Basking shark off Dun Laoghaire Pier 15th May

16th May 2012 Report II, 16/05/12
There were no further basking shark sightings today from the Dun Laoghaire area. This however doesn't mean that there are non present, but may reflect on the distribution of the plankton. Unless these tiny food particles are on or close to the surface, basking sharks will remain largely undetectable to the human eye. But the map below plots all validated sightings of this species so far in 2012. All basking shark sightings in Irish waters can also be interrogated on the "advanced search" facility on the sightings section of

Report I, 15/05/12
It's not too often that we can direct folk on the east coast to a potential local sighting that may be of interest; especially now that the novelty of the 3 local bottlenose dolphins that have taken up residence in the Killiney Bay since August 2010 has perhaps worn off.

But a sighting this morning (15th May) of a basking shark by Ronan Mc Laughlin of the Naval Service vessel L.E. Ciara, just at the entrance to Dun Laoghaire harbour may be a great opportunity to observe this giant from the relative comfort of an east coast pier.

Basking sharks, Waterford coast © Pádraig Whooley, IWDG

Ok… basking shark sightings are common at this time of year, but not along the east coast. In fact in recent years only between 1-5% of all basking shark sightings have been off the Irish East Coast, which is at odds with the fact that nearby, Isle of Man is considered to be one of the best sites on the planet to observe the planet's second biggest shark species.

So far 2012 has been another very good year for sightings of this “honorary whale”, with 78 validated sightings to date, almost all of which have come from the south and west coasts. Several of these sightings have been of large feeding aggregations of >20 individuals, but 1st place must go to Loop Head, Co. Clare, which on 2nd April produced an incredible tally of c50 basking sharks on one count. They were reported to IWDG by local angling charter operator, Luke Aston, who had never encountered this species in such numbers in many years of working in these local waters.

Basking shark showing gill rakers, Crow Head, Beara Peninsula, Co. Cork © David Riordan

The IWDG treat sightings of this plankton feeder in the same way as any sightings of cetaceans in Irish waters, and we'd encourage anyone fortunate enough to see one to report it on

The key identifications features are their very large size, specimens in the 20-30ft range are not uncommon. You may only see the dorsal fin but occasionally the tail (caudal fin) may also show above the surface. If they are feeding right on the surface, you might glimpse the tip of their snouts above water. Also don't be too surprised if you see one breach. For this reason we can't assume that a large animal breaching clear of the water is a whale species, as basking sharks are capable of leaps that are no less spectacular than those of their distant mammalian cousins.

Basking shark, Blasket Islands May 2008 © Nick Massett

We are hoping to enjoy some basking shark sightings on this month's Cape Clear whale watching weekend course on 25-27th May, which still has some vacancies (see banner on home page We have observed breaching basking sharks on each of the last 3 years during the May course. So this course is a great opportunity to learn more about basking sharks in Irish waters and how to observe them in the wild.

Best of luck if you head out to the somewhat less wilds of Dun Laoghaire, and let us know how you get on. Basking sharks are rarely solitary, and where there is one, there are likely to be more. Whether the plankton draws them to the that's a different matter!

For more information on the latest basking shark research and conservation issues concerning basking sharks in Irish waters visit our colleagues on

Pádraig Whooley
Sightings Co-ordinator

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