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The relation between columnar and surface aerosol optical properties in a background environment Texto completo
2017
Szczepanik, D. | Markowicz, K.M.
This work presents the results of observation and the numerical simulation relationship between columnar and surface aerosol optical properties. The presented data include sun photometer nephelometer, aethalometer, and ceilometer observation, as well as the Navy Aerosol Analysis and Prediction System (NAAPS) re-analysis obtained between 2013 and 2016. Measurements were made in Strzyzow station (south-eastern part of Poland), which belongs to the AERONET and Poland-AOD network. Observation and simulation data show that the correlation coefficient between aerosol optical depth and surface aerosol scattering coefficient depends on the averaging period. For the monthly mean both parameters are negatively correlated as a result of the seasonal variability of anthropogenic emission in Central Europe and long-range transport of natural aerosol, as well as the change of the meteorological conditions. Reduction of the averaging time leads to an increase in the correlation coefficient, which is almost zero for a 10-day period and 0.4 ± 0.05 when the six-hour data are selected. In addition, the correlation between columnar and surface aerosol optical properties shows significant variation with surface temperature gradient. During convective conditions the correlation coefficient between aerosol optical depth and aerosol scattering coefficient is as much as 0.89 ± 0.03 while during inversion it is approximately 0.48 ± 0.08.
Mostrar más [+] Menos [-]Microplastics as a vector for the transport of the bacterial fish pathogen species Aeromonas salmonicida Texto completo
2017
Viršek, Manca Kovač | Lovšin, Marija Nika | Koren, Špela | Kržan, Andrej | Peterlin, Monika
Microplastics is widespread in the marine environment where it can cause numerous negative effects. It can provide space for the growth of organisms and serves as a vector for the long distance transfer of marine microorganisms. In this study, we examined the sea surface concentrations of microplastics in the North Adriatic and characterized bacterial communities living on the microplastics. DNA from microplastics particles was isolated by three different methods, followed by PCR amplification of 16S rDNA, clone libraries preparation and phylogenetic analysis. 28 bacterial species were identified on the microplastics particles including Aeromonas spp. and hydrocarbon-degrading bacterial species. Based on the 16S rDNA sequences the pathogenic fish bacteria Aeromonas salmonicida was identified for the first time on microplastics. Because A. salmonicida is responsible for illnesses in fish, it is crucial to get answers if and how microplastics pollution is responsible for spreading of diseases.
Mostrar más [+] Menos [-]Fast assessment of bioaccessible metallic contamination in marine sediments Texto completo
2017
Terán-Baamonde, J. | Carlosena, A. | Soto-Ferreiro, R.M. | Andrade, J.M. | Prada, D.
A fast (16min) procedure to assess the bioaccessible metallic fraction of Cd, Cr, Cu, Ni, Pb and Zn simultaneously extracted (SEM) from marine sediments plus an indirect approach to determine acid volatile sulfides (AVS) are presented. For the extraction process magnetic agitation was compared with ultrasonic stirring (using a bath and a probe), and several stirring times were assayed. The proposed SEM procedure uses an ultrasonic probe and 1mL of HCl. It dramatically minimizes the turnaround time and the residues. AVS were evaluated as the difference between the amounts of sulphur in the solid residue after the extraction and total sulphur in the original sample. These procedures are fast, easy to implement and cost-effective to assess the potential risk posed by metals in marine sediments. They were tested using several CRMs and applied to sediments from two Galician Rias (NW Spain); their SEM-AVS differences indicated no biological risk.
Mostrar más [+] Menos [-]Ingestion of marine debris by the White-chinned Petrel (Procellaria aequinoctialis): Is it increasing over time off southern Brazil? Texto completo
2017
Petry, Maria V. | Benemann, Victória R.F.
