Уточнить поиск
Результаты 1461-1470 из 4,045
White-faced storm-petrels Pelagodroma marina predated by gulls as biological monitors of plastic pollution in the pelagic subtropical Northeast Atlantic Полный текст
2016
Furtado, Ricardo | Menezes, Dilia | Santos, Carolina Jardim | Catry, Paulo
White-faced storm-petrels Pelagodroma marina predated by gulls as biological monitors of plastic pollution in the pelagic subtropical Northeast Atlantic Полный текст
2016
Furtado, Ricardo | Menezes, Dilia | Santos, Carolina Jardim | Catry, Paulo
Marine plastic pollution is rapidly growing and is a source of major concern. Seabirds often ingest plastic debris and are increasingly used as biological monitors of plastic pollution. However, virtually no studies have assessed plastics in seabirds in the deep subtropical North Atlantic. We investigated whether remains of white-faced storm-petrels (WFSP) present in gull pellets could be used for biomonitoring. We analysed 263 pellets and 79.0% of these contained plastic debris originating in the digestive tract of WFSP. Pellets with no bird prey did not contain plastics. Most debris were fragments (83.6%) with fewer plastic pellets (8.2%). Light-coloured plastics predominated (71.0%) and the most frequent polymer was HDPE (73.0%). Stable isotopes in toe-nails of WFSP containing many versus no plastics did not differ, indicating no individual specialisation leading to differential plastic ingestion. We suggest WFSP in pellets are highly suitable to monitor the little known pelagic subtropical Northeast Atlantic.
Показать больше [+] Меньше [-]White-faced storm-petrels Pelagodroma marina predated by gulls as biological monitors of plastic pollution in the pelagic subtropical northeast atlantic Полный текст
2016
Furtado, Ricardo Miranda | Menezes, Dília | Santos, Carolina Jardim | Catry, Paulo
Marine plastic pollution is rapidly growing and is a source of major concern. Seabirds often ingest plastic debris and are increasingly used as biological monitors of plastic pollution. However, virtually no studies have assessed plastics in seabirds in the deep subtropical North Atlantic. We investigated whether remains of white-faced storm-petrels (WFSP) present in gull pellets could be used for biomonitoring. We analysed 263 pellets and 79.0% of these contained plastic debris originating in the digestive tract of WFSP. Pellets with no bird prey did not contain plastics. Most debris were fragments (83.6%) with fewer plastic pellets (8.2%). Light-coloured plastics predominated (71.0%) and the most frequent polymer was HDPE (73.0%). Stable isotopes in toe-nails of WFSP containing many versus no plastics did not differ, indicating no individual specialisation leading to differential plastic ingestion. We suggest WFSP in pellets are highly suitable to monitor the little known pelagic subtropical Northeast Atlantic. | Fundação para a Ciência e a Tecnologia (FCT)
Показать больше [+] Меньше [-]Absence of selenium protection against methylmercury toxicity in harbour seal leucocytes in vitro Полный текст
2016
Dāsa, Kr̥shṇā | Dupont, Aurélie | De Pauw-Gillet, Marie- Claire | Debier, Cathy | Siebert, Ursula
Absence of selenium protection against methylmercury toxicity in harbour seal leucocytes in vitro Полный текст
2016
Dāsa, Kr̥shṇā | Dupont, Aurélie | De Pauw-Gillet, Marie- Claire | Debier, Cathy | Siebert, Ursula
Previous studies described high concentrations of mercury (Hg) and selenium (Se) in the blood of harbour seals, Phoca vitulina from the North Sea. In the present study, we evaluated the in vitro potential protective effects of sodium selenite (Na2SeO3) and selenomethionine (SeMet) on cell proliferation of harbour seal lymphocytes exposed to MeHgCl 0.75μM. In vitro exposure of ConA-stimulated T lymphocytes resulted in severe inhibition of DNA synthesis, likely linked to severe loss of mitochondrial membrane potential at 0.75μM. Neither selenite nor SeMet showed a protective effect against MeHg toxicity expressed at the T lymphocyte proliferation level for harbour seals. Selenite and SeMet did not show negative effects regarding lymphocyte proliferation and mitochondrial membrane potential.To conclude, our results clearly demonstrated that MeHg affected in vitro immune cells exposure with no protective effects of selenium at a molar ratio Hg:Se of 1:10 in harbour seals from the North Sea.
