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A novel "Integrated Biomarker Response" calculation based on reference deviation concept
2013
Sanchez, Wilfried | Burgeot, Thierry | Porcher, Jean-marc
Multi-biomarker approaches are used to assess ecosystem health and identify impacts of environmental stress on organisms. However, exploration of large datasets by environmental managers represents a major challenge for regulatory application of this tool. Several integrative tools were developed to summarize biomarker responses. The aim of the present paper is to update calculation of the "Integrated Biological Response" (IBR) described by Beliaeff and Burgeot (Environ Toxicol Chem 21:1316-1322, 2002) to avoid weaknesses of this integrative tool. In the present paper, a novel index named "Integrated Biological Responses version 2" based on the reference deviation concept is presented. It allows a clear discrimination of sampling sites as for the IBR, but several differences are observed for contaminated sites according to up- and downregulation of biomarker responses. This novel tool could be used to integrate multi-biomarker responses not only in large-scale monitoring but also in upstream/downstream investigations.
Afficher plus [+] Moins [-]Risk assessment of herbicides and booster biocides along estuarine continuums in the Bay of Vilaine area (Brittany, France)
2013
Caquet, Th. | Roucaute, M. | Mazzella, N. | Delmas, F. | Madigou, C. | Farcy, E. | Burgeot, Thierry | Allenou, Jean-pierre | Gabellec, Raoul
A 2-year study was implemented to characterize the contamination of estuarine continuums in the Bay of Vilaine area (NW Atlantic Coast, Southern Brittany, France) by 30 pesticide and biocide active substances and metabolites. Among these, 11 triazines (ametryn, atrazine, desethylatrazine, desethylterbuthylazine, desisopropyl atrazine, Irgarol 1051, prometryn, propazine, simazine, terbuthylazine, and terbutryn), 10 phenylureas (chlortoluron, diuron, 1-(3,4-dichlorophenyl)-3-methylurea, fenuron, isoproturon, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl)-urea, linuron, metoxuron, and monuron), and 4 chloroacetanilides (acetochlor, alachlor, metolachlor, and metazachlor) were detected at least once. The objectives were to assess the corresponding risk for aquatic primary producers and to provide exposure information for connected studies on the responses of biological parameters in invertebrate sentinel species. The risk associated with contaminants was assessed using risk quotients based on the comparison of measured concentrations with original species sensitivity distribution-derived hazardous concentration values. For EU Water Framework Directive priority substances, results of monitoring were also compared with regulatory Environmental Quality Standards. The highest residue concentrations and risks for primary producers were recorded for diuron and Irgarol 1051 in Arzal reservoir, close to a marina. Diuron was present during almost the all survey periods, whereas Irgarol 1051 exhibited a clear seasonal pattern, with highest concentrations recorded in June and July. These results suggest that the use of antifouling biocides is responsible for a major part of the contamination of the lower part of the Vilaine River course for Irgarol 1051. For diuron, agricultural sources may also be involved. The presence of isoproturon and chloroacetanilide herbicides on some dates indicated a significant contribution of the use of plant protection products in agriculture to the contamination of Vilaine River. Concentration levels and associated risk were always lower in estuarine sites than in the reservoir, suggesting that Arzal dam reduces downstream transfer of contaminants and favors their degradation in the freshwater part of the estuary. Results of the additional monitoring of two tidal streams located downstream of Arzal dam suggested that, although some compounds may be transferred to the estuary, their impact was probably very low. Dilution by marine water associated with tidal current was also a major factor of concentration reduction. It is concluded that the highest risks associated to herbicides and booster biocides concerned the freshwater part of the estuary and that its brackish/saltwater part was exposed to a moderate risk, although some substances may sometimes exhibit high concentration but mainly at low tide and on an irregular basis.
Afficher plus [+] Moins [-]The regrowth of phytoplankton cultures after UV disinfection
2013
Martínez, Lucía F. | Mahamud, Manuel M. | Lavín, Antonio G. | Bueno, Julio L.
