There are 19 species of seal in the world and two of them live in the Wadden Sea: The common seal (Phoca vitulina) and the grey seal (Halichoerus grypus). The Wadden Sea is a suitable habitat for seals, because low tides create plenty of dry sandbanks for the animals to rest and nurse their young on. Seals' bodies are well adapted to their habitat. They are excellent divers, hunters and swimmers.