خيارات البحث
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Trace metal contamination of Beaufort’s Dyke, North Channel, Irish Sea: A legacy of ordnance disposal النص الكامل
2011
Callaway, Alexander | Quinn, Rory | Brown, Craig J. | Service, Matthew | Benetti, Sara
Beaufort’s Dyke is a disused ordnance disposal ground within the North Channel of the Irish Sea. Over 1 million tonnes of ordnance were disposed of in the dyke over a 40year period representing a substantial volume of trace metal pollutants introduced to the seabed. Utilising particle transport modelling software we simulated the potential transport of metal particles from Beaufort’s Dyke over a 3month period. This demonstrated that Beaufort’s Dyke has the potential to act as a source for trace metal contamination to areas beyond the submarine valley. Trace metal analysis of sediments from the Dyke and surrounding National Marine Monitoring Programme areas demonstrate that the Dyke is not the most contaminated site in the region. Particle transport modelling enables the transport pathways of trace metal contaminants to be predicted. Implementation of the technique in other munitions disposal grounds will provide valuable information for the selection of monitoring stations.
اظهر المزيد [+] اقل [-]Differential presence of anthropogenic compounds dissolved in the marine waters of Puget Sound, WA and Barkley Sound, BC النص الكامل
2011
Keil, Richard | Salemme, Keri | Forrest, Brittany | Neibauer, Jaqui | Logsdon, Miles
Organic compounds were evaluated in March 2010 at 22 stations in Barkley Sound, Vancouver Island Canada and at 66 locations in Puget Sound. Of 37 compounds, 15 were xenobiotics, 8 were determined to have an anthropogenic imprint over natural sources, and 13 were presumed to be of natural or mixed origin. The three most frequently detected compounds were salicyclic acid, vanillin and thymol. The three most abundant compounds were diethylhexyl phthalate (DEHP), ethyl vanillin and benzaldehyde (∼600ngL⁻¹ on average). Concentrations of xenobiotics were 10–100 times higher in Puget Sound relative to Barkley Sound. Three compound couplets are used to illustrate the influence of human activity on marine waters; vanillin and ethyl vanillin, salicylic acid and acetylsalicylic acid, and cinnamaldehyde and cinnamic acid. Ratios indicate that anthropogenic activities are the predominant source of these chemicals in Puget Sound.
اظهر المزيد [+] اقل [-]Comparison of metal accumulation between ‘Artificial Mussel’ and natural mussels (Mytilus galloprovincialis) in marine environments النص الكامل
2011
Gonzalez-Rey, M. | Lau, T.C. | Gomes, T. | Maria, V.L. | Bebianno, M.J. | Wu, R.
Comparison of metal accumulation between ‘Artificial Mussel’ and natural mussels (Mytilus galloprovincialis) in marine environments النص الكامل
2011
Gonzalez-Rey, M. | Lau, T.C. | Gomes, T. | Maria, V.L. | Bebianno, M.J. | Wu, R.
The passive sampler called ‘Artificial Mussel’ (AM) developed by Wu et al. (2007) can provide a time-integrated estimate of metal concentrations in the marine environment, and offers a potential device to assess and compare metal concentration in different marine environments worldwide. The aim of this study was to compare metal accumulation on AM and natural mussel Mytilus galloprovincialis at three sites with different metal loads along the Portuguese coast for four months. M. galloprovincialis were placed in cages alongside AMs at each site. Samples were collected monthly and Cd, Cr, Cu, Pb, and Zn concentrations in whole soft tissues and AMs compared. For both Cu and Cd, the results were similar between AMs and natural mussels. Higher concentrations of Zn were observed in natural mussels, whereas the inverse was shown for Pb (about 10-fold higher). Our results showed that AMs are promising tools for assessing metal concentrations in marine environments.
اظهر المزيد [+] اقل [-]Comparison of metal accumulation between ‘Artificial Mussel’ and natural mussels (Mytilus galloprovincialis) in marine environments النص الكامل
2011
Gonzalez-Rey, Maria | Lau, T. C. | Gomes, Tânia | Maria, Vera L. | Bebianno, Maria João | Wu, R.
The passive sampler called 'Artificial Mussel' (AM) developed by Wu et al. (2007) can provide a time-integrated estimate of metal concentrations in the marine environment, and offers a potential device to assess and compare metal concentration in different marine environments worldwide. The aim of this study was to compare metal accumulation on AM and natural mussel Mytilus galloprovincialis at three sites with different metal loads along the Portuguese coast for four months. M. galloprovincialis were placed in cages alongside AMs at each site. Samples were collected monthly and Cd, Cr, Cu, Pb, and Zn concentrations in whole soft tissues and AMs compared. For both Cu and Cd, the results were similar between AMs and natural mussels. Higher concentrations of Zn were observed in natural mussels, whereas the inverse was shown for Pb (about 10-fold higher). Our results showed that AMs are promising tools for assessing metal concentrations in marine environments. | Hong Kong Research Grants Council - AoE/P-04/2004, The Centre of Marine and Environmental Research (Portugal) and Foundation of Science and Technology (FCT) (Portugal) | info:eu-repo/semantics/publishedVersion
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.
اظهر المزيد [+] اقل [-]Spatial patterns of chemical contamination (metals, PAHs, PCBs, PCDDs/PCDFS) in sediments of a non-industrialized but densely populated coral atoll/small island state (Bermuda) النص الكامل
2011
Jones, Ross J.
