خيارات البحث
النتائج 671 - 680 من 1,310
Occurrence of priority pollutants in WWTP effluents and Mediterranean coastal waters of Spain النص الكامل
2011
Martí, N. | Aguado, D. | Segovia-Martínez, L. | Bouzas, A. | Seco, A.
A comprehensive study aimed at evaluating the occurrence, significance of concentrations and spatial distribution of priority pollutants (PPs) along the Comunidad Valenciana coastal waters (Spain) was carried out in order to fulfil the European Water Framework Directive (WFD). Additionally, PP concentrations were also analysed in the effluent of 28 WWTPs distributed along the studied area. In coastal waters 36 organic pollutants of the 71 analysed, including 26 PPs were detected although many of them with low frequency of occurrence. Only 13 compounds, which belong to four different classes (VOCs, organochlorinated pesticides, phthalates and tributyltin compounds (TBT)) showed a frequency of occurrence above 20% in coastal waters. In the results obtained until now, octylphenol, pentachlorobenzene, DEHP and TBT exceeded the annual average concentration (EQS-AAC), and only TBT surpassed the maximum allowable concentration (EQS-MAC). The most frequent contaminants determined in coastal waters were also present in WWTP effluents.
اظهر المزيد [+] اقل [-]Bearing the burden of boat harbours: Heavy contaminant and fouling loads in a native habitat-forming alga النص الكامل
2011
Johnston, E.L. | Marzinelli, E.M. | Wood, C.A. | Speranza, D. | Bishop, J.D.D.
Boat harbours are an increasingly common form of artificial habitat. This paper presents a comparative study of contaminants and foulers of a habitat-forming native kelp (Saccharina latissima) in four marinas and four reference locations along the south-west coast of the UK. Fouling of algal laminae was light (<2% cover) in reference locations, while epibiota cover ranged from 25% to 80% of laminae in marinas. Metals associated with antifouling paints were up to six times more concentrated in algal tissues from marinas than from the reference locations. Marinas also carried the greatest cover and diversity of non-indigenous epibiota on the kelp laminae. This indicates not only a potential stress to kelps in these environments, but also the possibility that detached laminae will act as vectors for the dispersal of non-indigenous species. The development of boat harbours creates habitats that are high risk source localities for pollution-tolerant fouling organisms.
اظهر المزيد [+] اقل [-]A simple osmium post-fixation paraffin-embedment technique to identify lipid accumulation in fish liver using medaka (Oryziaslatipes) eggs and eleutheroembryos as lipid rich models النص الكامل
2011
Mondon, J.A. | Howitt, J. | Tosiano, M. | Kwok, K.W.H. | Hinton, D.E.
Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.
اظهر المزيد [+] اقل [-]Risk mapping for sensitive species to underwater anthropogenic sound emissions: Model development and validation in two Mediterranean areas النص الكامل
2011
Azzellino, A. | Lanfredi, C. | D’Amico, A. | Pavan, G. | Podestà, M. | Haun, J.
Recent observations of cetacean mass strandings, coincident with anthropogenic sounds emissions, have raised concerns on the potential environmental impact of underwater noise. Cuvier’s beaked whale (Ziphius cavirostris) was reported in all the cited stranding events. Within the NATO Marine Mammal Risk Mitigation project (MMRM), multiple interdisciplinary sea trials have been conducted in the Mediterranean Sea with the objective of developing tools and procedures to mitigate the impact of underwater sound emissions. During these cruises, visual observations, passive acoustic detections and environmental data were collected. The aim of this study was to evaluate “a priori” predictions of Cuvier’s beaked whale presence in the Alboran Sea, using models developed in the Ligurian Sea that employ bathymetric and chlorophyll features as predictors. The accuracy of these predictions was found adequate and elements are given to account for the uncertainties associated to the use of models developed in areas different from their calibration site.
اظهر المزيد [+] اقل [-]Navy sonar, cetaceans and the US Supreme Court: A review of cetacean mitigation and litigation in the US النص الكامل
2011
Zirbel, K. | Balint, P. | Parsons, E.C.M.
One source of anthropogenic noise in the oceans which has attracted much concern is naval sonar. As a result of possible impacts of such sonar, several environmental NGOs have pursued legal cases in the United States criticizing environmental assessments conducted prior to exercises and proposed mitigation measures. Cases have been brought using the US National Environmental Protection Act, Marine Mammal Protection Act, Endangered Species Act, Coastal Zone Management Act and other statutes. This paper reviews the chronology and results of these various cases. During the G.W. Bush presidential administration, the legal battle went to the US Supreme Court in the case Winter vs. Natural Resources Defense Council. This case however, did not address the potential impacts of sonar on cetaceans or the effectiveness of mitigation measures. During the Obama administration, mitigation measures for naval exercises have been revised, and working groups planned, in an attempt to resolve conflict between parties.
