The cockles presented on the stalls of Trouville-sur-Mer's Fish Market are burrowing bivalve mollusks generally caught on foot at low tide. The minimum size authorized for capture is 1.18 inches (3 cm). An essential activity for professional shore-gathering fishermen, cockle fishing is regulated in terms of opening dates and duration as well as quotas for proper management of this highly variable resource from year to year. In Normandy, the main deposits are located in the Baie de Seine.