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Inter-annual changes in fish communities of a tropical bay in southeastern Brazil: What can be inferred from anthropogenic activities?
2017
Araújo, Francisco Gerson | Pinto, Samara Macedo | Neves, Leonardo Mitrano | de Azevedo, Márcia Cristina Costa
We assessed inter-annual changes in fish assemblages of a tropical bay which experienced a heavily industrialized process in the last decades. A highly significant difference in community structure among the bay zones, and a decrease in fish richness and abundance over time were found. Changes in fish richness and abundance between the two first (1987–1988 and 1993–1995) and the two latter time periods (1998–2001 and 2012–2013) were sharpest in the inner bay zone, the most impacted bay area, and in the middle zone, whereas the outer zone remained comparatively stable over time. These changes coincided with increased metal pollution (mainly, Zn and Cd) in the bay and with the enlargement of the Sepetiba Port. Spatial changes in the fish community structure among the bay zones were related to differences in salinity, transparency and depth with this latter variable acting as a buffer stabilizing temporal community changes.
Afficher plus [+] Moins [-]Spatio-temporal variations in bloom of the red-tide dinoflagellate Karenia mikimotoi in Imari Bay, Japan, in 2014: Factors controlling horizontal and vertical distribution
2017
Aoki, Kazuhiro | Kameda, Takahiko | Yamatogi, Toshifumi | Ishida, Naoya | Hirae, Sou | Kawaguchi, Mayumi | Syutou, Toshio
A massive bloom of the dinoflagellate Karenia mikimotoi appeared in 2014 in Imari Bay, Japan. Bloom dynamics and hydrographical conditions were examined by field survey. The bloom initially developed in the eastern area of Imari Bay, subsequently after rainfall during the neap tides, cell density exceeded over 10,000cellsml. Vertical distribution of K. mikimotoi was primarily controlled by the light intensity and secondarily by the water quality during the daytime. Almost all cell-density maxima occurred in depths with weak daytime light intensities of <300μmolm−2s−1. In some cases of weak light intensity, cell-density maxima occurred in depths with favorable hydrodynamic conditions for the growth. Spatially classified areas were identified by cluster analysis using the growth rate calculated from seawater temperature and salinity. This study quantitatively evaluated the environmental factors of the eastern area, where the bloom initially occurred, during the development of the bloom.
Afficher plus [+] Moins [-]The cumulative effects assessment of a coastal ecological restoration project in China: An integrated perspective
2017
Ma, Deqiang | Zhang, Liyu | Fang, Qinhua | Jiang, Yuwu | Elliott, Michael
Large scale coastal land-claim and sea-enclosing (CLASE) activities have caused habitat destruction, biodiversity losses and water deterioration, thus the local governments in China have recently undertaken seabed dredging and dyke opening (SDADO) as typical ecological restoration projects. However, some projects focus on a single impact on hydrodynamic conditions, water quality or marine organisms. In a case study in Xiamen, China, an integrated effects assessment framework centres on ecohydrology, using modeling of hydrodynamic conditions and statistical analysis of water quality, was developed to assess the effects of ecological restoration projects. The benefits of SDADO projects include improving hydrodynamic conditions and water quality, as a precursor to further marine biological improvements. This study highlights the need to comprehensively consider ecological effects of SDADO projects in the planning stage, and an integrative assessment method combining cumulative effects of hydrodynamic conditions, water quality and biological factors.
Afficher plus [+] Moins [-]A novel approach for monitoring vertical profiles of boundary-layer pollutants: Utilizing routine news helicopter flights
2017
Crosman, Erik T. | Jacques, Alexander A. | Horel, John D.
Air quality varies greatly in space and time across urban locales. However, criteria pollutants are typically monitored routinely at a relatively small number of surface sites within each metropolitan area, and routine vertical profiles of pollution are typically unavailable. We illustrate that a news helicopter provides an effective sensor platform to provide spatiotemporal analyses and vertical profiles of pollutant concentrations. We are unaware of any other air quality study that has utilized routine helicopter flights, despite the ubiquity of helicopters in urban environments across the world. Particulate and ozone concentration profiles have been collected since 2015 from sensors installed on a news helicopter that travels primarily over the metropolitan areas of northern Utah. The air quality data are retrieved in real time, archived, combined with surface-based observations, and disseminated in terms of time series and maps on a website for research, forecasting, and public awareness. Large vertical variations in particulate pollution concentrations were observed during the 2015–2016 winter associated with meteorological cold-air pool episodes. During the 2015 and 2016 summer seasons, ozone concentrations frequently exhibited complex spatial and temporal variations arising from many interrelated factors, including local terrain-forced circulations, lake breezes, and distant wildfires.
