The Site includes the most intact section of the (regulated) Pasvik River, characterized by many bays, lakes and islets. The area includes Scots pine (Pinus sylvestris) forests and extensive mires. Due to its very early ice break-up, the area is especially important for staging migratory waterbirds. Numerous threatened species breed at the Site, including the bean goose (Anser fabalis), ruff (Calidris pugnax) and the little bunting (Emberiza pusilla). The area is also important for a series of boreal species with limited distribution in Europe, such as the northern hawk-owl (Surnia ulula) and the great grey owl (Strix nebulosa). The Site has also a stable breeding population of the nationally threatened brown bear (Ursus arctos) and the European otter (Lutra lutra). The area is important for flood regulation, sediment transport and carbon sequestration. Human activities include nature protection, recreation, fishing, and some reindeer husbandry. The greater trilateral Pasvik area was featured as a Ramsar case study on transboundary wetland ecosystems in the 2nd Assessment of Transboundary Rivers and Lakes (UNECE 2011). The Pasvik river is regulated by two hydro-electric power plants; this has some influence on the fluctuation of the water level. There is also some contamination by air from industry and nearby military activities associated with border control in Russia.