Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021

Erindi/veggspjald / Talk/poster V25

Occurrence of long-finned pilot whales (Globicephala melas) and killer whales (Orcinus orca) in Icelandic coastal waters and their interspecific interactions

Höfundar / Authors: Anna Selbmann (1), Charla Basran (2), Chiara G. Bertulli (3), Tess Hudson (4), Marie-Thérèse Mrusczok (5,6), Marianne H. Rasmussen (2), Jonathan N. Rempel (7), Judith Scott (6), Jörundur Svavarsson (1), Paul J. Wensveen (1), Megan Whittaker (4), Filipa I. P. Samarra (8)

Starfsvettvangur / Affiliations: 1. University of Iceland, 2. University of Iceland's Research Center in Húsavík, 3. Sea Watch Foundation, 4. Elding Whale Watching, 5. Orca Guardians Iceland, 6. Láki Tours, 7. Special Tours, 8. University of Iceland's Institute of Research Centres

Kynnir / Presenter: Anna Selbmann

Long-finned pilot whales (Globicephala melas) are widely distributed across the North Atlantic, including in Icelandic offshore waters, but little is known about their occurrence in Icelandic coastal waters. Interactions with killer whales (Orcinus orca) have been reported from several locations in the North Atlantic and killer whales commonly occur in the coastal waters to the south and west of Iceland. Sightings data from research platforms and whale watching tours in six areas around Iceland from 2007 to 2020 indicate that the occurrence of both species varies with region and season. Killer whales were regularly encountered in the south of Iceland during summer and west of Iceland during winter/spring. Pilot whales were only seen during the summer and were relatively rare visitors in all locations until 2014, when sightings appear to have increased, particularly in the areas that were also frequented by killer whales. When both species were sighted on the same day, interactions were common and appeared to be antagonistic, with killer whales consistently avoiding pilot whales and sometimes fleeing at high speed. We discuss possible explanations for the apparent increase in pilot whale sightings but knowledge on the species in Icelandic waters is very limited. Potential drivers of the interactions include food competition or mobbing behaviour and further research into the interactions will be important to inform conservation management of both species.