اظهر المزيد [+] اقل [-]Hollow fiber liquid-phase microextraction as clean-up step for the determination of organophosphorus pesticides residues in fish tissue by gas chromatography coupled with mass spectrometry النص الكامل
2011
Sun, Xiaojin | Zhu, Fang | Xi, Jiabin | Lu, Tongbu | Liu, Hong | Tong, Yexiang | Ouyang, Gangfeng
Hollow fiber liquid-phase microextraction (HF-LPME) technique was used as a clean-up procedure for the determination of organophosphorus pesticides (OPPs) in fish tissue. In this study, eight OPPs were first extracted with acetone from fish sample, the organic extract after rotatory evaporation was then redissolved with water–methanol (95:5, v/v) solution, followed by polyvinylidene difluoride (PVDF) HF-LPME. Experimental HF-LPME and other sample preparation conditions were carefully investigated and optimized. Under the optimum conditions, good linearity were observed in the range of 20–500ng/g, limits of detections (LODs) were in the range of 2.1–4.5ng/g. The repeatability and recovery of the method also showed satisfactory results. Compared with traditional sample preparation method for the determination of OPPs in fish tissue, the method developed in this study eliminated the solid phase extraction (SPE) step, simplified the sample preparation procedure and lowered the cost of analysis.
اظهر المزيد [+] اقل [-]Bioaccumulation of metals by Fucus ceranoides in estuaries of South West England النص الكامل
2011
Varmā, Raṇajīta | Turner, Andrew | Brown, M. T.
Fucus ceranoides tolerates abiotic conditions encountered across the full range of estuarine salinities. We examined the bioaccumulation of metals in individuals and metal concentrations in accompanying sediment samples collected at different locations along estuaries of South West England. Intra- and inter-estuarine variations in metal accumulation by F. ceranoides, after correction for particulate contamination using Fe as a proxy, were attributed to variations in the availabilities and concentrations of aqueous metals. Greatest accumulation was observed in estuaries that remain most heavily impacted by historical mining activities and for metals that were mobilised to the greatest extent during these operations (As, Cu, Sn, Zn). Arsenic concentrations displayed a seaward increase in estuaries in which multiple samples were taken, whereas Cd concentrations were always greatest in samples collected from the most landward locations. Ongoing research aims to better understand the mechanisms and kinetics of metal interactions with F. ceranoides and their dependence on salinity.
اظهر المزيد [+] اقل [-]Biological neutralization of chlor-alkali industry wastewater النص الكامل
2011
Jain, Rakeshkumar M. | Mody, Kalpana H. | Keshri, Jitendra | Jha, Bhavanath
The present work reports biological neutralization of chlor-alkali industrial effluent by an alkaliphilic bacterium, isolated from the Gujarat coast, which was identified as Enterococcus faecium strain R-5 on the basis of morphological, biochemical and partial 16S rRNA gene sequencing. The isolate was capable of bringing down the pH of waste water from 12.0 to 7.0 within 3h in the presence of carbon and nitrogen sources, with simultaneous reduction in total dissolved solutes (TDS) up to 19–22%. This bacterium produced carboxylic acid, as revealed by FT-IR analysis, which facilitated neutralization of alkaline effluent. The presence of unconventional raw materials viz. Madhuca indica flowers or sugar cane bagasse as carbon and nitrogen sources could effectively neutralize alkaline effluent and thus making the bioremediation process economically viable. The time required for neutralization varied with size of inoculum. To the best of our knowledge, this is the first report on biological neutralization of a chlor-alkali industrial effluent.
اظهر المزيد [+] اقل [-]The effectiveness of double hulls in reducing vessel-accident oil spillage النص الكامل
2011
Yip, Tsz Leung | Talley, Wayne Kenneth | Jin, Di
While much work has been done in investigating determinants of oil spillage attributed to vessel accidents, little research has been conducted on the effectiveness of ship hull design in reducing marine pollution. This paper addresses whether the double-hull requirement reduces vessel-accident oil spillage. The volume of oil spillage due to oil-cargo vessel accidents was investigated using tobit regressions and an empirical data set of individual vessel accident pollution incidents investigated by the US Coast Guard from 2001 to 2008. The results indicate that the double hull design on average reduces the size of oil spills by 20% and 62% in tank barge and tanker ship accidents, respectively.
اظهر المزيد [+] اقل [-]Enormous PCBs increase in oysters from the coast of Guangdong, China النص الكامل
2011
Gan, Ju-Li | Jia, Xiao-Ping | Jia, Ting | Lin, Qin | Cai, Wen-Gui
PCBs equivalent to Aroclor 1242 and 1254 in soft tissues of oysters Crassostrea rivularis from the Guangdong coast, China, were measured using a GC-ECD. PCB concentrations (ngg⁻¹d.w.) ranged from 30 to 2040 with an average of 315 in 2003–2007, and 0.35–1.43 with an average of 0.56 in 1989–1991. Annual averages were 0.61, 0.65, 313, 290 and 342ngg⁻¹, respectively in 1989, 1991, 2003, 2006 and 2007. In east Guangdong, the Pearl River Estuary, and west Guangdong, regional means were 444, 273, 194ngg⁻¹, respectively in 2003–2007, and 0.43, 0.78, 0.38ngg⁻¹, respectively in 1989–1991, indicating PCB levels in oysters have risen greatly by ratios of 350–1032 compared with earlier data. PCB sources may derive from older transformers, printing materials and pressworks. Fortunately, current residual PCBs in the oysters were 0.004–0.253mgkg⁻¹ (w.w.), still below hygienic criteria of China and developed countries.
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