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| Registros recuperados: 165 | |
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| FARIA,MARCIA DE MELO; SANCHEZ,BRAZ A.. |
| Geochemical and clay mineralogical studies of bottom sediments collected along the Macacu and Caceribu rivers and Guanabara Bay were carried out in order to investigate the relationship between major source areas and recent sediments of the bay. Clay mineralogy includes different groups with selective distribution conditioned by geomorphic features and depositional settings. Micaceous clay minerals are abundant near parent rock in the upper course, whereas kaolinite derived from varied sources is gradually concentrated towards the estuary. In the Guanabara Bay, kaolinite accumulates near river mouths, while micaceous clay minerals are converted into mixed layers in the estuary. Analyses of heavy metal contents reveal higher levels of Zn and Cu in sediments... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Heavy metal; Clay mineral; Sediment; Guanabara Bay. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000100010 |
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| Spivak,Eduardo D.; Bas,Claudia C.; Luppi,Tomás A.. |
| ABSTRACT Two populations of the Southwestern Atlantic burrowing crab, Neohelice granulata (Dana, 1851), are separated by only 190 km. They inhabit bays that drain into a Patagonian gulf in the southernmost limit of the geographical distribution of the species: San Antonio Bay (SAO) and San José Gulf (RSJ). The population from SAO has been extensively studied, whereas that of RSJ has not. The main goal of this study is to compare the ecological and habitat characteristics of the two populations, based on samples collected on successive days during the middle of the reproductive season of the crab. The substrate of SAO is composed of a high proportion of gravel and scarce organic matter, whereas the substrate of RSJ presents twice as much silt and clay, and... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Argentine; Estuaries; Crab; Fecundity; Feeding; Growth; Maturity; Sediment. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702016000604001 |
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| Kassila, Jawad; Hussenot, Jerome. |
| A study was conducted in seabass (Dicentrarchus labrax) and oyster (Crassostrea gigas) ponds to assess the levels of heterogeneity of sediments and settling particles. The intensity of sampling to estimate with high accuracy some characteristics will depend on the magnitude of the variation within the population under consideration. Several variables, such as total phosphate (Tot-P), total iron (Tot-Fe), total ammonium nitrogen (TAN), organic carbon (Org-C), total nitrogen (Tot-N) and P fractions were analysed during the rearing period. The box-and-whisker plots were used as graphical/statistical tools to visualize the descriptive statistical characteristics of the data. In the fish pond, the sediments have high concentrations of Tot-P, Tot-Fe and TAN in... |
| Tipo: Text |
Palavras-chave: Sampling strategy; Resuspension; Sedimentation; Artificial aeration; Particles; Sediment. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1224.pdf |
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| Kempf, Marc; Cadour, Gwenael; Jeanneret, Hélène; Mear, Yan; Miramand, Pierre; Merceron, Michel. |
| This document is a result of an environmental impact study carried out between 1993 and 1995 on the site of a marine trout culture located in the Harbour of Cherbourg, France. It deals with the solid waste of the farm and concems deposition rate, sediment analysis and chemistry (fine fraction < 63 ~m, organic matter, carbon, nitrogen, copper and zinc), bottom living organisms and underwater video monitoring. The impact observed is very moderate and localised. This is mainly due to the strong d)'TIamics and flushing rate of the site. A seperate volume of the same study deals with dissolved waste and concems the water mass (volume 1 : water and pelagos). (Not controlled OCR) |
| Tipo: Text |
Palavras-chave: Rade de Cherbourg; Étude biosédimentaire; Impact; Salmoniculture marine; France; Cherbourg; Benthos; Sediment; Environmental impact; Trout; Marine fish farming. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/1997/rapport-3349.pdf |
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| Kervella, Youen. |
| Oyster farm structures represent artificial obstacles which can disturb tidal currents and wave propagation, and thus modify sediment transport patterns. Local deposition may result from these modifications, in proportions that may threaten the oyster farming. The impact of structures on hydrodynamics, waves and currents, is investigated at different spatial scales by means of in-situ measurements, experimental tests and numerical modeling. These different approaches show that in the near-field, tidal currents are modified in terms of intensity and direction but there is no significant impact on the waves. On the other hand, at the scale of the oyster farm, a significant reduction of the current velocities and a large wave height attenuation are recorded.... |
| Tipo: Text |
Palavras-chave: Tables à huîtres; Envasement; Courants; Vagues; Sédiments; Impact; Oyster tables; Silting up; Currents; Waves; Sediment; Impact. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00011/12262/9043.pdf |
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| Bedier, Edouard; Knoery, Joel Radford; Fleury, Pierre-gildas; Quiniou, Francoise; Langlade, Aime; Cozic, Amandine; Delesmont, Edith; Delesmont, Régis; Caisey, Xavier; Lecureuil, Laetitia. |
| The phenomenon of summer mortalities of the Pacific cupped oyster Crassostrea gigas is observed in France since the beginning of the 90's. These mortalities are classically associated to younger stages and summer temperatures and occur during the reproduction period of the animal. The studies undertaken during the project Morest (2001-2005), showed that a number of biological and environmental risks, the interaction of them induces lethal stresses for animals in physiological weakness, exists in summer. Among these risks, that which is withstood by the oysters bred close to the sediment proved to be significant in intertidal areas. In Quiberon bay (southern Brittany, France), the breeding practices of sowing oysters in deep water is thus likely to expose... |
