WorldWideScience

Sample records for brackish water ecosystems

  1. Biosorption treatment of brackish water

    International Nuclear Information System (INIS)

    Biosorptivity of different agricultural wastes have been evaluated for the treatment of brackish water and a new method, based on the principle of bio-sorption has been described. Wastes of the Saccharum officinarum, Moringa oleifera, Triticum aestivcum and Oryza sativa have been used in raw forms as well as after converting them into ash and activated carbon as biosorbents for treatment of brackish water in this study. Samples of brackish water have been analyzed before and after treatment for quality control parameters of water. A significant Improvement has been observed in quality control parameters of water after treatment. pH of the water samples slightly increased from 7.68 to 7.97 with different treatments. A substantial decrease in conductivity,. TDS, TH, concentrations of cations and anions was observed in the samples of brackish water after treatment with different biosorbents. (author)

  2. Membrane technology comparison in brackish water purification

    OpenAIRE

    Martorell Cebrián, Aleix

    2010-01-01

    This work reviews membrane technologies- specifically Brackish Water Revere Osmosis (BWRO), Nanofiltration (NF) and Electrodyalisis Reversal (EDR), for drinking water production from brackish waters at lab, pilot and industrial scale. In the recent years, many fresh water resources such as surface and groundwater have become overused or misused. As a result, these resources are either diminishing or becoming low quality waters, which are supplied to population due to scarcity. ...

  3. Growing floricultural crops with brackish water

    NARCIS (Netherlands)

    Cassaniti, C.; Romano, D.; Hop, M.E.C.M.; Flowers, T.J.

    2013-01-01

    In the current review we focus on the opportunity to use brackish water in the cultivation of floricultural plants, plants for which, due to their high economic value, growers have traditionally used good quality water for irrigation. Now, even for these crops the use of alternative water sources fo

  4. Desalting sea water and brackish waters: a cost update

    International Nuclear Information System (INIS)

    This report, based on first-quarter 1977 dollars, is an update of costs presented in ORNL/TM-5070 (Rev.), which gave cost estimates for desalting seawater and brackish waters based on first-quarter 1975 financial parameters. Cost estimates are given for desalting seawater by distillation and reverse osmosis and for brackish waters using reverse osmosis and electrodialysis. Cost data were computed as a function of plant size and energy cost. The cost of generating steam and electrical energy on-site using coal-fired boilers as well as oil-fired boilers and dual-purpose electric/seawater distillation plants is included. While the costs of energy, equipment and labor have continued to rise, they have increased at a relatively modest rate compared with the two years prior to 1975. On an average, the cost of desalting seawater by distillation has increased approximately 15%. Costs for desalting brackish waters by the membrance processes have increased about 7%

  5. Water, sediment and soil physicochemical interactions in freshwater, brackish and saline systems

    OpenAIRE

    Ferronato, Chiara

    2015-01-01

    The physicochemical interactions between water, sediment and soil deeply influence the formation and development of the ecosystem. In this research, different freshwater, brackish and saline subaqueous environments of Northern Italy were chosen as study area to investigate the physicochemical processes which occur at the interface between water and sediments, as well as the effects of soil submergence on ecosystem development. In the freshwater system of the Reno river basin, the main pur...

  6. Infrared Turbidimetric Titration Method for Sulfate Ions in Brackish Water

    OpenAIRE

    Benabadji Nouredine; Kherici Samira; Benouali Djillali

    2012-01-01

    In this work an infrared turbidimetric titration method is described for the determination of sulfate ions in brackish water. A suspension of barium sulfate is produced in an aqueous solution and/or brackish water sample by the addition of barium chloride solution and the turbidity is monitored with the help of an immersed infrared sensor. The developed sensor utilizes an optical system to measure the evolution of turbidity during the titration. This sensor is a simple device designed in th...

  7. Desalting seawater and brackish waters: 1981 cost update

    International Nuclear Information System (INIS)

    This is the fourth in a series of desalting cost update reports. Cost data are reported for desalting seawater by various distillation systems and by reverse osmosis. Costs of desalting four brackish waters, representative of those found in the United States by both reverse osmosis and electrodialysis are also given. Cost data are presented parametrically as a function of energy cost and plant size. The cost of desalting seawater by distillation has increased by 40% during the past two years, while desalting by reverse osmosis has increased by about 36% during the same period. Brackish water desalting by reverse osmosis has only increased by about 12%, and brackish water desalting by electrodialysis is up by 40%. Again, the continued increase in energy costs has had a major impact on all desalination systems

  8. Annual net ecosystem exchanges of carbon dioxide and methane from a temperate brackish marsh: should the focus of marsh restoration be on brackish environments?

    Science.gov (United States)

    Windham-Myers, L.; Anderson, F. E.; Bergamaschi, B. A.; Ferner, M. C.; Schile, L. M.; Spinelli, G.

    2015-12-01

    The exchange and transport of carbon in tidally driven, saline marsh ecosystems provide habitat and trophic support for coastal wildlife and fisheries, while potentially accumulating and storing carbon at some of the highest rates compared to other ecosystems. However, due to the predicted rise in sea level over the next century, the preservation and restoration of estuarine habitats is necessary to compensate for their expected decline. In addition, restoration of these marsh systems can also reduce the impacts of global climate change as they assimilate as much carbon as their freshwater counterparts, while emitting less methane due to the higher concentrations of sulfate in seawater. Unfortunately, in brackish marshes, with salinity concentrations less than 18 parts per thousand (ppt), simple relationships between methane production, salinity and sulfate concentrations are not well known. Here we present the net ecosystem exchange (NEE) of carbon dioxide and methane, as calculated by the eddy covariance method, from a brackish marsh ecosystem in the San Francisco Estuary where salinity ranges from oligohaline (0.5-5 ppt) to mesohaline (5-18 ppt) conditions. Daily rates of carbon dioxide and methane NEE ranged from approximately 10 gC-CO2 m-2 d-1 and 0 mgC-CH4 m-2 d-1, during the winter to -15 gC-CO2 m-2 d-1 and 30 mgC-CH4 m-2 d-1, in the summer growing season. A comparison between similar measurements made from freshwater wetlands in the Sacramento-San Joaquin Delta found that the daily rates of carbon dioxide NEE were similar, but daily rates of methane NEE were just a small fraction (0-15%). Our research also shows that the daily fluxes of carbon dioxide and methane at the brackish marsh were highly variable and may be influenced by the tidal exchanges of seawater. Furthermore, the observed decline in methane production from summer to fall may have resulted from a rise in salinity and/or a seasonal decline in water and air temperatures. Our research goals are

  9. Evaluation of Modern Irrigation Techniques with Brackish Water

    OpenAIRE

    Aboulila, Tarek Selim

    2012-01-01

    Modern irrigation techniques are becoming increasingly important in water-scarce countries especially in arid and semiarid regions. Higher crop production and better water use efficiency are usually achieved by drip irrigation as compared to other irrigation methods. Furthermore, by using drip irrigation simultaneously with brackish irrigation water, some of the water stress due to shortage of fresh water resources can be managed. The objective of the current study was to investigate the infl...

  10. Picocyanobacteria containing a novel pigment gene cluster dominate the brackish water Baltic Sea.

    Science.gov (United States)

    Larsson, John; Celepli, Narin; Ininbergs, Karolina; Dupont, Christopher L; Yooseph, Shibu; Bergman, Bigitta; Ekman, Martin

    2014-09-01

    Photoautotrophic picocyanobacteria harvest light via phycobilisomes (PBS) consisting of the pigments phycocyanin (PC) and phycoerythrin (PE), encoded by genes in conserved gene clusters. The presence and arrangement of these gene clusters give picocyanobacteria characteristic light absorption properties and allow the colonization of specific ecological niches. To date, a full understanding of the evolution and distribution of the PBS gene cluster in picocyanobacteria has been hampered by the scarcity of genome sequences from fresh- and brackish water-adapted strains. To remediate this, we analysed genomes assembled from metagenomic samples collected along a natural salinity gradient, and over the course of a growth season, in the Baltic Sea. We found that while PBS gene clusters in picocyanobacteria sampled in marine habitats were highly similar to known references, brackish-adapted genotypes harboured a novel type not seen in previously sequenced genomes. Phylogenetic analyses showed that the novel gene cluster belonged to a clade of uncultivated picocyanobacteria that dominate the brackish Baltic Sea throughout the summer season, but are uncommon in other examined aquatic ecosystems. Further, our data suggest that the PE genes were lost in the ancestor of PC-containing coastal picocyanobacteria and that multiple horizontal gene transfer events have re-introduced PE genes into brackish-adapted strains, including the novel clade discovered here. PMID:24621524

  11. Picocyanobacteria containing a novel pigment gene cluster dominate the brackish water Baltic Sea

    Science.gov (United States)

    Larsson, John; Celepli, Narin; Ininbergs, Karolina; Dupont, Christopher L; Yooseph, Shibu; Bergman, Bigitta; Ekman, Martin

    2014-01-01

    Photoautotrophic picocyanobacteria harvest light via phycobilisomes (PBS) consisting of the pigments phycocyanin (PC) and phycoerythrin (PE), encoded by genes in conserved gene clusters. The presence and arrangement of these gene clusters give picocyanobacteria characteristic light absorption properties and allow the colonization of specific ecological niches. To date, a full understanding of the evolution and distribution of the PBS gene cluster in picocyanobacteria has been hampered by the scarcity of genome sequences from fresh- and brackish water-adapted strains. To remediate this, we analysed genomes assembled from metagenomic samples collected along a natural salinity gradient, and over the course of a growth season, in the Baltic Sea. We found that while PBS gene clusters in picocyanobacteria sampled in marine habitats were highly similar to known references, brackish-adapted genotypes harboured a novel type not seen in previously sequenced genomes. Phylogenetic analyses showed that the novel gene cluster belonged to a clade of uncultivated picocyanobacteria that dominate the brackish Baltic Sea throughout the summer season, but are uncommon in other examined aquatic ecosystems. Further, our data suggest that the PE genes were lost in the ancestor of PC-containing coastal picocyanobacteria and that multiple horizontal gene transfer events have re-introduced PE genes into brackish-adapted strains, including the novel clade discovered here. PMID:24621524

  12. Infrared Turbidimetric Titration Method for Sulfate Ions in Brackish Water

    Directory of Open Access Journals (Sweden)

    Benabadji Nouredine

    2012-12-01

    Full Text Available In this work an infrared turbidimetric titration method is described for the determination of sulfate ions in brackish water. A suspension of barium sulfate is produced in an aqueous solution and/or brackish water sample by the addition of barium chloride solution and the turbidity is monitored with the help of an immersed infrared sensor. The developed sensor utilizes an optical system to measure the evolution of turbidity during the titration. This sensor is a simple device designed in the laboratory, consisting of two infrared diodes (LED, the first is an emitter and the second is used as detector (receiver. The data acquisition system is made with the help of a dataloger made on the basis of the microcontroller 16F877/874 accompanied with adaptable software both of them are self made. Concentration over 60 µg/mL of sulfate expressed as, SO42- can be measured with high reproducibility, by this method without a preliminary treatment or dilution of the sample. The method determines SO42 - concentration of brackish water with RSD of < 1.2%.

  13. Study on brackish water treatment technology

    Institute of Scientific and Technical Information of China (English)

    HE Xu-wen(何绪文); Xu De-ping (许德平); WU Bing(吴兵); WANG Tong(王通)

    2003-01-01

    Based on the characters of deep well-water quality in Fenxi Mining Group in Liulin, the feasibilities of two treatment technologies which use electrodialysis and reverse osmosis are analyzed. Through analyzing and comparing, reverse osmosis technology has several advantages, such as good treatment effect, convenient operating management and low run-cost.

  14. Sustainable use of Brackish water for crop production

    International Nuclear Information System (INIS)

    The good quality surface-water is not sufficient to meet the crop water requirement for potential crop production. To augment the inadequate supplies of good quality water the only alternative is the use of poor quality , ground water. To explore sustainable use of brackish water a study was conducted in Fordwah Eastern Sadiqia South, Bahawalnagar, Punjab during the year 1998-99 to 2000-2001 with the objective to evaluate the impact of different irrigation treatments on physical and chemical properties of soil and crops yield. The experiment was conducted on farmer's field with his collaboration. The initial soil pH was about 8.0 while ECe and SAR ranged between 2.0 to 4.1 dS m/sup -/1 and 7.1 to 15.1 (mmol/sub c/ L/sup -1/)1/2, respectively with sandy loam texture. The brackish water used for irrigation had ECiw, SAR and RSC between 5.6 to 6.7 dS m/sup -/1, 15.1 to 16.4 (mmolc L/sup -1/sup 1/2/ and 1.52 to 1.64 (mmol/sub c/ L/sup -1/.The crops tested were wheat during Rabi and cotton during Kharif season. The treatments tested were: irrigation with canal water (T/sub 1/), canal water during Rabi and drainage water during Kharif (T/sub 2/), drainage water for two years and canal water for one season(T/sub 3/); and drainage water for three years + application of gypsum at the rate of 25% of CWR and thereafter canal water for one season(T 4). Fertilizers were applied at the rate of 120-60-50 N, P/sub 2/O/sub 5/ and K20 kg ha/sup -1/, respectively in the form of urea, diammonium phosphate and sulfate of potash. Crops irrigated with drainage water visualized yield reduction depending upon the share of drainage water in the irrigation delta. Application of gypsum provided reasonable check against salinity build-up with brackish water irrigation besides a nominal boost of 3 and 5% in yield of wheat and cotton, respectively over comparable treatment of year-round brackish water irrigation lacking gypsum application. Drainage water in alternate arrangement of seasonal

  15. Desalination of brackish water and concentration of industrial effluents by electrodialysis

    OpenAIRE

    J. J. Schoeman; G. R. Botha

    1983-01-01

    Electrodialysis (ED) is, at present, used mainly for the desalination of brackish drinking-water. Brackish water with a high scaling potential can be successfully treated, using the electrodialysis reversal (EDR) process without the addition of chemicals. The reliability of the ED process makes it very attractive for water treatment. Although used mainly for brackish water desalination, ED also has certain industrial applications. Plating wash waters, cooling tower recirculation water and gla...

  16. Microplankton bloom in a brackish water lagoon of Terengganu.

    Science.gov (United States)

    Shamsudin, L; Shazili, N A

    1991-10-01

    Increased primary plankton productivity was observed in a brackish water lagoon of Terengganu during the study period between January 1988 to December 1988. The lagoon is also the site for the fish cage culture activities of sea bass during the study period. An examination of water quality at the sampling stations during the study period indicated that both the organic and inorganic nutrients were high during the pre-monsoon period. The source of the nutrient in the lagoon was believed to be derived from the agro-based industrial effluents, fertilisers from paddy fields as well as untreated human and animal wastes. This coincided with the peak production of plankton in the surface waters of the brackish water lagoon. During this period both cultured and indigenous fish species were seen to suffer from oxygen asphyxiation (suffocation due to lack of oxygen). The primary productivity values ranged from 9 to 22 μg/L/h during the peak period while the microplankton species were composed of diatom, flagellates and dinoflagellates. Reduction in the primary productivity values were obtained with reduction in sallinity, specially during the peak monsoon months (November to March) corresponding to the Northeast monsoon period. PMID:24233946

  17. Nitrate decontamination through functionalized chitosan in brackish water.

    Science.gov (United States)

    Appunni, Sowmya; Rajesh, Mathur P; Prabhakar, Sivaraman

    2016-08-20

    N, N, N-Triethyl ammonium functionalized cross-linked chitosan beads (TEACCB) was prepared by alkylation of glutaraldehyde cross-linked chitosan beads to remove nitrate from brackish water. Physico-chemical characteristics of TEACCB were analyzed using FTIR, SEM, EDAX, TGA, DTA, BET surface area, swelling ratio and pHzpc. The maximum nitrate removal capacity of TEACCB was 2.26meq/g and is higher than other reported chitosan based adsorbents. Nitrate removal ratio in the presence and absence of common anions like chloride and sulphate demonstrated the selectively of TEACCB towards nitrate. The kinetic data of nitrate removal fitted well with the pseudo-second-order kinetic model. The thermodynamic parameters indicated that nitrate removal could be spontaneous and exothermic in nature. TEACCB was reused with 100% efficiency after regenerating with 0.05N HCl. Column study was carried out to remove nitrate from brackish water. These results are very significant to develop TEACCB based nitrate removal technology with great efficiency. PMID:27178960

  18. Desalination of brackish water and concentration of industrial effluents by electrodialysis

    Directory of Open Access Journals (Sweden)

    J. J. Schoeman

    1983-03-01

    Full Text Available Electrodialysis (ED is, at present, used mainly for the desalination of brackish drinking-water. Brackish water with a high scaling potential can be successfully treated, using the electrodialysis reversal (EDR process without the addition of chemicals. The reliability of the ED process makes it very attractive for water treatment. Although used mainly for brackish water desalination, ED also has certain industrial applications. Plating wash waters, cooling tower recirculation water and glass etching effluents have been treated successfully with ED for water recovery and effluent volume reduction, while ED treatment of nickel plating wash waters is an established industrial process.

  19. Cellulose Derived Graphenic Fibers for Capacitive Desalination of Brackish Water.

    Science.gov (United States)

    Pugazhenthiran, Nalenthiran; Sen Gupta, Soujit; Prabhath, Anupama; Manikandan, Muthu; Swathy, Jakka Ravindran; Raman, V Kalyan; Pradeep, Thalappil

    2015-09-16

    We describe a simple and inexpensive cellulose-derived and layer-by-layer stacked carbon fiber network electrode for capacitive deionization (CDI) of brackish water. The microstructure and chemical composition were characterized using spectroscopic and microscopic techniques; electrochemical/electrical performance was evaluated by cyclic voltammetry and 4-probe electrical conductivity and surface area by Brunauer-Emmett-Teller analysis, respectively. The desalination performance was investigated using a laboratory batch model CDI unit, under fixed applied voltage and varying salt concentrations. Electro-adsorption of NaCl on the graphite reinforced-cellulose (GrC) electrode reached equilibrium quickly (within 90 min) and the adsorbed salts were released swiftly (in 40 min) back into the solution, during reversal of applied potential. X-ray photoelectron spectroscopic studies clearly illustrate that sodium and chloride ions were physisorbed on the negative and positive electrodes, respectively during electro-adsorption. This GrC electrode showed an electro-adsorption capacity of 13.1 mg/g of the electrode at a cell potential of 1.2 V, with excellent recyclability and complete regeneration. The electrode has a high tendency for removal of specific anions, such as fluoride, nitrate, chloride, and sulfate from water in the following order: Cl->NO3->F->SO4(2-). GrC electrodes also showed resistance to biofouling with negligible biofilm formation even after 5 days of incubation in Pseudomonas putida bacterial culture. Our unique cost-effective methodology of layer-by-layer stacking of carbon nanofibers and concurrent reinforcement using graphite provides uniform conductivity throughout the electrode with fast electro-adsorption, rapid desorption, and extended reuse, making the electrode affordable for capacitive desalination of brackish water. PMID:26305260

  20. Role of mangroves in brackish water fish culture

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, S.

    Mangroves is a specialized marine ecosystem consisting of a group of plants growing in muddy, loose and wet soils in tropical and subtropical areas, comprising of shallow, coastal waters, deltas, estuaries or lagoons. Besides ecological importance...

  1. High Recovery Desalination of Brackish Water by Chemically-Enhanced Seeded Precipitation

    OpenAIRE

    McCool, Brian Carey

    2012-01-01

    Various regions around the world are confronted with dwindling water supplies and thus the need for exploiting non-traditional inland brackish water resource, as well as reclamation and reuse of municipal wastewater and agricultural drainage (AD) water. Reverse osmosis (RO) membrane desalination is the primary technology for inland brackish water desalting. However, successful implementation of RO technology requires operation at high product water recovery (>85%) in order to minimize the vol...

  2. Desalination of Saline and Brackish Waters using Carbon Aerogel Technology

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Massoudinejad

    2012-10-01

    Full Text Available Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives: The increasing demand for drinking water has led scientists to the use of saline waters, but existing desalinating processes are very expensive. carbon aerogel is a type of organic aerogel that is suitable for desalination owing to its unique porous structure. Low potential of fouling and deposits, very low wastewater production, electrostatic regeneration of aerogels and, in turn, no need to acid consumption, and lower power consumption are some of this technology benefits.Materials and Method: In this experimental- analytical study, the purpose was survey of saline and brackish water desalination using carbon aerogel technology and its comparison with electrolysis.The community studied was synthetic salt water samples, using of TDS and EC indicators. The minimum synthetic samples were 243. In this regard, after polymerization of Resorsinol and Formaldehyde compounds under ambient pressure conditions and then its pyrolysis, we fabricated plates of carbon aerogel.Result: With manufacturing in the pilot-scale, the effect of different parameters, including input salt concentration, current, water flow, distance of between electrodes and pH, on NaCl sorption amount of carbon aerogel electrodes were studied. Generally, adsorption amount increased with increasing of current and NaCl concentration and decreased with increasing of distance electrodes, flow and pH.  Results: Fabricating reactor at pilot-scale, we studied the effect of different parameters, including input salt concentration, current, water flow, intra-distance of electrodes, and pH on the NaCl sorption using carbon aerogel electrodes. Generally, adsorption capacity increased with increasing of current and NaCl concentration in the inlet flow, and it decreased with increasing intra-distance of electrodes, flow, and pH.Conclusion: Under the most optimal

  3. Using mesoporous carbon electrodes for brackish water desalination.

    Science.gov (United States)

    Zou, Linda; Li, Lixia; Song, Huaihe; Morris, Gayle

    2008-04-01

    Electrosorptive deionisation is an alternative process to remove salt ions from the brackish water. The porous carbon materials are used as electrodes. When charged in low voltage electric fields, they possess a highly charged surface that induces adsorption of salt ions on the surface. This process is reversible, so the adsorbed salt ions can be desorbed and the electrode can be reused. In the study, an ordered mesoporous carbon (OMC) electrode was developed for electrosorptive desalination. The effects of pore arrangement pattern (ordered and random) and pore size distribution (mesopores and micropores) on the desalination performance was investigated by comparing OMC and activated carbon (AC). It were revealed from X-ray diffraction and N(2) sorption measurements that AC has both micropores and mesopores, whereas ordered mesopores are dominant in OMC. Their performance as potential electrodes to remove salt was evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests at a range of electrolyte concentrations and sweep rates. It is deduced that under the same electrochemical condition the specific capacitance values of OMC electrode (i.e. 133 F/g obtained from CV at a sweep rate of 1 mV/s in 0.1M NaCl solution) are larger than those of AC electrode (107 F/g), suggesting that the former has a higher desalting capacity than the latter. Furthermore, the OMC electrode shows a better rate capacity than the AC electrode. In addition, the desalination capacities were quantified by the batch-mode experiment at low voltage of 1.2V in 25 ppm NaCl solution (50 micros/cm conductivity). It was found that the adsorbed ion amounts of OMC and AC electrodes were 11.6 and 4.3 micromol/g, respectively. The excellent electrosorptive desalination performance of OMC electrode might be not only due to the suitable pore size (average of 3.3 nm) for the propagation of the salt ions, but also due to the ordered mesoporous structure that facilitates desorption of the

  4. Influence of nutrient input on the trophic state of a tropical brackish water lagoon

    Indian Academy of Sciences (India)

    D Ganguly; Sivaji Patra; Pradipta R Muduli; K Vishnu Vardhan; Abhilash K R; R S Robin; B R Subramanian

    2015-07-01

    Ecosystem level changes in water quality and biotic communities in coastal lagoons have been associated with intensification of anthropogenic pressures. In light of incipient changes in Asia’s largest brackish water lagoon (Chilika, India), an examination of different dissolved nutrients distribution and phytoplankton biomass, was conducted through seasonal water quality monitoring in the year 2011. The lagoon showed both spatial and temporal variation in nutrient concentration, mostly altered by fresh-water input, regulated the chlorophyll distribution as well. Dissolved inorganic N:P ratio in the lagoon showed nitrogen limitation in May and December, 2011. Chlorophyll in the lagoon varied between 3.38 and 17.66 mg m−3. Spatially, northern part of the lagoon showed higher values of DIN and chlorophyll during most part of the year, except in May, when highest DIN was recorded in the southern part. Statistical analysis revealed that dissolved NH$^{+}_{4}$–N and urea could combinedly explain 43% of Chlorophyll- (Chl-) variability which was relatively higher than that explained by NO$^{-}_{3}$–N and NO$^{-}_{2}$–N (12.4%) in lagoon water. Trophic state index calculated for different sectors of the lagoon confirmed the inter-sectoral and inter-seasonal shift from mesotrophic to eutrophic conditions largely depending on nutrient rich freshwater input.

  5. Influence of nutrient input on the trophic state of a tropical brackish water lagoon

    Science.gov (United States)

    Ganguly, D.; Patra, Sivaji; Muduli, Pradipta R.; Vardhan, K. Vishnu; R, Abhilash K.; Robin, R. S.; Subramanian, B. R.

    2015-07-01

    Ecosystem level changes in water quality and biotic communities in coastal lagoons have been associated with intensification of anthropogenic pressures. In light of incipient changes in Asia's largest brackish water lagoon (Chilika, India), an examination of different dissolved nutrients distribution and phytoplankton biomass, was conducted through seasonal water quality monitoring in the year 2011. The lagoon showed both spatial and temporal variation in nutrient concentration, mostly altered by freshwater input, regulated the chlorophyll distribution as well. Dissolved inorganic N:P ratio in the lagoon showed nitrogen limitation in May and December, 2011. Chlorophyll in the lagoon varied between 3.38 and 17.66 mg m -3. Spatially, northern part of the lagoon showed higher values of DIN and chlorophyll during most part of the year, except in May, when highest DIN was recorded in the southern part. Statistical analysis revealed that dissolved NH-N and urea could combinedly explain 43% of Chlorophyll- a (Chl- a) variability which was relatively higher than that explained by NO-N and NO-N (12.4%) in lagoon water. Trophic state index calculated for different sectors of the lagoon confirmed the inter-sectoral and inter-seasonal shift from mesotrophic to eutrophic conditions largely depending on nutrient rich freshwater input.

  6. Osmoregulatory adaptations of freshwater air-breathing snakehead fish (Channa striata) after exposure to brackish water.

    Science.gov (United States)

    Nakkrasae, La-iad; Wisetdee, Khanitha; Charoenphandhu, Narattaphol

    2015-07-01

    NaCl-rich rock salt dissolved in natural water source leads to salinity fluctuation that profoundly affects freshwater ecosystem and aquatic fauna. The snakehead (Channa striata) can live in saline water, but the osmoregulatory mechanisms underlying this ability remain unclear. Herein, we found that exposure to salinities ≥ 10‰ NaCl markedly elevated plasma cortisol and glucose levels, and caused muscle dehydration. In a study of time-dependent response after being transferred from fresh water (0‰ NaCl, FW) to salt-dissolved brackish water (10‰ NaCl, SW), FW-SW, cortisol increased rapidly along with elevations of plasma glucose and lactate. Interestingly, plasma cortisol returned to baseline after prolonged exposure, followed by a second peak that probably enhanced the branchial Na(+)/K(+)-ATPase activity. Under SW-FW condition, Na(+)/K(+)-ATPase activity was not altered as compared to SW-adapted fish. In conclusion, salinity change, especially FW-SW, induced a stress response and hence cortisol release in C. striata, which might increase plasma glucose and lactate to energize the branchial Na(+)/K(+)-ATPase. PMID:25899744

  7. 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.

  8. Selective demineralization of water by nanofiltration application to the defluorination of brackish water.

    Science.gov (United States)

    Lhassani, A; Rumeau, M; Benjelloun, D; Pontie, M

    2001-09-01

    Nanofiltration is generally used to separate monovalent ions from divalent ions, but it is also possible to separate ions of the same valency by careful application of the transfer mechanisms involved. Analysis of the retention of halide salts reveals that small ions like fluoride are the best retained, and that this is even more marked under reduced pressure when selectivity is greatest. The selectivity desalination of fluorinated brackish water is hence feasible and drinking water can be produced directly at much lower cost than using reverse osmosis by optimizing the pressure for the type of water treated. PMID:11487124

  9. Lettuce growth and water consumption in NFT hydroponic system using brackish water

    OpenAIRE

    Hammady R. Soares; Ênio F. de F. e Silva; Gerônimo F. da Silva; Pedrosa, Elvira M. R.; Mario M. Rolim; Alexandre N. Santos

    2015-01-01

    The qualitative aspects of water, such as the preparation or replenishment of the nutrient solution, are critical to the success of hydroponic crops. Therefore, the aim of this study was to evaluate the behavior of “Americana” lettuce (cv. Tainá) under increasing levels of saline stress (0.2 - control, 1.2, 2.2, 3.2, 4.2 and 5.2 dS m-1), replenishing the evapotranspiration with brackish water in Experiment I and supply water (0.2 dS m-1) in Experiment II, both used in the preparation of the n...

  10. Treatment of brackish produced water using carbon aerogel-based capacitive deionization technology.

    Science.gov (United States)

    Xu, Pei; Drewes, Jörg E; Heil, Dean; Wang, Gary

    2008-05-01

    Capacitive deionization (CDI) with carbon-aerogel electrodes represents a novel process in desalination of brackish water and has merit due to its low fouling/scaling potential, ambient operational conditions, electrostatic regeneration, and low voltage requirements. The objective of this study was to investigate the viability of CDI in treating brackish produced water and recovering iodide from the water. Laboratory- and pilot-scale experiments were conducted to identify ion selectivity, key operational parameters, evaluate desalination performance, and assess the challenges for its practical applications. The performance of the CDI technology (CDT) system tested was consistent throughout the laboratory- and field-scale experiments. Deterioration of the carbon-aerogel electrodes was not observed during testing. The degree of ions adsorbed to the carbon aerogel (in mol/g aerogel) during treatment of brackish water was dependent upon initial ion concentrations in the feed water with the following selectivity I>Br>Ca>alkalinity>Mg>Na>Cl. The preferential sorption of iodide revealed merit to efficiently recover iodide from brackish water even in the presence of dominant co-ions. The research findings derived from this study identified parameters that merit further improvements regarding design and operation, including modification of pore-size distribution of aerogel, development of high capacitance and low-cost electrode materials, reducing the dead volume after regeneration and rinsing, minimizing energy consumption, and maximizing system recovery. PMID:18258278

  11. Desalination of brackish ground waters and produced waters using in-situ precipitation.

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, James Lee; Pless, Jason; Nenoff, Tina Maria; Voigt, James A.; Phillips, Mark L. F.; Axness, Marlene; Moore, Diana Lynn; Sattler, Allan Richard

    2004-08-01

    The need for fresh water has increased exponentially during the last several decades due to the continuous growth of human population and industrial and agricultural activities. Yet existing resources are limited often because of their high salinity. This unfavorable situation requires the development of new, long-term strategies and alternative technologies for desalination of saline waters presently not being used to supply the population growth occurring in arid regions. We have developed a novel environmentally friendly method for desalinating inland brackish waters. This process can be applied to either brackish ground water or produced waters (i.e., coal-bed methane or oil and gas produced waters). Using a set of ion exchange and sorption materials, our process effectively removes anions and cations in separate steps. The ion exchange materials were chosen because of their specific selectivity for ions of interest, and for their ability to work in the temperature and pH regions necessary for cost and energy effectiveness. For anion exchange, we have focused on hydrotalcite (HTC), a layered hydroxide similar to clay in structure. For cation exchange, we have developed an amorphous silica material that has enhanced cation (in particular Na{sup +}) selectivity. In the case of produced waters with high concentrations of Ca{sup 2+}, a lime softening step is included.

  12. Lettuce growth and water consumption in NFT hydroponic system using brackish water

    Directory of Open Access Journals (Sweden)

    Hammady R. Soares

    2015-07-01

    Full Text Available The qualitative aspects of water, such as the preparation or replenishment of the nutrient solution, are critical to the success of hydroponic crops. Therefore, the aim of this study was to evaluate the behavior of “Americana” lettuce (cv. Tainá under increasing levels of saline stress (0.2 - control, 1.2, 2.2, 3.2, 4.2 and 5.2 dS m-1, replenishing the evapotranspiration with brackish water in Experiment I and supply water (0.2 dS m-1 in Experiment II, both used in the preparation of the nutrient solution. In both experiments, the treatments were arranged in a randomized block design, with six treatments and four replicates. Shoot fresh matter, shoot dry matter and leaf area in Experiment I suffered reductions of 15.22, 12.67 and 15.6% per unit increase of EC, respectively. In Experiment II, reductions of 8.01, 6.90 and 8.14% were observed for the same variables, respectively. In Experiments I and II, linear decrease in water consumption due to the increase in salinity was observed, with reductions of 8.83 and 5.63% for each unit increase of electrical conductivity of water when the evapotranspiration was replenished using brackish and supply water, respectively.

  13. Epiphytic bacterial community composition on two common submerged macrophytes in brackish water and freshwater

    OpenAIRE

    Blindow Irmgard; Blume Maja; Hempel Melanie; Gross Elisabeth M

    2008-01-01

    Abstract Background Plants and their heterotrophic bacterial biofilm communities possibly strongly interact, especially in aquatic systems. We aimed to ascertain whether different macrophytes or their habitats determine bacterial community composition. We compared the composition of epiphytic bacteria on two common aquatic macrophytes, the macroalga Chara aspera Willd. and the angiosperm Myriophyllum spicatum L., in two habitats, freshwater (Lake Constance) and brackish water (Schaproder Bodd...

  14. Effects of plant diversity on primary production and species interactions in brackish water angiosperm communities

    DEFF Research Database (Denmark)

    Salo, Tiina; Gustafsson, Camilla; Boström, Christoffer

    2009-01-01

    plant productivity in brackish water angiosperm communities, a 14 wk field experiment was conducted. Using a replacement design with a standardized initial aboveground biomass, shoots of Zostera marina, Potamogeton filiformis and P. perfoliatus were planted on a shallow, sandy bottom in replicated...

  15. On brackish water desalination economics and alternative renewable energies in Mena countries

    International Nuclear Information System (INIS)

    Nowadays, water management in MENA, no longer exclusive to a sectoral issue pertaining to engineering and technical expertise such as irrigation, water supply and water storage, becomes a shared developmental challenge. In order to face an increasingly growing water crisis, attention on balancing the supply and demand for water given the current constraints, needs analysis of conventional and non conventional water resources from a range of perspectives, including considerations about technological dynamics and alternative renewable energies, which are highly recommended. Thanks to engaged technical progress enabling sensitive desalination cost reduction, water crisis could be of lower impacts. For this region being the world leader in desalination technology investments, we are obliged to rexamine the characteristics of alternative renewable energies. To prevent water shortage from being a constraint to economic development and social stability in MENA, we argue brackish water desalination as one of the most promising and viable options, notably in long term for future generations. This paper contains four sections. brackish water characteristics are clarified in section 1. Then in section 2, we focus on factors affecting both desalination costs and desalination implementation costs. A particular attention is spent in section 3 to electro-dialysis reverse (EDR), subsequent capital and O and M costs approximations. Besides, since there is a pressing need for brackish water desalination, which is energy intensive, alternative renewable energies related to desalination technologies are hightlighted in section 4.

  16. A comparative study of boron and arsenic (III) rejection from brackish water by reverse osmosis membranes

    KAUST Repository

    Teychene, Benoît

    2013-02-01

    This study aims to compare at lab-scale the rejection efficiency of several reverse osmosis membranes (RO) toward arsenic (III) and boron during the filtration of a synthetic brackish water. The effect of pH and operating conditions on the rejection of each RO membrane was studied. Two types of membrane were investigated: "brackish water" and "sea water" membranes. Our results showed that the metalloid rejection depends on the membrane type, pH and transmembrane pressure applied. Increasing pH above the dissociation constant (pKa) of each specie improves significantly the metalloid rejection by RO membranes, whatever the membrane type. Moreover, at identical operating conditions (pH, transmembrane pressure), results showed that the brackish water membranes have a higher water flux and exhibit lower metalloid rejection. The highest As(III) rejection value for the tested brackish water membranes was 99% obtained at pH = 9.6 and 40 bars, whereas it was found that the sea water RO membranes could highly reject As(III), more than 99%, even at low pH and low pressure (pH = 7.6 and 24 bars).Regarding Boron rejection, similar conclusions could be drawn. The sea water RO membranes exert higher removal, with a high rejection value above 96% over the tested conditions. More generally, this study showed that, whatever the operating conditions or the tested membranes, the boron and As(III) permeate concentrations are below the WHO guidelines. In addition, new data about the boron and arsenic permeability of each tested RO membrane was brought thanks to a theoretical calculation. © 2012 Elsevier B.V.

  17. Brackish Eutrophic Water Treatment by Iris pseudacorus L.-Planted Microcosms: Physiological Responses of Iris pseudacorus L. to Salinity.

    Science.gov (United States)

    Zhao, Huilin; Wang, Fen; Ji, Min

    2015-01-01

    Iris pseudacorus L. has been widely used in aquatic ecosystem to remove nutrient and has achieved positive effects. However, little is known regarding the nutrient-removal performance and physiological responses of I. pseudacorus for brackish eutrophic water treatment due to high nutrients combined with certain salinity levels. In this study, I. pseudacorus-planted microcosms were established to evaluate the capacity of I. pseudacorus to remove excessive nutrients from fresh (salinity 0.05%) and brackish (salinity 0.5%) eutrophic waters. The degradation of total nitrogen and ammonia nitrogen were not affected by 0.5% salinity; 0.5% salinity promoted the degradation of nitrate nitrogen while severely inhibited the degradation of total phosphorus. Additionally, 0.5% salinity was found to induce stress responses quantified by measuring six physiological indexes. Compared to 0.05% salinity, 0.5% salinity resulted in significant decreases in the chlorophyll a, b and total chlorophyll contents of I. pseudacorus which closely related to photosynthesis (p < 0.05). Furthermore, the higher proline, malondialdehyde contents and antioxidant enzyme activities were detected in I. pseudacorus exposed to 0.5% salinity, which provided protection against reactive oxygen species. The results highlight that the cellular stress assays are efficient for monitoring the health of I. pseudacorus in salinity shock-associated constructed wetlands. PMID:25529785

  18. Microbially influenced corrosion in cooling water systems. Development of a new protection concept for system components conveying brackish water

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, Simone; Richter, Tobias [E.ON Kernkraft GmbH, Brokdorf Nuclear Power Plant, Brokdorf (Germany); Nowak, Erika [E.ON Kernkraft GmbH, Hannover (Germany)

    2009-07-01

    Corrosive findings ascribed to microbially influenced corrosion (MIC), have been increasingly observed on cooling water systems in Northern German nuclear power plants. By means of a research programme (field tests), high-alloyed materials with different pitting resistance equivalent numbers (PREN), various surface finishing and various coatings were evaluated, based on microbiological preliminary research, with respect to their corrosion behaviour in natural brackish water. Subsequent material evaluations, in combination with other measures, provided a new standard of knowledge for the development of a protection concept for components conveying brackish water. (orig.)

  19. Cultivation of gilthead sea bream (Sparus aurata Linnaeus, 1758 in low salinity inland brackish geothermal water

    Directory of Open Access Journals (Sweden)

    Samuel Appelbaum

    2009-04-01

    Full Text Available In the course of attempting to culture gilthead sea bream in inland brackish geothermal water, indoor and outdoor research studies have been ongoing from early 2006 at the "Bengis Centre for Desert Aquaculture" of the Institutes for Desert Research in Israel, some of which are described below. Gilthead sea bream fingerlings with an average weight of 19 g were acclimated to and reared for 56 days in brackish water of three salinities: 2.5, 3.5 and 4.5 ppt collected from three different locations. At the salinity of 3.5 ppt the fish grew best (P Artemia nauplii plus larval dry feed and were grown in brackish water of 2.6 ppt salinity for 8 weeks reaching a weight gain of 92% at a survival rate of 83%. The control groups at sea water (39 ppt reached at the same time a weight gain of 95% at a survival rate of 98%. In a further study gilthead sea bream juveniles with an average weight of 2.24 g were reared in brackish water with a salinity of 3.6 ppt for 8 weeks and received salt added diets of 4% and 6%. Compared with the control diet with no salt added, both salt rich diets significantly improved the fingerlings growth and survival rates as well as the feed conversion ratio. The 6% salt rich diet promoted fish weight gain by 560% which was the best performance (P <0.05 followed by 448% weight gain with the 4% salt rich diet while the lowest performance with a weight gain of only 360% was obtained with the control (no salt added diet. The next study with higher levels of salt added diets showed that gilthead sea bream post larvae with an average weight of 0.58 g reared in brackish geothermal water of 2.9 ppt salinity for 10 weeks grew best (P < 0.05 obtaining a weight gain of 778% with the highest survival rate of 88% when fed a diet containing 12% salt. In the studies with the salt rich diets, the salt incorporated was obtained by the evaporation of brine produced during the process of desalination of the brackish geothermal water from the same

  20. Radiological study of brackish and fresh water food samples in Lagos and Ondo states, southwestern Nigeria

    International Nuclear Information System (INIS)

    Measurement of the average radioactivity concentration in brackish and fresh water food samples in Lagos and Ondo States of Nigeria was carried out using a very sensitive gamma spectroscopic system consisting of a 76 mm x 76 mm Nal (TI) scintillation detector coupled to a computerized ACCUSPEC installation. All the radionuclide detected are traceable to the naturally occurring 4''0K and ''2''3''2Th. The average concentrations of ''2''3''8U and ''2''3''2Th were found to be higher in brackish water food samples, 50.92±7.04 Bq/kg and 24.60± 6.47 Bq/kg respectively. The average concentration of ''4''0K was found to be higher in food samples got from freshwater, 738.94±84.81Bq/kg

  1. Desalination of underground brackish waters using an electrodialysis system powered directly by photovoltaic energy

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, J.M.; Exposito, E.; Gallud, F.; Garcia-Garcia, V.; Montiel, V.; Aldaz, A. [Grupo de Electroquimica Aplicada y Electrocatalisis, Departamento de Quimica Fisica and Instituto Universitario de Electroquimica, Universidad de Alicante, Ap. 99, 03080 Alicante (Spain)

    2008-12-15

    The aims of this paper are: to demonstrate the feasibility of the desalination of brackish water from aquifers (total dissolved solids=2300-5100 g m{sup -3}) by means of an electrodialysis system powered directly by photovoltaic solar panels, and improve the mathematical model developed in a previous work in order to apply it to real brackish waters. The application of this model allows to predict the behaviour of the electrodialysis-photovoltaic system under different operational and meteorological conditions, and the time required to reach a given final concentration. Finally, the cost of electrodialysis-photovoltaic systems for small applications in isolated locations with lack of electric grid has been estimated. (author)

  2. Desalination of Saline and Brackish Waters using Carbon Aerogel Technology

    OpenAIRE

    Mohammad Reza Massoudinejad; Hamed Mohammadi; Akbar Eslami; Hossein Najafi; Behzad Rezayi fard; Gholam Hossein Joshani

    2012-01-01

    Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives: The increasing demand for drinking water has led scientists to the use of saline waters, but existing desalinating processes are very expensive. carbon aerogel is a type of organic aerogel that is suitable for desalination owing to its unique porous structure. Low potential of fouling and deposits, very low wastewater production, ele...

  3. Ascorbic Acid Biosynthesis and Brackish Water Acclimation in the Euryhaline Freshwater White-Rimmed Stingray, Himantura signifer

    OpenAIRE

    Wong, Samuel Z. H.; Ching, Biyun; Chng, You R.; Wong, Wai P.; Chew, Shit F.; Ip, Yuen K.

    2013-01-01

    L-gulono-γ-lactone oxidase (Gulo) catalyzes the last step of ascorbic acid biosynthesis, which occurs in the kidney of elasmobranchs. This study aimed to clone and sequence gulonolactone oxidase (gulo) from the kidney of the euryhaline freshwater stingray, Himantura signifer, and to determine the effects of acclimation from freshwater to brackish water (salinity 20) on its renal gulo mRNA expression and Gulo activity. We also examined the effects of brackish water acclimation on concentration...

  4. Influence of dispersants on petroleum bioavailability to primary producers in a brackish water food chain

    Energy Technology Data Exchange (ETDEWEB)

    Younghans-Haug, C.O.; Wolfe, M.F.; Tjeerdema, R.S. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry; Sowby, M.L. [Office of Oil Spill Prevention and Response, Sacramento, CA (United States)

    1994-12-31

    Petroleum is transported and processed within biologically rich brackish environments worldwide. Past research has investigated disposition of chemically dispersed oil in mammals, fish, and higher invertebrates, yet little is known about how chemical dispersion influences petroleum behavior within primary producers within brackish water food chains. One concern is whether chemical dispersion influences petroleum bioavailability to primary producers and the potential for increased petroleum bioaccumulation. This research examines changes in petroleum bioavailability to the euryhaline phytoplankton Isochrysis galbana by measuring bioconcentration factors (BCFS) including uptake and deputation rates for dispersed and undispersed brackish water oil spills. Isochrysis is a major food source for zooplankton which are consumed by a multitude of larval fish having both ecological and commercial importance. Prudhoe Bay Crude oil, Corexit 9527, and {sup 14}C-naphthalene were used for these studies. Constant-concentration flow-through exposures were employed for the uptake and BCF experiments. Work was performed below the ``no observable effect concentration`` to eliminate stress-induced metabolic altercations that could in themselves influence petroleum behavior. Exposure chamber and experimental design will be discussed, and study results presented. Understanding how chemical dispersion alters petroleum behavior within the lowest levels of the food chain leads to better delineation of consumer risks.

  5. Management of Brackish water for crop production under arid and semi-arid conditions

    International Nuclear Information System (INIS)

    For sustainable crop production, changing soil or water chemistry so as to counter the adverse effects of brackish water is a good option. This is normally accomplished by soil or water applied amendments such as gypsum. The other option of blending or cycling brackish and non-brackish water also has merits to reduce the potential hazards. The biological and organic amendments improve soil physical conditions which, otherwise, are expected to be deteriorated by the use of brackish water. Keeping this in view, a field experiment was conducted on a non saline-non sodic sandy loam soil (EC/sub e/ 1.31-1.76 dS m/sup -1/, pH = 8.47-8.61, SAR = 5.50-7.41, infiltration rate 0.6-0.8 cm/h, bulk density = 1.56-1.61 Mg m/sup -3/ for the upper 15 cm soil depth) to evaluate the growth response of cotton crop to different soil and water treatments. Treatments included: T/sub 1/ canal water), T/sub 2/ [tube well water (EC = 3.38 dS m/sup -1/, SAR = 16.43 and RSC = 5.57 mmol/sub c/ L/sup -1/)], T3 [cyclic use (alternate irrigations with canal and tube well waters)], T/sub 4/ (tube well water as such + FYM at the rate of 25 Mg ha/sup -1/annually) and T/sub 5/ (tube well water + gypsum at the rate of water gypsum requirement (WRSC to be decreased up to 00). During the first year of experimentation seed cotton yield was not significantly affected by the applied treatments and was in the decreasing order of: T/sub 3/ (2361 kg ha/sup -1/) > T/sub 4/ (2073 kg ha/sup -1/) > T 1 (2015 kg ha/sup -1/) > T/sub 5/ (2001 kg ha.1 and T 2 (1982 ha/sup -1/. Number of bolls picked per plant was in the decreasing order of: T 2 (33) > T/sub 4/ (32) > T/sub 1/ (31) > T/sub 3/ (30) and T/sub 5/ (26) with non-significant treatment differences. The pH, EC/sub e/ and SAR values remained below safe limits by this cotton (first) crop. (author)

  6. Artificial recharge to a freshwater-sensitive brackish-water sand aquifer, Norfolk, Virginia

    Science.gov (United States)

    Brown, Donald L.; Silvey, William Dudley

    1977-01-01

    Fresh water was injected into a brackish-water sand for storage and retrieval. The initial injection rate of 400 gpm decreased to 70 gpm during test 3. The specific capacity of the well decreased also, from 15.4 to 0.93 gpm. Current-meter surveys indicated uniform reduction in hydraulic conductivity of all contributing zones in the aquifer. Hydraulic and chemical data indicate this was caused by dispersion of the interstitial clay upon introduction of the calcium bicarbonate water into the sodium chloride bearing sand aquifer. The clay dispersion also caused particulate rearrangement and clogging of well screen. A pre-flush of 0.2 N calcium chloride solution injected in front of the fresh water at the start of test 4 stabilized the clay. However, it did not reverse the particulate clogging that permanently reduced permeability and caused sanding during redevelopment. Clogging can be prevented by stabilization of the clay using commercially available trivalent aluminum compounds. Test 1 and test 2 showed that 85 percent of the water injected can be recovered, and the water meets U.S. Public Health Standards. Storage of fresh water in a brackish-water aquifer appears feasible provided proper control measures are used. (Woodard-USGS)

  7. Radiative characteristics of ice-covered fresh- and brackish-water bodies

    OpenAIRE

    Leppäranta, Matti; Erm, Ants; Arst, Helgi; Reinart, Anu

    2006-01-01

    The structure and optics of ice and snow overlying bodies of water were studied in the years 2000–2003. The data were collected in the northern temperate region (nine Estonian and Finnish lakes and one brackish water site, Santala Bay, in the Gulf of Finland). In the present paper we describe the results concerning the radiative characteristics of the system “snow + ice cover on the water”: albedo, attenuation of light, and planar and scalar irradiances through the ice. The basic data consist...

  8. Frequency of recirculation of nutrient solution in hydroponic cultivation of coriander with brackish water

    OpenAIRE

    Mairton G. da Silva; Tales M. Soares; Hans R. Gheyi; Itamar de S. Oliveira; José A. da Silva Filho; Francicleiton F. do Carmo

    2016-01-01

    ABSTRACT The present study used a hydroponic system with leveled channels, in order to evaluate coriander cultivation under different intervals of nutrient solution recirculation and the use of freshwater and brackish water. The experiment was carried out in a randomized block design with five replicates, in a 2 x 4 factorial scheme, from February to March 2014. Two levels of electrical conductivity (EC) of water (0.32 and 4.91 dS m-1) and four frequencies of nutrient solution recirculation (...

  9. High pressure membrane foulants of seawater, brackish water and river water: origin assessed by sugar and bacteriohopanepolyol signatures.

    Science.gov (United States)

    Mondamert, L; Labanowski, J; N'Goye, F; Talbot, H M; Croue, J P

    2011-01-01

    The present work aimed to study the origin of foulant material recovered on membranes used in water treatment. Firstly, sugar signatures were assessed from the monosaccharide composition. As results were not conclusive, a statistical approach using discriminant analysis was applied to the sugar data set in order to predict the origin of the foulant material. Three groups of various origins (algal, microbial, continental dissolved organic matter) were used as sugar references for the prediction. The results of the computation showed that the origin of reverse osmosis (RO) seawater foulant material is influenced by both the location of the water sources and the season. RO brackish water and nanofiltration river water foulant materials had a terrestrial origin. Secondly, bacteriohopanepolyol signatures indicated that RO seawater foulant material had a marine signature, RO brackish water foulant material had both a marine and a terrestrial origin and the nanofiltration river water foulant material contained only a terrestrial signature. PMID:21104476

  10. High pressure membrane foulants of seawater, brackish water and river water: Origin assessed by sugar and bacteriohopanepolyol signatures

    KAUST Repository

    Mondamert, Leslie

    2011-01-01

    The present work aimed to study the origin of foulant material recovered on membranes used in water treatment. Firstly, sugar signatures were assessed from the monosaccharide composition. As results were not conclusive, a statistical approach using discriminant analysis was applied to the sugar data set in order to predict the origin of the foulant material. Three groups of various origins (algal, microbial, continental dissolved organic matter) were used as sugar references for the prediction. The results of the computation showed that the origin of reverse osmosis (RO) seawater foulant material is influenced by both the location of the water sources and the season. RO brackish water and nanofiltration river water foulant materials had a terrestrial origin. Secondly, bacteriohopanepolyol signatures indicated that RO seawater foulant material had a marine signature, RO brackish water foulant material had both a marine and a terrestrial origin and the nanofiltration river water foulant material contained only a terrestrial signature. © 2011 Taylor & Francis.

  11. Ascorbic Acid Biosynthesis and Brackish Water Acclimation in the Euryhaline Freshwater White-Rimmed Stingray, Himantura signifer.

    Directory of Open Access Journals (Sweden)

    Samuel Z H Wong

    Full Text Available L-gulono-γ-lactone oxidase (Gulo catalyzes the last step of ascorbic acid biosynthesis, which occurs in the kidney of elasmobranchs. This study aimed to clone and sequence gulonolactone oxidase (gulo from the kidney of the euryhaline freshwater stingray, Himantura signifer, and to determine the effects of acclimation from freshwater to brackish water (salinity 20 on its renal gulo mRNA expression and Gulo activity. We also examined the effects of brackish water acclimation on concentrations of ascorbate, dehydroascorbate and ascorbate + dehydroascorbate in the kidney, brain and gill. The complete cDNA coding sequence of gulo from the kidney of H. signifer contained 1323 bp coding for 440 amino acids. The expression of gulo was kidney-specific, and renal gulo expression decreased significantly by 67% and 50% in fish acclimated to brackish water for 1 day and 6 days, respectively. There was also a significant decrease in renal Gulo activity after 6 days of acclimation to brackish water. Hence, brackish water acclimation led to a decrease in the ascorbic acid synthetic capacity in the kidney of H. signifer. However, there were significant increases in concentrations of ascorbate and ascorbate + dehydroascorbate in the gills (after 1 or 6 days, and a significant increase in the concentration of ascorbate and a significant decrease in the concentration of dehydroascorbate in the brain (after 1 day of fish acclimated to brackish water. Taken together, our results indicate that H. signifer might experience greater salinity-induced oxidative stress in freshwater than in brackish water, possibly related to its short history of freshwater invasion. These results also suggest for the first time a possible relationship between the successful invasion of the freshwater environment by some euryhaline marine elasmobranchs and the ability of these elasmobranchs to increase the capacity of ascorbic acid synthesis in response to hyposalinity stress.

  12. Ascorbic Acid Biosynthesis and Brackish Water Acclimation in the Euryhaline Freshwater White-Rimmed Stingray, Himantura signifer.

    Science.gov (United States)

    Wong, Samuel Z H; Ching, Biyun; Chng, You R; Wong, Wai P; Chew, Shit F; Ip, Yuen K

    2013-01-01

    L-gulono-γ-lactone oxidase (Gulo) catalyzes the last step of ascorbic acid biosynthesis, which occurs in the kidney of elasmobranchs. This study aimed to clone and sequence gulonolactone oxidase (gulo) from the kidney of the euryhaline freshwater stingray, Himantura signifer, and to determine the effects of acclimation from freshwater to brackish water (salinity 20) on its renal gulo mRNA expression and Gulo activity. We also examined the effects of brackish water acclimation on concentrations of ascorbate, dehydroascorbate and ascorbate + dehydroascorbate in the kidney, brain and gill. The complete cDNA coding sequence of gulo from the kidney of H. signifer contained 1323 bp coding for 440 amino acids. The expression of gulo was kidney-specific, and renal gulo expression decreased significantly by 67% and 50% in fish acclimated to brackish water for 1 day and 6 days, respectively. There was also a significant decrease in renal Gulo activity after 6 days of acclimation to brackish water. Hence, brackish water acclimation led to a decrease in the ascorbic acid synthetic capacity in the kidney of H. signifer. However, there were significant increases in concentrations of ascorbate and ascorbate + dehydroascorbate in the gills (after 1 or 6 days), and a significant increase in the concentration of ascorbate and a significant decrease in the concentration of dehydroascorbate in the brain (after 1 day) of fish acclimated to brackish water. Taken together, our results indicate that H. signifer might experience greater salinity-induced oxidative stress in freshwater than in brackish water, possibly related to its short history of freshwater invasion. These results also suggest for the first time a possible relationship between the successful invasion of the freshwater environment by some euryhaline marine elasmobranchs and the ability of these elasmobranchs to increase the capacity of ascorbic acid synthesis in response to hyposalinity stress. PMID:23825042

  13. A New Turbidimetric method for the Determination of Sulphate in Brackish Waters

    Directory of Open Access Journals (Sweden)

    J. C. Chaudhuri

    1965-01-01

    Full Text Available A New turbidimetric method for the determination of sulphate in brackish waters is described. A suspension of barium sulphate is product in an acidified medium of glycerine d-glucose solution by the addition of barium chloride solution and the turbidity measured with the help of Bausch & Lomb Spectronic '20' Colorimeter. Concentrations upto 160 ppm of sulphate, mate ions do not interfere, nor do Cu/Sup2+, Fe/Sup3+, Co/Sup2+, Ni/Sup2+, and Cr/Sup3+. The method has been applied to the determination of sulphate in desert soils as well.

  14. Radiative characteristics of ice-covered fresh- and brackish-water bodies

    Directory of Open Access Journals (Sweden)

    Leppäranta, Matti

    2006-03-01

    Full Text Available The structure and optics of ice and snow overlying bodies of water were studied in the years 2000–2003. The data were collected in the northern temperate region (nine Estonian and Finnish lakes and one brackish water site, Santala Bay, in the Gulf of Finland. In the present paper we describe the results concerning the radiative characteristics of the system “snow + ice cover on the water”: albedo, attenuation of light, and planar and scalar irradiances through the ice. The basic data consist of irradiance measurements above and below ice cover for the PAR band of the solar spectrum (400–700 nm. Albedo varied across wide limits (0.20–0.70 for ice, 0.63–0.94 for snow, depending on the optical and physical properties of ice/snow and weather conditions. The vertically averaged light attenuation coefficient of the ice layer in the brackish waters of Santala Bay was higher than that in the lakes. The ratio of irradiance beneath the ice to incident irradiance increased 2.5–20 times after removing the snow, depending on the albedo and the thickness of ice and snow as well as on their optical properties. In the upper layer of water beneath the ice the ratio of planar to scalar quantum irradiances increased with depth (according to our earlier results obtained in summer this ratio decreased with increasing depth.

  15. The Energy-Water Nexus: Spatially-Resolved Analysis of the Potential for Desalinating Brackish Groundwater by Use of Solar Energy

    OpenAIRE

    Jill B. Kjellsson; Michael E. Webber

    2015-01-01

    This research looks at coupling desalination with renewable energy sources to create a high-value product (treated water) from two low value resources (brackish groundwater and intermittent solar energy). Desalination of brackish groundwater is already being considered as a potential new water supply in Texas. This research uses Texas as a testbed for spatially-resolved analysis techniques while considering depth to brackish groundwater, water quality, and solar radiation across Texas to dete...

  16. Anopheles culicifacies breeding in brackish waters in Sri Lanka and implications for malaria control

    Directory of Open Access Journals (Sweden)

    Surendran Sinnathamby N

    2010-04-01

    Full Text Available Abstract Background Anopheles culicifacies is the major vector of both falciparum and vivax malaria in Sri Lanka, while Anopheles subpictus and certain other species function as secondary vectors. In Sri Lanka, An. culicifacies is present as a species complex consisting of species B and E, while An. subpictus exists as a complex of species A-D. The freshwater breeding habit of An. culicifacies is well established. In order to further characterize the breeding sites of the major malaria vectors in Sri Lanka, a limited larval survey was carried out at a site in the Eastern province that was affected by the 2004 Asian tsunami. Methods Anopheline larvae were collected fortnightly for six months from a brackish water body near Batticaloa town using dippers. Collected larvae were reared in the laboratory and the emerged adults were identified using standard keys. Sibling species status was established based on Y-chromosome morphology for An. culicifacies larvae and morphometric characteristics for An. subpictus larvae and adults. Salinity, dissolved oxygen and pH were determined at the larval collection site. Results During a six month study covering dry and wet seasons, a total of 935 anopheline larvae were collected from this site that had salinity levels up to 4 parts per thousand at different times. Among the emerged adult mosquitoes, 661 were identified as An. culicifacies s.l. and 58 as An. subpictus s.l. Metaphase karyotyping of male larvae showed the presence of species E of the Culicifacies complex, and adult morphometric analysis the presence of species B of the Subpictus complex. Both species were able to breed in water with salinity levels up to 4 ppt. Conclusions The study demonstrates the ability of An. culicifacies species E, the major vector of falciparum and vivax malaria in Sri Lanka, to oviposit and breed in brackish water. The sibling species B in the An. subpictus complex, a well-known salt water breeder and a secondary malaria

  17. Production of halomethanes and isoprene in the culture of bacteria isolated from brackish water

    Science.gov (United States)

    Fujimori, T.; Taniai, G.; Kurihara, M.; Tamegai, H.; Hashimoto, S.

    2010-12-01

    Halomethanes produced naturally are important source of halogen in troposphere and stratosphere. In the ocean, macroalgae and phytoplankton have been considered to be the main producers of halomethanes. Recent investigations have shown that marine bacteria also produces halomethane such as iodomethane. However, knowledge of aquatic halomethane production, especially by bacteria, is insufficient. Here we survey bacteria, which produce volatile organic compounds (VOCs) including halomethanes, from brackish area (salinity: about 5‰) where high halomethane productions were observed. Bacteria was isolated and incubated in marine broth 2216, which is the media for marine bacteria. The VOCs such as halomethanes in the gas phase above cultured samples was determined using dynamic headspace (GESTEL DHS) - gas chromatograph (Agilent 6890N)- mass spectrometer (Agilent 5975C). The optical density at 600 nm (OD600) was also measured during the cultured period. From the result of the isolation and measurement of VOCs, some of the isolated bacteria produced halomethanes. For example, monohalomethanes (from 1 to about 600 nM) and isoprene (up to about 400 nM) were increased for several days in the culture (dibromomethane, chloroiodomethane, bromoiodomethane, and tribromomethane were not detected). Since halomethanes are abundant at the sampling point (under 1% of light intensity of the surface), bacteria is one of the possible candidates for halomethane producer there. Now, we are studying on the identification by 16S rRNA sequence analysis of bacteria collected from brackish water.

  18. Fecundity regulation in relation to habitat utilisation of two sympatric flounder (Platichtys flesus) populations in the brackish water Baltic Sea

    DEFF Research Database (Denmark)

    Nissling, Anders; Thorsen, Anders; da Silva, Filipa F.G.

    2015-01-01

    Two populations of flounder (Platichtys flesus) with different life history traits inhabit the brackish water Baltic Sea. Both types share feeding areas in coastal waters during summer-autumn but utilise different habitats for spawning in spring, namely offshore spawning with pelagic eggs and...

  19. Development of a sensor for the detection ofEscherichia coli in brackish waters

    Institute of Scientific and Technical Information of China (English)

    Mancuso Monique; Grossi Marco; Rappazzo Alessandro Ciro; Zaccone Renata; Caruso Gabriella; Ricc Bruno; Bergamasco Alessandro

    2016-01-01

    Monitoring of bacterial pathogens is important for marine environmental protection, because the presence of these microorganisms can be a serious risk for human health. For this reason, a portable sensor implemented as an electronic embedded system featuring disposable measurement cells was used to evaluate the ability and sensitivity of detection ofEscherichia coli (E. coli) as an indicator of fecal pollution in transitional environments and a water sample added withE. coli (102CFU/mL) was assayed. The first result obtained from the laboratory experiment seems promising for the determination ofE. coli in environmental samples, though further improvements will be needed for the field application of this sensor in marine and brackish waters.

  20. Development of a sensor for the detection of Escherichia coli in brackish waters

    Directory of Open Access Journals (Sweden)

    Mancuso Monique

    2016-03-01

    Full Text Available Monitoring of bacterial pathogens is important for marine environmental protection, because the presence of these microorganisms can be a serious risk for human health. For this reason, a portable sensor implemented as an electronic embedded system featuring disposable measurement cells was used to evaluate the ability and sensitivity of detection of Escherichia coli (E. coli as an indicator of fecal pollution in transitional environments and a water sample added with E. coli (102 CFU/mL was assayed. The first result obtained from the laboratory experiment seems promising for the determination of E. coli in environmental samples, though further improvements will be needed for the field application of this sensor in marine and brackish waters.

  1. Realized niche width of a brackish water submerged aquatic vegetation under current environmental conditions and projected influences of climate change.

    Science.gov (United States)

    Kotta, Jonne; Möller, Tiia; Orav-Kotta, Helen; Pärnoja, Merli

    2014-12-01

    Little is known about how organisms might respond to multiple climate stressors and this lack of knowledge limits our ability to manage coastal ecosystems under contemporary climate change. Ecological models provide managers and decision makers with greater certainty that the systems affected by their decisions are accurately represented. In this study Boosted Regression Trees modelling was used to relate the cover of submerged aquatic vegetation to the abiotic environment in the brackish Baltic Sea. The analyses showed that the majority of the studied submerged aquatic species are most sensitive to changes in water temperature, current velocity and winter ice scour. Surprisingly, water salinity, turbidity and eutrophication have little impact on the distributional pattern of the studied biota. Both small and large scale environmental variability contributes to the variability of submerged aquatic vegetation. When modelling species distribution under the projected influences of climate change, all of the studied submerged aquatic species appear to be very resilient to a broad range of environmental perturbation and biomass gains are expected when seawater temperature increases. This is mainly because vegetation develops faster in spring and has a longer growing season under the projected climate change scenario. PMID:24933438

  2. COMPOSITIONAL PROPERTIES OF THREE FRESHWATER CARP SPECIES GROWN IN BRACKISH WATER

    Directory of Open Access Journals (Sweden)

    Muhammad Ismail Chughtai

    2015-06-01

    Full Text Available Three freshwater fish species viz. Labeo rohita, Cirrhinus mrigala and Gibelion catla, grown in brackish water ponds were analyzed for compositional properties to assess the potential of this habitat to produce nutritionally adequate fish for human consumption. Overall, the unsaturated fatty acids were lower in L. rohita (46.6% than saturated fatty acids; while in C. mrigala and G. catla, the unsaturated fatty acids were 50.4% and 58.2%, respectively. The most abundant saturated fatty acid in examined species was palmitic acid (C16:0, 23.7 to 34.1%; mono-unsaturated fatty acid was oleic acid (C18:1 19.6 to 31.7% and poly-unsaturated fatty acid linoleic acid (C18:2 9.46 to 13.3%. A reasonable amount of essential fatty acids ω-3 (5.80 to 9.26% and ω-6 (9.46 to 13.3% was also found in these species while growing in brackish water on salt tolerant forages like Leptochloa fusca, Brachiaria mutica and Kochia indica as supplemental feed. The ω-3/ω-6 ratio was calculated as 0.46, 0.80 and 0.69 in L. rohita, C. mrigala and G. catla, respectively. The maximum EPA (eicosapentaenoic acid, C20:5 was observed in C. mrigala (2.23%, followed by G. catla (1.62% and L. rohita (0.98%. While the DHA (docosahexanenoic acids, C22:6 was found maximum in G. catla (1.97% and minimum in C. mrigala (0.95%. The results of body composition indicated that L. rohita found maximum protein contents (19.2% with minimum total fats (1.28% while C. mrigala found maximum total fats (2.11% but minimum protein contents (18.3%. Overall results indicated that the Indian carps grown in brackish water have comparable chemical composition and nutritive value with the same species grown in freshwater medium.

  3. Activated packed bed bioreactor for rapid nitrification in brackish water hatchery systems.

    Science.gov (United States)

    Kumar, V J Rejish; Achuthan, Cini; Manju, N J; Philip, Rosamma; Singh, I S Bright

    2009-03-01

    A packed bed bioreactor (PBBR) was developed for rapid establishment of nitrification in brackish water hatchery systems in the tropics. The reactors were activated by immobilizing ammonia-oxidizing (AMONPCU-1) and nitrite-oxidizing (NIONPCU-1) bacterial consortia on polystyrene and low-density polyethylene beads, respectively. Fluorescence in situ hybridization demonstrated the presence of autotrophic nitrifiers belong to Nitrosococcus mobilis, lineage of beta ammonia oxidizers and nitrite oxidizer Nitrobacter sp. in the consortia. The activated reactors upon integration to the hatchery system resulted in significant ammonia removal (P systems. With spent water the reactors could establish nitrification with high percentage removal of ammonia (78%), nitrite (79%) and BOD (56%) within 7 days of initiation of the process. PBBR is configured in such a way to minimize the energy requirements for continuous operation by limiting the energy inputs to a single stage pumping of water and aeration to the aeration cells. The PBBR shall enable hatchery systems to operate under closed recirculating mode and pave the way for better water management in the aquaculture industry. PMID:19039611

  4. [Effects of brackish water irrigation on soil enzyme activity, soil CO2 flux and organic matter decomposition].

    Science.gov (United States)

    Zhang, Qian-qian; Wang, Fei; Liu, Tao; Chu, Gui-xin

    2015-09-01

    Brackish water irrigation utilization is an important way to alleviate water resource shortage in arid region. A field-plot experiment was set up to study the impact of the salinity level (0.31, 3.0 or 5.0 g · L(-1) NaCl) of irrigated water on activities of soil catalase, invertase, β-glucosidase, cellulase and polyphenoloxidase in drip irrigation condition, and the responses of soil CO2 flux and organic matter decomposition were also determined by soil carbon dioxide flux instrument (LI-8100) and nylon net bag method. The results showed that in contrast with fresh water irrigation treatment (CK), the activities of invertase, β-glucosidase and cellulase in the brackish water (3.0 g · L(-1)) irrigation treatment declined by 31.7%-32.4%, 29.7%-31.6%, 20.8%-24.3%, respectively, while soil polyphenoloxidase activity was obviously enhanced with increasing the salinity level of irrigated water. Compared to CK, polyphenoloxidase activity increased by 2.4% and 20.5%, respectively, in the brackish water and saline water irrigation treatments. Both soil microbial biomass carbon and microbial quotient decreased with increasing the salinity level, whereas, microbial metabolic quotient showed an increasing tendency with increasing the salinity level. Soil CO2 fluxes in the different treatments were in the order of CK (0.31 g · L(-1)) > brackish water irrigation (3.0 g · L(-1)) ≥ saline water irrigation (5.0 g · L(-1)). Moreover, CO2 flux from plastic film mulched soil was always much higher than that from no plastic film mulched soil, regardless the salinity of irrigated water. Compared with CK, soil CO2 fluxes in the saline water and brackish water treatments decreased by 29.8% and 28.2% respectively in the boll opening period. The decomposition of either cotton straw or alfalfa straw in the different treatments was in the sequence of CK (0.31 g · L(-1)) > brackish water irrigation (3.0 g · L(-1)) > saline water treatment (5.0 g · L(-1)). The organic matter

  5. Assessment of the fresh-and brackish-water resources underlying Dunedin and adjacent areas on northern Pinellas County, Florida

    Science.gov (United States)

    Knochenmus, L.A.; Swenson, E.S.

    1996-01-01

    The city of Dunedin is enhancing their potable ground-water resources through desalination of brackish ground water. An assessment of the fresh- and brackish-water resources in the Upper Floridan aquifer was needed to estimate the changes that may result from brackish-water development. The complex hydrogeologic framework underlying Dunedin and adjacent areas of northern Pinellas County is conceptualized as a multilayered sequence of permeable zones and confining and semiconfining units. The permeable zones contain vertically spaced, discrete, water-producing zones with differing water quality. Water levels, water-level responses, and water quality are highly variable among the different permeable zones. The Upper Floridan aquifer is best characterized as a local flow system in most of northern Pinellas County. Pumping from the Dunedin well field is probably not influencing water levels in the aquifer outside Dunedin, but has resulted in localized depressions in the potentiometric surface surrounding production-well clusters. The complex geologic layering combined with the effects of production-well distribution probably contribute to the spatial and temporal variability in chloride concentrations in the Dunedin well field. Chloride concentrations in ground water underlying the Dunedin well field vary both vertically and laterally. In general, water-quality rapidly changes below depths of 400 feet below sea level. Additionally, randomly distributed water-producing zones with higher chloride concentrations may occur at shallow, discrete intervals above 400 feet. A relation between chloride concentration and distance from St. Joseph Sound is not apparent; however, a possible relation exists between chloride concentration and production-well density. Chloride-concentration data from production wells show a consistently increasing pattern that has accelerated since the late 1980's. Chloride-concentration data from 15 observation wells show increasing trends for 6 wells

  6. Heterotrophic bacteria from brackish water of the southern Baltic Sea: biochemical and molecular identification and characterisation

    Directory of Open Access Journals (Sweden)

    Agnieszka Cabaj

    2006-12-01

    Full Text Available Six bacterial strains isolated from the surface water of thesouthern Baltic Sea were described on the basis of their morphological,physiological and biochemical features, and were classified onthe basis of 16S rDNA sequence analysis. Comparative analysesof the 16S rDNA sequences of five of the six bacterial strainsexamined displayed a ≥98% similarity to the sequences availablein the NCBI GenBank. The 16S rDNA sequence of strain 2 sharedonly a 96% similarity with other published sequences, whichsuggests that this is a new, hitherto unknown species. The isolatedheterotrophic bacteria belong to the families Bacillaceae(strain 1, Flexibacteriaceae (strain 2, Sphingomonadaceae(strains 3, 5, Micrococcaceae (strain 4 and Aurantimonadaceae(strain 6.    This is the first study in which the polyphasic approach hasbeen applied to the identification of heterotrophic bacteriafrom the brackish waters of the Gulf of Gdańsk and Gdańsk Deep.

