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Metal concentrations in the growth bands of Porites sp.: A baseline record on the history of marine pollution in the Gulf of Mannar, India Полный текст
2015
Krishnakumar, S. | Ramasamy, S. | Magesh, N.S. | Chandrasekar, N. | Simon Peter, T.
The present study was carried out on the Porites coral growth bands (1979 to 2014) to measure the metal accumulation for assessing the environmental pollution status. The concentrations of studied metals are compared with similar global studies, which indicate that the metals are probably derived from natural sources. The identical peaks of Fe and Mn are perfectly matched with Cu, Cr and Ni concentrations. However, the metal profile trend is slightly depressed from a regular trend in Zn, Cd and Pb peaks. The metal accumulation affinity of the reef skeleton is ranked in the following order Cr>Cd>Pb>Fe>Mn>Cu>Ni>Zn. The distribution of metal constituents in coral growth bands is primarily controlled by Fe and Mn in the reef skeleton. Other reef associated metals such as Pb and Cd are derived from other sources like coastal developments and anthropogenic sources.
Показать больше [+] Меньше [-]Characterizing the parent and oxygenated polycyclic aromatic hydrocarbons in mangrove sediments of Hong Kong Полный текст
2015
Wang, Xiaowei | Yuan, Ke | Yang, Lihua | Lin, Li | Tam, Nora F.Y. | Chen, Baowei | Luan, Tiangang
Parent and oxygenated polycyclic aromatic hydrocarbons (PAHs) were investigated in mangrove sediments of Hong Kong. Most of the analytes were detected, and the dominant carbonylic and hydroxylated PAHs in mangrove sediments were 9-fluorenone and 2-hydroxy fluorene, respectively. The concentration of 9-fluorenone and 9,10-anthraquinone was higher than their parent PAHs. Moreover, the concentration of total organic matter (TOM) related with those of the parent PAHs and carbonylic PAHs, except for hydroxylated PAHs, which indicated that TOM was not the only factor regulating the distribution of oxygenated PAHs. Nevertheless, the parent PAHs in mangrove sediments was correlated positively with carbonylic PAHs which demostrated not only the similar source but also the fate of these two compound class. However, hydroxylated PAHs had different source by comparing with parent PAHs and carbonylic PAHs, they were probably originated from biodegradation and accumulated in mangrove sediments.
Показать больше [+] Меньше [-]Applying sediment quality guidelines on soft sediments of the Gulf of Finland, Baltic Sea Полный текст
2015
Vallius, Henry
The Gulf of Finland is known to have been rather largely contaminated by heavy metals during the last half of the 20th century, but indications of recovery have been reported. In order to investigate the recent levels of heavy metals and arsenic in the uppermost soft sediments of the off-shore Gulf of Finland coring of altogether 23 sites were performed. The subsamples of the cores are 605 in total and thus give a good picture of heavy metal levels in the surface sediments during the first decade of this century. In order to evaluate methods and predict sediment toxicity the sediment concentrations are compared to American SQG:s. Majority of the subsamples exceeded the threshold levels of both used SQG:s, but some exceeded also the midrange effects quality guidelines. As, Cd, Hg, and Zn concentrations still occur at unacceptably high levels in sediments of the off-shore Gulf of Finland.
Показать больше [+] Меньше [-]Mercury concentrations in feathers of marine birds in Arctic Canada Полный текст
2015
Mallory, Mark L. | Braune, Birgit M. | Provencher, Jennifer F. | Callaghan, D Benjamin | Gilchrist, H Grant | Edmonds, Samuel T. | Allard, Karel | O’Driscoll, Nelson J.
Mercury (Hg) concentrations are a concern in the Canadian Arctic, because they are relatively high compared to background levels and to similar species farther south, and are increasing in many wildlife species. Among marine birds breeding in the Canadian Arctic, Hg concentrations have been monitored regularly in eggs and intermittently in livers, but feathers have generally not been used as an indicator of Hg exposure or burden. We examined Hg concentrations in six marine bird species in the Canadian Arctic. Ivory gull Pagophila eburnea, feather Hg was exceptionally high, while glaucous gull Larus hyperboreus feather Hg was unexpectedly low, and ratios of feather THg to egg THg varied across species. The proportion of total Hg that was comprised of methyl Hg in ivory gull feathers was lower than in other species, and may be related to photo-demethylation or keratin breakdown in semi-opaque feather tissue.
