Humpback whale washes up in Roaringwater Bay, Co. Cork

Humpback adrift off Coney island, west Roaringwater bay, Co. Cork, Feb. 24

In recent years sightings of humpback whales have been on the increase and the Irish humpback catalogue now recognises 109 individuals in Irish waters. Many of which return year after year and some between decades. And so as this iconic species seems to be enjoying a recovery with different humpback populations recovering well, it comes as no surprise that we can expect more individuals stranding along the Irish coastline.

Historically however, humpback whale strandings are rare events and the IWDG had up until today recorded only 8 previous stranding records, which date back as far as 1893. So today’s specimen, which was initially seen in mid afternoon north of Long island and finally came ashore near Coney Island, west of Schull, is only the 9th ever recorded stranding of a humpback whale in Ireland, and only the 2nd for County Cork…the first being in Tralong Bay in July 1992.

Fluke image. IWDG could not match it on the Irish Humpback Catalogue

Images taken today reveal sufficient detail of the genital area to confirm this is a male, from the absence of mammary slits or a hemi-spherical lobe. Additional images on the ventral fluke surface (see image left) have enabled us run it through the Irish Humpback Whale Photo ID Catalogue curated by the IWDG and we can confirm that this is not an individual previously documented in Irish waters. Which of course is not to say that it has never been here before.  Measurements taken suggest it is just under 9 metres from tip of rostrum to caudal notch, and so this would put it in the sub-adult or juvenile length range, which is to expected as we are now moving into humpback breeding season and most adults of breeding age are either en route to or already at the low latitude breeding sites. This is something that some young humpbacks can opt out of, as it’s a long track south to places like the Cabo Verde and with no hope of successfully breeding there is nothing much in it for them.  So a cohort of young, independent humpbacks seem content to over winter at higher latitudes, where there is, or should be, plenty of food for them.

 

    Final resting place, Feb. 24th 2021

So the big question is what could have happened to this young animal? Well, the images we’ve received so far suggest it is in rather thin condition and so it may not have fed for some time.  There are no obvious signs of rope marks or net damage that may suggest entanglement in fishing gear…something that slow swimming humpbacks that remain inshore are prone to; and there are no large traumas to suggest ship-strike. So as is so often the case, the circumstances underpinning this stranding are unclear.  IWDG hope in the coming days to visit the site to take detailed measurements and get skin and blubber samples which can be used for genetics, contaminants and stable isotope analyses.

IWDG have consulted with local National Parks & Wildlife Service on this situation and will work closely with them and Cork County Council in relation to further examinations and to discuss its removal if this is what the Council decide. But at its current remote location, far from houses or popular beaches, there is no strong case for removal.  We extend a huge thanks to those on the ground today who kept us updated on events as they arose….in particular Roseanne and Robbie Shelly and local IWDG member Helen Tilson of Schull Sea Safari

Images above courtesy of Robbie Shelly and Helen Tilson

Any sightings or strandings of humpback whales should be reported to IWDG on www.iwdg.ie

By Pádraig Whooley, IWDG Sightings Officer