  7. Selective removal of arsenic and monovalent ions from brackish water reverse osmosis concentrate.

    Science.gov (United States)

    Xu, Pei; Capito, Marissa; Cath, Tzahi Y

    2013-09-15

    Concentrate disposal and management is a considerable challenge for the implementation of desalination technologies, especially for inland applications where concentrate disposal options are limited. This study has focused on selective removal of arsenic and monovalent ions from brackish groundwater reverse osmosis (RO) concentrate for beneficial use and safe environmental disposal using in situ and pre-formed hydrous ferric oxides/hydroxides adsorption, and electrodialysis (ED) with monovalent permselective membranes. Coagulation with ferric salts is highly efficient at removing arsenic from RO concentrate to meet a drinking water standard of 10 μg/L. The chemical demand for ferric chloride however is much lower than ferric sulfate as coagulant. An alternative method using ferric sludge from surface water treatment plant is demonstrated as an efficient adsorbent to remove arsenic from RO concentrate, providing a promising low cost, "waste treat waste" approach. The monovalent permselective anion exchange membranes exhibit high selectivity in removing monovalent anions over di- and multi-valent anions. The transport of sulfate and phosphate through the anion exchange membranes was negligible over a broad range of electrical current density. However, the transport of divalent cations such as calcium and magnesium increases through monovalent permselective cation exchange membranes with increasing current density. Higher overall salt concentration reduction is achieved around limiting current density while higher normalized salt removal rate in terms of mass of salt per membrane area and applied energy is attained at lower current density because the energy unitization efficiency decreases at higher current density. PMID:23892312

  8. Uptake and effects of americium-241 on a brackish-water amphipod

    International Nuclear Information System (INIS)

    The present paper reports the results of experimental work undertaken using the brackish-water amphipod Gammarus duebeni duebeni and the transuranium nuclide americium-241. Data on the accumulation of this actinide showed that the larger fraction of the total body burden is associated with the exoskeleton. It was found that the body burden remained constant in the range pH 8.0-6.5 even though the water concentration changed markedly. It would thus appear that the concept of a concentration factor should be re-examined and it is proposed that a factor should be defined in terms of environmental and chemical parameters which represent the bioavailable fraction of the actinide. The effect of americium on survival and moulting was studied at two activity concentrations; the dose rates and absorbed doses under the experimental conditions employed have been estimated. The differences in survival rates between the control and irradiated groups were statistically analyzed and the significant difference at the higher concentration is believed to be due to a synergism between physiological stress and radiotoxicity of americium rather than the chemical toxicity of the element. (orig.)

  9. Investigation of changes in the microflora of brackish water passing through power plant cooling systems

    International Nuclear Information System (INIS)

    Changes in the bacterial- and phytoplankton population in the brackish water during the passage of fresh water cooling systems in the community power plant of Kiel (GKK) and in the nuclear power plant of Brunsbuettel were subject of the examinations. In addition, laboratory tests were carried out and a method was developed to determine thermal changes in the bacterial activity (measured as glucose uptake) in the condensator independent on the mechanical influences. Following points describe the starting position in the incoming cooling water of the GKK: 1) The annual cycle of the bacterial activity is temporally delayed in relation to the natural course of the temperature. 2) The annual course of the phytoplankton is primarily regulated by the light and nutrition offered while the temperature is only of indirect importance. 3) The particular organic material is, beside the dissolved organic compounds, important for the biological oxygen household in the Kieler Foerde. Changes in the bacterial population and the phytoplankton flora occur during the passage of the cooling system in the community power plant of Kiel. In the heated water samples behind the condensator, an increase in the bacterial activity by 11% on an average is seen. This increase is also found in the biochemical oxygen consumption after 30 hours. On an average, it is about 19%. Changes in the phytoplankton in the cooling water are only insignificantly due to the thermal influences; here, the hazards are rather due to the mechanical burden. At the KBB, an annual cycle could not be recorded because of the numerous operational disturbances. The bacterial glucose uptake in the river Elbe shows no temperature-dependent fluctuations. (orig./MG)

  10. Assessment of wind energy to power solar brackish water greenhouse desalination units. A case study from Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudi, Hacene [Laboratory of Water and Environment, Hassiba Ben Bouali University, Chlef, P.O. Box 151 (Algeria); Faculty of Sciences and Engineering Sciences, Hassiba Ben Bouali University, Chlef (Algeria); Spahis, Nawel [Faculty of Sciences and Engineering Sciences, Hassiba Ben Bouali University, Chlef (Algeria); Goosen, Mattheus F. [Alfaisal University, P.O. Box 50927, Riyadh 11533, KSA (Saudi Arabia); Sablani, Shyam [Biological Systems Engineering, Washington State University, Pullman, WA (United States); Abdul-wahab, Sabah A. [College of Engineering, P.O. Box 33, Sultan Qaboos University, Al-Khod 123, Muscat (Oman); Ghaffour, Noreddine [Middle East Desalination Research Center, P.O. Box 21, P.C. 133, Muscat (Oman); Drouiche, Nadjib [Silicon Technology Development Unit (UDTS), 2 Bd Frantz Fanon BP399 Algiers (Algeria)

    2009-10-15

    The Algerian desert dominates large parts of the country's vast territory, and Algeria is among the countries filling most of the world's largest desert. In fact the country is over 80% desert. Even though more than 80% of the population is located in the northern Mediterranean coastal zone, most of oil and gas fields are located in the country's vast southern desert called Sahara. Furthermore, the desert region is developed into a major tourist destination. This arid zone region is characterized by a lack of potable water. However, in addition to the abundant solar energy, the region is also endowed with important wind and brackish groundwater resources with different qualities. Therefore, a brackish water greenhouse desalination unit that is powered by wind energy is a good solution for desalting groundwater for irrigation purposes in this region. Brackish water can be used to cool the greenhouse, creating the proper climate to grow valuable crops. Moreover, at the same time the fresh water that is produced in this system may be sufficient for the irrigation of crops grown inside the unit. In this study, five typical regions in the Sahara were selected and investigated. These regions were selected since they were areas of traditional agriculture. The frequency distributions of wind speed data were collected from Surface Meteorology and Solar Energy (SSE) statistics developed by NASA and evaluated for a 10-year period. The distributions were used to determine the average wind speed and the available wind power for the five locations. The results indicated that the available wind energy is a suitable resource for power production and can be used to provide the required electricity for the brackish groundwater greenhouse desalination units. (author)

  11. Differences in osmotolerance in freshwater and brackish water populations of Theodoxus fluviatilis (Gastropoda: Neritidae) are associated with differential protein expression

    OpenAIRE

    Symanowski, Frauke; Hildebrandt, J.-P.

    2010-01-01

    The euryhaline gastropod Theodoxus fluviatilis is found in northern Germany in freshwater or in brackish water habitats in the Baltic Sea. Previous studies have revealed that individuals from both habitats are not distinguishable by morphological characters or by sequence comparison of DNA encoding 16S RNA or cytochrome C. As reported in this study, animals collected in the two habitats differ substantially in their physiological ability to adapt to different salinities. Comparison of accumul...

  12. Stability of a carbon gel electrode when used for the electro-assisted removal of ions from brackish water

    OpenAIRE

    Haro Remón, Marta; Rasines, Gloria; Macías, C.; Ovín Ania, María Concepción

    2011-01-01

    [EN] A porous carbon gel obtained from the poly-condensation of resorcinol and formaldehyde was synthesized and used as an electrode material for the capacitive deionization (CDI) of synthetic brackish water. The desalting capacity of this material was evaluated in terms of applied voltage and zero-voltage regeneration over a number of cycles, and compared to that of commercially available carbon materials (powdered activated carbon and activated carbon cloth). Due to an adequate combination ...

  13. Tunisian brackish water desalination by Electrodialysis : Opposing scaling and process optimization

    International Nuclear Information System (INIS)

    Electrodialysis (ED) did not know a mattering development in the desalination field because of problems usually related to energy consumption, the scaling and/or precipitation phenomenon of certain mineral salts (CaSO4, CaCO3, etc.). and the importance of investments which they require. So, to mitigate some of these problems and to increase the electrodialysis processes potentialities, we introduced a crystallisation inhibitor (sodium polyacrylate RPI2000) into the concentration compartment during Ed's operations. Then we studied some parameters such as the applied potential or the circulation flow of studied solutions. The inhibitor addition allowed to delay the precipitation in the ED concentration comportment, confining so the brine in a small volume and decrease the frequency of replacement of membranes, which will reduce the cost of the process. Without adding scaling inhibitors, a set of experiment was performed using synthetic water supersaturated on CaCO3 and CaSO4 at room temperature. Several flows rates are tested (80, 60, 40 and 30 L/h). We applied 20 V until the conductivity measured in the dilute compartment dropped approximately from 9000 =μS/cm to 1500 μS/cm. We used the same concentrate solution to treat many synthetic water volumes. The results showed us that more the flow is important more the phenomenon of scaling is delayed. In order to increase the performance of the electrodialysis process we applied a pulsed electric field with different duty cycle (Ton = Toff = 1, 3, 10 and 30 seconds). Then, we compare conductivity evolution in the dilute as a function of the pulse mode. The results shows a faster decrease of the concentration in the dilute under pulsed field conditions. Pulsed electric field electrodialysis seems to be very promising for future development in brackish water desalination, to some extent it can remove some well known limitations of electrodialysis. Experiments on desalination of brackish water by pulse field

  14. Global diversity of aloricate Oligotrichea (Protista, Ciliophora, Spirotricha) in marine and brackish sea water.

    Science.gov (United States)

    Agatha, Sabine

    2011-01-01

    Oligotrichids and choreotrichids are ciliate taxa contributing to the multi-step microbial food web and episodically dominating the marine microzooplankton. The global diversity and distribution of aloricate Oligotrichea are unknown. Here, the geographic ranges of the 141 accepted species and their synonyms in marine and brackish sea water are analyzed, using hundreds of taxonomical and ecological studies; the quality of the records is simultaneously evaluated. The aloricate Oligotrichea match the moderate endemicity model, i.e., the majority (94) of morphospecies has a wide, occasionally cosmopolitan distribution, while 47 morphospecies show biogeographic patterns: they are restricted to single geographic regions and probably include 12 endemic morphospecies. These endemics are found in the Antarctic, North Pacific, and Black Sea, whereas the "flagship" species Strombidinopsis cercionis is confined to the Caribbean Sea. Concerning genera, again several geographic patterns are recognizable. The species richness is distinctly lower in the southern hemisphere than in the northern, ranging from nine morphospecies in the South Pacific to 95 in the North Atlantic; however, this pattern is probably caused by undersampling. Since the loss of species might affect higher trophical levels substantially, the aloricate Oligotrichea should not any longer be ignored in conservation issues. The ecophysiological diversity is considerably larger than the morphological, and even tops the richness of SSrRNA and ITS haplotypes, indicating that probably more than 83-89% of the diversity in aloricate Oligotrichea are unknown. The huge challenge to discover all these species can only be managed by combining the expertises of morphological taxonomists, molecular biologists, ecologists, and physiologists. PMID:21853034

  15. Autonomous system without batteries for brackish water desalination; Sistema autonomo sem baterias para dessalinizacao de agua salobra

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Eduardo Henrique Pereira de; Bezerra, Luiz Daniel Santos; Antunes, Fernando Luiz Marcelo [Universidade Federal do Ceara (PPGEE/UFC), Fortaleza, CE (Brazil). Programa de Pos -Graduacao em Engenharia Eletrica

    2008-07-01

    Ones of the goods most precious of the humanity, in the current times, with certainty is the drinking waters. Each scarcer and basic time for survival. In everybody more than 6,000 children die every day victims of some type of illness provoked for contaminated water (WHO, 2003). The underground water for being free of contamination is a good alternative, however its exploration if it becomes each more expensive time, since the water of better quality, is located in deeper sheets. In the state of the Ceara, techniques to explore water of deep well are each more frequent time, however, present a great inconvenience, most of the excavated wells, present brackish water, improper for the human consumption. In the attempt to make possible these wells the water is treated by desalination process. This article presents the practical implementation of a desalination the reverse Osmosis, Pump high-pressure supplied by solar photovoltaic energy system. (author)

  16. Hierarchical Ordered Mesoporous Carbon from Phloroglucinol-Glyoxal and its Application in Capacitive Deionization of Brackish Water

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Sheng [ORNL; DePaoli, David W [ORNL; Kiggans, Jim [ORNL; Mayes, Richard T [ORNL; Tsouris, Costas [ORNL; Mahurin, Shannon Mark [ORNL

    2010-01-01

    Templated carbon materials have recently received tremendous attention due to energy storage and separations applications. Hierarchical structures are ideal for increased mass-transport throughout the carbon material. A new ordered mesoporous carbon material has been developed using glyoxal which exhibits a hierarchical structure with pore sizes up to 200 nm. The hierarchical structure arises from the cross linking reagent and not from the standard spinodal decomposition of a secondary solvent. The carbon material was studied for potential application as a capacitive deionization (CDI) electrode for brackish water. Results indicate that the hierarchical structure provides a pathway for faster adsorption kinetics when compared to standard resorcinol-formaldehyde CDI electrodes.

  17. Influence of Chlorination and Choice of Materials on Fouling in Cooling Water System under Brackish Seawater Conditions

    Directory of Open Access Journals (Sweden)

    Pauliina Rajala

    2016-06-01

    Full Text Available Cooling systems remove heat from components and industrial equipment. Water cooling, employing natural waters, is typically used for cooling large industrial facilities, such as power plants, factories or refineries. Due to moderate temperatures, cooling water cycles are susceptible to biofouling, inorganic fouling and scaling, which may reduce heat transfer and enhance corrosion. Hypochlorite treatment or antifouling coatings are used to prevent biological fouling in these systems. In this research, we examine biofouling and materials’ degradation in a brackish seawater environment using a range of test materials, both uncoated and coated. The fouling and corrosion resistance of titanium alloy (Ti-6Al-4V, super austenitic stainless steel (254SMO and epoxy-coated carbon steel (Intershield Inerta160 were studied in the absence and presence of hypochlorite. Our results demonstrate that biological fouling is intensive in cooling systems using brackish seawater in sub-arctic areas. The microfouling comprised a vast diversity of bacteria, archaea, fungi, algae and protozoa. Chlorination was effective against biological fouling: up to a 10–1000-fold decrease in bacterial and archaeal numbers was detected. Chlorination also changed the diversity of the biofilm-forming community. Nevertheless, our results also suggest that chlorination enhances cracking of the epoxy coating.

  18. Identifying Economies of Size in Conventional Surface Water Treatment and Brackish-Groundwater Desalination: Case Study in the Rio Grande Valley of Texas

    OpenAIRE

    Boyer, Christopher N.; Rister, M. Edward; Sturdivant, Allen W.; Ronald D. Lacewell; Harris, Bill L.

    2008-01-01

    Two primary potable water-treatment technologies used in South Texas include conventional surface-water and reverse-osmosis (RO) desalination of brackish-groundwater. As the region's population continues to grow, municipalities are searching for economical means to expand their water supplies. Economies of size for both technologies are an important consideration for future expansion decisions.

  19. Vertical distribution of radiation dose rates in the water of a brackish lake in Aomori Prefecture, Japan

    International Nuclear Information System (INIS)

    Seasonal radiation dose rates were measured with glass dosemeters housed in watertight cases at various depths in the water of Lake Obuchi, a brackish lake in Aomori Prefecture, Japan, during fiscal years 2011-2013 to assess the background external radiation dose to aquatic biota in the lake. The mean radiation dose in the surface water of the lake was found to be 27 nGy h-1, which is almost the same as the absorption dose rate due to cosmic ray reported in the literature. Radiation dose rates decreased exponentially with water depth down to a depth of 1 m above the bottom sediment. In the water near the sediment, the dose rate increased with depth owing to the emission of γ-rays from natural radionuclides in the sediment. (authors)

  20. Isolation and evaluation of oil-producing microalgae from subtropical coastal and brackish waters.

    Directory of Open Access Journals (Sweden)

    David K Y Lim

    Full Text Available Microalgae have been widely reported as a promising source of biofuels, mainly based on their high areal productivity of biomass and lipids as triacylglycerides and the possibility for cultivation on non-arable land. The isolation and selection of suitable strains that are robust and display high growth and lipid accumulation rates is an important prerequisite for their successful cultivation as a bioenergy source, a process that can be compared to the initial selection and domestication of agricultural crops. We developed standard protocols for the isolation and cultivation for a range of marine and brackish microalgae. By comparing growth rates and lipid productivity, we assessed the potential of subtropical coastal and brackish microalgae for the production of biodiesel and other oil-based bioproducts. This study identified Nannochloropsis sp., Dunaniella salina and new isolates of Chlorella sp. and Tetraselmis sp. as suitable candidates for a multiple-product algae crop. We conclude that subtropical coastal microalgae display a variety of fatty acid profiles that offer a wide scope for several oil-based bioproducts, including biodiesel and omega-3 fatty acids. A biorefinery approach for microalgae would make economical production more feasible but challenges remain for efficient harvesting and extraction processes for some species.

  1. Strains of toxic and harmful microalgae, from waste water, marine, brackish and fresh water.

    Science.gov (United States)

    Rodríguez-Palacio, M C; Crisóstomo-Vázquez, L; Alvarez-Hernández, S; Lozano-Ramírez, C

    2012-01-01

    Some microalgae are economically important in Mexico and the world because they can be potentially toxic. Algal explosive population growths are named harmful algal blooms and are frequently recorded in Mexico. The authors set up potentially toxic microalgae cultures from the Gulf of Mexico (Garrapatas tideland, Barberena river, Carpintero lagoon in Tamaulipas State; Chalchoapan and Catemaco lakes in Veracruz State), from the Mexican Pacific Ocean, Guerrero, Colima and Michoacán States, and from interior water bodies such as Vicente Aguirre dam, Chapultepec lake and several waste water treatment plants. This research is about the diversity and abundance of phytoplankton in relation a specific site because of harmful algal bloom events. Microalgae cultures are useful in order to solve taxonomic problems, to know life cycles, molecular studies, for the study of toxic species, and the isolation of useful metabolites. The cultures for this research are clonal, non-axenic, semi-continuous, 12:12 light/dark photoperiod, 20 ± 1 °C temperature and 90.5 µmol m(-2)s(-1) illumination. Four different culture media were used. This collection is open to the worldwide scientific community as a source of organisms in controlled conditions that can be used as a useful tool for microalgae research work. PMID:21815840

  2. Cytological comparison of gill chloride cells and blood serum ion concentrations in kutum (Rutilus frisii kutum spawners from brackish (Caspian Sea and fresh water (Khoshkrood River environments

    Directory of Open Access Journals (Sweden)

    Ghahremanzadeh Zahra

    2014-09-01

    Full Text Available The size and number of chloride cells and serum ion concentrations in kutum, Rutillus frisii kutum Nordman, from brackish (Caspian Sea and fresh water (Khoshkrood River environments were studied to gain a better understanding of osmoregulation in this species. Twenty mature kutum specimens were collected from the Caspian Sea (Anzali coasts, 8.49 ppt salinity and 12.4°C temperature and 20 specimens from Khoshkrood River (0.18 ppt salinity and 18°C temperature. Gill samples were analyzed histologically and concentrations of Na+, Cl- , K+, and Mg2+ ions were determined in the blood serum. Concentrations of Na+, Cl- , K+, and Mg2+ ions and osmotic pressure in mature kutum from brackish water were significantly higher than in specimens from fresh water. The average size and number of chloride cells in the fish from seawater were considerably larger than those from fresh water. The mean size of chloride cells was 6.89 ± 1.16 μm in brackish water samples and 5.1 ± 0.81 μm in river samples. The average number of chloride cells in brackish and river water samples were 16.92 and 6.57, respectively. The density and size of chloride cells increased with increases in salinity

  3. The Energy-Water Nexus: Spatially-Resolved Analysis of the Potential for Desalinating Brackish Groundwater by Use of Solar Energy

    Directory of Open Access Journals (Sweden)

    Jill B. Kjellsson

    2015-06-01

    Full Text Available This research looks at coupling desalination with renewable energy sources to create a high-value product (treated water from two low value resources (brackish groundwater and intermittent solar energy. Desalination of brackish groundwater is already being considered as a potential new water supply in Texas. This research uses Texas as a testbed for spatially-resolved analysis techniques while considering depth to brackish groundwater, water quality, and solar radiation across Texas to determine the locations with the best potential for integrating solar energy with brackish groundwater desalination. The framework presented herein can be useful for policymakers, regional planners, and project developers as they consider where to site desalination facilities coupled with solar photovoltaics. Results suggest that the northwestern region of Texas—with abundant sunshine and groundwater at relatively shallow depths and low salinity in areas with freshwater scarcity—has the highest potential for solar powered desalination. The range in capacity for solar photovoltaic powered reverse osmosis desalination was found to be 1.56 × 10—6 to 2.93 × 10—5 cubic meters of water per second per square meter of solar panel (m3/s/m2.

  4. A coupled agronomic-economic model to consider allocation of brackish irrigation water

    NARCIS (Netherlands)

    Gal, Ben A.; Weikard, H.P.; Shah, S.H.H.; Zee, van der S.E.A.T.M.

    2013-01-01

    [1] In arid and semiarid regions, irrigation water is scarce and often contains high concentrations of salts. To reduce negative effects on crop yields, the irrigated amounts must include water for leaching and therefore exceed evapotranspiration. The leachate (drainage) water returns to water sourc

  5. Hepatic pathologies in the brackish water catfish (Chrysichthys nigrodigitatus) from contaminated locations of the Lagos lagoon complex

    Science.gov (United States)

    Olarinmoye, O.; Taiwo, V.; Clarke, E.; Kumolu-Johnson, C.; Aderinola, O.; Adekunbi, F.

    2010-01-01

    Several toxicological studies into the effects of aquatic pollutants on the liver of teleost fish exist in literature. The focus on the liver in these studies is predicated on its central nature in the scheme of biotransformation and excretion of xenobiotics following exposure in polluted water bodies. As a consequence of the latter primary role of the liver in these processes it is regarded as a predilective site for the sub lethal effects of xenobiotics on the organism usually detectable at histological level. Hepatic histopathology recorded in livers from feral populations of the brackish water catfish Chrysichthys nigrodigitatus from locations on the Lagos lagoon complex with significant anthropogenic inputs from denizen populations and industries are presented. Liver sections from sixty specimens from two locations on the Lagos lagoon complex (Badagry lagoon: 6??24'N, 2??56'E; and Lagos lagoon: 6??29'N, 3??22'E) were analysed. Observed pathologies included hydropic degeneration (58%), portal / sinusoidal congestion (33%), hepatic necrosis (26%), hemosiderosis (12%) and foci of cellular alterations (FCA's). No obvious oncologic features were observed; the presence of the hydropic Vacuolation lesion was taken as prelude to the development of neoplasms and discussed as such. ?? 2009, Penkala Bt., Budapest, Hungary.

  6. CONCENTRATED SOLAR DISTILLATION AS A MEANS TO PURIFY SALINE/BRACKISH WATER

    Science.gov (United States)

    Initial experiments focused on the ability of the lens to deliver enough energy to produce water with minimal salt content. Raw sample waters were prepared using quantities of Epsom salt (MgSO47H2O) dissolved in purchased distilled water. Three separate ...

  7. Growth and lipid accumulation of microalgae from fluctuating brackish and sea water locations in South East Queensland – Australia

    Directory of Open Access Journals (Sweden)

    Van Thang eDuong

    2015-05-01

    Full Text Available One challenge constraining the use of microalgae in the food and biofuels industry is growth and lipid accumulation. Microalgae with high growth characteristics are more likely to originate from the local environment. However, to be commercially effective, in addition to high growth microalgae must also have high lipid productivities and contain the desired fatty acids for their intended use. We isolated microalgae from intertidal locations in South East Queensland, Australia with adverse or fluctuating conditions, as these may harbor more opportunistic strains with high lipid accumulation potential. Screening was based on a standard protocol using growth rate and lipid accumulation as well as prioritizing fatty acid profiles suitable for biodiesel or nutraceuticals. Using these criteria, an initial selection of over 50 local microalgae strains from brackish and sea water was reduced to 16 strains considered suitable for further investigation. Among these 16 strains, the ones most likely to be effective for biodiesel feedstock were Nitzschia sp. CP3a, Tetraselmis sp. M8, Cymbella sp. CP2b and Cylindrotheca closterium SI1c, reaching growth rates of up to 0.53 day-1 and lipid productivities of 5.62 µg mL-1day-1. Omega-3 fatty acids were found in some strains such as Nitzschia sp. CP2a, Nitzschia sp. CP3a and Cylindrotheca closterium SI1c. These strains have potential for further research as commercial food supplements.

  8. Effects of predicted climatic changes on distribution of organic contaminants in brackish water mesocosms

    International Nuclear Information System (INIS)

    Predicted consequences of future climate change in the northern Baltic Sea include increases in sea surface temperatures and terrestrial dissolved organic carbon (DOC) runoff. These changes are expected to alter environmental distribution of anthropogenic organic contaminants (OCs). To assess likely shifts in their distributions, outdoor mesocosms were employed to mimic pelagic ecosystems at two temperatures and two DOC concentrations, current: 15 °C and 4 mg DOC L−1 and, within ranges of predicted increases, 18 °C and 6 mg DOC L−1, respectively. Selected organic contaminants were added to the mesocosms to monitor changes in their distribution induced by the treatments. OC partitioning to particulate matter and sedimentation were enhanced at the higher DOC concentration, at both temperatures, while higher losses and lower partitioning of OCs to DOC were observed at the higher temperature. No combined effects of higher temperature and DOC on partitioning were observed, possibly because of the balancing nature of these processes. Therefore, changes in OCs' fates may largely depend on whether they are most sensitive to temperature or DOC concentration rises. Bromoanilines, phenanthrene, biphenyl and naphthalene were sensitive to the rise in DOC concentration, whereas organophosphates, chlorobenzenes (PCBz) and polychlorinated biphenyls (PCBs) were more sensitive to temperature. Mitotane and diflufenican were sensitive to both temperature and DOC concentration rises individually, but not in combination. - Highlights: • More contaminants remained in the ecosystem at higher organic carbon levels. • More contaminants were lost in the higher temperature treatments. • The combined effects are competitive with respect to contaminant cycling. • The individual properties of each contaminant determine their respective fate

  9. Effects of predicted climatic changes on distribution of organic contaminants in brackish water mesocosms

    Energy Technology Data Exchange (ETDEWEB)

    Ripszam, M., E-mail: matyas.ripszam@chem.umu.se [Department of Chemistry, Umea University, 901 87 Umeå (Sweden); Gallampois, C.M.J. [Department of Chemistry, Umea University, 901 87 Umeå (Sweden); Berglund, Å. [Department of Ecology and Environmental Sciences, Umeå University, 901 87 Umeå (Sweden); Larsson, H. [Umeå Marine Sciences Centre, Umeå University, Norrbyn, 905 71 Hörnefors (Sweden); Andersson, A. [Department of Ecology and Environmental Sciences, Umeå University, 901 87 Umeå (Sweden); Tysklind, M.; Haglund, P. [Department of Chemistry, Umea University, 901 87 Umeå (Sweden)

    2015-06-01

    Predicted consequences of future climate change in the northern Baltic Sea include increases in sea surface temperatures and terrestrial dissolved organic carbon (DOC) runoff. These changes are expected to alter environmental distribution of anthropogenic organic contaminants (OCs). To assess likely shifts in their distributions, outdoor mesocosms were employed to mimic pelagic ecosystems at two temperatures and two DOC concentrations, current: 15 °C and 4 mg DOC L{sup −1} and, within ranges of predicted increases, 18 °C and 6 mg DOC L{sup −1}, respectively. Selected organic contaminants were added to the mesocosms to monitor changes in their distribution induced by the treatments. OC partitioning to particulate matter and sedimentation were enhanced at the higher DOC concentration, at both temperatures, while higher losses and lower partitioning of OCs to DOC were observed at the higher temperature. No combined effects of higher temperature and DOC on partitioning were observed, possibly because of the balancing nature of these processes. Therefore, changes in OCs' fates may largely depend on whether they are most sensitive to temperature or DOC concentration rises. Bromoanilines, phenanthrene, biphenyl and naphthalene were sensitive to the rise in DOC concentration, whereas organophosphates, chlorobenzenes (PCBz) and polychlorinated biphenyls (PCBs) were more sensitive to temperature. Mitotane and diflufenican were sensitive to both temperature and DOC concentration rises individually, but not in combination. - Highlights: • More contaminants remained in the ecosystem at higher organic carbon levels. • More contaminants were lost in the higher temperature treatments. • The combined effects are competitive with respect to contaminant cycling. • The individual properties of each contaminant determine their respective fate.

  10. Distribution, life cycle and demography in a brackish water population of the isopod Cyathura carinata (Kröyer) (Crustacea)

    Science.gov (United States)

    Ólafsson, Einar B.; Persson, Lars-Eric

    1986-11-01

    Cyathura carinata, an infaunal, fossorial, isopod is a dominant member of a brackish, shallow water macrobenthic community on the south coast of Sweden. It has a bi-annual life-cycle. Breeding occurs in June-July, and a single brood of between 18-63 eggs per female is produced. The eggs take about 3-4 weeks to develop, the juveniles emerge in mid-late July. Initial recruitment in the study area was estimated to be 1480-1850 juveniles m -2 for 1981-1983 year classes. About 5% of the recruits survive to reproductive age two years later. Growth was characterized by fast growth during summer-autumn, stagnation in winter, and a slow start in spring. Females and males were not separated until just prior to reproduction (i.e. in June of the second year). At this stage males were larger than females and sex ratio was 1:1. During the breeding season, the abundance of males decreased rapidly due to post-reproductive death. Females continued to live, carrying the developing eggs in their brood pouches. Adult females die shortly after the young are released. The entire generation of reproductive adults (two years of age) has died by mid August. No evidence of the stated protogynous hermaphroditism was found in our study. Cohort production was 1·83 g wet wt m -2 for the 1980 cohort and 1·33 for the 1981 cohort. P/B-ratios were 2·12 for the 1980 cohort and 2·48 for the 1981 cohort. The P/B-ratios found were closest to those calculated by the method of Waters when an accurate estimate of mortality was available.

  11. Fecundity regulation in relation to habitat utilisation of two sympatric flounder (Platichtys flesus) populations in the brackish water Baltic Sea

    Science.gov (United States)

    Nissling, Anders; Thorsen, Anders; da Silva, Filipa F. G.

    2015-01-01

    Two populations of flounder (Platichtys flesus) with different life history traits inhabit the brackish water Baltic Sea. Both types share feeding areas in coastal waters during summer-autumn but utilise different habitats for spawning in spring, namely offshore spawning with pelagic eggs and coastal spawning with demersal eggs respectively. Fecundity regulation by atresia was assessed as prevalence (portion of fish with atresia) and intensity (calculated as the average intensity of atresia in these fish) during the reproductive cycle following start of gonad development in the autumn up to spawning in spring, and evaluated in relation to fish condition (Fulton's condition factor reflecting energy reserves of the fish) and feeding incidence of the respective population. Peaking in winter (December-February), fecundity regulation was significantly higher for coastal spawning flounder than for flounder spawning offshore. For coastal spawners, the prevalence was 45-90% with an intensity of 6.4-9.3% vs. 0-25% and an intensity of 2.1-3.4% for offshore spawners during winter. Further, fecundity regulation ceased prior to spawning for offshore spawners but continued for coastal spawners. For coastal spawners, the prevalence was 12-29% and an intensity of 2.5-6.1% during spawning. The change in fish condition was strongly related to feeding incidence and differed between populations. As feeding ceased, condition of offshore spawners decreased during winter up to spawning, whereas condition of coastal spawners decreased during autumn but was maintained as feeding started again prior to spawning. Thus, habitat utilisation according to spawning strategy affects the timing of fecundity down-regulation reflecting availability of resources, namely limited food resources in deep areas and higher availability in coastal areas. Offshore spawning flounder display characteristics typical for a capital spawner with ceasing of feeding and oocyte down-regulation well before spawning

  12. The distribution and ecology of the fresh- and brackish-water Medusae of the world

    OpenAIRE

    Dumont, H.J.

    1994-01-01

    Limnocnida and Craspedacusta are the two main genera of Cnidaria from continental waters which have a free-swimming medusa in their life cycle. Both originated in tropical-subtropical Asia, but Limnocnida is also found in Africa, with one species (L. tanganjicae) perhaps endemic to lake Tanganyika. Halmomises from Trinidad, and two genera (Mansariella, Keralica) from India have limited ranges. No freshwater medusae evolved in Europe and the Americas (aside from Trinidad), but Craspedacusta so...

  13. Integration of Ultrafiltration and Reverse Osmosis on purification of brackish waters: optimization trials

    OpenAIRE

    Travesset Mezquita, Marc

    2012-01-01

    Ultrafiltration (UF), due to its reliability, robustness and stable quality of the water produced , offers technical advantages over conventional pretreatments such as sand filtration coupled with coagulation/flocculation or activated carbon. In this study, the real case of a prototype designed, commissioned and operated consisting of an advanced Ultrafiltration unit (DOW™ UF) followed by a Reverse Osmosis system (Filmtec ™ Reverse Osmosis elements) is evaluated. The work prese...

  14. Airborne EM sea-ice thickness profiling over brackish Baltic sea water

    OpenAIRE

    Haas, Christian

    2004-01-01

    Helicopter-borne electromagnetic-inductive (EM) ice thickness measurements have been performed in February 2003 along the Finish Baltic Sea coast. Both, the Gulf of Finland and the Gulf of Bothnia were surveyed. Measurements have been performed with a small, two-frequency EM-Bird, a towed sensor suspended 20 m below the heli-copter and operated 15 m above the ice surface. Results show that sufficiently accurate measurements were obtained even with minimum water salinities of 3 ppt in the Bay ...

  15. Nitrification in brackish water recirculating aquaculture system integrated with activated packed bed bioreactor.

    Science.gov (United States)

    Rejish Kumar, V J; Joseph, Valsamma; Philip, Rosamma; Bright Singh, I S

    2010-01-01

    Recirculation aquaculture systems (RAS) depend on nitrifying biofilters for the maintenance of water quality, increased biosecurity and environmental sustainability. To satisfy these requirements a packed bed bioreactor (PBBR) activated with indigenous nitrifying bacterial consortia has been developed and commercialized for operation under different salinities for instant nitrification in shrimp and prawn hatchery systems. In the present study the nitrification efficiency of the bioreactor was tested in a laboratory level recirculating aquaculture system for the rearing of Penaeus monodon for a period of two months under higher feeding rates and no water exchange. Rapid setting up of nitrification was observed during the operation, as the volumetric total ammonia nitrogen removal rates (VTR) increased with total ammonia nitrogen (TAN) production in the system. The average Volumetric TAN Removal Rates (VTR) at the feeding rate of 160 g/day from 54-60th days of culture was 0.1533+/-0.0045 kg TAN/m(3)/day. The regression between VTR and TAN explained 86% variability in VTR (P<0.001). The laboratory level RAS demonstrated here showed high performance both in terms of shrimp biomass yield and nitrification and environmental quality maintenance. Fluorescent in-situ Hybridization analysis of the reactor biofilm ensured the presence of autotrophic nitrifier groups such as Nitrosococcus mobilis lineage, Nitrobacter spp and phylum Nitrospira, the constituent members present in the original consortia used for activating the reactors. This showed the stability of the consortia on long term operation. PMID:20150717

  16. Rehabilitation of Seven (7) Hydrocarbon Contaminated Sites in a Brackish Water/Lagoon Environment in South Trinidad

    Science.gov (United States)

    Mohammed, Avryl; Ramnath, Kelvin; Dyal, Shyam; Lalla, Francesca; Roopchand, Jaipersad

    2007-12-01

    The Petroleum Company of Trinidad and Tobago Limited operates in a wide diversity of tropical habitats in South Trinidad one of which is a brackish water environment known as the Godineau Swamp. Historically this field was operated by predecessor multinational companies, who at that time employed operational practices based on the absence of legal requirements, that were not environmentally considerate. Following a detailed environmental audit of the field (also known as the Oropouche Field), seven (7) contaminated sites were found, that presented a risk to the lagoon and its associated mangrove swamp ecology. Remediation of the seven (7) sites was done in two (2) phases; phase 1 being sampling and characterization of the waste inclusive of migration and phase 2 the actual on-site soil remediation. Phase 1 conducted during the period December 2004 to February 2005, indicated a total of 19,484 m3 of contaminated material with TPH being the main contaminant. The average concentration of TPH was 3.25%. Phase 2 remediation was initiated in October 2005 and involved the following three (3) aspects to achieve a TPH concentration of less than 1%: ▪ Preparation of waste remediation sites adjacent to contaminated sites and excavation and spreading onto cells ▪ Bioremediation onsite using naturally occurring bacteria and rototilling ▪ Rehabilitation and closure of the site following accepted lab results. The benefits of conducting this project in the petroleum industry are to ensure compliance to the national Sensitive Areas Rules and Draft Waste Management Rules, conformance to ISO 14001 Certification requirements and conservation of biodiversity in the mangrove swamp.

  17. First European record of the invasive brackish water clam Rangia cuneata (G.B. Sowerby I, 1831) (Mollusca: Bivalvia)

    OpenAIRE

    Verween, A; Kerckhof, F; Vincx, M.; Degraer, S.

    2006-01-01

    A population of Rangia cuneata (G.B. Sowerby I, 1831), an estuarine bivalve, has been recorded in the harbour of Antwerp, Belgium. This species is new to the European brackish water fauna. After initially finding only a few small individuals in August 2005, R. cuneata was encountered frequently in the pipes of the cooling water system of an industrial plant from February 2006 onwards. Before this present record, R. cuneata was only known from the Gulf of Mexico and the Atlantic coast of North...

  18. Ecosystem level methane fluxes from tidal freshwater and brackish marshes of the Mississippi River Delta: Implications for coastal wetland carbon projects

    Science.gov (United States)

    Holm, Guerry O.; Perez, Brian C.; McWhorter, David E.; Krauss, Ken W.; Johnson, Darren J.; Raynie, Richard C.; Killebrew, Charles J.

    2016-01-01

    Sulfate from seawater inhibits methane production in tidal wetlands, and by extension, salinity has been used as a general predictor of methane emissions. With the need to reduce methane flux uncertainties from tidal wetlands, eddy covariance (EC) techniques provide an integrated methane budget. The goals of this study were to: 1) establish methane emissions from natural, freshwater and brackish wetlands in Louisiana based on EC; and 2) determine if EC estimates conform to a methane-salinity relationship derived from temperate tidal wetlands with chamber sampling. Annual estimates of methane emissions from this study were 62.3 g CH4/m2/yr and 13.8 g CH4/m2/yr for the freshwater and brackish (8–10 psu) sites, respectively. If it is assumed that long-term, annual soil carbon sequestration rates of natural marshes are ~200 g C/m2/yr (7.3 tCO2e/ha/yr), healthy brackish marshes could be expected to act as a net radiative sink, equivalent to less than one-half the soil carbon accumulation rate after subtracting methane emissions (4.1 tCO2e/ha/yr). Carbon sequestration rates would need case-by-case assessment, but the EC methane emissions estimates in this study conformed well to an existing salinity-methane model that should serve as a basis for establishing emission factors for wetland carbon offset projects.

  19. Branchial Na+:K+:2Cl- cotransporter 1 and Na+/K+-ATPase α-subunit in a brackish water-type ionocyte of the euryhaline freshwater white-rimmed stingray, Himantura signifer

    Directory of Open Access Journals (Sweden)

    Yuen K Ip

    2013-12-01

    Full Text Available Himantura signifer is a freshwater stingray which inhabits rivers in Southeast Asia. It can survive in brackish water but not seawater. In brackish water, it becomes partially ureosmotic, but how it maintains its plasma hypoionic to the external medium is enigmatic because of the lack of a rectal gland. Here, we report for the first time the expression of Na+:K+:2Cl− cotransporter 1 (nkcc1 in the gills of freshwater H. signifer, and its moderate up-regulation (~2-fold in response to brackish water (salinity 20 acclimation. The absence of the Ste20-related proline-alanine-rich kinase and oxidation stress response kinase 1 interaction site from the N-terminus of H. signifer Nkcc1 suggested that it might not be effectively activated by stress kinases in response to salinity changes as in more euryhaline teleosts. The increased activity of Nkcc1 during salt excretion in brackish water would lead to an influx of Na+ into ionocytes, and the maintenance of intracellular Na+ homeostasis would need the cooperation of Na+/K+-ATPase (Nka. We demonstrated for the first time the expression of nkaα1, nkaα2 and nkaα3 in the gills of H. signifer, and the up-regulation of the mRNA expression of nkaα3 and the overall protein abundance of Nkaα in response to acclimation to brackish water. Immunofluorescence microscopy revealed the presence of a sub-type of ionocyte, co-expressing Nkcc1 and Nkaα, near the base of the secondary lamellae in the gills of H. signifer acclimated to brackish water, but this type of ionocyte was absent from the gills of fish kept in fresh water. Hence, there could be a change in the function of the gills of H. signifer from salt absorption to salt excretion during brackish water acclimation in the absence of a functioning rectal gland.

  20. Branchial Na(+):K(+):2Cl(-) cotransporter 1 and Na(+)/K(+)-ATPase α-subunit in a brackish water-type ionocyte of the euryhaline freshwater white-rimmed stingray, Himantura signifer.

    Science.gov (United States)

    Ip, Yuen K; Hiong, Kum C; Wong, Samuel Z H; Ching, Biyun; Chen, Xiu L; Soh, Melody M L; Chng, You R; Ong, Jasmine L Y; Wilson, Jonathan M; Chew, Shit F

    2013-01-01

    Himantura signifer is a freshwater stingray which inhabits rivers in Southeast Asia. It can survive in brackish water but not seawater. In brackish water, it becomes partially ureosmotic, but how it maintains its plasma hypoionic to the external medium is enigmatic because of the lack of a rectal gland. Here, we report for the first time the expression of Na(+):K(+):2Cl(-) cotransporter 1 (nkcc1) in the gills of freshwaterH. signifer, and its moderate up-regulation (~2-fold) in response to brackish water (salinity 20) acclimation. The absence of the Ste20-related proline-alanine-rich kinase and oxidation stress response kinase 1 interaction site from the N-terminus of H. signifer Nkcc1 suggested that it might not be effectively activated by stress kinases in response to salinity changes as in more euryhaline teleosts. The increased activity of Nkcc1 during salt excretion in brackish water would lead to an influx of Na(+) into ionocytes, and the maintenance of intracellular Na(+) homeostasis would need the cooperation of Na(+)/K(+)-ATPase (Nka). We demonstrated for the first time the expression of nkaα1, nkaα2 and nkaα3 in the gills of H. signifer, and the up-regulation of the mRNA expression of nkaα3 and the overall protein abundance of Nkaα in response to acclimation to brackish water. Immunofluorescence microscopy revealed the presence of a sub-type of ionocyte, co-expressing Nkcc1 and Nkaα, near the base of the secondary lamellae in the gills of H. signifer acclimated to brackish water, but this type of ionocyte was absent from the gills of fish kept in fresh water. Hence, there could be a change in the function of the gills of H. signifer from salt absorption to salt excretion during brackish water acclimation in the absence of a functioning rectal gland. PMID:24339817

  1. Excluding the di-unsaturated alkenone in the UK37 index strengthens temperature correlation for the common lacustrine and brackish-water haptophytes

    Science.gov (United States)

    Zheng, Yinsui; Huang, Yongsong; Andersen, Robert A.; Amaral-Zettler, Linda A.

    2016-02-01

    Alkenone unsaturation indices, represented by either UK37 or UK‧37, are important tools for paleoclimate studies. The UK37 index is a reflection of the average number of double bonds from di-, tri-, tetra-unsaturated alkenones, but UK‧37 excludes the C37:4 in the calculation. Extensive studies indicate UK‧37 provides better regressions against in situ Sea Surface Temperatures (SST) than UK37 and is the most widely used SST proxy. However, recent studies have shown that including C37:4 alkenones for lacustrine or brackish water haptophytes such as Ruttnera (Chrysotila) lamellosa and Isochrysis galbana improves temperature correlations although there are still significant deviations at the extreme high and low temperatures. In this study, we use new culture-based calibration experiments alongside published culture data and in situ water column or surface sediment data, to demonstrate that a further improved temperature calibration for alkenones is, in fact, achieved when the di-unsaturated alkenone is excluded from the computation of the unsaturation index. We propose new indices, termed UK″ [UK″37 = C37:3/(C37:3 + C37:4) or UK″38 = C38:3/(C38:3 + C38:4)], for lacustrine, brackish and estuarine waters. Our observation suggests that di-unsaturated alkenones play a less important role than tri- and tetra-unsaturated alkenones in regulating cell functions to temperature variations in lacustrine and brackish waters. We suggest using UK″ indices for paleotemperature reconstructions in the lacustrine and estuarine settings.

  2. Agro-ecosystems water requirements for crops

    International Nuclear Information System (INIS)

    Crop water requirements were mainly influenced by meteorological factors like temperature, wind, humidity and radiational balance. In agro-ecosystems, the main water loss was through evapotranspiration. In the present article the water requirements for rice and wheat crops in India are presented. It was observed that there were strong gradients for water requirements in the north-western and south-western parts of the country

  3. The soil-water flow system beneath a cotton field in arid north-west China, serviced by mulched drip irrigation using brackish water

    Science.gov (United States)

    Li, Xianwen; Jin, Menggui; Huang, Jinou; Yuan, Jingjing

    2015-02-01

    A field experiment was carried out in southern Xinjiang, China, to reveal soil-water flow pattern beneath a combined plastic-mulch (film) and drip-irrigation system using brackish water. The soil-water flow system (SWFS) was characterized from soil surface to the water table based on observed spatio-temporal distribution of total soil-water potential, water content and electric conductivity. Root suction provided a strong inner sink. The results indicated that SWFS determined the soil salinity and moisture distribution. Drip-irrigation events could leach excess salts from the root zone and provide soil conditions with a tolerable salinity level that supports the growth of cotton. High-salinity strips were formed along the wetting front and at the bare soil surface. Hydrogeology conditions, irrigation regime, climate, plant growth and use of mulch would affect potential sources and sinks, boundary conditions and the size of the SWFS. At depth 0-60 cm, the soil salinity at the end of the irrigation season was 1.9 times that at the beginning. Beneath the mulch cover, the soil-water content in the `wide rows' zone (55 cm between the two rows with no drip line) was higher than that in the `narrow rows' zone (15 cm between the two rows with a drip line) due to the strong root-water uptake. The downward water flow below the divergent curved surface of zero flux before irrigation, and the water-table fluctuation with irrigation events, indicated that excessive irrigation occurred.

  4. Tracing groundwater salinization processes in coastal aquifers: a hydrogeochemical and isotopic approach in Na-Cl brackish waters of north-western Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    G. Mongelli

    2013-01-01

    Full Text Available In the Mediterranean area the demand of good quality water is often threatened by salinization, especially in coastal areas. The salinization is the result of concomitant processes due to both marine water intrusion and rock-water interaction, which in some cases are hardly distinguishable. In northwestern Sardinia, in the Nurra area, salinization due to marine water intrusion has been recently evidenced as consequence of bore hole exploitation. However, the geology of the Nurra records a long history from Paleozoic to Quaternary, resulting in relative structural complexity and in a wide variety of lithologies, including Triassic evaporites. To elucidate the origin of the saline component in the Nurra aquifer, may furnish a useful and more general model for the salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activities and recent climatic changes, the Nurra has become vulnerable to desertification and, similarly to other Mediterranean islands, surface-water resources can periodically suffer from drastic shortage.

    With this in mind we report new data, regarding brackish waters of Na-Cl type of the Nurra, including major ions and selected trace elements (B, Br, I and Sr and isotopic data, including δ18O, δD in water, and δ34S and δ18O in dissolved sulphate. To better depict the origin of the salinity we also analyzed a set of Nurra Triassic evaporites for mineralogical and isotopic composition. The brackish waters have Cl contents up to 2025 mg L−1 and the ratios between dissolved ions and chlorine, with the exception of the Br/Cl ratio, are not those expected on the basis of a simple mixing between rain water and seawater.

    The δ18O and δD data indicate that most of the waters are within the Regional Meteoric Water Line and the Global Meteoric Water

  5. Water-in-crude oil emulsion formation and stability for crude oils in fresh, brackish and salt water. Volume 2

    International Nuclear Information System (INIS)

    Crude oil spilled at sea is subjected to weathering. The main physical process of weathering are water-in-oil emulsification, evaporation, dispersion, dissolution and oil-sediment interaction. For medium to heavy oils, evaporation and dispersion are less important, and the onset of water-in-oil emulsion formation becomes the most important weathering process for spill response. Emulsification involves the incorporation of water droplets into the continuous oil phase. As such, it has a pronounced effect on the physical properties and characteristics of an oil, affecting its behaviour and ultimate fate. Emulsions formed from heavy oils contain higher proportions of asphaltenes and resins and may persist for long periods or indefinitely. This paper provided a direct comparison of stability for emulsions formed from crude oils with both fresh and salt water containing 20 or 33 per cent sodium chloride. Emulsions from 5 crude oil were compared. It was noted that oils that form emulsions in salt water will also form in fresh water, in the same stability class. Stable fresh water emulsions have lower values of the viscoelastic parameters, indicating decreased stability compared to stable salt water emulsions. The difference between stable and meso-stable emulsions formed from water of 20 and 33 per cent salinity was small, but meso-stable emulsions from fresh water could achieve higher levels of water content and have higher initial values of the viscoelastic parameters than with salt water. The nature of stabilizer deficiency determines the form of degraded meso-stable emulsions. It was concluded that since entrained water states are created by a different chemical-physical process or mixing mode, there is no difference in emulsions product due to the ionic content of salt water. However, wax content may be a contributor to the stabilization for entrained water states. 14 refs., 5 tabs., 6 figs

  6. The genus Perissocytheridea Stephenson, 1938 (Crustacea: Ostracoda) and evidence of brackish water facies along the Oligo-Miocene, Pirabas Formation, eastern Amazonia, Brazil

    Science.gov (United States)

    Evangelista Nogueira, Anna Andressa; Ramos, Maria Inês Feijó

    2016-01-01

    Perissocytheridea Stephenson is characteristic of brackish water facies. In 57 samples from the Upper Oligocene to Lower Miocene, from five localities, Pirabas Formation, Pará State, Brazil eleven species have been identified. Among these species, four are new reports: Perissocytheridea punctoreticulata n. sp., Perissocytheridea largulateralis n. sp., Perissocytheridea colini n. sp. and Perissocytheridea pirabensis n. sp.; five species in open nomenclature: Perissocytheridea sp. 1, P. sp. 2, P. sp. 3, P. sp. 4, and P. sp. 5 and two species left in "aff." abbreviation: Perissocytheridea aff. Perissocytheridea pumila and Perissocytheridea aff. Perissocytheridea brachyforma subsp. excavata. The distributional pattern of the Perissocytheridea combined with the occurrence of foraminifera Elphidium and Ammonia in the studied sections supports the presence of the brackish water facies to the respective layers. Their quantitative variation through the studied sections indicate more than one phase of salinity reduction (about >5 and genus has a wide paleobiogeographical occurrence and stratigraphic distribution ranging from the Cretaceous to Recent, and already been recorded in the northern of South America, especially in the Neogene of Solimões Basin, but this is the first report of a neotropical genus to the Oligo-Miocene deposits of Pirabas Formation, northern Brazilian Coast, Pará State.

  7. Tracing groundwater salinization processes in coastal aquifers: a hydrogeochemical and isotopic approach in the Na-Cl brackish waters of northwestern Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    G. Mongelli

    2013-07-01

    Full Text Available Throughout the Mediterranean, salinization threatens water quality, especially in coastal areas. This salinization is the result of concomitant processes related to both seawater intrusion and water–rock interaction, which in some cases are virtually indistinguishable. In the Nurra region of northwestern Sardinia, recent salinization related to marine water intrusion has been caused by aquifer exploitation. However, the geology of this region records a long history from the Palaeozoic to the Quaternary, and is structurally complex and comprises a wide variety of lithologies, including Triassic evaporites. Determining the origin of the saline component of the Jurassic and Triassic aquifers in the Nurra region may provide a useful and more general model for salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activity and recent climatic change, the Nurra has become vulnerable to desertification and, in common with other Mediterranean islands, surface water resources periodically suffer from severe shortages. With this in mind, we report new data regarding brackish and surface waters (outcrop and lake samples of the Na-Cl type from the Nurra region, including major ions and selected trace elements (B, Br, I, and Sr, in addition to isotopic data including δ18O, δD in water, and δ34S and δ18O in dissolved SO4. To identify the origin of the salinity more precisely, we also analysed the mineralogical and isotopic composition of Triassic evaporites. The brackish waters have Cl contents of up to 2025 mg L−1 , and the ratios between dissolved ions and Cl, with the exception of the Br / Cl ratio, are not those expected on the basis of simple mixing between rainwater and seawater. The δ18O and δD data indicate that most of the waters fall between the regional meteoric water line and the global meteoric water line, supporting the

  8. Observation Methods on Water Ecosystems

    International Nuclear Information System (INIS)

    In present work current situation of hydrometric network on the rivers of Georgia and division of observational stations, categorized according to economico-ecological principles, which study water hydrometric and physico-chemical characteristics, are considered. The necessity of searching of new methodology of taking hydrometric measurements and developing optimal plan of allocation of the stations, based on the modern standards, is proved. (author)

  9. Branchial Na+:K+:2Cl− cotransporter 1 and Na+/K+-ATPase α-subunit in a brackish water-type ionocyte of the euryhaline freshwater white-rimmed stingray, Himantura signifer

    OpenAIRE

    YuenKIp; JonathanMWilson; ShitFChew

    2013-01-01

    Himantura signifer is a freshwater stingray which inhabits rivers in Southeast Asia. It can survive in brackish water but not seawater. In brackish water, it becomes partially ureosmotic, but how it maintains its plasma hypoionic to the external medium is enigmatic because of the lack of a rectal gland. Here, we report for the first time the expression of Na+:K+:2Cl− cotransporter 1 (nkcc1) in the gills of freshwater H. signifer, and its moderate up-regulation (~2-fold) in response to brackis...

  10. Characterizing the Occurrence and Transport of Brackish Groundwater in Southwest Bangladesh

    Science.gov (United States)

    worland, S.; Hornberger, G. M.

    2013-12-01

    Bangladesh is host to the largest and the most active delta system in the world. The morphology of the southern part of the country is characterized by low lying deltaic plains partitioned by the distributary networks of the Ganges, Brahmaputra and Meghna river systems. Much of the tidal mangrove forest ecosystem of the lower delta has been converted into poldered islands that sustain shrimp farming and rice production. The polder inhabitants depend on shallow groundwater as a primary source for drinking water and sanitation. Understanding the origin and hydrologic controls on the distribution of the brackish water and freshwater on the polder is a necessary step to ensuring a sustainable and potable freshwater source for drinking and irrigation. Preliminary sampling from shallow tube wells on Polder 32 in southwest Bangladesh suggests sporadic lateral apportioning of fresh water in the primarily brackish aquifer. This research characterizes the occurrence, transport and fate of the brackish groundwater through a combination of 3H and 14C dating, geochemical signatures, subsurface mapping using inversions from electromagnetic induction, and a 1D finite difference model and a 2D finite element model. The geochemical analysis and radiometric dating suggest that the salt water originates from paleo-brackish estuarine water deposited ~5000 years ago along with the sediments that compose the shallow aquifer. Inversions of electromagnetic survey data show potential freshwater recharge areas where the clay cap pinches out. The finite difference model demonstrates that recharge from the distributary channels is unlikely due to the low transmissivity of the clay channel beds. The finite element model gives reasonable estimates of the flushing rates of the connate brackish water beneath the polder. Inversion of electromagnetic data from a two hundred meter transect taken on Polder 32 Head gradient and groundwater flow vectors for fixed head boundary conditions across Polder

  11. Morphological Analysis of Anopheles vagus Donitz, 1902 (Diptera : Culicidae in fresh water and brackish water habitats = Variasi Morfologi Anopheles vagus Donitz, 1902 (Diptera : Culicidae dari Habitat Air Tawar dan Air Payau

    Directory of Open Access Journals (Sweden)

    Siti Alfiah

    2014-10-01

    Full Text Available ENGLISHAbstractAnopheles subpictus had habitat variation and showed genetic difference. So, the variation of habitat of An. vagus may support the hypothesa that An. vagus had genetic and morphology variation, same as An. subpictus.The aimed of this research was analyze morphology and chaetotaxy difference between An. vagus in fresh water and brackish water. The subject of the study was An. vagus collected from Kesongo Village, Tuntang Subdistrict, Semarang (fresh water and Jatimalang Village, Purwodadi Subdistrict, Purworejo (brackish water. Anopheles vagus were collected and individually reared. One sample in every batch was used to make larvae skin, pupae skin and adult specimen of An. vagus. The result showed that there were intra and inter population variation between An. vagus in fresh water and brackish water. The variations were on the size and number of hair branches and filaments. The conclution of this research were the morphology and chaetotaxy of female An. vagus in fresh water and brackish water showed no different. Intra and interpopulation An. vagus in fresh water and brackish water were caused by the difference of geography location (allopatric speciation.INDONESIANVariasi habitat terjadi pada An. subpictus, variasi habitat yang berbeda menunjukkan variasi genetik yang berbeda. Oleh karena itu variasi habitat An. vagus diduga akan bepengaruh terhadap variasi genetik dan morfologi. Tujuan penelitian adalah menganalisis perbedaan morfologi dan kaetotaksi Anopheles vagus habitat air tawar dan air payau. Subyek penelitian adalah An. vagus habitat air tawar di Desa Kesongo, Kecamatan Tuntang, Kabupaten Semarang dan An. vagus habitat air payau di Desa Jatimalang, Kecamatan Purwodadi, Kabupaten Purworejo. Anopheles vagus yang diperoleh, di rearing secara individual. Tiap indukan diambil satu sampel keturunannya dan dibuat preparat skin larva, skin pupa dan nyamuk dewasa betina. Hasil menunjukkan bahwa Anopheles vagus betina habitat air

  12. Performance analysis of functioned brackish water for lighting-induced evaporation type solar desalination system%聚光蒸发式太阳能苦咸水淡化系统水体光热性能分析

    Institute of Scientific and Technical Information of China (English)

    侯静; 杨桔材; 郑宏飞; 常泽辉; 于苗苗; 马元波

    2015-01-01

    Fresh water demands are increasing day by day because of industrialization, motorization and increased life standards of mankind. Fresh water reserves available naturally are not capable of meeting the fresh water demands because of their less availability. Desalination is not only necessary to overcome the issue of fresh water shortage in the future, but also important for the oil-gas-coal industry which generates substantial amount of waste water during the production of oil, natural gas and coal. Compared to conventional water treatment technology, solar brackish water desalination has advantages of cleanness and sustainability. However, high cost and small scale have become the biggest obstacles for solar brackish water desalination technology, which is caused by the high-cost solar collector, the structural mismatch of the optimum working ranges between the solar collector system and the brackish water desalination system, and the large heat transfer resistance between them. To solve this problem, this paper has proposed a strong light-concentrating direct evaporationtype solar brackish water desalination system. It utilizes the concentrating solar energy which is directly shined into the functioned brackish water to produce steam for repeated usage. It should be noted that solar collector is introduced to collect much more solar energy and produce steam efficiently to improve the performance of solar desalination units. The light-induced evaporation type solardesalination units show small heat transfer resistance, heat capacity small and small cavity evaporation, which can largely reduce the cost and be beneficial for the economic performance of the solar desalination system. Generally, the functioned brackish water is in the boiling state during the system working. The transmissivity of the functioned brackish water in the boiling state was measured in optical darkroom. At the same time, thermal energy utilization efficiency of functioned brackish water was

  13. Assessment of the impacts of climate change and brackish irrigation water on rice productivity and evaluation of adaptation measures in Ca Mau province, Vietnam

    Science.gov (United States)

    Deb, Proloy; Tran, Duong Anh; Udmale, Parmeshwar D.

    2016-08-01

    This study investigates the temporal impacts of climate change on rice yield for summer-autumn (SA) and autumn-winter (AW) cropping pattern along with implication of brackish irrigation water for the SA season. Furthermore, evaluation of different agro-adaptations to overcome negative impacts of climate change was also done for Ca Mau province of Vietnam. Climatic variables were derived from six general circulation models which were further bias corrected at Ca Mau city station for three future time periods (2025s, 2055s, and 2085s). Calibrated AquaCrop 4.0 was used to project the future rice yield under climate change and different salinity levels in irrigation water. Simulation shows a decline in rice yield ranging from 1.60 to 23.69 % and 8.06 to 20.15 % by 2085s relative to baseline climate for A2 and B2 scenarios respectively in the case of the SA cropping season. However, an increase in rice yield ranging from 3.29 to 12.35 % and 6.64 to 17.23 % is observed for the corresponding time period and scenarios. Further simulations for the SA cropping season under climate change and increasing salinity in irrigation water suggest an insignificant increase in yield relative to the yield obtained without irrigation. Moreover, proper management practices, namely forward and early shifts in transplanting dates along with increasing fertilizer application rates, are observed to be beneficial to enhance the rice yield under climate change.

  14. Multi-isotope (C - O - S - H - B - Mg - Ca - Ba) and trace element variations along a vertical pore water profile across a brackish-fresh water transition, Baltic Sea

    Science.gov (United States)

    Böttcher, Michael E.; Lapham, Laura; Gussone, Nikolaus; Struck, Ulrich; Buhl, Dieter; Immenhauser, Adrian; Moeller, Kirsten; Pretet, Chloé; Nägler, Thomas F.; Dellwig, Olaf; Schnetger, Bernhard; Huckriede, Hermann; Halas, Stan; Samankassou, Elias

    2013-04-01

    The Holocene Baltic Sea has been switched several times between fresh water and brackish water modes. Modern linear sedimentation rates, based on 210-Pb, 137-Cs, and Hg dating of surface sediments, are between 0.1 and 0.2 mm per year. The change in paleo-environmental conditions caused downcore gradients in the concentrations of dissolved species from modern brackish waters towards fresh paleo-pore waters, interrupted by the brief brackish Yoldia stage. These strong physico-chemical changes had consequences for e.g., microbial activity and further physical and chemical water-solid interactions associated with multiple stable isotope fractionation processes, and, in turn, have strong implications for isotope and trace element partitioning upon early diagenetic mineral (trans)formations. In this communication, we present the results from the first integrated multi-isotope and trace element investigation conducted in this type of salinity-gradient system. It is found that concentrations of conservative elements (e.g., Na, Cl) decrease with depth due to diffusion of ions from brackish waters into underlying fresh waters. This is associated with pronounced depletions in H-2 and O-18 of pore water with depth. Covariations of both isotope systems are close to the meteoric water line as defined by modern Baltic Sea surface waters. A downward increase and decrease of Ca and Mg concentrations, respectively, is associated with decreasing Ca-44 and Mg-26 isotope values. B-11 isotope values decrease in the limnic part of the sediments, too. On the other hand, an increase in Ba concentrations with depth is associated with an increase in Ba-137/134 isotope values. Microbial sulfate reduction and organic matter oxidation lead to an increase in DIC, but a decrease in sulfate concentrations and in C-13 contents of DIC with depth. Suess (1981) was probably the first to propose, that desorption of Ca and Ba from glacial sediments due to downward diffusing ions may be responsible for a

  15. Ecosystem modelling in exposure assessments of radioactive waste in coastal waters

    International Nuclear Information System (INIS)

    Full text: Environmental transport and fate of radioactive isotopes in a brackish water bay of the Baltic Sea, was investigated in this study by using an ecosystem modelling approach. The purpose was to develop a method to assess the exposures to humans and to other organisms in the environment in case of discharges from an underground repository for radioactive operational waste. The radionuclides considered are long-lived, have high environmental mobility and bioavailability and pose a potential threat to living organisms for an extensive period of time. In the model, the radionuclide transport is tightly associated with a site-specific carbon flow model based on general ecological principles, that identifies and quantifies the main flows and storages of energy in the ecosystem, both in the physical environment and in the food web. In the model, the radionuclides are introduced into the food web via photosynthesising organisms. C-14 is assumed to assimilate in proportion to its presence compared to other carbon isotopes in the water while transfer factors are used in the initial uptake of other radionuclides. The trophic transfer in the food web are presumed to follow the flow of energy between the ecosystem compartments and to be proportional to the rate of predominant ecological processes, such as respiration, consumption and excretion. Modelling results demonstrates that this approach provides a method that allows evaluation of several scenarios. For instance, it is possible to compare the influence of different abiotic and biotic processes, such as accumulation pattern, excretion rates and water exchange, on radionuclide accumulation and transfer between the compartments of the ecosystem. This technique has potential to be a powerful tool in safety assessments of radioactive waste. (author)

  16. Ontogenetic changes in location and morphology of chloride cells during early life stages of the Nile tilapia Oreochromis niloticus adapted to fresh and brackish water.

    Science.gov (United States)

    Fridman, S; Bron, J E; Rana, K J

    2011-09-01

    Ontogenetic changes in the location, size, density and morphology of chloride cells in the Nile tilapia Oreochromis niloticus adapted to fresh and brackish water are described using Na(+) /K(+) -ATPase immunohistochemistry, light microscopy (LM), scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM). The pattern of chloride cell distribution changed during development under both treatments, with chloride cell density decreasing significantly from hatch to 7 days post-hatch, but appearing on the inner opercular area at 3 days post-hatch and increasing significantly thereafter (P larvae. In both treatments, chloride cells located on the outer operculum and tail showed a marked increase in size with age, but cells located on the abdominal epithelium of the yolk sac and the inner operculum showed a significant decrease in size (P larvae from 1 day post-hatch onwards were always significantly larger (P larvae. SEM revealed structural differences in chloride cell apical morphology according to environmental conditions. There appears to be clearly defined temporal staging of the appearance of adaptive mechanisms that confer an ability to cope with varying environmental conditions during early development. PMID:21884103

  17. Adaptive alterations on gill Na(+), K(+)-ATPase activity and mitochondrion-rich cells of juvenile Acipenser sinensis acclimated to brackish water.

    Science.gov (United States)

    Zhao, Feng; Wu, Beibei; Yang, Gang; Zhang, Tao; Zhuang, Ping

    2016-04-01

    Understanding the physiological changes and osmoregulatory strategy is critical for anadromous species to adapt to large changes between freshwater and marine environments. In this study, juvenile Chinese sturgeon (Acipenser sinensis) were acclimated for 2 months to freshwater (FW, c. 0 ‰) and brackish water (BW, 15 ‰). Blood was assessed for changes in osmolality and ions. Gill tissue was assayed for Na(+), K(+)-ATPase (NKA) activity and immunohistochemical analysis on mitochondria-rich cells (MRCs). Serum osmolality and ions concentrations (Na(+), Cl(-) and K(+)) examined, except K(+), increased significantly in those specimens adapted to BW. However, the variations were within the range of effective hyperosmotic adaptation. The specific activity of gill NKA of juveniles adapted to BW was significantly higher (c. 1.6 times) than that of fish adapted to FW. MRCs were mainly presented in the interlamellar region of the filament and at the base of the lamella in either FW- or BW-acclimated individuals. In BW, the number and size of MRCs on filaments greatly increased. However, there was no significant difference in the number and size of the MRCs at the lamella region. Results show that juvenile Chinese sturgeon keep osmotic homeostasis in hyperosmotic environments by increasing gill NKA activity and MRCs' size and number, which is similar to other sturgeons and euryhaline teleosts. PMID:26614501

  18. Preliminary design of seawater and brackish water reverse osmosis desalination systems driven by low-temperature solar organic Rankine cycles (ORC)

    International Nuclear Information System (INIS)

    In this paper, the coupling between the low-temperature solar organic Rankine cycle (ORC) and seawater and brackish water reverse osmosis desalination units has been carried out. Four substances have been considered as working fluids of the solar cycle (butane, isopentane, R245fa and R245ca). With these four fluids the volumetric flow of fresh water produced per unit of aperture area of stationary solar collector has been calculated. The former has been made with the optimized direct vapour generation (DVG) configuration and heat transfer fluid (HTF) configuration of the solar ORC. In the first one (DVG), working fluid of the ORC is directly heated inside the absorber of the solar collector. In the second one (HTF), a fluid different than the working fluid of the ORC (water in this paper) is heated without phase change inside the absorber of the solar collector. Once this fluid has been heated it is carried towards a heat exchanger where it is cooled. Thermal energy delivered in this cooling process is transferred to the working fluid of the ORC. Influence of condensation temperature of the ORC and regeneration's process effectiveness over productivity of the system has also been analysed. Finally, parameters of several preliminary designs of the low-temperature solar thermal driven RO desalination are supplied. R245fa is chosen as working fluid of the ORC in these preliminary designs. The information of the proposed preliminary designs can also be used, i.e., for the assessment of the use of thermal energy rejected by the solar cycle. Overall analysis of the efficiency of the solar thermal driven RO desalination technology is given with the results presented in this paper and the results obtained with the medium temperature solar thermal RO desalination system presented by the authors in previous papers. This work has been carried out within the framework of the OSMOSOL and POWERSOL projects.

