Consulta: subjectFacets:"Ulve"
Registros recuperados: 5
Data/hora: 07/06/2024 00:23:37

Simulation de l'effet sur l’eutrophisation côtière bretonne de 3 scénarios de réduction des teneurs en nitrate et phosphate de chaque bassin versant breton et de la Loire
Provedor de dados: 5
Autores: Dussauze, Morgan; Menesguen, Alain.
This study commissioned by the Région Bretagne and the Agence de l'Eau Loire Bretagne aimed at assessing on a mathematical modelling basis the marine influence of most of watersheds in Brittany, and the impact of 4 scenarios of reduction of the loadings of each of these watersheds on the phytoplanctonic biomass and ulva mass proliferation. The ecological 3D model ECOMARS3D has been applied to a domain containing Brittany (which is also used in an operational mode for putting everyday the 2dayforecasts on the website: http://www.previmer.org/previsions/production_primaire/modele_eco_mars3d_bretagne) and to 6 zooms which enabled a finer representation of coastal waters. This study highlighted the fact that: •a nitrate reduction for any river has no effect on...
Tipo: Text
Palavras-chave: Bretagne; Bassins versants; Eaux côtières; Nitrate; Phosphate; Marée verte; Ulve; Diatomée; Dinoflagellé; Modèle mathématique; Brittany; Watersheds; Coastal waters; Nitrate; Phosphate; Green tide; Ulva; Diatom; Dinoflagellate; Mathematical model.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00097/20804/18429.pdf

Inventaire des Ulves en Bretagne année 1998 - rapport de synthèse
Provedor de dados: 5
Autores: Merceron, Michel.
The 1998 survey of green tides on the Brittany coast was performed in the same way as that of 1997 in order to allow comparison. 11 includes an inventory ofail the concerned sites, and a precise assessment ofthirteen ofthem, the most loaded. On these ones, nitrogen fluxes were surveyed during the critical period, and the green seaweed stock on the beach and in the first waves was quantified. The climatic conditions were opposite between the two years, very dry in spring and summer 1997, and wet in 1998. The irradiance contrast was inverse, and less pronounced. The nitrate contents and mostly the flows were more important in 1998. They generated nitrogen fluxes about 3.3 times those of 1997. The total number of sites concerned in 1998 is clearly higher than...
Tipo: Text
Palavras-chave: Bretagne; Nitrate; Prolifération; Ulve; Eutrophisation; Brittany; Nitrate; Proliferation; Ulva; Eutrophication.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/rapport-2665.pdf

Simulation de l'effet de 3 scénarios de réduction des teneurs de l'Elorn en nitrate sur l'eutrophisation de la rade de Brest
Provedor de dados: 5
Autores: Menesguen, Alain.
This study commissioned by the Syndicat de l'Elorn et de la Rivière de Daoulas aimed at assessing on a mathemical modelling basis the impact of 3 scenarios of reduction of the loadings of Elorn river (imposed concentrations : 20, 15 et 10 mg/L NO3) on the status of ulva mass proliferation in the Moulin Blanc cowe (Bay of Brest). An ecological 3D model of N, P and Si cycling in the bay of Brest has been applied to a "reference situation": 2004 meteorological forcing combined to recent loadings of the new sewage plant. This model showed that: · the 3 reduction scenarios did not reduce significantly the early summer biomass of ulvae, but allowed to slightly reduce the subsequent summer and autumn levels of biomass (up to 20% reduction for 10 mg/L NO3). The...
Tipo: Text
Palavras-chave: Mathematical model; Dinoflagellate; Diatom; Ulva; Green tide; Nitrate; Moulin Blanc cowe; Elorn river; Bay of Brest; Modèle mathématique; Dinoflagellé; Diatomée; Ulve; Marée verte; Nitrate; Anse du Moulin Blanc; Elorn; Rade de Brest.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/rapport-6327.pdf

Inventaire des ulves en Bretagne. Année 1997. Rapport de synthese
Provedor de dados: 5
Autores: Merceron, Michel.
The yearly study of Ulva in Brittany aims at building a time series of its proliferations and corresponding nutrient loadings. The goal is to detect results of wilful loading reductions, and to distinguish them from natural variations. This first actually quantified study is the starting bench-mark of the process. Forty-five concerned sites were listed in 1997. They are nearly the same as in 1988, 1991 and 1994 (previous rough census). The Côtes d'Armor and then the Finistère are the most affected departments. The Morbihan is less and file et Vilaine not at all. Ulva biomass was precisely quantified in about fifteen locations during the growing season, along with nitrogen loadings of local streams (mostly nitrate). The fluxes of nitrogen - the limiting...
Tipo: Text
Palavras-chave: Bretagne; Nitrate; Prolifération; Ulve; Eutrophisation; Brittany; Nitrate; Proliferation; Ulva; Eutrophication.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/1998/rapport-1580.pdf

Les "marées vertes" en Bretagne, la responsabilité du nitrate
Provedor de dados: 5
Autores: Menesguen, Alain.
Since 25 years, an increasing number of beaches and coves along the Britanny coast are invaded from spring until autumn by proliferating green macroalgae (free ulvae, fixed enteromorphae). This typical case of eutrophication, which has been well studied in the bays of Saint-Brieuc, Lannion, Douarnenez and Brest, could be explained by the conjunction of a natural containment of shallow water masses with a recent enrichment of them by nitrate river loadings. In the naturally confined sites, field measurements of summer biomass showed a good correlation with the spring nitrate river loadings ; furthermore, the summer rarefaction of these loadings explains the fall of the nitrogen content of the ulvae, which induces the summer stop of the algal growth.  The...
Tipo: Text
Palavras-chave: Intensive farming; Biogeochemical models; Coastal eutrophication; Nitrate; Ulva; Green tide; Agriculture intensive; Modèles biogéochimiques; Eutrophisation côtière; Nitrate; Ulve; Marée verte.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/rapport-143.pdf