Dernière mise à jour le : 20 mars 2016

Changes in the annual harmful algal blooms of Alexandrium minutum : effects of environmental conditions and drainage basin inputs in the Rance estuary (Brittany, France)

DESCRIPTION

Time series of physico-chemical data and concentrations (cell L-1) of the toxic dinoflagellate Alexandrium minutum collected in the Rance macrotidal estuary (Brittany, France) were analyzed to understand the physico-chemical processes of the estuary and their relation to changes in bloom development from 1996 to 2009. The construction of the tidal power plant in the north and the presence of a lock in the south have greatly altered hydrodynamics, blocking the zone of maximum turbidity upstream, in the narrowest part of the estuary. Alexandrium minutum occurs in the middle part of the estuary. Most physical and chemical parameters of the Rance estuary are similar to those observed elsewhere in Brittany with water temperatures between 15–18 °C, slightly lowered salinities (31.8–33.1 PSU), low river flow rates upstream and significant solar radiation (8 h day-1). A notable exception is phosphate input from the drainage basin which seems to limit bloom development: in recent years, bloom decline can be significantly correlated with the decrease in phosphate input. On the other hand, the chemical processes occurring in the freshwater-saltwater interface do not seem to have an influence on these occurrences. The other hypotheses for bloom declines are discussed, including the prevalence of parasitism, but remain to be verified in further studies.

NOTICE BIBLIOGRAPHIQUE DETAILLÉE

keyboard_arrow_right Titre : Changes in the annual harmful algal blooms of Alexandrium minutum : effects of environmental conditions and drainage basin inputs in the Rance estuary (Brittany, France)
keyboard_arrow_right Type de documentation : Articles
keyboard_arrow_right Auteur(s) personne(s) : Le Bec Claude, Legendre Aurélie, Messiaen Grégory
keyboard_arrow_right Date de publication : 20 mars 2016
keyboard_arrow_right Nombre de pages : 13p
keyboard_arrow_right Editeur(s) : Edp Sciences S A
keyboard_arrow_right Tags thématiques : algue, estuaire, eutrophisation, marée
keyboard_arrow_right Mots-clés libres : dinoflagellate/drainage basin/eutrophication/Harmful algae/land runoff/nutrients/algue nocive/algues nocives/Rance macrotidal estuary/estuaire maritime de la Rance/estuaire de la Rance
keyboard_arrow_right Localisation : RANCE - FREMUR - BAIE DE BEAUSSAIS
keyboard_arrow_right Langue : Anglais
keyboard_arrow_right N° d'édition (ISBN,DOI...) : 10.1051/alr/2016006
keyboard_arrow_right Collection : Aquatic Living Resources

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