History and landscape
The area is characterized by small diversity of the land. Zalew Szczecinski constitutes the main part of the refuge. It is a large reservoir which average depth of 3.5-4 m. A belt of shallow water stretches along its shores.

Ecosystem
A basic element of the ecosystem are waters of Zalew Szczecinski and estuarial part of the Odra. The lagoon is shallow and mostly overgrown by vegetation. Land habitats cover only a little more than 10% of the refuge area. The lagoon is a transitional sphere between salty sea waters and inland fresh waters. The lagoon is connected with the Baltic Sea by the Dzwina, Swina and Piana rivers.

During heavy storms and long-lasting northern winds salty sea waters are pushed back to the lagoon and water level raises even by 1 m. Chemical parameters of the water change - mostly in terms of chlorine content, temperature and oxygenation. Inflow of salty waters into the lagoon results in presence of halophytes.

Due to these special conditions the lagoon waters are inhabited by many rare and protected species. The following plants deserve special attention: white water-lilies, yellow water-lilies or honeysuckle. Also species specified in 2 Appendix of the Habitats Directive occur here: brook lamprey, allis shad, twaite shad, salmon, asp, bitterling, weatherfish or spined loach.

We can also meet here great crested newt, firebelly toad, otter and beaver. There are perfect conditions for birds - white-tailed eagle, lesser spotted eagle, red kite, black kite, European honey-buzzard, peregrine falcon, bittern, great egret, black stork, crane, corn crake, black woodpecker and kingfisher.

Threats
Main threats to the natural qualities of the area are connected with water pollution. Together with waters pushed back from the Baltic Sea pollutions get into the lagoon. Moreover, the Odra river is another source of pollution, and a chemical factory Police is located near the lagoon.

There also is constant danger of contamination with oil from ships and fishing boats. Habitats situated at the edges of the refuge are affected by changes in land cultivation, particularly abandonment of traditional ways of cultivation which leads to overgrowing with scrub vegetation. Excessive pressure from predators causes loss of breeding grounds of many birds which nest here. There is also negative influence of pouching as well as excessive tourist pressure.

Nature protection
The area is included into the European ecological network Natura 2000 as the Site of Community Importance. There are two nature reserves: "Bialodrzew Kopicki" - a floristic reserve and "Czarnocin" - a forest reserve protecting a strap of marsh birchwood.