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Registros recuperados: 14 | |
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Migne, A; Davoult, Dominique; Gattuso, Jp. |
The production of calcium carbonate by a dense Ophiothrix fragilis population was calculated in order to investigate its role in the carbon budget of a temperate coastal ecosystem (Dover Strait, eastern English Channel). Production, calculated using monthly data of population density, demographic structure and a size/CaCO3 conversion, was 682 g CaCO3 m(-2) yr(-1). Assuming that the molar ratio of CO2 released to CaCO3 precipitated varied with temperature between 0.66 and 0.73, this production would result in the release of 4.8 mol CO2 m(-2) yr(-1). This calculation reinforces the suggestion that this coastal system is a source of CO2 to the atmosphere. |
Tipo: Text |
Palavras-chave: CO2 flux; CaCO3 production; Ophiuroid; Coastal ecosystem; Temperate sea. |
Ano: 1998 |
URL: https://archimer.ifremer.fr/doc/00248/35947/34474.pdf |
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Guyondet, T.; Comeau, L. A.; Bacher, Cedric; Grant, J.; Rosland, R.; Sonier, R.; Filgueira, R.. |
A spatially explicit coupled hydrodynamic-biogeochemical model was developed to study a coastal ecosystem under the combined effects of mussel aquaculture, nutrient loading and climate change. The model was applied to St Peter's Bay (SPB), Prince Edward Island, Eastern Canada. Approximately 40 % of the SPB area is dedicated to mussel (Mytilus edulis) longline culture. Results indicate that the two main food sources for mussels, phytoplankton and organic detritus, are most depleted in the central part of the embayment. Results also suggest that the system is near its ultimate capacity, a state where the energy cycle is restricted to nitrogen-phytoplankton-detritus-mussels with few resources left to be transferred to higher trophic levels. Annually, mussel... |
Tipo: Text |
Palavras-chave: Climate change; Nutrient loading; Mussel culture; Carrying capacity; Coastal ecosystem; Numerical modelling. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38624/37191.pdf |
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Savoye, N; Aminot, Alain; Treguer, Paul; Fontugne, M; Naulet, N; Kerouel, Roger. |
Two cruises (April and June 1997) were carried out in the Bay of Seine, a nitrate- and ammonium-enriched ecosystem of Western Europe, to identify the major mechanisms that control delta(15)N and VC in spring particulate organic matter (POM). Particulate organic nitrogen (PON) delta(15)N ranged between 0.8 and 5.2parts per thousand in April and between 2.2 and 6.2parts per thousand in June, while particulate organic carbon (POC) delta(13)C ranged between -24.3 and -19.7parts per thousand, and between -20.0 and -16.2parts per thousand during the same periods. During spring 1997, POM was highly dominated by autochthonous phytoplankton. It is shown that the variation of PON delta(15)N is due to both nitrate mixing between river and marine waters and... |
Tipo: Text |
Palavras-chave: C and N stable isotopes; Phytoplankton; Coastal ecosystem; Nitrate utilization; Bay of Seine. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10645/7593.pdf |
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Del Amo, Yolanda; Le Pape, Olivier; Treguer, Paul; Queguiner, Bernard; Menesguen, Alain; Aminot, Alain. |
The chemical factors (inorganic nitrogen, phosphate, silicic acid) that potentially or actually control primary production were determined for the Bay of Brest, France, a macrotidal ecosystem submitted to high-nitrate-loaded freshwater inputs (winter nitrate freshwater concentrations >700 mu M, Si:N molar ratio as low as 0.2, i.e. among the lowest ever published). Intensive data collection and observations were carried out from February 1993 to March 1994 to determine the variations of physical [salinity, temperature, photosynthetically active radiation (PAR), freshwater discharges] and chemical (oxygen and nutrients) parameters and their impacts on the phytoplankton cycle (fluorescence, pigments, primary production). With insufficient PAR the winter... |
Tipo: Text |
Palavras-chave: Coastal ecosystem; Phytoplankton dynamics; Macrotidal; Nutrient limitation; Silicon; Eutrophication. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00337/44782/44588.pdf |
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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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Brito,Letícia da Silva; Irmler,Ulrich; Forte,Bruno Vasconcelos Guimarães; Xavier,Tatiane Pereira; Martins,Rodrigo Lemes. |
