Sperm whales photographed off the coast of North West Scotland last month, have not been recorded in northern oceans before, confirms Dr Peter Evans, SWF director.
Two of the five sperm whales seen between Loch Torridon and South Rona were pictured diving, enabling unique markings on their tail flukes - to be compared with a North Atlantic sperm whale catalogue of previous sightings maintained by Lisa Steiner of WhaleWatch in the Azores, but with no match.
There has also been no immediate match with sperm whales recorded in a catalogue by Marta Acosta Plata from Marine Research and Education Fund of Andenes in Norway, where sperm whales regularly summer.
In addition, the pictures have also been compared with records from the Caribbean where sperm whales breed, and no matches have been found.
Dr Peter Evans said:
” It is very exciting to have identifiable images of two individual sperm whales. They are rarely seen off the UK, and when they are seen they are often in waters which are too shallow for them to dive. It is only when they dive that we can photograph the flukes and see the individual markings which allow us to recognise them if they are seen again.”
The five sperm whales were initially seen by creel fishermen between Loch Torridon and South Rona on Monday February 18th . They, at first, thought they were humpback whales
Dr Peter Evans was able to confirm them as sperm whales from the photographs, and says: “In recent years, squid, the main prey of sperm whales, have become common around the British Isles, possibly as a result of climate change, so sightings such as these may become more commonplace.
“Now that we have a photographic record of these individuals, we hope to be able to track them should they be sighted again in northern waters.”
The species normally lives in waters of 1,000 metres or more depth, beyond the continental shelf edge. When they were spotted last month, they had sought out the deepest area of NW Scotland – the Inner Sound between the Isle of Skye and the mainland.
Sperm whales are amongst the largest mammal species in the world. Adult males can weigh in at up to 45 tonnes – the iconic London Routemaster double-decker bus weighs less than 8 tons, unladen!
According to Sea Watch’s national database, there have been just 94 separate sightings in British waters since 1974, most of lone adult males, with the largest group on record being of 20 animals seen off the Isle of Mousa in the Shetland Islands, in 2007.