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Temporal variations of VOC concentrations in Bursa atmosphere Texte intégral
2017
Yurdakul, Sema | Civan, Mihriban | Kuntasal, Öznur | Doğan, Güray | Pekey, Hakan | Tuncel, Gürdal
The levels and sources of VOCs in the atmosphere of Bursa have been investigated by measuring C2–C12 VOCs which include alkanes, alkenes, alkines, aromatics and halogenated hydrocarbons in two different campaigns. The first campaign was carried out between September 14 and November 6, 2005, and the second one between March 17 and May 10, 2006. The concentrations of 112 VOCs were detected in the collected samples. The median total concentrations of VOCs were 115 and 86 μg m−3 for the first and second campaigns, respectively. Alkanes (x− = 51.50 μg m−3) are the most abundant group in the Bursa airshed, which is followed by aromatics (x− = 49.38 μg m−3), alkenes (x− = 36.86 m-3) and halogenated compounds (x− = 13.07 μg m−3). In the present study, the VOCs showed well defined diurnal, weekday/weekend and seasonal variations. Diurnal variation of most of the measured organic compounds followed traffic rush-hours. On the other hand, some VOCs such as 1-octene, 1-nonene, 1-undecene, n-nonane, n-decane, 1,2,3-trimethylbenzene, undecane and dodecane have displayed unusual profiles that do not follow the traffic pattern during the first campaign due to asphalting operations. Moreover, the average T/B ratio obtained in the first campaign was found to be significantly higher than the second one. This relatively high difference between T/B ratios is an indication of the availability of different sources rather than the traffic. Therefore, it can be suggested that there were additional VOC sources than traffic in Bursa city center.
Afficher plus [+] Moins [-]The iconic Torrey Canyon oil spill of 1967 - Marking its legacy Texte intégral
2017
Wells, P. G.
March 2017 marks the 50th anniversary of the SS Torrey Canyon oil spill and cleanup, off the Cornwall coast in the English Channel. It was the world's first major supertanker disaster. It was a signature event in the marine pollution field, especially related to oil spill response and the initiation of scientific studies of monitoring and researching the fate and effects of oil in the sea. This paper recalls this event, notes our growing understanding of marine pollution and global efforts for cleaner seas, and encourages further work on both oil and the many emerging environmental issues affecting the marine environment.
Afficher plus [+] Moins [-]Does energetic cost for leaf construction in Sonneratia change after introduce to another mangrove wetland and differ from native mangrove plants in South China? Texte intégral
2017
Li, Fenglan | Yang, Lei | Zan, Qi-Jie | Shin, Paul-K.S. | Cheung, Siu-Gin | Wong, Yuk-Shan | Tam, Nora Fung-Yee | Lei, An-Ping
Exotic species invasions are serious ecological problems. Leaf construction cost (CC) and growth traits of two Sonneratia (Sonneratia caseolaris and S. apetala) and four native species (Bruguiera gymnorrhiza, Kandelia obovata, Aegiceras corniculatum and Avicennia marina) in Hainan and Shenzhen mangrove wetlands were compared to evaluate invasive potentials of Sonneratia after introduced to Shenzhen, their new habitat. There were no significant differences in CC and growth traits between two wetlands, suggesting Sonneratia did not lose any advantage in the new habitat and were competitive in both wetlands. CC per unit mass (CCM), CC per unit area (CCA) and caloric values of Sonneratia were significantly lower than those of native mangrove species while specific leaf area (SLA) was just the opposite. CCM of S. caseolaris and S. apetala were 6.1% and 11.9% lower than those of natives, respectively. These findings indicated the invasive potential of Sonneratia in Shenzhen after their introduction.
