De Brakwaterkokkel Cerastoderma glaucum (Bruguière, 1789) (Bivalvia, Cardiidae) in de Waddenzee: een overzicht

For the first time a detailed overview is presented on the known occurrence of the Lagoon cockle (Cerastoderma glaucum) in the Wadden Sea area (Denmark-Germany-the Netherlands). The species occurs in semi-stagnant and brackish water bodies at the Wadden Sea islands. Records from the larger estuaries (Elbe, Weser) are missing. Information from the Danish Wadden Sea is very scarce; only one live specimen was reported from the island of Rømø. In Schleswig-Holstein, the Lagoon cockle was found at the island of Sylt and at some of the Halligen islands. No records are known from Lower Saxony, except for an observation in the Ems estuary in 1981. In the Netherlands, the species occurs mainly on the islands of Schiermonnikoog and Texel. Populations seem not to be stable; local extinction may be followed by re-colonization a few years later. There is no systematic monitoring of brackish water habitats in the Wadden Sea area.