Показать больше [+] Меньше [-]Absence of selenium protection against methylmercury toxicity in harbour seal leucocytes in vitro Полный текст
2016
Das, Krishna | Dupont, Aurélie | De Pauw-Gillet, Marie-Claire | Debier, Cathy | Siebert, Ursula | MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
peer reviewed | Previous studies described high concentrations of mercury (Hg) and selenium (Se) in the blood of harbour seals, Phoca vitulina from the North Sea. In the present study, we evaluated the in vitro potential protective effects of sodium selenite (Na2SeO3) and selenomethionine (SeMet) on cell proliferation of harbour seal lymphocytes exposed to MeHgCl 0.75 µM. In vitro exposure of ConA-stimulated T lymphocytes resulted in severe inhibition of DNA synthesis, likely linked to severe loss of mitochondrial membrane potential at 0.75 µM. Neither selenite nor SeMet showed a protective effect against MeHg toxicity expressed at the T lymphocyte proliferation level for harbour seals. Selenite and SeMet did not show negative effects regarding lymphocyte proliferation and mitochondrial membrane potential. To conclude, our results clearly demonstrated that MeHg affected in vitro immune cells exposure with no protective effects of selenium at a molar ratio Hg:Se of 1:10 in harbour seals from the North Sea.
Показать больше [+] Меньше [-]Plastic ingestion by pelagic and demersal fish from the North Sea and Baltic Sea Полный текст
2016
Rummel, Christoph D. | Löder, Martin G.J. | Fricke, Nicolai F. | Lang, Thomas | Griebeler, Eva-Maria | Janke, Michael | Gerdts, Gunnar
Plastic ingestion by pelagic and demersal fish from the North Sea and Baltic Sea Полный текст
2016
Rummel, Christoph D. | Löder, Martin G.J. | Fricke, Nicolai F. | Lang, Thomas | Griebeler, Eva-Maria | Janke, Michael | Gerdts, Gunnar
Plastic ingestion by marine biota has been reported for a variety of different taxa. In this study, we investigated 290 gastrointestinal tracts of demersal (cod, dab and flounder) and pelagic fish species (herring and mackerel) from the North and Baltic Sea for the occurrence of plastic ingestion. In 5.5% of all investigated fishes, plastic particles were detected, with 74% of all particles being in the microplastic (<5mm) size range. The polymer types of all found particles were analysed by means of Fourier transform infrared (FT-IR) spectroscopy. Almost 40% of the particles consisted of polyethylene (PE). In 3.4% of the demersal and 10.7% of the pelagic individuals, plastic ingestion was recorded, showing a significantly higher ingestion frequency in the pelagic feeders. The condition factor K was calculated to test differences in the fitness status between individuals with and without ingested plastic, but no direct effect was detected.
Показать больше [+] Меньше [-]Plastic ingestion by pelagic and demersal fish from the North Sea and Baltic Sea Полный текст
2016
Rummel, Christoph D. | Löder, Martin G. J. | Fricke, Nicolai F. | Lang, Thomas | Griebeler, Eva-Maria | Janke, Michael | Gerdts, Gunnar
Plastic ingestion by marine biota has been reported for a variety of different taxa. In this study, we investigated 290 gastrointestinal tracts of demersal (cod, dab and flounder) and pelagic fish species (herring and mackerel) from the North and Baltic Sea for the occurrence of plastic ingestion. In 5.5% of all investigated fishes, plastic particles were detected, with 74% of all particles being in the microplastic (< 5 mm) size range. The polymer types of all found particles were analysed by means of Fourier transform infrared (FT-IR) spectroscopy. Almost 40% of the particles consisted of polyethylene (PE). In 3.4% of the demersal and 10.7% of the pelagic individuals, plastic ingestion was recorded, showing a significantly higher ingestion frequency in the pelagic feeders. The condition factor K was calculated to test differences in the fitness status between individuals with and without ingested plastic, but no direct effect was detected
Показать больше [+] Меньше [-]Plastic ingestion by pelagic and demersal fish from the North Sea and Baltic Sea Полный текст
2016
Rummel, Christoph | Löder, Martin G. J. | Fricke, Nicolai Felix | Lang, Thomas | Griebeler, Eva-Maria | Janke, Michael | Gerdts, Gunnar
Plastic ingestion by marine biota has been reported for a variety of different taxa. In this study, we investigated 290 gastrointestinal tracts of demersal (cod, dab and flounder) and pelagic fish species (herring and mackerel) from the North and Baltic Sea for the occurrence of plastic ingestion. In 5.5% of all investigated fishes, plastic particles were detected, with 74% of all particles being in the microplastic (<5mm) size range. The polymer types of all found particles were analysed by means of Fourier transform infrared (FT-IR) spectroscopy. Almost 40% of the particles consisted of polyethylene (PE). In 3.4% of the demersal and 10.7% of the pelagic individuals, plastic ingestion was recorded, showing a significantly higher ingestion frequency in the pelagic feeders. The condition factor K was calculated to test differences in the fitness status between individuals with and without ingested plastic, but no direct effect was detected.
