خيارات البحث
النتائج 1041 - 1050 من 3,991
Measuring biological responses at different levels of organisation to assess the effects of diffuse contamination derived from harbour and industrial activities in estuarine areas
2016
de los Ríos, A. | Pérez, L. | Echavarri-Erasun, B. | Serrano, T. | Barbero, M.C. | Ortiz-Zarragoitia, M. | Orbea, A. | Juanes, J.A. | Cajaraville, M.P.
To evaluate the effects of diffuse contamination, biological measurements were applied in a scrap cargo harbour, a marina and an industrial area. Metal accumulation and biomarkers (survival in air, digestive gland and gonad histopathology, lysosomal membrane stability, intralysosomal metal accumulation, transcription of vitellogenin and MT20, peroxisome proliferation and micronuclei formation) were measured in transplanted mussels, together with metrics of benthic invertebrates. Benthic species were classified into ecological groups and univariate indexes were calculated. The marina showed high richness (16) and percentage of opportunistic species (55.1%) and low metal accumulation. Mussels in the scrap cargo harbour showed high metal accumulation, up-regulation of MT20 transcription, reduced health status (LP<6min) and increased micronuclei frequencies (up to 11.3‰). At the industrial area, low species richness (4) and badly organised assemblages were detected and chemical analyses indicated significant amounts of bioavailable metals. Overall, selected biological measurements showed potential for the assessment of diffuse contamination.
اظهر المزيد [+] اقل [-]Marine protected area design patterns in the Mediterranean Sea: Implications for conservation
2016
Rodríguez-Rodríguez, D. | Rodríguez, J. | Blanco, J.M. | Abdul Malak, D.
Mediterranean marine protected area (MPA) design patterns regarding geographic distribution, size, spacing and shape were analysed as a proxy of the region's MPA's ecological effectiveness and a first step towards an ecologically coherent MPA network.Results for legally designated MPAs and ecologically functional MPAs accounting for overlaps are presented. Geographically, Mediterranean MPA area is very unevenly distributed, with four-fifths concentrated in just three countries of the north-western part of the basin. Average distance between functional MPAs lies within recommended ecological thresholds, which suggests adequate potential connectivity of the Mediterranean MPA system. Mediterranean designated MPAs are larger than MPAs worldwide on average, although they are generally smaller than international guidance suggests at different levels: ecoregion, country and designation category. On average, Mediterranean designated and functional MPAs have relatively high compactness, which makes them prone to spillover and adequate viability, and less vulnerable to edge effects.
اظهر المزيد [+] اقل [-]Elemental composition and source identification of very fine aerosol particles in a European air pollution hot-spot
2016
Pokorná, Petra | Hovorka, Jan | Hopke, Philip K.
Positive Matrix Factorization (PMF) was used to identify sources of PM0.09–0.26, very fine aerosol particles, in a residential district of Ostrava Radvanice and Bartovice, a European air pollution hot-spot. Two-hours resolved elemental composition of very fine particulate matter samples were collected by the eighth stage of Davis Rotating-drum Universal-size-cut Monitoring (DRUM) impactor for the campaign period of the 26th January to the 21st February 2012. The campaign consists of smog (26.1–14.2) and post-smog (15–21.2) periods defined by their PM1 concentrations. Three factors were resolved by PMF: coal combustion, raw iron production and steel production. Coal combustion, associated with high concentrations of Se, Br, Pb, K, and As, dominated during the whole period. The contribution of raw iron production, a factor with high concentration of Mn, Fe, Co and Cr, increased significantly when ambient air temperature and the wind direction changed from NE to SW. Alternatively, the contributions of steel production, associated with Cl, K and Zn, were high under NE winds and decreased during the post-smog period. The mass of very fine particles correlated well with CO concentrations (smog r2 = 0.86, post-smog r2 = 0.43), which may indicate an industrial plume. The low value of S/Se (1448) suggests the impact of local/city-wide stationary coal combustion sources located to the N–NE of the monitoring site.
