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3 rÃ©sultat(s) recherche sur le mot-clÃ© 'estuaire de la Rance'
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Building functional groups of marine benthic macroinvertebrates on the basis of general community assembly mechanisms
article dans des revues - 2017-03
Alexandridis, Nikolaos, et al.
Titre Building functional groups of marine benthic macroinvertebrates on the basis of general community assembly mechanisms Type d'Ã©tude article dans des revues Auteurs personnes Alexandridis Nikolaos Auteur Bacher CÃ©dric Auteur Desroy Nicolas Auteur Jean Fred Auteur Date de publication 2017-03 Editeur(s) [S.l.] : Elsevier Journal of Sea Research, ISSN 1385-1101 vol.121 RÃ©sumÃ© The accurate reproduction of the spatial and temporal dynamics of marine benthic biodiversity requires the development of mechanistic models, based on the processes that shape macroinvertebrate communities. The modelled entities should, accordingly, be able to adequately represent the many functional roles that are performed by benthic organisms. With this goal in mind, we applied the emergent group hypothesis (EGH), which assumes functional equivalence within and functional divergence between groups of species. The first step of the grouping involved the selection of 14 biological traits that describe the role of benthic macroinvertebrates in 7 important community assembly mechanisms. A matrix of trait values for the 240 species that occurred in the Rance estuary (Brittany, France) in 1995 formed the basis for a hierarchical classification that generated 20 functional groups, each with its own trait values. The functional groups were first evaluated based on their ability to represent observed patterns of biodiversity. The two main assumptions of the EGH were then tested, by assessing the preservation of niche attributes among the groups and the neutrality of functional differences within them. The generally positive results give us confidence in the ability of the grouping to recreate functional diversity in the Rance estuary. A first look at the emergent groups provides insights into the potential role of community assembly mechanisms in shaping biodiversity patterns. Our next steps include the derivation of general rules of interaction and their incorporation, along with the functional groups, into mechanistic models of benthic biodiversity. CatÃ©gories thÃ©matiques benthosÃ©cosystÃ¨me benthiquedomaine benthiquemodÃ¨le de comportementestuairediversitÃ© biologique Mots-clÃ©s libres Assembly mechanisms/Benthic communities/Biological traits/Emergent groups/estuaire de la Rance/estuary/flore benthique/Functional diversity/Functional redundancy Echelle de territoire bassins versants Bassin(s) versant(s) Rance - Faluns Note DOI = 10.1016/j.seares.2017.01.007 Langue(s) Anglais Format p59 Ã p70 Document en ligne https://www.sciencedirect.com/science/article/pii/S1385110116300508 NÂ° d'Ã©dition (ISBN, DOI,...) 10.1016/j.seares.2017.01.007 Permalink http://etudes.bretagne-environnement.org/index.php?lvl=notice_display&id=159810Fish community responses to green tides in shallow estuarine and coastal areas
article dans des revues - 2016-03-31
Le Luherne, E., et al.
