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Toxicological impact assessment of heavy metal contamination on macrobenthic communities in southern coastal sediments of Korea
2013
Lim, Dhong-il | Choi, Jin-Woo | Shin, Hyeon Ho | Jeong, Do Hyun | Jung, Hoi Soo
In the heavily industrialized Masan Bay of southern coast, Korea, the potential harmful effects of heavy metals (Cd, Co, Cu, Ni, Pb, Sn, Zn, and Hg) were evaluated in terms of the pollution load index (PLI) and ecological risk assessment index (ERI) methods, and the results obtained were considered alongside the health of the macrobenthic fauna communities. The results revealed that the bay sediments, especially in the inner bay and the outfall area of a sewage treatment plant, are exposed to moderate to serious levels of metal pollution. Hg and Cd contributed the most to the potential toxicity response indices in sediments recently deposited in the bay. The potential ecological risk assessment of heavy metals in the bay was highlighted by the use of the benthic biological pollution index (BPI), suggesting that the ERI is a useful toxicity response index, which can quantify the overall ecological risk level to a target environment.
Afficher plus [+] Moins [-]Comparison of fate profiles of PAHs in soil, sediments and mangrove leaves after oil spills by QSAR and QSPR
2013
Tansel, Berrin | Lee, Mengshan | Tansel, Derya Z.
First order removal rates for 15 polyaromatic hydrocarbons (PAHs) in soil, sediments and mangrove leaves were compared in relation to the parameters used in fate transport analyses (i.e., octanol–water partition coefficient, organic carbon–water partition coefficient, solubility, diffusivity in water, HOMO–LUMO gap, molecular size, molecular aspect ratio). The quantitative structure activity relationships (QSAR) and quantitative structure property relationships (QSPR) showed that the rate of disappearance of PAHs is correlated with their diffusivities in water as well as molecular volumes in different media. Strong correlations for the rate of disappearance of PAHs in sediments could not be obtained in relation to most of the parameters evaluated. The analyses showed that the QSAR and QSPR correlations developed for removal rates of PAHs in soils would not be adequate for sediments and plant tissues.
Afficher plus [+] Moins [-]Harboring oil-degrading bacteria: A potential mechanism of adaptation and survival in corals inhabiting oil-contaminated reefs
2013
Al-Dahash, Lulwa M. | Mahmoud, Huda M.
Certain coral reef systems north of the Arabian Gulf are characterized by corals with a unique ability to thrive and flourish despite the presence of crude oil continuously seeping from natural cracks in the seabed. Harboring oil-degrading bacteria as a part of the holobiont has been investigated as a potential mechanism of adaptation and survival for corals in such systems. The use of conventional and molecular techniques verified a predominance of bacteria affiliated with Gammaproteobacteria, Actinobacteria and Firmicutes in the mucus and tissues of Acropora clathrata and Porites compressa. These bacteria were capable of degrading a wide range of aliphatic (C9–C28) aromatic hydrocarbons (Phenanthrene, Biphenyl, Naphthalene) and crude oil. In addition, microcosms supplied with coral samples and various concentrations of crude oil shifted their bacterial population toward the more advantageous types of oil degraders as oil concentrations increased.
Afficher plus [+] Moins [-]Using 222Rn to estimate submarine groundwater discharge (SGD) and the associated nutrient fluxes into Xiangshan Bay, East China Sea
2013
Wu, Zijun | Zhou, Huaiyang | Zhang, Shuai | Liu, Yang
Continuous radon (222Rn) monitoring was conducted at two stations (site A and site B) with different perpendicular distance from the shoreline in Xiangshan Bay, East China Sea. Based on a 222Rn balance model (various sources and sinks of 222Rn in coastal water), the average rate of SGD was estimated to be 0.69cm/day and 0.23cm/day for site A and site B, respectively. The results from a nutrient analysis of the groundwater indicate that the associated nutrients fluxes loading through the SGD pathway were 4.27×106mol/day for DIN, 2.24×104mol/day for DIP and 1.82×106mol/day for DSi, respectively, which were comparable to or even higher than the levels observed in the local streams. Therefore, adequate attention should be paid to the importance of SGD as one source of nutrients during the eutrophication control process in this area.
Afficher plus [+] Moins [-]The measurement of gamma-emitting radionuclides in beach sand cores of coastal regions of Ramsar, Iran using HPGe detectors
2013
Tari, Marziyeh | Moussavi Zarandi, Sayyed Ali | Mohammadi, Kheirollah | Zare, Mohammad Reza
Radionuclides which present in different beach sands are sources of external exposure that contribute to the total radiation exposure of human. 226Ra, 235U, 232Th, 40K and 137Cs analysis has been carried out in sand samples collected at six depth levels, from eight locations of the northern coast of Iran, Ramsar, using high-resolution gamma-ray spectroscopy. The average Specific activities of natural radionuclides viz., 226Ra, 235U, 232Th, 40K and 137Cs, in the 0–36cm depth sand were found as: 19.2±0.04, 2.67±0.17, 17.9±0.06, 337.5±0.61 and 3.35±0.12 Bqkg−1, respectively. The effects of organic matter content and pH value of sand samples on the natural radionuclide levels were also investigated. Finally, the measured radionuclide concentrations in the Ramsar beach were compared with the world average values, as reported by UNSCEAR (2000). None of the studied beaches were considered as a radiological risk.
