Lake Vansjø (3580)
Norway, Europe
Site overview
KBA status: confirmed
Year of last assessment: 2014
National site name: Vansjø
Central coordinates: Latitude: 59.6667, Longitude: 10.8333
System: freshwater, terrestrial
Elevation (m): 25 to 200
Area of KBA (km2): 98.64021
Protected area coverage (%): 9.93
KBA classification: Regional
Legacy site: Yes
Site details
Site description: The site is a large, nutrient-rich freshwater lake, situated near the city of Moss. The lake is connected with the Oslofjord by the Mosse-elva river. Forestry is widespread; military activity mainly comprises low-flying planes from a nearby air base.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that was identified using previously established criteria and thresholds for the identification of Important Bird and Biodiversity Areas (IBAs) and for which available data indicate that it does not meet global KBA criteria and thresholds set out in the Global Standard.
Additional biodiversity: This is an important breeding site for Pandion haliaetus, with the highest known density of natural nests in Norway.
Delineation rationale: Small amendments made to boundary (via Google Earth) to better match important breeding and feeding areas for the ospreys (Oddvar Heggøy).
Habitats
Land use: agriculture (10%) | fisheries/aquaculture (90%) | forestry (10%) | military | nature conservation and research | tourism/recreation | water management (90%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Wetlands(Inland) | 33 | |
| Forest | 33 | |
| Artificial - Terrestrial | 33 |
Threats
Summary of threats to biodiversity at KBA: Nutrient pollution by agricultural activities is a problem. Forestry may be a problem for Pandion haliaetus, since trees are cut close to the nests; such activity should be planned, to avoid nest-sites and to reduce disturbance to nesting birds. Vannsjo supplies drinking water to Moss, and the local authorities take action to reduce pollution at the lake. Low-flying planes do not seem to affect Pandion haliaetus in any way. There is limited tourism in the area, and there are restrictions on motor-boats (maximum 5 knots within 100 m of land). Access to the Nature Reserve is restricted during the breeding season. Local ornithologists ring several bird species in the area, including Pandion haliaetus.