Grey Seal Numbers in the Wadden Sea and on Helgoland in 2018-2019

Expert Group Seals

The Wadden Sea is becoming an important area for grey seals (Halichoerus grypus) to breed and haul out. Over the last decades, increasing numbers have been counted in the three Wadden Sea countries Germany (including Helgoland), the Netherlands and later, Denmark. Coordinated aerial, boat and land-based surveys during moulting and breeding assure that the counted numbers show a reliable indication of the numbers present throughout the Wadden Sea. The grey seals in the Wadden Sea are part of a larger North Sea population, and animals that breed in the Wadden Sea might moult elsewhere and vice versa (Brasseur et. al. 2015). Interpreting the results of the Wadden Sea counts in isolation in terms of population size is therefore complicated and of limited value in terms of population status.

Authors: Members of the Trilateral Expert Group Seals (EG-Seals): Jenny Cremer, Sophie Brasseur, Richard Czeck, Anders Galatius, Armin Jeß, Peter Körber, Ralf Pund, Ursula Siebert, Jonas Teilmann, Charlotte Bie Thøstesen, Julia A. Busch

This report was published 2019-07-02.

This report should be cites as: Cremer J, Brasseur S., Czeck R., Galatius A., Jeß A., Körber P., Pund R., Siebert U., Teilmann J., Bie Thøstesen C. & Busch J.A. (2019) EG-Seals grey seal surveys in the Wadden Sea and Helgoland in 2018-2019. Common Wadden Sea Secretariat, Wilhelmshaven, Germany.