Mystery whales

The identity of a group of nine killer whales off Scotland’s west coast, encountered during the Hebridean Whale and Dolphin Trust’s annual marine research expeditions last year, remains a mystery – despite recent research and a flurry of sightings of killer whales in the Hebrides.

The trust now hopes to encounter the elusive pod again during its surveys this summer.

It says that the unexplained killer whale pod sighting highlights how much there is still to learn about the remarkable marine life in Hebridean waters, and the need for long-term monitoring of cetaceans – the collective name for whales, dolphins and porpoises – and basking sharks.

The unidentified killer whales – which included two large males and two juveniles – were seen close to Vatersay.

Identifying features on the whales were checked against an existing database and showed the animals had never been recorded before.

Dr Lauren Hartny-Mills of the trust said: “Despite our collaboration with other organisations and experts to identify the animals, the pod remains an enigma.

“It shows there is still a lot to discover about the cetaceans visiting Scottish waters.

“We’re hoping to encounter these killer whales again during our 2019 expeditions, and with help from our colleagues across Scotland and beyond, we really hope to find a match and learn more about this group.”

Andrew Scullion, who runs Orca Survey Scotland, said: "I’ve been collating killer whale sightings from across Scotland since 2017 and it was fascinating to see these pictures of individuals I’ve not come across before.

“As more people share their sightings, and with surveys out there like the Hebridean Whale and Dolphin Trust’s, I’m hopeful we can put pieces of the puzzle together and discover more about this so far mysterious group."

Because it has not been possible to find a match with any known individuals for the mystery killer whales, researchers have suggested these animals may belong to part of a wider offshore population of killer whales that roam Scottish seas.

Globally, killer whales – also known as orcas – are one of the most widespread cetaceans, and they range from warm tropical waters to the polar regions.

There are two well-known communities of killer whales found in Scottish waters, and there have been several sightings of animals from both of these groups in recent weeks.

The wide-ranging West Coast community can be seen along the whole west coast of the UK, with most sightings in the Hebrides. This group of eight individuals is at imminent risk of extinction, as the trust has recorded no calves in 25 years of monitoring.

There have only been confirmed sightings of two individuals – the males John Coe and Aquarius – in recent years.

Scotland’s other group of killer whales, the Northern Isles community, is mainly seen around Orkney, Shetland and the north coast of Scotland.

The trust is looking for volunteers to join its team onboard MV Silurian for one to two week surveys until October 2020.

Mystery over killer whale pod spotted off the Hebrides

23 July 2019