The role of Crepidula proliferation in the modification of the sedimentarytidal environment in Mont-Saint-Michel Bay (The Channel, France)

Since 1980, several mudflat sediments have rapidly formed in Mont-Saint-Mic hel Bay. The appearance of these deposits in areas unfavorable for the deca ntation and stability of mud sediments coincides with the proliferation of a gastropod mollusc (Crepidula fornicata). The piling and the agglomeration of individuals favours the retention of these bio-agglomerates and the per manent installation of biogenic muds and modifies radically and irreversibl y the nature and the texture of sediment to the specific advantage of this species. ((C) Academie des sciences/Elsevier, Paris.).