01/10/2025
A few months back I was contacted by Kinsale Yacht Club to see if I was available to give an autumn talk on my favourite subject ….Whale Watching. Last week while making final arrangements, I was asked unprompted by the Club official about the lack of whales and dolphins in west Cork waters that had been commented on by club members during the season. If there was ever proof needed that things are changing fast down here, the fact that even weekend sailors are noticing it is quite telling. So just how bad are things?
Well, a quick glance at IWDG sightings data shows that our cetacean sightings are down 21% on the year to date. Some of this decline may in part be explained by the demise of our Reporting App which for a number of technical reasons has had to be retired. But the website as our primary reporting tool is working just fine and so there is clearly something else going on that can’t easily be explained by weather, as it wasn’t that poor a summer.
A deeper delve into our three main whale species show humpback sightings are down 20%, and while fin whales are holding their own, sightings of our most regularly recorded whale the minke are down 16%. These declines are hard to pin on climate change given that adjacent UK waters are similarly impacted and they’ve never recorded so many large whales.
Not only are we recording fewer whales this year, but we are noticing a very real shift in their distribution as their preferred southwest feeding areas have switched to the Northwest. So far this year the waters between Sligo and Donegal have for the 3rd consecutive year enjoyed a record number of fin and humpback whale sightings, with almost 41% of fin whale and 44% of humpbacks records coming from Donegal Bay this year. In fact we've just added our latest addition to the Irish Humpback Whale catalogue, , bringing to three (of 4) the number of new additions this season from Donegal Bay.
Now you could always make a case that given the vast migrations species like humpbacks endure to breeding areas in the Cabo Verde or Caribbean, that a few additional days swimming up the Irish west coast is no big deal for a highly mobile marine mammal. The key point however is that this is an area where historically IWDG received very few, if any, large whale sightings. And many of these humpbacks are individuals we’ve recorded in previous years in west Cork and west Kerry. So not only are we seeing fewer whales, but when we do, they are in completely new areas. This is unusual behaviour for animals that typically demonstrate strong site fidelity to feeding areas.
As the years go by I find myself spending more and more time looking at the sightings data rather than producing it, so I took advantage the recent spell of high pressure to grab my optics and visit my favourite headland, the Old Head of Kinsale, where I started carrying out regular watches back in the late 1990’s. Everything was perfect, with calm seas and clear skies and nothing but my spotting scope between me and the big blue. Throughout the watch I saw areas of splash and surface disturbance off to the east of the lighthouse. There were blue fin tuna shoals boiling over a vast swathe of water. Only at the end of the watch did I pick up a small group of common dolphins, but just as everyone was telling me, not a single whale of any species was seen after 100 minutes watching in near perfect conditions on what used to be one of Ireland’s foremost whale watch sites. Such a result would have been unthinkable at any time in the last 25 years. No tuna and lots of whales in west Cork, seems to have become no whales and lots of tuna, and in a relatively short time.
Clearly whales being highly mobile can switch to areas with better feeding opportunities. There would be some relief if we knew for fact that this was all down to climate change resulting in warming waters and pelagic fish pushing north in search of colder SST’s. It’s a convenient argument, but one that is not supported as of yet by any evidence. We do need to explore the very real possibility that the reason our whales have deserted us, is not so much that the pelagic fish on which they feed have also pushed further north, rather they’ve been pushed to a far more dangerous place. The brink.
Let’s hope that in the season ahead our fishing fleet, both over and under 18 mts, leave sufficient forage for other marine predators.
