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.
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.
Pressure/threats to key biodiversity
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.
National Partial International None150 ha of IBA covered by Nature Reserve (Mewia £acha, 150 ha).