This study addresses how cultures of three phytoplankton species –Chaetoceros calcitrans, Chlorella autotrophica and Phaeocystis globosa – can recover from the effects of UV-C exposure if the cells are placed in a rich medium. Flow cytometry and pulse amplitude modulation (PAM) were used to determine cell recovery after UV treatment. The recovery of C. calcitrans was complete 9days after treatment. For C. autotrophica, the recovery was noticeable 5days after treatment. P. globosa only recovered if the UV dose did not exceed 7.3×105μWs/cm2. The recovery of the UV-treated cultures introduced to a regrowth medium, compared with the recovery of the irradiated cultures kept in their original environment, had two main characteristics: cell recovery was slower but was more efficient. This pattern of recovery has very important implications for real ballast water management systems because such systems discharge treated water into the environment.
Afficher plus [+] Moins [-]Evaluation of the long-term variability of seawater salinity and temperature in response to natural and anthropogenic stressors in the Arabian Gulf
2013
Elhakeem, Abubaker | Elshorbagy, Walid
Evaluating the long-term variability of the seawater salinity and temperature due to climate change is a limiting economical and operational factor in planning the design of new and expansion of existing desalination plants. This need is amplified in the Arabian Gulf due to the natural arid climate and anthropological stresses related to energy exploration and ongoing major developments. The lack of data in this region further adds additional dimension to the problem. The present work represents a systematic innovative approach to evaluate the anticipated long-term changes in the seawater salinity and temperature under the stresses of projected climate change and massive industrial effluents using statistical correlation and hydrodynamic simulation. The proposed approach employs the direct relation between the net freshwater losses (evaporation) entrenched with the investigated stressors and the mean sea salinity and sea temperature variation of an inverse estuary to formulate the statistical correlation and the hydrodynamic simulation conditions.
Afficher plus [+] Moins [-]An assessment of temporal variations in physicochemical and microbiological properties of barmouths and lagoons in Chennai (Southeast coast of India)
2013
Jayakumar, Renganathan | Steger, Kristin | Chandra, T.S. | Seshadri, Sundaram
Two estuary and two coastal lagoon stations along Chennai, Southeast coast of India were monitored for 1year to study both physicochemical and microbiological properties of the water. Influence of the marine environment over the systems was evident by elevated salinity levels. Considerable concentrations of total heterotrophic bacterial count and fecal bacteria such as total coliforms, fecal coliforms and fecal streptococci were observed throughout the study period which evinced a pattern of anthropogenic activities. Principle component analysis was employed for assessing the overall pattern of variation within the data sets. Climatic variation was highly correlated with changes in water quality, i.e. the Northeast monsoon and Summer had influenced considerably the microbial occurrence as well as the physicochemical parameters such as total suspended solids, chloride, sulphate and salinity. However, the effect of the Southwest monsoon was less prominent than the Northeast monsoon with its heavy rains. As both estuaries revealed elevated concentrations of polluted water, these stations can be used as indicators or alerts for the water quality along the coastal zone of Chennai.
Afficher plus [+] Moins [-]The effect of urban sewage on benthic macrofauna: A multiple spatial scale approach
2013
Souza, F.M. | Brauko, K.M. | Lana, P.C. | Muniz, P. | Camargo, M.G.
We investigated the spatial scales of variation of macrofauna in intertidal flats subjected to different levels of contamination from urban effluents in two areas sampled in the Paranaguá Estuarine Complex. The scales considered were: Conditions; Tidal flats and Plots. Although the numerically dominant taxa showed the greatest variability at a scale of Tidal flats, the variability at the Condition scale was also significant. Tubificinae sp. 1, Laeonereis culveri and Heteromastus sp. were the most abundant organisms in the Contaminated area, while Heleobia australis was most abundant in the Non-contaminated area. Our results, contrary to those frequently observed in the literature, showed that the variability was significant at the scale of hundreds of metres (Tidal flats). At this scale, the intrinsic characteristics of each tidal flat are more important in determining macrofaunal distribution, while the effects of the urban sewage contamination represent the primary forces acting at a greater spatial scale.