Показать больше [+] Меньше [-]Ability of 3 extraction methods (BCR, Tessier and protease K) to estimate bioavailable metals in sediments from Huelva estuary (Southwestern Spain) Полный текст
2016
Rosado, Daniel | Usero, José | Morillo, José
Ability of 3 extraction methods (BCR, Tessier and protease K) to estimate bioavailable metals in sediments from Huelva estuary (Southwestern Spain) Полный текст
2016
Rosado, Daniel | Usero, José | Morillo, José
The bioavailable fraction of metals (Zn, Cu, Cd, Mn, Pb, Ni, Fe, and Cr) in sediments of the Huelva estuary and its littoral of influence has been estimated carrying out the most popular methods of sequential extraction (BCR and Tessier) and a biomimetic approach (protease K extraction). Results were compared to enrichment factors found in Arenicola marina. The linear correlation coefficients (R2) obtained between the fraction mobilized by the first step of the BCR sequential extraction, by the sum of the first and second steps of the Tessier sequential extraction, and by protease K, and enrichment factors in A. marina, are at their highest for protease K extraction (0.709), followed by BCR first step (0.507) and the sum of the first and second steps of Tessier (0.465). This observation suggests that protease K represents the bioavailable fraction more reliably than traditional methods (BCR and Tessier), which have a similar ability.
Показать больше [+] Меньше [-]Ability of 3 extraction methods (BCR, Tessier and protease K) to estimate bioavailable metals in sediments from Huelva estuary (Southwestern Spain) Полный текст
2016
Rosado Alcarria, Daniel | Usero García, José | Morillo Aguado, José | Universidad de Sevilla. Departamento de Ingeniería Química y Ambiental
The bioavailable fraction of metals (Zn, Cu, Cd, Mn, Pb, Ni, Fe, and Cr) in sediments of the Huelva estuary and its littoral of influence has been estimated carrying out the most popular methods of sequential extraction (BCR and Tessier) and a biomimetic approach (protease K extraction). Results were compared to enrichment factors found in Arenicola marina. The linear correlation coefficients (R^2) obtained between the fraction mobilized by the first step of the BCR sequential extraction, by the sum of the first and second steps of the Tessier sequential extraction, and by protease K, and enrichment factors in A. marina, are at their highest for protease K extraction (0.709), followed by BCR first step (0.507) and the sum of the first and second steps of Tessier (0.465). This observation suggests that protease K represents the bioavailable fraction more reliably than traditional methods (BCR and Tessier), which have a similar ability.
Показать больше [+] Меньше [-]Prevalence of microplastics in the marine waters of Qatar Полный текст
2016
Castillo, Azenith B. | Al-Maslamani, Ibrahim | Obbard, Jeffrey Philip
Prevalence of microplastics in the marine waters of Qatar Полный текст
2016
Castillo, Azenith B. | Al-Maslamani, Ibrahim | Obbard, Jeffrey Philip
Microplastics are firmly recognized as a ubiquitous and growing threat to marine biota and their associated marine habitats worldwide. The evidence of the prevalence of microplastics was documented for the first time in the marine waters of Qatar's Exclusive Economic Zone (EEZ). An optimized and validated protocol was developed for the extraction of microplastics from plankton-rich seawater samples without loss of microplastic debris present and characterized using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy. In total 30 microplastic polymers have been identified with an average concentration of 0.71particlesm−3 (range 0–3particlesm−3). Polypropylene, low density polyethylene, polyethylene, polystyrene, polyamide, polymethyl methacrylate, cellophane, and acrylonitrile butadiene styrene polymers were characterized with majority of the microplastics either granular shape, sizes ranging from 125μm to 1.82mm or fibrous with sizes from 150μm to 15.98mm. The microplastics are evident in areas where nearby anthropogenic activities, including oil-rig installations and shipping operations are present.
