Orca - Orcinus orca

Orca (Orcinus orca), also known as 'killer whale', are the largest dolphin in the world, with males reaching up to 9m in length (fig. 1). Their black and white body pattern and prominent dorsal fin makes them distinctive and hard to confuse with other cetaceans - females have a smaller 'sickle-shaped' dorsal fin whilst males have a large, tall, triangular dorsal fin (Couzens et al, 2017). Orca have a varied diet from fish such as herring and mackerel to seals. Shetland, Orkney, and NE Scotland orca have been seen feeding on grey and harbour seals - and even occasionally eider ducks (Beck et al, 2013; Deecke et al, 2011).

Due to their distinctive patterning and large dorsal fins, Orca can sometimes be identified down to individual level with several unique pods moving through Scottish waters - see the Scottish Killer Whale Photo Identification Catalogue 2021 linked below.   One notable pod in the East Coast area are the '27s' which are seen largely off of the coast of Shetland but have been recorded along the East Coast. Another noteworthy more recent sighting is W001 John Coe and W008 Aquarius from the West Coast Community reported off GIrdle Ness in September 2024.  Orca are a long lived species, for example John Coe (seen mostly off of the West Coast of Scotland) is believed to be at least 60 years old (Scullion et al, 2021). 

Range & Distribution:
Whilst Orca are more abundant along the West or North coasts of Scotland, they are recorded more or less annually in the East Coast region (fig 2 & 3) (Evans, Anderwald & Hepworth, 2008). There has been a notable increase in sightings in the 21st century, particularly around the Peterhead area but up and down the East Coast generally. The North East Scotland Bird Reports 2017-2022 (linked below) have detailed records in the following locations:
2022 - Kinnaird Head to Peterhead, Bullers of Buchan
2021 - Stonehaven Bay to Girdle Ness, Peterhead, Kinnaird Head
2020 - Fraserburgh
2019 - Peterhead, Boddam
2018 - New Slains Castle, Boddam, Nigg Bay
2017 - Rattray Head, Torry Battery

They are a very mobile species but deemed highly site-faithful, returning to the same areas in Scotland each year during spring and summer. For example, individuals have been photo-identified moving annually between Iceland to Shetland, Orkney, and the North East of Scotland (Samarra & Foote, 2015). However there has been a population decline seen in Scottish orca. This has been attributed to a decreasing rate of recruitment through births, with pods seen to consist of both older females (which perhaps are beyond breeding age) and a high ratio of males (Beck et al, 2013).

Factors Affecting Species:
Noise pollution impacts orca like it does with many other cetaceans, as noise from human activities can often overlap with the frequency range that orcas use to communicate. Noise disturbance can lead to orca changing their behaviour and movements, impacting on feeding and breeding success.
Fishing pressure & gear entanglement can also have an impact on orca. For example W006 Lulu from the West Coast Community was found dead on the Isle of Tiree in January 2016 entangled in fishing lines (Scullion et al, 2021). 
As Orca are an apex predator they are particularly vulnerable to bioaccumulation of toxic pollutants, with the level of chemicals such as polychlorinated biphenyls (PCBs) increasing up through the food chain. There is concern that PCB pollution could lead to a global population collapse of orca if not addressed (Schnitzler et al, 2019).

Conservation Status:
UK Biodiversity Action Plan: Priority Marine Species (BRIG, 2007)
Scottish Biodiversity List: Priority Species (NatureScot, 2020b)
Orca, like all cetaceans, are a European Protected Species, protected from deliberate and reckless injury or disturbance. Orca are also a Priority Marine Feature (PMF) in Scotland , considered to be a species of priority in marine nature conservation (NatureScot, 2020a).

Report any cetacean sightings to the SeaWatch Foundation or NESBReC via the links below.