The River Emån is one of the largest river systems in the south-east of Sweden. The catchment area is about 4 500 square km and the river flows 220 km from the source in the highland of Jönköping County, to the river mouth at the Baltic sea. Unlike other parts in southern Sweden, the water environment of Emån River is not severely affected by acidification and eutrophication. Surface water is mainly relatively nutrient poor, with moderate to high humic content. The designated Natura 2000 site Emån (västra; ie “the western part”) runs from lake Grumlan close to the city of Vetlanda to the border of Kalmar County at Kvillsfors. The catchment area of the Natura 2000 site is about 1 700 square km and dominated by forested areas. The river that runs through the Natura 2000 area, in total 35 km, is dominated by stretches with low water velocity. Along the stretch between Ädelfors and Turefors the river has a meandering course. Here, the river is surrounded by open fields and meadows. Agricultural land is concentrated to the valleys and adjacent to the moraine ridges within the drainage area. Otherwise, surroundings are dominated by wetlands in the lower parts and coniferous/mixed forest in the upper parts. Exploited areas in the surroundings are scarce and less than 15% of the riparian consists of urbanised areas, farmland or clear cuts of forested areas.
The River Emån has a high diversity of different taxa and species. Regarding fish, more than 30 species are represented. Also in the Natura 2000 area, a wide variety of fish species have been found, for Cottus poecilopus (alpine bullhead), Phoxinus phoxinus (minnow), Coregonus sp. (European white fish), Lota lota (burbot), Anguilla anguilla (eel) and Salmo trutta (brown trout). However, the Salmo trutta population is weak, being impacted by the migration obstacle of Högsby hydro-power plant. The dam at Högsby also represents the upper limit of the spawning run from the sea in Emån River. The Salmo salar (Atlantic salmon) population in the River Emån is one of few remaining populations in the southern part of Sweden.
The ongoing monitoring program shows that the invertebrate fauna in the River Emån is diverse, having high protection values. The following are examples of species found in the area; Calopteryx splendens (banded demoiselle), the mayfly Baetis buceratus, the caddisflies Oecetis notat and Brachycentrus subnilus, the beetle Stenelmis caniculata and the snails Marstoniopsis scholtzii, nautilus ramshorn (Gyraulus crista) and Bithynia leachi. Among the bird species found in the River Emån, one of the most notable species is the Alcedo atthis (kingfisher). It occurs on lush slow flowing sections with active erosion that creates appropriate sites for digging nests. Cinclus cinclus (dipper) uses ice-free sections for staying over winter. Parts of the adjacent land are flooded during spring, providing good resting places for Cygnus cygnus (the whooper swans). Pandion haliaetus (Osprey), Haliaeetus albicilla (white-tailed seaeagle) and Gavia arctica (black-throated loon) utilize the River Emån and the immediate vicinity for foraging. Lutra lutra is present mainly in the upstream parts of the river system.
The River Emån has a great significance from a cultural historical perspective. For example was the river a location of settlements for fisheries, hydro-power stations and timber floating. These activities generated many traces in the landscape, traces that have a cultural heritage value, but today, from a nature conservancy perspective can be problematic. This particularly applies to dams built to utilize waterpower, preventing migration of fish and other aquatic fauna. Other human activities in the river are vegetation removal, dredging of waterways and draining land in order to facilitate timber floating and agriculture.
The main purpose of the UC4LIFE related actions in River Emån is to restore habitats to obtain favourable conservation status at bio-geographic level for Unio crassus, Margaritifera margaritifera, and Lutra lutra. The presence of Unionid mussel species is overall high in the River Emån. Besides the endangered Margaritifera margaritifera and Unio crassus, Unio pictorum (painters mussel), Anodonta anatina (general duck mussel) and the endangered Pseudanodonta complanata (depressed river mussel) have been found in the Emån River system. Stocks of the later species appear to be viable, but further investigation is needed to verify its conservation status. Moreover, the River Emån is one of three areas in Jönköping County where Unio crassus has been found. The river system constitutes a high conservation value since it holds all seven native Swedish species of unionid mussels, high diversity of fish and aquatic invertebrates. Also a number of key freshwater habitats, covering approximately 9% of the area, have been identified. These are mainly lotic and semi-lentic habitats, lake inlets, eroding slopes and cultural sites.