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Registros recuperados: 54 | |
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LACERDA,LUIZ D.; SANTOS,JANAÍNA A.; MARINS,ROZANE V.; SILVA,FRANCISCO A.T.F. DA. |
Abstract This work reviews the limnology of the largest multi-use reservoir in NE Brazil, the Castanhão Reservoir in Ceará State, during 5 years of an extended drought when the reservoir’s volume decreased from 88% to about 30%. Major physical and chemical parameters of the water column, phytoplankton community, trophic state and sediment geochemistry were monitored, as well as the impact from extensive aquaculture. Water quality of the full reservoir was maintained due to hydrodynamics, which transport nutrients to the hypolimnion of a stratified water column, rendering an oligotrophic state to the reservoir, notwithstanding the large nutrient inputs from aquaculture and irrigated agriculture. However, with the extension of the drought period, the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hydrochemistry; Hydrodynamics; Nutrients; Water quality; Sediments; Aquaculture. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000502073 |
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Marín Jarrín,María José; Marín Jarrín,José R.; Borbor-Córdova,Mercy J.; Espinoza Celi,Maria Esther; Domínguez-Granda,Luis. |
ABSTRACT The Guayas estuary in Ecuador is the largest estuarine ecosystem on the Pacific coast of South America. This estuary provides nursery and fisheries habitats, as well as filtering and detoxification services provided by suspension feeders, vegetation, and wetlands. We used oceanographic and meteorological observations to understand the hydrodynamic variability of two areas in the inner part of the estuary, Manglares de Churute and Estero Salado, from February 2016 to February 2017. Churute has less anthropogenic impacts than Estero Salado, which is currently uncoupled from river flow and highly influenced by Guayaquil, the second largest city in Ecuador, and adjacent shrimp pond effluents. The influences from the ocean and river on Churute include... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hydrodynamics; Mangroves; Estuary; Guayas; Seasonality.. |
Ano: 2022 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612022000200129 |
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Plantecuny, M; Bodoy, Alain. |
In order to estimate energetic relationship, microphytic and benthic bivalve levels of a shallow (1.5 m), sandy ecosystem near Marseille (Gulf of Fos, Southern France) were sampled monthly during 1.5 year, in two sites differing by their wave exposure. In the sheltered area, the bivalve Ruditapes decussatus was the dominant species, while another bivalve, Donax trunculus , was found in the open, wave exposed site. Chlorophyll a and primary production of the phytoplankton and the microphytobenthos, as well as population dynamic, growth and biochemical composition of bivalves (lipids, proteins and carbohydrates) were monitored. |
Tipo: Text |
Palavras-chave: Ruditapes decussatus; Bivalvia; Periphyton; Phytoplankton; Biochemical composition; Growth; Marine molluscs; Hydrodynamics; Seasonal variations; Primary production; Trophic relationships. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1528.pdf |
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Alekseenko, Elena; Roux, Bernard; Sukhinov, A.; Kotarba, R.; Fougere, D.. |
The nonlinear hydrodynamics (3D RANS model) in a wide semi-enclosed windy lagoonal ecosystem is accurately investigated in the context of analyzing the limiting conditions of the recovery of submerged aquatic vegetation (SAV). Among the main natural hydrodynamical forcings, we consider the wind effect. We mainly focus attention to characteristic velocities (free surface and bottom) and to free surface elevation in the nearshore regions (with shallow water) where SAV were severely damaged in the past decades. Our main result relates to wind effects that form downwind coastal jets, alongshore, in shallow water areas, due to Berre bathymetry. Such coastal jets, which were never described previously in Berre lagoon literature, give rise to substantial bottom... |
Tipo: Text |
Palavras-chave: Hydrodynamics; Berre lagoon; Current structures; Zostera noltii; Seagrass protection. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00144/25511/24704.pdf |
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Cognat, Mathis; Ganthy, Florian; Auby, Isabelle; Barraquand, Frederic; Rigouin, Loic; Sottolichio, Aldo. |
The relative impact of light, depth, hydrology, hydrodynamics, sediment and nutrients on growth of the seagrass Zostera noltei was investigated in Arcachon Bay, where the extent of seagrass beds has been decreasing for 20 years. A comprehensive multi-parameter survey of 9 sites was conducted monthly over one year. A three-parameter logistic growth model was fitted to biomass data to unravel the relative contributions of environmental factors on seagrass growth. The present study highlights the fact that, in addition to the dominant positive effect of light on plant growth, the hydrological and hydrodynamic parameters were important drivers for Z. noltei growth at the scale of the whole Bay. At the scale of individual sites, other factors such as macroalgal... |
Tipo: Text |
Palavras-chave: Physical parameters; Light; Hydrodynamics; Adaptation; Statistical growth model. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00451/56229/57789.pdf |
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Barraquand, F.; Picoche, C.; Maurer, Daniele; Carassou, L.; Auby, Isabelle. |
Phytoplanktonic communities maintain a high diversity in a seemingly homogeneous environment, competing for the same set of resources. Many theories have been proposed to explain this coexistence despite likely competition, such as contrasted responses to temporal environmental variation. However, theory has developed at a faster pace than empirical evaluation using field data, which requires inferring drivers of community dynamics from observational time series. Here, we combine autoregressive models with a data set spanning more than 20 years of phytoplankton counts every two weeks, together with nutrients and physical variables. By comparing models dominated by nutrients or physical variables (hydrodynamics and climate), we first explore which abiotic... |
