The Icelandic killer whale population is a population of wild orca primarily found in the North Atlantic waters surrounding Iceland. This population, its social structures, and seasonal movements are still poorly understood, as research within this population only recently began.
Population and Identification[]
The management of the Icelandic killer whale population revolves around two primary identification catalogues, centred on Iceland's most abundant herring grounds: the West Iceland and South Iceland catalogues. The West Iceland killer whale catalogue stands as the most extensive record of Icelandic killer whales, encompassing over nine hundred individuals as of 2022. Focused on the west Iceland killer whales predominantly sighted in Breiðafjörður and around Snæfellsnes, this catalogue is overseen by Orca Guardians Iceland, a non-profit organisation dedicated to killer whale conservation. The South Iceland catalogue is overseen by the Icelandic Orca Project in collaboration with the Icelandic Marine and Freshwater Research Institute (MFRI), documenting the killer whales primarily observed off Iceland's south coast and around the Vestmannaeyjar archipelago.
Individuals within these regions are catalogued and assigned alphanumeric identification numbers in both catalogues if spotted in both areas. While some individuals might only be observed in one region, Icelandic killer whales can be identified through two main alphanumeric ID systems: the general Icelandic orca catalogue (e.g., IS076) and the other with SN for Snæfellsnes, west Iceland (e.g., SN090). The numbering indicates the order of inclusion in their respective catalogues.
Some Icelandic killer whales undertake seasonal migrations to Scotland, where they may receive additional ID numbers from Scottish research organisations. Thus, an Icelandic killer whale could possess up to four unique IDs if matched elsewhere or assigned an ID from a previous catalogue, such as the old MFRI catalogue. For instance, SN0065, known as "Defiance," had four distinct IDs during her lifetime.
Photo Identification Efforts[]
Efforts to photographically identify killer whales in Iceland began in the 1980s with the creation of a photo-ID catalogue for Icelandic killer whales by the Icelandic Marine and Freshwater Institute. The dedication to photo ID research intensified in 2008 when the Icelandic Orca Project initiated a dedicated programme in West and South Iceland, marking the start of the longest-running killer whale research project in Icelandic waters. Subsequently, in 2016, Orca Guardians Iceland, a non-profit killer whale conservation organisation, was established and began documenting and cataloguing individual killer whales near Snæfellsnes in West Iceland. As of 2025, the combined efforts of these initiatives have led to the recording and cataloguing of over 1,000 individual killer whales and counting in the waters surrounding Iceland.
Open-access photo ID catalogues:[]
- Killer whales of West Iceland (Mursczok, 2011-2022).
- Killer whales of West Iceland (Mrusczok, 2014-2017).
- Killer whales of South Iceland (Samarra, 2006-2015).
- Matrilineal catalogue of Icelandic killer whales (Mrusczok, 2014-2023)
Social Structure[]
While many killer whale populations around the world typically adhere to matrilineal structures, studies indicate that the Icelandic killer whale population exhibits greater flexibility in social associations. Groups in Iceland often disperse or interact with unrelated individuals.[1]
Seasonal Movements[]
Seasonal migratory patterns of Icelandic killer whales remain somewhat unknown, although records show that several dozen individuals undertake seasonal migrations to Scotland each year. This migratory behaviour appears to be increasing annually, as new individuals are identified through photo-identification and matched between the two regions.
In June 2022, three killer whales were identified and matched between Iceland and Norway for the first time in history. To date, these remain the sole individuals documented to have been matched between Iceland and Norway, other than Keiko.
Diet[]
Icelandic killer whales have predominantly been observed feeding on Atlantic herring (Clupea harengus). However, research conducted by the Icelandic Orca Project and various scientists in Iceland has revealed that different groups may exhibit diverse feeding preferences. Some groups specialise exclusively in herring throughout the year. In contrast, other groups may demonstrate a propensity to switch to prey at higher trophic levels, such as smaller marine mammals. [2]
History[]
- In 1954, more than 100 killer whales were killed by the U.S. Navy in Iceland using explosives dropped from aircraft. The killer whales had been feeding on herring populations that were in decline due to overfishing, and the government saw them as pests threatening the economy of the country's fishing industry.
- Between 1975 and 1989, a total of 64 killer whales were captured in Icelandic waters to be trained and sold to the aquarium industry. Out of the 64 wild-caught killer whales, 2 (Stella and Ulises) are still alive. There are currently 19 full-blooded Icelandic killer whales alive in human care, 17 of which are captive-born and descend from wild-caught Icelandic orca.
Individuals[]
For a list of individuals within the wild Icelandic orca population, see Icelandic Killer Whales (Category)
