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Bioassessment of water quality status using a potential bioindicator based on functional groups of planktonic ciliates in marine ecosystems Полный текст
2016
Xu, Henglong | Yong, Jiang | Xu, Guangjian
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.
Показать больше [+] Меньше [-]Bacterial inoculants for enhanced seed germination of Spartina densiflora: Implications for restoration of metal polluted areas Полный текст
2016
Paredes-Páliz, Karina I. | Pajuelo, Eloísa | Doukkali, Bouchra | Caviedes, Miguel Ángel | Rodríguez-Llorente, Ignacio D. | Mateos-Naranjo, Enrique
The design of effective phytoremediation programs is severely hindered by poor seed germination on metal polluted soils. The possibility that inoculation with plant growth promoting rhizobacteria (PGPR) could help overcoming this problem is hypothesized. Our aim was investigating the role of PGPR in Spartina densiflora seed germination on sediments with different physicochemical characteristics and metal pollution degrees. Gram negative Pantoea agglomerans RSO6 and RSO7, and gram positive Bacillus aryabhattai RSO25, together with the consortium of the three strains, were used for independent inoculation experiments. The presence of metals (As, Cu, Pb and Zn) in sediments reduced seed germination by 80%. Inoculation with Bacillus aryabhattai RSO25 or Pantoea agglomerans RSO6 and RSO7 enhanced up to 2.5 fold the germination rate of S. densiflora in polluted sediments regarding non-inoculated controls. Moreover, the germination process was accelerated and the germination period was extended. The consortium did not achieve further improvements in seed germination.
Показать больше [+] Меньше [-]Investigating ozone high levels and the role of sea breeze on its transport Полный текст
2016
Monteiro, Alexandra | Gama, Carla | Cândido, Marta | Ribeiro, Isabel | Carvalho, David | Lopes, Myriam
This works intends to investigate the ozone episodes reported in three different monitoring sites distributed along the Central region of Portugal (from the coast to inland direction). Ozone data time series are first analysed according to the legislation thresholds fulfilment (information threshold and target value) and two episodes are selected according to the magnitude and simultaneously exceedances at the three sites. The episodes are then analysed in terms of meteorological data (surface and vertical profiles) obtained with the WRF model and also using backtrajectories obtained with the HYSPLIT model. The integration of both results, together with the ozone and NO2 precursor concentration time series, allowed to conclude about the different origin of ozone in the two episodes. A sea breeze circulation is present in the first episode, inducing the transport of this pollutant and its precursors from the coast to inland (about 30 km), which is verified by the wind patterns and vertical profiles and by the daily profile of O3 measured at the three sites. The second episode studied does not show so clearly this influence.
Показать больше [+] Меньше [-]Small-scale temporal and spatial variability in the abundance of plastic pellets on sandy beaches: Methodological considerations for estimating the input of microplastics Полный текст
2016
Moreira, Fabiana Tavares | Prantoni, Alessandro Lívio | Martini, Bruno | de Abreu, Michelle Alves | Stoiev, Sérgio Biato | Turra, Alexander
Microplastics such as pellets have been reported for many years on sandy beaches around the globe. Nevertheless, high variability is observed in their estimates and distribution patterns across the beach environment are still to be unravelled. Here, we investigate the small-scale temporal and spatial variability in the abundance of pellets in the intertidal zone of a sandy beach and evaluate factors that can increase the variability in data sets. The abundance of pellets was estimated during twelve consecutive tidal cycles, identifying the position of the high tide between cycles and sampling drift-lines across the intertidal zone. We demonstrate that beach dynamic processes such as the overlap of strandlines and artefacts of the methods can increase the small-scale variability. The results obtained are discussed in terms of the methodological considerations needed to understand the distribution of pellets in the beach environment, with special implications for studies focused on patterns of input.
Показать больше [+] Меньше [-]Potential human health risk assessment of trace metals via the consumption of marine fish in Persian Gulf Полный текст
2016
Naji, Abolfazl | Khan, Farhan R. | Hashemi, Seyed Hassan
This study was carried out to evaluate the concentration of trace metals (Cd, Cu, Ni, Pb and Zn) in the muscle of four fish species from the Persian Gulf. Trace metals were analyzed using atomic absorption spectroscopy and consumption rates advisory for minimizing chronic systemic effects in children and adults were estimated. The metals concentrations in analyzed fish samples were lower than legal limits. Cadmium target hazard quotient values suggested that the threshold to avoid the potential risk for children health is an exposure level lower than 3 meals per week. Hazard index values based on four metals (not including Pb) for the child age class were higher than those of the adult age class, suggesting that children may suffer from a higher health risk. This study provides information about the consumption limits of certain metals, in particular Cd, necessary for minimizing potential health risks resulting from human consumption.
Показать больше [+] Меньше [-]Application of biological traits to further our understanding of the impacts of dredged material disposal on benthic assemblages Полный текст
2016
Bolam, S.G. | McIlwaine, P.S.O. | Garcia, C.
