Ostoja na Zatoce Pomorskiej: Mapping the Marine Nature Reserve in the Baltic Sea

The history of Ostoja na Zatoce Pomorskiej is closely tied to the development of the European Union's Natura 2000 ecological network, the largest coordinated system of protected areas in Europe. The site itself was initially created in 2009, when the European Commission formally designated it as a Site of Community Importance under the EU Habitats Directive.

The initial area was approximately 242,553 hectares, but the boundaries and extent were refined through subsequent decisions. In 2010, the European Commission adjusted the protected area to 243,132.7 hectares, and a further adjustment in 2014 brought it to its current size of about 243,058.55 hectares. These revisions reflect the ongoing process of refining Natura 2000 boundaries to reflect updated scientific understanding and ecological conditions.

Because the site is a marine area, governance was assigned to the Maritime Office in Szczecin, the Polish institution responsible for the administration of Poland's maritime waters. Today, the site also overlaps almost entirely with the Zatoka Pomorska Special Protection Area for birds, an associated Natura 2000 designation under the EU Birds Directive, reinforcing its role as a cornerstone of marine conservation in the western Polish Baltic Sea.

The landscape of Ostoja na Zatoce Pomorskiej is defined entirely by the marine environment of the southern Baltic Sea. Although the site is a sea territory, it displays substantial physical variability across its seabed, ranging from broad sandy banks and shallow sandy shoals to wide gravel plains and scattered boulder fields.

The most prominent underwater feature is the Odrzańska Ławica, a large shallow bank occupying the central portion of the Pomeranian Bay. This shallow area is one of the defining seabed structures of the region and is core to the site's protected habitat of submerged sandbanks permanently covered by shallow seawater, which covers roughly a quarter of the entire site area.

While the boundaries of the sanctuary are defined in the open sea, its westernmost extent is anchored at the eastern breakwater of the port of Świnoujście, and its eastern boundary reaches the spit of Lake Resko Przymorskie near Dźwirzyno. The farthest point of the site lies approximately 49 kilometers (around 26.5 nautical miles) from the Polish coast, illustrating the depth of open sea encompassed within the protected area.

The natural environment of the sanctuary is shaped by the specific conditions of the Pomeranian Bay, a relatively shallow, brackish arm of the southern Baltic Sea. The bay's seabed transitions through a wide range of substrate types, from fine sandy banks dominating the shallower central portions to gravel plains and boulder-rich areas elsewhere.

The site's protected natural habitat type is submerged sandbanks permanently covered by shallow seawater, which accounts for approximately 25 percent of the area and is explicitly listed under Annex I of the EU Habitats Directive as requiring conservation. Beyond this formally protected habitat, the surrounding waters host additional substrate communities that contribute to the area's ecological value.

The combination of shallow sandy banks and varied seabed morphologies creates habitat conditions that support a diverse range of marine fauna and serve as ecologically important zones for migratory and resident species in the southern Baltic.

The wildlife of the sanctuary reflects its identity as a marine Natura 2000 area. Rather than terrestrial species, it focuses on the protection of marine animals and seabirds whose populations are rare, threatened, or of European conservation concern.

Among the most significant species are the harbor porpoise (Phocoena phocoena) and the twaite shad (Alosa fallax), both of which are listed on Annex II of the EU Habitats Directive and regularly occur within the site's waters. The sanctuary is considered a critical zone for protecting the Baltic population of twaite shad and is a regular area of occurrence for the harbor porpoise. Other protected species associated with the site include the grey seal (Halichoerus grypus) and the sea lamprey (Petromyzon marinus).

The site also supports notable seabird and waterbird populations. Four bird species listed on Annex I of the EU Birds Directive have been recorded, including the red-throated diver (Gavia stellata), the black-throated diver (Gavia arctica), the horned grebe (Podiceps auritus), and the smew (Mergus albellus). Additional migratory waterbirds regularly observed include the great crested grebe, the red-necked grebe, the long-tailed duck, the common scoter, the velvet scoter, the red-breasted merganser, and the black guillemot.

Ostoja na Zatoce Pomorskiej carries considerable conservation significance as one of the key marine areas in the southern Baltic Sea included in the European Natura 2000 network. Its designation as a Site of Community Importance places it within the European Union's largest coordinated ecological network, designed to ensure the long-term survival of Europe's most valuable and threatened species and habitats.

The core conservation aim is the long-term safeguarding of natural habitats and populations of rare animal species, with the explicit exclusion of birds under the Habitats Directive designation. Habitats protected within the area include submerged sandbanks permanently covered by shallow seawater, a habitat type listed under Annex I of the Habitats Directive.

The site's overlapping relationship with the Zatoka Pomorska Special Protection Area, designated under the Birds Directive, further reinforces its conservation value by providing protection for both the marine habitats and the seabird populations that depend on them. Conservation oversight is exercised by the Director of the Maritime Office in Szczecin.

The site's standout features include the Odrzańska Ławica, the large central shallow bank that defines much of the Pomeranian Bay's marine character. Approximately one-quarter of the site consists of protected submerged sandbanks that are permanently covered by shallow seawater, making it one of the more significant such habitats in the Polish maritime zone.

It is the only major Natura 2000 marine area along this stretch of the Polish coast whose identity is essentially synonymous with the Polish section of the Pomeranian Bay itself. Its importance for protected species such as the harbor porpoise and the twaite shad, combined with the presence of multiple Annex I bird species, distinguishes it as a concentrated zone of marine biodiversity in the southern Baltic.