Abstract: Method of and apparatus for use in the depuration of bivalves requires an underground tank for a substantial volume of seawater and is divided into upper and lower sections by a transverse filter. A series of treatment tanks are provided for batches of bivalves dug in a polluted area. Water is pumped continuously from the lower section of the underground tank to the treatment tanks after being filtered and disinfected by ultraviolet light and is returned to the upper section of the underground tank after passing through an open filter. All above ground portions of the apparatus are shielded against sunlight. The circulating water is continuously aerated. Sources of aerobic bacteria are added to each filter. The temperature, salinity, dissolved oxygen and pH of the seawater is maintained at levels appropriate for the bivalves.