic of the Marshall Islands. This information can provide new estimates on the recovery and resilience of coastal groundwater resources on such islands to expected climate change-driven perturbations.

  2. Nutrient removal from Chinese coastal waters by large-scale seaweed aquaculture

    KAUST Repository

    Xiao, Xi

    2017-04-21

    China is facing intense coastal eutrophication. Large-scale seaweed aquaculture in China is popular, now accounting for over 2/3\\'s of global production. Here, we estimate the nutrient removal capability of large-scale Chinese seaweed farms to determine its significance in mitigating eutrophication. We combined estimates of yield and nutrient concentration of Chinese seaweed aquaculture to quantify that one hectare of seaweed aquaculture removes the equivalent nutrient inputs entering 17.8 ha for nitrogen and 126.7 ha for phosphorus of Chinese coastal waters, respectively. Chinese seaweed aquaculture annually removes approximately 75,000 t nitrogen and 9,500 t phosphorus. Whereas removal of the total N inputs to Chinese coastal waters requires a seaweed farming area 17 times larger than the extant area, one and a half times more of the seaweed area would be able to remove close to 100% of the P inputs. With the current growth rate of seaweed aquaculture, we project this industry will remove 100% of the current phosphorus inputs to Chinese coastal waters by 2026. Hence, seaweed aquaculture already plays a hitherto unrealized role in mitigating coastal eutrophication, a role that may be greatly expanded with future growth of seaweed aquaculture.

  3. Nutrient removal from Chinese coastal waters by large-scale seaweed aquaculture

    KAUST Repository

    Xiao, Xi; Agusti, Susana; Lin, Fang; Li, Ke; Pan, Yaoru; Yu, Yan; Zheng, Yuhan; Wu, Jiaping; Duarte, Carlos M.

    2017-01-01

    China is facing intense coastal eutrophication. Large-scale seaweed aquaculture in China is popular, now accounting for over 2/3's of global production. Here, we estimate the nutrient removal capability of large-scale Chinese seaweed farms to determine its significance in mitigating eutrophication. We combined estimates of yield and nutrient concentration of Chinese seaweed aquaculture to quantify that one hectare of seaweed aquaculture removes the equivalent nutrient inputs entering 17.8 ha for nitrogen and 126.7 ha for phosphorus of Chinese coastal waters, respectively. Chinese seaweed aquaculture annually removes approximately 75,000 t nitrogen and 9,500 t phosphorus. Whereas removal of the total N inputs to Chinese coastal waters requires a seaweed farming area 17 times larger than the extant area, one and a half times more of the seaweed area would be able to remove close to 100% of the P inputs. With the current growth rate of seaweed aquaculture, we project this industry will remove 100% of the current phosphorus inputs to Chinese coastal waters by 2026. Hence, seaweed aquaculture already plays a hitherto unrealized role in mitigating coastal eutrophication, a role that may be greatly expanded with future growth of seaweed aquaculture.

  4. Diurnal changes in ocean color in coastal waters

    Science.gov (United States)

    Arnone, Robert; Vandermeulen, Ryan; Ladner, Sherwin; Ondrusek, Michael; Kovach, Charles; Yang, Haoping; Salisbury, Joseph

    2016-05-01

    Coastal processes can change on hourly time scales in response to tides, winds and biological activity, which can influence the color of surface waters. These temporal and spatial ocean color changes require satellite validation for applications using bio-optical products to delineate diurnal processes. The diurnal color change and capability for satellite ocean color response were determined with in situ and satellite observations. Hourly variations in satellite ocean color are dependent on several properties which include: a) sensor characterization b) advection of water masses and c) diurnal response of biological and optical water properties. The in situ diurnal changes in ocean color in a dynamic turbid coastal region in the northern Gulf of Mexico were characterized using above water spectral radiometry from an AErosol RObotic NETwork (AERONET -WavCIS CSI-06) site that provides up to 8-10 observations per day (in 15-30 minute increments). These in situ diurnal changes were used to validate and quantify natural bio-optical fluctuations in satellite ocean color measurements. Satellite capability to detect changes in ocean color was characterized by using overlapping afternoon orbits of the VIIRS-NPP ocean color sensor within 100 minutes. Results show the capability of multiple satellite observations to monitor hourly color changes in dynamic coastal regions that are impacted by tides, re-suspension, and river plume dispersion. Hourly changes in satellite ocean color were validated with in situ observation on multiple occurrences during different times of the afternoon. Also, the spatial variability of VIIRS diurnal changes shows the occurrence and displacement of phytoplankton blooms and decay during the afternoon period. Results suggest that determining the temporal and spatial changes in a color / phytoplankton bloom from the morning to afternoon time period will require additional satellite coverage periods in the coastal zone.

  5. Noninvasive mapping of water diffusional exchange in the human brain using filter-exchange imaging.

    Science.gov (United States)

    Nilsson, Markus; Lätt, Jimmy; van Westen, Danielle; Brockstedt, Sara; Lasič, Samo; Ståhlberg, Freddy; Topgaard, Daniel

    2013-06-01

    We present the first in vivo application of the filter-exchange imaging protocol for diffusion MRI. The protocol allows noninvasive mapping of the rate of water exchange between microenvironments with different self-diffusivities, such as the intracellular and extracellular spaces in tissue. Since diffusional water exchange across the cell membrane is a fundamental process in human physiology and pathophysiology, clinically feasible and noninvasive imaging of the water exchange rate would offer new means to diagnose disease and monitor treatment response in conditions such as cancer and edema. The in vivo use of filter-exchange imaging was demonstrated by studying the brain of five healthy volunteers and one intracranial tumor (meningioma). Apparent exchange rates in white matter range from 0.8±0.08 s(-1) in the internal capsule, to 1.6±0.11 s(-1) for frontal white matter, indicating that low values are associated with high myelination. Solid tumor displayed values of up to 2.9±0.8 s(-1). In white matter, the apparent exchange rate values suggest intra-axonal exchange times in the order of seconds, confirming the slow exchange assumption in the analysis of diffusion MRI data. We propose that filter-exchange imaging could be used clinically to map the water exchange rate in pathologies. Filter-exchange imaging may also be valuable for evaluating novel therapies targeting the function of aquaporins. Copyright © 2012 Wiley Periodicals, Inc.

  6. Air-sea exchange of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, D C.E.; De Baar, H J.W.; De Jong, E; Koning, F A [Netherlands Institute for Sea Research NIOZ, Den Burg Texel (Netherlands)

    1996-12-31

    The greenhouse gas carbon dioxide is emitted by anthropogenic activities. The oceans presumably serve as a net sink for 17 to 39% of these emissions. The objective of this project is to quantify more accurately the locality, seasonality and magnitude of the net air-sea flux of CO2 with emphasis on the South Atlantic Ocean. In situ measurements of the fugacity of CO2 in surface water and marine air, of total dissolved inorganic carbon, alkalinity and of air-sea exchange of CO2 have been made at four Atlantic crossings, in the Southern Ocean, in a Norwegian fjord and in the Dutch coastal zone. Skin temperature was detected during several of the cruises. The data collected in the course of the project support and refine previous findings. Variability of dissolved CO2 in surface water is related in a complex way to biological and physical factors. The carbonate equilibria cause dissolved gaseous CO2 to react in an intricate manner to disturbances. Dissolved gaseous CO2 hardly ever attains equilibrium with the atmospheric CO2 content by means of air-sea exchange, before a new disturbance occurs. Surface water fCO2 changes could be separated in those caused by seasonal warming and those by biological uptake in a Southern Ocean spring. Incorporation of a thermal skin effect and a change of the wind speed interval strongly increased the small net oceanic uptake for the area. The Atlantic crossings point to a relationship between water mass history and surface water CO2 characteristics. In particular, current flow and related heat fluxes leave their imprint on the concentration dissolved gaseous CO2 and on air-sea exchange. In the Dutch coastal zone hydrography and inorganic carbon characteristics of the water were heterogeneous, which yielded variable air-sea exchange of CO2. figs., tabs., refs.

  7. 226Ra, 228Ra, 223Ra, and 224Ra in coastal waters with application to coastal dynamics and groundwater input

    International Nuclear Information System (INIS)

    Moore, W.S.

    1997-01-01

    Four radium isotopes offer promise in unraveling the complex dynamics of coastal ocean circulation and groundwater input. Each isotope is produced by decay of a thorium parent bound to sediment. The activities of these thorium isotopes and the sediment-water distribution coefficient for radium provide an estimate of the source function of each Ra isotope to the water. In salt marshes that receive little surface water input, Ra activities which exceed coastal ocean values must originate within the marsh. In North Inlet, South Carolina, the activities of 226 Ra exported from the marsh far exceed the activities generated within the marsh. To supply the exported activities, substantial groundwater input is required. In the coastal region itself, 226 Ra activities exceed the amount that can be supplied from rivers. Here also, substantial groundwater input is required. Within the coastal ocean, 223 Ra and 224 Ra may be used to determine mixing rates with offshore waters. Shore-perpendicular profiles of 223 Ra and 224 Ra show consistent trends which may be modeled as eddy diffusion coefficients of 350-540 m 2 s -1 . These coefficients allow an assessment of cross-shelf transport and provide further insight on the importance of groundwater to coastal regions. (author)

  8. Automatic Optimization for Large-Scale Real-Time Coastal Water Simulation

    Directory of Open Access Journals (Sweden)

    Shunli Wang

    2016-01-01

    Full Text Available We introduce an automatic optimization approach for the simulation of large-scale coastal water. To solve the singular problem of water waves obtained with the traditional model, a hybrid deep-shallow-water model is estimated by using an automatic coupling algorithm. It can handle arbitrary water depth and different underwater terrain. As a certain feature of coastal terrain, coastline is detected with the collision detection technology. Then, unnecessary water grid cells are simplified by the automatic simplification algorithm according to the depth. Finally, the model is calculated on Central Processing Unit (CPU and the simulation is implemented on Graphics Processing Unit (GPU. We show the effectiveness of our method with various results which achieve real-time rendering on consumer-level computer.

  9. General review of literature relevant to coastal water discharges

    International Nuclear Information System (INIS)

    Pentreath, R.J.

    1985-01-01

    This review on the behaviour of radionuclides released into coastal water from the radioactive discharges, prepared on the basis of existing publications and documents, is divided into parts on pathways of exposure, behaviour of radionuclides in coastal environments, biological avialability of radionuclides, habit surveys and critical groups, assessment of dose to man and the effects of radiation on aquatic organisms

  10. Physicochemical parameters and seasonal variation of coastal water from Balochistan coast, Pakistan

    Directory of Open Access Journals (Sweden)

    Naeema Elahi

    2015-03-01

    Full Text Available Objective: To determine common physico-chemical parameters of coastal water. Methods: Physicochemical properties of water were determined according to the standards of the American Public Health Association. Generally, all those parameters were recorded a small variation between stations. The variation in physico-chemical parameters like salinity, temperature, dissolved oxygen and pH at Gwadar (Coastal water of Balochistan were recorded. Results: The range of air temperature of coastal water of Balochistan during 2004 and 2006 varies from 25 ºC to 37 ºC, water temperature ranged from 15.00 ºC to 33.00 ºC, pH ranged from 7.08 to 8.95, salinity ranged from 37.4‰ to 41.3‰ and dissolved oxygen ranged from 5.32 to 8.67 mg/L. Conclusions: Results showed that these parameters of Balochistan coast of Pakistan is not dangerous for marine habitat and the use of these parameters in monitoring programs to assess ecosystem health has the potential to inform the general public and decision-makers about the state of the coastal ecosystems. To save this vital important habitat, the government agencies and scientists should work with proper attention.

  11. Management-focused approach to investigating coastal water-quality drivers and impacts in the Baltic Sea

    Science.gov (United States)

    Vigouroux, G.; Destouni, G.; Chen, Y.; Bring, A.; Jönsson, A.; Cvetkovic, V.

    2017-12-01

    Coastal areas link human-driven conditions on land with open sea conditions, and include crucial and vulnerable ecosystems that provide a variety of ecosystem services. Eutrophication is a common problem that is not least observed in the Baltic Sea, where coastal water quality is influenced both by land-based nutrient loading and by partly eutrophic open sea conditions. Robust and adaptive management of coastal systems is essential and necessitates integration of large scale catchment-coastal-marine systems as well as consideration of anthropogenic drivers and impacts, and climate change. To address this coastal challenge, relevant methodological approaches are required for characterization of coupled land, local coastal, and open sea conditions under an adaptive management framework for water quality. In this paper we present a new general and scalable dynamic characterization approach, developed for and applied to the Baltic Sea and its coastal areas. A simple carbon-based water quality model is implemented, dividing the Baltic Sea into main management basins that are linked to corresponding hydrological catchments on land, as well as to each other though aggregated three-dimensional marine hydrodynamics. Relevant hydrodynamic variables and associated water quality results have been validated on the Baltic Sea scale and show good accordance with available observation data and other modelling approaches. Based on its scalability, this methodology is further used on coastal zone scale to investigate the effects of hydrodynamic, hydro-climatic and nutrient load drivers on water quality and management implications for coastal areas in the Baltic Sea.

  12. Evidence of local and regional freshening of Northeast Greenland coastal waters

    DEFF Research Database (Denmark)

    Sejr, Mikael K.; Stedmon, Colin A; Bendtsen, Jørgen

    2017-01-01

    coast and providing evaluation basis for ocean models. Here we present 13 years of summer measurements along a 120 km transect in Young Sound, Northeast Greenland and show that sub-surface coastal waters are decreasing in salinity with an average rate of 0.12 ± 0.05 per year. This is the first...... coastal currents thus reducing density of water masses influencing major deep water formation areas in the Subarctic Atlantic Ocean. Ultimately, the observed freshening could have implications for the Atlantic meridional overturning circulation....

  13. Artesian water in the Malabar coastal plain of southern Kerala, India

    Science.gov (United States)

    Taylor, George C.; Ghosh, P.K.

    1964-01-01

    The present report is based on a geological and hydrological reconnaissance during 1954 of the Malabar Coastal Plain and adjacent island area of southern Kerala to evaluate the availability of ground water for coastal villages and municipalities and associated industries and the potentialities for future development. The work was done in cooperation with the Geological Survey of India and under the auspices of the U.S. Technical Cooperation Mission to India. The State of Kerala, which lies near the southern tip of India and along the eastern shore of the Caspian Sea, contains a total area of 14,937 square miles. The eastern part of the state is s rugged mountainous highland which attains altitudes of more than 6,000 feet. This highland descends westward through piedmont upland to s narrow coastal plain, which reaches a maximum width of about 16 miles in the latitude of Shertalli. A tropical monsoon rain-forest climate prevails in most of Kerala, and annual rainfall ranges from 65 to 130 inches in the southern part of the coastal plain to as much a 200 inches in the highland. The highland and piedmont upland tracts of Kerala are underlain by Precambrian meamorphic and igneous rocks belonging in large parabola-the so-called Charnockite Series. Beneath ahe coastal plain are semiconsolidated asunconsolidated sedimentary deposits whose age ranges from Miocene to Recent. These deposits include sofa sandstone and clay shale containing some marl or limestone and sand, and clay and pea containing some gravel. The sofa sandstone, sand, and gravel beds constitute important aquifers a depths ranging from a few tens of feet to 400 feet or more below the land surface. The shallow ground war is under water-able or unconfined conditions, but the deeper aquifers contain water under artesian pressure. Near the coast, drilled wells tapping the deeper aquifers commonly flow with artesian heads as much as 10 to 12 feet above the land surface. The draft from existing wells in the

  14. Assessment of natural radioactivity levels in waters from the higher Ribeira Valley to the southern Sao Paulo state coastal plain

    International Nuclear Information System (INIS)

    Jesus, Sueli Carvalho de

    2010-01-01

    The complex exchange of fluvial, subsurface and seawater within a coastal area directly affects global biogeochemical cycles and the application of isotopic tracers, mainly natural radionuclides from U and Th series, is a powerful tool to track sources and sinks of trace elements and nutrients to this systems. The unique Ra signature applied to quantify the contribution of such fluxes is acquired within the subterranean estuary, a mixing zone between fresh groundwater and seawater in coastal aquifers. In the U and Th natural radioactive decay series there are four radium isotopes: 223 Ra (t 1/2 = 11.4 d), 224 Ra (t 1/2 = 3.7 d), 228 Ra (t 1/2 = 5.7 y) and 226 Ra (t 1/2 = 1,600 y). Their wide range in half-lives corresponds well with the duration of many coastal processes. All these Ra isotopes derive from decay of Th parents, which are tightly bound to particles. Because Ra is mobilized in the marine environment, sediments provide a continuous source of Ra isotopes to estuarine waters at rates set by its decay constants. The Th isotope activities in the sediments and the distribution coefficient of Ra between the sediments and water determine the potential input of each Ra isotope to the water. Because 228 Ra is regenerated much faster than 226 Ra, estuaries with high 228 Ra/ 226 Ra activity ratios in the water must have a high degree of exchange with sediments on the sea bed or with groundwater draining nearby. This information is useful to elucidate the contribution of estuarine systems to the exchange of trace elements, N, P and C in the mixing zone. The combined source functions for Ra in a coastal area include riverine particulates/dissolved input, oceanic dissolved concentrations, input from sediments and groundwater. The relative significance of each of these sources is usually a function of the site-specific hydrogeology and where the samples are taken relative to the salinity gradient (extent of freshwater/saltwater mixing). Thus, the Ra isotopes provide

  15. Development of MODIS data-based algorithm for retrieving sea surface temperature in coastal waters.

    Science.gov (United States)

    Wang, Jiao; Deng, Zhiqiang

    2017-06-01

    A new algorithm was developed for retrieving sea surface temperature (SST) in coastal waters using satellite remote sensing data from Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Aqua platform. The new SST algorithm was trained using the Artificial Neural Network (ANN) method and tested using 8 years of remote sensing data from MODIS Aqua sensor and in situ sensing data from the US coastal waters in Louisiana, Texas, Florida, California, and New Jersey. The ANN algorithm could be utilized to map SST in both deep offshore and particularly shallow nearshore waters at the high spatial resolution of 1 km, greatly expanding the coverage of remote sensing-based SST data from offshore waters to nearshore waters. Applications of the ANN algorithm require only the remotely sensed reflectance values from the two MODIS Aqua thermal bands 31 and 32 as input data. Application results indicated that the ANN algorithm was able to explaining 82-90% variations in observed SST in US coastal waters. While the algorithm is generally applicable to the retrieval of SST, it works best for nearshore waters where important coastal resources are located and existing algorithms are either not applicable or do not work well, making the new ANN-based SST algorithm unique and particularly useful to coastal resource management.

  16. Deuterium exchange between liquid water and gaseous hydrogen

    International Nuclear Information System (INIS)

    Dave, S.M.; Ghosh, S.K.; Sadhukhan, H.K.

    1982-01-01

    The overall separation factors for the deuterium exchange between liquid water and gaseous hydrogen have been calculated over a wide range of temperature, pressure and deuterium concentrations. These data would be useful in the design and other considerations for heavy water production, based on hydrogen-water exchange. (author)

  17. Coastal hypoxia and sediment biogeochemistry

    Directory of Open Access Journals (Sweden)

    J. J. Middelburg

    2009-07-01

    Full Text Available The intensity, duration and frequency of coastal hypoxia (oxygen concentration <63 μM are increasing due to human alteration of coastal ecosystems and changes in oceanographic conditions due to global warming. Here we provide a concise review of the consequences of coastal hypoxia for sediment biogeochemistry. Changes in bottom-water oxygen levels have consequences for early diagenetic pathways (more anaerobic at expense of aerobic pathways, the efficiency of re-oxidation of reduced metabolites and the nature, direction and magnitude of sediment-water exchange fluxes. Hypoxia may also lead to more organic matter accumulation and burial and the organic matter eventually buried is also of higher quality, i.e. less degraded. Bottom-water oxygen levels also affect the organisms involved in organic matter processing with the contribution of metazoans decreasing as oxygen levels drop. Hypoxia has a significant effect on benthic animals with the consequences that ecosystem functions related to macrofauna such as bio-irrigation and bioturbation are significantly affected by hypoxia as well. Since many microbes and microbial-mediated biogeochemical processes depend on animal-induced transport processes (e.g. re-oxidation of particulate reduced sulphur and denitrification, there are indirect hypoxia effects on biogeochemistry via the benthos. Severe long-lasting hypoxia and anoxia may result in the accumulation of reduced compounds in sediments and elimination of macrobenthic communities with the consequences that biogeochemical properties during trajectories of decreasing and increasing oxygen may be different (hysteresis with consequences for coastal ecosystem dynamics.

  18. Impact of river basin management on coastal water quality and ecosystem services: A southern Baltic estuary

    Science.gov (United States)

    Schernewski, Gerald; Hürdler, Jens; Neumann, Thomas; Stybel, Nardine; Venohr, Markus

    2010-05-01

    Eutrophication management is still a major challenge in the Baltic Sea region. Estuaries or coastal waters linked to large rivers cannot be managed independently. Nutrient loads into these coastal ecosystems depend on processes, utilisation, structure and management in the river basin. In practise this means that we need a large scale approach and integrated models and tools to analyse, assess and evaluate the effects of nutrient loads on coastal water quality as well as the efficiency of river basin management measures on surface waters and especially lagoons and estuaries. The Odra river basin, the Szczecin Lagoon and its coastal waters cover an area of about 150,000 km² and are an eutrophication hot-spot in the Baltic region. To be able to carry out large scale, spatially integrative analyses, we linked the river basin nutrient flux model MONERIS to the coastal 3D-hydrodynamic and ecosystem model ERGOM. Objectives were a) to analyse the eutrophication history in the river basin and the resulting functional changes in the coastal waters between early 1960's and today and b) to analyse the effects of an optimal nitrogen and phosphorus management scenario in the Oder/Odra river basin on coastal water quality. The models show that an optimal river basin management with reduced nutrient loads (e.g. N-load reduction of 35 %) would have positive effects on coastal water quality and algae biomass. The availability of nutrients, N/P ratios and processes like denitrification and nitrogen-fixation would show spatial and temporal changes. It would have positive consequences for ecosystems functions, like the nutrient retention capacity, as well. However, this optimal scenario is by far not sufficient to ensure a good coastal water quality according to the European Water Framework Directive. A "good" water quality in the river will not be sufficient to ensure a "good" water quality in the coastal waters. Further, nitrogen load reductions bear the risk of increased

  19. Monitoring water quality in Northwest Atlantic coastal waters using dinoflagellate cysts

    Science.gov (United States)

    Nutrient pollution is a major environmental problem in many coastal waters around the US. Determining the total input of nutrients to estuaries is a challenge. One method to evaluate nutrient input is through nutrient loading models. Another method relies upon using indicators as...

  20. Assessment of Surface Water Quality in the Malaysian Coastal Waters by Using Multivariate Analyses

    International Nuclear Information System (INIS)

    Yap, C.K.; Chee, M.W.; Shamarina, S.; Edward, F.B.; Chew, W.; Tan, S.G.

    2011-01-01

    Coastal water samples were collected from 20 sampling sites in the southern part of Peninsular Malaysia. Seven physico-chemical parameters were measured directly in-situ while water samples were collected and analysed for 6 dissolved trace metal concentrations. The surface water (0-20 cm) physico-chemical parameters including temperature, salinity, dissolved oxygen (DO), pH, total dissolved solids (TDS), specific conductance (SpC) and turbidity while the dissolved trace metals were Cd, Cu, Fe, Ni, Pb and Zn. The ranges for the physico-chemical parameters were 28.07-35.6 degree Celsius for temperature, 0.18-32.42 ppt for salinity, 2.20-12.03 mg/ L for DO, 5.50-8.53 for pH, 0.24-31.65 mg/ L for TDS, 368-49452 μS/ cm for SpC and 0-262 NTU for turbidity while the dissolved metals (mg/ L) were 0.013-0.147 for Cd, 0.024-0.143 for Cu, 0.266-2.873 for Fe, 0.027-0.651 for Ni, 0.018-0.377 for Pb and 0.032-0.099 for Zn. Based on multivariate analysis (including correlation, cluster and principal component analyses), the polluted sites were found at Kg. Pasir Puteh and Tg. Kupang while Ni and Pb were identified as two major dissolved metals of high variation in the coastal waters. Therefore, water quality monitoring and control of release of untreated anthropogenic wastes into rivers and coastal waters are strongly needed. (author)

  1. Emerging organic contaminants in coastal waters: anthropogenic impact, environmental release and ecological risk.

    Science.gov (United States)

    Jiang, Jheng-Jie; Lee, Chon-Lin; Fang, Meng-Der

    2014-08-30

    This study provides a first estimate of the sources, distribution, and risk presented by emerging organic contaminants (EOCs) in coastal waters off southwestern Taiwan. Ten illicit drugs, seven nonsteroidal anti-inflammatory drugs (NSAIDs), five antibiotics, two blood lipid regulators, two antiepileptic drugs, two UV filters, caffeine, atenolol, and omeprazole were analyzed by solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry (SPE-LC-MS/MS). Thirteen EOCs were detected in coastal waters, including four NSAIDs (acetaminophen, ibuprofen, ketoprofen, and codeine), three antibiotics (ampicillin, erythromycin, and cefalexin), three illicit drugs (ketamine, pseudoephedrine, and MDMA), caffeine, carbamazepine, and gemfibrozil. The median concentrations for the 13 EOCs ranged from 1.47 ng/L to 156 ng/L. Spatial variation in concentration of the 13 EOCs suggests discharge into coastal waters via ocean outfall pipes and rivers. Codeine and ampicillin have significant pollution risk quotients (RQ>1), indicating potentially high risk to aquatic organisms in coastal waters. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. An economically viable alternative to coastal discharge of produced water

    International Nuclear Information System (INIS)

    D'Unger, C.V.; Carr, R.S.; Chapman, D.C.

    1993-01-01

    The discharge of produced waters to coastal estuaries has been common practice on the Texas coast for many years as these discharges are currently exempt from NPDES permitting. A study of the active produced water discharges in Nueces Bay, Texas revealed that all eight effluents were highly toxic as determined by the sea urchin (Arbacia punctulata) fertilization and embryological development assays. An alternative to discharging produced water into coastal estuaries is the use of disposal wells. Inactive wells can be converted to produced water disposal wells. Production records for the Nueces Bay, Texas area reveal that 52% of the gas wells produce less than 100 mcf/d and 50% of the oil wells produce less than 10 b/d. Using conservative estimates, the cost of converting an inactive well to a disposal well was calculated to be $31,500 which could be paid out by a gas well producing as little as 100 mcf/d in 26 months using only 50% of the well's profit. Combining multiple leases to a single disposal well would reduce proportionately the cost to each operation. This study has demonstrated that economically viable disposal options could be achieved in the Nueces Bay area through the imaginative and cooperative formation of produced water disposal ventures. This same model could be applied to produced water discharges in other coastal areas

  3. The bottom water exchange between the Singapore Strait and the West Johor Strait

    Science.gov (United States)

    Sun, Yunfang; Eltahir, Elfatih; Malanotte-Rizzoli, Paola

    2017-08-01

    As a part of the border between Singapore and Malaysia, the West Johor Strait (WJS) suffered newly from harmful algal blooms. There is no previous study showing the source of the nutrients in the WJS. This paper is investigating the possible water exchange between the water in the WJS and the bottom water in Singapore Strait. This paper adopts a two-level nesting atmosphere-ocean coupled models to downscale the global atmosphere-ocean model into the Singapore coastal water, keeping the large-scale and long-term ocean and climate circulation signals and the advantages of the high-resolution. Based on the high-resolution ocean circulation fields, a Lagrangian particle tracking model is used to trace the Singapore Strait's bottom water movement and the water mixing in the WJS. The results showed that the numerical models well resolved the Singapore coastal water regional circulation. There is a small but significant bottom water (1.25%) transport from the Singapore Strait to the WJS, which occurs from the southwest coastline of Singapore. The bottom water in the Singapore Strait prefers to enter the WJS during the spring tide and the flood period, and stay in Johor Strait for 6.4 days. The spring tide is the first-order factor for the water vertical mixing in the WJS, the wind is also very important for the vertical mixing especially in neap tide condition. An overall very important factor is the light perturbation. With the strongest vertical mixing of nutrients and bottom sediments due to the spring tide, the latter ones may inhibit the light penetration during the spring tide and reduce the algal bloom. The light penetration otherwise is greater during the neap tide, when the winds are the most important factor and hence favor the algal bloom. With the strongest wind in February and the longest permanence time in June and the sufficient nutrient supply in February and June, the most serious algal blooms may happen in February and June in the WJS.

  4. Hydrochemical studies along the coastal waters off Mangalore

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, T.; Balachandran, K.K.; Nair, M.; Sankaranarayanan, V.N.

    Environmental parameters such as temperature, salinity, dissolved oxygen, BOD pH, nutrients suspended load and chlorophyll 'a' were estimated in the coastal waters of Mangalore. Four transects, each consisting of four stations extending from old...

  5. Experimental study of heat transfer and pressure drop characteristics of air/water and air-steam/water heat exchange in a polymer compact heat exchanger

    NARCIS (Netherlands)

    Cheng, L.; Geld, van der C.W.M.

    2005-01-01

    Experiments of heat transfer and pressure drop in a polymer compact heat exchanger made of PolyVinyliDene-Fluoride were conducted under various conditions for air/water heat exchange and air-steam/water heat exchange, respectively. The overall heat transfer coefficients of air-steam/water heat

  6. Remote sensing reflectance simulation of coastal optical complex water in the East China Sea

    Science.gov (United States)

    He, Shuo; Lou, Xiulin; Zhang, Huaguo; Zheng, Gang

    2018-02-01

    In this work, remote sensing reflectance (Rrs) spectra of the Zhejiang coastal water in the East China Sea (ECS) were simulated by using the Hydrolight software with field data as input parameters. The seawater along the Zhejiang coast is typical Case II water with complex optical properties. A field observation was conducted in the Zhejiang coastal region in late May of 2016, and the concentration of ocean color constituents (pigment, SPM and CDOM), IOPs (absorption and backscattering coefficients) and Rrs were measured at 24 stations of 3 sections covering the turbid to clear inshore coastal waters. Referring to these ocean color field data, an ocean color model suitable for the Zhejiang coastal water was setup and applied in the Hydrolight. A set of 11 remote sensing reflectance spectra above water surface were modeled and calculated. Then, the simulated spectra were compared with the filed measurements. Finally, the spectral shape and characteristics of the remote sensing reflectance spectra were analyzed and discussed.

  7. Health status of the coastal waters of Mumbai and regions around

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Govindan, K.

    in the drainage zones also contribute to pollution loads. These inputs have affected the water quality, sediment quality and biological characteristics of receiving waters to varying degrees. BOD in coastal water is often high and water is enriched in dissolved...

  8. Human recreational exposure to antibiotic resistant bacteria in coastal bathing waters.

    Science.gov (United States)

    Leonard, Anne F C; Zhang, Lihong; Balfour, Andrew J; Garside, Ruth; Gaze, William H

    2015-09-01

    Infections caused by antibiotic resistant bacteria (ARB) are associated with poor health outcomes and are recognised globally as a serious health problem. Much research has been conducted on the transmission of ARB to humans. Yet the role the natural environment plays in the spread of ARB and antibiotic resistance genes is not well understood. Antibiotic resistant bacteria have been detected in natural aquatic environments, and ingestion of seawater during water sports is one route by which many people could be directly exposed. The aim was to estimate the prevalence of resistance to one clinically important class of antibiotics (third-generation cephalosporins (3GCs)) amongst Escherichia coli in coastal surface waters in England and Wales. Prevalence data was used to quantify ingestion of 3GC-resistant E. coli (3GCREC) by people participating in water sports in designated coastal bathing waters. A further aim was to use this value to derive a population-level estimate of exposure to these bacteria during recreational use of coastal waters in 2012. The prevalence of 3GC-resistance amongst E. coli isolated from coastal surface waters was estimated using culture-based methods. This was combined with the density of E. coli reported in designated coastal bathing waters along with estimations of the volumes of water ingested during various water sports reported in the literature to calculate the mean number of 3GCREC ingested during different water sports. 0.12% of E. coli isolated from surface waters were resistant to 3GCs. This value was used to estimate that in England and Wales over 6.3 million water sport sessions occurred in 2012 that resulted in the ingestion of at least one 3GCREC. Despite the low prevalence of resistance to 3GCs amongst E. coli in surface waters, there is an identifiable human exposure risk for water users, which varies with the type of water sport undertaken. The relative importance of this exposure is likely to be greater in areas where a

  9. Exchange across the shelf break at high southern latitudes

    Directory of Open Access Journals (Sweden)

    J. M. Klinck

    2010-05-01

    Full Text Available Exchange of water across the Antarctic shelf break has considerable scientific and societal importance due to its effects on circulation and biology of the region, conversion of water masses as part of the global overturning circulation and basal melt of glacial ice and the consequent effect on sea level rise. The focus in this paper is the onshore transport of warm, oceanic Circumpolar Deep Water (CDW; export of dense water from these shelves is equally important, but has been the focus of other recent papers and will not be considered here. A variety of physical mechanisms are described which could play a role in this onshore flux. The relative importance of some processes are evaluated by simple calculations. A numerical model for the Ross Sea continental shelf is used as an example of a more comprehensive evaluation of the details of cross-shelf break exchange. In order for an ocean circulation model to simulate these processes at high southern latitudes, it needs to have high spatial resolution, realistic geometry and bathymetry. Grid spacing smaller than the first baroclinic radius of deformation (a few km is required to adequately represent the circulation. Because of flow-topography interactions, bathymetry needs to be represented at these same small scales. Atmospheric conditions used to force these circulation models also need to be known at a similar small spatial resolution (a few km in order to represent orographically controlled winds (coastal jets and katabatic winds. Significantly, time variability of surface winds strongly influences the structure of the mixed layer. Daily, if not more frequent, surface fluxes must be imposed for a realistic surface mixed layer. Sea ice and ice shelves are important components of the coastal circulation. Ice isolates the ocean from exchange with the atmosphere, especially in the winter. Melting and freezing of both sea ice and glacial ice influence salinity and thereby the character of shelf

  10. Determination of strontium isotopic composition in natural waters: examples of application in subsurface waters of the coastal zone of Bragantina region, Para, BR

    International Nuclear Information System (INIS)

    Bordalo, Adriana Oliveira; Moura, Candido Augusto Veloso; Scheller, Thomas

    2007-01-01

    Analytical procedures used for determining the concentrations and isotope composition of strontium in subsurface waters, by mass spectrometry, are described. Sampling was performed in coastal plateaus, salt marsh and mangrove environments in the coastal region of Para. Coastal plateau waters have δ 87 Sr between 1.51 and 6.26 per mille and Sr concentration bellow 58 ppb. Salt marsh waters show δ 87 Sr between 0.55 and 0.90 per mille and Sr concentration between 93 and 114 ppm, while mangrove waters have δ 87 Sr per mille around zero and Sr concentration above 15 ppm. Differences in the 87 Sr/ 86 Sr ratio in these subsurface waters are detected, as well as seasonal variations in the coastal plateau waters. (author)

  11. Coastal Morphology and Coastal Protection

    NARCIS (Netherlands)

    Van de Graaff, J.

    2009-01-01

    Lecture notes ct5309. Tides, currents and water; coastal problems; sediment transport processes; coastal transport modes; longshore transport; cross-shore transport; fundamentals of mud; channels and trenches; coastal protection; application of structures; application of nourishments.

  12. Discriminating sediment and clear water over coastal water using GD technique

    Directory of Open Access Journals (Sweden)

    Amin Abd Rahman Mat

    2017-03-01

    Full Text Available Currently two algorithms are being used routinely by the MODIS Atmosphere and Ocean Team in order to distinguish sediment influence and clear water pixels over turbid water area. These two algorithms require complicated computational analyses. In this paper, a simple algorithm based on empirical technique to detect the sediment-influenced pixels over coastal waters is proposed as an alternative to these two algorithms. This study used apparent reflectance acquired from MODIS L1B product. This algorithm is based on the gradient difference of the line connecting the 0.47- and 1.24-μm channels and 0.47- and 0.66-μm channels of a log-log graph of the apparent reflectance values against MODIS wavelengths. Over clear-water areas (deep blue sea, the 0.47-, 0.66- and 1.24-μm channels fitted very well in line with correlation R > 0.99. Over turbid waters, a substantial increase of 0.66 μm in the reflectance leads to a low correlation value. By computing the difference between the gradient of the line connecting 0.47 and 0.66 μm and the gradient of the line connecting 0.47 and 1.24 μm, the threshold to discriminate turbid and shallow coastal waters from clear-water pixels can be obtained. If the gradient difference is greater than 0, the pixels were then marked as sediment-influenced pixels. This proposed algorithm works well for MODIS Terra and Aqua sensor. The comparison of this algorithm with an established algorithm also showed a good agreement.

  13. Acetone and Water on TiO(110): H/D Exchange

    International Nuclear Information System (INIS)

    Henderson, Michael A.

    2005-01-01

    Isotopic H/D exchange between coadsorbed acetone and water on the TiO(110) surface was examined using temperature programmed desorption (TPD) as a function of coverage and two surface pretreatments (oxidation and reduction). Coadsorbed acetone and water interact repulsively on reduced TiO(110) based on results from the companion paper to this study, with water exerting a greater influence in destabilizing acetone and acetone having only a nominal influence on water. Despite the repulsive interaction between these coadsorbates, about 0.02 ML of a 1 ML d6-acetone on the reduced surface exhibits H/D exchange with coadsorbed water, with the exchange occurring exclusively in the high temperature region of the d?-acetone TPD spectrum at ∼340 K. The effect was confirmed with combinations of d?-acetone and D?O. The extent of exchange decreased on the reduced surface with water coverages above ∼0.3 ML due to the ability of water to displace coadsorbed acetone from first layer sites to the multilayer. In contrast, the extent of exchange increased by a factor of 3 when the surface was pre-oxidized prior to coadsorption. In this case, there was no evidence for the negative influence of high water coverages on the extent of H/D exchange. Comparison of the TPD spectra from the exchange products (either d?- or d?-acetone depending on the coadsorption pairing) suggests that, in addition to the 340 K exchange process seen on the reduced surface, a second exchange process was observed on the oxidized surface at ∼390 K. In both cases (oxidized and reduced), desorption of the H/D exchange products appeared to be reaction limited and to involve the influence of OH/OD groups (or water formed during recombinative desorption of OH/OD groups) instead of molecularly adsorbed water. The 340 K exchange process is assigned to reaction at step sites and the 390 K exchange process is attributed to the influence of oxygen adatoms deposited during surface oxidation. The H/D exchange

  14. Heat exchanger for solar water heaters

    Science.gov (United States)

    Cash, M.; Krupnick, A. C.

    1977-01-01

    Proposed efficient double-walled heat exchanger prevents contamination of domestic water supply lines and indicates leakage automatically in solar as well as nonsolar heat sources using water as heat transfer medium.

  15. Dissolved Platinum Concentrations in Coastal Seawater: Boso to Sanriku Areas, Japan.

    Science.gov (United States)

    Mashio, Asami Suzuki; Obata, Hajime; Gamo, Toshitaka

    2017-08-01

    Platinum, one of the rarest elements in the earth's crust, is now widely used in a range of products, such as catalytic converters in automobiles and anticancer drugs. Increasing use and dispersal of platinum has the potential to affect aquatic environments. Platinum concentrations in open ocean seawater have been found to be very low (approximately 0.2 pmol/L); however, Pt distributions and biogeochemical cycles in coastal areas are unknown. In this study, we investigated Pt concentrations in coastal waters between the Boso and Sanriku areas, Japan, after the 2011 tsunami. We determined sub-picomolar levels of dissolved Pt using isotope-dilution Inductively coupled plasma mass spectrometry after column preconcentration with an anion exchange resin. Dissolved Pt concentrations were found to be in the range 0.20-1.5 pmol/L, with the highest concentration in bottom water of the Boso coastal area, and at stations close to Tokyo Bay. Assuming thermodynamical equilibrium, Pt was determined to be present in the form PtCl 5 (OH) 2- , even in low-oxygen coastal waters. Vertical profiles indicated Pt levels increased toward seafloors near coastal stations and were similar to those of the open ocean at trench stations. High concentrations of dissolved Pt are thought to be derived from coastal sediments.

  16. Influence of microorganism content in suspended particles on the particle–water partitioning of mercury in semi-enclosed coastal waters

    International Nuclear Information System (INIS)

    Jang, Jiyi; Kim, Hyunji; Han, Seunghee

    2014-01-01

    It is known that particle scavenging of mercury (Hg) can be affected by the abundance of particulate organic matter in coastal waters. However, the role of living organic particles in Hg scavenging is not yet completely understood. In this study, we hypothesized that an abundance of living organic particles (i.e., phytoplankton and bacteria) would influence the particle–water partitioning of Hg in coastal waters. Surface seawater samples were collected from eight stations in Gwangyang Bay, Korea, in three seasons (November 2009, April 2010, and October 2010) for the determination of concentrations of suspended particulate matter (including chlorophyll-a and bacteria), and Hg in unfiltered and filtered waters. We found that more Hg partitioned toward particulate matter when phytoplankton biomass, indicated from the chlorophyll-a concentration in a particle, was higher. In the low algal season, when [chlorophyll-a] −1 , the bacterial number, instead of chlorophyll-a concentration in particle, showed a positive correlation with the particle–water partition coefficient of Hg. Overall, microbial abundance seems to play a critical role in particle scavenging of Hg in coastal water. Taking this result in light of Hg in pristine coastal zones, we predict that increases in algal biomass amplify the potential for algae to transfer Hg to marine food chains. - Highlights: • Abundance of phytoplankton and bacteria influenced particle–water partitioning of Hg. • More Hg partitioned toward particles when microorganism biomass in particle is large. • Increases of algal biomass may enhance Hg bioaccumulation in coastal ecosystem

  17. Influence of microorganism content in suspended particles on the particle–water partitioning of mercury in semi-enclosed coastal waters

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jiyi [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Global Bioresources Research Center, Korea Institute of Ocean Science and Technology (KIOST), Ansan 426-744 (Korea, Republic of); Kim, Hyunji [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Han, Seunghee, E-mail: shan@gist.ac.kr [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of)

    2014-02-01

    It is known that particle scavenging of mercury (Hg) can be affected by the abundance of particulate organic matter in coastal waters. However, the role of living organic particles in Hg scavenging is not yet completely understood. In this study, we hypothesized that an abundance of living organic particles (i.e., phytoplankton and bacteria) would influence the particle–water partitioning of Hg in coastal waters. Surface seawater samples were collected from eight stations in Gwangyang Bay, Korea, in three seasons (November 2009, April 2010, and October 2010) for the determination of concentrations of suspended particulate matter (including chlorophyll-a and bacteria), and Hg in unfiltered and filtered waters. We found that more Hg partitioned toward particulate matter when phytoplankton biomass, indicated from the chlorophyll-a concentration in a particle, was higher. In the low algal season, when [chlorophyll-a] < 0.6 μg L{sup −1}, the bacterial number, instead of chlorophyll-a concentration in particle, showed a positive correlation with the particle–water partition coefficient of Hg. Overall, microbial abundance seems to play a critical role in particle scavenging of Hg in coastal water. Taking this result in light of Hg in pristine coastal zones, we predict that increases in algal biomass amplify the potential for algae to transfer Hg to marine food chains. - Highlights: • Abundance of phytoplankton and bacteria influenced particle–water partitioning of Hg. • More Hg partitioned toward particles when microorganism biomass in particle is large. • Increases of algal biomass may enhance Hg bioaccumulation in coastal ecosystem.

  18. A simulation-optimization model for effective water resources management in the coastal zone

    Science.gov (United States)

    Spanoudaki, Katerina; Kampanis, Nikolaos

    2015-04-01

    Coastal areas are the most densely-populated areas in the world. Consequently water demand is high, posing great pressure on fresh water resources. Climatic change and its direct impacts on meteorological variables (e.g. precipitation) and indirect impact on sea level rise, as well as anthropogenic pressures (e.g. groundwater abstraction), are strong drivers causing groundwater salinisation and subsequently affecting coastal wetlands salinity with adverse effects on the corresponding ecosystems. Coastal zones are a difficult hydrologic environment to represent with a mathematical model due to the large number of contributing hydrologic processes and variable-density flow conditions. Simulation of sea level rise and tidal effects on aquifer salinisation and accurate prediction of interactions between coastal waters, groundwater and neighbouring wetlands requires the use of integrated surface water-groundwater mathematical models. In the past few decades several computer codes have been developed to simulate coupled surface and groundwater flow. However, most integrated surface water-groundwater models are based on the assumption of constant fluid density and therefore their applicability to coastal regions is questionable. Thus, most of the existing codes are not well-suited to represent surface water-groundwater interactions in coastal areas. To this end, the 3D integrated surface water-groundwater model IRENE (Spanoudaki et al., 2009; Spanoudaki, 2010) has been modified in order to simulate surface water-groundwater flow and salinity interactions in the coastal zone. IRENE, in its original form, couples the 3D shallow water equations to the equations describing 3D saturated groundwater flow of constant density. A semi-implicit finite difference scheme is used to solve the surface water flow equations, while a fully implicit finite difference scheme is used for the groundwater equations. Pollution interactions are simulated by coupling the advection

  19. Modeling of Dense Water Production and Salt Transport from Alaskan Coastal Polynyas

    Science.gov (United States)

    Signorini, Sergio R.; Cavalieri, Donald J.

    2000-01-01

    The main significance of this paper is that a realistic, three-dimensional, high-resolution primitive equation model has been developed to study the effects of dense water formation in Arctic coastal polynyas. The model includes realistic ambient stratification, realistic bottom topography, and is forced by time-variant surface heat flux, surface salt flux, and time-dependent coastal flow. The salt and heat fluxes, and the surface ice drift, are derived from satellite observations (SSM/I and NSCAT sensors). The model is used to study the stratification, salt transport, and circulation in the vicinity of Barrow Canyon during the 1996/97 winter season. The coastal flow (Alaska coastal current), which is an extension of the Bering Sea throughflow, is formulated in the model using the wind-transport regression. The results show that for the 1996/97 winter the northeastward coastal current exports 13% to 26% of the salt produced by coastal polynyas upstream of Barrow Canyon in 20 to 30 days. The salt export occurs more rapidly during less persistent polynyas. The inclusion of ice-water stress in the model makes the coastal current slightly weaker and much wider due to the combined effects of surface drag and offshore Ekman transport.

  20. Coastal circulation off Bombay in relation to waste water disposal

    Digital Repository Service at National Institute of Oceanography (India)

    Josanto, V.; Sarma, R.V.

    Flow patterns in the coastal waters of Bombay were studied using recording current meters, direct reading current meters, floats and dye in relation to the proposed waste water disposal project of the Municipal Corporation of Greater Bombay from...

  1. Coastal Water Quality Modeling in Tidal Lake: Revisited with Groundwater Intrusion

    Science.gov (United States)

    Kim, C.

    2016-12-01

    A new method for predicting the temporal and spatial variation of water quality, with accounting for a groundwater effect, has been proposed and applied to a water body partially connected to macro-tidal coastal waters in Korea. The method consists of direct measurement of environmental parameters, and it indirectly incorporates a nutrients budget analysis to estimate the submarine groundwater fluxes. Three-dimensional numerical modeling of water quality has been used with the directly collected data and the indirectly estimated groundwater fluxes. The applied area is Saemangeum tidal lake that is enclosed by 33km-long sea dyke with tidal openings at two water gates. Many investigations of groundwater impact reveal that 10 50% of nutrient loading in coastal waters comes from submarine groundwater, particularly in the macro-tidal flat, as in the west coast of Korea. Long-term monitoring of coastal water quality signals the possibility of groundwater influence on salinity reversal and on the excess mass outbalancing the normal budget in Saemangeum tidal lake. In the present study, we analyze the observed data to examine the influence of submarine groundwater, and then a box model is demonstrated for quantifying the influx and efflux. A three-dimensional numerical model has been applied to reproduce the process of groundwater dispersal and its effect on the water quality of Saemangeum tidal lake. The results show that groundwater influx during the summer monsoon then contributes significantly, 20% more than during dry season, to water quality in the tidal lake.

  2. Hydrographic features of the coastal waters of Kakinada

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, B.P.; RamaRaju, V.S.

    The physical characteristics of coastal waters - temperature, salinity and currents at the surface and subsurface levels - off Kakinada in the Bay of Bengal at 4 stations (bottom depth 5, 12, 22 and 42 m) along 17 degrees N latitude during January...

  3. A new general dynamic model predicting radionuclide concentrations and fluxes in coastal areas from readily accessible driving variables

    International Nuclear Information System (INIS)

    Haakanson, Lars

    2004-01-01

    This paper presents a general, process-based dynamic model for coastal areas for radionuclides (metals, organics and nutrients) from both single pulse fallout and continuous deposition. The model gives radionuclide concentrations in water (total, dissolved and particulate phases and concentrations in sediments and fish) for entire defined coastal areas. The model gives monthly variations. It accounts for inflow from tributaries, direct fallout to the coastal area, internal fluxes (sedimentation, resuspension, diffusion, burial, mixing and biouptake and retention in fish) and fluxes to and from the sea outside the defined coastal area and/or adjacent coastal areas. The fluxes of water and substances between the sea and the coastal area are differentiated into three categories of coast types: (i) areas where the water exchange is regulated by tidal effects; (ii) open coastal areas where the water exchange is regulated by coastal currents; and (iii) semi-enclosed archipelago coasts. The coastal model gives the fluxes to and from the following four abiotic compartments: surface water, deep water, ET areas (i.e., areas where fine sediment erosion and transport processes dominate the bottom dynamic conditions and resuspension appears) and A-areas (i.e., areas of continuous fine sediment accumulation). Criteria to define the boundaries for the given coastal area towards the sea, and to define whether a coastal area is open or closed are given in operational terms. The model is simple to apply since all driving variables may be readily accessed from maps and standard monitoring programs. The driving variables are: latitude, catchment area, mean annual precipitation, fallout and month of fallout and parameters expressing coastal size and form as determined from, e.g., digitized bathymetric maps using a GIS program. Selected results: the predictions of radionuclide concentrations in water and fish largely depend on two factors, the concentration in the sea outside the given

  4. Study on the cumulative impact of reclamation activities on ecosystem health in coastal waters.

    Science.gov (United States)

    Shen, Chengcheng; Shi, Honghua; Zheng, Wei; Li, Fen; Peng, Shitao; Ding, Dewen

    2016-02-15

    The purpose of this study is to develop feasible tools to investigate the cumulative impact of reclamations on coastal ecosystem health, so that the strategies of ecosystem-based management can be applied in the coastal zone. An indicator system and model were proposed to assess the cumulative impact synthetically. Two coastal water bodies, namely Laizhou Bay (LZB) and Tianjin coastal waters (TCW), in the Bohai Sea of China were studied and compared, each in a different phase of reclamations. Case studies showed that the indicator scores of coastal ecosystem health in LZB and TCW were 0.75 and 0.68 out of 1.0, respectively. It can be concluded that coastal reclamations have a historically cumulative effect on benthic environment, whose degree is larger than that on aquatic environment. The ecosystem-based management of coastal reclamations should emphasize the spatially and industrially intensive layout. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Retrieval of aerosol properties and water leaving radiance from multi-angle spectro-polarimetric measurement over coastal waters

    Science.gov (United States)

    Gao, M.; Zhai, P.; Franz, B. A.; Hu, Y.; Knobelspiesse, K. D.; Xu, F.; Ibrahim, A.

    2017-12-01

    Ocean color remote sensing in coastal waters remains a challenging task due to the complex optical properties of aerosols and ocean water properties. It is highly desirable to develop an advanced ocean color and aerosol retrieval algorithm for coastal waters, to advance our capabilities in monitoring water quality, improve our understanding of coastal carbon cycle dynamics, and allow for the development of more accurate circulation models. However, distinguishing the dissolved and suspended material from absorbing aerosols over coastal waters is challenging as they share similar absorption spectrum within the deep blue to UV range. In this paper we report a research algorithm on aerosol and ocean color retrieval with emphasis on coastal waters. The main features of our algorithm include: 1) combining co-located measurements from a hyperspectral ocean color instrument (OCI) and a multi-angle polarimeter (MAP); 2) using the radiative transfer model for coupled atmosphere and ocean system (CAOS), which is based on the highly accurate and efficient successive order of scattering method; and 3) incorporating a generalized bio-optical model with direct accounting of the total absorption of phytoplankton, CDOM and non-algal particles(NAP), and the total scattering of phytoplankton and NAP for improved description of ocean light scattering. The non-linear least square fitting algorithm is used to optimize the bio-optical model parameters and the aerosol optical and microphysical properties including refractive indices and size distributions for both fine and coarse modes. The retrieved aerosol information is used to calculate the atmospheric path radiance, which is then subtracted from the OCI observations to obtain the water leaving radiance contribution. Our work aims to maximize the use of available information from the co-located dataset and conduct the atmospheric correction with minimal assumptions. The algorithm will contribute to the success of current MAP

  6. An integrated strategy for biological effects monitoring in Scottish coastal waters

    International Nuclear Information System (INIS)

    Park, R.A.; Dobson, J.; Richardson, L.; Hill, A.

    1999-01-01

    The paper summarises SEPA's current programme of water quality and biological effects monitoring and, using recent examples, discusses the current environmental issues affecting the condition of our coastal waters. (author)

  7. 77 FR 74923 - Water Quality Standards for the State of Florida's Estuaries, Coastal Waters, and South Florida...

    Science.gov (United States)

    2012-12-18

    ... proposing numeric water quality criteria to protect ecological systems, aquatic life, and human health from... III surface waters share water quality criteria established to protect fish consumption, recreation... Water Quality Standards for the State of Florida's Estuaries, Coastal Waters, and South Florida Inland...

