Pedestrian Seaside Pier at the Bay of Greifswald on the Baltic Sea. The Bay of Greifswald is a lagoon in the southern Baltic Sea. It is limited by the island of Rügen, the Western Pomeranian mainland and the opening for Baltic Sea with the islands of Ruden and Greifswalder Oie. The bay coast is an ideal habitat for breeding birds such as great blue heron, swans and seagulls. In spring and autumn so-called „migrant and winter guests“ such as cranes encounter the bay and its surrounding area. The total area of Strelasund and the Bay of Greifswald is recognized as the European bird sanctuary.