The analysis of the official statistics of commercialised production of oysters (.Crassostrea angutata and Crassostrea gigas ) is achieved from 1866 to 1984 in term of their numbers and weights for the bay of Marennes-Oleron. The number of sanitary labels, multiplied by the mean weight of a crate can also give out the commercialised production provided it is increased by the bias and decreased by the exterior production of the bay . Thus the production of Portuguese oysters is only 45 000 tons from 1948 to 1957 with a maximum of 52, 000 tons for respectively 70 000 tons and 280 000 tons for the statistics . AIso, after the epizooties of Crassostrea angulata the production, fell down to 25 000 tons in 1971 according to the number of sanitary labels... |