Last week, two friends enjoying a beach-walk in the Isles of Scilly saw an unusual-looking whale not far off the shore.  They quickly used their mobile phone to take some photos, and noted down the relevant sighting details.  This information was later submitted to the Sea Watch Foundation, a UK marine environmental research charity.  As the whale did not appear to have a dorsal fin, the ladies assumed it was a sperm whale – which would have been unusual in itself, given that this species is a deep-water specialist.

The Mystery Whale

When the cetacean experts at the Sea Watch Foundation reviewed the photos, they were astonished to realise that what the ladies had sighted was even more unusual!

Dr Peter Evans, Founder and Director of Sea Watch Foundation, admits that the photos were a challenge.  “Even with enlarging them, and trying to sharpen them up within Adobe Photoshop, it was very hard to pick out the more subtle features due to the low resolution of the pictures, or even to tell exactly what part of the body was showing in some of the photos“, he says.  “One image, however, showed the animal closer than the rest, and revealed the shape of the head and even the jaw-line“.

This curving jaw-line eliminated sperm whale as an option, as this toothed species has a very straight mandible as opposed to baleen whale species who show a downwards-curving jaw.  Dr Evans sought second-opinions from colleagues in the US, including experts such as Dr Tom Jefferson from Texas A&M University, Dr Phil Clapham from the government agency NOAA in Washington DC, and Dr Scott Kraus from New England Whale Museum in Provincetown. They isolated identifying features, including the curved jaw-line, the lack of a dorsal fin, a light patch under the chin and some black spotting along the top of the head.

And the Answer is…

The consensus agreement was as exciting as it was unexpected – a bowhead whale.  Given the context of a photo showing one of the ladies entering the water with the whale, this animal is thought to be a juvenile.  Adults can grow up to 20 metres long and weigh almost 90 tonnes.  Bowheads appear to be one of the longest-lived whale species around, with some animals thought to be 200 years old, based on old Inuit harpoon heads recovered from hunted individuals.

A First for Europe – But Why Now?

Excitingly, this is the first sighting of a bowhead whale in not just the UK, but the rest of Europe.  These whales normally live in the high Arctic, where they suffered severe exploitation by commercial whales since the 1500s.  By the 1920s, there was thought to be only around 3,000 individuals left.  However, thanks to the cessation of commercial whaling in 1986, their numbers appear to have increased to around 15,000 – 20,000 animals, mainly in the Beaufort Sea and Arctic Ocean.

But the question now is, what was a bowhead whale doing so far south?  There have been increased sightings of warmer-water species around the UK over the past decade, presumably as a result of global warming encouraging species to extend their ranges north-wards.  So to find a cold-water specialist so far south is enigmatic, particularly as bowheads generally tend to never stray far from the ice-edge.  Dr Peter Evans suggests that global warming could still be to blame.

“In March 2012, a bowhead whale was photographed in Cape Cod Bay, New England, and the same individual re-appeared in the same area a year later, in early April“, he explains.  “These records far from the natural range of the species may in fact be the result of ice fragmentation, leading to animals straying further south. The welcome increase in the size of the West Greenland population may also be a contributory factor for why this creature appeared some two thousand miles from its normal range.“

The Value of Citizen Science

From my point of view, one of the other important realisations from this sighting is the role citizen science has to play in research.  It is obviously impossible for researchers to be everywhere at once – to be honest, the further you progress into a marine research career, the more time you spend land-locked at your desk!  So having trained eyes, in the form of citizen scientists, scattered around the coast provides whole new opportunities for data collection.  Citizen science also promotes awareness of the natural world, by educating volunteers, connecting them with scientists, and actively engaging them in conservation.

The Sea Watch Foundation was founded in 1991 to find out more about cetaceans in British and Irish waters.  It aimed to do this by involving the public in the study of these animals, rather than relying on occasional scientist-led surveys and examination of dead animals from strandings.  Sea Watch Foundation now has two main offices in the UK, as well as 35 local groups of observers who have generated thousands of sightings.

Why not explore what citizen science projects operate near you?