Titre Fish community responses to green tides in shallow estuarine and coastal areas Type d'Ã©tude article dans des revues Auteurs personnes Le Luherne E. Auteur Reveillac E. Auteur PONSERO A. Auteur Sturbois, Anthony Auteur Ballu S. Auteur PERDRIAU M Auteur Le Pape, O. Auteur Date de publication 2016-03-31 Editeur(s) [S.l.] : Elsevier Revue Estuarine, Coastal and Shelf Science, ISSN 0272-7714 nÂ°175 RÃ©sumÃ© Â© rÃ©sumÃ© Ã©diteur :
"All over the world, numerous bays and estuarine systems that are known to shelter essential fish habitats are experiencing proliferations of green macroalgae known as green tides. Although the processes that enhance green tides in response to nutrient enrichment are well known, their consequences for ecological communities despecially for ichthyofauna remain poorly studied. To estimate these consequences, this analysis focused on the two types of shallow systems that are experiencing green tides: sandy beaches and estuarine mudflats. In these two systems, macroalgae proliferation and fish community were surveyed along seasonal cycles at control and impacted sites that shared similar physico-chemical parameters and sediment structure. To analyse the consequences of green tides on the fish community, a Before-After Control-Impact approach was used. This approach reveals no difference between fish communities at the control and impacted sites before the macroalgal bloom. Then, it underlines an influence of green tides on the fish community, and this influence varies according to the composition, density and duration of the macroalgal bloom. Indeed, when intertidal systems experienced short proliferation and/or weak density, green tides did not seem to impact the fish community. How-ever, when green macroalgae proliferated in large quantities and/or when the proliferation lasted for long periods, the fish community was significantly affected. These modifications in the fish community led to a significant decrease in fish species diversity and density until fish disappeared from impacted sites at high proliferations. Furthermore, the response of fish species to green tides differed according to their functional guilds. Negative consequences for benthic and marine juvenile fish species were beginning at low proliferations, whereas for pelagic fish species they occurred only at high proliferations. Thus, green tides significantly affect fish habitat suitability because they lead to changes in the composition of the fish community and eventually to the local disappearance of fish at high proliferations."
CatÃ©gories thÃ©matiques marÃ©e vertealgueprolifÃ©ration d'algueseutrophisationpoissonsableestuairebouevase Mots-clÃ©s libres Fish community/Sandy beaches and estuarine mudflats/Green tides/Macroalgae/Nursery/Sandy beach and estuarine mudflat/Green tide/estuary/estuaire de la Rance Echelle de territoire baies et rades Note DOi = doi:10.1016/j.ecss.2016.03.031
Article de la revue "Estuarine, Coastal and Shelf Science" Ã©ditÃ©e par Elsevier (ISSN 0272-7714) vol.175 paru en 2016, pp 79-92.
Notice sur ScienceDirect = http://www.sciencedirect.com/science/article/pii/S0272771416300981
Texte intÃ©gral = http://www.reservebaiedesaintbrieuc.com/wp-content/IMG/pdf/publication/etudes_scientifiques/LeLuherne2016.pdf
Langue(s) Anglais Format p79 Ã p92 Document en ligne http://www.reservebaiedesaintbrieuc.com/wp-content/IMG/pdf/publication/etudes_scientifiques/LeLuherne2016.pdf NÂ° d'Ã©dition (ISBN, DOI,...) doi:10.1016/j.ecss.2016.03.031 Permalink http://etudes.bretagne-environnement.org/index.php?lvl=notice_display&id=155240Changes in the annual harmful algal blooms of Alexandrium minutum : effects of environmental conditions and drainage basin inputs in the Rance estuary (Brittany, France)
article dans des revues - 2016-03
Le Bec, Claude, et al.
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) Type d'Ã©tude article dans des revues Auteurs personnes Le Bec Claude Auteur Legendre AurÃ©lie Auteur Messiaen GrÃ©gory Auteur Date de publication 2016-03 Editeur(s) [S.l.] : Edp Sciences S A Aquatic Living Resources, ISSN 1765-2952 vol.29 nÂ°1 RÃ©sumÃ© 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 15â18 Â°C, slightly lowered salinities (31.8â33.1 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. CatÃ©gories thÃ©matiques algueestuaireeutrophisationmarÃ©e Mots-clÃ©s 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 Echelle de territoire bassins versants Bassin(s) versant(s) Rance - Faluns Note DOI = 10.1051/alr/2016006.
Article numÃ©ro 104.
Â© EDP Sciences 2016
Langue(s) Anglais Format 13p Document en ligne http://www.alr-journal.org/10.1051/alr/2016006 Localisation du document AccÃ¨s rÃ©servÃ© au texte intÃ©gral sur le site ALR Journal NÂ° d'Ã©dition (ISBN, DOI,...) 10.1051/alr/2016006 Permalink http://etudes.bretagne-environnement.org/index.php?lvl=notice_display&id=158081