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Результаты 1241-1250 из 3,991
Young of the year bluefish (Pomatomus saltatrix) as a bioindicator of estuarine health: Establishing a new baseline for persistent organic pollutants after Hurricane Sandy for selected estuaries in New Jersey and New York
2016
Smalling, Kelly L. | Deshpande, Ashok D. | Blazer, Vicki S. | Dockum, Bruce W. | Timmons, DeMond | Sharack, Beth L. | Baker, Ronald J. | Samson, Jennifer | Reilly, Timothy J.
Atlantic coastal bays of the US are essential habitat for young of year bluefish (Pomatomus saltatrix). Their residence in these estuaries during critical life stages, high lipid content, and piscivory make bluefish an ideal bioindicator species for evaluating estuarine health. Individual whole fish from four estuaries impacted by Hurricane Sandy were collected in August 2013, analyzed for a suite of persistent organic pollutants (POPs) including polychlorinated biphenyls, polybrominated diphenyl ethers and organochlorine pesticides and evaluated using health metrics. Concentrations in whole bluefish differed by estuary; however, concentrations for many POPs decreased or were similar to those observed prior to the hurricane. Prevalence of the ectoparasitic gill isopod (Lironeca ovalis) varied by estuary and no relationships between contaminants and lesions were observed. Bluefish should be considered for monitoring programs and, if sampled frequently, could be an effective bioindicator of incremental and episodic changes in contaminants within aquatic food webs.
Показать больше [+] Меньше [-]Polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the intertidal zone of Bohai Bay, Northeast China: Spatial distribution, composition, sources and ecological risk assessment
2016
Qian, Xiao | Liang, Baocui | Fu, Wenjun | Liu, Xinhui | Cui, Baoshan
Polycyclic aromatic hydrocarbons (PAHs) can enter intertidal zones by various pathways and pose potential threats to intertidal ecosystem. We investigated distribution, composition, sources and risk assessment of PAHs in intertidal surface sediments of Bohai Bay. Total PAH concentrations ranged from 37.2ng·g−1 to 206.6ng·g−1, among which high values occurred near Nanpaishuihe River Estuary and Haihe River Estuary. The composition patterns of PAHs were characterized by the predominance of 3-ring and 4-ring PAHs, and acenaphthylene was the most dominant component. Diagnostic ratios and principal component analysis have confirmed that PAH contaminants originated from mixed sources, and the major was local combustion. The mean benzo(a)pyrene equivalent concentration of total PAHs in intertidal sediments was 15.67ng·g−1, which was mostly contributed by seven carcinogenic PAHs. According to ecological risk assessment, negative effects related to acenaphthylene would occur occasionally in partial survey regions of the study.
Показать больше [+] Меньше [-]Metabolic responses of clams, Ruditapes decussatus and Ruditapes philippinarum, to short-term exposure to lead and zinc
2016
Aru, Violetta | Sarais, Giorgia | Savorani, Francesco | Engelsen, S. B. (Søren Balling) | Cesare Marincola, Flaminia
This study investigated the effects of 48h heavy metal exposure upon the metabolic profiles of Ruditapes decussatus and Ruditapes philippinarum using 1H NMR metabolomics. Both species were exposed to increasing concentrations of lead nitrate (10, 40, 60 and 100μg/L) and zinc chloride (20, 50, 100 and 150μg/L), under laboratory conditions. ICP-OES analysis was further performed on the clams' samples in order to verify the occurrence of heavy metal bioaccumulation. With respect to the controls, the metabolic profiles of treated R. decussatus exhibited higher levels of organic osmolytes and lower contents of free amino acids. An opposite behavior was shown by R. philippinarum. In terms of heavy metal, the exposure effects were more evident in the case of Pb rather than Zn. These findings show that NMR-based metabolomics has the required sensitivity and specificity for the identification of metabolites that can act as sensitive indicators of contaminant-induced stress.
Показать больше [+] Меньше [-]Fine-scale detection of pollutants by a benthic marine jellyfish
2016
Epstein, Hannah E. | Templeman, Michelle A. | Kingsford, Michael J.
Local sources of pollution can vary immensely on small geographic scales and short time frames due to differences in runoff and adjacent land use. This study examined the rate of uptake and retention of trace metals in Cassiopea maremetens, a benthic marine jellyfish, over a short time frame and in the presence of multiple pollutants. This study also validated the ability of C. maremetens to uptake metals in the field. Experimental manipulation demonstrated that metal accumulation in jellyfish tissue began within 24h of exposure to treated water and trended for higher accumulation in the presence of multiple pollutants. C. maremetens was found to uptake trace metals in the field and provide unique signatures among locations. This fine-scale detection and rapid accumulation of metals in jellyfish tissue can have major implications for both biomonitoring and the trophic transfer of pollutants through local ecosystems.
Показать больше [+] Меньше [-]Use of Arius thalassinus fish in a pollution biomonitoring study, applying combined oxidative stress, hematology, biochemical and histopathological biomarkers: A baseline field study
2016
Saleh, Yousef S. | Marie, Mohamed-Assem S.
The present field study aimed to determine the extent of pollution in the Red Sea coast of Yemen Republic using a battery of biomarkers in sea catfish, Arius thalassinus, originating from a reference site in comparison with a polluted site. We reported the concentration of heavy metals in some vital fish organs and their effects on the morphological, hematological, biochemical and oxidative stress biomarkers accompanied by the examination of histopathological alterations. The obtained results showed clear signs of stress in fish from a polluted site. Linear correlation analysis exhibited that the biomarkers response could be linked to the detected metals bioaccumulation. In addition, principal component analysis showed a clear separation of sampling sites in two different assemblages. Semi-quantitative analysis for the observed histopathological lesions revealed that gills were the most affected organs with signs of severe alterations. This field investigation provides a baseline data on pollution status in this region.
