Volunteers are being sought to help identify a mystery pod of killer whales spotted off the Hebrides.
The group of nine orcas was encountered during the Hebridean Whale and Dolphin Trust’s marine research expeditions last year.
The trust said it has yet to find a match with any known individuals, and the animals may belong to part of a wider offshore population of killer whales roaming Scotland’s seas.
It is looking for volunteers to join its team on board the research yacht Silurian for surveys running between now and October 2020.
Dr Lauren Hartny-Mills, science and policy manager, said: “Securing good photographs of these killer whales has allowed us to carry out some detective work using photo-identification techniques.
“This involves matching identifying features on individual animals to database records to see if they have been seen before.
“But 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.”
The unidentified killer whales were seen around 300 metres away from the Silurian after it left an anchorage at Vatersay last June.