Abstract: Restingas are sandy areas spread along the Brazilian coast made up of a mosaic of forest and open woodland vegetation adapted to varying conditions of aridity, oligotrophy and salinity. Two vegetation types are very common in southeast Brazilian restingas, open Clusia formations and seasonally dry forest formation. Litter production and nutrient (C and N) turnover were studied comparatively in forest formations and Clusia formations, in vegetation patches with and without Clusia hilariana. The results showed that the breakdown process is extremely retarded in Clusia formations, with or without C. hilariana, leading to C accumulation in the soil. Microbial and soil fauna activity is lower in Clusia formations in comparison to forest formations;... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coastal ecosystem; Decomposition litterfall; Nutrient cycling; Nurse plant. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032018000400208 |
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Frere, Laura; Maignien, Lois; Chalopin, Morgane; Huvet, Arnaud; Rinnert, Emmanuel; Morrison, Hilary; Kerninon, Sandrine; Cassone, Anne-laure; Lambert, Christophe; Reveillaud, Julie; Paul-pont, Ika. |
Microplastics (<5 mm) exhibit intrinsic features such as density, hydrophobic surface, or high surface/volume ratio, that are known to promote microbial colonization and biofilm formation in marine ecosystems. Yet, a relatively low number of studies have investigated the nature of microplastic associated bacterial communities in coastal ecosystems and the potential factors influencing their composition and structure. Here, we characterized microplastics collected in the Bay of Brest by manual sorting followed by Raman spectroscopy and studied their associated bacterial assemblages using 16S amplicon high-throughput sequencing. Our methodology allowed discriminating polymer type (polyethylene, polypropylene and polystyrene) within small size ranges... |
Tipo: Text |
Palavras-chave: Bacteria; Microplastics; Coastal ecosystem; Metabarcoding; Vibrios. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00449/56082/57614.pdf |
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Trommer, Gabriele; Leynaert, Aude; Klein, Cecile; Naegelen, Aurore; Beker, Beatriz. |
Phytoplankton nutrient limitation patterns were investigated in an anthropogenically influenced coastal ecosystem with a high nutrient load. Weekly nutrient limitation bioassays, and water chemistry and stoichiometry measurements were performed in the Bay of Brest, France, from February to July 2011. Each limitation bioassay included phosphorus, nitrogen, silicate and all possible combined nutrient additions, and lasted over 72 h. Results showed that the phytoplankton community experienced a general P limitation from March to July. N limitation alone was observed only during 1 week in early March. Subsequently, all limitation bioassays revealed primary P limitation, indicated by significantly increased growth rates in all samples containing P additions.... |
Tipo: Text |
Palavras-chave: Phytoplankton; Stoichiometry; Bioassays; Nutrient limitation; Coastal ecosystem. |
Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00368/47947/48023.pdf |
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Magnago,Luiz F.S.; Martins,Sebastião V.; Schaefer,Carlos E.G.R.; Neri,Andreza V.. |
The aim of this study was to determine changes in composition, abundance and richness of species along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/tree species was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vegetation; Flooded Forests; Coastal ecosystem; Sandy Soils; Quaternary deposits; Marine influence; Riparian forests. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652012000300023 |
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Gremare, A; Amouroux, Jm; Cauwet, G; Charles, F; Courties, C; De Bovee, F; Dinet, A; Devenon, Jean-luc; Durrieu De Madron, X; Ferre, B; Fraunie, P; Joux, F; Lantoine, F; Lebaron, P; Naudin, Jj; Palanques, A; Pujo-pay, M; Zudaire, L. |
A survey involving both permanent mooring and high frequency sampling was carried in the Bay of Banyuls-sur-Mer during the fall of 1999 to assess the effect of strong and unpredictable meteorological events on the functioning of a coastal Mediterranean ecosystem. A severe winter storm took place on 12 November, which generated waves with a significant height of 7 m and a sea surface rise of about 0.5 m. The near-bottom current speed at 24 m reached 30 cm s(-1). This storm induced a significant increase in total suspended matter through resuspension and then a subsequent increase in gross sedimentation rates. It also resulted in an increase of the proportion of refractory particulate organic matter in the water column. It also tended to increase nutrient... |
Tipo: Text |
Palavras-chave: Impact à une tempête; Méditerranée nord-occidentale; Ecosystème côtier; Impact of storm; NW Mediterranean Sea; Coastal ecosystem. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00321/43265/42996.pdf |
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Registros recuperados: 14 | |
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