Dithmarschen

part of Heligoland Bight

railway line in North Germany

thumb|right|A Harbor seal on the Medemsand at low tide, 2007. Medemsand island was a small island of Germany in the mouth of the Elbe on the Schleswig-Holstein coast opposite Otterndorf (Lower Saxony), where the Medem river flows into the Elbe. It was also known locally as Flak island. The island belonged to the district of Dithmarschen and was managed by the Brunsbüttel Water Management Office. It was eroded due to water flow and no longer exists today.