Показать больше [+] Меньше [-]Microplastic contamination in brown shrimp (Crangon crangon, Linnaeus 1758) from coastal waters of the Southern North Sea and Channel area Полный текст
2015
Devriese, Lisa I. | van der Meulen, Myra D. | Maes, Thomas | Bekaert, Karen | Paul Pont, Ika | Frère, Laura | Robbens, Johan | Vethaak, A Dick
This study assessed the capability of Crangon crangon (L.), an ecologically and commercially important crustacean, of consuming plastics as an opportunistic feeder. We therefore determined the microplastic content of shrimp in shallow water habitats of the Channel area and Southern part of the North Sea. Synthetic fibers ranging from 200μm up to 1000μm size were detected in 63% of the assessed shrimp and an average value of 0.68±0.55microplastics/g w. w. (1.23±0.99microplastics/shrimp) was obtained for shrimp in the sampled area. The assessment revealed no spatial patterns in plastic ingestion, but temporal differences were reported. The microplastic uptake was significantly higher in October compared to March. The results suggest that microplastics >20μm are not able to translocate into the tissues.
Показать больше [+] Меньше [-]Inactivation of microalgae in ballast water with pulse intense light treatment Полный текст
2015
Feng, Daolun | Shi, Jidong | Sun, Dan
The exotic emission of ballast water has threatened the coastal ecological environment and people’s health in many countries. This paper firstly introduces pulse intense light to treat ballast water. 99.9±0.09% inactivation of Heterosigma akashiwo and 99.9±0.16% inactivation of Pyramimonas sp. are observed under treatment conditions of 350V pulse peak voltage, 15Hz pulse frequency, 5ms pulse width and 1.78L/min flow rate. The energy consumption of the self-designed pulse intense light treatment system is about 2.90–5.14 times higher than that of the typical commercial UV ballast water treatment system. The results indicate that pulse intense light is an effective technique for ballast water treatment, while it is only a competitive one when drastic decreasing in energy consumption is accomplished.
Показать больше [+] Меньше [-]Magnetic properties of sediments in cores from the Mandovi estuary, western India: Inferences on provenance and pollution Полный текст
2015
Prajith, A. | Rao, V Purnachandra | Kessarkar, Pratima M.
Magnetic properties of sediments were investigated in 7 gravity cores recovered along a transect of the Mandovi estuary, western India to understand their provenance and pollution. The maximum magnetic susceptibility of sediments was at least 6 times higher in the upper/middle estuary than in lower estuary/bay. The χfd% and χARM/SIRM of sediments indicated coarse, multi-domain and pseudo-single domain magnetic grains, resembling ore material in the upper/middle estuary and coarse stable single domain (SSD) to fine SSD grains in the lower estuary/bay. Mineralogy parameters indicated hematite and goethite-dominated sediments in the upper/middle estuary and magnetite-dominated sediments in the lower estuary/bay. Two sediment types were discernible because of deposition of abundant ore material in the upper/middle estuary and detrital sediment in the lower estuary/bay. The enrichment factor and Index of geo-accumulation of metals indicated significant to strong pollution with respect to Fe and Mn in sediments from the upper/middle estuary.
Показать больше [+] Меньше [-]The behaviour of 129I released from nuclear fuel reprocessing factories in the North Atlantic Ocean and transport to the Arctic assessed from numerical modelling Полный текст
2015
Villa, M. | López-Gutiérrez, J.M. | Suh, Kyung-Suk | Min, Byung-Il | Periáñez, R.
A quantitative evaluation of the fate of 129I, released from the European reprocessing plants of Sellafield (UK) and La Hague (France), has been made by means of a Lagrangian dispersion model. Transport of radionuclides to the Arctic Ocean has been determined. Thus, 5.1 and 16.6TBq of 129I have been introduced in the Arctic from Sellafield and La Hague respectively from 1966 to 2012. These figures represent, respectively, 48% and 55% of the cumulative discharge to that time. Inventories in the North Atlantic, including shelf seas, are 4.4 and 13.8TBq coming from Sellafield and La Hague respectively. These figures are significantly different from previous estimations based on field data. The distribution of these inventories among several shelf seas and regions has been evaluated as well. Mean ages of tracers have been finally obtained, making use of the age-averaging hypothesis. It has been found that mean ages for Sellafield releases are about 3.5year larger than for La Hague releases.
