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Hg bioaccumulation in marine copepods around hydrothermal vents and the adjacent marine environment in northeastern Taiwan النص الكامل
2013
The Hg concentration in seawater and copepod samples collected from the area around hydrothermal vents at Kueishan Island and the adjacent marine environment in northeastern Taiwan were analyzed to study Hg bioaccumulation in copepods living in polluted and clean marine environments. The seawater collected from the hydrothermal vent area had an extremely high concentration of dissolved Hg, 50.6–256ngl−1. There was slightly higher Hg content in the copepods, 0.08–0.88μgg−1. The dissolved Hg concentration in the hydrothermal vent seawater was two to three orders of magnitude higher than that in the adjacent environment. The bioconcentration factor of the studied copepods ranged within 103–106, and showed higher dissolved concentration as the bioconcentration factor was lower. A substantial abundance, but with less copepod diversity was recorded in the seawater around the hydrothermal vent area. Temora turbinata was the species of opportunity under the hydrothermal vent influence.
اظهر المزيد [+] اقل [-]Modeling jellyfish Pelagia noctiluca transport and stranding in the Ligurian Sea النص الكامل
2013
Jellyfish blooms are generally attributed to a biological response to the environment, neglecting the role of transport patterns in redistributing existing populations. Here, we use high-resolution (1.25km) ocean modeling to examine the role of transport in the onshore arrival and abundance of the pelagic stinging jellyfish Pelagia noctiluca on the Ligurian Sea coast. Jellyfish are modeled as Lagrangian particles with a 0–300-m diel vertical migration typical of P. noctiluca. Over the course of a year, onshore arrivals are not restricted to the summer. Arrivals are concentrated at capes, but abundance can reach maxima in bays and in the lee of capes. Two factors impact jellyfish arrivals at the coast: the position of the Northern Current and the wind. A comparison of summer 2006 and available onshore jellyfish observations suggests a correct capture of the main stranding events by the model. These results have implications for understanding long-term fluctuations.
اظهر المزيد [+] اقل [-]Baseline occurrence of organochlorine pesticides and other xenobiotics in the marine environment: Caribbean and Pacific collections النص الكامل
2013
Menzies, Robert | Soares Quinete, Natalia | Gardinali, Piero | Seba, Douglas
This ongoing survey reports the levels of persistent organic pollutants (POPs) in sea surface slicks collected on a global circumnavigation. Hydrophobic xenobiotic compounds such as POPs are known to accumulate on the sea surface in slicks at concentrations many fold greater than the underlying water column, raising concerns about the ecological impacts due to the high biological activity associated with this zone. Six different categories of POPs were reported: chlorobenzenes, hexachlorocyclohexanes, chlordane related compounds, organochlorine pesticides and other cyclodiene pesticides, DDTs and metabolites, and polychlorinated biphenyls. Concentrations ranged from <1ngL−1 to 18.45μgL−1. Ranking analysis indicates an independence of detected concentrations for each class of compounds and their geographical locations. Although concentrations observed were normally low and below commonly accepted toxic levels to animals and humans, they fall within the effective range of concentrations of many hormones and neurotransmitters, thus could potentially act as endocrine disrupters.
اظهر المزيد [+] اقل [-]Assessing the damage caused by Deepwater Horizon: Not just another Exxon Valdez النص الكامل
2013
Perrons, Robert K.
In light of the high stakes of the Deepwater Horizon civil trial and the important precedent-setting role that the case will have on the assessment of future marine disasters, the methodologies underpinning the calculations of damage on both sides will be subjected to considerable scrutiny. Despite the importance of the case, however, there seems to be a pronounced lack of convergence about it in the academic literature. Contributions from scientific journals frequently make comparisons to the Ixtoc I oil spill off the coast of Mexico in 1979; the legal literature, by stark contrast, seems to be much more focused on the Exxon Valdez spill that occurred off the shores of Alaska in 1989. This paper accordingly calls for a more thorough consideration of other analogs beyond the Exxon Valdez spill—most notably, the Ixtoc I incident—in arriving at an assessment of the damage caused by the Deepwater Horizon disaster.
