Data/hora: 15/06/2024 00:44:54

Provedor de dados: | 5
País: | France
Título: | Baie de Vilaine : juillet 1982 mortalité massive de poissons l'analyse des causes et des mécanismes du phénomène, les propositions d'actions
Autores: | Merceron, Michel.
Data: | 1989
Ano: | 1989
Resumo: | At the end of July 1982, a massive number of fish and benthic invertebrates died in Vilaine Bay. The mass of fish concerned has been estimated at several tens of tonnes. The analysis of the event's conditions indicates that it was asphyxiation caused by a very pronounced depletion of dissolved oxygen in the bay's bottom waters. The appearance of toxic phytoplankton in the years that followed (Dinophysis) is aseparate topic of research by IFREMER.   The most likely mechanism of that anoxia is a succession of events: (1) a first flood of Vilaine River inducing a vertical stratification of waters in Vilaine Bay, (2) an intense and superficial bloom of marine phytoplankton, (3) a stormy weather breaking up the stratification and mixing superficial phytoplankton into the whole water column, (4) a second freshwater flood inducing second stratification and superficial bloom of phytoplankton shading the underneath phytoplankton issued from the first bloom. Cells cannot produce oxygen by photosynthesis and they consume it by respiration.  High nitrogen discharges from Vilaine River and coastal morphology of Vilaine Bay makes this zone often affected by eutrophication and hypoxia. Nitrogen sources in the catchment area of Vilaine River might be precisely assessed and reduced to avoid other fish kills.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/1989/publication-2833.pdf
Editor: | Ifremer
Relação: | http://archimer.ifremer.fr/doc/00000/2833/
Formato: | application/pdf
Fonte: | Equinoxe (Ifremer), 1989 , Vol. 21 , P. 4-9
Fonte: | 1989 Ifremer