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La crépidule en rade de Brest : un modèle biologique d'espèce introduite proliférante en répons aux fluctuations de l'environnement

Abstract : In a context of coastal system management, the approach developped in this study -associating the monitoring of environmental parameters with the monitoring of pelagic and benthic populations- helps to understand the ecosystem functioning. The ecological monitoring undertaken for more than 20 years in the Bay of Brest highlighted a new ecological (and economical) risk: the proliferation of an exotic benthic suspensive feeder and potential competitor of scallop, the slipper limpet Crepidula fornicata (L.). The mechanisms of its proliferation were still unknown in the Bay, notably concerning the recent acceleration (15-20 years) of the process. The multidisciplinary approach of this work allows to study the mechanisms of adaptation and natural regulation of the slipper limpet in the Bay of Brest towards natural fluctuations of the environment (hydroclimat) and anthropic disturbances (like eutrophication) and to identify its impacts on the ecosystem functioning.
Causes of the current proliferation of the slipper limpet in the Bay and its impacts on the structure and the ecosystem functioning were specified: the suspensive feeders exercise a retro-control over the primary production (filtration, biological deposit). The analysis of the favourable conditions for the slipper limpet proliferation showed the important place taken by this invasive species in the ecosystem and allowed a better comprehension of the evolution processes of its distribution surfaces and its stock. The description of the benthic populations subjected to this invasion, realized in this study, constitutes a reference for the megafauna of the Bay of Brest in 2000. The impacts of the slipper limpet on the ecosystem (water column, sediment and biocoenoses) were precized. Future evolutions are considered and recommendations are made to limit its extension and to ensure the scallop fisheries in the Bay of Brest. Prospects are proposed in a context of integrated coastal zone management of this ecosystem.
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Contributor : Laurent Guérin <>
Submitted on : Monday, November 13, 2006 - 4:27:47 PM
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Laurent Guérin. La crépidule en rade de Brest : un modèle biologique d'espèce introduite proliférante en répons aux fluctuations de l'environnement. Ecologie, Environnement. Université de Bretagne occidentale - Brest, 2004. Français. ⟨tel-00113505⟩

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