اظهر المزيد [+] اقل [-]Mercury isotope fractionation during transfer from post-desulfurized seawater to air
2016
Huang, Shuyuan | Lin, Kunning | Yuan, Dongxing | Gao, Yaqin | Sun, Lumin
Samples of dissolved gaseous mercury (DGM) in the post-desulfurized seawater discharged from a coal-fired power plant together with samples of gaseous elemental mercury (GEM) over the post-desulfurized seawater surface were collected and analyzed to study the mercury isotope fractionation during transfer from post-desulfurized seawater to air. Experimental results showed that when DGM in the seawater was converted to GEM in the air, the δ202Hg and Δ199Hg values were changed, ranging from −2.98 to −0.04‰ and from −0.31 to 0.64‰, respectively. Aeration played a key role in accelerating the transformation of DGM to GEM, and resulted in light mercury isotopes being more likely to be enriched in the GEM. The ratio Δ199Hg/Δ201Hg was 1.626 in all samples, suggesting that mercury mass independent fractionation occurred owing to the nuclear volume effect during the transformation. In addition, mass independent fractionation of mercury even isotopes was found in the GEM above the post-desulfurized seawater surface in the aeration pool.
اظهر المزيد [+] اقل [-]Water flux management and phytoplankton communities in a Mediterranean coastal lagoon. Part II: Mixotrophy of dinoflagellates as an adaptive strategy?
2016
Cecchi, P. | Garrido, M. | Collos, Y. | Pasqualini, V.
Dinoflagellate proliferation is common in coastal waters, and trophic strategies are often advanced to explain the success of these organisms. The Biguglia lagoon is a Mediterranean brackish ecosystem where eutrophication has long been an issue, and where dominance of dinoflagellates has persisted for several years. Monthly monitoring of fluorescence-based properties of phytoplankton communities carried out in 2010 suggested that photosynthesis alone could not support the observed situation all year round. Contrasting food webs developed depending on the hydrological season, with a gradual shift from autotrophy to heterotrophy. Progressively, microphytoplankton assemblages became unequivocally dominated by a Prorocentrum minimum bloom, which exhibited very weak effective photosynthetic performance, whereas paradoxically its theoretical capacities remained fully operational. Different environmental hypotheses explaining this discrepancy were examined, but rejected. We conclude that P. minimum bloom persistence is sustained by mixotrophic strategies, with complex compromises between phototrophy and phagotrophy, as evidenced by fluorescence-based observations.
اظهر المزيد [+] اقل [-]Arsenic speciation in water, suspended particles, and coastal organisms from the Taehwa River Estuary of South Korea
2016
Hong, Seongjin | Kwon, Hye-Ok | Choi, Sung-Deuk | Lee, Jung-Suk | Khim, Jong Seong
Water, suspended particulate matter (SPM), and biota samples were collected from the Taehwa River Estuary to determine the distributions, partitioning, and bioaccumulation of arsenicals. Six forms of As were quantitated by the use of HPLC-ICP/MS. As was found mainly near urban and industrial areas, and inorganic AsV was the predominant As form in both water and SPM. Particulate arsenicals were found at the greatest concentrations in coarse particles (>180μm), followed by medium (30–180μm) and fine (0.45–30μm) particles, in freshwater. Arsenical concentrations were similar across the three particle fractions in saltwater. Field-based distribution coefficient (Kd) values for As depended strongly on SPM, with a less robust dependence on salinity. Concentrations of As were greater in macroalgae than in marine animals, such as fishes, bivalves, crabs, shrimps, and gastropods. Overall, the results of the present study provide useful information on the behaviors and fate of arsenicals in an estuarine environment.
اظهر المزيد [+] اقل [-]Impact of sea-land breezes on 210Pb in southern Iberian Peninsula – Feasibility study on using submicron-sized aerosol particles to analyze 210Pb hourly patterns
2016
Hernández-Ceballos, M.A. | Sorribas, M. | San Miguel, E.G. | Cinelli Calvoli, Giovanni | Adame, J.A. | Bolívar, J.P.
This work addresses the impact of mesoscale circulations on 210Pb concentrations in southwestern Iberian Peninsula by analysing the 210Pb database at El Arenosillo station during 2004–2011 (128 periods with a time scale of 48 h).The analysis of surface winds during each one of these periods has revealed the positive impact of the two sea-land breeze patterns (pure and non-pure), previously identified in this region, on 210Pb activity concentrations. An average value of 0.80 ± 0.09 mBq m−3 was obtained for the pure pattern (34 periods), 0.54 ± 0.09 mBq m−3 for the non-pure pattern (23 periods) and 0.46 ± 0.04 mBq m−3 for the rest (71 periods).The analysis of one representative period of each sea-land breeze patterns is also presented. To perform this analysis we have used: hourly surface wind observations, surface wind fields simulated by the WRF mesoscale model and the hourly database of sub-micron-particle size range in the accumulation mode (NACC). The use of this type of particles to investigate the hourly temporal variability of 210Pb is based on the high correlation, obtained in the present work, between 210Pb activity and particles in the accumulation mode (R = 0.90).The analysis reveals that the highest concentrations of NACC, and hence, 210Pb, are obtained when the sampling area is under the influence of the pure breeze, due to it favours the accumulation of particles previously transported by Mediterranean flows along the Guadalquivir valley. In the case of the non-pure pattern, the increase in the concentration of particles is related to the arrival of background synoptic winds from the continental areas of western Iberian Peninsula. In the latest, the increment of NACC is faster and around 400 particles cm−3, while in the case of the pure pattern, it is progressive up to 1400 particles cm−3.
