Location
The refuge lies at Pobrzeze Gdanskie (Gdansk Shoreland), eastward from Gdansk.

History and Land Formation
The refuge encompasses waters of a shallow lagoon (average depth is 2.3 m), the sand bar separating them from the sea as well as a narrow strap of land which encircles the lagoon from south, a bit lower than the sea level. Mierzeja Wislana is a young geological formation. It appeared as a result of activity of sea waves which were bringing material washed off the cliff shore, the Wisla and other rivers as well as by the wind. All these processes led to creation of a narrow belt of irregular dunes with steep slopes and a belt of sandy beach parallel to them. The highest dune, charmingly named "Camel's Back", elevates to a height of almost 50 m.

Ecosystem
The refuge is dominated by water habitats which cover more than 70% of its area. In shallow waters occur various communities of water and marsh vegetation. The rushes create even a few hundred meters wide belts along the shore. Underwater vegetation is also well developed. A characteristic feature of waters of the lagoon is considerable fluctuation of their level, which can change even 1.5 m over one twenty-four hours.

Mierzeja Wislana which separates the lagoon's waters from the sea in 80% is overgrown with forest. In the past it was a deciduous forest, but later it was thinned out, and alders, lindens, oaks and maples were replaced mostly with pines, which now dominate forests of the sand bar. In addition to pine woods we can come across acidophilous oak forests, and in depressions between dunes - marsh birchwood and alder swamps. Non-forest habitats are represented by transition mires and active raised bogs occurring in cavities, as well as white and grey dunes.

Diversity of habitat condition results in richness of flora and fauna species. We can come across Atlantic species for which it is the farthest eastern point of occurrence. It is the area valuable for animals, including birds, which winter, breed and rest during migrations. Most interesting species include: white-tailed eagle, marsh harrier, hen harrier and Montagu's harrier, bittern, little bittern, black stork and many species of ducks and geese, recorded here during passages.

Threats
Among main threats are water pollution, resulting mainly from communal waste damp, and communal waste disposal. Another problem is eutrophication of waters. Fishing poses threat to animals, including birds, which accidentally entangle in nets. For migrating birds threat comes also from a nearby power station.

Protection of Nature
The area has been included into the European ecological netwok Natura 2000, as the Site of Community Importance. Part of the refuge belongs to "Wysoczyzna Krajobrazowa" Landscape Park and "Mierzeja Wislana" Landscape Park. Small fragments are also part of Areas of Protected Landscape of the Szkarpawa river and Warminsko-Mazurskie voivodship. Here are located a few nature reserves:

• "Katy Rybackie" - orinitological reserve protecting a colony of great cormorant and grey heron;
• "Buki Mierzei Wislanej" - protects over 100 year old beech wood with a participation of oak-hornbeam complex;
• "Zatoka Elblaska" - orinitological reserve, created mostly with regard to water-swamp birds which nest here;
• "Ujscie Nogatu";
• "Cieletnik" - protects a stand of low birch growing on blanket peat bog.