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| Registros recuperados: 99 | |
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| Plus, Martin; Chapelle, Annie; Lazure, Pascal; Auby, Isabelle; Levavasseur, G; Verlaque, M; Belsher, Thomas; Deslous-paoli, Jean-marc; Zaldivar, J; Murray, C. |
| A three-dimensional model coupling physical and biological processes for the whole Than lagoon (Mediterranean coast of France) was developed in order to assess the relationships between macrophytes and the oxygen and nitrogen cycles. Ten species have been inserted as forcing variables in the model. Plankton dynamics, shellfish cultivation impact and mineralization of organic matter are also considered, as well as nutrient and oxygen exchanges between the sediment and the water column. Simulations with and without the macrophytes have shown that the system can be characterized as having a highly structured pattern involving lagoon nitrogen and oxygen cycles. This pattern is created by the combined influence of macrophytes, watershed and oyster farming.... |
| Tipo: Text |
Palavras-chave: Thau lagoon; Biogeochemical cycles; Ecological modelling; Macrophytes. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/2003/publication-459.pdf |
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| Planque, Benjamin; Bellier, Edwige; Lazure, Pascal. |
| Large amplitude variations in recruitment of small pelagic fish result from interactions between a fluctuating environment and population dynamics processes such as spawning. The spatial extent and location of spawning, which is critical to the fate of eggs and larvae, can vary strongly from year to year, as a result of changing population structure and environmental conditions. Spawning habitat can be divided into 'potential spawning habitat', defined as habitat where the hydrographic conditions are suitable for spawning, 'realized spawning habitat', defined as habitat where spawning actually occurs, and 'successful spawning habitat', defined as habitat from where successful recruitment has resulted. Using biological data collected during the period... |
| Tipo: Text |
Palavras-chave: Sardine; Potential spawning habitat; Generalized additive models; Environmental effects; Bay of Biscay; Anchovy. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2180.pdf |
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| Plus, Martin; La Jeunesse, I; Bouraoui, F; Zaldivar, J; Chapelle, Annie; Lazure, Pascal. |
| The Soil and Water Assessment Tool (SWAT model, 2001 Version) has been applied to the Than lagoon catchment area in order to simulate water discharges and nutrient inputs into the lagoon over a 10 years period (1989-1999), and to provide routing inflows to a previously developed lagoon ecosystem model. The watershed model has been calibrated and validated using measured data available for the two main rivers. The results indicate that the mean annual nitrogen inputs into the Thau lagoon is 117 +/- 57 tons y(-1), with the two main rivers, contributing for 80% of total annual nitrogen export. The variations of outputs to the lagoon are nonetheless important from 1 year to another. Due to the local agricultural practices and a reduced in-stream natural... |
| Tipo: Text |
Palavras-chave: Thau lagoon; Primary production; Integrated modelling; Lagoon model; Watershed model. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1118.pdf |
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| Costoya, X.; Fernandez-novoa, D.; Decastro, M.; Santos, F.; Lazure, Pascal; Gomez-gesteira, M.. |
| The influence of Loire and Gironde River discharges over the sea surface temperature (SST) in the eastern Bay of Biscay (0.6º–36.6ºW, 44.2º–47.8ºW) was analyzed by means of two complementary databases (MODIS and OISST1/4). The area influenced by river plume showed a different SST when compared with the adjacent oceanic area for the months when the plume attains its highest extension (December, January, and February). Ocean was observed to warm at a rate of approximately 0.3ºC dec−1 while temperature at the area influenced by the rivers cooled at a rate of −0.15ºC dec−1 over the period 1982–2014. The mere presence of a freshwater layer is able to modulate the warming observed at adjacent ocean locations since the coastal area is isolated from the rest of... |
| Tipo: Text |
Palavras-chave: Loire; Gironde; SST; River plume; Warming modulation. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00311/42172/41472.pdf |
