Basking shark season update and new sightings milestone

Yesterday we received one of many sighting reports of basking sharks that have been sent to us by recorders and public alike since the shark season kick started off Cleggan- Inisboffin back on Feb. 19th. This record however by Ina Krüger, of a pair of sharks she saw feeding near Purteen on Achill Island was a special record. Not only was it our 60th shark record of the season, it was also sighting #46,000 generated by our database numbering system. It seems like we reach these milestones faster with each passing year, which of course means we are getting more sighting reports. Please do keep it up.

Basking shark at Purteen, Cross Achill 12/04/2024 © Ina Kruger

As stated, it’s been a record season thus far for the planet’s 2nd largest shark, with 62 unique sightings. The actual number of reports sent to us on either our website or reporting App is much higher, as a lot of people send us in reports of what are likely to be the same animals and in these cases, we add the observer names to a merged report, thus avoiding duplicate records entering the system. But don’t worry, we’d far prefere get too many reports than too few, so we don’t miss out on important data.

Not only has it been a busy shark season in terms of the sheer volume of reports, their distribution has been really interesting too, with the majority (92%) of the 63 reports coming from the Galway/Mayo area and almost all of which are associated with Islands such as the Aran islands, Inisboffin, Inishark, Achill Isl. , Clare Isl and the Iniskeas to name but a few. What’s going on in the waters around our inshore islands that’s drawing these filter feeders specifically to these sites?

Just to highlight how concentrated this year’s shark sightings are, it’s worth breaking them down by County….. Cork (1), Sligo (1) Donegal (1), Clare (2), Galway (21) & Mayo (35). It’s also noteworthy that this exceptional number of reports is despite absolutely awful weather, with low pressure systems dominating the weather charts. So we have to assume that many sharks are going undetected as they are a species that are not so much difficult to detect in poor weather, but well nigh impossible to spot, because the zooplankton they are feeding on tends not to migrate towards the surface layer in these conditions. So a little bit of established high pressure and sunshine should bring the feed closer to the surface, and the sharks should follow…well that’s the theory any. Let’s see what happens from Tuesday onwards, next week!

Moving away from sharks for a moment, we are delighted to attach our site map for this year’s all-Ireland Whale Watch day which will be held on Saturday 18th May @ 5:00 PM at 11 sites around the country. This year’s event is 3 months earlier than in previous years, to coincide with Biodiversity Week, which is supported by the Irish Environmental Network. These 2 hour watches are free and will be guided by experienced IWDG personnel. For more site specific details see the events section of in the next few days. We’d also like to acknowledge Inis support for this years Whale Watch Ireland 2024 event. #IWDG #Sightingscheme #CitizenScience #baskingshark #ien #whalewatchireland #inis

By Pádraig Whooley, IWDG Sightings Officer

Map of all Basking shark sightings report to date (April 12th) to IWDG….note the Galway/Mayo bias.


Basking shark feeding at Keem, Achill island, Co. Mayo 03/04/2024 © Briana Hegarty



Keep this date free in your diaries for Whale Watch Ireland 2024, Sat. 18th May @ 17:00