  8. Metabolism and Gaseous Exchanges in Two Coastal Lagoons from Rio de Janeiro with Distinct Limnological Characteristics

    Directory of Open Access Journals (Sweden)

    Sidinei M. Thomaz

    2001-12-01

    Full Text Available The global metabolism and exchange of gases with the atmosphere were measured during a diel cycle in two tropical coastal lagoons, using the curves of carbon dioxide and dissolved oxygen. Heterotrophic metabolism (net CO2 production and net O2 consumption was observed in a black water lagoon (Comprida, and autotrophic metabolism (net O2 production and net CO2 consumption in a clear water lagoon (Imboassica. These differences were attributed to the limnological characteristics of both ecosystems, especially to dissolved organic carbon and the attenuation coefficient of light, which are much higher in the first environment. During the diel cycle analyzed there was a net release of carbon dioxide into the atmosphere in the first lagoon and a net uptake by the water in the second one. Thus, the importance of coastal lagoons for the global carbon budget deserves further study.O metabolismo global e as trocas gasosas com a atmosfera foram medidos durante um ciclo diurno em duas lagoas costeiras tropicais usando as curvas do dióxido de carbono e do oxigênio dissolvido. Metabolismo heterotrófico (produção líquida de CO2 e consumo líquido de O2 foi observado em uma lagoa de águas escuras (Comprida e metabolismo autotrófico (produção líquida de O2 e consumo líquido de CO2 em uma lagoa de águas claras (Imboassica. Essas diferenças foram atribuídas às características limnológicas de ambos os ecossistemas, especialmente ao carbono orgânico dissolvido e coeficiente de atenuação luminosa, maiores na primeira lagoa. Durante o ciclo diurno analisado, houve liberação líquida de dióxido de carbono para a atmosfera na primeira lagoa e transferência da atmosfera para a água na segunda. Assim, a importância de lagoas costeiras para o balanço global de carbono merece ser investigado com atenção.

  9. Simulation of integrated surface-water/ground-water flow and salinity for a coastal wetland and adjacent estuary

    Science.gov (United States)

    Langevin, C.; Swain, E.; Wolfert, M.

    2005-01-01

    The SWIFT2D surface-water flow and transport code, which solves the St Venant equations in two dimensions, was coupled with the SEAWAT variable-density ground-water code to represent hydrologic processes in coastal wetlands and adjacent estuaries. A sequentially coupled time-lagged approach was implemented, based on a variable-density form of Darcy's Law, to couple the surface and subsurface systems. The integrated code also represents the advective transport of salt mass between the surface and subsurface. The integrated code was applied to the southern Everglades of Florida to quantify flow and salinity patterns and to evaluate effects of hydrologic processes. Model results confirm several important observations about the coastal wetland: (1) the coastal embankment separating the wetland from the estuary is overtopped only during tropical storms, (2) leakage between the surface and subsurface is locally important in the wetland, but submarine ground-water discharge does not contribute large quantities of freshwater to the estuary, and (3) coastal wetland salinities increase to near seawater values during the dry season, and the wetland flushes each year with the onset of the wet season. ?? 2005 Elsevier B.V. All rights reserved.

  10. The European water framework directive: A challenge for nearshore, coastal and continental shelf research

    Science.gov (United States)

    Borja, Ángel

    2005-09-01

    The European Water Framework Directive (WFD) establishes a framework for the protection of groundwater, inland surface waters, estuarine waters, and coastal waters. The WFD constitutes a new view of the water resources management in Europe because, for the first time, water management is: (i) based mainly upon biological and ecological elements, with ecosystems being at the centre of the management decisions; (ii) applied to European water bodies, as a whole; and (iii) based upon the whole river basin, including also the adjacent coastal area. Although the marine water bodies affected by the WFD relate to only 19.8% of the whole of the European continental shelf, its application constitutes a challenge and an opportunity in nearshore, coastal and continental shelf research. This contribution highlights some of the main tasks and the research to be undertaken in the coming years, proposing investigations into: typologies; physico-chemical processes; indicator species; reference conditions; integration of the quality assessment; methodologies in determining ecological status, etc.

  11. Respiratory Problems Associated with Surfing in Coastal Waters

    OpenAIRE

    O Halloran, C; Silver, MW; Lahiff, M; Colford, J

    2017-01-01

    © 2016, International Association for Ecology and Health. A pilot project was conducted to examine the health status and possible adverse health effects associated with seawater exposure (microbial water-quality indicators and phytoplankton abundance and their toxins) of surfers in Monterey Bay, Central California coastal waters. Forty-eight surfers enrolled in the study and completed an initial health background survey and weekly health surveys online using Survey Monkey. Descriptive statist...

  12. Towards environmental management of water turbidity within open coastal waters of the Great Barrier Reef.

    Science.gov (United States)

    Macdonald, Rachael K; Ridd, Peter V; Whinney, James C; Larcombe, Piers; Neil, David T

    2013-09-15

    Water turbidity and suspended sediment concentration (SSC) are commonly used as part of marine monitoring and water quality plans. Current management plans utilise threshold SSC values derived from mean-annual turbidity concentrations. Little published work documents typical ranges of turbidity for reefs within open coastal waters. Here, time-series turbidity measurements from 61 sites in the Great Barrier Reef (GBR) and Moreton Bay, Australia, are presented as turbidity exceedance curves and derivatives. This contributes to the understanding of turbidity and SSC in the context of environmental management in open-coastal reef environments. Exceedance results indicate strong spatial and temporal variability in water turbidity across inter/intraregional scales. The highest turbidity across 61 sites, at 50% exceedance (T50) is 15.3 NTU and at 90% exceedance (T90) 4.1 NTU. Mean/median turbidity comparisons show strong differences between the two, consistent with a strongly skewed turbidity regime. Results may contribute towards promoting refinement of water quality management protocols. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

    KAUST Repository

    Schnetzer, Astrid; Jones, Burton; Schaffner, Rebecca A.; Cetinić, Ivona; Fitzpatrick, Elizabeth; Miller, Peter E.; Seubert, Erica L.; Caron, David A.

    2013-01-01

    Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.

  14. Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

    KAUST Repository

    Schnetzer, Astrid

    2013-06-10

    Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.

  15. Biogeochemical processes and buffering capacity concurrently affect acidification in a seasonally hypoxic coastal marine basin

    Science.gov (United States)

    Hagens, M.; Slomp, C. P.; Meysman, F. J. R.; Seitaj, D.; Harlay, J.; Borges, A. V.; Middelburg, J. J.

    2015-03-01

    Coastal areas are impacted by multiple natural and anthropogenic processes and experience stronger pH fluctuations than the open ocean. These variations can weaken or intensify the ocean acidification signal induced by increasing atmospheric pCO2. The development of eutrophication-induced hypoxia intensifies coastal acidification, since the CO2 produced during respiration decreases the buffering capacity in any hypoxic bottom water. To assess the combined ecosystem impacts of acidification and hypoxia, we quantified the seasonal variation in pH and oxygen dynamics in the water column of a seasonally stratified coastal basin (Lake Grevelingen, the Netherlands). Monthly water-column chemistry measurements were complemented with estimates of primary production and respiration using O2 light-dark incubations, in addition to sediment-water fluxes of dissolved inorganic carbon (DIC) and total alkalinity (TA). The resulting data set was used to set up a proton budget on a seasonal scale. Temperature-induced seasonal stratification combined with a high community respiration was responsible for the depletion of oxygen in the bottom water in summer. The surface water showed strong seasonal variation in process rates (primary production, CO2 air-sea exchange), but relatively small seasonal pH fluctuations (0.46 units on the total hydrogen ion scale). In contrast, the bottom water showed less seasonality in biogeochemical rates (respiration, sediment-water exchange), but stronger pH fluctuations (0.60 units). This marked difference in pH dynamics could be attributed to a substantial reduction in the acid-base buffering capacity of the hypoxic bottom water in the summer period. Our results highlight the importance of acid-base buffering in the pH dynamics of coastal systems and illustrate the increasing vulnerability of hypoxic, CO2-rich waters to any acidifying process.

  16. Assessment of water exchange between a discharge region and the open sea A comparison of different methodological concepts

    Science.gov (United States)

    Döös, Kristofer; Engqvist, Anders

    2007-09-01

    Two different methods of estimating the water exchange through the Baltic coastal region of Laxemar have been used, consisting of particle trajectories and passive tracers. Water is traced from and to a small discharge region near the coast. The discharge material in this region is treated as zero-dimensional particles or tracers with neutral buoyancy. The real discharge material could be a leakage of radio-nuclides through the sea floor from an underground repository of nuclear waste. Water exchange rates between the discharge region and the model domain are estimated using both forward and backward trajectories as well as passive tracers. The Lagrangian trajectories can account for the time evolution of the water exchange while the tracers give one average age per model grid box. Water exchange times such as residence time, age and transient times have been calculated with trajectories but only the average age (AvA) for tracers. The trajectory calculations provide a more detailed time evolution than the tracers. On the other hand the tracers are integrated "on-line" simultaneously in the sea circulation model with the same time step while the Lagrangian trajectories are integrated "off-line" from the stored model velocities with its inherent temporal resolution, presently 1 h. The sub-grid turbulence is parameterised as the Laplacian diffusion for the passive tracers and with an extra stochastic velocity for trajectories. The importance of the parameterised sub-grid turbulence for the trajectories is estimated to give an extra diffusion of the same order as the Laplacian diffusion by comparing the Lagrangian dispersions with and without parameterisation. The results of the different methods are similar but depend on the chosen diffusivity coefficient with a slightly higher correlation between trajectories and tracers when integrated with a lower diffusivity coefficient.

  17. SPATIAL AND TEMPORAL DISTRIBUTION OF COLORED DISSOLOVED ORGANIC MATTER (CDOM) IN SOUTHERN NEW ENGALND COASTAL WATERS

    Science.gov (United States)

    The concentration of colored dissolved organic matter (CDOM) is a primary factor affecting the absorption of incident sunlight in coastal and estuarine waters. CDOM is extracted from water-soluble humic substances and transported by runoff into lakes and coastal waters. CDOM is a...

  18. The magnitude and origin of groundwater discharge to eastern U.S. and Gulf of Mexico coastal waters

    Science.gov (United States)

    Befus, Kevin; Kroeger, Kevin D.; Smith, Christopher G.; Swarzenski, Peter W.

    2017-01-01

    Fresh groundwater discharge to coastal environments contributes to the physical and chemical conditions of coastal waters, but the role of coastal groundwater at regional to continental scales remains poorly defined due to diverse hydrologic conditions and the difficulty of tracking coastal groundwater flow paths through heterogeneous subsurface materials. We use three-dimensional groundwater flow models for the first time to calculate the magnitude and source areas of groundwater discharge from unconfined aquifers to coastal waterbodies along the entire eastern U.S. We find that 27.1 km3/yr (22.8–30.5 km3/yr) of groundwater directly enters eastern U.S. and Gulf of Mexico coastal waters. The contributing recharge areas comprised ~175,000 km2 of U.S. land area, extending several kilometers inland. This result provides new information on the land area that can supply natural and anthropogenic constituents to coastal waters via groundwater discharge, thereby defining the subterranean domain potentially affecting coastal chemical budgets and ecosystem processes.

  19. Evaluation of polar organic micropollutants as indicators for wastewater-related coastal water quality impairment

    International Nuclear Information System (INIS)

    Nödler, Karsten; Tsakiri, Maria; Aloupi, Maria; Gatidou, Georgia; Stasinakis, Athanasios S.; Licha, Tobias

    2016-01-01

    sampling locations irgarol 1051 exceeded its annual average EQS value but not the maximum allowable concentration of 16 ng L"−"1. - Highlights: • Coastal water monitoring for 58 micropollutants was performed. • A water quality status indicator-quartet for efficient water monitoring was tested. • The selected compounds were acesulfame, caffeine, valsartan, and valsartan acid. • The detection frequencies of acesulfame and caffeine were 100%. • Atrazine was used to verify water exchange and mixing processes on a large scale. - A wastewater indicator quartet was used to detect point sources and contamination hot-spots with untreated and treated wastewater in the coastal environment of Lesvos Island (Greece).

  20. A multi-detector continuous monitor for assessment of 222Rn in the coastal ocean

    International Nuclear Information System (INIS)

    Dulaiova, H.; Peterson, R.; Burnett, W.C.

    2005-01-01

    Radon-222 is a good natural tracer of groundwater discharge and other physical processes in the coastal ocean. Unfortunately, its usefulness is limited by the time consuming nature of collecting individual samples and traditional analysis schemes. An automated multi-detector system is demonstrated that can be used in a continuous survey basis to assess radon activities in coastal ocean waters. The system analyses 222 Rn from a constant stream of water delivered by a submersible pump to an air-water exchanger where radon in the water phase equilibrates with radon in a closed air loop. The air stream is fed to 3 commercial radon-in-air monitors connected in parallel to determine the activity of 222 Rn. By running the detectors out of phase, it is possible to obtain as many as 6 readings per hour with a precision of approximately ±5-15% for typical coastal seawater concentrations. (author)

  1. Bromide in some coastal and oceanic waters of India

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, F.P.; Dalal, V.N.K.

    Bromide concentration and bromide/chlorinity ratio are estimated in coastal waters of Goa, Minicoy Lagoon, Western Arabian Sea and Western Bay of Bengal. The influence of precipitation and river runoff on bromide and bromide/chlorinity ratio...

  2. Specific absorption and backscatter coefficient signatures in southeastern Atlantic coastal waters

    Science.gov (United States)

    Bostater, Charles R., Jr.

    1998-12-01

    Measurements of natural water samples in the field and laboratory of hyperspectral signatures of total absorption and reflectance were obtained using long pathlength absorption systems (50 cm pathlength). Water was sampled in Indian River Lagoon, Banana River and Port Canaveral, Florida. Stations were also occupied in near coastal waters out to the edge of the Gulf Stream in the vicinity of Kennedy Space Center, Florida and estuarine waters along Port Royal Sound and along the Beaufort River tidal area in South Carolina. The measurements were utilized to calculate natural water specific absorption, total backscatter and specific backscatter optical signatures. The resulting optical cross section signatures suggest different models are needed for the different water types and that the common linear model may only appropriate for coastal and oceanic water types. Mean particle size estimates based on the optical cross section, suggest as expected, that particle size of oceanic particles are smaller than more turbid water types. The data discussed and presented are necessary for remote sensing applications of sensors as well as for development and inversion of remote sensing algorithms.

  3. Analysis of Compound Water Hazard in Coastal Urbanized Areas under the Future Climate

    Science.gov (United States)

    Shibuo, Y.; Taniguchi, K.; Sanuki, H.; Yoshimura, K.; Lee, S.; Tajima, Y.; Koike, T.; Furumai, H.; Sato, S.

    2017-12-01

    Several studies indicate the increased frequency and magnitude of heavy rainfalls as well as the sea level rise under the future climate, which implies that coastal low-lying urbanized areas may experience increased risk against flooding. In such areas, where river discharge, tidal fluctuation, and city drainage networks altogether influence urban inundation, it is necessary to consider their potential interference to understand the effect of compound water hazard. For instance, pump stations cannot pump out storm water when the river water level is high, and in the meantime the river water level shall increase when it receives pumped water from cities. At the further downstream, as the tidal fluctuation regulates the water levels in the river, it will also affect the functionality of pump stations and possible inundation from rivers. In this study, we estimate compound water hazard in the coastal low-lying urbanized areas of the Tsurumi river basin under the future climate. We developed the seamlessly integrated river, sewerage, and coastal hydraulic model that can simulate river water levels, water flow in sewerage network, and inundation from the rivers and/or the coast to address the potential interference issue. As a forcing, the pseudo global warming method, which applies the changes in GCM anomaly to re-analysis data, is employed to produce ensemble typhoons to drive the seamlessly integrated model. The results show that heavy rainfalls caused by the observed typhoon generally become stronger under the pseudo global climate condition. It also suggests that the coastal low-lying areas become extensively inundated if the onset of river flooding and storm surge coincides.

  4. Selection of site coolant intake and discharge of shore based power stations - coastal oceanographic considerations

    Digital Repository Service at National Institute of Oceanography (India)

    Swamy, G.N.; Suryanarayana, A.; Krishnakumar, V.

    Many new nuclear power plants, reactors are proposed along coastal area of Indian coastline apart from the existing ones. All these, being ultimately a heat exchange process, necessitate enormous quantity of cooling water drawn from the sea...

  5. Novel catalysts for isotopic exchange between hydrogen and liquid water

    International Nuclear Information System (INIS)

    Butler, J.P.; Rolston, J.H.; Stevens, W.H.

    1978-01-01

    Catalytic isotopic exchange between hydrogen and liquid water offers many inherent potential advantages for the separation of hydrogen isotopes which is of great importance in the Canadian nuclear program. Active catalysts for isotopic exchange between hydrogen and water vapor have long been available, but these catalysts are essentially inactive in the presence of liquid water. New, water-repellent platinum catalysts have been prepared by: (1) treating supported catalysts with silicone, (2) depositing platinum on inherently hydrophobic polymeric supports, and (3) treating platinized carbon with Teflon and bonding to a carrier. The activity of these catalysts for isotopic exchange between countercurrent streams of liquid water and hydrogen saturated with water vapor has been measured in a packed trickle bed integral reactor. The performance of these hydrophobic catalysts is compared with nonwetproofed catalysts. The mechanism of the overall exchange reaction is briefly discussed. 6 figures

  6. ANALYSIS OF SEA WATER POLLUTION IN COASTAL MARINE DISTRICT TUBAN TO THE QUALITY STANDARDS OF SEA WATER WITH USING STORET METHOD

    Directory of Open Access Journals (Sweden)

    Perdana Ixbal Spanton

    2017-05-01

    Full Text Available The sea water is a component that interacts with the terrestrial environment, where sewage from the land will lead to the sea. Waste containing these pollutants will enter into coastal waters and marine ecosystems. Partially soluble in water, partially sinks to the bottom and was concentrated sediment, and partly into the body tissues of marine organisms. This study was conducted to determine the level of pollution of sea water on the coast in the district of Tuban. This research was conducted in the Coastal Water Tuban, East Java. The main material used in research on Analysis of Water Pollution in Coastal Sea on Tuban. The method used in this research is using storet method and compared to the quality standards of the Environment Decree No. 51 in 2004. Based on the analysis of testing at five sampling point’s seawater around Bodies Tuban, obtained by sea water quality measurement results either in physics, chemistry, and microbiology varied. The level of pollution of sea water around Coastal Tuban obtained by using Storet Method average value of analysis is -4.2 included in class B are lightly blackened, while using values obtained Pollution Index average pollution index of 3.60 is included in the category lightly blackened. Keywords: Analysis of the pollution level of seawater on the coast in Tuban, Quality Standards of Sea Water, Storet Method.

  7. Ecological Studies in the Coastal Waters of Kalpakkam, Southeast Coast of India, in the Vicinity of a Nuclear Island

    Energy Technology Data Exchange (ETDEWEB)

    Satpathy, K. K.; Mohanty, A. K.; Sahu, Gouri; Prasad, M. V.R.; Bramha, S. N. [Environmetal Safety Division, Radiological and Environmental Safety Group, REG, Indira Gandhi Center for Atomic Research, Tamil Nadu (India); Smita Achary, M.; Samantara, M. K.; Biswas, S.; Selvanayagam, M. [Loyola Institute of Frontier Energy, Loyola College, Chennai (India)

    2013-07-15

    Ecological monitoring of the coastal waters at Kalpakkam, which presently harbour various nuclear facilities, has been in progress for the last four years to create a benchmark dataset on water quality, phytoplankton, zooplankton, fisheries, sedentary organisms and molluscan species diversity. Results indicated a significant impact of monsoonal rain and backwaters on the coastal water quality. About 325 phytoplankton, 140 zooplankton, 350 fish, 130 molluscs and 100 species of sedentary organisms have been catalogued. Two fish species, which are native to Indonesia, were recorded for the first time in Indian coastal water. The study indicated that the coastal water is rich in biodiversity. Similarly, results of studies on costal sediment characteristics indicated the influence of monsoonal rain and backwater discharge. Overall, the study indicated little impact of nuclear activity on coastal water biodiversity and water quality. (author)

  8. Development of a coastal information system for the management of Jeddah coastal waters in Saudi Arabia

    Science.gov (United States)

    Mayerle, R.; Al-Subhi, A.; Fernández Jaramillo, J.; Salama, A.; Bruss, G.; Zubier, K.; Runte, K.; Turki, A.; Hesse, K.; Jastania, H.; Ladwig, N.; Mudarris, M.

    2016-04-01

    This paper presents results of the development and application of a web-based information system, Jeddah CIS, for assisting decision makers in the management of Jeddah coastal waters, in Saudi Arabia. The system will support coastal planning, management of navigation and tackle pollution due to accidents. The system was developed primarily to nowcast in quasi-real time and to deliver short-term forecasts of water levels, current velocities and waves with high spatial and temporal resolution for the area near Jeddah. Therefor it will hasten response when adverse weather conditions prevail. The Jeddah-CIS integrates sensors transmitting in real time, meteorological, oceanographic and water quality parameters and operational models for flow and waves. It also provides interactive tools using advanced visualization techniques to facilitate dissemination of information. The system relies on open source software and has been designed to facilitate the integration of additional components for enhanced information processing, data evaluation and generation of higher water level, current velocity and wave for the general public. Jeddah-CIS has been operational since 2013. Extensions of the system to speed operations and improving the accuracy of the predictions to the public are currently underway.

  9. Albemarle Sound demonstration study of the national monitoring network for US coastal waters and their tributaries

    Science.gov (United States)

    Michelle Moorman; Sharon Fitzgerald; Keith Loftin; Elizabeth Fensin

    2016-01-01

    The U.S. Geological Survey’s (USGS) is implementing a demonstration project in the Albemarle Sound for the National Monitoring Network for U.S. coastal waters and their tributaries. The goal of the National Monitoring Network is to provide information about the health of our oceans and coastal ecosystems and inland influences on coastal waters for improved resource...

  10. Noctiluca Scintillans (Dinophyceae) in Central Coastal Waters of ...

    African Journals Online (AJOL)

    A one-year study (July 2003 – June 2004) to explore the spatial and temporal variability of potentially harmful dinoflagellates was carried out in the central coastal waters of Tanzania. During the course of the study a green dinoflagellate, Noctiluca scintillans, which has cosmopolitan distribution, was encountered for the first ...

  11. Estimation of air-water gas exchange coefficient in a shallow lagoon based on 222Rn mass balance.

    Science.gov (United States)

    Cockenpot, S; Claude, C; Radakovitch, O

    2015-05-01

    The radon-222 mass balance is now commonly used to quantify water fluxes due to Submarine Groundwater Discharge (SGD) in coastal areas. One of the main loss terms of this mass balance, the radon evasion to the atmosphere, is based on empirical equations. This term is generally estimated using one among the many empirical equations describing the gas transfer velocity as a function of wind speed that have been proposed in the literature. These equations were, however, mainly obtained from areas of deep water and may be less appropriate for shallow areas. Here, we calculate the radon mass balance for a windy shallow coastal lagoon (mean depth of 6m and surface area of 1.55*10(8) m(2)) and use these data to estimate the radon loss to the atmosphere and the corresponding gas transfer velocity. We present new equations, adapted to our shallow water body, to express the gas transfer velocity as a function of wind speed at 10 m height (wind range from 2 to 12.5 m/s). When compared with those from the literature, these equations fit particularly well with the one of Kremer et al. (2003). Finally, we emphasize that some gas transfer exchange may always occur, even for conditions without wind. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Proton exchange in systems: Glucose-water and uric acid-water

    International Nuclear Information System (INIS)

    Maarof, S.

    2007-01-01

    It is clear that formation of glucose-water and uric acid-water solutions is related in principle to interaction accepter - donor between hydrogen atom in water and oxygen atom in glucose or uric acid. The proton exchange in hydrogen bond system is an integral process and it goes by tunnel mechanism (transfer of proton within the hydrogen bridge in these structures). Proton exchange process goes very quickly at low concentrations for glucose and uric acid solutions, because these compounds are able to form more than one hydrogen bond, which helps the proton transfer within obtained structure. However, at its high concentrations, the process becomes very slow due to higher viscosity of its solutions, which result in break down of the structures, and more hydrogen bonds. (author)

  13. A resilience framework for chronic exposures: water quality and ecosystem services in coastal social-ecological systems

    Science.gov (United States)

    We outline a tailored resilience framework that applies ecosystem service concepts to coastal social-ecological systems (SES) affected by water quality degradation. Unlike acute coastal disturbances such as hurricanes or oil spills, water quality issues, particularly those relate...

  14. Countercurrent exchange of water in canine jejunum

    International Nuclear Information System (INIS)

    Ryu, K.H.; Grim, E.

    1985-01-01

    The possibility of countercurrent exchange of water molecules in canine intestinal villi has been examined. Tritium-labeled water ( 3 H 2 O) molecules were introduced either into the fluid lavaging the intestinal lumen or into the arterial blood supply for varying periods of time. Quickly frozen samples of intestinal tissue were sectioned such that isotopic concentrations at the villus tip, midvillus, villus base, and underlying submucosa and muscle could be determined. The villus concentration gradients observed were consistent with the existence of a countercurrent exchange but could also be explained by alternative arrangements. More convincing evidence of a countercurrent was obtained from experiments in which [ 14 C]inulin was introduced simultaneously with 3 H 2 O into the intestinal artery. The villus tip-to-base concentration ratio for 3 H 2 O was less than one while the ratio for inulin was greater than one, thus vitiating the alternative explanations and leading to the conclusion that the labeled water molecules must have undergone a countercurrent exchange

  15. Analysis of Multi Temporal Satellite Imagery for Total Suspended Sediments in a Wave-Active Coastal Area-Gaza Strip Coastal Water, Palestine

    Directory of Open Access Journals (Sweden)

    Midyan D.I. Aldabash

    2016-03-01

    Full Text Available Sediment load materials is one of the key factors that determine the surface water quality, both of oceanic and river water, and it specifies water optical properties. Thus it provides a background for a plenty of applications and projects in the water and oceanography community. Landsat detects and classifies reflected solar energy from bodies on the earth's surface. Suspended sediments existing in water column have an optical influences. So that, Landsat images could detect suspended sediments concentration in such a water surface. In this study we have three main objectives to be achieved as; TSS Concentration maps generation in the Gaza Strip coastal zone, achieving analysis processes on TSS trend itself and TSS related coastal phenomenon, and investigation of the ability of Landsat images to detect TSS comprehensively in a wavy coastal zone. For this purpose two landsat TM5 images acquired in 1999 and 2010, one Landsat TM7 images acquired in 2003, and 2 Landsat Oli 8 images acquired in 2014 and 2015 were used for TSS mapping. In addition, 64 TSS in-situ tested samples were also to calculate a correlation equation between Digital Numbers - DN in each image pixels and TSS values in the ground data. All image analysis and remote sensing steps have been done in this study using Integrated Land and Water Information System - ILWIS software version ILWIS academic 3.3. Green and Red bands in all used Landsat images contained the highest linear correlation factors -R- for the images acquired in 1999, 2003, 2010, 2014, and 2015. Resulted correlation factors were higher by reducing time difference between acquisition time and sampling time. Generated maps showed that circulation in Gaza coastal area are counterclockwise, and it brings the sediments from Nile River Delta toward Gaza Strip.

  16. An approach to the coastal water circulation in the Piratuba Lake Biological Reservation, Northeast of Amapa State, Brazil

    Science.gov (United States)

    Takiyama, L. R.; Silveira, O. M.

    2007-05-01

    This study shows the pioneer results of the water quality characterization of a lake region, including the Piratuba lake (within the limits of the Piratuba Lake Biological Reservation) and the Sucuriju river, localized at the northeast portion of the Amapa State, Brazil, and left margin of the Amazon River mouth. Due to the influence of the Amazon river and another important river, the Araguari river, the northeast coast of Amapa State receive little impact of salty water from the Atlantic ocean. The highest salinity values detected on this coastal area is 20 psu. The Piratuba Lake region which can be described as an unique wetland system formed by recent geological processes (Quaternary), it constitutes a very fragile environment and possesses a number of shallow water lakes distributed into a mixed mangrove and "varzea" type of vegetation and it is considered very important looking at the biological point of view. The borderline between this lake system with the coastal waters is a narrow portion of mangrove containing species of Rizhophora and Avicennia parallel to the coast line. A preliminary water circulation could be accessed through the detection of variation in water quality parameters throughout three field studies conducted on March, 2004, June 2005 and November 2005. Surface water sampling points spatially distributed on the study area with distances less than 2 km were set, covering almost 800 square kilometers. Among the parameters studied (pH, electrical conductivity, turbidity, concentration of suspended solids, depth, temperature, chloride, dissolved oxygen, nitrate, nitrite and phosphate) the turbidity, electrical conductivity and pH were the most important for identifying the entering of coastal waters into the lake region. Mainly, three points of direct contact were identified; one of them is a manmade illegal entrance to the Biological Reservation. The seasonal variation was also very important factor and as expected, during the dry season

  17. Bark water uptake promotes localized hydraulic recovery in coastal redwood crown

    Science.gov (United States)

    J. Mason Earles; Or Sperling; Lucas C. R. Silva; Andrew J. McElrone; Craig R. Brodersen; Malcolm P. North; Maciej A. Zwieniecki

    2015-01-01

    Coastal redwood (Sequoia sempervirens), the world’s tallest tree species, rehydrates leaves via foliar water uptake during fog/rain events. Here we examine if bark also permits water uptake in redwood branches, exploring potential flow mechanisms and biological significance. Using isotopic labelling and microCT imaging, we observed that water...

  18. Coastal ground water at risk - Saltwater contamination at Brunswick, Georgia and Hilton Head Island, South Carolina

    Science.gov (United States)

    Krause, Richard E.; Clarke, John S.

    2001-01-01

    IntroductionSaltwater contamination is restricting the development of ground-water supply in coastal Georgia and adjacent parts of South Carolina and Florida. The principal source of water in the coastal area is the Upper Floridan aquifer—an extremely permeable and high-yielding aquifer—which was first developed in the late 1800s. Pumping from the aquifer has resulted in substantial ground-water-level decline and subsequent saltwater intrusion of the aquifer from underlying strata containing highly saline water at Brunswick, Georgia, and with encroachment of sea-water into the aquifer at the northern end of Hilton Head Island, South Carolina. The saltwater contamination at these locations has constrained further development of the Upper Floridan aquifer in the coastal area and has created competing demands for the limited supply of freshwater. The Georgia Department of Natural Resources, Georgia Environmental Protection Division (GaEPD) has restricted permitted withdrawal of water from the Upper Floridan aquifer in parts of the coastal area (including the Savannah and Brunswick areas) to 1997 rates, and also has restricted additional permitted pumpage in all 24 coastal area counties to 36 million gallons per day above 1997 rates. These actions have prompted interest in alternative management of the aquifer and in the development of supplemental sources of water supply including those from the shallower surficial and upper and lower Brunswick aquifers and from the deeper Lower Floridan aquifer.

  19. The assessment of waters ecological state of the Crimea coastal near high-rise construction zones

    Science.gov (United States)

    Vetrova, Natalya; Ivanenko, Tatyana; Mannanov, Emran

    2018-03-01

    The relevance of our study is determined by the significant level of coastal sea waters pollution by sewage near high-rise construction zones, which determines the violation of the sanitary and hygienic of sea waters `characteristics and limits the possibilities for organizing recreational activities. The purpose of this study is to identify the ecological state of the marine aquatic area by the example of the Western Crimea near high-rise construction zones. The studies confirmed that the recreational and coastal area wastewater is intensely mixed with seawater, as a result, the pollution in the coastal strip of the sea in the area of deep water discharges sharply decrease. This happens because of water rapid rise to the surface and under the influence of the continuous movement of sea water huge masses with deep-water discharge, fresh wastewater is actively mixed with sea water. However, with no doubt, it is inadmissible to discharge sewage into the sea directly from the shore, but only at the estimated distance from the coast. The materials of the article can be useful for the management bodies and organizations involved in monitoring the quality of the coastal zone of the sea, teachers and students of higher educational institutions when assessing the ecological situation of the territories.

  20. On factors influencing air-water gas exchange in emergent wetlands

    Science.gov (United States)

    Ho, David T.; Engel, Victor C.; Ferron, Sara; Hickman, Benjamin; Choi, Jay; Harvey, Judson W.

    2018-01-01

    Knowledge of gas exchange in wetlands is important in order to determine fluxes of climatically and biogeochemically important trace gases and to conduct mass balances for metabolism studies. Very few studies have been conducted to quantify gas transfer velocities in wetlands, and many wind speed/gas exchange parameterizations used in oceanographic or limnological settings are inappropriate under conditions found in wetlands. Here six measurements of gas transfer velocities are made with SF6 tracer release experiments in three different years in the Everglades, a subtropical peatland with surface water flowing through emergent vegetation. The experiments were conducted under different flow conditions and with different amounts of emergent vegetation to determine the influence of wind, rain, water flow, waterside thermal convection, and vegetation on air-water gas exchange in wetlands. Measured gas transfer velocities under the different conditions ranged from 1.1 cm h−1 during baseline conditions to 3.2 cm h−1 when rain and water flow rates were high. Commonly used wind speed/gas exchange relationships would overestimate the gas transfer velocity by a factor of 1.2 to 6.8. Gas exchange due to thermal convection was relatively constant and accounted for 14 to 51% of the total measured gas exchange. Differences in rain and water flow among the different years were responsible for the variability in gas exchange, with flow accounting for 37 to 77% of the gas exchange, and rain responsible for up to 40%.

  1. PRTR ion exchange vault water removal

    International Nuclear Information System (INIS)

    Ham, J.E.

    1995-11-01

    This report documents the removal of radiologically contaminated water from the Plutonium Recycle Test Reactor (PRTR) ion exchange vault. Approximately 57,000 liters (15,000 gallons) of water had accumulated in the vault due to the absence of a rain cover. The water was removed and the vault inspected for signs of leakage. No evidence of leakage was found. The removal and disposal of the radiologically contaminated water decreased the risk of environmental contamination

  2. Operating experiences on ammonia water exchange system at Heavy Water Plant, Talcher (paper No. 6.12)

    International Nuclear Information System (INIS)

    Venkat Ram, D.; Sharma, A.K.

    1992-01-01

    The Heavy Water Plant at Talcher employs bithermal ammonia hydrogen exchange process for the production of heavy water. The paper describes about the existing ammonia water exchange column, its start-up, operating experience and the problems encountered in operation of the column. The operating experiences gained and the data collected over the last few years can be utilised for design and operation of new ammonia water exchange column. (V.R). 2 figs

  3. Pharmaceuticals, alkylphenols and pesticides in Mediterranean coastal waters: Results from a pilot survey using passive samplers

    OpenAIRE

    Munaron, Dominique; Tapie, Nathalie; Budzinski, Helene; Andral, Bruno; Gonzalez, Jean-louis

    2012-01-01

    21 pharmaceuticals, 6 alkylphenols and 27 hydrophilic pesticides and biocides were investigated using polar organic contaminant integrative samplers (POCIS) during a large-scale study of contamination of French Mediterranean coastal waters. Marine and transitional water-bodies, defined under the EU Water Framework Directive were monitored. Our results show that the French Mediterranean coastal waters were contaminated with a large range of emerging contaminants, detected at low concentrations...

  4. Estimating dissolved organic carbon concentration in turbid coastal waters using optical remote sensing observations

    Science.gov (United States)

    Cherukuru, Nagur; Ford, Phillip W.; Matear, Richard J.; Oubelkheir, Kadija; Clementson, Lesley A.; Suber, Ken; Steven, Andrew D. L.

    2016-10-01

    Dissolved Organic Carbon (DOC) is an important component in the global carbon cycle. It also plays an important role in influencing the coastal ocean biogeochemical (BGC) cycles and light environment. Studies focussing on DOC dynamics in coastal waters are data constrained due to the high costs associated with in situ water sampling campaigns. Satellite optical remote sensing has the potential to provide continuous, cost-effective DOC estimates. In this study we used a bio-optics dataset collected in turbid coastal waters of Moreton Bay (MB), Australia, during 2011 to develop a remote sensing algorithm to estimate DOC. This dataset includes data from flood and non-flood conditions. In MB, DOC concentration varied over a wide range (20-520 μM C) and had a good correlation (R2 = 0.78) with absorption due to coloured dissolved organic matter (CDOM) and remote sensing reflectance. Using this data set we developed an empirical algorithm to derive DOC concentrations from the ratio of Rrs(412)/Rrs(488) and tested it with independent datasets. In this study, we demonstrate the ability to estimate DOC using remotely sensed optical observations in turbid coastal waters.

  5. Effect of climate change on sea water intrusion in coastal aquifers

    Science.gov (United States)

    Sherif, Mohsen M.; Singh, Vijay P.

    1999-06-01

    There is increasing debate these days on climate change and its possible consequences. Much of this debate has focused in the context of surface water systems. In many arid areas of the world, rainfall is scarce and so is surface runoff. These areas rely heavily on groundwater. The consequences of climate change on groundwater are long term and can be far reaching. One of the more apparent consequences is the increased migration of salt water inland in coastal aquifers. Using two coastal aquifers, one in Egypt and the other in India, this study investigates the effect of likely climate change on sea water intrusion. Three realistic scenarios mimicking climate change are considered. Under these scenarios, the Nile Delta aquifer is found to be more vulnerable to climate change and sea level rise.

  6. Monitoring Environmental Recovery at Terminated Produced Water Discharge Sites in Coastal Louisiana Waters

    Energy Technology Data Exchange (ETDEWEB)

    Continental Shelf Associates, Inc.

    1999-08-16

    This report presents the results of a study of terminated produced water discharge sites in the coastal waters of Louisiana. Environmental recovery at the sites is documented by comparing pre-termination and post-termination (six months and one year) data. Produced water, sediments, and sediment interstitial water samples were analyzed for radionuclides, metals, and hydrocarbons. Benthic infauna were identified from samples collected in the vicinity of the discharge and reference sites. Radium isotope activities were determined in fish and crustacean samples. In addition, an environmental risk assessment is made on the basis of the concentrations of metals and hydrocarbons determined in the samples.

  7. Pharmaceuticals, alkylphenols and pesticides in Mediterranean coastal waters: Results from a pilot survey using passive samplers

    Science.gov (United States)

    Munaron, Dominique; Tapie, Nathalie; Budzinski, Hélène; Andral, Bruno; Gonzalez, Jean-Louis

    2012-12-01

    21 pharmaceuticals, 6 alkylphenols and 27 hydrophilic pesticides and biocides were investigated using polar organic contaminant integrative samplers (POCIS) during a large-scale study of contamination of French Mediterranean coastal waters. Marine and transitional water-bodies, defined under the EU Water Framework Directive were monitored. Our results show that the French Mediterranean coastal waters were contaminated with a large range of emerging contaminants, detected at low concentrations during the summer season. Caffeine, carbamazepine, theophilline and terbutaline were detected with a detection frequency higher than 83% in the coastal waters sampled, 4-nonylphenol (4-NP), 4-tert-octylphenol (4-OP) and 4-nonylphenol diethoxylate (NP2EO) were detected in all coastal waters sampled, and diuron, terbuthylazine, atrazine, irgarol and simazine were detected in more than 77% of samples. For pharmaceuticals, highest time-weighted average (TWA) concentrations were measured for caffeine and carbamazepine (32 and 12 ng L-1, respectively). For alkylphenols, highest TWA concentrations were measured for 4-nonylphenol mono-ethoxylate and 4-nonylphenol (41 and 33 ng L-1, respectively), and for herbicides and biocides, they were measured for diuron and irgarol (33 and 2.5 ng L-1, respectively). Except for Diana lagoon, lagoons and semi-enclosed bays were the most contaminated areas for herbicides and pharmaceuticals, whilst, for alkylphenols, levels of contamination were similar in lagoons and coastal waters. This study demonstrates the relevance and utility of POCIS as quantitative tool for measuring low concentrations of emerging contaminants in marine waters.

  8. Climatic variability and trends in the surface waters of coastal British Columbia

    Science.gov (United States)

    Cummins, Patrick F.; Masson, Diane

    2014-01-01

    Multi-decadal records of monthly sea surface temperature (SST) and sea surface salinity (SSS) collected at a set of lighthouse stations are used to examine climatic variability and trends in the coastal waters of British Columbia. Particular attention is given to relations between the water property anomalies and variability in coastal freshwater discharge and alongshore wind stress. Within the Strait of Georgia, SSS anomalies are closely related to Fraser River discharge anomalies. Along the Pacific coast, anomalies in alongshore wind stress and freshwater runoff have the characteristics of white noise processes. A cross-correlation analysis demonstrates that SST and SSS variability along the open west coast is consistent with the response of a first-order autoregressive process driven by anomalous alongshore wind stress and coastal freshwater discharge, respectively. Thus climatic variability of SST and SSS along the Pacific coast of British Columbia occurs, in part, through the integration of noisy atmospheric forcing and coastal precipitation. Seasonal correlations show that SST is strongly related to wind stress during winter and fall. Conversely, SSS is relatively weakly related to the alongshore wind during spring, suggesting that variability in upwelling makes only a modest contribution to variability of SSS in the nearshore environment. Consistent with previous studies, secular trends indicate long-term warming and freshening of the coastal ocean at most stations. It is shown that long-term SST trends can be obscured by the pronounced climatic variability of these waters, requiring that time series extend for several decades to be reliably detected.

  9. Multivariate analysis of the influences of oceanic and meteorological processes on suspended particulate matter distributions in Mississippi coastal waters

    Science.gov (United States)

    O'Brien, S. J.; Fitzpatrick, P. J.; Dzwonkowski, B.; Dykstra, S. L.; Wallace, D. J.; Church, I.; Wiggert, J. D.

    2016-02-01

    The Mississippi Sound is influenced by a high volume of sediment discharge from the Biloxi River, Mobile Bay via Pas aux Herons, Pascagoula River, Pearl River, Wolf River, and Lake Pontchartrain through the Rigolets. The river discharge, variable wind speed, wind direction and tides have a significant impact on the turbidity and transport of sediments in the Sound. Level 1 Moderate Resolution Imaging Spectroradiometer (MODIS) data is processed to extract the remote sensing reflectance at the wavelength of 645 nm and binned into an 8-day composite at a resolution of 500 m. The study uses a regional ocean color algorithm to compute suspended particulate matter (SPM) concentration based on these 8-day composite images. Multivariate analysis is applied between the SPM and time series of tides, wind, turbidity and river discharge measured at federal and academic institutions' stations and moorings. The multivariate analysis also includes in situ measurements of suspended sediment concentration and advective exchanges through the Mississippi Sound's tidal inlets between the coastal shelf and the nearshore estuarine waters. Mechanisms underlying the observed spatiotemporal distribution of SPM, including material exchange between the Sound and adjacent shelf waters, will be explored. The results of this study will contribute to current understanding of exchange mechanisms and pathways with the Mississippi Bight via the Mississippi Sound's tidal inlets.

  10. Experimental investigation of water sprayed finned heat exchanger tube bundles

    International Nuclear Information System (INIS)

    Sommer, A.

    1987-07-01

    Experimental investigations have been made to study the performance of two finned tube-bundle heat exchangers (FORGO type) when wetted by water sprays. The heat exchangers are designed to cool water in a dry cooling tower. The test-elements had a frontal area of 1 m 2 . The water sprays were created by 20 nozzles, 200 mm in front of the heat exchangers. Air velocities at the inlet of the coolers were in the range 0,8 m/s to 12 m/s and initial temperature differences ITD reached 45 degrees C. The test facility was designed to determine the combined latent and sensible heat fluxes in the wetted heat exchanger, the airside pressure drop and the air humidity and temperature at the exchanger inlet and outlet, and to measure the weight of the water wetting the cooler's surface. The sprayed test elements were investigated in different positions, but most of the experiments were carried out in the position with the fins horizontal

  11. A study on the influence of tides on the water table conditions of the shallow coastal aquifers

    Science.gov (United States)

    Singaraja, C.; Chidambaram, S.; Jacob, Noble

    2018-03-01

    Tidal variation and water level in aquifer is an important function in the coastal environment, this study attempts to find the relationship between water table fluctuation and tides in the shallow coastal aquifers. The study was conducted by selecting three coastal sites and by monitoring the water level for every 2-h interval in 24 h of observation. The study was done during two periods of full moon and new moon along the Cuddalore coastal region of southern part of Tamil Nadu, India. The study shows the relationship between tidal variation, water table fluctuations, dissolved oxygen, and electrical conductivity. An attempt has also been made in this study to approximate the rate of flow of water. Anyhow, the differences are site specific and the angle of inclination of the water table shows a significant relation to the mean sea level, with respect to the distance of the point of observation from the sea and elevation above mean sea level.

  12. Exchange reaction between tritiated hydrogen and water vapor

    International Nuclear Information System (INIS)

    Yamada, Koichi; Takano, Kenichi; Watanabe, Tamaki.

    1979-01-01

    Exchange reaction of tritiated hydrogen to water vapor under the condition of tritium gas concentration between 1 μCi/l and 1 mCi/l was studied. Tritium gas with hydrogen gas of 5 Torr and water of 20 mg were enclosed in a Pyrex glass ampule with volume of about 100 ml. The mixed gas with water vapor was heated with electric furnace. The heating time was between 2 and 100 hr, and the temperature was 776, 725, 675, 621, and 570.5 0 K. After heating, tritiated water was trapped with liquid nitrogen, and counted with a liquid scintillation counter. The radioactive concentration of initial tritiated hydrogen was measured with a calibrated ionization chamber. The main results obtained are as follows; 1) the concentration of produced tritiated water is well proportioned to that of initial tritiated hydrogen, 2) the activation energy of exchange reaction from tritiated hydrogen to tritiated water is 26.2 kcal/mol and that of inverse reaction is 27.4 kcal/mol, 3) the reaction rate at room temperature which calculated with activation energy is 1.04 x 10 -13 day -1 , and then exchange reaction at room temperature is negligible. (author)

  13. Global land–ocean linkage: direct inputs of nitrogen to coastal waters via submarine groundwater discharge

    International Nuclear Information System (INIS)

    Beusen, A H W; Slomp, C P; Bouwman, A F

    2013-01-01

    The role of submarine groundwater discharge (SGD), the leakage of groundwater from aquifers into coastal waters, in coastal eutrophication has been demonstrated mostly for the North American and European coastlines, but poorly quantified in other regions. Here, we present the first spatially explicit global estimates of N inputs via SGD to coastal waters and show that it has increased from about 1.0 to 1.4 Tg of nitrate (NO 3 -N) per year over the second half of the 20th century. Since this increase is not accompanied by an equivalent increase of groundwater phosphorus (P) and silicon (Si), SGD transport of nitrate is an important factor for the development of harmful algal blooms in coastal waters. Groundwater fluxes of N are linked to areas with high runoff and intensive anthropogenic activity on land, with Southeast Asia, parts of North and Central America, and Europe being hot spots. (letter)

  14. Concentration factors for Cs-137 in marine algae from Japanese coastal waters

    International Nuclear Information System (INIS)

    Tateda, Yutaka; Koyanagi, Taku.

    1994-01-01

    Concentration factors (CF: Bq·kg -1 in wet algae/Bq·kg -1 in filtered seawater) for Cs-137 in Japanese coastal algae, were investigated during 1984-1990. Cs-137/Cs (stable) atom ratios were also examined to clarify the distribution equilibrium of Cs-137 in marine algae and sea water. The CFs in marine algae were within the range of 5.4-92, and the geometric mean of CF was 28±2 (standard error) in Japanese coastal species. The CFs in edible species were within the range of 5.4-67, and the geometric means of CF was 26±4 (standard error). The values of Cs-137/Cs atom ratios in marine algae and sea water indicated that Cs-137 reached an equilibrium state in partition between algae and sea water. Therefore, the CF value obtained in the present study can be regarded as an equilibrated value. Our results showed that hte CF for Cs-137 in Japanese coastal algae were consistent with the Japanese guideline CFs, but were smaller than the recommended value by IAEA. (author)

  15. Regional Jurassic geologic framework of Alabama coastal waters area and adjacent Federal waters area

    Science.gov (United States)

    Mink, R.M.; Bearden, B.L.; Mancini, E.A.

    1989-01-01

    To date, numerous Jurassic hydrocarbon fields and pools have been discovered in the Cotton Valley Group, Haynesville Formation, Smackover Formation and Norphlet Formation in the tri-state area of Mississippi, Alabama and Florida, and in Alabama State coastal waters and adjacent Federal waters area. Petroleum traps are basement highs, salt anticlines, faulted salt anticlines and extensional faults associated with salt movement. Reservoirs include continental and marine sandstones, limestones and dolostones. Hydrocarbon types are oil, condensate and natural gas. The onshore stratigraphic and structural information can be used to establish a regional geologic framework for the Jurassic for the State coastal waters and adjacent Federal waters areas. Evaluation of the geologic information along with the hydrocarbon data from the tri-state area indicates that at least three Jurassic hydrocarbon trends (oil, oil and gas condensate, and deep natural gas) can be identified onshore. These onshore hydrocarbon trends can be projected into the Mobile area in the Central Gulf of Mexico and into the Pensacola, Destin Dome and Apalachicola areas in the Eastern Gulf of Mexico. Substantial reserves of natural gas are expected to be present in Alabama State waters and the northern portion of the Mobile area. Significant accumulations of oil and gas condensate may be encountered in the Pensacola, Destin Dome, and Apalachicola areas. ?? 1989.

  16. Pigment specific in vivo light absorption of phytoplankton from estuarine, coastal and oceanic waters

    DEFF Research Database (Denmark)

    Stæhr, A.; Markager, S.; Sand-Jensen, K.

    2004-01-01

    The influence of phytoplankton photoacclimation and adaptation to natural growth conditions on the chlorophyll a-specific in vivo absorption coefficient (a* ph) was evaluated for samples collected in estuarine, coastal and oceanic waters. Despite an overall gradient in the physio......-chemical environment from estuaries, over coastal, to oceanic waters, no clear relationships were found between a* ph and the prevailing light, temperature, salinity and nutrient concentrations, indicating that short-term cellular acclimation was of minor importance for the observed variability in a* ph. The clear...... decline in a* ph from oceanic, over coastal, to estuarine waters was, however, strongly correlated with an increase in cell size and intracellular chlorophyll a (chl a) content of the phytoplankton, and a reduction of photosynthetic carotenoids relative to chl a. Variations in photoprotective carotenoids...

  17. Investigation of different coastal processes in Indonesian waters using SeaWiFS data

    Science.gov (United States)

    Hendiarti, Nani; Siegel, Herbert; Ohde, Thomas

    2004-01-01

    SeaWiFS data were applied to investigate coastal processes in Indonesian waters around the most populated island of Java. Coastal processes due to wind forcing were studied the first time using SeaWiFS-derived chlorophyll and TSM concentrations in combination with AVHRR-derived SST in the period from September 1997 to December 2001. Upwelling events were studied along the southern coast of Java during the southeast monsoon (June to September). Satellite-derived chlorophyll concentrations higher than 0.8 mg/ m3 and sea-surface temperatures lower than 28°C are indications of upwelling. Upwelling events influence the distribution and growth of phytoplankton and provide by that good feeding condition for zooplankton, larvae, juvenile and adult of pelagic fish. Coastal discharge into the western Java Sea contains organic and inorganic materials originating from different sources. Diffuse impacts, particularly from fish farms and aquaculture, as well as coastal erosion influence large coastal areas during the rainy season (December to March), and to a lesser extent during the dry season. Strong Citarum river discharge was observed during the transition phase from the rainy to the dry season (March and April), when the maximum amount of transported material reaches the sea. The river plume is evident from chlorophyll concentrations higher than 2.5 mg/ m3, and suspended particulate matter concentrations of more than 8 mg/dm3. The Sunda Strait is seasonally influenced by water transport from the Java Sea and from the Indian Ocean. The satellite data show that water transport from the Java Sea occurs during the pre-dominantly easterly winds period (June to September). This is characterized by warm water (SST higher than 29.5°C) and chlorophyll concentrations higher than 0.5 mg/ m3. This water transport influences the fish abundance in the Sunda Strait. High fish catches coincide with the presence of Java Sea water, while the surface currents lead to the migration of

  18. Salmonella rarely detected in Mississippi coastal waters and sediment.

    Science.gov (United States)

    Carr, M R; Wang, S Y; McLean, T I; Flood, C J; Ellender, R D

    2010-12-01

    Standards for the rapid detection of individual pathogens from environmental samples have not been developed, but in their absence, the use of molecular-based detection methods coupled with traditional microbiology techniques allows for rapid and accurate pathogen detection from environmental waters and sediment. The aim of this research was to combine the use of enrichment with PCR for detection of Salmonella in Mississippi coastal waters and sediment and observe if that presence correlated with levels of enterococci and climatological variables. Salmonella were primarily found in samples that underwent nutrient enrichment and were present more frequently in freshwater than marine waters. Salmonella were detected infrequently in marine and freshwater sediments. There was a significant positive correlation between the presence of detectable Salmonella and the average enterococcal count. An inverse relationship, however, was observed between the frequency of detection and the levels of salinity, turbidity and sunlight exposure. Results from this study indicated the presence of Salmonella in Mississippi coastal waters, and sediments are very low with significant differences between freshwater and marine environments. Using pathogenic and novel nonpathogenic molecular markers, Salmonella do not appear to be a significant pathogenic genus along the Mississippi Coast. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  19. Water detritiation: better catalysts for liquid phase catalytic exchange

    International Nuclear Information System (INIS)

    Braet, J.

