خيارات البحث
النتائج 1211 - 1220 من 4,044
Spatial variability and response to anthropogenic pressures of assemblages dominated by a habitat forming seaweed sensitive to pollution (northern coast of Alboran Sea) النص الكامل
2016
Bermejo, Ricardo | de la Fuente, Gina | Ramírez-Romero, Eduardo | Vergara, Juan J. | Hernández, Ignacio
The Cystoseira ericaefolia group is conformed by three species: C. tamariscifolia, C. mediterranea and C. amentacea. These species are among the most important habitat forming species of the upper sublittoral rocky shores of the Mediterranean Sea and adjacent Atlantic coast. This species group is sensitive to human pressures and therefore is currently suffering important losses. This study aimed to assess the influence of anthropogenic pressures, oceanographic conditions and local spatial variability in assemblages dominated by C. ericaefolia in the Alboran Sea. The results showed the absence of significant effects of anthropogenic pressures or its interactions with environmental conditions in the Cystoseira assemblages. This fact was attributed to the high spatial variability, which is most probably masking the impact of anthropogenic pressures. The results also showed that most of the variability occurred on at local levels. A relevant spatial variability was observed at regional level, suggesting a key role of oceanographic features in these assemblages.
اظهر المزيد [+] اقل [-]Plastic ingestion by Atlantic cod (Gadus morhua) from the Norwegian coast النص الكامل
2016
Bråte, Inger Lise N. | Eidsvoll, David P. | Steindal, Calin Constantin | Thomas, Kevin V.
This study documents the occurrence of microplastic (<5mm), mesoplastics (5–20mm) and macroplastic (>20mm) in Atlantic cod (Gadus morhua), a common and economically important species of marine fish in Norway. Fish stomachs (n=302) were examined from six different locations along the coast of Norway. Three percent of the individual stomachs contained items identified by Fourier transform infrared spectroscopy (FTIR) as synthetic polymers. Bergen City Harbour was a hotspot with 27% of the cod examined found to contain plastic. Polyester was the most frequently detected polymer. All bar one of the stomachs that contained plastic were full of organic stomach content, suggesting a plastic gut clearance rate similar to the ingested food. It is proposed that stomach fullness is an important metric in order to avoid underestimations when assessing the levels of microplastic ingested by fish.
اظهر المزيد [+] اقل [-]Regional differences in plastic ingestion among Southern Ocean fur seals and albatrosses النص الكامل
2016
Ryan, Peter G. | de Bruyn, P.J Nico | Bester, Marthán N.
We provide data on regional differences in plastic ingestion for two Southern Ocean top predators: Arctocephalus fur seals and albatrosses (Diomedeidae). Fur seals breeding on Macquarie Island in the 1990s excreted small (mainly 2–5mm) plastic fragments, probably derived secondarily from myctophid fish. No plastic was found in the scats of these seals breeding on three islands in the southwest Indian and central South Atlantic Oceans, despite myctophids dominating their diets at these locations. Compared to recent reports of plastic ingestion by albatrosses off the east coast of South America, we confirm that plastic is seldom found in the stomachs of Thalassarche albatrosses off South Africa, but found no Diomedea albatrosses to contain plastic, compared to 26% off South America. The reasons for such regional differences are unclear, but emphasize the importance of reporting negative as well as positive records of plastic ingestion by marine biota.
اظهر المزيد [+] اقل [-]Metabolic performance of the coral reef fish Siganus guttatus exposed to combinations of water borne diesel, an anionic surfactant and elevated temperature in Indonesia النص الكامل
2016
Baum, G. | Kegler, P. | Scholz-Böttcher, B.M. | Alfiansah, Y.R. | Abrar, M. | Kunzmann, A.
