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Результаты 2211-2220 из 62,084
Spatial variations in trace element concentrations of the sea urchin, Paracentrotus lividus, a first reference study in the Mediterranean Sea
2018
Ternengo, Sonia | Marengo, Michel | El Idrissi, Ouafa | Yepka, Joseph | Pasqualini, Vanina | Gobert, Sylvie | FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège
peer reviewed | A study on Trace Elements (TE) from sea urchin gonads has been conducted in the western Mediterranean Sea. Contamination data were used to determine a Trace Method Pollution Index (TEPI). TE concentrations varied considerably depending on the location of the sampling stations. The results showed that five trace elements (Zn, Fe, As, Al, Cu) are ubiquitous. The geographical area considered (Corsica) represents an important range of environmental conditions and types of pressure that can be found in the western Mediterranean Sea. TEPI was used to classify the studied sites according to their degree of contamination and allowed reliable comparison of TE contamination between local and international sites. TE contamination of the western Mediterranean Seadisplayed a north-to-south gradient, from the Italian coasts down through the insular Corsican coasts to the north African littoral. Due to the increasing environmental pressure on the Mediterranean Sea, a regular monitoring of TE levels in marine organisms is necessary to prevent any further environmental deterioration.
Показать больше [+] Меньше [-]Biomarker responses of Cu-induced toxicity in European seabass Dicentrarchus labrax: assessing oxidative stress and histopathological alterations
2017
Díaz de Alba, Margarita Isabel | Canalejo Raya, Antonio | Granado Castro, María Dolores | Oliva Ramírez, Milagrosa | El Mai, Bahija | Córdoba García, Francisco | Troyano Montoro, Miriam | Espada Bellido, Estrella | Torronteras Santiago, Rafael | Galindo Riaño, María Dolores | Química Analítica
A comprehensive approach to chemical accumulation and biological effects of short-term Cu exposure in juveniles of European seabass (Dicentrarchus labrax) has been achieved. Fish were exposed to 0.01–10 mg L− 1 nominal Cu concentrations for 24–96 h. Metal concentrations in water and gills, liver, muscle and brain tissues were studied along with oxidative stress biomarkers (superoxide dismutase, catalase, glutathione peroxidase, lipid peroxidation). Induction of oxidative damage was observed in all the organs with differential antioxidant responses; gills appearing as the most sensitive from low environmentally water Cu concentrations as 0.01 mg L− 1. Histopathological alterations were also observed in liver and gills, even without a significant Cu accumulation. The results show that the combination of oxidative stress parameters, particularly lipid peroxidation and glutathione peroxidase activities, and histopathological alterations provide a good model fish and reliable early biomarkers for monitoring Cu pollution in seawater and might call for the protection agencies to revise the Cu environmental standards.
Показать больше [+] Меньше [-]Citizen scientists reveal: marine litter pollutes Arctic beaches and affects wild life
2017
Bergmann, Melanie | Lutz, Birgit | Tekman, Mine Banu | Gutow, Lars
Recent data indicate accumulation areas of marine litter in Arctic waters and significant increases over time. Beaches on remote Arctic islands may be sinks for marine litter and reflect pollution levels of the surrounding waters particularly well. We provide the first quantitative data from surveys carried out by citizen scientists on six beaches of Svalbard. Litter quantities recorded by cruise tourists varied from 9-524 g m-2 and were similar to those from densely populated areas. Plastics accounted for >80% of the overall litter, most of which originated from fisheries. Photographs provided by citizens show deleterious effects of beach litter on Arctic wildlife, which is already under strong pressure from global climate change. Our study highlights the potential of citizen scientists to provide scientifically valuable data on the pollution of sensitive remote ecosystems. The results stress once more that current legislative frameworks are insufficient to tackle the pollution of Arctic ecosystems.
Показать больше [+] Меньше [-]Environmental effects of the Deepwater Horizon oil spill: A review
2016
Beyer, Jonny | Trannum, Hilde C. | Bakke, Torgeir | Hodson, Peter V. | Collier, Tracy K.