  19. Estratégias de uso de água salobra na produção de alface em hidroponia NFT Strategies for use of brackish water in NFT hydroponic lettuce production

    Directory of Open Access Journals (Sweden)

    Márcio S. Alves

    2011-05-01

    Full Text Available Plantas de alface crespa 'Verônica' foram cultivadas em condições hidropônicas, objetivando avaliar três diferentes estratégias de emprego de águas salobras: 1 águas salobras para reposição das perdas por evapotranspiração (ETc e água doce para o preparo da solução nutritiva (SN; 2 águas salobras para o preparo da SN e água doce para reposição da ETc; 3 águas salobras para o preparo da SN e reposição da ETc. Os níveis de salinidade da água foram obtidos pela adição de NaCl à água doce (0,27 dS m-1: 1,45; 2,51; 3,6; 5,41 e 7,5 dS m-1. O experimento foi conduzido em quatro blocos aleatorizados, com quatro repetições por tratamento. Uma estrutura de pesquisa foi construída com 72 parcelas que simulam a técnica do fluxo laminar de nutrientes (NFT. O uso de água salobra apenas para repor a ETc não produziu efeito sobre a produção da alface. Por outro lado, o uso de águas salobras para o preparo da SN e água doce para reposição da ETc, reduziu o rendimento da alface (massa de matéria fresca da parte aérea em 4,99% por (dS m-1. O rendimento foi reduzido em 7% por dS m-1 quando águas salobras foram usadas tanto para o preparo da SN quanto para reposição da ETc. Apesar da redução linear da produção da alface com o aumento da salinidade da água, sintomas depreciativos para a qualidade da alface hidropônica não foram registrados.Plants of crisphead lettuce cv. 'Verônica' were grown under hydroponic conditions aiming to evaluate three different strategies of brackish waters utilization: 1 brackish waters to replace the evapotranspiration loss (ETc and fresh water to prepare nutrient solution (NS; 2 brackish waters to prepare NS and fresh water to replace the ETc; 3 brackish waters to prepare NS and replace ETc. The levels of water salinity were obtained by addition of NaCl to fresh water (0.27 dS m-1: 1.45; 2.51; 3.6; 5.41 and 7.5 dS m-1. The experiment was conducted in randomized blocks with four

  20. Early diagenetic high-magnesium calcite and dolomite indicate that coal balls formed in marine or brackish water: Stratigraphic and paleoclimatic implications

    Science.gov (United States)

    Raymond, Anne

    2016-04-01

    Coal balls are carbonate and pyrite permineralizations of peat that contain three-dimensional plant fossils preserved at the cellular level. Coal balls, which occur in Pennsylvanian and earliest Permian equatorial coals, provide a detailed record of terrestrial ecology and tropical climate during the Late Paleozoic Ice Age; yet their depositional environment remains controversial. The exquisite preservation of some coal-ball fossils, e.g. pollen with pollen tubes and leaves with mesophyll, indicates rapid formation. The presence of abundant, cement-filled, void spaces within and between the plant debris in most coal balls indicates that they formed in uncompacted peat, near the surface of the mire. Botanical, taphonomic and isotopic evidence point to a freshwater origin for coal balls. The nearest living relatives of coal ball plants (modern lycopsids, sphenopsids, marratialean ferns and conifers) grow in fresh water. Coal-ball peat contains a high percentage of aerial debris, similar to modern freshwater peat. The stable oxygen isotopes of coal-ball carbonate (δ18O = 16 to 3 per mil) suggest a freshwater origin. However, the widespread occurrence of marine invertebrates and early diagenetic framboidal pyrite in coal balls suggests that many formed in close proximity to marine water. Indeed, carbonate petrology points to a marine or brackish water origin for the first-formed carbonate cements in coal balls. Petrographic and geochemical (microprobe) analysis of coal-ball carbonates in Pennsylvanian coals from the midcontinent of North America (Western Interior Basin, West Pangaea) and the Ruhr and Donets Basins (East Pangaea) indicate that the first formed carbonate is either radaxial, nonstochiometric dolomite or high magnesium calcite (9 - 17 mol % MgCO3, indicating precipitation in marine or brackish water. Although both primary dolomite and high magnesium calcite can form in lacustrine settings, the lakes in which these minerals form occur in carbonate terranes

  1. 微咸水灌溉对斥水土壤水盐运移的影响%Effect of brackish water irrigation on water and salt movement in repellent soils

    Institute of Scientific and Technical Information of China (English)

    刘春成; 李毅; 郭丽俊; 关冰艺; 廖轶群; 王娟

    2011-01-01

    The existence of soil water-repellency had impacts on crop yields. In order to study soil water and salt movements of water-repellent soils irrigated by brackish water, laboratory soil column infiltration experiments were conducted. Impacts of different mineralization degrees and different water-repellency degrees on the movements of soil water and soil salt were compared for two soil textures. The variations of soil water-repellency during infiltration were also discussed. The results showed that infiltration ability of non-water-repellent soils increased with the increase of mineralization degrees. Both the infiltration rates of wettable and repellent soils could be simply fitted by Kostiakov equation. For the water repellent soils, the infiltration ability was largest at mineral degree of lg/L, but decreased with the increase of mineralization degree when mineralization degree were larger than lg/L. There was good linear relationship between cumulative infiltration and the wetting front distance when irrigated by brackish water. Soil water content and soil salt content at the same depth of the water repellent soil profiles were smaller than those of the wettable soil profiles. To some extent, soil water repellency was caused after irrigated by brackish water. This work indicated that brackish water irrigation had some impacts on distributions of soil water and soil salt as well as water-repellency of salinized soil.%土壤斥水性影响着作物的产量,为了研究微成水灌溉对斥水土壤水盐运移的影响,进行了室内土柱微咸水入渗试验.对比了不同矿化度和斥水程度对两种土质水盐运移的影响,探讨了微咸水入渗后土壤斥水性的变化特征.结果表明,不斥水土壤的入渗能力随矿化度的增加而增加.亲水和斥水土壤的入渗率均可采用Kostiakov公式简单模拟.斥水土壤入渗能力在矿化度为1g/L时达到最大,超过1 g/L后则随矿化度的增大而减小.微咸水入渗的

  2. Aquaculture, Salt and Brackish Water, Rhode Island Aquaculture Locations; Point Locations for Aquaculture operations in Narragansett Bay and the coastal ponds of Rhode Island., Published in 2005, 1:7200 (1in=600ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aquaculture, Salt and Brackish Water dataset, published at 1:7200 (1in=600ft) scale, was produced all or in part from Hardcopy Maps information as of 2005. It...

  3. Aquaculture, Salt and Brackish Water, The G-WIS data are created to support environmental assessments associated with oil and gas exploration, production, and transportation activities in the Gulf of Mexico., Published in 2001, 1:24000 (1in=2000ft) scale, Louisiana State University.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aquaculture, Salt and Brackish Water dataset, published at 1:24000 (1in=2000ft) scale as of 2001. It is described as 'The G-WIS data are created to support...

  4. Water pollution by intensive brackish shrimp farming in south-east Vietnam: Causes and options for control

    NARCIS (Netherlands)

    Pham Thi Ahn,; Kroeze, C.; Bush, S.R.; Mol, A.P.J.

    2010-01-01

    This paper focuses on both the environmental impact of intensive shrimp farming in the coastal region of Vietnam and the identification of options for cleaner production. We investigated water pollution, sediment contamination and the spread of diseases related to shrimp farming in the Can Gio distr

  5. Free amino acids in the clam Macoma balthica (L.) (Bivalvia, Mollusca) from brackish waters of southern Baltic Sea

    NARCIS (Netherlands)

    Sokolowski, A.; Wolowicz, M.; Hummel, H.

    2003-01-01

    Fourteen acidic and neutral free amino acids (FAA) were investigated in soft tissue of Macoma balthica from different depth zones of the Gulf of Gdansk (Baltic Sea) over a full seasonal cycle. The dry weight of the bivalves and physico-chemical parameters of overlying bottom water and surface sedime

  6. 间歇供水对微咸水土壤入渗与水盐分布特性的影响研究%Study of the Influence of Intermittent Water supply on brackish soil infiltration and water-salt distribution characteristics

    Institute of Scientific and Technical Information of China (English)

    邵俊昌

    2015-01-01

    China is a country of relatively water resources shortage ,to solve water shortage will be a pressing problem currently.China is rich in salty water resources ,scientific and rational use of brackish water to allevi-ate water shortages ,to ensure that agricultural production has an extremely important role in drought resis-tance.In this paper, the indoor one-dimensional vertical soil column infiltration test ,intermittent water brackish water infiltration and infiltration characteristics of soil water and salt distribution were studied ,focusing on dif-ferent salinity brackish water in different cycles and under conditions of circulation rate of infiltration ,and brackish water infiltration for continuous analysis and comparison reveals infiltration mechanism of intermittent water brackish,brackish water on soil intermittent water and salt for the future brackish water irrigation some test data and technical support ,provide theoretical and practical basis for the rational use of brackish water ir-rigation.%我国是一个水资源相对贫乏的国家,解决水资源的短缺将是我国目前面临的一个迫切问题。中国有着丰富的咸水资源,科学合理的利用微咸水对于缓解水资源短缺,确保农业增产抗旱有着极其重要的作用。本文采用室内一维垂直土柱入渗试验,对间歇供水条件下微咸水入渗土壤水分入渗特性及水盐分布特征进行研究,重点介绍不同矿化度的微咸水在不同的周期和循环率的入渗条件下,与微咸水连续入渗作分析比较,揭示微咸水间歇供水的入渗机理,分析微咸水间歇供水对土壤水分和盐分的影响,为今后微咸水灌溉提供一些试验数据和技术支撑,为微咸水灌溉的合理利用提供理论基础和实践依据。

  7. Host-dependent variations in the seasonal prevalence and intensity of heterophyid encysted metacercariae (Digenea: Heterophyidea) in brackish water fish in Egypt.

    Science.gov (United States)

    Elsheikha, Hany M; Elshazly, Attef M

    2008-05-01

    The prevalence of heterophyid (Digenea: Heterophyidae) encysted metacercariae (EMC) in its second intermediate host, the fish Mugil spp. and Tilapia spp. was studied in a subtropical permanent Lake in northeastern Egypt. Seasonal changes in the occurrence of the EMC in different fish hosts were monitored in a longitudinal field survey lasting 12 months from June 2006 to May 2007. This study tested two hypotheses; (i) prevalence and intensity of heterophyid EMC fluctuate seasonally throughout the year and (ii) variation in the prevalence and intensity of heterophyid EMC is host-dependent. A total of 832 fish specimens comprising 5 species collected from Manzala Lake, northeastern Egypt were examined by artificial gastric juice digestion for EMC. All five species of brackish water fish examined were found to harbor the EMC of the family Heterophyidae in their muscles. The overall infection prevalence of EMC over 12 months was 23.2%. The adult flukes recovered from puppies experimentally infected with morphologically different metacercariae from different fish species were compatible with six species belong to five genera of Heterophyidae, namely, Heterophyes heterophyes, Heterophyes aequalis, Pygidiopsis genata, Phagicola sp., Haplorchis sp. and Stictodora sp. EMC of H. heterophyes were most abundant, detected in 56% of the total fish examined. P. genata was ranked second, followed by Phagicola sp., H. aequalis, Haplorchis sp., and Stictodora sp., respectively. Seasonal differences in infection were observed for all heterophyid species studied in all fish species examined. Heterophyid infections reached peak prevalences during the summer season 38.2% followed by spring 26.6% and autumn 19.3% seasons, whereas the lowest prevalence was recorded in the winter 8.7%. Intensity of heterophyid EMC followed the same seasonal pattern, being high during summer months and low in winter months. All fish species were infected with all the heterophyid digeneans, but with different

  8. Arsenic removal from contaminated brackish sea water by sorption onto Al hydroxides and Fe phases mobilized by land-use.

    Science.gov (United States)

    Yu, Changxun; Peltola, Pasi; Nystrand, Miriam I; Virtasalo, Joonas J; Österholm, Peter; Ojala, Antti E K; Hogmalm, Johan K; Åström, Mats E

    2016-01-15

    This study examines the spatial and temporal distribution patterns of arsenic (As) in solid and aqueous materials along the mixing zone of an estuary, located in the south-eastern part of the Bothnian Bay and fed by a creek running through an acid sulfate (AS) soil landscape. The concentrations of As in solution form (<1 kDa) increase steadily from the creek mouth to the outer estuary, suggesting that inflowing seawater, rather than AS soil, is the major As source in the estuary. In sediments at the outer estuary, As was accumulated and diagenetically cycled in the surficial layers, as throughout much of the Bothnian Bay. In contrast, in sediments in the inner estuary, As concentrations and accumulation rates showed systematical peaks at greater depths. These peaks were overall consistent with the temporal trend of past As discharges from the Rönnskär smelter and the accompanied As concentrations in past sea-water of the Bothnian Bay, pointing to a connection between the historical smelter activities and the sediment-bound As in the inner estuary. However, the concentrations and accumulation rates of As peaked at depths where the smelter activities had already declined, but a large increase in the deposition of Al hydroxides and Fe phases occurred in response to intensified land-use in the mid 1960's and early 1970's. This correspondence suggests that, apart from the inflowing As-contaminated seawater, capture by Al hydroxides, Fe hydroxides and Fe-organic complexes is another important factor for As deposition in the inner estuary. After accumulating in the sediment, the solid-phase As was partly remobilized, as reflected by increased pore-water As concentrations, a process favored by As(V) reduction and high concentrations of dissolved organic matter. PMID:26558848

  9. The role of freshwater habitats for the reproduction of common bream Abramis brama (L.) in a brackish water system

    Science.gov (United States)

    Kafemann, R.; Thiel, R.; Finn, J.E.; Neukamm, R.

    1998-01-01

    Abundance and biomass data for juveniles and adults, length frequency histograms and the electron microprobe analysis (EPMA) of otoliths were used to indicate density, migration and reproduction of common bream Abramis brama in the Kiel Canal drainage, Germany. The reproduction of common bream was primarily restricted to two types of spawning habitats: one in the Haaler Au, a freshwater tributary and another in shallow, oligohaline portion of the main Canal. Both spawning habitats were morphologically characterized as shallow with submerged vegetation. During April to June concentrations of spawners were observed, whereas age-0 common bream dominated from August through December. The distribution of age-0 common bream was primarily restricted to fresh and oligohaline waters. Outside the spawning season, the distribution of common bream was less obvious. Adult fish were more widely distributed within the Canal, indicating a tolerance for higher salinities. During the spawning season common bream seem to show an exceptional mobility between spawning and feeding habitats, which are denoted by different salinities.

  10. Brackish to hypersaline lake dolostones of the Mississippian

    Science.gov (United States)

    Bennett, Carys; Kearsey, Timothy; Davies, Sarah; Millward, David; Marshall, John

    2016-04-01

    Flat-lying ferroan dolomite beds are common in the Mississippian and occur along the southern margin of Laurassia, from Kentucky USA to Poland. These rocks are important as they record shallow marine to coastal plain environments that may have acted as a pathway or refugia for animals that were radiating into freshwaters such as tetrapods, fish, molluscs and arthropods. This study is a contribution to the TW:eed Project (Tetrapod World: early evolution and diversification), that examines the rebuilding of Carboniferous ecosystems following a mass extinction at the end of the Devonian. The project focuses on the Tournaisian Ballagan Formation of Scotland, which contains rare fish and tetrapod fossils. The formation is characterised by an overbank facies association of siltstone, sandstone and palaeosols, interbedded with dolostone and evaporite units, and cut by fluvial sandstone facies associations of fining-upwards conglomerate lags, cross-bedded sandstone and rippled siltstone. Two sites are used as a case study to describe the sedimentological, faunal and ichnofaunal diversity of these dolostones. More than 270 dolostone beds are recorded in each of the 500 metre depth Norham Core (near Berwick-upon-Tweed) and from a 520 metre thick field section at Burnmouth. The beds are laterally extensive, over ˜1 km, although individual units do not appear to correlate between the core and the field site. In the Norham Core dolostones comprise up to 14% of the succession. 17% of the beds contain marginal marine fossils: Spirorbis, rare orthocones, brachiopods and putative marine sharks. More common fauna include ostracods, bivalves, plants, eurypterids, gastropods and sarcopterygian fish, which are interpreted as brackish to freshwater tolerant. Bioturbation is fairly common with Serpula colonies within dolostone beds and Chondrites burrowing down from the base of dolostone beds. Some rare units in the field section have a bulbous bed surface and preserve tree root traces

  11. Variation in Salt Content of Heavily-textured Coastal Saline Soils Leached by Brackish Water%微咸水淋洗重壤质滨海盐土的盐分变化研究

    Institute of Scientific and Technical Information of China (English)

    廉晓娟; 李明悦; 王艳; 张余良; 王立艳; 王正祥

    2011-01-01

    In order to save fresh water resource, it was necessary to explore and utilize reasonably brackish water replacing fresh water to improve saline soils, the author investigated the desalination effect of heavily-textured coastal saline soils leached by brackish water in field plot experiment. The results showed that in the well drained soils, using the brackish water with salinity of 3.5 g/L could lead to a fast and mark desalination effect. Taking saving water and desalination effect into account, the author suggested that an optimal leaching method was to sequentially leaching soil for three times with 1200 m3/hm2 brackish water. This method could decreased total salt content of soil (0-60 cm) to 3 g/kg and even below, make the desalination ratio to 60%, so that soil salt content met the requirement of common landscape plants.%为了节约淡水资源,合理开发利用微咸水代替淡水来改良盐碱地土壤.采用野外小区试验的方法,对不同灌水条件下滨海盐土土壤的脱盐效果进行分析.结果表明:在良好的排水条件下,采用矿化度约3.5 g/L的微咸水淋洗滨海盐土,能使土壤迅速脱盐,脱盐效果明显.综合节水和脱盐效果双重考虑,微咸水淋洗重壤质滨海盐土,以淋洗量1200 m3/hm2,连续淋洗3次为适宜的淋洗方式,能使0~60 cm土壤剖面的全盐量降低到3 g/kg以下,脱盐率达60%以上,土壤盐分含量达到一般绿化植物的生长要求.

  12. Freshwater Ecosystem Conservation: Towards a Comprehensive Water Resources Management Strategy

    OpenAIRE

    Enrique Bucher; Gonzalo Castro; Vinio Floris

    1997-01-01

    Conservation of freshwater biodiversity has been seriously neglected throughout the world, and entire ecosystems are threatened with extinction. Unfortunately, freshwater sustainability issues do not appear to be a primary consideration in the planning and implementation of water use projects, nor in the allocation of use permits. This paper discusses the value and function of Latin American freshwater ecosystems and gives a comprehensive approach to developing a sustainable water resources m...

  13. Effects of PAM on Characteristics of Water and Salt Movement in Soil under Brackish Water Infiltration%微咸水入渗下施加PAM土壤水盐运移特性研究

    Institute of Scientific and Technical Information of China (English)

    王全九; 张继红; 谭帅

    2016-01-01

    土壤改良剂与微咸水灌溉相结合,对于合理开发利用微咸水、改善盐碱土结构及促进作物生长有着重要意义。基于一维垂直土柱积水入渗和水平土柱吸渗试验,研究了微咸水入渗条件下,不同聚丙烯酰胺(polyacrylamide,PAM)施量(0、0.02%、0.04%和0.06%)对盐碱土水盐运移特性的影响。结果表明:(1)微咸水入渗条件下,施加PAM能够降低土壤入渗速率,增加土壤保水性能。(2)施加PAM对Philip及Kostiakov入渗模型参数有显著影响,在PAM施量0.04%时,吸渗率S和经验系数K最小,而经验指数β最大。(3)在PAM施量为0.04%时,土壤饱和体积含水量最大,Brooks-Corey模型进气吸力hd增加了15.30%,土壤持水性能显著提高;土壤水分扩散率最小,水分分布最均匀。(4)施加PAM能够显著提高土层的持水效率和微咸水的淋洗效果,在PAM施量为0.04%时,土层持水效率最高,盐分淋洗量最大。%It is of great significance to use soil amendment in combination with brackish water irrigation in rationalizing the exploitation of brackish water,improving saline soil structure and promoting crop growth. Polyacrylamide(PAM),a kind of organic polymer material,is regarded as an effective soil amendment because of its strong water holding capacity. In this paper,ponding infiltration experiments on one-dimension vertical soil columns and absorbing infiltration experiments on horizontal soil columns were carried out for investigation of effect of PAM application rate(0,0.02%,0.04% and 0.06%)on water and salt movement in soils with brackish water. Results show that(1)PAM reduced soil infiltration rate and enhanced soil water retention capability in the soil under brackish water infiltration,and the soil amended with 0.04% PAM was the highest in soil water retention capability;(2)PAM application significantly affected the parameters of the Philip and Kostiakov infiltration

  14. Desalination of brackish groundwater and concentrate disposal by deep well injection

    NARCIS (Netherlands)

    Wolthek, N.; Raat, K.; Ruijter, J.A.; Kemperman, A.J.B.; Oosterhof, A.

    2013-01-01

    In the province of Friesland (in the Northern part of The Netherlands), problems have arisen with the abstraction of fresh groundwater due to salinization of wells by upcoming of brackish water. A solution to this problem is to intercept (abstract) the upcoming brackish water, desalinate it with a b

  15. Progress in Investigation and Application of High Recovery Brackish Water Membrane Desalination Technology%高回收率膜法苦咸水淡化工艺的应用研究进展

    Institute of Scientific and Technical Information of China (English)

    宋跃飞; 苏现伐; 周建国; 苏保卫; 高从堦

    2015-01-01

    膜法苦咸水淡化过程中,符合环境保护要求的浓排水处理方法成本高昂,所以只有当回收率达到较高值时,在实际运行中才具有经济可行性。目前,在不加剧膜污染的条件下进一步提高苦咸水淡化系统回收率的方法已成为该领域研究热点。本文详细综述了高回收率膜法苦咸水淡化工艺的应用研究进展,包括基于反渗透、纳滤、正渗透、膜蒸馏、电渗析和电容去离子化淡化工艺过程,以及这些过程面临的热点问题,并对此提出了建议。%The costs of environmentally responsible brine disposal methods at inland sites can be prohibitively expensive in membrane brackish water desalination processes. As a result, it is often economically infeasible to develop such ground water sources unless very high product water recovery is attained. High product water recovery in membrane desalination processes is often limited by scaling of sparingly soluble salts when the concentrate above the solubility limits in the highly concentrated brine. Therefore, attempt was currently made to solve or mitigate scaling of membrane for brackish water desalination while remaining or further increasing overall system product water recovery. In this paper, the progress in improving the recovery of brackish water desalination by membrane technology including reverse osmosis (RO), nanofiltration (NF), forward osmosis (FO), membrane distillation (MD), electrodialysis (ED) and capacitive deionization (CDI), the scaling problem therein, as well as critical issues existing in this region were presented and commented extensively. In addition, the problems and suggestions for the current research status are proposed.

  16. Water stress and harmful insects in agri-forest ecosystems

    Directory of Open Access Journals (Sweden)

    Mario Solinas

    2011-02-01

    Full Text Available Present knowledge on ecological services supplied by insects to natural terrestrial ecosystems, allow us to identify many homeostatic mechanisms regulating biological balance as well as life perpetuation of the said ecosystems; at the same time, that knowledge represents a sound referring point to understanding how those mechanisms do work so as to manage them in the anthropized ecosystems (i.e., agriculture and forests, and especially in order to identify in the latter the natural meaning of the so called insect outbreaks, so as to forecast and possibly prevent them; as well as, when needed, to conceive and formulate efficient control strategies having minimal environmental impact. Water factor is crucial with genesis, configuration and conservation of a terrestrial ecosystem (both natural or anthropized as a whole or in its individual components, but especially concerning plant life as well as plant interactions with phytophagous invertebrates, mainly insects. Insect-plant trophic interactions are principally influenced by the water conditions in the ecosystem, and the impact of phytophagous insects on crops is markedly affected. Extremely severe water stress, especially if prolonged, prevent insect life just like plant’s life but a moderate and not so prolonged water stress, while depressing plant vigour, paradoxically can improve development and multiplication of phytophagous arthropods, with severe consequences on woody plants especially, and forest trees markedly.

  17. Water stress and harmful insects in agri-forest ecosystems

    Directory of Open Access Journals (Sweden)

    Mario Solinas

    Full Text Available Present knowledge on ecological services supplied by insects to natural terrestrial ecosystems, allow us to identify many homeostatic mechanisms regulating biological balance as well as life perpetuation of the said ecosystems; at the same time, that knowledge represents a sound referring point to understanding how those mechanisms do work so as to manage them in the anthropized ecosystems (i.e., agriculture and forests, and especially in order to identify in the latter the natural meaning of the so called insect outbreaks, so as to forecast and possibly prevent them; as well as, when needed, to conceive and formulate efficient control strategies having minimal environmental impact. Water factor is crucial with genesis, configuration and conservation of a terrestrial ecosystem (both natural or anthropized as a whole or in its individual components, but especially concerning plant life as well as plant interactions with phytophagous invertebrates, mainly insects. Insect-plant trophic interactions are principally influenced by the water conditions in the ecosystem, and the impact of phytophagous insects on crops is markedly affected. Extremely severe water stress, especially if prolonged, prevent insect life just like plant’s life but a moderate and not so prolonged water stress, while depressing plant vigour, paradoxically can improve development and multiplication of phytophagous arthropods, with severe consequences on woody plants especially, and forest trees markedly.

  18. The Winddrinker. Brackish water desalination in Somalia by means of wind energy; De Winddrinker. Brak water ontzilting in Somaliland door middel van windenergie

    Energy Technology Data Exchange (ETDEWEB)

    Generaal, C. [Faculteit Luchtvaart- en Ruimtetechniek, Technische Universiteit Delft TUD, Delft (Netherlands)

    2011-04-15

    The Winddrinker turns salt water into clean drinking water utilizing solely wind energy. It is a promising solution to solve water problems in dry coastal areas of developing countries. The Winddrinker combines a windmill and a desalination pump in the most efficient way. A mechanical coupling ensures a cheap, simple and reliable technology. [Dutch] De Winddrinker kan brak water ontzouten en veranderen in drinkwater met behulp van wind energie. Het is een veelbelovende oplossing voor het drinkwaterprobleem in droge kustgebieden in ontwikkelingslanden. De Winddrinker is een zeer efficient systeem bestaande uit een windmolen en een ontziltingspomp. Een mechanische koppeling zorgt voor een goedkope, eenvoudige en betrouwbare technologie.

  19. Report on follow-up for joint research of valuable resources recovery techniques from brackish water; Kansuichu no yuka shigen kaishu gijutsu ni kansuru kenkyu kyoryoku follow up hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This report describes follow-up for research and development on the recovery of valuable resources, such as magnesium, bromine and boron, contained in the brackish water for manufacture of common salt in the coastal region of Mexico. For the field survey, salt garden, irrigation plant and manufacturing plant of dinning salt were inspected. The optimum site was examined by assuming desalination plant and solar pond. The groundwater in coastal regions is progressively salified. Since the coastal region is a tourist resort with an round-trip area of whales, environmental protection is indispensable. For the joint research with invited researchers, the solar pond system and fresh water generation were studied. As a result, it was found that the solar pond system is an excellent method for keeping thermal energy in a low cost at the salt garden with abundant solar energy, and that the desalination system combined with distilling is the most suitable method. 7 refs., 8 figs., 1 tab.

  20. Sustainable Irrigation with Brackish Groundwater in Heilonggang Region, China

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Saline groundwater is widely distributed in Heilonggang region. While deep confined water is being mined, saline water has not been used in most part of the region. Extension of saline water irrigation is of significance to resolve water shortage, slow down environmental degradation and support the sustainable development of the local agriculture. Four key points are proposed to be managed by comprehensive measures: (1) adapting salt-resistant ability; (2) reducing salt input; (3) decreasing soil surface evaporation and salt accumulation in the root zone, and (4) washing away salt from the root zone. Experiments and farming practices demonstrated that brackish water with TDS (total dissolved solids) of 2-5 g/l can be used for crop irrigation. For example, winter wheat can be sustainably irrigated by brackish water with a water limitation of 120 mm every year. Irrigation in combination with different comprehensive measures can increase the efficiency of saline water irrigation.

  1. Phosphorus binding by aluminium in sediment: a tool for restoring water quality in the Baltic Sea and other brackish surface waters

    OpenAIRE

    Huser, Brian

    2014-01-01

    Lake and sea sediments act as stores for historical inputs of pollutants from both direct and diffuse sources including urbanization, agriculture, municipal and indus- trial waste waters, among others. Historical accumulation in sediments can provide a continual source of phosphorus to the water column for decades or longer after external sources have been controlled. Addition of metal salts, e.g. aluminium salts, can permanently bind this excess phosphorus in the sediment, thereby reducing i...

  2. Integrated Water Resources Management Improving Langat Basin Ecosystem Health

    Directory of Open Access Journals (Sweden)

    Mazlin B. Mokhtar

    2008-01-01

    Full Text Available The ecosystem provides us with all the goods and services that form the base of our economic, social cultural and spiritual life. Good scientific information will be required for managing the environment by using the Ecosystem approach. The groundwater is considered as a possible supplementary of alternative water source, and some factories already started shifting their water source from surface water to groundwater. Uncontrolled use of groundwater, however, may induce serious environmental problems, e.g., land subsidence, saltwater intrusion to the aquifer. The establishment of a balanced multi-sector and integrated groundwater resources and environmental management plan is deemed urgent to attain a sustainable groundwater resources use and to maintain a favorable groundwater quality in the Langat Basin. To achieve sustainable lifestyle in large scale ecosystem requires integrated and holistic approaches from all stakeholders. Through Aquifer Storage Recovery (ASR it was determined a revolutionized water resources management, providing a sustainable supply while minimizing the environmental impact of surface storage. By using underground geologic formations to store water, by integrated water resources management advisory system (IWRMAS aquifer recharge can now easily applied to obviate water resource and environmental problems, including seasonal shortages, emergency storage, ground subsidence and saline intrusion.

  3. Water cycle investigations in Hungarian forest ecosystems

    Institute of Scientific and Technical Information of China (English)

    Judit Sitkey

    2006-01-01

    From the biological point of view the value of autotrophy plant association is determined by the carbon fixation and the carbon cycle. Among the plant associations of Hungary, forest has the largest biological carbon fixation and carbon cycle. In general,the annual water cycle is the key factor in the organic material production of the Hungarian forests. The most intensive water consumption and organic material production take place from May till July, which period is named main water consumption and respectively main growing period. In Hungary the categories of the forest climate are characterized by main tree species and based on the forest climate covers 8% of the forest area, hornbeam-oak forest climate covers 22%, sessile oak-Turkey oak forest climate covers48% and forest steppe climate covers 22%. Partly in the frame of ICP-Forests, the Department of Ecology in the Forest Research Institute carries out long term, complex ecophysiological investigations on several sample plots (so-called basic plots) throughout the whole country. The organic material production (growth), the nutrient and water cycle, the measurements of air pollutants and meteorological parameters, as well as chemical analyses are all part of the investigations. As a comparison the figure of two basic plotsforest steppe climate in the hydrological year of 2001-2002. In the Hungarian forest 60%-70% of the precipitation is used for interception, evaporation, and in the vegetation season, for the transpiration both in beech and forest steppe climate. From other point of view, only 30%-40% of the open air precipitation infiltrates into the soil and can be utilized by the forest.

  4. Kinetic partitioning of Co, Mn, Cs, Fe, Ag, Zn and Cd in fresh waters (Loire) mixed with brackish waters (Loire estuary): experimental and modelling approaches

    International Nuclear Information System (INIS)

    To simulate the behavior of radionuclides along a salinity gradient, in vitro sorption and desorption kinetics of Co, Mn, Cs, Fe, Ag, Zn and Cd were studied in Loire river water and the macrotidal Loire estuarine water over two different seasons. Partitioning between the dissolved phase and suspended solids were followed up over 100 h after adding radioactive tracers to freshly collected freshwater (sorption stage); this stage was followed by desorption in fresh and estuarine waters. A kinetic model describing the interactions between trace metals and particles under a salinity gradient was developed and calibrated. Among parameters and/or processes that control the fate and behavior of contaminated particles during their transfer in estuarine systems, this study shows that the speciation of trace metals is controlled by: (i) the chemical water composition: for all the elements except for Fe, desorption increased with salinity; however, the amplitude of such an effect strongly depended on the element and/or on the composition of the particulate phase (and consequently on the season); (ii) the possibility for a given element to form (or not) stable surface particle moieties such as oxides or inner-sphere complexes; (iii) the distribution of a given element among different types of sites characterised by different binding forces that can lead (or not) to re-adsorption processes after mixing of contaminated particles with uncontaminated water. Our model enabled the quantification of the contribution and the characteristic time of reactions that took place over short and long periods on the global partitioning between particulate and dissolved phases during sorption and desorption and to determine the extent to which these reactions were modified by the salinity

  5. Revealing Invisible Water: Moisture Recycling as an Ecosystem Service.

    Science.gov (United States)

    Keys, Patrick W; Wang-Erlandsson, Lan; Gordon, Line J

    2016-01-01

    An ecosystem service is a benefit derived by humanity that can be traced back to an ecological process. Although ecosystem services related to surface water have been thoroughly described, the relationship between atmospheric water and ecosystem services has been mostly neglected, and perhaps misunderstood. Recent advances in land-atmosphere modeling have revealed the importance of terrestrial ecosystems for moisture recycling. In this paper, we analyze the extent to which vegetation sustains the supply of atmospheric moisture and precipitation for downwind beneficiaries, globally. We simulate land-surface evaporation with a global hydrology model and track changes to moisture recycling using an atmospheric moisture budget model, and we define vegetation-regulated moisture recycling as the difference in moisture recycling between current vegetation and a hypothetical desert world. Our results show that nearly a fifth of annual average precipitation falling on land is from vegetation-regulated moisture recycling, but the global variability is large, with many places receiving nearly half their precipitation from this ecosystem service. The largest potential impacts for changes to this ecosystem service are land-use changes across temperate regions in North America and Russia. Likewise, in semi-arid regions reliant on rainfed agricultural production, land-use change that even modestly reduces evaporation and subsequent precipitation, could significantly affect human well-being. We also present a regional case study in the Mato Grosso region of Brazil, where we identify the specific moisture recycling ecosystem services associated with the vegetation in Mato Grosso. We find that Mato Grosso vegetation regulates some internal precipitation, with a diffuse region of benefit downwind, primarily to the south and east, including the La Plata River basin and the megacities of Sao Paulo and Rio de Janeiro. We synthesize our global and regional results into a generalized

  6. Phytoplankton of water bodies of Khmelnitsky NPP techno-ecosystem and its background water bodies

    International Nuclear Information System (INIS)

    The results of phytoplankton studies of background water bodies of techno-ecosystem of Khmelnitsky NPP were presented. It is shown that the study of background reservoirs is an important constituent of hydro biological and environmental monitoring. In this case the mutual negative influence between NPP techno-ecosystem and background reservoirs was not observed

  7. On the Vulnerability of Water Limited Ecosystems to Climate Change

    Directory of Open Access Journals (Sweden)

    Kelly K. Caylor

    2013-06-01

    Full Text Available Society is facing growing environmental problems that require new research efforts to understand the way ecosystems operate and survive, and their mutual relationships with the hydrologic cycle. In this respect, ecohydrology suggests a renewed interdisciplinary approach that aims to provide a better comprehension of the effects of climatic changes on terrestrial ecosystems. With this aim, a coupled hydrological/ecological model is adopted to describe simultaneously vegetation pattern evolution and hydrological water budget at the basin scale using as test site the Upper Rio Salado basin (Sevilleta, NM, USA. The hydrological analyses have been carried out using a recently formulated framework for the water balance at the daily level linked with a spatial model for the description of the spatial organization of vegetation. This enables quantitatively assessing the effects on soil water availability on future climatic scenarios. Results highlighted that the relationship between climatic forcing (water availability and vegetation patterns is strongly non-linear. This implies, under some specific conditions which depend on the ecosystem characteristics, small changes in climatic conditions may produce significant transformation of the vegetation patterns.

  8. Produção de girassol ornamental com uso de águas salobras em sistema hidropônico NFT Production of ornamental sunflower with use of brackish waters in NFT hydroponic system

    Directory of Open Access Journals (Sweden)

    Marlo P Maciel

    2012-02-01

    Full Text Available Plantas de girassol ornamental 'Sol Vermelho' foram cultivadas em hidroponia com o objetivo de avaliar o uso de águas salobras sobre seu rendimento e qualidade da inflorescência. As águas salobras foram usadas para preparar a solução nutritiva e repor as perdas por evapotranspiração. O experimento foi conduzido em delineamento inteiramente aleatorizado com cinco níveis de salinidade da água: 1,51; 2,56; 3,86 e 6,19 dS m-1, obtidos pela adição de NaCl na água doce local (0,47 dS m-1 que também foi usada como testemunha. Cada tratamento foi repetido quatro vezes e cada parcela (com quatro plantas foi construída para simular um sistema independente da técnica do fluxo laminar de nutrientes (NFT. Observou-se uma redução linear causada pelo aumento da salinidade da água sobre a altura das plantas, o diâmetro do caule e a massa da matéria seca da parte aérea. Tanto a altura da planta quanto o diâmetro do caule foram reduzidos em 3,2% e a massa de matéria seca da parte aérea foi reduzida em 5,78% (dS m-1-1, para cada acréscimo unitário da salinidade da água (dS m-1. Por outro lado, a salinidade da água não afetou o tamanho do capítulo do girassol e não foram registrados sintomas de toxicidade causados pela salinidade. Esses resultados sustentam a viabilidade técnica do uso de águas salobras para produção hidropônica de girassol ornamental.Plants of ornamental sunflower 'Sol Vermelho' were grown under hydroponic conditions aiming to evaluate the effects of use of brackish water on its yield and inflorescence (capitulum quality. The brackish waters were utilized to prepare nutrient solution and to replace water due to evapotranspiration loss. The experiment was carried out in a completely randomized experimental design with five levels of water salinity: 1.51; 2.56; 3.86 and 6.19 dS m-1, obtained by addition of NaCl to local fresh water; this fresh water (0.47 dS m-1 was also studied as control treatment. Each

  9. 76 FR 10892 - Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor...

    Science.gov (United States)

    2011-02-28

    ... AGENCY Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor.... SUMMARY: EPA is announcing the release of the draft report titled, ``Aquatic Ecosystems, Water Quality... relative vulnerability of water quality and aquatic ecosystems, across the United States, to the...

  10. Influence of environmental factors on the abundance of Anopheles farauti larvae in large brackish water streams in Northern Guadalcanal, Solomon Islands

    Directory of Open Access Journals (Sweden)

    Butafa Charles

    2011-09-01

    Full Text Available Abstract Background The main vector of malaria in Solomon Islands is Anopheles farauti, which has a mainly coastal distribution. In Northern Guadalcanal, Solomon Islands, high densities of An. farauti are supported by large brackish streams, which in the dry season are dammed by localized sand migration. The factors controlling the high larval productivity of these breeding sites have not been identified. Accordingly the influence of environmental factors on the presence and density of An. farauti larvae was assessed in three large naturally dammed streams. Methods Larval sites were mapped and anopheline larvae were collected monthly for 12 months (July 2007 to June 2008 from three streams using standard dippers. Larval collections were made from 10 locations spaced at 50 m intervals along the edge of each stream starting from the coast. At each collection point, floating filamentous algae, aquatic emergent plants, sun exposure, and salinity were measured. These environmental parameters along with rainfall were correlated with larval presence and density. Results The presence and abundance of An. farauti larvae varied between streams and was influenced by the month of collection, and distance from the ocean (p 0.001. Larvae were more frequently present and more abundant within 50 m of the ocean during the dry season when the streams were dammed. The presence and density of larvae were positively associated with aquatic emergent plants (presence: p = 0.049; density: p = 0.001. Although filamentous algae did not influence the presence of larvae, this factor did significantly influence the density of larvae (p Conclusion This study has demonstrated that the presence and abundance An. farauti larvae are influenced by environmental factors within the large streams. Understanding these parameters will allow for targeted cost effective implementation of source reduction and larviciding to support the frontline malaria control measures i.e. indoor

  11. The origin of brackish and saline groundwater in the coastal area of the Netherlands

    OpenAIRE

    Post, VEA; Van der Plicht, H; Meijer, HAJ

    2003-01-01

    An explanation is presented for the origin of brackish to saline groundwater in the coastal area of the Netherlands based on geological, chemical (chlorinity), isotopic and geophysical data. A critical review of all possible salinization mechanisms shows that the origin of the brackish water is related to former transgressions. Both the vertical salinity distribution and the carbon-14 activity of the groundwater indicate that connate sea water from the Pliocene to Early Pleistocene is not the...

  12. 正渗透—纳滤耦合处理苦咸水脱盐工艺%Technological Processes of Desalination Treatment for Brackish Water with Coupled Forward Osmosis-Nanofiltration System

    Institute of Scientific and Technical Information of China (English)

    时强; 张乾; 阮国岭; 初喜章

    2012-01-01

    Simulating 2 000 mg/L NaCl as brackish water, using divalent salt (Na2SO4, MgSO4, MgCl2 and their mixture solution) as draw solution, the water flux of forward osmosis(FO) for brackish water desalination was investigated. The nanofiltration (NF) performance for the recovery of draw solution was determined by software and experiment, and a dual NF process was designed for the recovery of diluted draw solution. Results show that the water flux of MgSO4 in FO process is lowest, and that of MgCl2 is highest. It is opposite in NF process that the NF performance of MgSO4 is best, and that of MgCl2 is worst. When the diluted draw solution of Na2SO4 is 30 g / L, it could be concentrated to the initial concentration (60 g/L) by a dual stage NF process, and the permeate TDS is lower than 500 mg/L.%以2000 mg/L氯化钠模拟苦咸水,采用二价无机盐作为汲取液,研究了正渗透淡化苦咸水时的水通量;通过软件计算和试验研究了不同组成汲取液的纳滤性能,并且设计了二级纳滤系统用于汲取液的回收.结果表明:相同浓度时硫酸镁汲取液正渗透水通量最低,而氯化镁汲取液水通量最高;相反在纳滤过程中,硫酸镁汲取液性能最佳,氯化镁最差;稀释硫酸钠汲取液浓度为30 g/L时,二级纳滤过程可以将汲取液浓缩至初始浓度(60g/L),并制得浓度低于500 mg/L的产水.

  13. Phosphorus Management and Water Quality Problems in Grazingland Ecosystems

    Directory of Open Access Journals (Sweden)

    Maria L. Silveira

    2010-01-01

    Full Text Available Phosphorus management in grazingland ecosystems represents a major challenge of agronomic and environmental importance. Because of the extensive acreage occupied by grazinglands, decisions concerning pasture fertilization and nutrient management in forage-based livestock systems are crucial to both farmers and regulatory agencies. The purpose of this paper is to provide an overview of the literature relevant to pasture P fertilization and the potential impacts on water quality. There continue to be uncertainties regarding interrelationships between pasture management and water quality issues. Despite the extensive body of literature on nutrient transport from grazinglands, limited information is available on the relationships between land use, transport potential, water management, and climatic conditions affecting nutrient losses at a watershed scale. As agriculture continues to modernize and intensify, public concerns about the impacts of plant nutrients on environmental quality will likely increase. Managing water quality protection and profitable agriculture will be a major challenge for the next generations.

  14. Seasonal changes of water carbon relations in savanna ecosystems

    Science.gov (United States)

    Kutsch, W. L.; Merbold, L.; Archibald, S.

    2011-12-01

    During evolution plant species have developed different strategies to optimize the water carbon relations. These stratgies summarize to ecosystem properties. As an example we show how tropical and subtropical savannas and woodlands can respond flexibly to changes in temperature and water availability and thus optimize carbon and water fluxes between land surface and atmosphere. Several phenomena are presented and discussed in this overview from African flux sites in Zambia, Burkina Faso and South Africa: Pre-rain leaf development: Many trees developed new leaves before the first rain appeared. As a consequence of this early timing of leaf flush, the phenological increase of photosynthetic capacity (Amax) was steeper than in temperate forests. Mid-term response of conductance and photosynthesis to soil water relations: The regulation of canopy conductance was temporally changing in two ways: changes due to phenology during the course of the growing season and short-term (hours to days) acclimation to soil water conditions. The most constant parameter was water use efficiency. It was influenced by water vapour pressure deficit (VPD) during the day, but the VPD response curve of water usage only changed slightly during the course of the growing season, and decreased by about 30% during the transition from wet to dry season. The regulation of canopy conductance and photosynthetic capacity were closely related. This observation meets recent leaf-level findings that stomatal closure triggers down-regulation of Rubisco during drought. Our results may show the effects of these processes on the ecosystem scale. Furthermore, we observed that the close relationship between stomatal conductance and photosynthesis resulted in different temperature optima of GPP that were close to the average daytime temperature. Adaptation of respiration to rain pulses: Finally, the response of respiration to rain pulses showed changes throughout the growing season. The first rain events early

  15. Relevant factors for membrane fouling in brackish water reverse osmosis desalination%苦咸水反渗透淡化中影响膜面的污染因素∗

    Institute of Scientific and Technical Information of China (English)

    宋跃飞; 李铁梅; 周建国; 苏保卫; 高从堦

    2015-01-01

    Fouling phenomenon, type and degree in brackish water reverse osmosis ( BWRO ) desalination are significantly different from seawater reverse osmosis ( SWRO) process, due to the complex components of brackish water in different regions and the higher concentrate factor ( CF ) value in the majority of BWRO processes. Currently, membrane fouling as one of the bottlenecks for the large⁃scale BWRO application, has attracted in creasing attentions. In this review, overseas and domestic research progresses in application factors influencing the fouling on membrane surface in BWRO desalination were summarized in detail. The fouling components, fouling potential and quality indicators in water resources, and the physical properties influencing membrane fouling were introduced respectively. Two types of pretreatment methods including conventional and membrane technology were analysed, and the advantage of consistently high quality independent of influent associated with for membrane pretreatment was pointed out. In addition, the problems and suggestions for the current research status were proposed.%由于苦咸水的化学组成和浓度分布在不同地区有着显著的差异,以及淡化工艺中普遍较高的浓缩因子( concentrate factor, CF)值(在4—10之间),苦咸水反渗透( brackish water reverse osmosis, BWRO)淡化过程中的膜污染现象、类型和程度较海水反渗透( seawater reverse osmosis, SWRO)淡化过程有明显的不同。目前,膜污染已成为BWRO大规模应用于苦咸水淡化领域的瓶颈之一,如何解决这一问题成为该领域的研究热点。本文详细综述了国内外BWRO淡化过程中影响膜面污染因素的应用研究进展,重点介绍了进水来源污染成分及污染倾向、进水水质优劣指标和进水物性对膜面污染的影响;按照分离技术的不同,分类讨论了常规预处理和膜法预处理工艺,指出后者不易受进水水质变化的

  16. 基质栽培对微咸水灌溉下不同种类蔬菜生长的影响%Effect of substrate culture on the growth of different vegetables under brackish water irrigation

    Institute of Scientific and Technical Information of China (English)

    翟红梅; 董宝娣; 乔匀周; 师长海; 杨静; 李东晓; 刘月岩; 刘孟雨

    2013-01-01

      环渤海区淡水资源匮乏,咸水资源丰富,为解决水资源短缺以及微咸水灌溉引起土壤盐渍化问题,研究了在微咸水灌溉条件下,基质栽培对番茄、青椒和茄子生长发育的影响,以土壤栽培为对照,基质为腐熟秸秆、珍珠岩和炉渣按质量比1∶1∶1混合,深30 cm ,整个生育期灌溉3 g・L-1微咸水。结果表明:基质栽培条件下番茄和茄子的生长发育受到显著抑制,相对于土壤栽培,株高分别下降44.1%和25.1%,生物量分别下降80.4%和48.9%,产量下降49.2%和27.6%;青椒的株高和生物量下降15.2%和27.0%,但是产量没有显著变化。通过测定基质和土壤的盐分,发现在基质栽培条件下蔬菜受到盐分胁迫,植株耐盐性能降低,细胞膜完整性被破坏,导致番茄、青椒和茄子的光合速率分别下降18.5%、15.3%和14.1%。可见这种基质栽培条件适宜于浅根系作物,不适宜深根系作物,并且基质材料应该选择不含有盐碱土的炉渣。%Bohai Sea region has plenty of brackish water but short of freshwater resources .In attempt to find the so-lution to solve the problems of freshwater shortages and soil salinization caused by brackish water irrigation ,we studied the effect of substrate culture on the growth of tomato ,green pepper and eggplant under brackish water irrigation .The substrate used in this study was made of composting straw ,perlite ,and slag mixed in a mass ratio of 1∶1∶1 .The depth of groove was 30 cm .All vegetables were irrigated with 3 g・L-1 saline water .The results showed the growth and devel-opment of tomato and eggplant was significantly inhibited in substrate culture .Compared with soil cultivation ,the plant height of tomato and eggplant were decreased 44 .1% and 25 .1% respectively ,the biomass was decreased 80 .4% and 48 .9% ,respectively ,and the yield was decreased 49 .2% and 27

  17. Ecosystem attributes related to tidal wetland effects on water quality.

    Science.gov (United States)

    Findlay, S; Fischer, D

    2013-01-01

    Biogeochemical functioning of ecosystems is central to nutrient cycling, carbon balance, and several ecosystem services, yet it is not always clear why levels of function might vary among systems. Wetlands are widely recognized for their ability to alter concentrations of solutes and particles as water moves through them, but we have only general expectations for what attributes of wetlands are linked to variability in these processes. We examined changes in several water quality variables (dissolved oxygen, dissolved organic carbon, nutrients, and suspended particles) to ascertain which constituents are influenced during tidal exchange with a range of 17 tidal freshwater wetlands along the Hudson River, New York, USA. Many of the constituents showed significant differences among wetlands or between flooding and ebbing tidal concentrations, indicating wetland-mediated effects. For dissolved oxygen, the presence of even small proportional cover by submerged aquatic vegetation increased the concentration of dissolved oxygen in water returned to the main channel following a daytime tidal exchange. Nitrate concentrations showed consistent declines during ebbing tides, but the magnitude of decline varied greatly among sites. The proportional cover by graminoid-dominated high intertidal vegetation accounted for over 40% of the variation in nitrate decline. Knowing which water-quality alterations are associated with which attributes helps suggest underlying mechanisms and identifies what functions might be susceptible to change as sea level rise or salinity intrusion drives shifts in wetland vegetation cover. PMID:23600246

  18. Statutory protection for the water requirements of natural ecosystems

    Directory of Open Access Journals (Sweden)

    Maritza Uys

    1992-09-01

    Full Text Available A project was recently registered with the National Parks Board to investigate the need for legal protection of the water requirements of natural ecosystems and the existing legislation which provides such protection. There is a distinct lack of legal protection, which is identified and discussed in this paper. It is submitted that the current South African water law is outdated and in need of reform so as to accommodate the demands of a wider spectrum of user sectors. Since the amendment of the existing water allocation system (in a country where water is a scarce resource could be politically a disconcerting step, it should be made only after due consideration of the various needs for water, the historical foundation of the existing system, and a study made of effective systems in countries with similar water problems. An in-depth study of the historical development of South African water law has already revealed interesting yet abrogated concepts, which can possibly serve as a means of protecting the natural water requirements.

  19. Radioactive contamination of water ecosystems and sources of drinking water

    International Nuclear Information System (INIS)

    The contribution of aqueous components to the individual and collective doses received by the population as a result of the accident at Chernobyl in 1986 did not exceed 1-2%. In the first few days after the accident, the total beta radioactivity of the water was 1x10-7 Ci/L. Subsequently, the concentration of radionuclides in the water fell steadily and throughout 1987 was stable at 1-3x10-10 Ci/L. The highest recorded figure was 4x10-9 Ci/L in May 1986 caused by iodine-131 (for the Dnepr). (author). 1 fig

  20. Bryozoans are returning home: recolonization of freshwater ecosystems inferred from phylogenetic relationships.

    Science.gov (United States)

    Koletić, Nikola; Novosel, Maja; Rajević, Nives; Franjević, Damjan

    2015-01-01

    Bryozoans are aquatic invertebrates that inhabit all types of aquatic ecosystems. They are small animals that form large colonies by asexual budding. Colonies can reach the size of several tens of centimeters, while individual units within a colony are the size of a few millimeters. Each individual within a colony works as a separate zooid and is genetically identical to each other individual within the same colony. Most freshwater species of bryozoans belong to the Phylactolaemata class, while several species that tolerate brackish water belong to the Gymnolaemata class. Tissue samples for this study were collected in the rivers of Adriatic and Danube basin and in the wetland areas in the continental part of Croatia (Europe). Freshwater and brackish taxons of bryozoans were genetically analyzed for the purpose of creating phylogenetic relationships between freshwater and brackish taxons of the Phylactolaemata and Gymnolaemata classes and determining the role of brackish species in colonizing freshwater and marine ecosystems. Phylogenetic relationships inferred on the genes for 18S rRNA, 28S rRNA, COI, and ITS2 region confirmed Phylactolaemata bryozoans as radix bryozoan group. Phylogenetic analysis proved Phylactolaemata bryozoan's close relations with taxons from Phoronida phylum as well as the separation of the Lophopodidae family from other families within the Plumatellida genus. Comparative analysis of existing knowledge about the phylogeny of bryozoans and the expansion of known evolutionary hypotheses is proposed with the model of settlement of marine and freshwater ecosystems by the bryozoans group during their evolutionary past. In this case study, brackish bryozoan taxons represent a link for this ecological phylogenetic hypothesis. Comparison of brackish bryozoan species Lophopus crystallinus and Conopeum seurati confirmed a dual colonization of freshwater ecosystems throughout evolution of this group of animals. PMID:25691955

  1. Quantification of the surface brackish water layer and frontal zones in southern Chilean fjords between Boca del Guafo (43°30‧S) and Estero Elefantes (46°30‧S)

    Science.gov (United States)

    Calvete, Carolina; Sobarzo, Marcus

    2011-03-01

    The southern Chilean region between the Boca del Guafo passage and Estero Elefantes contains one of the estuarine zones with the greatest freshwater influence on the planet. At the surface, plumes of freshwater from the fjord heads to their mouths, emptying into the Moraleda-Costa-Elefantes channel system and then the coastal ocean. The influence of this freshwater on the region's estuarine dynamics, coastal ecology, and biogeochemical processes has only recently begun to be elucidated. Using hydrographic data from the CIMAR-Fiordos cruises (1998-2001), this study quantifies the equivalent height of freshwater, emphasizing the role it plays in the potential energy anomaly and front locations, as well as its relationship with river discharges. Using a criterion of equivalent height of freshwater >15% (density 0.005 J/m 4. The frontal zones were located in the extreme southeast of Jacaf Channel, at the head of Ventisquero Sound, in the central part of the Puyuguapi and Moraleda channels, and at the head and mouth of Aysén Fjord. The equivalent height of freshwater and potential energy anomaly showed a good correlation with the accumulated (5-day) river discharges ( r2=0.87), which were greatest toward the fjord heads in spring. The brackish surface water had short residence times (3.5 days) in Aysen Fjord, unlike the deep layer, which other authors report to have a longer residence time (near 1 year).

  2. Water contamination and environmental ecosystem in the Harlem River

    Science.gov (United States)

    Wang, J.

    2013-12-01

    Nutrients, bacteria, polychlorinated biphenyls (PCBs) and other contaminates have degraded water quality of the Harlem River. The Harlem River is a natural straight connected to the Hudson River and the East River, and it has been used for navigation and boating. Water samples have been collected and analyzed from 2011 to 2013. Phosphorus, ammonia, turbidity, fecal coliform, E.Coli., and enterococcus all exceed regulated levels for New York City waters. There is only one wastewater treatment plant (Wards Island WWTP) that serves this river. Combined sewer overflows (CSOs) discharge raw sewage into the river during storms in spring and summer. Commercial fishing is banned, .however, individuals still fish. While some fishermen catch and release, it is likely some fish are consumed, creating concern for the environmental health of the community along the river. Storm water runoff, CSOs, and wastewater effluents are major pollutant sources of PCB 11 (3,3' dichlorobiphenyl), nutrient and bacteria. Nutrients, bacteria levels and their spatial/temporal variations were analyzed, and PCB analysis is underway. This data is a critical first step towards improving the water quality and environmental ecosystem in the Harlem River.

  3. Linking economic water use, freshwater ecosystem impacts, and virtual water trade in a Great Lakes watershed

    Science.gov (United States)

    Mubako, S. T.; Ruddell, B. L.; Mayer, A. S.

    2013-12-01

    The impact of human water uses and economic pressures on freshwater ecosystems is of growing interest for water resource management worldwide. This case study for a water-rich watershed in the Great Lakes region links the economic pressures on water resources as revealed by virtual water trade balances to the nature of the economic water use and the associated impacts on the freshwater ecosystem. A water accounting framework that combines water consumption data and economic data from input output tables is applied to quantify localized virtual water imports and exports in the Kalamazoo watershed which comprises ten counties. Water using economic activities at the county level are conformed to watershed boundaries through land use-water use relationships. The counties are part of a region implementing the Michigan Water Withdrawal Assessment Process, including new regulatory approaches for adaptive water resources management under a riparian water rights framework. The results show that at local level, there exists considerable water use intensity and virtual water trade balance disparity among the counties and between water use sectors in this watershed. The watershed is a net virtual water importer, with some counties outsourcing nearly half of their water resource impacts, and some outsourcing nearly all water resource impacts. The largest virtual water imports are associated with agriculture, thermoelectric power generation and industry, while the bulk of the exports are associated with thermoelectric power generation and commercial activities. The methodology is applicable to various spatial levels ranging from the micro sub-watershed level to the macro Great Lakes watershed region, subject to the availability of reliable water use and economic data.

  4. Struvite crystallization under a marine/brackish aquaculture condition.

    Science.gov (United States)

    Zhang, Xuedong; Hu, Jianmei; Spanjers, Henri; van Lier, Jules B

    2016-10-01

    The results in this study show that struvite was formed in the digester at pH 7.7 due to the magnesium naturally present and the released ammonia and phosphate, resulting in low phosphate concentration in the digester. Apparently the digester already provided proper conditions for struvite formation. Under the brackish condition, the estimated thermodynamic solubility product and enthalpy change of struvite formation were 10(-13.06) and 25.7kJmol(-1), respectively. The average crystal size under marine/brackish condition decreased with pH, but increased with temperature. X-ray diffraction measurements indicate struvite (NH4MgPO4·6H2O) and dittmarite (NH4MgPO4·H2O) were predominant phosphorus species produced in filtrates of the digester. However, struvite and newberyite (HMgPO4·3H2O) were the predominant species precipitated from synthetic brackish waters after dosing MgCl2. It is pronounced that (waste)water characteristics played also an important role on the nature of phosphate precipitates. Under high NH4(+) condition, phosphorus precipitates containing ammonia were dominant, compared to other amorphous phosphates. PMID:27469096

  5. Implementation of Brackish Groundwater Desalination Using Wind-Generated Electricity: A Case Study of the Energy-Water Nexus in Texas

    OpenAIRE

    Clayton, Mary; Stillwell, Ashlynn; Webber, Michael

    2014-01-01

    Growing populations and periodic drought conditions have exacerbated water stress in many areas worldwide. In response, some municipalities have considered desalination of saline water as a freshwater supply. Unfortunately, desalination requires a sizeable energy investment. However, renewable energy technologies can be paired with desalination to mitigate concern over the environmental impacts of increased energy use. At the same time, desalination can be operated in an intermittent way to m...

  6. Variations in egg characteristics of ruffe Gymnocephalus cernua inhabiting brackish and freshwater environments

    Science.gov (United States)

    Svirgsden, Roland; Albert, Anu; Rohtla, Mehis; Taal, Imre; Saks, Lauri; Verliin, Aare; Kesler, Martin; Hubel, Kalvi; Vetemaa, Markus; Saat, Toomas

    2015-09-01

    Egg characteristics of teleost fishes are affected by various abiotic and biotic factors. In order to reproduce successfully, freshwater fishes inhabiting brackish environments must alter their reproductive characteristics, including egg properties, to increased osmotic pressure. Ruffe Gymnocephalus cernua was used as a model species to compare egg characteristics between fish populations inhabiting brackish and freshwater environments. Fish from the brackish environment had larger eggs with higher energy content than the individuals originating from freshwater. In freshwater, eggs from the first batch were larger than from the second. Female size correlated positively with egg size in the brackish water population. In freshwater, this correlation was evident only with eggs from the first batch. Only a weak positive correlation was found between fish condition and egg size in females from the brackish water population. Egg size variation did not differ between sites, nor was it correlated with mean egg size or any other maternal traits within populations. These results indicate significant modifications in reproductive strategies between brackish and freshwater ruffe populations. Additionally, results show that at least in freshwater, the first batch of eggs is of the highest quality and therefore more important for reproduction.

  7. Ecosystem effects from produced water and potash mine disposal activities

    International Nuclear Information System (INIS)

    This study was initiated to determine the chemical, physical, and ecosystem effects of produced water and potash mine disposal practices upon naturally occurring-hypersaline playas in southeast New Mexico, Several playas that receive discharges were compared to several nearby reference playas. Results revealed that the treatment playas had been significantly altered when compared to the reference playas. For example, the salinity of treatment playas were greater than 300 per-thousand and those of reference playas were less than 200 per-thousand. The dominant ions in water and sediments of treatment playas were sodium and chloride. The major ions in reference playa water and sediments were sodium, calcium, chloride, and sulfate. In some instances aromatic hydrocarbon concentrations exceeded 13,000 ng/g in sediments from treatment playas. Aromatic hydrocarbon concentrations were less than 100 ng/g in sediments from reference playas. Surveys revealed that treatment playas supported few, if any, invertebrates. On the other hand, reference playas supported dense populations of brine shrimp Artemis and brine fly Hydropyrus larvae. Surveys also indicated that reference playas were used by shorebirds for nesting and feeding, whereas treatment playas were used as loafing areas by waterfowl. Unfortunately, dead waterfowl were found along the shores of several treatment playas. Necropsies revealed that the most likely cause of death was salt toxicosis

  8. Spatial variability of water use efficiency in China's terrestrial ecosystems

    Science.gov (United States)

    Zhu, Xian-Jin; Yu, Gui-Rui; Wang, Qiu-Feng; Hu, Zhong-Min; Zheng, Han; Li, Sheng-Gong; Sun, Xiao-Min; Zhang, Yi-Ping; Yan, Jun-Hua; Wang, Hui-Min; Zhao, Feng-Hua; Zhang, Jun-Hui; Shi, Pei-Li; Li, Ying-Nian; Zhao, Liang; Zhang, Fa-Wei; Hao, Yan-Bin

    2015-06-01

    Water use efficiency (WUE) reflects the coupling of carbon and water cycles. Analyzing the spatial variability of WUE can improve our understanding on the interaction between carbon and water cycles at a large scale, which also provides a basis for improving the regional carbon budget assessment. Based on China's eddy covariance measurements, we examined the spatial variation of China's WUE and its affecting factors. WUE showed a decreasing trend with the increasing altitude, which was the result of ecosystem type distribution resulting from the climatic gradient. After fully considering the vertical variation of WUE, we found that not only mean annual air temperature (MAT), mean annual precipitation (MAP), and mean leaf area index (MLAI) but also mean annual total photosynthesis active radiation (MAR) affected the spatial variation of WUE. With the increasing MAT, MAP, and MLAI, WUE increased significantly but the increasing MAR decreased WUE. The spatial variation of WUE could be directly depicted by MLAI and altitude, the equation including which explained 65% of the spatial variation of WUE. The effects of MAT and MAP on the spatial variation of WUE may be achieved through altering MLAI, while the mechanism underlying the effect of MAR on the spatial variation of WUE was still unclear, which should be the subject of future investigations. This study reveals the vertical variation of WUE and provides a new approach to generate the spatial variation in WUE, which will benefit the regional carbon budget assessment.

  9. 连续多年地下微咸水灌溉对食葵土壤养分和微生物的影响%The Effect of Consecutive Years with Brackish Water Irrigation on Soil Nutrients and Microorganisms in Sunflower Fields

    Institute of Scientific and Technical Information of China (English)

    郭永昌

    2012-01-01

    采用大田试验,以农十师种植面积最大的食葵为研究对象,研究了以4种不同量的微咸水灌溉对新疆食葵盐碱地的土壤理化性质和微生物特性的影响。结果表明:与渠水灌溉相比,连续多年微咸水灌溉使食葵土壤盐分积累和pH值升高,分别增加31.9%和12.6%,并且造成土壤有效养分降低,碱解氮、速效磷和速效钾分别降低了7.0%、12.4%和45.5%,而且微咸水灌溉明显减少了土壤微生物种群数量和土壤酶活性,因此,长期微咸水灌溉使土壤生物质量下降,不利于农田的持续利用。%A field experiment is carried out to study the effect of four concentrations of brackish water irrigation on physical and chemical properties of soil and microbial properties in sunflowers in the largest agricultural planting area in Xinjiang Production and Construction Corps Agricultural Division 10. The results show that total salt content and pH changes are significantly greater in soil receiving consecutive years with brackish water (P〈0. 05), compared with fresh water irrigation, total soil salt content and pH increase by 31.9% and 12.6%, respectively, and soil nutrients changes are significantly lower in soil receiving consecutive years with brackish water, nitrogen, available phosphorus and potassium are reduced by 7. 0%, 12.4% and 45.5% In the salt affected soil, the soil microbial population and soil enzyme activity are reduced. These results reveal that consecutive years with brackish water irrigation influences not only the chemical and physical characteristics of soils, but also soil biological properties. Therefore, the consecutive years with brackish water irrigation has important implications for soil health and sustainability in arid agricultural areas.

  10. Ecotoxicity studies in Jamaican environment I. Toxicity, bioaccumulation, elimination and tissue partitioning of ethoprophos by the fish Tilapia in brackish water microcosm

    International Nuclear Information System (INIS)

    The present study was conducted on the toxicity of ethoprophos to sexually mature red hybrid Tilapia. The NOEC and LOEC were 1 and 4 mg/L of ethoprophos; the 24-h LC50 and LC95 values were 8.41 and 21.00 mg/L. Bioconcentration of the insecticide from NOEC and LOEC in the surrounding water by the fish peaked (3.25'' 0.412 and 12.50'' 1.831 μg/g, respectively) eight to twelve hours after exposure. Bioconcentration from LOEC was 3.8-fold greater than at NOEC. The contaminated fish (after 24-h exposure to LOEC) eliminated 83% of the ethoprophos residues within 12-h exposure to uncontaminated water. The order of partitioning of ethoprophos in the different tissues of the fish was gonads > liver > gut > gills > skin-muscle-bone. (author)

  11. Hydrochemical Facies, Groundwater Pattern in 'Red Beds and Basaltic aquifers', origin of Brackish waters and salt encrustation, Khanapur Plateau, Western Ghats, Maharashtra, India.

    OpenAIRE

    Siddig M.E; Al-Imam, O. A. O.; Hussein A.H.

    2013-01-01

    An integrated Hydrochemical, geochemistry and mineralogy of the salts encrustation on the 'red beds' on the Khanapur plateau, along the eastern side of the Western Ghats (Hills) of India region of the Indian peninsula. This area receives low precipitation (638 mm/year) as compared to the western side (4000 to 6000mm/year). Over a greater of the Deccan Volcanic Province of India, the basaltic aquifers contain fresh water with TDS1000ppm and

  12. Terrestrial ecosystems in a changing environment: a dominant role for water.

    Science.gov (United States)

    Bernacchi, Carl J; VanLoocke, Andy

    2015-01-01

    Transpiration--the movement of water from the soil, through plants, and into the atmosphere--is the dominant water flux from the earth's terrestrial surface. The evolution of vascular plants, while increasing terrestrial primary productivity, led to higher transpiration rates and widespread alterations in the global climate system. Similarly, anthropogenic influences on transpiration rates are already influencing terrestrial hydrologic cycles, with an even greater potential for changes lying ahead. Intricate linkages among anthropogenic activities, terrestrial productivity, the hydrologic cycle, and global demand for ecosystem services will lead to increased pressures on ecosystem water demands. Here, we focus on identifying the key drivers of ecosystem water use as they relate to plant physiological function, the role of predicted global changes in ecosystem water uses, trade-offs between ecosystem water use and carbon uptake, and knowledge gaps. PMID:25621516

  13. Managing Forests for Water in the Anthropocene—The Best Kept Secret Services of Forest Ecosystems

    OpenAIRE

    Creed, Irena F.; Marian Weber; Francesco Accatino; Kreutzweiser, David P.

    2016-01-01

    Water and forests are inextricably linked. Pressures on forests from population growth and climate change are increasing risks to forests and their aquatic ecosystem services (AES). There is a need to incorporate AES in forest management but there is considerable uncertainty about how to do so. Approaches that manage forest ecosystem services such as fiber, water and carbon sequestration independently ignore the inherent complexities of ecosystem services and their responses to management act...

  14. Vegetation dynamics and soil water balance in a water-limited Mediterranean ecosystem on Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    N. Montaldo

    2008-01-01

    Full Text Available Mediterranean ecosystems are commonly heterogeneous savanna-like ecosystems, with contrasting plant functional types (PFTs, e.g., grass and woody vegetation competing for the water use. Mediterranean ecosystems are also commonly characterized by strong inter-annual rainfall variability, which influences the distributions of PFTs that vary spatially and temporally. With the objective to investigate interactions between vegetation dynamics, soil water budget and land-surface fluxes in a water-limited ecosystem, an extensive field campaign in a Mediterranean setting was performed. Also a vegetation dynamic model (VDM is coupled to a 3-component (bare soil, grass and woody vegetation Land surface model (LSM. The case study is in Orroli, situated in the mid-west of Sardegna within the Flumendosa river basin. The landscape is a mixture of Mediterranean patchy vegetation types: trees, including wild olives and cork oaks, different shrubs and herbaceous species. Land surface fluxes, soil moisture and vegetation growth were monitored during the May 2003–June 2006 period. Interestingly, hydrometeorological conditions of the monitored years strongly differ, with dry and wet years in turn, such that a wide range of hydrometeorological conditions can be analyzed. The coupled VDM-LSM model is successfully tested for the case study, demonstrating high model performance for the wide range of eco-hydrologic conditions. The use of the VDM in the LSM is demonstrated to be essential when studying the climate-soil-vegetation interactions of these water-limited ecosystems. Results demonstrate also that vegetation dynamics are strongly influenced by the inter-annual variability of atmospheric forcing, with grass leaf area index changing significantly each spring season according to seasonal rainfall amount.

  15. Sediment-water nutrient interactions in fish pond ecosystems

    International Nuclear Information System (INIS)

    The sediment-water nutrient interactions in simulated fish pond ecosystems under organic and inorganic fertiliser applications were evaluated with particular reference to nitrogen and phosphorus. These were measured in terms of fertiliser use efficiencies using different isotopes. In the control, cowdung and inorganic fertiliser applications, the total per cent nitrogen recovery in water and sediment media during a period of 15 days were in the ranges of 37 to 41, 36 to 53 and 39 to 74, respectively, with a relatively larger fraction in the sediment. The corresponding values of percent phosphorus recovery were 2.01 to 29.73, 2.20 to 21.13 and 1.97 to 20.24. The N and P recoveries in the algal fraction were 54.93 per cent and 37.03 per cent, respectively, indicating an active uptake process. With mean primary production levels of 2.33, 3.72 and 2.90 mg C/l day in the three treatments, the photosynthetic efficiencies were 1.20, 1.93 and 1.50. (author). 15 refs., 2 tabs

  16. Water Use in Los Angeles, California: Consumption Patterns, Ecosystem Response and Impact on Regional Water Budgets

    Science.gov (United States)

    Hogue, T. S.

    2014-12-01

    The City of Los Angeles relies heavily on external water sources, primarily the Eastern Sierra, Northern California and the Colorado River, and approximately 90% of the City's water supply is snowpack dependent. In recent years, water conservation measures have been implemented in response to regional drought, which include a tiered pricing structure and watering restrictions. As a result of implemented conservation policies, Los Angeles reported the lowest water consumption per capita per day in 2011 among cities over 1 million people in the U.S. This presentation will highlight our ongoing work to better understand the coupling between humans, ecosystems and water across the City of Los Angeles, especially during the recent drought period. Our work is unique in that we integrate social, ecological, and hydrologic data, including ten years of residential water consumption data for the entire city of Los Angeles, extensive groundwater well data, socio-economic information and remote sensing to evaluate relationships as well as spatial and temporal patterns. Developed statistical models demonstrated that Single-Family Residential (SFR) water use across the City is primarily driven by household income, landscape greenness, water rates and water volume allocation,, with higher consumption rates in the northern, warmer and more affluent parts, and lower consumption rates in the less affluent neighborhoods near Downtown. Landscape use also varies greatly across the city, averaging 50% of total SFR. Our evaluation of conservation efforts shows that the combination of mandatory watering restrictions and price increase led to a water reduction of 23%, while voluntary restrictions led to only a 6% reduction in water use. Relationships of water use to ecosystems (greenness) and groundwater variability were also evaluated and will be highlighted. Our ultimate goal is to improve predictions of human-water interactions in order to drive policy change and guide future demand

  17. A Wider Notion of the Scope of Water Services in EU Water LawBoosting Payment for Water-Related Ecosystem Services to Ensure Sustainable Water Management?

    Directory of Open Access Journals (Sweden)

    Petra E. Lindhout

    2012-11-01

    Full Text Available The services ecosystems on the Earth providing for mankind, like the provision of (clean water for drinking and other purposes, are under pressure. Payment for (water-related ecosystem services, incentive pricing policies and the recovery of service costs are instruments to attain a sustainable use of scarce environmental resources and ecosystems. Although the European Water Framework Directive (WFD, whose purpose explicitly includes striving for sustainable water use, includes an obligation to recover the costs of water services, the scope of application of this obligation depends on the width of the interpretation of 'water services' in the WFD. If 'water services' are interpreted broadly, the WFD embraces the concept of payment for water-related ecosystem services, but raises a number of questions that need to be addressed.

