Iceland 2013: Saga #7 – Orca research

Dr Filipa Sammara from the Marine Research Institute in Reykjavik and her team from the University of St Andrews in Scotland are currently in Grundarfjordur studying the orcas that spend the winter hunting for herring in the local fjords.

Dr Filipa Sammara

Here, Filipa explains the research goals.

The aim of the project is to study how the feeding behaviour of Icelandic orcas changes within the same population. Icelandic orcas feed mainly on herring and appear to follow the herring in its migration during the year. At different times of the year the behaviour of the herring changes, depending on whether it is spawning, in the summer, or overwintering, in the winter. Over the last few years herring has been coming to the waters of Grundafjordur to overwinter and orcas were observed feeding on herring in this area in 2011. By taking photo-identification pictures and making acoustic recordings we can identify the whales that are seen in this area and investigate the sounds they produce during feeding. This data will then be compared to previous information collected in the summer in Vestmannaeyjar to investigate if the same whales are travelling between the two areas to feed on herring and how their feeding behaviour varies at different times of the year. This will greatly increase our knowledge of the Icelandic orca population and how they adapt to changes in their prey behaviour.

Male orca, Westmann Islands seen in the summer off the south coast of Iceland

The same male seen in Grundarfjordur on the west coast in the winter.

It is estimated there are 6,618 orcas in Icelandic and offshore waters and a photo-ID catalogue dating back to the 1980’s has identified about 400 individuals. Recent studies along the south coast during the summer months have documented 123 orcas. Here in Grundarfjordur, after just one season, researchers have identified 24 individuals. 14 of these were ‘matched’ as the same orcas seen off the south in summer, two matched whales seen off the Snaefellsnes peninsula In the summer of 2008 and one matched with the orcas that were seen in the fjords in the east of Iceland in the 1980’s.