Показать больше [+] Меньше [-]Prevalence of microplastics in the marine waters of Qatar Полный текст
2016
Castillo, Azenith B. | Al-Maslamani, Ibrahim | Obbard, Jeffrey Philip
Microplastics are firmly recognized as a ubiquitous and growing threat to marine biota and their associated marine habitats worldwide. The evidence of the prevalence of microplastics was documented for the first time in the marine waters of Qatar's Exclusive Economic Zone (EEZ). An optimized and validated protocol was developed for the extraction of microplastics from plankton-rich seawater samples without loss of microplastic debris present and characterized using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy. In total 30 microplastic polymers have been identified with an average concentration of 0.71 particles m− 3 (range 0–3 particles m− 3). Polypropylene, low density polyethylene, polyethylene, polystyrene, polyamide, polymethyl methacrylate, cellophane, and acrylonitrile butadiene styrene polymers were characterized with majority of the microplastics either granular shape, sizes ranging from 125 μm to 1.82 mm or fibrous with sizes from 150 μm to 15.98 mm. The microplastics are evident in areas where nearby anthropogenic activities, including oil-rig installations and shipping operations are present. | Scopus
Показать больше [+] Меньше [-]Baseline levels of oxidative stress biomarkers in species from a subtropical estuarine system (Paranaguá Bay, southern Brazil) Полный текст
2016
Sardi, Adriana E. | Renaud, Paul E. | Lana, Paulo da Cunha | Camus, Lionel
Baseline levels of oxidative stress biomarkers in species from a subtropical estuarine system (Paranaguá Bay, southern Brazil) Полный текст
2016
Sardi, Adriana E. | Renaud, Paul E. | Lana, Paulo da Cunha | Camus, Lionel
Offshore petroleum exploration has increased the risks of oil spills in coastal tropical and subtropical habitats. Monitoring tools are needed to assess and protect environmental health. We determined baseline values of antioxidant biomarkers (CAT, SOD, GPx, GST, MDA) for five ecologically relevant species in a subtropical system in southern Brazil. Regional baseline levels are compared with literature data as a basis to eventually test their efficacy as post-spill monitoring tools. Differences in the antioxidant response among species, contamination, and seasons were tested using univariate and multivariate analyses. The bivalves Anomalocardia flexuosa and Crassostrea rhizophorae and the catfish Genidens genidens emerge as suitable sentinel species. Seasonality is the main factor accounting for biomarkers variability, and not background contamination level. However, interactions between season and contamination level are also significant, indicating that biomarkers respond to complex environmental settings, a fact that needs to be fully understood for designing proper monitoring programs.
Показать больше [+] Меньше [-]Baseline levels of oxidative stress biomarkers in species from a subtropical estuarine system (Paranaguá Bay, southern Brazil) Полный текст
2016
Sardi Sulvarán, Adriana Eva | Renaud, Paul | Lana, Paulo Da Cunha | Camus, Lionel
Link to publishers version: 10.1016/j.marpolbul.2016.08.014 | Offshore petroleum exploration has increased the risks of oil spills in coastal tropical and subtropical habitats. Monitoring tools are needed to assess and protect environmental health. We determined baseline values of antioxidant biomarkers (CAT, SOD, GPx, GST, MDA) for five ecologically relevant species in a subtropical system in southern Brazil. Regional baseline levels are compared with literature data as a basis to eventually test their efficacy as post-spill monitoring tools. Differences in the antioxidant response among species, contamination, and seasons were tested using univariate and multivariate analyses. The bivalves Anomalocardia flexuosa and Crassostrea rhizophorae and the catfish Genidens genidens emerge as suitable sentinel species. Seasonality is the main factor accounting for biomarkers variability, and not background background contamination level. However, interactions between season and contamination level are also significant, indicating that biomarkers respond to complex environmental settings, a fact that needs to be fully understood for designing proper monitoring programs.
