Harbour Seal Numbers in the Wadden Sea and on Helgoland in 2023

Expert Group Marine Mammals

To obtain an estimate of the number of harbour seals and pups hauled out in the entire Wadden Sea area (including Helgoland), counts are synchronized between the three Wadden Sea countries, Denmark, Germany and the Netherlands.

Harbour seals are counted when hauling out on land and counts are scheduled to be carried out when low tide occurs. The counts are conducted on five coordinated dates. Three counts during the pupping season in June and two during the moulting season in August. In June, the number of pups is counted and in August the total number of harbour seals is counted in the respective regions, providing for an index of the population.

Authors: Anders Galatius, Sophie Brasseur, Thea Hamm, Armin Jeß, Kristine Meise, Julia Meyer, Jessica Schop, Ursula Siebert, Ole Stejskal, Jonas Teilmann, Charlotte B. Thøstesen

This report was published 2023-11-01.

This report should be cites as: Galatius A., Brasseur S., Hamm T., Jeß A., Meise K., Meyer J., Schop J., Siebert U., Stejskal O., Teilmann J., Thøstesen C. B. (2023) Survey Results of Harbour Seals in the Wadden Sea in 2023. Common Wadden Sea Secretariat, Wilhelmshaven, Germany.