اظهر المزيد [+] اقل [-]Study on the association between air pollution and mortality in İstanbul, 2007–2012
2016
Çapraz, Özkan | Efe, Bahtiyar | Deniz, Ali
We examined the associations between the daily variations of air pollutants and mortality in the population of İstanbul, Turkey, using generalized linear models while controlling for time trends and meteorological factors over a 6-year period (2007–2012) at different time lags (0–10 days). Effects of the pollutants (Relative Risk (RR) on current-day (lag 0) mortality to the first ten days (lag 10) were determined. Data on daily mortality, daily mean concentrations of air pollutants of PM10, SO2 and NO2 and daily mean concentrations of temperature and humidity for İstanbul were used in the study. We found significant associations between air pollution and daily mortality from cardiovascular disease, respiratory diseases, and total non-accidental causes in İstanbul. An increase of 10 μg/m3 in concentrations of PM10, SO2 and NO2 over 10 days of lag corresponds to RR = 1.0222 (95% Confidence Interval (CI) = 0.9957–1.0494), RR = 1.1639 (95% CI = 1.0279–1.3177) and RR = 1.0327 (95% CI = 1.0105–1.0554) increase of cardiovascular mortality, respectively. The associations for total non-accidental and respiratory mortality were also positive. Among the three air pollutants, SO2 was associated with the largest RR for deaths from cardiovascular disease, respiratory disease and total mortality. In conclusion, our study showed that short-term exposure to air pollution was associated with increased cardiovascular, respiratory and total non-accidental mortality in the city during 2007–2012. These findings may have implications for local environmental and social policies.
اظهر المزيد [+] اقل [-]Is climate change an unforeseen, irresistible and external factor – A force majeure in marine environmental law?
2016
Saul, Roxanne | Barnes, Richard | Elliott, Michael
Several environmental laws include provisions on natural causes or force majeure, which except States from their commitments if it can be proven that the failure to meet the commitment is due to factors outside their control. The European Union Marine Strategy Framework Directive (MSFD) has a pivotal role in managing EU marine waters. This paper analyses natural causes and force majeure provisions of the MFSD and other marine legislation, and addresses their interaction with climate change and its consequences, especially the effect on the obligation of ensuring seas are in Good Environmental Status. Climate change is an exogenic unmanaged pressure in that it emanates from outside the area being managed but in which the management authority has to respond to the consequences of climate change, such as sea level rise and temperature elevation, rather than its causes. It is suggested that a defence by a Member State of force majeure may be accepted if an event was proven to be due to an externality of control, irresistible and unforeseeable. The analysis contends that countering such a legal defence would centre on the fact that climate change is a well-accepted phenomenon, is foreseen with an accepted level of confidence and probability and is due to human actions. However, as yet, this has not been legally tested.
اظهر المزيد [+] اقل [-]Risk assessment for marine spills along European coastlines
2016
Fernández-Macho, Javier
A marine-spill risk index is proposed to measure and compare the relative vulnerability of coastal regions to marine spills in European waters. It is applied to 301 spills in European waters between 1970 and 2014 for 429 Eurostat territorial units and 156 regions in Europe's coasts. The results show a high heterogeneity among European coastal regions with areas, predominantly on the Atlantic coast, with high marine-spill risks. In particular, UK coasts are markedly affected as there are only five non-British coastal territories within the first 25 territorial units most at risk from marine spills. Across countries, European Atlantic countries face highest risks versus coastal countries on other European waters that are relatively safer. The index also shows a tendency of sea currents to have positive dispersal effects leading to smaller risks rather than otherwise. The index may help to design protection policies and reduce the vulnerability of sensitive resources.
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