Показать больше [+] Меньше [-]Investigation of fungal volatile organic compounds in hospital air Полный текст
2016
Pantoja, Lydia Dayanne Maia | do Nascimento, Ronaldo Ferreira | de Araújo Nunes, Ana Barbara
Fungal growth within the structure of buildings or in ventilation filters generates “hidden contamination”, which cannot be detected only through visual inspection. At the beginning of development, the fungi release fungal volatile organic compounds (FVOCs) into the atmosphere, which can originate from metabolic pathways or from the enzymatic degradation of materials. This study analyzed the air quality of a public referral hospital in Fortaleza, Ceará, Brazil in terms of FVOCs, to establish ways to improve methods of monitoring and control of specific sectors in the hospital. For that, we created and validated a protocol for detection of FVOCs, using GC/MS, while fungal samples were identified by analysis of macro and micromorphology. In total, 48 samples (60.5% positive) were analyzed for FVOCs; 7 were detected in at least one of the sectors analyzed, with 2-heptanone (179.5 μg/m3) and 2-methyl-1-propanol (121.5 μg/m3) as the most abundant. With respect to fungal findings, 24 samples were analyzed, with a high number of colony-forming units per cubic meter (CFU/m3) observed in all sectors. The airborne fungal spectrum revealed the existence of 19 genera, composed predominantly by hyaline filamentous deuteromycetes. Analysis with periodic monitoring is still needed to allow improvement in the data quality. Also, further discussion on the subject in the academic and legislative environment is needed to contribute to the systematic study of aerobiology.
Показать больше [+] Меньше [-]Characterization of microplastic and mesoplastic debris in sediments from Kamilo Beach and Kahuku Beach, Hawai'i Полный текст
2016
Young, Alan M. | Elliott, James A.
Sediment samples were collected from two Hawai'ian beaches, Kahuku Beach on O'ahu and Kamilo Beach on the Big Island of Hawai'i. A total of 48,988 large microplastic and small mesoplastic (0.5–8mm) particles were handpicked from the samples and sorted into four size classes (0.5–1mm, 1–2mm, 2–4mm, 4–8mm) and nine color categories. For all sizes combined the most common plastic fragment color was white/transparent (71.8%) followed by blue (8.5%), green (7.5%), black/grey (7.3%), red/pink (2.6%), yellow (1.2%), orange (0.6%), brown (0.3%) and purple (0.2%). Color frequency distribution based on both numbers and mass of particles was not significantly different among the various size classes nor between the two beaches. White and black/grey resin pellets accounted for 11.3% of the particles collected from Kahuku Beach and 4.2% of the particles from Kamilo Beach. Plastic type based on Raman Spectrometer analysis of a small representative subsample indicated that most of the fragments were polyethylene and a few were polypropylene.
Показать больше [+] Меньше [-]Assessment of heavy metal contamination in surface sediments of the west Guangdong coastal region, China Полный текст
2016
Zhao, Guangming | Lu, Qingyuan | Ye, Siyuan | Yuan, Hongming | Ding, Xigui | Wang, Jin
Heavy metals (As, Cd, Cr, Cu, Hg, Pb, Zn), organic carbon and grain size of 237 surface sediment samples and one sediment core, taken from the west Guangdong coastal region in January 2008, were analyzed to evaluate the spatial distribution and pollution status. Results show that the ranges of the measured heavy metal concentrations in sediments are as follows: 8.33–39.49mg/kg for As, 0.1–1.49mg/kg for Cd, 33–108mg/kg for Cr, 11.5–78.8mg/kg for Cu, 0.04–0.26mg/kg for Hg, 21–73mg/kg for Pb, 56–248mg/kg for Zn. The heavy metal enrichment is closely associated with Corg and grain size. Both the metal enrichment factor and geoaccumulation index indicate that there was no detected pollution on metals As, Cr, Cu, Pb in our study area and a slight to moderate contamination of Cd, Hg and Zn. However, As, Cr and Cu have showed a certain risk.
Показать больше [+] Меньше [-]Hydrodynamic properties of San Quintin Bay, Baja California: Merging models and observations Полный текст
2016
Melaku Canu, Donata | Aveytua-Alcázar, Leslie | Camacho-Ibar, Victor F. | Querin, Stefano | Solidoro, Cosimo
We investigated the physical dynamics of San Quintin Bay, a coastal lagoon located on the Pacific coast of northern Baja California, Mexico. We implemented, validated and used a finite element 2-D hydrodynamic model to characterize the spatial and temporal variability of the hydrodynamic of the bay in response to variability in the tidal regime and in meteorological forcing patterns. Our analysis of general circulation, residual currents, residence times, and tidal propagation delays allowed us to characterize spatial variability in the hydrodynamic basin features. The eulerian water residence time is –on average and under reference conditions– approximately 7days, although this can change significantly by region and season and under different tidal and meteorological conditions. Ocean upwelling events that bring colder waters into the bay mouth affect hydrodynamic properties in all areas of the lagoon and may affect ecological dynamics. A return to pre-upwelling conditions would take approximately 10days.
Показать больше [+] Меньше [-]