Afficher plus [+] Moins [-]Photodegradation of diclofenac in seawater by simulated sunlight irradiation: The comprehensive effect of nitrate, Fe(III) and chloride
2017
Zhang, N. | Li, J.M. | Liu, G.G. | Chen, X.L. | Jiang, K.
Diclofenac is one of the most frequently detected pharmaceuticals in various aquatic environments. The photodegradation of diclofenac in the absence/presence of nitrate, Fe(III) and chloride, especially their interactions, were systematically studied. Under the study conditions, photodegradation rate was decreased with increasing nitrate, Fe(III) and chloride concentrations. Nitrate has an synergistic action for Fe(III). Nitrate and chloride have antagonistic effect. An antagonistic action is present between nitrate, Fe(III) and chloride. Moreover, a simple linear model which very well describes the results is given.
Afficher plus [+] Moins [-]Combined observation of a dust storm over the Loess Plateau using a dual-wavelength lidar and an aethalometer
2017
Gao, Xingai | Cao, Xianjie | Tian, Pengfei | Zhang, Lei | Huang, Zhongwei | Zhou, Tian
A dust storm was observed at the Semi-Arid Climate and Environment observatory of Lanzhou University (SACOL) using a dual-wavelength lidar and an aethalometer from 16 March to 22 March 2010. After the arrival of the dust storm, the lidar backscattered signal increased suddenly, the volume depolarization ratio ranged from 0.2 to 0.4. The dust aerosol was detected mainly in a layer below 2.5 km altitude. A higher attenuated backscatter coefficient (0.005–0.02 km−1/sr) was distributed in a lower layer (below 2.5 km) during the dust storm. The evolution of the dust storm was also clearly revealed by the integrated particle backscatter coefficient (BE). Particles in the coarse mode are predominant during the dust storm because Ångström exponent mainly ranged from 0.5 to 1.0. An aethalometer was used to measure the aerosol absorption coefficient as well as aerosol mass concentration. The average mass concentration of aerosol was 1.3 μg/m3 during the dust free period but increased to 1.8 μg/m3 during the dust storm, so the dust aerosol apparently played an important role. The main absorptive particle was black carbon during the dust free period. In addition, the peaks of dust aerosol concentration mainly occurred at around 08:00 and 20:00 (Beijing Time), one reason was that the increase of wind speed result in more dust particles blown up into the atmosphere in the neighborhood of SACOL and another reason was that the boundary layer convection was undeveloped in the morning and the temperature inversion appeared easily in the evening. The trend of the aerosol absorption coefficient was similar to that of mass concentration, and the aerosol absorption coefficient significantly increased during the dust storm.
Afficher plus [+] Moins [-]Particle dry deposition of polycyclic aromatic hydrocarbons and its risk assessment in a typical coal-polluted and basin city, northern China
2017
He, Qiusheng | Zhang, Lu | Cui, Yang | Cheng, Mingchao | Guo, Lili | Liu, Ming | Chen, Laiguo
Atmospheric dry deposition is a major pathway of pollutants removal from the atmosphere to the water and soil ecosystem. Polycyclic aromatic hydrocarbons (PAHs) in Taiyuan, China, are one class of the most hazardous air pollutants due to the high emission intensity from coal consumption. To better understand the PAHs removing from the atmosphere, 16 USEPA priority PAHs (except for naphthalene) in the particle dry deposition samples were detected from August 2013 to November 2014 at an urban site in Taiyuan. Dry deposition fluxes of particles were estimated as 157.44–358.17 mg/(m2·d), with the highest value in spring and lowest in autumn. Particle dry deposition fluxes of ∑15-PAHs ranged from 2436.20 to 14,967.36 ng/(m2·d), and was the highest in winter and lowest in summer. Higher PAHs particle dry deposition fluxes were related to higher PAHs emission, lower air temperature, less precipitation as well as wind speed. Overall dry deposition velocities of 15-PAHs were 0.056 ± 0.027 cm/s in winter and 0.42 ± 0.050 cm/s in summer, respectively, and high molecular weight PAHs showed low dry deposition velocities. Positive matrix factorization model's results indicated that coking, vehicle exhaust, coal combustion were the primary PAHs sources in particle dry deposition samples, accounting for 18.64%, 26.54% and 54.82% of total PAHs, respectively. The toxic equivalent concentrations (BaPeq) of ∑15-PAHs in particle dry deposition samples was in the range of 0.69–2.94 μg/g, which might be a good explanation to high soil PAHs concentrations reported in Shanxi province, China. Furthermore, this work could prove the significance of coal combustion, and related pollution control works are needed to conduct to alleviate the PAHs pollution situation.
