Dear all, My co-authors and I are happy to announce our new publication on the sperm whale mortality event that occurred around the North Sea in 2016 and involved 30 sperm whales and five countries. Citation: Lonneke L. IJsseldijk, Abbo van Neer, Rob Deaville, Lineke Begeman, Marco van de Bildt, Judith M.A. van den Brand, Andrew Brownlow, Richard Czeck, Willy Dabin, Mariel ten Doeschate, Vanessa Herder, Helena Herr, Jooske IJzer, Thierry Jauniaux, Lasse Fast Jensen, Paul D. Jepson, Wendy Karen Jo, Jan Lakemeyer, Kristina Lehnert, Mardik F. Leopold, Albert Osterhaus, Matthew W. Perkins, Uwe Piatkowski, Ellen Prenger-Berninghoff, Ralf Pund, Peter Wohlsein, Andrea Gröne & Ursula Siebert, Beached bachelors: An extensive study on the largest recorded sperm whale Physeter macrocephalus mortality event in the North Sea, PLOS ONE, DOI: 10.1371/journal.pone.0201221 Abstract: Between the 8th January and the 25th February 2016, the largest sperm whale Physeter macrocephalus mortality event ever recorded in the North Sea occurred with 30 sperm whales stranding in five countries within six weeks. All sperm whales were immature males. Groups were stratified by size, with the smaller animals stranding in the Netherlands, and the largest in England. The majority (n = 27) of the stranded animals were necropsied and/or sampled, allowing for an international and comprehensive investigation into this mortality event. The animals were in fair to good nutritional condition and, aside from the pathologies caused by stranding, did not exhibit significant evidence of disease or trauma. Infectious agents were found, including various parasite species, several bacterial and fungal pathogens and a novel alphaherpesvirus. In nine of the sperm whales a variety of marine litter was found. However, none of these findings were considered to have been the primary cause of the stranding event. Potential anthropogenic and environmental factors that may have caused the sperm whales to enter the North Sea were assessed. Once sperm whales enter the North Sea and head south, the water becomes progressively shallower (<40 m), making this region a global hotspot for sperm whale strandings. We conclude that the reasons for sperm whales to enter the southern North Sea are the result of complex interactions of extrinsic environmental factors. As such, these large mortality events seldom have a single ultimate cause and it is only through multidisciplinary, collaborative approaches that potentially multifactorial large-scale stranding events can be effectively investigated. The publication is open access and can be downloaded from: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0201221 Kind regards, Lonneke IJsseldijk Lonneke L. IJsseldijk, MSc Project Manager Cetacean Research Faculty of Veterinary Medicine, Utrecht University Department of Pathobiology T +31 30 253 5312, M +31 6 244 556 98 Website: http://www.uu.nl/strandingsonderzoek Instagram: https://www.instagram.com/strandingresearch/