  18. Comparing two tools for ecosystem service assessments regarding water resources decisions.

    Science.gov (United States)

    Dennedy-Frank, P James; Muenich, Rebecca Logsdon; Chaubey, Indrajeet; Ziv, Guy

    2016-07-15

    We present a comparison of two ecohydrologic models commonly used for planning land management to assess the production of hydrologic ecosystem services: the Soil and Water Assessment Tool (SWAT) and the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) annual water yield model. We compare these two models at two distinct sites in the US: the Wildcat Creek Watershed in Indiana and the Upper Upatoi Creek Watershed in Georgia. The InVEST and SWAT models provide similar estimates of the spatial distribution of water yield in Wildcat Creek, but very different estimates of the spatial distribution of water yield in Upper Upatoi Creek. The InVEST model may do a poor job estimating the spatial distribution of water yield in the Upper Upatoi Creek Watershed because baseflow provides a significant portion of the site's total water yield, which means that storage dynamics which are not modeled by InVEST may be important. We also compare the ability of these two models, as well as one newly developed set of ecosystem service indices, to deliver useful guidance for land management decisions focused on providing hydrologic ecosystem services in three particular decision contexts: environmental flow ecosystem services, ecosystem services for potable water supply, and ecosystem services for rainfed irrigation. We present a simple framework for selecting models or indices to evaluate hydrologic ecosystem services as a way to formalize where models deliver useful guidance. PMID:27111651

  19. Placing ecosystem services at the heart of urban water systems management.

    Science.gov (United States)

    Garcia, X; Barceló, D; Comas, J; Corominas, Ll; Hadjimichael, A; Page, T J; Acuña, V

    2016-09-01

    Current approaches have failed to deliver a truly integrated management of the different elements of the urban water system, such as freshwater ecosystems, drinking water treatment plants, distribution networks, sewer systems and wastewater treatment plants. Because the different parts of urban water have not been well integrated, poor decisions have been made for society in general, leading to the misuse of water resources, the degradation of freshwater ecosystems and increased overall treatment costs. Some attempts to solve environmental issues have adopted the ecosystem services concept in a more integrated approach, however this has rarely strayed far away from pure policy, and has made little impact in on-the-ground operational matters. Here, we present an improved decision-making framework to integrate the management of urban water systems. This framework uses the ecosystem service concept in a practical way to make a better use of both financial and water resources, while continuing to preserve the environment. PMID:27216967

  20. Interacting Coastal Based Ecosystem Services: Recreation and Water Quality in Puget Sound, WA

    OpenAIRE

    Kreitler, Jason; Papenfus, Michael; Byrd, Kristin; Labiosa, William

    2013-01-01

    Coastal recreation and water quality are major contributors to human well-being in coastal regions. They can also interact, creating opportunities for ecosystem based management, ecological restoration, and water quality improvement that can positively affect people and the environment. Yet the effect of environmental quality on human behavior is often poorly quantified, but commonly assumed in coastal ecosystem service studies. To clarify this effect we investigate a water quality dataset fo...

  1. VEGETATION SYNTAXONOMY AND LAND MANAGEMENT EFFECT ON METHANE AND CARBON DIOXIDE EMISSIONS FROM WETLANDS: A CASE STUDY FROM TIDAL SALT AND BRACKISH MARSH

    Directory of Open Access Journals (Sweden)

    Annisa Satyanti

    2014-07-01

    Full Text Available Carbon dioxide (CO2 and methane (CH4 emission from wetlands significantly contribute to climate change and global warming. The interaction between among vegetation type, various environmental factors, and management regimes such as grazing and mowing is considered important in the calculation of CO2 and CH4 gas flux for an ecosystem. In this study, vegetation composition, CH4 and CO2 flux, soil characteristics, air temperature and humidity from the brackish marsh and salt marsh wetland ecosystems on Terschelling Island in Northern Holland were measured. We aimed to investigate the relationship between vegetation composition, grazing, and mowing on CH4 and CO2 emission. The abundance and number of plant species were higher in brackish than in salt marsh. Grazing was found to influence species richness, 39 species being found in a grazed site of brackish marsh compared to 31 species in a similar ungrazed site. CO2 fluxes in salt and brackish marsh were found to be similar while CH4 flux in the salt marsh was found to be lower than in the brackish marsh. Within the brackish marsh, a higher methane emission was recorded in the grazed zone. However the overall effect of grazing and mowing was found to be negligible for CH4 flux but is suggested to clearly reduce CO2 flux in both the salt and brackish marsh.

  2. [A review on carbon and water interactions of forest ecosystem and its impact factors].

    Science.gov (United States)

    Song, Chun-lin; Sun, Xiang-yang; Wang, Gen-xu

    2015-09-01

    Interaction between carbon and water in forest ecosystem is a coupling process in terrestrial ecosystem, which is an indispensable aspect for the study of forest carbon pool, ecohydrological processes and the responses to global change. In the context of global change, the interaction and coupling of carbon and water in forest ecosystem has attracted much attention among scientists. In this paper, we reviewed the process mechanism of forest carbon and water relationships based on previous studies, which consisted of advance in forest water use efficiency, carbon and water interactions at different scales, scaling, and model simulation. We summed up the factors affecting for- est water and carbon interaction, including water condition, carbon dioxide enrichment, warming, nitrogen deposition, ozone concentration variation, solar radiation, and altitudinal gradients. Finally, we discussed the problems in the previous studies, and prospected the possible future research fields, among which we thought the inherent dynamics mechanism and scaling of forest carbon and water interactions should be enhanced. PMID:26785576

  3. Study on Soil and Water Conservation Benefit Models of Grassland Ecosystem-A Case Study on Jianou Mountain Grassland Ecosystem

    Institute of Scientific and Technical Information of China (English)

    ZHU Lian-qi; WANG Yu-biao; ZHAO Qing-liang

    2001-01-01

    This paper studies the mechanism of grassland ecosystem's soil and water conservation function on the basis of two years experiment and inspection in Jianou mountain grassland ecosystem experiment station, Fujian province. After analysis on the data of soil erosion and runoff coefficient, relations between eroded soil. runoff and slope gradient, we establish soil and water conservation benefit models. According to the models, experiment and inspection results, some proposals have been made to decrease the area of soil erosion in Fujian mountainous areas, e. g. , optimizing land use structure in mountainous areas, taking suitable measures for local condition, closing hills for grassland development, accelerating restoration and raising quality of mountain grassland ecosystem, strengthening scientific and technological input, breeding the grass species that are suitable to local physical geographic condition.

  4. Uso do rejeito da dessalinização de água salobra para irrigação da erva-sal (Atriplex nummularia The use of the brine from desalting brackish water to irrigate saltbush (Atriplex nummularia

    Directory of Open Access Journals (Sweden)

    Everaldo R. Porto

    2001-04-01

    Full Text Available Com o objetivo de se reduzir os impactos causados pela dessalinização de água salobra proveniente do cristalino no trópico semi-árido brasileiro, a erva-sal (Atriplex nummularia foi cultivada durante um ano, nos campos da Estação Experimental da Embrapa Semi-Árido. As plantas foram irrigadas com rejeito do processo de dessalinização, com concentração salina média de 11,38 dS m-1, e cada uma recebeu 75 L de água por semana, durante 48 semanas. A salinidade média do perfil de solo, da camada de 0 a 90 cm, era de 0,64 dS m-1 antes de se iniciar a irrigação das plantas; depois da colheita das plantas, a salinidade do mesmo perfil de solo foi de 12,74 dS m-1, enquanto a produtividade da erva-sal foi de 6.537,0 kg ha-1 de matéria seca, com teor de proteína bruta de 18,40% nas folhas. A Atriplex apresentou grande potencial de extração de sais do perfil de solo, mas quando as plantas são irrigadas com rejeito de alta concentração salina, a quantidade de sais extraída desse perfil pela planta, é da ordem de 3,93% do total de sais adicionados ao solo pelas irrigações; isto implica no fato de que, para um manejo de água sustentável, há necessidade de se gerar mais informações sobre as relações de solo e água para a erva-sal, nas condições das zonas áridas do Brasil.Looking forward to reducing environmental impacts resulting from desalting brackish water in the region of the crystalline rocks in the semi-arid tropic of Brazil, saltbush (Atriplex nummularia was cultivated during one year in an experimental field of Embrapa Semi-Arid. The plants were irrigated with the brine from the desalting plant which presented a salt concentration of 11.38 dS m-1. Each plant received 75 L of water per week, during 48 weeks. The soil salinity, at the depth of 0-90 cm, of the cropped area averaged 0.64 dS m-1 before starting the irrigation process. After the plants were harvested, the soil salinity in the same profile averaged 12.74 d

  5. The Function and Value of Water Conservation of Forest Ecosystem in Gongbo Nature Reserve of Tibet

    OpenAIRE

    Tang, Jia; Fang, Jiang-ping; Li, Ping; Guo, Jian-bin; Lu, Jie; Yuan, Qing-juan

    2012-01-01

    Gongbo Nature Reserve, located in Nyingchi of Tibet, is by far the largest construction project of forest reserves that China approves and invests in. This article adopts the shadow project method, and estimates the water conservation function of forest ecosystem of Gongbo Nature Reserve based on the Specifications for Assessment of Forest Ecosystem Services in China promulgated by State Forestry Administration of China. The results show that the total value of water conservation of forest ec...

  6. Estimating cultural benefits from surface water status improvements in freshwater wetland ecosystems.

    Science.gov (United States)

    Roebeling, Peter; Abrantes, Nelson; Ribeiro, Sofia; Almeida, Pedro

    2016-03-01

    Freshwater wetlands provide crucial ecosystem services, though are subject to anthropogenic/natural stressors that provoke negative impacts on these ecosystems, services and values. The European Union Water Framework Directive aims to achieve good status of surface waters by 2015, through implementation of Catchment Management Plans. Implementation of Catchment Management Plans is costly, though associated benefits from improvements in surface water status are less well known. This paper establishes a functional relationship between surface water status and cultural ecosystem service values of freshwater systems. Hence, we develop a bio-economic valuation approach in which we relate ecological status and chemical status of surface waters (based on local physio-chemical and benthic macro-invertebrates survey data) to willingness-to-pay (using benefit-function transfer). Results for the Pateira de Fermentelos freshwater wetland (Portugal) show that the current status of surface waters is good from a chemical though only moderate from an ecological perspective. The current cultural ecosystem service value of the wetland is estimated at 1.54 m€/yr- increasing to 2.02 m€/yr in case good status of surface waters is obtained. Taking into account ecosystem services and values in decision making is essential to avoid costs from externalities and capture benefits from spill-overs--leading to more equitable, effective and efficient water resources management. PMID:26747985

  7. The Function and Value of Water Conservation of Forest Ecosystem in Gongbo Nature Reserve of Tibet

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Gongbo Nature Reserve, located in Nyingchi of Tibet, is by far the largest construction project of forest reserves that China approves and invests in. This article adopts the shadow project method, and estimates the water conservation function of forest ecosystem of Gongbo Nature Reserve based on the Specifications for Assessment of Forest Ecosystem Services in China promulgated by State Forestry Administration of China. The results show that the total value of water conservation of forest ecosystem in Gongbo Nature Reserve is 8.485 billion yuan, while the function of water conservation is a small fraction of ecological service function, indicating that there is great ecological value in service function of forest ecosystem in Gongbo Nature Reserve, that is, Gongbo Nature Reserve has vital ecological value.

  8. High salinity tolerance in eggs and fry of a brackish Esox lucius population

    DEFF Research Database (Denmark)

    Jørgensen, A.T.; Hansen, B.W.; Vismann, B.;

    2010-01-01

    Knowledge on the biology and physiology of pike, Esox lucius L., populations inhabiting saline environments is scarce. An experimental setup was used to examine egg development and fry behaviour and growth under varying salinity levels in a brackish-water pike population from the western Baltic Sea...

  9. Quality Evaluation and Its Application to Surface Water Ecosystem Based on Maximum Flux Principle

    Institute of Scientific and Technical Information of China (English)

    刘年磊; 毛国柱; 赵林

    2010-01-01

    Based on the maximum flux principle(MFP),a water quality evaluation model for surface water ecosystem is presented by using self-organization map(SOM) neural network simulation algorithm from the aspect of systematic structural evolution.This evaluation model is applied to the case of surface water ecosystem in Xindu District of Chengdu City in China.The values reflecting the water quality of five cross-sections of the system at different developing stages are obtained,with stable values of 1.438,2.952,1.86...

  10. A review of the pollution of coastal waters in Nigeria.

    OpenAIRE

    Ajao, E.A.; Oyewo, E.O.; Unyimadu, J.P.

    1996-01-01

    The coastal waters in Nigeria are described in relation to the general morphology, vegetation and beach Type along the 850km coastal. The environmental sensitivity of the fragile Niger delta ecosystem is expressed by the numerous estuaries, rivers, creeks, lacustrine and inshore waters which support freshwater and brackish water mangrove swamps. Ocean resources exploited from the Niger delta and adjacent Continental platform include oil, gas and fishes. The general hydrograph and superfial ...

  11. Temporal and among-site variability of inherent water use efficiency at the ecosystem level

    Science.gov (United States)

    Beer, C.; Ciais, P.; Reichstein, M.; Baldocchi, D.; Law, B. E.; Papale, D.; Soussana, J.-F.; Ammann, C.; Buchmann, N.; Frank, D.; Gianelle, D.; Janssens, I. A.; Knohl, A.; KöStner, B.; Moors, E.; Roupsard, O.; Verbeeck, H.; Vesala, T.; Williams, C. A.; Wohlfahrt, G.

    2009-06-01

    Half-hourly measurements of the net exchanges of carbon dioxide and water vapor between terrestrial ecosystems and the atmosphere provide estimates of gross primary production (GPP) and evapotranspiration (ET) at the ecosystem level and on daily to annual timescales. The ratio of these quantities represents ecosystem water use efficiency. Its multiplication with mean daylight vapor pressure deficit (VPD) leads to a quantity which we call "inherent water use efficiency" (IWUE*). The dependence of IWUE* on environmental conditions indicates possible adaptive adjustment of ecosystem physiology in response to a changing environment. IWUE* is analyzed for 43 sites across a range of plant functional types and climatic conditions. IWUE* increases during short-term moderate drought conditions. Mean annual IWUE* varied by a factor of 3 among all sites. This is partly explained by soil moisture at field capacity, particularly in deciduous broad-leaved forests. Canopy light interception sets the upper limits to canopy photosynthesis, and explains half the variance in annual IWUE* among herbaceous ecosystems and evergreen needle-leaved forests. Knowledge of IWUE* offers valuable improvement to the representation of carbon and water coupling in ecosystem process models.

  12. Improved aquifer characterization and the optimization of the design of brackish groundwater desalination systems

    KAUST Repository

    Malivaa, Robert G.

    2011-07-01

    Many water scarce regions possess brackish-water resources that can be desalted to provide alternative water supplies. Brackish groundwater desalination by reverse osmosis (RO) is less expensive than seawater systems because of reduced energy and pretreatment requirements and lesser volumes of concentrate that require disposal. Development of brackish groundwater wellfields include the same hydraulic issues that affect conventional freshwater wellfields. Managing well interference and prevention of adverse impacts such as land subsidence are important concerns. RO systems are designed to treat water whose composition falls within a system-specific envelope of salinities and ion concentrations. A fundamental requirement for the design of brackish groundwater RO systems is prediction of the produced water chemistry at both the start of pumping and after 10-20 years of operation. Density-dependent solute-transport modeling is thus an integral component of the design of brackish groundwater RO systems. The accuracy of groundwater models is dependent upon the quality of the hydrogeological data upon which they are based. Key elements of the aquifer characterization are the determination of the three-dimensional distribution of salinity within the aquifer and the evaluation of aquifer heterogeneity with respect to hydraulic conductivity. It is necessary to know from where in a pumped aquifer (or aquifer zone) water is being produced and the contribution of vertical flow to the produced water. Unexpected, excessive vertical migration (up-coning) of waters that are more saline has adversely impacted some RO systems because the salinity of the water delivered to the system exceeded the system design parameters. Improved aquifer characterization is possible using advanced geophysical techniques, which can, in turn, lead to more accurate solute-transport models. Advanced borehole geophysical logs, such as nuclear magnetic resonance, were run as part of the exploratory test

  13. Linking levels of societal and ecosystems metabolism of water in a Mediterranean watershed

    Science.gov (United States)

    Cabello, V.

    2014-12-01

    Water resources degradation is a complex environmental problem that involves multiple dimensions and scales of analysis. The Socio-Ecological Systems Water Metabolism has been proposed as a general holistic framework to deal with integrated analysis of water use sustainability (Madrid and Giampietro 2014). The innovation of the approach is that it sets the research focus beyond the classical supply-demand modeling to societal integrity and ecosystems integrity. To do so, it integrates quantitative grammars of water use (relating water exchange to societal and ecosystems organization) and qualitative methods (discourse analysis). This work presents the first case study focused at a river basin extent: the Upper Andarax, in South-East Spain. Water metabolism is indicated at multiple levels for ecosystems and society. To deal with the interfaces among them, relational indicators of water exploitation, water use and impact over ecosystems are used alongside policies and narratives analysis.While being a rather not intensively exploited river basin (year Water Exploitation Index~0.3 blue water,~0.15 green water), impacts over water bodies are yet important (periodic aquifer overdraft, biological degradation of the river) especially during dry season. Perceived mayor problems of water sustainability are generated by the not integration of different policies at European, national and regional scales: while the water authority establishes a compulsory reduction over water withdrawal to attend environmental flows, agricultural markets force to raise productivity increasing water demands. Adaptation strategies are divided among irrigation efficiency improvement and a reorientation of the economy towards touristic activities. Both of them entail specific trade-offs to be deemed. Aquifer-river interactions and climate change impacts are yet mayor research challenges.

  14. Integrated modelling for assessing the risk of groundwater contaminants to human health and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Rasmussen, Jes; Funder, Simon G.;

    2010-01-01

    evaluating the impact of a TCE groundwater plume, located in an area with protected drinking water interests, to human health and surface water ecosystems. This is accomplished by coupling the system dynamicsbased decision support system CARO-Plus to the aquatic ecosystem model AQUATOX via an analytical...... volatilisation model for the stream. The model is tested on a Danish case study involving a 750 m long TCE groundwater plume discharging into a stream. The initial modelling results indicate that TCE contaminant plumes with μgL-1 concentrations entering surface water systems do not pose a significant risk to...

  15. 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 AMB

  16. 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,

  17. Background risk of water quality (nutrients and contaminants) for local ecosystems of Singapore

    NARCIS (Netherlands)

    Slijkerman, D.M.E.; Tamis, J.E.; Klok, T.C.; Langenberg, V.T.; Lescinski, J.

    2011-01-01

    Aim of this study was to assess the present impact of water quality as a consequence of human activities on local coastal ecosystems in Singapore in order to assess its relevance in relation to marine infrastructure developments as reclamation and associated dredging. Water quality aspects in this r

  18. Regional differences of water conservation in Beijing's forest ecosystem

    Institute of Scientific and Technical Information of China (English)

    ZHANG Biao; XIE Gao-di; YAN Yu-ping; YANG Yan-gang

    2011-01-01

    The water conservation capacities of main forests in Beijing,China were estimated through the quantitative analysis. Various methods developed in published papers on forest hydrology were employed. The forests in Huairou, Yanqing, Miyun, Mentougou and Fangshan districts are the main contributors to water conservation (the cumulative ratio reaches 65%), and the forests in Tongzhou, Chaoyang, Shunyi and Daxing districts have the highest water conservation capacity (3000 m3/ha).Altitude and slope are the key factors to affect the water conservation capacity. The forests located in Plain Area, Hilly Area, Low Mountain,and Middle Mountain contributes 27%, 28%, 24% and 21% of the conserved water, respectively. The water conservation capacity of forests in Plain Area (2 948 m3/ha), is superior to the forests in other regions. And the forests situated on Flat Slope, Moderate Slope and Genre Slope constitute the largest proportion (nearly 93%) of water conservation,while the forests on Flat Slope has the highest water conservation capacity (2 797 m3/ha), and the forest on Steep slope has the lowest water conservation capacity (948 m3/ha).

  19. Contrasting responses of water use efficiency to drought across global terrestrial ecosystems.

    Science.gov (United States)

    Yang, Yuting; Guan, Huade; Batelaan, Okke; McVicar, Tim R; Long, Di; Piao, Shilong; Liang, Wei; Liu, Bing; Jin, Zhao; Simmons, Craig T

    2016-01-01

    Drought is an intermittent disturbance of the water cycle that profoundly affects the terrestrial carbon cycle. However, the response of the coupled water and carbon cycles to drought and the underlying mechanisms remain unclear. Here we provide the first global synthesis of the drought effect on ecosystem water use efficiency (WUE = gross primary production (GPP)/evapotranspiration (ET)). Using two observational WUE datasets (i.e., eddy-covariance measurements at 95 sites (526 site-years) and global gridded diagnostic modelling based on existing observation and a data-adaptive machine learning approach), we find a contrasting response of WUE to drought between arid (WUE increases with drought) and semi-arid/sub-humid ecosystems (WUE decreases with drought), which is attributed to different sensitivities of ecosystem processes to changes in hydro-climatic conditions. WUE variability in arid ecosystems is primarily controlled by physical processes (i.e., evaporation), whereas WUE variability in semi-arid/sub-humid regions is mostly regulated by biological processes (i.e., assimilation). We also find that shifts in hydro-climatic conditions over years would intensify the drought effect on WUE. Our findings suggest that future drought events, when coupled with an increase in climate variability, will bring further threats to semi-arid/sub-humid ecosystems and potentially result in biome reorganization, starting with low-productivity and high water-sensitivity grassland. PMID:26983909

  20. Ecosystem services and biogeochemical cycles on a global scale: valuation of water, carbon and nitrogen processes

    International Nuclear Information System (INIS)

    Ecosystem services (ES) are provided by healthy ecosystems and are fundamental to support human life. However, natural systems have been degraded all over the world and the process of degradation is partially attributed to the lack of knowledge regarding the economic benefits associated with ES, which usually are not captured in the market. To valuate ES without using conventional approaches, such as the human's willingness-to-pay for ecosystem goods and services, this paper uses a different method based on Energy Systems Theory to estimate prices for biogeochemical flows that affect ecosystem services by considering their emergy content converted to equivalent monetary terms. Ecosystem services related to water, carbon and nitrogen biogeochemical flows were assessed since they are connected to a range of final ecosystem services including climate regulation, hydrological regulation, food production, soil formation and others. Results in this paper indicate that aquifer recharge, groundwater flow, carbon dioxide sequestration, methane emission, biological nitrogen fixation, nitrous oxide emission and nitrogen leaching/runoff are the most critical biogeochemical flows in terrestrial systems. Moreover, monetary values related to biogeochemical flows on a global scale could provide important information for policymakers concerned with payment mechanisms for ecosystem services and costs of greenhouse gas emissions.

  1. Tracking Ecosystem Water Use Efficiency of Cropland by Exclusive Use of MODIS EVI Data

    OpenAIRE

    Xuguang Tang; Hengpeng Li; Tim J. Griffis; Xibao Xu; Zhi Ding; Guihua Liu

    2015-01-01

    One of the most important linkages that couple terrestrial carbon and water cycles is ecosystem water use efficiency (WUE), which is relevant to the reasonable utilization of water resources and farming practices. Eddy covariance techniques provide an opportunity to monitor the variability in WUE and can be integrated with Moderate Resolution Imaging Spectroradiometer (MODIS) observations. Scaling up in situ observations from flux tower sites to large areas remains challenging and few studies...

  2. Water and Energy Balance of a Riparian and Agricultural Ecosystem along the Lower Colorado River

    OpenAIRE

    Taghvaeian, Saleh

    2011-01-01

    Spatially-distributed water consumption was modeled over a segment of the Lower Colorado River, which contains irrigated agricultural and Tamarisk-dominated riparian ecosystems. For the irrigation scheme, distributed evapotranspiration data were analyzed in conjunction with point measurements of precipitation and surface flow in order to close daily and annual water balance. The annual closure error was less than 1% of the total water diversion to the area. In addition, it was found that t...

  3. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity. The GLOBAQUA project

    OpenAIRE

    Navarro-Ortega, Alícia; Acuña, Vicenç; Bellin, Alberto; Burek, Peter; Cassiani, Giorgio; Choukr-Allah, Redouane; Dolédec, Sylvain; Elosegi, Arturo; Ferrari, Federico; Ginebreda, Antoni; Grathwohl, Peter; Jones, Colin; Rault, Philippe Ker; Kok, Kasper; Koundouri, Phoebe

    2015-01-01

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence...

  4. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity

    OpenAIRE

    Navarro-Ortega, A.; Acuña, V.; Bellin, A.; Burek, P.; G. Cassiani; Choukr-Allah, R.; Dolédec, S.; Elosegi, A.; Ferrari, F.; Ginebreda, A.; Grathwohl, P.; C. Jones; Ker Rault, P.A.; Kok, K; P. Koundouri

    2015-01-01

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence...

  5. Integrated Assessment of the impact of Aqueous Contaminant Stressors on Surface Water Ecosystems

    OpenAIRE

    McKnight, Ursula S.; Rasmussen, Jes J.; Kronvang, Brian; Bjerg, Poul Løgstrup; Binning, Philip John

    2011-01-01

    Release of chemicals, either by accidental spillage (e.g. xenobiotics) or direct application/release (e.g. pesticides, micropollutants), is recognized as a significant threat to water resources worldwide. However, little is known about the impact of groundwater contamination on surface water ecosystems. Traditional approaches for managing aquatic resources have often failed to account for the potential effects of anthropogenic disturbances on biota. To fulfil the requirements of the EU Water ...

  6. Integrated Assessment of the impact of Aqueous Contaminant Stressors on Surface Water Ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Rasmussen, Jes J.; Kronvang, Brian;

    2011-01-01

    ecosystems. Traditional approaches for managing aquatic resources have often failed to account for the potential effects of anthropogenic disturbances on biota. To fulfil the requirements of the EU Water Framework Directive will be challenging, as it is difficult to successfully separate and evaluate all...... pressures stressing an ecosystem. Here, methods for determining ecological status in streams are evaluated to see if they are capable of capturing the effects of stressors potentially affecting ecosystems. Specifically, they are tested on a case study where the effects of physical habitat degradation can be...... adversely impact ecosystems at expected environmentally-relevant concentrations. In general, thresholds determined for all compounds in the study were within the source mass discharge ranges expected at sites where contaminants may leach into groundwater (ITR C, 2010). Results of a sensitivity analysis...

  7. Deep Atomic Binding (DAB) Approach in Interpretation of Fission Products Behavior in Terrestrial and Water Ecosystems

    International Nuclear Information System (INIS)

    A large number of studies and models were established to explain the fission products (FP) behavior within terrestrial and water ecosystems, but a number of behaviors were non understandable, which always attributed to unknown reasons. According to DAB hypothesis, almost all fission products behaviors in terrestrial and water ecosystems could be interpreted in a wide coincidence. The gab between former models predictions, and field behavior of fission products after accidents like Chernobyl have been explained. DAB represents a tool to reduce radio-phobia as well as radiation protection expenses. (author)

  8. Water, ecology and health: ecosystems as settings for promoting health and sustainability.

    Science.gov (United States)

    Parkes, Margot W; Horwitz, Pierre

    2009-03-01

    Despite the proposed ecological and systems-based perspectives of the settings-based approach to health promotion, most initiatives have tended to overlook the fundamental nature of ecosystems. This paper responds to this oversight by proposing an explicit re-integration of ecosystems within the healthy settings approach. We make this case by focusing on water as an integrating unit of analysis. Water, on which all life depends, is not only an integral consideration for the existing healthy settings (schools, hospitals, workplaces) but also highlights the ecosystem context of health and sustainability. A focus on catchments (also know as watersheds and river basins) exemplifies the scaled and upstream/downstream nature of ecosystems and draws into sharp focus the cross-sectoral and transdisciplinary context of the social and environmental determinants of health. We position this work in relation to the converging agendas of health promotion and ecosystem management at the local, regional and global scales--and draw on evidence from international initiatives as diverse as the WHO Commission on Social Determinants of Health, and the Millennium Ecosystem Assessment. Using water as a vehicle for understanding the systemic context for human wellbeing, health promotion and disease prevention draws inevitable attention to key challenges of scale, intersectoral governance and the complementary themes of promoting resilience and preventing vulnerability. We conclude by highlighting the importance of building individual and institutional capacity for this kind of integration--equipping a new generation of researchers, practitioners and decision-makers to be conversant with the language of ecosystems, capable of systemic thought and focused on settings that can promote both health and sustainability. PMID:19171669

  9. Water Use Efficiency of China's Terrestrial Ecosystems and Responses to Drought

    Science.gov (United States)

    Liu, Y.; Xiao, J.; Ju, W.; Zhou, Y.; Wang, S.; Wu, X.

    2015-12-01

    Yibo Liu1, 2, Jingfeng Xiao2, Weimin Ju3, Yanlian Zhou4, Shaoqiang Wang5, Xiaocui Wu31 Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China, 2Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA, 3 International Institute for Earth System Sciences, Nanjing University, Nanjing, 210023, China, 4 School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China, 5 Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China Water use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems, and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns, and trends of WUE of China's terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg-1 H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. "Turning-points" were observed for southern China where moderate and extreme drought reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate

  10. Benefits Evaluation of Water Resources Used for Ecosystem in Shiyang River Basin of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    SU Xiaoling; KANG Shaozhong; LI Fusheng; ZHANG Lu; TONG Ling

    2009-01-01

    Among the numerous inland river basins in the arid northwest China, Shiyang River basin is known for its most serious water shortage that constrains its social and economic developments and for some of the worst eco-logical and environmental deterioration in China. The research on the value of water resources used for ecosystem is the basis for reasonable allocation of water resources between users of ecosystem and economic system. In this paper the concept of dynamic value for the ecosystem services is proposed. A modified coefficient for the ecosys-tem service value per unit area is proposed according to the cover degrees of biomes combined with expert consul-tation. Based on the developmental stage coefficient and scarcity of ecological resources, a dynamic evaluation method is proposed. The theoretical formula and simple calculation formula of the sharing benefits coefficient and benefits per unit ecological water utilization are proposed. The result shows that the benefit of unit ecological water utilization in the lower reach was greater than that in the upper reach in the Shiyang River basin.

  11. Water striders (family Gerridae): mercury sentinels in small freshwater ecosystems

    International Nuclear Information System (INIS)

    To circumvent some of the previous limitations associated with contaminant-monitoring programs, we tested the suitability of the water strider (Hemiptera: Gerridae) as a mercury sentinel by comparing total mercury concentrations in water striders and brook trout (Salvelinus fontinalis) from a variety of stream sites in New Brunswick, Canada. There was a strong association between the two variables across sites (r2 = 0.81, P < 0.001) in systems where both atmospheric deposition and a point source (an abandoned gold mine) were likely contributing to ambient mercury levels. In a small stream draining the gold mine tailings pile, water striders had mercury concentrations an order of magnitude higher than those from reference locations. Temporal variation at three southern New Brunswick stream sites was non-significant. These results suggest that water strider mercury levels accurately quantify food chain entry of the element. The use of sentinel species holds great potential for expanding contaminant-monitoring programs. - Water striders accurately reflect the entry of mercury in food chains of small freshwater systems

  12. Does the water footprint concept provide relevant information to address the water–food–energy–ecosystem nexus?

    OpenAIRE

    VANHAM DAVY

    2014-01-01

    This paper is a perspective paper, which investigates whether the water footprint (WF) concept addresses the water–food–energy–ecosystem nexus. First, the nexus links between (1) the planetary boundary freshwater resources (green and blue water resources) and (2) food security, energy security, blue water supply security and water for environmental flows/water for other ecosystem services (ES) are analysed and graphically presented. Second, the WF concept is concisely discussed. Third, with r...

  13. Ligophorus spp. (Monogenoidea: Dactylogyridae) parasitizing mullets (Teleostei: Mugiliformes: Mugilidae) occurring in the fresh and brackish waters of the Shatt Al-Arab River and Estuary in southern Iraq, with the description of Ligophorus sagmarius sp. n. from the greenback mullet Chelon subviridis (Valenciennes).

    Science.gov (United States)

    Kritsky, Delane C; Khamees, Najim R; Ali, Atheer H

    2013-12-01

    The gills of three of five species of mullets (Teleostei: Mugiliformes: Mugilidae) collected from the brackish and fresh waters of southern Iraq were infected with species of Ligophorus (Monogenoidea: Dactylogyridae) as follows: greenback mullet Chelon subviridis (Valenciennes) infected with Ligophorus lebedevi Dmitrieva, Gerasev, Gibson, Pronkina and Galli, 2012, Ligophorus bantingensis Soo and Lim, 2012, Ligophorus sagmarius n. sp., and Ligophorus fluviatilis (Bychowsky, 1949) Dmitrieva, Gerasev, Gibson, Pronkina, and Galli, 2012; Klunzinger’s mullet Liza klunzingeri (Day) with L. bantingensis, L. fluviatilis, and an apparently undescribed species of Ligophorus; and abu mullet Liza abu (Heckel) with L. bantingensis and L. fluviatilis. The keeled mullet Liza carinata (Valenciennes) and Speigler’s mullet Valamugil speigleri (Bleeker) were uninfected. L. sagmarius n. sp. is described, and L. lebedevi and L. bantingensis are redescribed. Available specimens of L. fluviatilis and the undescribed species of Ligophorus from Klunzinger’s mullet were insufficient for description. PMID:24022128

  14. Quality Evaluation and Its Application to Surface Water Ecosystem Based on Maximum Flux Principle

    Institute of Scientific and Technical Information of China (English)

    LIU Nianlei; MAO Guozhu; ZHAO Lin

    2010-01-01

    Based on the maximum flux principle(MFP),a water quality evaluation model for surface water ecosystem is presented by using self-organization map(SOM)neural network simulation algorithm from the aspect of systematic structural evolution.This evaluation model is applied to the case of surface water ecosystem in Xindu District of Chengdu City in China.The values reflecting the water quality of five cross-sections of the system at different developing stages are obtained,with stable values of 1.438,2.952,1.869,2.443 and 2.479,respectively.The simulation also indicates that the larger the value,the more serious the water pollution.Furthermore,a classification graph is given to reflect the evolution of structural pattern.The combination of MFP and SOM neural network reveals the formation of different structural patterns in the system during the interaction of internal components.It is shown that a dominant pattern is finally reserved,which starts from a variety of combination patterns for a time period.The results agree with those from traditional evaluation methods,which indicates that the proposed model has high accuracy.This model embodies the evolutionary dynamic mechanisms and characteristics of temporal and spatial changes,which helps to guide the prediction of water quality status of surface water ecosystem.

  15. Length-mass relationships for transitional water benthic macroinvertebrates in Mediterranean and Black Sea ecosystems

    Science.gov (United States)

    Rosati, I.; Barbone, E.; Basset, A.

    2012-11-01

    Length-mass relationships are potentially useful tools to estimate individual biomass, assuming a relative invariance within and among populations and, sometimes, among species pertaining to a same family or order. Here, we present a field test of these assumptions in guilds of benthic macroinvertebrates colonising transitional water ecosystems. To this aim, we are analysing length-mass relationships of benthic macroinvertebrates of transitional water ecosystems and assessing their variability among populations of a same species and among species of a same family and/or order. Data are from synoptic studies carried out at four oligohaline transitional water ecosystems, from the Southern Italy and the Danube delta ecoregions; they refer to 40 macroinvertebrate taxa selected from the overall species pool according to absolute and relative density requirements. Species composition differed widely among ecoregions while length-mass relationships of the species occurring in both ecoregions did not; the variability of length-mass parameters of these species among ecosystems was lower than 10%. Length-mass regressions were relatively conservative also with respect to taxonomic resolution; significant differences were observed among species within 5 out of the 7 orders tested but differences in slopes and intercepts were on average lower than 15%. Therefore, our results, representing one of the first efforts to catalogue length-mass relationships for benthic macroinvertebrates in transitional waters, support the assumption of relative invariance of length-mass relationships and their use in studies where gross estimates of population biomasses are required.

  16. Graduate Education and Training at the Intersection of Water, Climate, Ecosystems, and People

    Science.gov (United States)

    Denning, S.; Ramirez, J. A.; Poff, L.; Grigg, N.

    2015-12-01

    Since 2010, an interdisciplinary group of researchers have worked with a talented and energetic group of graduate students at Colorado State University on issues at the intersection of water with climate, ecosystems, and people. Over 20 graduate students and 15 faculty from nearly a dozen Departments were involved. Research and training were offered in hydrology, ecology, economics, political science, biology, and atmospheric science. We mapped student research on a triangular conceptual framework. At the vertices of the triangle are climate, ecosystems, and people; water is at the center. Our guiding principle was that students should be trained along the sides of the triangle (e.g., climate/water/ecosystems or ecosystems/water/people) rather than at the vertices. We developed four new academic core courses and students engaged in significant collaborative research projects and professional development activities in addition to their dissertation projects. Student engagement and achievement was very high. In addition, vibrant new collaborations have emerged among faculty across the Departments involved.

  17. Simulating the Energy and Water Fluxes from Two Alkaline Desert Ecosystems over Central Asia

    Directory of Open Access Journals (Sweden)

    Chang-Qing Jing

    2016-01-01

    Full Text Available The Central Asia region is covered by vast desert ecosystems, where the characteristic of energy and water fluxes is different from other humid ecosystems. The application of land surface models (LSMs in arid and semiarid ecosystems was largely limited. This paper presents a detailed evaluation of Common Land Model (CoLM at two eddy covariance (EC sites in alkaline desert ecosystems over Central Asia. Simulations of the net radiation (Rnet, latent heat flux (Qle, sensible heat flux (Qh, and soil temperature showed that refined estimate of roughness length (Z0m significantly improved the performance of CoLM in simulating turbulent heat fluxes. Qle was increased but Qh was decreased, which were in better agreement with the observations from EC system. The results indicated that accurate parameterization of Z0m is of crucial importance for predicting energy and water fluxes in LSM when applied in Central Asia desert ecosystems. Sensitivity analysis regarding leaf area index (LAI, Z0m, and albedo (α showed that Rnet is very sensitive to α but Qle, Qh, and soil temperature (Tsoil are sensitively varying with the estimate of Z0m at the two EC sites over Central Asia.

  18. Improving SWAT for simulating water and carbon fluxes of forest ecosystems.

    Science.gov (United States)

    Yang, Qichun; Zhang, Xuesong

    2016-11-01

    As a widely used watershed model for assessing impacts of anthropogenic and natural disturbances on water quantity and quality, the Soil and Water Assessment Tool (SWAT) has not been extensively tested in simulating water and carbon fluxes of forest ecosystems. Here, we examine SWAT simulations of evapotranspiration (ET), net primary productivity (NPP), net ecosystem exchange (NEE), and plant biomass at ten AmeriFlux forest sites across the U.S. We identify unrealistic radiation use efficiency (Bio_E), large leaf to biomass fraction (Bio_LEAF), and missing phosphorus supply from parent material weathering as the primary causes for the inadequate performance of the default SWAT model in simulating forest dynamics. By further revising the relevant parameters and processes, SWAT's performance is substantially improved. Based on the comparison between the improved SWAT simulations and flux tower observations, we discuss future research directions for further enhancing model parameterization and representation of water and carbon cycling for forests. PMID:27401278

  19. Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change.

    Science.gov (United States)

    McCluney, Kevin E; Belnap, Jayne; Collins, Scott L; González, Angélica L; Hagen, Elizabeth M; Nathaniel Holland, J; Kotler, Burt P; Maestre, Fernando T; Smith, Stanley D; Wolf, Blair O

    2012-08-01

    Species interactions play key roles in linking the responses of populations, communities, and ecosystems to environmental change. For instance, species interactions are an important determinant of the complexity of changes in trophic biomass with variation in resources. Water resources are a major driver of terrestrial ecology and climate change is expected to greatly alter the distribution of this critical resource. While previous studies have documented strong effects of global environmental change on species interactions in general, responses can vary from region to region. Dryland ecosystems occupy more than one-third of the Earth's land mass, are greatly affected by changes in water availability, and are predicted to be hotspots of climate change. Thus, it is imperative to understand the effects of environmental change on these globally significant ecosystems. Here, we review studies of the responses of population-level plant-plant, plant-herbivore, and predator-prey interactions to changes in water availability in dryland environments in order to develop new hypotheses and predictions to guide future research. To help explain patterns of interaction outcomes, we developed a conceptual model that views interaction outcomes as shifting between (1) competition and facilitation (plant-plant), (2) herbivory, neutralism, or mutualism (plant-herbivore), or (3) neutralism and predation (predator-prey), as water availability crosses physiological, behavioural, or population-density thresholds. We link our conceptual model to hypothetical scenarios of current and future water availability to make testable predictions about the influence of changes in water availability on species interactions. We also examine potential implications of our conceptual model for the relative importance of top-down effects and the linearity of patterns of change in trophic biomass with changes in water availability. Finally, we highlight key research needs and some possible broader impacts

  20. Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change

    Science.gov (United States)

    McCluney, Kevin E.; Belnap, Jayne; Collins, Scott L.; González, Angélica L.; Hagen, Elizabeth M.; Holland, J. Nathaniel; Kotler, Burt P.; Maestre, Fernando T.; Smith, Stanley D.; Wolf, Blair O.

    2012-01-01

    Species interactions play key roles in linking the responses of populations, communities, and ecosystems to environmental change. For instance, species interactions are an important determinant of the complexity of changes in trophic biomass with variation in resources. Water resources are a major driver of terrestrial ecology and climate change is expected to greatly alter the distribution of this critical resource. While previous studies have documented strong effects of global environmental change on species interactions in general, responses can vary from region to region. Dryland ecosystems occupy more than one-third of the Earth's land mass, are greatly affected by changes in water availability, and are predicted to be hotspots of climate change. Thus, it is imperative to understand the effects of environmental change on these globally significant ecosystems. Here, we review studies of the responses of population-level plant-plant, plant-herbivore, and predator-prey interactions to changes in water availability in dryland environments in order to develop new hypotheses and predictions to guide future research. To help explain patterns of interaction outcomes, we developed a conceptual model that views interaction outcomes as shifting between (1) competition and facilitation (plant-plant), (2) herbivory, neutralism, or mutualism (plant-herbivore), or (3) neutralism and predation (predator-prey), as water availability crosses physiological, behavioural, or population-density thresholds. We link our conceptual model to hypothetical scenarios of current and future water availability to make testable predictions about the influence of changes in water availability on species interactions. We also examine potential implications of our conceptual model for the relative importance of top-down effects and the linearity of patterns of change in trophic biomass with changes in water availability. Finally, we highlight key research needs and some possible broader impacts

  1. Spatial Scales of Bacterial Diversity in Cold-Water Coral Reef Ecosystems

    OpenAIRE

    Sandra Schöttner; Christian Wild; Friederike Hoffmann; Antje Boetius; Alban Ramette

    2012-01-01

    Background: Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning. Methodology/Principal Findings: Bacterial community structure, as determined by Automated Riboso...

  2. Water Management Supporting the Delivery of Ecosystem Services for Grassland, Heath and Moorland

    OpenAIRE

    Henk Ritzema; Hilary Kirkpatrick; Jakub Stibinger; Hans Heinhuis; Heinrich Belting; Raymond Schrijver; Herbert Diemont

    2016-01-01

    In the present era, permanent grasslands and other grazed habitats, i.e., moorlands and heath, are appreciated as avant la lettre green infrastructure (GI) resources, providing a wide range of ecosystem services, the delivery of many of which require water management to be in place. This paper discusses the role of water management and, in particular, that of drainage. We contend that controlled drainage and drainage-irrigation systems can contribute to the sustainable use of grasslands and a...

  3. The application of methods of ecosystem analysis to the evaluation of water quality

    OpenAIRE

    Kozhova, O.M.

    1980-01-01

    Guided by experience and the theoretical development of hydrobiology, it can be considered that the main aim of water quality control should be the establishment of the rates of the self-purification process of water bodies which are capable of maintaining communities in a state of dynamic balance without changing the integrity of the ecosystem. Hence, general approaches in the elaboration of methods for hydrobiological control are based on the following principles: a. the balance of matter a...

  4. Dioecy Impacts on Plant Water Fluxes in Riparian Ecosystems

    Science.gov (United States)

    Hultine, K. R.; Bush, S. E.; West, A. G.; Ehleringer, J. R.

    2005-12-01

    Dioecious plants are frequently associated with different spatial distributions of the two sexes across resource gradients. Segregation between sexes might be expected to occur if the cost of reproduction is greater in females than in males. If so, females would be under stronger selection to increase rates of resource uptake. Acer negundo is a dioecious riparian tree species that show spatial segregation among sexes: females are typically more common along streamside (high resource) environments than males. The spatial segregation of the sexes leads to the hypothesis that male and female individuals have varying influence on ecohydrological processes. To address this, we measured sap flux, water relations and hydraulic architecture of mature streamside (less than 1 m from stream channel) male and female Acer negundo trees occurring near Salt Lake City, Utah, USA during the 2004 growing season. Despite similar predawn and midday leaf water potentials, sap flux density ( Js) was 40 percent higher in female trees than in male trees during the 2004 growing season (n = 42 days, F = 73.56, P genders showed a similar relationship between conducting sapwood area to stem diameter ratio suggesting that differences in Js scale to the whole tree level. Sap flux data from Acer negundo trees was compared to five other co-occurring riparian tree species. Female Acer negundo trees showed the highest Js among all species while Js in male Acer negundo trees was lower than all other species except one ( Acer grandidentatum). These data demonstrate that individual female Acer negundo trees have the capacity remove water at higher rates than males in high resource environments. The spatial segregation of the sexes along streamside environments may therefore have profound impacts on ecohydrological processes such as stream discharge, groundwater recharge, and nutrient cycling.

  5. Final Technical Report: Effects of Changing Water and Nitrogen Inputs on a Mojave Desert Ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Stanley D. [University of Nevada, Las Vegas; Nowak, Robert S. [University of Nevada, Reno

    2007-11-30

    Questions addressed under this grant shared the common hypothesis that plant and ecosystem performance will positively respond to the augmentation of the most limiting resources to plant growth in the Mojave Desert, e.g., water and nitrogen. Specific hypothesis include (1) increased summer rainfall will significantly increase plant production thorugh an alleviation of moisture stress in the dry summer months, (2) N-deposition will increase plan production in this N-limited system, particularly in wet years or in concert with added summer rain, and (3) biological crust disturbance will gradually decrease bio-available N, with concomitant long-term reductions in photosynthesis and ANPP. Individual plan and ecosystem responses to global change may be regulated by biogeochemical processes and natural weather variability, and changes in plant and ecosystem processes may occur rapidly, may occur only after a time lag, or may not occur at all. During the first PER grant period, we observed changes in plant and ecosystem processes that would fall under each of these time-response intervals: plant and ecosystem processes responded rapidly to added summer rain, whereas most processes responded slowly or in a lag fashion to N-deposition and with no significant response to crust disturbance. Therefore, the primary objectives of this renewal grant were to: (1) continue ongoing measurements of soil and plant parameters that assess primary treatment responses; (2) address the potential heterogeneity of soil properties and (3) initiate a new suite of measurements that will provide data necessary for scaling/modeling of whole-plot to ecosystem-level responses. Our experimental approach included soil plan-water interactions using TDR, neutron probe, and miniaturized soil matric potential and moisture sensors, plant ecophysiological and productivity responses to water and nitrogen treatments and remote sensing methodologies deployed on a radio control platform.

  6. Resolving conflicts in public health protection and ecosystem service provision at designated bathing waters.

    Science.gov (United States)

    Quilliam, Richard S; Kinzelman, Julie; Brunner, Joel; Oliver, David M

    2015-09-15

    Understanding and quantifying the trade-off between the requirement for clean safe bathing water and beaches and their wider ecosystem services is central to the aims of the European Union (EU) Marine Strategy Framework Directive (MSFD), and vital for the sustainability and economic viability of designated bathing waters. Uncertainty surrounding the impacts of ensuing bathing water policy transitions, e.g. the EU revised Bathing Waters Directive (rBWD), puts new urgency on our need to understand the importance of natural beach assets for human recreation, wildlife habitat and for protection from flooding and erosion. However, managing coastal zones solely in terms of public health could have potentially negative consequences on a range of other social and cultural ecosystem services, e.g. recreation. Improving our knowledge of how bathing waters, surrounding beach environments and local economies might respond to shifts in management decisions is critical in order to inform reliable decision-making, and to evaluate future implications for human health. In this paper we explore the conflicts and trade-offs that emerge at public beach environments, and propose the development of an evaluative framework of viable alternatives in environmental management whereby bathing waters are managed for their greatest utility, driven by identifying the optimal ecosystem service provision at any particular site. PMID:26188988

  7. Role of canopy interception on water and nutrient cycling in Chinese fir plantation ecosystem

    Institute of Scientific and Technical Information of China (English)

    KANG Wenxing; DENG Xiangwen; ZHAO Zhonghui

    2007-01-01

    The role of canopy interception on nutrient cycling in Chinese fir plantation ecosystem was studied on the basis of the position data during four years.Results indicate that the average canopy interception amount was 267.0 mm/year.Canopy interception play a significant role in water cycle and nutrient cycle processes in ecosystem,and was an important part of evaporation from the Chinese fir plantation ecosystem,being up to 27.2%.The evaporation from the canopy interception was an important way of water output from ecosystem,up to 19.9%.The flush-eluviation of branches and leaves caused by canopy interception brought nutrient input of 143.629 kg/(hm2·year),which was 117.2% of the input 63.924kg/(hm2·year)from the atmospheric precipitation.The decreased amount of 80.1 mm precipitation input caused by canopy interception reduced the amount of rainfall into the stand surface and infiltration into the soil,reduced the output with runoff and drainage,and decreased nutrient loss through output water.Therefore,the additional preserve of nutrient by canopy interception was 8.664 kg/(hm2·year).

  8. Managing the ecosystem to improve human health: integrated approaches to safe drinking water.

    Science.gov (United States)

    Forget, G; Sanchez-Bain, W A

    1999-01-01

    The ecosystem approach to human health is a holistic concept of health for both humans and the environment in which they live. This approach requires a holistic management of all facets of the ecosystem, be they physical, biologic, or indeed human-such as culture, economy, and developmental needs. This paradigm may at first glance seem theoretical and difficult to put into practice in everyday field research. However, using basic human needs, such as water and sanitation, as entry points illustrates how ecosystem health can indeed prove a powerful tool for sustainable development, promoting both human well-being and sustainable ecosystems. The authors describe the efforts of international agencies, particularly the International Development Research Centre (IDRC), to promote household safe drinking water security in developing countries. Essential to the success of these endeavors are strong partnerships with communities, research institutions, and donor agencies. The roles of these players are delineated. An important feature of IDRC projects, which is critical to their success, is the establishment of a simple, community-based water-quality monitoring program that the people can maintain with the limited resources available to them. The process and outcomes of past IDRC projects are presented and ongoing efforts are described. PMID:10092746

  9. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity. The GLOBAQUA project.

    Science.gov (United States)

    Navarro-Ortega, Alícia; Acuña, Vicenç; Bellin, Alberto; Burek, Peter; Cassiani, Giorgio; Choukr-Allah, Redouane; Dolédec, Sylvain; Elosegi, Arturo; Ferrari, Federico; Ginebreda, Antoni; Grathwohl, Peter; Jones, Colin; Rault, Philippe Ker; Kok, Kasper; Koundouri, Phoebe; Ludwig, Ralf Peter; Merz, Ralf; Milacic, Radmila; Muñoz, Isabel; Nikulin, Grigory; Paniconi, Claudio; Paunović, Momir; Petrovic, Mira; Sabater, Laia; Sabaterb, Sergi; Skoulikidis, Nikolaos Th; Slob, Adriaan; Teutsch, Georg; Voulvoulis, Nikolaos; Barceló, Damià

    2015-01-15

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence, interaction and linkages between stressors, and to assess their effects on the chemical and ecological status of freshwater ecosystems in order to improve water management practice and policies. GLOBAQUA assembles a multidisciplinary team of 21 European plus 2 non-European scientific institutions, as well as water authorities and river basin managers. The project includes experts in hydrology, chemistry, biology, geomorphology, modelling, socio-economics, governance science, knowledge brokerage, and policy advocacy. GLOBAQUA studies six river basins (Ebro, Adige, Sava, Evrotas, Anglian and Souss Massa) affected by water scarcity, and aims to answer the following questions: how does water scarcity interact with other existing stressors in the study river basins? How will these interactions change according to the different scenarios of future global change? Which will be the foreseeable consequences for river ecosystems? How will these in turn affect the services the ecosystems provide? How should management and policies be adapted to minimise the ecological, economic and societal consequences? These questions will be approached by combining data-mining, field- and laboratory-based research, and modelling. Here, we outline the general structure of the project and the activities to be conducted within the fourteen work-packages of GLOBAQUA. PMID:25005236

  10. Ecohydrological optimization of pattern and processes in water-limited ecosystems

    Science.gov (United States)

    Caylor, K. K.; Scanlon, T. M.; Rodriguez-Iturbe, I.

    2006-12-01

    The coupled nature of hydrological and ecological dynamics is perhaps nowhere more evident than in water- limited ecosystems. Despite the close coupling that exists between dynamics of surface water and vegetation structure, the challenge of predicting vegetation response to changing climate in these environments is particularly daunting. A central challenge is defining the ecologically and hydrologically relevant processes that led to the formation of vegetation patterns in water-limited ecosystems. There remains a need to clarify the manner by which vegetation self-organizes across scales within semi-arid landscapes, and how regional, landscape, and individual-based patterns of vegetation interact with their accompanying climates and soils. Such clarification necessitates the development of conceptual models capable of interpreting and predicting spatial pattern formation in savannas (and similar dry woodland ecosystems) as well as metrics for assessing optimization or organization of patterns - from individual canopies to landscapes and beyond. This presentation focuses on the spatial aspects of interactions between plants, soils, and climates in two different water-limited systems. The first is a series of savanna sites spanning a large rainfall gradient within southern African, and the second is a semi-arid river basin organized around a drainage network in central New Mexico. We explore the drivers of ecohydrological spatial pattern formation at a hierarchy of scales that range from climate gradients spanning thousands of kilometers to that of individual tree canopies spanning only a few meters. In each case, we link the dynamics of soil moisture to patterns of vegetation in order to explore the general hypothesis that many semi-arid ecosystems tend to self-organize with respect to optimizing water use. Model results indicate that observed patterns are likely due to an optimization scheme that both maximizes water use while minimizing water stress.

  11. Assessment of the Water Quality and Ecosystem Health of the Great Barrier Reef (Australia): Conceptual Models

    Science.gov (United States)

    Haynes, David; Brodie, Jon; Waterhouse, Jane; Bainbridge, Zoe; Bass, Deb; Hart, Barry

    2007-12-01

    Run-off containing increased concentrations of sediment, nutrients, and pesticides from land-based anthropogenic activities is a significant influence on water quality and the ecologic conditions of nearshore areas of the Great Barrier Reef World Heritage Area, Australia. The potential and actual impacts of increased pollutant concentrations range from bioaccumulation of contaminants and decreased photosynthetic capacity to major shifts in community structure and health of mangrove, coral reef, and seagrass ecosystems. A detailed conceptual model underpins and illustrates the links between the main anthropogenic pressures or threats (dry-land cattle grazing and intensive sugar cane cropping) and the production of key contaminants or stressors of Great Barrier Reef water quality. The conceptual model also includes longer-term threats to Great Barrier Reef water quality and ecosystem health, such as global climate change, that will potentially confound direct model interrelationships. The model recognises that system-specific attributes, such as monsoonal wind direction, rainfall intensity, and flood plume residence times, will act as system filters to modify the effects of any water-quality system stressor. The model also summarises key ecosystem responses in ecosystem health that can be monitored through indicators at catchment, riverine, and marine scales. Selected indicators include riverine and marine water quality, inshore coral reef and seagrass status, and biota pollutant burdens. These indicators have been adopted as components of a long-term monitoring program to enable assessment of the effectiveness of change in catchment-management practices in improving Great Barrier Reef (and adjacent catchment) water quality under the Queensland and Australian Governments’ Reef Water Quality Protection Plan.

  12. Ecosystem services and urban heat riskscape moderation: water, green spaces, and social inequality in Phoenix, USA.

    Science.gov (United States)

    Jenerette, G Darrel; Harlan, Sharon L; Stefanov, William L; Martin, Chris A

    2011-10-01

    Urban ecosystems are subjected to high temperatures--extreme heat events, chronically hot weather, or both-through interactions between local and global climate processes. Urban vegetation may provide a cooling ecosystem service, although many knowledge gaps exist in the biophysical and social dynamics of using this service to reduce climate extremes. To better understand patterns of urban vegetated cooling, the potential water requirements to supply these services, and differential access to these services between residential neighborhoods, we evaluated three decades (1970-2000) of land surface characteristics and residential segregation by income in the Phoenix, Arizona, USA metropolitan region. We developed an ecosystem service trade-offs approach to assess the urban heat riskscape, defined as the spatial variation in risk exposure and potential human vulnerability to extreme heat. In this region, vegetation provided nearly a 25 degrees C surface cooling compared to bare soil on low-humidity summer days; the magnitude of this service was strongly coupled to air temperature and vapor pressure deficits. To estimate the water loss associated with land-surface cooling, we applied a surface energy balance model. Our initial estimates suggest 2.7 mm/d of water may be used in supplying cooling ecosystem services in the Phoenix region on a summer day. The availability and corresponding resource use requirements of these ecosystem services had a strongly positive relationship with neighborhood income in the year 2000. However, economic stratification in access to services is a recent development: no vegetation-income relationship was observed in 1970, and a clear trend of increasing correlation was evident through 2000. To alleviate neighborhood inequality in risks from extreme heat through increased vegetation and evaporative cooling, large increases in regional water use would be required. Together, these results suggest the need for a systems evaluation of the

  13. Simulation of coupled pelagic-benthic ecosystem of the Yellow Sea Cold Water Mass

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A one-dimensional coupled pelagic-benthic box model for the Yellow Sea Cold Water Mass (YSCWM) is developed. The model is divided into three boxes vertically according to the depths of thermocline and euphotic layer. It simulates well the oligotrophic shelf ecosystem of the YSCWM considering effects of nutrients deposition and microbial loop. Main features of vertical structure of various variables in ecosystem of the YSCWM were captured and seasonal variability of the ecosystem was well reconstructed. Calculation shows that the contribution of microbial loop to the zooplankton can reach up to 60%. Besides, input of inorganic nutrients from atmospheric deposition is an important mechanism of production in upper layer of the YSCWM when stratified.

  14. Cut off from supplies - sulfate exhaustion and implications for methane emissions in a brackish rewetted peatland after separation from the coast

    Science.gov (United States)

    Koebsch, Franziska; Liu, Bo; Schmiedinger, Iris; Spitzy, Alejandro; Köhler, Stefan; Koch, Marian; Jurasinski, Gerald; Gehre, Matthias; Sachs, Torsten; Böttcher, Michael

    2016-04-01

    Coastal ecosystems are at the interface between marine and freshwater and exhibit a special geochemistry. We investigate the S and C geochemistry of a coastal, degraded fen peatland. The site has been cut off from the Baltic Sea since 1995 and was rewetted with freshwater from the surrounding catchment in 2010. Despite of locally high pore water sulfate (SO42-) concentrations, the fen turned into a strong source for methane (CH4) with annual budgets up to 0.26±0.06 kg m-2 (Hahn et al. 2015). To reconcile this apparent contradiction we use concentration patterns and stable isotope signatures of water, SO42-, pyrite, dissolved carbon, and CH4 (δ2H, δ13C, δ18O, δ34S) along a transect with increasing distance to the Baltic coastline (300-1500 m). The current peatland geochemistry is characterized by a combination of relict signals reflecting former brackish water intrusion events and indicators of recent human activities such as internal eutrophication and increasing freshwater contribution. The shallow peat layer (depth mostly ≤ 55 cm) exhibited a pronounced vertical gradient with a freshwater-front lying on top of the brackish water layer. S geochemistry was decoupled from present brackish water distribution as marine SO42- was almost completely biotically reduced and converted to pyrite. The remaining pore water SO42- pool was remarkably 34S-enriched in relation to Baltic Sea SO42- (up to +86.4 and +21‰, respectively) and also δ34S-values of pyrite were comparatively high (+4.8‰), thereby demonstrating a distinct reservoir effect under closed-system conditions. However, one of the profiles situated 1150 m from the Baltic Sea coast line exhibited a contrasting S pattern with pronounced excess of isotopically lighter SO42- at depth (up to 32.8 mM and +22.7‰). We hypothesize, that local groundwater seeps might provide electron acceptors such as NO3- for the contemporary oxidation of pyrite. δ13C in DIC exhibited a pronounced vertical shift from -23.9

  15. Final Technical Report: Effects of Changing Water and Nitrogen Inputs on a Mojave Desert Ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Stanley, D.; Nowak, Robert S.; Fenstermaker, Lynn, F.; Young, Michael,H.

    2007-11-30

    In order to anticipate the effects of global change on ecosystem function, it is essential that predictive relationships be established linking ecosystem function to global change scenarios. The Mojave Desert is of considerable interest with respect to global change. It contains the driest habitats in North America, and thus most closely approximates the world’s great arid deserts. In order to examine the effects of climate and land use changes, in 2001 we established a long-term manipulative global change experiment, called the Mojave Global Change Facility. Manipulations in this study include the potential effects of (1) increased summer rainfall (75 mm over three discrete 25 mm events), (2) increased nitrogen deposition (10 and 40 kg ha-1), and (3) the disturbance of biological N-fixing crusts . Questions addressed under this grant shared the common hypothesis that plant and ecosystem performance will positively respond to the augmentation of the most limiting resources to plant growth in the Mojave Desert, e.g., water and nitrogen. Specific hypotheses include (1) increased summer rainfall will significantly increase plant production through an alleviation of moisture stress in the dry summer months, (2) N-deposition will increase plant production in this N-limited system, particularly in wet years or in concert with added summer rain, and (3) biological crust disturbance will gradually decrease bio-available N, with concomitant long-term reductions in photosynthesis and ANPP. Individual plant and ecosystem responses to global change may be regulated by biogeochemical processes and natural weather variability, and changes in plant and ecosystem processes may occur rapidly, may occur only after a time lag, or may not occur at all. During the first PER grant period, we observed changes in plant and ecosystem processes that would fall under each of these time-response intervals: plant and ecosystem processes responded rapidly to added summer rain, whereas most

  16. Managing Forests for Water in the Anthropocene—The Best Kept Secret Services of Forest Ecosystems

    Directory of Open Access Journals (Sweden)

    Irena F. Creed

    2016-03-01

    Full Text Available Water and forests are inextricably linked. Pressures on forests from population growth and climate change are increasing risks to forests and their aquatic ecosystem services (AES. There is a need to incorporate AES in forest management but there is considerable uncertainty about how to do so. Approaches that manage forest ecosystem services such as fiber, water and carbon sequestration independently ignore the inherent complexities of ecosystem services and their responses to management actions, with the potential for unintended consequences that are difficult to predict. The ISO 31000 Risk Management Standard is a standardized framework to assess risks to forest AES and to prioritize management strategies to manage risks within tolerable ranges. The framework consists of five steps: establishing the management context, identifying, analyzing, evaluating and treating the risks. Challenges to implementing the framework include the need for novel models and indicators to assess forest change and resilience, quantification of linkages between forest practice and AES, and the need for an integrated systems approach to assess cumulative effects and stressors on forest ecosystems and AES. In the face of recent international agreements to protect forests, there are emerging opportunities for international leadership to address these challenges in order to protect both forests and AES.

  17. Understanding ecosystems' sub-daily water and carbon flux changes during dry-down events

    Science.gov (United States)

    Nelson, Jacob; Jung, Martin; Carvalhais, Nuno; Migliavacca, Mirco; Reichstein, Markus

    2016-04-01

    Sub-daily water and carbon flux patterns give important and sometimes overlooked information about ecosystem processes and land-atmosphere feedbacks. While models often perform well down to daily timescales, they can be uncertain with respect to the diurnal courses, especially during dry-down events where the fraction of T to ET is shifting. We analyzed events from multiple locations for unique pattern changes that were robust across sites. Of particular interest were the divergence of water and carbon fluxes during high radiation periods, which indicates changes in water use efficiency as drought conditions intensified. The validity of attributing the signatures to ecosystem transitions such as changes in phenology, switches in soil evaporation vs transpiration dominance, and physiological stress were evaluated by comparing to site specific sap flow, soil moisture, and remote sensing data. Going forward, these findings can be used to further understand ecosystem physiology under drought conditions, and can also be used to partition of water fluxes and better constrain future models.

  18. Linkages Among Water Vapor Flows, Food Production, and Terrestrial Ecosystem Services

    Directory of Open Access Journals (Sweden)

    Malin Falkenmark

    1999-12-01

    Full Text Available Global freshwater assessments have not addressed the linkages among water vapor flows, agricultural food production, and terrestrial ecosystem services. We perform the first bottom-up estimate of continental water vapor flows, subdivided into the major terrestrial biomes, and arrive at a total continental water vapor flow of 70,000 km3/yr (ranging from 56,000 to 84,000 km3/yr. Of this flow, 90% is attributed to forests, including woodlands (40,000 km3/yr, wetlands (1400 km3/yr, grasslands (15,100 km3/yr, and croplands (6800 km3/yr. These terrestrial biomes sustain society with essential welfare-supporting ecosystem services, including food production. By analyzing the freshwater requirements of an increasing demand for food in the year 2025, we discover a critical trade-off between flows of water vapor for food production and for other welfare-supporting ecosystem services. To reduce the risk of unintentional welfare losses, this trade-off must become embedded in intentional ecohydrological landscape management.

  19. Landform-Water-Vegetation Feedbacks: Exploring Ecosystem Stability and Restoration Potential in Semiarid Hillslopes

    Science.gov (United States)

    Moreno de las Heras, M.; Saco, P. M.; Merino-Martin, L.; Espigares, T.; Nicolau, J. M.

    2014-12-01

    Vegetation dynamics and soil surface processes (e.g. runoff, soil erosion, sedimentation) are tightly coupled in drylands, where vegetation cover is patchy and plant production largely depends on favourable redistribution of water and sediments. At the same time, the amount and spatial distribution of vegetation control hillslope runoff and erosion, and strongly influence the redistribution of water and soil resources in these systems. Large shifts in the structure and organization of vegetation are associated with land degradation, frequently involving nonlinear responses to both human and climatic pressures. The study of landform-water-vegetation feedbacks has, therefore, a critical role for the comprehension of ecosystem stability and restoration potential in arid and semiarid environments. We present a synthesis of field-based, remote-sensed and modelling studies on soil-vegetation patterns in semiarid rangelands of Australia and water-restricted reclaimed mining slopes of Spain. Our results indicate that the organization and stability of vegetation patterns strongly depends on feedbacks with coevolving landforms. Exploration of degradation trends in banded Mulga shrublands of central Australia reveals that human disturbances (e.g. grazing) can strongly alter landform-water-vegetation feedbacks and particularly the way water is spatially redistributed and used by vegetation, resulting in threshold-like responses of ecosystem function. Successful experiences on the restoration of these systems highlight that the management of runoff and sediment flows is decisive to recover vegetation patchiness and landscape function. The study of vegetation-water-landform feedbacks in Mediterranean-dry reclaimed mining slopes of Spain offers additional indications on the restoration of drylands, particularly on the effects of rill and gully erosion on the stability of restored vegetation. The development of rill and gully networks provides very efficient drainage networks for

  20. Managing aquatic ecosystems and water resources under multiple stress--an introduction to the MARS project.

    Science.gov (United States)

    Hering, Daniel; Carvalho, Laurence; Argillier, Christine; Beklioglu, Meryem; Borja, Angel; Cardoso, Ana Cristina; Duel, Harm; Ferreira, Teresa; Globevnik, Lidija; Hanganu, Jenica; Hellsten, Seppo; Jeppesen, Erik; Kodeš, Vit; Solheim, Anne Lyche; Nõges, Tiina; Ormerod, Steve; Panagopoulos, Yiannis; Schmutz, Stefan; Venohr, Markus; Birk, Sebastian

    2015-01-15

    Water resources globally are affected by a complex mixture of stressors resulting from a range of drivers, including urban and agricultural land use, hydropower generation and climate change. Understanding how stressors interfere and impact upon ecological status and ecosystem services is essential for developing effective River Basin Management Plans and shaping future environmental policy. This paper details the nature of these problems for Europe's water resources and the need to find solutions at a range of spatial scales. In terms of the latter, we describe the aims and approaches of the EU-funded project MARS (Managing Aquatic ecosystems and water Resources under multiple Stress) and the conceptual and analytical framework that it is adopting to provide this knowledge, understanding and tools needed to address multiple stressors. MARS is operating at three scales: At the water body scale, the mechanistic understanding of stressor interactions and their impact upon water resources, ecological status and ecosystem services will be examined through multi-factorial experiments and the analysis of long time-series. At the river basin scale, modelling and empirical approaches will be adopted to characterise relationships between multiple stressors and ecological responses, functions, services and water resources. The effects of future land use and mitigation scenarios in 16 European river basins will be assessed. At the European scale, large-scale spatial analysis will be carried out to identify the relationships amongst stress intensity, ecological status and service provision, with a special focus on large transboundary rivers, lakes and fish. The project will support managers and policy makers in the practical implementation of the Water Framework Directive (WFD), of related legislation and of the Blueprint to Safeguard Europe's Water Resources by advising the 3rd River Basin Management Planning cycle, the revision of the WFD and by developing new tools for

  1. Interacting coastal based ecosystem services: recreation and water quality in Puget Sound, WA

    Science.gov (United States)

    Kreitler, Jason; Papenfus, Michael; Byrd, Kristin; Labiosa, William

    2013-01-01

    Coastal recreation and water quality are major contributors to human well-being in coastal regions. They can also interact, creating opportunities for ecosystem based management, ecological restoration, and water quality improvement that can positively affect people and the environment. Yet the effect of environmental quality on human behavior is often poorly quantified, but commonly assumed in coastal ecosystem service studies. To clarify this effect we investigate a water quality dataset for evidence that environmental condition partially explains variation in recreational visitation, our indicator of human behavior. In Puget Sound, WA, we investigate variation in visitation in both visitation rate and fixed effects (FE) models. The visitation rate model relates the differences in annual recreational visitation among parks to environmental conditions, park characteristics, travel cost, and recreational demand. In our FE model we control for all time-invariant unobserved variables and compare monthly variation at the park level to determine how water quality affects visitation during the summer season. The results of our first model illustrate how visitation relates to various amenities and costs. In the FE analysis, monthly visitation was negatively related to water quality while controlling for monthly visitation trends. This indicates people are responding to changes in water quality, and an improvement would yield an increase in the value of recreation. Together, these results could help in prioritizing water quality improvements, could assist the creation of new parks or the modification of existing recreational infrastructure, and provide quantitative estimates for the expected benefits from potential changes in recreational visitation and water quality improvements. Our results also provide an example of how recreational visitation can be quantified and used in ecosystem service assessments.

  2. Interacting coastal based ecosystem services: recreation and water quality in Puget Sound, WA.

    Directory of Open Access Journals (Sweden)

    Jason Kreitler

    Full Text Available Coastal recreation and water quality are major contributors to human well-being in coastal regions. They can also interact, creating opportunities for ecosystem based management, ecological restoration, and water quality improvement that can positively affect people and the environment. Yet the effect of environmental quality on human behavior is often poorly quantified, but commonly assumed in coastal ecosystem service studies. To clarify this effect we investigate a water quality dataset for evidence that environmental condition partially explains variation in recreational visitation, our indicator of human behavior. In Puget Sound, WA, we investigate variation in visitation in both visitation rate and fixed effects (FE models. The visitation rate model relates the differences in annual recreational visitation among parks to environmental conditions, park characteristics, travel cost, and recreational demand. In our FE model we control for all time-invariant unobserved variables and compare monthly variation at the park level to determine how water quality affects visitation during the summer season. The results of our first model illustrate how visitation relates to various amenities and costs. In the FE analysis, monthly visitation was negatively related to water quality while controlling for monthly visitation trends. This indicates people are responding to changes in water quality, and an improvement would yield an increase in the value of recreation. Together, these results could help in prioritizing water quality improvements, could assist the creation of new parks or the modification of existing recreational infrastructure, and provide quantitative estimates for the expected benefits from potential changes in recreational visitation and water quality improvements. Our results also provide an example of how recreational visitation can be quantified and used in ecosystem service assessments.