Tipo: Text |
Palavras-chave: Competition; Diatoms; Dinoflagellates; Hydrodynamics; Interactions; MAR; Mutualism; Network; Population dynamics; Seasonality; Time series. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57257/59285.pdf |
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Jonsson, Per R.; Van Duren, Luca A.; Amielh, Muriel; Asmus, Ragnhild; Aspden, Rebecca J.; Daunys, Darius; Friedrichs, Michael; Friend, Patrick L.; Olivier, Frédéric; Pope, Nick; Precht, Elimar; Sauriau, Pierre-guy; Schaaff, Estelle. |
Flume tanks are becoming increasingly important research tools in aquatic ecology, to link biological to hydrodynamical processes. There is no such thing as a "standard flume tank", and no flume tank is suitable for every type of research question. A series of experiments has been carried out to characterise and compare the hydrodynamic characteristics of 12 different flume tanks that are designed specifically for biological research. These facilities are part of the EU network BioFlow. The flumes could be divided into four basic design types: straight, racetrack, annular and field flumes. In each facility, two vertical velocity profiles were measured: one at 0.05 m s(-1) and one at 0.25 m s(-1). In those flumes equipped with Acoustic Doppler Velocimeters... |
Tipo: Text |
Palavras-chave: Methods; Hydrodynamics; Flume tanks; Biological physical interaction; Benthic boundary layer. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2242.pdf |
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Gomez, E; Millet, B; Picot, B. |
The Mejean-Perols Lagoon is situated on the French Mediterranean coast. It is a small (747 ha) and shallow (70 cm) lagoon. Some treated effluent from Montpellier flows into this hypereutrophic lagoon. The cartography of C, N and P concentrations in the sediment was studied based on 35 bottom samples. The nitrogen and organic carbon concentrations were more or less homogeneous, the highest concentrations being found in the middle of the lagoon. The phosphate was principally bound onto the sediment in the west zone. The observed distribution was independent of grain size, the distribution of which was rather homogeneous. In this lagoon water circulation is wind induced. Four different water flow structures were observed, as functions of the prevailing winds... |
Tipo: Text |
Palavras-chave: Sédiment; Lagune côtière; Hydrodynamique; Sels nutritifs; Carbone; Sediment; Coastal lagoon; Hydrodynamics; Nutrients; Carbon. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00325/43642/43247.pdf |
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Augris, Claude; Hamon, Dominique. |
This atlas presents in a synthetic form the hydrodynamical, geological and biological characteristics of one of the most studied region of the French littoral. Geologic and geophysical data of the Saint-Brieuc Bay show that the deep basement consists of pre-palaeozoic or palaeozoic sedimentary series in the centre of the Bay, whereas metamorphic and magmatic formations are dominant in coastal regions. The location of superficial sediments in the Bay, is mainly due to marine currents. A granulometric gradient, from very fine to coarse sediments, appears in two directions: from the coast towards the high sea, and from the west to the east. Rocky substrates disrupt the sediment distribution, with, most of the time, a concentration of coarse sediments near the... |
Tipo: Text |
Palavras-chave: Atlas; Bathymetry; Bottom topography; Commercial species; Geomorphology; Hydrodynamics; Marine resources; Sediment analysis; Sedimentary basins; Zoobenthos. |
Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00031/14246/11527.pdf |
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Plus, Martin; Dumas, Franck; Stanisiere, Jean-yves; Maurer, Daniele. |
A numerical model (MARS-2D) was developed, with the aim of describing the hydrodynamics that prevail in Arcachon Bay. Direct model results as well as derived mixing and transport time-scales (tidal prism, local and integrated flushing times, age of water masses), were used to understand the behaviour of water masses and exchanges between the Bay and its frontiers. Particular attention was paid to the processes that drive the hydrodynamics (tides, wind and rivers), in order to understand their respective influence. The Arcachon Bay hydrodynamic system appears primarily to be highly influenced by tides; secondarily, by winds. About two third of the lagoon total volume is flushed in and out at each tidal cycle, which represent a mean tidal prism of 384... |
Tipo: Text |
Palavras-chave: Arcachon Bay; Tracer; Age of seawater; Flushing time; Tidal prism; Residual fluxes; Hydrodynamics. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6424.pdf |
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Pernet, Fabrice; Barret, Jean; Le Gall, Patrik; Corporeau, Charlotte; Degremont, Lionel; Lagarde, Franck; Pepin, Jean-francois; Keck, Nicolas. |
Experiments were conducted to investigate the effects of farming sites, seeding date, age of oysters, ploidy level and rearing structures on mortality, pathogens and energetic reserves of oysters Crassostrea gigas. Mortality of oysters coincided with infections involving, primarily, the ostreid herpesvirus OsHV-1 and, secondarily, bacteria of the group Vibrio splendidus, when seawater temperature was between 17 and 24°C. Mortality started in early May and lasted until late September, with an interruption in July and August when seawater temperatures rose above 24°C. Mortality varied with farming site: oysters maintained in the open Mediterranean Sea showed no mortality and OsHV-1 was occasionally detected at a low level only, while oysters maintained in... |
Tipo: Text |
Palavras-chave: Pacific oyster; Mortality; Disease; Farming practices; Hydrodynamics; Energetic. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00086/19739/17379.pdf |
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Registros recuperados: 54 | |
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