In the Gulf of Finland is the State reserve "Birch Island". This is - a wetland created in 1994 and is of international importance. It is located 2 km south-west of the town of Primorsk, Leningrad Region. To reach the reserve by following from St. Petersburg to the town of Primorsk, then - in the south-west through the strait Berkezund 2 km. The reserve covers an area of ​​55,295 hectares on land and 47,020 hectares in the Gulf of Finland.

The aim of this reserve was to improve the living conditions of waterfowl and waterfowl during all periods of their life cycle. No less important is the preservation of the natural hydrological regime and the great diversity of ecosystems, including the protection of rare species of birds and animals, the maintenance of an optimal environment of water and riparian vegetation necessary for their food and protection.

The area is perfect for the development of family-friendly, eco-tourism, recreational, sports, and exclusive fishing.

The territory includes a large number of different-sized islands, the largest of them: North Birch, Big Birch, West Birch, Little Birch, southern and western portions of the waters.

Forest vegetation predominates in the vegetation cover of the archipelago .  The most common on all the islands of the archipelago type of coniferous forests - pine .  Only in the North Birch Island widespread spruce forests .  The vegetation islands are important birch forests that replace coniferous forests after felling, fires are the main type of communities in the overgrown farmland .  Small arrays and very rare aspen .  Mostly confined to the coasts of black alder forests, which are a key element of vegetation islands .  Absolutely unique deciduous forests Birch Small island, among them there are some very old perennial oaks .  This is - the typical deciduous forests of oak, ash, maple, linden, with the presence of grass cover many of the groves of plants (Corydalis solida, Mercurialis perennis, perlovnik pied) . 

The archipelago presents the different types of wetlands: fens, transition, riding. Botanically on Big Birch Birch and Western Isles are most interesting pine-sphagnum bogs. There besides the usual marsh plants, there are some species that are rare in the Leningrad Oblast: rhynchospora brown, plaunok flooded, Bolotnitsa Soddy, Drosera intermedia.

Different species of fish live and spawn around Birch Island: smelt, perch, herring, bream and perch. There are here and a small but rare and valuable species of fish: whitefish, whitefish, slingshot.

Areas in which there are large parking waterfowl, are shallow water, bays and straits between the islands formed on the spring migration. Especially numerous parking river ducks (mallard, shoveler, wigeon, teal, Garganey, Pintail, Teal), Geese (black and barnacle) swans (tundra and whooper), diving ducks (scoter, black scoter, long-tailed duck, tufted duck, goldeneye ), mergansers (long-nosed, and large).

The favorite nesting waterfowl are smaller islands. They formed the mixed colony of terns, gulls with numerous nests of ducks inside. On the islands of Little Birch, Rondo, Big Shoal, ludas and numerous small islands and known for such settlements.

Breeding sites of the Baltic ringed seal is the southern and western area. From year to year, depending on the boundary edge of the freeze-changing area where seals reproduce, but usually it is 6 - 10 kilometers south of Big Birch Island.