1. Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Foundation, Werftstrasse 6, 25761 Büsum, Germany
2. Professor Krzysztof Skóra Hel Marine Station, Department of Oceanography and Geography, University of Gdansk, Morska 2, 84-150 Hel, Poland
3. Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, 51005 Tartu, Estonia
4. Stiftung Deutsches Meeresmuseum, Katharinenberg 14-20, 18439 Stralsund, Germany
5. Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany