Investigating an elusive whale seen in Cornwall; a first for Europe

Recording and identifying species is not always straightforward and sometimes requires consulting experienced recorders and experts to ensure records are accurate. A extremely unusual sighting during the winter of 2015 was no exception. 

It was sighted it on 20 February 2015, just off the coast of the island of St Martin's, Isles of Scilly. The large, grey marine mammal surfaced and dove without any hint of a dorsal fin—intriguing evidence that it was not any of the species of whale most commonly spotted in the area. Eager observers Anna Cawthray and Fay Page surmised that their visitor was a sperm whale and reported the sighting to the Sea Watch Foundation.

Sperm whales are not entirely unheard of around Cornwall, but they are uncommon enough that members of the Sea Watch Foundation were excited to confirm the sighting with cetacean experts—inadvertently triggering a worldwide quest among marine mammal scientists across the globe to ascertain the identity of the mysterious whale. Cawthray and Page sent over a few cell phone pictures they had valiantly managed to snap in the midst of the excitement, but the photos’ fuzziness made identification difficult. At moments it seemed that even Scotland’s reclusive Loch Ness monster has been photographed more clearly!

Bowhead Whale by Faye Page, IoS 2015

Cornwall’s own Nick Tregenza agreed that the lack of dorsal fin suggested either a humpback or a sperm whale, but when Duncan and Hannah Jones of Marine Discovery Penzance forwarded the pictures to Dutch whale expert Marijke de Boer, it was pointed out that enigmatic creature in the photographs seemed to have a uniquely arched line to its lower jaw—suggesting something else entirely. When Tregenza and fellow cetacean expert Paul Semmens re-examined the photographs, they realised they needed yet another pair of eyes to confirm the observation. The distinctive arched jaw line meant Cornwall’s visitor was definitely not a sperm whale, which made it—what? The rare Northern right whale, perhaps?

But at long last, after yet more queries and passing of photos and scratching of heads, the world’s cetacean experts came to a conclusion: based on subtle but crucial features of the whale noticeable to only the keenest of eyes (most importantly that arched jaw line) they agreed that the mysterious mammal was—astonishingly—the species Balaena mysticetus: a bowhead whale. This sighting is a historic first of leviathan proportions. This was not only the first bowhead whale sighting in Cornwall, but also the first in England; the first in the United Kingdom; in fact, the first bowhead whale sighting in all of Europe! Bowhead whales are a strictly Arctic species and this is the first time they’ve been spotted south of the Barents Sea (which lies north of even Finland, Norway, and Sweden). One of the many concerns associated with global climate change and rising ocean temperatures is that coldwater species are going to be forced to migrate closer and closer to the poles in search of respite from the heat. Yet species that are already polar—like bowhead whales—may consequently have nowhere else to go. This sighting of a bowhead exploring waters further south may be a positive indication of bowhead whales’ ability to adapt to warmer seas…or, it may have simply been one confused juvenile whale who became very, very lost!

Bowhead Whale by Faye Page, IoS 2015Either way, last February’s find is certainly one for the history books and a prime example of the value of scientific communication and partnership. By sharing data freely and reaching out to other scientists it was possible to engage local, national, and even international experts in a common cause. It was only through combining of all of their backgrounds and years of experience could the mystery be solved at last. Perhaps even more importantly, this sighting was also an excellent illustration of the power of citizen scientists recording their observations. If Cawthray and Page had not been so attentive in reporting the sighting and taking photos, the world would have never known of the bowhead whale’s silent passage through Cornish waters.

 

The contribution of diligent recorders and members of the public is crucial to the work of ERCCIS and many other scientific organisations, so please report the biological observations that you may come across (such as a rare species or unusual animal behaviour) and if possible include pictures, video, or any additional details. Remember to keep a weather eye open—you never know when an exciting scientific discovery may swim by!

Article by Caitlin Fikes, ERCCIS volunteer and University of Exeter student and photos by Faye Page