Vistula Lagoon (922)
Poland, Europe
Site overview
KBA status: confirmed
Global KBA criteria: D1a
Year of last assessment: 2010
National site name: Zalew Wislany
Central coordinates: Latitude: 54.3167, Longitude: 19.4833
System: marine, terrestrial
Elevation (m): 2 to 2
Area of KBA (km2): 304.38417
Protected area coverage (%): 99.91
KBA classification: Global
Legacy site: Yes
Site details
Site description: The site comprises the Polish part of this large, shallow coastal lagoon (up to 5 m deep) of brackish water, which is cut off from the Baltic Sea by the Wiœla spit. A narrow channel in the Russian part of the lagoon, through which sea water flows during heavy storms, joins the water-body with the Baltic Sea (Gulf of Gdañsk). There is some river flow to the Polish part of the lagoon from the west, comprising a few branches of the Wis³a (Vistula) river deriving from the uplands. The water-level fluctuates significantly on a daily basis (by up to 1.5 m) because of wind effects. There are extensive reedbeds (Phragmites) along the shore, forming one or two belts up to 100 m wide, as well as rich floating and submerged vegetation (Nymphaea, Potamogeton) which supports a very rich invertebrate and fish fauna. Land-uses include intensive reed-harvesting (`Other').
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: The site regularly supports 20,000 or more waterbirds, mainly wildfowl Anser/Anas. Breeding species of global conservation concern that do not meet IBA criteria: Haliaeetus albicilla (at least one pair), Crex crex (4-10 pairs). The most important parts of the site for birds in general are Elbl¹g Bay and the Pas³êka mouth. Non-breeding birds occur mainly in the coastal zone, from Przebrno village to the Pas³êka mouth.
Habitats
Land use: fisheries/aquaculture (60%) | hunting (10%) | tourism/recreation (20%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Marine Coastal/Supratidal | 98 | |
| Grassland | 1 | |
| Forest | 1 |
Threats
Summary of threats to biodiversity at KBA: Heavy nutrient pollution from agriculture, industry and domestic sewage is a threat. Birds become trapped in fish-nets. The changes in water-level affect breeding birds. Intensive reed-harvesting is also a problem (`Other'). The entire IBA lies within the buffer zones of two Landscape Parks (Mierzeja Wiœlana, 22,390 ha; Wzniesienie Elbl¹skie, 48,591 ha), approximately equally divided between the two.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Natural system modifications | Fire & fire suppression | Increase in fire frequency/intensity | Ongoing |
| Agriculture & aquaculture | Annual & perennial non-timber crops | Small-holder farming | Ongoing |
| Agriculture & aquaculture | Marine & freshwater aquaculture | Subsistence/artisinal aquaculture | Ongoing |
| Natural system modifications | Dams & water management/use | Abstraction of ground water (agricultural use) | 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 |
| Natural system modifications | Other ecosystem modifications | Only in the past and unlikely to return | |
| Residential & commercial development | Tourism & recreation areas | Ongoing | |
| Transportation & service corridors | Shipping lanes | Ongoing |