Since 2001, an annual stock assessment of Japanese clam (Ruditapes philippinarum) and European clam (Ruditapes decussatus) has been carried out in March-April in the Gulf of Morbihan and the Noyalo River. The objectives of this survey are:

1. to estimate, by direct assessment, the biomass of the stock and its geographical distribution;
2. to estimate the exploitable biomass and exploitation potential for the sampled sites in particular, in areas reserved for professional fishing;
3. to establish a diagnosis, with a medium-term vision, on the state of the stock;
4. to propose the implementation of appropriate management measures.