In conclusion, the archaeomalacological study shows that the shell remains discovered at Clos des Châtaigniers represent mainly food waste. Despite the size and the diversity of the samples, mussels seem to have been the only shellfish to have really played a role in the diet of local inhabitants during the Bronze Age. The choice of this shellfish can be explained as a result of easy access and abundance at the coastline of Normandy. Other marine invertebrates may have been brought to the site during the transport of mussels or represent the collection of empty shells. The study also reveals the consumption of other marine animals such as fish or birds, whose stomach contents contained small amounts of shells. The site is characterised by high numbers of mussels with medium to large sizes. Gathered in a rocky or muddy/rocky environment, they were then transported 10km inland. The absence of small-sized specimens of mussels might indicate prior selection during collection at the seashore. This sorting would reduce the number of mussels to be transported, thus less effort was required. The presence of numerous barnacles may signify that the mussels were washed and prepared at the site of Clos des Châtaigniers. The high ratio of burnt mussel remains at the site could be associated with a particular cooking method or the management of marine waste.
The presence of common mussels (Mytilus edulis) is frequent in protohistorical sites in Normandy (Dupont 2006b; Mougne and Dupont 2012; Mougne et al. 2013; Mougne in prep). Therefore, the consumption of mussels at the site of Clos des Châtaigniers is not an isolated phenomenon but corresponds to an activity practiced in Normandy during the Bronze and Iron Ages.