The Site consists of four reserves on the island of Harøya and its smaller neighbour Finnøya: Selvikvågen, Lomstjønna, Malesanden og Huse, and Lyngholman. The habitat types include shallow bays, extensive tidal, mud and sand flats with seaweed zones, sand dune systems, mires, and freshwater and salt marshes. Large quantities of seaweed accumulate, creating rich feeding areas for large numbers of breeding, migrating and wintering birds, including globally vulnerable species such as white winged scoter (Melannitta fusca) and long-tailed duck (Clangula hyemalis). The Site also offers habitat to the European otter (Lutra lutra). The rocky shores are important for shoreline stabilization. Human activities include nature conservation, fishing, livestock grazing, birdwatching and other recreational activities. Threats to the Site include changes in agricultural practices and related overgrowth of bird habitats. A partial management plan has been prepared and an information booklet on Ramsar Sites has been produced by the management authorities.