Data/hora: 10/06/2024 09:15:44

Provedor de dados: | 5
País: | France

Título:

Rôle des sédiments dans le cycle des nutriments et impacts sur l’eutrophisation des écosystèmes côtiers

Role of sediments in the nutrient cycle and impact on eutrophication of coastal ecosystems

Autores: | Ratmaya, Widya.
Data: | 2018-10-19
Ano: | 2018
Palavras-chave: | Eutrophisation; Cycle des nutriments; Régénération benthique; Nutriment limitant; Baie de Vilaine; Eutrophication; Nutrient cycling; Benthic regeneration; Nutrient limitation; Vilaine Bay.
Resumo: | Eutrophication was studied in the coastal waters of Vilaine Bay (VB) in relation to that in the Loire and Vilaine rivers, by analyzing long-term trends of phytoplankton biomass and nutrient concentrations during the past decades. The reduction in dissolved riverine inorganic phosphorus concentrations (DIP) during the last two decades led to the significant decrease in chlorophyll a concentrations. However, dissolved inorganic nitrogen concentrations (DIN) decreased only slightly in the Vilaine and actually increased in the Loire, especially during summer. Simultaneously, phytoplankton in VB has undergone the following changes: 1) increase in biomass, 2) change in timing of the annual peak of biomass from spring to summer, 3) modification in seasonal course of diatoms and dinoflagellates. These results can be explained by increased summer DIN loads from the Loire, sustained by internal regeneration of DIP and dissolved silicate (DSi) from sediments. The study of benthic fluxes of DIN, DIP and DSi in VB, combined with steady state modeling of nitrogen (N) and phosphorus (P) cycles in sediments support the hypothesis that benthic nutrient regeneration could induce DIN limitation in coastal waters in summer. If DIN fluvial loads do not decrease significantly, eutrophication in VB coastal waters is likely to continue due to internal nutrient input, especially PID and DSi from sediments particularly during summer periods. The steady state modeling performed in this work should enable improvements of the existing ECO-MARS3D model and better simulation of coastal ecosystems responses to DIN and DIP reduction scenarios in river waters.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00476/58799/61337.pdf

https://archimer.ifremer.fr/doc/00476/58799/

Editor: | Université de Nantes
Formato: | application/pdf

Fonte:

info:eu-repo/semantics/openAccess

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