Recrutement et prolifération de la population de Lanice conchilega (Pallas) en Baie-des-Veys, baie de Seine Occidentale
Ropert, M.; Dauvin, J.-C. (2000). Recrutement et prolifération de la population de Lanice conchilega (Pallas) en Baie-des-Veys, baie de Seine Occidentale. Oceanol. Acta 23(4): 529-546
In: Oceanologica Acta. Elsevier/Gauthier-Villars: Montreuil. ISSN 0399-1784; e-ISSN 1878-4143, more
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| Authors | | Top |
- Ropert, M.
- Dauvin, J.-C., more
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| Abstract |
Since the mid-1980s, an increase in abundance of the annelid polychaete Lanice conchilega (Pallas) (Annelida: Polychaeta, 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 colonised surface of 18%, with a slight reduction of abundance. The consequence was a remarkable biomass stability which represented 3 500 tons of fresh weight excluding worm tubes (against 1400 tons for the cultured oysters). A topographic survey was carried out in order to better understand the colonisation strategy developed by this population. A survey was also made in order to assess the extension of this species in the subtidal area. Overall, results suggest that population renewal can occur by transfer of benthic populations from offshore towards the coast, allowing the intertidal population to maintain high abundance levels in the absence of recruitment of juveniles. |
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