Afficher plus [+] Moins [-]Evaluation of AhR-agonists and AhR-agonist activity in sediments of Liaohe River protected areas, China
2017
Zhang, Yun | Ke, Xin | Gui, Shaofeng | Wu, Xiaoqiong | Wang, Chunyong | Zhang, Haijun
A total of 9 sediment samples of Liaohe River protected areas were collected to evaluate aryl hydrocarbon receptor agonists (AhR-agonists) and AhR-agonist activity via chemical analysis and in vitro H4IIE cell bioassay. Results indicated that bioassay-derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (Bio-TEQs) ranged from 89.1 to 251.1pg/g dry weight. Concentrations of 16 EPA polycyclic aromatic hydrocarbons (PAHs), 12 dioxin-like polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) ranged from 256.8 to 560.1ng/g, 79.2 to 416.2pg/g, and 199.6 to 538.4pg/g, respectively. According to potency balance analysis, TEQchems based on PAHs, PCBs, and PCDD/Fs could contribute 16.56% to 26.11% of Bio-TEQs. This could be explained by the potential existence of unidentified AhR-agonists and the potential non-additive interactions among AhR-agonists in sediment extracts. Through the different contributions to Bio-TEQs, this study confirms that PCDD/Fs were the main pollutants that induced significantly AhR-agonist activity in sediments of Liaohe River protected areas.
Afficher plus [+] Moins [-]Oil permeability variations on lagoon sand beaches in the Patos-Guaíba system in Rio Grande do Sul, Brazil
2017
Oliveira, Elaine Baroni | Nicolodi, João Luiz
Permeability is the ability of a sediment deposit to allow fluids to pass through it. It depends on the local types of sediments. When the fluid is oil, high permeability implies greater interaction with the site and more extensive damage, which makes recovery most difficult. Knowledge of permeability oscillations is necessary to understand oil behavior and improve cleanup techniques. The goal is to determine oil permeability variations on lagoon sand beaches. Oil permeability tests were performed at the beach face, using a Modified Phillip Dunne Permeameter and parameters were sampled. Permeability of lagoon beaches is driven by grain diameter and roundness, soil compaction, and depth of the water table. Factors that enhance permeability include: sand sorting, vertical distribution of sediments and gravel percentage. High permeability on lagoon beaches is related to polymodal distribution, to the sediment package, and to the system's low mobility.
Afficher plus [+] Moins [-]Occurrence of pharmaceuticals and UV-filters in riverine run-offs and waters of the German Baltic Sea
2017
Fisch, Kathrin | Waniek, J. J. (Joanna J.) | Schulz-Bull, Detlef E.
The occurrence of pharmaceuticals and personal care products (PPCPs) in the marine environment is of great concern. This study was done to determine the emergence of eight pharmaceuticals and eleven ultraviolet filters (UV-Filters) in 5 rivers/streams discharging into the Baltic Sea. Furthermore, a focus was put on the influence of wastewater treatment plant as indirect source and the occurrence of the PPCPs in close beach proximity. Two pharmaceuticals (sulfamethoxazole, salicylic acid) and two UV-filters (2-phenylbenzimidazole-5-sulfonic acid, octocrylene) were detected in all analyzed water samples, with concentration ranging from 0.6ng/L to 836.3ng/L. In all rivers the PPCP concentration decreases towards the Baltic Sea. Sulfamethoxazole was detected at comparable concentration along the coast, which leads to the assumption of stable concentration in beach proximity. Along the coast UV-filters appeared in varying concentrations, leading to the conclusion that the direct input into the marine environment plays a bigger role than the indirect input.
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