خيارات البحث
النتائج 581 - 590 من 1,546
Laboratory testing protocol for the impact of dispersed petrochemicals on seagrass النص الكامل
2012
Wilson, K.G. | Ralph, P.J.
To improve the effectiveness of oil spill mitigation, we developed a rapid, logistically simple protocol to detect petrochemical stress on seagrass. Sections of leaf blades from Zostera muelleri subsp. capricorni were exposed to the water accommodated fraction (WAF) of non-dispersed and dispersed Tapis crude oil and fuel oil (IFO-380) for 5h. Photosynthetic health was monitored by assessing changes in effective quantum yield of photosystem II (ΔF/Fₘ ′) and chlorophyll a pigment concentrations. Loss of total petroleum hydrocarbons (TPH) was measured using an oil-in-water fluorometer, whilst GC–MS analyses quantified the hydrocarbon components within each treatment. Few significant differences were detected in the chlorophyll a pigment analyses; however, ΔF/Fₘ ′ appeared sensitive to petrochemical exposure. Dispersing both types of oil resulted in a substantial increase in the TPH of the WAF and was generally correlated with a greater physiological impact to the seagrass health, compared with the oil alone.
اظهر المزيد [+] اقل [-]Razorbills (Alca torda) as bioindicators of mercury pollution in the southwestern Mediterranean النص الكامل
2012
Espín, Silvia | Martínez-López, Emma | Gómez-Ramírez, Pilar | María-Mojica, Pedro | García-Fernández, Antonio J.
Levels of mercury (Hg) were analyzed in the tissues of 50 Razorbills (Alca torda), from the Mediterranean area, which had drowned in fishing nets. The mercury distribution pattern in tissues was similar to those of other studies (liver>feather vane>kidney>muscle>brain>feather shaft), with mercury concentrations of 2.85±0.90, 2.66±1.60, 2.23±0.87, 1.54±0.54, 1.48±0.54 and 1.30±0.76mg/kg (dry weight), respectively. It could be considered that Razorbills in the southwestern Mediterranean were chronically exposed to relatively low levels of MeHg, probably below 0.5ppm, via dietary intake. We have proposed prediction equations for brain and kidney Hg concentrations using feather shafts as non-invasive samples. This work provides a solid understanding of Razorbill Hg exposure both in their wintering and breeding grounds, and shows that this species can be useful for assessing marine environmental health in the Mediterranean area.
اظهر المزيد [+] اقل [-]Persistent organic pollutants in juvenile Magellan penguins (Spheniscus magellanicus) found on the northern shore of the state of São Paulo and southern shore of the state of Rio de Janeiro, Brazil النص الكامل
2012
Baldassin, Paula | Taniguchi, Satie | Gallo, Hugo | Silva, Reinaldo José | Montone, Rosalinda Carmela
In the present study, persistent organic pollutants (POPs) were determined in 25 livers from Magellanic penguins, Spheniscus magellanicus, found on the state of São Paulo and Rio de Janeiro (Brazil). The following concentrations of POPs (wet weight) were found: ∑ PCBs: 18.9–775.8ngg⁻¹; ∑ DDTs: 2.3–275ngg⁻¹; and ∑ HCHs: 1.0–11.8ngg⁻¹. Among the PCBs, there was a predominance of hexachlorobiphenyls (138 and 153) and heptachlorobiphenyls (180 and 187). Among the organochlorines, DDT predominated. Through histopathologic exams a positive correlation was found between HCB and cardiovascular failure (p=0.012), as HCB values (wet weight) were 6.33–96.49ngg⁻¹ for positive animals and 2.45–19.63ngg⁻¹ for negative animals. Studies on POPs in Magellan penguins contribute to a better understanding of the distribution and trends of these pollutants in the western South Atlantic Ocean.
