Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2019

Erindi/veggspjald / Talk/poster V61

Feeding ecology of Icelandic killer whales

Höfundar / Authors: Filipa Samarra (1), Sverrir Daníel Halldórsson (1) and Gísli A. Víkingsson (1)

Starfsvettvangur / Affiliations: 1. Marine and Freshwater Research Institute (Hafrannsóknastofnun), Skúlagata 4, 101 Reykjavík

Kynnir / Presenter: Filipa Samarra

In the North Atlantic, two ecotypes of killer whales have been described using morphological traits and stable isotope ratios of samples from across the region: a generalist type 1 and a mammal eating specialist type 2. In Iceland, killer whales have long been known to associate with herring and were proposed herring specialists. Recent research in herring grounds, however, suggests the existence of herring specialists and whales that also include higher trophic level prey in their diet. Killer whales have been observed targeting a variety of prey in Iceland but our understanding of the variation in feeding ecology of this population is still limited. This is particularly the case outside herring grounds, where little research has been conducted. In this study we analyse stable isotopes of carbon and nitrogen of skin samples from 62 live whales collected between 2013-2017 in herring grounds and compare them to 12 whales stranded across the country between 1990-2016. The majority of stranded whales grouped with whales presumed to be herring specialists, supporting a similar ecological niche of whales found across Iceland. This preliminary analysis suggests little evidence of the existence of a marine mammal specialist ecotype in Icelandic waters. However, future work, including stable isotope analysis of further stranded samples, will be needed to broaden our understanding of the feeding ecology of this population and its resilience to ecosystem changes.