Vistula river mouth (921)
Poland, Europe
Site overview
KBA status: confirmed
Global KBA criteria: D1a
Year of last assessment: 2010
National site name: Ujscie Wisly
Central coordinates: Latitude: 54.3500, Longitude: 18.9500
System: marine, terrestrial
Elevation (m): 0 to 2
Area of KBA (km2): 20.97526
Protected area coverage (%): 93.44
KBA classification: Global
Legacy site: Yes
Site details
Site description: A 6 km stretch of the lower Wis³a (Vistula) river from Przegalina sluice to the river mouth, including a strip of meadows along the right bank (between Mikoszewo and Drewnica). Habitats include sandy peninsulas, mobile sandflats, small sandy islets, temporary lakes and adjacent dunes, freshwater lakes on either side of the Wis³a channel, and a small patch of coastal forest. The vegetation is very species-rich and at the river mouth shows all stages of natural succession from bare sandflats to bushes and forest on the oldest areas. Willow Salix has been planted to stabilize dunes. The meadows are flooded in spring (occasionally at other seasons) and are grazed, mainly by cattle.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Additional biodiversity: A very important site for wintering, migrating and breeding waterbirds, regularly holding well over 20,000 individuals, sometimes exceeding 150,000 birds. In late summer and early autumn wader passage is intense, with very high rates of turn-over; Calidris species dominate (up to 8,000 waders ringed in a season). When flooded, the meadows near the southern border of the IBA support thousands of ducks and waders. Other waterbirds supported in high numbers include Clangula hyemalis (30,000, winter) and non-breeding terns in summer/autumn (max. 1,000 Sterna sandvicensis; max. 3,000 Sterna hirundo). Overall, at least 22 waterbird species have been recorded breeding, with at least 120 waterbird species recorded in the non-breeding season.
Habitats
Land use: agriculture (5%) | fisheries/aquaculture (50%) | forestry (5%) | hunting | nature conservation and research (35%) | tourism/recreation (5%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Grassland | 25 | |
| Marine Intertidal | 30 | |
| Shrubland | 5 | |
| Forest | 10 | |
| Marine Coastal/Supratidal | 30 |
Threats
Summary of threats to biodiversity at KBA: Tourism/recreation, hunting, poaching and uncontrolled human access all lead to significant disturbance of birds. Storms in spring/summer flood the tern Sterna colonies on islets, forcing birds to re-nest in less safe areas. Locally increasing populations of gulls Larus argentatus and mammalian predators are reducing the number of nesting waders and terns. A proposed series of dams along the lower Wis³a (`cascadization') is potentially a great threat to the area. Gdañsk Ornithological Station is carrying out a long-term study of wader migration.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Agriculture & aquaculture | Marine & freshwater aquaculture | Subsistence/artisinal aquaculture | Ongoing |
| Biological resource use | Hunting & collecting terrestrial animals | Intentional use (species being assessed is the target) | Ongoing |
| Biological resource use | Fishing & harvesting aquatic resources | Unintentional effects: large scale (species being assessed is not the target) [harvest] | Ongoing |
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Unspecified species | Ongoing |
| Invasive & other problematic species, genes & diseases | Problematic native species/diseases | Unspecified species | Ongoing |
| Pollution | Domestic & urban waste water | Type Unknown/Unrecorded | Ongoing |
| Pollution | Industrial & military effluents | Type Unknown/Unrecorded | Ongoing |
| Residential & commercial development | Tourism & recreation areas | Only in the future | |
| Human intrusions & disturbance | Recreational activities | Ongoing | |
| Pollution | Garbage & solid waste | Ongoing | |
| Climate change & severe weather | Temperature extremes | Ongoing | |
| Climate change & severe weather | Storms & flooding | Ongoing |