Afficher plus [+] Moins [-]Opportunistic sampling to quantify plastics in the diet of unfledged Black Legged Kittiwakes (Rissa tridactyla), Northern Fulmars (Fulmarus glacialis) and Great Cormorants (Phalacrocorax carbo) Texte intégral
2017
Acampora, Heidi | Newton, Stephen | O'Connor, Ian
Seabirds can interact with marine litter, mainly by entanglement or ingestion. The ingestion of plastics can lead to starvation or physical damage to the digestive tract. For chicks, it could additionally lead to reduced growth, affecting survival and fledging. This study quantified the ingestion of plastics by seabird chicks via an opportunistic sampling strategy. When ringing is carried out at colonies, birds may spontaneously regurgitate their stomach contents due to the stress or as a defence mechanism. Regurgitates were collected from nestlings of three different species: Black-legged Kittiwake (Rissa tridactyla, n=38), Northern Fulmar (Fulmarus glacialis, n=14) and Great Cormorant (Phalacrocorax carbo, n=28). Plastic was present in all species, with the highest frequency of occurrence (FO) in Northern Fulmar chicks (28.6%), followed by Black-legged Kittiwakes (7.9%) and Great Cormorants (7.1%). The observed load of plastics on chicks, which have not yet left the nest, highlights the pervasive nature of plastic pollution.
Afficher plus [+] Moins [-]Variation in the health and biochemical condition of the coral Acropora tenuis along two water quality gradients on the Great Barrier Reef, Australia Texte intégral
2017
Rocker, Melissa M. | Francis, David S. | Fabricius, Katharina E. | Willis, Bette L. | Bay, Line K.
This study explores how plasticity in biochemical attributes, used as indicators of health and condition, enables the coral Acropora tenuis to respond to differing water quality regimes in inshore regions of the Great Barrier Reef. Health attributes were monitored along a strong and weak water quality gradient, each with three reefs at increasing distances from a major river source. Attributes differed significantly only along the strong gradient; corals grew fastest, had the least dense skeletons, highest symbiont densities and highest lipid concentrations closest to the river mouth, where water quality was poorest. High nutrient and particulate loads were only detrimental to skeletal density, which decreased as linear extension increased, highlighting a trade-off. Our study underscores the importance of assessing multiple health attributes in coral reef monitoring. For example, autotrophic indices are poor indicators of coral health and condition, but improve when combined with attributes like lipid content and biomass.
Afficher plus [+] Moins [-]Use of common carp (Cyprinus carpio) and Aeromonas salmonicida for detection of immunomodulatory effects of chemicals on fish Texte intégral
2017
Nakayama, Kei | Yamashita, Ryohei | Kitamura, Shin-Ichi
To develop a test for assessing the immunomodulatory effects of chemical pollutants on fish, we evaluated the effects of dexamethasone on the natural host–pathogen interaction between common carp (Cyprinus carpio) and Aeromonas salmonicida. Carp were exposed to 1mgL−1 dexamethasone for the entire experimental period. One week after the exposure test started, the exposed fish, as well as unexposed fish, were bath-infected with A. salmonicida. One hundred percent mortality was observed in bacteria-infected fish exposed to dexamethasone, whereas no infection-associated mortality was observed in infected fish in the absence of dexamethasone exposure. In a separate experiment, dexamethasone exposure significantly suppressed hemolytic complement activity in bacteria-infected fish. These results clearly indicate that exposure to a high concentration of dexamethasone suppressed the carp immune system and caused subsequent mortality. Thus, this proposed test method is likely to be useful for evaluating the immunomodulatory effects of chemicals in fish.
Afficher plus [+] Moins [-]Seasonal circulation assessments of the Northern Arabian/Persian Gulf Texte intégral
2017
Alosairi, Y. | Pokavanich, T.