    2005-01-01

    Fusion reactors are our hope for a clean nuclear energy. But as they shall handle huge amounts of tritium, 1.5 10 19 Bq GWth -1 a -1 or about 50 000 times more tritium than light water fission reactors, they need detritiation. Most tritium losses can be trapped as or can easily be transformed into tritiated water. Water detritiation is preferably based on the multiplication of the large equilibrium isotope effect during the exchange reaction of tritium between hydrogen gas and liquid water in a counter current trickle bed reactor. Such LPCE (Liquid Phase Catalytic Exchange) requires an efficient hydrophobic catalyst. SCK-CEN invented and developed such a catalyst in the past. In combination with an appropriate packing, different batches of this catalyst performed very well during years of extensive testing, allowing to develop the ELEX process for water detritiation at inland reprocessing plants. The main objectives of this study were to reproduce and possibly improve the SCK-CEN catalyst for tritium exchange between hydrogen and liquid water; and to demonstrate the high overall exchange rate and thus high detritiation factors that can be realized with it in a small and simple LPCE column under typical but conservative operating conditions

  20. Drinking water contributes to high salt consumption in young adults in coastal Bangladesh.

    Science.gov (United States)

    Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Phung, Dung; Malek, Abdul; Khan, Sheela; Chu, Cordia

    2016-04-01

    Increasing salinity of freshwater from environmental and anthropogenic influences is threatening the health of 35 million inhabitants in coastal Bangladesh. Yet little is known about the characteristics of their exposure to salt (sodium), a major risk factor for hypertension and related chronic diseases. This research examined sodium consumption levels and associated factors in young adults. We assessed spot urine samples for 282 participants (19-25 years) during May-June 2014 in a rural sub-district in southwestern coastal Bangladesh and measured sodium levels of their potable water sources. The significant factors associated with high sodium consumption were determined from logistic regression analyses. Mean sodium content in tube-well water (885 mg/L) was significantly higher than pond water (738 mg/L) (P = 0.01). Fifty three percent of subjects were consuming sodium at levels above the WHO recommended level (≥2 g/day). The users of tube-well water were more likely to consume sodium above this recommended level than pond water users. Salinity problems are projected to increase with climate change, and with large populations potentially at risk, appropriate public health and behavior-change interventions are an urgent priority for this vulnerable coastal region along with targeted research to better understand sodium exposure pathways and health benefits of alternative water supplies.

  1. Biofouling evaluation in the seawater cooling circuit of an operating coastal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, P.S.; Veeramani, P.; Ershath, M.I.M.; Venugopalan, V.P. [BARC Facilities, Water and Steam Chemistry Div., Kalpakkam, Tamil Nadu (India)

    2010-07-01

    Chlorination is the most commonly used method of biofouling control in cooling water systems of coastal power stations. In the present study, we report results of extensive sampling in different sections of the cooling water system of an operating power station undertaken during three consecutive maintenance shutdowns. The power plant employed continuous low level chlorination (0.2 ± 0.1 mg L{sup -1} TRO) with twice-a-week booster dosing (0.4 ± 0.1 mg L-1 TRO for 8 hours). In addition, the process seawater heat exchangers received supplementary dosing of bromide treatment (0.2 ± 0.1 mg L{sup -1} TRO for 1 hour in every 8 h shift). Biofouling samples were collected from the cooling water conduits, heat exchanger water boxes, pipelines, heated discharge conduits and outfall section during the annual maintenance shutdown of the plant in the years 2007, 2008 and 2009. Simultaneous monitoring of biofouling on test coupons in coastal waters enabled direct comparison of fouling situation on test panels and that in the cooling system. The data showed significant reduction in biofouling inside the cooling circuit as compared to the coastal waters. However, significant amount of fouling was still evident at several places, indicating inadequacy of the biocide treatment regime. The maximum load of 31.3 kg m{sup 2} y{sup -1} was observed in the conduits leading to the process seawater heat exchangers (PSW-HX) and the minimum of 1.3 kg m{sup 2} y{sup -1} was observed in the outfall section. Fouling loads of 12.2 - 14.7 kg m{sup 2} y{sup -1} were observed in the concrete conduits feeding the main condensers. Bromide treatment ahead of the PSW-HX could marginally reduce the fouling load in the downstream section of the dosing point; the HX inlets still showed good biofouling. Species diversity across the cooling water system showed the pre-condenser section to be dominated by green mussels (Perna viridis), pearl oysters (Pinctada sp.) and edible oysters (Crassostrea sp

  2. Biofouling evaluation in the seawater cooling circuit of an operating coastal power plant

    International Nuclear Information System (INIS)

    Murthy, P.S.; Veeramani, P.; Ershath, M.I.M.; Venugopalan, V.P.

    2010-01-01

    Chlorination is the most commonly used method of biofouling control in cooling water systems of coastal power stations. In the present study, we report results of extensive sampling in different sections of the cooling water system of an operating power station undertaken during three consecutive maintenance shutdowns. The power plant employed continuous low level chlorination (0.2 ± 0.1 mg L -1 TRO) with twice-a-week booster dosing (0.4 ± 0.1 mg L-1 TRO for 8 hours). In addition, the process seawater heat exchangers received supplementary dosing of bromide treatment (0.2 ± 0.1 mg L -1 TRO for 1 hour in every 8 h shift). Biofouling samples were collected from the cooling water conduits, heat exchanger water boxes, pipelines, heated discharge conduits and outfall section during the annual maintenance shutdown of the plant in the years 2007, 2008 and 2009. Simultaneous monitoring of biofouling on test coupons in coastal waters enabled direct comparison of fouling situation on test panels and that in the cooling system. The data showed significant reduction in biofouling inside the cooling circuit as compared to the coastal waters. However, significant amount of fouling was still evident at several places, indicating inadequacy of the biocide treatment regime. The maximum load of 31.3 kg m 2 y -1 was observed in the conduits leading to the process seawater heat exchangers (PSW-HX) and the minimum of 1.3 kg m 2 y -1 was observed in the outfall section. Fouling loads of 12.2 - 14.7 kg m 2 y -1 were observed in the concrete conduits feeding the main condensers. Bromide treatment ahead of the PSW-HX could marginally reduce the fouling load in the downstream section of the dosing point; the HX inlets still showed good biofouling. Species diversity across the cooling water system showed the pre-condenser section to be dominated by green mussels (Perna viridis), pearl oysters (Pinctada sp.) and edible oysters (Crassostrea sp.), whereas the post-condenser section and heat

  3. Universal model for water costs of gas exchange by animals and plants

    OpenAIRE

    Woods, H. Arthur; Smith, Jennifer N.

    2010-01-01

    For terrestrial animals and plants, a fundamental cost of living is water vapor lost to the atmosphere during exchange of metabolic gases. Here, by bringing together previously developed models for specific taxa, we integrate properties common to all terrestrial gas exchangers into a universal model of water loss. The model predicts that water loss scales to gas exchange with an exponent of 1 and that the amount of water lost per unit of gas exchanged depends on several factors: the surface t...

  4. Dependency of high coastal water level and river discharge at the global scale

    Science.gov (United States)

    Ward, P.; Couasnon, A.; Haigh, I. D.; Muis, S.; Veldkamp, T.; Winsemius, H.; Wahl, T.

    2017-12-01

    It is widely recognized that floods cause huge socioeconomic impacts. From 1980-2013, global flood losses exceeded $1 trillion, with 220,000 fatalities. These impacts are particularly hard felt in low-lying densely populated deltas and estuaries, whose location at the coast-land interface makes them naturally prone to flooding. When river and coastal floods coincide, their impacts in these deltas and estuaries are often worse than when they occur in isolation. Such floods are examples of so-called `compound events'. In this contribution, we present the first global scale analysis of the statistical dependency of high coastal water levels (and the storm surge component alone) and river discharge. We show that there is statistical dependency between these components at more than half of the stations examined. We also show time-lags in the highest correlation between peak discharges and coastal water levels. Finally, we assess the probability of the simultaneous occurrence of design discharge and design coastal water levels, assuming both independence and statistical dependence. For those stations where we identified statistical dependency, the probability is between 1 and 5 times greater, when the dependence structure is accounted for. This information is essential for understanding the likelihood of compound flood events occurring at locations around the world as well as for accurate flood risk assessments and effective flood risk management. The research was carried out by analysing the statistical dependency between observed coastal water levels (and the storm surge component) from GESLA-2 and river discharge using gauged data from GRDC stations all around the world. The dependence structure was examined using copula functions.

  5. Coupling bacterioplankton populations and environment to community function in coastal temperate waters

    DEFF Research Database (Denmark)

    Traving, S. J.; Bentzon-Tilia, Mikkel; Knudsen-Leerbeck, H.

    2016-01-01

    drivers of bacterioplankton community functions, taking into account the variability in community composition and environmental conditions over seasons, in two contrasting coastal systems. A Least Absolute Shrinkage and Selection Operator (LASSO) analysis of the biological and chemical data obtained from...... surface waters over a full year indicated that specific bacterial populations were linked to measured functions. Namely, Synechococcus (Cyanobacteria) was strongly correlated with protease activity. Both function and community composition showed seasonal variation. However, the pattern of substrate...... of common drivers of bacterioplankton community functions in two different systems indicates that the drivers may be of broader relevance in coastal temperate waters....

  6. Cumulant expansions for measuring water exchange using diffusion MRI

    Science.gov (United States)

    Ning, Lipeng; Nilsson, Markus; Lasič, Samo; Westin, Carl-Fredrik; Rathi, Yogesh

    2018-02-01

    The rate of water exchange across cell membranes is a parameter of biological interest and can be measured by diffusion magnetic resonance imaging (dMRI). In this work, we investigate a stochastic model for the diffusion-and-exchange of water molecules. This model provides a general solution for the temporal evolution of dMRI signal using any type of gradient waveform, thereby generalizing the signal expressions for the Kärger model. Moreover, we also derive a general nth order cumulant expansion of the dMRI signal accounting for water exchange, which has not been explored in earlier studies. Based on this analytical expression, we compute the cumulant expansion for dMRI signals for the special case of single diffusion encoding (SDE) and double diffusion encoding (DDE) sequences. Our results provide a theoretical guideline on optimizing experimental parameters for SDE and DDE sequences, respectively. Moreover, we show that DDE signals are more sensitive to water exchange at short-time scale but provide less attenuation at long-time scale than SDE signals. Our theoretical analysis is also validated using Monte Carlo simulations on synthetic structures.

  7. Land-based sources of marine pollution: Pesticides, PAHs and phthalates in coastal stream water, and heavy metals in coastal stream sediments in American Samoa

    International Nuclear Information System (INIS)

    Polidoro, Beth A.; Comeros-Raynal, Mia T.; Cahill, Thomas; Clement, Cassandra

    2017-01-01

    The island nations and territories of the South Pacific are facing a number of pressing environmental concerns, including solid waste management and coastal pollution. Here we provide baseline information on the presence and concentration of heavy metals and selected organic contaminants (pesticides, PAHs, phthalates) in 7 coastal streams and in surface waters adjacent to the Futiga landfill in American Samoa. All sampled stream sediments contained high concentrations of lead, and some of mercury. Several coastal stream waters showed relatively high concentrations of diethyl phthalate and of organophosphate pesticides, above chronic toxicity values for fish and other aquatic organisms. Parathion, which has been banned by the US Environmental Protection Agency since 2006, was detected in several stream sites. Increased monitoring and initiatives to limit non-point source land-based pollution will greatly improve the state of freshwater and coastal resources, as well as reduce risks to human health in American Samoa. - Highlights: • Several coastal stream sediments in American Samoa are high in lead and mercury. • Organophosphate pesticides, including Parathion, are present in coastal streams. • More research is needed on the sources, fate and impacts of these contaminants.

  8. Potable water scarcity: options and issues in the coastal areas of Bangladesh.

    Science.gov (United States)

    Islam, Atikul; Sakakibara, Hiroyuki; Karim, Rezaul; Sekine, Masahiko

    2013-09-01

    In the coastal areas of Bangladesh, scarcity of drinking water is acute as freshwater aquifers are not available at suitable depths and surface water is highly saline. Households are mainly dependent on rainwater harvesting, pond sand filters and pond water for drinking purposes. Thus, individuals in these areas often suffer from waterborne diseases. In this paper, water consumption behaviour in two southwestern coastal districts of Bangladesh has been investigated. The data for this study were collected through a survey conducted on 750 rural households in 39 villages of the study area. The sample was selected using a random sampling technique. Households' choice of water source is complex and seasonally dependent. Water sourcing patterns, households' preference of water sourcing options and economic feasibility of options suggest that a combination of household and community-based options could be suitable for year-round water supply. Distance and time required for water collection were found to be difficult for water collection from community-based options. Both household and community-based options need regular maintenance. In addition to installation of water supply facilities, it is necessary to make the residents aware of proper operation and maintenance of the facilities.

  9. Geochemistry of shallow ground water in coastal plain environments in the southeastern United States: implications for aquifer susceptibility

    International Nuclear Information System (INIS)

    Tesoriero, Anthony J.; Spruill, Timothy B.; Eimers, Jo L.

    2004-01-01

    Ground-water chemistry data from coastal plain environments have been examined to determine the geochemical conditions and processes that occur in these areas and assess their implications for aquifer susceptibility. Two distinct geochemical environments were studied to represent a range of conditions: an inner coastal plain setting having more well-drained soils and lower organic carbon (C) content and an outer coastal plain environment that has more poorly drained soils and high organic C content. Higher concentrations of most major ions and dissolved inorganic and organic C in the outer coastal plain setting indicate a greater degree of mineral dissolution and organic matter oxidation. Accordingly, outer coastal plain waters are more reducing than inner coastal plain waters. Low dissolved oxygen (O 2 ) and nitrate (NO 3 - ) concentrations and high iron (Fe) concentrations indicate that ferric iron (Fe (III)) is an important electron acceptor in this setting, while dissolved O 2 is the most common terminal electron acceptor in the inner coastal plain setting. The presence of a wide range of redox conditions in the shallow aquifer system examined here underscores the importance of providing a detailed geochemical characterization of ground water when assessing the intrinsic susceptibility of coastal plain settings. The greater prevalence of aerobic conditions in the inner coastal plain setting makes this region more susceptible to contamination by constituents that are more stable under these conditions and is consistent with the significantly (p 3 - found in this setting. Herbicides and their transformation products were frequently detected (36% of wells sampled), however concentrations were typically low (<0.1 μg/L). Shallow water table depths often found in coastal plain settings may result in an increased risk of the detection of pesticides (e.g., alachlor) that degrade rapidly in the unsaturated zone

  10. Seasonal variability of heat flux divergence in the coastal waters of Visakhapatnam

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, B.P.; Sadhuram, Y.

    Heat flux divergence (Qv) in the coastal waters of Visakhapatnam, Andhra, Pradesh, India during different seasons, was estimated for the period February 1980-January 1981. It is found that the water column (0-60 m) gains heat during winter...

  11. Continuous measurement of air-water gas exchange by underwater eddy covariance

    Science.gov (United States)

    Berg, Peter; Pace, Michael L.

    2017-12-01

    Exchange of gases, such as O2, CO2, and CH4, over the air-water interface is an important component in aquatic ecosystem studies, but exchange rates are typically measured or estimated with substantial uncertainties. This diminishes the precision of common ecosystem assessments associated with gas exchanges such as primary production, respiration, and greenhouse gas emission. Here, we used the aquatic eddy covariance technique - originally developed for benthic O2 flux measurements - right below the air-water interface (˜ 4 cm) to determine gas exchange rates and coefficients. Using an acoustic Doppler velocimeter and a fast-responding dual O2-temperature sensor mounted on a floating platform the 3-D water velocity, O2 concentration, and temperature were measured at high-speed (64 Hz). By combining these data, concurrent vertical fluxes of O2 and heat across the air-water interface were derived, and gas exchange coefficients were calculated from the former. Proof-of-concept deployments at different river sites gave standard gas exchange coefficients (k600) in the range of published values. A 40 h long deployment revealed a distinct diurnal pattern in air-water exchange of O2 that was controlled largely by physical processes (e.g., diurnal variations in air temperature and associated air-water heat fluxes) and not by biological activity (primary production and respiration). This physical control of gas exchange can be prevalent in lotic systems and adds uncertainty to assessments of biological activity that are based on measured water column O2 concentration changes. For example, in the 40 h deployment, there was near-constant river flow and insignificant winds - two main drivers of lotic gas exchange - but we found gas exchange coefficients that varied by several fold. This was presumably caused by the formation and erosion of vertical temperature-density gradients in the surface water driven by the heat flux into or out of the river that affected the turbulent

  12. Continuous measurement of air–water gas exchange by underwater eddy covariance

    Directory of Open Access Journals (Sweden)

    P. Berg

    2017-12-01

    Full Text Available Exchange of gases, such as O2, CO2, and CH4, over the air–water interface is an important component in aquatic ecosystem studies, but exchange rates are typically measured or estimated with substantial uncertainties. This diminishes the precision of common ecosystem assessments associated with gas exchanges such as primary production, respiration, and greenhouse gas emission. Here, we used the aquatic eddy covariance technique – originally developed for benthic O2 flux measurements – right below the air–water interface (∼ 4 cm to determine gas exchange rates and coefficients. Using an acoustic Doppler velocimeter and a fast-responding dual O2–temperature sensor mounted on a floating platform the 3-D water velocity, O2 concentration, and temperature were measured at high-speed (64 Hz. By combining these data, concurrent vertical fluxes of O2 and heat across the air–water interface were derived, and gas exchange coefficients were calculated from the former. Proof-of-concept deployments at different river sites gave standard gas exchange coefficients (k600 in the range of published values. A 40 h long deployment revealed a distinct diurnal pattern in air–water exchange of O2 that was controlled largely by physical processes (e.g., diurnal variations in air temperature and associated air–water heat fluxes and not by biological activity (primary production and respiration. This physical control of gas exchange can be prevalent in lotic systems and adds uncertainty to assessments of biological activity that are based on measured water column O2 concentration changes. For example, in the 40 h deployment, there was near-constant river flow and insignificant winds – two main drivers of lotic gas exchange – but we found gas exchange coefficients that varied by several fold. This was presumably caused by the formation and erosion of vertical temperature–density gradients in the surface water driven by the heat flux into or

  13. Contamination of diuron in coastal waters around Malaysian Peninsular.

    Science.gov (United States)

    Ali, Hassan Rashid; Arifin, Marinah Mohd; Sheikh, Mohammed Ali; Shazili, Noor Azhar Mohamed; Bakari, Said Suleiman; Bachok, Zainudin

    2014-08-15

    The use of antifouling paints to the boats and ships is one among the threats facing coastal resources including coral reefs in recent decades. This study reports the current contamination status of diuron and its behaviour in the coastal waters of Malaysia. The maximum concentration of diuron was 285 ng/L detected at Johor port. All samples from Redang and Bidong coral reef islands were contaminated with diuron. Temporal variation showed relatively high concentrations but no significant difference (P>0.05) during November and January (North-East monsoon) in Klang ports (North, South and West), while higher levels of diuron were detected during April, 2012 (Inter monsoon) in Kemaman, and Johor port. Although no site has shown concentration above maximum permissible concentration (430 ng/L) as restricted by the Dutch Authorities, however, long term exposure studies for environmental relevance levels of diuron around coastal areas should be given a priority in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Spatio-temporal distribution patterns of the epibenthic community in the coastal waters of Suriname

    Science.gov (United States)

    Willems, Tomas; De Backer, Annelies; Wan Tong You, Kenneth; Vincx, Magda; Hostens, Kris

    2015-10-01

    This study aimed to characterize the spatio-temporal patterns of the epibenthic community in the coastal waters of Suriname. Data were collected on a (bi)monthly basis in 2012-2013 at 15 locations in the shallow (turbid-water zone (6-20 m depth), dominated by Atlantic seabob shrimp Xiphopenaeus kroyeri (Crustacea: Penaeoidea). Near the 30 m isobath, sediments were much coarser (median grain size on average 345±103 μm vs. 128±53 μm in the coastal assemblage) and water transparency was much higher (on average 7.6±3.5 m vs. 2.4±2.1 m in the coastal assemblage). In this zone, a diverse offshore assemblage was found, characterized by brittle stars (mainly Ophioderma brevispina and Ophiolepis elegans) and a variety of crabs, sea stars and hermit crabs. In between both zones, a transition assemblage was noted, with epibenthic species typically found in either the coastal or offshore assemblages, but mainly characterized by the absence of X. kroyeri. Although the epibenthic community was primarily structured in an on-offshore gradient related to depth, sediment grain size and sediment total organic carbon content, a longitudinal (west-east) gradient was apparent as well. The zones in the eastern part of the Suriname coastal shelf seemed to be more widely stretched along the on-offshore gradient. Although clear seasonal differences were noted in the environmental characteristics (e.g. dry vs. rainy season), this was not reflected in the epibenthic community structure. X. kroyeri reached very high densities (up to 1383 ind 1000 m-²) in the shallow coastal waters of Suriname. As X. kroyeri is increasingly exploited throughout its range, the current study provides the ecological context for its presence and abundance, which is crucial for an ecosystem approach and the sustainable management of this commercially important species and its habitat.

  15. Baseline metals pollution profile of tropical estuaries and coastal waters of the Straits of Malacca

    International Nuclear Information System (INIS)

    Looi, Ley Juen; Aris, Ahmad Zaharin; Wan Johari, Wan Lutfi; Yusoff, Fatimah Md.; Hashim, Zailina

    2013-01-01

    Highlights: • Order of metals distribution were as follow: Fe > Al > Se > Cu > As > Zn > Mn > Ni > Ba > Pb > Cd > Cr > Co. • As and Cu levels have exceeded Malaysia Marine Water Quality Criteria and Standard. • Seven principal components of PCA were extracted from estuaries and coastal waters. • Mineral-related parameters are main pollution sources in the waters. -- Abstract: The status report on metal pollution in tropical estuaries and coastal waters is important to understand potential environmental health hazards. Detailed baseline measurements were made on physicochemical parameters (pH, temperature, redox potential, electrical conductivity, salinity, dissolved oxygen, total dissolved solid), major ions (Na, Ca, Mg, K, HCO 3 , Cl, SO 4 and NO 3 ) and metals concentrations ( 27 Al, 75 As, 138 Ba, 9 Be, 111 Cd, 59 Co, 63 Cu, 52 Cr, 57 Fe, 55 Mn, 60 Ni, 208 Pb, 80 Se, 66 Zn) at estuaries and coastal waters along the Straits of Malacca. Principal component analysis (PCA) was employed to reveal potential pollution sources. Seven principal components were extracted with relation to pollution contribution from minerals-related parameters, natural and anthropogenic sources. The output from this study will generate a profound understanding on the metal pollution status and pollution risk of the estuaries and coastal system

  16. Universal model for water costs of gas exchange by animals and plants.

    Science.gov (United States)

    Woods, H Arthur; Smith, Jennifer N

    2010-05-04

    For terrestrial animals and plants, a fundamental cost of living is water vapor lost to the atmosphere during exchange of metabolic gases. Here, by bringing together previously developed models for specific taxa, we integrate properties common to all terrestrial gas exchangers into a universal model of water loss. The model predicts that water loss scales to gas exchange with an exponent of 1 and that the amount of water lost per unit of gas exchanged depends on several factors: the surface temperature of the respiratory system near the outside of the organism, the gas consumed (oxygen or carbon dioxide), the steepness of the gradients for gas and vapor, and the transport mode (convective or diffusive). Model predictions were largely confirmed by data on 202 species in five taxa--insects, birds, bird eggs, mammals, and plants--spanning nine orders of magnitude in rate of gas exchange. Discrepancies between model predictions and data seemed to arise from biologically interesting violations of model assumptions, which emphasizes how poorly we understand gas exchange in some taxa. The universal model provides a unified conceptual framework for analyzing exchange-associated water losses across taxa with radically different metabolic and exchange systems.

  17. Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Edward Levy; Harun Bilirgen; John DuPoint

    2011-03-31

    Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: (1) An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing high-moisture, low rank coals. (2) Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. (3) Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. (4) Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. (5) Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. (6) Condensed flue gas water treatment needs and costs. (7) Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. (8) Results of cost-benefit studies of condensing heat exchangers.

  18. Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Levy, Edward; Bilirgen, Harun; DuPont, John

    2011-03-31

    Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: • An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing highmoisture, low rank coals. • Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. • Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. • Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. • Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. • Condensed flue gas water treatment needs and costs. • Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. • Results of cost-benefit studies of condensing heat exchangers.

  19. Tidal Wetlands and Coastal Ocean Carbon Dynamics

    Science.gov (United States)

    Hopkinson, C.; Wang, S. R.; Forbrich, I.; Giblin, A. E.; Cai, W. J.

    2017-12-01

    Recent overviews of coastal ocean C dynamics have tidal wetlands in a prominent position: a local sink for atmospheric CO2, a local store of OC, and a source of DIC and OC for the adjacent estuary and nearshore ocean. Over the past decade there have been great strides made in quantifying and understanding these flows and linkages. GPP and R of the wetlands are not nearly as imbalanced as thought 30 yrs ago. Heterotrophy of adjacent estuarine waters is not solely due to the respiration of OC exported from the marsh, rather we see the marsh directly respiring into the water during tidal inundation and accumulated marsh DIC draining into tidal creeks. Organic carbon burial on the marsh is still a relatively minor flux, but it is large relative to marsh NEE. Using literature and unpublished data on marsh DIC export, we used examples from Sapelo Island GA USA and Plum Island MA USA to constrain estimates of NEP and potential OC export. P. There remain large uncertainties in quantifying C dynamics of coupled wetland - estuary systems. Gas exchange from the water to atmosphere is one of the largest uncertainties. Work at Sapelo suggests that upwards of 40% of all daily exchange occurs from water flooding the marsh, which is but a few hours a day. This estimate is based on the intercept value for gas exchange vs wind velocity. Another major uncertainty comes from converting between O2 based estimates of metabolism to C. At Sapelo we find PQ and RQ values diverging greatly from Redfield. Finally, C dynamics of the coastal ocean, especially the role of tidal wetlands is likely to change substantially in the future. Studies at Plum Island show a reversal of the 4000 yr process of marsh progradation with marshes eroding away at their edges because of inadequate sediment supply and rising sea level. The fate of eroded OC is questionable. Landward transgression with SLR is the only likely counter to continued wetland loss - but that's a complex social issue requiring new

  20. Critical overview on water - hydrogen isotopic exchange; a case study

    International Nuclear Information System (INIS)

    Peculea, Marius

    2002-01-01

    Water - hydrogen isotopic exchange process is attractive due to its high separation factor; it is neither corrosive or pollutant and, when used as a technological process of heavy water production, it requires water as raw material. Its efficiency depends strongly on the catalyst performance and geometry of the isotopic water - hydrogen exchange zone in which the isotopic transfer proceeds in two steps: liquid vapor distillation in the presence of an inert gas and a catalytic reaction in vapor - gas gaseous phase. An overview of the water hydrogen isotopic exchange is presented and technological details of the Trail - Canada facility as well as characteristics of the two pilots operated in Romania with Ni, Cr and hydrophobic catalysts are described. The mathematical approach of the successive water-water vapor-hydrogen isotopic exchange process given is based on a mathematical model worked out earlier by Palibroda. Discrepancies between computation and experimental results, lower than 11% for extreme cases and around 6% for the average range are explained as due to the ratio of the exchange potentials. Assumption is made in the theoretical approach that this ratio is positive and constant all long the column while the measurements showed that it varies within 0.7 and 1.1 at the upper end and within - 2.5 and - 4.4 at the lower end, what indicates a strong end effect. In conclusion it is stressed that a competing technological solution is emerging based on a monothermal electrolytic process or a bithermal - bibaric process both for heavy water and tritium separation process

  1. Resting Stage of Plankton Diversity from Singapore Coastal Water: Implications for Harmful Algae Blooms and Coastal Management

    Science.gov (United States)

    Trottet, Aurore; Wilson, Bryan; Sew Wei Xin, Genevieve; George, Christaline; Casten, Lemuel; Schmoker, Claire; Rawi, Nurul Syazana Binte Modh; Chew Siew, Moon; Larsen, Ole; Eikaas, Hans S.; Tun, Karenne; Drillet, Guillaume

    2018-02-01

    Resting strategies of planktonic organisms are important for the ecological processes of coastal waters and their impacts should be taken into consideration in management of water bodies used by multiple industries. We combined different approaches to evaluate the importance of resting stages in Singapore coastal waters. We used molecular approaches to improve the knowledge on Singapore biodiversity, we sampled and extracted cysts from sediments to evaluate the density of resting stages in Johor Strait, and we compared systematically information on Singapore planktonic biodiversity to existing published information on resting stages from these reported organisms. This is the first study evaluating the importance of resting stages in Singapore waters. Above 120 species reported in Singapore are known to produce resting stages though no previous work has ever been done to evaluate the importance of these strategies in these waters. The results from the resting stage survey confirmed 0.66 to 5.34 cyst g-1 dry weight sediment were present in the Johor Strait suggesting that cysts may be flushed by tidal currents into and out of the strait regularly. This also suggest that the blooms occurring in Singapore are likely due to secondary growth of Harmful Algae Bloom species in the water rather than from direct germination of cysts from sediment. Finally, we discuss the importance of these resting eggs for three main national industries in Singapore (shipping, marine aquaculture and provision of drinking water through seawater desalination). We argue that this study will serve as a baseline for some of the future management of Singapore waters.

  2. Nitrite-induced enhancement of toxicity of phenanthrene in fish and its implications for coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Shailaja, M.S.; Rodrigues, A

    Coastal areas are prone to varying degrees of anthropogenic chemical contamination. In many coastal environments experiencing reducing conditions in the water column, nitrite is produced as a result of denitrification. With a view to determining...

  3. Environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks, New Jersey Coastal Plain, USA: migration to the water table.

    Science.gov (United States)

    Szabo, Zoltan; Jacobsen, Eric; Kraemer, Thomas F; Parsa, Bahman

    2010-01-01

    Fate of radium (Ra) in liquid regeneration brine wastes from water softeners disposed to septic tanks in the New Jersey Coastal Plain was studied. Before treatment, combined Ra ((226)Ra plus (228)Ra) concentrations (maximum, 1.54 Bq L(-1)) exceeded the 0.185 Bq L(-1) Maximum Contaminant Level in 4 of 10 studied domestic-well waters (median pH, 4.90). At the water table downgradient from leachfields, combined Ra concentrations were low (commonly 5.3, indicating sequestration; when pH was septic-tank effluents (maximum, 0.243 Bq L(-1))), indicating Ra mobilization from leachfield sediments. Confidence in quantification of Ra mass balance was reduced by study design limitations, including synoptic sampling of effluents and ground waters, and large uncertainties associated with analytical methods. The trend of Ra mobilization in acidic environments does match observations from regional water-quality assessments.

  4. Understanding human impacts to tropical coastal ecosystems through integrated hillslope erosion measurements, optical coastal waters characterization, watershed modeling, marine ecosystem assessments, and natural resource valuations in two constrasting watersheds in Puerto Rico.

    Science.gov (United States)

    Ortiz-Zayas, J.; Melendez, J.; Barreto, M.; Santiago, L.; Torres-Perez, J. L.; Ramos-Scharron, C. E.; Figueroa, Y.; Setegn, S. G.; Guild, L. S.; Armstrong, R.

    2017-12-01

    Coastal ecosystems are an asset to many tropical island economies. In Puerto Rico, however, many invaluable coastal ecosystems are at risk due to multiple social and natural environmental stressors. To quantify the role of anthropogenic versus natural stressors, an integrated multidisciplinary approach was applied in two contrasting watersheds in Puerto Rico. The Rio Loco (RL) watershed in Southeastern Puerto Rico is hydrologically modified with interbasin water transfers, hydroelectric generation, and with water extraction for irrigation and water supply. Intensive agricultural production dominates both the lower and upper portions of the basin. In contrast, the Rio Grande de Manatí (RGM) shows a natural flow regime with minor flow regulation and limited agriculture. The Surface Water Assessment Tool (SWAT) was applied to each watershed to assess the effects of land use changes on water and sediment fluxes to coastal areas. From 1977 to 2016, forest areas increased in both watersheds due to the abandonment of farms in the mountains. However, in upper and lower RL, agricultural lands have remained active. Coffee plantations in the upper watershed contribute with high sediment loads, particularly in unpaved service roads. We hypothesize that water fluxes will be higher in the larger RGM than in RL. However, suspended sediment fluxes will be higher in the agriculturally active RL basin. A willingness-to-pay approach was applied to assess how residents from each watershed value water and coastal ecosystems revealing a general higher natural resources valuation in the RGM than in RL. Coastal ecosystems at each site revealed structural differences in benthic coral communities due to local currents influenced largely by coastal morphology. The optical properties of coastal waters are also being determined and linked to fluvial sediment fluxes. Stakeholder meetings are being held in each watershed to promote transfer of scientific insights into a sustainable coastal and

  5. Evaluating Sea water Quality in the Coastal Zone of North Lebanon using Telemac-2DTM

    International Nuclear Information System (INIS)

    Awad, Mohamad; Darwich, T.

    2009-01-01

    The coastal zones of the Mediterranean are undergoing rapid development withgrowing and conflicting demands on the natural resources. Coastal zones are often subjected to irreversible land degradation and environmental deterioration. Lebanon is located in the eastern part of the Mediterranean basin and the integrated management of the environment in the Lebanese coastal zone must be given concern. Most of the successful decisions addressing the environment protection or the elaboration of preventive measures in the coastal zone. These decisions depend on the availability of efficient simulation tools. The existence of these tools can help protecting the environment and establishing the ground for sustainable natural resources in the coastal zones. In this paper, a simulation tool called Telemac-2D TM software was used to simulate the business as usual, pessimistic, and optimistic status of the sea water quality in the coastal zone of Tripoli (North Lebanon). The coastal zone is affected by the effluents of solid and liquid wastes from Abou-Ali river. The different quality states of the coastal zone represent the normal, high, and low flow of the effluents (plume pollutants) from Abou-Ali river. In addition, it represents the variation of different factors such as wind and sea currents speed and direction. This simulation will help the decision makers to implement pre-cautious measures before a disaster takes place by assessing the quality of the sea water near the coastal zones. (author)

  6. Remote Sensing of Selected Water-Quality Indicators with the Hyperspectral Imager for the Coastal Ocean (HICO) Sensor

    Science.gov (United States)

    The Hyperspectral Imager for the Coastal Ocean (HICO) offers the coastal environmental monitoring community an unprecedented opportunity to observe changes in coastal and estuarine water quality across a range of spatial scales not feasible with traditional field-based monitoring...

  7. Key parameters and processes affecting the re-establishment of eelgrass in estuaries and coastal water

    DEFF Research Database (Denmark)

    Canal Vergés, Paula

    and sediment trapping. In the last decades seagrass, in general and eelgrass (Zostera marina) in particular, have been heavily reduced, primarily due to a generalized euthrophication of the coastal waters. In Denmark, a numerous efforts on nutrient reduction and improvement on coastal water quality have been....... As a result it was proven that macroalgae generated SPM affected the light climate by dampening greatly the light availability at the sea bed in shallow coastal waters. An agent based model to simulate opportunistic and slower growing macroalgae species transport in Odense fjord was created. In this model......Seagrass are considered engineering species, and as such, provide numerous “ecosystem functions, services and goods”. Among them, seagrass systems offers structural functionality, shelter and food for a diverse trophic chain, high productivity, slow nutrient turnover, reduced hydrodynamic forcing...

  8. A STUDY OF BRACKISH WATER MEMBRANE WITH ULTRAFILTRATION PRETREATMENT IN INDONESIA´S COASTAL AREA

    Directory of Open Access Journals (Sweden)

    Elis Hastuti

    2012-01-01

    Full Text Available Water pollution and sea water intrusion to water sources in coastal areas result lack of provision safe drinking water by the drinking water regional company or coastal community. The existing water treatment plant that operated on brackish surface water or groundwater feed requires improving process. Membrane process could be a choice to treat the quality of brackish water to the level of potable water that designed to lower cost with high stabil flux and longer lifetime. This research focus on application of pilot plant of brackish water treatment using Ultrafiltration (UF membrane-air lift system as pretreatment of Reverse Osmosis (RO membrane-low pressure. Brackish water sources contain high colloidal and suspended solids that can cause fouling load of RO membranes and impair its performance. UF pretreatment operation tested by addition of compressed air into the feed (air lift system, resulted stable flux, reduces membrane fouling and low feed pressure. A flux of RO with UF pretreatment can produce drinking water of 30--61 L/m2·hour. It was observed, the good quality of RO permeate resulted by using a pretreatment of UF--PS (Polysulfone-UF with total dissolved solid rejection about 96--98% and color rejection about 99--100% at 5 or 8 bars of operation pressure. This paper concludes that performance of membrane technology with UF--air lift system pretreatment and RO membrane-low pressure could be accepted as condition of brackish water source in Indonesia coastal areas in producing drinking water.

  9. A study of brackish water membrane with ultrafiltration pretreatment in Indonesia’s coastal area

    Directory of Open Access Journals (Sweden)

    Elis Hastuti

    2012-06-01

    Full Text Available Water pollution and sea water intrusion to water sources in coastal areas result lack of provision safe drinking water by the drinking water regional company or coastal community. The existing water treatment plant that operated on brackish surface water or groundwater feed requires improving process. Membrane process could be a choice to treat the quality of brackish water to the level of potable water that designed to lower cost with high stabil flux and longer lifetime. This research focus on application of pilot plant of brackish water treatment using Ultrafiltration (UF membrane-air lift system as pretreatment of Reverse Osmosis (RO membrane-low pressure. Brackish water sources contain high colloidal and suspended solids that can cause fouling load of RO membranes and impair its performance. UF pretreatment operation tested by addition of compressed air into the feed (air lift system, resulted stable flux, reduces membrane fouling and low feed pressure. A flux of RO with UF pretreatment can produce drinking water of 30–61 L/m2∙hour. It was observed, the good quality of RO permeate resulted by using a pretreatment of UF–PS (Polysulfone-UF with total dissolved solid rejection about 96–98% and color rejection about 99–100% at 5 or 8 bars of operation pressure. This paper concludes that performance of membrane technology with UF–air lift system pretreatment and RO membrane-low pressure could be accepted as condition of brackish water source in Indonesia coastal areas in producing drinking water.

  10. Reducing future river export of nutrients to coastal waters of China in optimistic scenarios

    NARCIS (Netherlands)

    Strokal, Maryna; Kroeze, Carolien; Wang, Mengru; Ma, Lin

    2017-01-01

    Coastal waters of China are rich in nitrogen (N) and phosphorus (P) and thus often eutrophied. This is because rivers export increasing amounts of nutrients to coastal seas. Animal production and urbanization are important sources of nutrients in Chinese rivers. In this study we explored the

  11. [Assessment of resource situation of Collichthys lucidus in coastal waters of the Yangtze estuary].

    Science.gov (United States)

    Hu, Yan; Zhang, Tao; Yang, Gang; Zhao, Feng; Hou, Jun-li; Zhang, Long-zhen; Zhuang, Ping

    2015-09-01

    In order to assess the resource status of Collichthys lucidus in coastal waters of Yangtze estuary, the growth and population parameters were studied by the length frequency distribution method based on the bottom trawl investigation data from 2012 to 2013. Von Bertalanffy growth parameters were calculated by using the ELEFAN module in FiSAT II software while the natural mortality rate (M) was estimated via Pauly's empirical equation. Besides, the Beverton-Holt dynamic model was developed to predict the variation trend of C. lucidus resource in coastal waters of Yangtze estuary. The results showed that in 2012-2013, a total of 4201 samples of C. lucidus with body lengths ranging from 18 to 155 mm were collected from the coastal waters of Yangtze estuary. The growth parameter (K) and limit length (L.) were 1.1 and 162.75 mm while the total mortality rate (Z), the natural mortality rate (M) and the fishing mortality rate (F) were 4.040, 1.683 and 2.357, respectively. Moreover, the current exploitation (E) of C. lucidus in coastal waters of Yangtze estuary was 0.583 per year, which was larger than Fopt (0.5). Corresponding to the average stock of 576.02 t, the resource amount of C. lucidus reached up to 1.33 x 10(8) individuals. These indicated that C. lucidus has been overfished in Yangtze estuary area.

  12. Local and regional scale exchanges of dissolved organic carbon (DOC) between tidal wetlands and their adjacent coastal waters

    Science.gov (United States)

    Osburn, C. L.; Joshi, I.; Lebrasse, M. C.; Oviedo-Vargas, D.; Bianchi, T. S.; Bohnenstiehl, D. R.; D'Sa, E. J.; He, R.; Ko, D.; Arellano, A.; Ward, N. D.

    2017-12-01

    of CDOM, amenable to high resolution observations from multiple platforms, as a basis for constraining the heterogeneity of DOC exports from tidal wetlands to estuaries and coastal waters using numerical models at local and regional scales.

  13. The effect of drinking water salinity on blood pressure in young adults of coastal Bangladesh

    International Nuclear Information System (INIS)

    Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Phung, Dung; Islam, Mohammad Zahirul; Chu, Cordia

    2016-01-01

    More than 35 million people in coastal Bangladesh are vulnerable to increasing freshwater salinization. This will continue to affect more people and to a greater extent as climate change projections are realised in this area in the future. However the evidence for health effects of consuming high salinity water is limited. This research examined the association between drinking water salinity and blood pressure in young adults in coastal Bangladesh. We conducted a cross-sectional study during May-June 2014 in a rural coastal sub-district of Bangladesh. Data on blood pressure (BP) and salinity of potable water sources was collected from 253 participants aged 19–25 years. A linear regression method was used to examine the association between water salinity exposure categories and systolic BP (SBP) and diastolic BP (DBP) level. Sixty five percent of the study population were exposed to highly saline drinking water above the Bangladesh standard (600 mg/L and above). Multivariable linear regression analyses identified that compared to the low water salinity exposure category (<600 mg/L), those in the high water salinity category (>600 mg/L), had statistically significantly higher SBP (B 3.46, 95% CI 0.75, 6.17; p = 0.01) and DBP (B 2.77, 95% CI 0.31, 5.24; p = 0.03). Our research shows that elevated salinity in drinking water is associated with higher BP in young coastal populations. Blood pressure is an important risk factor of hypertension and cardiovascular diseases. Given the extent of salinization of freshwater in many low-lying countries including in Bangladesh, and the likely exacerbation related to climate change-induced sea level rise, implementation of preventative strategies through dietary interventions along with promotion of low saline drinking water must be a priority in these settings. - Highlights: • Freshwater salinization will affect more people and to a greater extent as climate projections are realised in low-lying regions of the world.

  14. Assessing the Nation's Coastal Waters....Better

    Science.gov (United States)

    The USEPA has been assessing estuarine and coastal condition in the United States since 1999 via the National Coastal Assessment (NCA) and National Aquatic Resources Surveys (NARS) programs. Approximately 1500 randomly selected coastal sites were surveyed annually during summers ...

  15. Long-term spatiotemporal trends and health risk assessment of oyster arsenic levels in coastal waters of northern South China Sea.

    Science.gov (United States)

    Wang, Xuefeng; Wang, Lifei; Jia, Xiaoping; Jackson, Donald A

    2017-09-01

    Long-term spatiotemporal trends and health risk assessment of oyster arsenic levels in the coastal waters of northern South China Sea were investigated in order to help improve the quality and safety control and sustainable aquaculture for mollusks in China. Cultured oysters (Crassostrea rivularis) collected from the waters of 23 bays, harbors, and estuaries along the coast of northern South China Sea from 1989 to 2012 were examined for spatial patterns and long-term temporal trends of oyster arsenic levels. Single-factor index and health risk assessment were used to quantify arsenic exposure to human health through oyster consumption. Overall, arsenic was detected in 97.4% of the oyster samples, and oyster arsenic levels were non-detectable-2.51 mg/kg with an average of 0.63 ± 0.54 mg/kg. Oyster arsenic levels in the coastal waters of northern South China Sea showed an overall decline from 1989 to 2012, remained relatively low since 2005, and slightly increased after 2007. Oyster arsenic levels in Guangdong coastal waters were much higher with more variation than in Guangxi and Hainan coastal waters, and the long-term trends of oyster arsenic levels in Guangdong coastal waters dominated the overall trends of oyster arsenic levels in the coastal waters of northern South China Sea. Within Guangdong Province, oyster arsenic levels were highest in east Guangdong coastal waters, followed by the Pearl River estuary and west Guangdong coastal waters. Single-factor index ranged between 0.27 and 0.97, and average health risk coefficient was 3.85 × 10 -5 , both suggesting that oyster arsenic levels in northern South China Sea are within the safe range for human consumption. However, long-term attention should be given to seafood market monitoring in China and the risk of arsenic exposure to human health through oyster consumption.

  16. Identification of a new Irgarol-1051 related s-triazine species in coastal waters

    International Nuclear Information System (INIS)

    Lam, K.-H.; Cai Zongwei; Wai, H.-Y.; Tsang, Vic W.-H.; Lam, Michael H.-W.; Cheung, Richard Y.-H.; Yu Hongxia; Lam, Paul K.-S.

    2005-01-01

    A previously unknown s-triazine species present in commercially available Irgarol-1051, a booster biocide additive in copper-based antifouling paints for the replacement of organotin-based antifoulants, has been identified in the coastal aquatic environment. After careful isolation, purification and characterization by high resolution MS-MS and 1 H NMR, the molecular structure of that unknown species is found to be N,N'-di-tert-butyl-6-methylthiol-s-triazine-2,4-diamine (designated as M3). Levels of Irgarol-1051, its major degradation product (M1) and the newly identified M3 in the coastal waters of Hong Kong, one of the world's busiest ports located in the southern coast of China, were monitored by SPME-GC-MS and SPME-GC-FID. Water samples from five locations within Hong Kong waters were analysed and the levels of Irgarol-1051, M1 and M3 were found to be 0.1-1.6 μg l -1 , 36.8-259.0 μg l -1 and 0.03-0.39 μg l -1 , respectively. Our results indicate that M3 is relatively stable against photo-and bio-degradation and may pose considerable risk to primary producer communities in the coastal marine environment. - An s-triazine species resists degradation and may be a chemical risk for marine coastal communities

  17. Land-based sources of marine pollution: Pesticides, PAHs and phthalates in coastal stream water, and heavy metals in coastal stream sediments in American Samoa.

    Science.gov (United States)

    Polidoro, Beth A; Comeros-Raynal, Mia T; Cahill, Thomas; Clement, Cassandra

    2017-03-15

    The island nations and territories of the South Pacific are facing a number of pressing environmental concerns, including solid waste management and coastal pollution. Here we provide baseline information on the presence and concentration of heavy metals and selected organic contaminants (pesticides, PAHs, phthalates) in 7 coastal streams and in surface waters adjacent to the Futiga landfill in American Samoa. All sampled stream sediments contained high concentrations of lead, and some of mercury. Several coastal stream waters showed relatively high concentrations of diethyl phthalate and of organophosphate pesticides, above chronic toxicity values for fish and other aquatic organisms. Parathion, which has been banned by the US Environmental Protection Agency since 2006, was detected in several stream sites. Increased monitoring and initiatives to limit non-point source land-based pollution will greatly improve the state of freshwater and coastal resources, as well as reduce risks to human health in American Samoa. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Drinking water insecurity: water quality and access in coastal south-western Bangladesh.

    Science.gov (United States)

    Benneyworth, Laura; Gilligan, Jonathan; Ayers, John C; Goodbred, Steven; George, Gregory; Carrico, Amanda; Karim, Md Rezaul; Akter, Farjana; Fry, David; Donato, Katherine; Piya, Bhumika

    2016-01-01

    National drinking water assessments for Bangladesh do not reflect local variability, or temporal differences. This paper reports on the findings of an interdisciplinary investigation of drinking water insecurity in a rural coastal south-western Bangladesh. Drinking water quality is assessed by comparison of locally measured concentrations to national levels and water quality criteria; resident's access to potable water and their perceptions are based on local social surveys. Residents in the study area use groundwater far less than the national average; salinity and local rainwater scarcity necessitates the use of multiple water sources throughout the year. Groundwater concentrations of arsenic and specific conductivity (SpC) were greater than surface water (pond) concentrations; there was no statistically significant seasonal difference in mean concentrations in groundwater, but there was for ponds, with arsenic higher in the dry season. Average arsenic concentrations in local water drinking were 2-4 times times the national average. All of the local groundwater samples exceeded the Bangladesh guidance for SpC, although the majority of residents surveyed did not perceive their water as having a 'bad' or 'salty' taste.

  19. Rate of oxygen isotope exchange between selenate and water.

    Science.gov (United States)

    Kaneko, Masanori; Poulson, Simon R

    2012-04-17

    The rate of oxygen isotope exchange between selenate and water was investigated at conditions of 10 to 80 °C and pH -0.6 to 4.4. Oxygen isotope exchange proceeds as a first-order reaction, and the exchange rate is strongly affected by reaction temperature and pH, with increased rates of isotope exchange at higher temperature and lower pH. Selenate speciation (HSeO(4)(-) vs SeO(4)(2-)) also has a significant effect on the rate of isotope exchange. The half-life for isotope exchange at example natural conditions (25 °C and pH 7) is estimated to be significantly in excess of 10(6) years. The very slow rate of oxygen isotope exchange between selenate and water under most environmental conditions demonstrates that selenate-δ(18)O signatures produced by biogeochemical processes will be preserved and hence that it will be possible to use the value of selenate-δ(18)O to investigate the biogeochemical behavior of selenate, in an analogous fashion to the use of sulfate-δ(18)O to study the biogeochemical behavior of sulfate.

  20. Experimental evidence of nitrogen control on pCO2 in phosphorus-enriched humic and clear coastal lagoon waters

    Science.gov (United States)

    Peixoto, Roberta B.; Marotta, Humberto; Enrich-Prast, Alex

    2013-01-01

    Natural and human-induced controls on carbon dioxide (CO2) in tropical waters may be very dynamic (over time and among or within ecosystems) considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication by nitrogen (N) and phosphorus (P) inputs into coastal lagoons waters may be a relevant component of the carbon cycle, showing controls on partial pressure of CO2 (pCO2) that are still poorly understood. Here we assessed the strength of N control on pCO2 in P-enriched humic and clear coastal lagoons waters, using four experimental treatments in microcosms: control (no additional nutrients) and three levels of N additions coupled to P enrichments. In humic coastal lagoons waters, a persistent CO2 supersaturation was reported in controls and all nutrient-enriched treatments, ranging from 24- to 4-fold the atmospheric equilibrium value. However, both humic and clear coastal lagoons waters only showed significant decreases in pCO2 in relation to the controlled microcosms in the two treatments with higher N addition levels. Additionally, clear coastal lagoons water microcosms showed a shift from CO2 sources to CO2 sinks, in relation to the atmosphere. Only in the two more N-enriched treatments did pCO2 substantially decrease, from 650 µatm in controls and less N-enriched treatments to 10 µatm in more N-enriched microcosms. Humic substrates and N inputs can modulate pCO2 even in P-enriched coastal lagoons waters, thereby being important drivers on CO2 outgassing from inland waters. PMID:23390422

  1. Radioactivity and natural radionuclides distribution in river water, coastal water, sediment and Eichornia Crassipes (Mart) solms and their accumulation factor at Surabaya area

    International Nuclear Information System (INIS)

    Agus Taftazani; Sumining; Muzakky

    2002-01-01

    Distributions of radioactivity and natural radionuclides in water, sediment and eichornia crassipes (mart) solms from Surabaya River and coastal area have been evaluated. Five sampling locations were selected to represent fresh water and coastal water environment. The samples consist of water (fresh & coastal), bottom surface sediment and eichornia crassipes (mart) solms. The result showed that the gross-β activity from water environment were lower than the threshold value of Environmental Minister Act. Kep.02/MENKLH/I/1988 (1000 mBq/L) and indicated that β-radio ecological quality of water were still good. But the activity of the gross-α of water environment were higher than the threshold value of Environmental Minister Act. Kep.02/MENKLH/I/1988 (100 mBq/L). The eichornia crassipes (mart) solms (gross) activity were higher than water and sediment activities and indicated that transfer of radio nuclides from water to sediment and organism can be detected in water environment. Two natural radionuclide can be identified by γ-Spectrometric technique, they were K"4"0 and Tl"2"0"8. Generally the distribution factors F_D were smaller than bioaccumulation factor F_B. (author)

  2. bioSearch : A glimpse into marine biodiversity of Indian coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Kakodkar, A.P.; Alornekar, A.; DSouza, R.; Thomas, T.R.A.; Divekar, R.; Nath, I.V.A.; Kavlekar, D.P.; Ingole, B.S.; Bharathi, P.A.L.

    bioSearch is a database application developed to digitize marine biodiversity of Indian coastal waters. A user can obtain information on organism’s binomial and common names, synonyms, taxonomy, morphology, ecology, economic importance, geographical...

  3. Exchange studies in the Kiel Bight

    Energy Technology Data Exchange (ETDEWEB)

    Hubrich, L M; Schott, F

    1975-11-01

    The knowledge of exchange and mixing parameters and their dependence on meteorological and oceanographic factors in coastal waters plays a predominant role in the estimation of the capacity of those areas for waste water and waste heat. On this subject experimental investigations are carried out in the Kiel Bight, part of the Western Baltic. The paper reports about dye mixing experiments, about the development of a combined aircraft-ship measuring method and about experimental results with low wind velocities and low current velocities. On the basis of measured horizontal surface temperature distributions an estimation of the local heat load in the inner Kiel Fjord from the cooling water of a power plant is also given.

  4. Phosphate solubilizing bacteria and alkaline phosphatase activity in coastal waters off Trivandrum

    Digital Repository Service at National Institute of Oceanography (India)

    Mamatha, S.S.; Gobika, A.; Janani, P.