اظهر المزيد [+] اقل [-]Dissolved oxygen in the rehabilitation phase of an estuary: Influence of sewage pollution abatement and hydro-climatic factors النص الكامل
2013
Villate, Fernando | Iriarte, Arantza | Uriarte, Ibon | Intxausti, Lander | de la Sota, Alejandro
Seasonal and inter-annual variations of dissolved oxygen (DO) along the estuary of Bilbao were investigated from 1998 to 2008, during its rehabilitation phase from pollution, to determine whether anthropogenic or natural forcings or both govern DO dynamics and hypoxia. Both seasonal and inter-annual variations of DO were best explained by hydro-climatic factors, sewage pollution and phytoplankton dynamics in the inner, intermediate and outer estuary respectively. The most remarkable intra-decadal improvement in DO occurred in the halocline layer of the intermediate estuary, where the factor that best explained these changes was sewage pollution abatement. However, in the estuarine hotspot for hypoxia, i.e. inner estuary bottom waters, no parallel response to sewage pollution abatement was observed and hydro-climatic factors were the main drivers of inter-annual DO variations. Differences in the degree of stratification and flushing accounted for this differential response of DO to anthropogenic and climate-related forcings at both axial and vertical scales.
اظهر المزيد [+] اقل [-]Source apportionment of polycyclic aromatic hydrocarbons in surface sediment of mud areas in the East China Sea using diagnostic ratios and factor analysis النص الكامل
2013
Deng, Wei | Li, Xian'guo | Li, Sheng Yong | Ma, Yan Yan | Zhang, Da Hai
Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs) have been quantified for surface sediments collected from the East China Sea (ECS). Our results showed that relatively high levels of PAHs and AHs occurred in both the inner and outer mud areas, while their concentrations at the control site were much lower. AHs for all samples were dominated by the unresolved complex mixture (UCM). Results from diagnostic ratios revealed that sedimentary PAHs were mainly originated from mixed combustion residues of biomass, coal, and petroleum. Combustion residues of petroleum and oil were responsible for the presence of high AHs concentrations. We also conducted factor analysis (FA) to further characterize the PAH and AH sources. Four factors were identified based on the loading of components and attributed to coal and wood combustion (Factor 1), traffic-related sources (Factor 2), petrogenic source (Factor 3) and natural gas combustion (Factor 4).
اظهر المزيد [+] اقل [-]Perfluorinated compounds: Levels, trophic web enrichments and human dietary intakes in transitional water ecosystems النص الكامل
2013
Renzi, Monia | Guerranti, Cristiana | Giovani, Andrea | Perra, Guido | Focardi, Silvano E.
The results of a study on levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), analyzed in terms of HPLC-ESI-MS in water, sediment, macrophyte, bivalve, crustacean and fish samples, are reported here. The aim of the research is to define, for the first time, PFOA/S levels in a heavily human-stressed transitional water ecosystem (Orbetello lagoon, Italy) and evaluate trophic web enrichments and human dietary intakes. The results obtained show that: (i) levels significantly higher than those reported in the literature were found in mussels, clams and crabs; (ii) the river is a significant pollution source; (iii) although absolute levels are relatively low, macroalgae proliferation contributes to redistribute pollutants from river-affected areas throughout the entire lagoon basin; (iv) to the best of our current knowledge, water-filtering species considered in this study are the most exposed to PFOA/S pollution; (v) human daily dietary intakes of PFOA/S through Slow Food-endorsed product consumption are below maximum tolerable levels suggested by the EFSA.
اظهر المزيد [+] اقل [-]Use of skin and blubber tissues of small cetaceans to assess the trace element content of internal organs النص الكامل
2013
Aubail, A. | Méndez-Fernandez, P. | Bustamante, P. | Churlaud, C. | Ferreira, M. | Vingada, J.V. | Caurant, F.
Use of skin and blubber tissues of small cetaceans to assess the trace element content of internal organs النص الكامل
2013
Aubail, A. | Méndez-Fernandez, P. | Bustamante, P. | Churlaud, C. | Ferreira, M. | Vingada, J.V. | Caurant, F.
In order to evaluate the use of biopsy samples as non-destructive tool for assessing trace element concentrations in small cetaceans, the concentrations of 14 trace elements were determined in skin, blubber, liver and kidneys of four species of small cetaceans (i.e. common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, bottlenose dolphin Tursiops truncatus and striped dolphin Stenella coeruleolba), stranded and/or by-caught along the NE Atlantic Ocean coast between 2001 and 2008. Only Cu, Fe, Hg, Mn, Ni and Zn were above the detection limit of the instruments and showed recoveries satisfactory enough to be interpreted. Among these trace elements, Hg was the only one showing a significant correlation between concentrations in and those in liver and kidneys. In consequence skin and blubber can only be used as non-invasive monitoring tissues to investigate Hg bioaccumulation in internal tissues for cetacean populations.
