Réseau de suivi de la croissance de l'huître creuse en Bretagne. Synthèse des quatre années 1989 à 1992

Since 1989, an homogeneous Crassostrea gigas oyster stock has been distributed once a year on several rearing sites in Brittany (3 populations per site). The main quantitative and qualitative growth descriptors, which reflect water quality effects during the monitoring period, are estimated at the end of each year. The 1989-1992 analysis prompted us to describe various growth responses correlated to biotops: oyster production in open areas influenced by oceanic waters was fairly constant in quality, including size and Polydora sp. infestation. In contrast, oysters in estuarine areas, partly affected by eutrophication (e.g., Aber Benoît, Pen Bé), or with a low carrying capacity, were characterized by weight and Polydora sp. infestation heterogeneity. These characteristics were almost constant over the years on all sites but Morlaix where oyster population growth tended to decrease. In 1993, the regional monitoring survey has been integrated into a national network called REMORA.