Показать больше [+] Меньше [-]Environmental factors modulating the extent of impact in coastal invasions: The case of a widespread invasive caprellid (Crustacea: Amphipoda) in the Iberian Peninsula Полный текст
2015
Ros, Macarena | Vázquez-Luis, Maite | Guerra-García, José M.
Environmental factors modulating the extent of impact in coastal invasions: The case of a widespread invasive caprellid (Crustacea: Amphipoda) in the Iberian Peninsula Полный текст
2015
Ros, Macarena | Vázquez-Luis, Maite | Guerra-García, José M.
Understanding the respective roles of environment and interspecific interactions in shaping species’ distributions is a critical aspect in determining the potential impacts of newcomer species on occupied habitats. The invasive caprellid amphipod Caprella scaura has successfully spread along southern Europe in a short time period, coinciding with a decline in the population of an ecologically similar congener, Caprella equilibra. To understand the mechanisms underlying the establishment success of this aggressive species and its potential role in shaping C. equilibra’s distribution, we analyze the biotic and abiotic factors involved in the patterns of distribution and co-occurrence of both species along the Iberian Peninsula and northern Africa. Our analyses support that C. scaura is competitively displacing C. equilibra from the study area, but also point out the critical role of salinity and temperature in modulating this interaction and limiting the invasive success of C. scaura on the Iberian North-Atlantic coast.
Показать больше [+] Меньше [-]Environmental factors modulating the extent of impact in coastal invasions: The case of a widespread invasive caprellid (Crustacea: Amphipoda) in the Iberian Peninsula Полный текст
2015
Ros Clemente, Macarena | Vázquez-Luis, Maite | Guerra García, José Manuel | Universidad de Sevilla. Departamento de Zoología | Ministerio de Economía y Competitividad (MINECO). España | Junta de Andalucía
Understanding the respective roles of environment and interspecific interactions in shaping species' distributions is a critical aspect in determining the potential impacts of newcomer species on occupied habitats. The invasive caprellid amphipod Caprella scaura has successfully spread along southern Europe in a short time period, coinciding with a decline in the population of an ecologically similar congener, Caprella equilibra. To understand the mechanisms underlying the establishment success of this aggressive species and its potential role in shaping C. equilibra's distribution, we analyze the biotic and abiotic factors involved in the patterns of distribution and co-occurrence of both species along the Iberian Peninsula and northern Africa. Our analyses support that C. scaura is competitively displacing C. equilibra from the study area, but also point out the critical role of salinity and temperature in modulating this interaction and limiting the invasive success of C. scaura on the Iberian North-Atlantic coast. | Ministerio de Economía y Competitividad CGL2011-22474 | Junta de Andalucía P11-RNM-7041
Показать больше [+] Меньше [-]Seasonal oxygen depletion in the North Sea, a review Полный текст
2015
Topcu, H.D. | Brockmann, U.H.
Seasonal mean oxygen depletion in offshore and coastal North Sea bottom waters was shown to range between 0.9 and 1.8mg/L, corresponding to 95–83% saturation, between July and October over a 30-year assessment period (1980–2010). The magnitude of oxygen depletion was controlled by thermal stratification, modulated by water depth and nitrogen availability. Analyses were based on about 19,000 combined data sets. Eutrophication problem areas were identified mainly in coastal waters by oxygen minima, the lower 10th percentile of oxygen concentrations, and deviations of oxygen depletion from correlated stratification values. Connections between oxygen consumption and nitrogen sources and conversion, including denitrification, were indicated by correlations. Mean oxygen consumption reflected a minimum seasonal turnover of 3.1gN/m2 in the south-eastern North Sea, including denitrification of 1gN/m2. Oxygen depletion was underestimated in shallow coastal waters due to repeated erosion of stratification as indicated by local high variability.
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