اظهر المزيد [+] اقل [-]Use of skin and blubber tissues of small cetaceans to assess the trace element content of internal organs النص الكامل
2013
Aubail, A. | Méndez-Fernandez, P. | Bustamante, P. | Churlaud, C. | Ferreira, M. | Vingada, J. V. | Caurant, F.
In order to evaluate the use of biopsy samples as non-destructive tool for assessing trace element concentrations in small cetaceans, the concentrations of 14 trace elements were determined in skin, blubber, liver and kidneys of four species of small cetaceans (i.e. common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, bottlenose dolphin Tursiops truncatus and striped dolphin Stenella coeruleolba), stranded and/or by-caught along the NE Atlantic Ocean coast between 2001 and 2008. Only Cu, Fe, Hg, Mn, Ni and Zn were above the detection limit of the instruments and showed recoveries satisfactory enough to be interpreted. Among these trace elements, Hg was the only one showing a significant correlation between concentrations in and those in liver and kidneys. In consequence skin and blubber can only be used as non-invasive monitoring tissues to investigate Hg bioaccumulation in internal tissues for cetacean populations. | We greatly acknowledge the stranding networks from France (Observatoire PELAGIS), Spain (CEMMA), and Portugal (SPVS) for providing us cetacean samples. We also thank A. F. Guerra and F. Read from the Instituto de Investigaciones Marinas (C.S.I.C) in Vigo, Spain, and W. Dabin from the Observatoire PELAGIS in La Rochelle, France, for the age determination of the individuals. We also wish to thank C. Pignon-Mussaud from the Cellule Géomatique (UMR LIENSs) for providing the map of the study area and M. Kalombo from the Centre Commun d’Analyses (Fédération de Recherche en Environnement pour le Développement Durable FR 3097 CNRS-IFREMER-Université de La Rochelle) for running part of the trace element analyses. This work has been funded by the CPER 13 (Contrat de Plan Etat Région) through a post-doctoral grant to AA and PMF acknowledges support from the Portuguese Foundation for Science and Technology of the Government of Portugal (SFRH/BD/36766/2007). | published
اظهر المزيد [+] اقل [-]Optimization of nutrient component for diesel oil degradation by Acinetobacter beijerinckii ZRS النص الكامل
2013
Huang, Lei | Xie, Jing | Lv, Bo-yi | Shi, Xiao-feng | Li, G. Q. | Liang, Feng-lai | Lian, Jing-yan
A new bacterial strain that is capable of using diesel as the sole carbon source was isolated from the petroleum-contaminated soil of Xinjiang oil field, Northwest China. This bacterium was identified on the basis of its morphological and physiological characteristics and 16S rRNA gene sequence analysis, and it showed the greatest similarity with Acinetobacter beijerinckii 302-PWB-OH1 (99.86%). In order to enhance degradation efficiency, single-factor experiments and response surface methodology (RSM) were employed to optimize the nutrients used in artificial seawater. The results of this study revealed that 2.05gL−1 (NH4)2SO4, 1.46gL−1 Na2HPO4, and 14mgL−1 yeast extract in artificial seawater resulted in increasing the diesel degradation rate of the bacterial strain from 20.87% to 80.40% within 7days. The actual experimental results were in agreement with the prediction.
اظهر المزيد [+] اقل [-]Acid-volatile sulfide and simultaneously extracted metals in surface sediments of the southwestern coastal Laizhou Bay, Bohai Sea: Concentrations, spatial distributions and the indication of heavy metal pollution status النص الكامل
2013
Zhuang, Wen | Gao, Xuelu
Surface sediments were collected from the coastal waters of southwestern Laizhou Bay and the rivers it connects with during summer and autumn 2012. The acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) were measured to assess the sediment quality. The results showed that not all sediments with [SEM]–[AVS]>0 were capable of causing toxicity because the organic carbon is also an important metal-binding phase in sediments. Suppose the sediments had not been disturbed and the criteria of US Environmental Protection Agency had been followed, heavy metals in this area had no adverse biological effects in both seasons except for few riverine samples. The major ingredient of SEM was Zn, whereas the contribution of Cd – the most toxic metal studied – to SEM was <1%. The distributions of AVS and SEM in riverine sediments were more easily affected by anthropogenic activity compared with those in marine sediments.
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