Seabirds are amongst the most affected organisms by plastic pollution worldwide. Ingestion of marine debris has been reported in at least 122 species, and owing to the increasing global production and persistence of these anthropogenic materials within the marine environment, it is expected to be a growing problem to the marine fauna. Here we report evidence of an increasing frequency in marine debris ingestion and a decrease in the amount of plastic pellets ingested by White-chinned Petrels attending south Brazilian waters during the last three decades. Future studies comprising large temporal scales and large sample sizes are needed to better understand the trends of marine debris ingestion by seabirds. We expect our findings to highlight the need for prevention policies and mitigation measures to reduce the amount of solid litter in the oceans.
Mostrar más [+] Menos [-]The plastic in microplastics: A review Texto completo
2017
Andrady, A. L. (Anthony L.)
Microplastics [MPs], now a ubiquitous pollutant in the oceans, pose a serious potential threat to marine ecology and has justifiably encouraged focused biological and ecological research attention. But, their generation, fate, fragmentation and their propensity to sorb/release persistent organic pollutants (POPs) are determined by the characteristics of the polymers that constitutes them. Yet, physico-chemical characteristics of the polymers making up the MPs have not received detailed attention in published work. This review assesses the relevance of selected characteristics of plastics that composes the microplastics, to their role as a pollutant with potentially serious ecological impacts. Fragmentation leading to secondary microplastics is also discussed underlining the likelihood of a surface-ablation mechanism that can lead to preferential formation of smaller sized MPs.
Mostrar más [+] Menos [-]Trace element exposure of whooper swans (Cygnus cygnus) wintering in a marine lagoon (Swan Lake), northern China Texto completo
2017
Wang, Feng | Xu, Shaochun | Zhou, Yi | Wang, Pengmei | Zhang, Xiaomei
Trace element poisoning remains a great threat to various waterfowl and waterbirds throughout the world. In this study, we determined the trace element exposure of herbivorous whooper swans (Cygnus cygnus) wintering in Swan Lake (Rongcheng), an important swan protection area in northern China. A total of 70 samples including abiotic factors (seawater, sediments), food sources (seagrass, macroalgae), feathers and feces of whooper swans were collected from the marine lagoon during the winters of 2014/2015 and 2015/2016. Concentrations of Cu, Zn, Pb, Cr, Cd, Hg and As were determined to investigate the trace element exposure of whooper swans wintering in the area. Results showed that there was an increasing trend in sediment trace element concentrations, compared with historical data. The trace element concentrations in swan feces most closely resembled those of Zostera marina leaves, especially for Cd and Cr. The Zn and Hg concentrations in the swan feces (49.57 and 0.01mg/kg, respectively) were lower than the minimum values reported in the literature for other waterfowls, waterbirds and terrestrial birds. However, the concentrations of the other five trace elements fell within the lower and mediate range of values reported for birds across the world. These results suggest that the whooper swans wintering in Swan Lake, Rongcheng are not suffering severe trace element exposure; however, with the increasing input of trace elements to the lagoon, severe adverse impacts may occur in the future, and we therefore suggest that the input of trace elements to this area should be curbed.
Mostrar más [+] Menos [-]Restoring rocky intertidal communities: Lessons from a benthic macroalgal ecosystem engineer Texto completo
2017
Bellgrove, Alecia | McKenzie, Prudence F. | Cameron, Hayley | Pocklington, Jacqueline B.
As coastal population growth increases globally, effective waste management practices are required to protect biodiversity. Water authorities are under increasing pressure to reduce the impact of sewage effluent discharged into the coastal environment and restore disturbed ecosystems. We review the role of benthic macroalgae as ecosystem engineers and focus particularly on the temperate Australasian fucoid Hormosira banksii as a case study for rocky intertidal restoration efforts. Research focussing on the roles of ecosystem engineers is lagging behind restoration research of ecosystem engineers. As such, management decisions are being made without a sound understanding of the ecology of ecosystem engineers. For successful restoration of rocky intertidal shores it is important that we assess the thresholds of engineering traits (discussed herein) and the environmental conditions under which they are important.
