Health Status of Bycaught Common Eiders (<i>Somateria mollissima</i>) from the Western Baltic Sea
Luca A. Schick,
Peter Wohlsein,
Silke Rautenschlein,
Arne Jung,
Joy Ometere Boyi,
Gildas Glemarec,
Anne-Mette Kroner,
Stefanie A. Barth,
Ursula Siebert
Affiliations
Luca A. Schick
Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761 Büsum, Germany
Peter Wohlsein
Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany
Silke Rautenschlein
Clinic for Poultry, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany
Arne Jung
Clinic for Poultry, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17, 30559 Hannover, Germany
Joy Ometere Boyi
Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761 Büsum, Germany
Gildas Glemarec
National Institute of Aquatic Resources, Technical University of Denmark, 2800 Lyngby, Denmark
Anne-Mette Kroner
National Institute of Aquatic Resources, Technical University of Denmark, 2800 Lyngby, Denmark
Stefanie A. Barth
Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743 Jena, Germany
Ursula Siebert
Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, 25761 Büsum, Germany
The Common Eider (Somateria mollissima) inhabits the entire northern hemisphere. In northern Europe, the flyway population reaches from the southern Wadden Sea to the northern Baltic coast. The European population is classified as endangered due to declines in Common Eider numbers across Europe since 1990. In this study, we assessed 121 carcasses of Common Eiders, captured incidentally in gillnets in the Western Baltic between 2017 and 2019. The most common findings were parasitic infections of the intestine by acanthocephalans in 95 animals, which correlated with enteritis in 50% of the cases. Parasites were identified as Profilicollis botulus in 25 selected animals. Additionally, oesophageal pustules, erosions, and ulcerations, presumably of traumatic origin, were frequently observed. Nephritis and hepatitis were frequent, but could not be attributed to specific causes. Lung oedema, fractures and subcutaneous haemorrhages likely resulted from entangling and drowning. Two Common Eiders had mycobacterial infections and in one of these, Mycobacterium avium subspecies (ssp.) avium was identified. This study gives an overview of morphological changes and infectious diseases from one location of the European flyway population. It contributes to future health studies on Common Eiders in the Baltic and Wadden Seas by providing baseline information to compare with other areas or circumstances.