Jakarta Bay in Indonesia and its offshore island chain, the Thousand Islands, are facing extreme pollution. Surfactants and diesel-borne compounds from sewage and bilge water discharges are common pollutants. However, knowledge of their effects on reef fish physiology is scarce. This study investigated combined and single effects of a) the water accommodated fraction of diesel (WAF-D, determined by ƩEPA polycyclic aromatic hydrocarbons (PAHs)) and b) the surfactant linear alkylbenzene sulfonate (LAS) on metabolic performance of the coral reef fish Siganus guttatus. Responses to combinations of each pollutant with elevated temperature (+3°C) were determined. Short-term exposure to WAF-D led to a significant decrease in standard metabolic rates, while LAS led to an increase. During combined exposure, metabolic depression was observed. Effects of pollutants were not amplified by elevated temperature. This study highlights the need to reduce import of these pollutants and to avoid negative long-term effects on fish health.
اظهر المزيد [+] اقل [-]The significance of cephalopod beaks in marine ecology studies: Can we use beaks for DNA analyses and mercury contamination assessment? النص الكامل
2016
Xavier, José Carlos | Ferreira, Sônia | Tavares, Sílvia | Santos, Nuno | Mieiro, Cláudia Leopoldina | Trathan, Phil N. | Lourenço, Silvia | Martinho, Filipe | Steinke, Dirk | Seco, José | Pereira, Eduarda | Pardal, Miguel | Cherel, Yves
Cephalopod beaks found in the diet of predators have been a major source of scientific information. In this study, we evaluated the usefulness of DNA and contaminants analysis (total mercury — T-Hg) in cephalopod beaks in order to assess their applicability as tools in marine ecology studies. We concluded that, when applying DNA techniques to cephalopod beaks from Antarctic squid species, when using flesh attached to those beaks, it was possible to obtain DNA and to successfully identify cephalopod species; DNA was not found on the beaks themselves. This study also showed that it is possible to obtain information on T-Hg concentrations in beaks: the T-Hg concentrations found in the beaks were 6 to 46 times lower than in the flesh of the same cephalopod species. More research on the relationships of mercury concentrations in cephalopod beaks (and other tissues), intra- and inter-specifically, are needed in the future.
اظهر المزيد [+] اقل [-]A novel approach for estimating the removal efficiencies of endocrine disrupting chemicals and heavy metals in wastewater treatment processes النص الكامل
2016
Chiu, Jill M.Y. | Degger, Natalie | Leung, Jonathan Y.S. | Po, Beverly H.K. | Zheng, Gene J. | Richardson, Bruce J. | Lau, T.C. | Wu, Rudolf S.S.
The wide occurrence of endocrine disrupting chemicals (EDCs) and heavy metals in coastal waters has drawn global concern, and thus their removal efficiencies in sewage treatment processes should be estimated. However, low concentrations coupled with high temporal fluctuations of these pollutants present a monitoring challenge. Using semi-permeable membrane devices (SPMDs) and Artificial Mussels (AMs), this study investigates a novel approach to evaluating the removal efficiency of five EDCs and six heavy metals in primary treatment, secondary treatment and chemically enhanced primary treatment (CEPT) processes. In general, the small difference between maximum and minimum values of individual EDCs and heavy metals measured from influents/effluents of the same sewage treatment plant suggests that passive sampling devices can smooth and integrate temporal fluctuations, and therefore have the potential to serve as cost-effective monitoring devices for the estimation of the removal efficiencies of EDCs and heavy metals in sewage treatment works.
اظهر المزيد [+] اقل [-]Seasonal variation and annual trends of metals and metalloids in the blood of the Little Penguin (Eudyptula minor) النص الكامل
2016
Finger, Annett | Lavers, Jennifer L. | Orbell, John D. | Dann, Peter | Nugegoda, Dayanthi | Scarpaci, Carol
Little Penguins (Eudyptula minor) are high-trophic coastal feeders and are effective indicators of bioavailable pollutants in their foraging zones. Here, we present concentrations of metals and metalloids in blood of 157 Little Penguins, collected over three years and during three distinct seasons (breeding, moulting and non-breeding) at two locations: the urban St Kilda colony and the semi-rural colony at Phillip Island, Victoria, Australia. Penguin metal concentrations were foremostly influenced by location (St Kilda>Phillip Island for non-essential elements) and differed among years and seasons at both locations, reflecting differences in seasonal metal bioaccumulation or seasonal exposure through prey. Mean blood mercury concentrations showed an increasing annual trend and a negative correlation with flipper length at St Kilda. Notably, this study is the first to report on blood metal concentrations during the different stages of moult, showing the mechanism of non-essential metal mobilisation and detoxification.