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| Gentien, Patrick; Lunven, Michel; Lazure, Pascal; Youenou, Agnes; Crassous, Marie-pierre. |
| Karenia mikimotoi is one of the most common red-tide dinoflagellates proliferating in the eastern North Atlantic and around Japan. Kills of marine fauna are associated with its blooms. In mixed water columns it migrates vertically, while in stratified water columns, the population remains confined within pycnocline layers. Wind events, increasing mixing and agitation initiate declines in its populations. This paper is focused on the formulation of mortality rate relative to shear rate. Autotoxicity is demonstrated by the use of a synthetic toxin. Bioconvection observed in cultures allows the establishment of a trade-off between phototropism, which leads to the local accumulation of cells, and their autotoxicity, which would prevent cell concentration. The... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2436.pdf |
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| Delord, Karine; Barbraud, Christophe; Pinaud, David; Letournel, Bruno; Jaugeon, Baptiste; Goraguer, Herle; Lazure, Pascal; Lormée, Hervé. |
| Among seabirds, alcids are particularly sensitive to bycatch in fisheries and oil pollution, yet their distribution at sea remains scarcely known in most of their breeding areas. GPS telemetry data of fifteen individuals of alcids (5 Razorbills 6 Common Murres and 4 Puffins) were analyzed to determine their distribution during the breeding period of 2016 at Saint Pierre and Miquelon Archipelago (SPM). Two analytical methods (threshold and a switching state-space model) were used to identify behavioral modes and foraging areas. We compared foraging movements and estimated the overlap between the species. Distribution and foraging covered an area located between SPM and Newfoundland. Our results revealed that the three species headed northward of their... |
| Tipo: Text |
Palavras-chave: Telemetry; Behavioral models; Animal movement; Distribution overlap; Fratercula arctica; Alca torda; Uria aalge. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00588/70038/68016.pdf |
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| Petitgas, Pierre; Magri Hoeltzener, Stephanie; Lazure, Pascal. |
| Modelling the vertical distribution of fish eggs is important when assessing fish stocks with egg production methods and for monitoring the reproductive potential of fish populations. Fish eggs are passive particles and their vertical distribution is determined by a few parameters such as egg density, egg diameter, wind- and tide-induced turbulence, and vertical hydrographic structure. A one-dimensional vertical biophysical, numerical model was developed which was adapted to the hydrography of shelf seas under the influence of tidal currents, wind-induced circulation, and river discharges. The biological part of the model parameterized the ascent velocity of the egg as a function of egg properties (diameter, density) and water properties (density,... |
| Tipo: Text |
Palavras-chave: Vertical distribution; Sprat; Sardine; Fish egg buoyancy; CUFES; Biophysical coupling; Anchovy. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2277.pdf |
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| Michel, Guillaume; Dupre, Stephanie; Baltzer, Agnes; Ehrhold, Axel; Imbert, Patrice; Pitel, Mathilde; Loubrieu, Benoit; Scalabrin, Carla; Lazure, Pascal; Marie, Louis; Geldof, Jean-baptiste; Deville, Eric. |
| Inactive and mostly elongated pockmarks of 100–200 m in dimension were recently discovered on the South Aquitaine Margin continental slope. They are distributed at water depths greater than 350 m in both interfluve and sediment-wave areas, and are strongly controlled by the sedimentary morphology and architecture. Water column and seafloor backscatter and sub-bottom profiler data do not exhibit present-day or past gas evidence, e.g., massive and continuous gas releases at the seabed and fossil methane-derived authigenic carbonates. It is thus proposed that the pockmarks originated from a shallow source and result from relatively recent and short-duration gas or water expulsion events. Former near-bottom currents may have contributed to the elongation of... |
| Tipo: Text |
Palavras-chave: Pockmark; Fluid; Seabed morphology; Aquitaine slope; GIS; Currents. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00413/52491/53279.pdf |
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| Registros recuperados: 99 | |
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