Main environmental changes since the Weichselian glaciation in the Danish waters between the North Sea and the Baltic Sea as reflected in the molluscan fauna

The Danish waters forming the transition zone between the North Sea and the Baltic Sea are described through changes in the molluscan fauna and bottom communities during the Holocene. The major change in the fauna at the Pleistocene-Holocene boundary is thought to be caused by changes in the palaeocurrents at this time. A sudden sea-level rise marked by floodwaters is recorded at the levels from −24.5 to +4.0 m between ca. 8600 and 7800 cal. years BP corresponding to a sea-level rise of around 3.5 m every 100 years. An expiring tide is identified in the early Subboreal affecting the prolific fjord faunas of the Atlantic time.