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An analysis of ozone variation in the Greater Athens Area using Granger Causality Полный текст
2013
Sfetsos, Athanasios | Vlachogiannis, Diamando
Air pollution in urban areas is a topic of interest for many researchers as it impacts negatively the human health, the environment and the quality of life. As part of the effort in exploring ways for efficient and timely assessment of the urban air pollution patterns and their association with the local meteorology and photochemistry, an advanced statistical approach is proposed for the analysis of the spatiotemporal ozone (O3) variations and interdependencies to other pollutants. The focus of the work is placed on the investigation and determination of the causality between the local and regional factors causing the observed ozone variability, by applying a holistic methodology on multiple–year meteorological data and air pollution monitoring data, referenced in Athens (Greece). The methodology includes the Positive Matrix Factorization (PMF), for data scaling and reduction, a k–means clustering algorithm, for determining groups of data with common properties, and importantly, the Granger Causality test, for obtaining the causal links between the ozone and nitrogen oxides as well as the local meteorological conditions. The methodology revealed six dominant combined patterns of weather and air pollution. The application of the Granger Causality allowed the determination of relationships across the pollution patterns of dispersed geographic locations and the interdependence of those with the local meteorological conditions and photochemistry effects.
Показать больше [+] Меньше [-]Plastic debris in Mediterranean seabirds Полный текст
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.
Показать больше [+] Меньше [-]Recruitment of marine biota onto hard and soft artificially created subtidal habitats in Sabah Al-Ahmad Sea City, Kuwait Полный текст
2013
Jones, David A. | Nithyanandan, Manickam
Remediation of coastal habitats from impacts such as dredging and excavation in Gulf coastal waters is hampered by a lack of information on natural recolonisation rates and recruitment patterns of subtidal biota. For soft substrate habitats recovery information is only available for severely polluted sites where recovery takes many years (Jones et al., 2008).Construction of the Sabah Al-Ahmad Sea City provides a unique opportunity to follow benthic recruitment and community development on a range of artificially created benthic habitats over time. The three phases completed were each flooded by the sea separately and annual ecological surveys allow comparison of colonisation patterns and community development rates over time.Species diversity similar to that seen in comparable natural open sea habitats is reached within 2–5years for mixed sand/rock biota, but longer (2–6years) for sand biota. Biotic abundance exceeds open sea levels within 1–2years due to settlement of opportunistic species. Coral recruitment occurred within 3years. Present data provides a reference point for recovery rates into none polluted benthic habitats for the Gulf.
Показать больше [+] Меньше [-]Risk assessment and national measure plan for oil and HNS spill accidents near Korea Полный текст
2013
Lee, Moonjin | Jung, Jung-Yeul
Many oil and HNS spill accidents occur in the waters surrounding the Korean Peninsula because Korea is one of the biggest trading partners in the world. In this study, we analyzed the oil and HNS spill accidents that occurred between 1994 and 2005 and created risk matrices to assess these accidents. The worst scenarios of future oil and HNS spill accidents were established, and the maximum spill amounts were estimated using historic accident data and a correlation from IPIECA. The maximum spill amounts are estimated to be between 77,000 and 10,000tons of oil and HNS, respectively. One third of the spill materials should be removed using recovery equipment within three days of the spill event, according to the national measure plan. The capability of recovery equipment to remove spill materials can be estimated, and the equipment should then be prepared to mitigate the harmful effects of future oil and HNS accidents on humans and marine ecosystems.
Показать больше [+] Меньше [-]Comparison of fate profiles of PAHs in soil, sediments and mangrove leaves after oil spills by QSAR and QSPR Полный текст
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.
Показать больше [+] Меньше [-]Assessment of metal contamination in surface sediments from Zhelin Bay, the South China Sea Полный текст
2013
Wang, Zhao-Hui | Feng, Jie | Jiang, Tao | Gu, Yang-Guang
Metals and biogenic elements were analyzed from surface sediments collected from Zhelin Bay in the South China Sea in December 2008. The high concentrations of TOC, TN and BSi indicate the high nutrient level and diatom productivity in Zhelin Bay. The concentrations of metals were generally far lower than the effects-range-low (ERL) values that define pollutant levels. Enrichment factors (EF) and geoaccumulation indices (Igeo) suggest there are pollution levels of Cd, Cu and Zn at some stations. As, Cu, and Pb are potentially biotoxic in some stations. Correlation and principal component analyses indicate that most of the metals primarily originate from natural sources, and from maricultural activities as well. Mariculture contributes considerable Cd and Cu contamination. As and Pb comes primarily from combustion of gasoline and diesel fuel by ships.
Показать больше [+] Меньше [-]Bioavailability of trace elements in surface sediments from Kongsfjorden, Svalbard Полный текст
2013
Grotti, Marco | Soggia, Francesco | Ianni, Carmela | Magi, Emanuele | Udisti, Roberto
The bioavailability of trace elements in marine sediments from Kongsfjorden (Svalbard Islands, Norwegian Arctic) was assessed and discussed. Total concentrations of several elements were determined in two granulometric fractions and their bioavailability evaluated by both applying a sequential-selective extraction procedure and using a biomimetic approach based on proteolytic enzymes. Total concentration values and solid speciation patterns indicated overall that the anthropogenic impact of trace elements in the investigated area is negligible, although a minor enrichment with respect to crustal values was found for As, Cd, Cr, Ni, and V. Enrichment of trace elements in the <63-μm fraction compared to the coarser one was evident for As, Cd, Cr, and Ni. The evaluation of the bioavailable fractions showed that a large part of the total content of trace elements cannot enter the aquatic food chain and emphasised the risk of overestimating the environmental impact of heavy metals if the assessment is only based on total concentrations.
Показать больше [+] Меньше [-]Three dimensional marine seismic survey has no measurable effect on species richness or abundance of a coral reef associated fish community Полный текст
2013
Miller, Ian | Cripps, Edward
Underwater visual census was used to determine the effect of a three dimensional seismic survey on the shallow water coral reef slope associated fish community at Scott Reef. A census of the fish community was conducted on six locations at Scott Reef both before and after the survey. The census included small site attached demersal species belonging to the family Pomacentridae and larger roving demersal species belonging to the non-Pomacentridae families. These data were combined with a decade of historical data to assess the impact of the seismic survey. Taking into account spatial, temporal, spatio-temporal and observer variability, modelling showed no significant effect of the seismic survey on the overall abundance or species richness of Pomacentridae or non-Pomacentridae. The six most abundant species were also analysed individually. In all cases no detectable effect of the seismic survey was found on the abundance of these fish species at Scott Reef.
Показать больше [+] Меньше [-]Macrobenthos habitat potential mapping using GIS-based artificial neural network models Полный текст
2013
Lee, Saro | Park, Inhye | Koo, Bon Joo | Ryu, Joo-Hyung | Choi, Jong-Kuk | Woo, Han Jun
This paper proposes and tests a method of producing macrobenthos habitat potential maps in Hwangdo tidal flat, Korea based on an artificial neural network. Samples of macrobenthos were collected during field work, and eight control factors were compiled as a spatial database from remotely sensed data and GIS analysis. The macrobenthos habitat potential maps were produced using an artificial neural network model. Macrobenthos habitat potential maps were made for Macrophthalmus dilatatus, Cerithideopsilla cingulata, and Armandia lanceolata. The maps were validated by compared with the surveyed habitat locations. A strong correlation between the potential maps and species locations was revealed. The validation result showed average accuracies of 74.9%, 78.32%, and 73.27% for M. dilatatus, C. cingulata, and A. lanceolata, respectively. A GIS-based artificial neural network model combined with remote sensing techniques is an effective tool for mapping the areas of macrobenthos habitat potential in tidal flats.
Показать больше [+] Меньше [-]Determining trigger values of suspended sediment for behavioral changes in a coral reef fish Полный текст
2013
Wenger, Amelia S. | McCormick, Mark I.
Sediment from land use increases water turbidity and threatens the health of inshore coral reefs. This study performed experiments with a damselfish, Pomacentrus moluccensis, in four sediment treatments, control (0mgl−1), 10mgl−1(∼1.7NTU), 20mgl−1(∼3.3NTU) and 30mgl−1 (∼5NTU), to determine when sediment triggers a change in habitat use and movement. We reviewed the literature to assess how frequently P. moluccensis would experience sub-optimal sediment conditions on the reef. Preference for live coral declined from 49.4% to 23.3% and movement between habitats declined from 2.1 to 0.4times between 20mgl−1 and 30mgl−1, suggesting a sediment threshold for behavioral changes. Inshore areas of the Great Barrier Reef, P. moluccensis may encounter sub-optimal conditions between 8% and 53% of the time. Changes in these vital processes may have long-term effects on the persistence of populations, particularly as habitat loss on coral reefs increases.
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