  3. Long-term increase in forest water-use efficiency observed across ecosystem carbon flux networks

    Science.gov (United States)

    Keenan, Trevor; Bohrer, Gil; Dragoni, Danilo; Hollinger, David; Munger, James W.; Schmid, Hans Peter; Richardson, Andrew

    2014-05-01

    Terrestrial plants remove CO2 from the atmosphere through photo- synthesis, a process that is accompanied by the loss of water vapour from leaves. The ratio of water loss to carbon gain, or water-use efficiency, is a key characteristic of ecosystem function that is central to the global cycles of water, energy and carbon. Here we analyse direct, long-term measurements of whole-ecosystem carbon and water exchange. We find a substantial increase in water-use efficiency in temperate and boreal forests of the Northern Hemisphere over the past two decades. We systematically assess various competing hypotheses to explain this trend, and find that the observed increase is most consistent with a strong CO2 fertilization effect. The results suggest a partial closure of stomata - small pores on the leaf surface that regulate gas exchange - to maintain a near- constant concentration of CO2 inside the leaf even under continually increasing atmospheric CO2 levels. The observed increase in forest water-use efficiency is larger than that predicted by existing theory and 13 terrestrial biosphere models. The increase is associated with trends of increasing ecosystem-level photosynthesis and net carbon uptake, and decreasing evapotranspiration. Our findings demonstrate the utility of maintaining long-term eddy-covariance flux measurement sites. The results suggest a shift in the carbon- and water-based economics of terrestrial vegetation, which may require a reassessment of the role of stomatal control in regulating interactions between forests and climate change, and a re-evaluation of coupled vegetation-climate models.

  4. Water use strategies and ecosystem-atmosphere exchange of CO2 in two highly seasonal environments

    Directory of Open Access Journals (Sweden)

    A. Arneth

    2006-01-01

    Full Text Available We compare assimilation and respiration rates, and water use strategies in four divergent ecosystems located in cold-continental central Siberia and in semi-arid southern Africa. These seemingly unrelated systems have in common a harsh and highly seasonal environment with a very sharp transition between the dormant and the active season, with vegetation facing dry air and soil conditions for at least part of the year. Moreover, the northern high latitudes and the semi-arid tropics will likely experience changes in key environmental parameters (e.g., air temperature and precipitation in the future; indeed, in some regions marked climate trends have already been observed over the last decade or so. The magnitude of instantaneous or daily assimilation and respiration rates, derived from one to two years of eddy covariance measurements in each of the four ecosystems, was not related to the growth environment. For instance, respiration rates were clearly highest in the two deciduous systems included in the analysis (a Mopane woodland in northern Botswana and a Downy birch forest in Siberia; >300 mmol m−2 d−1, while assimilation rates in the Mopane woodland were relatively similar to a Siberian Scots pine canopy for a large part of the active season (ca. 420 mmol m−2 d−1. Acknowledging the limited number of ecosystems compared here, these data nevertheless demonstrate that factors like vegetation type, canopy phenology or ecosystem age can override larger-scale climate differences in terms of their effects on carbon assimilation and respiration rates. By far the highest rates of assimilation were observed in Downy birch, an early successional species. These were achieved at a rather conservative water use, as indicated by relatively low levels of λ, the marginal water cost of plant carbon gain. Surprisingly, the Mopane woodland growing in the semi-arid environment had significantly higher values of λ. However, its water use strategy included

  5. Water use strategies and ecosystem-atmosphere exchange of CO2 in two highly seasonal environments

    Directory of Open Access Journals (Sweden)

    O. Kolle

    2006-04-01

    Full Text Available We compare assimilation and respiration rates, and water use strategies in four divergent ecosystems located in cold-continental central Siberia and in semi-arid southern Africa. These seemingly unrelated systems have in common a harsh and highly seasonal environment with a very sharp transition between the dormant and the active season, and with vegetation facing dry air and soil conditions for at least part of the year. Moreover, the northern high latitudes and the semi-arid tropics will likely experience changes in key environmental parameters (e.g., air temperature and precipitation in the future; indeed, in some regions marked climate trends have already been observed over the last decade or so. The magnitude of instantaneous or daily assimilation and respiration rates, derived from one to two years of eddy covariance measurements in each of the four ecosystems, was not related to the growth environment. For instance, respiration rates were clearly highest in the two deciduous systems included in the analysis (a Mopane woodland in northern Botswana and a Downy birch forest in Siberia; >300 mmol m−2 d−1, while assimilation rates in the Mopane woodland were relatively similar to a Siberian Scots pine canopy for a large part of the active season (ca. 420 mmol m−2 d−1. Acknowledging the limited number of ecosystems compared here, these data nevertheless suggest that factors like vegetation type, canopy phenology or ecosystem age can override larger-scale climate differences in terms of their effects on carbon assimilation and respiration rates. By far the highest rates of assimilation were observed in Downy birch, an early successional species. These were achieved at a rather conservative water use, as indicated by relatively low levels of λ, the marginal water cost of plant carbon gain. Surprisingly, the Mopane woodland growing in the semi-arid environment had significantly higher values of λ. However, its water use strategy

  6. Science to support management of receiving waters in an event-driven ecosystem: from land to river to sea

    OpenAIRE

    Leigh, C.; Burford, M.A.; Connolly, R.M.; Olley, J.M.; Saeck, E.; Sheldon, F.; Smart, J.C.R.; Bunn, S.E.

    2013-01-01

    Managing receiving-water quality, ecosystem health and ecosystem service delivery is challenging in regions where extreme rainfall and runoff events occur episodically, confounding and often intensifying land-degradation impacts. We synthesize the approaches used in river, reservoir and coastal water management in the event-driven subtropics of Australia, and the scientific research underpinning them. Land-use change has placed the receiving waters of Moreton Bay, an internationally-significa...

  7. Science to Support Management of Receiving Waters in an Event-Driven Ecosystem: From Land to River to Sea

    OpenAIRE

    Bunn, Stuart E.; Smart, James C.R.; Fran Sheldon; Emily Saeck; Connolly, Rod M.; Jon M. Olley; Michele A. Burford; Catherine Leigh

    2013-01-01

    Managing receiving-water quality, ecosystem health and ecosystem service delivery is challenging in regions where extreme rainfall and runoff events occur episodically, confounding and often intensifying land-degradation impacts. We synthesize the approaches used in river, reservoir and coastal water management in the event-driven subtropics of Australia, and the scientific research underpinning them. Land-use change has placed the receiving waters of Moreton Bay, an internationally-significa...

  8. Decontamination and functional reclamation of dredged brackish sediments

    OpenAIRE

    Doni, Serena; Macci, Cristina; Peruzzi, Eleonora; Bianchi, Veronica; Iannelli, Renato; Ceccanti, Brunello; Masciandaro, Grazia

    2012-01-01

    The continuous stream of sediment dredged from harbors and channels to provide shipping traffic efficiency is a considerable and ongoing problem worldwide recognized. In this study (European Project AGRIPORT) phytoremediation has been considered as a sustainable reclamation technology for bringing slightly polluted brackish sediments into productive use. The experimentation has been carried out in containers of about 1 m3 filled with contaminated (heavy metals and hydrocarbons) brackish sedim...

  9. Earth Observation Based Assessment of the Water Production and Water Consumption of Nile Basin Agro-Ecosystems

    Directory of Open Access Journals (Sweden)

    Wim G.M. Bastiaanssen

    2014-10-01

    Full Text Available The increasing competition for water resources requires a better understanding of flows, fluxes, stocks, and the services and benefits related to water consumption. This paper explains how public domain Earth Observation data based on Moderate Resolution Imaging Spectroradiometer (MODIS, Second Generation Meteosat (MSG, Tropical Rainfall Measurement Mission (TRMM and various altimeter measurements can be used to estimate net water production (rainfall (P > evapotranspiration (ET and net water consumption (ET > P of Nile Basin agro-ecosystems. Rainfall data from TRMM and the Famine Early Warning System Network (FEWS-NET RainFall Estimates (RFE products were used in conjunction with actual evapotranspiration from the Operational Simplified Surface Energy Balance (SSEBop and ETLook models. Water flows laterally between net water production and net water consumption areas as a result of runoff and withdrawals. This lateral flow between the 15 sub-basins of the Nile was estimated, and partitioned into stream flow and non-stream flow using the discharge data. A series of essential water metrics necessary for successful integrated water management are explained and computed. Net water withdrawal estimates (natural and humanly instigated were assumed to be the difference between net rainfall (Pnet and actual evapotranspiration (ET and some first estimates of withdrawals—without flow meters—are provided. Groundwater-dependent ecosystems withdraw large volumes of groundwater, which exceed water withdrawals for the irrigation sector. There is a strong need for the development of more open-access Earth Observation databases, especially for information related to actual ET. The fluxes, flows and storage changes presented form the basis for a global framework to describe monthly and annual water accounts in ungauged river basins.

  10. The food-water-land-ecosystems nexus in Europe: an integrated assessment

    OpenAIRE

    Kebede, Abiy S.

    2016-01-01

    Climate and socio-economic change impacts interact in complex ways. These are likely to cross traditional sectoral and regional boundaries with cascading indirect and potentially far reaching repercussions. This is particularly important for the food-water-land-ecosystems (FWLE) nexus. A holistic understanding of these interactions is central for devising appropriate adaptation strategies. This thesis presents a systematic methodological framework that provides new insights into understanding...

  11. Irrigation Strategies and Crop Breeding As Complementary Measures for Improved Water Management and Ecosystem Services

    Science.gov (United States)

    Vico, G.; Manzoni, S.; Weih, M.; Porporato, A. M.

    2014-12-01

    The projected population growth and changes in climate and dietary habits will further increase the pressure on water resources globally. Within precision farming, a host of technical solutions has been developed to reduce water consumption for agricultural uses. Examples are the shift from scheduled to demand-based irrigation and the use of sophisticated water distribution techniques. The next frontier for a more sustainable agriculture is the combination of reduced water requirements with enhanced ecosystem services. Currently, staple grains are obtained from annuals crops. Enhanced ecosystem services could be obtained shifting from annual to perennial crops, obtained by means of targeted breeding. In fact, perennial plants, with their continuous soil cover and the higher allocation of resources to the below ground, contribute to the reduction of soil erosion, water and nutrient losses, while enhancing carbon sequestration in the root zone. We explore here the implications for water management at the field- to farm-scale of both improved irrigation methods and targeted breeding. A probabilistic description of the soil water balance and crop development is employed to quantify water requirements and yields and their inter-annual variability, as a function of rainfall patterns, soil and crop features. Optimal irrigation strategies are thus defined in terms of maximization of yield and minimization of required irrigation volumes and their inter-annual variability. The probabilistic model is parameterized based on an extensive meta-analysis of traits of co-generic annual and perennial species (including both selected and wild species) to explore the consequences for water requirements of shifting from annual to perennial crops under current and future climates. The larger and more developed roots of perennial crops may allow a better exploitation of soil water resources than annual species. At the same time, perennial crops may require adequate water supply for

  12. Ecosystem services in Mediterranean river basin: climate change impact on water provisioning and erosion control.

    Science.gov (United States)

    Bangash, Rubab F; Passuello, Ana; Sanchez-Canales, María; Terrado, Marta; López, Alfredo; Elorza, F Javier; Ziv, Guy; Acuña, Vicenç; Schuhmacher, Marta

    2013-08-01

    The Mediterranean basin is considered one of the most vulnerable regions of the world to climate change and such changes impact the capacity of ecosystems to provide goods and services to human society. The predicted future scenarios for this region present an increased frequency of floods and extended droughts, especially at the Iberian Peninsula. This paper evaluates the impacts of climate change on the water provisioning and erosion control services in the densely populated Mediterranean Llobregat river basin of. The assessment of ecosystem services and their mapping at the basin scale identify the current pressures on the river basin including the source area in the Pyrenees Mountains. Drinking water provisioning is expected to decrease between 3 and 49%, while total hydropower production will decrease between 5 and 43%. Erosion control will be reduced by up to 23%, indicating that costs for dredging the reservoirs as well as for treating drinking water will also increase. Based on these data, the concept for an appropriate quantification and related spatial visualization of ecosystem service is elaborated and discussed. PMID:23660520

  13. Intrinsic climate dependency of ecosystem light and water-use-efficiencies across Australian biomes

    International Nuclear Information System (INIS)

    The sensitivity of ecosystem gross primary production (GPP) to availability of water and photosynthetically active radiation (PAR) differs among biomes. Here we investigated variations of ecosystem light-use-efficiency (eLUE: GPP/PAR) and water-use-efficiency (eWUE: GPP/evapotranspiration) among seven Australian eddy covariance sites with differing annual precipitation, species composition and temperature. Changes to both eLUE and eWUE were primarily correlated with atmospheric vapor pressure deficit (VPD) at multiple temporal scales across biomes, with minor additional correlations observed with soil moisture and temperature. The effects of leaf area index on eLUE and eWUE were also relatively weak compared to VPD, indicating an intrinsic dependency of eLUE and eWUE on climate. Additionally, eLUE and eWUE were statistically different for biomes between summer and winter, except eWUE for savannas and the grassland. These findings will improve our understanding of how light- and water-use traits in Australian ecosystems may respond to climate change. (letter)

  14. Partitioning of catchment water budget and its implications for ecosystem carbon exchange

    Directory of Open Access Journals (Sweden)

    D. Lee

    2010-06-01

    Full Text Available Spatially averaged annual carbon budget is one of the key information needed to understand ecosystem response and feedback to climate change. Water availability is a primary constraint of carbon uptake in many ecosystems and therefore the estimation of ecosystem water use may serve as an alternative to quantify Gross Primary Productivity (GPP. To examine this concept, we estimated a long-term steady state water budget for the Han River basin (~26 000 km2 in Korea and examined its application for catchment scale carbon exchange. For this, the catchment scale evapotranspiration (ET was derived from the long term precipitation (P and discharge (Q data. Then, using stable isotope data of P and Q along with other hydrometeorological information, ET was partitioned into evaporation from soil and water surfaces (ES, evaporation from intercepted rainfall (EI, and transpiration (T. ES was identified as a minor component of ET in the study areas regardless of the catchment scales. The annual T, estimated from ET after accounting for EI and ES for the Han River basin from 1966 to 2007, was 22~31% of annual P and the proportion decreased with increasing P. Assuming that T further constrains the catchment scale GPP in terms of water use efficiency (WUE, we examined the possibility of using T as a relative measure for the strength and temporal changes of carbon uptake capacity. The proposed relationship would provide a simple and practical way to assess the spatial distribution of ecosystem GPP, provided the WUE estimates in terms of GPP/T at ecosystem scale could be obtained. For carbon and water tracking toward a sustainable Asia, ascertaining such a spatiotemporally representative WUE and their variability is a

  15. Exploring industry specific social welfare maximizing rates of water pollution abatement in linked terrestrial and marine ecosystems

    NARCIS (Netherlands)

    Roebeling, P.C.; Hendrix, E.M.T.; Grieken, van M.E.

    2009-01-01

    Marine ecosystems are severely affected by water pollution originating from coastal catchments, while these ecosystems are of vital importance from an environmental as well as an economic perspective. To warrant sustainable economic development of coastal regions, we need to balance the marginal cos

  16. Modelling carbon and water flows in terrestrial ecosystems in the boreal zone - examples from Oskarshamn

    Energy Technology Data Exchange (ETDEWEB)

    Karlberg, Louise [Stockholm Environment Institute (SEI), Stockholm (Sweden); Gu stafsson, David; Jansson, Per-Erik [Royal Inst. of Technology, Dept. of Land and Water Resources Engineering, Stockholm (Sweden)

    2007-12-15

    Carbon budgets and mean residence times were estimated in four hypothetical ecosystems. The greatest uncertainties in the estimations lie in the calculation of fluxes to and from the field layer. A parametrisation method based on multiple criteria, synthesising a wide range of empirical knowledge on ecosystem behaviour, proved to be useful both in the estimation of unknown parameters, to demonstrate model sensitivity, and to identify processes where our current knowledge is limited. The parameterizations derived from the study of the hypothetical systems were used to estimate site-specific carbon and water budgets for four ecosystems located within the Oskarshamn study-area. Measured soil respiration was used to calibrate the simulations. An analysis of the simulated carbon fluxes indicated that two of the ecosystems, namely the grassland and the spruce forest, were net sources of carbon dioxide, while the alder and the pine forest were net sinks of CO{sub 2}. In the former case, this was interpreted as a result of recent drainage of the organogenic soils and the concurrent increase in decomposition. The results from the study conformed rather well with results from a previous study on carbon budgets from the Oskarshamn study area.

  17. Modelling carbon and water flows in terrestrial ecosystems in the boreal zone - examples from Oskarshamn

    International Nuclear Information System (INIS)

    Carbon budgets and mean residence times were estimated in four hypothetical ecosystems. The greatest uncertainties in the estimations lie in the calculation of fluxes to and from the field layer. A parametrisation method based on multiple criteria, synthesising a wide range of empirical knowledge on ecosystem behaviour, proved to be useful both in the estimation of unknown parameters, to demonstrate model sensitivity, and to identify processes where our current knowledge is limited. The parameterizations derived from the study of the hypothetical systems were used to estimate site-specific carbon and water budgets for four ecosystems located within the Oskarshamn study-area. Measured soil respiration was used to calibrate the simulations. An analysis of the simulated carbon fluxes indicated that two of the ecosystems, namely the grassland and the spruce forest, were net sources of carbon dioxide, while the alder and the pine forest were net sinks of CO2. In the former case, this was interpreted as a result of recent drainage of the organogenic soils and the concurrent increase in decomposition. The results from the study conformed rather well with results from a previous study on carbon budgets from the Oskarshamn study area

  18. Ecosystem-level water-use efficiency inferred from eddy covariance data: definitions, patterns and spatial up-scaling

    Science.gov (United States)

    Reichstein, M.; Beer, C.; Kuglitsch, F.; Papale, D.; Soussana, J. A.; Janssens, I.; Ciais, P.; Baldocchi, D.; Buchmann, N.; Verbeeck, H.; Ceulemans, R.; Moors, E.; Köstner, B.; Schulze, D.; Knohl, A.; Law, B. E.

    2007-12-01

    In this presentation we discuss ways to infer and to interpret water-use efficiency at ecosystem level (WUEe) from eddy covariance flux data and possibilities for scaling these patterns to regional and continental scale. In particular we convey the following: WUEe may be computed as a ratio of integrated fluxes or as the slope of carbon versus water fluxes offering different chances for interpretation. If computed from net ecosystem exchange and evapotranspiration on has to take of counfounding effects of respiration and soil evaporation. WUEe time-series at diurnal and seasonal scale is a valuable ecosystem physiological diagnostic for example about ecosystem-level responses to drought. Most often WUEe decreases during dry periods. The mean growing season ecosystem water-use efficiency of gross carbon uptake (WUEGPP) is highest in temperate broad-leaved deciduous forests, followed by temperate mixed forests, temperate evergreen conifers, Mediterranean broad-leaved deciduous forests, Mediterranean broad-leaved evergreen forests and Mediterranean evergreen conifers and boreal, grassland and tundra ecosystems. Water-use efficiency exhibits a temporally quite conservative relation with atmospheric water vapor pressure deficit (VPD) that is modified between sites by leaf area index (LAI) and soil quality, such that WUEe increases with LAI and soil water holding capacity which is related to texture. This property and tight coupling between carbon and water cycles is used to estimate catchment-scale water-use efficiency and primary productivity by integration of space-borne earth observation and river discharge data.

  19. Rock, Water, Critters: Lake Huron’s Groundwater-Fueled Submerged Sinkhole Ecosystems (Invited)

    Science.gov (United States)

    Biddanda, B. A.; Ruberg, S. A.; Kendall, S.; Nold, S.; Hawley, N.

    2009-12-01

    Dissolution of the Paleozoic (~400 mya) carbonate bedrock in the Lake Huron Basin has produced numerous underwater karst sinkholes through which groundwater emerges onto the lake floor at various depths. Some of these submerged sinkholes adjacent to the coastline are visible from space (e.g., go to 45 5.181’N, 83 19.065’W or 45 11.921’N, 83 19.661’W in Google Earth). Recent underwater explorations have revealed unique hotspots of biogeochemical activity at several such submerged groundwater vents in Lake Huron. On average, the inflowing water is ten-fold higher in specific conductivity than ambient lake water (1.8 mS/cm in groundwater vs. 0.1 mS/cm in lake water) suggesting active groundwater venting to the lake floor. Fueled by venting groundwater containing high sulfate (>1000 mg/L in groundwater vs. 8mg/L in lake water), these underwater ecosystems are characterized by sharp physical and chemical gradients and spectacularly colorful benthic microbial mats that overly carbon-rich sediments. Here, typical lake inhabitants are replaced by communities dominated by microorganisms - Bacteria, Archaea and Eukarya that perform unique ecosystem functions. Lake Huron’s sinkhole ecosystems bear many similarities to geographically distant ecosystems such as deep-sea marine vents, subsurface sulfur springs and permanently ice-covered Antarctic lakes. In Lake Huron, shallow sunlit sinkholes are dominated by photosynthetic microorganisms and processes, while food webs in deep aphotic sinkholes are supported primarily by chemosynthesis. Metabolic processes occurring in sediment cores overlaid by purple cyanobacterial benthic mats from intermediate depth sinkholes receiving ~10-20% of surface solar radiation include oxygenic photosysnthesis, anoxygenic photosynthesis, chemosynthesis, sulfate reduction, sulfur oxidation, methanogenesis, and methane oxidation. Additional data from flow rates of emerging groundwater, pore water chemistry, microbial molecular fingerprints

  20. Total nitrogen concentrations in surface water of typical agro- and forest ecosystems in China, 2004-2009.

    Directory of Open Access Journals (Sweden)

    Zhiwei Xu

    Full Text Available We assessed the total nitrogen (N concentrations of 28 still surface water (lake and pond, and 42 flowing surface water (river, monitoring sites under 29 typical terrestrial ecosystems of the Chinese Ecosystem Research Network (CERN using monitoring data collected between 2004 and 2009. The results showed that the median total N concentrations of still surface water were significantly higher in the agro- (1.5 mg · L(-1 and oasis agro- ecosystems (1.8 mg · L(-1 than in the forest ecosystems (1.0 mg · L(-1. This was also the case for flowing surface water, with total N concentrations of 2.4 mg · L(-1, 1.8 mg · L(-1 and 0.5 mg · L(-1 for the agro-, oasis agro- and forest ecosystems, respectively. In addition, more than 50% of the samples in agro- and oasis agro- ecosystems were seriously polluted (>1.0 mg · L(-1 by N. Spatial analysis showed that the total N concentrations in northern and northwestern regions were higher than those in the southern region for both still and flowing surface waters under agro- and oasis agro- ecosystems, with more than 50% of samples exceeding 1.0 mg · L(-1 (the Class III limit of the Chinese National Quality Standards for Surface Waters in surface water in the northern region. Nitrogen pollution in agro- ecosystems is mainly due to fertilizer applications, while the combination of fertilizer and irrigation exacerbates nitrogen pollution in oasis agro- ecosystems.

  1. The behavior of 89Sr and tritium water (HTO) in a model terrestrial-aquatic ecosystem

    International Nuclear Information System (INIS)

    The effect of land polluted by 89Sr on water body and the immigration of HTO from water body to land were studied in a modelling terrestrial-aquatic ecosystem. The results are as follows: (1) The 89Sr in soil quickly migrated to common bean plants and its concentration in common bean plants was increasing with the time, but the concentration of 89Sr in soil was exponentially declining with the depth. About 5% of 89Sr was migrated to water body by rainfall then distributed to other components, and it can be concentrated by aquatics in a certain degree. (2) when HTO entered into the water body, it would migrate to other components of the ecosystem. and the HTO in the pool was linearly decreasing with the time. However, the concentration of HTO in the sediments and aquatics would firstly increase then reached the peak and went down. The tritium of HTO was existed in two forms in the sediments and aquatics, free water (HTO) and bound tritium. HTO was also migrated to the adjacent land soil and absorbed by land crop plants, within one and half months the land system contained 24% of the total tritium in the aquatic system

  2. Water quality assessment of Gautami — Godavari mangrove estuarine ecosystem of Andhra Pradesh, India during September 2001

    Indian Academy of Sciences (India)

    S C Tripathy; A K Ray; S Patra; V V Sarma

    2005-04-01

    Some chemical and biological parameters were analysed at sixteen stations in the mangrove ecosystem, of the neighbouring Gautami-Godavari (GG) river estuary and Kakinada (KKD) bay to understand the present status of water quality and the impact of external terrigenous inputs during southwest (SW) monsoon in the study areas. High concentrations of nutrients in the mangrove ecosystem compared to the bay and estuarine ecosystems reveal the importance of this zone as a source of nutrients to the adjacent coastal ecosystems. Low Si :N:P (29 : 4 : 1) ratios in these ecosystems are due to the enrichment of these nutrients through external anthropogenic inputs even after the utilization by phytoplankton in the biological cycle. The mean Chl /Chl and Chl /Chl ratios and high phaeopigments (Pp) concentrations compared to Chl and high ratios of Chl /Pp suggests the possibility of the potential growth of phytoplankton populations in lower light intensity and low turbulent areas of these mangrove ecosystems.

  3. Water demand for ecosystem protection in rivers with hyper-concentrated sediment-laden flow

    Institute of Scientific and Technical Information of China (English)

    LUO; Huaming; LI; Tianhong; NI; Jinren; WANG; Yudong

    2004-01-01

    Sediment transport is one of the main concerns in a river system with hyper-concentrated flows. Therefore, the water use for sediment transport must be considered in study on the water demand for river ecosystem. The conventional methods for calculating the Minimum Water Demand for River Ecosystem (MWDRE) are not appropriate for rivers with high sediment concentration. This paper studied the MWDRE in wet season, dry season and the whole year under different water-and-sediment conditions in the Lower Yellow River, which is regarded as a typical river with sediment-laden flows. The characteristics of MWDRE in the river are analyzed. Firstly,the water demand for sediment transport (WDST) is much larger than the demands for other riverine functions, the WDST accounts for the absolute majority of the MWDRE.Secondly, in wet season when the WDST is satisfied, not only most of the annual incoming sediment can be transported downstream, but also the water demands for other river functions can be satisfied automatically, so that the MWDRE in wet season is identical to the WDST. Thirdly, in dry season, when the WDST is satisfied, the water demands for other river functions can also be satisfied, but the low sediment transport efficiency results in significant waste of water resources. According to these characteristics and aiming at decreasing sediment deposition in the riverbed and improving the utilization efficiency of water resources, hydrological engineering works can be used to regulate or control flow and sediment so that the sediment incoming in dry season can be accumulated and be transported downstream intensively and thus efficiently in wet season.

  4. Predicting tree water use and drought tolerance from leaf traits in the Los Angeles urban ecosystem

    Science.gov (United States)

    John, G. P.; Scoffoni, C.; Sack, L.

    2013-12-01

    Urban green space provides a suite of valuable ecosystem services. In semiarid systems, like Los Angeles, trees rely primarily on irrigation water for transpiration. Managers may need to reduce irrigation associated with urban trees given climate change, urban expansion, and the steady decrease in available freshwater. While leaf and whole plant water relations have been extensively studied, we are only now gaining a detailed understanding of diverse leaf anatomical designs, and their use for predicting physiology and water use at landscape scale. For 50 diverse urban species, we quantified leaf anatomical and physiological traits important to tree drought tolerance and water use efficiency including turgor loss point, vein architecture, cellular anatomy, leaf mass per unit area, and petiole and leaf dimensions. We hypothesized detailed relationships to develop models relating leaf functional traits to tree water relations. These models provide key insights regarding the role of anatomical designs in leaf stress tolerance and water use efficiency. Additionally we predicted how traits measured at the leaf level would scale with existing data for individuals at the whole plant level. We tested our predictions by determining correlations between leaf level anatomical traits and drought tolerance. Additionally, we determined correlations between functional traits, physiology and water use, and the climate of origin for the urban species. Leaf level measurements will be valuable for rapid estimation of more difficult to measure whole plant water relations traits important at the landscape scale. The Los Angeles urban ecosystem can serve as a model for other semiarid system and provide more informed system wide water conservation strategies.

  5. Diffuse radiation increases global ecosystem-level water-use efficiency

    Science.gov (United States)

    Moffat, A. M.; Reichstein, M.; Cescatti, A.; Knohl, A.; Zaehle, S.

    2012-12-01

    Current environmental changes lead not only to rising atmospheric CO2 levels and air temperature but also to changes in air pollution and thus the light quality of the solar radiation reaching the land-surface. While rising CO2 levels are thought to enhance photosynthesis and closure of stomata, thus leading to relative water savings, the effect of diffuse radiation on transpiration by plants is less clear. It has been speculated that the stimulation of photosynthesis by increased levels of diffuse light may be counteracted by higher transpiration and consequently water depletion and drought stress. Ultimately, in water co-limited systems, the overall effect of diffuse radiation will depend on the sensitivity of canopy transpiration versus photosynthesis to diffuse light, i.e. whether water-use efficiency changes with relative levels of diffuse light. Our study shows that water-use efficiency increases significantly with higher fractions of diffuse light. It uses the ecosystem-atmosphere gas-exchange observations obtained with the eddy covariance method at 29 flux tower sites. In contrast to previous global studies, the analysis is based directly on measurements of diffuse radiation. Its effect on water-use efficiency was derived by analyzing the multivariate response of carbon and water fluxes to radiation and air humidity using a purely empirical approach based on artificial neural networks. We infer that per unit change of diffuse fraction the water-use efficiency increases up to 40% depending on diffuse fraction levels and ecosystem type. Hence, in regions with increasing diffuse radiation positive effects on primary production are expected even under conditions where water is co-limiting productivity.

  6. Ecohydrology of managed ecosystems: Linking rainfall unpredictability, agronomic performance, and sustainable water use

    Science.gov (United States)

    Vico, Giulia; Porporato, Amilcare

    2014-05-01

    The field of ecohydrology, traditionally focusing on natural ecosystems, can offer the necessary quantitative tools to assess and compare the sustainability of agriculture across climates, soil types, crops, and irrigation strategies, including rainfall unpredictability. In particular, irrigation is one of the main strategies to enhance and stabilize agricultural productivity, but represents a cost in terms of often scarce water resources. Here, the sustainability of irrigated and rainfed agriculture is assessed by means of water productivity (defined as the ratio between yield and total supplied water), yields, water requirements, and their variability. These indicators are quantified using a probabilistic description of the soil water balance and crop development. Employing this framework, we interpret changes in water productivity as total water input is altered, in two staple crops (maize and wheat) grown under different soils, climates, and irrigation strategies. Climate change scenarios are explored by using the same approach and altering the rainfall statistics. For a given irrigation strategy, intermediate rainfall inputs leads to the highest variability in yield and irrigation water requirement - it is under these conditions that water management is most problematic. When considering the contrasting needs of limiting water requirements while ensuring adequate yields, micro-irrigation emerges as the most sustainable strategy at the field level, although consideration should be given to its profitability and long-term environmental implications.

  7. Science to Support Management of Receiving Waters in an Event-Driven Ecosystem: From Land to River to Sea

    Directory of Open Access Journals (Sweden)

    Stuart E. Bunn

    2013-06-01

    Full Text Available Managing receiving-water quality, ecosystem health and ecosystem service delivery is challenging in regions where extreme rainfall and runoff events occur episodically, confounding and often intensifying land-degradation impacts. We synthesize the approaches used in river, reservoir and coastal water management in the event-driven subtropics of Australia, and the scientific research underpinning them. Land-use change has placed the receiving waters of Moreton Bay, an internationally-significant coastal wetland, at risk of ecological degradation through increased nutrient and sediment loads. The event-driven climate exacerbates this issue, as the waterways and ultimately Moreton Bay receive large inputs of nutrients and sediment during events, well above those received throughout stable climatic periods. Research on the water quality and ecology of the region’s rivers and coastal waters has underpinned the development of a world-renowned monitoring program and, in combination with catchment-source tracing methods and modeling, has revealed the key mechanisms and management strategies by which receiving-water quality, ecosystem health and ecosystem services can be maintained and improved. These approaches provide a useful framework for management of water bodies in other regions driven by episodic events, or where novel stressors are involved (e.g., climate change, urbanization, to support sustained ecosystem service delivery and restoration of aquatic ecosystems.

  8. Predicting drivers and distributions of deep-sea ecosystems: A cold-water coral case study

    DEFF Research Database (Denmark)

    Mohn, Christian; Rengstorf, Anna; Brown, Colin;

    2015-01-01

    Little is yet known about species distribution patterns and physical drivers in deep-sea environments due the expensive and time consuming sampling effort. The increasing need to manage and protect vulnerable marine ecosystems, such as cold-water corals, has motivated the use of predictive......, facilitating species distribution modelling with high spatial detail. In this study, we used high resolution data (250 m grid size) from a newly developed hydrodynamic model to explore linkages between key physical drivers and occurrences of the cold-water coral Lophelia pertusa in selected areas of the NE...... to provide decision support for marine spatial planning and conservation in the deep sea. Mohn et al., 2014.Linking benthic hydrodynamics and cold water coral occurrences: A high-resolution model study at three cold-water coral provinces in the NE Atlantic. Progress in Oceanography 122, 92...

  9. Studies on the distribution of trace and major elements in a tropical fresh water ecosystem

    International Nuclear Information System (INIS)

    This study presents the results of characterization of some environmental components of aquatic ecosystem in Kadra reservoir. Concentration of eight trace and major elements in water, sediment and some commonly available fish species in the reservoir were estimated using Atomic Absorption Spectrophotometer. The concentration (mg/kg dry wt.) in the sediment was found to be Na: 100-843, K: 1267-9370, Ca: 85-1597, Mg: 2101-5511, Mn: 695- 3380, Fe: 40398-99086, Cu: 33-99 and Zn: 43-129 respectively. The elemental concentration in water is almost same in all the locations. Among all the elements studied in this experiment, maximum Kd of sediment/water system was observed in Fe and Mn. Maximum water-to-fish TF of Fe, Cu and Zn was observed in Horabagrus sps. (1.5, 0.13, 1.6) respectively and Mn was observed in Periopthalmus sps. (2.7). (author)

  10. Tropical organic soils ecosystems in relation to regional water resources in southeast Asia

    Energy Technology Data Exchange (ETDEWEB)

    Armentano, T. V.

    1982-01-01

    Tropical organic soils have functioned as natural sinks for carbon, nitrogen, slfur and other nutrients for the past 4000 years or more. Topographic evolution in peat swamp forests towards greater oligotrophy has concentrated storage of the limited nutrient stock in surface soils and biota. Tropical peat systems thus share common ecosystem characteristics with northern peat bogs and certain tropical oligotrophic forests. Organic matter accumulation and high cation-exchange-capacity limit nutrient exports from undisturbed organic soils, although nutrient retention declines with increasing eutrophy and wetland productivity. Peat swamps are subject to irreversible degradation if severely altered because disturbance of vegetation, surface peats and detritus can disrupt nuttrient cycles and reduce forest recovery capacity. Drainage also greatly increases exports of nitrogen, phosphorus and other nutrients and leads to downstream eutrophication and water quality degradation. Regional planning for clean water supplies must recognize the benefits provided by natural peatlands in balancing water supplies and regulating water chemistry.

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

    International Nuclear Information System (INIS)

    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

  12. Solute concentrations in water samples from clearfelled and standing Sitka spruce (Picea sitchensis) forest ecosystems, Kershope Forest: dataset documentation

    OpenAIRE

    C. M. Wood; Adamson, J. K.

    2014-01-01

    This document describes an associated dataset which consists of solute concentrations (Potassium, Calcium, Magnesium, Iron, Sodium, Aluminium, Phosphate, Nitrate, Ammonium, Chlorine, Sulphate), also pH and suspended solids, in waters sampled from clear felled and standing Sitka spruce (Picea sitchensis) forest ecosystems in Kershope Forest, Cumbria, UK. Water samples were collected from the ecosystem of a Sitka spruce plantation at weekly intervals for six years. The drainage system of the si...

  13. Hydrologic Modeling of Urbanizing Oregon Basins for Water-Related Ecosystem Service Assessment using SWAT

    Science.gov (United States)

    Psaris, A. M.; Chang, H.; Winfield, T.; Lambrinos, J.

    2012-12-01

    Since humans rely on nature for certain goods and services, there should be accurate economic representations for them. These goods and services are commonly called ecosystem services. Our research seeks to investigate how water-related ecosystem services - water yield, sediment retention, and nutrient retention, can be measured and quantified spatially, and explores how the issue of scale affects these measurements. The water model of the ecosystem service evaluation tool Integrated Valuation of Ecosystem Services and Tradeoff (InVEST) is being tested against the well-known, physically based model, SWAT (Soil and Water Assessment Tool) in the Yamhill and Tualatin basins, located in Oregon, USA. Both models are being used to assess the potential hydrologic changes that may result from climate and land use changes in the middle of the 21st century. We build a total of five sub-basin models representing an urban-rural gradient, and use SWAT-CUP for calibration. Our study area contains a mixture of forested, agricultural, and developed land, and the Tualatin River is a regulated river with one dam and four wastewater treatment plants. Fanno Creek is a highly developed subwatershed of Tualatin and has the best model results with an NSE = 0.87 and a % BIAS = -1.15 after calibration for simulating monthly hydrograph. Dairy Creek is a forested sub-basin of the Tualatin and has an NSE = 0.72 and a % BIAS = 0.29. The upstream Tualatin gage (Dilley) has good results with an NSE = 0.77 and a % BIAS = 2.50 after calibration. While the Dilley results are acceptable, the monthly hydrograph shows clear problems during the summer due to water releases from Hagg Lake and Barney reservoirs which are not included in the model at this time. Yamhill basin has an NSE = 0.80 and a % BIAS = -13.0. This basin is mostly agricultural land which utilizes water withdrawls for irrigation. This may account for the consistent over estimation of flow. Finally, the whole Tualatin River basin has an

  14. Monitoring and modeling water-vegetation interactions in groundwater-dependent ecosystems

    Science.gov (United States)

    Orellana, Felipe; Verma, Parikshit; Loheide, Steven P., II; Daly, Edoardo

    2012-09-01

    In many regions around the world, groundwater is the key source of water for some vegetation species, and its availability and dynamics can define vegetation composition and distribution. In recent years the interaction between groundwater and vegetation has seen a renewed attention because of the impact of groundwater extraction on natural ecosystems' health and increasing interest in the restoration of riparian zones and wetlands. The literature provides studies that approach this problem from very different angles. Information on the vegetation species that are likely to depend on groundwater and the physical characteristics of such species can be found in a large body of literature in ecology and plant physiology. Environmental engineers, hydrologists, and geoscientists are more focused on ecosystem restoration and the estimation of a catchment's water balance, for which the groundwater transpired by vegetation might be an important component. Here we join together these different bodies of literature with the aim of providing the state of knowledge on groundwater-dependent vegetation. We describe the physiological features that characterize groundwater-dependent vegetation, review different methods to study vegetation water use in the field, discuss recent advances in the understanding of how groundwater levels might determine vegetation composition, and present a summary of the available mathematical models that include the interaction between groundwater levels and vegetative water use. Several future research directions are identified, such as the quantification and modeling of the partitioning of transpiration between unsaturated and saturated zones and the development of integrated models able to link hydrology, ecology, and geomorphology.

  15. Mercury in sediment, water, and fish in a managed tropical wetland-lake ecosystem.

    Science.gov (United States)

    Malczyk, Evan A; Branfireun, Brian A

    2015-08-15

    Mercury pollution has not been well documented in the inland lakes or fishes of Mexico, despite the importance of freshwater fish as a source of protein in local diets. Total mercury and methylmercury in waters, sediments, and the commercial fish catch were investigated in Lake Zapotlán, Mexico. Concentrations of total and methylmercury were very high in runoff and wastewater inputs, but very low in sediments and surface waters of the open water area of the lake. Concentrations of total mercury in tilapia and carp were very low, consistent with the low concentrations in lake water and sediments. Particle settling, sorption, the biogeochemical environment, and/or bloom dilution are all plausible explanations for the significant reductions in both total mercury and methylmercury. Despite very high loading of mercury, this shallow tropical lake was not a mercury-impaired ecosystem, and these findings may translate across other shallow, alkaline tropical lakes. Importantly, the ecosystem services that seemed to be provided by peripheral wetlands in reducing mercury inputs highlight the potential for wetland conservation or restoration in Mexico. PMID:25909268

  16. Plant responses, climate pivot points, and trade-offs in water-limited ecosystems

    Science.gov (United States)

    Munson, Seth M.

    2013-01-01

    Plant species in dryland ecosystems are limited by water availability and may be vulnerable to increases in aridity. Methods are needed to monitor and assess the rate of change in plant abundance and composition in relation to climate, understand the potential for degradation in dryland ecosystems, and forecast future changes in plant species assemblages. I employ nearly a century of vegetation monitoring data from three North American deserts to demonstrate an approach to determine plant species responses to climate and critical points over a range of climatic conditions at which plant species shift from increases to decreases in abundance (climate pivot points). I assess these metrics from a site to regional scale and highlight how these indicators of plant performance can be modified by the physical and biotic environment. For example, shrubs were more responsive to drought and high temperatures on shallow soils with limited capacity to store water and fine-textured soils with slow percolation rates, whereas perennial grasses were more responsive to precipitation in sparse shrublands than in relatively dense grasslands and shrublands, where competition for water is likely more intense. The responses and associated climate pivot points of plant species aligned with their lifespan and structural characteristics, and the relationship between responses and climate pivot points provides evidence of the trade-off between the capacity of a plant species to increase in abundance when water is available and its drought resistance.

  17. Sustainable Development of Water Conservancy Ecosystem%水利生态系统可持续发展研究

    Institute of Scientific and Technical Information of China (English)

    陈青青

    2015-01-01

    Sustainable development, ecosystem services and ecosystem ecology of the value of water with three research goals for a detailed analysis, draw some conclusions of the study of ecosystem water conservation and sustainable development.%对可持续发展、生态系统服务和生态配水这三个研究目标的生态学研究价值进行了详细的分析,得出一些水利生态系统可持续发展研究的结论。

  18. Synergy of extreme drought and shrub invasion reduce ecosystem functioning and resilience in water-limited climates

    Science.gov (United States)

    Caldeira, Maria C.; Lecomte, Xavier; David, Teresa S.; Pinto, Joaquim G.; Bugalho, Miguel N.; Werner, Christiane

    2015-10-01

    Extreme drought events and plant invasions are major drivers of global change that can critically affect ecosystem functioning and alter ecosystem-atmosphere exchange. Invaders are expanding worldwide and extreme drought events are projected to increase in frequency and intensity. However, very little is known on how these drivers may interact to affect the functioning and resilience of ecosystems to extreme events. Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event (2011/2012) in a Mediterranean woodland, we show that native shrub invasion and extreme drought synergistically reduced ecosystem transpiration and the resilience of key-stone oak tree species. Ecosystem transpiration was dominated by the water use of the invasive shrub Cistus ladanifer, which further increased after the extreme drought event. Meanwhile, the transpiration of key-stone tree species decreased, indicating a competitive advantage in favour of the invader. Our results suggest that in Mediterranean-type climates the invasion of water spending species and projected recurrent extreme drought events may synergistically cause critical drought tolerance thresholds of key-stone tree species to be surpassed, corroborating observed higher tree mortality in the invaded ecosystems. Ultimately, this may shift seasonally water limited ecosystems into less desirable alternative states dominated by water spending invasive shrubs.

  19. Modelling water provision as an ecosystem service in a large East African river basin

    Science.gov (United States)

    Notter, B.; Hurni, H.; Wiesmann, U.; Abbaspour, K. C.

    2012-01-01

    Reconciling limited water availability with an increasing demand in a sustainable manner requires detailed knowledge on the benefits people obtain from water resources. A frequently advocated approach to deliver such information is the ecosystem services concept. This study quantifies water provision as an ecosystem service for the 43 000 km2 Pangani Basin in Tanzania and Kenya. The starting assumption that an ecosystem service must be valued and accessible by people necessitates the explicit consideration of stakeholders, as well as fine spatial detail in order to determine their access to water. Further requirements include the use of a simulation model to obtain estimates for unmeasured locations and time periods, and uncertainty assessment due to limited data availability and quality. By slightly adapting the hydrological model Soil and Water Assessment Tool (SWAT), developing and applying tools for input pre-processing, and using Sequential Uncertainty Fitting ver. 2 (SUFI-2) in calibration and uncertainty assessment, a watershed model is set up according to these requirements for the Pangani Basin. Indicators for water provision for different uses are derived from model results by combining them with stakeholder requirements and socio-economic datasets such as census or water rights data. Overall water provision is rather low in the basin, however with large spatial variability. On average, for domestic use, livestock, and industry, 86-105 l per capita and day (95% prediction uncertainty, 95 PPU) are available at a reliability level of 95%. 1.19-1.50 ha (95 PPU) of farmland on which a growing period with sufficient water of 3-6 months is reached at the 75% reliability level - suitable for the production of staple crops - are available per farming household, as well as 0.19-0.51 ha (95 PPU) of farmland with a growing period of ≥6 months, suitable for the cultivation of cash crops. The indicators presented reflect stakeholder information needs and can be

  20. Modelling water provision as an ecosystem service in a large East African river basin

    Directory of Open Access Journals (Sweden)

    B. Notter

    2011-08-01

    Full Text Available Reconciling limited water availability with an increasing demand in a sustainable manner requires detailed knowledge on the benefits people obtain from water resources. A frequently advocated approach to deliver such information is the ecosystem services concept. This study quantifies water provision as an ecosystem service for the 43 000 km2 Pangani Basin in Tanzania and Kenya. The starting assumption that an ecosystem service must be valued and accessible by people necessitates the explicit consideration of stakeholders, as well as fine spatial detail in order to determine their access to water. Further requirements include the use of a simulation model to obtain estimates for unmeasured locations and time periods, and uncertainty assessment due to limited data availability and quality. By slightly adapting the hydrological model Soil and Water Assessment Tool (SWAT, developing and applying tools for input pre-processing, and using Sequential Uncertainty Fitting ver. 2 (SUFI-2 in calibration and uncertainty assessment, a watershed model is set up according to these requirements for the Pangani Basin. Indicators for water provision for different uses are derived from model results by combining them with stakeholder requirements and socio-economic datasets such as census or water rights data.

    Overall water provision is rather low in the Basin, however with large spatial variability. On average, for domestic use, livestock, and industry, 86–105 l per capita and day (95 % prediction uncertainty, 95 PPU are available at a reliability level of 95%. 1.19–1.50 ha (95 PPU of farmland on which a growing period with sufficient water of 3-6 months is reached at the 75 % reliability level – suitable for the production of staple crops – are available per farming household, as well as 0.19–0.51 ha (95 PPU of farmland with a growing period of ≥6~months, suitable for the cultivation of cash crops.

    The indicators

  1. Modelling water provision as an ecosystem service in a large East African river basin

    Directory of Open Access Journals (Sweden)

    B. Notter

    2012-01-01

    Full Text Available Reconciling limited water availability with an increasing demand in a sustainable manner requires detailed knowledge on the benefits people obtain from water resources. A frequently advocated approach to deliver such information is the ecosystem services concept. This study quantifies water provision as an ecosystem service for the 43 000 km2 Pangani Basin in Tanzania and Kenya. The starting assumption that an ecosystem service must be valued and accessible by people necessitates the explicit consideration of stakeholders, as well as fine spatial detail in order to determine their access to water. Further requirements include the use of a simulation model to obtain estimates for unmeasured locations and time periods, and uncertainty assessment due to limited data availability and quality. By slightly adapting the hydrological model Soil and Water Assessment Tool (SWAT, developing and applying tools for input pre-processing, and using Sequential Uncertainty Fitting ver. 2 (SUFI-2 in calibration and uncertainty assessment, a watershed model is set up according to these requirements for the Pangani Basin. Indicators for water provision for different uses are derived from model results by combining them with stakeholder requirements and socio-economic datasets such as census or water rights data.

    Overall water provision is rather low in the basin, however with large spatial variability. On average, for domestic use, livestock, and industry, 86–105 l per capita and day (95% prediction uncertainty, 95 PPU are available at a reliability level of 95%. 1.19–1.50 ha (95 PPU of farmland on which a growing period with sufficient water of 3–6 months is reached at the 75% reliability level – suitable for the production of staple crops – are available per farming household, as well as 0.19–0.51 ha (95 PPU of farmland with a growing period of ≥6 months, suitable for the cultivation of cash crops.

    The indicators

  2. The Climate change impact on the water balance and use efficiency of two contrasting water limited Mediterranean ecosystems in Sardinia

    Science.gov (United States)

    Montaldo, Nicola; Corona, Roberto; Albertson, John

    2016-04-01

    Mediterranean ecosystems are commonly heterogeneous savanna-like ecosystems, with contrasting plant functional types (PFT) competing for the water use. Often deforestation activities have been more intensive along the plan and alluvial river valleys, where deep soils are well suited for agricultural and grass became the primary PFT, while more natural woody vegetation (trees and shrubs) survived in the steep hillslopes and mountain areas, where soil thickness is low, i.e. less attractive for agricultural. Hence, Mediterranean regions are characterized by two main ecosystems, grassland and woodland, which for both natural and anthropogenic causes can grow in soils with also different characteristics (texture, hydraulic properties, depth), highly impacting water resources. Mediterranean regions suffer water scarcity produced in part by natural (e.g., climate variations) influences. For instance, in the Flumendosa basin water reservoir system, which plays a primary role in the water supply for much of southern Sardinia, the average annual input from stream discharge in the latter part of the 20th century was less than half the historic average rate. The precipitation over the Flumendosa basin has decreased, but not at such a drastic rate as the discharge, suggesting a marked non-linear response of discharge to precipitation changes. Indeed, precipitation decreased in winter months, which are crucial for reservoirs recharge through runoff. At the same time air temperature increased during the spring-summer season, when the precipitation slightly increased. The IPCC models predicts a further increase of drought in the Mediterranean region during winter, increasing the uncertainty on the future of the water resources system of these regions. Hence, there is the need to investigate the role of the PFT vegetation dynamics on the soil water budget of these ecosystems in the context of the climate change, and predict hydrologic variables for climate change scenarios

  3. Water use efficiency of net primary production in global terrestrial ecosystems

    Indian Academy of Sciences (India)

    Lei Xia; Fei Wang; Xingmin Mu; Kai Jin; Wenyi Sun; Peng Gao; Guangju Zhao

    2015-07-01

    The carbon and water cycles of terrestrial ecosystems, which are strongly coupled via water use efficiency (WUE), are influenced by global climate change. To explore the relationship between the carbon and water cycles and predict the effect of climate change on terrestrial ecosystems, it is necessary to study the WUE in global terrestrial ecosystems. In this study, the 13-year WUE (i.e., net primary production (NPP)/evapotranspiration (ET)) of global terrestrial ecosystems was calculated based on the Moderate Resolution Imaging Spectro-radiometer (MODIS) NPP (MOD17A3) and ET (MOD16A3) products from 2000 to 2012. The results indicate that the annual average WUE decreased but not significantly, and the 13-year mean value was 868.88 mg C m−2 mm−1. The variation trend of WUE value for each pixel differed greatly across the terrestrial ecosystems. A significant variation ( < 0.05) occurred in about 18.50% of the land surface. WUE was spatially distributed from 0 to 2541 mg C m−2 mm−1, and 58.78% of the WUE values were concentrated in the interval of 600–1200 mg C m−2 mm−1. The WUE increased from north to south in Africa and Oceania and from east to west in Europe and South America. Both latitudinal and longitudinal gradients existed in Asia and North America. The following trends in the WUE of different continents and Köppen–Geiger climates were observed: Europe (1129.71 mg C m−2 mm−1) > Oceania (1084.46 mg C m−2 mm−1) > Africa (893.51 mg C m−2 mm−1) > South America (893.07 mg C m−2 mm−1) > North America (870.79 mg C m−2 mm−1) > Asia (738.98 mg C m−2 mm−1) and warm temperate climates (1094 mg C m−2 mm−1) > snowy climates (862 mg C m−2 mm−1) > arid climates (785 mg C m−2 mm−1) > equatorial climates (732 mg C m−2 mm−1) > polar climates (435 mg C m−2 mm−1). Based on the WUE value and the present or future rainfall, the maximum carbon that fixed in one region may be theoretically calculated. Also, under the

  4. In hot water: the future of Australia's coastal and marine ecosystems

    International Nuclear Information System (INIS)

    Full text: Full text: Marine ecosystems are extremely important economically and ecologically to Australia in terms of tourism, coastal defence, resources, and ecosystem services such as nutrient cycling and waste disposal. Australia is also a globally important repository of biodiversity. Here we describe the observed and potential future impacts of climate change on Australia's marine diversity. Climate simulations project oceanic warming, an increase in stratification, a strengthening of the Eastern Australian Current, increased ocean acidification, a rise in sea level, and altered storm and rainfall regimes, which taken collectively will fundamentally change marine ecosystems. There has already been widespread bleaching of tropical corals, poleward shifts of temperate fish and plankton populations, and a decline in cold-water giant kelp off Tasmania. Future changes are likely to be even more dramatic and have considerable economic and ecological consequences, especially in 'hot spots' of climate change such as theTasman Sea and the Great Barrier Reef area. Corals are likely to bleach more frequently and decline in abundance in response to both warming and ocean acidification. Planktonic animals with calcium carbonate shells, such as winged pteropod snails and coccolithophorid phytoplankton, are likely to decline as increased ocean acidification impairs their ability to maintain carbonate body structures. The projected high warming off south-east Australia is of particular concern. Marine ecosystems in this region are already stressed by high metal concentrations, sewage pollution, and overfishing, and climate models project that this region will warm more than anywhere else in the Southern Hemisphere this century because of enhanced southerly penetration of the East Australian Current. Venomous jellyfish and harmful algal blooms, which are major threats to human health, will potentially extend further south and occur more frequently. Temperate species

  5. Carbon and water cycling in flooded and rainfed rice (Oryza Sativa) ecosystem: Disentangling agronomical and ecological aspects of water use efficiency

    Science.gov (United States)

    Nay-Htoon, Bhone; Xue, Wei; Dubbert, Maren; Lindner, Steve; Cuntz, Matthias; Ko, Jonghan; Tenhunen, John; Werner, Christiane

    2015-04-01

    Agricultural crops play an important role in the global carbon and water cycling process and there is intense research to understand and predict carbon and water fluxes, productivity and water use of cultivated crops under climate change. Mechanistic understanding of the trade of between ecosystem water use efficiency and agronomic water use efficiency to maintain higher crop yield and productive water loss is necessary for the ecosystem sustainability. . We compared water and carbon fluxes of paddy and rainfed rice by canopy scale gas exchange measurements, crop growth, and daily evapotranspiration, transpiration and carbon flux modeling. According to our findings, evaporation contributed strongly (maximum 100% to minimum 45%) to paddy rice evapotranspiration while transpiration of rainfed is almost 50 % of daily evapotranspiration. Water use efficiency (WUE) was higher in rainfed rice both from an agronomic (WUEagro, i.e. grain yield per evapotranspiration) and ecosystem (WUEeco, i.e. gross primary production per evapotranspiration) perspective. However, rainfed rice showed also high ecosystem respiration losses and a slightly lower crop yield, demonstrating that higher WUE in rainfed rice comes at the expense of higher respiration losses of assimilated carbon and lower plant production, compared to paddy rice. Our results highlighted the need to partition water and carbon fluxes to improve our mechanistic understanding of water use efficiency and environmental impact of different agricultural practices. Keywords: Rainfed rice, Paddy rice, water use efficiency, Transpiration/Evapotranspiration, ecosystem WUE, agronomic WUE, Evapotranspiration

  6. Characterisation of ecosystem water-use efficiency of european forests from eddy covariance measurements

    Directory of Open Access Journals (Sweden)

    F. G. Kuglitsch

    2008-11-01

    Full Text Available Water-use efficiency (WUE has been recognized as an important characteristic of vegetation productivity in various natural scientific disciplines for decades, but only recently at the ecosystem level, where different ways exist to characterize water-use efficiency. Hence, the objective of this research was (a to systematically compare different ways of calculating ecosystem water-use efficiency (WUEe from eddy-covariance measurements, (b quantify the diurnal, seasonal and interannual variability of WUEe in relation to meteorological conditions, and (c analyse between-site variability of WUEe as affected by vegetation type and climatic conditions, across sites in European forest ecosystems.

    Day-to-day variability of gross primary productivity (GPP and evapotranspiration (ET were more strongly coupled than net ecosystem production (NEP and ET, obviously because NEP also depends on the respiration that is not heavily coupled to water fluxes. However, the slope of daytime NEP versus ET (mNEP from half-hourly measurements of a single day may also be used as a WUEe-estimate giving very similar results to those of the GPP-ET slope (mGPP, since the diurnal variation is dominated by GPP. Since ET is the sum of transpiration (linked to GPP and evaporation from wet vegetation and soil surfaces (not linked to GPP we expected that WUEe is increasing when days after rain are excluded from the analysis. However only very minor changes were found, justifying an analysis of WUEe related to vegetation type.

    In most of the studied ecosystems the instantaneous WUEGPP was quite sensitive to diurnally varying meteorological conditions and tended to decline from the morning to the afternoon by more than 50% because of increasing vapour pressure deficits (VPD.

    Seasonally, WUEGPP increased with a rising monthly precipitation sum and rising average monthly temperatures up to a threshold of 11, 14 and

  7. Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems.

    Science.gov (United States)

    Rix, Laura; de Goeij, Jasper M; Mueller, Christina E; Struck, Ulrich; Middelburg, Jack J; van Duyl, Fleur C; Al-Horani, Fuad A; Wild, Christian; Naumann, Malik S; van Oevelen, Dick

    2016-01-01

    Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated. Here we used laboratory stable isotope tracer experiments to show the transfer of coral mucus into the bulk tissue and phospholipid fatty acids of the warm-water sponge Mycale fistulifera and cold-water sponge Hymedesmia coriacea, demonstrating a direct trophic link between corals and reef sponges. Furthermore, 21-40% of the mucus carbon and 32-39% of the nitrogen assimilated by the sponges was subsequently released as detritus, confirming a sponge loop on Red Sea warm-water and north Atlantic cold-water coral reefs. The presence of a sponge loop in two vastly different reef environments suggests it is a ubiquitous feature of reef ecosystems contributing to the high biogeochemical cycling that may enable coral reefs to thrive in nutrient-limited (warm-water) and energy-limited (cold-water) environments. PMID:26740019

  8. Termites as Mediators of the Water Economy of Arid Savanna Ecosystems

    Science.gov (United States)

    Turner, S.

    2002-05-01

    Termites of the genus Macrotermes are major movers of carbon, minerals and soil through arid savanna ecosystems. They and their fungal symbionts concentrate cellulose digestion and metabolism in a tightly regulated nest environment, which results in a very high metabolic power density in the nest. Cellulose, their principal food, is a potent source of stored energy through the photosynthetic fixation of carbon dioxide. However, cellulose is also fixed water, which is released by its metabolism. Because of the highly seasonal rains in arid savannas, plants often experience drought conditions in the summer months. However, termite metabolism can make water available year-round to plants growing near termite colonies. Long-term variations in rainfall and drought (such as periodic El Nino events) can be further ameliorated by the regulated release of fixed water by termites.

  9. Relating Ctenophore Population to Water Mass Indices in the Northeast U.S. Continental Shelf Ecosystem

    Directory of Open Access Journals (Sweden)

    Rebecca Sparks

    2015-01-01

    Full Text Available Ctenophores exist throughout the Northeast U.S. Continental Shelf Ecosystem, but the underlying mechanisms that control ctenophore populations at this scale are not clear. Ctenophore population data over the last 30 years coincides with changes in several water masses on the shelf, but discovering which water mass was most influential was problematic without mechanistic clarity. This paper strives to identify the relationship between oceanography and ctenophore populations over the last 30 years. Using a numerical modeling approach, we found a strong relationship between the North Atlantic Oscillation index, percent Labrador Subarctic Slope Water, and ctenophore population. We suggest these results might inform future efforts to develop a predictive capability for major changes in ctenophore population.

  10. Ecosystem scale measurements of biomass water using cosmic-ray neutrons

    Science.gov (United States)

    Franz, T. E.; Zreda, M. G.; Rosolem, R.; Hornbuckle, B. K.; Irvin, S.; Adams, H. D.; Kolb, T.; Zweck, C.; Shuttleworth, W. J.

    2013-12-01

    Accurate estimates of biomass are imperative for understanding the global carbon cycle. However, measurements of biomass and water in the biomass are difficult to obtain at a scale consistent with measurements of mass and energy transfer, ~ 1 km, leading to substantial uncertainty in dynamic global vegetation models. Here we use a novel cosmic-ray neutron method to estimate a stoichiometric predictor of ecosystem-scale biomass and biomass water equivalent over tens of hectares. We present results from three experimental studies, a ponderosa pine forest, a maize field, and a desert shrubland, where neutron-derived estimates of biomass water equivalent are compared and found consistent with direct observations. In addition, we will describe the uncertainty in the measurements, which are dominated by the largest hydrogen pool sensed of soil moisture. Given the new hectometer scale of nondestructive observation and potential for continuous measurements we anticipate this technique to be useful for validation of remote sensing products.

  11. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity

    Science.gov (United States)

    Barceló Cullerés, Damià; Ludwig, Ralf

    2015-04-01

    Water and water-related services are major components of the human wellbeing, and as such are major factors of socio-economic development in Europe; yet freshwater systems are under threat by a variety of stressors (organic and inorganic pollution, geomorphological alterations, land cover change, water abstraction, invasive species and pathogens. Some stressors, such as water scarcity, can be a stressor on its own because of its structural character, and drive the effects of other stressors. The relevance of water scarcity as a stressor is more important in semi-arid regions, such as the Mediterranean basin, which are characterized by highly variable river flows and the occurrence of low flows. This has resulted in increases in frequency and magnitude of extreme flow events. Furthermore, in other European regions such as eastern Germany, western Poland and England, water demand exceeds water availability and water scarcity has become an important management issue. Water scarcity is most commonly associated with inappropriate water management, with resulting river flow reductions. It has become one of the most important drivers of change in freshwater ecosystems. Conjoint occurrence of a myriad of stressors (chemical, geomorphological, biological) under water scarcity will produce novel and unfamiliar synergies and most likely very pronounced effects. Within this context, GLOBAQUA has assembled a multidisciplinary team of leading scientists in the fields of hydrology, chemistry, ecology, ecotoxicology, economy, sociology, engineering and modeling in order to study the interaction of multiple stressors within the frame of strong pressure on water resources. The aim is to achieve a better understanding how current management practices and policies could be improved by identifying the main drawbacks and alternatives.

  12. Tracking Ecosystem Water Use Efficiency of Cropland by Exclusive Use of MODIS EVI Data

    Directory of Open Access Journals (Sweden)

    Xuguang Tang

    2015-08-01

    Full Text Available One of the most important linkages that couple terrestrial carbon and water cycles is ecosystem water use efficiency (WUE, which is relevant to the reasonable utilization of water resources and farming practices. Eddy covariance techniques provide an opportunity to monitor the variability in WUE and can be integrated with Moderate Resolution Imaging Spectroradiometer (MODIS observations. Scaling up in situ observations from flux tower sites to large areas remains challenging and few studies have been reported on direct estimation of WUE from remotely-sensed data. This study examined the main environmental factors driving the variability in WUE of corn/soybean croplands, and revealed the prominent role of solar radiation and temperature. Time-series of MODIS-derived enhanced vegetation indices (EVI, which are proxies for the plant responses to environmental controls, were also strongly correlated with ecosystem WUE, thereby implying great potential for remote quantification. Further, both performance of the indirect MODIS-derived WUE from gross primary productivity (GPP and evapotranspiration (ET, and the direct estimates by exclusive use of MODIS EVI data were evaluated using tower-based measurements. The results showed that ecosystem WUE were overpredicted at the beginning and ending of crop-growth periods and severely underestimated during the peak periods by the indirect estimates from MODIS products, which was mainly attributed to the error source from MODIS GPP. However, a simple empirical model that is solely based on MODIS EVI data performed rather well to capture the seasonal variations in WUE, especially for the growing periods of croplands. Independent validation at different sites indicates the method has potential for broad application.

  13. Analysis of selection procedures to determine priority areas for payment for water ecosystem services programs

    Directory of Open Access Journals (Sweden)

    Ana Feital Gjorup

    2016-03-01

    Full Text Available The approach of ecosystem services has shown promise for the evaluation of interactions between ecosystems and society, integrating environmental and socioeconomic concepts which require interdisciplinary knowledge. However, its usefulness in decision making is limited due to information gaps. This study was therefore developed in order to contribute to the application of principles of ecosystem services in the decision-making for water resources management. It aims to identify procedures and methodologies used for decision-making in order to select priority areas to be included in projects or compensation programs for environmental services. To do so, we searched technical and scientific literature describing methods and experiences used to select priority areas. Key steps in the process of selecting priority areas were identified; then a survey was conducted of the procedures adopted for each key step considering the literature selected; and, finally, the information collected was analyzed and classified. Considering the study’s sample, we noted that the selection of priority areas was based on the direct use of predetermined criteria. The use of indicators and spatial analyses are practices still scarcely employed. We must highlight, however, that most of the analyzed documents did not aim to describe the process of selecting priority areas in detail, which may have resulted in some omissions. Although these conditions may limit the analysis in this study, the results presented here allow us to identify the main objectives, actions and criteria used to select priority areas for programs or compensation projects for environmental services.

  14. Perfluorinated compounds: Levels, trophic web enrichments and human dietary intakes in transitional water ecosystems

    International Nuclear Information System (INIS)

    Highlights: • PFOA/S levels in a trophic web of a heavily human-stressed lagoon are measured. • High levels were found in mussels, clams and crabs. • The principal PFCs inflow sources for the ecosystem is the river. • Biota (i.e. macroalgae proliferation) contributes to redistribute pollutants in the lagoon. • Human daily dietary intakes are below maximum tolerable levels suggested by the EFSA. -- Abstract: The results of a study on levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), analyzed in terms of HPLC-ESI-MS in water, sediment, macrophyte, bivalve, crustacean and fish samples, are reported here. The aim of the research is to define, for the first time, PFOA/S levels in a heavily human-stressed transitional water ecosystem (Orbetello lagoon, Italy) and evaluate trophic web enrichments and human dietary intakes. The results obtained show that: (i) levels significantly higher than those reported in the literature were found in mussels, clams and crabs; (ii) the river is a significant pollution source; (iii) although absolute levels are relatively low, macroalgae proliferation contributes to redistribute pollutants from river-affected areas throughout the entire lagoon basin; (iv) to the best of our current knowledge, water-filtering species considered in this study are the most exposed to PFOA/S pollution; (v) human daily dietary intakes of PFOA/S through Slow Food-endorsed product consumption are below maximum tolerable levels suggested by the EFSA

  15. Any Way the Wind Blows does Really Matter to Ecosystem Water Use Efficiency

    Science.gov (United States)

    Montaldo, Nicola; Oren, Ram

    2015-04-01

    In many regions, atmospheric conditions change frequently with shifts of wind direction, extending maritime influences far inland or continental influences to coastal ecosystems. However, depending on their origin, high velocity winds can bring dry continental air to the coast (e.g., Santa Ana winds along the mid-eastern Pacific coast2-3) or cool maritime air far inland. In these regions, water and carbon fluxes may respond to meso- and macroscale weather patterns, yet the effects of wind direction have been explicitly considered only in footprint analyses, limited mostly to CO2] on We, and should be considered in earth-system models.

  16. The effects of climatic fluctuations and extreme events on running water ecosystems

    Science.gov (United States)

    Woodward, Guy; Bonada, Núria; Brown, Lee E.; Death, Russell G.; Durance, Isabelle; Gray, Clare; Hladyz, Sally; Ledger, Mark E.; Milner, Alexander M.; Ormerod, Steve J.; Thompson, Ross M.

    2016-01-01

    Most research on the effects of environmental change in freshwaters has focused on incremental changes in average conditions, rather than fluctuations or extreme events such as heatwaves, cold snaps, droughts, floods or wildfires, which may have even more profound consequences. Such events are commonly predicted to increase in frequency, intensity and duration with global climate change, with many systems being exposed to conditions with no recent historical precedent. We propose a mechanistic framework for predicting potential impacts of environmental fluctuations on running-water ecosystems by scaling up effects of fluctuations from individuals to entire ecosystems. This framework requires integration of four key components: effects of the environment on individual metabolism, metabolic and biomechanical constraints on fluctuating species interactions, assembly dynamics of local food webs, and mapping the dynamics of the meta-community onto ecosystem function. We illustrate the framework by developing a mathematical model of environmental fluctuations on dynamically assembling food webs. We highlight (currently limited) empirical evidence for emerging insights and theoretical predictions. For example, widely supported predictions about the effects of environmental fluctuations are: high vulnerability of species with high per capita metabolic demands such as large-bodied ones at the top of food webs; simplification of food web network structure and impaired energetic transfer efficiency; and reduced resilience and top-down relative to bottom-up regulation of food web and ecosystem processes. We conclude by identifying key questions and challenges that need to be addressed to develop more accurate and predictive bio-assessments of the effects of fluctuations, and implications of fluctuations for management practices in an increasingly uncertain world. PMID:27114576

  17. The effects of climatic fluctuations and extreme events on running water ecosystems.

    Science.gov (United States)

    Woodward, Guy; Bonada, Núria; Brown, Lee E; Death, Russell G; Durance, Isabelle; Gray, Clare; Hladyz, Sally; Ledger, Mark E; Milner, Alexander M; Ormerod, Steve J; Thompson, Ross M; Pawar, Samraat

    2016-05-19

    Most research on the effects of environmental change in freshwaters has focused on incremental changes in average conditions, rather than fluctuations or extreme events such as heatwaves, cold snaps, droughts, floods or wildfires, which may have even more profound consequences. Such events are commonly predicted to increase in frequency, intensity and duration with global climate change, with many systems being exposed to conditions with no recent historical precedent. We propose a mechanistic framework for predicting potential impacts of environmental fluctuations on running-water ecosystems by scaling up effects of fluctuations from individuals to entire ecosystems. This framework requires integration of four key components: effects of the environment on individual metabolism, metabolic and biomechanical constraints on fluctuating species interactions, assembly dynamics of local food webs, and mapping the dynamics of the meta-community onto ecosystem function. We illustrate the framework by developing a mathematical model of environmental fluctuations on dynamically assembling food webs. We highlight (currently limited) empirical evidence for emerging insights and theoretical predictions. For example, widely supported predictions about the effects of environmental fluctuations are: high vulnerability of species with high per capita metabolic demands such as large-bodied ones at the top of food webs; simplification of food web network structure and impaired energetic transfer efficiency; and reduced resilience and top-down relative to bottom-up regulation of food web and ecosystem processes. We conclude by identifying key questions and challenges that need to be addressed to develop more accurate and predictive bio-assessments of the effects of fluctuations, and implications of fluctuations for management practices in an increasingly uncertain world. PMID:27114576

  18. Dissemination of the radionuclides in the basic components of some water ecosystems in the left-bank water meadow of the Pripyat river

    International Nuclear Information System (INIS)

    The paper presents data about the content of radionuclides in the water suspended particles bottom sediments, mollusks and higher water plants in the most contaminated by the radionuclides part of the 30-km area of Chernobyl Atomic power station-water ecosystems of the left bank water-meadow of Pripyat river from 1989 till 1991. According to this data the accounting of radionuclide stocks in the different components of water ecosystems has been carried out. It shows that the main part of 137 Cs and 90 Sr is deposed in the bottom sediments

  19. Ecosystem impacts of Alpine water intakes for hydropower: the challenge of sediment management

    Science.gov (United States)

    Gabbud, Chrystelle; Lane, Stuart

    2016-04-01

    Natural Alpine flow regimes are strongly modified by anthropogenic activities, notably water abstraction or impoundment for hydroelectric power production, which impacts upon both river discharge and sediment transfer systems, and in turn upon flora and fauna downstream. These kinds of impacts are well studied where rivers are regulated by dams, with sediment retained in the associated reservoirs although occasional flushing may be required (a frequency typically of many years). Such impacts may be managed by environmental flows or e-flows, whose restoration value has been shown in a number of research publications. However, there has been less attention in relation to the e-flows needed at water intakes which in Alpine environments may be associated with serious sediment-related problems. Water intakes have a very smaller sediment storage capacity than dams and thus may need to be flushed of accumulated sediment more regularly. In an Alpine setting, because rates of erosion are naturally higher, sediment is flushed in 'purges' with a frequency that may even be sub-daily at certain times of the year. Purges feed the river with solid material, but as the means of transporting it, the water, is being abstracted, sediment transport capacity is reduced. In theory, this does not eliminate sediment connectivity, but rather reduces it: the sediment is still delivered, but it can only be transported for a reduced duration; and the results may be profound hydrogeomorphic and ecosystem impacts, including downstream aggradation. In this study, we present results from a combined study of fluvial geomorphology, hydrology and ecosystem impacts of flow abstraction at water intakes. Using hydrodynamic modelling, we show that because the duration of remobilisation of purges and the peak discharge are much shorter than under natural flows, this causes the formation of a zone of sediment aggradation that moves progressively downstream as a sediment wave, leading to sedimentation

  20. The biophysical link between climate, water, and vegetation in bioenergy agro-ecosystems

    International Nuclear Information System (INIS)

    Land use change for bioenergy feedstocks is likely to intensify as energy demand rises simultaneously with increased pressure to minimize greenhouse gas emissions. Initial assessments of the impact of adopting bioenergy crops as a significant energy source have largely focused on the potential for bioenergy agroecosystems to provide global-scale climate regulating ecosystem services via biogeochemical processes. Such as those processes associated with carbon uptake, conversion, and storage that have the potential to reduce global greenhouse gas emissions (GHG). However, the expansion of bioenergy crops can also lead to direct biophysical impacts on climate through water regulating services. Perturbations of processes influencing terrestrial energy fluxes can result in impacts on climate and water across a spectrum of spatial and temporal scales. Here, we review the current state of knowledge about biophysical feedbacks between vegetation, water, and climate that would be affected by bioenergy-related land use change. The physical mechanisms involved in biophysical feedbacks are detailed, and interactions at leaf, field, regional, and global spatial scales are described. Locally, impacts on climate of biophysical changes associated with land use change for bioenergy crops can meet or exceed the biogeochemical changes in climate associated with rising GHG's, but these impacts have received far less attention. Realization of the importance of ecosystems in providing services that extend beyond biogeochemical GHG regulation and harvestable yields has led to significant debate regarding the viability of various feedstocks in many locations. The lack of data, and in some cases gaps in knowledge associated with biophysical and biochemical influences on land–atmosphere interactions, can lead to premature policy decisions. - Highlights: • The physical basis for biophysical impacts of expanding bioenergy agroecosystems on climate and water is described. • We

  1. Pyrosequencing analysis of bacterial communities in Lake Bosten, a large brackish inland lake in the arid northwest of China.