| Tipo: Text |
Palavras-chave: Huître; Crassostrea gigas; Mortalité; Sédiment; Composé réduit; Flux; Sulfure; Ammonium; Oyster; Crassostrea gigas; Mortality; Sediment; Reduced compound; Flux; Sulphide; Ammonia. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00108/21956/19550.pdf |
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| Andrieux, Francoise; Azandegbe, Afi; Caradec, Florian; Philippon, Xavier; Kerouel, Roger; Youenou, Agnes; Nicolas, Jean-louis. |
| This study aims to compare the impact of oyster cultures on diagenetic processes and the phosphorus cycle in the sediments of the Aber Benoît and the Rivière d’Auray, estuary of Brittany, France. Our results showed clear evidence of the seasonal impact of oyster cultures on sediment characteristics (grain size, organic matter parameters), and the phosphorus cycle, especially in the Aber Benoît. At this site, seasonal variations of sulfide and Fe concentrations in pore waters, as well as Fe-P concentrations in the solid-phase highlighted a shift from a system governed by iron reduction (Reference) to a system governed by sulphate reduction (Beneath Oyster). This could be partly explained by the increase in labile organic matter (ie, biodeposits) beneath... |
| Tipo: Text |
Palavras-chave: Sediment; Phosphorus; Sulfide; Dissolved Fe/P ratios; Labile organic matter; Oyster cultures. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00209/32003/30441.pdf |
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| OLIVEIRA, M. D. de; RODRIGUES, L.. |
| As macrófitas aquáticas são muito abundantes em áreas alagadas como as do Pantanal, e fornecem um vasto substrato para a microbiota, em particular para a comunidade perifítica. Foi avaliado o efeito da deposição de sedimento sobre a comunidade perifítica ao longo de 40km do trecho final do rio Taquari, em 12 estações de amostragem, em setembro de 1998. Foram coletados pecíolos de Eichhornia azurea, raspados e filtrados para análise da biomassa perifítica (clorofila a e peso seco). Foram tomadas amostras de raízes, caules e folhas da macrófita para análise do sedimento aderido. E as características da água também foram estudadas. Do sedimento suspenso analisado, 55% foi depositado até a última estação, e 86% é de origem inorgânica. A transparência da água... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Deposição; Macrófita aquática; Rio Taquari; Sediment; Deposition; Aquatic macrophyte; Aquatic plant; Taquari river; Wetland.; Impacto Ambiental; Perifiton; Planta Aquatica; Sedimento.; Pantanal; Environmental impact; Periphyton.. |
| Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/810756 |
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| Frere, L.; Paul-pont, I.; Rinnert, Emmanuel; Petton, Sebastien; Jaffre, J; Bihannic, Isabelle; Soudant, P.; Lambert, C.; Huvet, Arnaud. |
| The concentration and spatial distribution of microplastics in the Bay of Brest (Brittany, France) was investigated in two surveys. Surface water and sediment were sampled at nine locations in areas characterized by contrasting anthropic pressures, riverine influences or water mixing. Microplastics were categorized by their polymer type and size class. Microplastic contamination in surface water and sediment was dominated by polyethylene fragments (PE, 53–67%) followed by polypropylene (PP, 16–30%) and polystyrene (PS, 16–17%) microparticles. The presence of buoyant microplastics (PE, PP and PS) in sediment suggests the existence of physical and/or biological processes leading to vertical transfer of lightweight microplastics in the bay. In sediment (upper... |
| Tipo: Text |
Palavras-chave: Microplastic; Coastal ecosystem; Surface water; Sediment; Raman spectroscopy; Hydrodynamic; Dispersal particle modelling. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00379/48994/51083.pdf |
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| Azandegbe, Afi; Poly, Franck; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
| Bacterial community structure and some biogeochemical parameters were studied in the sediment of two Pacific oyster farming sites, Aber Benoît (AB) and Rivière d'Auray (RA) in Brittany (France), to examine the ecological impact of oysters and to evaluate the emission of sulfide and ammonia from sediment. At AB, the organic matter accumulated in the sediment beneath the oyster tables was rapidly mineralized, with strong fluxes of ammonia and sulfide that reached 1014 μmol m−2 h−1 - and 215 μmol m−2 h−1, respectively, in June 2007. At RA, the fluxes were about half as strong on average and better distributed through the year. The ammonia and sulfide concentrations in the overlying water never reached levels that would be toxic to oysters in either site, nor... |
| Tipo: Text |
Palavras-chave: Sediment; Biogeochemical parameters; Fluxes; Bacterial structure; Crassostrea gigas. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/19010/17083.pdf |
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| Zheng, Li-wei; Hsiao, Silver Sung-yun; Ding, Xiao-dong; Li, Dawei; Chang, Yuan-pin; Kao, Shuh-ji. |
| Total organic carbon to total nitrogen ratios (C/N) and their isotopic compositions (δ13CTOC and δ15NTN) are oft-applied proxies to discern terrigenous from marine-sourced organics and to unravel ancient environmental information. In high depositional Asian marginal seas, the inclusion of N-bearing minerals in the bulk sediment dilutes or masks signals sought after in δ15N and δ13C analyses, thus leading to incorrect and even contradictory interpretations. We used KOH-KOBr to separate operationally defined total organic matter into oxidizable (labile) and residual fractions for content and isotope measurements. In a sediment core in the Okinawa Trough, significant amounts of carbon and nitrogen existed in the residual phase, in which the C/N ratio was ~9,... |
| Tipo: Text |
Palavras-chave: Carbon; Nitrogen; Isotope; Okinawa Trough; Sediment; Total organic carbon. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00295/40584/39503.pdf |
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| Registros recuperados: 165 | |
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