Показать больше [+] Меньше [-]Metal contaminant fluxes across the sediment water interface
2016
Frogner-Kockum, Paul | Göransson, Peter | Åslund, Henrik | Ländell, Märta | Stevens, Rodney | Tengberg, Anders | Göransson, Gunnel | Ohlsson, Yvonne
To date, most estimates of contaminant fluxes across the sediment/water interface in risk assessments have been done using diffusive flux models. However, the reliability of these is limited as the overall flux from the sediment may have contributions caused by advection and bioturbation. We found through a comparison of modelled fluxes versus measured fluxes, that the methods Benthic Flux Chamber and surface leaching tests in a risk assessment context showed similar magnitude while calculated fluxes deviated at least by a factor of 100 from measured fluxes. This may be explained by the flux contribution in connection with bioturbation. The chamber-measured fluxes of copper were low compared to those of zinc and cobalt, but this is consistent with leaching tests that indicated copper to be more strongly bound. Risk assessments based on total concentrations may be misleading.
Показать больше [+] Меньше [-]Algicidal and denitrification characterization of Acinetobacter sp. J25 against Microcystis aeruginosa and microbial community in eutrophic landscape water
2016
Su, Jun feng | Ma, Min | Wei, Li | Ma, Fang | Lu, Jin suo | Shao, Si cheng
Acinetobacter sp. J25 exhibited good denitrification and high algicidal activity against toxic Microcystis aeruginosa. Response surface methodology (RSM) experiments showed that the maximum algicidal ratio occurred under the following conditions: temperature, 30.46°C; M. aeruginosa density, 960,000cellsmL−1; and inoculum, 23.75% (v/v). Of these, inoculum produced the maximum effect. In the eutrophic landscape water experiment, 10% bacterial culture was infected with M. aeruginosa cells in the landscape water. After 24days, the removal ratios of nitrate and chlorophyll-a were high, 100% and 87.86%, respectively. The denitrification rate was approximately 0.118mgNO3−–N·L−1·h−1. Moreover, the high-throughput sequencing result showed that Acinetobacter sp. J25 was obviously beneficial for chlorophyll-a and nitrate removal performance in the eutrophic landscape water treatment. Therefore, strain J25 is promising for the simultaneous removal of chlorophyll-a and nitrate in the eutrophic landscape water treatment.
Показать больше [+] Меньше [-]Distribution of beach litter along the coastline of Cádiz, Spain
2016
Williams, Allan Thomas | Randerson, Peter | Di Giacomo, Carlo | Anfuso, Giorgio | Macias, Ana | Perales, José Antonio
A total of 59 categories of litter items were found at 20 beaches (13 mechanically cleaned, 7 non-cleaned) in the Cádiz tourist environment, Spain. Cluster Analysis and Principal Components Analysis were used to highlight similarities and contrasts between sites and/or associations between litter categories. Multivariate analyses separated beaches according to the total numbers of litter items present. Non-cleaned sites showed a variety of litter category abundance with distinct origins and abundant, ubiquitous items (plastic and glass fragments). Of the 7 non-cleaned beaches (49 litter categories) river-mouth sites were distinct due with high numbers of litter items. The sheltered inner part of Cádiz Bay beaches had a wide range of litter type. Many sites were associated with locally deposited recreational litter categories; while industrial/commercial/fishing categories were abundant only at a few sites, indicating items transported onto the shore from the Guadalete river.
Показать больше [+] Меньше [-]Turbulent transport of particle-bound PAHs: A feasibility study combining GC-APLI-MS and eddy covariance
2016
Stader, Christian | Deventer, Malte Julian | Klemm, Otto | Achten, Christine
A novel approach combining gas chromatography-atmospheric pressure laser ionization-time-of-flight-mass spectrometry (GC-APLI-MS) with the micrometeorological eddy covariance (EC) technique is demonstrated to quantify particle-bound polycyclic aromatic hydrocarbons (PAH) mass fluxes above a central European city. During the case study, 18 different PAH compounds could be identified in two one-hour particle samples and, in combination with size-resolved particle deposition velocities obtained from EC measurements, inferred particulate PAH mass fluxes for two respective size fractions (0.060–0.108 μm and 0.170–10 μm) were quantified. Maximum concentrations and fluxes (in the order of 0.9 ± 0.09–17 ± 8 ng m−2 hr−1) were estimated for the 5-ring PAHs benzo[e]pyrene, benzo[a]pyrene and perylene. Fingerprints of PAH concentrations suggest strong pyrogenic sources, particularly wood burning.
Показать больше [+] Меньше [-]Effects of oil and oil burn residues on seabird feathers
2016
Fritt-Rasmussen, Janne | Linnebjerg, Jannie Fries | Sørensen, Martin X. | Brogaard, Nicholas L. | Rigét, Frank F. | Kristensen, Paneeraq | Jomaas, Grunde | Boertmann, David M. | Wegeberg, Susse | Gustavson, Kim
It is well known, that in case of oil spill, seabirds are among the groups of animals most vulnerable. Even small amounts of oil can have lethal effects by destroying the waterproofing of their plumage, leading to loss of insulation and buoyancy. In the Arctic these impacts are intensified. To protect seabirds, a rapid removal of oil is crucial and in situ burning could be an efficient method. In the present work exposure effects of oil and burn residue in different doses was studied on seabird feathers from legally hunted Common eider (Somateria mollissima) by examining changes in total weight of the feather and damages on the microstructure (Amalgamation Index) of the feathers before and after exposure. The results of the experiments indicate that burn residues from in situ burning of an oil spill have similar or larger fouling and damaging effects on seabird feathers, as compared to fresh oil.
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