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Polycyclic aromatic hydrocarbons in surface sediments of the East China Sea and their relationship with carbonaceous materials Texto completo
2011
Hung, Chin-Chang | Gong, Gwo-Ching | Ko, Fung-Chi | Lee, Hung-Jen | Chen, Hung-Yu | Wu, Jian-Ming | Hsu, Min-Lan | Peng, Sen-Chueh | Nan, Fan-Hua | Santschi, Peter H.
This study measured concentrations of polycyclic aromatic hydrocarbons (PAHs) in surface sediments in the East China Sea (ECS) to investigate possible sources and fate of PAHs. Total concentration of PAHs in the sediments of the ECS ranged from 22 to 244ngg⁻¹, with the highest levels in the coastal area and outer shelf. The observed PAH results showed elevated levels in both inner and outer shelf areas, a finding that is different from predictions by an ocean circulation model, suggesting that terrestrial sources are important for PAH contaminations in the ECS, while sediment resuspension, tidal changes and lateral transport may be important in affecting the distribution of PAHs in the outer shelf. The distribution of PAHs in the surface sediments of the ECS is similar to the distribution of carbonaceous materials (e.g., particulate organic carbon and black carbon), suggesting that carbonaceous materials may strongly affect the distribution of PAHs.
Mostrar más [+] Menos [-]Temporal distributions of anthropogenic Al, Zn and Pb in Hong Kong Porites coral during the last two centuries Texto completo
2011
Wang, Bo-Shian | Goodkin, Nathalie F. | Angeline, N. | Switzer, Adam D. | You, Chen-Feng | Hughen, Konrad
A 182-year long record of trace metal concentrations of aluminum, zinc and lead was reconstructed from a massive Porites coral skeleton from southeastern Hong Kong to evaluate the impacts of anthropogenic activity on the marine environment. Zn/Ca and Pb/Ca ratios fluctuate synchronously from the early 19th century to the present, indicating that the marine environment has been anthropogenically influenced since industrialization. Additionally, land reclamation, mining, and ship building activities are recorded by elevated Al/Ca ratios from 1900 to 1950. The coral record indicates that high levels of Zn, Pb and Al occur coincidentally with local wars, and may have contributed to partial colony mortality. Pb/Ca does not correlate well with hemispheric proxy records after 1950, indicating that coastal corals may be recording local rather than hemispheric contamination. Pb/Ca levels in Hong Kong, Guangdong and Hainan corals imply a continuous supply of Pb-based contamination to southern China not reflected in hemispheric signals.
Mostrar más [+] Menos [-]Dioxin-like compounds in sediments from the Daliao River Estuary of Bohai Sea: Distribution and their influencing factors Texto completo
2011
Zhao, Xiaofeng. | Zhang, Haijun | Fan, Jingfeng | Guan, Daoming | Zhao, Huade | Ni, Yuwen | Li, Yun | Chen, Jiping
The concentrations, compositional profiles, and potential ecological risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in sediments of the Daliao River Estuary were investigated. Total concentrations of PCDD/Fs, PCBs, and PCNs were in the range of 11.3–133.2ng/kg dry weight (dw), 1 971–37 632ng/kg dw and 33.1–284.4ng/kg dw, respectively. The total TEQ values varied from 0.37 to 4.08ng/kg dw, with the dominant contributions by PCDD/Fs, then by PCBs and PCNs. The spatial distributions of PCDD/Fs, PCBs and PCNs in the river estuary were much related to hydrodynamic conditions. The risk of contamination to the deeper sea was increased in the flood seasons. Moreover, our data confirmed that both organic matter in sediments and molecular properties of dioxin-like compounds were the factors which strongly influenced the partition behavior of these dioxin-like compounds between sediments and water phase in the estuarine zone.
Mostrar más [+] Menos [-]Effects of environmental stresses on the responses of mangrove plants to spent lubricating oil Texto completo
2011
Ke, Lin | Zhang, Chunguang | Guo, Chuling | Lin, Guang Hui | Tam, Nora Fung Yee
The influence of different environmental stresses, including salinity (5–35‰), tidal cycle (6/6, 12/12 and 24/24h of high/low tidal regimes) and nutrient addition (1–6 times background nitrogen and phosphorus content) on Bruguiera gymnorrhiza and Aegiceras corniculatum grown in sediment contaminated with spent lubricating oil (7.5Lm⁻²) were investigated. The oil-treated 1-year-old mangrove seedlings subject to low (5‰) and high (35‰) salinity had significantly more reduction in growth, more release of superoxide radical (O₂ ⁻) and higher activity of superoxide dismutase (SOD) than those subject to moderate salinity (15‰). Extended flooding (24/24h of high/low tidal regime) enhanced O₂ ⁻ release and malondialdehyde (MDA) content in both oil-treated species but had little negative effects on biomass production (P>0.05) except the stem of A. corniculatum (P=0.012). The addition of nutrients had no beneficial or even posed harmful effects on the growth and cellular responses of the oil-treated seedlings.
Mostrar más [+] Menos [-]Phosphorus mass balance in a highly eutrophic semi-enclosed inlet near a big metropolis: A small inlet can contribute towards particulate organic matter production Texto completo
2011
Asaoka, Satoshi | Yamamoto, Tamiji
Terrigenous loading into enclosed water bodies has been blamed for eutrophic conditions marked by massive algal growth and subsequent hypoxia due to decomposition of dead algal cells. This study aims to describe the eutrophication and hypoxia processes in a semi-enclosed water body lying near a big metropolis. Phosphorus mass balance in a small inlet, Ohko Inlet, located at the head of Hiroshima Bay, Japan, was quantified using a numerical model. Dissolved inorganic phosphorous inflow from Kaita Bay next to the inlet was five times higher than that from terrigenous load, which may cause an enhancement of primary production. Therefore, it was concluded that not only the reduction of material load from the land and the suppression of benthic flux are needed, but also reducing the inflow of high phosphorus and oxygen depleted water from Kaita Bay will form a collective alternative measure to remediate the environmental condition of the inlet.
