Уточнить поиск
Результаты 1611-1620 из 4,044
Bioaccumulation of trace element concentrations in common dolphins (Delphinus delphis) from Portugal Полный текст
2016
Monteiro, Sílvia S. | Pereira, Andreia T. | Costa, Élia | Torres, Jordi | Oliveira, Isabel | Bastos-Santos, Jorge | Araujo, Helder | Ferreira, Marisa | Vingada, José | Eira, Catarina
The common dolphin (Delphinus delphis) is one of the most abundant species in Atlantic Iberia, representing a potentially important tool to assess the bioaccumulation of trace elements in the Iberian marine ecosystem. Nine elements (As, Cd, Cu, Hg, Mn, Ni, Pb, Se and Zn) were evaluated in 36 dolphins stranded in continental Portugal. Dolphins had increasing Hg concentrations (16.72μg·g−1 ww, liver) compared with previous studies in Atlantic Iberia, whereas Cd concentrations (2.26μg·g−1 ww, kidney) fell within reported ranges. The concentrations of some trace elements (including Cd and Hg) presented positive relationships with dolphin length, presence of parasites and gross pathologies. Common dolphins may help biomonitoring more offshore Atlantic Iberian areas in future studies, which would otherwise be difficult to assess.
Показать больше [+] Меньше [-]Abnormally high phytoplankton biomass near the lagoon mouth in the Huangyan Atoll, South China Sea Полный текст
2016
Ke, Zhixin | Liu, Huajian | Wang, Junxing | Liu, Jiaxing | Tan, Yehui
Nutrient concentration and phytoplankton biomass were investigated in Huangyan Atoll in May 2015. The concentrations of nutrients were very low, and dissolved inorganic nitrogen was composed mainly of ammonia. Nitrogen likely was the primary limiting factor for phytoplankton growth. The spatial variation of phytoplankton biomass was significant among the lagoon, reef flats, and outer reef slopes. Extremely high chlorophyll a concentration and micro-phytoplankton abundance were found in the region near the lagoon mouth. This high phytoplankton biomass might be due to nutrient input from fishing vessels and phytoplankton aggregation driven by the southwestern wind. Our results indicate that phytoplankton biomass could be a reliable indicator of habitat differences in this coral reef ecosystem, and micro-phytoplankton seems to be more sensitive to nutrient input than pico-phytoplankton.
Показать больше [+] Меньше [-]An assessment of mercury in estuarine sediment and tissue in Southern New Jersey using public domain data Полный текст
2016
Ng, Kara | Szabó, Zoltán | Reilly, Pamela A. | Barringer, Julia L. | Smalling, Kelly L.
Mercury (Hg) is considered a contaminant of global concern for coastal environments due to its toxicity, widespread occurrence in sediment, and bioaccumulation in tissue. Coastal New Jersey, USA, is characterized by shallow bays and wetlands that provide critical habitat for wildlife but share space with expanding urban landscapes. This study was designed as an assessment of the magnitude and distribution of Hg in coastal New Jersey sediments and critical species using publicly available data to highlight potential data gaps. Mercury concentrations in estuary sediments can exceed 2μg/g and correlate with concentrations of other metals. Based on existing data, the concentrations of Hg in mussels in southern New Jersey are comparable to those observed in other urbanized Atlantic Coast estuaries. Lack of methylmercury data for sediments, other media, and tissues are data gaps needing to be filled for a clearer understanding of the impacts of Hg inputs to the ecosystem.
Показать больше [+] Меньше [-]Combined proteomic and metallomic analyses in Scrobicularia plana clams to assess environmental pollution of estuarine ecosystems Полный текст
2016
González-Domínguez, Raul | Santos, Hugo Miguel | Bebianno, Maria João | García Barrera, Tamara | Gómez-Ariza, José Luis | Capelo, José Luis
Estuaries are very important ecosystems with great ecological and economic value, but usually highly impacted by anthropogenic pressure. Thus, the assessment of pollution levels in these habitats is critical in order to evaluate their environmental quality. In this work, we combined complementary metallomic and proteomic approaches with the aim to monitor the effects of environmental pollution on Scrobicularia plana clams captured in three estuarine systems from the south coast of Portugal; Arade estuary, Ria Formosa and Guadiana estuary. Multi-elemental profiling of digestive glands was carried out to evaluate the differential pollution levels in the three study areas. Then, proteomic analysis by means of two-dimensional gel electrophoresis and mass spectrometry revealed twenty-one differential proteins, which could be associated with multiple toxicological mechanisms induced in environmentally stressed organisms. Accordingly, it could be concluded that the combination of different omic approaches presents a great potential in environmental research.
Показать больше [+] Меньше [-]Bioaccumulation of polycyclic aromatic hydrocarbons, polychlorinated biphenyls and hexachlorobenzene by three Arctic benthic species from Kongsfjorden (Svalbard, Norway) Полный текст
2016
Szczybelski, Ariadna S. | van den Heuvel-Greve, Martine J. | Kampen, Tineke | Wang, Chenwen | Brink, Nico W. van den | Koelmans, Albert A.