اظهر المزيد [+] اقل [-]Pollutants and parasites in bycatch teleosts from south eastern Spanish Mediterranean's fisheries: Concerns relating the foodstuff harnessing النص الكامل
2016
Casadevall, Margarida | Torres, Jordi | El Aoussimi, Ahmed | Carbonell, Ana | Delgado, Eulàlia | Sarrà-Alarcón, Lídia | García-Ruíz, Cristina | Esteban Drake, Antonio | Mallol, Sandra | Bellido, José María
This research provides an evaluation of the quality and health status of some locally abundant fish species, usually otter-trawl bycatch species. The study was conducted in the southern and eastern Spanish Mediterranean coast. Mean concentration of heavy metals in muscle and parasitisation indices showed moderate levels. Higher lead concentration was found in fish from the western Alboran and arsenic, cadmium and mercury were more present on fishes from the eastern Alboran area, although most species analysed contain moderate levels of heavy metals in muscle. Concerning parasitisation, F. Anisakidae nematodes were present in all the species, except sardine. Only mercury showed a positive relationship with parasitisation.We also considered three feeding guilds. Metal mean concentrations were higher in benthivores and more littoral fishes. Pelagic planktivores species are the healthiest and the more suitable for consumers from the sanitary point of view.
اظهر المزيد [+] اقل [-]Effects of an environmentally relevant concentration of diuron on oyster genitors during gametogenesis: responses of early molecular and cellular markers and physiological impacts النص الكامل
2016
Akcha, Farida | Barranger, Audrey | Bachere, Evelyne | Berthelin, C. Heude | Piquemal, D. | Alonso, P. | Sallan, R. Rondon | Dimastrogiovanni, G. | Porte, C. | Menard, Dominique | Szczybelski, A. | Benabdelmouna, Abdellah | Auffret, M. | Rouxel, Julien | Burgeot, Thierry
Effects of an environmentally relevant concentration of diuron on oyster genitors during gametogenesis: responses of early molecular and cellular markers and physiological impacts النص الكامل
2016
Akcha, Farida | Barranger, Audrey | Bachere, Evelyne | Berthelin, C. Heude | Piquemal, D. | Alonso, P. | Sallan, R. Rondon | Dimastrogiovanni, G. | Porte, C. | Menard, Dominique | Szczybelski, A. | Benabdelmouna, Abdellah | Auffret, M. | Rouxel, Julien | Burgeot, Thierry
Genitors of the Pacific oyster Crassostrea gigas were submitted during gametogenesis to a short pulse exposure to the herbicide diuron at a realistic environmental concentration. Histological analysis showed no effect of diuron on gametogenesis course, sex ratio and reproductive effort. A non-significant increase in testosterone and progesterone levels was observed in genitors exposed to the herbicide. At cell level, diuron exposure was shown to modulate the phagocytic activity of circulating hemocytes. The results of a transcriptional analysis showed that diuron affected the expression of genes belonging to functions known to play a major role during oyster gametogenesis such as gene transcription regulation, DNA replication and repair, DNA methylation and cytokinesis. Taking into account the results we previously obtained on the same genitors, this study showed a negative effect of diuron on oyster reproduction by inducing both structural and functional modifications of the DNA.
اظهر المزيد [+] اقل [-]Effects of an environmentally relevant concentration of diuron on oyster genitors during gametogenesis: responses of early molecular and cellular markers and physiological impacts النص الكامل
2016
Akcha, F. | Barranger, A. | Bachère, E. | Berthelin, C Heude | Piquemal, D. | Alonso, P. | Sallan, R Rondon | Dimastrogiovanni, G. | Porte, C. | Menard, D. | Szczybelski, A. | Benabdelmouna, A. | Auffret, M. | Rouxel, J. | Burgeot, T.