Mostrar más [+] Menos [-]Method for generating parameterized ecotoxicity data of dispersed oil for use in environmental modelling Texto completo
2011
Nordtug, Trond | Olsen, Anders Johny | Altin, Dag | Meier, Sonnich | Overrein, Ingrid | Hansen, Bjørn Henrik | Johansen, Øistein
The aim of the work was to establish methodology for realistic laboratory-based test exposures of organisms to oil dispersions, specifically designed to generate parameterized toxicity data. Such data are needed to improve the value of numerical models used to predict fate and effects of oil spills and different oil spill responses. A method for continuous and predictable in-line production of oil dispersions with defined size distribution of different oil qualities was successfully established. The system enables simultaneous comparison between the effects of different concentrations of dispersion and their corresponding equilibrium water soluble fractions. Thus, net effects of the oil droplet fraction may be estimated. The method provides data for comparing the toxicity of oil dispersions generated both mechanically and with the use of chemical dispersions, incorporating the toxicity of both dissolved oil and droplets of oil.
Mostrar más [+] Menos [-]Actually achieving marine sustainability demands a radical re-think in approach, not ‘more of the same’ Texto completo
2011
Morris, Dave | O’Brien, Carl | Larcombe, Piers
The UK is committed to meeting a series of ‘high-level marine objectives’ which are required to satisfy national obligations and to meet international commitments for the marine environment. There are more than 16 such international high-level policy driven obligations and commitments, together with more than 18 European and more than 12 of national origin. In the UK, there is an assumption that the current and planned monitoring will provide evidence to demonstrate achievement against these high-level objectives.
Mostrar más [+] Menos [-]River discharge reduces reef coral diversity in Palau Texto completo
2011
Golbuu, Yimnang | van Woesik, Robert | Richmond, Robert H. | Harrison, Peter | Fabricius, Katharina E.
Coral community structure is often governed by a suite of processes that are becoming increasingly influenced by land-use changes and related terrestrial discharges. We studied sites along a watershed gradient to examine both the physical environment and the associated biological communities. Transplanted corals showed no differences in growth rates and mortality along the watershed gradient. However, coral cover, coral richness, and coral colony density increased with increasing distance from the mouth of the bay. There was a negative relationship between coral cover and mean suspended solids concentration. Negative relationships were also found between terrigenous sedimentation rates and the richness of adult and juvenile corals. These results have major implications not only for Pacific islands but for all countries with reef systems downstream of rivers. Land development very often leads to increases in river runoff and suspended solids concentrations that reduce coral cover and coral diversity on adjacent reefs.
Mostrar más [+] Menos [-]PCBs in Central Vietnam coastal lagoons: Levels and trends in dynamic environments Texto completo
2011
Giuliani, Silvia | Piazza, Rossano | Bellucci, Luca Giorgio | Cu, Nguyen Huu | Vecchiato, Marco | Romano, Stefania | Mugnai, Cristian | Nhon, Dang Hoai | Frignani, Mauro
PCBs were analysed in surficial sediments and selected sediment cores collected between 2002 and 2008 in Central Vietnam coastal lagoons. The aim was to determine contamination levels and trends, and to evaluate the effects of anthropogenic pressures and natural events. Samples were mostly fine-grained with low total PCB concentrations (0.367–44.7μgkg⁻¹). Atmospheric transport and post depositional processes modify to some degree the fingerprint of PCB inputs to the environment favouring the predominance of 3, 4 and 5 chlorinated congeners. The similarity of congener distributions in contemporary surficial samples also suggests the presence of a unique source over the entire study area, probably connected to mobilisation and long range transports from land-based stocks. The removal of consistent sediment layers is hypothesised based on repeated samplings of the same area. Natural meteorological events (such as typhoons) are suspected to be responsible for these sediment losses.
Mostrar más [+] Menos [-]Occurrence of perfluorinated compounds in water, sediment and mussels from the Cantabrian Sea (North Spain) Texto completo
2011
Gómez, Cristian | Vicente, Joana | Echavarri-Erasun, Beatriz | Porte, Cinta | Lacorte, Silvia
Perfluorinated compounds (PFCs) have emerged as significant global environmental pollutants with persistent, bioaccumulative and toxic properties. The aim of this study was to determine the occurrence of PFCs in water (wastewater, submarine emissaries and port-waters), sediment and transplanted mussels in estuarine areas of high urban and industrial impact from Northern Spain. Five PFCs of industrial use were studied: perfluorooctanesulfonate, perfluorohexanesulfonate, perfluorobutanesulfonate, perfluorooctanoate acid and perfluorononanoate acid. After selective extraction, samples were analyzed by Ultra Performance Liquid Chromatography coupled to tandem mass spectrometry. ΣPFCs ranged from 0.06 to 10.9ng/L in water, with higher levels in wastewater treatment plants effluents and port waters than in submarine emissaries. Little accumulation was observed in sediments and mussels with ΣPFCs ranging from 0.01–0.13ng/g dw and 0.01–0.06ng/g ww, respectively. Most ubiquitous compounds were PFOS and PFOA. Mass fluxes of PFCs to the Cantabrian Sea are estimated and the impact to the coastal ecosystem is discussed.
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