The Seal Centre Friedrichskoog is the only authorized sanctuary and rehabilitation centre for young seals found abandoned or sick in Schleswig-Holstein in accordance with the international seal convention.

There are two native seal species in Germany: harbor seal & grey seal.

The birth season for harbor seals begins at the beginning of May, with the last births occasionally taking place at the end of July. The main birthing season in Schleswig-Holstein is in June. Grey seals, on the other hand, give birth to their pups in winter. The exact whelping time varies depending on the distribution area. In Schleswig-Holstein, the pups are mainly born in November and December.