ReMoNor : Résultats 2000

At the end of its third year, the regional network for monitoring REMONOR, confirms the particularities of oyster from Normandy in matter of growth and quality. Results from 2 000 are globally very close of those from 1998. Mortality of adults reached 14% and juvenile 6% which represent a low death rate. For this year the most blow area is the Baie des Veys with 31% death rate at Géfosse. Observed growth this year had been weaker than the past two years despite the spring and automnal growth. At spring, the higher recorded growth rate on the West coast with 0.42% (regional average : 0.29%). This seasonal trend seems more and more obvious every year. Regarding the classification of the special oysters, despite the change of the standard, the Baie des Veys is the best sector in which the filling index are the most higher with an average index of 15 (regional average : 11.3). Here again, results from 2 000 are together very close of those from the past two years. Concerning the problem of shell infestation by annelids worms (Polydora and Boccardia), results shown for this year a low compare with 1999. This precisely confirms that the West coast is relatively saved with regard to the other sectors with an average index of 0.22 for the adults and 0.05 for the juveniles (regional average : 0.31 for adults, 0.11 for juveniles). The strong rates observed in 1999 were because of a primary infestation of the oysters.