    Science.gov (United States)

    Zhang, Lei; Gao, Guang; Tang, Xiangming; Shao, Keqiang; Gong, Yi

    2016-06-01

    The bacteria inhabiting brackish lake environments are poorly known, and there are few studies on the microbial diversity of these environments. Lake Bosten, a large brackish inland lake, is the largest lake in Xinjiang Province in northwestern China. Because sediments record past limnic changes, the analysis of sedimentary bacteria in Lake Bosten may help elucidate bacterial responses to environmental change. We employed 454 pyrosequencing to investigate the diversity and bacterial community composition in Lake Bosten. A total of 48 230 high-quality sequence reads with 16 314 operational taxonomic units were successfully obtained from the 4 selected samples, and they were numerically dominated by members of the Deltaproteobacteria (17.1%), Chloroflexi (16.1%), Betaproteobacteria (12.6%), Bacteroidetes (6.6%), and Firmicutes (5.7%) groups, accounting for more than 58.1% of the bacterial sequences. The sediment bacterial communities and diversity were consistently different along the 2 geographic environmental gradients: (i) freshwater-brackish water gradient and (ii) oligotrophic-mesotrophic habitat gradient. Deltaproteobacteria, Chloroflexi, and Betaproteobacteria were amplified throughout all of the sampling sites. More Bacteroidetes and Firmicutes were found near the Kaidu River estuary (site 14). Our investigation showed that Proteobacteria did not display any systematic change along the salinity gradient, and numerous 16S rRNA sequences could not be identified at the genus level. Our data will provide a better understanding of the diversity and distribution of bacteria in arid region brackish lakes. PMID:27045804

  2. Quantifying thermal constraints on carbon and water fluxes in a mixed-conifer sky island ecosystem

    Science.gov (United States)

    Braun, Z.; Minor, R. L.; Potts, D. L.; Barron-Gafford, G. A.

    2012-12-01

    Western North American forests represent a potential, yet uncertain, sink for atmospheric carbon. Revealing how predicted climatic conditions of warmer temperatures and longer inter-storm periods of moisture stress might influence the carbon status of these forests requires a fuller understanding of plant functional responses to abiotic stress. While data related to snow dominated montane ecosystems has become more readily available to parameterize ecosystem function models, there is a paucity of data available for Madrean sky island mixed-conifer forests, which receive about one third of their precipitation from the North American Monsoon. Thus, we quantified ecophysiological responses to moisture and temperature stress in a Madrean mixed-conifer forest near Tucson, Arizona, within the footprint of the Mt. Bigelow Eddy Covariance Tower. In measuring a series of key parameters indicative of carbon and water fluxes within the dominant species across pre-monsoon and monsoon conditions, we were able to develop a broader understanding of what abiotic drivers are most restrictive to plant performance in this ecosystem. Within Pinus ponderosa (Ponderosa Pine), Pseudotsuga menziesii (Douglas Fir), and Pinus strobiformis (Southwestern White Pine) we quantified: (i) the optimal temperature (Topt) for maximum photosynthesis (Amax), (ii) the range of temperatures over which photosynthesis was at least 50% of Amax (Ω50), and (iii) each conifer's water use efficiency (WUE) to relate to the balance between carbon uptake and water loss in this high elevation semiarid ecosystem. Our findings support the prediction that photosynthesis decreases under high temperatures (>30°C) among the three species we measured, regardless of soil moisture status. However, monsoon moisture reduced sensitivity to temperature extremes and fluctuations (Ω50), which substantially magnified total photosynthetic productivity. In particular, wet conditions enhanced Amax the most dramatically for P

  3. Environmental impacts on the evapotranspiration of an water limited and heterogeneous Mediterranean ecosystem.

    Science.gov (United States)

    Montaldo, N.; Curreli, M.; Corona, R.; Oren, R.

    2015-12-01

    Mediterranean water limited ecosystems are characterized by an heterogeneous spatial distribution of different plant functional types (PFT), such as grass and trees, competing for water use. Typically, during the dry summers, these ecosystems are characterized by a simple dual PFTs system with strong-resistant woody vegetation and bare soil, since grass died. The coupled use of sap flow measurements and eddy covariance technique is essential to estimate Evapotransiration (ET) in an heterogeneous ecosystem. An eddy covariance - micrometeorological tower has been installed since 2003 and 33 thermo-dissipation probes based on the Granier technique have installed at the Orroli site in Sardinia (Italy). The site landscape is a mixture of Mediterranean patchy vegetation types: wild olives, different shrubs and herbaceous species, which died during the summer. The sensors have been installed at the Orroli site into 15 wild olives clumps with different characteristics in terms of tree size, exposition to wind and solar radiation and soil depth. A network of 30 soil moisture sensors has also been installed for monitoring soil moisture spatial and temporal dynamics and their correlation with trees. Sap flow measurements show the significantly impacts on ET of soil moisture, radiation, vapor pressure deficit (VPD) and interestingly of tree position into the clump, showing double rates for the trees inside the wild olive clumps. The sap flow sensor outputs are analyzed for estimating innovative allometric relationships between sapwood area, diameter, canopy cover area, which are needed for the correct upscale of the local tree measurements to the site plot larger scale. Finally using an innovative scaling procedure, the sap-flow transpiration at field scale have been compared to the eddy covariance ET, showing the approximation of the eddy covariance technique. Finally the impact of environmental factors on ET for different soil depth and tree position is demonstrated.

  4. Seasonal dynamics of water use efficiency of typical forest and grassland ecosystems in China

    CERN Document Server

    Zhu, Xianjin; Wang, Qiufeng; Hu, Zhongmin; Han, Shijie; Yan, Junhua; Wang, Yanfen; Zhao, Liang

    2014-01-01

    We selected four sites of ChinaFLUX representing four major ecosystem types in China-Changbaishan temperate broad-leaved Korean pine mixed forest (CBS), Dinghushan subtropical evergreen broadleaved forest (DHS), Inner Mongolia temperate steppe (NM), and Haibei alpine shrub-meadow (HBGC)-to study the seasonal dynamics of ecosystem water use efficiency (WUE = GPP/ET, where GPP is gross primary productivity and ET is evapotranspiration) and factors affecting it. Our seasonal dynamics results indicated single-peak variation of WUE in CBS, NM, and HBGC, which were affected by air temperature (Ta) and leaf area index (LAI), through their effects on the partitioning of evapotranspiration (ET) into transpiration (T) (i.e., T/ET). In DHS, WUE was higher at the beginning and the end of the year, and minimum in summer. Ta and soil water content affected the seasonal dynamics of WUE through their effects on GPP/T. Our results indicate that seasonal dynamics of WUE were different because factors affecting the seasonal dyn...

  5. Carbon-water Cycling in the Critical Zone: Understanding Ecosystem Process Variability Across Complex Terrain

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, Holly [Univ. of Colorado, Boulder, CO (United States); Brooks, Paul [Univ. of Utah, Salt Lake City, UT (United States); Univ. of Arizona, Tucson, AZ (United States)

    2016-06-16

    One of the largest knowledge gaps in environmental science is the ability to understand and predict how ecosystems will respond to future climate variability. The links between vegetation, hydrology, and climate that control carbon sequestration in plant biomass and soils remain poorly understood. Soil respiration is the second largest carbon flux of terrestrial ecosystems, yet there is no consensus on how respiration will change as water availability and temperature co-vary. To address this knowledge gap, we use the variation in soil development and topography across an elevation and climate gradient on the Front Range of Colorado to conduct a natural experiment that enables us to examine the co-evolution of soil carbon, vegetation, hydrology, and climate in an accessible field laboratory. The goal of this project is to further our ability to combine plant water availability, carbon flux and storage, and topographically driven hydrometrics into a watershed scale predictive model of carbon balance. We hypothesize: (i) landscape structure and hydrology are important controls on soil respiration as a result of spatial variability in both physical and biological drivers: (ii) variation in rates of soil respiration during the growing season is due to corresponding shifts in belowground carbon inputs from vegetation; and (iii) aboveground carbon storage (biomass) and species composition are directly correlated with soil moisture and therefore, can be directly related to subsurface drainage patterns.

  6. How is water-use efficiency of terrestrial ecosystems distributed and changing on Earth?

    Science.gov (United States)

    Tang, Xuguang; Li, Hengpeng; Desai, Ankur R; Nagy, Zoltan; Luo, Juhua; Kolb, Thomas E; Olioso, Albert; Xu, Xibao; Yao, Li; Kutsch, Werner; Pilegaard, Kim; Köstner, Barbara; Ammann, Christof

    2014-01-01

    A better understanding of ecosystem water-use efficiency (WUE) will help us improve ecosystem management for mitigation as well as adaption to global hydrological change. Here, long-term flux tower observations of productivity and evapotranspiration allow us to detect a consistent latitudinal trend in WUE, rising from the subtropics to the northern high-latitudes. The trend peaks at approximately 51°N, and then declines toward higher latitudes. These ground-based observations are consistent with global-scale estimates of WUE. Global analysis of WUE reveals existence of strong regional variations that correspond to global climate patterns. The latitudinal trends of global WUE for Earth's major plant functional types reveal two peaks in the Northern Hemisphere not detected by ground-based measurements. One peak is located at 20° ~ 30°N and the other extends a little farther north than 51°N. Finally, long-term spatiotemporal trend analysis using satellite-based remote sensing data reveals that land-cover and land-use change in recent years has led to a decline in global WUE. Our study provides a new framework for global research on the interactions between carbon and water cycles as well as responses to natural and human impacts. PMID:25500908

  7. Multimodeling Framework for Predicting Water Quality in Fragmented Agriculture-Forest Ecosystems

    Science.gov (United States)

    Rose, J. B.; Guber, A.; Porter, W. F.; Williams, D.; Tamrakar, S.; Dechen Quinn, A.

    2012-12-01

    Both livestock and wildlife are major contributors of nonpoint pollution of surface water bodies. The interactions among them can substantially increase the chance of contamination especially in fragmented agriculture-forest landscapes, where wildlife (e.g. white tailed deer) can transmit diseases between remote farms. Unfortunately, models currently available for predicting fate and transport of microorganisms in these ecosystems do not account for such interactions. The objectives of this study are to develop and test a multimodeling framework that assesses the risk of microbial contamination of surface water caused by wildlife-livestock interactions in fragmented agriculture-forest ecosystems. The framework consists of a modified Soil Water Assessment Tool (SWAT), KINematic Runoff and EROSion model (KINEROS2) with the add-on module STWIR (Microorganism Transport with Infiltration and Runoff), RAMAS GIS, SIR compartmental model and Quantitative Microbial Risk Assessment model (QMRA). The watershed-scale model SWAT simulates plant biomass growth, wash-off of microorganisms from foliage and soil, overland and in-stream microbial transport, microbial growth, and die-off in foliage and soil. RAMAS GIS model predicts the most probable habitat and subsequent population of white-tailed deer based on land use and crop biomass. KINEROS-STWIR simulates overland transport of microorganisms released from soil, surface applied manure, and fecal deposits during runoff events at high temporal and special resolutions. KINEROS-STWIR and RAMAS GIS provide input for an SIR compartmental model which simulates disease transmission within and between deer groups. This information is used in SWAT model to account for transmission and deposition of pathogens by white tailed deer in stream water, foliage and soil. The QMRA approach extends to microorganisms inactivated in forage and water consumed by deer. Probabilities of deer infections and numbers of infected animals are computed

  8. Evaluation of the Ecosystem Services of Inland Waters in the Slovak Republic - To Date Findings

    Directory of Open Access Journals (Sweden)

    Bujnovský Radoslav

    2015-03-01

    Full Text Available Ecosystem services (ES (goods and services represent the outputs of natural systems from which people can have benefits. Evaluation of the benefits resulting from ES of inland waters or the benefits, which are lost when the necessary measures are not implemented, is one of the methods of evaluating the external costs of environmental damage - environmental and resource costs. Evaluation of ES is based on the CICES classification v. 4.3, which defines provision, regulation/ maintenance and cultural services. In the assessment of ES also enters groundwater, although in comparison with surface waters in lesser extent. At present, the evaluation is performed at the level of sub-basins of the Slovak Republic. In this paper, evaluation of selected ES is presented. Use of evaluation in practice is also discussed.

  9. Ecosystem health evaluation system of the water-fluctuating zone in the Three Gorges Area

    Institute of Scientific and Technical Information of China (English)

    WANG Li-ao; YUAN Hui; ZHANG Yan-hui; HU Gang

    2004-01-01

    This paper discribes the definition of ecosystem health for the water-level flutuation zone of the Three Gorges Region and puts forward an evaluation system involving indicators in three groups: 1) structural indicators comprise slope, biodiversity,environmental capacity, stability, restoration ability and damage situation; 2) functional indicators including probability of geological hazard, erosion rate, habitat rate, land use intension and days of tourist season; 3) environmental indicatiors made up of population quality, potential intension of human, ground water quality, ambient air quality, wastewater treatment rate, pesticide use rate, fertilizer use rate, environmental management and public participation. In the design of the system, the subject zone is regarded as the type similar to wetland and the impacts of human activities on the zone are attached great importance to.

  10. Water Management Supporting the Delivery of Ecosystem Services for Grassland, Heath and Moorland

    Directory of Open Access Journals (Sweden)

    Henk Ritzema

    2016-05-01

    Full Text Available In the present era, permanent grasslands and other grazed habitats, i.e., moorlands and heath, are appreciated as avant la lettre green infrastructure (GI resources, providing a wide range of ecosystem services, the delivery of many of which require water management to be in place. This paper discusses the role of water management and, in particular, that of drainage. We contend that controlled drainage and drainage-irrigation systems can contribute to the sustainable use of grasslands and associated habitats in the European Union. We present examples from a range of habitats in several EU Member States and attempt to identify the contemporary (short-term costs as well as the short-term revenues covering these costs. Options for enhancing the role of the Green Infrastructure in Europe to achieve sustainable land use by including all “permanent grassland” are discussed.

  11. Ballast water management that adapts to climate changes and reduces harmful bio-invasions in marine eco-systems

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard; Hansen, Mette Sanne

    2015-01-01

    marine ecosystem of changed factors in the shipping sector, for instance change of number, size, and design of vessels as well as treatment technologies of ballast water. New areas for shipping due to climate changes are also included. Our study would contribute to improve decision support tools, usable......The shipping ballast water is defined as water taken on board a ship to control trim, cargo, draught, stability and stress of the ship. Alien bio-organisms in ballast water have a range of ecological impacts, for instance reducing native bio-diversity, altering habitat and potentially the overall...... food-webs and eco-systems. Economic impacts include reductions in fisheries production and algae blooms harmful for fish farms, tourism and human health. Due to the rising temperatures of the Oceans, organisms that prefer a warm climate may take roots in marine ecosystems that were previously too cold...

  12. Effective Ecological Restoration of Collapsed Ecosystems - Linking Soil, Water and Society

    Science.gov (United States)

    Petursdottir, Thorunn; Finger, David

    2014-05-01

    All natural resources, utilized by humans are embedded in complex social-ecological systems (SESs). To maintain the systems' sustainability, the SESs needs to be managed within their resilience optimum, considering both social and ecological elements. Throughout the centuries the humankind has often failed in doing so. Overexploitation of natural resources has thus widely disrupted equilibrium within the respective SESs, driving unforeseen changes of ecosystems worldwide. Anthropogenic factors such as poor institutional structure on resource utilization and weak policies in combination to environmental factors like droughts, fires or other unpredictable events have ruptured ecosystems' resilience and caused global degradation on a scale that currently threatens the Earth's welfare. As an example it's worth to mention that up to 40% of the world's agricultural land is severely degraded mainly due to unsustainable landuse. Once an ecosystem, or part/s of it, have collapsed, ecological restoration is almost always necessary to overcome the threshold/s that may prevent the system from self-recovering. It also re-activates the system's environmental cycles like the water, carbon and nutrient circulation. Although soil is the fundamental body of terrestrial ecosystems, water availability is of equal importance and should be taken more into consideration in restoration than currently is done. Based on that, we will focus on how to best manage effective large-scale ecological restoration (LSER) of collapsed ecosystems and link it to water catchment areas. LSER is a fundamental social-ecological activity that substantially can improve ecosystem condition, human livelihood and if well organized, facilitate improved management of natural resources. By definition, restoration of ecological integrity and functions is the fundamental basis for all restoration activities. But to achieve long-term sustainability of LSER activities the initial set of rules/policies established by

  13. The Impact of a Severe Drought on Ecosystem CO2 and Water Fluxes in a Subtropical Forest

    Science.gov (United States)

    Wang, L.; Xie, Z.; Jia, B.; Yuan, X.

    2015-12-01

    Southern China experienced an extreme drought in 2013, where the precipitation dropped 23% below the long-term norm and the abnormally high temperature lasted for 67 days. In this study, the impact of the severe drought on a mixed evergreen subtropical forest ecosystem was analyzed using eddy covariance measurements from a newly established flux tower at Ningxiang county of Hunan Province and simulations with the Community Land Model version 4.5 (CLM4.5) driven by high resolution forcing data from China Meteorological Administration Land Data Assimilation System and the in-situ meteorological data. When soil moisture reduced from 0.35 m3 m-3 to 0.12 m3 m-3, both vegetation productivity and evapotranspiration (ET) experienced a strong reduction in July-August period due to drought-induced stomatal closure. Results also showed that the ecosystem respiration (Reco) decreased together with gross ecosystem productivity (GEP), instead of accelerating with the increase of temperature under extremely dry soil condition (carbon uptake and release, the magnitude of net ecosystem productivity also experienced a large reduction from 11.8 to 7.7 μmol m-2 s-1 and the ecosystem even switched to a net source of carbon. In addition, persistent soil water content deficit in summer limited the plant water uptake and led to a reduction of the stomatal conductance, which weakened the coupling relationship between carbon and water fluxes. Water availability severely limited the carbon sequestration of the targeted ecosystem with water use efficiency (WUE) plummeted during the drought period. With high quality of meteorological forcing data, CLM4.5 captured the variability of water fluxes during the growing season quite well with correlation coefficients of 0.95 for soil moisture and 0.82 for ET, except for an underestimation of GEP at the end of drought period. Further improvement in simulating the response to drought in subtropical forest ecosystem is required.

  14. Partitioning of catchment water budget and its implications for ecosystem carbon exchange

    Directory of Open Access Journals (Sweden)

    D. Lee

    2009-12-01

    Full Text Available Spatially averaged annual carbon budget is one of the key information to understand ecosystem response and feedback to climate change. Water availability is a primary constraint of carbon uptake in many ecosystems and therefore the estimation of transpiration (T may serve as an alternative to quantify carbon budget. To apply this concept, we estimated long-term steady state water budget for the Han River basin (~26 000 km2 in Korea and examined its implication for catchment scale carbon exchange. For this, the catchment scale evapotranspiration (ET was derived from the long term precipitation (P and discharge (Q data. Then, using stable isotope data of P and Q along with hydrometeorological information, ET was partitioned into evaporation from soil and water surfaces (ES, evaporation from intercepted rainfall (El, and transpiration. ES was identified as a minor component of ET in the study areas regardless of the catchment scales. T was estimated from ET after accounting for El and ES. For the Han River basin, the estimated annual T from 1966 to 2007 was 22–31% of annual P and the proportion decreased with increasing P. Assuming that T further constrains catchment scale carbon uptake in terms of water use efficiency (WUE, we examined the possibility of using T as a relative measure for the strength and temporal changes of carbon uptake capacity. The proposed relations provide a simple and practical way to assess the distribution and strength of carbon sink.

  15. Spatial scales of bacterial diversity in cold-water coral reef ecosystems.

    Directory of Open Access Journals (Sweden)

    Sandra Schöttner

    Full Text Available BACKGROUND: Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning. METHODOLOGY/PRINCIPAL FINDINGS: Bacterial community structure, as determined by Automated Ribosomal Intergenic Spacer Analysis (ARISA, was investigated with respect to (i microbial habitat type and (ii coral species and color, as well as the three spatial components (iii geomorphologic reef zoning, (iv reef boundary, and (v reef location. Communities revealed fundamental differences between coral-generated (branch surface, mucus and ambient microbial habitats (seawater, sediments. This habitat specificity appeared pivotal for determining bacterial community shifts over all other study levels investigated. Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types. Within the reef center, no community distinction corresponded to geomorphologic reef zoning for both coral-generated and ambient microbial habitats. Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity. CONCLUSIONS/SIGNIFICANCE: This study presents the first multi-scale survey of bacterial diversity in cold-water coral reefs, spanning a total of five observational levels including three spatial scales. It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has

  16. A freshwater species wintering in a brackish environment: Habitat selection and diet of Slavonian grebes in the southern Baltic Sea

    Science.gov (United States)

    Sonntag, Nicole; Garthe, Stefan; Adler, Sven

    2009-09-01

    After the breeding season, Slavonian grebes ( Podiceps auritus) leave their freshwater breeding habitats and migrate to wintering grounds in marine or brackish waters. The most important wintering area in northwestern Europe is located in the southern Baltic Sea, with the largest concentrations in the offshore area of the Pommeranian Bight. Analysis of ship-based surveys revealed that the habitat selection of Slavonian grebes in this brackish area is significantly influenced by water depth and bottom sediment type. The grebes prefer shallow waters of 4-14 m depth and occur only over sandy sediments. While the diving depths of endothermic animals is limited due to energetic constraints and thermoregulation, sediment type is regarded to be a proxy for food choice. The diet of Slavonian grebes in the Pomeranian Bight consists mainly of demersal gobies (Gobiidae) that frequently occur over sandy bottom substrates.

  17. Mangrove coservation in coastal areas Samas beach lagoon for controlling sea water abrasion

    OpenAIRE

    Nurhayati, A.P.; Siwi, B.R.F. Raka; Muzoffar, C.A.

    2013-01-01

    Lagoon is a puddle of water (like a lake/pond) near the beach that was once a part of the (united with) the sea, but because of geological events, apart from the sea and coastal wetland ecosystems forming new ones. Samas beach lagoon is one of the lagoons are located in Bantul, Daerah Istimewa Yogyakarta. From the perspective of the Environment, lagoon is a unique ecosystem that consists of a body of water (lagoon) is brackish, mangrove forests and land affected low tide. Ecosyste...

  18. Building a framework to explore water-human interaction for sustainable agro ecosystems in US Midwest

    Science.gov (United States)

    Mishra, S. K.; Ding, D.; Rapolu, U.

    2012-12-01

    Human activity is intricately linked to the quality and quantity of water resources. Although many studies have examined water-human interaction, the complexity of such coupled systems is not well understood largely because of gaps in our knowledge of water-cycle processes which are heavily influenced by socio-economic drivers. On this context, this team has investigated connections among agriculture, policy, climate, land use/land cover, and water quality in Iowa over the past couple of years. To help explore these connections the team is developing a variety of cyber infrastructure tools that facilitate the collection, analysis and visualization of data, and the simulation of system dynamics. In an ongoing effort, the prototype system is applied to Clear Creek watershed, an agricultural dominating catchment in Iowa in the US Midwest, to understand water-human processes relevant to management decisions by farmers regarding agro ecosystems. The primary aim of this research is to understand the connections that exist among the agricultural and biofuel economy, land use/land cover change, and water quality. To help explore these connections an agent-based model (ABM) of land use change has been developed that simulates the decisions made by farmers given alternative assumptions about market forces, farmer characteristics, and water quality regulations. The SWAT model was used to simulate the impact of these decisions on the movement of sediment, nitrogen, and phosphorus across the landscape. The paper also demonstrate how through the use of this system researchers can, for example, search for scenarios that lead to desirable socio-economic outcomes as well as preserve water quantity and quality.

  19. Water Quality of Four Major Lakes in Mississippi, USA: Impacts on Human and Aquatic Ecosystem Health

    Directory of Open Access Journals (Sweden)

    Padmanava Dash

    2015-09-01

    Full Text Available Harmful algal blooms (HABs, harmful microorganisms (pathogens and toxic metals represent three major agents of water quality deterioration. Water quality of three northern lakes (Sardis, Enid, and Grenada and a central lake (Ross Barnett Reservoir of Mississippi, USA were examined in this study. While all these lakes are heavily used for recreational purposes, the Ross Barnett Reservoir serves additionally as the primary water supply for the City of Jackson, the capital city of Mississippi. The main goal of this study was to comprehensively assess the water quality of these lakes employing field and satellite data, and evaluate the potential human and aquatic health impacts. A time-series of true color images derived from satellite data indicated that algal blooms have been a recurring phenomenon in these lakes. Cyanobacteria, the algal group that predominantly occur in freshwater and form toxic blooms, were always present in these lakes and were most abundant on many occasions. The most toxic cyanotoxin, microcystin-LR, was found in all lakes, and its concentrations exceeded federal drinking water guidelines for children under six years of age many times. Potential bioaccumulation and biomagnification of microcystin-LR may pose serious risk to the aquatic ecosystem and human health including adults. Nutrient measurements indicated that all four lakes were eutrophic. Among bacterial populations, total coliforms and enterococci exceeded guideline values on several occasions. Arsenic, cadmium, chromium, and lead were found in the water of all the lakes, with arsenic exceeding the guideline values at two sites in Ross Barnett Reservoir. While it is apparent from this study that these lakes face many water quality issues, data across all seasons will be required to document potential trends and to devise management strategies. Use of remote sensing technology is recommended to monitor some of the water quality parameters such as suspended

  20. Interacting effects of elevated temperature and additional water on plant physiology and net ecosystem carbon fluxes in a high Arctic ecosystem

    Science.gov (United States)

    Maseyk, Kadmiel; Seibt, Ulrike; Lett, Céline; Lupascu, Massimo; Czimczik, Claudia; Sullivan, Patrick; Welker, Jeff

    2013-04-01

    Arctic ecosystems are experiencing temperature increases more strongly than the global average, and increases in precipitation are also expected amongst the climate impacts on this region in the future. These changes are expected to strongly influence plant physiology and soil biogeochemistry with subsequent implications for system carbon balance. We have investigated the effects of a long-term (10 years) increase in temperature, soil water and the combination of both on a tundra ecosystem at a field manipulation experiment in NW Greenland. Leaf gas exchange, chlorophyll fluorescence, carbon (C) and nitrogen (N) content and leaf isotopic composition, and leaf morphology were measured on Salix arctica plants in treatment and control plots in June-July 2011, and continuous measurements of net plant and soil fluxes of CO2 and water were made using automatic chambers coupled to a trace gas laser analyzer. Plants in the elevated temperature (T2) treatment had the highest photosynthetic capacity in terms of net CO2 assimilation rates and photosystem II efficiencies, and lowest rates of non-photochemical energy dissipation during photosynthesis. T2 plants also had the highest leaf N content, specific leaf area (SLA) and saturation light level of photosynthesis. It appears that warming increases soil N availability, which the plants direct towards increasing photosynthetic capacity and producing larger thinner leaves. On the other hand, the plants in the plots with both elevated temperatures and additional water (T2W) had the lowest photosystem II efficiencies and the highest rates of non-photochemical energy dissipation, due more to higher levels of constitutive energy dissipation than regulated thermal quenching. Watering, both in combination with higher temperatures and alone (W treatment), also reduced leaf SLA and leaf N relative to control plots. However, net photosynthetic rates remained similar to control plants, due in part to higher stomatal conductance (W) and

  1. Methane production induced by dimethylsulfide in surface water of an upwelling ecosystem

    Science.gov (United States)

    Florez-Leiva, Lennin; Damm, Ellen; Farías, Laura

    2013-05-01

    Coastal upwelling ecosystems are areas of high productivity and strong outgassing, where most gases, such as N2O and CH4, are produced in subsurface waters by anaerobic metabolisms. We describe seasonal CH4 variation as well as potential mechanisms producing CH4 in surface waters of the central Chile upwelling ecosystem (36°S). Surface waters were always supersaturated in CH4 (from 125% up to 550%), showing a clear seasonal signal triggered by wind driven upwelling processes (austral spring-summer period), that matched with the periods of high chlorophyll-a and dimethylsulfoniopropionate (DMSP) levels. Methane cycling experiments, with/without the addition of dimethylsulfide (including 13C-DMS) and acetylene (a nonspecific inhibitor of CH4 oxidation) along with monthly measurements of CH4, DMSP and other oceanographic variables revealed that DMS can be a CH4 precursor. Net CH4 cycling rates (control) fluctuated between -0.64 and 1.44 nmol L-1 d-1. After the addition of acetylene, CH4 cycling rates almost duplicated relative to the control, suggesting a strong methanotrophic activity. With a spike of DMS, the net CH4 cycling rate significantly increased relative to the acetylene and control treatment. Additionally, the δ13C values of CH4 at the end of the incubations (after addition of 13C enriched-DMS) were changed, reaching -32‰ PDB compared to natural values between -44‰ and -46‰ PDB. These findings indicate that, in spite of the strong CH4 consumption by methanotrophs, this upwelling area is an important source of CH4 to the atmosphere. The effluxes are derived partially from in situ surface production and seem to be related to DMSP/DMS metabolism.

  2. Interactions among vegetation and ozone, water and nitrogen fluxes in a coastal Mediterranean maquis ecosystem

    Directory of Open Access Journals (Sweden)

    G. Gerosa

    2009-01-01

    Full Text Available Ozone, water and energy fluxes were measured over a Mediterranean maquis ecosystem from 5 May until 31 July by means of the eddy covariance technique. Additional measurements of NOx fluxes were performed by the aerodynamic gradient technique. Stomatal ozone fluxes were obtained from water fluxes by a Dry Deposition Inferential Method based on a big leaf concept. The maquis ecosystem acted as a net sink for ozone. The different water availability between late spring and summer was the major cause of the changes observed in stomatal fluxes, which decreased, together with evapotranspiration, when the season became drier. NOx concentrations were significantly dependent on the local meteorology. NOx fluxes resulted less intense than the ozone fluxes. However an average upward flux of both NO and NO2 was measured. The non-stomatal pathways of ozone deposition were investigated. A correlation of non-stomatal deposition with air humidity and, in a minor way, with NO2 fluxes was found. Ozone risk assessment was performed by comparing the exposure and the dose metrics: AOT40 (Accumulated dose over a threshold of 40 ppb and AFst1.6 (Accumulated stomatal flux of ozone over a threshold of 1.6 nmol m−2 s−1. AOT40, both at the measurement height and at canopy height was greater than the Critical Level (5000 ppb·h adopted by UN-ECE. Also the AFst1.6 value (12.6 mmol m−2 PLA, Projected Leaf Area was higher than the provisional critical dose of 4 mmol m−2 PLA. The cumulated dose grew more regularly than the exposure but it showed two different growth rates in the spring and in the summer periods.

  3. Ecosystem relevance of variable jellyfish biomass in the Irish Sea between years, regions and water types

    Science.gov (United States)

    Bastian, Thomas; Lilley, Martin K. S.; Beggs, Steven E.; Hays, Graeme C.; Doyle, Thomas K.

    2014-08-01

    Monitoring the abundance and distribution of taxa is essential to assess their contribution to ecosystem processes. For marine taxa that are difficult to study or have long been perceived of little ecological importance, quantitative information is often lacking. This is the case for jellyfish (medusae and other gelatinous plankton). In the present work, 4 years of scyphomedusae by-catch data from the 2007-2010 Irish Sea juvenile gadoid fish survey were analysed with three main objectives: (1) to provide quantitative and spatially-explicit species-specific biomass data, for a region known to have an increasing trend in jellyfish abundance; (2) to investigate whether year-to-year changes in catch-biomass are due to changes in the numbers or in the size of medusa (assessed as the mean mass per individual), and (3) to determine whether inter-annual variation patterns are consistent between species and water masses. Scyphomedusae were present in 97% of samples (N = 306). Their overall annual median catch-biomass ranged from 0.19 to 0.92 g m-3 (or 8.6 to 42.4 g m-2). Aurelia aurita and Cyanea spp. (Cyanea lamarckii and Cyanea capillata) made up 77.7% and 21.5% of the total catch-biomass respectively, but species contributions varied greatly between sub-regions and years. No consistent pattern was detected between the distribution and inter-annual variations of the two genera, and contrasting inter-annual patterns emerged when considering abundance either as biomass or as density. Significantly, A. aurita medusae were heavier in stratified than in mixed waters, which we hypothesize may be linked to differences in timing and yield of primary and secondary productions between water masses. These results show the vulnerability of time-series from bycatch datasets to phenological changes and highlight the importance of taking species- and population-specific distribution patterns into account when integrating jellyfish into ecosystem models.

  4. Effects of Different Planting Patterns on Cotton Yield and Soil Water-salt under Brackish Water Irrigation before Sowing%微咸水造墒条件下植棉方式对产量与土壤水盐的影响

    Institute of Scientific and Technical Information of China (English)

    张俊鹏; 曹彩云; 冯棣; 孙景生; 李科江; 刘浩

    2013-01-01

    Effects of six planting patterns on cotton soil water-salt movement, seedling rate, leaf area index, yield and fiber quality under irrigation before sowing with 5 g/L brackish water were studied by plot comparative trial. The planting patterns were respectively seeding raising and soil-substrate transplanting with plastic mulching, seeding raising in sand and root-naked transplanting with plastic mulching, seeding raising and soil-substrate transplanting without plastic mulching, seeding raising in sand and root-naked transplanting without plastic mulching, and bunch planting without plastic mulching. The results showed that salt stress towards cotton was reduced by applying plastic film mulching to decrease soil evaporation, improve soil temperature as well as inhibit salt accumulation in surface. Under the film mulching conditions, the cotton seedling rate, leaf area index before blossoming and boll forming stage, pre-frost yield and yield were higher than that without plastic mulching. Fiber quality was also improved. The techniques of seeding raising and soil-substrate transplanting and seeding raising in sand and root-naked transplanting showed a good yield-increasing potential. Especially during the successive overcast days in the middle-late stages of cotton (in 2011 ) , the yield of seedling transplantation cotton was greatly improved.%采用小区对比试验,研究了5g/L微咸水造墒条件下不同种植方式(基质育苗移栽覆膜、沙培育苗移栽覆膜、点播覆膜与基质育苗移栽不覆膜、沙培育苗移栽不覆膜、点播不覆膜)对棉花土壤水盐变化过程、成苗率、叶面积指数、产量以及纤维品质的影响.结果表明,地膜覆盖通过减少土壤蒸发、提高土壤温度和抑制盐分表聚,削弱了盐分胁迫对棉花的危害程度,棉花的成苗率、花铃期前的叶面积指数、霜前花率以及产量均高于无覆盖处理,同时有效地提高了棉花的纤维品质;基质育苗移栽

  5. Reducing and correcting for contamination of ecosystem water stable isotopes measured by isotope ratio infrared spectroscopy.

    Science.gov (United States)

    Schmidt, Markus; Maseyk, Kadmiel; Lett, Céline; Biron, Philippe; Richard, Patricia; Bariac, Thierry; Seibt, Ulli

    2012-01-30

    Concern exists about the suitability of laser spectroscopic instruments for the measurement of the (18)O/(16)O and (2)H/(1)H values of liquid samples other than pure water. It is possible to derive erroneous isotope values due to optical interference by certain organic compounds, including some commonly present in ecosystem-derived samples such as leaf or soil waters. Here we investigated the reliability of wavelength-scanned cavity ring-down spectroscopy (CRDS) (18)O/(16)O and (2)H/(1)H measurements from a range of ecosystem-derived waters, through comparison with isotope ratio mass spectrometry (IRMS). We tested the residual of the spectral fit S(r) calculated by the CRDS instrument as a means to quantify the difference between the CRDS and IRMS δ-values. There was very good overall agreement between the CRDS and IRMS values for both isotopes, but differences of up to 2.3‰ (δ(18)O values) and 23‰ (δ(2)H values) were observed in leaf water extracts from Citrus limon and Alnus cordata. The S(r) statistic successfully detected contaminated samples. Treatment of Citrus leaf water with activated charcoal reduced, but did not eliminate, δ(2)H(CRDS) - δ(2)H(IRMS) linearly for the tested range of 0-20% charcoal. The effect of distillation temperature on the degree of contamination was large, particularly for δ(2)H values but variable, resulting in positive, negative or no correlation with distillation temperature. S(r) and δ(CRDS) - δ(IRMS) were highly correlated, in particular for δ(2)H values, across the range of samples that we tested, indicating the potential to use this relationship to correct the δ-values of contaminated plant water extracts. We also examined the sensitivity of the CRDS system to changes in the temperature of its operating environment. We found that temperature changes ≥4 °C for δ(18)O values and ≥10 °C for δ(2)H values resulted in errors larger than the CRDS precision for the respective isotopes and advise the use of such

  6. Spatio-temporal patterns in benthic macrofauna on a brackish mudflat (Schelde estuary, NW-Europe): results of ten years monitoring

    OpenAIRE

    Verbessem, I.; Ysebaert, T.J.; Van den Bergh, E.; P. Meire

    2002-01-01

    Estuarine ecosystems are charac­terized by largely varying physicochemi­cal condi­tions, especially in the meso-/oligohaline zones. Knowledge of the environmental variability and related population effects on a range of spatio-temporal scales is fundamental to a better understanding of their functioning, stability, resilience and the way they are influenced by human impacts. This study combines spatial and temporal variations in macrobenthic populations (and their environment) on a brackish m...

  7. Effects of Drought and Water Resource Management on Biophysical and Sociocultural Ecosystem Services in South-Central United States

    Science.gov (United States)

    Julian, J.; Castro, A.; Vaughn, C.; Atkinson, C.

    2014-12-01

    South-Central United States is one of the fastest growing regions in the nation; however, it is experiencing water supply limitations. In response, multiple interests have focused on the Kiamichi River watershed in southeast Oklahoma as a future inter-basin water supply. The Kiamichi River provides many ecosystem services, including freshwater provision to 19 cities/towns, outdoor recreation hub for the South-Central U.S., cultural capital of the Choctaw Indian Nation, and a national biodiversity hotspot. With multiple recent stressors, these ecosystem services are highly threatened. Here we present how drought and water management have impacted these benefits over the past 20 years. First, we assessed the river's sensitivity to drought (which is cyclical) and water regulation (which has increased over the past three decades). Second, we analyzed how these hydrologic changes have impacted freshwater habitat, focusing on mussels because of their sensitivity to flow alterations and because they provide additional ecosystem services such as biofiltration, nutrient recycling/storage, and cultural resources. Third, we performed a sociocultural valuation for a suite of ecosystem services provided by the Kiamichi River watershed, including 505 interviews of five different ecosystem services beneficiary (ESB) groups. We obtained ESB perceptions on how ecosystem services changed with different flow conditions and water management strategies. Analyses revealed that increased regulation (fewer dam releases) has caused the Kiamichi River to have long no flow periods during droughts (e.g. 176 days with no flow in 2006). These long dry periods have been the main culprit for a 60% decline in mussel biomass over the past 20 years, and subsequent large losses in biofiltration and nutrient recycling. Interestingly, ESBs perceived similar losses of ecosystem services. Without being provided any information on flow, more than half of the ESBs believed that water supply, freshwater

  8. 76 FR 55060 - Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor...

    Science.gov (United States)

    2011-09-06

    ... and aquatic ecosystems across the United States to the potential impacts of global change. Using a... directly evaluate the potential impacts of global change on ecosystems and watersheds. Rather, it...

  9. Polonium-210 and other radionuclides in terrestrial, freshwater and brackish environments Results from the NKS project GAPRAD (Filling knowledge gaps in radiation protection methodologies for non-human biota)

    Energy Technology Data Exchange (ETDEWEB)

    Gjelsvik, R.; Brown, J.; Holm, E.; Roos, P.; Saxen, R.; Outola, I.

    2012-01-15

    The background and rationale to filling knowledge gaps in radiation protection methodologies for biota are presented. Concentrations of Po-210 and Pb-210 are reported for biota sampled in Dovrefjell, Norway and selected lake and brackish ecosystems in Finland. Furthermore, details in relation to Po-210 uptake and biokinetics in humans based on experimental studies are recounted. (Author)

  10. Polonium-210 and other radionuclides in terrestrial, freshwater and brackish environments Results from the NKS project GAPRAD (Filling knowledge gaps in radiation protection methodologies for non-human biota)

    International Nuclear Information System (INIS)

    The background and rationale to filling knowledge gaps in radiation protection methodologies for biota are presented. Concentrations of Po-210 and Pb-210 are reported for biota sampled in Dovrefjell, Norway and selected lake and brackish ecosystems in Finland. Furthermore, details in relation to Po-210 uptake and biokinetics in humans based on experimental studies are recounted. (Author)

  11. Gulf-Wide Information System, Environmental Sensitivity Index Brackish Marsh, Geographic NAD83, LDWF (2001) [esi_brackish_marsh_LDWF_2001

    Data.gov (United States)

    Louisiana Geographic Information Center — This data set contains Environmental Sensitivity Index (ESI) brackish marshes data of coastal Louisiana. The ESI is a classification and ranking system, which...

  12. Bioaccumulation of gasoline in brackish green algae and popular clams

    Directory of Open Access Journals (Sweden)

    Gihan A. El-Shoubaky

    2016-03-01

    Full Text Available The green algae (Ulva lactuca and Enteromorpha clathrata and the clams (Tapes decussates and Venerupis aurea grow together in Timsah Lake, Suez Canal, Egypt. Our ultimate goal is to validate the bioaccumulation of gasoline in the marine organisms and their behavior after exposure to the pollutant, experimentally. These species were treated with a serial treatment of gasoline (1000, 4000, 16,000 and 64,000 μl in aquaria with brackish sea-water for 72 h. The tested green algae and clams were taken for an analysis of total hydrocarbon accumulation daily. The statistical analysis showed significant differences between the four species and also between the duration of exposure. The accumulation of gasoline in U. lactuca and E. clathrata reached their maximum after 48 h at 1000 and 4000 μl. The highest absorption was registered after 24 h only at 16,000 and at 64,000 μl. U. lactuca recorded complete mortality in 64,000 μl at 72 h whereas E. clathrata registered death at 48 h and 72 h in the same treatment. V. aurea was more sensitive than T. decussates. The accumulation of gasoline reached its maximum in V. aurea after only 24 h in the first treatment while it retarded to 48 h in T. decussates with a lesser accumulation. However, both clam species accumulated the highest amount of petroleum hydrocarbons during the first hour of exposure at the first treatment. In the third and fourth treatments, clams did not accumulate gasoline but began to dispose it from their tissues till it became less than that in the control. Mortality gradually increased with time in each treatment except the last one (64,000 μl in which 100% death of the specimens was observed. In general, the bioaccumulation of gasoline level was in a descending order as follows: U. lactuca > E. clathrata > V. aurea > T. decussates. Their behavior changed from accumulation to detoxification with time and with the increase in pollutant concentration. Generally, these

  13. Emerging contaminants in wastewater and river water: Risks for human water security and aquatic ecosystem sustainability?

    OpenAIRE

    Fries, Elke; Mahjoub, Olfa; Mahjoub, Borhane; Klasmeier, Jörg; Bahadir, Müfit

    2014-01-01

    International audience In recent years, there has been increasing concern about the environmental risks of the so called "emerging contaminants (ECs) "in conventional and non conventional water resources. According to the EU NORMAN network ECs are "substances that have been detected in the environment, but which are currently not included in routine monitoring programs at EU level and whose fate, behavior and (eco)toxicological effects are not well understood." ECs originate from a variety...

  14. TIPEX (Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment Program

    Directory of Open Access Journals (Sweden)

    Dongchull Jeon

    2013-09-01

    Full Text Available One of the factors influencing the climate around Korea is the oceanic-atmospheric variability in the tropical region between the eastern Indian and the western Pacific Oceans. Lack of knowledge about the air-sea interaction in the tropical Indo-Pacific region continues to make it problematic forecasting the ocean climate in the East Asia. The ‘Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment (TIPEX’ is a program for monitoring the ocean circulation variability between Pacific and Indian Oceans and for improving the accuracy of future climate forecasting. The main goal of the TIPEX program is to quantify the climate and ocean circulation change between the Indian and the Pacific Oceans. The contents of the program are 1 to observe the mixing process of different water masses and water transport in the eastern Indian and the western Pacific, 2 to understand the large-scale oceanic-climatic variation including El Niño-Southern Oscillation (ENSO/Warm Pool/Pacific Decadal Oscillation (PDO/Indian Ocean Dipole (IOD, and 3 to monitor the biogeochemical processes, material flux, and biological changes due to the climate change. In order to effectively carry out the monitoring program, close international cooperation and the proper co-work sharing of tasks between China, Japan, Indonesia, and India as well as USA is required.

  15. Perfluorinated compounds: levels, trophic web enrichments and human dietary intakes in transitional water ecosystems.

    Science.gov (United States)

    Renzi, Monia; Guerranti, Cristiana; Giovani, Andrea; Perra, Guido; Focardi, Silvano E

    2013-11-15

    The results of a study on levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), analyzed in terms of HPLC-ESI-MS in water, sediment, macrophyte, bivalve, crustacean and fish samples, are reported here. The aim of the research is to define, for the first time, PFOA/S levels in a heavily human-stressed transitional water ecosystem (Orbetello lagoon, Italy) and evaluate trophic web enrichments and human dietary intakes. The results obtained show that: (i) levels significantly higher than those reported in the literature were found in mussels, clams and crabs; (ii) the river is a significant pollution source; (iii) although absolute levels are relatively low, macroalgae proliferation contributes to redistribute pollutants from river-affected areas throughout the entire lagoon basin; (iv) to the best of our current knowledge, water-filtering species considered in this study are the most exposed to PFOA/S pollution; (v) human daily dietary intakes of PFOA/S through Slow Food-endorsed product consumption are below maximum tolerable levels suggested by the EFSA. PMID:24095201

  16. Morphology and phylogenies of two hypotrichous brackish-water ciliates from China, Neourostylopsis orientalis n. sp. and Protogastrostyla sterkii (Wallengren, 1900) n. comb., with establishment of a new genus Neourostylopsis n. gen. (Protista, Ciliophora, Hypotrichia).

    Science.gov (United States)

    Chen, Xiangrui; Shao, Chen; Liu, Xihan; Huang, Jie; Al-Rasheid, Khaled A S

    2013-03-01

    This paper investigates the morphology, infraciliature and small-subunit (SSU) rRNA gene sequences of two hypotrichous ciliates, Neourostylopsis orientalis n. sp., and Protogastrostyla sterkii (Wallengren, 1900) n. comb. (basionym Gastrostyla sterkii), collected from coastal waters in southern China. Neourostylopsis orientalis n. sp. is diagnosed mainly by the arrangement of brownish cortical granules, the numbers of adoral membranelles and frontal and transverse cirri and the characteristics of its midventral cirral pairs. The SSU rRNA gene phylogeny strongly supports the establishment of the new genus Neourostylopsis n. gen., which is characterized mainly by the following features: frontal and transverse cirri clearly differentiated, buccal cirri present, two frontoterminal cirri, midventral complex composed of midventral pairs only and not exceeding the halfway point of the cell, more than one row of marginal cirri on each side which derive from individual anlagen within each parental row, caudal cirri lacking. Thus, two new combinations are required: Neourostylopsis songi (Lei et al., 2005) n. comb., and Neourostylopsis flavicana (Wang et al., 2011) n. comb. Additionally, improved diagnoses for both Metaurostylopsis and Apourostylopsis are supplied in this study. Protogastrostyla sterkii (Wallengren, 1900) n. comb. differs from the similar congener Protogastrostyla pulchra mainly in body shape, ratio of buccal field to body length in vivo and molecular data. Based on the present studies, we conclude that the estuarine population of P. pulchra collected by J. Gong and others [Gong et al., J Eukaryot Microbiol (2007) 54, 468-478] is a population of P. sterkii. PMID:23355699

  17. Origin and characteristics of brackish groundwater in Abu Madi coastal area, Northern Nile Delta, Egypt

    Science.gov (United States)

    Salem, Zenhom E.; Al Temamy, A. M.; Salah, Mohamed K.; Kassab, M.

    2016-09-01

    Hydrogeochemical and geoelectrical resistivity investigations were carried out to assess the origin and characteristics of a brackish groundwater in Abu Madi coastal area. Twenty six surface water, shallow and deep groundwater samples were collected and analyzed for various ionic concentrations as well as oxygen and hydrogen stable isotopic contents. In addition, a total of 20 vertical electrical sounding sites were conducted to investigate layers' thicknesses, resistivities, and to detect the water-bearing layers. Then, 2-D Electrical Resistivity Tomography (ERT) along two profiles in the study area was conducted to get information about the surface water effect on recharge. The stable isotopic composition and the chloride concentrations strongly suggest that the deep groundwater in Abu Madi area is dominated by inland freshwater with a minor seawater component. This groundwater was recharged during the first and the third Holocene humid climatic cycles where the sea surface was about 125 and 25 m below the current sea level, respectively. The brackish nature and higher piezometric surface of the groundwater, as well as the occurrence of vertical low-salinity seawater zone in front of the study area, support the possibility of submarine groundwater discharge. The geoelectrical resistivity surveying, on the other hand, revealed a number of geoelectrical groundwater-bearing layers. The main water-bearing layer in the study area is represented by the sixth geoelectrical layer, which has relatively high resistivity and a considerable thickness being consistent with the hydrogeochemical observations. ERT results point to the presence of shallow water-bearing layers recharged from the surface water drains with low resistivity and surface rain water of moderate resistivity. Results from the hydrogeochemical analyses and the different hydrogeological data are consistent with the high resistivity values of this geoelectrical layer. However, the overall high specific

  18. Quantifying energy and water fluxes in dry dune ecosystems of the Netherlands

    Science.gov (United States)

    Voortman, B. R.; Bartholomeus, R. P.; van der Zee, S. E. A. T. M.; Bierkens, M. F. P.; Witte, J. P. M.

    2015-09-01

    Coastal and inland dunes provide various ecosystem services that are related to groundwater, such as drinking water production and biodiversity. To manage groundwater in a sustainable manner, knowledge of actual evapotranspiration (ETa) for the various land covers in dunes is essential. Aiming at improving the parameterization of dune vegetation in hydrometeorological models, this study explores the magnitude of energy and water fluxes in an inland dune ecosystem in the Netherlands. Hydrometeorological measurements were used to parameterize the Penman-Monteith evapotranspiration model for four different surfaces: bare sand, moss, grass and heather. We found that the net longwave radiation (Rnl) was the largest energy flux for most surfaces during daytime. However, modeling this flux by a calibrated FAO-56 Rnl model for each surface and for hourly time steps was unsuccessful. Our Rnl model, with a novel submodel using solar elevation angle and air temperature to describe the diurnal pattern in radiative surface temperature, improved Rnl simulations considerably. Model simulations of evaporation from moss surfaces showed that the modulating effect of mosses on the water balance is species-dependent. We demonstrate that dense moss carpets (Campylopus introflexus) evaporate more (5 %, +14 mm) than bare sand (total of 258 mm in 2013), while more open-structured mosses (Hypnum cupressiforme) evaporate less (-30 %, -76 mm) than bare sand. Additionally, we found that a drought event in the summer of 2013 showed a pronounced delayed signal on lysimeter measurements of ETa for the grass and heather surfaces, respectively. Due to the desiccation of leaves after the drought event, and their feedback on the surface resistance, the potential evapotranspiration in the year 2013 dropped by 9 % (-37 mm) and 10 % (-61 mm) for the grass and heather surfaces, respectively, which subsequently led to lowered ETa of 8 % (-29 mm) and 7 % (-29 mm). These feedbacks are of importance for

  19. Fluoride and nitrate removal from brackish groundwaters by batch-mode capacitive deionization.

    Science.gov (United States)

    Tang, Wangwang; Kovalsky, Peter; He, Di; Waite, T David

    2015-11-01

    Capacitive deionization (CDI) is an emerging water desalination technology in which pairs of porous electrodes are electrically charged to remove ionic species from water. In this work, the feasibility of fluoride and nitrate removal from brackish groundwaters by batch-mode CDI was investigated. Initially, the effects of flow rate, initial fluoride concentration, and initial coexisting NaCl concentration on fluoride removal were studied. The steady-state fluoride concentration declined as the initial fluoride concentration decreased while initial NaCl concentration remained constant. Due to the competitive electrosorption between fluoride and chloride for limited pore surface sites, a higher initial chloride concentration resulted in a higher equilibrium dissolved fluoride concentration. A simplified one-dimensional transport model for dual anions was developed and found to reliably describe the dynamic process of removal of both fluoride and chloride ions in CDI cells over a range of well-defined operating conditions. Based on the ability of the model to describe fluoride removal, it was extended to description of nitrate removal from brackish groundwaters and also found to perform well. Thus, the approach to description of ion removal, at least in batch studies, appears robust and should assist in optimization of design and operating conditions such that optimal removal of trace ionic species is achieved even when high background concentrations of salt are present. PMID:26278188

  20. Harpacticoida (Copepoda) fauna and the taxocenes structure of brackish lagoons and estuaries of the Russian far east

    Science.gov (United States)

    Chertoprud, E. S.; Frenkel, S. E.; Novichkova, A. A.; Vodop'yanov, S. S.

    2014-11-01

    On the basis of original data and literature sources, the species composition of Harpacticoida (Copepoda) in the plankton of the brackish waters of four Far Eastern regions was described: Khabarovsk krai, Sakhalin Island, Kamchatka Peninsula, and the Commander Islands. The compiled list includes 32 harpacticoid species of 22 genera and 10 families. The representatives of the typical brackish families Canthocamptidae and Ectinosomatidae account for about one-third of the total. Six of the species are new to science: 4 species of Halectinosoma, Amphiascus sp. 1, and Schizopera sp. 1. Cosmopolitan species constitute the major portion of the fauna (38% of the total number), while a smaller proportion is typical of endemics (25%), as well as species with the arctic (12%), tropical (9%), and North American (9%) types of areas. There are 17 types of harpacticoid taxocenes of the observed water bodies. Also, the influence of the salinity and temperature on these species complexes was characterized. The hypotheses about the cosmopolitanism of the brackish water fauna and the intrazonality of the estuarine harpacticoid taxocenes structure were tested. It is shown that the structure of the genera dominance in the taxocenes allocated for the temperature latitudes of the Far East demonstrates significant similarity with the arctic and tropical regions.

  1. The management of water providing strategic ecosystems. The case of the basins that supply Medellin and Bogota in Colombia

    International Nuclear Information System (INIS)

    The population growth and the urban concentration involve a sustained increment in water demand, which requires an adequate effort and management of the ecosystems that provide the liquid to guarantee a plenty future offer. The performance of the entities in charge of the management of such ecosystems and the results obtained in the basins that supply drinkable water to two cities in Colombia are analyzed; financial topics and their relation with the local community are considered. Management is delegated to governmental entities, whose work is insufficient and unsatisfactory. Thus, application of economical, legal and social tools is proposed in order to improve ecosystem's conservation and life quality of farmers that inhabit in their influence areas, partially transferring management to the local community's orbit.

  2. SPATIAL AND MULTIVARIATE ANALYSIS OF TRACE ELEMENTS IN THE SURFACE WATER AND DEEP SEDIMENTS OF FRESH WATER AQUATIC ECOSYSTEM

    Directory of Open Access Journals (Sweden)

    Kantha Deivi Arunachalam

    2014-01-01

    Full Text Available The aim of this study was to assess the levels of various trace metals present in water and sediment of fresh water aquatic ecosystem during the post monsoon season. The study was extended to identify the trace metal contamination in the water and sediment samples collected along the shores of Lambapur and Peddagattu the tribal villages in India using an Inductively Coupled Plasma Optical Emission Spectrometer (ICPMS. The trace metal contents in water samples were copper- 24.2 to 47.5, chromium- 4.4 to 8.2, cadmium- 0.1 to 0.3, lead- 2.1 to 3.8, Nickel- 5.9 to 9.7, Zinc- 4.6 to 9.7, Manganese- 10.8 to 13.2, Iron- 52.9 to 157.2 (µg L-1 cobalt and arsenic were in BDL and the values were within the limits of Indian drinking water standards (BIS 10500: 1991. The trace metals concentration in the sediment samples ranged from (mg kg-1: Copper- 61.5 to 113.7, chromium- 138.4 to 177.5, cobalt- 33.2 to 42.7, cadmium- 1.0 to 2.1, lead- 57.9 to 103.4, Nickel- 36.1 to 56.6, Zinc- 51.2 to 102.1, Manganese- 610.8 to 1301.7 and Iron- 2.5 to 2.9%. In our study, four reliable indices such as Enrichment factor, Contamination factor, Geoaccumulation Index and Pollution Load Index were applied to estimate metal pollution and the results comparison are discussed below. The data generated were used to determine the quality of the sediments based on the enrichment factor, contamination factor and degree of contamination, geochemical index and Pollution Load Index (PLI.

  3. Wind effects on prey availability: How northward migrating waders use brackish and hypersaline lagoons in the sivash, Ukraine

    Science.gov (United States)

    Verkuil, Yvonne; Koolhaas, Anita; Van Der Winden, Jan

    Large numbers of waders migrating northward in spring use the Sivash, a large system of shallow, brackish and hypersaline lagoons in the Black Sea and Azov Sea region (Ukraine). The bottoms of these lagoons are often uncovered by the wind. Hence, for waders the time and space available for feeding depend on wind conditions. In hypersaline lagoons the benthic and pelagic fauna was very poor, consisting mainly of chironomid larvae (0.19 g AFDM·m -2) and brine shrimps Artemia salina, respectively. Brine shrimp abundance was correlated with salinity, wind force, wind direction and water depth. Dunlin Calidris alpina and curlew sandpiper Calidris ferruginea were the only species feeding on brine shrimp. As brine shrimp densities are higher in deeper water, smaller waders such as broad-billed sandpipers Limicola falcinellus are too short-legged to reach exploitable densities of brine shrimp. In brackish lagoons the benthic and pelagic fauna was rich, consisting of polychaetes, bivalves, gastropods, chironomid larvae, isopods and amphipods (8.9 to 30.5 g AFDM·m -2), but there were no brine shrimps. Prey biomass increased with the distance from the coast, being highest on the site that was most frequently inundated. Dunlin, broad-billed sandpiper and grey plover Pluvialis squatarola were the most abundant birds in the brackish lagoon. Due to the effects of wind-tides only a small area was usually available as a feeding site. Gammarus insensibilis was the alternative prey resource in the water layer, and their density varied with wind direction in the same way as brine shrimp. Curlew sandpipers and dunlins in the hypersaline lagoons and broad-billed sandpipers in the brackish lagoons often changed feeding sites, probably following the variation in prey availability. Only because of the large size and variety of lagoons are waders in the Sivash always able to find good feeding sites.

  4. A natural driven membrane process for brackish and wastewater treatment: photovoltaic powered ED and FO hybrid system.

    Science.gov (United States)

    Zhang, Yang; Pinoy, Luc; Meesschaert, Boudewijn; Van der Bruggen, Bart

    2013-09-17

    In isolated locations, remote areas, or islands, potable water is precious because of the lack of drinking water treatment facilities and energy supply. Thus, a robust and reliable water treatment system based on natural energy is needed to reuse wastewater or to desalinate groundwater/seawater for provision of drinking water. In this work, a hybrid membrane system combining electrodialysis (ED) and forward osmosis (FO), driven by renewable energy (solar energy), denoted as EDFORD (ED-FO Renewable energy Desalination), is proposed to produce high-quality water (potable) from secondary wastewater effluent or brackish water. In this hybrid membrane system, feedwater (secondary wastewater effluent or synthetic brackish water) was drawn to the FO draw solution while the organic and inorganic substances (ions, compounds, colloids and particles) were rejected. The diluted draw solution was then pumped to the solar energy driven ED. In the ED unit, the diluted draw solution was desalted and high-quality water was produced; the concentrate was recycled to the FO unit and reused as the draw solution. Results show that the water produced from this system contains a low concentration of total organic carbon (TOC), carbonate, and cations derived from the feedwater; had a low conductivity; and meets potable water standards. The water production cost considering the investment for membranes and solar panel is 3.32 to 4.92 EUR m(-3) (for 300 days of production per year) for a small size potable water production system. PMID:23957893

  5. A new approach to assessing the water footprint of hydroelectric power based on allocation of water footprints among reservoir ecosystem services

    Science.gov (United States)

    Zhao, Dandan; Liu, Junguo

    Hydroelectric power is an important energy source to meet the growing demand for energy, and large amounts of water are consumed to generate this energy. Previous studies often assumed that the water footprint of hydroelectric power equaled the reservoir's water footprint, but failed to allocate the reservoir water footprint among the many beneficiaries; dealing with this allocation remains a challenge. In this study, we developed a new approach to quantify the water footprint of hydroelectric power (WFh) by separating it from the reservoir water footprint (WF) using an allocation coefficient (ηh) based on the ratio of the benefits from hydroelectric power to the total ecosystem service benefits. We used this approach in a case study of the Three Gorges Reservoir, the world's largest reservoir, which provides multiple ecosystem services. We found large differences between the WFh and the water footprint of per unit of hydroelectric production (PWFh) calculated using ηh and those calculated without this factor. From 2003 to 2012, ηh decreased sharply (from 0.76 in 2005 to 0.41 in 2012), which was due to the fact that large increases in the value of non-energy ecosystem services, and particularly flood control. In 2009, flood control replaced hydroelectricity as the largest ecosystem service of water from the Three Gorges Reservoir. Using our approach, WFh and PWFh averaged 331.0 × 106 m3 and 1.5 m3 GJ-1, respectively. However, these values would almost double without allocating water footprints among different reservoir ecosystem services. Thus, previous studies have overestimated the WFh and PWFh of reservoirs, especially for reservoirs that serve multiple purposes. Thus, the allocation coefficient should not be ignored when calculating the WF of a product or service.

  6. Effects of climate change on climatic water deficit and wildfire in Greater Yellowstone Ecosystem forests

    Science.gov (United States)

    Westerling, A. L.; Turner, M. G.; Lubetkin, K.

    2011-12-01

    Effects of climate change on climatic water deficit and wildfire in Greater Yellowstone Ecosystem forests Climate change is likely to alter wildfire regimes, but the magnitude and timing of potential climate-driven changes in regional fire regimes are not well understood. Westerling et al (2011) considered how the occurrence, size, and spatial location of large fires might respond to climate projections in the Greater Yellowstone ecosystem (GYE), a large wildland ecosystem dominated by conifer forests and characterized by infrequent, high-severity fire. They developed statistical models that related climate data (1972-1999) to the occurrence and size of fires >200 ha in the northern Rocky Mountains. Cumulative deficit was particularly important for modeling extreme value distributions for fire size, and was also a statistically significant predictor of the occurrence and number of large fires. Most of the area burned in large fires in the GYE from 1972-99 occurred in 1988 in extremely large fires. Climate projections imply that conditions associated with extreme fires in the region will become more common in coming decades. Thus, in order to estimate climate change impacts on GYE fire regimes, it was imperative that models capture extremes in fire occurrence and particularly fire size distributions. We will discuss the role of cumulative deficit versus other climate variables and land-surface characteristics in modeling extremes in fire activity in the GYE and the Northern Rockies more generally. Westerling et al (2011) used their suite of models with downscaled climate projections from three global climate models to predict fire occurrence and area burned in the GYE through 2099. All models predicted substantial increases in fire by midcentury, with fire rotation reduced to fires were common historically but are expected to become rare as annual area burned and the frequency of regionally synchronous fires increase. These findings suggest a shift to novel fire

  7. Convergence of the effect of root hydraulic functioning and root hydraulic redistribution on ecosystem water and carbon balance across divergent forest ecosystems

    Science.gov (United States)

    domec, J.; King, J. S.; Ogée, J.; Noormets, A.; Warren, J.; Meinzer, F. C.; Sun, G.; Jordan-Meille, L.; Martineau, E.; Brooks, R. J.; Laclau, J.; Battie Laclau, P.; McNulty, S.

    2012-12-01

    INVITED ABSTRACT: Deep root water uptake and hydraulic redistribution (HR) play a major role in forest ecosystems during drought, but little is known about the impact of climate change on root-zone processes influencing HR and its consequences on water and carbon fluxes. Using data from two old growth sites in the western USA, two mature sites in the eastern USA, one site in southern Brazil, and simulations with the process-based model MuSICA, our objectives were to show that HR can 1) mitigate the effects of soil drying on root functioning, and 2) have important implications for carbon uptake and net ecosystem exchange (NEE). In a dry, old-growth ponderosa pine (USA) and a eucalyptus stand (Brazil) both characterized by deep sandy soils, HR limited the decline in root hydraulic conductivity and increased dry season tree transpiration (T) by up to 30%, which impacted NEE through major increases in gross primary productivity (GPP). The presence of deep-rooted trees did not necessarily imply high rates of HR unless soil texture allowed large water potential gradients to occur, as was the case in the wet old-growth Douglas-fir/mixed conifer stand. At the Duke mixed hardwood forest characterized by a shallow clay-loam soil, modeled HR was low but not negligible, representing annually up to 10% of T, and maintaining root conductance high. At this site, in the absence of HR, it was predicted that annual GPP would have been diminished by 7-19%. At the coastal loblolly pine plantation, characterized by deep organic soil, HR limited the decline in shallow root conductivity by more than 50% and increased dry season T by up to 40%, which increased net carbon gain by the ecosystem by about 400 gC m-2 yr-1, demonstrating the significance of HR in maintaining the stomatal conductance and assimilation capacity of the whole ecosystem. Under future climate conditions (elevated atmospheric [CO2] and temperature), HR is predicted to be reduced by up to 50%; reducing the resilience of

  8. Using watershed water balance to evaluate the accuracy of eddy covariance evaporation measurements for three semiarid ecosystems

    Science.gov (United States)

    The eddy covariance (EC) technique is a widely-used and accepted method to quantify ecosystem-scale mass and energy fluxes. Measurements of evaporation from EC are used to determine local, regional and global water budgets, calibrate and validate land surface models, and acquire understanding of ec...

  9. Ecosystem respiration in a heterogeneous temperate peatland and its sensitivity to peat temperature and water table depth

    Czech Academy of Sciences Publication Activity Database

    Juszczak, R.; Humphreys, E.; Acosta, Manuel; Michalak-Galczewska, M.; Kayzer, D.; Olejnik, Janusz

    2013-01-01

    Roč. 366, 1-2 (2013), s. 505-520. ISSN 0032-079X Institutional support: RVO:67179843 Keywords : Ecosystem respiration * Geogenous peatland * Chamber measurements * CO2 fluxes * Water table depth Subject RIV: EH - Ecology, Behaviour Impact factor: 3.235, year: 2013

  10. Net ecosystem exchange of carbon dioxide and water of far eastern Siberian larch (Larix cajanderii) on permafrost

    NARCIS (Netherlands)

    Dolman, A.J.; Maximov, T.C.; Moors, E.J.; Maximov, A.P.; Elbers, J.A.; Kononov, A.V.; Waterloo, M.J.; Molen, van der M.K.

    2004-01-01

    Observations of the net ecosystem exchange of water and CO2 were made during two seasons in 2000 and 2001 above a Larch forest in Far East Siberia (Yakutsk). The measurements were obtained by eddy correlation. There is a very sharply pronounced growing season of 100 days when the forest is leaved. M

  11. The contribution of mosses to the carbon and water exchange of artic ecosystems: quantification and relationships with system properties

    NARCIS (Netherlands)

    Douma, J.C.; Wijk, van M.T.; Lang, S.I.; Shaver, G.R.

    2007-01-01

    Water vapour and CO2 exchange were measured in moss-dominated vegetation using a gas analyser and a 0.3 × 0.3 m chamber at 17 sites near Abisko, Northern Sweden and 21 sites near Longyearbyen, Svalbard, to quantify the contribution of mosses to ecosystem level fluxes. With the help of a simple light

  12. Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor Vulnerability Assessments (Final Report)

    Science.gov (United States)

    This report investigates the issues and challenges associated with identifying, calculating, and mapping indicators of the relative vulnerability of water quality and aquatic ecosystems, across the United States, to the potential impacts of global change. Using a large set of en...

  13. Germination of Acacia harpophylla (Brigalow) seeds in relation to soil water potential: implications for rehabilitation of a threatened ecosystem

    OpenAIRE

    Sven Arnold; Yolana Kailichova; Thomas Baumgartl

    2014-01-01

    Initial soil water conditions play a critical role when seeding is the primary approach to revegetate post-mining areas. In some semi-arid climates, such as the Brigalow Belt Bioregion in eastern Australia, extensive areas are affected by open-cut mining. Together with erratic rainfall patterns and clayey soils, the Brigalow Belt denotes a unique biome which is representative of other water-limited ecosystems worldwide. Apart from other environmental stressors, germination is governed by the ...