The predicted expansion of oil and gas (O&G) activities in the Arctic urges for a better understanding of impacts of these activities in this region. Here we investigated the influence of location, feeding strategy and animal size on the bioaccumulation of Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs) and Hexachlorobenzene (HCB) by three Arctic benthic species in Kongsfjorden (Svalbard, Norway). No toxicity was expected based on biota PAH critical body residues. Biota PCB levels were mainly below limit of detection, whereas samples were moderately polluted by HCB. PAH concentrations in biota and Biota Sediment Accumulation Factors (BSAFs) were generally higher in Blomstrandhalvøya than in Ny-Ålesund, which was explained by a higher abundance of black carbon in Ny-Ålesund harbour. BSAFs differed significantly among species and stations. We conclude that contaminant body residues are a less variable and more straightforward monitoring parameter than sediment concentrations or BSAFs in Arctic benthos.
Показать больше [+] Меньше [-]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 Полный текст
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 sediments of Zhelin Bay, the largest mariculture base on the eastern Guangdong coast, South China: Characterization and risk implications Полный текст
2016
Gu, Yang-Guang | Ke, Chang-Liang | Liu, Qi | Lin, Qin
We investigated distribution, sources, and potential risks of polycyclic aromatic hydrocarbons (PAHs) in the surface sediments from the largest mariculture base in the eastern part of the province of Guangdong in southern China. Total concentrations of ∑PAHs were 29.38–815.46ng/g (dry weight), with a mean of 421.48ng/g. The composition of PAHs was characterized by an abundance of low molecular weight PAHs (2–3 benzenoid ring), and Phenanthrene (PHE), Anthracene (AN) and Fluoranthene (FA) were the predominant constituents. PAHs in this area appear to have mainly originated from petroleum sources and the combustion of grass, wood, and coal. PAHs in surface sediments of Zhelin Bay had a 9% incidence of causing adverse biological effects on aquatic organisms, according to the mean effects range–median quotient.
Показать больше [+] Меньше [-]Isolation, screening, and characterization of surface-active agent-producing, oil-degrading marine bacteria of Mumbai Harbor Полный текст
2016
Mohanram, Rajamani | Jagtap, Chandrakant | Kumar, Pradeep
Diverse marine bacterial species predominantly found in oil-polluted seawater produce diverse surface-active agents. Surface-active agents produced by bacteria are classified into two groups based on their molecular weights, namely biosurfactants and bioemulsifiers. In this study, surface-active agent-producing, oil-degrading marine bacteria were isolated using a modified Bushnell–Haas medium with high-speed diesel as a carbon source from three oil-polluted sites of Mumbai Harbor. Surface-active agent-producing bacterial strains were screened using nine widely used methods. The nineteen bacterial strains showed positive results for more than four surface-active agent screening methods; further, these strains were characterized using biochemical and nucleic acid sequencing methods. Based on the results, the organisms belonged to the genera Acinetobacter, Alcanivorax, Bacillus, Comamonas, Chryseomicrobium, Halomonas, Marinobacter, Nesterenkonia, Pseudomonas, and Serratia. The present study confirmed the prevalence of surface-active agent-producing bacteria in the oil-polluted waters of Mumbai Harbor.
Показать больше [+] Меньше [-]Spatial variation of VOCs and inorganic pollutants in a university building Полный текст
2016
Yurdakul, Sema | Civan, Mihriban | Özden, Özlem | Gaga, Eftade | Döğeroğlu, Tuncay | Tuncel, Gürdal
Indoor concentrations of 34 volatile organic compounds (VOCs), sulfur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3) were measured at 32 sampling points in classes, offices and hallways of the Environmental Engineering Department (ENVE) in the Middle East Technical University (METU) in Ankara. Outdoor samples were also collected around the department during the sampling campaigns. Two passive sampling campaigns, one in summer and the other one in winter, were conducted. Indoor concentrations of most pollutants were higher than their outdoor concentrations owing to the presence of indoor sources. The notable exception to this general pattern is O3. The average indoor/outdoor concentration ratio (I/O) was 10.9 in winter and 3.7 in summer. For most of the VOCs, the winter concentrations were higher than their summer concentrations due to more effective ventilation of the building and variation of emissions during summer months. Compounds with higher concentrations in the summer samples were the ones that were strongly affected by solvent evaporation in laboratories.
Показать больше [+] Меньше [-]Photochemical changes in water accommodated fractions of MC252 and surrogate oil created during solar exposure as determined by FT-ICR MS Полный текст
2016
Vaughan, Pamela P. | Wilson, Tashiema | Kamerman, Rebecca | Hagy, Melissa E. | McKenna, Amy | Chen, Huan | Jeffrey, Wade H.
To determine effects of photochemical weathering of petroleum, surrogate and Macondo (MC252) crude oils were exposed to solar radiation during the formation of Water Accommodated Fractions (WAFs) in sterile seawater. Samples were incubated in either unfiltered sunlight, with ultraviolet radiation blocked (Photosynthetically Active Radiation [PAR] only), or in darkness. WAFs were collected at two time points over the course of a week. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) analyses of water soluble species formed during exposure to sunlight were compared for the different treatments. Photochemical alterations resulted in differences in compound class distributions. In general, surrogate oil was photo-oxidized across a wider carbon number range compared to MC252. While photochemical differences were observed between MC252 and surrogate oils, microbial production in seawater responded similarly to both WAFs from both types of oils with the majority of the inhibition resulting from oil exposure to visible light.
Показать больше [+] Меньше [-]