    , Korea. Marine Pollution Bulletin. 62. pp. 2476–2482. 98 Journal of Coastal Environment Illmer, P. and Schinner, F. 1995. Solubilization of inorganic calcium phosphates solubilization mechanisms. Soil Biology and Biochemistry. 27. pp. 57...-solubilising microorganisms associated with the rhizosphere of mangroves in a semiarid coastal lagoon. Biology and Fertility of Soils. 30. 460-468. Wurl, O. 2009. Practical guidelines for the analysis of sea water. CRC Press, Boca Raton. pp. 143-178. Zohary, T...

  5. 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)

  6. Spatial distribution of dinoflagellates from the tropical coastal waters of the South Andaman, India: Implications for coastal pollution monitoring

    Digital Repository Service at National Institute of Oceanography (India)

    Narale, D.D.; Anil, A.C.

    Dinoflagellate community structure from two semi-enclosed areas along the South Andaman region, India, was investigated to assess the anthropogenic impact on coastal water quality. At the densely inhabited Port Blair Bay, the dominance of mixotrophs...

  7. Four decades of working experience of Cirus primary cooling water heat exchangers

    International Nuclear Information System (INIS)

    Dubey, P.K.; Ullas, O.P.; Rao, D.V.H.; Zope, A.K.; Kharpate, A.V.

    2006-01-01

    CIRUS is a 40 MW (Th.) research reactor, commissioned in the year 1960. The reactor has natural uranium fuel rods, heavy water as moderator, demineralised water (DM water) as primary coolant, and seawater as secondary coolant. There are six Heat Exchangers in the primary cooling water (PCW) system. Five of them are required for the normal operation of the reactor and one is kept stand by. DM water flows on the shell side of the heat exchanger in two passes. Seawater is used as coolant on the tube side of the heat exchangers in four passes. Cirus has been in operation for around 41 years excluding refurbishment period. During these four decades of reactor operation, PCW heat exchangers have experienced many failures and undergone many modifications in the circuit for ensuring better performance. This paper tries to capture the essence of working experiences with PCW heat exchangers, various problems faced, remedial measures taken during those four decades of reactor operation. (author)

  8. Heat exchangers in heavy water reactor systems

    International Nuclear Information System (INIS)

    Mehta, S.K.

    1988-01-01

    Important features of some major heat exchange components of pressurized heavy water reactors and DHRUVA research reactor are presented. Design considerations and nuclear service classifications are discussed

  9. The effect of drinking water salinity on blood pressure in young adults of coastal Bangladesh.

    Science.gov (United States)

    Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Phung, Dung; Islam, Mohammad Zahirul; Chu, Cordia

    2016-07-01

    More than 35 million people in coastal Bangladesh are vulnerable to increasing freshwater salinization. This will continue to affect more people and to a greater extent as climate change projections are realised in this area in the future. However the evidence for health effects of consuming high salinity water is limited. This research examined the association between drinking water salinity and blood pressure in young adults in coastal Bangladesh. We conducted a cross-sectional study during May-June 2014 in a rural coastal sub-district of Bangladesh. Data on blood pressure (BP) and salinity of potable water sources was collected from 253 participants aged 19-25 years. A linear regression method was used to examine the association between water salinity exposure categories and systolic BP (SBP) and diastolic BP (DBP) level. Sixty five percent of the study population were exposed to highly saline drinking water above the Bangladesh standard (600 mg/L and above). Multivariable linear regression analyses identified that compared to the low water salinity exposure category (water salinity category (>600 mg/L), had statistically significantly higher SBP (B 3.46, 95% CI 0.75, 6.17; p = 0.01) and DBP (B 2.77, 95% CI 0.31, 5.24; p = 0.03). Our research shows that elevated salinity in drinking water is associated with higher BP in young coastal populations. Blood pressure is an important risk factor of hypertension and cardiovascular diseases. Given the extent of salinization of freshwater in many low-lying countries including in Bangladesh, and the likely exacerbation related to climate change-induced sea level rise, implementation of preventative strategies through dietary interventions along with promotion of low saline drinking water must be a priority in these settings. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Seagrass restoration enhances "blue carbon" sequestration in coastal waters.

    Science.gov (United States)

    Greiner, Jill T; McGlathery, Karen J; Gunnell, John; McKee, Brent A

    2013-01-01

    Seagrass meadows are highly productive habitats that provide important ecosystem services in the coastal zone, including carbon and nutrient sequestration. Organic carbon in seagrass sediment, known as "blue carbon," accumulates from both in situ production and sedimentation of particulate carbon from the water column. Using a large-scale restoration (>1700 ha) in the Virginia coastal bays as a model system, we evaluated the role of seagrass, Zosteramarina, restoration in carbon storage in sediments of shallow coastal ecosystems. Sediments of replicate seagrass meadows representing different age treatments (as time since seeding: 0, 4, and 10 years), were analyzed for % carbon, % nitrogen, bulk density, organic matter content, and ²¹⁰Pb for dating at 1-cm increments to a depth of 10 cm. Sediment nutrient and organic content, and carbon accumulation rates were higher in 10-year seagrass meadows relative to 4-year and bare sediment. These differences were consistent with higher shoot density in the older meadow. Carbon accumulation rates determined for the 10-year restored seagrass meadows were 36.68 g C m⁻² yr⁻¹. Within 12 years of seeding, the restored seagrass meadows are expected to accumulate carbon at a rate that is comparable to measured ranges in natural seagrass meadows. This the first study to provide evidence of the potential of seagrass habitat restoration to enhance carbon sequestration in the coastal zone.

  11. Gas exchange rates across the sediment-water andd air-water interfaces in south San Francisco Bay

    International Nuclear Information System (INIS)

    Hartman, B.; Hammond, D.E.

    1984-01-01

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainity of the determinations, about 20%. The annual average of bethic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water inteface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2--6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models

  12. Gas exchange rates across the sediment-water and air-water interfaces in south San Francisco Bay

    Science.gov (United States)

    Hartman, Blayne; Hammond, Douglas E.

    1984-01-01

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainty of the determinations, about 20%. The annual average of benthic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water interface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2–6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models.

  13. Phytoremediation potential of Eichornia crassipes in metal-contaminated coastal water.

    Science.gov (United States)

    Agunbiade, Foluso O; Olu-Owolabi, Bamidele I; Adebowale, Kayode O

    2009-10-01

    The potential of Eichornia crassipes to serve as a phytoremediation plant in the cleaning up of metals from contaminated coastal areas was evaluated in this study. Ten metals, As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, V and Zn were assessed in water and the plant roots and shoots from the coastal area of Ondo State, Nigeria and the values were used to evaluate the enrichment factor (EF) and translocation factor (TF) in the plant. The critical concentrations of the metals were lower than those specified for hyperaccumulators thus classifying the plant as an accumulator but the EF and TF revealed that the plant accumulated toxic metals such as Cr, Cd, Pb and As both at the root and at the shoot in high degree, which indicates that the plant that forms a large biomass on the water surface and is not fed upon by animals can serve as a plant for both phytoextraction and rhizofiltration in phytoremediation technology.

  14. Benthic and tissue toxin data from stations in U.S. coastal waters from 19840101 to 19891231 (NODC Accession 9300199)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The accession contains Benthic and Tissue toxin data from stations in U.S. coastal waters (Coastal Waters of Western U.S. and North American Coastline-North)...

  15. Analysis of Ion-Exchange Resin Capability of the RSG-GAS Demineralized Water System (GCA01)

    International Nuclear Information System (INIS)

    Diyah Erlina Lestari; Setyo Budi Utomo; Harsono

    2012-01-01

    The Demineralized water system (GCA01) is a system which is function to process raw water to be demineralized water using ion exchange resin unit consisting of a column of cation exchange resins, anion exchange resin column and the column resin mix bed. After certain time the ion exchange resins to be saturated so that is needed regeneration. The RSG-GAS demineralized water system (GCA01) not operated continuously and indication of when does an ion exchange resin regeneration on The RSG-GAS demineralized water system (GCA01) is the water conductivity from anion exchange resin column output indicates ≥ 5μS/cm. Analysis of capability of the ion exchange resin demineralized water system (GCA01) line I has been performed. The analysis was done by comparing the time required in the system operating cycle of regeneration to the next regeneration during the period 2011 and 2012. From the results of the analysis showed the cycle regeneration time is varies. This shows that ion exchange resin capability of the RSG-GAS demineralized water system (GCA01) is varies depending on the raw water quality and success of the regeneration ion exchange resin. (author)

  16. Summer water use by California coastal prairie grasses: fog, drought, and community composition.

    Science.gov (United States)

    Corbin, Jeffrey D; Thomsen, Meredith A; Dawson, Todd E; D'Antonio, Carla M

    2005-10-01

    Plants in the Mediterranean climate region of California typically experience summer drought conditions, but correlations between zones of frequent coastal fog inundation and certain species' distributions suggest that water inputs from fog may influence species composition in coastal habitats. We sampled the stable H and O isotope ratios of water in non-photosynthetic plant tissue from a variety of perennial grass species and soil in four sites in northern California in order to determine the proportion of water deriving from winter rains and fog during the summer. The relationship between H and O stable isotopes from our sample sites fell to the right of the local meteoric water line (LMWL) during the summer drought, providing evidence that evaporation of water from the soil had taken place prior to the uptake of water by vegetation. We developed a novel method to infer the isotope values of water before it was subjected to evaporation in which we used experimental data to calculate the slope of the deltaH versus deltaO line versus the LMWL. After accounting for evaporation, we then used a two-source mixing model to evaluate plant usage of fog water. The model indicated that 28-66% of the water taken up by plants via roots during the summer drought came from fog rather than residual soil water from winter rain. Fog use decreased as distance from the coast increased, and there were significant differences among species in the use of fog. Rather than consistent differences in fog use by species whose distributions are limited to the coast versus those with broader distributions, species responded individualistically to summer fog. We conclude that fogwater inputs can mitigate the summer drought in coastal California for many species, likely giving an advantage to species that can use it over species that cannot.

  17. Evaluation of MERIS products from Baltic Sea coastal waters rich in CDOM

    Science.gov (United States)

    Beltrán-Abaunza, J. M.; Kratzer, S.; Brockmann, C.

    2014-05-01

    In this study, retrievals of the medium resolution imaging spectrometer (MERIS) reflectances and water quality products using four different coastal processing algorithms freely available are assessed by comparison against sea-truthing data. The study is based on a pair-wise comparison using processor-dependent quality flags for the retrieval of valid common macro-pixels. This assessment is required in order to ensure the reliability of monitoring systems based on MERIS data, such as the Swedish coastal and lake monitoring system (http://vattenkvalitet.se). The results show that the pre-processing with the Improved Contrast between Ocean and Land (ICOL) processor, correcting for adjacency effects, improves the retrieval of spectral reflectance for all processors. Therefore, it is recommended that the ICOL processor should be applied when Baltic coastal waters are investigated. Chlorophyll was retrieved best using the FUB (Free University of Berlin) processing algorithm, although overestimations in the range 18-26.5%, dependent on the compared pairs, were obtained. At low chlorophyll concentrations (definition at relatively low chlorophyll concentrations in the presence of high CDOM attenuation.

  18. Physico-chemical analysis of ground water samples of coastal areas of south Chennai in the post-Tsunami scenario.

    Science.gov (United States)

    Rajendran, A; Mansiya, C

    2015-11-01

    The study of changes in ground water quality on the east coast of chennai due to the December 26, 2004 tsunami and other subsequent disturbances is a matter of great concern. The post-Tsunami has caused considerable plant, animal, material and ecological changes in the entire stretch of chennai coastal area. Being very close to sea and frequently subjected to coastal erosion, water quality has been a concern in this coastal strip, and especially after the recent tsunami this strip seems to be more vulnerable. In the present investigation, ten ground water samples were collected from various parts of south chennai coastal area. Physico-chemical parameters such as pH, temperature, Biochemical oxygen demand (BOD), Dissolved oxygen (DO), total solids; turbidity and fecal coliform were analyzed. The overall Water quality index (WQI) values for all the samples were found to be in the range of 68.81-74.38 which reveals a fact that the quality of all the samples is only medium to good and could be used for drinking and other domestic uses only after proper treatment. The long term adverse impacts of tsunami on ground water quality of coastal areas and the relationships that exist and among various parameters are carefully analyzed. Local residents and corporation authorities have been made aware of the quality of their drinking water and the methods to conserve the water bodies. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Water quality assessment by pollution-index method in the coastal waters of Hebei Province in western Bohai Sea, China.

    Science.gov (United States)

    Liu, Shuguang; Lou, Sha; Kuang, Cuiping; Huang, Wenrui; Chen, Wujun; Zhang, Jianle; Zhong, Guihui

    2011-10-01

    Sources of pollution discharges and water quality samples at 27 stations in 2006 in the coastal waters of Hebei Province, western Bohai Sea, have been analyzed in this study. Pollutant loads from industrial sewages have shown stronger impact on the water environment than those from the general sewages. Analysis indicates that pollution of COD is mainly resulted from land-based point pollutant sources. For phosphate concentration, non-point source pollution from coastal ocean (fishing and harbor areas) plays an important role. To assess the water quality conditions, Organic Pollution Index and Eutrophication Index have been used to quantify the level of water pollution and eutrophication conditions. Results show that pollution was much heavier in the dry season than flood season in 2006. Based on COD and phosphate concentrations, results show that waters near Shahe River, Douhe River, Yanghe River, and Luanhe River were heavily polluted. Water quality in the Qinhuangdao area was better than those in the Tangshan and Cangzhou areas. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Remote sensing for water quality and biological measurements in coastal waters

    International Nuclear Information System (INIS)

    Johnson, R.W.; Harriss, R.C.

    1980-01-01

    Recent remote sensing experiments in the United States' coastal waters indicate that certain biological and water quality parameters have distinctive spectral characteristics. Data outputs from remote sensors, to date, include: (1) high resolution measurements to determine concentrations and distributions of total suspended particulates, temperature, salinity, chlorophyll a, and phytoplankton color group associations from airborne and/or satellite platforms, and (2) low resolution measurements of total suspended solids, temperature, ocean color, and possibly chlorophyll from satellite platforms. A summary of platforms, sensors and parameters measured is given. Remote sensing, especially when combined with conventional oceanographic research methods, can be useful in such high priority research areas as estuarine and continental shelf sediment transport dynamics, transport and fate of marine pollutants, marine phytoplankton dynamics, and ocean fronts

  1. Study on extreme high temperature of cooling water in Chinese coastal nuclear power plant

    International Nuclear Information System (INIS)

    Yu Fan; Jiang Ziying

    2012-01-01

    In order to protect aquatic life from the harmful effects of thermal discharge, the appropriate water temperature limits or the scope of the mixing zone is a key issue in the regulatory control of the environmental impact of thermal discharge. Based on the sea surface temperature in the Chinese coastal waters, the extreme value of the seawater temperature change was analyzed by using the Gumbel model. The limit of the design temperature rise of cooling water in the outfall is 9 ℃, and the limit of the temperature rise of cooling water in the edge of the mixing zone is 4 ℃. The extreme high temperature of the cooling water in Chinese coastal nuclear power plant is 37 ℃ in the Bohai Sea, Yellow Sea, and is 40 ℃ in East China Sea, South China Sea. (authors)

  2. Hydrogen-water isotopic exchange process

    International Nuclear Information System (INIS)

    Cheung, H.

    1983-01-01

    Deuterium is concentrated in a hydrogen-water isotopic exchange process enhanced by the use of catalyst materials in cold and hot tower contacting zones. Water is employed in a closed liquid recirculation loop that includes the cold tower, in which deuterium is concentrated in the water, and the upper portion of the hot tower in which said deuterium is concentrated in the hydrogen stream. Feed water is fed to the lower portion of said hot tower for contact with the circulating hydrogen stream. The feed water does not contact the water in the closed loop. Catalyst employed in the cold tower and the upper portion of the hot tower, preferably higher quality material, is isolated from impurities in the feed water that contacts only the catalyst, preferably of lower quality, in the lower portion of the hot zone. The closed loop water passes from the cold zone to the dehumidification zone, and a portion of said water leaving the upper portion of the hot tower can be passed to the humidification zone and thereafter recycled to said closed loop. Deuterium concentration is enhanced in said catalytic hydrogen-water system while undue retarding of catalyst activity is avoided

  3. Radioactivity and Natural Radio nuclides Distribution in River Water, Coastal Water, Sediment and Eichornia Crassipes (Mart) Sloms and Their Accumulation Factor at Surabaya Area

    International Nuclear Information System (INIS)

    Agus Taftazani; Sumining; Muzakky

    2002-01-01

    Distribution of radioactivity and natural radionuclide in water, sediment and eichornia crassipes (mart) sloms from Surabaya river and coastal area have been evaluated. Five sampling locations were selected to represent fresh water and coastal water environment. The samples consist of water (fresh and coastal), bottom surface sediment and eichornia crassipes (mart) sloms The result showed that the gross-β activity from water environment were lower than the threshold value of Environmental Minister Act. Kep.02/MENKLH/I/1988 (1000 mBq/L) and indicated that β-radioecological quality of water were still good. But the activity of the gross-α of water environment were higher than the threshold value of Environmental Minister Act. Kep.02/MENKLH/I/1988 (100 mBq/L). The eichornia crassipes (mart) sloms (gross) activity were higher than water and sediment activities and indicated that transfer of radionuclides from water to sediment and organism can be detected in water environment. Two natural radionuclides can be identified by γ-Spectrometric technique, they were K-40 and TI-208. Generally the distribution factor F D were smaller than bioaccumulation factor F B . (author)

  4. Urea as nitrogen source for phytoplankton production in coastal waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.

    Annual variation of urea in coastal waters off Goa, India is 0 to 2.92 mu g-at N.1/1 and 0 to 4.69 mu g-at N.1/1 in adjacent estuarine waters of Mandovi. Peaks of phytoplankton production accompanied with the decrease in urea in June and October...

  5. Drinking water vulnerability to climate change and alternatives for adaptation in coastal South and South East Asia

    OpenAIRE

    Hoque, M. A.; Scheelbeek, P. F. D.; Vineis, P.; Khan, A. E.; Ahmed, K. M.; Butler, A. P.

    2016-01-01

    Drinking water in much of Asia, particularly in coastal and rural settings, is provided by a variety of sources, which are widely distributed and frequently managed at an individual or local community level. Coastal and near-inland drinking water sources in South and South East (SSE) Asia are vulnerable to contamination by seawater, most dramatically from tropical cyclone induced storm surges. This paper assesses spatial vulnerabilities to salinisation of drinking water sources due to meteoro...

  6. Contingency plan improvement for managing oil spills in the coastal waters of Thailand.

    Science.gov (United States)

    Singkran, Nuanchan

    2014-12-15

    The estimated risks of being impacted by oil spills in the coastal waters were used to improve the oil spill contingency plan of Thailand. Functional roles of local agencies are integrated into the plan. Intensive measures are suggested for the coastal provinces located in high-very high risk zones, whereas light and moderate measures are suggested for the coastal provinces located in low and moderate risk zones, respectively. The estimated percentage risks due to simulated oil slicks hitting the coast and/or important resources (PRoilspill) were used to guide the year-round water activities that should be carefully handled at a certain radius with a low-moderate PRoilspill, whereas they should be avoided at a certain radius with a high-very high PRoilspill. Important measures before, during, and post periods of an oil spill incident are suggested to prevent and monitor oil spill incidents and mitigate their impacts on the environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Air-sea flux of CO2 in arctic coastal waters influenced by glacial melt water and sea ice

    DEFF Research Database (Denmark)

    Sejr, Mikael Kristian; Krause-Jensen, Dorte; Rysgaard, Søren

    2011-01-01

    Annual air–sea exchange ofCO2 inYoung Sound,NEGreenlandwas estimated using pCO2 surface-water measurements during summer (2006–2009) and during an ice-covered winter 2008. All surface pCO2 values were below atmospheric levels indicating an uptake of atmospheric CO2. During sea ice formation...... and thereby efficiently blocked air–sea CO2 exchange. During sea ice melt, dissolution of CaCO3 combined with primary production and strong stratification of the water column acted to lower surface-water pCO2 levels in the fjord. Also, a large input of glacial melt water containing geochemically reactive...... year-to-year variation in annual gas exchange....

  8. A study on the formation of fouling in a heat exchanging system for Han-river water as cooling water

    International Nuclear Information System (INIS)

    Sung, Sun Kyung; Suh, Sang Ho; Rho, Hyung Woon; Cho, Young Il

    2003-01-01

    Scale is formed when hard water is heated or cooled in heat transfer equipments such as heat exchangers, condensers, evaporators, cooling towers, boilers, and pipe walls. When scale deposits in a heat exchanger surface, it is traditionally called fouling. The objective of the present study is to investigate the formation of fouling in a heat exchanging system. A lab-scale heat exchanging system is built-up to observe and measure the formation of fouling experimentally. Water analyses are conducted to obtain the properties of Han river water. In the present study a microscopic observation is conducted to visualize the process of scale formation. Hardness of Han-river water is higher than that of tap water in Seoul

  9. Two-Dimensional Hydrodynamic Simulation of Surface-Water Flow and Transport to Florida Bay through the Southern Inland and Coastal Systems (SICS)

    Science.gov (United States)

    Swain, Eric D.; Wolfert, Melinda A.; Bales, Jerad D.; Goodwin, Carl R.

    2004-01-01

    Successful restoration of the southern Florida ecosystem requires extensive knowledge of the physical characteristics and hydrologic processes controlling water flow and transport of constituents through extremely low-gradient freshwater marshes, shallow mangrove-fringed coastal creeks and tidal embayments, and near-shore marine waters. A sound, physically based numerical model can provide simulations of the differing hydrologic conditions that might result from various ecosystem restoration scenarios. Because hydrology and ecology are closely linked in southern Florida, hydrologic model results also can be used by ecologists to evaluate the degree of ecosystem restoration that could be achieved for various hydrologic conditions. A robust proven model, SWIFT2D, (Surface-Water Integrated Flow and Transport in Two Dimensions), was modified to simulate Southern Inland and Coastal Systems (SICS) hydrodynamics and transport conditions. Modifications include improvements to evapotranspiration and rainfall calculation and to the algorithms that describe flow through coastal creeks. Techniques used in this model should be applicable to other similar low-gradient marsh settings in southern Florida and elsewhere. Numerous investigations were conducted within the SICS area of southeastern Everglades National Park and northeastern Florida Bay to provide data and parameter values for model development and testing. The U.S. Geological Survey and the National Park Service supported investigations for quantification of evapotranspiration, vegetative resistance to flow, wind-induced flow, land elevations, vegetation classifications, salinity conditions, exchange of ground and surface waters, and flow and transport in coastal creeks and embayments. The good agreement that was achieved between measured and simulated water levels, flows, and salinities through minimal adjustment of empirical coefficients indicates that hydrologic processes within the SICS area are represented properly

  10. Behaviour of Radium in coastal marine water of India - Behaviour of Radium in coastal marine environment of India

    Energy Technology Data Exchange (ETDEWEB)

    Jha, S.K.; Sartandel, S.; Tripathi, R.M. [Environmental Radioactivity measurement Section, Health Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2014-07-01

    In the recent years, there has also been an increased recognition of the radiological significance of non-nuclear process of natural radioactivity in particular {sup 226}Ra, {sup 228}Ra, {sup 222}Rn, {sup 210}Po and {sup 210}Pb produced, for example by Phosphate processing plants, offshore oil and gas installations and ceramic industries etc. Keeping this in mind, special distribution of radium was carried out to generate region specific values of Radium. The Indian Ocean differs from the Atlantic and Pacific Oceans in its limited northward extent, to only 25 deg. N. Indian subcontinent divides the Indian ocean in the north into two tropical basin namely Arabian sea and Bay of Bengal both being located within same latitude and being under the direct influence of monsoon. For measurements of {sup 226}Ra and {sup 228}Ra concentration in the coastal marine waters of India, MnO{sub 2} impregnated cartridge based in-situ pre-concentration technique was applied by passing 1000 liters of seawater at thirty locations covering Arabian Sea in the west of India and Bay of Bengal in the east. {sup 226}Ra was estimated using gamma ray peak of its daughter radionuclides {sup 214}Bi and {sup 214}Pb while {sup 228}Ra was estimated from its daughter {sup 228}Ac. {sup 214}Pb emissions occur at 295 and 352 keV; {sup 214}Bi has an emission at 609 keV. For {sup 228}Ac gamma emissions at 911 keV, 968 keV and 338 keV were used. In the coastal waters, {sup 226}Ra and {sup 228}Ra concentration was observed to be in the range of 0.69 to 4.10 mBql{sup -1} and 0.70 to 8 Bq m{sup -3} respectively with an average of 1.52 and 4.53 Bq m{sup -3}. The concentration of {sup 228}Ra was observed to be more than {sup 226}Ra in all the locations. The activity ratio of {sup 228}Ra/{sup 226}Ra in coastal marine water from the Bay of Bengal showed a ratio varying from 0.8 to 2.4 with a mean of 2.1.In the present study, activity ratio varies from 1.9 to 2.4 at Karaikkal. But the regions of Rameswaram and

  11. Approach to developing numeric water quality criteria for coastal waters: a transition from SeaWiFS to MODIS and MERIS satellites.

    Science.gov (United States)

    Human activities on land increase nutrient loads to coastal waters, which can increase phytoplankton production and biomass and potentially cause harmful ecological effects. States can adopt numeric water quality criteria into their water quality standards to protect the designa...

  12. Interactions of aquaculture, marine coastal ecosystems, and near-shore waters: A bibliography. Bibliographies and literature of agriculture (Final)

    International Nuclear Information System (INIS)

    Hanfman, D.T.; Coleman, D.E.; Tibbitt, S.J.

    1991-01-01

    The bibliography contains selected literature citations on the interactions of aquaculture and marine coastal ecosystems. The focus is on aquaculture effluents and their impact on marine coastal ecosystems and waterways as well as the impact of pollutants on aquaculture development. Factors affecting these issues include domestic and industrial wastes, thermal discharges, acid rain, heavy metals, oil spills, and microbial contamination of marine waters and aquatic species. Coastal zone management, environmenal impact of aquaculture, and water quality issues are also included in the bibliography

  13. Influence of microorganism content in suspended particles on the particle-water partitioning of mercury in semi-enclosed coastal waters.

    Science.gov (United States)

    Jang, Jiyi; Kim, Hyunji; Han, Seunghee

    2014-02-01

    It is known that particle scavenging of mercury (Hg) can be affected by the abundance of particulate organic matter in coastal waters. However, the role of living organic particles in Hg scavenging is not yet completely understood. In this study, we hypothesized that an abundance of living organic particles (i.e., phytoplankton and bacteria) would influence the particle-water partitioning of Hg in coastal waters. Surface seawater samples were collected from eight stations in Gwangyang Bay, Korea, in three seasons (November 2009, April 2010, and October 2010) for the determination of concentrations of suspended particulate matter (including chlorophyll-a and bacteria), and Hg in unfiltered and filtered waters. We found that more Hg partitioned toward particulate matter when phytoplankton biomass, indicated from the chlorophyll-a concentration in a particle, was higher. In the low algal season, when [chlorophyll-a]algae to transfer Hg to marine food chains. © 2013.

  14. Factors controlling physico-chemical characteristics in the coastal waters off Mangalore-A multivariate approach

    International Nuclear Information System (INIS)

    Shirodkar, P.V.; Mesquita, A.; Pradhan, U.K.; Verlekar, X.N.; Babu, M.T.; Vethamony, P.

    2009-01-01

    Water quality parameters (temperature, pH, salinity, DO, BOD, suspended solids, nutrients, PHc, phenols, trace metals-Pb, Cd and Hg, chlorophyll-a (chl-a) and phaeopigments) and the sediment quality parameters (total phosphorous, total nitrogen, organic carbon and trace metals) were analysed from samples collected at 15 stations along 3 transects off Karnataka coast (Mangalore harbour in the south to Suratkal in the north), west coast of India during 2007. The analyses showed high ammonia off Suratkal, high nitrite (NO 2 -N) and nitrate (NO 3 -N) in the nearshore waters off Kulai and high nitrite (NO 2 -N) and ammonia (NH 3 -N) in the harbour area. Similarly, high petroleum hydrocarbon (PHc) values were observed near the harbour, while phenols remained high in the nearshore waters of Kulai and Suratkal. Significantly, high concentrations of cadmium and mercury with respect to the earlier studies were observed off Kulai and harbour regions, respectively. R-mode varimax factor analyses were applied separately to surface and bottom water data sets due to existing stratification in the water column caused by riverine inflow and to sediment data. This helped to understand the interrelationships between the variables and to identify probable source components for explaining the environmental status of the area. Six factors (each for surface and bottom waters) were found responsible for variance (86.9% in surface and 82.4% in bottom) in the coastal waters between Mangalore and Suratkal. In sediments, 4 factors explained 86.8% of the observed total variance. The variances indicated addition of nutrients and suspended solids to the coastal waters due to weathering and riverine transport and are categorized as natural sources. The observed contamination of coastal waters indicated anthropogenic inputs of Cd and phenol from industrial effluent sources at Kulai and Suratkal, ammonia from wastewater discharges off Kulai and harbour, PHc and Hg from boat traffic and harbour

  15. Spatio-temporal assessment and trend analysis of surface water salinity in the coastal region of Bangladesh.

    Science.gov (United States)

    Shammi, Mashura; Rahman, Md Mostafizur; Islam, Md Atikul; Bodrud-Doza, Md; Zahid, Anwar; Akter, Yeasmin; Quaiyum, Samia; Kurasaki, Masaaki

    2017-06-01

    The study was designed to collect water samples over two seasons-wet-monsoon season (n = 96) (March-April) and dry-monsoon season (n = 44) (September-October)-to understand the seasonal variation in anion and cation hydrochemistry of the coastal rivers and estuaries contributing in the spatial trend in salinity. Hydrochemical examination of wet-monsoon season primarily revealed Ca-Mg-HCO 3 type (66%) and followed by Na-Cl type (17.70%) water. In the dry-monsoon season, the scenario reversed with primary water being Na-Cl type (52.27%) followed by Ca-Mg-HCO 3 type (31.81%). Analysis of Cl/Br molar ratio vs. Cl (mg/L) depicted sampling area affected by seawater intrusion (SWI). Spatial analysis by ordinary kriging method confirmed approximately 77% sample in the dry-monsoon, and 34% of the wet-monsoon season had shown SWI. The most saline-intruded areas in the wet-monsoon seasons were extreme south-west coastal zone of Bangladesh, lower Meghna River floodplain and Meghna estuarine floodplain and south-eastern part of Chittagong coastal plains containing the districts of Chittagong and Cox's Bazar adjacent to Bay of Bengal. In addition, mid-south zone is also affected slightly in the dry-monsoon season. From the analyses of data, this study could further help to comprehend seasonal trends in the hydrochemistry and water quality of the coastal and estuarine rivers. In addition, it can help policy makers to obligate some important implications for the future initiatives taken for the management of land, water, fishery, agriculture and environment of coastal rivers and estuaries of Bangladesh.

  16. Examining Water Quality Variations of Tidal Pond System

    Science.gov (United States)

    Chui, T. F. M.; Cui, W.

    2014-12-01

    Brackish tidal shrimp ponds, traditionally referred to as gei wais, have been constructed along coastal areas in many parts of the world. The regular exchange of pond water with the surrounding coastal environment is important as it brings shrimp larvae and nutrients, etc. into and out of the pond. Such a water exchange can reduce the quality of the receiving waters; though there are opposing views recently because farming practices are becoming more sustainable while other sources of pollutions in the surroundings are increasing. This project monitors the water quality of a tidal shrimp pond and its receiving water at high temporal resolution. The pond is located within the wetland complex of Mai Po Nature Reserve in Hong Kong, China. Water quality parameters (i.e., dissolved oxygen, temperature, salinity, pH, water depth and chlorophyll) were recorded at 15-minute interval from December 2013 to March 2014 within the pond and also at its receiving water which is a water channel within a mangrove forest. Data reveals both daily and fortnightly fluctuations. Daily variations in mangrove correspond to both tidal flushing and insolation, whereas those within the pond correspond mainly to insolation. For example, dissolved oxygen in mangrove shows two peaks daily which correlate with tidal elevation, and that within the pond shows only one peak which correlates with sunlight. Dissolved oxygen within the pond also shows a fortnightly pattern that corresponds to the schedule of water exchange. Such high temporal resolution of monitoring reveals the two-way water quality influences between the pond and the mangrove. It sheds insights that can possibly lead to refinement of water exchange practice and water sampling schedule given the temporal variations of the water quality both inside and outside the pond. It thus enables us to take a step closer in adopting more sustainable farming practices despite increasing pollution in the surrounding areas.

  17. Discontinuous gas exchange, water loss, and metabolism in Protaetia cretica (Cetoniinae, Scarabaeidae).

    Science.gov (United States)

    Matthews, Philip G D; White, Craig R

    2012-01-01

    Insects are at high risk of desiccation because of their small size, high surface-area-to-volume ratio, and air-filled tracheal system that ramifies throughout their bodies to transport O(2) and CO(2) to and from respiring cells. Although the tracheal system offers a high-conductance pathway for the movement of respiratory gases, it has the unintended consequence of allowing respiratory transpiration to the atmosphere. When resting, many species exchange respiratory gases discontinuously, and an early hypothesis for the origin of these discontinuous gas exchange cycles (DGCs) is that they serve to reduce respiratory water loss. In this study, we test this "hygric" hypothesis by comparing rates of CO(2) exchange and water loss among flower beetles Protaetia cretica (Cetoniinae, Scarabaeidae) breathing either continuously or discontinuously. We show that, consistent with the expectations of the hygric hypothesis, rates of total water loss are higher during continuous gas exchange than during discontinuous gas exchange and that the ratio of respiratory water loss to CO(2) exchange is lower during discontinuous gas exchange. This conclusion is in agreement with other studies of beetles and cockroaches that also support the hygric hypothesis. However, this result does not exclude other adaptive hypotheses supported by work on ants and moth pupae. This ambiguity may arise because there are multiple independent evolutionary origins of DGCs and no single adaptive function underlying their genesis. Alternatively, the observed reduction in water loss during DGCs may be a side effect of a nonadaptive gas exchange pattern that is elicited during periods of inactivity.

  18. Challenges and potential solutions for European coastal ocean modelling

    Science.gov (United States)

    She, Jun; Stanev, Emil

    2017-04-01

    Coastal operational oceanography is a science and technological platform to integrate and transform the outcomes in marine monitoring, new knowledge generation and innovative technologies into operational information products and services in the coastal ocean. It has been identified as one of the four research priorities by EuroGOOS (She et al. 2016). Coastal modelling plays a central role in such an integration and transformation. A next generation coastal ocean forecasting system should have following features: i) being able to fully exploit benefits from future observations, ii) generate meaningful products in finer scales e.g., sub-mesoscale and in estuary-coast-sea continuum, iii) efficient parallel computing and model grid structure, iv) provide high quality forecasts as forcing to NWP and coastal climate models, v) resolving correctly inter-basin and inter-sub-basin water exchange, vi) resolving synoptic variability and predictability in marine ecosystems, e.g., for algae bloom, vi) being able to address critical and relevant issues in coastal applications, e.g., marine spatial planning, maritime safety, marine pollution protection, disaster prevention, offshore wind energy, climate change adaptation and mitigation, ICZM (integrated coastal zone management), the WFD (Water Framework Directive), and the MSFD (Marine Strategy Framework Directive), especially on habitat, eutrophication, and hydrographic condition descriptors. This presentation will address above challenges, identify limits of current models and propose correspondent research needed. The proposed roadmap will address an integrated monitoring-modelling approach and developing Unified European Coastal Ocean Models. In the coming years, a few new developments in European Sea observations can expected, e.g., more near real time delivering on profile observations made by research vessels, more shallow water Argo floats and bio-Argo floats deployed, much more high resolution sea level data from SWOT

  19. Tracers vs. trajectories in a coastal region

    Science.gov (United States)

    Engqvist, A.; Döös, K.

    2008-12-01

    Two different methods of estimating the water exchange through a Baltic coastal region have been used, consisting of particle trajectories and passive tracers. Water is traced from and to a small discharge region near the coast. The discharge material in this region is treated as zero dimensional particles or tracers with neutral buoyancy. The real discharge material could be a leakage of radio-nuclides through the sea floor from an underground repository of nuclear waste. Water exchange rates between the discharge region and the model domain are estimated using both forward and backward trajectories as well as passive tracers. The Lagrangian trajectories can account for the time evolution of the water exchange while the tracers give one average age per model grid box. Water exchange times such as residence time, age and transient times have been calculated with trajectories but only the average age (AvA) for tracers. The trajectory calculations provide a more detailed time evolution than the tracers. On the other hand the tracers are integrated "on-line" simultaneously in the sea circulation model with the same time step while the Lagrangian trajectories are integrated "off-line" from the stored model velocities with its inherent temporal resolution, presently one hour. The sub-grid turbulence is parameterised as a Laplacian diffusion for the passive tracers and with an extra stochastic velocity for trajectories. The importance of the parameterised sub-grid turbulence for the trajectories is estimated to give an extra diffusion of the same order as the Laplacian diffusion by comparing the Lagrangian dispersions with and without parameterisation. The results of the different methods are similar but depend on the chosen diffusivity coefficient with a slightly higher correlation between trajectories and tracers when integrated with a lower diffusivity coefficient.

  20. Simultaneous optimization of water and heat exchange networks

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhiyou; Hou, Yanlong; Li, Xiaoduan; Wang, Jingtao [Tianjin University, Tianjin (China)

    2014-04-15

    This paper focuses on the simultaneous optimization of the heat-integrated water allocation networks. A mathematic model is established to illustrate the modified state-space representation of this problem. An easy logical method is employed to help identify the streams of hot or cold ones. In this model, the water exchange networks (WEN), heat exchange networks (HEN), and the interactions between the WEN and HEN combine together as one unity. Thus, the whole network can be solved at one time, which enhances the possibility to get a global optimal result. Examples from the literature and a PVC plant are analyzed to illustrate the accuracy and applicability of this method.

  1. Resting Stage of Plankton Diversity from Singapore Coastal Water: Implications for Harmful Algae Blooms and Coastal Management.

    Science.gov (United States)

    Trottet, Aurore; Wilson, Bryan; Sew Wei Xin, Genevieve; George, Christaline; Casten, Lemuel; Schmoker, Claire; Rawi, Nurul Syazana Binte Modh; Chew Siew, Moon; Larsen, Ole; Eikaas, Hans S; Tun, Karenne; Drillet, Guillaume

    2018-02-01

    Resting strategies of planktonic organisms are important for the ecological processes of coastal waters and their impacts should be taken into consideration in management of water bodies used by multiple industries. We combined different approaches to evaluate the importance of resting stages in Singapore coastal waters. We used molecular approaches to improve the knowledge on Singapore biodiversity, we sampled and extracted cysts from sediments to evaluate the density of resting stages in Johor Strait, and we compared systematically information on Singapore planktonic biodiversity to existing published information on resting stages from these reported organisms. This is the first study evaluating the importance of resting stages in Singapore waters. Above 120 species reported in Singapore are known to produce resting stages though no previous work has ever been done to evaluate the importance of these strategies in these waters. The results from the resting stage survey confirmed 0.66 to 5.34 cyst g -1 dry weight sediment were present in the Johor Strait suggesting that cysts may be flushed by tidal currents into and out of the strait regularly. This also suggest that the blooms occurring in Singapore are likely due to secondary growth of Harmful Algae Bloom species in the water rather than from direct germination of cysts from sediment. Finally, we discuss the importance of these resting eggs for three main national industries in Singapore (shipping, marine aquaculture and provision of drinking water through seawater desalination). We argue that this study will serve as a baseline for some of the future management of Singapore waters.

  2. Defining restoration targets for water depth and salinity in wind-dominated Spartina patens (Ait.) Muhl. coastal marshes

    Science.gov (United States)

    Nyman, J.A.; LaPeyre, Megan K.; Caldwell, Andral W.; Piazza, Sarai C.; Thom, C.; Winslow, C.

    2009-01-01

    Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable.

  3. Experimental evidence of nitrogen control on pCO2 in phosphorus-enriched humic and clear coastal lagoon waters

    Directory of Open Access Journals (Sweden)

    Roberta Bittencourt Peixoto

    2013-02-01

    Full Text Available Natural and human-induced controls on carbon dioxide (CO2 in tropical waters may be very dynamic (over time and among or within ecosystems considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication by nitrogen (N and phosphorus (P inputs into inland waters may be a relevant component of the C cycle, showing controls on partial pressure of CO2 (pCO2 that are still poorly understood. Here we assessed the strength of N control on pCO2 in P-enriched humic and clear coastal lagoons waters, using four experimental treatments in microcosms: control (no additional nutrients and three levels of N additions coupled to P enrichments. In humic coastal lagoon waters, a persistent CO2 supersaturation was reported in controls and all nutrient-enriched treatments, ranging from 24-fold to fourfold the atmospheric equilibrium value. However, both humic and clear coastal lagoon waters only showed significant decreases in pCO2 in relation to the controlled microcosms in the two treatments with higher N addition levels. Additionally, clear coastal lagoon water microcosms showed a shift from CO2 sources to CO2 sinks, in relation to the atmosphere. Only in the two more N-enriched treatments did pCO2 substantially decrease, from 650 µatm in controls and less N-enriched treatments to 10 µatm in more N-enriched microcosms. Humic substrates and N inputs can modulate pCO2 even in P-enriched coastal lagoon waters, thereby being important drivers on CO2 outgassing from inland waters.

  4. Environmental setting and factors that affect water quality in the Georgia-Florida Coastal Plain study unit

    Science.gov (United States)

    Berndt, M.P.; Oaksford, E.T.; Darst, M.R.; Marella, R.L.

    1996-01-01

    The Georgia-Florida Coastal Plain study unit covers an area of nearly 62,000 square miles in the southeastern United States, mostly in the Coastal Plain physiographic province. Land resource provinces have been designated based on generalized soil classifications. Land resource provinces in the study area include: the Coastal Flatwoods, the Southern Coastal Plain, the Central Florida Ridge, the Sand Hills, and the Southern Piedmont. The study area includes all or parts of seven hydrologic subregions: the Ogeechee-Savannah, the Altamaha- St.Marys, the Suwannee, the Ochlockonee, the St. Johns, the Peace-Tampa Bay, and the Southern Florida. The primary source of water for public supply in the study area is ground water from the Upper Floridan aquifer. In 1990, more than 90 percent of the 2,888 million gallons per day of ground water used came from this aquifer. The population of the study area was 9.3 million in 1990. The cities of Jacksonville, Orlando, St. Petersburg, Tallahassee, and Tampa, Florida, and parts of Atlanta and Savannah, Georgia, are located in the study area. Forest and agricultural areas are the most common land uses in the study area, accounting for 48 percent and 25 percent of the study area, respectively. Climatic conditions range from temperate in Atlanta, Georgia, where mean annual temperature is about 61.3 degrees Fahrenheit, to subtropical in Tampa, Florida, where mean annual temperature is about 72.4 degrees Fahrenheit. Long-term average precipitation (1961-90) ranges from 43.9 inches per year in Tampa, Florida, and 44.6 in Macon, Georgia, to 65.7 inches per year in Tallahassee, Florida. Floods in the study area result from frontal systems, hurricanes, tropical storms, or severe thunderstorms. Droughts are not common in the study area,especially in the Florida part of the study area due to extensive maritime exposure. The primary physical and cultural characteristics in the study area include physiography, soils and land resource provinces

  5. Satellite Assessment of Bio-Optical Properties of Northern Gulf of Mexico Coastal Waters Following Hurricanes Katrina and Rita

    OpenAIRE

    Lohrenz, Steven E.; Cai, Wei-Jun; Chen, Xiaogang; Tuel, Merritt

    2008-01-01

    The impacts of major tropical storms events on coastal waters include sediment resuspension, intense water column mixing, and increased delivery of terrestrial materials into coastal waters. We examined satellite imagery acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) ocean color sensor aboard the Aqua spacecraft following two major hurricane events: Hurricane Katrina, which made landfall on 29 August 2005, and Hurricane Rita, which made landfall on 24 September. MODIS A...

  6. Process for exchanging tritium between gaseous hydrogen and water

    International Nuclear Information System (INIS)

    Hindin, S.G.; Roberts, G.W.

    1981-01-01

    An improved method of exchanging and concentrating the radioactive isotope of hydrogen from water or hydrogen gas is described. This heavy water enrichment system involves a low pressure, dual temperature process. (U.K.)

  7. Oxygen isotope exchange rate between dissolved sulfate and water at hydrothermal temperatures

    International Nuclear Information System (INIS)

    Chiba, H.; Sakai, H.

    1985-01-01

    Oxygen isotope exchange rate between dissolved sulfate and water was experimentally determined at 100, 200 and 300 deg C. The isotope exchange rate is strongly dependent on temperature and pH of the solution. Combining the temperature and pH dependence of the reaction rate, the exchange reaction was estimated to be first-order with respect to sulfate. The logarithm of apparent rate constant of exchange reaction at a given temperature is a function of the pH calculated at the experimental temperatures. From the pH dependence of the apparent rate constant, it was deduced that the isotope exchange reaction between dissolved sulfate and water proceeds through collision between H 2 SO 4 0 and H 2 O at low pH, and between HSO 4 - and H 2 O at intermediate pH. The isotope exchange rate obtained indicates that oxygen isotope geothermometry utilizing the studied isotope exchange is suitable for temperature estimation of geothermal reservoirs. The extrapolated half-life of this reaction to oceanic temperature is about 10 9 years, implying that exchange between oceanic sulfate and water cannot control the oxygen isotope ratio of oceanic sulfates. (author)

  8. Assessment of a Bidirectional Reflectance Distribution Correction of Above-Water and Satellite Water-Leaving Radiance in Coastal Waters

    Science.gov (United States)

    Hlaing, Soe; Gilerson, Alexander; Harmal, Tristan; Tonizzo, Alberto; Weidemann, Alan; Arnone, Robert; Ahmed, Samir

    2012-01-01

    Water-leaving radiances, retrieved from in situ or satellite measurements, need to be corrected for the bidirectional properties of the measured light in order to standardize the data and make them comparable with each other. The current operational algorithm for the correction of bidirectional effects from the satellite ocean color data is optimized for typical oceanic waters. However, versions of bidirectional reflectance correction algorithms specifically tuned for typical coastal waters and other case 2 conditions are particularly needed to improve the overall quality of those data. In order to analyze the bidirectional reflectance distribution function (BRDF) of case 2 waters, a dataset of typical remote sensing reflectances was generated through radiative transfer simulations for a large range of viewing and illumination geometries. Based on this simulated dataset, a case 2 water focused remote sensing reflectance model is proposed to correct above-water and satellite water-leaving radiance data for bidirectional effects. The proposed model is first validated with a one year time series of in situ above-water measurements acquired by collocated multispectral and hyperspectral radiometers, which have different viewing geometries installed at the Long Island Sound Coastal Observatory (LISCO). Match-ups and intercomparisons performed on these concurrent measurements show that the proposed algorithm outperforms the algorithm currently in use at all wavelengths, with average improvement of 2.4% over the spectral range. LISCO's time series data have also been used to evaluate improvements in match-up comparisons of Moderate Resolution Imaging Spectroradiometer satellite data when the proposed BRDF correction is used in lieu of the current algorithm. It is shown that the discrepancies between coincident in-situ sea-based and satellite data decreased by 3.15% with the use of the proposed algorithm.

  9. Development of a Coupled Ocean-Hydrologic Model to Simulate Pollutant Transport in Singapore Coastal Waters

    Science.gov (United States)

    Chua, V. P.

    2015-12-01

    Intensive agricultural, economic and industrial activities in Singapore and Malaysia have made our coastal areas under high risk of water pollution. A coupled ocean-hydrologic model is employed to perform three-dimensional simulations of flow and pollutant transport in Singapore coastal waters. The hydrologic SWAT model is coupled with the coastal ocean SUNTANS model by outputting streamflow and pollutant concentrations from the SWAT model and using them as inputs for the SUNTANS model at common boundary points. The coupled model is calibrated with observed sea surface elevations and velocities, and high correlation coefficients that exceed 0.97 and 0.91 are found for sea surface elevations and velocities, respectively. The pollutants are modeled as Gaussian passive tracers, and are released at five upstream locations in Singapore coastal waters. During the Northeast monsoon, pollutants released in Source 1 (Johor River), Source 2 (Tiram River), Source 3 (Layang River) and Source 4 (Layau River) enter the Singapore Strait after 4 days of release and reach Sentosa Island within 9 days. Meanwhile, pollutants released in Source 5 (Kallang River) reach Sentosa Island after 4 days. During the Southwest monsoon, the dispersion time is roughly doubled, with pollutants from Sources 1 - 4 entering the Singapore Strait only after 12 days of release due to weak currents.

  10. 75 FR 44938 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery

    Science.gov (United States)

    2010-07-30

    ... Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery AGENCY: National... moratorium on fishing for Atlantic coastal sharks in the State waters of New Jersey. NMFS canceled the... Fisheries Commission's (Commission) Interstate Fishery Management Plan for Atlantic Coastal Sharks (Coastal...

  11. NASA COAST and OCEANIA Airborne Missions in Support of Ecosystem and Water Quality Research in the Coastal Zone

    Science.gov (United States)

    Guild, Liane S.; Hooker, Stanford B.; Kudela, Raphael; Morrow, John; Russell, Philip; Myers, Jeffrey; Dunagan, Stephen; Palacios, Sherry; Livingston, John; Negrey, Kendra; hide

    2015-01-01

    Worldwide, coastal marine ecosystems are exposed to land-based sources of pollution and sedimentation from anthropogenic activities including agriculture and coastal development. Ocean color products from satellite sensors provide information on chlorophyll (phytoplankton pigment), sediments, and colored dissolved organic material. Further, ship-based in-water measurements and emerging airborne measurements provide in situ data for the vicarious calibration of current and next generation satellite ocean color sensors and to validate the algorithms that use the remotely sensed observations. Recent NASA airborne missions over Monterey Bay, CA, have demonstrated novel above- and in-water measurement capabilities supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The results characterize coastal atmospheric and aquatic properties through an end-to-end assessment of image acquisition, atmospheric correction, algorithm application, plus sea-truth observations from state-of-the-art instrument systems. The primary goal of the airborne missions was to demonstrate the following in support of calibration and validation exercises for satellite coastal ocean color products: 1) the utility of a multi-sensor airborne instrument suite to assess the bio-optical properties of coastal California, including water quality; and 2) the importance of contemporaneous atmospheric measurements to improve atmospheric correction in the coastal zone. Utilizing an imaging spectrometer optimized in the blue to green spectral domain enables higher signal for detection of the relatively dark radiance measurements from marine and freshwater ecosystem features. The novel airborne instrument, Coastal Airborne In-situ Radiometers (C-AIR) provides measurements of apparent optical properties with high dynamic range and fidelity for deriving exact water leaving radiances at the land-ocean boundary, including radiometrically shallow aquatic

  12. Desalination Brine Discharge Impacts on Coastal Biology and Water Chemistry - A Case Study from Carlsbad Southern California

    Science.gov (United States)

    Petersen, K. L.; Heck, N.; Potts, D. C.; Paytan, A.

    2017-12-01

    Fresh water demand is increasing world-wide due to on-going droughts, climate change and increasing human population and associated demand for food and water. Desalination of seawater is a reliable source of potable water; however the effects of byproduct brine discharge from desalination plants on coastal areas have not been thoroughly assessed. Here we report results from in-situmeasurements of the effects of brine discharge on water chemistry and coastal biology from a desalination plant in Carlsbad, Southern California. We compared select parameters in the coastal zone around the discharge site before and after operation began and conducted additional controlled laboratory incubations with key coastal species and brine effluent. Our in-situ data shows differences in salinity and temperature between the discharge area and a control site both before and after the desalination plant started operation. The discharge water is warmer by 3-5 Co than the ambient seawater and a temperature gradient is seen around the discharge channel. This is likely a result of mixing of the desalination brine with power plant cooling water for dilution prior to discharge and the higher temperatures are not directly attributed to the desalination. Our post-discharge results show a decipherable salinity plume at the bottom of the water column ( 6 m depth) reaching up to 600 m offshore from the discharge site. This indicates inefficient mixing of the brine in the coastal discharge zone. No significant differences are found in nutrient levels, organic carbon or chlorophyll a concentrations around the discharge. The benthic biology assemblage post-discharge is significantly different from the pre-discharge organisms' assemblage. However, the role of seasonal changes in temperature may also have impacted the data as the sampling was conducted during different seasons. Controlled incubation experiments of brittle stars (Ophiothrix spiculata) shows no significant difference in growth or

  13. Structure of Mesozooplankton Communities in the Coastal Waters of Morocco

    Science.gov (United States)

    Lidvanov, V. V.; Grabko, O. G.; Kukuev, E. I.; Korolkova, T. G.

    2018-03-01

    Mero- and holoplanktonic organisms from 23 large taxa have been detected in the coastal waters of Morocco. Seven Cladocera species and 164 Copepoda species were identified. Copepod fauna mostly consisted of oceanic epipelagic widely tropical species, but the constant species group (frequency of occurrence over 50%) included neritic and neritic-oceanic widely tropical species. The neritic community that formed a biotopic association with coastal upwelling waters and the distant-neritic community associated with Canary Current waters were the two major communities detected. The former community was characterized by a high abundance and biomass (5700 ind./m3 and 260 mg/m3) and predominance of neritic species. The trophic structure was dominated by thin filter feeders, mixed-food consumers, and small grabbers; the species structure was dominated by Paracalanus indicus, Acartia clausi, and Oncaea curta; the indices of species diversity (3.07 bit/ind.) and evenness (0.63) were relatively low. The latter community was characterized by low abundance and biomass (1150 ind./m3 and 90 mg/m3); variable biotopic, trophic, and species structure; and higher Shannon indices (3.99 bit/ind.) and Pielou (0.75). Seasonal variation of the abundance of organisms was not detected in the communities. Anomalous mesozooplankton states were observed in summer 1998 and winter 1998-1999.