The Deepwater Horizon oil spill constituted an ecosystem-level injury in the northern Gulf of Mexico. Much oil spread at 1100–1300 m depth, contaminating and affecting deepwater habitats. Factors such as oil-biodegradation, ocean currents and response measures (dispersants, burning) reduced coastal oiling. Still, > 2100 km of shoreline and many coastal habitats were affected. Research demonstrates that oiling caused a wide range of biological effects, although worst-case impact scenarios did not materialize. Biomarkers in individual organisms were more informative about oiling stress than population and community indices. Salt marshes and seabird populations were hard hit, but were also quite resilient to oiling effects. Monitoring demonstrated little contamination of seafood. Certain impacts are still understudied, such as effects on seagrass communities. Concerns of long-term impacts remain for large fish species, deep-sea corals, sea turtles and cetaceans. These species and their habitats should continue to receive attention (monitoring and research) for years to come. | acceptedVersion
Показать больше [+] Меньше [-]Disinfection by-products and ecotoxicity of ballast water after oxidative treatment – Results and experiences from seven years of full-scale testing of ballast water management systems
2013
Delacroix, Stephanie | Vogelsang, Christian | Tobiesen, August | Liltved, Helge
Since 2005, five different ballast water management systems (BWMS) based on chlorination treatment have been tested by Norwegian Institute for Water Research (NIVA) according to guidelines from the International Maritime Organization (IMO). 25 % and >50 % of all the tested discharge samples exhibited acute and chronic toxic effects on algae, respectively. In most cases this toxicity was plausibly caused by a high free residual oxidant (FRO) level (>0.08 mg Cl/l). Of the 22 disinfection by-products (DBPs) that were identified in treated water at discharge, four compounds were at times found at concentrations that may pose a risk to the local aquatic environment. However, there seemed to be no clear indication that the measured DBP concentrations contributed to the observed algal toxicity. The addition of methylcellulose instead of lignin in the test water to comply with IMO requirements seemed to limit the formation of DBP.
Показать больше [+] Меньше [-]Modelling of cadmium uptake by plant roots in agricultural soil: construction and sensitivity analysis of the model
2012
Zhongbin, Lin | Nguyen, Christophe | Schneider, Andre
Modelling of cadmium uptake by plant roots in agricultural soils. Exploration by steady-state analytical solution of numeric simulation results
2012
Schneider, Andre | Zhongbin, Lin | Nguyen, Christophe
Emission factors and detailed chemical characterization of PM and VOCs from 4 in-use petrol and diesel passenger cars
2012
Polo, L. | Goriaux, M. | Jaffrezo, J.L. | Besombes, Jean-Luc | André, M. | Charron, A.
From soil to edible plant parts: how to predict and limit contaminationof crops by inorganic trace elements?
2012
Nguyen, Christophe | Cornu, Jean-Yves | Denaix, Laurence | Laporte, Marie-Aline | Sappin-Didier, Valerie, | Schneider, Andre | Zarouali, Nadia
Carbon isotope composition, macronutrient concentrations, and carboxylating enzymes in relation to the growth of Pinus halepensis mill. when subject to ozone stress
2010
Inclan , Rosa (Ecotoxicology of Air Pollution, Madrid(Espagne).) | Gimeno , Benjamin S. (Ecotoxicology of Air Pollution, Madrid(Espagne).) | Peñuelas , Josep (Universitat Autónoma de Barcelona, Barcelone(Espagne).) | Gerant , Dominique (INRA , Champenoux (France). UMR 1137 Ecologie et Ecophysiologie Forestières) | Querido , Alberto (Ecotoxicology of Air Pollution, Madrid(Espagne).)
We present here the effects of ambient ozone (O3)-induced decline in carbon availability, accelerated foliar senescence, and a decrease in aboveground biomass accumulation in the Aleppo pine (Pinus halepensis Mill.). Aleppo pine seedlings were continuously exposed in open-top chambers for 39 months to three different types of O3 treatments, which are as follows: charcoal-filtered air, nonfiltered air (NFA), and nonfiltered air supplemented with 40 ppb O3 (NFA+). Stable carbon isotope discrimination (Δ) and derived time-integrated ci/ca ratios were reduced after an accumulated ozone exposure over a threshold of 40 ppb (AOT40) value from April to September of around 20,000 ppb·h. An AOT40 of above 67,000 ppb·h induced reductions in ribulose-1, 5-biphosphate carboxylase/oxygenase activity, aboveground C and needle N and K concentrations, the C/N ratio, Ca concentrations in twigs under 3 mm, and the aerial biomass, as well as increases in needle P concentrations and phosphoenolpyruvate carboxylase (PEPC) activity and the N and K concentrations in twigs under 3 mm. Macronutrients losses, the limitations placed on carbon uptake, and increases in catabolic processes may be the causes of carbon gain diminution in leaves which was reflected as a reduction in aboveground biomass at tree level. Stimulation of PEPC activity, the consequent decreased Δ, and compensation processes in nutrient distribution may increase O3 tolerance and might be interpreted as part of Aleppo pine acclimation response to O3.
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