Háhyrningur is the Icelandic word for orca, meaning 'high horn' in reference to the tall male dorsal fin. Studies on Icelandic orca began in the 1980s in east Iceland, where the orca could be found following the Icelandic summer-spawning herring winter migration. There are around 400 individuals in the Icelandic ID catalogue, although the total population size is unknown. It has been suggested the Icelandic orca have a similar group structure to other fish-eating populations found around the world (highly complex, matrilinial, family groups), although this is based on very few sightings. The Icelandic orca produce a unique long, low-frequency call for herding herring and like the Shetland herring-eating orca, they use ultrasonic frequencies to produce whistles which are out of the range of human hearing. Five Icelandic orca have been sighted off the Shetland coast.
Project NAKID started researching the Icelandic orca in Vestmannaeyjar, Iceland in 2007. Research focuses on photo-identification and acoustic studies. A total of 123 orca have been recorded off Vestmannaeyjar, although actual numbers are likely to be higher.