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| Menesguen, Alain. |
| Following lakes and rivers, a lot of estuaries (during the last twenty years) and shallow coastal zones (during the last decade) have been severely eutrophicated because of the too much increasing loads of nitrogen and phsophorus. In situ stutdy and numerical modelling of two french case studies bring some explanation to the facts that, in some sites, enrichment turns into green macroalgal proliferation whereas, in others, mass blooms of phytoplankton are induced. Whatever the case may be, the prominent role of the residence time of water in the enriched zone has been proven. In open coastal ecosystems, the difficulty in determining this residence time as well as the limiting factor (nitrogen, or phosphorus, or light) lowers considerably the reliability of... |
| Tipo: Text |
Palavras-chave: Eutrophisation côtière; Elément limitant; Temps de résidence; Modèles hydrodynamiques; Modèles écologiques; Coastal eutrophication; Limiting factor; Residence time; Hydrodynamical models; Ecological models. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00423/53416/54295.pdf |
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| 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 |
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