Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E125
Höfundar / Authors: Guðjón Már Sigurðsson (1), Gísli Víkingsson (1), Valerie Chosson (1), Teunis Jansen (2,3), Warsha Singh (1)
Starfsvettvangur / Affiliations: 1. Hafrannsóknastofnun. 2. Greenland Institute of Natural Resources. 3. DTU-Aqua
Kynnir / Presenter: Guðjón Már Sigurðsson
The waters between Iceland and East Greenland have undergone considerable changes in the last 30 years, which has resulted in large scale changes to the ecosystem. Keystone species such as capelin has changed its distribution northwards and subsequently marine mammals in the region have changed their distribution to the point that the term regime shift has been raised. In this study we investigated the relationship between whales and capelin during these times of change. To explore this question, we counted whales systematically using dedicated observers and measured capelin with acoustic measures during in autumn in East Greenlandic waters. A total of 205 whales of seven species were observed in 2017 while 1295 whales of eight species were observed in 2018. The most observed species was humpback whale in both years. Whale and capelin abundance data were then summed per statistical square. Whales were found at a higher frequency than expected where capelin was present, with the relationship being stronger for baleen whales than toothed whales. Further, a GAM showed a weak but significant relationship between capelin- and total whale abundance. When modeled separately by the most common whale species, this positive relationship was stronger. The results show that whales are likely following the capelin during these changing times, and likely indicate predation on capelin by some of the whales.