Due to the continuous human activities linked to economic expansion in the Arabian Gulf area (also known as Persian Gulf), various activities have had an adverse impact on the coastal environment. Furthermore, reduction of precipitation and river flows has resulted in alterations to the hydro-environment regime at various levels. The current study uses a detailed numerical model that was validated with recent field measurements to determine the comprehensive seasonal circulations of the Northern Arabian/Persian Gulf (NAG). The seasons were studied individually using a three-dimensional setup and by considering the baroclinic effects and meteorological forcing. It was found that the NAG exhibits distinctive circulation characteristics each season. In winter, a dense water mass that forms near Kuwait flows toward the southeast near-bed, whereas relatively weak Indian Ocean Surface Waters (IOSW) flow along the Iranian coast and, to a lesser extent, oppose these currents. In spring, the southeast near bed circulations are weaker, while the IOSW is in highest conditions reaching the northern latitudes of the Gulf without being significantly diluted. In summer, a thermocline develops, particularly at the main axis of the NAG, and increases the chances of upwelling. The surface water during this season is significantly controlled by wind. Most distinctive, a non-uniform flow is evident at the offshore regions along the Arabian coast due to strong density gradients. In the fall, the circulations are relatively weaker compared to other seasons; however, cyclonic features are evident at the southeast of the estuary. Well-known counter clockwise circulations NAG are evident throughout the season, but at various strengths; summer is the most active season, while fall is the least active season. In a similar manner, the along shore current varied spatially and temporally throughout the seasons.
Afficher plus [+] Moins [-]Low incidence of plastics in food loads delivered to nestlings by a zooplanktivorous seabird over a 21-year period Texte intégral
2017
Hipfner, J.M. | Studholme, K.R. | Galbraith, M.
We quantified the amount of plastic found in food loads delivered to nestlings in Cassin's Auklet (Ptychoramphus aleuticus), a small, zooplanktivorous seabird, on Triangle Island, British Columbia, in 1996–2016. The density of plastic in surrounding waters is moderately high, yet few food loads contained any plastic (3 of 850), and none more than two pieces. That result accords well with previous observations on the other four North Pacific auklets (Aethia spp.), leading us to conclude that true auklets rarely transfer plastic to nestlings. However, many hatch-year Cassin's Auklets found dead in coastal British Columbia, Washington and Oregon during the mass mortality event of fall and winter 2014–15 had plastic in their ventriculi. We suggest that these plastic particles would have been obtained at sea after fledging, perhaps while the birds transited south through a region of high plastic density off the west coast of Vancouver Island, Washington and Oregon.
Afficher plus [+] Moins [-]Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C). Part 1. The Irish Sea Texte intégral
2017
Muir, Graham K.P. | Tierney, Kieran M. | Cook, Gordon T. | MacKinnon, Gillian | Howe, John A. | Heymans, Johanna J. | Hughes, D. J. (David J.) | Xu, Sheng
Ecosystem uptake and transfer processes of Sellafield-derived radiocarbon (14C) within the Irish Sea were examined. Highly variable activities in sediment, seawater and biota indicate complex 14C dispersal and uptake dynamics. All east basin biota exhibited 14C enrichments above ambient background while most west basin biota had 14C activities close to background, although four organisms including two slow-moving species were significantly enriched. The western Irish Sea gyre is a suggested pathway for transfer of 14C to the west basin and retention therein. Despite ongoing Sellafield 14C discharges, organic sediments near Sellafield were significantly less enriched than associated benthic organisms. Rapid scavenging of labile, 14C-enriched organic material by organisms and mixing to depth of 14C-enriched detritus arriving at the sediment/water interface are proposed mechanisms to explain this. All commercially important fish, crustaceans and molluscs showed 14C enrichments above background; however, the radiation dose from their consumption is extremely low and radiologically insignificant.
Afficher plus [+] Moins [-]Production of sorbent from paper industry solid waste for oil spill cleanup Texte intégral
2017
Demirel Bayık, G. | Altın, A.
The aim of the study is to select a cellulosic waste material from paper industry solid wastes and process it for sorbent production. Four different solid wastes were collected from a local paper production facility and rejects were selected due to its sorption capacity and processability. Oil sorption experiments were conducted according to the ASTM F 726-12 method. Effect of sorbent dosage, contact and dripping time, recovery of the oil, reusability of the sorbent and sorption from the water surface were also determined. Maximum oil sorption capacity was determined as 9.67, 12.92 and 12.84g/g for diesel oil, 0W30 and 10W30 motor oils respectively for the static test and 8.27, 10.45 and 11.69g/g for the dynamic test. An efficient and low-cost sorbent was produced from paper industry rejects that can be used on land and on water.
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