Afficher plus [+] Moins [-]Baseline metals pollution profile of tropical estuaries and coastal waters of the Straits of Malacca
2013
Looi, Ley Juen | Ahmad Zaharin Aris, | Wan Johari, Wan Lutfi | Md. Yusoff, Fatimah | Hashim, Zailina
The status report on metal pollution in tropical estuaries and coastal waters is important to understand potential environmental health hazards. Detailed baseline measurements were made on physicochemical parameters (pH, temperature, redox potential, electrical conductivity, salinity, dissolved oxygen, total dissolved solid), major ions (Na, Ca, Mg, K, HCO3, Cl, SO4 and NO3) and metals concentrations (27Al, 75As, 138Ba, 9Be, 111Cd, 59Co, 63Cu, 52Cr, 57Fe, 55Mn, 60Ni, 208Pb, 80Se, 66Zn) at estuaries and coastal waters along the Straits of Malacca. Principal component analysis (PCA) was employed to reveal potential pollution sources. Seven principal components were extracted with relation to pollution contribution from minerals-related parameters, natural and anthropogenic sources. The output from this study will generate a profound understanding on the metal pollution status and pollution risk of the estuaries and coastal system.
Afficher plus [+] Moins [-]Biogeochemical characterization of MC252 oil:sand aggregates on a coastal headland beach
2013
Urbano, Marilany | Elango, Vijaikrishnah | Pardue, John H.
MC252 oil:sand aggregates, termed surface residue balls (SRBs), were sampled for physical, chemical and microbial characteristics from different tidal zones on a coastal headland beach in Louisiana, USA. Supratidal SRBs were smaller, had low moisture content, and salinities that were <2ppt. Intertidal SRBs were hypersaline and had higher N and sulfate concentrations, consistent with regular tidal inundation. Crude oil components were highest in the intertidal “oil mat” SRBs with C1- and C2-phenanthrenes, C2- and C3-dibenzothiophenes comprising the majority of the PAH concentrations. In the other SRB categories, PAHs and alkanes were depleted and profiles were skewed toward higher molecular weight compounds. Oxygen microelectrode measurements demonstrated that saturated O2 is present immediately after wetting, but O2 consumption in the interior of the aggregate occurs after a few days. Microbial populations varied with position on the beach but sequences similar to known PAH-degrading taxa (Mycobacterium sp. and Stenotrophomonas sp.) were observed.
Afficher plus [+] Moins [-]Marine water quality monitoring: A review
2013
Karydis, Michael | Kitsiou, Dimitra
Marine water quality monitoring is performed for compliance with regulatory issues, trend detection, model validation and assessment of the effectiveness of adopted policies. As the end users are managers and policy makers, the objectives should be of practical interest and the answers should reduce the uncertainty concerning environmental impact, supporting planning and decision making. Simple and clearcut answers on environmental issues require synthesis of the field information using statistics, simulation models and multiple criteria analysis (MCA). Statistics is easy to apply whereas simulation models enable researchers to forecast future trends as well as test different scenarios. MCA allows the co-estimation of socio-economic variables providing a compromise between scientists’ and policy makers’ priorities. In addition, stakeholders and the public have the right to know and participate. This article reviews marine water quality monitoring principles, design and data analysis procedures. A brief review of international conventions of regional seas is also included.
Afficher plus [+] Moins [-]Dominance patterns in macroalgal and phytoplankton biomass under different nutrient loads in subtropical coastal lagoons of the SE Gulf of California
2013
Páez-Osuna, F. | Piñón-Gimate, A. | Ochoa-Izaguirre, M.J. | Ruiz-Fernández, A.C. | Ramírez-Reséndiz, G. | Alonso-Rodríguez, R.
Nine macroalgal blooms were studied in five coastal lagoons of the SE Gulf of California. The nutrient loads from point and diffuse sources were estimated in the proximity of the macroalgal blooms. Chlorophyll a and macroalgal biomass were measured during the dry, rainy and cold seasons. Shrimp farms were the main point source of nitrogen and phosphorus loads for the lagoons. High biomasses were found during the dry season for phytoplankton at site 6 (791.7±34.6mgm−2) and during the rainy season for macroalgae at site 4 (296.0±82.4gm−2). Depending on the season, the phytoplankton biomass ranged between 40.0 and 791.7mgm−2 and the macroalgal biomass between 1 and 296.0gm−2. The bulk biomass (phytoplankton+macroalgal) displayed the same tendency as the nutrient loads entering the coastal lagoons. Phytoplankton and macroalgal biomass presented a significant correlation with the atomic N:P ratio.
Afficher plus [+] Moins [-]Plastic debris in Mediterranean seabirds
2013
Codina-García, Marina | Militão, Teresa | Moreno Lázaro, Javier | González-Solís, Jacob
Plastic debris is often ingested by marine predators and can cause health disorders and even death. We present the first assessment of plastic ingestion in Mediterranean seabirds. We quantified and measured plastics accumulated in the stomach of 171 birds from 9 species accidentally caught by longliners in the western Mediterranean from 2003 to 2010. Cory’s shearwaters (Calonectris diomedea) showed the highest occurrence (94%) and large numbers of small plastic particles per affected bird (on average N=15.3±24.4 plastics and mass=23.4±49.6mg), followed by Yelkouan shearwaters (Puffinus yelkouan, 70%, N=7.0±7.9, 42.1±100.0mg), Balearic shearwaters (Puffinus mauretanicus, 70%, N=3.6±2.9, 5.5±9.7mg) and the rest of species (below 33%, N=2.7, 113.6±128.4mg). Plastic characteristics did not differ between sexes and were not related to the physical condition of the birds. Our results point out the three endemic and threatened shearwater species as being particularly exposed to plastic accumulation.
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