  14. Geochemical indicators and characterization of soil water repellence in three dominant ecosystems of Western Australia

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Jiménez-Morillo, Nicasio T.; Jordan, Antonio; Zavala, Lorena M.; Stevens, Jason; González-Pérez, Jose Antonio

    2016-04-01

    Introduction Soil water repellency (SWR) has critical implications for restoration of vegetation in degraded areas as it is responsible of poor plant establishment and a high incidence of erosion processes. Different organic substances are capable of inducing SWR but polar molecules such as certain fatty acids, and waxes i.e. esters and salts of fatty acids, appear to be the main constituents of hydrophobic coatings on soil mineral particles (Doerr et al., 2005). Plant species most commonly associated with SWR are evergreen trees with a considerable amount of resins, waxes or aromatic oils such as eucalypts and pines. Most of these substances are abundant in ecosystems and are released to soil by plants as root exudates or decaying organic debris, and by soil fauna, fungi and other microorganisms, but a thorough knowledge of substances capable of inducing hydrophobicity in soils is still not complete (Jordan et al., 2013). Although SWR has been reported in most continents of the world for different soil types, climate conditions and land uses, there are still many research gaps in this area, particularly in semi-arid areas largely affected by this phenomenon. Materials and methods This research was conducted in three dominant ecosystems of Western Australia (WA), e.g. semi-arid grassland in the Pilbara region (North WA), Banksia woodland, and a coastal dune (both located in South WA). These environments have different climate characteristics and soil types but similar vegetation communities. Soil samples were collected under the canopy of a broad range of plant species that compose the dominant vegetation communities of these ecosystems, and SWR was measured under lab conditions in oven-dry samples (48 h, 105 °C). Soil microbial activity was measured with the 1-day CO2 test, a cost-effective and rapid method to determine soil microbial respiration rate based on the measurement of the CO2 burst produced after moistening dry soil (Muñoz-Rojas et al., 2016). Soil p

  15. Agricultural Best Management Practice Abundance and Location does not Influence Stream Ecosystem Function or Water Quality in the Summer Season

    Directory of Open Access Journals (Sweden)

    Nolan J. T. Pearce

    2015-12-01

    Full Text Available Best management practices (BMPs are tools commonly used to mitigate negative impacts of agriculture on water quality; however, the relationship between BMPs and aquatic ecological function is unknown. Our research goal was to determine the association between both stream ecosystem metabolism and water quality, and the abundance and location of four different BMPs in agricultural catchments. Dissolved oxygen was measured over a two-week period in mid-June and used to estimate ecosystem metabolism of 13 headwater streams representing a gradient of BMP implementation in Southern Ontario, Canada. Stepwise regression analyses were used to associate stream metabolism and water quality with metrics describing the abundance and location of BMPs within each catchment. Studied streams exhibited rates of metabolism comparable to catchments from other agricultural regions. However, metrics of BMP implementation were not associated with either stream metabolism or water quality. Our results suggest that BMPs in the studied agricultural catchments are not improving water quality or mitigating water quality impacts on stream metabolism during the summer season. We propose that seasonality of catchment hydrology and time lag effects associated with past agricultural land use may be masking the mitigation benefits of BMPs on stream ecosystem conditions during the summer season.

  16. Impact of converison of mangrove ecosystem for aquaculture purposes

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Wafar, S.

    in Indian mangroves. Conversion of mangroves for coconut and paddy cultivation alongwith setting of fish ponds is an age old practice in coastal India and is called as 'filtration' or 'trapping'. The brackish water aquaculture covers an area of 45...

  17. Content of short-lived radionuclides in the Kanevskoe water reservoir and its coastal ecosystems after the Chernobyl NPP accident

    International Nuclear Information System (INIS)

    The content of Te 132, Np 239, Ba 140, I 131 in components of ecosystem of Kanevskoe reservoir of river Dnepr and adjoining to it surface ecosystems studied in 1986. The maximal content of investigated radionuclides was registered in water and surface vegetation. Contamination of hydrobionts by Ba 140 and I 131 has been generated practically at once after fall-out of these radionuclides directly on a mirror of the reservoir during the period from 30.04.1986 to 02.05.1986. Cancers Astacus Leptodactilus Eichw. and fishes intensively accumulated Ba 140 and I 131. (authors)

  18. Duckweed Lemna minor (Liliopsida, Lemnaceae as a natural biofilter in brackish and fresh closed recirculating systems

    Directory of Open Access Journals (Sweden)

    Tharwat S. Nashashibi

    2012-12-01

    Full Text Available This study attempted to assess the potential use of common duckweed Lemna minor asnatural biofilter in brackish closed recirculating systems of 4 g/L salinity and to evaluate the effect ofsalinities in the ranges of 1-7 g L-1 on the duckweed’s ammonium NH4 +1uptake. Furthermore thepossibility of nitrification as a second mechanism of nitrogen removal in closed recirculating systems wasinvestigated. Three closed recirculating systems each having 20 mixed Oreochromis niloticus were used.Duckweed L. minor and fresh water were added in system 1, fresh water only in system 2, and duckweedwith brackish water in system 3. Ammonium NH4 +1and nitrate NO3-1 were tested periodically in eachsystem during a 1.5 month period. Another three experiments were run in parallel using aquariumsincubated with 60.00 g fresh weight L. minor at salinities in the ranges of 1-7 g L-1 for two weeks.Aquariums were exposed directly to sunlight in experiment 1 and 3, and were placed in the dark inexperiment 2. The nitrogen source in experiment 1 and 2 was 100 mg L-1 of NH4Cl, and 280 mg L-1 ofNH4Cl in experiment 3. NH4 +1and NO3-1 levels were monitored as above. L. minor managed to reduce theaverage NH4 +1levels to 0.5 mg L-1, 0.43 mg L-1below the standard recommended levels in both brackishand fresh water systems, respectively. Ammonium NH4 +1 uptake was coupled with nitrate NO3-1 uptakeunder favorable conditions of sunlight. Salinity in the ranges from 1-7 g L-1 enhanced ammonium NH4 +1uptake (r = 0.8819, p = 0.023 without affecting nitrate NO3-1 uptake or any observed mortality of theduckweed. Nitrification was a second mechanism of nitrogen removal in a closed recirculating system,but it was affected by salinity and light. Average ammonium NH4 +1of 51.8 mg L-1 was toxic to L. minorand death was observed within a week in experiment 3. The duckweed L. minor was an efficient naturalbiofilter in both brackish and fresh water closed recirculating systems.

  19. Accounting for "hot spots" and "hot moments" in soil carbon models for water-limited ecosystems

    Science.gov (United States)

    O'Donnell, Frances; Caylor, Kelly

    2010-05-01

    Soil organic carbon (SOC) dynamics in water-limited ecosystems are complicated by the stochastic nature of rainfall and patchy structure of vegetation, which can lead to "hot spots" and "hot moments" of high biological activity. Non-linear models that use spatial and temporal averages of forcing variables are unable to account for these phenomena and are likely to produce biased results. In this study we present a model of SOC abundance that accounts for spatial heterogeneity at the plant scale and temporal variability in soil moisture content at the daily scale. We approximated an existing simulation-based model of SOC dynamics as a stochastic differential equation driven by multiplicative noise that can be solved numerically for steady-state sizes of three SOC pools. We coupled this to a model of water balance and SOC input rate at a point for a given cover type, defined by the number of shrub and perennial grass root systems and canopies overlapping the point. Using a probabilistic description of vegetation structure based on a two dimensional Poisson process, we derived analytical expressions for the distribution of cover types across a landscape and produced weighted averages of SOC stocks. An application of the model to a shortgrass steppe ecosystem in Colorado, USA, replicated empirical data on spatial patterns and average abundance of SOC, whereas a version of the model using spatially averaged forcing variables overestimated SOC stocks by 12%. The model also successfully replicated data from paired desert grassland sites in New Mexico, USA, that had and had not been affected by woody plant encroachment, indicating that the model could be a useful tool for understanding and predicting the effect of woody plant encroachment on regional carbon budgets. We performed a theoretical analysis of a simplified version of the model to estimate the bias introduced by using spatial averages of forcing variables to model SOC stocks across a range of climatic conditions

  20. Aspects of the biodiversity of brackish water foraminifera

    Digital Repository Service at National Institute of Oceanography (India)

    Jayalakshmy, K.V.; Rao, K.K.

    of species are very valuable, despite giving only very little insight into the highly important biotic constraints of the dynamic processes that establish the real niches of animals. Lee (1974) attempted to quantify the biotic and abiotic parameters for some... that take into account the joint absences are not robust enough to be generally applicable (Field et al., 1982). There- fore the measure used by Bray and Curtis (1957) (Clifford and Stephenson, 1975) has been applied here since it is not affected by joint...

  1. Desalination of brackish waters by electrodialysis. I. Process variable studies

    International Nuclear Information System (INIS)

    This study was carried out with solutions of 5000, 3000 and 1000 ppm of NaCl, and 3000 and 1000 ppm of NaSO4. A stack-pack of 20 pairs membranes, Nepton lonics 61 AZL 183 -cationic- and 111 BZL 183 -anionic- with 220 cm2/membrane was used. For the above mentioned Solutions the following values were determined: Limiting current density; the values of n and K in the expression which relates the L.C.D. with flow rate; dependence of spent energy on flow rate; spent energy and time of operation versus initial current and concentration of the solution, and finally the influence of the concentration potential on the electrodialytic process. A discussion of the results obtained is included. (Author) 18 refs

  2. DNA barcoding identifies Argentine fishes from marine and brackish waters.

    Directory of Open Access Journals (Sweden)

    Ezequiel Mabragaña

    Full Text Available BACKGROUND: DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region. METHODOLOGY/PRINCIPAL FINDINGS: Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species, and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; www.barcodinglife.org. Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125 examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles. CONCLUSIONS/SIGNIFICANCE: This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha taxonomy, barcodes provide robust support for most morphologically based taxon concepts and also highlight key areas of taxonomic uncertainty worthy of reappraisal.

  3. DNA Barcoding Identifies Argentine Fishes from Marine and Brackish Waters

    Science.gov (United States)

    Mabragaña, Ezequiel; Díaz de Astarloa, Juan Martín; Hanner, Robert; Zhang, Junbin; González Castro, Mariano

    2011-01-01

    Background DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region. Methodology/Principal Findings Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species), and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; www.barcodinglife.org). Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125) examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles. Conclusions/Significance This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha taxonomy, barcodes provide robust support for most morphologically based taxon concepts and also highlight key areas of taxonomic uncertainty worthy of reappraisal. PMID:22174860

  4. Application of the Benthic Ecosystem Quality Index 2 to benthos in Dutch transitional and coastal waters

    Science.gov (United States)

    van Loon, W. M. G. M.; Boon, A. R.; Gittenberger, A.; Walvoort, D. J. J.; Lavaleye, M.; Duineveld, G. C. A.; Verschoor, A. J.

    2015-09-01

    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, as in the multivariate m-AMBI. The latter MMI has been adopted by several European countries in the context of WFD implementation. In contrast to m-AMBI, the BEQI2 calculation procedure has been strongly simplified and consists of two steps, i.e. the separate indicator values are normalized using their long-term reference values resulting in three Ecological Quality Ratios (EQRs), which are subsequently averaged to give one BEQI2 value. Using this method only small numbers of samples need to be analysed by Dutch benthos laboratories annually, without the necessity to co-analyse a larger historical dataset. BEQI2 EQR values appeared to correlate quantitatively very well with m-AMBI EQR values. In addition, a data pooling procedure has been added to the BEQI2 tool which enables the pooling of small core samples (0.01-0.025 m2) into larger standardized data pools of 0.1 m2 in order to meet the data requirements of the AMBI indicator and to obtain comparable reference values. Furthermore, the BEQI2 tool automatically and efficiently converts species synonym names into standardized species names. The BEQI2 tool has been applied to all Dutch benthos data monitored by Rijkswaterstaat in the period of 1991-2010 in the transitional and coastal waters and salt lakes and these results are reported here for the first time. Reference values for species richness and Shannon index (99 percentile values) and AMBI reference values (1 percentile values) were estimated for all water body-ecotopes and are discussed. BEQI2 results for all these water bodies are discussed in view of natural and human pressures. The pressure sensitivity of the BEQI2 for sewage and dredging/dumping, via the

  5. River basins as social-ecological systems: linking levels of societal and ecosystem water metabolism in a semiarid watershed

    Directory of Open Access Journals (Sweden)

    Violeta Cabello

    2015-09-01

    Full Text Available River basin modeling under complexity requires analytical frameworks capable of dealing with the multiple scales and dimensions of environmental problems as well as uncertainty in the evolution of social systems. Conceptual and methodological developments can now be framed using the wide socio-eco-hydrological approach. We add hierarchy theory into the mix to discuss the conceptualization of river basins as complex, holarchic social-ecological systems. We operationalize the social-ecological systems water metabolism framework in a semiarid watershed in Spain, and add the governance dimension that shapes human-environment reciprocity. To this purpose, we integrate an eco-hydrological model with the societal metabolism accounting scheme for land use, human activity, and water use. We explore four types of interactions: between societal organization and water uses/demands, between ecosystem organization and their water requirements/supplies, between societal metabolism and aquatic ecosystem health, and between water demand and availability. Our results reveal a metabolic pattern of a high mountain rural system striving to face exodus and agricultural land abandonment with a multifunctional economy. Centuries of social-ecological evolution shaping waterscapes through traditional water management practices have influenced the eco-hydrological functioning of the basin, enabling adaptation to aridity. We found a marked spatial gradient on water supply, use pattern, and impact on water bodies from the head to the mouth of the basin. Management challenges posed by the European water regulatory framework as a new driver of social-ecological change are highlighted.

  6. An integrated model for assessing the risk of TCE groundwater contamination to human receptors and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Funder, S.G.; Rasmussen, J.J.;

    2010-01-01

    accomplished by coupling the system dynamics-based decision support system CARO-PLUS to the aquatic ecosystem model AQUATOX using an analytical volatilization model for the stream. The model was applied to a case study where a TCE contaminated groundwater plume is discharging to a stream. The TCE source will...... not be depleted for many decades, however measured and predicted TCE concentrations in surface water were found to be below human health risk management targets. Volatilization rapidly attenuates TCE concentrations in surface water. Thus, only a 300 m stream reach fails to meet surface water quality...... criteria. An ecological risk assessment found that the TCE contamination did not impact the stream ecosystem. Uncertainty assessment revealed hydraulic conductivity to be the most important site-specific parameter. These results indicate that contaminant plumes with μgL-1 concentrations of TCE entering...

  7. Exploring the Capacity of Water Framework Directive Indices to Assess Ecosystem Services in Fluvial and Riparian Systems: Towards a Second Implementation Phase

    Science.gov (United States)

    Vidal-Abarca, M. R.; Santos-Martín, F.; Martín-López, B.; Sánchez-Montoya, M. M.; Suárez Alonso, M. L.

    2016-06-01

    We explored the capacity of the biological and hydromorphological indices used in the Water Framework Directive (WFD) to assess ecosystem services by evaluating the ecological status of Spanish River Basins. This analysis relies on an exhaustive bibliography review which showed scientific evidence of the interlinkages between some ecosystem services and different hydromorphological and biological elements which have been used as indices in the WFD. Our findings indicate that, of a total of 38 ecosystem services analyzed, biological and hydromorphological indices can fully evaluate four ecosystem services. In addition, 18 ecosystem services can be partly evaluated by some of the analyzed indices, while 11 are not related with the indices. While Riparian Forest Quality was the index that was able to assess the largest number of ecosystem services ( N = 12), the two indices of macrophytes offered very poor guarantees. Finally, biological indices related to diatoms and aquatic invertebrates and the Fluvial Habitat Index can be related with 7, 6, and 6 ecosystem services, respectively. Because the WFD indices currently used in Spain are not able to assess most of the ecosystem services analyzed, we suggest that there is potential to develop the second phase of the WFD implementation taking this approach into consideration. The incorporation of the ecosystem services approach into the WFD could provide the framework for assess the impacts of human activities on the quality of fluvial ecosystems and could give insights for water and watershed management in order to guarantee the delivery of multiple ecosystem services.

  8. Exploring the Capacity of Water Framework Directive Indices to Assess Ecosystem Services in Fluvial and Riparian Systems: Towards a Second Implementation Phase.

    Science.gov (United States)

    Vidal-Abarca, M R; Santos-Martín, F; Martín-López, B; Sánchez-Montoya, M M; Suárez Alonso, M L

    2016-06-01

    We explored the capacity of the biological and hydromorphological indices used in the Water Framework Directive (WFD) to assess ecosystem services by evaluating the ecological status of Spanish River Basins. This analysis relies on an exhaustive bibliography review which showed scientific evidence of the interlinkages between some ecosystem services and different hydromorphological and biological elements which have been used as indices in the WFD. Our findings indicate that, of a total of 38 ecosystem services analyzed, biological and hydromorphological indices can fully evaluate four ecosystem services. In addition, 18 ecosystem services can be partly evaluated by some of the analyzed indices, while 11 are not related with the indices. While Riparian Forest Quality was the index that was able to assess the largest number of ecosystem services (N = 12), the two indices of macrophytes offered very poor guarantees. Finally, biological indices related to diatoms and aquatic invertebrates and the Fluvial Habitat Index can be related with 7, 6, and 6 ecosystem services, respectively. Because the WFD indices currently used in Spain are not able to assess most of the ecosystem services analyzed, we suggest that there is potential to develop the second phase of the WFD implementation taking this approach into consideration. The incorporation of the ecosystem services approach into the WFD could provide the framework for assess the impacts of human activities on the quality of fluvial ecosystems and could give insights for water and watershed management in order to guarantee the delivery of multiple ecosystem services. PMID:26884142

  9. Nitrogen biogeochemistry in the Adirondack Mountains of New York: hardwood ecosystems and associated surface waters

    International Nuclear Information System (INIS)

    Factors that regulate the fate of atmospherically deposited nitrogen to hardwood forests and subsequent transport to surface waters in the Adirondack region of New York are described. - Studies on the nitrogen (N) biogeochemistry in Adirondack northern hardwood ecosystems were summarized. Specific focus was placed on results at the Huntington Forest (HFS), Pancake-Hall Creek (PHC), Woods Lake (WL), Ampersand (AMO), Catlin Lake (CLO) and Hennessy Mountain (HM). Nitrogen deposition generally decreased from west to east in the Adirondacks, and there have been no marked temporal changes in N deposition from 1978 through 1998. Second-growth western sites (WL, PHC) had higher soil solution NO3- concentrations and fluxes than the HFS site in the central Adirondacks. Of the two old-growth sites (AMO and CLO), AMO had substantially higher NO3- concentrations due to the relative dominance of sugar maple that produced litter with high N mineralization and nitrification rates. The importance of vegetation in affecting N losses was also shown for N-fixing alders in wetlands. The Adirondack Manipulation and Modeling Project (AMMP) included separate experimental N additions of (NH4)2SO4 at WL, PHC and HFS and HNO3 at WL and HFS. Patterns of N loss varied with site and form of N addition and most of the N input was retained. For 16 lake/watersheds no consistent changes in NO3- concentrations were found from 1982 to 1997. Simulations suggested that marked NO3- loss will only be manifested over extended periods. Studies at the Arbutus Watershed provided information on the role of biogeochemical and hydrological factors in affecting the spatial and temporal patterns of NO3- concentrations. The heterogeneous topography in the Adirondacks has generated diverse landscape features and patterns of connectivity that are especially important in regulating the temporal and spatial patterns of NO3- concentrations in surface waters

  10. Robust decision-making under uncertainty for a moorland ecosystem's water resources management under scenarios of climate variability

    Science.gov (United States)

    Flores-Lopez, F.; Forni, L.; Escobar, M.; Purkey, D. R.

    2013-12-01

    A climate-informed water resources decision-making framework can help effectively manage the complexity of water resources while adapting to climate change effects. The decision-making framework allows for more effective and inclusive water resources management, and results in better informed decisions about water allocation and adaptation strategies. This study focuses on modeling the moorland ecosystem's water resources management under climate variability, and strengthening the capacities of local actors through a robust decision-making under uncertainty framework to analyze and plan water resources use in the region of Piura, Peru. The objective is to determine the reliability of the moorland ecosystem's water supply and to provide relevant hydrological information under scenarios of climate variability and other non-climate uncertainties. As a first step, a participatory workshop was carried out with key regional actors to obtain information that would help to define the uncertainties that define availability of water resources, the potential strategies for adaptation to improve existing conditions, and the performance indicators by which to assess these uncertainties and strategies. For the identification of these factors, we used the XLRM assessment framework (eXogenous uncertainties, policy Levers, Relationships, and Measures). The XLRM framework allows us to organize the important elements of risk analysis and vulnerability in the four assessment categories. This study also used the WEAP (Water Evaluation And Planning system) platform to support water resources planning and decision-making under uncertainty e.g. climate change and other stresses in the system. Within the R component, WEAP was used to model the hydrological response of the moorland ecosystem. The model includes the results of the XLRM framework and seeks to determine the importance that the moorlands have on the regional water system. Results of this model include the head flows produced

  11. Framing Scenarios of Binational Water Policy with a Tool to Visualize, Quantify and Valuate Changes in Ecosystem Services

    Directory of Open Access Journals (Sweden)

    William Labiosa

    2013-06-01

    Full Text Available In the Santa Cruz Watershed, located on the Arizona-Sonora portion of the U.S.-Mexico border, an international wastewater treatment plant treats wastewater from cities on both sides of the border, before discharging it into the river in Arizona. These artificial flows often subsidize important perennial surface water ecosystems in the region. An explicit understanding of the benefits of maintaining instream flow for present and future generations requires the ability to assess and understand the important trade-offs implicit in water-resource management decisions. In this paper, we outline an approach for modeling and visualizing impacts of management decisions in terms of rare terrestrial and aquatic wildlife, vegetation, surface water, groundwater recharge, real-estate values and socio-environmental vulnerable communities. We identify and quantify ecosystem services and model the potential reduction in effluent discharge to the U.S. that is under scrutiny by binational water policy makers and of concern to stakeholders. Results of service provisioning are presented, and implications for policy makers and resource managers are discussed. This paper presents a robust ecosystem services assessment of multiple scenarios of watershed management as a means to discern eco-hydrological responses and consider their potential values for future generations living in the borderlands.

  12. Long-term increase in forest water-use efficiency observed across ecosystem carbon flux networks (Invited)

    Science.gov (United States)

    Keenan, T. F.; Hollinger, D. Y.; Bohrer, G.; Dragoni, D.; Munger, J. W.; Schmid, H. E.; Richardson, A. D.

    2013-12-01

    Terrestrial plants remove CO2 from the atmosphere through photo- synthesis, a process that is accompanied by the loss of water vapour from leaves. The ratio of water loss to carbon gain, or water-use efficiency, is a key characteristic of ecosystem function that is central to the global cycles of water, energy and carbon. Here we analyse direct, long-term measurements of whole-ecosystem carbon and water exchange. We find a substantial increase in water-use efficiency in temperate and boreal forests of the Northern Hemisphere over the past two decades. We systematically assess various competing hypotheses to explain this trend, and find that the observed increase is most consistent with a strong CO2 fertilization effect. The results suggest a partial closure of stomata - small pores on the leaf surface that regulate gas exchange - to maintain a near- constant concentration of CO2 inside the leaf even under continually increasing atmospheric CO2 levels. The observed increase in forest water-use efficiency is larger than that predicted by existing theory and 13 terrestrial biosphere models. The increase is associated with trends of increasing ecosystem-level photosynthesis and net carbon uptake, and decreasing evapotranspiration. Our findings demonstrate the utility of maintaining long-term eddy-covariance flux measurement sites. The results suggest a shift in the carbon- and water-based economics of terrestrial vegetation, which may require a reassessment of the role of stomatal control in regulating interactions between forests and climate change, and a re-evaluation of coupled vegetation-climate models.

  13. The stochastic structure of critical transitions in water-stressed ecosystems

    Science.gov (United States)

    Cueto-Felgueroso, L.; Dentz, M.; Juanes, R.

    2013-12-01

    Changes in the stochastic structure of natural forcing mechanisms, such as precipitation or temperature, are likely to transform the form and function of ecological systems. Climate models and global datasets show that an increase in global temperature may result in an amplification of the hydrological cycle, not necessarily accompanied by significant changes in mean annual precipitation. In arid and semiarid environments, feedbacks between climate, soil moisture and vegetation are linked to the existence of alternative stable ecosystem states. It has been hypothesized that bistability is associated with tipping points, whereby slow changes in rainfall forcing, and random or anthropogenic disturbances, may trigger catastrophic shifts towards degraded states of the ecosystem. Identifying tipping points and characterizing ecosystem resilience are essential in the assessment of ecological services in a changing environment. We develop a stochastic framework to understand the joint probability density function (pdf) of soil moisture and vegetation biomass under stochastic rainfall. We emphasize the impact of amplified hydrological cycles on ecosystems where alternative states are possible. The joint pdf characterizes the states in which the ecosystem is most likely to be found. We show that the structure of precipitation, not just the mean annual precipitation, controls the most likely state of the ecosystem. We synthesize our analysis by proposing a definition of ecosystem resilience that is based on the modality and time dynamics of the soil moisture-biomass joint pdf.

  14. The influence of climate variability and change on the ecosystems of the Barents Sea and adjacent waters: Review and synthesis of recent studies from the NESSAS Project

    Science.gov (United States)

    Drinkwater, Kenneth F.

    2011-07-01

    The Norwegian Component of the Ecosystem Studies of Sub-Arctic Seas (NESSAS) was funded by the Research Council of Norway from 2005 to 2008. Its aim was to quantify the impact of climate variability on the structure and function of the marine ecosystem of the Barents Sea and adjacent waters in order to predict the ecosystem responses to possible future climate change and their possible economic impact. This paper reviews

  15. Seasonal responses of terrestrial ecosystem water-use efficiency to climate change.

    Science.gov (United States)

    Huang, Mengtian; Piao, Shilong; Zeng, Zhenzhong; Peng, Shushi; Ciais, Philippe; Cheng, Lei; Mao, Jiafu; Poulter, Ben; Shi, Xiaoying; Yao, Yitong; Yang, Hui; Wang, Yingping

    2016-06-01

    Ecosystem water-use efficiency (EWUE) is an indicator of carbon-water interactions and is defined as the ratio of carbon assimilation (GPP) to evapotranspiration (ET). Previous research suggests an increasing long-term trend in annual EWUE over many regions and is largely attributed to the physiological effects of rising CO2 . The seasonal trends in EWUE, however, have not yet been analyzed. In this study, we investigate seasonal EWUE trends and responses to various drivers during 1982-2008. The seasonal cycle for two variants of EWUE, water-use efficiency (WUE, GPP/ET), and transpiration-based WUE (WUEt , the ratio of GPP and transpiration), is analyzed from 0.5° gridded fields from four process-based models and satellite-based products, as well as a network of 63 local flux tower observations. WUE derived from flux tower observations shows moderate seasonal variation for most latitude bands, which is in agreement with satellite-based products. In contrast, the seasonal EWUE trends are not well captured by the same satellite-based products. Trend analysis, based on process-model factorial simulations separating effects of climate, CO2 , and nitrogen deposition (NDEP), further suggests that the seasonal EWUE trends are mainly associated with seasonal trends of climate, whereas CO2 and NDEP do not show obvious seasonal difference in EWUE trends. About 66% grid cells show positive annual WUE trends, mainly over mid- and high northern latitudes. In these regions, spring climate change has amplified the effect of CO2 in increasing WUE by more than 0.005 gC m(-2)  mm(-1)  yr(-1) for 41% pixels. Multiple regression analysis further shows that the increase in springtime WUE in the northern hemisphere is the result of GPP increasing faster than ET because of the higher temperature sensitivity of GPP relative to ET. The partitioning of annual EWUE to seasonal components provides new insight into the relative sensitivities of GPP and ET to climate, CO2, and NDEP. PMID

  16. Water content differences have stronger effects than plant functional groups on soil bacteria in a steppe ecosystem.

    Directory of Open Access Journals (Sweden)

    Ximei Zhang

    Full Text Available Many investigations across natural and artificial plant diversity gradients have reported that both soil physicochemical factors and plant community composition affect soil microbial communities. To test the effect of plant diversity loss on soil bacterial communities, we conducted a five-year plant functional group removal experiment in a steppe ecosystem in Inner Mongolia (China. We found that the number and composition type of plant functional groups had no effect on bacterial diversity and community composition, or on the relative abundance of major taxa. In contrast, bacterial community patterns were significantly structured by soil water content differences among plots. Our results support researches that suggest that water availability is the key factor structuring soil bacterial communities in this semi-arid ecosystem.

  17. Soil and water related forest ecosystem services and resilience of social ecological system in the Central Highlands of Ethiopia

    Science.gov (United States)

    Tekalign, Meron; Muys, Bart; Nyssen, Jan; Poesen, Jean

    2014-05-01

    In the central highlands of Ethiopia, deforestation and forest degradation are occurring and accelerating during the last century. The high population pressure is the most repeatedly mentioned reason. However, in the past 30 years researchers agreed that the absence of institutions, which could define the access rights to particular forest resources, is another underlying cause of forest depletion and loss. Changing forest areas into different land use types is affecting the biodiversity, which is manifested through not proper functioning of ecosystem services. Menagesha Suba forest, the focus of this study has been explored from various perspectives. However the social dimension and its interaction with the ecology have been addressed rarely. This research uses a combined theoretical framework of Ecosystem Services and that of Resilience thinking for understanding the complex social-ecological interactions in the forest and its influence on ecosystem services. For understanding the history and extent of land use land cover changes, in-depth literature review and a GIS and remote sensing analysis will be made. The effect of forest conversion into plantation and agricultural lands on soil and above ground carbon sequestration, fuel wood and timber products delivery will be analyzed with the accounting of the services on five land use types. The four ecosystem services to be considered are Supporting, Provisioning, Regulating, and Cultural services as set by the Millennium Ecosystem Assessment. A resilience based participatory framework approach will be used to analyze how the social and ecological systems responded towards the drivers of change that occurred in the past. The framework also will be applied to predict future uncertainties. Finally this study will focus on the possible interventions that could contribute to the sustainable management and conservation of the forest. An ecosystem services trade-off analysis and an environmental valuation of the water

  18. Thermal regulation of functional groups in running water ecosystems. Progress report, October 1, 1975--June 30, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, K.W.; Klug, M.J.

    1976-07-01

    Progress is reported on the following research projects: characterization of functional groups of running water organisms, particularly macroconsumers; studies on relationship of functional groups to qualitative and quantitative characteristics of organic inputs to stream ecosystems; studies on relationship of functional groups to thermal regimes; and dimensioning the control of feeding and growth by temperature and food quality and quantity and determining the extent of compensatory action of each. (HLW)

  19. Above and belowground controls on litter decomposition in semiarid ecosystems: effects of solar radiation, water availability and litter quality

    Science.gov (United States)

    Austin, A. T.; Araujo, P. I.; Leva, P. E.; Ballare, C. L.

    2008-12-01

    The integrated controls on soil organic matter formation in arid and semiarid ecosystems are not well understood and appear to stem from a number of interacting controls affecting above- and belowground carbon turnover. While solar radiation has recently been shown to have an important direct effect on carbon loss in semiarid ecosystems as a result of photochemical mineralization of aboveground plant material, the mechanistic basis for photodegradative losses is poorly understood. In addition, there are large potential differences in major controls on above- and belowground decomposition in low rainfall ecosystems. We report on a mesocosm and field study designed to examine the relative importance of different wavelengths of solar radiation, water availability, position of senescent material above- and belowground and the importance of carbon litter quality in determining rates of abiotic and biotic decomposition. In a factorial experiment of mesocosms, we incubated leaf and root litter simultaneously above- and belowground and manipulated water availability with large and small pulses. Significant interactions between position-litter type and position-pulse sizes demonstrated interactive controls on organic mass loss. Aboveground decomposition showed no response to pulse size or litter type, as roots and leaves decomposed equally rapidly under all circumstances. In contrast, belowground decomposition was significantly altered by litter type and water pulses, with roots decomposing significantly slower and small water pulses reducing belowground decomposition. In the field site, using plastic filters which attenuated different wavelengths of natural solar radiation, we found a highly significant effect of radiation exclusion on mass loss and demonstrated that both UV-A and short-wave visible light can have important impacts on photodegradative carbon losses. The combination of position and litter quality effects on litter decomposition appear to be critical for the

  20. Vegetation–soil water interaction within a dynamical ecosystem model of grassland in semi-arid areas

    OpenAIRE

    Zeng, Xiaodong; Zeng, Xubin; Shen, Samuel S. P.; Dickingson, Robert E.; Zeng, Qing-Cun

    2011-01-01

    A dynamical ecosystem model with three variables, living biomass, wilted biomass and available soil wetness, isdeveloped to examine the vegetation–soil water interaction in semi-arid areas. The governing equations are based onthe mass conservation law. The physical and biophysical processes are formulated with the parameters estimated fromobservational data. Both numerical results and qualitative analysis of the model as well as observational data indicate thatthe maintenance of a grassland r...

  1. Simulated carbon and water processes of forest ecosystems in Forsmark and Oskarshamn during a 100-year period

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, David; Jansson, Per-Erik [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Land and Water Resources Engineering; Gaerdenaes, Annemieke [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Soil Sciences; Eckersten, Henrik [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Crop Production Ecology

    2006-12-15

    The Swedish Nuclear Fuel and Waste Management Co (SKB) is currently investigating the Forsmark and Oskarshamn areas for possible localisation of a repository for spent nuclear fuel. Important components of the investigations are characterizations of the land surface ecosystems in the areas with respect to hydrological and biological processes, and their implications for the fate of radionuclide contaminants entering the biosphere from a shallow groundwater contamination. In this study, we simulate water balance and carbon turnover processes in forest ecosystems representative for the Forsmark and Oskarshamn areas for a 100-year period using the ecosystem process model CoupModel. The CoupModel describes the fluxes of water and matter in a one-dimensional soil-vegetation-atmosphere system, forced by time series of meteorological variables. The model has previously been parameterized for many of the vegetation systems that can be found in the Forsmark and Oskarshamn areas: spruce/pine forests, willow, grassland and different agricultural crops. This report presents a platform for further use of models like CoupModel for investigations of radionuclide turnover in the Forsmark and Oskarshamn area based on SKB data, including a data set of meteorological forcing variables for Forsmark 1970-2004, suitable for simulations of a 100-year period representing the present day climate, a hydrological parameterization of the CoupModel for simulations of the forest ecosystems in the Forsmark and Oskarshamn areas, and simulated carbon budgets and process descriptions for Forsmark that correspond to a possible steady state of the soil storage of the forest ecosystem.

  2. Simulated carbon and water processes of forest ecosystems in Forsmark and Oskarshamn during a 100-year period

    International Nuclear Information System (INIS)

    The Swedish Nuclear Fuel and Waste Management Co (SKB) is currently investigating the Forsmark and Oskarshamn areas for possible localisation of a repository for spent nuclear fuel. Important components of the investigations are characterizations of the land surface ecosystems in the areas with respect to hydrological and biological processes, and their implications for the fate of radionuclide contaminants entering the biosphere from a shallow groundwater contamination. In this study, we simulate water balance and carbon turnover processes in forest ecosystems representative for the Forsmark and Oskarshamn areas for a 100-year period using the ecosystem process model CoupModel. The CoupModel describes the fluxes of water and matter in a one-dimensional soil-vegetation-atmosphere system, forced by time series of meteorological variables. The model has previously been parameterized for many of the vegetation systems that can be found in the Forsmark and Oskarshamn areas: spruce/pine forests, willow, grassland and different agricultural crops. This report presents a platform for further use of models like CoupModel for investigations of radionuclide turnover in the Forsmark and Oskarshamn area based on SKB data, including a data set of meteorological forcing variables for Forsmark 1970-2004, suitable for simulations of a 100-year period representing the present day climate, a hydrological parameterization of the CoupModel for simulations of the forest ecosystems in the Forsmark and Oskarshamn areas, and simulated carbon budgets and process descriptions for Forsmark that correspond to a possible steady state of the soil storage of the forest ecosystem

  3. Rendimento da Atriplex nummularia irrigada com efluentes da criação de tilápia em rejeito da dessalinização de água Behavior of saltbush (Atriplex nummularia irrigated with effluents from tilapia raised in brackish water

    Directory of Open Access Journals (Sweden)

    Everaldo R. Porto

    2006-03-01

    Full Text Available Com o objetivo de avaliar a influência no rendimento da erva-sal (Atriplex nummularia e em algumas características do solo, quando irrigada com efluentes da criação de tilápia (Oreochromis sp. em rejeito da dessalinização de água salobra no semi-árido brasileiro, a erva-sal foi irrigada durante um ano com quatro volumes de efluentes na Embrapa Semi-Árido, em Petrolina, PE, cuja salinidade média foi, de 8,29 dS m-1. O delineamento experimental foi de blocos ao acaso com quatro tratamentos e três repetições. Os tratamentos T1, T2, T3 e T4 correspondem, respectivamente, aos volumes de efluentes aplicados semanalmente, de 75, 150, 225 e 300 L planta-1 . A salinidade média do solo na profundidade 0 - 90 cm foi de 0,40 dS m-1, antes de serem iniciadas as irrigações. Após a colheita, respectivamente para os tratamentos T1, T2, T3 e T4, as salinidades médias dos perfis de solo na mesma profundidade (0 - 90 cm foram de 8,02, 6,09, 4,97 e 4,60 dS m-1 e os rendimentos de matéria seca da erva-sal, de 9,75, 12,26, 14,49 e 13,81 t ha-1. O maior rendimento de matéria seca por litro de efluente aplicado foi para o tratamento T1, com 4,84 g L-1 que apresentou, também, a melhor relação entrada/saída de sal, removendo 13,84% do total de sal incorporado ao solo.Looking forward to reduce environmental impacts resulting from desalinization of brackish water in the region of the crystalline rocks in the semi-arid Brazil, saltbush (Atriplex nummularia was cultivated during one year with four different volumes of aquiculture effluent generated from an intensive tilapia (Oreochromis sp raising system, with a mean salinity of 8.29 dS m-1, in an experimental field of Embrapa Semi-Arid. A completely randomized block design, with four treatments and three replications was used. The treatments T1, T2, T3 and T4 corresponded, respectively, to the weekly volumes of irrigation of 75, 150, 225 and 300 L of water per plant. The mean soil salinity of the

  4. Rising sea level, temperature, and precipitation impact plant and ecosystem responses to elevated CO2 on a Chesapeake Bay wetland: review of a 28-year study.

    Science.gov (United States)

    Drake, Bert G

    2014-11-01

    An ongoing field study of the effects of elevated atmospheric CO2 on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects of elevated CO2 on an ecosystem. Since the beginning of the study, atmospheric CO2 increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as predicted for global warming in the 21st century. This review looks back at this study for clues about how the effects of rising sea level, temperature, and precipitation interact with high atmospheric CO2 to alter the physiology of C3 and C4 photosynthetic species, carbon assimilation, evapotranspiration, plant and ecosystem nitrogen, and distribution of plant communities in this brackish wetland. Rising sea level caused a shift to higher elevations in the Scirpus olneyi C3 populations on the wetland, displacing the Spartina patens C4 populations. Elevated CO2 stimulated carbon assimilation in the Scirpus C3 species measured by increased shoot and root density and biomass, net ecosystem production, dissolved organic and inorganic carbon, and methane production. But elevated CO2 also decreased biomass of the grass, S. patens C4. The elevated CO2 treatment reduced tissue nitrogen concentration in shoots, roots, and total canopy nitrogen, which was associated with reduced ecosystem respiration. Net ecosystem production was mediated by precipitation through soil salinity: high salinity reduced the CO2 effect on net ecosystem production, which was zero in years of severe drought. The elevated CO2 stimulation of shoot density in the Scirpus C3 species was sustained throughout the 28 years of the study. Results from this study suggest that rising CO2 can add substantial amounts of carbon to ecosystems through stimulation of carbon assimilation, increased root exudates to supply nitrogen fixation, reduced dark respiration, and improved water and nitrogen use efficiency. PMID:24820033

  5. Hierarchical levels in agro-ecosystems: selective case studies on water and nitrogen.

    OpenAIRE

    Ridder, de, N.

    1997-01-01

    The subject of this thesisToday, agronomic research faces the triple challenge to develop knowledge and insight to manage agro-ecosystems which are inherently sustainable, to diminish the undesirable side effects and to meet the increasing demand of food of a still growing world population, without claiming all the available land. Sound management of agro-ecosystems is not solely a matter of the individual farmer, nor of only field and farm level. Local, national and international policy leve...

  6. Dynamic Changes of Water Conservation Service of Typical Ecosystems in China within a Year Based on Data from CERN

    Directory of Open Access Journals (Sweden)

    Sha Pei

    2015-12-01

    Full Text Available In this study, we compared and analyzed the dynamic changes of water conservation and its value of some typical forests, grasslands, and farmlands in China within a year based on the dataset of the Chinese Ecosystem Research Net (CERN. Results showed that forest, grassland, and farmland provide different kinds of water conservation services which vary in size and dynamic processes within a year. Water conservation of forest consisted of water regulation service, here referred to as water retaining service, and water supply service, while water conservation of grassland and farmland was mainly water regulation service. Different types of forests/grasslands/farmlands can serve different water conservation services in both size and change patterns. In general, the water conservation service and value of forests is the largest (Xishuangbanna forest being $712·hm−2·year−1, Dingshu Mountains forest being $823·hm−2·year−1, and Changbai Mountains forest being $366·hm−2·year−1, and then is the farmlands (Yucheng farmland being $147·hm−2·year−1, Changshu farmland being $92·hm−2·year−1, Qianyanzhou farmland being $247 hm−2·year−1, and that of the grasslands is the least (Haibei alpine meadow being $75·hm−2·year−1, Mongolia grassland being $30·hm−2·year−1. The monthly water conservation and its value of each ecosystem had its own changing pattern throughout the year.

  7. Using the Soil and Water Assessment Tool (SWAT) to model ecosystem services: A systematic review

    Science.gov (United States)

    Francesconi, Wendy; Srinivasan, Raghavan; Pérez-Miñana, Elena; Willcock, Simon P.; Quintero, Marcela

    2016-04-01

    SWAT, a watershed modeling tool has been proposed to help quantify ecosystem services. The concept of ecosystem services incorporates the collective benefits natural systems provide primarily to human beings. It is becoming increasingly important to track the impact that human activities have on the environment in order to determine its resilience and sustainability. The objectives of this paper are to provide an overview of efforts using SWAT to quantify ecosystem services, to determine the model's capability examining various types of services, and to describe the approach used by various researchers. A literature review was conducted to identify studies in which SWAT was explicitly used for quantifying ecosystem services in terms of provisioning, regulating, supporting, and cultural aspects. A total of 44 peer reviewed publications were identified. Most of these used SWAT to quantify provisioning services (34%), regulating services (27%), or a combination of both (25%). While studies using SWAT for evaluating ecosystem services are limited (approximately 1% of SWAT's peered review publications), and usage (vs. potential) of services by beneficiaries is a current model limitation, the available literature sets the stage for the continuous development and potential of SWAT as a methodological framework for quantifying ecosystem services to assist in decision-making.

  8. Ecosystem productivity is associated with bacterial phylogenetic distance in surface marine waters.

    Science.gov (United States)

    Galand, Pierre E; Salter, Ian; Kalenitchenko, Dimitri

    2015-12-01

    Understanding the link between community diversity and ecosystem function is a fundamental aspect of ecology. Systematic losses in biodiversity are widely acknowledged but the impact this may exert on ecosystem functioning remains ambiguous. There is growing evidence of a positive relationship between species richness and ecosystem productivity for terrestrial macro-organisms, but similar links for marine micro-organisms, which help drive global climate, are unclear. Community manipulation experiments show both positive and negative relationships for microbes. These previous studies rely, however, on artificial communities and any links between the full diversity of active bacterial communities in the environment, their phylogenetic relatedness and ecosystem function remain hitherto unexplored. Here, we test the hypothesis that productivity is associated with diversity in the metabolically active fraction of microbial communities. We show in natural assemblages of active bacteria that communities containing more distantly related members were associated with higher bacterial production. The positive phylogenetic diversity-productivity relationship was independent of community diversity calculated as the Shannon index. From our long-term (7-year) survey of surface marine bacterial communities, we also found that similarly, productive communities had greater phylogenetic similarity to each other, further suggesting that the traits of active bacteria are an important predictor of ecosystem productivity. Our findings demonstrate that the evolutionary history of the active fraction of a microbial community is critical for understanding their role in ecosystem functioning. PMID:26289961

  9. Behavior of super-austenitic stainless steels in chlorinated brackish seawater

    Energy Technology Data Exchange (ETDEWEB)

    Ives, M.B. [McMaster Univ., Hamilton, Ontario (Canada)

    1994-12-31

    A series of highly-alloyed austenitic stainless steels has been exposed in a model heat exchanger cooled with water from a brackish inlet in southeast Florida. The behavior of the alloys has been found to depend significantly on the formation of adherent surface deposits. These deposits may occur under certain conditions when natural seawater is used, but the use of chlorination has been found invariably to produce significant deposits, beneath which even the more highly alloyed tubing suffered considerable localized corrosion. It is suggested from noise analysis of the electrochemical potential of individual electrically isolated tubes that the noise analysis might be appropriate as an on-line corrosion monitoring technique for complete heat exchangers, as an alternative to the use of independent monitoring probes.

  10. Water- and Plant-Mediated Responses of Ecosystem Carbon Fluxes to Warming and Nitrogen Addition on the Songnen Grassland in Northeast China

    Science.gov (United States)

    Jiang, Li; Guo, Rui; Zhu, Tingcheng; Niu, Xuedun; Guo, Jixun; Sun, Wei

    2012-01-01

    Background Understanding how grasslands are affected by a long-term increase in temperature is crucial to predict the future impact of global climate change on terrestrial ecosystems. Additionally, it is not clear how the effects of global warming on grassland productivity are going to be altered by increased N deposition and N addition. Methodology/Principal Findings In-situ canopy CO2 exchange rates were measured in a meadow steppe subjected to 4-year warming and nitrogen addition treatments. Warming treatment reduced net ecosystem CO2 exchange (NEE) and increased ecosystem respiration (ER); but had no significant impacts on gross ecosystem productivity (GEP). N addition increased NEE, ER and GEP. However, there were no significant interactions between N addition and warming. The variation of NEE during the four experimental years was correlated with soil water content, particularly during early spring, suggesting that water availability is a primary driver of carbon fluxes in the studied semi-arid grassland. Conclusion/Significance Ecosystem carbon fluxes in grassland ecosystems are sensitive to warming and N addition. In the studied water-limited grassland, both warming and N addition influence ecosystem carbon fluxes by affecting water availability, which is the primary driver in many arid and semiarid ecosystems. It remains unknown to what extent the long-term N addition would affect the turn-over of soil organic matter and the C sink size of this grassland. PMID:23028848

  11. Modeling impacts of water and fertilizer management on ecosystem services from rice rotated crop systems in China

    Science.gov (United States)

    Chen, Han; Yu, Chaoqing; Li, Changsheng; Huang, Xiao; Zhang, Jie; Yue, Yali; Huang, Guorui

    2015-04-01

    Sustainable intensification in agriculture has stressed the need for management practices that could increase crop yields while simultaneously reducing environmental impacts. It is well recognized that water and nutrient management hold great promise to address these goals. This study uses the DNDC biogeochemical model to stimulate the impacts of water regime and nitrogen fertilizer management interactions on ecosystem services of rice rotated crop systems in China. County-level optimal nitrogen fertilizer application rates under various water management practices were captured and then multiple scenarios of water and nitrogen fertilizer management were set to more than 1600 counties with rice rotations in China. Results indicate that an national average of 15.7±5.9% (the mean value and standard deviation derive from variability of three water management practices) reduction of nitrogen fertilizer inputs can be achieved without significantly sacrificing rice yields. On a national scale, shallow flooding with optimal N application rates appear most potential to enhance ecosystem services, which led to 10.6% reduction of nitrogen fertilizer inputs, 34.3% decrease of total GHG emissions, 2.8% less of overall N loss (NH3 volatilization, denitrification and N leaching) and a 1.7% increase of rice yields compared to the baseline scenario. Regional GHG emissions mitigation derived from water regime change vary with soil properties and the multiple crop index. Among the main production regions of rice in China, the highest reduction happened in Jiangxu, Yunnan, Guizhou and Hubei (more than 40% reduction) with high SOC, high multiple crop index and low clay fraction. The highest reduction of GHG emissions derived from reducing current N application rate to optimal rate appeared in Zhejiang, Guangdong, Jiangsu where the serious over-application of mineral N exit. It was concluded that process models like DNDC would act an essential tool to identify sustainable agricultural

  12. Predicting future US water yield and ecosystem productivity by linking an ecohydrological model to WRF dynamically downscaled climate projections

    Science.gov (United States)

    Sun, S.; Sun, G.; Cohen, E.; McNulty, S. G.; Caldwell, P.; Duan, K.; Zhang, Y.

    2015-12-01

    Quantifying the potential impacts of climate change on water yield and ecosystem productivity (i.e., carbon balances) is essential to developing sound watershed restoration plans, and climate change adaptation and mitigation strategies. This study links an ecohydrological model (Water Supply and Stress Index, WaSSI) with WRF (Weather Research and Forecasting Model) dynamically downscaled climate projections of the HadCM3 model under the IPCC SRES A2 emission scenario. We evaluated the future (2031-2060) changes in evapotranspiration (ET), water yield (Q) and gross primary productivity (GPP) from the baseline period of 1979-2007 across the 82 773 watersheds (12 digit Hydrologic Unit Code level) in the conterminous US (CONUS), and evaluated the future annual and monthly changes of hydrology and ecosystem productivity for the 18 Water Resource Regions (WRRs) or 2-digit HUCs. Across the CONUS, the future multi-year means show increases in annual precipitation (P) of 45 mm yr-1 (6 %), 1.8 °C increase in temperature (T), 37 mm yr-1 (7 %) increase in ET, 9 mm yr-1 (3 %) increase in Q, and 106 g C m-2 yr-1 (9 %) increase in GPP. Response to climate change was highly variable across the 82, 773 watersheds, but in general, the majority would see consistent increases in all variables evaluated. Over half of the 82 773 watersheds, mostly found in the northeast and the southern part of the southwest would have an increase in annual Q (>100 mm yr-1 or 20 %). This study provides an integrated method and example for comprehensive assessment of the potential impacts of climate change on watershed water balances and ecosystem productivity at high spatial and temporal resolutions. Results will be useful for policy-makers and land managers in formulating appropriate watershed-specific strategies for sustaining water and carbon sources in the face of climate change.

  13. Partitioning understory evapotranspiration in semi-arid ecosystems in Namibia using the isotopic composition of water vapour

    Science.gov (United States)

    de Blécourt, Marleen; Gaj, Marcel; Holtorf, Kim-Kirsten; Gröngröft, Alexander; Brokate, Ralph; Himmelsbach, Thomas; Eschenbach, Annette

    2016-04-01

    In dry environments with a sparse vegetation cover, understory evapotranspiration is a major component of the ecosystem water balance. Consequently, knowledge on the size of evapotranspiration fluxes and the driving factors is important for our understanding of the hydrological cycle. Understory evapotranspiration is made up of soil evaporation and plant transpiration. Soil evaporation can be measured directly from patches free of vegetation. However, when understory vegetation is present distinguishing between soil evaporation and plant transpiration is challenging. In this study, we aim to partition understory evapotranspiration based on an approach that combines the measurements of water-vapour fluxes using the closed chamber method with measurements of the isotopic composition of water vapour. The measurements were done in the framework of SASSCAL (Southern African Science Service Centre for Climate Change and Adaptive Land Management). The study sites were located in three different semi-arid ecosystems in Namibia: thornbush savanna, Baikiaea woodland and shrubland. At each site measurements were done under tree canopies as well as at unshaded areas between the canopies. We measured evaporation from the bare soil and evapotranspiration from patches covered with herbaceous species and shrubs using a transparent chamber connected with an infrared gas analyser (LI-8100A, LICOR Inc.). The stable isotope composition of water vapour inside the chamber and depth profiles of soil water stable isotopes were determined in-situ using a tuneable off-axis integrated cavity output spectroscope (OA-ICOS, Los Gatos Research, DLT 100). Xylem samples were extracted using the cryogenic vacuum extraction method and the isotopic composition of the extracted water was measured subsequently with a cavity-ring-down spectrometer (CRDS L2120-i, Picarro Inc.). We will present the quantified fluxes of understory evapotranspiration measured in the three different ecosystems, show the

  14. Responses of aquatic ecosystems to environmental changes in Finland and China

    Directory of Open Access Journals (Sweden)

    Jan eWeckström

    2015-11-01

    Full Text Available The concern for the state of global freshwater reservoirs has increased due to deterioration of the water quality during the last decades. This has prompted monitoring and restoration efforts such as the European Water Framework Directive and the national-scale 2nd-investigation and monitoring of the water quality, water volume and biota resources in China. The challenge so far has been the determination of the natural state (reference conditions of freshwater ecosystems. We used the sediment archives of five lakes and one brackish water embayment in Finland and China to assess the impact of selected variables of climatology, hydrology, nutrients, and changes in human population on these ecosystems during the last few centuries. The study sites represent catchment areas with varying land use. Despite the long distance between the sites and their different land-use characteristics, the direction and timing of changes during the last few centuries are well comparable between the high latitudes of Finland and the mid-low latitudes of China. This study reinforces the sensitivity of aquatic ecosystems to environmental change and underlines the usefulness of the palaeolimnological approach as a tool for determining reference conditions.

  15. Sulfur and carbon isotope biogeochemistry of a rewetted brackish fen

    Science.gov (United States)

    Koebsch, Franziska; Gehre, Matthias; Winkel, Matthias; Koehler, Stefan; Koch, Marian; Jurasinski, Gerald; Spitzy, Alejandro; Liebner, Susanne; Sachs, Torsten; Schmiedinger, Iris; Kretzschmann, Lisett; Saborowski, Anke; Böttcher, Michael E.

    2015-04-01

    Coastal wetlands are at the interface between terrestrial freshwater and marine and exhibit very specific biogeochemical conditions. Intermittent sea water intrusion affects metabolic pathways, i. e. anaerobic carbon metabolism is progressively dominated by sulfate reduction with lower contribution of methanogenesis whilst methane production is increasingly shifted from acetoclastic to hydrogenotrophic. Due to expanding anthropogenic impact a large proportion of coastal ecosystems is degraded with severe implications for the biogeochemical processes. We use concentration patterns and stable isotope signatures of water, sulfate, dissolved carbonate, and methane (δ2H, δ13C, δ18O, δ34S) to investigate the S and C metabolic cycle in a rewetted fen close to the southern Baltic Sea border. Such studies are crucial to better predict dynamic ecosystem feedback to global change like organic matter (OM) decomposition or greenhouse gas emissions. Yet, little is known about the metabolic pathways in such environments. The study site is part of the TERENO Observatory "Northeastern German Lowlands' and measurements of methane emissions have run since 2009. High methane fluxes up to 800 mg m-2 hr-1 indicate that methanogenesis is the dominant C metabolism pathway despite of high sulfate concentrations (up to 37 mM). The presented data are part of a comprehensive biogeochemical investigation that we conducted in autumn 2014 and that comprises 4 pore water profiles and sediment samples within a transect of 300-1500 m distance to the Baltic Sea. Depth of organic layers ranged from 25 to 140 cm with high OM contents (up to 90 dwt.%). Sulfate/chloride ratios in the pore waters were lower than in the Baltic Sea for most sites and sediment depths indicated a substantial net sulfate loss. Sulfide concentrations were negligible at the top and increased parallel to the sulfate concentrations with depth to values of up to 0.3 mM. One pore water profiles situated 1150 m from the Baltic

  16. Extreme drought event and shrub invasion combine to reduce ecosystem functioning and resilience in water-limited climates

    Science.gov (United States)

    Caldeira, Maria; Lecomte, Xavier; David, Teresa; Pinto, Joaquim; Bugalho, Miguel; Werner, Christiane

    2016-04-01

    Extreme droughts and plant invasions are major drivers of global change that can critically affect ecosystem functioning. Shrub encroachment is increasing in many regions worldwide and extreme events are projected to increase in frequency and intensity, namely in the Mediterranean region. Nevertheless, little is known about how these drivers may interact and affect ecosystem functioning and resilience to extreme droughts. Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event (2011/2012) in a Mediterranean woodland, we show that the native shrub invasion and extreme drought combined to reduce ecosystem transpiration and the resilience of the key-stone oak tree species. We established six 25 x 25 m paired plots in a shrub (Cistus ladanifer L.) encroached Mediterranean cork-oak (Quercus suber L.) woodland. We measured sapflow and pre-dawn leaf water potential of trees and shrubs and soil water content in all plots during three years. We determined the resilience of tree transpiration to evaluate to what extent trees recovered from the extreme drought event. From February to November 2011 we conducted baseline measurements for plot comparison. In November 2011 all the shrubs from one of all the paired plots were cut and removed. Ecosystem transpiration was dominated by the water use of the invasive shrub, which further increased after the extreme drought. Simultaneously, tree transpiration in invaded plots declined much stronger (67 ± 13 %) than in plots cleared from shrubs (31 ± 11%) relative to the pre-drought year. Trees in invaded plots were not able to recover in the following wetter year showing lower resilience to the extreme drought event. Our results imply that in Mediterranean-type of climates invasion by water spending species can combine with projected recurrent extreme droughts causing critical drought tolerance thresholds of trees to be overcome increasing the probability of tree mortality (Caldeira et.al. 2015

  17. The interactive effects of excess reactive nitrogen and climate change on aquatic ecosystems and water resources of the United States

    Science.gov (United States)

    Baron, J.S.; Hall, E.K.; Nolan, B.T.; Finlay, J.C.; Bernhardt, E.S.; Harrison, J.A.; Chan, F.; Boyer, E.W.

    2012-01-01

    Nearly all freshwaters and coastal zones of the US are degraded from inputs of excess reactive nitrogen (Nr), sources of which are runoff, atmospheric N deposition, and imported food and feed. Some major adverse effects include harmful algal blooms, hypoxia of fresh and coastal waters, ocean acidification, long-term harm to human health, and increased emissions of greenhouse gases. Nitrogen fluxes to coastal areas and emissions of nitrous oxide from waters have increased in response to N inputs. Denitrification and sedimentation of organic N to sediments are important processes that divert N from downstream transport. Aquatic ecosystems are particularly important denitrification hotspots. Carbon storage in sediments is enhanced by Nr, but whether carbon is permanently buried is unknown. The effect of climate change on N transport and processing in fresh and coastal waters will be felt most strongly through changes to the hydrologic cycle, whereas N loading is mostly climate-independent. Alterations in precipitation amount and dynamics will alter runoff, thereby influencing both rates of Nr inputs to aquatic ecosystems and groundwater and the water residence times that affect Nr removal within aquatic systems. Both infrastructure and climate change alter the landscape connectivity and hydrologic residence time that are essential to denitrification. While Nr inputs to and removal rates from aquatic systems are influenced by climate and management, reduction of N inputs from their source will be the most effective means to prevent or to minimize environmental and economic impacts of excess Nr to the nation’s water resources.

  18. Modeling water, ecosystems, economics and culture in traditional acequia irrigation communities of New Mexico and their linked watersheds

    Science.gov (United States)

    Fernald, A.; Tidwell, V. C.; Rivera, J.; Rodriguez, S.; Guldan, S.; Steele, C. M.; Ochoa, C. G.; Hurd, B. H.; Ortiz, M.; Boykin, K.; Cibils, A.

    2012-12-01

    Water scarcity, land use conversion, and cultural and ecosystem changes threaten the way of life for traditional irrigation communities of the semi-arid southwestern United States. Nowhere are traditions as strong or potential upheaval as great as in these communities that rely on acequia irrigation systems. Acequias are ancient ditch systems brought from the Iberian Peninsula to the New World over 400 years ago; they are simultaneously gravity flow water delivery systems and shared water governance institutions. Acequias have survived periods of drought and external shocks from changing economics, demographics, and resource uses. Now, climate change and urbanization threaten water availability, ecosystem functions, and the acequia communities themselves. To explore this issue we translated disciplinary understanding into a uniform format of causal loop diagrams to conceptualize the subsystems of the entire acequia-based human-natural system. Four subsystems are identified in this study: hydrology, ecology, land use/economics, and sociocultural. Important linkages between subsystems were revealed as well as variables indicating community cohesion (e.g., total irrigated land, intensity of upland grazing, mutualism). These results will be tested with field data and modeling exercises to capture tipping points for non-sustainability and thresholds for sustainable water use and community longevity.

  19. Self-organized multi-species vegetation patterns: the role of connectivity of environmental niches in natural water harvesting ecosystems

    Science.gov (United States)

    Callegaro, Chiara; Ursino, Nadia

    2016-04-01

    Self-organizing vegetation patterns are natural water harvesting systems in arid and semi-arid regions of the world and should be imitated when designing man-managed water-harvesting systems for rain-fed crop. Disconnected vegetated and bare zones, functioning as a source-sink system of resources, sustain vegetation growth and reduce water and soil losses. Mechanisms such as soil crusting over bare areas and soil loosening in vegetated areas feed back to the local net facilitation effect and contribute to maintain the patterned landscape structure. Dis-connectivity of run-off production and run-on infiltration sites reduces runoff production at the landscape scale, and increases water retention in the vegetated patches. What is the effect of species adaptation to different resource niches on the landscape structure? A minimal model for two coexisting species and soil moisture balance was formulated, to improve our understanding of the effects of species differentiation on the dynamics of plants and water at single-pattern and landscape scale within a tiger bush type ecosystem. A basic assumption of our model was that soil moisture availability is a proxy for the environmental niche of plant species. Connectivity and dis-connectivity of specific niches of adaptation of two differing plant species was an input parameter of our model, in order to test the effect of coexistence on the ecosystem structure. The ecosystem structure is the model outcome, including: patterns persistence of coexisting species; patterns persistence of one species with exclusion of the other; patterns decline with just one species surviving in a non organized structure; bare landscape with loss of both species. Results suggest that pattern-forming-species communities arise as a result of complementary niche adaptation (niche dis-connecivity), whereas niche superposition (niche connectivity) may lead to impoverishment of environmental resources and loss of vegetation cover and diversity.

  20. Hydrogeology of northern Sierra de Chiapas, Mexico: a conceptual model based on a geochemical characterization of sulfide-rich karst brackish springs

    Science.gov (United States)

    Rosales Lagarde, Laura; Boston, Penelope J.; Campbell, Andrew R.; Hose, Louise D.; Axen, Gary; Stafford, Kevin W.

    2014-09-01

    Conspicuous sulfide-rich karst springs flow from Cretaceous carbonates in northern Sierra de Chiapas, Mexico. This is a geologically complex, tropical karst area. The physical, geologic, hydrologic and chemical attributes of these springs were determined and integrated into a conceptual hydrogeologic model. A meteoric source and a recharge elevation below 1,500 m are estimated from the spring-water isotopic signature regardless of their chemical composition. Brackish spring water flows at a maximum depth of 2,000 m, as inferred from similar chemical attributes to the produced water from a nearby oil well. Oil reservoirs may be found at depths below 2,000 m. Three subsurface environments or aquifers are identified based on the B, Li+, K+ and SiO2 concentrations, spring water temperatures, and CO2 pressures. There is mixing between these aquifers. The aquifer designated Local is shallow and contains potable water vulnerable to pollution. The aquifer named Northern receives some brackish produced water. The composition of the Southern aquifer is influenced by halite dissolution enhanced at fault detachment surfaces. Epigenic speleogenesis is associated with the Local springs. In contrast, hypogenic speleogenesis is associated with the brackish sulfidic springs from the Northern and the Southern environments.

  1. Water quality assessment of aquatic ecosystems using ecological criteria – case study in Bulgaria

    OpenAIRE

    Damyanova, Sonya; Ivanova, Iliana; Ignatova, Nadka

    2014-01-01

    Four aquatic ecosystems (two rivers and two dams) situated in the western part of Bulgaria were investigated over a three years’ period. The River Egulya and Petrohan dam are situated in mountainous regions at about 1000 m altitude, and are not influenced by any anthropogenic sources. Petrohan dam is a site for long-term ecosystem research as a part of Bulgarian long-term ecological research network. The other two systems belong to populated industrial areas. The River Martinovska flows throu...

  2. Integrated assessment of the impact of chemical stressors on surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S; Rasmussen, Jes J; Kronvang, Brian;

    2012-01-01

    chemical stressors on stream ecosystems are evaluated for a stream in Denmark where the effects of major physical habitat degradation can be disregarded. The methods are: (i) the Danish Stream Fauna Index, (ii) Toxic Units (TU), (iii) SPEAR indices, (iv) Hazard Quotient (HQ) index and (v) AQUATOX, an...... ecological impact are not sufficient for capturing - and ideally separating - the effects of all anthropogenic stressors affecting ecosystems. Predictive modelling techniques can be especially useful in supporting early decisions on prioritising hot spots, serving to identify knowledge gaps and thereby...

  3. Tracing the allocation of water in rainfed rice ecosystem by partitioning evapotranspiration of rainfed rice (Oryza Sativa L.)

    Science.gov (United States)

    Nay-Htoon, Bhone; Dubbert, Maren; Wei, Xue; Cuntz, Matthias; Ko, Jonghan; Tenhunen, John; Werner, Christiane

    2015-04-01

    To understand productive and unproductive water use of crop production, partitioning evapotranspiration (ET ) into evaporation (E) and transpiration (T ) is important. Water movements within the eco-hydrologic cycle of agroecosystems can be traced by stable oxygen isotopes of water (δ18O) and plant transpiration and soil evaporation can also be estimated by tracing the δ18O. We quantified the contribution of transpiration to total ecosystem evapotranspiration of rainfed rice field by a stable oxygen isotope approach and FAO 56 dual crop modelling approach. Our study aims to provide quantification of ecosystem water cycle of rainfed rice by partitioning productive and unproductive water use since productivity and water use of rice which is a highly water demanding agroecosystem, is under intense research. Crop season total evapotranspiration fluxes from rainfed rice was mainly dominated by transpiration (T to ET contribution (T /ET ) = 65%) and domination of transpiration over evaporation fluxes was noted since early vegetative stage (Leaf Area Index = 0.8 m2 m-2) until harvesting. T /ET of rainfed rice fluctuated with changes in soil water content (SWC) and the highest T /ET was found at SWC of 0.34 m3 m-3, during seedling stage. Our results demonstrate that partitioning ET by FAO 56 dual crop model is in a good agreement with δ18O isotope based ET partitioning results. Using monthly mean values of leaf resistance and vegetation index derived crop coefficients instead of original fixed parameters of the FAO 56 dual crop model resulted better agreement with δ18O isotope based ET partitioning.

  4. Decontamination and functional reclamation of dredged brackish sediments.

    Science.gov (United States)

    Doni, S; Macci, C; Peruzzi, E; Iannelli, R; Ceccanti, B; Masciandaro, G

    2013-07-01

    The continuous stream of sediments, dredged from harbors and waterways for keeping shipping traffic efficiency, is a considerable ongoing problem recognized worldwide. This problem gets worse as most of the sediments dredged from commercial ports and waterways turn out to be polluted by a wide range of organic and inorganic contaminants. In this study, phytoremediation was explored as a sustainable reclamation technology for turning slightly-polluted brackish dredged sediments into a matrix feasible for productive use. To test this possibility, a phytoremediation experimentation was carried out in containers of about 0.7 m(3) each, filled with brackish dredged sediments contaminated by heavy metals and hydrocarbons. The sediments were pre-conditioned by adding an agronomic soil (30 % v/v) to improve their clayey granulometric composition, and by topping the mixture with high quality compost (4 kg m(-2)) to favour the initial adaptation of the selected vegetal species. The following plant treatments were tested: (1) Paspalum vaginatum, (2) Phragmites australis, (3) Spartium junceum + P. vaginatum, (4) Nerium oleander + P. vaginatum, (5) Tamarix gallica + P. vaginatum, and (6) unplanted control. Eighteen months after the beginning of the experimentation, all the plant species were found in healthy condition and well developed. Throughout the whole experiment, the monitored biological parameters (total microbial population and dehydrogenase activity) were generally observed as constantly increasing in all the planted sediments more than in the control, pointing out an improvement of the chemico-physical conditions of both microorganisms and plants. The concentration decrease of organic and inorganic contaminants (>35 and 20 %, respectively) in the treatments with plants, particularly in the T. gallica + P. vaginatum, confirmed the importance of the root-microorganism interaction in activating the decontamination processes. Finally, the healthy state of

  5. Effect of water stress on ecosystem photosynthesis and respiration of a Leymus chinensis steppe in Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>Many studies on global climate have forecast major changes in the amounts and spatial patterns of precipitation that may significantly affect temperate grasslands in arid and semi-arid regions. As a part of ChinaFLUX, eddy covariance flux measurements were made at a semi-arid Leymus chinensis steppe in Inner Mongolia, China during 2003-2004 to quantify the response of carbon exchange to environmental changes. Results showed that gross ecosystem production (FGEP) and ecosystem respiration (Reco) of the steppe were significantly depressed by water stress due to lack of precipitation during the growing season. Temperature was the dominant factor affecting FGEP and Reco in 2003, whereas soil moisture imposed a significant influence on both Reco and FGEP in 2004. Under wet conditions, Reco showed an exponentially increasing trend with temperature (Q10 = 2.0), but an apparent reduction in the value of Reco and its temperature sensitivity were observed during the periods of water stress (Q10=1.6). Both heat and water stress can cause decrease in FGEP. The sea-sonality of ecosystem carbon exchange was strongly correlated with the variation of precipitation. With less precipitation in 2003, the steppe sequestrated carbon in June and July, and went into a senescence in early August due to water stress. As compared to 2003, the severe drought during the spring of 2004 delayed the growth of the steppe until late June, and the steppe became a CO2 sink from early July until mid-September, with ample precipitation in August. The semi-arid steppe released a total of 9.7 g C·m-2 from May 16 to the end of September 2003, whereas the net carbon budget during the same period in 2004 was close to zero. Long-term measurements over various grasslands are needed to quantify carbon balance in temperate grasslands.

  6. How Much for Water? Economic Assessment and Mapping of Floodplain Water Storage as a Catchment-Scale Ecosystem Service of Wetlands

    Directory of Open Access Journals (Sweden)

    Weronika Chrzanowska

    2013-11-01

    Full Text Available The integration of water management goals in protected wetland areas agriculturally managed in an intensive manner recalls the comparison of apples (ecological values and oranges (economic dimension of agriculture. Sustainable wetland management frequently fails if environmental features are not referred to as ecosystem services and quantified in economic terms. In our hydrological-economical study on floodplain wetlands located in the Lower Basin of the Biebrza Valley, we attempt to quantify the monetary value of water storage in the floodplain during flood phenomena as an important ecosystem service. The unit monetary value of water storage in the catchment of Biebrza Valley was assessed on the basis of small artificial water reservoirs, constructed in recent years and located in the area of research, and reached 0.53 EUR·m−3·year−1. In a GIS-based study on hydrological floodplain processes in the years 1995–2011, we assessed the average annual volume of active water storage in the floodplain which reached 10.36 M m3 year−1, giving a monetary value of EUR 5.49 million per annum. We propose that the methodology presented in our analysis could be applied as water storage subsidies in valuable floodplains, to prevent their deterioration originating from agriculture intensification.

  7. Vulnerability assessment of urban ecosystems driven by water resources, human health and atmospheric environment

    Science.gov (United States)

    Shen, Jing; Lu, Hongwei; Zhang, Yang; Song, Xinshuang; He, Li

    2016-05-01

    As ecosystem management is a hotspot and urgent topic with increasing population growth and resource depletion. This paper develops an urban ecosystem vulnerability assessment method representing a new vulnerability paradigm for decision makers and environmental managers, as it's an early warning system to identify and prioritize the undesirable environmental changes in terms of natural, human, economic and social elements. The whole idea is to decompose a complex problem into sub-problem, and analyze each sub-problem, and then aggregate all sub-problems to solve this problem. This method integrates spatial context of Geographic Information System (GIS) tool, multi-criteria decision analysis (MCDA) method, ordered weighted averaging (OWA) operators, and socio-economic elements. Decision makers can find out relevant urban ecosystem vulnerability assessment results with different vulnerable attitude. To test the potential of the vulnerability methodology, it has been applied to a case study area in Beijing, China, where it proved to be reliable and consistent with the Beijing City Master Plan. The results of urban ecosystem vulnerability assessment can support decision makers in evaluating the necessary of taking specific measures to preserve the quality of human health and environmental stressors for a city or multiple cities, with identifying the implications and consequences of their decisions.

  8. Hierarchical levels in agro-ecosystems: selective case studies on water and nitrogen.

    NARCIS (Netherlands)

    Ridder, de N.

