Dynamique de population de la crépidule (Crepidula fornicata) en baie de Saint-Brieuc (Manche-Ouest)

The limpet (Crepidula fornicata), a gastropod mollusc belonging to the Calyptraeidae, native of the Atlantic coast of northern America, was introduced by accident on the French coasts in different steps (Blanchard, 1995, 1997). The most important, at the beginning of the 1970s, is linked to the massive importation of the Japanese oyster (Crassostrea gigas), in replacement of the Portuguese oyster (Crassostrea angulata), decimated by an epizooty. It is an opportunistic species proliferating in the neighbourhood of the main oyster basins of the English Channel and the Atlantic Ocean. Such is the case of the oyster culture areas of the Norman-Breton Gulf where stock assessments accounted for hundreds of thousands of tonnes of them (Hamon and Blanchard, 1994; Noël et al., 1995; Blanchard, 1999; Blanchard and Ehrhold, 1999). [...]