is an uninhabited island in the Meldorf Bay, about 14 kilometres (8.7 miles) off the North Sea coast of Dithmarschen in north Germany – about 12 kilometres (7.5 miles) from the Trischendamm embankment. The island belongs to the municipality of Friedrichskoog and is only occupied from March to October by a bird warden from the Nature and Biodiversity Conservation Union or NABU. Otherwise it is out-of-bounds. Trischen originated about 400 years ago and moves about 3 m per month towards Büsum on the mainland.