Dear colleagues, We are pleased to share the publication of our paper about Icelandic killer whales site fidelity and movement around Iceland. Tatiana M. J. Marchon, Marianne H. Rasmussen, Charla J. Basran, Megan Whittaker, Chiara G. Bertulli, Cathy Harlow, Rob Lott, Oliver Boisseau, Frédéric Gendron, Luisa Guo, Tess Hudson, Hörður Jónsson, Alexa Kershaw, Joonas Kinni, Laetitia A. M. G. Lionnet, Marie Louis, Matt Messina, Hanna Michel, Barbara K. Neubarth, Belén G. Ovide, Annemieke E. Podt, Jonathan N. Rempel, Conor Ryan, Eddy Savage, Judith Scott, Ronald Smit, Hans Verdaat, Solvi R. Vignisson & Filipa I. P. Samarra (2023) Geographical movements, site fidelity and connectivity of killer whales within and outside herring grounds in Icelandic coastal waters. Marine Biology. https://doi.org/10.1007/s00227-023-04345-7 Abstract Investigating the movements and site fidelity of individuals enhances our understanding of population ecology and structure. Killer whales occur around the coast of Iceland; however, information on the connectivity between different regions is limited to herring grounds, where they are observed frequently. In this study, we used photo-identification data to investigate the movements and site fidelity of whales within (South and West) and outside (Southwest, Northwest, Northeast and East) Icelandic herring grounds. Additionally, we used a 10-year photo-identification dataset in the South to investigate long-term site fidelity patterns to a single location. Of the 440 individuals sighted more than once, nearly half (48%) moved between herring grounds and site fidelity was higher within, compared to outside, herring grounds. Outside herring grounds, individuals showed: more movement from Southwest to West compare to South, indicating this region is not exclusively a passage between herring grounds; low site fidelity to the Northeast with fewer photographic matches to other regions, suggesting individuals found here may be part of an offshore population that occasionally visits the area; and low proportion of matches to other regions in the Northwest and East, although small sample sizes precluded firm conclusions. Finally, long-term residency of killer whales in the South showed dynamic patterns, likely caused by prey availability and/or environmental changes. This study elucidates the complexities of killer whale occurrence and connectivity within the North Atlantic and suggests population structure that should be further investigated for appropriate regional conservation assessments. The pdf is available in view-only here: https://rdcu.be/dtyqa and can be downloaded from here: https://link.springer.com/article/10.1007/s00227-023-04345-7<https://link.springer.com/article/10.1007/s00227-023-04345-7?fbclid=IwAR33ka2N5ycwz05ikOIxM6utx6kFvSbot8jlptUWFhx1oIS267cVHWRKneA> Please feel free to contact me if you have any questions. For the co-authors, Tatiana Marchon PhD Candidate Faculty of Life and Environmental Sciences University of Iceland