  14. Oxo-exchange of gas-phase uranyl, neptunyl, and plutonyl with water and methanol.

    Science.gov (United States)

    Lucena, Ana F; Odoh, Samuel O; Zhao, Jing; Marçalo, Joaquim; Schreckenbach, Georg; Gibson, John K

    2014-02-17

    A challenge in actinide chemistry is activation of the strong bonds in the actinyl ions, AnO2(+) and AnO2(2+), where An = U, Np, or Pu. Actinyl activation in oxo-exchange with water in solution is well established, but the exchange mechanisms are unknown. Gas-phase actinyl oxo-exchange is a means to probe these processes in detail for simple systems, which are amenable to computational modeling. Gas-phase exchange reactions of UO2(+), NpO2(+), PuO2(+), and UO2(2+) with water and methanol were studied by experiment and density functional theory (DFT); reported for the first time are experimental results for UO2(2+) and for methanol exchange, as well as exchange rate constants. Key findings are faster exchange of UO2(2+) versus UO2(+) and faster exchange with methanol versus water; faster exchange of UO2(+) versus PuO2(+) was quantified. Computed potential energy profiles (PEPs) are in accord with the observed kinetics, validating the utility of DFT to model these exchange processes. The seemingly enigmatic result of faster exchange for uranyl, which has the strongest oxo-bonds, may reflect reduced covalency in uranyl as compared with plutonyl.

  15. Reaction of subsurface coastal aquifers to climate and land use changes in Greece: modelling of groundwater refreshening patterns under natural recharge conditions

    Science.gov (United States)

    Lambrakis, N.; Kallergis, G.

    2001-05-01

    This paper studies the multicomponent ion exchange process and freshening time under natural recharge conditions for three coastal aquifers in Greece. Due to over-pumping and the dry years of 1980-1990 decline in groundwater quality has been observed in most of the Greek coastal aquifers. This decline is caused by a lack of reliable water resource management, water abstraction from great depths, and seawater intrusion resulting in a rise of the fresh/salt water interface (salinisation process) due to a negative water balance. The reverse phenomenon, which should lead to groundwater freshening, is a long process. The freshening process shows chromatographic patterns that are due to chemical reactions such as calcite dissolution and cation exchange, and simultaneously occurring transport and dispersion processes. Using the geochemical simulation codes PHREEQE and PHREEQM (Parkhurst et al., US Geol. Surv. Water Resour. Invest., 80-96 (1980) 210; Appelo and Postma, Geochemistry, Groundwater and Pollution (1994)), these patterns were analysed and the above-mentioned processes were simulated for carefully selected aquifers in Peloponnesus and Crete (Greece). Aquifers of the Quaternary basin of Glafkos in Peloponnesus, the Neogene formations in Gouves, Crete, and the carbonate aquifer of Malia, Crete, were examined as representative examples of Greek coastal aquifer salinisation. The results show that when pumping was discontinued, the time required for freshening under natural conditions of the former two aquifers is long and varies between 8000 and 10,000 years. The Malia aquifer on the other hand, has a freshening time of 15 years. Freshening time was shown to depend mainly on cation exchange capacities and the recharge rate of the aquifers.

  16. Phytoplankton blooms in estuarine and coastal waters: Seasonal patterns and key species

    Science.gov (United States)

    Carstensen, Jacob; Klais, Riina; Cloern, James E.

    2015-01-01

    Phytoplankton blooms are dynamic phenomena of great importance to the functioning of estuarine and coastal ecosystems. We analysed a unique (large) collection of phytoplankton monitoring data covering 86 coastal sites distributed over eight regions in North America and Europe, with the aim of investigating common patterns in the seasonal timing and species composition of the blooms. The spring bloom was the most common seasonal pattern across all regions, typically occurring early (February–March) at lower latitudes and later (April–May) at higher latitudes. Bloom frequency, defined as the probability of unusually high biomass, ranged from 5 to 35% between sites and followed no consistent patterns across gradients of latitude, temperature, salinity, water depth, stratification, tidal amplitude or nutrient concentrations. Blooms were mostly dominated by a single species, typically diatoms (58% of the blooms) and dinoflagellates (19%). Diatom-dominated spring blooms were a common feature in most systems, although dinoflagellate spring blooms were also observed in the Baltic Sea. Blooms dominated by chlorophytes and cyanobacteria were only common in low salinity waters and occurred mostly at higher temperatures. Key bloom species across the eight regions included the diatoms Cerataulina pelagica and Dactyliosolen fragilissimus and dinoflagellates Heterocapsa triquetra and Prorocentrum cordatum. Other frequent bloom-forming taxa were diatom genera Chaetoceros, Coscinodiscus, Skeletonema, and Thalassiosira. Our meta-analysis shows that these 86 estuarine-coastal sites function as diatom-producing systems, the timing of that production varies widely, and that bloom frequency is not associated with environmental factors measured in monitoring programs. We end with a perspective on the limitations of conclusions derived from meta-analyses of phytoplankton time series, and the grand challenges remaining to understand the wide range of bloom patterns and

  17. Anthropogenic Impacts on Biological Carbon Sequestration in the Coastal Waters

    Science.gov (United States)

    Jiao, N.

    2016-02-01

    be considered in management, especially in the coastal waters where eutrophication and hypoxia are severe. Currently, farm over-fertilization is found world widely to be responsible for coastal water eutrophication. Therefore nutrients input must be under control for optimum outputs of the sum of BP and MCP towards sustainable coastal ecosystems.

  18. Carbapenemase VCC-1-Producing Vibrio cholerae in Coastal Waters of Germany

    DEFF Research Database (Denmark)

    Hammerl, Jens A.; Jaeckel, Claudia; Bortolaia, Valeria

    2017-01-01

    During antimicrobial drug resistance testing for Vibrio spp. from coastal waters of Germany, we identified 4 nontoxigenic, carbapenem-resistant V. cholerae isolates. We used whole-genome sequencing to identify the carbapenemase gene bla(VCC-1). In addition, a molecular survey showed that more bla...

  19. Cecal intubation time between cap-assisted water exchange and water exchange colonoscopy: a randomized-controlled trial.

    Science.gov (United States)

    Tseng, Chih-Wei; Koo, Malcolm; Hsieh, Yu-Hsi

    2017-11-01

    The water exchange (WE) method can decrease the discomfort of the patients undergoing colonoscopy. It also provides salvage cleansing and improves adenoma detection, but a longer intubation time is required. Cap-assisted colonoscopy leads to a significant reduction in cecal intubation time compared with traditional colonoscopy with air insufflation. The aim of this study was to investigate whether combined cap-assisted colonoscopy and water exchange (CWE) could decrease the cecal intubation time compared with WE. A total of 120 patients undergoing fully sedated colonoscopy at a regional hospital in southern Taiwan were randomized to colonoscopy with either CWE (n=59) or WE (n=61). The primary endpoint was cecal intubation time. The mean cecal intubation time was significantly shorter in CWE (12.0 min) compared with WE (14.8 min) (P=0.004). The volume of infused water during insertion was lower in CWE (840 ml) compared with WE (1044 ml) (P=0.003). The adenoma detection rate was 50.8 and 47.5% for CWE and WE, respectively (P=0.472). The Boston Bowel Preparation Scale scores were comparable in the two groups. Results from the multiple linear regression analysis indicated that WE with a cap, a higher degree of endoscopist's experience, a higher Boston Bowel Preparation Scale score, and a lower volume of water infused during insertion, without abdominal compression, without change of position, and without chronic laxative use, were significantly associated with a shorter cecal intubation time. In comparison with WE, CWE could shorten the cecal intubation time and required lower volume of water infusion during insertion without compromising the cleansing effect of WE.

  20. Exploring Techniques for Improving Retrievals of Bio-optical Properties of Coastal Waters

    Science.gov (United States)

    2013-09-30

    site, compared with WaveCIS site in Gulf of Mexico . Two Neural Networks (NN) approaches are explored for the retrieval of chlorophyll concentration...AERONET-OC sites (Long Island Sound and Gulf of Mexico respectively) as well as OC retrievals of the MODIS sensor. The underlying cause of the...cases of water conditions ranging from clear oceanic waters to turbid coastal waters, while ξ for both types of particles is fixed at 4.0, and for

  1. Distribution and abundance of diatom species from coastal waters of Karachi, Pakistan

    International Nuclear Information System (INIS)

    Khokhar, F. N.; Burhan, Z.; Iqbal, P.; Abbasi, J.; Siddiqui, P.

    2016-01-01

    This is the first comprehensive study on the distribution and abundance of diatom species from the coastal and nearshore waters of Karachi, Pakistan, bordering northern Arabian Sea. A total of 20 genera are recorded in high abundance (Cerataulina, Chaetoceros, Coscinodiscus, Cylindrotheca, Eucampia, Guinardia, Haslea, Hemiaulus, Lauderia, Lennoxia, Leptocylindrus, Navicula, Nitzschia, Trieres, Planktoniella, Pleurosigma, Pseudo-nitzschia, Rhizosolenia, Thalassionema and Thalassiosira). The most abundant genera were observed Guinardia, Chaetoceros, Leptocylindrus, Nitzschia and Lennoxia at all stations. Manora coastal station (MI-1) had high abundance corresponding with high Chlorophyll a (130 meu gL- l) values. Minimum abundance and low chlorophyll a value (0.05μgL-l) were observed at Mubarak Village coastal station (MV-1). Diatom abundance showed significant correlation with Chlorophyll a. In present study 12 centric and 8 pennate forms were recorded and similarly high diversity of centric taxa was observed compared to pennate forms. A total of 134 species are recorded of which 40 species were observed at four stations, 31species at three stations, 23 at two stations and 40 species only at one station. The total phytoplankton and diatom peak abundance was observed during NE monsoon (winter season) associated with nutrient loading through up-sloping of nutrient rich water upwelled off of Oman during South West monsoon. Overall higher diversity was observed at Manora coastal and nearshore stations (MI-1, MI-2) indicating the influence of organic pollution loading from Layari and Malir rivers. (author)

  2. Poster 29. Modelling of ion exchange processes in ultrapure water

    International Nuclear Information System (INIS)

    Berg, A.; Torstenfelt, B.; Fejes, P.; Foutch, G.L.

    1992-01-01

    The ion exchange process of the Reactor Water Clean-up (RWCU) system has been studied to better use the maximum possible exchange capacity of the ion exchange resin. Laboratory data have been correlated with computer simulations of the ion exchange process. Data were correlated using a mixed-bed ion exchange model for ultralow ionic concentrations developed at Oklahoma State University. Experimental results of the ion exchange column operation in the concentration range of 10 -3 M boric acid is compared with the simulated performance predicted by the computer model. The model is found to agree reasonably well with the data. (author)

  3. Optimum contracted-for water supply for hotels in arid coastal regions.

    Science.gov (United States)

    Lamei, A; von Münch, E; van der Zaag, P; Imam, E

    2009-01-01

    Hotels in arid coastal areas use mainly desalinated water for their domestic water demands, and treated wastewater for irrigating green areas. Private water companies supply these hotels with their domestic water needs. There is normally a contractual agreement stating a minimum requirement that has to be supplied by the water company and that the hotel management has to pay for regardless of its actual consumption ("contracted-for water supply"). This paper describes a model to determine what value a hotel should choose for its contracted-for water supply in order to minimize its total annual water costs. An example from an arid coastal tourism-dominated city is presented: Sharm El Sheikh, Egypt.The managers of hotels with expected high occupancy rates (74% and above) can contract for more than 80%. On the other hand, hotels with expected lower occupancy rates (60% and less) can contract for less than 70% of the peak daily domestic water demand. With a green area ratio of 40 m(2)/room or less, an on-site wastewater treatment plant can satisfy the required irrigation demand for an occupancy rate as low as 42%. Increasing the ratio of green irrigated area to 100 m(2)/room does not affect the contracted-for water supply at occupancy rates above 72%; at lower occupancy rates, however, on-site treated wastewater is insufficient for irrigating the green areas. Increasing the green irrigated area to 120 m(2)/room increases the need for additional water, either from externally sourced treated wastewater or potable water. The cost of the former is much lower than the latter (0.58 versus 1.52 to 2.14 US$/m(3) in the case study area).

  4. Antifouling herbicides in the coastal waters of western Japan.

    Science.gov (United States)

    Okamura, H; Aoyama, I; Ono, Y; Nishida, T

    2003-01-01

    Residue analyses of some antifouling herbicides (Diuron, Irgarol 1051 and the latter's degradation product M1, which is also known as GS26575), were conducted in waters collected along the coast of western Japan. In total, 142 water samples were collected from fishery harbours (99 sites), marinas (27 sites), and small ports (16 sites) around the Seto Inland Sea, the Kii Peninsula, and Lake Biwa, in August 1999. A urea-based herbicide, Diuron, was positively identified for the first time in Japanese aquatic environments. Diuron was detected in 121 samples (86%) up to a highest concentration of 3.05 microg/l, and was found in 86% of samples from fishery harbours, 89% from marinas, and 75% from ports. Four freshwater samples out of 11 collected at Lake Biwa contained Diuron. Neither Irgarol 1051 nor M1 was found in the lake waters, but both were found in many coastal waters. Irgarol 1051 was found in 84 samples (60%) at a highest concentration of 0.262 microg/l. The concentrations detected were of similar magnitude to those in our previous surveys, taken in 1997 and 1998. M1 was found in 40 samples (28%) up to a highest concentration of 0.080 microg/l. The concentrations detected were generally lower than those found in our previous surveys. The detection frequency among fishery harbours, marinas, and ports was 57-70% for Irgarol 1051 and 25-30% for M1. Ninety-five per cent of the coastal waters in which M1 was detected also contained Irgarol 1051, and 93% of the samples in which Irgarol 1051 was detected also contained Diuron. These results clearly suggest that commercial ship-bottom paints containing both Diuron and Irgarol 1051 are used extensively in the survey area.

  5. Pollutant dispersion studies - An update on the problems in Indian coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Swamy, G.N.

    Pollutant dispersion problems along the Indian coastal waters are characterisEd. by site-specificity, as a result of seasonal and physiographic variabilities. Presence of large rivers, estuaries and backwaters add to the problems of waste disposal...

  6. The exchangeable cations in soils flooded with sea water

    NARCIS (Netherlands)

    Molen, van der W.H.

    1958-01-01

    The changes in the exchangeable cations of soils flooded with sea-water were extensively studied in the Netherlands after the inundations of 1940, 1945 and 1953. A synopsis of the results was given, both from a theoretical and a practical viewpoint.

    Current formulae for ion-exchange tested in the

  7. Temporal and Spatial Diversity of Bacterial Communities in Coastal Waters of the South China Sea

    Science.gov (United States)

    Du, Jikun; Xiao, Kai; Li, Li; Ding, Xian; Liu, Helu; Lu, Yongjun; Zhou, Shining

    2013-01-01

    Bacteria are recognized as important drivers of biogeochemical processes in all aquatic ecosystems. Temporal and geographical patterns in ocean bacterial communities have been observed in many studies, but the temporal and spatial patterns in the bacterial communities from the South China Sea remained unexplored. To determine the spatiotemporal patterns, we generated 16S rRNA datasets for 15 samples collected from the five regularly distributed sites of the South China Sea in three seasons (spring, summer, winter). A total of 491 representative sequences were analyzed by MOTHUR, yielding 282 operational taxonomic units (OTUs) grouped at 97% stringency. Significant temporal variations of bacterial diversity were observed. Richness and diversity indices indicated that summer samples were the most diverse. The main bacterial group in spring and summer samples was Alphaproteobacteria, followed by Cyanobacteria and Gammaproteobacteria, whereas Cyanobacteria dominated the winter samples. Spatial patterns in the samples were observed that samples collected from the coastal (D151, D221) waters and offshore (D157, D1512, D224) waters clustered separately, the coastal samples harbored more diverse bacterial communities. However, the temporal pattern of the coastal site D151 was contrary to that of the coastal site D221. The LIBSHUFF statistics revealed noticeable differences among the spring, summer and winter libraries collected at five sites. The UPGMA tree showed there were temporal and spatial heterogeneity of bacterial community composition in coastal waters of the South China Sea. The water salinity (P=0.001) contributed significantly to the bacteria-environment relationship. Our results revealed that bacterial community structures were influenced by environmental factors and community-level changes in 16S-based diversity were better explained by spatial patterns than by temporal patterns. PMID:23785512

  8. A model to calculate exposure from radioactive discharges into the coastal waters of Northern Europe

    International Nuclear Information System (INIS)

    Clark, M.J.; Grimwood, P.D.; Camplin, W.C.

    1980-11-01

    A regional marine model is described which can be used to estimate the exposure of populations as a result of the discharge of radioactive effluents into the coastal waters of Northern Europe. The model simulates the dispersion of radionuclides in marine waters, Their interaction with marine sediments and the concentration mechanisms occurring in seafoods. There is a local/regional interface defined in the modelling approach whereby releases are assumed to first enter a local marine compartment prior to widespread dispersion in coastal waters. Depletion mechanisms operate within both the local and regional environments influencing the fraction of radionuclide release which contributes to collective exposure. General results of the regional marine model are presented in a form which can be combined with independent local marine models; collective intakes per unit release of various radionuclides into coastal waters are given for a series of integration times. For caesium-137 and plutonium-239 collective effective dose equivalent commitments have been calculated using a defined local marine model. Some general conclusions have been drawn from the results and there is some discussion of the various features of the modelling approach. (author)

  9. Semi-analytical Model for Estimating Absorption Coefficients of Optically Active Constituents in Coastal Waters

    Science.gov (United States)

    Wang, D.; Cui, Y.

    2015-12-01

    The objectives of this paper are to validate the applicability of a multi-band quasi-analytical algorithm (QAA) in retrieval absorption coefficients of optically active constituents in turbid coastal waters, and to further improve the model using a proposed semi-analytical model (SAA). The ap(531) and ag(531) semi-analytically derived using SAA model are quite different from the retrievals procedures of QAA model that ap(531) and ag(531) are semi-analytically derived from the empirical retrievals results of a(531) and a(551). The two models are calibrated and evaluated against datasets taken from 19 independent cruises in West Florida Shelf in 1999-2003, provided by SeaBASS. The results indicate that the SAA model produces a superior performance to QAA model in absorption retrieval. Using of the SAA model in retrieving absorption coefficients of optically active constituents from West Florida Shelf decreases the random uncertainty of estimation by >23.05% from the QAA model. This study demonstrates the potential of the SAA model in absorption coefficients of optically active constituents estimating even in turbid coastal waters. Keywords: Remote sensing; Coastal Water; Absorption Coefficient; Semi-analytical Model

  10. Preparation of anion exchange membrane using polyvinyl chloride (PVC) for alkaline water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Gab-Jin; Bong, Soo-Yeon; Ryu, Cheol-Hwi [Hoseo University, Asan (Korea, Republic of); Lim, Soo-Gon [Energy and Machinery Korea Co., Ltd., Changwon (Korea, Republic of); Choi, Ho-Sang [Kyungil University, Gyeongsan (Korea, Republic of)

    2015-09-15

    An anion exchange membrane was prepared by the chloromethylation and the amination of polyvinyl chloride (PVC), as the base polymer. The membrane properties of the prepared anion exchange membrane, including ionic conductivity, ion exchange capacity, and water content were measured. The ionic conductivity of the prepared anion exchange membrane was in the range of 0.098x10{sup -2} -7.0x10{sup -2}S cm{sup -1}. The ranges of ion exchange capacity and water content were 1.9-3.7meq./g-dry-membrane and 35.1-63.1%, respectively. The chemical stability of the prepared anion exchange membrane was tested by soaking in 30 wt% KOH solution to determine its availability as a separator in the alkaline water electrolysis. The ionic conductivity during the chemical stability test largely did not change.

  11. Using National Coastal Assessment Data to Model Estuarine Water Quality at Large Spatial Scales.

    Science.gov (United States)

    The water quality of the Nation’s estuaries is attracting scrutiny in light of population growth and enhanced nutrient delivery. The USEPA has evaluated water quality in the National Coastal Assessment (NCA) and National Aquatic Resource Surveys (NARS) programs. Here we rep...

  12. Starling forces drive intracranial water exchange during normal and pathological states.

    Science.gov (United States)

    Linninger, Andreas A; Xu, Colin; Tangen, Kevin; Hartung, Grant

    2017-12-31

    To quantify the exchange of water between cerebral compartments, specifically blood, tissue, perivascular pathways, and cerebrospinal fluid-filled spaces, on the basis of experimental data and to propose a dynamic global model of water flux through the entire brain to elucidate functionally relevant fluid exchange phenomena. The mechanistic computer model to predict brain water shifts is discretized by cerebral compartments into nodes. Water and species flux is calculated between these nodes across a network of arcs driven by Hagen-Poiseuille flow (blood), Darcy flow (interstitial fluid transport), and Starling's Law (transmembrane fluid exchange). Compartment compliance is accounted for using a pressure-volume relationship to enforce the Monro-Kellie doctrine. This nonlinear system of differential equations is solved implicitly using MATLAB software. The model predictions of intraventricular osmotic injection caused a pressure rise from 10 to 22 mmHg, followed by a taper to 14 mmHg over 100 minutes. The computational results are compared to experimental data with R2=0.929. Moreover, simulated osmotic therapy of systemic (blood) injection reduced intracranial pressure from 25 to 10 mmHg. The modeled volume and intracranial pressure changes following cerebral edema agree with experimental trends observed in animal models with R2=0.997. The model successfully predicted time course and the efficacy of osmotic therapy for clearing cerebral edema. Furthermore, the mathematical model implicated the perivascular pathways as a possible conduit for water and solute exchange. This was a first step to quantify fluid exchange throughout the brain.

  13. Source identification and exchangeability of heavy metals accumulated in vegetable soils in the coastal plain of eastern Zhejiang province, China.

    Science.gov (United States)

    Qiutong, Xu; Mingkui, Zhang

    2017-08-01

    Vegetable production in China is suffering increasingly heavy metal damages from various pollution sources including agricultural, industrial and other activities. It is of practical significance to understand the effects of human activities on the accumulation and exchangeability of soil heavy metals in vegetable fields. In this study, seventy-two arable layer samples of vegetable soils were collected from the Shaoxing coastal plain, a representative region of the coastal plain of eastern Zhejiang province, China for characterizing the effects of fertilization methods on accumulation and exchangeable heavy metals in soils (Exchangeable heavy metals in the soil samples were extracted by 0.01molL -1 CaCl 2 ). The different origins of heavy metals in the vegetable soils were investigated by multivariate statistical techniques, including principal component analysis (PCA) and cluster analysis (CA). Marked increases were noted for soil heavy metals due to long-term manure or chemical fertilizer application. Three significant components were extracted by PCA, explaining 78.86% of total variance. Mn, Co, Ni, Fe, and Al were associated in lithogenic components, while an anthropogenic origin was identified for Cu, Cr, Pb, Zn, Cd, Hg. However, As level was due to the geochemical background and was not linked to soil management. The results obtained by cluster analysis elucidated individual relationships between metals and agreed with PCA. Cu, Cr, Pb, and Zn in the soils that were mainly associated with the application of chemical fertilizers, organic manures or other activities regarding soil management. Although the origin of Cd, Hg, and As was also attributed to soil management, other sources like vehicle exhaust or aerial depositions were not discarded as possible contributors. Soil amended with organic fertilizer contained more Cu, Pb, Zn and Cr; whereas the soil amended with chemical fertilizer had more Cd. Application of fertilizers also had significant effect on the

  14. Seasonal variation of 228Ra/226Ra ratio in seaweed: implications for water circulation patterns in coastal areas of the Noto Peninsula, Japan

    International Nuclear Information System (INIS)

    Inoue, M.; Kofuji, H.; Yamamoto, M.; Komura, K.

    2005-01-01

    To examine water circulation patterns of coastal water, 72 seaweed (Sargasso) samples and 27 coastal water samples were collected from coastal areas of the Noto Peninsula, Japan, during the period from December 1998 to June 2002. The 228 Ra and 226 Ra activities of those samples were measured by low-background γ-ray spectrometry. There was a wide range of activities of 228 Ra (0.5-2 Bq/kg-fresh) and 226 Ra (0.5-1.2 Bq/kg-fresh) in the Sargasso samples. The 228 Ra/ 226 Ra activity ratio of Sargasso samples exhibited seasonal variation with minimum values in June ( 228 Ra/ 226 Ra = ∼1) and maximum values in December (1.5-2.5), which was mainly governed by changes in 228 Ra activity. It is also notable that the seasonal variation of the 228 Ra/ 226 Ra ratio of Sargasso is in approximate agreement with that of the ambient coastal water. Sargasso samples appear to have retained the 228 Ra/ 226 Ra ratio of the ambient coastal waters, and the temporal variations in that ratio provide insight into seasonal changes in water circulation in the Noto Peninsula coastal area

  15. Echolocation by the harbour porpoise: Life in coastal waters

    Directory of Open Access Journals (Sweden)

    Lee Anton Miller

    2013-04-01

    Full Text Available The harbour porpoise is one of the smallest and most widely spread of all toothed whales. They are found abundantly in coastal waters all around the northern hemisphere. They are among the 11 species known to use high frequency sonar of relative narrow bandwidth. Their narrow biosonar beam helps isolate echoes from prey among those from unwanted items and noise. Obtaining echoes from small objects like net mesh, net floats and small prey is facilitated by the very high peak frequency around 130 kHz with a wavelength of about 12 mm. We argue that such echolocation signals and narrow band auditory filters give the harbour porpoise a selective advantage in a coastal environment. Predation by killer whales and a minimum noise region in the ocean around 130 kHz may have provided selection pressures for using this frequency band for biosonar signals.

  16. Interrelationships and distribution of hydrochemical parameters in coastal waters off Visakhapatnam, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.; Rao, T.V.N.; RamaRaju, V.S.; Rathod, V.; Suguna, C.

    The distribution of hydrochemical parameters in the coastal waters off Visakhapatnam during the July 1979-June 1980 showed distinct changes with time The observed supersaturation and saturation of oxygen in surface waters was due to favourable...

  17. Swarming of Creseis acicula Rang (Pteropoda) in the coastal waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    Swarms of Creseis acicula Rang (Pteropoda) were observed in the coastal waters of Goa regularly in October, from 1976 to 1980. The highest biomass value obtained for this species was 494 ml/100 m@u3@@, forming 96% of zooplankton population...

  18. National Coastal Condition Report I Factsheet

    Science.gov (United States)

    The National Coastal Condition Report describes the ecological and environmental conditions in U.S. coastal waters. This first-of-its-kind Report, presents a broad baseline picture of the overall condition of U.S. coastal waters as fair to poor.

  19. Distribution of perfluoroalkyl compounds in Osaka Bay and coastal waters of Western Japan.

    Science.gov (United States)

    Beškoski, Vladimir P; Yamamoto, Katsuya; Yamamoto, Atsushi; Okamura, Hideo; Hayashi, Mitsuru; Nakano, Takeshi; Matsumura, Chisato; Fukushi, Keiichi; Wada, Shinpei; Inui, Hideyuki

    2017-03-01

    Perfluoroalkyl acids (PFAAs) including perfluoroalkyl sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs) were analyzed in sediment samples taken from Ajifu Waterway in Osaka city, from Osaka Bay, and from Kagoshima Bay, as well as in fifteen seawater samples collected from Osaka Bay and coastal waters of Western Japan. In all sediment samples, only PFCAs were detected, and the highest concentration was determined in Ajifu Waterway, where ΣPFAA was 58990 ng kg -1 dry weight. The total concentrations of PFAAs in sea water samples ranged between the limit of quantification and 53.4 ng L -1 , and perfluorohexanoic acid was the most prevalent and had the highest concentration of 37 ng L -1 . The changes in the patterns and concentrations of PFAAs in Osaka Bay and coastal waters of Western Japan indicate that the PFAAs in surface waters are influenced by sources from Keihanshin Metropolitan Area, mainly the Yodo River basin, and the dilution effect which naturally occurs during their transport to the Pacific Ocean. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Optical Algorithms at Satellite Wavelengths for Total Suspended Matter in Tropical Coastal Waters.

    Science.gov (United States)

    Ouillon, Sylvain; Douillet, Pascal; Petrenko, Anne; Neveux, Jacques; Dupouy, Cécile; Froidefond, Jean-Marie; Andréfouët, Serge; Muñoz-Caravaca, Alain

    2008-07-10

    Is it possible to derive accurately Total Suspended Matter concentration or its proxy, turbidity, from remote sensing data in tropical coastal lagoon waters? To investigate this question, hyperspectral remote sensing reflectance, turbidity and chlorophyll pigment concentration were measured in three coral reef lagoons. The three sites enabled us to get data over very diverse environments: oligotrophic and sediment-poor waters in the southwest lagoon of New Caledonia, eutrophic waters in the Cienfuegos Bay (Cuba), and sediment-rich waters in the Laucala Bay (Fiji). In this paper, optical algorithms for turbidity are presented per site based on 113 stations in New Caledonia, 24 stations in Cuba and 56 stations in Fiji. Empirical algorithms are tested at satellite wavebands useful to coastal applications. Global algorithms are also derived for the merged data set (193 stations). The performances of global and local regression algorithms are compared. The best one-band algorithms on all the measurements are obtained at 681 nm using either a polynomial or a power model. The best two-band algorithms are obtained with R412/R620, R443/R670 and R510/R681. Two three-band algorithms based on Rrs620.Rrs681/Rrs412 and Rrs620.Rrs681/Rrs510 also give fair regression statistics. Finally, we propose a global algorithm based on one or three bands: turbidity is first calculated from Rrs681 and then, if turbidity range and for the three sites sampled (mean bias: 3.6 %, rms: 35%, mean quadratic error: 1.4 FTU). This shows that defining global empirical turbidity algorithms in tropical coastal waters is at reach.

  1. Seasonal variation in physicochemical properties of coastal waters of Kalpakkam, east coast of India with special emphasis on nutrients.

    Science.gov (United States)

    Satpathy, K K; Mohanty, A K; Natesan, U; Prasad, M V R; Sarkar, S K

    2010-05-01

    A study pertaining to the seasonal variation in physicochemical properties of the coastal waters was carried out at Kalpakkam coast for a period of 1 year (February 2006 to January 2007). It revealed that the coastal water was significantly influenced by freshwater input during North East (NE) monsoon and post-monsoon periods. Concentration of all the nutrients and dissolved oxygen (DO) was relatively high during the NE monsoon, whereas, salinity and chlorophyll-a (chl-a) were at their minimum level during this period. Phytoplankton production peak was observed in summer during which a typical marine condition prevailed. The present observed values of nitrate, phosphate, silicate, and turbidity are significantly high (five to ten times) compared to that of the pre-Tsunami period from this coast. Relatively low DO and chl-a concentration was noticed during the post-Tsunami period. A notable feature of this study is that though nutrient concentration in the coastal waters during post-Tsunami period has increased significantly, turbidity, the most single dominating factor, was found to adversely affect the phytoplankton production during post-Tsunami period as reflected by relatively low chl-a concentration. Thus, the post-Tsunami period may result in a change in coastal biodiversity pattern concomitant with change in coastal water quality.

  2. Determination of natural Ra isotopes in samples from northern Sao Paulo state coastal area

    International Nuclear Information System (INIS)

    Teixeira, Washington Eugenio

    2004-01-01

    The present work aims the determination of natural Ra isotopes in coastal samples collected at Ubatuba region, with the application of the obtained inventories to estimate coastal water mixing rates and assess submarine groundwater discharge. Since these radionuclides are present in sea water in trace form (10''- 16 g/ L), the methodology included pre-concentration of huge volumes of sea water using MnO 2 coated acrylic fiber, leaching of these fibers in HCl media and co-precipitation of the long-lived Ra isotopes with BaSO 4 . Before long-lived radium isotopes determination, the isotopes 223 Ra e 224 Ra were quantified using a delayed coincidence system. The delayed coincidence system utilizes the difference in decay constants of the short-lived Po daughters of radon 219 Rn and 220 Rn to identify alpha particles derived from its decay products. The activities of 226 Ra and 228 Ra were determined by gross alpha and beta counting respectively, of the Ba(Ra)SO 4 precipitate in low-level gas flow proportional detector. Considering the results obtained in 2002 and 2003, the coastal waters exchange time were estimated for Flamengo, Fortaleza and Mar Virado embayments using the activity concentrations of 223 Ra, 224 Ra, 226 Ra and 228 Ra. (author)

  3. Discobiol program : investigation of dispersant use in coastal and estuarine waters

    Energy Technology Data Exchange (ETDEWEB)

    Merlin, F.X.; Le Floch, S.; Dussauze, M. [Cedre, Brest Cedex (France); Theron, M. [Brest Univ., European University of Britanny, Rennes (France); Quentel, C. [AFSSA, French Food Safety Agency, Paris (France); Thomas, H. [LIENS, CNRS-Univ. of La Rochelle, La Rochelle Cedex (France)

    2009-07-01

    This paper reported on the Discobiol work program designed to acquire comparable information on the impact of mechanically and chemically dispersed oil on different habitats and resources, particularly in estuaries or close to bays. The study involved 3 phases for the analysis of lethal and sub-lethal effects in pelagic and benthic communities, notably organisms in the water column, mudflats and salt marshes. The ultimate objective was to use the information to make recommendations regarding the use of dispersants in these 3 areas. Dispersants are known to be effective for offshore oil spill response when dilution conditions are high and dispersed oil concentrations decrease rapidly below levels that could harm the environment. However, dilution can be restricted in coastal areas, thus limiting the use of dispersant. All the tests conducted in this study were conducted using brut Arabian light oil that was pre-evaporated to simulate realistic conditions. The study examined whether the presence of oil leads to different effects than the control and whether the chemically dispersed oil gave different effects than the mechanical dispersion. The comparison with chemical dispersion in clear sea water examined whether the presence of suspended materials change the effect of the chemical dispersion. Results for the different phases of the project were presented. The preliminary results tend to open the use of chemical dispersion of oil slicks in coastal areas. The mixture of dispersant plus oil seems to be less detrimental than oil alone, particularly for turbot. The final conclusion regarding chemical dispersion of oil slicks in coastal areas will have to be formulated at the end of the project because coastal ecosystems depend on biotic and abiotic factors. The final phase will take place in a realistic environment in a salt marsh ecosystem at La Rochelle, France. 6 refs., 6 tabs., 6 figs.

  4. Discobiol program : investigation of dispersant use in coastal and estuarine waters

    International Nuclear Information System (INIS)

    Merlin, F.X.; Le Floch, S.; Dussauze, M.; Theron, M.; Quentel, C.; Thomas, H.

    2009-01-01

    This paper reported on the Discobiol work program designed to acquire comparable information on the impact of mechanically and chemically dispersed oil on different habitats and resources, particularly in estuaries or close to bays. The study involved 3 phases for the analysis of lethal and sub-lethal effects in pelagic and benthic communities, notably organisms in the water column, mudflats and salt marshes. The ultimate objective was to use the information to make recommendations regarding the use of dispersants in these 3 areas. Dispersants are known to be effective for offshore oil spill response when dilution conditions are high and dispersed oil concentrations decrease rapidly below levels that could harm the environment. However, dilution can be restricted in coastal areas, thus limiting the use of dispersant. All the tests conducted in this study were conducted using brut Arabian light oil that was pre-evaporated to simulate realistic conditions. The study examined whether the presence of oil leads to different effects than the control and whether the chemically dispersed oil gave different effects than the mechanical dispersion. The comparison with chemical dispersion in clear sea water examined whether the presence of suspended materials change the effect of the chemical dispersion. Results for the different phases of the project were presented. The preliminary results tend to open the use of chemical dispersion of oil slicks in coastal areas. The mixture of dispersant plus oil seems to be less detrimental than oil alone, particularly for turbot. The final conclusion regarding chemical dispersion of oil slicks in coastal areas will have to be formulated at the end of the project because coastal ecosystems depend on biotic and abiotic factors. The final phase will take place in a realistic environment in a salt marsh ecosystem at La Rochelle, France. 6 refs., 6 tabs., 6 figs.

  5. Occurrence of pharmaceuticals and personal care products in effluent-dominated Saudi Arabian coastal waters of the Red Sea.

    Science.gov (United States)

    Ali, Aasim M; Rønning, Helene Thorsen; Alarif, Walied; Kallenborn, Roland; Al-Lihaibi, Sultan S

    2017-05-01

    The occurrence of selected pharmaceuticals and personal care products (PPCPs) and the pesticide atrazine were investigated in seawater samples collected from stations located at effluent dominated sites in the Saudi Arabian coastal waters of the Red Sea. PPCPs were analysed using solid phase extraction (SPE) followed by high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS). A multi component method for the ultra-trace level quantification of 13 target PPCPs in Seawater was developed and validated for the here performed study. The method procedure is described in detail in the supplementary material section. 26 samples from 7 distinct locations (2 directly influenced by continuous sewage release) were chosen for the sampling of surface seawater. Based upon local sales information, 25 target substances (20 PPCPs, 4 pesticides and 1 stimulant) were chosen for the here reported method development. Thirteen PPCPs were detected and quantified in a total of 26 seawater samples. Metformin, diclofenac, acetaminophen, and caffeine were identified as the most abundant PPCPs, detected in maximum concentration higher than 3 μg/L (upper quantification limit for the here developed method). Concentrations were in the range of 7- >3000 (metformin), 3000 ng/L (caffeine). The contribution of direct sewage release on the PPCP levels detected was obvious, the target PPCPs were detected in the Al-Arbaeen and Al-Shabab coastal lagoons in high concentrations due to the low water exchange with the open sea and still ongoing sewage releases in the lagoons. Also, substantial amounts of antibiotics were detected in all samples. Levels and distribution profile of the detected PPCPs revealed high level release rates and give raise to concern on potential environmental risks associated with the here document long term exposure on the fragile coastal marine environment of the region but particularly in the nearby protected coral reef environment outside the harbour

  6. Accurate Quantitation of Water-amide Proton Exchange Rates Using the Phase-Modulated CLEAN Chemical EXchange (CLEANEX-PM) Approach with a Fast-HSQC (FHSQC) Detection Scheme

    International Nuclear Information System (INIS)

    Hwang, Tsang-Lin; Zijl, Peter C.M. van; Mori, Susumu

    1998-01-01

    Measurement of exchange rates between water and NH protons by magnetization transfer methods is often complicated by artifacts, such as intramolecular NOEs, and/or TOCSY transfer from Cα protons coincident with the water frequency, or exchange-relayed NOEs from fast exchanging hydroxyl or amine protons. By applying the Phase-Modulated CLEAN chemical EXchange (CLEANEX-PM) spin-locking sequence, 135 o (x) 120 o (-x) 110 o (x) 110 o (-x) 120 o (x) 135 o (-x) during the mixing period, these artifacts can be eliminated, revealing an unambiguous water-NH exchange spectrum. In this paper, the CLEANEX-PM mixing scheme is combined with Fast-HSQC (FHSQC) detection and used to obtain accurate chemical exchange rates from the initial slope analysis for a sample of 15N labeled staphylococcal nuclease. The results are compared to rates obtained using Water EXchange filter (WEX) II-FHSQC, and spin-echo-filtered WEX II-FHSQC measurements, and clearly identify the spurious NOE contributions in the exchange system

  7. Chromate ion-exchange study for cooling water

    International Nuclear Information System (INIS)

    Sengupta, A.K.

    1985-01-01

    In spite of high chromate selectivity, the ion-exchange process for Cr(IV) recovery from cooling tower blowdown is yet to be commercially popular. Possible degradation of the ion-exchange resin by the oxidative action of Cr(IV) during ion exchange has been considered as the prime obstacle. Resins have been manufactured with fairly acceptable properties to withstand both physical attrition and chemical oxidation. Demonstrated during the course of this research is early, gradual Cr(VI) breakthrough during fixed-bed column runs at acidic pH in the presence of competing sulfate and chloride anions. The advantage of high chromate selectivity is essentially lost due to the early Cr(VI) breakthrough because the column runs are always terminated after a pre-determined level of Cr(VI) has appeared in the treated water. Experimental results provide sufficient evidence that this is not due to poor column kinetics or electrolyte penetration. The chromate ion-exchange mechanism has been investigated in order to explain the foregoing anomalies for the chromate-exchange process. The knowledge of chromate ion-exchange mechanism has been used to overcome the shortcoming of gradual Cr(VI) breakthrough. This study shows that: (a) a continuous counter-current ion-exchange system theoretically offers much higher Cr(VI) removal capacity compared to conventional single-unit fixed-bed system for any pre-determined level of Cr(VI) breakthrough; (b) by modifying the resin composition, the gradual Cr(VI) breakthrough can be greatly eliminated

  8. Determination of T90 in the coastal waters near Punta Lobos final report

    International Nuclear Information System (INIS)

    Suarez Antola, R.; Luchini, L.; Gesto, J.

    2001-01-01

    The concept of the T--90 in estuarine and coastal waters is reviewed.A mathematical diagnostics model to describe advection,dispersion and bacterial mortality in complex stratified receiving waters is developed and solved using regular perturbation techniques.Four field experiments were designed and executed in the estuarine coastal waters of Punta Lobos,Department of Montevideo,Uruguay.Fluorescent dyes were used to measure dilution.The classic method of counting in the laboratory the number of colony forming units was employed to estimate bacterial concentrations.Drogues and an auxiliary dye were used to facilitate the sailor maneuvers.Three ships were used in the field experiments.Winds,currents,temperature,conductivity,salinity,ph and other parameters were measured in each campaign.Using the measured parameters and mathematical prognostic models the mass of tracer required was calculated on board and subsequently injected jointly with the bacterial population.The experimental data were used to estimate a value of T90 in each scenario

  9. Spatial distribution of per- and polyfluoroalkyl compounds in coastal waters from the East to South China Sea

    International Nuclear Information System (INIS)

    Cai Minghong; Zhao Zhen; Yang Haizhen; Yin Zhigao; Hong Qingquan; Sturm, Renate; Ebinghaus, Ralf; Ahrens, Lutz; Cai Minggang; He, Jianfeng; Xie Zhiyong

    2012-01-01

    The spatial distribution of per- and polyfluoroalkyl compounds (PFCs) were investigated in coastal waters collected onboard research vessel Snow Dragon from the East to South China Sea in 2010. All samples were prepared by solid-phase extraction and analyzed using high performance liquid chromatography/negative electrospray ionization-tandem mass spectrometry (HPLC/(−)ESI-MS/MS). Concentrations of 9 PFCs, including C 4 and C 8 (PFBS, PFOS) perfluoroalkyl sulfonate (PFSAs), C 5 –C 9 and C 13 (PFPA, PFHxA, PFHpA, PFOA, PFNA, PFTriDA) perfluoroalkyl carboxylates (PFCAs), and N-ethyl perfluorooctane sulfonamide (EtFOSA) were quantified. The ΣPFC concentrations ranged from 133 pg/L to 3320 pg/L, with PFOA (37.5–1541 pg/L), PFBS (23.0–941 pg/L) and PFHpA (0–422 pg/L) as dominant compounds. Concentrations of PFCs were greater in coastal waters along Shanghai, Ningbo, Taizhou, Xiamen and along coastal cities of the Guangdong province compared to less populated areas along the east Chinese coast. Additionally, the comparison with other seawater PFC measurements showed lower levels in this study. - Highlights: ► Concentrations of various ionic PFCs were firstly quantified in coastal waters of China Sea for the first time. ► PFOA and PFBS, PFHxA, PFNA, PFOS, PFHpA were positively correlated which indicates that the same sources. ► The result of this study is useful for global transport models of PFCs. - Concentrations of 9 PFCs were quantified in coastal waters from the East to South China Sea for the first time.

  10. Integrated hydrologic and hydrodynamic modeling to assess water exchange in a data-scarce reservoir

    Science.gov (United States)

    Wu, Binbin; Wang, Guoqiang; Wang, Zhonggen; Liu, Changming; Ma, Jianming

    2017-12-01

    Integrated hydrologic and hydrodynamic modeling is useful in evaluating hydrodynamic characteristics (e.g. water exchange processes) in data-scarce water bodies, however, most studies lack verification of the hydrologic model. Here, water exchange (represented by water age) was investigated through integrated hydrologic and hydrodynamic modeling of the Hongfeng Reservoir, a poorly gauged reservoir in southwest China. The performance of the hydrologic model and parameter replacement among sub-basins with hydrological similarity was verified by historical data. Results showed that hydrological similarity based on the hierarchical cluster analysis and topographic index probability density distribution was reliable with satisfactory performance of parameter replacement. The hydrodynamic model was verified using daily water levels and water temperatures from 2009 and 2010. The water exchange processes in the Hongfeng Reservoir are very complex with temporal, vertical, and spatial variations. The temporal water age was primarily controlled by the variable inflow and outflow, and the maximum and minimum ages for the site near the dam were 406.10 d (15th June) and 90.74 d (3rd August), respectively, in 2010. Distinct vertical differences in water age showed that surface flow, interflow, and underflow appeared alternately, depending on the season and water depth. The worst water exchange situation was found in the central areas of the North Lake with the highest water ages in the bottom on both 15th June and 3rd August, in 2010. Comparison of the spatial water ages revealed that the more favorable hydraulic conditions on 3rd August mainly improved the water exchange in the dam areas and most areas of the South Lake, but had little effect on the bottom layers of the other deepest areas in the South and North Lakes. The presented framework can be applied in other data-scarce waterbodies worldwide to provide better understanding of water exchange processes.

  11. Human impacts and changes in the coastal waters of south China.

    Science.gov (United States)

    Wang, Linlin; Li, Qiang; Bi, Hongsheng; Mao, Xian-Zhong

    2016-08-15

    Human impact on the environment remains at the center of the debate on global environmental change. Using the Hong Kong-Shenzhen corridor in south China as an example, we present evidence that rapid urbanization and economic development in coastal areas were the dominant factors causing rapid changes in coastal waters. From 1990 to 2012, coastal seawater temperature increased ~0.060°C per year, sea level rose 4.4mm per year and pH decreased from 8.2 to 7.7, much faster than global averages. In the same period, there were exponential increases in the local population, gross domestic product and land fill area. Empirical analyses suggest that the large increase in the population affected local temperature, and economic development had a major impact on local pH. Results also show that pH and temperature were significantly correlated with local sea level rise, but pH had more predictive power, suggesting it could be considered a predictor for changes in local sea level. We conclude that human activities could significantly exacerbate local environmental changes which should be considered in predictive models and future development plans in coastal areas. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Integration of Tidal Prism Model and HSPF for simulating indicator bacteria in coastal watersheds

    Science.gov (United States)

    Sobel, Rose S.; Rifai, Hanadi S.; Petersen, Christina M.

    2017-09-01

    Coastal water quality is strongly influenced by tidal fluctuations and water chemistry. There is a need for rigorous models that are not computationally or economically prohibitive, but still allow simulation of the hydrodynamics and bacteria sources for coastal, tidally influenced streams and bayous. This paper presents a modeling approach that links a Tidal Prism Model (TPM) implemented in an Excel-based modeling environment with a watershed runoff model (Hydrologic Simulation Program FORTRAN, HSPF) for such watersheds. The TPM is a one-dimensional mass balance approach that accounts for loading from tidal exchange, runoff, point sources and bacteria die-off at an hourly time step resolution. The novel use of equal high-resolution time steps in this study allowed seamless integration of the TPM and HSPF. The linked model was calibrated to flow and E. Coli data (for HSPF), and salinity and enterococci data (for the TPM) for a coastal stream in Texas. Sensitivity analyses showed the TPM to be most influenced by changes in net decay rates followed by tidal and runoff loads, respectively. Management scenarios were evaluated with the developed linked models to assess the impact of runoff load reductions and improved wastewater treatment plant quality and to determine the areas of critical need for such reductions. Achieving water quality standards for bacteria required load reductions that ranged from zero to 90% for the modeled coastal stream.

  13. Speciative determination of phosphorus in environmental water by the isotope exchange method

    International Nuclear Information System (INIS)

    Ikeda, N.; Yoshikawa, M.; Murakami, S.; Kunika, J.

    1988-01-01

    An isotope exchage method for the speciative determination of phosphorus (PO 4 3- ,PO 3 3- and total P) in natural water samples is proposed by using the exchange system of molybdophosphate in the aqueous phase and tetraphenylarsonium molybdophosphate in the organic phase. In this exchange system, only PO 4 3- exchanges and is determined. When the sample water is treated with Br 2 water in advance, the amount of PO 4 3- +PO 3 3- can be obtained. When the sample is treated with H 2 SO 4 and HNO 3 , the amount of total P can be determined. (author) 4 refs.; 5 tabs

  14. Ion exchange separation of low boric acid concentrations from water

    International Nuclear Information System (INIS)

    Kysela, J.; Brabec, J.; Peterka, F.

    1975-01-01

    Boric acid poisoning of the moderator of the TR-O experimental heavy water reactor was studied. The possibility is discussed of removing boric acid from heavy water by means of a strong basic anion exchanger, below the residual concentration of 0.01 mg B/l. Measurements of the usable capacities of the strong basic anion exchanger Zerollit FF showed that the penetration of boric acid during the sorption period does not exceed the value of 0.015 mg B/l. The dependence was found of capacity on the boric acid concentration in the solution. Analytical methods used to determine B in water are also described. (author)

  15. EFFECTS OF A COASTAL GOLF COMPLEX ON WATER QUALITY, PERIPHYTON, AND SEAGRASS.

    Science.gov (United States)

    The objective of this study was to determine the effects of a golf course complex on water quality, colonized periphyton and seagrass meadows in adjacent freshwater, near-coastal and wetland areas. The environmental impact of the recreational facility, which uses spray wastewater...

  16. The exploration of trophic structure modeling using mass balance Ecopath model of Tangerang coastal waters

    Science.gov (United States)

    Dewi, N. N.; Kamal, M.; Wardiatno, Y.; Rozi

    2018-04-01

    Ecopath model approach was used to describe trophic interaction, energy flows and ecosystem condition of Tangerang coastal waters. This model consists of 42 ecological groups, of which 41 are living groups and one is a detritus group. Trophic levels of these groups vary between 1.0 (for primary producers and detritus) to 4.03 (for tetraodontidae). Groups with trophic levels 2≤TLfish, while detritus has a positive impact on the majority of demersal fish. Leiognathidae havea negative impact on phytoplankton, zooplankton and several other groups. System omnivory index for this ecosystem is 0.151. System primary production/respiration (P/R) ratio of Tangerang coastal waters is 1.505. This coastal ecosystem is an immatureecosystem because it hasdegraded. Pedigree index for this model is 0.57. This model describes ecosystem condition affected by overfishing and antropogenic activities. Therefore, through Ecopath model we provide some suggestions about the ecosystem-based fisheries management.

  17. [The marine coastal water monitoring program of the Italian Ministry of the Environment].

    Science.gov (United States)

    Di Girolamo, Irene

    2003-01-01

    The Ministry of the Environment carries out marine and coastal monitoring programs with the collaboration of the coastal Regions. The program in progress (2001-2003), on the basis of results of the previous one, has identified 73 particulary significant areas (57 critical areas and 16 control areas). The program investigates several parameters on water, plancton, sediments, mollusks and benthos with analyses fortnightly, six-monthly and annual. The main aim of these three year monitoring programs is to assess the quality of national marine ecosystem.

  18. Probing water structure and transport in proton exchange membranes

    NARCIS (Netherlands)

    Ling, X.

    2018-01-01

    Proton exchange membrane fuel cells (PEMFCs) have attracted tremendous attention as alternative energy sources because of their high energy density and practically zero greenhouse gas emission - water is their only direct by-product. Critical to the function of PEMFCs is fast proton and water

  19. Development of a Waste Water Regenerative System - Using Sphagnum Moss Ion-exchange

    Science.gov (United States)

    McKeon, M.; Wheeler, R.; Leahy, Jj

    The use of inexpensive, light weight and regenerative systems in an enclosed environment is of great importance to sustained existence in such habitats as the International Space Station, Moon or even Mars. Many systems exist which utilise various synthetic ion exchangers to complete the process of waste water clean-up. These systems do have a very good exchange rate for cations but a very low exchange rate for anions. They also have a maximum capacity before they need regeneration. This research proposes a natural alternative to these synthetic ion-exchangers that utilises one of natures greatest ion-exchangers, that of Sphagnum Moss. Sphagna can be predominantly found in the nutrient poor environment of Raised Bogs, a type of isolated wetland with characteristic low pH and little interaction with the surrounding water table. All nutrients come from precipitation. The sphagna have developed as the bog's sponges, soaking up all available nutrients (both cation & anion) from the precipitation and eventually distributing them to the surrounding flora and fauna, through the water. The goal of this research is to use this ability in the processing of waste water from systems similar to isolated microgravity environments, to produce clean water for reuse in these environments. The nutrients taken up by the sphagna will also be utilised as a growth medium for cultivar growth, such as those selected for hydroponics' systems.

  20. Morphology and phylogeny of Triadinium polyedricum (Pouchet) Dodge (Dinophyceae) from Korean coastal waters

    Science.gov (United States)

    Shin, Hyeon Ho; Li, Zhun; Kim, Eun Song; Youn, Joo Yeon; Jeon, Seul Gi; Oh, Seok Jin; Lim, Weol-Ae

    2016-12-01

    To identify features that can be used to differentiate Triadinium polyedricum from other related species, such as Fukuyoa paulensis and Alexandrium species, the detailed morphology and phylogeny of T. polyedricum collected from Korean coastal waters were investigated. The cells had a plate formula of Po, 3', 7″, 5‴, 1p and 2″″, which is consistent with morphological descriptions in previous reports. Large subunit ribosomal DNA sequences also revealed that T. polyedricum from Korean coastal waters is identical to previously recorded isolates. T. polyedricum is morphologically characterized by a ventral pore in the 1″ plate that is comparable to F. paulensis and Alexandrium species. This result indicates that the location and presence of this ventral pore seems suitable for differentiating T. polyedricum from other related species.