Genitors of the Pacific oyster Crassostrea gigas were submitted during gametogenesis to a short pulse exposure to the herbicide diuron at a realistic environmental concentration. Histological analysis showed no effect of diuron on gametogenesis course, sex ratio and reproductive effort. A non-significant increase in testosterone and progesterone levels was observed in genitors exposed to the herbicide. At cell level, diuron exposure was shown to modulate the phagocytic activity of circulating hemocytes. The results of a transcriptional analysis showed that diuron affected the expression of genes belonging to functions known to play a major role during oyster gametogenesis such as gene transcription regulation, DNA replication and repair, DNA methylation and cytokinesis. Taking into account the results we previously obtained on the same genitors, this study showed a negative effect of diuron on oyster reproduction by inducing both structural and functional modifications of the DNA.
اظهر المزيد [+] اقل [-]Assessment of the contamination of marine fauna by chlordecone in Guadeloupe and Martinique (Lesser Antilles) النص الكامل
2016
Dromard, Charlotte | Bodiguel, Xavier | Lemoine, Soazig | Bouchon-navaro, Yolande | Reynal, Lionel | Thouard, Emmanuel | Bouchon, Claude
Assessment of the contamination of marine fauna by chlordecone in Guadeloupe and Martinique (Lesser Antilles) النص الكامل
2016
Dromard, Charlotte | Bodiguel, Xavier | Lemoine, Soazig | Bouchon-navaro, Yolande | Reynal, Lionel | Thouard, Emmanuel | Bouchon, Claude
Chlordecone is an organochlorine pesticide, used in the Lesser Antilles from 1972 to 1993 to fight against a banana weevil. That molecule is very persistent in the natural environment and ends up in the sea with runoff waters. From 2003 to 2013, seven campaigns of samplings have been conducted to evaluate the level of contamination of fish, crustaceans, and mollusks. The present study is the first assessment and the first comparison of the concentrations of chlordecone between marine areas, taxonomic groups, and ecological factors like trophic groups or preferential habitat of fish species. The four most contaminated marine areas are located downstream the contaminated rivers and banana plantations. Crustaceans seemed to be more sensitive to the contamination than fish or mollusks. Finally, when comparing contamination of fish according to their ecology, we found that fish usually living at the border of mangrove and presenting detritivores-omnivores diets were the most contaminated by chlordecone. These results are particularly useful to protect the health of the local population by controlling the fishing and the commercialization of seafood products, potentially contaminated by chlordecone.
اظهر المزيد [+] اقل [-]Assessment of the contamination of marine fauna by chlordecone in Guadeloupe and Martinique (Lesser Antilles) النص الكامل
2016
Dromard, Charlotte R. | Bodiguel, Xavier | Lemoine, Soazig | Bouchon-Navaro, Yolande | Reynal, Lionel | Thouard, Emmanuel | Bouchon, Claude
Chlordecone is an organochlorine pesticide, used in the Lesser Antilles from 1972 to 1993 to fight against a banana weevil. That molecule is very persistent in the natural environment and ends up in the sea with runoff waters. From 2003 to 2013, seven campaigns of samplings have been conducted to evaluate the level of contamination of fish, crustaceans, and mollusks. The present study is the first assessment and the first comparison of the concentrations of chlordecone between marine areas, taxonomic groups, and ecological factors like trophic groups or preferential habitat of fish species. The four most contaminated marine areas are located downstream the contaminated rivers and banana plantations. Crustaceans seemed to be more sensitive to the contamination than fish or mollusks. Finally, when comparing contamination of fish according to their ecology, we found that fish usually living at the border of mangrove and presenting detritivores-omnivores diets were the most contaminated by chlordecone. These results are particularly useful to protect the health of the local population by controlling the fishing and the commercialization of seafood products, potentially contaminated by chlordecone.
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