    1997-01-01

    The subject of this thesisToday, agronomic research faces the triple challenge to develop knowledge and insight to manage agro-ecosystems which are inherently sustainable, to diminish the undesirable side effects and to meet the increasing demand of food of a still growing world population, without

  9. Modification of a fire drought index for tropical wetland ecosystems by including water table depth

    NARCIS (Netherlands)

    Taufik, Muh; Setiawan, B.I.; Lanen, van H.A.J.

    2015-01-01

    In this paper, we discuss how an existing empirical drought index, i.e. the Keetch-Byram Drought Index (KBDI) that is commonly used for assessing forest fire danger, has been adjusted and modified for improved use in tropical wetland ecosystems. The improvement included: (i) adjustment of the dro

  10. Coupling of soil water and dissolved carbon measurements to estimate the carbon flux in forest ecosystems a case study

    Science.gov (United States)

    Fink, M.; Krause, P.; Gleixner, G.

    2003-04-01

    We used the 250 year old forest of the national park Hainich, Germany, to estimate carbon storage and export to the ground water in old grown forests. The Hainich is one of the largest deciduous forest ecosystems in middle Europe and the protected area is unmanaged for at least 50 years. It is one of the flux sites of the Carboeurop cluster (www.carboeurop.de) equipped with an eddy covariance system to measure net ecosystem exchange (NEE). Surprisingly NEE of this old grown forest is about 5 t carbon/ha*a. This high amount of carbon uptake can not be explained only by biomass or litter increase. Therefore we quantified the amount of carbon lost as dissolved carbon from the upper soil layer. To determine if carbon is washed out and transported by water fluxes in form of dissolved carbon, the measurement campaign was extended by sophisticated hydrometrical instruments, like frequency domain reflectrometry (FDR) probes, high frequency rain measurement equipment and ceramic plates to take soil water samples. The FDR probes characterize the soil hydrology and quantify the amount of water percolating horizontal and vertical through the soil. In the water samples dissolved organic carbon and dissolved inorganic carbon were determined. Both the quantification of the soil hydrology and the chemical characterization of the soil water enable the calculation of the carbon export from the system. The measurement equipment and layout will be presented and results of dissolved carbon contents in the subsurface water fluxes will be presented. Preliminary estimations of the carbon loss by seepages will be presented also.

  11. Bioassessment of water quality status using a potential bioindicator based on functional groups of planktonic ciliates in marine ecosystems.

    Science.gov (United States)

    Xu, Henglong; Yong, Jiang; Xu, Guangjian

    2016-09-15

    The feasibility of a potential ecological indicator based on functional groups of planktonic ciliates for bioassessment of water quality status were studied in a bay, northern Yellow Sea. Samples were biweekly collected at five stations with different water quality status during a 1-year period. The multivariate approach based on "bootstrap-average" analysis was used to summarize the spatial variation in functional structure of the samples. The functional patterns represented a significant spatial variability, and were significantly correlated with the changes of nutrients (mainly nitrate nitrogen, NO3-N), alone or in combination with dissolve oxygen and salinity among five stations. The functional diversity represented a clear spatial variation among five stations, and was found to be significantly related to the nutrient NO3-N. According to the results, we suggest that the ecological parameter based on functional groups of planktonic ciliates may be used as a potential bioindicator of water quality status in marine ecosystems. PMID:27318762

  12. Fukushima Daiichi - delivery of contaminated water into the Pacific ocean and possible consequences for the marine ecosystem

    International Nuclear Information System (INIS)

    The nuclear power plant Fukushima Daiichi is sited at the coast of the Japanese island Honshu. Most of the cooling water for the three destroyed reactors units 1-3 and the nuclear fuel in the spent fuel pool of unit-4 were uncontrolled delivered into the groundwater and the Pacific Ocean. As a consequence high concentrations of I-131, Cs-134 and Cs-137 in the coastal waters have to be assumed. The contribution analyzed the possible consequences for the marine ecosystem. A drift time of 5 to 7 years toward the coast of North America is expected. The planning of the marine monitoring program MEXT is described. Radiation measurements in the coastal water up to 200 km distance from Daiichi were performed. The highest radionuclide concentrations of Cs-137 and Cs-134 were found in the fine grained sediments. No increased radioactivity in seafood is expected.

  13. Two prototype tools for assessing good environmental/ecological status (GES) in aquatic ecosystems – DEVOTES and WATERS

    DEFF Research Database (Denmark)

    Murray, Ciarán; Carstensen, Jacob; Andersen, Jesper

    2015-01-01

    We present two prototype tools for assessment of GES (good ecological status and good environmental status) in aquatic ecosystems: the DEVOTES biodiversity assessment tool (for the MSFD) and the WATERS ecological status assessment tool (for the WFD). Both tools are multi-metric indicator...... / “waterbodies” in WATERS) resulting in both an overall status for the geographical entity as well as classifications within indicator groups. Both tools are Excel-based and share many similarities. Whilst the WATERS tool performs assessments for a simple “flat” set of waterbodies, the DEVOTES tools allows for......-based tools, which classify ecological/environmental status in two classes (good or not good) and five classes (High, Good, Moderate, Poor or Bad) by comparing observed indicator values with specified status classification boundaries. Assessments are made for geographical entities (“sectors” in DEVOTES...

  14. Are harmful algal blooms becoming the greatest inland water quality threat to public health and aquatic ecosystems?

    Science.gov (United States)

    Brooks, Bryan W; Lazorchak, James M; Howard, Meredith D A; Johnson, Mari-Vaughn V; Morton, Steve L; Perkins, Dawn A K; Reavie, Euan D; Scott, Geoffrey I; Smith, Stephanie A; Steevens, Jeffery A

    2016-01-01

    In this Focus article, the authors ask a seemingly simple question: Are harmful algal blooms (HABs) becoming the greatest inland water quality threat to public health and aquatic ecosystems? When HAB events require restrictions on fisheries, recreation, and drinking water uses of inland water bodies significant economic consequences result. Unfortunately, the magnitude, frequency, and duration of HABs in inland waters are poorly understood across spatiotemporal scales and differentially engaged among states, tribes, and territories. Harmful algal bloom impacts are not as predictable as those from conventional chemical contaminants, for which water quality assessment and management programs were primarily developed, because interactions among multiple natural and anthropogenic factors determine the likelihood and severity to which a HAB will occur in a specific water body. These forcing factors can also affect toxin production. Beyond site-specific water quality degradation caused directly by HABs, the presence of HAB toxins can negatively influence routine surface water quality monitoring, assessment, and management practices. Harmful algal blooms present significant challenges for achieving water quality protection and restoration goals when these toxins confound interpretation of monitoring results and environmental quality standards implementation efforts for other chemicals and stressors. Whether HABs presently represent the greatest threat to inland water quality is debatable, though in inland waters of developed countries they typically cause more severe acute impacts to environmental quality than conventional chemical contamination events. The authors identify several timely research needs. Environmental toxicology, environmental chemistry, and risk-assessment expertise must interface with ecologists, engineers, and public health practitioners to engage the complexities of HAB assessment and management, to address the forcing factors for HAB formation, and

  15. Radionuclide accumulation by aquatic biota exposed to contaminated water in artificial ecosystems before and after its passage through the ground

    International Nuclear Information System (INIS)

    This study was designed to investigate the comparative accumulation of radionuclides from contaminated water in artificial ecosystems before and after the water's passage through the ground. Fish, clams, algae, and an emergent vascular plant were experimentally exposed to mixtures of radionuclides in three aqueous streams. Two streams consisted of industrial water discharged directly into a leaching trench, and the same water after it had migrated through the ground for a distance of 260 meters. The third stream was river water, which served as a background or control. Biota exposed to river water in the control stream had very low concentrations of 60Co, less than 3 pCi per gram dry weight (pCi/g DW). Other radionuclides were essentially unmeasurable. Biota exposed to trench water accumulated very high relative concentrations of 60Co. Biota exposed to trench water also had measurable concentrations of 155Eu, 144Ce, 141Ce, 125Sb, 124Sb, 103Ru, 106Ru, 137Cs, 95Zr, 95Nb, 58Co, 54Mn, 59Fe, 65Zn, 90Sr, /sup 239,240/Pu, and 238Pu. Biota exposed to ground water had concentrations of 60Co that ranged between 50 and 1200 pCi/g DW. Fish flesh had the lowest concentration of 60Co and algae the highest. Strontium-90 was measured in the tissues of aquatic biota at concentrations ranging between 360 pCi/g DW in clam flesh to 3400 pCi/g DW in leaves and stems of Veronica. Leaves and fruits of tomato plants rooted in the ground water accumulated 90Sr at concentrations of 160 pCi in fruits and 4200 pCi in leaves. Data indicate that 60Co and 90Sr migrated through the ground along with ground-water flow and were available to all classes of aquatic biota and tomato plants rooted in the water via root uptake, sorption, and food chain transfers. 8 refs., 4 figs., 6 tabs

  16. Evaluating Responses in Complex Adaptive Systems: Insights on Water Management from the Southern African Millennium Ecosystem Assessment (SAfMA

    Directory of Open Access Journals (Sweden)

    Timothy Lynam

    2005-06-01

    Full Text Available Ecosystem services are embedded in complex adaptive systems. These systems are riddled with nonlinearities, uncertainties, and surprises, and are made increasingly complex by the many human responses to problems or changes arising within them. In this paper we attempt to determine whether there are certain factors that characterize effective responses in complex systems. We construct a framework for response evaluation with three interconnected scopes or spatial and temporal domains: the scope of an impact, the scope of the awareness of the impact, and the scope of the power or influence to respond. Drawing from the experience of the Southern African Millennium Ecosystem Assessment (SAfMA, we explore the applicability of this framework to the example of water management in southern Africa, where an ongoing paradigm shift in some areas has enabled a transition from supply-side to demand-side responses and the creation of new institutions to manage water across scales. We suggest that the most effective responses exhibit congruence between the impact, awareness, and power scopes; distribute impacts across space and time; expand response options; enhance social memory; and depend on power-distributing mechanisms. We conclude by stressing the need for sufficient flexibility to adapt responses to the specific, ever-evolving contexts in which they are implemented. Although our discussion focuses on water in southern Africa, we believe that the framework has broad applicability to a range of complex systems and places.

  17. Improving ASR Recovery Efficiency by Partially-penetrating Wells in Brackish Aquifers

    Science.gov (United States)

    Chen, Y.

    2015-12-01

    Aquifer storage and recovery (ASR) is a proven cost-effective powerful technology for environmental protection and water resources optimization. The recovery efficiency (RE) is regarded as the key criteria for evaluating the ASR performance. In this study, a particular ASR scheme with the fully-penetrating well (FPW) for injection and the partially-penetrating well (PPW) for recovery is proposed to improve the RE for ASR schemes implemented in brackish aquifers. This design appreciates the tilting shape of the interface with underlying heavier salt water. For the FPW, recovery has to be terminated as soon as the interface toe reaches the well, while the toe can be pulled up to the PPW for recovery termination, resulting in later breakthrough of salt water into the pumping well, more recoverable water extracted from the shallow layers, and a higher RE. Key hydrogeological and operational parameters affecting the RE were investigated by numerical simulations. Results demonstrated the effectiveness and efficiency of the new ASR scheme and provided practical guidance for designing such a scheme in various hydrogeological conditions.

  18. An integrated approach shows different use of water resources from Mediterranean maquis species in a coastal dune ecosystem

    OpenAIRE

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

    2009-01-01

    An integrated approach has been used to analyse the dependence of three Mediterranean species, A. unedo L., Q. ilex L., and P. latifolia L. co-occurring in a coastal dune ecosystem on two different water resources: groundwater and rainfed upper soil layers. The approach included leaf level gas exchanges, sap flow measurements and structural adaptations between 15 May and 31 July 2007. During this period it was possible to capture differ...

  19. Radioecological study of fresh water ecosystems influenced by the operation of nuclear cycle facilities in the Urals

    International Nuclear Information System (INIS)

    Nuclear cycle facilities have been functioning in the Urals for over four decades which resulted in significant impacts on the environment. The researchers of the Department of Continental Radioecology of the Institute for Plant and Animal Ecology (IPAE) has for long years conducted radioecological studies of the river Techa and water basins in the East-Urals Radiation Trace (KURT) area, and in the vicinity of the Beloyarsk APS. The present paper only contains integral indices, such as inventory of the radionuclides contained in the ecosystems studied. (author)

  20. Assessing the Impact of Climate Change on Land-Water-Ecosystem Quality in Polar and Mountainous Regions: A New Interregional Project (INT5153)

    International Nuclear Information System (INIS)

    The INT5153 project aims to improve the understanding of the impact of climate change on fragile polar and mountainous ecosystems on both a local and global scale for their better management and conservation. Seven core and five related benchmark sites have been selected from different global regions for specific assessments of the impact of climate change with the following expected outcomes and outputs: Outcomes: • Improved understanding of the impact of climate change on the cryosphere in polar and mountainous ecosystems and its effects on landwater- ecosystem quality at both local and global scales. • Recommendations for improvement of regional policies for soil and agricultural water management, conservation, and environmental protection in polar and mountainous regions. Outputs: • Specific strategies to minimize the adverse effects of, and adapt to, reduced seasonal snow and glacier covered areas on land-water-ecosystem quality in polar and mountain regions across the world. • Enhanced interregional network of laboratories and institutions competent in the assessment of climate change impacts on the cryosphere and land-water-ecosystem quality, using isotopic and nuclear techniques. • Increased number of young scientists trained in the use of isotope and nuclear techniques to assess the impact of climate change on the cryosphere and land-water-ecosystem quality in polar and mountainous ecosystems. • Platform/database with global access for continuing work and monitoring of impact of climate change on fragile polar and mountainous ecosystems at local and global scales, as well as for communicating findings to policy makers and communities. • Improved understanding of the effects of climate change disseminated through appropriate publications, policy briefs, and through a dedicated internet platform. • Methodologies and protocols for investigations in specific ecosystems and conservation/adaptation measures for agriculture areas

  1. Germination of Acacia harpophylla (Brigalow seeds in relation to soil water potential: implications for rehabilitation of a threatened ecosystem

    Directory of Open Access Journals (Sweden)

    Sven Arnold

    2014-02-01

    Full Text Available Initial soil water conditions play a critical role when seeding is the primary approach to revegetate post-mining areas. In some semi-arid climates, such as the Brigalow Belt Bioregion in eastern Australia, extensive areas are affected by open-cut mining. Together with erratic rainfall patterns and clayey soils, the Brigalow Belt denotes a unique biome which is representative of other water-limited ecosystems worldwide. Apart from other environmental stressors, germination is governed by the water potential of the surrounding soil material. While previous studies have confirmed the high tolerance of Brigalow (Acacia harpophylla seeds to a broad range of temperature and salinity, the question of how soil water potential triggers seed germination remains. In this study, we used three replicates of 50 seeds of Brigalow to investigate germination in relation to water potential as an environmental stressor. Solutions of Polyethylene Glycol (PEG 6000 were applied to expose seeds to nine osmotic water potentials ranging from soil water saturation (0 MPa and field capacity (−.01 to −.03 MPa to the permanent wilting point (−1.5 MPa. We measured germinability (number of germinated seeds relative to total number of seeds per lot and mean germination time (mean time required for maximum germination of a seed lot to quantify germination. Based on the empirical data of the germination we estimated the parameters of the hydrotime model which simulates timing and success of seed emergence. Our findings indicate that Brigalow seeds are remarkably tolerant to water stress, with germination being observed at a water potential as low as −1.5 MPa. Likewise, the average base water potential of a seed population (hydrotime model was very low and ranged between −1.533 and −1.451 MPa. In general, Brigalow seeds germinate opportunistically over a broad range of abiotic conditions related to temperature, salinity, and water availability. Direct seeding and

  2. Germination of Acacia harpophylla (Brigalow) seeds in relation to soil water potential: implications for rehabilitation of a threatened ecosystem.

    Science.gov (United States)

    Arnold, Sven; Kailichova, Yolana; Baumgartl, Thomas

    2014-01-01

    Initial soil water conditions play a critical role when seeding is the primary approach to revegetate post-mining areas. In some semi-arid climates, such as the Brigalow Belt Bioregion in eastern Australia, extensive areas are affected by open-cut mining. Together with erratic rainfall patterns and clayey soils, the Brigalow Belt denotes a unique biome which is representative of other water-limited ecosystems worldwide. Apart from other environmental stressors, germination is governed by the water potential of the surrounding soil material. While previous studies have confirmed the high tolerance of Brigalow (Acacia harpophylla) seeds to a broad range of temperature and salinity, the question of how soil water potential triggers seed germination remains. In this study, we used three replicates of 50 seeds of Brigalow to investigate germination in relation to water potential as an environmental stressor. Solutions of Polyethylene Glycol (PEG 6000) were applied to expose seeds to nine osmotic water potentials ranging from soil water saturation (0 MPa) and field capacity (-.01 to -.03 MPa) to the permanent wilting point (-1.5 MPa). We measured germinability (number of germinated seeds relative to total number of seeds per lot) and mean germination time (mean time required for maximum germination of a seed lot) to quantify germination. Based on the empirical data of the germination we estimated the parameters of the hydrotime model which simulates timing and success of seed emergence. Our findings indicate that Brigalow seeds are remarkably tolerant to water stress, with germination being observed at a water potential as low as -1.5 MPa. Likewise, the average base water potential of a seed population (hydrotime model) was very low and ranged between -1.533 and -1.451 MPa. In general, Brigalow seeds germinate opportunistically over a broad range of abiotic conditions related to temperature, salinity, and water availability. Direct seeding and germination of native

  3. Energy-Water-Vegetation Based Environmental Accounting of Ecosystem Services and Stocks

    Czech Academy of Sciences Publication Activity Database

    Seják, J.; Pokorný, Jan; Cudlín, Pavel; Burešová, Renata; Prokopová, Marcela

    Ústí n. Labem : Univerzita Jana Evangelisty Purkyně v Ústí nad Labem, 2009, s. 1-11. ISBN 978-80-7414-124-9. [Proceedings of the 5th International Conference "EMAN 2009:Environmental Accounting - Sustainable Development Indicators". Praha (CZ), 23.04.2009-24.04.2009] Institutional research plan: CEZ:AV0Z60870520 Keywords : environmental accounting * ecosystem services * flow and stock values Subject RIV: AH - Economics

  4. Water quality of four major lakes in Mississippi, USA: Impacts on human and aquatic ecosystem health

    Science.gov (United States)

    Harmful algal blooms (HABs), harmful microorganisms (pathogens) and toxic metals represent three major agents of water quality deterioration. Better water quality is of utmost importance to water bodies that provide recreational opportunities, even better quality is expected in the water bodies that...

  5. 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.

  6. A Systems Approach to the Estimation of Ecosystem and Human Health Stressors in Air, Land and Water

    Science.gov (United States)

    Cooter, E. J.; Dennis, R. L.; Bash, J. O.

    2013-12-01

    Nitrogen (N) and sulfur oxides (SOx) in air, land and water media are parts of tightly coupled geophysical systems resulting in multiple routes for human and ecosystem exposure. For instance, excess forms of total reactive N in water can lead to harmful algal blooms, with the depletion of oxygen and adverse impacts to aquatic ecosystem productivity in coastal estuaries. Acidic deposition can result in lost forest productivity for terrestrial ecosystem and impacts to trout and other fishery resources in inland waters. Human pulmonary health can be impaired when N and SOx in the atmosphere lead to the generation of ozone and particulate matter (PM). Atmospheric N deposition can also contribute to eutrophication of drinking water sources. The U.S. Environmental Protection Agency (USEPA) Office of Research and Development (ORD) has embarked on the development of a multi-media 'one environment' systems approach to these issues to help develop management decisions that create win-win policies. The purpose of this project is to develop a 'one environment' set of models that can inform protection of ecosystems and human health in both the current state and under future climate scenarios. The research framework focuses on three interrelated themes; coupling air quality with land use and agricultural land management, connecting the hydrosphere (i.e., coupling meteorology and hydrology) and linking the air/land/hydrosphere with ecosystem models and benefits models. We will present an overall modeling framework and then move to the presentation of on-going research results related to direct linkage of air quality with land use and agricultural land management. A modeling interface system has been developed that facilitates the simulation of field-scale agricultural land management decisions over a gridded domain at multiple grid resolutions for the Contiguous United States (CONUS) using a modified version of the USDA EPIC (Environmental Policy Integrated Climate) model. EPIC

  7. Decision-making for south Florida water resources: ecosystem service valuation, hydro-economic optimization, and conflict resolution modeling

    Science.gov (United States)

    Sukop, M. C.; Bolson, J.

    2013-12-01

    Water, sustainability, and climate issues faced by South Florida are complex and pressing. There are multiple competing water demands, vulnerability to sea level rise (SLR), and exposure to climate variability that expose the region to a unique severity and diversity of challenges. This project is investigating strategies for the optimization of water use over a 50-year time horizon. The basis for optimization is hydro-economic and seeks to incorporate the value of ecosystem services - especially fisheries and carbon dynamics - in south Florida, along with more traditional agricultural, industrial, and urban economic drivers. Behavioral aspects of water management and land use planning decision-making under different potential future scenarios are also being studied. In particular, how individuals' perceptions of risks to the water supply differ, and how these differences influence their decisions when faced with an uncertain future, such as the one faced by south Floridians due to uncertainty about sea level rise. Experiments will determine how information type and uncertainty levels impact decisions made by individuals and stakeholder groups. The results of the experiments will be used to devise more effective decision-making forums that foster more widespread support of regional water management plans.

  8. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    Science.gov (United States)

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, p<0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r=0.88, p<0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p<0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. PMID:26360459

  9. Adaptive management, monitoring, and the ecological sustainability of a thermal-polluted water ecosystem: a case in SW Spain.

    Science.gov (United States)

    Lavado Contador, J F

    2005-05-01

    The construction of the Almaraz nuclear power plant in Spain in the 1970s posed interesting environmental problems concerning the construction of a cooling reservoir (Arrocampo reservoir) to cool the steam condensers and the consequent heating of the reservoir's water. The socio-political context forced decision makers to set up a project for the monitoring and management of the environmental impacts derived from the construction and operation of the power plant. Numerous scientific and technical specialists collaborated with the representatives of social groups towards two goals: the improvement of the biodiversity and of the efficiency of the cooling system. These goals involved the monitoring and managing of the system with respect to different biological aspects, mainly limnology, ichthyology, avian fauna and vegetation. The management plan yielded numerous results. The control of the water eutrophy is one of the most important due to its repercussion on the rest of the ecosystem, especially the fish fauna. The development of the shore vegetation slowly increased the patchwork nature of the reservoir, leading to a greater diversity of the avian species. This paper describes the monitoring and management of the Arrocampo ecosystem, the condition before and after the construction of the reservoir and the results obtained concerning some biological communities. PMID:15931975

  10. 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; Torres-Perez, Juan

    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

  11. Impact of herbaceous understory vegetation to ecosystem water cycle, productivity and infiltration in a semi arid oak woodland assessed by stable oxygen isotopes

    Science.gov (United States)

    Dubbert, Maren; Piayda, Arndt; Silva, Filipe Costa e.; Correia, Alexandra C.; Pereira, Joao S.; Cuntz, Matthias; Werner, Christiane

    2015-04-01

    Water is one of the key factors driving ecosystem productivity, especially in water-limited ecosystems. Thus a separation of these component fluxes is needed to gain a functional understanding on the development of net ecosystem water and carbon fluxes. Oxygen isotope signatures are valuable tracers for such water movements within the ecosystem because of the distinct isotopic compositions of water in the soil and vegetation. Here, a novel approach was used (Dubbert et al., 2013), combining a custom build flow-through gas-exchange branch chamber with a Cavity Ring-Down Spectrometer in a Mediterranean cork-oak woodland where two vegetation layers respond differently to drought: oak-trees (Quercus suber L.) avoid drought due to their access to ground water while herbaceous plants survive the summer as seeds. We used this approach to quantify the impact of the understory herbaceous vegetation on ecosystem carbon and water fluxes throughout the year and disentangle how ET components of the ecosystem relate to carbon dioxide exchange. Partitioning ecosystem ET and NEE into its three sources revealed that understory vegetation contributed markedly to ecosystem ET and gross primary production (GPP; max. 43 and 51%, respectively). It reached similar water-use efficiencies (WUE) as cork-oak trees and significantly contributed to the ecosystem sink-strength in spring and fall. The understory vegetation layer further strongly inhibited soil evaporation (E) and, although E was large during wet periods, it did not diminish ecosystem WUE during water-limited times (Dubbert et al., 2014a). Although, during most of the year, interactions with trees neither facilitated nor hampered the development of the understory vegetation, strong competition for water could be observed at the end of the growing period, which shortened the life-cycle of understory plants and significantly reduced the carbon uptake of the ecosystem in spring (Dubbert et al., 2014b). Finally, herbaceous understory

  12. Changes of evapotranspiration and water yield in China's terrestrial ecosystems during the period from 2000 to 2010

    Directory of Open Access Journals (Sweden)

    Y. Liu

    2013-04-01

    Full Text Available Terrestrial carbon and water cycles are interactively linked at various spatial and temporal scales. Evapotranspiration (ET plays a key role in the terrestrial water cycle and altering carbon sequestration of terrestrial ecosystems. The study of ET and its response to climate and vegetation changes is critical in China since water availability is a limiting factor for the functioning of terrestrial ecosystems in vast arid and semiarid regions. In this study, the process-based Boreal Ecosystem Productivity Simulator (BEPS model was employed in conjunction with a newly developed leaf area index (LAI dataset and other spatial data to simulate daily ET and water yield at a spatial resolution of 500 m over China for the period from 2000 to 2010. The spatial and temporal variations of ET and water yield and influences of temperature, precipitation, land cover types, and LAI on ET were analyzed. The validations with ET measured at 5 typical ChinaFLUX sites and inferred using statistical hydrological data in 10 basins showed that the BEPS model was able to simulate daily and annual ET well at site and basin scales. Simulated annual ET exhibited a distinguishable southeast to northwest decreasing gradient, corresponding to climate conditions and vegetation types. It increased with the increase of LAI in 74% of China's landmass and was positively correlated with temperature in most areas of southwest, south, east, and central China and with precipitation in the arid and semiarid areas of northwest and north China. In the Tibet Plateau and humid southeast China, the increase in precipitation might cause ET to decrease. The national mean annual ET varied from 345.5 mm yr−1 in 2001 to 387.8 mm yr−1 in 2005, with an average of 369.8 mm yr−1 during the study period. The overall increase rate of 1.7 mm yr−2 (r = 0.43 p = 0.19 was mainly driven by the increase of total ET in forests. During the period from 2006 to 2009, precipitation and LAI decreased

  13. Role of vegetation in modulating rainfall interception and soil water flux in ecosystems under transition from grassland to woodland

    Science.gov (United States)

    Zou, Chris; Will, Rodney; Stebler, Elaine; Qiao, Lei

    2014-05-01

    Vegetation exerts strong control on the hydrological budget by shielding the soil from rainfall through interception and modulating water transmission in the soil by altering soil properties and rooting zone water extraction. Therefore, a change in vegetation alters the water cycle by a combination of a passive, rainfall redistribution mechanism controlled by the physical dimensions of vegetation and active, water extracting processes resulting from physiological attributes of different plants. As a result, the role of vegetation on the water cycle is likely to change where vegetation is under transition such as in the southern Great Plains of USA due to woody plant encroachment. However, it remains largely unknown how this physiognomic transformation from herbaceous cover to woody canopy alters rainfall influx, soil water transmission and efflux from the soil profile and consequently alters historic patterns of runoff and groundwater recharge. This knowledge is critical for both water resource and ecosystem management. We conducted a comprehensive, 5-year study involving direct quantification of throughfall and stemflow for grassland and encroached juniper woodland (Juniperus virginiana), water efflux through transpiration using an improved Granier thermal dissipation method (trees) and ET chamber (grassland), soil moisture storage and dynamics (capacitance probe) and streamflow (small catchment). We calibrated a prevailing hydrological model (SWAT) based on observed data to simulate potential change in runoff and recharge for the Cimarron River basin (study site located within this basin) under various phases of grassland to woodland transition. Our results show that juniper encroachment reduces throughfall reaching the soil surface compared with grassland under moderate grazing. The evergreen junipers transpired water year-round including fall and winter when the warm season grasses were senescent. As a result, soil water content and soil water storage on the

  14. Facing climate change by securing water for food, livelihoods and ecosystems

    OpenAIRE

    Fraiture, C. de; Smakhtin, V.; D Bossio; McCornick, P.; C Hoanh; Noble, A; Molden, D.; F Gichuki; Giordano, M; Finlayson, M.; H Turral

    2007-01-01

    Future changes in water availability due to climate change (CC) are of paramount importance for food security of millions of rural people worldwide. Many recent extremes of water shortage followed by devastating floods reflect some of the climate change predictions, which are gradually becoming more certain and alarming. Appropriate measures in agricultural water management can greatly reduce poor people’s vulnerability to CC by reducing water related risks and creating buffers against often ...

  15. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity

    NARCIS (Netherlands)

    Navarro-Ortega, A.; Acuña, V.; Bellin, A.; Burek, P.; Cassiani, G.; Choukr-Allah, R.; Dolédec, S.; Elosegi, A.; Ferrari, F.; Ginebreda, A.; Grathwohl, P.; Jones, C.; Ker Rault, P.A.; Kok, K.; Koundouri, P.; Ludwig, R.P.; Merz, R.; Milacic, R.

    2015-01-01

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts

  16. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity. The GLOBAQUA project

    NARCIS (Netherlands)

    Navarro-Ortega, A.; Acuña, V.; Bellin, A.; Burek, P.; Cassiani, G.; Choukr-Allah, R.; Dolédec, S.; Elosegi, A.; Ferrari, F.; Ginebreda, A.; Grathwohl, P.; Jones, C.; Rault, P.K.; Kok, K.; Koundouri, P.; Ludwig, R.P.; Merz, R.; Milacic, R.; Muñoz, I.; Nikulin, G.; Paniconi, C.; Paunović, M.; Petrovic, M.; Sabater, L.; Sabaterb, S.; Skoulikidis, N.T.; Slob, A.; Teutsch, G.; Voulvoulis, N.; Barceló, D.

    2015-01-01

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts

  17. Assessment of groundwater input and water quality changes impacting natural vegetation in the Loxahatchee River and floodplain ecosystem, Florida

    Science.gov (United States)

    Orem, William H.; Swarzenski, Peter W.; McPherson, Benjamin F.; Hedgepath, Marion; Lerch, Harry E.; Reich, Christopher; Torres, Arturo E.; Corum, Margo D.; Roberts, Richard E.

    2007-01-01

    The Loxahatchee River and Estuary are small, shallow, water bodies located in southeastern Florida. Historically, the Northwest Branch (Fork) of the Loxahatchee River was primarily a freshwater system. In 1947, the river inlet at Jupiter was dredged for navigation and has remained permanently open since that time. Drainage patterns within the basin have also been altered significantly due to land development, road construction (e.g., Florida Turnpike), and construction of the C-18 and other canals. These anthropogenic activities along with sea level rise have resulted in significant adverse impacts on the ecosystem over the last several decades, including increased saltwater encroachment and undesired vegetation changes in the floodplain. The problem of saltwater intrusion and vegetation degradation in the Loxahatchee River may be partly induced by diminished freshwater input, from both surface water and ground water into the River system. The overall objective of this project was to assess the seasonal surface water and groundwater interaction and the influence of the biogeochemical characteristics of shallow groundwater and porewater on vegetation health in the Loxahatchee floodplain. The hypothesis tested are: (1) groundwater influx constitutes a significant component of the overall flow of water into the Loxahatchee River; (2) salinity and other chemical constituents in shallow groundwater and porewater of the river floodplain may affect the distribution and health of the floodplain vegetation.

  18. Water-Rock Interactions Influencing Mercury Fate and Transport from an Abandoned Mine Site to an Aquatic Ecosystem

    Science.gov (United States)

    Jewett, D. G.; Engle, M. A.; Reller, G. J.; Bauman, J. B.; Manges, E.

    2001-12-01

    Clear Lake, located 150 km north of San Francisco, is one of the largest fresh water lakes in California and is an important economic resource for the region. Elevated mercury levels in fish in Clear Lake were identified in the late 1970s, resulting in a fish consumption advisory for the lake. Although Clear Lake is located in a region of naturally occurring mercury deposits, the Sulphur Bank Mercury Mine (SBMM) Superfund Site, an abandoned mine adjacent to the lake, also is a source for a modern-day mercury flux to the local aquatic ecosystem. An investigation to characterize the hydrogeologic and geochemical setting at the SBMM and understand water-rock interactions and their influence on mercury migration into Clear Lake is in progress. Historic mining operations produced ~4.7 x 106 kg of Hg from the SBMM, leaving a 9.3 ha open pit surrounded by 49 ha of mine waste. The pit, which receives water from the underlying hydrothermal system and surface and ground waters from the immediate watershed, filled when mining ceased. Water in the pit is acidic due to the oxidation of H2S gas and sulfur-bearing minerals. Clear Lake and the open pit are separated by a distance of about 250 m, but the water level in the pit is 3-4 m greater than that of the lake. Subsurface outflow is a major component of discharge from the pit with ground water flowing to Clear Lake through the mercury-laden waste rock and overburden. Ground-water outflow from the pit through mine wastes is greatest when water levels create a combination of near-maximum hydraulic gradients and increased saturated thickness. Major ion and trace element analyses have identified several distinct water types at the SBMM, which, with the exception of Hg, are stable at most locations over time. Elevated Hg concentrations are associated with low pH ( ~pH 3), high Eh (typically >400 mV) waters, with the highest concentrations (up to 350 μ g/L) reported for water samples collected from wells located between the pit and

  19. [Assessment of ecosystem energy flow and carrying capacity of swimming crab enhancement in the Yellow River estuary and adjacent waters].

    Science.gov (United States)

    Lin Qun; Wang, Jun; Li, Zhong-yi; Wu, Qiang

    2015-11-01

    Stock enhancement is increasingly proved to be an important measure of the fishery resources conservation, and the assessment of carrying capacity is the decisive factor of the effects of stock enhancement. Meanwhile, the variations in the energy flow patterns of releasing species and ecosystem were the basis for assessing carrying capacity of stock enhancement. So, in the present study, based on the survey data collected from the Yellow River estuary and adjacent waters during 2012-2013, three Ecopath mass-balance models were established in June, August and October, and the variations in ecosystem energy flow in these months were analyzed, as well as the assessment of carrying capacity of swimming crab enhancement. The energy flow mainly concentrated on trophic level I-III in Yellow River estuary and adjacent waters, and was relatively less on trophic level IV or above. The system flow proportion on the trophic level I was the highest in June, and was the lowest in August. The highest system flow proportion on the trophic level II was found in August, and the lowest in June. The relative and absolute energy flow of swimming crab mainly concentrated on the trophic level III, and the mean trophic level of swimming crab among June, August and October were 3.28. Surplus production was relatively higher in Yellow River estuary and adjacent waters, the highest value was found in June, and the lowest value in August. The ratios of total primary production/total respiration (TPP/TR) were 5.49, 2.47 and 3.01 in June, August and October, respectively, and the ratios of total primary production/total biomass (TPP/B) were 47.61, 33.30 and 29.78, respectively. Combined with the low Finn' s cycling index (FCI: 0.03-0.06), these changes indicated that the Yellow River estuary ecosystem was at an early development stage with higher vulnerability. The energy conversion efficiency of system was from 7.3% to 11.5%, the mean trophic levels of the catch were 3.23, 2.97 and 2.82 in

  20. Modelling effects of seasonal variation in water table depth on net ecosystem CO2 exchange of a tropical peatland

    Science.gov (United States)

    Mezbahuddin, M.; Grant, R. F.; Hirano, T.

    2014-02-01

    Seasonal variation in water table depth (WTD) determines the balance between aggradation and degradation of tropical peatlands. Longer dry seasons together with human interventions (e.g. drainage) can cause WTD drawdowns making tropical peatland C storage highly vulnerable. Better predictive capacity for effects of WTD on net CO2 exchange is thus essential to guide conservation of tropical peat deposits. Mathematical modelling of basic eco-hydrological processes under site-specific conditions can provide such predictive capacity. We hereby deploy a process-based mathematical model ecosys to study effects of seasonal variation in WTD on net ecosystem productivity (NEP) of a drainage affected tropical peat swamp forest at Palangkaraya, Indonesia. Simulated NEP suggested that the peatland was a C source (NEP ~ -2 g C m-2 d-1, where a negative sign represents a C source and a positive sign a C sink) during rainy seasons with shallow WTD, C neutral or a small sink (NEP ~ +1 g C m-2 d-1) during early dry seasons with intermediate WTD and a substantial C source (NEP ~ -4 g C m-2 d-1) during late dry seasons with deep WTD from 2002 to 2005. These values were corroborated by regressions (P CO2 fluxes which yielded R2 > 0.8, intercepts approaching 0 and slopes approaching 1. We also simulated a gradual increase in annual NEP from 2002 (-609 g C m-2) to 2005 (-373 g C m-2) with decreasing WTD which was attributed to declines in duration and intensity of dry seasons following the El Niño event of 2002. This increase in modelled NEP was corroborated by EC-gap filled annual NEP estimates. Our modelling hypotheses suggested that (1) poor aeration in wet soils during shallow WTD caused slow nutrient (predominantly phosphorus) mineralization and consequent slow plant nutrient uptake that suppressed gross primary productivity (GPP) and hence NEP (2) better soil aeration during intermediate WTD enhanced nutrient mineralization and hence plant nutrient uptake, GPP and NEP and (3

  1. Isotopic model for underground water circulation of the limitrophe zone of the Danube Delta ecosystem

    International Nuclear Information System (INIS)

    The zone investigated is confined at North by Sf.Gheorghe arm, at East by Dunavatu de Sus and Dunavatu de Jos zones, at South by the Razelm Lake and at West by the Tulcea-Babadag highroad. By following in time the values of δDSMOW (o/oo) and Δdens (mg/l) for the water sources (18 wells, 3 springs and 8 drilling wells) information concerning the origin of the water in the sources and the interplay between different categories of ground water were obtained. The time variation of δD revealed the existence of two categories of water: one, having Danube River as supply source (sources of low variability) and another one, having, as supply source, the local infiltration waters (sources of high variability). It was found that the water sources of the first category intercept the phreatic water table which follows the terrain form while those of the second category show the existence a phreatic stratum fed by meteoric waters. For the drilling wells, the time variations of δD values indicate a process of mixing of water belonging to distinct aquifer regions. The space variations of the δD indicated the feeding of phreatic stratum from the Danube River as well as the interplay of different supply sources and ground water conductivity

  2. Assessment of Ganga river ecosystem at Haridwar, Uttarakhand, India with reference to water quality indices

    Science.gov (United States)

    Bhutiani, R.; Khanna, D. R.; Kulkarni, Dipali Bhaskar; Ruhela, Mukesh

    2016-06-01

    The river Ganges is regarded as one of the most holy and sacred rivers of the world from time immemorial. The evaluation of river water quality is a critical element in the assessment of water resources. The quality/potability of water that is consumed defines the base line of protection against many diseases and infections. The present study aimed to calculate Water Quality Index (WQI) by the analysis of sixteen physico-chemical parameters on the basis of River Ganga index of Ved Prakash, weighted arithmetic index and WQI by National sanitation foundation (NSF) to assess the suitability of water for drinking, irrigation purposes and other human uses. These three water quality indices have been used to assess variation in the quality of the River Ganga at monitored locations over an 11-year period. Application of three different indexes to assess the water quality over a period of 11 years shows minor variations in water quality. Index values as per River Ganga Index by Ved Prakash et al. from 2000 to 2010 ranged between medium to good, Index values as per NSF Index for years 2000-2010 indicate good water quality, while Index values as per the weighted arithmetic index method for the study period indicate poor water quality.

  3. Hyperspectral reflectance response of freshwater macrophytes to salinity in a brackish subtropical marsh.

    Science.gov (United States)

    Tilley, David R; Ahmed, Muneer; Son, Ji Ho; Badrinarayanan, Harish

    2007-01-01

    Coastal freshwater wetlands are threatened by increased salinity due to relative sea level rise and reduced freshwater inputs. Remote radiometric measurement of freshwater marsh canopies to detect small shifts in water column salinity would be useful for assessing salinity encroachment. We measured leaf hyperspectral (300-1100 nm) reflectance of freshwater macrophytes (cattail, Typha latifolia and sea oxeye, Borrichia frutescens) in a field study in a subtropical brackish (2.5-4.5 parts per thousand salinity, per thousand) marsh to determine salinity effects on visible and near-infrared spectral band reflectance and to identify reflectance indices sensitive to small (1 per thousand) changes in wetland salinity. For sea oxeye, floating-position water band index [fWBI = R(900)/minimum(R(930) - R(980)), where R(lambda) = reflectance at band lambda], normalized difference vegetation index [NDVI = (R(774) - R(681))/(R(774) + R(681))], and a proposed wetland salinity reflectance ratio (WSRR = R(990)/R(933)) were sensitive to salinity with R2 of 40, 35, and 65%, respectively (p wetland salinity, which would help with monitoring salinity effects on coastal wetlands. PMID:17412913

  4. Pacific connections for health, ecosystems and society: new approaches to the land-water-health nexus.

    Science.gov (United States)

    Parkes, Margot W

    2016-03-01

    Renewed effort to understand the social-ecological context of health is drawing attention to the dynamics of land and water resources and their combined influence on the determinants of health. A new area of research, education and policy is emerging that focuses on the land-water-health nexus: this orientation is applicable from small wetlands through to large-scale watersheds or river basins, and draws attention to the benefits of combined land and water governance, as well as the interrelated implications for health, ecological and societal concerns. Informed by research precedents, imperatives and collaborations emerging in Canada and parts of Oceania, this review profiles three integrative, applied approaches that are bringing attention to the importance the land-water-health nexus within the Pacific Basin: wetlands and watersheds as intersectoral settings to address land-water-health dynamics; tools to integrate health, ecological and societal dynamics at the land-water-health nexus; and indigenous leadership that is linking health and well-being with land and water governance. Emphasis is given to key characteristics of a new generation of inquiry and action at the land-water-health nexus, as well as capacity-building, practice and policy opportunities to address converging environmental, social and health objectives linked to the management and governance of land and water resources. PMID:26953704

  5. Mercury cycling in stream ecosystems. 2. Benthic methylmercury production and bed sediment - Pore water partitioning

    Science.gov (United States)

    Marvin-DiPasquale, M.; Lutz, M.A.; Brigham, M.E.; Krabbenhoft, D.P.; Aiken, G.R.; Orem, W.H.; Hall, B.D.

    2009-01-01

    Mercury speciation, controls on methylmercury (MeHg) production, and bed sediment - pore water partitioning of total Hg (THg) and MeHg were examined in bed sediment from eight geochemically diverse streams where atmospheric deposition was the predominant Hg input. Across all streams, sediment THg concentrations were best described as a combined function of sediment percent fines (%fines; particles water distribution coefficients (log Kd's) for both THg and MeHg were inversely related to the log-transformed ratio of pore water dissolved organic carbon (DOC) to bed sediment %fines. The stream with the highest drainage basin wetland density also had the highest pore water DOC ?? 2009 American Chemical Society.

  6. Water quality assessment in the Mexican Caribbean: Impacts on the coastal ecosystem

    Science.gov (United States)

    Hernández-Terrones, Laura M.; Null, Kimberly A.; Ortega-Camacho, Daniela; Paytan, Adina

    2015-07-01

    Coastal zones are dominated by economically important ecosystems, and excessive urban, industrial, agricultural, and tourism activities can lead to rapid degradation of those habitats and resources. Groundwater in the Eastern Yucatan Peninsula coastal aquifer discharges directly into the coastal ocean affecting the coral reefs, which are part of the Mesoamerican Coral Reef System. The composition and impacts of groundwater were studied at different coastal environments around Akumal (SE Yucatan Peninsula). Radium isotopes and salinity were used to quantify fresh groundwater and recirculated seawater contributions to the coastal zone. Excess Ra distribution suggests spatially variable discharge rates of submarine groundwater. High NO3- levels and high coliform bacteria densities indicate that groundwater is polluted at some sites. Dissolved phosphorous content is elevated in the winter and during the high tourism season, likely released from untreated sewage discharge and from aquifer sediments under reducing conditions.

  7. An ecosystem-based assessment of hairtail ( Trichiurus lepturus) harvested by multi-gears and management implications in Korean waters

    Science.gov (United States)

    Kang, Hee Joong; Zhang, Chang Ik; Lee, Eun Ji; Seo, Young Il

    2015-06-01

    Hairtail ( Trichiurus lepturus) has been traditionally harvested by multi-gear types in the Yellow Sea and the East China Sea, except for the East Sea (Sea of Japan) in Korean waters. Six different fishery types such as offshore stownet fishery, offshore longline fishery, large pair-trawl fishery, large purse seine fishery, large otter trawl fishery and offshore angling fishery target to harvest the hairtail stock accounting for about 90% of the total annual catch. We attempted to develop an ecosystem-based fisheries assessment approach, which determines the optimal allocation of catch quotas and fishing efforts for major fisheries. We conducted standardization of fishing effort for six types of hairtail fisheries using a general linear model (GLM), and then estimated maximum sustainable yield (MSY) and maximum economic yield (MEY). Estimated MSY and MEY for the hairtail stock were estimated as 100,151 mt and 97,485 mt, respectively. In addition, we carried out an ecosystem-based risk analysis to obtain species risk index (SRI), which was applied to adjusting the optimal proportion of fishing effort for six hairtail fisheries as a penalty or an incentive. As a result, fishing effort ratios were adjusted by SRI for the six fisheries types. Also, the total allowable catch (TAC) was estimated as 97,485 mt and the maximum net profit at TAC by the hairtail fisheries was estimated as 778 billion won (USD 765 million).

  8. Climatic Versus Biotic Constraints on Carbon and Water Fluxes in Seasonally Drought-affected Ponderosa Pine Ecosystems. Chapter 2

    Science.gov (United States)

    Schwarz, P. A.; Law, B. E.; Williams, M.; Irvine, J.; Kurpius, M.; Moore, D.

    2005-01-01

    We investigated the relative importance of climatic versus biotic controls on gross primary production (GPP) and water vapor fluxes in seasonally drought-affected ponderosa pine forests. The study was conducted in young (YS), mature (MS), and old stands (OS) over 4 years at the AmeriFlux Metolius sites. Model simulations showed that interannual variation of GPP did not follow the same trends as precipitation, and effects of climatic variation were smallest at the OS (50%), and intermediate at the YS (climate, although leaf area is a function of climate in that climate can interact with age-related shifts in carbon allocation and affect whole-tree hydraulic conductance. Older forests, with well-established root systems, appear to be better buffered from effects of seasonal drought and interannual climatic variation. Interannual variation of net ecosystem exchange (NEE) was also lowest at the OS, where NEE is controlled more by interannual variation of ecosystem respiration, 70% of which is from soil, than by the variation of GPP, whereas variation in GPP is the primary reason for interannual changes in NEE at the YS and MS. Across spatially heterogeneous landscapes with high frequency of younger stands resulting from natural and anthropogenic disturbances, interannual climatic variation and change in leaf area are likely to result in large interannual variation in GPP and NEE.

  9. Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems

    NARCIS (Netherlands)

    Rix, L.; de Goeij, J.M.; Mueller, C.E.; Struck, U.; Middelburg, J.J.; van Duyl, F.C.; Al-Horani, F.A.; Wild, C.; Naumann, M.S.; Van Oevelen, D.

    2016-01-01

    Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrient

  10. Integrity of Local Ecosystems and Storm Water Management in Residential Areas

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; WANG Weida; GONG Zhaoguo

    2006-01-01

    The authors designed an ecological storm water system in a residential area to replace the conventional underground channels for the collection of storm water so as to reduce the nutrients and sediments discharged. This system contains natural sub-creeks as drainage channels discharging overflow to nearby creeks, an open green trench, a storage pond,and natural sub-creeks. The sub-creeks were designed to be integrated into community landscape, which not only increases the efficiency of water usage, but also improves the aesthetic qualities of the community residence area as required by Agenda 21. This research proved the feasibility of an open storm water collection and utilization system for the design of a community water system.

  11. Integrated modelling for assessing the risk of TCE groundwater contamination to human and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Funder, Simon Goltermann; Finkel, Michael; Binning, Philip John; Bjerg, Poul Løgstrup

    2009-01-01

    The practical implementation of the European Water Framework Directive has resulted in an increased focus on the groundwater-surface water interaction zone. Due to increasing global exploitation of both stream water and groundwater resources, a better awareness of the connections between these two...... management tools designed to work with sparse data sets from preliminary site assessments are needed which can explicitly link contaminant point sources with groundwater, surface water and ecological impacts. Here, a novel integrated modelling approach was employed for evaluating the impact of a TCE...... systems and the roles they play in maintaining water quality is essential, as well as on how human activities may impair them. A gap exists with respect to preliminary assessment methodologies that are capable of evaluating and prioritising point sources of contamination. In particular, adaptive...

  12. Chemical Considerations for an Updated National Assessment of Brackish Groundwater Resources.

    Science.gov (United States)

    McMahon, P B; Böhlke, J K; Dahm, K G; Parkhurst, D L; Anning, D W; Stanton, J S

    2016-07-01

    Brackish groundwater (BGW) is increasingly used for water supplies where fresh water is scarce, but the distribution and availability of such resources have not been characterized at the national scale in the United States since the 1960s. Apart from its distribution and accessibility, BGW usability is a function of the chemical requirements of the intended use, chemical characteristics of the resource, and treatment options to make the resource compatible with the use. Here, we discuss relations between these three chemical factors using national-scale examples and local case studies. In a preliminary compilation of BGW data in the United States, five water types accounted for the major-ion composition of 70% of samples. PHREEQC calculations indicate that 57-77% of samples were oversaturated with respect to barite, calcite, or chalcedony. In the study, 5-14% of samples had concentrations of arsenic, fluoride, nitrate, or uranium that exceeded drinking-water standards. In case studies of the potential use of BGW for drinking water, irrigation, and hydraulic fracturing, PHREEQC simulations of a hypothetical treatment process resembling reverse osmosis (RO) showed that BGW had the potential to form various assemblages of mineral deposits (scale) during treatment that could adversely affect RO membranes. Speciation calculations showed that most boron in the irrigation example occurred as boric acid, which has relatively low removal efficiency by RO. Results of this preliminary study indicate that effective national or regional assessments of BGW resources should include geochemical characterizations that are guided in part by specific use and treatment requirements. PMID:26312379

  13. Dynamic belowground ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Harris, W. F.; Santantonio, D.; McGinty, D.

    1979-01-01

    Roots comprise the primary interface between plant and soil for uptake of water and nutrients. Much is known about the biochemistry, cell physiology and membrane physics associated with these important processes. In this paper we discuss the role of the belowground ecosystem, especially the autotrophic root component, in the structure and function of forest ecosystems. Beyond recognizing roles of anchoring terrestrial plants and uptake of water and nutrients, this component of the forest has been largely neglected in an ecosystem context. In order to focus discussion on the properties of the belowground ecosystem, we use the term rhizosphere to include roots, mycorrhizae, microbes, and rhizophagus invertebrates.

  14. Earth observation based assessment of the water production and water consumption of Nile basin agro-ecosystems

    NARCIS (Netherlands)

    Bastiaanssen, W.G.M.; Karimi, P.; Rebelo, L.M.; Duan, Z.; Senay, G.; Muttuwatte, L.; Smakhtin, V.

    2014-01-01

    The increasing competition for water resources requires a better understanding of flows, fluxes, stocks, and the services and benefits related to water consumption. This paper explains how public domain Earth Observation data based on Moderate Resolution Imaging Spectroradiometer (MODIS), Second Gen

  15. Influence of short-term experimental warming on heat-water processes of the active layer in a swamp meadow ecosystem of the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    GuangSheng Liu; GenXu Wang

    2016-01-01

    Climate change is now evident in the Qinghai-Tibet Plateau (QTP), with impacts on the alpine ecosystem, particularly on water and heat balance between the active layer and the atmosphere. Thus, we document the basic characteristics of changes in the water and heat dynamics in response to experimental warming in a typical alpine swamp meadow ecosystem. Data sets under open top chambers (OTC) and the control manipulations were collected over a complete year. The results show that annual (2008) air temperatures of OTC-1 and OTC-2 were 6.7 °C and 3.5 °C warmer than the control. Rising temperature promotes plant growth and development. The freeze-thaw and isothermal days of OTCs appeared more frequently than the control, owing to comparably higher water and better vegetation conditions. OTCs soil moisture decreased with the decrease of soil depth; however, there was an obviously middle dry aquifer of the control, which is familiar in QTP. Moreover, experimental warming led to an increase in topsoil water content due to poorly drained swamp meadow ecosystem with higher organic matter content and thicker root horizons. The results of this study will have some contributions to alpine cold ecosystem water-heat process and water cycle under climate change.

  16. Hurricane Effects on a Shallow Lake Ecosystem and Its Response to a Controlled Manipulation of Water Level

    Directory of Open Access Journals (Sweden)

    Karl E. Havens

    2001-01-01

    Full Text Available In order to reverse the damage to aquatic plant communities caused by multiple years of high water levels in Lake Okeechobee, Florida (U.S., the Governing Board of the South Florida Water Management District (SFWMD authorized a "managed recession" to substantially lower the surface elevation of the lake in spring 2000. The operation was intended to achieve lower water levels for at least 8 weeks during the summer growing season, and was predicted to result in a large-scale recovery of submerged vascular plants. We treated this operation as a whole ecosystem experiment, and assessed ecological responses using data from an existing network of water quality and submerged plant monitoring sites. As a result of large-scale discharges of water from the lake, coupled with losses to evaporation and to water supply deliveries to agriculture and other regional users, the lake surface elevation receded by approximately 1 m between April and June. Water depths in shoreline areas that historically supported submerged plant communities declined from near 1.5 m to below 0.5 m. Low water levels persisted for the entire summer. Despite shallow depths, the initial response (in June 2000 of submerged plants was very limited and water remained highly turbid (due at first to abiotic seston and later to phytoplankton blooms. Turbidity decreased in July and the biomass of plants increased. However, submerged plant biomass did not exceed levels observed during summer 1999 (when water depths were greater until August. Furthermore, a vascular plant-dominated assemblage (Vallisnera, Potamogeton, and Hydrilla that occurred in 1999 was replaced with a community of nearly 98% Chara spp. (a macro-alga in 2000. Hence, the lake’s submerged plant community appeared to revert to an earlier successional stage despite what appeared to be better conditions for growth. To explain this unexpected response, we evaluated the impacts that Hurricane Irene may have had on the lake in the

  17. A shift from extensive to intensive livestock production system in Uruguay : Driver of local changes in water-related ecosystem services?

    OpenAIRE

    Ran, Ylva

    2012-01-01

    Livestock production is one of the largest and fastest growing agricultural subsectors in the world, contributing almost 40 % of agricultural GDP. The present global trend of livestock intensification affects water demand, resulting in local alterations of hydrological features. This study quantifies water requirements for livestock production and links them to local changes in water-related ecosystem services (WRES). It examines the present situation in Uruguayan beef production as it underg...

  18. Vegetation-induced soil water repellency as a strategy in arid ecosystems. A geochemical approach in Banksia woodlands (SW Australia)

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Jiménez-Morillo, Nicasio T.; González-Pérez, Jose Antonio; Zavala, Lorena M.; Stevens, Jason; Jordan, Antonio

    2016-04-01

    Introduction Banksia woodlands (BW) are iconic ecosystems of Western Australia (WA) composed by an overstorey dominated by Proteaceae, e.g. Banksia menziesii and Banksia attenuata, in combination with other species, such as Eucalyptus spp., Verticordia spp. or Melaleuca spp. Although located in very poor dune soils, BW provide numerous ecosystem services and sustain a high biodiversity. In this area, annual rainfall is relatively high (about 800 mm) but permeability of the sandy substrate leads to a functionally arid ecosystem. Currently, BW are threatened by sand mining activities and urban expansion; therefore conservation and restoration of these woodlands are critical. Despite numerous efforts, the success of restoration plans is usually poor mostly due to the high sensitivity to drought stress and poor seedling survival rates (5-30%) (Benigno et al., 2014). A characteristic feature of BW is their root architecture, formed by a proteoid (cluster) system that spreads to form thick mats below the soil surface, favouring the uptake of nutrients (especially, P), and preventing soil erosion. Root exudates are related to numerous plant functions, as they facilitate penetration of roots in soil and enhance the extraction of scarce mineral nutrients and its further assimilation. Exudates may also interact directly with soil or indirectly through microbial mediated events being also related to soil water repellency (SWR; Lozano et al, 2014). Knowledge about the specific compounds able to induce SWR is limited (Doerr et al., 2000), but it is generally accepted that is caused by organic molecules coating the surface of soil mineral particles and aggregates (Jordán et al., 2013). Proteaceae release short-chained organic acids to enhance phosphate acquisition, which have been also reported to be related with SWR (Jiménez-Morillo et al., 2014). It is hypothesized that disruption of water dynamics in mature BW soils is underlying the failure of restoration plans. This

  19. WATER QUALITY ANALYSIS OF LOTIC ECOSYSTEMS FROM UPPER MUREŞ RIVER CATCHMENT AREA USING DIFFERENT BIOTIC INDICES

    Directory of Open Access Journals (Sweden)

    Milca PETROVICI

    2012-01-01

    Full Text Available Present paper approach the issue of assessing the water quality of tributaries located in the upper basin of the river Mureş, taking into account changes in the value of biotic indices. In this sense, have been selected the next five biotic indices: Ephemeroptera Plecoptera Trichoptera index (EPT, Total Invertebrates index (T, Chironomidae index (Ch, EPT / Total invertebrates index (EPT / T, EPT / Chironomidae index (EPT / Ch and % Chironomidae index (% Chironomidae. Considering all these indices, it was found existence of a medium to best quality water in Mureş tributaries from Harghita Mountains and a good quality water which comes from the Maramureş Mountains and Transylvania Plateau.

  20. An integrated approach shows different use of water resources from Mediterranean maquis species in a coastal dune ecosystem

    Science.gov (United States)

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

    2009-11-01

    An integrated approach has been used to analyse the dependence of three Mediterranean species, A. unedo L., Q. ilex L., and P. latifolia L. co-occurring in a coastal dune ecosystem on two different water resources: groundwater and rainfed upper soil layers. The approach included leaf level gas exchanges, sap flow measurements and structural adaptations between 15 May and 31 July 2007. During this period it was possible to capture different species-specific response patterns to an environment 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, combined with previous studies in the same area, response differences between species have been partially attributed to different root distributions. Sap flow of A. unedo decreased rapidly with the decline of soil water content, while that of Q. ilex decreased only moderately. Midday leaf water potential of P. latifolia and A. unedo ranged between -2.2 and -2.7 MPa throughout the measuring period, while in Q. ilex it decreased down to -3.4 MPa at the end of the season. A. unedo was the only species that responded to drought with a decrease of its leaf area to sapwood area ratio from 23.9±1.2 (May) to 15.2±1.5 (July). While A. unedo also underwent an almost stepwise loss on hydraulic conductivity, such a loss did not occur for Q. ilex, whereas P. latifolia was able to slightly increase its hydraulic conducitivity. These differences show how different plant compartments coordinate differently between species in their responses to drought. The different responses appear to be mediated by different root distributions of the species and their relative resistances to drought are likely to depend on the duration of the periods in which water remains extractable in the upper soil layers.

  1. [An example of anthropogeneous succession in the ecosystem of the Verkhnetulomsky Water Reservoir (the Tuloma River Basin, the Kola region)].

    Science.gov (United States)

    Mitenev, V K; Shul'man, B S; Karasev, A B; Ponomarev, S V

    2010-01-01

    The destruction of initial biocenoses in the ecosystem of the Verkhnetulomsky Water Reservoir caused deep succession processes. As a result of the loss of the amphipod group in the benthos, replacement of the trophic links in fishes took place in the biocenosis of the reservoir. Benthos feeders changed over to the feeding on zooplankton and, as a result, became the constituent of the predators'diet. The structure of parasitic systems has changed. The parasites using amphipods as intermediate hosts have been and, on the contrary, the abundance of parasites infesting fishes through feeding of the latter on zooplankton has increased. Among the parasites, Triaenophorus crassus Forel became the cause of the appearance of stable triaenophorosis focus. PMID:21061595

  2. Impact of agricultural extensification on the relation between soil biodiversity and ecosystem services (soil structure maintenance, water regulation)

    DEFF Research Database (Denmark)

    Faber, J.; Pérès, G.; Groot, A. de;

    Introduction – There are increasing pressures on soil biodiversity and soil degradation remains a pertinent issue. In this context, one aim of the EcoFINDERS European project was to assess the impact of agricultural extensification, across a broad range of European land-use systems, on the...... relationships between soil biodiversity and ecosystem services. Special attention was given to the relation between i) soil biodiversity and aggregate stability, and ii) earthworms and soil macroporosity and water infiltration.  Method - Data from seven long-term field studies (France, Germany, United......-Kingdom, Slovenia, Denmark) on replicated plots of different land management scenarios (grassland, arable cropping, mixed crop-grassland, reduced or conventional tillage) were analysed. Earthworms were sampled using hand sorting and chemical extraction. Aggregate stability was measured using wet sieving method...

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

    Directory of Open Access Journals (Sweden)

    S. Mereu

    2009-02-01

    Full Text Available 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.

  4. A coupled carbon and plant hydraulic model to predict ecosystem carbon and water flux responses to disturbance and environmental change

    Science.gov (United States)

    Mackay, D. S.; Ewers, B. E.; Roberts, D. E.; McDowell, N. G.; Pendall, E.; Frank, J. M.; Reed, D. E.; Massman, W. J.; Mitra, B.

    2011-12-01

    Changing climate drivers including temperature, humidity, precipitation, and carbon dioxide (CO2) concentrations directly control land surface exchanges of CO2 and water. In a profound way these responses are modulated by disturbances that are driven by or exacerbated by climate change. Predicting these changes is challenging given that the feedbacks between environmental controls, disturbances, and fluxes are complex. Flux data in areas of bark beetle outbreaks in the western U.S.A. show differential declines in carbon and water flux in response to the occlusion of xylem by associated fungi. For example, bark beetle infestation at the GLEES AmeriFlux site manifested in a decline in summer water use efficiency to 60% in the year after peak infestation compared to previous years, and no recovery of carbon uptake following a period of high vapor pressure deficit. This points to complex feedbacks between disturbance and differential ecosystem reaction and relaxation responses. Theory based on plant hydraulics and extending to include links to carbon storage and exhaustion has potential for explaining these dynamics with simple, yet rigorous models. In this spirit we developed a coupled model that combines an existing model of canopy water and carbon flow, TREES [e.g., Loranty et al., 2010], with the Sperry et al., [1998] plant hydraulic model. The new model simultaneously solves carbon uptake and losses along with plant hydraulics, and allows for testing specific hypotheses on feedbacks between xylem dysfunction, stomatal and non-stomatal controls on photosynthesis and carbon allocation, and autotrophic and heterotrophic respiration. These are constrained through gas exchange, root vulnerability to cavitation, sap flux, and eddy covariance data in a novel model complexity-testing framework. Our analysis focuses on an ecosystem gradient spanning sagebrush to subalpine forests. Our modeling results support hypotheses on feedbacks between hydraulic dysfunction and 1) non

  5. Study on the mangrove ecosystem services value change in Zhangjiang River estuary based on remote sensing and grey relational analysis

    Science.gov (United States)

    Zhang, Dongshui; Lan, Zhangren; Wang, Qinmin; Wang, Xiaoqin; Zhang, Wei; Li, Zheng

    2007-11-01

    The services of ecosystem are critical to human existence and prosperity, providing necessary ecological products for human production and life as well as indispensable natural conditions for life system. The Natural Mangrove Reserve in Zhangjiang River Estuary is one of the most important National Natural Mangrove Reserve in China. Its environment has been degrading during the past decades for people neglecting the ecosystem services function value which is hard to currency turn. Thus, it is necessary to monitor and assess the Mangrove Reserve's dynamics, both to gain a better understanding of their basic biology and to help guide conservation and restoration efforts. Using Landsat TM/ETM+ Satellite data acquired in 1989, 1992, 1998, 2001 and an Aster image from the year 2003, the land use of the Reserve and its environment were extracted adopting the supervised Maximum Likelihood Classification Algorithm. The changes of land use and ecosystem services value were analyzed using Costanza's method of evaluating the global ecosystem service values. The total value change of ecosystem services in the study area per year are 2945.95×10 4, 2861.74×10 4, 2904.05×10 4, 2794.67×10 4, 2730.82×10 4$ respectively during the four periods (1989-1992, 1992-1998, 1998-2001, 2001-2003). The ecosystem services value change has a close relationship with W&B, population, build-up and forest. The results indicate that the ecosystem services value in the study area has been constantly deteriorating due to the human activities imposed on it, which is highly associated with the local expanding of build-up and brackish water fishponds all the while. And the downward trend of the ecosystem services value has become even more acute, with the development of the local economy.

  6. Effects of peat-winning on the water environment at a sedge fen ecosystem

    International Nuclear Information System (INIS)

    Peatlands are used in agriculture and forestry for vegetational growth and in peat-winning for soil improvement, horticulture production and as fuel. A prerequisite in peatland use is drainage, with influences on water conditions in the peatland and its surroundings. Environmental effects from such peatland use have been investigated at a sedge fen in central Sweden. Groundwater, runoff, water chemistry and stream water biology were studied during almost 14 years. This period started with a virgin undrained peatland, later being drained for forest production and after a period of seven years intensively drained for peat-winning and with peat harvesting going on for another seven years period with hydrological investigations. Results show a lowered groundwater level, increased runoff and both higher concentrations of most elements and higher leaching from the drained peatland. Biomass and number of individuals of the benthic fauna in stream water also increased. 7 refs, 7 figs, 2 tabs

  7. Assessment of the ecotoxic effects of Ignalina NPP waste waters on Lake Druksiai ecosystems

    International Nuclear Information System (INIS)

    The aim of our studies was to assess the toxic and genotoxic effect of the Ignalina NPP waste waters, waters of Lake Druksiai and bottom sediments on various test organisms (Spiridela polyrrhyza, Lepidium savitum and Tradescantia). Long-term study has shown a tendency of increasing toxic effects of water, and particularly of bottom sediments, in the waste water discharge sites of Lake Druksiai. The toxic effect varies seasonally. High heavy metals concentration were related to toxic effect, which were most pronounced in surface foam produced at the waste water discharge sites. It is evident that the toxic effect of the Ignalina NPP sewage and Lake Druksiai water and bottom sediments is due to chemical pollutants rather than the radioactive isotopes, but their mixture may cause a synergistic effect. Although the Ignalina NPP sewage inputs may be ranked as low-toxic, their pronounced genotoxic effect and the high toxicity of the bottom sediments have caused the ecotoxicological conditions of Lake Druksiai to worsen. (author)

  8. National summary of NOAA's shallow-water benthic habitat mapping of U.S. coral reef ecosystems

    OpenAIRE

    Monaco, Mark E.; Andersen, S. Miles; Battista, Timothy A.; Kendall, Matthew S.; Rohmann, Steven O.; Wedding, Lisa M.; Clarke, Alicia M.

    2012-01-01

    Coral reef ecosystems are some of the most complex and important ecosystems in the marine environment. They are also among the most biologically diverse and economically valuable ecosystems on earth, producing billions of dollars in food, as well as providing a suite of ecological services, such as recreation and tourism activities and coastal protection from storm and wave action. Yet, despite their value and importance, these fragile ecosystems are declining at an alarming rate (Waddell and...

  9. Polonium (210Po) distribution pattern in the fresh water ecosystem of Nagarjuna Sagar Dam, Andhra Pradesh, India

    International Nuclear Information System (INIS)

    A systematic study of natural radionuclide of 210Po in the environmental matrices of freshwater ecosystem of Nagarjuna Sagar Dam has been carried out to establish the baseline data. The seasonal samples of surface water and bottom sediments were collected for every three months for the period of two years during the period of 2009-2011 from ten sampling locations along the shores of Lambapur and Peddagattu in Nagarjuna Sagar Dam for the analysis of polonium (210Po). The polonium was separated radiochemically and analyzed by alpha counting system. The observed levels of 210Po activities in the surface water samples (n = 70) of ten sampling locations of all the seasons ranged from d 0.56 mBq l-1 to 6 mBq l-1 with an average of 1.85 mBq 1-1 and in the bottom sediment samples (n= 70) of ten sampling locations of all the seasons ranged from 3.5 Bq kg-1 dry to 63.2 Bq kg-1 dry with an average of 34.96 Bq kg-1. There was no major variation observed in the polonium concentration in the surface water and bottom sediments collected during the different seasons. (author)

  10. Arsenic species in ecosystems affected by arsenic-rich spring water near an abandoned mine in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.T. [Department of Earth System Science, Yonsei University, 134 Shinchon-Dong, Sudaemoon-Gu, Seoul 120-749 (Korea, Republic of); Nano Environment Materials Research Team, Korea Basic Science Institute, Seoul 136-600 (Korea, Republic of); Yoon, H.O., E-mail: dunee@kbsi.re.k [Nano Environment Materials Research Team, Korea Basic Science Institute, Seoul 136-600 (Korea, Republic of); Yoon, C. [Nano Environment Materials Research Team, Korea Basic Science Institute, Seoul 136-600 (Korea, Republic of); Woo, N.C., E-mail: ncwoo@yonsei.ac.k [Department of Earth System Science, Yonsei University, 134 Shinchon-Dong, Sudaemoon-Gu, Seoul 120-749 (Korea, Republic of)

    2009-12-15

    The objectives of this study were to quantitatively estimate the distribution of arsenic with its speciation and to identify potential pathways for transformation of arsenic species from samples of water, sediments, and plants in the ecosystem affected by the Cheongog Spring, where As(V) concentration reached levels up to 0.270 mg L{sup -1}. After flowing about 100 m downstream, the arsenic level showed a marked reduction to 0.044 mg L{sup -1} (about 84% removal) without noticeable changes in major water chemistry. The field study and laboratory hydroponic experiments with the dominant emergent plants along the creek (water dropwort and thunbergian smartweed) indicated that arsenic distribution, reduction, and speciation appear to be controlled by, (i) sorption onto stream sediments in exchangeable fractions, (ii) bioaccumulation by and possible release from emergent plants, and (iii) transformation of As(V) to As(III) and organic species through biological activities. - Biogeochemical reactions with emergent plants and sediments control the fate of arsenic along creeks originating from a high-As Spring.

  11. Report of the workshop on ecosystem characterisation of Indian coastal waters, Dona Paula, Goa, India, 20-22 October, 2014

    OpenAIRE

    Kumar, S.K.; Sreepada, R.A.; Ramaiah, N.

    2014-01-01

    The goals of the workshop were to: conduct an interactive workshop for characterizing Indian coastal ecosystems; verification of the ecosystem characterisation report for the East coast of India; and development of ecosystem characterisation for the west coast of India based on ecological/biophysical systems.

  12. Assessment of Water Deficiency in Forest Ecosystems: Can a Simple Model of Forest Water Balance Produce Reliable Results?

    Czech Academy of Sciences Publication Activity Database

    Baláž, P.; Střelcová, K.; Blaženec, M.; Pokorný, Radek; Klimánková, Z.

    Nizozemí: Springer, 2009, s. 207-217. ISBN 978-1-4020-8875-9. [International Scientific Conference on Bioclimatology and Natural Hazards. Polana (SK), 17.02.2007] R&D Projects: GA ČR GD526/03/H036; GA MŠk 1P05OC027 Institutional research plan: CEZ:AV0Z60870520 Keywords : drought * european beech * Norway spruce * transpiration * water balance * water demands Subject RIV: GK - Forestry

  13. Hurricane Katrina sediment slowed elevation loss in subsiding brackish marshes of the Mississippi River delta

    Science.gov (United States)

    McKee, K.L.; Cherry, J.A.

    2009-01-01

    Although hurricanes can damage or destroy coastal wetlands, they may play a beneficial role in reinvigorating marshes by delivering sediments that raise soil elevations and stimulate organic matter production. Hurricane Katrina altered elevation dynamics of two subsiding brackish marshes in the Mississippi River deltaic pl