Researchers on flights to count grey seals in Wadden Sea

Seals experts in the Wadden Sea World Heritage are currently facing perfect weather conditions for the second phase of their annual grey seal counts. The Trilateral Expert Group Seals (EG-Seals) organises annual trilaterally coordinated surveys to observe both adult grey seals and pups. The first counting period was conducted during the pupping season in the winter months to monitor the newborns. Now it is moulting season, when grey seals spend substantial time on land, and the researchers set out to survey adult grey seals in all parts of the Wadden Sea and on Helgoland.

“It will be some time until we have the final results of our survey”, says Sascha Klöpper, Secretary of the EG-Seals. “One reason is that we are lucky enough to have a growing population of grey seals – with 6,538 individuals counted last year. But this means that during the flights it is impossible to make an instant of large colonies. In addition, harbour seals and grey seals may share the sand bank or beach, making it difficult to separate the two species. Hence, we take pictures during the flights we can enlarge on computer screens, to accurately count and distinguish the grey seal from its neighbour.” The results of the trilateral monitoring will be published in the beginning of July.

Grey seals are the largest predators along the Wadden Sea coast and, like harbour seals, they are one of the iconic species of the region. In former times grey seals were most possibly numerous in the Wadden Sea until they disappeared most probably after excessive hunting practices. They recolonised in the second half of the 20th century, originating from UK waters. Part of the Trilateral Wadden Sea Cooperation, the Trilateral Expert Group Seals (EG-Seals) (former TSEG) coordinates the counts and harmonizes the data from across the Wadden Sea region. The most numerous seal species in the Wadden Sea, the harbour seal, is specially protected under the Agreement on the Conservation of Seals in the Wadden Sea (WSSA) concluded under the auspices of the UN Convention on the Conservation of Migratory Species of Wild Animals (CMS). Although the WSSA does not officially cover the grey seal, the species benefits from the agreement’s protection measures. CWSS acts as the secretariat of WSSA.