Afficher plus [+] Moins [-]Assessment of sediment quality in two important areas of mariculture in the Bohai Sea and the northern Yellow Sea based on acid-volatile sulfide and simultaneously extracted metal results
2013
Gao, Xuelu | Li, Peimiao | Chen, Chen-Tung Arthur
The surface sediments from Laizhou Bay (LB) and the coastal sea around Zhangzi Island (ZI) were analyzed for acid-volatile sulfide (AVS) and simultaneously extracted metals (SEMs) to assess the sediment quality. These two areas, especially LB, are important mariculture bases in China and are significantly affected by the Yellow River. The concentrations of AVS ([AVS]) and SEM ([SEM]) varied in the ranges 0.71–11.03 and 0.10–0.74μmolg−1 dry weight, respectively. [AVS] was generally low in the river outlet area and increased in the seaward direction in LB. [AVS] was significantly and positively correlated with TOC. [SEM] was significantly and positively correlated with TOC, the water content of sediment and the fine sediment fraction and it was significantly and negatively correlated with coarse sediment fraction. The obtained results suggest that the surface sediments of LB and ZI were of high quality and not likely to cause negative effects on their ecosystems.
Afficher plus [+] Moins [-]Carbonaceous aerosols in a wood burning community in rural New Zealand
2013
Ancelet, Travis | Davy, P. K. (Perry K.) | Trompetter, William J. | Markwitz, A. (Andreas) | Weatherburn, David C.
Particulate matter (PM) in Masterton, New Zealand, a rural community with a population of 20 000, was studied during the winter to gain an understanding of the carbonaceous species and their influence on PM concentrations. The average PM10 concentration during the winter was 21.0±14.8 µg m–3, of which 64% was PM2.5. PM2.5 concentrations were found to be the main cause of elevated PM10 concentrations, and were responsible for exceedances of the New Zealand National Environmental Standard for PM10. Carbonaceous species were 47 and 77% of the total PM10 and PM2.5, respectively. Organic carbon (OC) concentrations were always higher than elemental carbon (EC) concentrations. OC and EC concentrations showed excellent correlation with PM2.5 concentrations, suggesting that combustion processes were the dominant source of PM. Stable isotope analysis yielded δ13C values ranging from –24.9 to –27.6‰, which is indicative of wood combustion. Analysis of particle–phase PAHs by thermal desorption GC/MS yielded an average total PAH concentration of 38.9±25.9ng m–3, accounting for 0.3% of the PM2.5. Analysis of all of the results revealed that residential wood burning for domestic heating was the main source of PM pollution in Masterton. The results of this study suggest that a PM10 standard alone, particularly in areas where wood combustion is common, may not be providing an adequate level of protection for the exposed population.
Afficher plus [+] Moins [-]Dividing the common pond: Regionalizing EU ocean governance
2013
Maier, Nina | Markus, Till
EU ocean policies increasingly incorporate regional measures. Under the long standing Common Fisheries Policy, such measures aim at improving and reforming existing policy, either by taking into account region specific social or ecologic requirements or by establishing procedures and institutions to achieve a regional fit. By contrast, the EU’s emerging integrated Marine Environmental Policy was designed to draw heavily on regional procedural and institutional mechanisms from the outset. The developing regional measures raise the question whether they contribute to improving institutional structures governing the use and conservation of EU waters. This article analyzes the existing and future regional measures of the two policies and their varying purposes and scopes. It develops a typology for categorizing the regional aspects and examines the effects of regional measures on EU institutions and the theoretical EU integration debate.
Afficher plus [+] Moins [-]Sources, trends and ecotoxicological risks of PAH pollution in surface sediments from the northern Adriatic Sea (Croatia)
2013
Traven, Luka
In this study, the levels, sources and historical trends (2007–2012) of PAH pollution in surface sediments in the northern Adriatic Sea (Croatia) have been assessed. In addition, ecotoxicological risks have been estimated by evaluating the PAH dataset against Sediment Quality Guidelines (SQGs). The results indicate that PAH in surface sediments are of pyrolitic origin with no clear positive or negative trend in PAH concentration over the investigated period. Evaluations against SQG and mSQGq indicate that surface sediments at all sampling sites have a low to medium ecotoxicological risk. In order to improve trend analysis and characterization of PAH pollution in surface sediments in this region an increase in spatial resolution of sampling points is recommended.
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