Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Giulia Bellon1, Paul Wensveen1, Marianne Rasmussen2, Amelie Laute3, Xavier Mouy4,5, Anna Selbmann1, Filipa Samarra6
Starfsvettvangur / Affiliations: 1 Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland 2; The University of Iceland’s Research Centre in Húsavík, Hafnarstétt 3, 640 Húsavík 3; Whale Wise, Swansea SA3 1LB, UK 4; JASCO Applied Sciences Ltd, Victoria, BC, Canada; 5 Integrated Statistics, Inc., Under Contract to National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center, Woods Hole, MA, USA; 6 University of Iceland's Institute of Research Centres, Ægisgata 2, 900 Vestmannaeyjar, Iceland
Kynnir / Presenter: Giulia Bellon
The movement patterns of Icelandic and Norwegian killer whales are strongly linked to herring, a favoured prey. Prior to the collapse of the Norwegian-spring spawning (NSS) herring in the 1960s, reports suggested killer whales migrated between the two regions, following the herring. Its recent recovery brought NSS herring to resume its migration to Icelandic waters, raising the question of potential movement of killer whales between these regions. In this study, opportunistic passive acoustic monitoring (PAM) data from locations across Icelandic inshore and offshore waters were used to investigate killer whale distribution and potential connectivity with Norway. Data was run through an automatic detector-and-classifier algorithm to detect killer whale burst-pulse calls. Detections were manually analysed using Raven Pro. Calls were detected in 18% of acoustic files, with calls confirmed in all locations. Call comparisons revealed 760 matches to 28 call types of the Icelandic catalogue and 6 matches to 2 call types of the Norwegian catalogue. Icelandic killer whales were detected year-round and across a wider geographic area than previously known. The matches to the Norwegian catalogue suggest connectivity between both populations, with NSS herring being targeted by both Icelandic and Norwegian killer whales in Icelandic waters. This study illustrates the advantage of using PAM to monitor year-round occurrence and connectivity of killer whales in the North Atlantic.