On Sunday the 15th of May I went out with Marine Discovery Penzance. We were alerted to a possible stranded young humpback whale off Long Rock and were requested to assist/check out the situation.

Upon arrival it soon became clear that the whale in question was very close to the strandline but still fully submerged so it was evident that the whale had not stranded yet.

A bowhead whale in Mount's Bay

The whale was regularly surfacing at 1-2 minute intervals.

When surfacing, the whale would typically expose the blowholes and not much more. The splash guards were rather large and resembled those of a bow-head whale. Whilst approaching the whale, the whale slowly turned around and briefly approached the vessel before veering away and keeping clear of the MV Shearwater and the now arriving second boat (with a stronger inboard diesel engine which were quite audible). The whale steadily increased speed and was well visibly as a dark silhouette seen just under the surface.

The distinctive high splash guards of a bowhead whale

The whale never surfaced during this time until it was well ahead of the second boat. In my opinion the whale became aware and was possibly startled by the arriving of both boats – indeed it had been our intention to try to get the whale to move away from the strandline in the high tide before it would strand itself.

When the whale surfaced following this long dive, it showed the well separated two blowholes and created a diagnostic V-shaped blow.

Bowhead whale dive sequence

The head was clearly very large and for a little while nothing was visible before the dark back with no dorsal fin became obvious – this is called a ‘double-humped’ appearance (typical for this species) although the two humps (blowholes and back) were never seen simultaneously.

The back was highly arched but the animal was not rising the flukes-instead the animal was side-lifting the flukes only in a shallow way – so the tips of one side of the flukes was briefly visible.

The v-shaped blow of a bowhead whale.

The whale was making good speed and would typically surface 2 or 3 times before arching the tailstock and shallow (side)-lifting the flukes. The whale kept traveling in a southerly direction at times exposing its large head – diagnostic for this species.

At no times was the diagnostic ‘white chin’ visible although the strongly arched lower jaw is visible in some of the photographs.

The whale’s silhouette when seen close to the strandline was estimated to be at least 6-7 m. However whilst at sea (further offshore) the whale appeared larger, had a strong blow well audible to the human ear and was estimated to have a body length not exceeding 10 m. However, when only seeing body parts it can be very difficult to estimate the length. I am familiar with seeing adult bow-head whales and they do appear much larger to me. My best estimate is around 7-9m.

The Marine Discovery Team (Duncan, Hannah and myself) were carefully recording the breathing rate of the whale. Together with GPS track and details on behaviour there was nothing more we could do but leave the whale when it had arrived in deep waters (> 50m).

We are currently trying to matching this whale with photo-ID databases of Bowhead whales in the Arctic using the distinct scar visible on the left flank. And also against an animal which has been seen in the Gulf of Maine on the other side of the Atlantic.

It will be very interesting to try and gather as much information regarding this iconic creature. Closely working together and with colleagues from further afield, we are currently writing up a short note regarding this unique encounter to be submitted as a short note for publication in a scientific journal.

Marijke de Boer,

PhD, Marine Mammal Ecology

Bowhead whale range