  1. Influence of Microsprinkler Irrigation Amount on Water, Soil, and pH Profiles in a Coastal Saline Soil

    Directory of Open Access Journals (Sweden)

    Linlin Chu

    2014-01-01

    Full Text Available Microsprinkler irrigation is a potential method to alleviate soil salinization. After conducting a homogeneous, highly saline, clayey, and coastal soil from the Bohai Gulf in northern China in a column experiment, the results show that the depth of the wetting front increased as the water amount applied increased, low-salinity and low-SAR enlarged after irrigation and water redistribution, and the soil pH increased with an increase in irrigation amount. We concluded that a water amount of 207 mm could be used to reclaim the coastal saline soil in northern China.

  2. Advantages of paramagnetic chemical exchange saturation transfer (CEST) complexes having slow to intermediate water exchange properties as responsive MRI agents.

    Science.gov (United States)

    Soesbe, Todd C; Wu, Yunkou; Dean Sherry, A

    2013-07-01

    Paramagnetic chemical exchange saturation transfer (PARACEST) complexes are exogenous contrast agents that have great potential to further extend the functional and molecular imaging capabilities of magnetic resonance. As a result of the presence of a central paramagnetic lanthanide ion (Ln(3+) ≠ La(3+) , Gd(3+) , Lu(3+) ) within the chelate, the resonance frequencies of exchangeable protons bound to the PARACEST agent are shifted far away from the bulk water frequency. This large chemical shift, combined with an extreme sensitivity to the chemical exchange rate, make PARACEST agents ideally suited for the reporting of significant biological metrics, such as temperature, pH and the presence of metabolites. In addition, the ability to turn PARACEST agents 'off' and 'on' using a frequency-selective saturation pulse gives them a distinct advantage over Gd(3+) -based contrast agents. A current challenge for PARACEST research is the translation of the promising in vitro results into in vivo systems. This short review article first describes the basic theory behind PARACEST contrast agents, their benefits over other contrast agents and their applications to MRI. It then describes some of the recent PARACEST research results: specifically, pH measurements using water molecule exchange rate modulation, T2 exchange contrast caused by water molecule exchange, the use of ultrashort TEs (TE < 10 µs) to overcome T2 exchange line broadening and the potential application of T2 exchange as a new contrast mechanism for MRI. Copyright © 2012 John Wiley & Sons, Ltd.

  3. Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

    Science.gov (United States)

    Booij, Petra; Sjollema, Sascha B.; van der Geest, Harm G.; Leonards, Pim E. G.; Lamoree, Marja H.; de Voogt, W. Pim; Admiraal, Wim; Laane, Remi W. P. M.; Vethaak, A. Dick

    2015-08-01

    For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and coastal waters are the most productive ecosystems with high primary production by microalgae. The toxic pressure of specific phytotoxic chemicals now poses a major threat to these ecosystems. In a previous study, six herbicides (atrazine, diuron, irgarol, isoproturon, terbutryn and terbutylazine) were identified as the main contaminants affecting photosynthesis in marine microalgae. The purpose of this study is to investigate the toxic pressure of these herbicides in the Dutch estuarine and coastal waters in relation to the effective photosystem II efficiency (ΦPSII) in microalgae. Temporal and spatial variations in the concentrations of these herbicides were analyzed based on monitoring data. Additionally, a field study was carried out in which chemical analysis of water was performed and also a toxicity assessment using the Pulse Amplitude Modulation (PAM) fluorometry assay that measures ΦPSII. The toxic pressure on ΦPSII in microalgae has decreased with 55-82% from 2003 to 2012, with the Western Scheldt estuary showing the highest toxic pressure. By combining toxicity data from the PAM assay with chemical analysis of herbicide concentrations, we have identified diuron and terbutylazine as the main contributors to the toxic pressure on microalgae. Although direct effects are not expected, the toxic pressure is close to the 10% effect level in the PAM assay. A compliance check with the current environmental legislation of the European Union revealed that the quality standards are not sufficient to protect marine microalgae.

  4. Estimating the beam attenuation coefficient in coastal waters from AVHRR imagery

    Science.gov (United States)

    Gould, Richard W.; Arnone, Robert A.

    1997-09-01

    This paper presents an algorithm to estimate particle beam attenuation at 660 nm ( cp660) in coastal areas using the red and near-infrared channels of the NOAA AVHRR satellite sensor. In situ reflectance spectra and cp660 measurements were collected at 23 stations in Case I and II waters during an April 1993 cruise in the northern Gulf of Mexico. The reflectance spectra were weighted by the spectral response of the AVHRR sensor and integrated over the channel 1 waveband to estimate the atmospherically corrected signal recorded by the satellite. An empirical relationship between integrated reflectance and cp660 values was derived with a linear correlation coefficient of 0.88. Because the AVHRR sensor requires a strong channel 1 signal, the algorithm is applicable in highly turbid areas ( cp660 > 1.5 m -1) where scattering from suspended sediment strongly controls the shape and magnitude of the red (550-650 nm) reflectance spectrum. The algorithm was tested on a data set collected 2 years later in different coastal waters in the northern Gulf of Mexico and satellite estimates of cp660 averaged within 37% of measured values. Application of the algorithm provides daily images of nearshore regions at 1 km resolution for evaluating processes affecting ocean color distribution patterns (tides, winds, currents, river discharge). Further validation and refinement of the algorithm are in progress to permit quantitative application in other coastal areas. Published by Elsevier Science Ltd

  5. NASA COAST and OCEANIA Airborne Missions Support Ecosystem and Water Quality Research in the Coastal Zone

    Science.gov (United States)

    Guild, Liane; Kudela, Raphael; Hooker, Stanford; Morrow, John; Russell, Philip; Palacios, Sherry; Livingston, John M.; Negrey, Kendra; Torres-Perez, Juan; Broughton, Jennifer

    2014-01-01

    NASA has a continuing requirement to collect high-quality in situ data for the vicarious calibration of current and next generation ocean color satellite sensors and to validate the algorithms that use the remotely sensed observations. Recent NASA airborne missions over Monterey Bay, CA, have demonstrated novel above- and in-water measurement capabilities supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The results characterize coastal atmospheric and aquatic properties through an end-to-end assessment of image acquisition, atmospheric correction, algorithm application, plus sea-truth observations from state-of-the-art instrument systems. The primary goal is to demonstrate the following in support of calibration and validation exercises for satellite coastal ocean color products: 1) the utility of a multi-sensor airborne instrument suite to assess the bio-optical properties of coastal California, including water quality; and 2) the importance of contemporaneous atmospheric measurements to improve atmospheric correction in the coastal zone. The imaging spectrometer (Headwall) is optimized in the blue spectral domain to emphasize remote sensing of marine and freshwater ecosystems. The novel airborne instrument, Coastal Airborne In-situ Radiometers (C-AIR) provides measurements of apparent optical properties with high dynamic range and fidelity for deriving exact water leaving radiances at the land-ocean boundary, including radiometrically shallow aquatic ecosystems. Simultaneous measurements supporting empirical atmospheric correction of image data are accomplished using the Ames Airborne Tracking Sunphotometer (AATS-14). Flight operations are presented for the instrument payloads using the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter flown over Monterey Bay during the seasonal fall algal bloom in 2011 (COAST) and 2013 (OCEANIA) to support bio-optical measurements of

  6. Optical Algorithms at Satellite Wavelengths for Total Suspended Matter in Tropical Coastal Waters

    OpenAIRE

    Ouillon, Sylvain; Douillet, Pascal; Petrenko, Anne; Neveux, Jacques; Dupouy, C?cile; Froidefond, Jean-Marie; Andr?fou?t, Serge; Mu?oz-Caravaca, Alain

    2008-01-01

    Is it possible to derive accurately Total Suspended Matter concentration or its proxy, turbidity, from remote sensing data in tropical coastal lagoon waters? To investigate this question, hyperspectral remote sensing reflectance, turbidity and chlorophyll pigment concentration were measured in three coral reef lagoons. The three sites enabled us to get data over very diverse environments: oligotrophic and sediment-poor waters in the southwest lagoon of New Caledonia, eutrophic waters in the C...

  7. [Distribution of polycyclic aromatic hydrocarbons in water and sediment from Zhoushan coastal area, China].

    Science.gov (United States)

    Jiang, Min; Tuan, Le Huy; Mei, Wei-Ping; Ruan, Hui-Hui; Wu, Hao

    2014-07-01

    The spatial and temporal distribution of 16 polycyclic aromatic hydrocarbons (PAHs) has been investigated in water and sediments of Zhoushan coastal area every two months in 2012. The concentrations of total PAHs ranged from 382.3 to 816.9 ng x L(-1), with the mean value of 552.5 ng x L(-1) in water; whereas it ranged from 1017.9 to 3047.1 ng x g(-1), with the mean value of 2 022.4 ng x g(-1) in sediment. Spatial distribution showed that Yangshan and Yanwoshan offshore area had the maximum and minimum of total PAHs contents in water, while the maximum and minimum occurred at Yangshan and Zhujiajian Nansha offshore area in sediment. Temporal distribution revealed that total PAHs contents in water reached the maximum and minimum values in October and June, however in sediments these values were found in August and June, respectively. The PAHs pollution was affected by oil emission, charcoal and coal combustion. Using the biological threshold and exceeded coefficient method to assess the ecological risk of PAHs in Zhoushan coastal area, the result showed that sigma PAHs had a lower probability of potential risk, while there was a higher probability of potential risk for acenaphthylene monomer, and there might be ecological risk for acenaphthene and fluorene. Distribution of PAHs between sediment and water showed that Zhoushan coastal sediment enriched a lot of PAHs, meanwhile the enrichment coefficient (K(d) value) of sediment in Daishan island was larger than that in Zhoushan main island.

  8. Recycle attuned catalytic exchange (RACE) for reliable and low inventory processing of highly tritiated water

    International Nuclear Information System (INIS)

    Iseli, M.; Schaub, M.; Ulrich, D.

    1992-01-01

    The detritiation of highly tritiated water by liquid phase catalytic exchange needs dilution of the feed with water to tritium concentrations suitable for catalyst and safety rules and to assure flow rates large enough for wetting the catalyst. Dilution by recycling detritiated water from within the exchange process has three advantages: the amount and concentration of the water for dilution is controlled within the exchange process, there is no additional water load to processes located downstream RACE, and the ratio of gas to liquid flow rates in the exchange column could be adjusted by using several recycles differing in amount and concentration to avoid an excessively large number of theoretical separation stages. In this paper, the flexibility of the recycle attuned catalytic exchange (RACE) and its effect on the cryogenic distillation are demonstrated for the detritiation of the highly tritiated water from a tritium breeding blanket

  9. A new methodology to assess antimicrobial resistance of bacteria in coastal waters; pilot study in a Mediterranean hydrosystem

    Science.gov (United States)

    Almakki, Ayad; Estèves, Kevin; Vanhove, Audrey S.; Mosser, Thomas; Aujoulat, Fabien; Marchandin, Hélène; Toubiana, Mylène; Monfort, Patrick; Jumas-Bilak, Estelle; Licznar-Fajardo, Patricia

    2017-10-01

    The global resistome of coastal waters has been less studied than that of other waters, including marine ones. Here we develop an original method for characterizing the antimicrobial resistance of bacterial communities in coastal waters. The method combines the determination of a new parameter, the community Inhibitory Concentration (c-IC) of antibiotics (ATBs), and the description of the taxonomic richness of the resistant bacteria. We test the method in a Mediterranean hydrosystem, in the Montpellier region, France. Three types of waters are analyzed: near coastal river waters (Lez), lagoon brackish waters (Mauguio), and lake freshwaters (Salagou). Bacterial communities are grown in vitro in various conditions of temperature, salinity, and ATB concentrations. From these experiments, we determine the concentrations of ATB that decrease the bacterial community abundance by 50% (c-IC50) and by 90% (c-IC90). In parallel, we determine the taxonomic repertory of the resistant growing bacteria communities (repertory of Operational Taxonomic Units [OTU]). Temperature and salinity influence the abundance of the cultivable bacteria in presence of ATBs and hence the c-ICs. Very low ATB concentrations can decrease the bacterial abundance significantly. Beside a few ubiquitous genera (Bacillus, Pseudomonas, Shewanella, Vibrio), most resistant OTUs are specific of a type of water. In brackish water, resistant OTUs are more diverse and their community structure less vulnerable to ATBs than those in freshwater. We anticipate that c-IC measurement combined with taxonomic description can be applied to any littoral region to characterize the resistant bacterial communities in the coastal waters. This would help us to evaluate the vulnerability of aquatic ecosystems to antimicrobial pressure.

  10. Separation of hydrogen isotope by hydrogen-water exchange

    International Nuclear Information System (INIS)

    Isomura, Shohei; Kaetsu, Hayato; Nakane, Ryohei

    1979-01-01

    The deuterium exchange reaction between gaseous hydrogen and liquid water is studied by use of three kinds of trickle bed exchange columns packed with hydrophobic catalysts supporting platinum. All columns have the effective lengths of 30 cm. They are 17 mm, 30 mm, and 95 mm in diameters, respectively. The separation experiments are carried out by the once-through methods. The separation efficiencies of the columns are evaluated by the parameters such as the height equivalent to a theoretical plate (H. E. T. P.) and the mass transfer co-efficient. It is found that the operating condition of the exchange column is optimum when the superficial hydrogen flow velocity is 0.3 m/sec. (author)

  11. Design of Anion Exchange Membranes and Electrodialysis Studies for Water Desalination

    Directory of Open Access Journals (Sweden)

    Muhammad Imran Khan

    2016-05-01

    Full Text Available Anion exchange membranes are highly versatile and nowadays have many applications, ranging from water treatment to sensing materials. The preparation of anion exchange membranes (AEMs from brominated poly(2,6-dimethyl-1,6-phenylene oxide (BPPO and methyl(diphenylphosphine (MDPP for electrodialysis was performed. The physiochemical properties and electrochemical performance of fabricated membranes can be measured by changing MDPP contents in the membrane matrix. The influence of a quaternary phosphonium group associated with the removal of NaCl from water is discussed. The prepared membranes have ion exchange capacities (IEC 1.09–1.52 mmol/g, water uptake (WR 17.14%–21.77%, linear expansion ratio (LER 7.96%–11.86%, tensile strength (TS 16.66–23.97 MPa and elongation at break (Eb 485.57%–647.98%. The prepared anion exchange membranes were employed for the electrodialytic removal of 0.1 M NaCl aqueous solution at a constant applied voltage. It is found that the reported membranes could be the promising candidate for NaCl removal via electrodialysis.

  12. The “shallow-waterness” of the wave climate in European coastal regions

    Directory of Open Access Journals (Sweden)

    K. H. Christensen

    2017-07-01

    Full Text Available In contrast to deep water waves, shallow water waves are influenced by bottom topography, which has consequences for the propagation of wave energy as well as for the energy and momentum exchange between the waves and the mean flow. The ERA-Interim reanalysis is used to assess the fraction of wave energy associated with shallow water waves in coastal regions in Europe. We show maps of the distribution of this fraction as well as time series statistics from eight selected stations. There is a strong seasonal dependence and high values are typically associated with winter storms, indicating that shallow water wave effects can occasionally be important even in the deeper parts of the shelf seas otherwise dominated by deep water waves.

  13. Natural and human-induced hypoxia and consequences for coastal areas: synthesis and future development

    Directory of Open Access Journals (Sweden)

    J. Zhang

    2010-05-01

    Full Text Available Hypoxia has become a world-wide phenomenon in the global coastal ocean and causes a deterioration of the structure and function of ecosystems. Based on the collective contributions of members of SCOR Working Group #128, the present study provides an overview of the major aspects of coastal hypoxia in different biogeochemical provinces, including estuaries, coastal waters, upwelling areas, fjords and semi-enclosed basins, with various external forcings, ecosystem responses, feedbacks and potential impact on the sustainability of the fishery and economics. The obvious external forcings include freshwater runoff and other factors contributing to stratification, organic matter and nutrient loadings, as well as exchange between coastal and open ocean water masses. Their different interactions set up mechanisms that drive the system towards hypoxia. Coastal systems also vary in their relative susceptibility to hypoxia depending on their physical and geographic settings. It is understood that coastal hypoxia has a profound impact on the sustainability of ecosystems, which can be seen, for example, by the change in the food-web structure and system function; other influences include compression and loss of habitat, as well as changes in organism life cycles and reproduction. In most cases, the ecosystem responds to the low dissolved oxygen in non-linear ways with pronounced feedbacks to other compartments of the Earth System, including those that affect human society. Our knowledge and previous experiences illustrate that there is a need to develop new observational tools and models to support integrated research of biogeochemical dynamics and ecosystem behavior that will improve confidence in remediation management strategies for coastal hypoxia.

  14. Natural and human-induced hypoxia and consequences for coastal areas: synthesis and future development

    Science.gov (United States)

    Zhang, J.; Gilbert, D.; Gooday, A. J.; Levin, L.; Naqvi, S. W. A.; Middelburg, J. J.; Scranton, M.; Ekau, W.; Peña, A.; Dewitte, B.; Oguz, T.; Monteiro, P. M. S.; Urban, E.; Rabalais, N. N.; Ittekkot, V.; Kemp, W. M.; Ulloa, O.; Elmgren, R.; Escobar-Briones, E.; van der Plas, A. K.

    2010-05-01

    Hypoxia has become a world-wide phenomenon in the global coastal ocean and causes a deterioration of the structure and function of ecosystems. Based on the collective contributions of members of SCOR Working Group #128, the present study provides an overview of the major aspects of coastal hypoxia in different biogeochemical provinces, including estuaries, coastal waters, upwelling areas, fjords and semi-enclosed basins, with various external forcings, ecosystem responses, feedbacks and potential impact on the sustainability of the fishery and economics. The obvious external forcings include freshwater runoff and other factors contributing to stratification, organic matter and nutrient loadings, as well as exchange between coastal and open ocean water masses. Their different interactions set up mechanisms that drive the system towards hypoxia. Coastal systems also vary in their relative susceptibility to hypoxia depending on their physical and geographic settings. It is understood that coastal hypoxia has a profound impact on the sustainability of ecosystems, which can be seen, for example, by the change in the food-web structure and system function; other influences include compression and loss of habitat, as well as changes in organism life cycles and reproduction. In most cases, the ecosystem responds to the low dissolved oxygen in non-linear ways with pronounced feedbacks to other compartments of the Earth System, including those that affect human society. Our knowledge and previous experiences illustrate that there is a need to develop new observational tools and models to support integrated research of biogeochemical dynamics and ecosystem behavior that will improve confidence in remediation management strategies for coastal hypoxia.

  15. Air-sea exchanges of materials in the Indian Ocean: Concerns and strategies

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    biological production is entirely due to leakage of agricultural effluents into coastal waters, as the present knowledge on the seasonal variability of nutrients and biological production in waters along the Indian coast is still limited. If this theory... to gaseous CO2 with minor reduction in pH. The gaseous CO2 in seawater determines the extent of air-sea exchange. But small changes in temperature or pH can modify gaseous CO2 content in seawater. Thus shifts in physico- chemical and biological regimes...

  16. Optical Algorithms at Satellite Wavelengths for Total Suspended Matter in Tropical Coastal Waters

    Directory of Open Access Journals (Sweden)

    Alain Muñoz-Caravaca

    2008-07-01

    Full Text Available Is it possible to derive accurately Total Suspended Matter concentration or its proxy, turbidity, from remote sensing data in tropical coastal lagoon waters? To investigate this question, hyperspectral remote sensing reflectance, turbidity and chlorophyll pigment concentration were measured in three coral reef lagoons. The three sites enabled us to get data over very diverse environments: oligotrophic and sediment-poor waters in the southwest lagoon of New Caledonia, eutrophic waters in the Cienfuegos Bay (Cuba, and sediment-rich waters in the Laucala Bay (Fiji. In this paper, optical algorithms for turbidity are presented per site based on 113 stations in New Caledonia, 24 stations in Cuba and 56 stations in Fiji. Empirical algorithms are tested at satellite wavebands useful to coastal applications. Global algorithms are also derived for the merged data set (193 stations. The performances of global and local regression algorithms are compared. The best one-band algorithms on all the measurements are obtained at 681 nm using either a polynomial or a power model. The best two-band algorithms are obtained with R412/R620, R443/R670 and R510/R681. Two three-band algorithms based on Rrs620.Rrs681/Rrs412 and Rrs620.Rrs681/Rrs510 also give fair regression statistics. Finally, we propose a global algorithm based on one or three bands: turbidity is first calculated from Rrs681 and then, if < 1 FTU, it is recalculated using an algorithm based on Rrs620.Rrs681/Rrs412. On our data set, this algorithm is suitable for the 0.2-25 FTU turbidity range and for the three sites sampled (mean bias: 3.6 %, rms: 35%, mean quadratic error: 1.4 FTU. This shows that defining global empirical turbidity algorithms in tropical coastal waters is at reach.

  17. Optical Algorithms at Satellite Wavelengths for Total Suspended Matter in Tropical Coastal Waters

    Science.gov (United States)

    Ouillon, Sylvain; Douillet, Pascal; Petrenko, Anne; Neveux, Jacques; Dupouy, Cécile; Froidefond, Jean-Marie; Andréfouët, Serge; Muñoz-Caravaca, Alain

    2008-01-01

    Is it possible to derive accurately Total Suspended Matter concentration or its proxy, turbidity, from remote sensing data in tropical coastal lagoon waters? To investigate this question, hyperspectral remote sensing reflectance, turbidity and chlorophyll pigment concentration were measured in three coral reef lagoons. The three sites enabled us to get data over very diverse environments: oligotrophic and sediment-poor waters in the southwest lagoon of New Caledonia, eutrophic waters in the Cienfuegos Bay (Cuba), and sediment-rich waters in the Laucala Bay (Fiji). In this paper, optical algorithms for turbidity are presented per site based on 113 stations in New Caledonia, 24 stations in Cuba and 56 stations in Fiji. Empirical algorithms are tested at satellite wavebands useful to coastal applications. Global algorithms are also derived for the merged data set (193 stations). The performances of global and local regression algorithms are compared. The best one-band algorithms on all the measurements are obtained at 681 nm using either a polynomial or a power model. The best two-band algorithms are obtained with R412/R620, R443/R670 and R510/R681. Two three-band algorithms based on Rrs620.Rrs681/Rrs412 and Rrs620.Rrs681/Rrs510 also give fair regression statistics. Finally, we propose a global algorithm based on one or three bands: turbidity is first calculated from Rrs681 and then, if < 1 FTU, it is recalculated using an algorithm based on Rrs620.Rrs681/Rrs412. On our data set, this algorithm is suitable for the 0.2-25 FTU turbidity range and for the three sites sampled (mean bias: 3.6 %, rms: 35%, mean quadratic error: 1.4 FTU). This shows that defining global empirical turbidity algorithms in tropical coastal waters is at reach. PMID:27879929

  18. Research of the heat exchanging processes running in the heating and hot water supply loops of the coil heat exchangers

    Directory of Open Access Journals (Sweden)

    Ірина Геннадіївна Шитікова

    2016-11-01

    Full Text Available The fuel-energy complex research has made it possible to disclose a huge power-saving potential in the municipal heat-and-power engineering. Power-and-resource-saving units and systems are becoming extremely urgent because of the power engineering crisis expansion. The self-adjusting heat supply system from the individual heating points with the heat-accumulating units and coil heat exchangers for independent heating and water supply systems has been examined. Coil heat exchangers are used in municipal heating for heat transfer (e.g. geothermal waters for the independent mains of the heating and hot water supply systems. The heat engineering calculation of the heating and accumulating unit with the coil heat exchanger for independent heat supply systems from individual heater was performed and experimental data were received at the experimental industrial unit under the laboratory conditions. The peculiarities of the flows in the intertubular space, their influence on the heat exchange and temperatures of the first and intermediate mains have been shown. It is important to know the processes running inside the apparatus to be able to improve the technical characteristics of the three-loop coil heat exchanger. The task solution will make it possible to save the materials consumption for the three-loop coil heat exchangers in the future

  19. NOAA Water Level Predictions Stations for the Coastal United States and Other Non-U.S. Sites

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Ocean Service (NOS) maintains a long-term database containing water level measurements and derived tidal data for coastal waters of the United States...

  20. Remote Sensing of Suspended Sediments and Shallow Coastal Waters

    Science.gov (United States)

    Li, Rong-Rong; Kaufman, Yoram J.; Gao, Bo-Cai; Davis, Curtiss O.

    2002-01-01

    Ocean color sensors were designed mainly for remote sensing of chlorophyll concentrations over the clear open oceanic areas (case 1 water) using channels between 0.4 and 0.86 micrometers. The Moderate Resolution Imaging Spectroradiometer (MODIS) launched on the NASA Terra and Aqua Spacecrafts is equipped with narrow channels located within a wider wavelength range between 0.4 and 2.5 micrometers for a variety of remote sensing applications. The wide spectral range can provide improved capabilities for remote sensing of the more complex and turbid coastal waters (case 2 water) and for improved atmospheric corrections for Ocean scenes. In this article, we describe an empirical algorithm that uses this wide spectral range to identifying areas with suspended sediments in turbid waters and shallow waters with bottom reflections. The algorithm takes advantage of the strong water absorption at wavelengths longer than 1 micrometer that does not allow illumination of sediments in the water or a shallow ocean floor. MODIS data acquired over the east coast of China, west coast of Africa, Arabian Sea, Mississippi Delta, and west coast of Florida are used in this study.

  1. An autonomous underwater vehicle "Maya", for monitoring coastal waters, estuaries, rivers and dams

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.A; Navelkar, G.S.; Madhan, R.; Dabholkar, N.A; Prabhudesai, S.P.; Maurya, P.K.; Desa, E.; Afzulpurkar, S.; Suresh, T.; Matondkar, S.G.P.; Mahalunkar, A

    This article demonstrates the use of Maya, Autonomous Underwater Vehicle (AUV) for monitoring coastal waters, estuaries, rivers and dams. Maya is a mono hull structure with detachable nose and tail cones. The nose cone is mission specific...

  2. Applications of MODIS Fluorescence Line Height Measurements to Monitor Water Quality Trends and Algal Bloom Activity in Coastal and Estuarine Waters

    Science.gov (United States)

    Fischer, A.; Ryan, J. P.; Moreno-Madriñán, M. J.

    2012-12-01

    Recent advances in satellite and airborne remote sensing, such as improvements in sensor and algorithm calibrations and atmospheric correction procedures have provided for increased coverage of remote-sensing, ocean color products for coastal regions. In particular, for the Moderate Resolution Imaging Spectrometer (MODIS), calibration updates, improved aerosol retrievals, and new aerosol models have led to improved atmospheric correction algorithms for turbid waters and have improved the retrieval of ocean-color. This has opened the way for studying coastal ocean phenomena and processes at finer spatial scales. Human population growth and changes in coastal management practices have brought about significant changes in the concentrations of organic and inorganic, particulate and dissolved substances entering the coastal ocean. There is increasing concern that these inputs have led to declines in water quality and increases in local concentrations of phytoplankton, which could result in harmful algal blooms. In two case studies we present improved and validated MODIS coastal observations of fluorescence line height (FLH) to: (1) assess trends in water quality for Tampa Bay, Florida; and (2) illustrate seasonal and annual variability of algal bloom activity in Monterey Bay, California, as well as document estuarine/riverine plume induced red tide events. In a comprehensive analysis of long term (2003-2011) in situ monitoring data and imagery from Tampa Bay, we assess the validity of the MODIS FLH product against chlorophyll-a and a suite of water quality parameters taken in a variety of conditions throughout this large, optically complex estuarine system. A systematic analysis of sampling sites throughout the bay illustrates that the correlations between FLH and in situ chlorophyll-a are influenced by water quality parameters of total nitrogen, total phosphorous, turbidity and biological oxygen demand. Sites that correlated well with satellite imagery were in depths

  3. Dynamic surface water-groundwater exchange and nitrogen transport in the riparian aquifer of a tidal river

    Science.gov (United States)

    Sawyer, A. H.; Barnes, R.; Wallace, C.; Knights, D.; Tight, D.; Bayer, M.

    2017-12-01

    Tides in coastal rivers can propagate tens to hundreds of kilometers inland and drive large daily changes in water and nitrogen exchange across the sediment-water interface. We use field observations and numerical models to illuminate hydrodynamic controls on nitrogen export from the riparian aquifer to a fresh, tidal reach of White Clay Creek (Delaware, USA). In the banks, an aerobic zone with high groundwater nitrate concentrations occurs near the fluctuating water table. Continuous depth-resolved measurements of redox potential suggest that this zone is relatively stable over tidal timescales but moves up or down in response to storms. The main source of dissolved oxygen is soil air that is imbibed in the zone of water table fluctuations, and the source of nitrate is likely nitrification of ammonium produced locally from the mineralization of organic matter in floodplain soils. Much of the nitrate is removed by denitrification along oscillating flow paths towards the channel. Within centimeters of the sediment-water interface, denitrification is limited by the mixing of groundwater with oxygen-rich river water. Our models predict that the benthic zones of tidal rivers play an important role in removing new nitrate inputs from discharging groundwater but may be less effective at removing nitrate from river water. Nitrate removal and production rates are expected to vary significantly along tidal rivers as permeability, organic matter content, tidal range vary. It is imperative that we understand nitrogen dynamics along tidal rivers and their role in nitrogen export to the coast.

  4. Water exchange traded funds: A study on idiosyncratic risk using Markov switching analysis

    Directory of Open Access Journals (Sweden)

    Gurudeo Anand Tularam

    2016-12-01

    Full Text Available We investigate the relationship between idiosyncratic risk and return among four water exchange traded funds—PowerShares Water Resources Portfolio, Power Shares Global Water, First Trust ISE Water Index Fund, and Guggenheim S&P Global Water Index ETF using the Markov switching model for the period 2007–2015. The generated transition probabilities in this paper show that there is a high and low probability of switching between Regimes 1 and 3, respectively. Moreover, we find that the idiosyncratic risk for most of the exchange traded funds move from low volatility (Regime 2 to very low volatility (Regime 1 and 3. Our study also identify that the beta coefficients are positive and entire values are less than 1. Thus, it seems that water investment has a lower systematic risk and a positive effect on the water exchange traded index funds returns during different regimes.

  5. Some analytic diagnostic models for transport processes in estuarine and coastal waters

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2001-03-01

    Advection and dispersion processes in estuarine and coastal waters are briefly reviewed. Beginning from the basic macroscopic equations of transport for a substance diluted or suspended in the considered body of water,several levels of filtering in time and space are described and applied to obtain suitable diagnostic mathematical models both with scale effects and gaussian.The solutions of the aforementioned models,for initial distributions and boundary conditions with enough symmetry,are discussed, as well as their applications to a parameter characterization of the transport properties of the receiving body of water

  6. Salinity and water temperature data from the Coastal Waters of Washington/Oregon from 01 March 2001 to 31 December 2001 (NODC Accession 0001142)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity and water temperature data were collected using conductivity sensor and temperature probe in the Coastal Waters of Washington/Orgen from March 1, 2001 to...

  7. The delta18O composition of Antarctic coastal current waters

    International Nuclear Information System (INIS)

    Frew, R.; Heywood, K.; Dennis, P.

    1997-01-01

    The varying proportions of 18 O to 16 O in sea water provide an oceanographic trace like salinity, but with an extra degree of freedom: salt is a tracer for the oceanic fluid, whereas the isotopic composition is a tracer specifically for the water component of that fluid. Hydrogen and oxygen isotopes are the variables most intimately related to the water component in the sea, therefore thay furnish a direct link to the water in the atmosphere and on continents and to the precipitation cycle which caused the salinity changes. The ratio of 18 O to 16 O (delta 18 O) ot waters is a powerful tracer in polar regions where sea and glacial ice processes decouple delta 18 O from salinity. Here we present observations from a significant but relatively unexplored component of the Southern Ocean current system, the Antarctic Coastal Current, and its associated Antarctic Slope Front. (author)

  8. Spatiotemporal variability in archaeal communities of tropical coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, S.K.

    properties on SST biases and the South Asian summer monsoon in a coupled GCM. Clim Dyn 39:811–826 Urakawa H, Martens-Habbena W, Stahl DA (2010) High abundance of ammonia-oxidizing archaea in coastal waters, determined using a modified DNA extraction method...- ments suggests that archaea play a major role in the global nitrification process (Francis et al. 2005; Prosser and Nicol 2008; Wuchter et al. 2006). Denaturing gradient gel electrophoresis (DGGE) is among the reliable techniques for microbial...

  9. Algae as bioindicators for radionuclides in Nordic coastal waters

    International Nuclear Information System (INIS)

    Neumann, G.; Notter, M.

    1991-01-01

    During the later part of the 1970's NKS decided to introduce the bladder wrack (Fucus vesiculosus) as a suitable organism for monitoring radionuclides in Nordic coastal waters. During the past few years studies on this subject have been going on to a varying extent in the different Nordic countries. At this miniseminar the participants described different ongoing studies and projects. The lectures are summarized in the abstracts in the appendix, in which the speakers themselves are responsible for their contributions. (au)

  10. Water on BN doped benzene: A hard test for exchange-correlation functionals and the impact of exact exchange on weak binding

    International Nuclear Information System (INIS)

    Al-Hamdani, Yasmine S.; Michaelides, Angelos; Alfè, Dario; Lilienfeld, O. Anatole von

    2014-01-01

    Density functional theory (DFT) studies of weakly interacting complexes have recently focused on the importance of van der Waals dispersion forces, whereas the role of exchange has received far less attention. Here, by exploiting the subtle binding between water and a boron and nitrogen doped benzene derivative (1,2-azaborine) we show how exact exchange can alter the binding conformation within a complex. Benchmark values have been calculated for three orientations of the water monomer on 1,2-azaborine from explicitly correlated quantum chemical methods, and we have also used diffusion quantum Monte Carlo. For a host of popular DFT exchange-correlation functionals we show that the lack of exact exchange leads to the wrong lowest energy orientation of water on 1,2-azaborine. As such, we suggest that a high proportion of exact exchange and the associated improvement in the electronic structure could be needed for the accurate prediction of physisorption sites on doped surfaces and in complex organic molecules. Meanwhile to predict correct absolute interaction energies an accurate description of exchange needs to be augmented by dispersion inclusive functionals, and certain non-local van der Waals functionals (optB88- and optB86b-vdW) perform very well for absolute interaction energies. Through a comparison with water on benzene and borazine (B 3 N 3 H 6 ) we show that these results could have implications for the interaction of water with doped graphene surfaces, and suggest a possible way of tuning the interaction energy

  11. Physical, Nutrient, and Biological Measurements of Coastal Waters off Central California in November 2007

    National Research Council Canada - National Science Library

    Rago, Thomas A; Michisaki, Reiko; Marinovic, Baldo; Blum, Marguerite; Whitaker, Katherine

    2008-01-01

    The results of analyses of hydrographic, nutrient, and biological data collected in coastal ocean waters off Central California in November 2007 aboard the NOAA Ship David Starr Jordan are presented...

  12. Fortnightly atmospheric tides forced by spring and neap tides in coastal waters.

    Science.gov (United States)

    Iwasaki, Shinsuke; Isobe, Atsuhiko; Miyao, Yasuyuki

    2015-05-18

    The influence of sea surface temperature (SST) on atmospheric processes over the open ocean has been well documented. However, atmospheric responses to SST in coastal waters are poorly understood. Oceanic stratification (and consequently, SST) in coastal waters largely depends on the fortnightly spring-neap tidal cycle, because of variations in vertical tidal mixing. Here we investigate how changes in SST during the fortnightly tidal cycle affect the lower-level atmosphere over the Seto Inland Sea, Japan. We use a combination of in situ measurements, satellite observations and a regional atmospheric model. We find that the SST in summer shows cool (warm) anomalies over most of the inland sea during spring (neap) tides. Additionally, surface air temperature is positively correlated with the SST as it varies during the fortnightly tidal cycle. Moreover, the fortnightly spring-neap cycle also influences the surface wind speed because the atmospheric boundary layer becomes stabilized or destabilized in response to the difference between air temperature and SST.

  13. Mixed filling for the successive isotopic exchange in the phase sequence water - water vapors - hydrogen

    International Nuclear Information System (INIS)

    Stefanescu, D.; Peculea, M.; Hirean, I.; Croitoru, C.

    1995-01-01

    The paper deals with the process of the isotopic exchange implied in heavy water production. Details concerning the structural arrangement of the process contact elements inside the exchange columns are presented. A hydrophilic filling, based on phosphorous bronze, and the platinum catalyst structure , resulted from this work, are to be implemented in the column equipment of the heavy water distillation pilot operating in connection with the CANDU type reactors. The performances of the mixed catalyst components were derived from experimental data by means of the three fluids model equations

  14. A meta-analysis of leaf gas exchange and water status responses to drought.

    Science.gov (United States)

    Yan, Weiming; Zhong, Yangquanwei; Shangguan, Zhouping

    2016-02-12

    Drought is considered to be one of the most devastating natural hazards, and it is predicted to become increasingly frequent and severe in the future. Understanding the plant gas exchange and water status response to drought is very important with regard to future climate change. We conducted a meta-analysis based on studies of plants worldwide and aimed to determine the changes in gas exchange and water status under different drought intensities (mild, moderate and severe), different photosynthetic pathways (C3 and C4) and growth forms (herbs, shrubs, trees and lianas). Our results were as follows: 1) drought negatively impacted gas exchange and water status, and stomatal conductance (gs) decreased more than other physiological traits and declined to the greatest extent in shrubs and C3 plants. Furthermore, C4 plants had an advantage compared to C3 plants under the same drought conditions. 2) The decrease in gs mainly reduced the transpiration rate (Tr), and gs could explain 55% of the decrease in the photosynthesis (A) and 74% of the decline in Tr. 3). Finally, gas exchange showed a close relationship with the leaf water status. Our study provides comprehensive information about the changes in plant gas exchange and water status under drought.

  15. Ground-water geology of the coastal zone, Long Beach-Santa Ana area, California

    Science.gov (United States)

    Poland, J.F.; Piper, A.M.

    1956-01-01

    This paper is the first chapter of a comprehensive report on the ground-water features in the southern part of the coastal plain in Los Angeles and Orange Counties, Calif., with special reference to the effectiveness of the so-called coastal barrier--the Newport-Inglewood structural zone--in restraining landwar,-1 movement of saline water. The coastal plain in Los Angeles and Orange Counties, which covers some 775 square miles, sustains a large urban and rural population, diverse industries, and intensive agricultural developments. The aggregate ground-water withdrawal in 1945 was about 400,000 acre-feet a year, an average of about 360 million gallons a day. The dominant land-form elements are a central lowland plain with tongues extending to the coast, bordering highlands and foothills, and a succession of low hills and mesas aligned northwestward along the coastal edge of the central low- land plain. These low hills and mesas are the land-surface expression of geologic structure in the Newport-Inglewood zone. The highland areas that border the inland edge of the coastal plain are of moderate altitude and relief; most of the ridge crests range from 1,400 to 2,500 feet in altitude, but Santiago Peak in the Santa Ana Mountains attains a height of 5,680 feet above sea level. From these highlands the land surface descends across foothills and aggraded alluvial aprons to the central lowland, Downey Plain, here defined as the surface formed by alluvial aggradation during the post-Pleistocene time of rising base level. The Newport-Inglewood belt of hills and plains (mesas) has a maximum relief of some 500 feet but is widely underlain at a depth of about 30 feet by a surface of marine plantation. As initially formed in late Pleistocene time that surface was largely a featureless plain. Thus the present land-surface forms within the Newport-Inglewood belt measure the earth deformation that has occurred there since late Pleistocene time and so are pertinent with respect to

  16. Exchangeable pulmonary water space evaluation using giant liposomes

    International Nuclear Information System (INIS)

    Santos, A.C.; Ribeiro, M.J.; Ferreira, N.; De Lima, J.J.P.

    1998-01-01

    The present work aims to study the potential use of liposomes for the evaluation of pulmonary exchangeable water space, important parameter in some pulmonary oedema situations. This study is based upon the delivery of a diffusible water radiotracer into pulmonary capillary network, which equilibrates with interstitial water space of the lung and returns to the blood circulation. The time constant of this phenomena depends on the magnitude of the water space under study. The release of the diffusible radiotracer in lung capillaries is performed using liposomes with specific formulation. The giant liposomes (15-30μm diameter) used in this study are instable at 37 deg. C. They are biocompatible, biodegradable, with low toxicity and showed no immunogenicity. A water tracer labelled with 99m Tc, encapsulated in the aqueous phase of giant liposomes, has been used. Liposomes were prepared in sterile conditions and with apyrogenic materials. The lipid films composition is L-α-diestearoylphosphatidylcholine (DSPC), L-α-phosphatidyl-DL-glycerol (EPG) and cholesterol (CHOL) (60%/10%/30% mass ratio). After iv injection at +-20 deg. C in the femoral vein of Wistar rats (300g-600g) or albine rabbits (4.5-5Kg), the thermolabile liposomes will be entrapped in lung capillaries and release the radiotracer locally. When the radiodrug is diffusible we will evaluate the volume of the exchangeable pulmonary water analyzing the activity/time curves. These curves are slower for greater water spaces. When the radiotracer is non-diffusible, the disappearance curves are not influenced by the extravascular water space. (author)

  17. Rainwater Harvesting-based Safe Water Access in Diarrhea-endemic Coastal Communities of Bangladesh under Threats of Climate Change

    Science.gov (United States)

    Akanda, A. S.; Redwan, A. M.; Ali, M. A.; Alam, M.; Jutla, A.; Colwell, R. R.

    2014-12-01

    The highly populated coastal floodplains of the Bengal Delta have a long history of water-related natural calamities such as droughts, floods, and cyclones. Population centers along the floodplain corridors of the GBM (Ganges-Brahmaputra-Meghna) river system remain vulnerable to such natural hazards and waterborne epidemic outbreaks due to increasing intensity and changing frequency of extreme events over many areas in the delta region. Such changes in hydrologic extremes and resulting environmental conditions would likely lengthen the transmission seasons of prevalent waterborne diseases and alter their geographic range as well as seasonality. In addition, the combination of changing upstream precipitation and temperature, and coastal sea-level rise are exposing a vast area in Southwestern Bangladesh to increased diarrheal disease outbreaks due to higher salinity and water scarcity in the dry season as well as coastal flooding and water resources contamination in the wet season. It is thus essential to establish sustainable safe water access practices in these regions for the rural communities of low-income people. The impact of climate change in the recent past on the people of coastal rural areas of Bangladesh has been severe, and the water sector is one of its biggest victims. Previously, pond and groundwater sources were considered dependable, but salinity intrusion in both water resources have left the vulnerable people with only a few scarce ponds and forced them to depend more on rainwater than before. The poorest group is suffering the most for this crisis even though paying more of the percentage of their income especially in the dry season (December-March). As rainwater is their most preferred and dependable option during this part of the year, outbreaks of waterborne diseases can be minimized by installing rainwater harvesting systems with effective disinfection system at both household and community levels. In this study, we explore the technical

  18. Process for exchanging hydrogen isotopes between gaseous hydrogen and water

    International Nuclear Information System (INIS)

    Hindin, S. G.; Roberts, G. W.

    1980-01-01

    A process for exchanging isotopes of hydrogen, particularly tritium, between gaseous hydrogen and water is provided whereby gaseous hydrogen depeleted in tritium and liquid or gaseous water containing tritium are reacted in the presence of a metallic catalyst

  19. Spatio-temporal variability in hydro-chemical characteristics of coastal waters of Salimpur, Chittagong along the Bay of Bengal

    Directory of Open Access Journals (Sweden)

    Avijit Talukder

    2016-04-01

    Full Text Available Diverse seasonal characteristics of hydro-chemical parameters in the coastal zone are significantly related to aquaculture development. In this paper, general water quality condition derived from laboratory analysis from the coastal waters of Salimpur, Chittagong is presented. Samples were collected from onshore and offshore site of two adjacent coastal locations named as North Salimpur (experimental location and South Kattoli (control during a monsoon and a dry season spanning 2013-14. The spatio-temporal variability of studied parameters were found as air temperature 26.5-32.5 ˚C, water temperature 23-33 °C, pH 7.1-7.9, DO 4.29-7.11 mg/L, BOD 1.10-3.25 mg/L, salinity 1.6-21 ppt, EC 3.40-35.68 mS/cm, TDS 2.02-21.99 g/L, TSS 0.62-2.76 g/L, transparency 4.5-14 cm, precipitation 64-1992 mm, NO2-N 1.94-2.58 µg/L, PO4-P 0.45-1.84 µg/L, SiO3-Si 130.46-956.31 µg/L during investigation period. Average values of physicochemical parameters were found to be in compliance with standard guidelines. The ship breaking activities near experimental location possess negative impacts on local geomorphology, freshwater inputs, precipitation and aquatic environment as well. Moreover, wind driven forces, tidal action, wave characteristics and changes in monsoon pattern regulate the coastal processes. This research suggests the importance of regular monitoring to assess present status of water quality and future prospect of aquaculture in the Chittagong coastal zone.

  20. Ion exchange-based treatment of "6"0Co contaminated well-water for storing γ irradiation source

    International Nuclear Information System (INIS)

    Bi Meng; Miao Shilin; Zhang Xiaolu; Zhang Youjiu

    2014-01-01

    Objective: To select an efficient ion exchange resin to purify the "6"0Co contaminated well-water for storing radioactive source and to ensure the radioactivity of "6"0Co in treated well-water below 10 Bq/L. Methods: The radioactivity of "6"0Co in the water samples was measured by using the potassium cobaltinitrite coprecipitation-β counting method. The treatment efficiencies of two different ion exchange resins for the simulated "6"0Co-bearing waste water were compared to select a better one to dispose of the "6"0Co contaminated well-water. Results: The treatment efficiency of MBD-15-SC mixed ion exchange resin was about 5.8 times higher than ZGCNR50 strong-acid cation exchange resin. The radioactivity of "6"0Co in the contaminated well-water could be reduced from 4.16 × 10"5 Bq/L to 1.16 Bq/L by two-stage sorption of MBD-15-SC mixed ion exchange resin. Conclusions: Using several times of two-stage MBD-15-SC mixed ion exchange resin could effectively purify the "6"0Co contaminated well-water. The quality of the treated well-water could meet the sewage discharge standards. (authors)

  1. Analysis of Tide and Offshore Storm-Induced Water Table Fluctuations for Structural Characterization of a Coastal Island Aquifer

    Science.gov (United States)

    Trglavcnik, Victoria; Morrow, Dean; Weber, Kela P.; Li, Ling; Robinson, Clare E.

    2018-04-01

    Analysis of water table fluctuations can provide important insight into the hydraulic properties and structure of a coastal aquifer system including the connectivity between the aquifer and ocean. This study presents an improved approach for characterizing a permeable heterogeneous coastal aquifer system through analysis of the propagation of the tidal signal, as well as offshore storm pulse signals through a coastal aquifer. Offshore storms produce high wave activity, but are not necessarily linked to significant onshore precipitation. In this study, we focused on offshore storm events during which no onshore precipitation occurred. Extensive groundwater level data collected on a sand barrier island (Sable Island, NS, Canada) show nonuniform discontinuous propagation of the tide and offshore storm pulse signals through the aquifer with isolated inland areas showing enhanced response to both oceanic forcing signals. Propagation analysis suggests that isolated inland water table fluctuations may be caused by localized leakage from a confined aquifer that is connected to the ocean offshore but within the wave setup zone. Two-dimensional groundwater flow simulations were conducted to test the leaky confined-unconfined aquifer conceptualization and to identify the effect of key parameters on tidal signal propagation in leaky confined-unconfined coastal aquifers. This study illustrates that analysis of offshore storm signal propagation, in addition to tidal signal propagation, provides a valuable and low resource approach for large-scale characterization of permeable heterogeneous coastal aquifers. Such an approach is needed for the effective management of coastal environments where water resources are threatened by human activities and the changing climate.

  2. Achieving reduced fouling of cooling water exchangers with stainless steel tubes

    International Nuclear Information System (INIS)

    Iftikhar, A.; Mir, N.

    2010-01-01

    Good performance of cooling water heat exchangers plays a vital role in the over all energy efficiency of a chemical plant. Heavy fouling on carbon steel tubes of the cooling water exchangers was causing poor performance and frequent cleaning requirement. The carbon steel tubes were replaced with stainless steel tubes. Improved performance was achieved and cleaning frequency reduced. The paper covers the details of study and methodology applied for the above changes along with summary of results. (author)

  3. Uncertainty Analysis of Phytoplankton Dynamics in Coastal Waters

    NARCIS (Netherlands)

    Niu, L.

    2015-01-01

    There is an increasing concern about the interactions between phytoplankton and coastal ecosystems, especially on the negative effects from coastal eutrophication and phytoplankton blooms. As the key indicator of the coastal ecosystem, phytoplankton plays an important role in the whole impact-effect

  4. Hydrology and Salt Balance in a Large, Hypersaline Coastal Lagoon: Lagoa de Araruama, Brazil

    Science.gov (United States)

    Kjerfve, Björn; Schettini, C. A. F.; Knoppers, Bastiaan; Lessa, Guilherme; Ferreira, H. O.

    1996-06-01

    Lagoa de Araruama in the state of Rio de Janeiro, Brazil, is a hypersaline coastal lagoon as a result of semi-arid climate conditions, a small drainage basin and a choked entrance channel. The lagoon has been continuously hypersaline for at least 4·5 centuries, but the mean salinity has varied substantially. It has recently decreased from 57 to 52 as indicated by density (salinity) measurements between 1965 and 1990. Analysis of more than 20 years of salinity time series data, in addition to monthly lagoon cruises to measure the spatial salinity distribution, indicate that the lagoon salinity largely fluctuates in response to the difference between evaporation and precipitation. The major factor explaining the long-term trend of decreasing salinity in the lagoon is the constant pumping of 1 m 3s -1of freshwater to the communities surrounding the lagoon from an adjacent watershed, and subsequent discharge of this water into Lagoa de Araruama. The net salt budget is primarily a balance between the advective import of salt from the coastal ocean and eddy diffusive export of salt to the ocean, although the extensive mining of salt from the lagoon during past decades is also a small but significant contribution to the salt budget. The flushing half-life is proposed as a useful time scale of water exchange, is calculated based on a combination of hydrological and tidal processes, and is excellent for comparison of lagoons and assessing water quality changes. The flushing half-life measures 83·5 days for Lagoa de Araruama, considerably longer than for most other coastal lagoons. The proposed dredging of a second ocean channel to Lagoa de Araruama is probably not a good idea. It is likely to accelerate the decrease of lagoon salinity and somewhat improve the lagoon water exchange. At the same time, this will eliminate the apparent buffering capacity provided by the hypersaline environment, and thus may potentially cause water quality problems.

  5. Grey mullet (Mugilidae) as possible indicators of global warming in South African estuaries and coastal waters.

    Science.gov (United States)

    James, Nicola C; Whitfield, Alan K; Harrison, Trevor D

    2016-12-01

    The grey mullet usually occur in large numbers and biomass in the estuaries of all three South African biogeographic regions, thus making it an ideal family to use in terms of possibly acting as an environmental indicator of global warming. In this analysis the relative estuarine abundance of the dominant three groups of mugilids, namely tropical, warm-water and cool-water endemics, were related to sea surface coastal temperatures. The study suggests a strong link between temperature and the distribution and abundance of the three mullet groups within estuaries and indicates the potential of this family to act as an indicator for future climate change within these systems and adjacent coastal waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Fisheries management in inland and coastal waters in Denmark from 1987 to 1999

    DEFF Research Database (Denmark)

    Rasmussen, Gorm; Geertz-Hansen, Peter

    2001-01-01

    Fishing is a major recreational activity in Denmark, involving both inland and coastal waters. Anglers, aged 18-67, and amateur fishermen, aged 12-67, must hold a valid fishing pen- nit. Fees are used for stocking, river restoration and fisheries research. All proposals for stocking inland waters...... for several generations. Stocking is also subject to genetic guidelines. This paper reviews the status of fisheries in Danish inland waters, their regulation, socio-economic aspects, stocking, aquaculture and the main problems and trends....

  7. Analytical characterization of selective benthic flux components in estuarine and coastal waters

    Science.gov (United States)

    King, Jeffrey N.

    2011-01-01

    Benthic flux is the rate of flow across the bed of a water body, per unit area of bed. It is forced by component mechanisms, which interact. For example, pressure gradients across the bed, forced by tide, surface gravity waves, density gradients, bed–current interaction, turbulence, and terrestrial hydraulic gradients, drive an advective benthic flux of water and constituents between estuarine and coastal waters, and surficial aquifers. Other mechanisms also force benthic flux, such as chemical gradients, bioturbation, and dispersion. A suite of component mechanisms force a total benthic flux at any given location, where each member of the suite contributes a component benthic flux. Currently, the types and characteristics of component interactions are not fully understood. For example, components may interact linearly or nonlinearly, and the interaction may be constructive or destructive. Benthic flux is a surface water–groundwater interaction process. Its discharge component to a marine water body is referred to, in some literature, as submarine groundwater discharge. Benthic flux is important in characterizing water and constituent budgets of estuarine and coastal systems. Analytical models to characterize selective benthic flux components are reviewed. Specifically, these mechanisms are for the component associated with the groundwater tidal prism, and forced by surface gravity wave setup, surface gravity waves on a plane bed, and the terrestrial hydraulic gradient. Analytical models are applied to the Indian River Lagoon, Florida; Great South Bay, New York; and the South Atlantic Bight in South Carolina and portions of North Carolina.

