Lake Hjälstaviken (868)
Sweden, Europe
Site overview
KBA status: confirmed
Year of last assessment: 2000
National site name: Hjälstaviken
Central coordinates: Latitude: 59.6683, Longitude: 17.3917
System: freshwater, terrestrial
Elevation (m): 3 to 35
Area of KBA (km2): 8.02574
Protected area coverage (%): 98.97
KBA classification: Regional
Legacy site: Yes
Site details
Site description: Shallow (average depth 1 m), almost enclosed bay of Lake Mälaren, surrounded by wet, tussocky meadows which merge into drier pasture and fields. Deciduous copses overlook the bay and there is a conifer-covered hill with bare rock outcrops along the eastern edge. Only 30 ha of open water remain, the rest being choked by invasive Phragmites, Scirpus and Typha.
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: The IBA supports important numbers of passage wildfowl, and the surrounding arable land is an important feeding area. Species of global conservation concern that do not meet IBA criteria: Anser erythropus (up to 5 passage birds), Crex crex (1-3 breeding pairs) and Gallinago media (5-10 passage birds).
Delineation rationale: old area: 820ha changed due to more accurate information on borders and size. /Robert Ekblom (2007-10-19)
Habitats
Land use: agriculture (35%) | forestry (15%) | nature conservation and research (100%) | tourism/recreation (80%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Artificial - Terrestrial | 20 | |
| Grassland | 20 | |
| Wetlands(Inland) | 40 | |
| Rocky Areas(e.g., inland cliffs, mountain peaks) | 5 | |
| Shrubland | 5 | |
| Forest | 10 |
Threats
Summary of threats to biodiversity at KBA: Threats include overgrowth of grassland vegetation due to undergrazing and the effects of introduced American mink Mustela vison. Submerged aquatic vegetation has been greatly impoverished in recent years and this, together with the decreasing area of open water, has resulted in the decline of some bird species, notably ducks (`Other' threat). The water-level is artificially managed˜a more beneficial management regime was decided upon in 1996.