اظهر المزيد [+] اقل [-]Using EUNIS habitat classification for benthic mapping in European seas: Present concerns and future needs النص الكامل
2012
Galparsoro, Ibon | Connor, David W. | Borja, Angel | Aish, Annabelle | Amorim, Patricia | Bajjouk, Touria | Chambers, Caroline | Coggan, Roger | Dirberg, Guillaume | Ellwood, Helen | Evans, Douglas | Goodin, Kathleen L. | Grehan, Anthony | Haldin, Jannica | Howell, K. L. (Kerry L.) | Jenkins, Chris | Michez, Noëmie | Mo, Giulia | Buhl-Mortensen, Pål | Pearce, B. (Bryony) | Populus, Jacques | Salomidi, Maria | Sánchez, Francisco | Serrano, Alberto | Shumchenia, Emily | Tempera, Fernando | Vasquez, Mickaël
Using EUNIS habitat classification for benthic mapping in European seas: Present concerns and future needs النص الكامل
2012
Galparsoro, Ibon | Connor, David W. | Borja, Angel | Aish, Annabelle | Amorim, Patricia | Bajjouk, Touria | Chambers, Caroline | Coggan, Roger | Dirberg, Guillaume | Ellwood, Helen | Evans, Douglas | Goodin, Kathleen L. | Grehan, Anthony | Haldin, Jannica | Howell, K. L. (Kerry L.) | Jenkins, Chris | Michez, Noëmie | Mo, Giulia | Buhl-Mortensen, Pål | Pearce, B. (Bryony) | Populus, Jacques | Salomidi, Maria | Sánchez, Francisco | Serrano, Alberto | Shumchenia, Emily | Tempera, Fernando | Vasquez, Mickaël
The EUNIS (European Union Nature Information System) habitat classification system aims to provide a common European reference set of habitat types within a hierarchical classification, and to cover all terrestrial, freshwater and marine habitats of Europe. The classification facilitates reporting of habitat data in a comparable manner, for use in nature conservation (e.g. inventories, monitoring and assessments), habitat mapping and environmental management. For the marine environment the importance of a univocal habitat classification system is confirmed by the fact that many European initiatives, aimed at marine mapping, assessment and reporting, are increasingly using EUNIS habitat categories and respective codes. For this reason substantial efforts have been made to include information on marine benthic habitats from different regions, aiming to provide a comprehensive geographical coverage of European seas. However, there still remain many concerns on its applicability as only a small fraction of Europe’s seas are fully mapped and increasing knowledge and application raise further issues to be resolved. This paper presents an overview of the main discussion and conclusions of a workshop, organised by the MeshAtlantic project, focusing upon the experience in using the EUNIS habitats classification across different countries and seas, together with case studies. The aims of the meeting were to: (i) bring together scientists with experience in the use of the EUNIS marine classification and representatives from the European Environment Agency (EEA); (ii) agree on enhancements to EUNIS that ensure an improved representation of the European marine habitats; and (iii) establish practices that make marine habitat maps produced by scientists more consistent with the needs of managers and decision-makers. During the workshop challenges for the future development of EUNIS were identified, which have been classified into five categories: (1) structure and hierarchy; (2) biology; (3) terminology; (4) mapping; and (5) future development. The workshop ended with a declaration from the attendees, with recommendations to the EEA and European Topic Centre on Biological Diversity, to take into account the outputs of the workshop, which identify weaknesses in the current classification and include proposals for its modification, and to devise a process to further develop the marine component of the EUNIS habitat classification.
اظهر المزيد [+] اقل [-]Using EUNIS habitat classification for benthic mapping in European seas: Present concerns and future needs
2012
Galparsoro, D.W. | Connor, A. | Borja, A. | Aish, P. | Amorim, T. | Bajjouk, C. | Chambers, R. | Coggan, G. | Dirberg, H. | Ellwood, D. | Evans, D. | Goodin, K.L. | Grehan, A. | Haldin, J. | Howell, K. | Jenkins, Ch. | Michez, N. | Mo, G. | Buhl-Mortensen, P. | Pearce, B. | Populus, J. | Salomidi, M. | Sánchez, F. | Serrano-López, A. (Alberto) | Shumchenia, E. | Tempera, F. | Vásquez, M.