  8. Adaptation and application of multivariate AMBI (M-AMBI) in US coastal waters

    Science.gov (United States)

    The multivariate AMBI (M-AMBI) is an extension of the AZTI Marine Biotic Index (AMBI) that has been used extensively in Europe, but not in the United States. In a previous study, we adapted AMBI for use in US coastal waters (US AMBI), but saw biases in salinity and score distribu...

  9. Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

    NARCIS (Netherlands)

    Booij, P; Sjollema, S.B.; van der Geest, H.G.; Leonards, P.E.G.; Lamoree, M.H.; de Voogt, W.P.; Admiraal, W.; Laane, R.W.P.M.; Vethaak, A.D.

    2015-01-01

    For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and

  10. Eddy-induced cross-shelf export of high Chl-a coastal waters in the SE Bay of Biscay

    KAUST Repository

    Rubio, Anna

    2017-12-08

    Different remote sensing data were combined to characterise a winter anticyclonic eddy in the southeastern Bay of Biscay and to infer its effects on cross-shelf exchanges, in a period when typical along shelf-slope currents depict a cyclonic pattern. While the joint analysis of available satellite data (infrared, visible and altimetry) permitted the characterisation and tracking of the anticyclone properties and path, data from a coastal high-frequency radar system enabled a quantitative analysis of the surface cross-shelf transports associated with this anticyclone. The warm core anticyclone had a diameter of around 50km, maximum azimuthal velocities near 50cms−1 and a relative vorticity of up to −0.45f. The eddy generation occurred after the relaxation of a cyclonic wind-driven current regime over the shelf-slope; then, the eddy remained stationary for several weeks until it started to drift northwards along the shelf break. The surface signature of this eddy was observed by means of high-frequency radar data for 20 consecutive days, providing a unique opportunity to characterise and quantify, from a Lagrangian perspective, the associated transport and its effect on the Chl-a surface distribution. We observed the presence of mesoscale structures with similar characteristics in the area during different winters within the period 2011–2014. Our results suggest that the eddy-induced recurrent cross-shelf export is an effective mechanism for the expansion of coastal productive waters into the adjacent oligotrophic ocean basin.

  11. Lead isotope exchange between dissolved and fluvial particulate matter: a laboratory study from the Johor River estuary

    Science.gov (United States)

    Chen, Mengli; Boyle, Edward A.; Lee, Jong-Mi; Nurhati, Intan; Zurbrick, Cheryl; Switzer, Adam D.; Carrasco, Gonzalo

    2016-11-01

    Atmospheric aerosols are the dominant source of Pb to the modern marine environment, and as a result, in most regions of the ocean the Pb isotopic composition of dissolved Pb in the surface ocean (and in corals) matches that of the regional aerosols. In the Singapore Strait, however, there is a large offset between seawater dissolved and coral Pb isotopes and that of the regional aerosols. We propose that this difference results from isotope exchange between dissolved Pb supplied by anthropogenic aerosol deposition and adsorbed natural crustal Pb on weathered particles delivered to the ocean by coastal rivers. To investigate this issue, Pb isotope exchange was assessed through a closed-system exchange experiment using estuarine waters collected at the Johor River mouth (which discharges to the Singapore Strait). During the experiment, a known amount of dissolved Pb with the isotopic composition of NBS-981 (206Pb/207Pb = 1.093) was spiked into the unfiltered Johor water (dissolved and particulate 206Pb/207Pb = 1.199) and the changing isotopic composition of the dissolved Pb was monitored. The mixing ratio of the estuarine and spike Pb should have produced a dissolved 206Pb/207Pb isotopic composition of 1.161, but within a week, the 206Pb/207Pb in the water increased to 1.190 and continued to increase to 1.197 during the next two months without significant changes of the dissolved Pb concentration. The kinetics of isotope exchange was assessed using a simple Kd model, which assumes multiple sub-reservoirs within the particulate matter with different exchange rate constants. The Kd model reproduced 56% of the observed Pb isotope variance. Both the closed-system experiment and field measurements imply that isotope exchange can be an important mechanism for controlling Pb and Pb isotopes in coastal waters. A similar process may occur for other trace elements. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

  12. Effects of Hydrologic Restoration on the Residence Times and Water Quality of a Coastal Wetland in the Florida Everglades

    Science.gov (United States)

    Sandoval, E.; Price, R. M.; Melesse, A. M.; Whitman, D.

    2013-05-01

    The Everglades, located in southern Florida, is a dominantly freshwater coastal wetland ecosystem that has experienced many alterations and changes led by urbanization and water management practices with most cases resulting in decreased water flow across the system. The Comprehensive Everglades Restoration Plan, passed in 2000, has the final goal of restoring natural flow and clean water to the Everglades while also balancing flood control and water supply needs of the south Florida population with approximately 60 projects to be constructed and completed in the following 30 years. One way to assess the success of restoration projects is to observe long-term hydrological and geochemical changes as the projects undergo completion. The purpose of this research was to investigate the effects of restoration on the water balance, flushing time, and water chemistry of Taylor Slough; one of the main natural waterways located within the coastal Everglades. A water balance equation was used to solve for groundwater-surface water exchange. The major parameters for the water balance equation (precipitation, evapotranspiration (ET), surface water storage, inflow and outflow) were obtained from the U.S. Geological Survey and Everglades National Park databases via the Everglades Depth Estimation Network (EDEN). Watershed flushing times were estimated as the surface water volume divided by the total outputs from the watershed. Both the water balance equation and water flushing time were calculated on a monthly time step from 2001 - 2011. Water chemistry of major ions and Total Nitrogen (TN) and Total Phosphorus (TP) was analyzed on water samples, 3-day composites collected every 18 hours from 2008 - 2012, and correlated with water flushing times. Stable isotopes of oxygen and hydrogen of water samples were obtained to support the dominant inputs of water into Taylor Slough as identified by the water budget equation. Results for flushing times varied between 3 and 78 days, with

  13. Carbon and Water Fluxes in a Drained Coastal Clearcut and a Pine Plantation in Eastern North Carolina

    Science.gov (United States)

    J. L. Deforest; Ge Sun; A. Noormets; J. Chen; Steve McNulty; M. Gavazzi; Devendra M. Amatya; R. W. Skaggs

    2006-01-01

    The effects of clear-cutting and cultivating for timber on ecosystem carbon and water fluxes were evaluated by comparative measurements of two drained coastal wetland systems in the North Carolina coastal plain. Measurements were conducted from January through September, 2005 in a recent clearcut (CC) of native hardwoods and a loblolly pine (Pinus tacda...

  14. The exchange reaction between deuterium and water vapour on platinum deposited over a hydrophobic support

    International Nuclear Information System (INIS)

    Itsuo, Iida; Junko, Kato; Kenzi, Tamuru

    1977-01-01

    Isotope exchange reaction between deuterium gas and water vapour at room temperature and below on platinum deposited on hydrophobic supports such as polytetrafluoroethylene (PTFE) or Porapak Q (copolymer of styrene and divinylbenzene) was studied and the results were compared with those of the exchange reaction on platinum over hydrophilic support such as alumina. It was demonstrated that the exchange reaction at temperatures below the boiling point of water is markedly retarded by the multilayer adsorption of water over the platinum catalyst deposited on hydrophilic support, whereas the platinum catalyst on hydrophobic support exhibited a high catalytic activity, being not retarded by the water, forming no multilayer of adsorbed water over platinum surface. Therefore in the case of the hydrogen isotope exchange reaction on platinum over hydrophobic support, the chemical exchange rate can be measured even under a saturated vapour pressure of water. The surface area of platinum was estimated by hydrogen chemisorption and hydrogen titration and specific activities of the catalyst were calculated at both room temperature and freezing point of water, which revealed that the specific rate of this reaction does not differ so much over various supports. (orig.) [de

  15. Dual-Level Material and Psychological Assessment of Urban Water Security in a Water-Stressed Coastal City

    Directory of Open Access Journals (Sweden)

    Yajing Huang

    2015-04-01

    Full Text Available The acceleration of urbanization and industrialization has been gradually aggravating water security issues, such as water shortages, water pollution, and flooding or drought disasters and so on. Water security issues have become a great challenge to urban sustainable development. In this context, we proposed a dual-level material and psychological assessment method to assess urban water security. Psychological security coefficients were introduced in this method to combine material security and residents’ security feelings. A typical water-stressed coastal city in China (Dalian was chosen as a case study. The water security status of Dalian from 2010 to 2012 was analysed dynamically. The results indicated that the Dalian water security statuses from 2010 to 2012 were basically secure, but solutions to improve water security status and solve water resource problems are still required. This dual-level material and psychological assessment for urban water security has improved conventional material assessment through the introduction of psychological security coefficients, which can benefit decision-making for urban water planning, management and protection.

  16. Spatial variation in energy exchange across coastal environments in Greenland

    Science.gov (United States)

    Lund, M.; Abermann, J.; Citterio, M.; Hansen, B. U.; Larsen, S. H.; Stiegler, C.; Sørensen, L. L.; van As, D.

    2015-12-01

    The surface energy partitioning in Arctic terrestrial and marine areas is a crucial process, regulating snow, glacier ice and sea ice melt, and permafrost thaw, as well as modulating Earth's climate on both local, regional, and eventually, global scales. The Arctic region has warmed approximately twice as much as the global average, due to a number of feedback mechanisms related to energy partitioning, most importantly the snow and ice-albedo feedback. However, direct measurements of surface energy budgets in the Arctic are scarce, especially for the cold and dark winter period and over transects going from the ice sheet and glaciers to the sea. This study aims to describe annual cycles of the surface energy budget from various surface types in Arctic Greenland; e.g. glacier, snow, wet and dry tundra and sea ice, based on data from a number of measurement locations across coastal Greenland related to the Greenland Ecosystem Monitoring (GEM) program, including Station Nord/Kronprins Christians Land, Zackenberg/Daneborg, Disko, Qaanaq, Nuuk/Kobbefjord and Upernaviarsuk. Based on the available time series, we will analyze the sensitivity of the energy balance partitioning to variations in meteorological conditions (temperature, cloudiness, precipitation). Such analysis would allow for a quantification of the spatial variation in the energy exchange in aforementioned Arctic environments. Furthermore, this study will identify uncertainties and knowledge gaps in Arctic energy budgets and related climate feedback effects.

  17. Assessment of the Temporal Evolution of Storm Surge via Land to Water Isopleths in Coastal Louisiana

    Science.gov (United States)

    Siverd, C. G.; Hagen, S. C.; Bilskie, M. V.; Braud, D.; Gao, S.; Peele, H.; Twilley, R.

    2017-12-01

    The low-lying coastal Louisiana deltaic landscape features an intricate system of fragmented wetlands, natural ridges, man-made navigation canals and flood protection infrastructure. Since 1900 and prior to the landfall of Hurricane Katrina in 2005, Louisiana lost approximately 480,000 ha (1,850 sq mi) of coastal wetlands and an additional 20,000 ha (77 sq mi) due to Katrina. This resulted in a total wetland storm protection value loss of USD 28.3 billion and USD 1.1 billion, respectively (Costanza 2008). To investigate the response of hurricane storm surge (e.g. peak water levels, inundation time and extent) through time due to land loss, hydrodynamic models that represent historical eras of the Louisiana coastal landscape were developed. Land:Water (L:W) isopleths (Gagliano 1970, 1971, Twilley 2016) have been calculated along the coast from the Sabine River to the Pearl River. These isopleths were utilized to create a simplified coastal landscape (bathymetry, topography, bottom roughness) representing circa 2010. Similar methodologies are employed with the objective of developing storm surge models that represent the coastal landscape for past eras. The goal is to temporally examine the evolution of storm surge along coastal Louisiana. The isopleths determined to best represent the Louisiana coast as a result of the methodology devised to develop the simple storm surge model for c.2010 are applied in the development of surge models for historical eras c.1930 and c.1970. The ADvaced CIRCulation (ADCIRC) code (Luettich 2004) is used to perform storm surge simulations with a predetermined suite of hurricane wind and pressure forcings. Hydrologic Unit Code 12 (HUC12) sub-watersheds provide geographical bounds to quantify mean maximum water surface elevations (WSEs), volume of inundation, and area of inundation. HUC12 sub-watersheds also provide a means to compare/contrast these quantified surge parameters on a HUC12-by-HUC12 basis for the c.1930, c.1970 and c.2010

  18. Integrated modelling of nitrate loads to coastal waters and land rent applied to catchment-scale water management

    DEFF Research Database (Denmark)

    Refsgaard, A.; Jacobsen, T.; Jacobsen, Brian H.

    2007-01-01

    The EU Water Framework Directive (WFD) requires an integrated approach to river basin management in order to meet environmental and ecological objectives. This paper presents concepts and full-scale application of an integrated modelling framework. The Ringkoebing Fjord basin is characterized by ...... the potential and limitations of comprehensive, integrated modelling tools.  ......The EU Water Framework Directive (WFD) requires an integrated approach to river basin management in order to meet environmental and ecological objectives. This paper presents concepts and full-scale application of an integrated modelling framework. The Ringkoebing Fjord basin is characterized...... by intensive agricultural production and leakage of nitrate constitute a major pollution problem with respect groundwater aquifers (drinking water), fresh surface water systems (water quality of lakes) and coastal receiving waters (eutrophication). The case study presented illustrates an advanced modelling...

  19. PRIMARILY RESULTS OF PHYTOPLANKTON DNA AND VARIATION TO ENVIRONMENTAL FACTORS IN DURRES`S BAY COASTAL WATERS (ALBANIA

    Directory of Open Access Journals (Sweden)

    Laura Gjyli

    2013-10-01

    Full Text Available After isolation of phytoplankton DNA in coastal waters of Durres Bay, Albania, quantification and analysis of quality were investigated with spectrophotometric analysis. Analysis of UV absorption by the nucleotides provides a simple and accurate estimation of the concentration of nucleic acids in a sample. This method is however limited by the quantity of DNA and the purity of the preparation. Also biotic environment factors as Chlorophyll a and abiotic environment factors as temperature, salinity, pH, dissolved oxygen, turbidity, nitrate, phosphate were investigated to assess DNA quantities in different environment conditions. The Chlorophyll a was studied also to access the level of trophy. The sample stations were: Golem Beach (GB, Channel of Plepa (ChP, Hekurudha Beach (HB, Ex-Fuel Quay in Marine Durres Harbour (EFQ, Water Channel of Durres City (WChDC and Currila Beach (CB. Samples are taken in one meter depth from the water surface. Water samples were collected monthly from April to October 2011. The most abundant stations with phytoplankton DNA are Channel of Plepa and Water Channel of Durres City. This confirms that there are spills of fresh waters, sewage or agricultural water spills, often discharge in coastal waters. Referring Mutliple Regression Analysis and single regression analysis, the association between phytoplankton DNA and environment factors was strong (R2 = 0.75. Basing in single correlation and statistically significance (p-value ≤ 0.05, the enviroment factors that correlated to phytoplankton DNA were pH, salinity and phosphate; explaining thus the variation of total phytoplankton in Durres Bay coastal waters.

  20. Time-series variations of the short-lived Ra in coastal waters: implying input of SGD to the coastal zone of Da-Chia River, Taichung, Taiwan

    Science.gov (United States)

    Hsu, Feng-Hsin; Su, Chih-Chieh; Lin, In-Tain; Huh, Chih-An

    2015-04-01

    Submarine groundwater discharge (SGD) has been recognized as an important pathway for materials exchanging between land and sea. Input of SGD carries the associated nutrients, trace metals, and inorganic carbon that may makes great impacts on ecosystem in the coastal zone. Due to the variability of SGD magnitude, it is difficult to estimate the flux of those associated materials around the world. Even in the same area, SGD magnitude also varies in response to tide fluctuation and seasonal change on hydraulic gradient. Thus, long-term investigation is in need. In Taiwan, the SGD study is rare and the intrusion of seawater in the coastal aquifer is emphasized in previous studies. According to the information from Hydrogeological Data Bank (Central Geological Survey, MOEA), some areas still show potentiality of SGD. Here, we report the preliminary investigation result of SGD at Gaomei Wildlife Conservation Area which located at the south of the Da-Chia River mouth. This study area is characterized by a great tidal rang and a shallow aquifer with high groundwater recharge rate. Time-series measurement of the short-lived Ra in surface water was done in both dry and wet seasons at a tidal flat site and shows different trends of excess Ra-224 between dry and wet seasons. High excess Ra-224 activities (>20 dpm/100L) occurred at high tide in dry season but at low tide in wet season. The plot of salinity versus excess Ra-224, showing non-conservative curve, suggests that high excess Ra-224 activities derive from desorption in dry season but from SGD input in wet season.

  1. Monsoon-induced changes in the size-fractionated phytoplankton biomass and production rate in the estuarine and coastal waters of southwest coast of India.

    Science.gov (United States)

    Madhu, N V; Jyothibabu, R; Balachandran, K K

    2010-07-01

    Changes in the autotrophic pico- (0.2-2 microm), nano- (2-20 microm), and microplankton (>20 microm) biomass (chlorophyll a) and primary production were measured in the estuarine and coastal waters off Cochin, southwest coast of India during the onset and establishment of a monsoon. During this period, the estuary was dominated by nutrient-rich freshwater, whereas the coastal waters were characterized with higher salinity values (>30 psu) and less nutrients. The average surface chlorophyll a concentrations and primary production rates were higher in the estuary (average 13.7 mg m(-3) and 432 mgC m(-3) day(-1)) as compared to the coastal waters (5.3 mg m(-3) and 224 mgC m(-3) day(-1)). The nanoplankton community formed the major fraction of chlorophyll a and primary production, both in the estuary (average 85 +/- SD 8.3% and 81.2 +/- SD 3.2%) and the coastal waters (average 73.2 +/- SD 17.2% and 81.9 +/- 15.7%). Nanoplankton had the maximum photosynthetic efficiency in the coastal waters (average 4.8 +/- SD 3.9 mgC mgChl a m(-3) h(-1)), whereas in the estuary, the microplankton had higher photosynthetic efficiency (average 7.4 +/- 7 mgC mgChl a m(-3) h(-1)). The heavy cloud cover and increased water column turbidity not only limit the growth of large-sized phytoplankton in the Cochin estuary and coastal waters but also support the proliferation of nanoplankton community during the monsoon season, even though large variation in nanoplankton chlorophyll a and production exists between these two areas.

  2. Strategies to combat salt water intrusion in coastal aquifers : A model-based exploratory analysis

    NARCIS (Netherlands)

    Kwakkel, J.H.; Slinger, J.H.

    2011-01-01

    Coastal communities dependent upon groundwater resources for drinking water and irrigation are vulnerable to salinization of the groundwater reserve. The increasing uncertainty associated with changing climatic conditions, population and economic development, and technological advances in

  3. A system dynamics mode-based exploratory analysis of salt water intrusion in coastal aquifers

    NARCIS (Netherlands)

    Kwakkel, J.H.; Slinger, J.H.

    2012-01-01

    Coastal communities dependent upon groundwater resources for drinking water and irrigation are vulnerable to salinization of the groundwater reserve. The increasing uncertainty associated with changing climatic conditions, population and economic development, and technological advances poses

  4. Storms do not alter long-term watershed development influences on coastal water quality.

    Science.gov (United States)

    Chen, Yushun; Cebrian, Just; Lehrter, John; Christiaen, Bart; Stutes, Jason; Goff, Josh

    2017-09-15

    A twelve year (2000-2011) study of three coastal lagoons in the Gulf of Mexico was conducted to assess the impacts of local watershed development and tropical storms on water quality. The lagoons have similar physical and hydrological characteristics, but differ substantially in the degree of watershed urban development and nutrient loading rates. In total the lagoons experienced 22 storm events during the period studied. Specifically, we examine (1) whether there are influences on water quality in the lagoons from watershed development, (2) whether there are influences on water quality in the lagoons from storm activity, and (3) whether water quality is affected to a greater degree by watershed development versus storm activity. The two urbanized lagoons typically showed higher water-column nitrate, dissolved organic nitrogen, and phosphate compared with the non-urbanized lagoon. One of the urbanized lagoons had higher water-column chlorophyll a concentrations than the other two lagoons on most sampling dates, and higher light extinction coefficients on some sampling dates. The non-urbanized lagoon had higher water-column dissolved oxygen concentrations than other lagoons on many sampling dates. Our results suggest long-term influences of watershed development on coastal water quality. We also found some evidence of significant storm effects on water quality, such as increased nitrate, phosphate, and dissolved oxygen, and decreased salinity and water temperature. However, the influences of watershed development on water quality were greater. These results suggest that changes in water quality induced by human watershed development pervade despite the storm effects. These findings may be useful for environmental management since they suggest that storms do not profoundly alter long-term changes in water quality that resulted from human development of watersheds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The Cross Surfzone/Inner-shelf Dye Exchange (CSIDE) Experiment Overview: Binational Dye Tracer Releases to Study Pollution Transport and Dilution.

    Science.gov (United States)

    Feddersen, F.; Giddings, S. N.; Kumar, N.; Grimes, D. J.; Pawlak, G. R.; Rivas, D.; Diaz, M.

    2016-02-01

    Per square km, the surfzone and inner-shelf are by far the most economically and ecologically important ocean regions, vital for recreation, food, and ecosystem services. Despite the importance of clean coastal waters to our economy and well-being, declining water quality threatens coastal ecosystem and human health worldwide. Healthy coasts are a significant priority to federal agencies, local government, and NGOs. In particular the San Diego US and Tijuana Mexico border region have unique and persistent water quality issues due to a range of pollution sources. Cross-shore exchange of tracers (e.g., pathogens, anthropogenic nutrients, harmful algal blooms - HABs, larvae) between the well-mixed surfzone and stratified inner-shelf is poorly understood. The surfzone, inner- and mid-shelf span drastically different dynamical regimes, with varying cross-shelf exchange mechanisms due to wave, wind, buoyancy, and tidal processes and intrinsic variability. The NSF funded CSIDE (Cross Surfzone/Inner-shelf Dye Exchange) experiment (Sept & Oct 2015) aims to increase our understanding of cross-shelf material exchange by performing 3 shoreline dye release experiments that are tracked for up to 20 km alongshore and over 48+ hrs. One dye release will be performed in Mexico and the dye transport tracked across the border. The dye will be tracked via a broad range of binational instrumentation. In this presentation, we present an overview of the CSIDE experiment, in particular the binational aspects of the study,

  6. Cooperation between bound waters and hydroxyls in controlling isotope-exchange rates

    Science.gov (United States)

    Panasci, Adele F.; McAlpin, J. Gregory; Ohlin, C. André; Christensen, Shauna; Fettinger, James C.; Britt, R. David; Rustad, James R.; Casey, William H.

    2012-02-01

    Mineral oxides differ from aqueous ions in that the bound water molecules are usually attached to different metal centers, or vicinal, and thus separated from one another. In contrast, for most monomeric ions used to establish kinetic reactivity trends, such as octahedral aquo ions (e.g., Al(H 2O) 63+), the bound waters are closely packed, or geminal. Because of this structural difference, the existing literature about ligand substitution in monomer ions may be a poor guide to the reactions of geochemical interest. To understand how coordination of the reactive functional groups might affect the rates of simple water-exchange reactions, we synthesized two structurally similar Rh(III) complexes, [Rh(phen) 2(H 2O) 2] 3+ [ 1] and [Rh(phen) 2(H 2O)Cl] 2+ [ 2] where (phen) = 1,10-phenanthroline. Complex [ 1] has two adjacent, geminal, bound waters in the inner-coordination sphere and [ 2] has a single bound water adjacent to a bound chloride ion. We employed Rh(III) as a trivalent metal rather than a more geochemically relevant metal like Fe(III) or Al(III) to slow the rate of reaction, which makes possible measurement of the rates of isotopic substitution by simple mass spectrometry. We prepared isotopically pure versions of the molecules, dissolved them into isotopically dissimilar water, and measured the rates of exchange from the extents of 18O and 16O exchange at the bound waters. The pH dependency of rates differ enormously between the two complexes. Pseudo-first-order rate coefficients at 298 K for water exchanges from the fully protonated molecules are close: k0298 = 5 × 10 -8(±0.5 × 10 -8) s -1 for [ 1] and k0298 = 2.5 × 10 -9(±1 × 10 -9) for [ 2]. Enthalpy and entropy activation parameters (Δ H‡ and Δ S‡) were measured to be 119(±3) kJ mol -1, and 14(±1) J mol -1 K -1, respectively for [ 1]. The corresponding parameters for the mono-aquo complex, [ 2], are 132(±3) kJ mol -1 and 41.5(±2) J mol -1 K -1. Rates increase by many orders of magnitude

  7. Dissolved organic nutrients and phytoplankton production in the Mandovi estuary and coastal waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.

    Total organic nitrogen (TON) and dissolved organic phosphorus (DOP) in the coastal and estuarine waters of Goa, India varied from 0.6 to 47.1 mu g-at N 1-1 and 0.12 to 3.49 mu g-at P l-1 respectively. The chlorophyll content of these waters...

  8. Comparative approach to capture bacterial diversity in coastal waters

    DEFF Research Database (Denmark)

    Na, Hyunsoo; Kim, Ok-Sun; Yoon, Suk-hwan

    2011-01-01

    Despite the revolutionary advancements in DNA sequencing technology and cultivation techniques, few studies have been done to directly compare these methods. In this study, a 16S rRNA gene-based, integrative approach combining culture-independent techniques with culture-dependent methods was taken...... to investigate the bacterial community structure of coastal seawater collected from the Yellow Sea, Korea. For culture-independent studies, we used the latest model pyrosequencer, Roche/454 Genome Sequencer FLX Titanium. Pyrosequencing captured a total of 52 phyla including 27 candidate divisions from the water...

  9. Response of bacterial community structure to seasonal fluctuation and anthropogenic pollution on coastal water of Alang-Sosiya ship breaking yard, Bhavnagar, India.

    Science.gov (United States)

    Patel, Vilas; Munot, Hitendra; Shouche, Yogesh S; Madamwar, Datta

    2014-06-01

    Bacterial community structure was analyzed from coastal water of Alang-Sosiya ship breaking yard (ASSBY), world's largest ship breaking yard, near Bhavnagar, using 16S rRNA gene sequencing (cultured dependent and culture independent). In clone libraries, total 2324 clones were retrieved from seven samples (coastal water of ASSBY for three seasons along with one pristine coastal water) which were grouped in 525 operational taxonomic units. Proteobacteria was found to be dominant in all samples. In pristine samples, Gammaproteobacteria was found to be dominant, whereas in polluted samples dominancy of Gammaproteobacteria has shifted to Betaproteobacteria and Epsilonproteobacteria. Richness and diversity indices also indicated that bacterial community in pristine sample was the most diverse followed by summer, monsoon and winter samples. To the best of knowledge, this is the first study describing bacterial community structure from coastal water of ASSBY, and it suggests that seasonal fluctuation and anthropogenic pollutions alters the bacterial community structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Storms do not alter long-term watershed development influences on coastal water quality

    Science.gov (United States)

    A twelve year (2000 − 2011) study of three coastal lagoons in the Gulf of Mexico was conducted to assess the impacts of local watershed development and tropical storms on water quality. The lagoons have similar physical and hydrological characteristics, but differ substantially i...

  11. Preliminary results of algorithms to determine horizontal and vertical underwater visibilities of coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Joshi, Shreya; Talaulikar, M.; Desa, E.J.

    the underwater average cosine. These algorithms for vertical and horizontal visibilities have been validated for the coastal waters of Goa with the measured and those derived from the ocean color data of OCM-2 and MODIS...

  12. Coastal Freshening Prevents Fjord Bottom Water Renewal in Northeast Greenland: A Mooring Study From 2003 to 2015

    Science.gov (United States)

    Boone, Wieter; Rysgaard, Søren; Carlson, Daniel F.; Meire, Lorenz; Kirillov, Sergei; Mortensen, John; Dmitrenko, Igor; Vergeynst, Leendert; Sejr, Mikael K.

    2018-03-01

    The freshwater content of the Arctic Ocean and its bordering seas has recently increased. Observing freshening events is an important step toward identifying the drivers and understanding the effects of freshening on ocean circulation and marine ecosystems. Here we present a 13 year (2003-2015) record of temperature and salinity in Young Sound-Tyrolerfjord (74°N) in Northeast Greenland. Our observations show that strong freshening occurred from August 2005 to August 2007 (-0.92 psu or -0.46 psu yr-1) and from August 2009 to August 2013 (-0.66 psu or -0.17 psu yr-1). Furthermore, temperature-salinity analysis from 2004 to 2014 shows that freshening of the coastal water ( range at sill depth: 33.3 psu in 2005 to 31.4 psu in 2007) prevented renewal of the fjord's bottom water. These data provide critical observations of interannual freshening rates in a remote fjord in Greenland and in the adjacent coastal waters and show that coastal freshening impacts the fjord hydrography, which may impact the ecosystem dynamics in the long term.

  13. Petroleum oil and mercury pollution from shipwrecks in Norwegian coastal waters.

    Science.gov (United States)

    Ndungu, Kuria; Beylich, Björnar A; Staalstrøm, André; Øxnevad, Sigurd; Berge, John A; Braaten, Hans Fredrik Veiteberg; Schaanning, Morten; Bergstrøm, Rune

    2017-09-01

    Worldwide there are tens of thousands of sunken shipwrecks lying on the coastal seabed. These potentially polluting wrecks (PPW) are estimated to hold 3-25milliont of oil. Other hazardous cargo in PPW includes ordnance, chemicals and radioactive waste. Here, we present and discuss studies on mercury (Hg) and oil pollution in coastal marine sediment caused by two of the >2100 documented PPW in Norwegian marine waters. The German World War II (WWII) submarine (U-864) lies at about 150m below the sea surface, near the Norwegian North Sea island of Fedje. The submarine is estimated to have been carrying 67t of elemental Hg, some of which has leaked on to surrounding sediment. The total Hg concentration in bottom surface sediment within a 200m radius of the wreckage decreases from 100g/kgd.w. at the wreckage hotspot to about 1mg/kgd.w. at 100m from the hotspot. The second wreck is a German WWII cargo ship (Nordvard), that lies at a depth of ca. 30m near the Norwegian harbor of Moss. Oil leakage from Nordvard has contaminated the bottom coastal sediment with polycyclic aromatic hydrocarbons (PAH). The findings from this study provide useful insight to coastal administration authorities involved in assessing and remediating wreck-borne pollution from any of the tens of thousands of sunken shipwrecks. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Mercury concentrations in China's coastal waters and implications for fish consumption by vulnerable populations

    International Nuclear Information System (INIS)

    Tong, Yindong; Wang, Mengzhu; Bu, Xiaoge; Guo, Xin; Lin, Yan; Lin, Huiming; Li, Jing; Zhang, Wei; Wang, Xuejun

    2017-01-01

    We assessed mercury (Hg) pollution in China's coastal waters, including the Bohai Sea, the Yellow Sea, the East China Sea and the South China Sea, based on a nationwide dataset from 301 sampling sites. A methylmercury (MeHg) intake model for humans based on the marine food chain and human fish consumption was established to determine the linkage between water pollutants and the pollutant intake by humans. The predicted MeHg concentration in fish from the Bohai Sea was the highest among the four seas included in the study. The MeHg intake through dietary ingestion was dominant for the fish and was considerably higher than the MeHg intake through water respiration. The predicted MeHg concentrations in human blood in the coastal regions of China ranged from 1.37 to 2.77 μg/L for pregnant woman and from 0.43 to 1.00 μg/L for infants, respectively, based on different diet sources. The carnivorous fish consumption advisory for pregnant women was estimated to be 288–654 g per week to maintain MeHg concentrations in human blood at levels below the threshold level (4.4 μg/L established by the US Environmental Protection Agency). With a 50% increase in Hg concentrations in water in the Bohai Sea, the bioaccumulated MeHg concentration (4.5 μg/L) in the fish consumers will be higher than the threshold level. This study demonstrates the importance in controlling Hg pollution in China's coastal waters. An official recommendation guideline for the fish consumption rate and its sources will be necessary for vulnerable populations in China. - Graphical abstract: MeHg transfer route from the marine food chain to vulnerable population. - Highlights: • Predicted MeHg concentrations in pregnant woman and infant’s blood in China’s coastal regions are below threshold level. • The carnivorous fish consumption advisory for pregnant women is estimated to be 288–654 g per week. g • If with a 50% increase in Hg in Bohai Sea, the bioaccumulated MeHg concentration in

  15. National Coastal Condition Report IV Factsheet

    Science.gov (United States)

    Overall condition of the Nation’s coastal waters is fair. This rating is based on five indices of ecologicalcondition: water quality index, sediment quality index, benthic index, coastal habitat index, and fish tissue contaminants index.

  16. Microbiological Study in Coastal Water of Port Dickson, Malaysia

    International Nuclear Information System (INIS)

    Ainon Hamzah; Saiful Hazwa Kipli; Siti Rahil Ismail; Rawlins Una; Sukiman Sarmani

    2011-01-01

    The microbial composition in coastal water of the Port Dickson beach in Negeri Sembilan, Malaysia was analyzed using several microbial indicators for the purpose of selecting the best indicator for marine water pollution. The indicators studied were total coliform (TC), fecal coliform (FC), fecal streptococci (FS) and coliphage. Five locations were selected along the Port Dickson beaches and samplings were carried out in 1998 and 2001. The results showed an increase in the number of total coliform (TC), fecal coliform (FC) and fecal streptococci (FS) between these two sampling by 98.12 %, 86.12 % and 99 %, respectively. The numbers of TC, FC and FS exceeded the recommended limit for recreational seawater based on U.S. EPA 1986 standard. There was a positive correlation between TC, FC and FS and negative to coliphages. (author)

  17. Vertical Existence of Coprostanol in a Sediment Core From Semarang Coastal Waters, Central Java, Indonesia

    OpenAIRE

    Bachtiar, Tonny

    2004-01-01

    Coprostanol has been proposed as an indicator of domestic (sewage) pollution by researchers because constraint of using coliform bacteria as the indicators of domestic pollution in the environment with high environmental stress, such as urban coastal waters. Increasing the volume of industrial wastes, toxic and heated, the changing of water salinity from low (freshwater) to high (sea water), and decreasing of dissolved oxygen (DO) in the waters, are the constrain factors of bacteria growth. ...

  18. Light pollution offshore: Zenithal sky glow measurements in the mediterranean coastal waters

    Science.gov (United States)

    Ges, Xavier; Bará, Salvador; García-Gil, Manuel; Zamorano, Jaime; Ribas, Salvador J.; Masana, Eduard

    2018-05-01

    Light pollution is a worldwide phenomenon whose consequences for the natural environment and the human health are being intensively studied nowadays. Most published studies address issues related to light pollution inland. Coastal waters, however, are spaces of high environmental interest, due to their biodiversity richness and their economical significance. The elevated population density in coastal regions is accompanied by correspondingly large emissions of artificial light at night, whose role as an environmental stressor is increasingly being recognized. Characterizing the light pollution levels in coastal waters is a necessary step for protecting these areas. At the same time, the marine surface environment provides a stage free from obstacles for measuring the dependence of the skyglow on the distance to the light polluting sources, and validating (or rejecting) atmospheric light propagation models. In this work we present a proof-of-concept of a gimbal measurement system that can be used for zenithal skyglow measurements on board both small boats and large vessels under actual navigation conditions. We report the results obtained in the summer of 2016 along two measurement routes in the Mediterranean waters offshore Barcelona, travelling 9 and 31.7 km away from the coast. The atmospheric conditions in both routes were different from the ones assumed for the calculation of recently published models of the anthropogenic sky brightness. They were closer in the first route, whose results approach better the theoretical predictions. The results obtained in the second route, conducted under a clearer atmosphere, showed systematic differences that can be traced back to two expected phenomena, which are a consequence of the smaller aerosol content: the reduction of the anthropogenic sky glow at short distances from the sources, and the slower decay rate of brightness with distance, which gives rise to a relative excess of brightness at large distances from the

  19. Fish larval transport in the coastal waters through ecological modelling

    Digital Repository Service at National Institute of Oceanography (India)

    George, G.

    are as follows: (i) to find out the influence of environmental parameters on the biology of the given ecosystem (ii) to track larval transport and biological abundance in relation to environmental vari- ables (iii) to compare biological abundance and fish larval... include the following investigations: (i) analysis of satellite chlorophyll data along the southwest coastal waters of India to derive a biological calender for sardine (ii) tracking the larval survival and establish a link between food and sardine inter...

  20. On-bead combinatorial synthesis and imaging of chemical exchange saturation transfer magnetic resonance imaging agents to identify factors that influence water exchange.

    Science.gov (United States)

    Napolitano, Roberta; Soesbe, Todd C; De León-Rodríguez, Luis M; Sherry, A Dean; Udugamasooriya, D Gomika

    2011-08-24

    The sensitivity of magnetic resonance imaging (MRI) contrast agents is highly dependent on the rate of water exchange between the inner sphere of a paramagnetic ion and bulk water. Normally, identifying a paramagnetic complex that has optimal water exchange kinetics is done by synthesizing and testing one compound at a time. We report here a rapid, economical on-bead combinatorial synthesis of a library of imaging agents. Eighty different 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid (DOTA)-tetraamide peptoid derivatives were prepared on beads using a variety of charged, uncharged but polar, hydrophobic, and variably sized primary amines. A single chemical exchange saturation transfer image of the on-bead library easily distinguished those compounds having the most favorable water exchange kinetics. This combinatorial approach will allow rapid screening of libraries of imaging agents to identify the chemical characteristics of a ligand that yield the most sensitive imaging agents. This technique could be automated and readily adapted to other types of MRI or magnetic resonance/positron emission tomography agents as well.

  1. Coastal fog during summer drought improves the water status of sapling trees more than adult trees in a California pine forest.

    Science.gov (United States)

    Baguskas, Sara A; Still, Christopher J; Fischer, Douglas T; D'Antonio, Carla M; King, Jennifer Y

    2016-05-01

    Fog water inputs can offset seasonal drought in the Mediterranean climate of coastal California and may be critical to the persistence of many endemic plant species. The ability to predict plant species response to potential changes in the fog regime hinges on understanding the ways that fog can impact plant physiological function across life stages. Our study uses a direct metric of water status, namely plant water potential, to understand differential responses of adult versus sapling trees to seasonal drought and fog water inputs. We place these measurements within a water balance framework that incorporates the varying climatic and soil property impacts on water budgets and deficit. We conducted our study at a coastal and an inland site within the largest stand of the regionally endemic bishop pine (Pinus muricata D. Don) on Santa Cruz Island. Our results show conclusively that summer drought negatively affects the water status of sapling more than adult trees and that sapling trees are also more responsive to changes in shallow soil moisture inputs from fog water deposition. Moreover, between the beginning and end of a large, late-season fog drip event, water status increased more for saplings than for adults. Relative to non-foggy conditions, we found that fog water reduces modeled peak water deficit by 80 and 70 % at the inland and coastal sites, respectively. Results from our study inform mechanistically based predictions of how population dynamics of this and other coastal species may be affected by a warmer, drier, and potentially less foggy future.

  2. The Dynamics of Mercury Speciation and Transport at a Central California Coastal Lagoon

    Science.gov (United States)

    Ganguli, P. M.; Swarzenski, P. W.; Dimova, N. T.; Merckling, J.; Kehrlein, N. C.; Hohn, R. A.; Richardson, C. M.; Johnson, C. D.; Fisher, A. T.; Lamborg, C. H.; Flegal, A. R., Jr.

    2014-12-01

    We evaluated spatial and temporal trends in total mercury and monomethylmercury (MMHg) in groundwater, lagoon water, and nearshore seawater to assess the drivers of MMHg production in a coastal lagoon system. Many West Coast streams transition from estuarine to lagoon conditions in the dry season when a sand berm develops at the stream mouth, restricting surface water exchange with the ocean. Because lagoons accumulate nutrients from their upstream watershed they are susceptible to eutrophication, which can promote the growth of anaerobic bacteria. In nearshore settings, these bacteria are primarily responsible for producing MMHg, a bioaccumulative neurotoxin. We found that MMHg concentrations in lagoon water (1 - 5 pM) were higher than in groundwater (0.2 - 1 pM) and coastal seawater (0.1 - 0.6 pM). Groundwater depth profiles combined with subsurface resistivity images suggest MMHg in lagoon water was transported through the sand berm to adjacent seawater. MMHg in seawater and groundwater followed similar trends, providing additional evidence of groundwater-surface water interaction. MMHg in groundwater directly below the lagoon was consistently higher where dissolved oxygen and NO3- decreased, implying MMHg production by anaerobic bacteria. Over a ~7-hour period we observed a 0.6 pM decrease in groundwater MMHg (1 to 0.4 pM) that coincided with a decrease in water temperature (16.5 to 13 °C). We hypothesize that microbial activity, and consequently MMHg production, were enhanced in warmer water. Because coastal lagoons support intricate food webs and serve as nurseries for a variety of organisms, processes that influence mercury speciation and transport in these ecosystems may have a disproportionate impact on nearshore mercury biogeochemical cycling.

  3. Replica exchange with solute tempering: A method for sampling biological systems in explicit water

    Science.gov (United States)

    Liu, Pu; Kim, Byungchan; Friesner, Richard A.; Berne, B. J.

    2005-09-01

    An innovative replica exchange (parallel tempering) method called replica exchange with solute tempering (REST) for the efficient sampling of aqueous protein solutions is presented here. The method bypasses the poor scaling with system size of standard replica exchange and thus reduces the number of replicas (parallel processes) that must be used. This reduction is accomplished by deforming the Hamiltonian function for each replica in such a way that the acceptance probability for the exchange of replica configurations does not depend on the number of explicit water molecules in the system. For proof of concept, REST is compared with standard replica exchange for an alanine dipeptide molecule in water. The comparisons confirm that REST greatly reduces the number of CPUs required by regular replica exchange and increases the sampling efficiency. This method reduces the CPU time required for calculating thermodynamic averages and for the ab initio folding of proteins in explicit water. Author contributions: B.J.B. designed research; P.L. and B.K. performed research; P.L. and B.K. analyzed data; and P.L., B.K., R.A.F., and B.J.B. wrote the paper.Abbreviations: REST, replica exchange with solute tempering; REM, replica exchange method; MD, molecular dynamics.*P.L. and B.K. contributed equally to this work.

  4. Using containment analysis to improve component cooling water heat exchanger limits

    International Nuclear Information System (INIS)

    Da Silva, H.C.; Tajbakhsh, A.

    1995-01-01

    The Comanche Peak Steam Electric Station design requires that exit temperatures from the Component Cooling Water Heat Exchanger remain below 330.37 K during the Emergency Core Cooling System recirculation stage, following a hypothetical Loss of Coolant Accident (LOCA). Due to measurements indicating a higher than expected combination of: (a) high fouling factor in the Component Cooling Water Heat Exchanger with (b) high ultimate heat sink temperatures, that might lead to temperatures in excess of the 330.37 K limit, if a LOCA were to occur, TUElectric adjusted key flow rates in the Component Cooling Water network. This solution could only be implemented with improvements to the containment analysis methodology of record. The new method builds upon the CONTEMPT-LT/028 code by: (a) coupling the long term post-LOCA thermohydraulics with a more detailed analytical model for the complex Component Cooling Water Heat Exchanger network and (b) changing the way mass and energy releases are calculated after core reflood and steam generator energy is dumped to the containment. In addition, a simple code to calculate normal cooldowns was developed to confirm RHR design bases were met with the improved limits

  5. A nuclear magnetic relaxation study of hydrogen exchange and water dynamics in aqueous systems

    International Nuclear Information System (INIS)

    Lankhorst, D.

    1983-01-01

    In this thesis exchange of water protons in solutions of some weak electrolytes and polyelectrolytes is studied. Also the dynamical behaviour of water molecules in pure water is investigated. For these purposes nuclear magnetic resonance relaxation measurements, in solutions of oxygen-17 enriched water, are interpreted. The exchange rate of the water protons is derived from the contribution of 1 H- 17 O scalar coupling to the proton transverse relaxation rate. This rate is measured by the Carr-Purcell technique. (Auth.)

  6. Intertidal beach sands as monitors for heavy metal pollution in coastal water bodies

    International Nuclear Information System (INIS)

    Lacerda, L.D. de; Pfeiffer, W.C.; Fiszman, M.

    Intertidal beach sands were investigated for their use as indicators of metal transport in a contaminated water body, Sepetiba Bay, Rio de Janeiro, Brazil, and are proposed as an alternative and rapid screening method to determine metal pollution status of coastal areas. The results showed that, at least for Cu, Cr, Zn and Pb, beach sands can be included in the existing environmental monitoring programs for heavy metal pollution in water bodies. (Author) [pt

  7. Drinking Water Sodium and Elevated Blood Pressure of Healthy Pregnant Women in Salinity-Affected Coastal Areas.

    Science.gov (United States)

    Scheelbeek, Pauline F D; Khan, Aneire E; Mojumder, Sontosh; Elliott, Paul; Vineis, Paolo

    2016-08-01

    Coastal areas in Southeast Asia are experiencing high sodium concentrations in drinking water sources that are commonly consumed by local populations. Salinity problems caused by episodic cyclones and subsequent seawater inundations are likely (partly) related to climate change and further exacerbated by changes in upstream river flow and local land-use activities. Dietary (food) sodium plays an important role in the global burden of hypertensive disease. It remains unknown, however, if sodium in drinking water-rather than food-has similar effects on blood pressure and disease risk. In this study, we examined the effect of drinking water sodium on blood pressure of pregnant women: increases in blood pressure in this group could severely affect maternal and fetal health. Data on blood pressure, drinking water source, and personal, lifestyle, and environmental confounders was obtained from 701 normotensive pregnant women residing in coastal Bangladesh. Generalized linear mixed regression models were used to investigate association of systolic and diastolic blood pressure of these-otherwise healthy-women with their water source. After adjustment for confounders, drinkers of tube well and pond water (high saline sources) were found to have significantly higher average systolic (+4.85 and +3.62 mm Hg) and diastolic (+2.30 and +1.72 mm Hg) blood pressures than rainwater drinkers. Drinking water salinity problems are expected to exacerbate in the future, putting millions of coastal people-including pregnant women-at increased risk of hypertension and associated diseases. There is an urgent need to further explore the health risks associated to this understudied environmental health problem and feasibility of possible adaptation strategies. © 2016 American Heart Association, Inc.

  8. Unstable Pore-Water Flow in Intertidal Wetlands

    Science.gov (United States)

    Barry, D. A.; Shen, C.; Li, L.

    2014-12-01

    Salt marshes are important intertidal wetlands strongly influenced by interactions between surface water and groundwater. Bordered by coastal water, the marsh system undergoes cycles of inundation and exposure driven by the tide. This leads to dynamic, complex pore-water flow and solute transport in the marsh soil. Pore-water circulations occur over vastly different spatial and temporal scales with strong link to the marsh topography. These circulations control solute transport between the marsh soil and the tidal creek, and ultimately affect the overall nutrient exchange between the marsh and coastal water. The pore-water flows also dictate the soil condition, particularly aeration, which influences the marsh plant growth. Numerous studies have been carried out to examine the pore-water flow process in the marsh soil driven by tides, focusing on stable flow with the assumption of homogeneity in soil and fluid properties. This assumption, however, is questionable given the actual inhomogeneous conditions in the field. For example, the salinity of surface water in the tidal creek varies temporally and spatially due to the influence of rainfall and evapotranspiration as well as the freshwater input from upland areas to the estuary, creating density gradients across the marsh surface and within the marsh soil. Many marshes possess soil stratigraphy with low-permeability mud typically overlying high-permeability sandy deposits. Macropores such as crab burrows are commonly distributed in salt marsh sediments. All these conditions are prone to the development of non-uniform, unstable preferential pore-water flow in the marsh soil, for example, funnelling and fingering. Here we present results from laboratory experiments and numerical simulations to explore such unstable flow. In particular, the analysis aims to address how the unstable flow modifies patterns of local pore-water movement and solute transport, as well as the overall exchange between the marsh soil and

  9. Stratigraphic controls on fluid and solute fluxes across the sediment-water interface of an estuary

    Science.gov (United States)

    Sawyer, Audrey H.; Lazareva, Olesya; Kroeger, Kevin D.; Crespo, Kyle; Chan, Clara S.; Stieglitz, Thomas; Michael, Holly A.

    2014-01-01

    Shallow stratigraphic features, such as infilled paleovalleys, modify fresh groundwater discharge to coastal waters and fluxes of saltwater and nutrients across the sediment–water interface. We quantify the spatial distribution of shallow surface water–groundwater exchange and nitrogen fluxes near a paleovalley in Indian River Bay, Delaware, using a hand resistivity probe, conventional seepage meters, and pore-water samples. In the interfluve (region outside the paleovalley) most nitrate-rich fresh groundwater discharges rapidly near the coast with little mixing of saline pore water, and nitrogen transport is largely conservative. In the peat-filled paleovalley, fresh groundwater discharge is negligible, and saltwater exchange is deep (∼1 m). Long pore-water residence times and abundant sulfate and organic matter promote sulfate reduction and ammonium production in shallow sediment. Reducing, iron-rich fresh groundwater beneath paleovalley peat discharges diffusely around paleovalley margins offshore. In this zone of diffuse fresh groundwater discharge, saltwater exchange and dispersion are enhanced, ammonium is produced in shallow sediments, and fluxes of ammonium to surface water are large. By modifying patterns of groundwater discharge and the nature of saltwater exchange in shallow sediments, paleovalleys and other stratigraphic features influence the geochemistry of discharging groundwater. Redox reactions near the sediment–water interface affect rates and patterns of geochemical fluxes to coastal surface waters. For example, at this site, more than 99% of the groundwater-borne nitrate flux to the Delaware Inland Bays occurs within the interfluve portion of the coastline, and more than 50% of the ammonium flux occurs at the paleovalley margin.

  10. Self-similar distribution of oil spills in European coastal waters

    International Nuclear Information System (INIS)

    Redondo, Jose M; Platonov, Alexei K

    2009-01-01

    Marine pollution has been highlighted thanks to the advances in detection techniques as well as increasing coverage of catastrophes (e.g. the oil tankers Amoco Cadiz, Exxon Valdez, Erika, and Prestige) and of smaller oil spills from ships. The new satellite based sensors SAR and ASAR and new methods of oil spill detection and analysis coupled with self-similar statistical techniques allow surveys of environmental pollution monitoring large areas of the ocean. We present a statistical analysis of more than 700 SAR images obtained during 1996-2000, also comparing the detected small pollution events with the historical databases of great marine accidents during 1966-2004 in European coastal waters. We show that the statistical distribution of the number of oil spills as a function of their size corresponds to Zipf's law, and that the common small spills are comparable to the large accidents due to the high frequency of the smaller pollution events. Marine pollution from tankers and ships, which has been detected as oil spills between 0.01 and 100 km 2 , follows the marine transit routes. Multi-fractal methods are used to distinguish between natural slicks and spills, in order to estimate the oil spill index in European coastal waters, and in particular, the north-western Mediterranean Sea, which, due to the influence of local winds, shows optimal conditions for oil spill detection.

  11. Methods of eutrophication assessment in the context of the water framework directive: Examples from the Eastern Mediterranean coastal areas

    Science.gov (United States)

    Pavlidou, Alexandra; Simboura, Nomiki; Rousselaki, Eleni; Tsapakis, Manolis; Pagou, Kalliopi; Drakopoulou, Paraskevi; Assimakopoulou, Georgia; Kontoyiannis, Harilaos; Panayotidis, Panayotis

    2015-10-01

    A set of methodological tools were tested in order to assess the eutrophication quality of selected coastal areas in Eastern Mediterranean Sea, Greece, in the context of the Water Framework Directive under various anthropogenic pressures. Three, five-step tools, namely, TRIX, chlorophyll-a (chl-a) biomass classification scheme, and eutrophication index (E.I.) were applied in oligotrophic waters for (a) the whole water column and (b) the euphotic zone. The relationship among the eutrophication assessment indices and the ecological quality status (EcoQ) assessment indices for benthic macroinvertebrates (BENTIX index) and macroalgae (ecological evaluation index-EEIc) was also explored. Agricultural activities and mariculture are the pressures mostly related to the eutrophication assessment of the selected Greek coastal water bodies. Chl-a proved to be the criterion with the best overall correlation with the EcoQ indices, while TRIX with the lowest. Moreover, among the eutrophication indices, E.I. showed better overall agreement with BENTIX showing that probably it reflects the indirect relation of macroinvertebrates with water eutrophication in a better way. Among the eutrophication indices used, TRIX rather overestimated the eutrophication status of the selected coastal areas. The first stage of eutrophication was reflected more efficiently using E.I. than TRIX, but E.I. seems to be a rather sensitive index. A future modification of the high to good boundary of E.I. may be needed in order to demonstrate the high status of the relatively undisturbed Greek coastal sites.