Mostrar más [+] Menos [-]How the dispersant Corexit impacts the formation of sinking marine oil snow Texto completo
2017
Passow, Uta | Sweet, Julia | Quigg, Antonietta
The vertical transport of sinking marine oil snow (MOS) and oil-sediment aggregations (OSA) during the Deepwater Horizon (DwH) spill contributed appreciably to the unexpected, and exceptional accumulation of oil on the seafloor. However, the role of the dispersant Corexit in mediating oil-sedimentation is still controversial. Here we demonstrate that the formation of diatom MOS is enhanced by chemically undispersed oil, but inhibited by Corexit-dispersed oil. Nevertheless, the sedimentation rate of oil may at times be enhanced by Corexit application, because of an elevated oil content per aggregate when Corexit is used. A conceptual framework explains the seemingly contradictory effects of Corexit application on the sedimentation of oil and marine particles. The redistribution of oil has central ecological implications, and future decisions on mediating measures or damage assessment will have to take the formation of sinking, oil-laden, marine snow into account.
Mostrar más [+] Menos [-]In situ estimates of horizontal turbulent diffusivity at the sea surface for oil transport simulation Texto completo
2017
Matsuzaki, Yoshitaka | Fujita, Isamu
Despite many previous in situ estimates of horizontal diffusivity below the sea surface, horizontal diffusivity at the sea surface, which is a parameter required in the prediction of oil diffusion, has not been formulated. This study conducted in situ estimations to quantify horizontal diffusivity at the sea surface. To measure the horizontal diffusivity at and below the sea surface, clusters of thin sponge rubbers (simulating spilled oil), together with drifting buoys, were deployed on successive occasions in Sagami Bay, Japan. The experimental results revealed that horizontal diffusivity was larger at the sea surface than below. Based on the results, a procedure for estimating horizontal diffusivity at the sea surface was introduced to predict the diffusion of spilled oil, which was verified using numerical simulations. The simulation results showed good agreement with observations, suggesting the procedure is appropriate for the estimation of horizontal diffusivity at the sea surface.
Mostrar más [+] Menos [-]Atmospheric Nitrogen Emission, Deposition, and Air Quality Impacts in China: an Overview Texto completo
2017
Liu, Xuejun | Xu, Wen | Duan, Lei | Du, Enzai | Pan, Yuepeng | Lu, Xiankai | Zhang, Lin | Wu, Zhiyong | Wang, Xuemei | Zhang, Ying | Shen, Jianlin | Song, Ling | Feng, Zhaozhong | Liu, Xueyan | Song, Wei | Tang, Aohan | Zhang, Yangyang | Zhang, Xiuying | Collett, Jeffrey L. Jr
Atmospheric reactive nitrogen (N) has induced large impacts on air pollution and ecosystem health worldwide. Atmospheric reactive N emission and deposition have largely increased in China since 1980 due to rapid agricultural, industrial, and urban development. But scientific gaps still remain in the regional and temporal variability in atmospheric N emissions and deposition. Meanwhile, the environmental impacts of N pollution and deposition are of great concern in China. This paper overviews the status of anthropogenic N emissions and deposition and their linkages to air pollution in China. The major findings include two aspects: (1) anthropogenic reactive N (e.g., NH₃ and NOₓ) emissions contribute greatly to secondary inorganic aerosol formation and haze pollution and (2) dry N deposition is comparable in importance to wet N deposition, suggesting that both dry and wet deposition should be quantified simultaneously. Future research challenges on atmospheric N emission and deposition are discussed as well. China needs to (1) reduce the uncertainties of national emission inventory of various N species, especially organic N compounds; (2) establish national networks for atmospheric N concentration and deposition monitoring; and (3) evaluate ecological and environmental impacts of N pollution and deposition in typical ecosystems. Last but not least, N deposition modeling tools should be improved based on localized parameters and further used in future N regulation.
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