The Site consists of a 30-kilometre stretch of the lower River Mörrumsån and the shore surrounding the bay at the river mouth. The Site includes areas of high national interest for nature conservation, cultural heritage, and geology. The range of fungi close to the river is unique: 15 rare species of fungi have been found, including the endemic Hygroaster lacteus present on small islands on the river. The Site holds one of the foremost areas in Sweden for populations of Atlantic salmon Salmo salar and brown trout Salmo trutta, and constitutes an internationally important spawning and recruitment area for fish. It is an important breeding site for birds of European and national importance such as common kingfisher, Caspian tern and little tern. Sport and commercial fishing, mainly for salmon and trout, are of great importance. The main threats to the ecological character of the Site relate to hydroelectric power plants which prevent fish from migrating; however measures have been taken to address the problem. Three dams within the Site and several others further upstream affect the water regime.