Essais d'affinage en mer ouverte d'huîtres creuses Crassostrea gigas issues de l'étang de Thau

Mud blisters related to the Parasite worm Polydora or to the presence of TBT in the Thau Basin waters depreciate the market value of the oysters produced in this lagoon. A solution to this problem was searched by immersing during 1 to 3 months the oysters in the open sea before being marketed, this shell improvment operation being called "affinage en mer". The objective or this study carried out over 2,5 months in automn '1991 was to quantify possible differences, biometrical or biochemical, between oyster immersed for "affinage" on bottom open-sea structures, or remained for a normal cultivation .in the Thau lagoon. No significant differences were measured, although the external aspect of shells was modified for open sea oysters. Complementary studies at other seasons of the year should be necessary to assess the possible interest of this operation.