Using EUNIS habitat classification for benthic mapping in European seas: Present concerns and future needs النص الكامل
2012
Galparsoro, Ibon | Connor, David W. | Borja, Angel | Aish, Annabelle | Amorim, Patricia | Bajjouk, Touria | Chambers, Caroline | Coggan, Roger | Dirberg, Guillaume | Ellwood, Helen | Evans, Douglas | Goodin, Kathleen L. | Grehan, Anthony | Haldin, Jannica | Howell, Kerry | Jenkins, Chris | Michez, Noemie | Mo, Giulia | Buhl-mortensen, Pal | Pearce, Bryony | Populus, Jacques | Salomidi, Maria | Sanchez, Francisco | Serrano, Alberto | Shumchenia, Emily | Tempera, Fernando | Vasquez, Mickael
The EUNIS (European Union Nature Information System) habitat classification system aims to provide a common European reference set of habitat types within a hierarchical classification, and to cover all terrestrial, freshwater and marine habitats of Europe. The classification facilitates reporting of habitat data in a comparable manner, for use in nature conservation (e.g. inventories, monitoring and assessments), habitat mapping and environmental management. For the marine environment the importance of a univocal habitat classification system is confirmed by the fact that many European initiatives, aimed at marine mapping, assessment and reporting, are increasingly using EUNIS habitat categories and respective codes. For this reason substantial efforts have been made to include information on marine benthic habitats from different regions, aiming to provide a comprehensive geographical coverage of European seas. However, there still remain many concerns on its applicability as only a small fraction of Europe's seas are fully mapped and increasing knowledge and application raise further issues to be resolved. This paper presents an overview of the main discussion and conclusions of a workshop, organised by the MeshAtlantic project, focusing upon the experience in using the EUNIS habitats classification across different countries and seas, together with case studies. The aims of the meeting were to: (i) bring together scientists with exper_ience_in the use of the EUNIS marine classification and representatives from the European Environment Agency (EEA); (ii) agree on enhancements to EUNIS that ensure an improved representation of the European marine habitats; and (iii) establish practices that make marine habitat maps produced by scientists more consistent with the needs of managers and decision-makers. During the workshop challenges for the future development of EUNIS were identified, which have been classified into five categories: (1) structure and hierarchy; (2) biology; (3) terminology; (4) mapping; and (5) future development. The workshop ended with a declaration from the attendees, with recommendations to the EEA and European Topic Centre on Biological Diversity, to take into account the outputs of the workshop, which identify weaknesses in the current classification and include proposals for its modification, and to devise a process to further develop the marine component of the EUNIS habitat classification. (C) 2012 Elsevier Ltd. All rights reserved.
اظهر المزيد [+] اقل [-]Mercury levels in selected bycatch fish species from industrial shrimp-trawl fishery in the SE Gulf of California النص الكامل
2012
Ruelas-Inzunza, Jorge | Sánchez-Osuna, Karla | Amezcua-Martínez, Felipe | Spanopoulos-Zarco, Pamela | Manzano-Luna, Lucero
Baseline Hg concentration in bycatch fish from the SE Gulf of California were determined in muscle and liver of 19 species. Levels of Hg in muscle were compared with legal limits of this element in national and international legislation. Considering all fish species, mean concentrations in liver (2.458±1.997μgg⁻¹) were significantly higher (p<0.05) than in muscle (0.993±0.670μgg⁻¹). The sequence of averaged Hg concentrations in most ichthyofauna was liver>muscle. Highest level of Hg in muscle (2.556μgg⁻¹) and liver (7.515μgg⁻¹) corresponded to Diapterus peruvianus and Ophioscion strabo, respectively. Considering muscle samples, none of the species had levels of Hg above the limit (1.0μgg⁻¹ wet weight) in the Mexican legislation; with respect to the Japanese (0.4μgg⁻¹ wet weight) and British (0.3μgg⁻¹ wet weight) legislations, 26.3% and 31.6% of the species respectively, were above the corresponding limits.
اظهر المزيد [+] اقل [-]Nanoporous polystyrene fibers for oil spill cleanup النص الكامل
2012
Lin, Jinyou | Shang, Yanwei | Ding, Bin | Yang, Jianmao | Yu, Jianyong | Al-Deyab, Salem S.
The development of oil sorbents with high sorption capacity, low cost, scalable fabrication, and high selectivity is of great significance for water environmental protection, especially for oil spillage on seawater. In this work, we report nanoporous polystyrene (PS) fibers prepared via a one-step electrospinning process used as oil sorbents for oil spill cleanup. The oleophilic–hydrophobic PS oil sorbent with highly porous structures shows a motor oil sorption capacity of 113.87g/g, approximately 3–4times that of natural sorbents and nonwoven polypropylene fibrous mats. Additionally, the sorbents also exhibit a relatively high sorption capacity for edible oils, such as bean oil (111.80g/g) and sunflower seed oil (96.89g/g). The oil sorption mechanism of the PS sorbent and the sorption kinetics were investigated. Our nanoporous material has great potential for use in wastewater treatment, oil accident remediation and environmental protection.
