Since the mid-1980s, an increase in abundance of the annelid polychaete Lanice conchilega (Pallas) (Annelida: Polychacta, Terebellidae) has been observed in the Bay des Veys (western Bay of Seine). The first particularity of this population is that it is strictly limited to the eastern side of the bay, in an oyster aquaculture area. Its proliferation (over 7 000 ind.m(-2)) has had a significant impact on the local aquaculture. Several studies have been carried out since 1993; monthly monitoring of population densities and size structure has demonstrated the lack of significant juvenile recruitment between 1993 and 1996. In terms of geographical occupation, maps of population spatial distributions were drawn in 1995 and 1998. They showed an increase in... |