 The Portuguese oyster ("Crassostrea angulata") cultivated off the Atlantic coast of France and Portugal was largely killed by an iridoviral disease in 1969.To replace the stock, large quantities of Pacific oyster ("Crassostrea gigas") spat were imported from Japan.Some efforts were made to kill any fouling organisms that might be associated with the spat by immersing it for two periods, each of one hour, in fresh water.