There is a recognized dearth of standard environmental quality data in the wider Caribbean area, especially on coral atolls/small island states. Extensive surveys of sediment contamination (n=109 samples) in Bermuda revealed a wide spectrum of environmental quality. Zinc and especially copper levels were elevated at some locations, associated with boating (antifouling paints and boatyard discharges). Mercury contamination was surprisingly prevalent, with total levels as high as 12mgkg⁻¹DW, although methyl mercury levels were quite low. PAH, PCB and PCDD/PCDF contamination was detected a several hotspots associated with road run-off, a marine landfill, and a former US Naval annexe. NOAA sediment quality guidelines were exceeded at several locations, indicating biological effects are possible, or at some locations probable. Overall, and despite lack of industrialization, anthropogenic chemicals in sediments of the atoll presented a risk to benthic biodiversity at a number of hotspots suggesting a need for sediment management strategies.
اظهر المزيد [+] اقل [-]Large-scale oil-in-ice experiment in the Barents Sea: Monitoring of oil in water and MetOcean interactions النص الكامل
2011
Faksness, Liv-Guri | Brandvik, Per Johan | Daae, Ragnhild L. | Leirvik, Frode | Børseth, Jan Fredrik
A large-scale field experiment took place in the marginal ice zone in the Barents Sea in May 2009. Fresh oil (7000L) was released uncontained between the ice floes to study oil weathering and spreading in ice and surface water. A detailed monitoring of oil-in-water and ice interactions was performed throughout the six-day experiment. In addition, meteorological and oceanographic data were recorded for monitoring of the wind speed and direction, air temperature, currents and ice floe movements. The monitoring showed low concentrations of dissolved hydrocarbons and the predicted acute toxicity indicated that the acute toxicity was low. The ice field drifted nearly 80km during the experimental period, and although the oil drifted with the ice, it remained contained between the ice floes.
اظهر المزيد [+] اقل [-]Gilthead seabream (Sparus aurata) carrying antibiotic resistant enterococci. A potential bioindicator of marine contamination? النص الكامل
2011
Barros, Joana | Igrejas, Gilberto | Andrade, Margarida | Radhouani, Hajer | López, Maria | Torres, Carmen | Poeta, Patrícia
Antibiotic resistance in bacteria is a growing problem that is not only restricted to the clinical setting but also to other environments such as marine species that harbor antibiotic resistant bacteria and therefore may serve as reservoirs for antibiotic-resistance genetic determinants. The aim of this study was to evaluate antibiotic resistance phenotypes in enterococci isolated from fecal samples of gilthead seabream and the associated mechanisms of resistance. A collection of 118 samples were analyzed and 73 enterococci were recovered. The strains showed high percentages of resistance to erythromycin and tetracycline (58.9% and 17.8%, respectively). Lower level of resistance (<13%) was detected for quinupristin–dalfopristin, ampicillin, high-level-gentamicin, high-level-streptomycin, high-level-kanamycin, ciprofloxacin and chloramphenicol. The erm(B), tet(L) or tet(M), aac(6′)-aph(2″) and aph(3′)-IIIa genes were shown in isolates resistant to erythromycin, tetracycline, high-level gentamicin and high-level kanamycin, respectively. Antibiotic resistance in natural microbiota is becoming a concern of human and environmental health.
اظهر المزيد [+] اقل [-]Heavy metal concentrations and biomarkers of oxidative stress in native mussels (Mytilus edulis chilensis) from Beagle Channel coast (Tierra del Fuego, Argentina) النص الكامل
2011
Duarte, Claudia A. | Giarratano, Erica | Amin, Oscar A. | Comoglio, Laura I.
The aim of this study was to evaluate the usefulness of oxidative stress biomarkers of pollution in native mussels Mytilus edulis chilensis from the Beagle Channel. Spatial and seasonal variations of catalase, glutathione-S-transferase and lipid peroxidation in gills and digestive gland were analyzed in relation to environmental parameters, heavy metals in sediment and in tissue. Four sites with anthropogenic impact and a control site were selected and monitored during the four seasons of 2007. We found significant differences among sites in concentrations of dissolved nutrients and heavy metals in sediments, with the highest values recorded at sites with anthropogenic pressure. Different patterns were observed between concentrations of metals in tissues and in sediments suggesting differences in bioavailability. There were also significant differences in biomarker responses among sites, despite the strong seasonal variability. Our results showed relatively moderate levels of pollution in the study area as a result of urban influences.
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 [-]Vessel traffic patterns in the Port of Kaohsiung and the management implications for preventing the introduction of non-indigenous aquatic species النص الكامل
2011
Liu, Dagang | Tsai, Tzung-Kuen
Data on shipping traffic in one of the busiest seaports in the world, the Port of Kaohsiung, were analyzed to evaluate the implications for ballast water management. Results show that 67% of the arriving vessels were registered to a flag of convenience, which typically have a lower degree of environmental records. The top five donor countries historically suffer from harmful algal bloom problems. The short journey and busy trading between these countries and Taiwan lead to a higher risk of inoculation. In addition, only 1.4% of all vessels visited more than once every year during the 9-year span, indicating that the port authority encounters many new vessels each year. These findings could influence the design and application of ballast water management strategies as well as highlight the challenges in their implementation. We suggest that an analysis of vessel traffic patterns should be coupled with other useful vessel information to make risk assessment successful.
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