Dear colleagues, together with my co-authors, I am pleased to share with you our recent publication in the Journal of Sea Research: Westphal L, Klemens L, Reif F, van Neer A, & Dähne M (2023). First evidence of grey seal predation on marine mammals in the German Baltic Sea. Journal of Sea Research, 102350. doi: 10.1016/j.seares.2023.102350 This paper describes the first cases of grey seal predation on marine mammals in the Baltic Sea, a behaviour which was not documented in the Baltic subspecies until now. The investigated carcasses were retrieved at the German Baltic coastline. The open access pdf is available here: doi.org/10.1016/j.seares.2023.102350<https://doi.org/10.1016/j.seares.2023.102350> Abstract: Grey seal predation on marine mammals has been reported throughout the northern hemisphere except for the Baltic Sea. After the Baltic subspecies (Halichoerus grypus grypus) was on the brink of extinction in the early 1990s, numbers increased steadily during the past three decades from a few thousands to > 40,000 in 2020. In recent years, grey seals were observed more frequently in the southern and western Baltic Sea, areas where the subspecies was a rare guest for many decades. Nevertheless, <10% of the Baltic grey seals are counted in the southern Baltic Sea. A standing stranding monitoring programme investigates carcasses of marine mammals washed up in Mecklenburg- Western Pomerania, Germany. In August 2021 a harbour seal (Phoca vitulina) carcass was found with lesions typical for grey seal predation: amongst others the typical “cork-screw”, helical and cut like lesions with smooth wound margins. The juvenile harbour seal showed 9 of 10 parameters indicating grey seal predation according to van Neer et al., 2021. Earlier suspicious cases in harbour porpoise (Phocoena phocoena) suggest that the presented case may not be an isolated one. Rather, it is a so far rare observation of a behaviour that may become more common with the ongoing recovery of grey seals in the southern Baltic Sea in an area of overlapping habitats with harbour porpoise and harbour seals. In this region harbour seals and harbour porpoise are more abundant than in the Northern Baltic Sea where, as of yet, grey seals are more numerous. Best regards Linda Westphal FB Wissenschaft / Scientifc departement Deutsches Meeresmuseum / German Oceanographic Museum Museum für Meereskunde und Fischerei ∙ Aquarium Stiftung des bürgerlichen Rechts Tel.: +49 3831 2650 396 Fax: +49 3831 2650 309 Mobil: +49 173 9688 286 linda.westphal@meeresmuseum.de<mailto:linda.westphal@meeresmuseum.de> www.deutsches-meeresmuseum.de<http://www.deutsches-meeresmuseum.de/> Director Prof. Dr. Burkard Baschek Andreas Tanschus Ust. ID Nr.: DE 162 772 269 Steuernr.: 082/126/00068 Postanschrift: Katharinenberg 14 - 20 18439 Stralsund Dienstsitz: Neue Badenstraße 4 18439 Stralsund