  12. Detection of a Planktothrix agardhii Bloom in Portuguese Marine Coastal Waters

    Directory of Open Access Journals (Sweden)

    Catarina Churro

    2017-12-01

    Full Text Available Cyanobacteria blooms are frequent in freshwaters and are responsible for water quality deterioration and human intoxication. Although, not a new phenomenon, concern exists on the increasing persistence, scale, and toxicity of these blooms. There is evidence, in recent years, of the transfer of these toxins from inland to marine waters through freshwater outflow. However, the true impact of these blooms in marine habitats has been overlooked. In the present work, we describe the detection of Planktothrix agardhii, which is a common microcystin producer, in the Portuguese marine coastal waters nearby a river outfall in an area used for shellfish harvesting and recreational activities. P. agardhii was first observed in November of 2016 in seawater samples that are in the scope of the national shellfish monitoring system. This occurrence was followed closely between November and December of 2016 by a weekly sampling of mussels and water from the sea pier and adjacent river mouth with salinity ranging from 35 to 3. High cell densities were found in the water from both sea pier and river outfall, reaching concentrations of 4,960,608 cells·L−1 and 6810.3 × 106 cells·L−1 respectively. Cultures were also established with success from the environment and microplate salinity growth assays showed that the isolates grew at salinity 10. HPLC-PDA analysis of total microcystin content in mussel tissue, water biomass, and P. agardhii cultures did not retrieve a positive result. In addition, microcystin related genes were not detected in the water nor cultures. So, the P. agardhii present in the environment was probably a non-toxic strain. This is, to our knowledge, the first report on a P. agardhii bloom reaching the sea and points to the relevance to also monitoring freshwater harmful phytoplankton and related toxins in seafood harvesting and recreational coastal areas, particularly under the influence of river plumes.

  13. Drinking Water Salinity and Raised Blood Pressure: Evidence from a Cohort Study in Coastal Bangladesh.

    Science.gov (United States)

    Scheelbeek, Pauline FD; Chowdhury, Muhammad A H; Haines, Andy; Alam, Dewan S; Hoque, Mohammad A; Butler, Adrian P; Khan, Aneire E; Mojumder, Sontosh K; Blangiardo, Marta A G; Elliott, Paul; Vineis, Paolo

    2017-05-30

    Millions of coastal inhabitants in Southeast Asia have been experiencing increasing sodium concentrations in their drinking-water sources, likely partially due to climate change. High (dietary) sodium intake has convincingly been proven to increase risk of hypertension; it remains unknown, however, whether consumption of sodium in drinking water could have similar effects on health. We present the results of a cohort study in which we assessed the effects of drinking-water sodium (DWS) on blood pressure (BP) in coastal populations in Bangladesh. DWS, BP, and information on personal, lifestyle, and environmental factors were collected from 581 participants. We used generalized linear latent and mixed methods to model the effects of DWS on BP and assessed the associations between changes in DWS and BP when participants experienced changing sodium levels in water, switched from "conventional" ponds or tube wells to alternatives [managed aquifer recharge (MAR) and rainwater harvesting] that aimed to reduce sodium levels, or experienced a combination of these changes. DWS concentrations were highly associated with BP after adjustments for confounding factors. Furthermore, for each 100 mg/L reduction in sodium in drinking water, systolic/diastolic BP was lower on average by 0.95/0.57 mmHg, and odds of hypertension were lower by 14%. However, MAR did not consistently lower sodium levels. DWS is an important source of daily sodium intake in salinity-affected areas and is a risk factor for hypertension. Considering the likely increasing trend in coastal salinity, prompt action is required. Because MAR showed variable effects, alternative technologies for providing reliable, safe, low-sodium fresh water should be developed alongside improvements in MAR and evaluated in "real-life" salinity-affected settings. https://doi.org/10.1289/EHP659.

  14. Drinking Water Salinity and Raised Blood Pressure: Evidence from a Cohort Study in Coastal Bangladesh

    Science.gov (United States)

    Chowdhury, Muhammad A.H.; Haines, Andy; Alam, Dewan S.; Hoque, Mohammad A.; Butler, Adrian P.; Khan, Aneire E.; Mojumder, Sontosh K.; Blangiardo, Marta A.G.; Elliott, Paul; Vineis, Paolo

    2017-01-01

    Background: Millions of coastal inhabitants in Southeast Asia have been experiencing increasing sodium concentrations in their drinking-water sources, likely partially due to climate change. High (dietary) sodium intake has convincingly been proven to increase risk of hypertension; it remains unknown, however, whether consumption of sodium in drinking water could have similar effects on health. Objectives: We present the results of a cohort study in which we assessed the effects of drinking-water sodium (DWS) on blood pressure (BP) in coastal populations in Bangladesh. Methods: DWS, BP, and information on personal, lifestyle, and environmental factors were collected from 581 participants. We used generalized linear latent and mixed methods to model the effects of DWS on BP and assessed the associations between changes in DWS and BP when participants experienced changing sodium levels in water, switched from “conventional” ponds or tube wells to alternatives [managed aquifer recharge (MAR) and rainwater harvesting] that aimed to reduce sodium levels, or experienced a combination of these changes. Results: DWS concentrations were highly associated with BP after adjustments for confounding factors. Furthermore, for each 100mg/L reduction in sodium in drinking water, systolic/diastolic BP was lower on average by 0.95/0.57mmHg, and odds of hypertension were lower by 14%. However, MAR did not consistently lower sodium levels. Conclusions: DWS is an important source of daily sodium intake in salinity-affected areas and is a risk factor for hypertension. Considering the likely increasing trend in coastal salinity, prompt action is required. Because MAR showed variable effects, alternative technologies for providing reliable, safe, low-sodium fresh water should be developed alongside improvements in MAR and evaluated in “real-life” salinity-affected settings. https://doi.org/10.1289/EHP659 PMID:28599268

  15. Numerical analyses of soft bottom macroinvertebrates to diagnose the pollution in tropical coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Rodrigues, N.R.

    of techniques to assess the impact of pollution on benthic community structure. Hence, to test this hypotheses some of the univariate and multivariate techniques were applied to soft bottom macro-invertebrates data of coastal waters of Mangalore, central west...

  16. Gains from trans-boundary water quality management in linked catchment and coastal socio-ecological systems: a case study for the Minho region

    Science.gov (United States)

    Roebeling, P. C.; Brito, A. G.; Rocha, J.; Alves, H.; Mamede, J.

    2012-04-01

    Worldwide, aquatic and coastal ecosystems are affected by point and diffuse source water pollution originating from rural, urban and industrial land uses in catchments, even though these ecosystems are of vital importance from an environmental and economic perspective. Integrated Catchment and Coastal Zone Management (ICCZM) specifically takes into account this inherent relationship between terrestrial land use, surface and ground water pollution, aquatic and coastal ecosystem state, and associated environmental values. To warrant sustainable regional economic development, we need to balance the marginal costs from terrestrial water pollution abatement and the associated marginal benefits from aquatic and coastal resource appreciation. In doing so, however, we need to differentiate between intra- and trans-boundary catchments because benefactors and beneficiaries from water quality improvement are not one and the same. In trans-boundary catchments, private (national) welfare maximizing rates of water quality improvement differ across nations as benefits from water quality improvement generally accrue to one nation while the costs are paid by multiple nations. While approaches for water quality management in linked catchment and coastal socio-ecological systems are fairly recent though existent, water quality management in trans-boundary catchments poses additional challenges. The objective of this paper is to develop and apply a deterministic optimal control approach that allows us to explore private and social welfare maximizing rates of water pollution abatement in linked catchment and coastal socio-ecological systems. For a case study of the Minho region in the Iberian Peninsula, we estimate nation-specific water pollution abatement cost (based on management practice adoption) and benefit (based on aquatic and coastal environmental values) functions, to determine as well as compare private (national) and social (trans-national) welfare maximizing rates of water

  17. Hypoxia in Korean Coastal Waters: A Case Study of the Natural Jinhae Bay and Artificial Shihwa Bay

    Directory of Open Access Journals (Sweden)

    Jiyoung Lee

    2018-03-01

    Full Text Available Several coastal regions in Korea have suffered from hypoxia since the 1970s. We present the first review of Korean coastal hypoxia, focusing on its spatiotemporal variation, controlling factors, and effects on marine ecosystems. The review considers the two hotspots of the natural Jinhae Bay (JB and artificial Shihwa Bay (SB, which are referred to as “Korean dead zones.” The hypoxia in the JB is attributed to eutrophication due to domestic and land-used waste input and thermal stratification based on the naturally sluggish water circulation, whereas the hypoxia in the SB is due to eutrophication resulting from domestic, land-used, and industrial waste input and haline stratification as a consequence of the artificially created water stagnation. The bottom-water hypoxia and stratification has led to an imbalance in nitrogen:phosphorus ratio between surface and bottom waters. Hypoxia has also created undesirable benthic community changes in the both bays: (1 mass mortality of large species and recolonization with elevated abundances of opportunists in JB, and (2 decrease of the number of species, abundance, and diversity of benthic communities in SB. Therefore, it behooves us to pay attention to these environmental changes. This review will be helpful in determining the direction of future studies of Korean coastal hypoxia.

  18. Waste assimilative capacity of coastal waters along Mumbai mega city, west coast of India using MIKE-21 and WASP simulation models.

    Digital Repository Service at National Institute of Oceanography (India)

    Renjith, V.; Vethamony, P.; Zainudin, Z.; VinodKumar, K.

    as aquatic ecosystem health, depletion in water resources and increase in water pollution. There are abounding instances [4-7] of irreversible and indelible decline in the ambient coastal water quality around the globe due to unchecked and perpetual release... region encountered the tropical cyclone, Phyan (9-11 November 2009) within the simulation period. The physical and biological response of the Arabian Sea due to the cyclone [68] and coastal circulation during the event was already investigated by other...

  19. A Novel Ion Exchange System to Purify Mixed ISS Waste Water Brines for Chemical Production and Enhanced Water Recovery

    Science.gov (United States)

    Lunn, Griffin; Spencer, LaShelle; Ruby, Anna-Maria; McCaskill, Andrew

    2014-01-01

    Current International Space Station water recovery regimes produce a sizable portion of waste water brine. This brine is highly toxic and water recovery is poor: a highly wasteful proposition. With new biological techniques that do not require waste water chemical pretreatment, the resulting brine would be chromium-free and nitrate rich which can allow possible fertilizer recovery for future plant systems. Using a system of ion exchange resins we can remove hardness, sulfate, phosphate and nitrate from these brines to leave only sodium and potassium chloride. At this point modern chlor-alkali cells can be utilized to produce a low salt stream as well as an acid and base stream. The first stream can be used to gain higher water recovery through recycle to the water separation stage while the last two streams can be used to regenerate the ion exchange beds used here, as well as other ion exchange beds in the ISS. Conveniently these waste products from ion exchange regeneration would be suitable as plant fertilizer. In this report we go over the performance of state of the art resins designed for high selectivity of target ions under brine conditions. Using ersatz ISS waste water we can evaluate the performance of specific resins and calculate mass balances to determine resin effectiveness and process viability. If this system is feasible then we will be one step closer to closed loop environmental control and life support systems (ECLSS) for current or future applications.

  20. The effects of ozone and water exchange rates on water quality and rainbow trout Oncorhynchus mykiss performance in replicated water recirculating systems

    Science.gov (United States)

    Rainbow trout Oncorhynchus mykiss performance and water quality were evaluated and compared within six replicated 9.5 cubic meter water recirculating aquaculture systems (WRAS) operated with and without ozone at various water exchange rates. Three separate studies were conducted: 1) low water exchan...

  1. Catalytic isotope exchange reaction between deuterium gas and water pre-adsorbed on platinum/alumina

    International Nuclear Information System (INIS)

    Iida, Itsuo; Kato, Junko; Tamaru, Kenzi.

    1976-01-01

    The catalytic isotope exchange reaction between deuterium gas and the water pre-adsorbed on Pt/Al 2 O 3 was studied. At reaction temperatures above 273 K, the exchange rate was proportional to the deuterium pressure and independent of the amount of adsorbed water, which suggests that the rate determining step is the supply of deuterium from the gas phase. Its apparent activation energy was 38 kJ mol -1 . Below freezing point of water, the kinetic behaviour was different from that above freezing point. At higher deuterium pressures the rate dropped abruptly at 273 K. Below the temperature the apparent activation energy was 54 kJ mol -1 and the exchange rate depended not on the deuterium pressure but on the amount of the pre-adsorbed water. At lower pressures, however, the kinetic behaviour was the same as the above 273 K, till the rate of the supply of deuterium from the gas phase exceeded the supply of hydrogen from adsorbed water to platinum surface. These results suggest that below 273 K the supply of hydrogen is markedly retarded, the state of the adsorbed water differing from that above 273 K. It was also demonstrated that when the adsorbed water is in the state of capillary condensation, the exchange rate becomes very small. (auth.)

  2. Observed changes in ocean acidity and carbon dioxide exchange in the coastal Bay of Bengal - a link to air pollution

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Krishna, M.S.; Paul, Y.S.; Murty, V.S.N.

    acidity and carbon dioxide exchange in the coastal Bay of Bengal � a link to air pollution By V. V. S. S. SARMA*, M. S. KRISHNA, Y. S. PAUL and V. S. N. MURTY, CSIR�National Institute of Oceanography, 176 Lawsons Bay Colony, Visakhapatnam, India... atmosphere boundary layer over the Bay of Bengal (mean: 5.7 mg m�3) compared to fluxes in the Arabian Sea (mean: 2.9 mg m�3), indicating that the former receives more pollutants than the latter region during January to April when air flow from land to sea...

  3. Ammonia-water exchange front end process for ammonia-hydrogen heavy water plants (Preprint No. PD-1)

    International Nuclear Information System (INIS)

    Sadhukhan, H.K.; Varadarajan, T.G.; Nair, N.K.; Das, S.K.; Nath, G.K.

    1989-04-01

    The ammonia-hydrogen exchange process, which utilizes the deutrium exchange between liquid ammonia and gaseous hydrogen is a parasitic process and the heavy water plants (HWP) based on this process has to be linked with the fertilizer plant (FP) for its enormous requirements of hydrogen (synthesis gas, N 2 +3H 2 ). This dependence of HWP on FP gives rise to certain constraints which are listed. These deficiencies of the ammonia-hydrogen process can be overcome to a great extent by delinking the HWP from FP by incorporating NH 3 -H 2 O exchange as the front end step. In addition to the elimination of the above limitations, by employing water as the ultimate feed for the HWP, the plant capacity can be increased substantially and this would go a long way in achieving economies of the large capacity plants. A schematic diagram of this integrated plant is given. Some of the results of developmental efforts and feasibility studies of this NH 3 -H 2 O exchange are briefly reviewed. (author). 4 figs

  4. Uncertainty quantification of surface-water/groundwater exchange estimates in large wetland systems using Python

    Science.gov (United States)

    Hughes, J. D.; Metz, P. A.

    2014-12-01

    Most watershed studies include observation-based water budget analyses to develop first-order estimates of significant flow terms. Surface-water/groundwater (SWGW) exchange is typically assumed to be equal to the residual of the sum of inflows and outflows in a watershed. These estimates of SWGW exchange, however, are highly uncertain as a result of the propagation of uncertainty inherent in the calculation or processing of the other terms of the water budget, such as stage-area-volume relations, and uncertainties associated with land-cover based evapotranspiration (ET) rate estimates. Furthermore, the uncertainty of estimated SWGW exchanges can be magnified in large wetland systems that transition from dry to wet during wet periods. Although it is well understood that observation-based estimates of SWGW exchange are uncertain it is uncommon for the uncertainty of these estimates to be directly quantified. High-level programming languages like Python can greatly reduce the effort required to (1) quantify the uncertainty of estimated SWGW exchange in large wetland systems and (2) evaluate how different approaches for partitioning land-cover data in a watershed may affect the water-budget uncertainty. We have used Python with the Numpy, Scipy.stats, and pyDOE packages to implement an unconstrained Monte Carlo approach with Latin Hypercube sampling to quantify the uncertainty of monthly estimates of SWGW exchange in the Floral City watershed of the Tsala Apopka wetland system in west-central Florida, USA. Possible sources of uncertainty in the water budget analysis include rainfall, ET, canal discharge, and land/bathymetric surface elevations. Each of these input variables was assigned a probability distribution based on observation error or spanning the range of probable values. The Monte Carlo integration process exposes the uncertainties in land-cover based ET rate estimates as the dominant contributor to the uncertainty in SWGW exchange estimates. We will discuss

  5. Seasonal Dynamics of River Corridor Exchange Across the Continental United States

    Science.gov (United States)

    Gomez-Velez, J. D.; Harvey, J. W.; Scott, D.; Boyer, E. W.; Schmadel, N. M.

    2017-12-01

    River corridors store and convey mass and energy from landscapes to the ocean, altering water quality and ecosystem functioning at the local, reach, and watershed scales. As water moves through river corridors from headwaters streams to coastal estuaries, dynamic exchange between the river channel and its adjacent riparian, floodplain, and hyporheic zones, combined with ponded waters such as lakes and reservoirs, results in the emergence of hot spots and moments for biogeochemical transformations. In this work, we used the model Networks with EXchange and Subsurface Storage (NEXSS) to estimate seasonal variations in river corridor exchange fluxes and residence times along the continental United States. Using a simple routing scheme, we translate these estimates into a cumulative measure of river corridor connectivity at the watershed scale, differentiating the contributions of hyporheic zones, floodplains, and ponded waters. We find that the relative role of these exchange subsystems changes seasonally, driven by the intra-seasonal variability of discharge. In addition, we find that seasonal variations in discharge and the biogeochemical potential of hyporheic zones are out of phase. This behavior results in a significant reduction in hyporheic water quality functions during high flows and emphasizes the potential importance of reconnecting floodplains for managing water quality during seasonal high flows. Physical parameterizations of river corridor processes are critical to model and predict water quality and to sustainably manage water resources under present and future socio-economic and climatic conditions. Parsimonious models like NEXSS can play a key role in the design, implementation, and evaluation of sustainable management practices that target both water quantity and quality at the scale of the nation. This research is a product of the John Wesley Powell Center River Corridor Working Group.

  6. Rate of Isotope Exchange Reaction Between Tritiated Water in a Gas Phase and Water on the Surface of Piping Materials

    International Nuclear Information System (INIS)

    Nakashio, Nobuyuki; Yamaguchi, Junya; Kobayashi, Ryusuke; Nishikawa, Masabumi

    2001-01-01

    The system effect of tritium arises from the interaction of tritium in the gas phase with water on the surface of piping materials. It has been reported that the system effect can be quantified by applying the serial reactor model to the piping system and that adsorption and isotope exchange reactions play the main roles in the trapping of tritium. The isotope exchange reaction that occurs when the chemical form of tritium in the gas phase is in the molecular form, i.e., HT or T 2 , has been named isotope exchange reaction 1, and that which occurs when tritium in the gas phase is in water form, i.e., HTO or T 2 O, has been named isotope exchange reaction 2.The rate of isotope exchange reaction 2 is experimentally quantified, and the rate is observed to be about one-third of the rate of adsorption. The trapping and release behavior of tritium from the piping surface due to isotope exchange reaction 2 is also discussed. It is certified that swamping of water vapor to process gas is effective to release tritium from the surface contaminated with tritium

  7. Avoiding the Water-Climate-Poverty Trap: Adaptive Risk Management for Bangladesh's Coastal Embankments

    Science.gov (United States)

    Hall, J. W.

    2015-12-01

    Our recent research on water security (Sadoff et al., 2015, Dadson et al., 2015) has revealed the dynamic relationship between water security and human well-being. A version of this dynamic is materialising in the coastal polder areas of Khulna, Bangladesh. Repeated coastal floods increase salinity, wipe out agricultural yields for several years and increase out-migration. As a tool to help inform and target future cycles of investment in improvements to the coastal embankments, in this paper we propose a dynamical model of biophysical processes and human well-being, which downscales our previous research to the Khulna region. State variables in the model include agricultural production, population, life expectancy and child mortality. Possible infrastructure interventions include embankment improvements, groundwater wells and drainage infrastructure. Hazard factors include flooding, salinization and drinking water pollution. Our system model can be used to inform adaptation decision making by testing the dynamical response of the system to a range of possible policy interventions, under uncertain future conditions. The analysis is intended to target investment and enable adaptive resource reallocation based on learning about the system response to interventions over the seven years of our research programme. The methodology and paper will demonstrate the complex interplay of factors that determine system vulnerability to climate change. The role of climate change uncertainties (in terms of mean sea level rise and storm surge frequency) will be evaluated alongside multiple other uncertain factors that determine system response. Adaptive management in a 'learning system' will be promoted as a mechanism for coping with climate uncertainties. References:Dadson, S., Hall, J.W., Garrick, D., Sadoff, C. and Grey, D. Water security, risk and economic growth: lessons from a dynamical systems model, Global Environmental Change, in review.Sadoff, C.W., Hall, J.W., Grey, D

  8. Comparison of Geophysical Model Functions for SAR Wind Speed Retrieval in Japanese Coastal Waters

    DEFF Research Database (Denmark)

    Takeyama, Yuko; Ohsawa, Teruo; Kozai, Katsutoshi

    2013-01-01

    This work discusses the accuracies of geophysical model functions (GMFs) for retrieval of sea surface wind speed from satellite-borne Synthetic Aperture Radar (SAR) images in Japanese coastal waters characterized by short fetches and variable atmospheric stability conditions. In situ observations...

  9. The geographical conditions of intensity of salty waters intrusions to coastal lakes on Polish Southern Baltic coast

    Science.gov (United States)

    Cieslinski, R.

    2009-04-01

    Lakes situated on the coast of the southern Baltic function in different conditions than those in which typically inland reservoirs occur. They are situated in the contact zone of two environments: land and sea. These reservoirs together with their direct catchments form specific hydrographic arrangement, in which the course of physical, chemical and biological processes depends on the fact which of these two environments exerts a stronger influence at a given moment. This is important as the lakes situated in the shore zone of the southern Baltic are not exposed to phenomena caused by constant tides, as it is the case in open seas (Ataie-Ashtiani et al., 1999), but only to extreme hydrometeorological conditions, which lead to the formation of the phenomenon of intrusions of sea waters and of damming the free outflow of potamic waters (Demirel, 2004; Cieśliński, Drwal, 2005). What should also be remembered are the local hydrographic, hydrological and morphometric conditions. As a result of intrusions, in the waters of coastal lakes, apart from inland waters there are also waters of sea origin. The proportions of these genetically distinct waters are variable and differ in individual lakes (Grassi, Netti, 2000; Drwal, Cieśliński, 2007). Despite the difference in the causal factor triggering the phenomenon of salt water intrusions, the effect is usually the same as that observed, for instance, in lakes and lagoons of seas with tides (Ishitobi et al., 1999; De Louw, Oude Essink, 2001) and poorly flushed lagoon (Hsing-Juh et al., 2006) or estuaries (Uncles et al., 2002), though the scale of qualitative changes is greater in the case of open seas than in half-closed and closed seas. The status of the research carried out so far enables proposing a hypothesis that chlorides concentrations, as the best indicators for establishing the occurrence of the phenomenon of intrusions, depend not only on the meteorological factor but in some of the lakes on various

  10. Effect of Leaf Water Potential on Internal Humidity and CO2 Dissolution: Reverse Transpiration and Improved Water Use Efficiency under Negative Pressure.

    Science.gov (United States)

    Vesala, Timo; Sevanto, Sanna; Grönholm, Tiia; Salmon, Yann; Nikinmaa, Eero; Hari, Pertti; Hölttä, Teemu

    2017-01-01

    The pull of water from the soil to the leaves causes water in the transpiration stream to be under negative pressure decreasing the water potential below zero. The osmotic concentration also contributes to the decrease in leaf water potential but with much lesser extent. Thus, the surface tension force is approximately balanced by a force induced by negative water potential resulting in concavely curved water-air interfaces in leaves. The lowered water potential causes a reduction in the equilibrium water vapor pressure in internal (sub-stomatal/intercellular) cavities in relation to that over water with the potential of zero, i.e., over the flat surface. The curved surface causes a reduction also in the equilibrium vapor pressure of dissolved CO 2 , thus enhancing its physical solubility to water. Although the water vapor reduction is acknowledged by plant physiologists its consequences for water vapor exchange at low water potential values have received very little attention. Consequences of the enhanced CO 2 solubility to a leaf water-carbon budget have not been considered at all before this study. We use theoretical calculations and modeling to show how the reduction in the vapor pressures affects transpiration and carbon assimilation rates. Our results indicate that the reduction in vapor pressures of water and CO 2 could enhance plant water use efficiency up to about 10% at a leaf water potential of -2 MPa, and much more when water potential decreases further. The low water potential allows for a direct stomatal water vapor uptake from the ambient air even at sub-100% relative humidity values. This alone could explain the observed rates of foliar water uptake by e.g., the coastal redwood in the fog belt region of coastal California provided the stomata are sufficiently open. The omission of the reduction in the water vapor pressure causes a bias in the estimates of the stomatal conductance and leaf internal CO 2 concentration based on leaf gas exchange

  11. The links between global carbon, water and nutrient cycles in an urbanizing world — the case of coastal eutrophication

    NARCIS (Netherlands)

    Kroeze, C.; Hofstra, N.; Ivens, W.; Löhr, A.; Strokal, M.; Wijnen, van J.

    2013-01-01

    The natural cycles of carbon (C), nitrogen (N), phosphorus (P) and water have been disturbed substantially by human activities. Urbanizing coastal drainage basins and large river deltas are located at the interface of freshwater and coastal components of the larger earth system and the process of

  12. Impact of anthropogenic development on coastal ground-water hydrology in southeastern Florida, 1900-2000

    Science.gov (United States)

    Renken, Robert A.; Dixon, Joann; Koehmstedt, John A.; Ishman, Scott; Lietz, A.C.; Marella, Richard L.; Telis, Pamela A.; Rodgers, Jeff; Memberg, Steven

    2005-01-01

    Southeastern Florida is an area that has been subject to widely conflicting anthropogenic stress to the Everglades and coastal ecosystems. This stress is a direct consequence of the 20th century economic competition for limited land and water resources needed to satisfy agricultural development and its expansion, its displacement by burgeoning urban development, and the accompanying growth of the limestone mining industry. The development of a highly controlled water-management system designed to reclaim land for urban and agricultural development has severely impacted the extent, character, and vitality of the historic Everglades and coastal ecosystems. An extensive conveyance system of canals, levees, impoundments, surface- water control structures, and numerous municipal well fields are used to sustain the present-day Everglades hydrologic system, prevent overland flow from moving eastward and flooding urban and agricultural areas, maintain water levels to prevent saltwater intrusion, and provide an adequate water supply. Extractive mining activities expanded considerably in the latter part of the 20th century, largely in response to urban construction needs. Much of the present-day urban-agricultural corridor of southeastern Florida lies within an area that is no more than 15 feet above NGVD 1929 and formerly characterized by freshwater marsh, upland, and saline coastal wetland ecosystems. Miami- Dade, Broward, and Palm Beach Counties have experienced explosive population growth, increasing from less than 4,000 inhabitants in 1900 to more than 5 million in 2000. Ground-water use, the principal source of municipal supply, has increased from about 65 Mgal/d (million gallons per day) obtained from 3 well fields in 1930 to more than 770 Mgal/d obtained from 65 well fields in 1995. Water use for agricultural supply increased from 505 Mgal/d in 1953 to nearly 1,150 Mgal/d in 1988, but has since declined to 764 Mgal/d in 1995, partly as a result of displacement of the

  13. Origin of water salinity in the coastal Sarafand aquifer (South-Lebanon)

    International Nuclear Information System (INIS)

    Hashash, Adnan; Aranyossy, J.F.

    1996-01-01

    Author.The geochemical and isotopic study, based on the analysis of twenty water samples from well in the coastal plain of Sarafand (South-Lebanon), permit to eliminate the hypothesis of marine intrusion in this aquifer. The increase of salinity observed in certain wells is due to the contamination of cretaceous aquifer water by the quaternary formations. The two poles of mixing are respectively characterized: by weak tritium contents (between 2 and 3 UT) and a value of stable isotopes (-5,9<0,18<-5,5) corresponding to the appearance of cretaceous formation area; by the high tritium contents and enrichment relative to heavy isotope in the mineralized water of superficial formations. On the other hand, the isotope contents permit the set a rapid renewal of the cretaceous aquifer water due to quick circulation in the Karstic system

  14. GROUNDWATER-SURFACE WATER EXCHANGE AND IMPLICATIONS FOR LARGE RIVER RESTORATION

    Science.gov (United States)

    Movement of river water into and out of high-porosity alluvial deposits can have an important influence on surface water quality and aquatic habitat. In our study of a 60-km reach of the Willamette River in Oregon, USA, we: 1) used tracers to estimate the rate of exchange betw...

  15. Nano-Pervaporation Membrane with Heat Exchanger Generates Medical-Grade Water

    Science.gov (United States)

    Tsai, Chung-Yi; Alexander, Jerry

    2009-01-01

    A nanoporous membrane is used for the pervaporation process in which potable water is maintained, at atmospheric pressure, on the feed side of the membrane. The water enters the non-pervaporation (NPV) membrane device where it is separated into two streams -- retentate water and permeated water. The permeated pure water is removed by applying low vapor pressure on the permeate side to create water vapor before condensation. This permeated water vapor is subsequently condensed by coming in contact with the cool surface of a heat exchanger with heat being recovered through transfer to the feed water stream.

  16. Environmental variation, vegetation distribution, carbon dynamics and water/energy exchange at high latitudes

    Science.gov (United States)

    McGuire, A.D.; Wirth, C.; Apps, M.; Beringer, J.; Clein, J.; Epstein, H.; Kicklighter, D.W.; Bhatti, J.; Chapin, F. S.; De Groot, B.; Efremov, D.; Eugster, W.; Fukuda, M.; Gower, T.; Hinzman, L.; Huntley, B.; Jia, G.J.; Kasischke, E.; Melillo, J.; Romanovsky, V.; Shvidenko, A.; Vaganov, E.; Walker, D.

    2002-01-01

    The responses of high latitude ecosystems to global change involve complex interactions among environmental variables, vegetation distribution, carbon dynamics, and water and energy exchange. These responses may have important consequences for the earth system. In this study, we evaluated how vegetation distribution, carbon stocks and turnover, and water and energy exchange are related to environmental variation spanned by the network of the IGBP high latitude transects. While the most notable feature of the high latitude transects is that they generally span temperature gradients from southern to northern latitudes, there are substantial differences in temperature among the transects. Also, along each transect temperature co-varies with precipitation and photosynthetically active radiation, which are also variable among the transects. Both climate and disturbance interact to influence latitudinal patterns of vegetation and soil carbon storage among the transects, and vegetation distribution appears to interact with climate to determine exchanges of heat and moisture in high latitudes. Despite limitations imposed by the data we assembled, the analyses in this study have taken an important step toward clarifying the complexity of interactions among environmental variables, vegetation distribution, carbon stocks and turnover, and water and energy exchange in high latitude regions. This study reveals the need to conduct coordinated global change studies in high latitudes to further elucidate how interactions among climate, disturbance, and vegetation distribution influence carbon dynamics and water and energy exchange in high latitudes.

  17. Satellite tagging highlights the importance of productive Mozambican coastal waters to the ecology and conservation of whale sharks

    Science.gov (United States)

    Richardson, Anthony J.; Jaine, Fabrice R. A.; Bennett, Michael B.; Weeks, Scarla J.; Cliff, Geremy; Robinson, David P.; Reeve-Arnold, Katie E.; Pierce, Simon J.

    2018-01-01

    The whale shark Rhincodon typus is an endangered, highly migratory species with a wide, albeit patchy, distribution through tropical oceans. Ten aerial survey flights along the southern Mozambican coast, conducted between 2004–2008, documented a relatively high density of whale sharks along a 200 km stretch of the Inhambane Province, with a pronounced hotspot adjacent to Praia do Tofo. To examine the residency and movement of whale sharks in coastal areas around Praia do Tofo, where they may be more susceptible to gill net entanglement, we tagged 15 juveniles with SPOT5 satellite tags and tracked them for 2–88 days (mean = 27 days) as they dispersed from this area. Sharks travelled between 10 and 2,737 km (mean = 738 km) at a mean horizontal speed of 28 ± 17.1 SD km day−1. While several individuals left shelf waters and travelled across international boundaries, most sharks stayed in Mozambican coastal waters over the tracking period. We tested for whale shark habitat preferences, using sea surface temperature, chlorophyll-a concentration and water depth as variables, by computing 100 random model tracks for each real shark based on their empirical movement characteristics. Whale sharks spent significantly more time in cooler, shallower water with higher chlorophyll-a concentrations than model sharks, suggesting that feeding in productive coastal waters is an important driver of their movements. To investigate what this coastal habitat choice means for their conservation in Mozambique, we mapped gill nets during two dedicated aerial surveys along the Inhambane coast and counted gill nets in 1,323 boat-based surveys near Praia do Tofo. Our results show that, while whale sharks are capable of long-distance oceanic movements, they can spend a disproportionate amount of time in specific areas, such as along the southern Mozambique coast. The increasing use of drifting gill nets in this coastal hotspot for whale sharks is likely to be a threat to regional

  18. WaterML, an Information Standard for the Exchange of in-situ hydrological observations

    Science.gov (United States)

    Valentine, D.; Taylor, P.; Zaslavsky, I.

    2012-04-01

    The WaterML 2.0 Standards Working Group (SWG), working within the Open Geospatial Consortium (OGC) and in cooperation with the joint OGC-World Meteorological Organization (WMO) Hydrology Domain Working Group (HDWG), has developed an open standard for the exchange of water observation data; WaterML 2.0. The focus of the standard is time-series data, commonly generated from in-situ style monitoring. This is high value data for hydrological applications such as flood forecasting, environmental reporting and supporting hydrological infrastructure (e.g. dams, supply systems), which is commonly exchanged, but a lack of standards inhibits efficient reuse and automation. The process of developing WaterML required doing a harmonization analysis of existing standards to identify overlapping concepts and come to agreement on a harmonized definition. Generally the formats captured similar requirements, all with subtle differences, such as how time-series point metadata was handled. The in-progress standard WaterML 2.0 incorporates the semantics of the hydrologic information: location, procedure, and observations, and is implemented as an application schema of the Geography Markup Language version 3.2.1, making use of the OGC Observations & Measurements standards. WaterML2.0 is designed as an extensible schema to allow encoding of data to be used in a variety of exchange scenarios. Example areas of usage are: exchange of data for operational hydrological monitoring programs; supporting operation of infrastructure (e.g. dams, supply systems); cross-border exchange of observational data; release of data for public dissemination; enhancing disaster management through data exchange; and exchange in support of national reporting The first phase of WaterML2.0 focused on structural definitions allowing for the transfer of time-series, with less work on harmonization of vocabulary items such as quality codes. Vocabularies from various organizations tend to be specific and take time to

  19. Water and sediment temperature dynamics in shallow tidal environments: The role of the heat flux at the sediment-water interface

    Science.gov (United States)

    Pivato, M.; Carniello, L.; Gardner, J.; Silvestri, S.; Marani, M.

    2018-03-01

    In the present study, we investigate the energy flux at the sediment-water interface and the relevance of the heat exchanged between water and sediment for the water temperature dynamics in shallow coastal environments. Water and sediment temperature data collected in the Venice lagoon show that, in shallow, temperate lagoons, temperature is uniform within the water column, and enabled us to estimate the net heat flux at the sediment-water interface. We modeled this flux as the sum of a conductive component and of the solar radiation reaching the bottom, finding the latter being negligible. We developed a "point" model to describe the temperature dynamics of the sediment-water continuum driven by vertical energy transfer. We applied the model considering conditions characterized by negligible advection, obtaining satisfactory results. We found that the heat exchange between water and sediment is crucial for describing sediment temperature but plays a minor role on the water temperature.

  20. Application of the Benthic Ecosystem Quality Index 2 to benthos in Dutch transitional and coastal waters

    NARCIS (Netherlands)

    Van Loon, W.M.G.M.; Boon, A.R.; Gittenberger, A.; Walvoort, D.J.J.; Lavaleye, M.S.S.; Duineveld, G.C.A.; Verschoor, A.J.

    2015-01-01

    The Benthic Ecosystem Quality Index 2 (BEQI2) is the Dutch multi-metric index (MMI) for assessing the status and trend of benthic invertebrates in transitional and coastal waters for the Water Framework Directive (WFD). It contains the same indicators, i.e. species richness, Shannon index and AMBI,

  1. Application of the Benthic Ecosystem Quality Index 2 to benthos in Dutch transitional and coastal waters

    NARCIS (Netherlands)

    Loon, van W.M.G.M.; Boon, A.R.; Gittenberger, A.; Walvoort, D.J.J.; Lavaleye, M.; Duineveld, G.C.A.; Verschoor, A.J.

    2015-01-01

    The Benthic Ecosystem Quality Index 2 (BEQI2) is the Dutch multi-metric index (MMI) for assessing the status and trend of benthic invertebrates in transitional and coastal waters for the Water Framework Directive (WFD). It contains the same indicators, i.e. species richness, Shannon index and

  2. Gas exchange patterns and water loss rates in the Table Mountain cockroach, Aptera fusca (Blattodea: Blaberidae).

    Science.gov (United States)

    Groenewald, Berlizé; Bazelet, Corinna S; Potter, C Paige; Terblanche, John S

    2013-10-15

    The importance of metabolic rate and/or spiracle modulation for saving respiratory water is contentious. One major explanation for gas exchange pattern variation in terrestrial insects is to effect a respiratory water loss (RWL) saving. To test this, we measured the rates of CO2 and H2O release ( and , respectively) in a previously unstudied, mesic cockroach, Aptera fusca, and compared gas exchange and water loss parameters among the major gas exchange patterns (continuous, cyclic, discontinuous gas exchange) at a range of temperatures. Mean , and per unit did not differ among the gas exchange patterns at all temperatures (P>0.09). There was no significant association between temperature and gas exchange pattern type (P=0.63). Percentage of RWL (relative to total water loss) was typically low (9.79±1.84%) and did not differ significantly among gas exchange patterns at 15°C (P=0.26). The method of estimation had a large impact on the percentage of RWL, and of the three techniques investigated (traditional, regression and hyperoxic switch), the traditional method generally performed best. In many respects, A. fusca has typical gas exchange for what might be expected from other insects studied to date (e.g. , , RWL and cuticular water loss). However, we found for A. fusca that expressed as a function of metabolic rate was significantly higher than the expected consensus relationship for insects, suggesting it is under considerable pressure to save water. Despite this, we found no consistent evidence supporting the conclusion that transitions in pattern type yield reductions in RWL in this mesic cockroach.

  3. Spatial and Temporal Distribution of Sea Surface Salinity in Coastal Waters of China Based on Aquarius

    International Nuclear Information System (INIS)

    Wang, Ying; Jiang, Hong; Zhang, Xiuying; Jin, Jiaxin

    2014-01-01

    Sea surface salinity (SSS) is a fundamental parameter for the study of global ocean dynamics, water cycle, and climate variability. Aquarius launched by NASA and the Space Agency of Argentina is a breakthrough which could achieve the remote sensing data of SSS. The present paper takes the coastal of China as study area, which is a representative area of ocean boundary and influenced by continental rivers (Yangtze River and Pearl River). After analyze the temporal and spatial variation of SSS in the coastal of China, the estuary area has obvious low salinity because the injected of freshwater from continent. Take the East China Sea (ECS) and South China Sea (SCS) as representative region to discuss the effect of freshwater to SSS. The salinity is almost equal in winter when the diluted water is inadequate in both rivers. However, an obvious decrease appeared in summer especial July in Yangtze River for abundance discharge inflow the ECS. This is a reasonable expression of Yangtze River discharge is remarkable influence the SSS in coastal area then Pearl River. Survey the distribution range of Yangtze River diluted water (SSS<31psu). The range is small in winter and expands to peak value in summer

  4. Uncertainties and applications of satellite-derived coastal water quality products

    Science.gov (United States)

    Zheng, Guangming; DiGiacomo, Paul M.

    2017-12-01

    Recent and forthcoming launches of a plethora of ocean color radiometry sensors, coupled with increasingly adopted free and open data policies are expected to boost usage of satellite ocean color data and drive the demand to use these data in a quantitative and routine manner. Here we review factors that introduce uncertainties to various satellite-derived water quality products and recommend approaches to minimize the uncertainty of a specific product. We show that the regression relationships between remote-sensing reflectance and water turbidity (in terms of nephelometric units) established for different regions tend to converge and therefore it is plausible to develop a global satellite water turbidity product derived using a single algorithm. In contrast, solutions to derive suspended particulate matter concentration are much less generalizable; in one case it might be more accurate to estimate this parameter based on satellite-derived particulate backscattering coefficient, whereas in another the nonagal particulate absorption coefficient might be a better proxy. Regarding satellite-derived chlorophyll concentration, known to be subject to large uncertainties in coastal waters, studies summarized here clearly indicate that the accuracy of classical reflectance band-ratio algorithms depends largely on the contribution of phytoplankton to total light absorption coefficient as well as the degree of correlation between phytoplankton and the dominant nonalgal contributions. Our review also indicates that currently available satellite-derived water quality products are restricted to optically significant materials, whereas many users are interested in toxins, nutrients, pollutants, and pathogens. Presently, proxies or indicators for these constituents are inconsistently (and often incorrectly) developed and applied. Progress in this general direction will remain slow unless, (i) optical oceanographers and environmental scientists start collaborating more closely

  5. Green seaweed Ulva as a monitor for pollution in coastal waters

    Energy Technology Data Exchange (ETDEWEB)

    Levine, H.G.

    1983-01-01

    Methods have been developed which capitalize on the capacity of Ulva to function as a bioindicator of pollution in coastal waters. Studies have been performed evaluating the growth of both Ulva tissue discs and Ulva germlings as they relate to physical and chemical parameters of the environment. The Ulva tissue disc method for the in situ monitoring of organic load (nitrogen and phosphorus) in coastal waters was demonstrated to be marginally effective. The in situ differential growth reponse of parthenogenetically developed germlings fulfilled the monitoring objective, but multi-faceted environmental considerations introduced complications which reduced the feasibility of the germling deployment method for routine monitoring. The assessment of Ulva as a bioaccumulator was undertaken. Use of Ulva as an in situ sampling device has demonstrated appreciable success. This in situ monitor can provide concentrated samples of environmental pollutants. Analytical techniques have been employed to extract information on trace metals, pesticides, PCBs and other accumulated organohalides. Ulva is a bioacumulator which, by all standards, has much to recommend it. Precedures have been developed to reduce much of the inherent biological varation. Ulva has world-wide occurrence, and is therefore capable of providing a standard for comparison of data. This alga merits consideration as an international monitor for pollutants in the marine environment.

  6. The Application and Usefulness of Economic Analyses for Water Quality Management in Coastal Areas

    Science.gov (United States)

    Economic studies are increasingly sought as tools to contribute to water quality management in estuaries and coastal communities, yet little is known about how the results from existing studies have been received and utilized by the organizations who solicited them. We interviewe...

  7. Status of the amphipod Diporeia ssp. in coastal waters of the Laurentian Great Lakes

    Science.gov (United States)

    Diporeia has historically been the dominant benthic macroinvertebrate in deeper waters of the Laurentian Great Lakes, and its abundance has been proposed as an indicator of ecological condition. In 2010, the USEPA incorporated the Great Lakes into the National Coastal Condition A...

  8. Natural and human-induced hypoxia and consequences for coastal areas: synthesis and future development

    Science.gov (United States)

    Zhang, J.; Gilbert, D.; Gooday, A.; Levin, L.; Naqvi, W.; Middelburg, J.; Scranton, M.; Ekau, W.; Pena, A.; Dewitte, B.; Oguz, T.; Monteiro, P. M. S.; Urban, E.; Rabalais, N.; Ittekkot, V.; Kemp, W. M.; Ulloa, O.; Elmgren, R.; Escobar-Briones, E.; van der Plas, A.

    2009-11-01

    Hypoxia has become a world-wide phenomenon in the global coastal ocean and causes deterioration of structure and function of ecosystems. Based on the collective contributions of members of SCOR Working Group #128, the present study provides an overview of the major aspects of coastal hypoxia in different biogeochemical provinces, including estuaries, upwelling areas, fjords and semi-enclosed basins, with various external forcings, ecosystem responses, feedbacks and potential impact on the sustainability of the fishery and economics. The obvious external forcings include fresh water runoff and other factors contributing to stratification, organic matter and nutrient loadings, as well as exchange between coastal and open ocean water masses; their different interactions set up mechanisms that drive the system towards hypoxia. However, whether the coastal environment becomes hypoxic or not, under the combination of external forcings, depends also on the nature of the ecosystem, e.g. physical and geographic settings. It is understood that coastal hypoxia has a profound impact on the sustainability of ecosystems, which can be seen, for example, by the change in the food-web structure and system function; other influences can be compression and loss of habitat, as well as change in life cycle and reproduction. In most cases, the ecosystem responds to the low dissolved oxygen in a non-linear way and has pronounced feedbacks to other compartments of the Earth System, hence affecting human society. Our knowledge and previous experiences illustrate that there is a need to develop new observational tools and models to support integrated research of biogeochemical dynamics and ecosystem behaviour that will improve confidence in remediation management strategies for coastal hypoxia.

  9. Chemical characteristics of surface waters in the Forsmark area. Evaluation of data from lakes, streams and coastal sites

    International Nuclear Information System (INIS)

    Sonesten, Lars

    2005-06-01

    This report is an evaluation of the chemical composition of surface water in lakes, streams, and at coastal sampling sites in the Forsmark area. The aim with this study is to characterise the surface water systems in the area, and the further aim with this characterisation is to be used as input material to the safety analyses and environmental impact assessments for the potential deep repository of used nuclear fuels. The data used consist of water chemical composition of lakes, streams and coastal sites from the period March 2002 - April 2004. The sampling has been performed predominantly on a monthly basis. The emphasis of the assessment has been on surface waters (0.5 m), as the water depth at all sampling locations is limited, and thereby the water systems are rarely stratified for prolonged periods. The characterisations have been restricted to the most commonly measured chemical parameters.The assessment has been divided into three parts: Comparisons within and between the lakes, streams, and coastal sites, respectively; Temporal and spatial variation, predominantly within lakes and stream sites; and Relationships between the various chemical parameters. Beside comparisons between the sampling sites within the Forsmark area, comparisons have also been made with regional and national data from the latest Swedish National Survey (2000). The analyses of temporal and spatial variation have been concentrated on the freshwater systems in the Norra Bassaengen catchment area. This catchment area is the most comprehensively investigated, and it also includes the Bolundsfjaerden sub-catchment, which is the area where the continued site investigations will be concentrated. The relationships among the sampling sites, the catchment areas, as well as the chemical parameters investigated, were examined by applying PCA analyses on the lake and stream data. In general, the freshwater systems in the Forsmark area are characterised by small and shallow oligotrophic hardwater

  10. Chemical characteristics of surface waters in the Forsmark area. Evaluation of data from lakes, streams and coastal sites

    Energy Technology Data Exchange (ETDEWEB)

    Sonesten, Lars [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Environmental Assessment

    2005-06-01

    This report is an evaluation of the chemical composition of surface water in lakes, streams, and at coastal sampling sites in the Forsmark area. The aim with this study is to characterise the surface water systems in the area, and the further aim with this characterisation is to be used as input material to the safety analyses and environmental impact assessments for the potential deep repository of used nuclear fuels. The data used consist of water chemical composition of lakes, streams and coastal sites from the period March 2002 - April 2004. The sampling has been performed predominantly on a monthly basis. The emphasis of the assessment has been on surface waters (0.5 m), as the water depth at all sampling locations is limited, and thereby the water systems are rarely stratified for prolonged periods. The characterisations have been restricted to the most commonly measured chemical parameters.The assessment has been divided into three parts: Comparisons within and between the lakes, streams, and coastal sites, respectively; Temporal and spatial variation, predominantly within lakes and stream sites; and Relationships between the various chemical parameters. Beside comparisons between the sampling sites within the Forsmark area, comparisons have also been made with regional and national data from the latest Swedish National Survey (2000). The analyses of temporal and spatial variation have been concentrated on the freshwater systems in the Norra Bassaengen catchment area. This catchment area is the most comprehensively investigated, and it also includes the Bolundsfjaerden sub-catchment, which is the area where the continued site investigations will be concentrated. The relationships among the sampling sites, the catchment areas, as well as the chemical parameters investigated, were examined by applying PCA analyses on the lake and stream data. In general, the freshwater systems in the Forsmark area are characterised by small and shallow oligotrophic hardwater

  11. Spatiotemporal Distribution and Assemblages of Planktonic Fungi in the Coastal Waters of the Bohai Sea

    Directory of Open Access Journals (Sweden)

    Yaqiong Wang

    2018-03-01

    Full Text Available Fungi play a critical role in the nutrient cycling and ecological function in terrestrial and freshwater ecosystems. Yet, many ecological aspects of their counterparts in coastal ecosystems remain largely elusive. Using high-throughput sequencing, quantitative PCR, and environmental data analyses, we studied the spatiotemporal changes in the abundance and diversity of planktonic fungi and their abiotic and biotic interactions in the coastal waters of three transects along the Bohai Sea. A total of 4362 ITS OTUs were identified and more than 60% of which were unclassified Fungi. Of the classified OTUs three major fungal phyla, Ascomycota, Basidiomycota, and Chytridiomycota were predominant with episodic low dominance phyla Cryptomycota and Mucoromycota (Mortierellales. The estimated average Fungi-specific 18S rRNA gene qPCR abundances varied within 4.28 × 106 and 1.13 × 107copies/L with significantly (P < 0.05 different abundances among the transects suggesting potential influence of the different riverine inputs. The spatiotemporal changes in the OTU abundance of Ascomycota and Basidiomycota phyla coincided significantly (P < 0.05 with nutrients traced to riverine inputs and phytoplankton detritus. Among the eight major fungal orders, the abundance of Hypocreales varied significantly (P < 0.01 across months while Capnodiales, Pleosporales, Eurotiales, and Sporidiobolales varied significantly (P < 0.05 across transects. In addition, our results likely suggest a tripartite interaction model for the association within members of Cryptomycota (hyperparasites, Chytridiomycota (both parasites and saprotrophs, and phytoplankton in the coastal waters. The fungal network featured several hubs and keystone OTUs besides the display of cooperative and competitive relationship within OTUs. These results support the notion that planktonic fungi, hitherto mostly undescribed, play diverse ecological roles in marine habitats and further outline niche processes

  12. Salinity and temperature variations around Peninsula Malaysia coastal waters

    International Nuclear Information System (INIS)

    Abdul Kadir Ishak; Jeremy Andy Anak Dominic; Nazrul Hizam Yusof; Mohd Rafaei Murtadza

    2004-01-01

    Vertical profiles of salinity and temperature were measured at several offshore stations along east and west coast of Peninsula Malaysia coastal waters. The measurements which covered South China Sea and Straits of Malacca were made during sampling cruises for Marine Database Project for Peninsula Malaysia, and during an IAEA regional training course for Marine Pollution Project. The results show that the water temperature is highest at the surface and minimum at bottom, while the salinity is lowest at the surface and highest at the bottom. In Malacca Straits, the highest surface water temperature was 30.6 degree C and the lowest bottom water temperature was 20.4 degree C, recorded at a station located in Andaman Sea. The same station also recorded the highest surface and bottom salinity i.e. 31.3 ppt and 34.4 ppt, respectively. For South China Sea, the maximum surface water temperature was 30.4 degree C and the minimum bottom temperature was 25.9 degree C, while the highest surface salinity was 33.2 ppt and the highest bottom salinity was 34.1 ppt. The water in South China Sea also showed some degrees of stratifications with thermocline zones located between 10-40 m water depths. In Malacca Straits, stronger thermocline develops at higher latitude, while at lower latitude the water is more readily mixed. Beside the spatial variations, the seawater temperature and salinity around Peninsula Malaysia also subjected to temporal variation as seawater. (Author)

  13. Organic and Inorganic Matter in Louisiana Coastal Waters: Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi Regions.

    Science.gov (United States)

    Chromophoric dissolved organic matter (CDOM) spectral absorption, dissolved organic carbon (DOC) concentration, and the particulate fraction of inorganic (PIM) and organic matter (POM) were measured in Louisiana coastal waters at Vermilion, Atchafalaya, Terrebonne, Barataria, and...

  14. Variability of solar radiation and CDOM in surface coastal waters of the northwestern Mediterranean sea

    OpenAIRE

    Sempéré, Richard; Para, J.; Tedetti, Marc; Charriere, B.; Mallet, M.

    2015-01-01

    Atmospheric and in-water solar radiation, including UVR-B, UVR-A and PAR, as well as chromophoric dissolved organic matter absorption [a(CDOM)()] in surface waters were monthly measured from November 2007 to December 2008 at a coastal station in the Northwestern Mediterranean Sea (Bay of Marseilles, France). Our results showed that the UVR-B/UVR-A ratio followed the same trend in the atmosphere and at 2m depth in the water (P

  15. Alkali metal ion-proton exchange equilibria and water sorption studies on nafon 117 membrane and dowex 50 W exchange resins: effect of long storage or aging

    International Nuclear Information System (INIS)

    Ramkumar, Jayshree; Venkataramani, B.

    2004-09-01

    Alkali metal ion -H + exchanges on Nafion 117 membrane treated differently, Dowex 50 W x 4 and Dowex 50 W x 8 resins have been studied at a total ionic strength of 0.1 mol dm -3 . The water sorption isotherms of these exchangers in different ionic forms generated over the entire range of water activity, have been analysed by the D'Arcy and Watt equation (DWE). Water sorption studies have shown that the physical structure of the exchangers have changed due to long -storage or aging, resulting in poorer water sorption and even formation of pores in the case of Dowex 50 W x 8 resin. As a result, the counter ions in the exchangers are not hydrated and the water is present in a free form, albeit structured, in the resin phase. The selectivity sequence for the alkali metal ions with reference to the H + (Li + + + ) for the exchangers used in the present study is in accordance with that reported in the literature for the ionomers having sulphonic acid as the functional group. In view of the absence of hydration of the cations in the resin phase, the driving force for the selectivity of the cation, namely, the net gain in entropy, is expected to come from the loss of structured water during the exchange process. Pre treating the Nafion 117 membrane with boiling acid solution activates the clustered region of the membrane in the H + form, while pretreatment with boiling water expands the non-ionic domain (the region connecting the clusters). These modifications influence the state of water present in the Nafion