اظهر المزيد [+] اقل [-]Monitoring of suspended sediment variation using Landsat and MODIS in the Saemangeum coastal area of Korea النص الكامل
2012
Min, Jee-Eun | Ryu, Joo-Hyung | Lee, Seok | Son, SeungHyun
Suspended sediment concentration (SS) is an important indicator of marine environmental changes due to natural causes such as tides, tidal currents, and river discharges, as well as human activities such as construction in coastal regions. In the Saemangeum area on the west coast of Korea, construction of a huge tidal dyke for land reclamation has strongly influenced the coastal environment. This study used remotely sensed data to analyze the SS changes in coastal waters caused by the dyke construction. Landsat and MODIS satellite images were used for the spatial analysis of finer patterns and for the detailed temporal analysis, respectively. Forty Landsat scenes and 105 monthly composite MODIS images observed during 1985–2010 were employed, and four field campaigns (from 2005 to 2006) were performed to verify the image-derived SS. The results of the satellite data analyses showed that the seawater was clear before the dyke construction, with SS values lower than 20g/m³. These values increased continuously as the dyke construction progressed. The maximum SS values appeared just before completion of the fourth dyke. Values decreased to below 5g/m³ after dyke construction. These changes indicated tidal current modification. Some eddies and plumes were observed in the images generated from Landsat data. Landsat and MODIS can reveal that coastal water turbidity was greatly reduced after completion of the construction.
اظهر المزيد [+] اقل [-]NH₄⁺ enrichment and UV radiation interact to affect the photosynthesis and nitrogen uptake of Gracilaria lemaneiformis (Rhodophyta) النص الكامل
2012
Xu, Zhiguang | Gao, Kunshan
Solar ultraviolet radiation (UVR, 280–400nm) is known to inhibit the photosynthesis of macroalgae, whereas nitrogen availability may alter the sensitivity of the algae to UVR. Here, we show that UV-B (280–315nm) significantly reduced the net photosynthetic rate of Gracilaria lemaneiformis. This inhibition was alleviated by enrichment with ammonia, which also caused a decrease in dark respiration. The presence of both UV-A (315–400nm) and UV-B stimulated the accumulation of UV-absorbing compounds. However, this stimulation was not affected by enrichment with ammonia. The content of phycoerythrin (PE) was increased by the enrichment of ammonia only in the absence of UVR. Ammonia uptake and the activity of nitrate reductase were repressed by UVR. However, exposure to UVR had an insignificant effect on the rate of nitrate uptake. In conclusion, increased PE content associated with ammonia enrichment played a protective role against UVR in this alga, and UVR differentially affected the uptake of nitrate and ammonia.
اظهر المزيد [+] اقل [-]Kandelia obovata (S., L.) Yong tolerance mechanisms to Cadmium: Subcellular distribution, chemical forms and thiol pools النص الكامل
2012
Weng, Bosen | Xie, Xiangyu | Weiss, Dominik J. | Liu, Jingchun | Lu, Haoliang | Yan, Chongling
In order to explore the detoxification mechanisms adopted by mangrove under cadmium (Cd) stress, we investigated the subcellular distribution and chemical forms of Cd, in addition to the change of the thiol pools in Kandelia obovata (S., L.) Yong, which were cultivated in sandy culture medium treated with sequential Cd solution. We found that Cd addition caused a proportional increase of Cd in the organs of K. obovata. The investigation of subcellular distribution verified that most of the Cd was localized in the cell wall, and the lowest was in the membrane. Results showed sodium chloride and acetic acid extractable Cd fractions were dominant. The contents of non-protein thiol compounds, Glutathione and phytochelatins in K. obovata were enhanced by the increasing strength of Cd treatment. Therefore, K. obovata can be defined as Cd tolerant plant, which base on cell wall compartmentalization, as well as protein and organic acids combination.
اظهر المزيد [+] اقل [-]Modelling the impact of a La Niña event on a South West Pacific Lagoon النص الكامل
2012
Fuchs, R. | Dupouy, C. | Douillet, P. | Caillaud, M. | Mangin, A. | Pinazo, C.
In view of increasing environmental awareness and biodiversity conservation, understanding the main forcing mechanism driving biogeochemical cycles in coral reefs and lagoon coastal areas is a priority. La Niña events cause unbalanced situations in the Equatorial Pacific and result in enhanced precipitation in South West Pacific coastal areas. We investigated the impact of heavy rainfalls during the 2008 La Niña event on the New Caledonia lagoon using a 3D coupled on-line hydrodynamic–biogeochemical model. Simulations and data showed that the whole lagoon was impacted by river inputs and stronger hydrodynamics, enhancing chlorophyll-a concentration by a factor between 1.7 and 1.9. The coupled model provided new insights into plume transport, highlighting that eastern plumes can be advected northwards or can reach the South West Lagoon, depending on the balance between regional, tide-induced, and wind-induced surface currents. It also provided a synoptic view of lagoon biogeochemical–hydrodynamic response, when remote sensing data are not available due to cloud coverage.
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