While the effects of coastal disposal of dredged material on benthic assemblage structure have been well studied, our understanding of the mechanism of such responses, and their potential ecological implications, remain relatively unknown. Data from a licenced disposal site off the northeast coast of England are analysed to address this and improve our ability to make informed licencing decisions for this activity. Assemblages within the disposal site displayed reduced number of species and total invertebrate density, an altered assemblage taxonomic structure, and a shift towards a greater numerical dominance of less-productive individuals. Following separate analyses of biological response and effect traits, a novel approach for marine benthic trait analysis, we identify the traits responsible (i.e. response traits) for the observed structural alterations. Furthermore, analysis of the effect traits revealed that the assemblages characterising the disposal site possess a greater bioturbative capability compared to those not directly impacted by disposal.
Показать больше [+] Меньше [-]New diagnostic ratios based on phenanthrenes and anthracenes for effective distinguishing heavy fuel oils from crude oils Полный текст
2016
Zhang, Haijiang | Wang, Chuanyuan | Zhao, Ruxiang | Yin, Xiaonan | Zhou, Hongyang | Tan, Liju | Wang, Jiangtao
The heavy fuel oils (HFOs) and crude oils are the main oil types in the marine oil spill accidents in China. It is usually a challenge to distinguish the HFOs from crude oils due to the highly similar physicochemical characteristics. In this paper, the distributions of phenanthrene (Phe), anthracene (Ant), methyl-phenanthrene (MP) and methyl-anthracene (MA) in hundreds of HFOs and crude oils samples which were collected from all over the world were characterized. Nine new diagnostic indexes, such as Ant/(Ant+Phe) and other eight diagnostic ratios based on the MP isomers and MA, were developed for effective distinguishing HFOs from crude oils. The histogram with normal fit plots, the double ratio plots and Bayes discriminant analysis (BDA) method were employed to illustrate the effectiveness of the new diagnostic indexes. BDA model based on nine new diagnostic indexes demonstrated high precision with discriminant ratio which lay between 93.92% and 99.32%.
Показать больше [+] Меньше [-]Trace elements in striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean: A 10-years perspective Полный текст
2016
Shoham-Frider, Efrat | Goffman, Oz | Harlavan, Yehudit | Kress, Nurit | Morick, Danny | Roditi-Elasar, Mia | Shefer, Edna | Kerem, Dan
Concentrations of Hg, Se, Cd, Cu, Zn, Fe, Mn and As, in kidney, liver, muscle and blubber from 7 specimens of Stenella coeruleoalba, stranded along the Israeli Mediterranean coast (IMC) from 2006 to 2011 (2011-series) were determined and compared to previous data on S. coeruleoalba from the IMC (2001-series). No differences were observed in essential and toxic elements concentrations, between the two series, except for hepatic Mn which was higher in the latter. Hg/Se molar ratios in blubber, kidney and liver increased linearly with log Hg concentrations, while muscle was more heterogenic in this respect. Means (±SD) of hepatic Hg concentrations (134±89 and 181±200mgkg−1, from the 2011 and 2001 series, respectively) were similar to that found in 2007–2009 specimens from Spain, possibly reflecting the relatively high natural background levels of mercury in the Mediterranean Sea.
Показать больше [+] Меньше [-]Coral reef health response to chronic and acute changes in water quality in St. Thomas, United States Virgin Islands Полный текст
2016
Ennis, Rosmin S. | Brandt, Marilyn E. | Wilson Grimes, Kristin R. | Smith, Tyler B.
It is suspected that land cover alteration on the southern coast of St. Thomas, USVI has increased runoff, degrading nearshore water quality and coral reef health. Chronic and acute changes in water quality, sediment deposition, and coral health metrics were assessed in three zones based upon perceived degree of human influence. Chlorophyll (p<0.0001) and turbidity (p=0.0113) were significantly higher in nearshore zones and in the high impact zone during heavy precipitation. Net sediment deposition and terrigenous content increased in nearshore zones during periods of greater precipitation and port activity. Macroalgae overgrowth significantly increased along a gradient of decreasing water quality (p<0.0001). Coral bleaching in all zones peaked in November with a regional thermal stress event (p<0.0001). However, mean bleaching prevalence was significantly greater in the most impacted zone compared to the offshore zone (p=0.0396), suggesting a link between declining water quality and bleaching severity.
Показать больше [+] Меньше [-]Evaluation of mobile metals in sediments of Burullus Lagoon, Egypt Полный текст
2016
Khalil, Mona | El-Gharabawy, Suzan
The Burullus Lagoon north Nile Delta of Egypt is a UNESCO-protected area. Recently it has become a sediment sink which led to shrinking in its area and depth accompanying with increasing contaminant levels. In this study we attempt to explore the spatial distribution and their mobility of heavy metals (Zn, Cu, Ni, Cr and Pb) based on 21surface sediment samples recovered from Burullus lagoon basin and nine drains. The risk assessment code of the studied heavy metals can be arranged as Zn>Cu>Pb>Cr>Ni for all the samples collected from the lagoon basin and nine different drains. The heavy metals tend to accumulate in fine sediments and human activities promote the accumulation of contaminated sediments in water courses.
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