Sightings update

January is an exciting month for me as sightings officer, as it gives me an opportunity to mop up any sightings not yet sent to or processed by IWDG from the previous year, which enables us to tally the year’s sightings and see how the scheme performed, at least quantitatively anyway.

So, with the last of the 2023 effort watch data uploaded and the big batch of trip-based sightings from Cork Whale Watch, the 2023 tally comes to a total of 2,679 validated cetacean and basking shark sighting records, which compares with 2,471 records (2022) but most importantly 2,630 (2021) making last year our busiest year ever in terms of sightings reported to IWDG.  While I’m not going to attempt to analyse what produced this record number of sightings, it does surely reflect the collective inputs from the growing team at IWDG.


We are only three weeks into the new year and January 2024 sightings to date are already showing a 62% increase on the same period in 2023, which is a great start to the year.  Many of these are sightings of species that are behaving pretty much as we’d expect, such as fin whales feeding inshore along the east Cork/Waterford coast and with them large numbers of common dolphins which have been in the Waterford Estuary now for some months and even foraging for prolonged periods before and after Christmas in the River Suir/Waterford City area, on occasions extending into Co. Kilkenny.  But the data is starting to suggest that common dolphins, as with their larger baleen whale cousins, are spreading out from their Celtic Sea core area.

One case in point which illustrates this was the pod of around 9 common dolphins that were photographed feeding inside Dun Laoghaire harbour on Jan. 8th.  While we’ve documented a single common dolphin in here before (2019), this was our first documented pod inside the harbour walls.  And as if to demonstrate this wasn’t a one off, Jan. 24th saw a larger pod of C. 20 common dolphins off Howth Head, Co. Dublin, on occasion mixing with the resident harbour porpoises (see pic). Thankfully our man up on Howth’s cliffs, Dave O’ Connor, was on hand to document this unusual event.  It’ll be interesting in the year ahead to use this well-watched site as a barometer to gauge common dolphin progress along the east coast. We also note that twice this week alone, we’ve recorded common dolphins in the Inner Shannon Estuary from the Killimer-Tarbert ferry. So it looks like they are picking up where they left off in 2023 along the west coast too.

Images (Common dolphins off Howth Hd, 24/01/2024 © Dave O’Connor)

Common dolphin (left)s with Hbr. Porpoise off Howth Hd, 24/01/2024 © Dave O’Connor)

The strength of the IWDG recording schemes is its ability to detect these changes early on, and in the case of the Shannon Estuary, home to the resident population of bottlenose dolphins for as long as IWDG can recall, and decades if not centuries before, we’ve now started to detect fairly regular incursions by the smaller but more numerous common dolphin into the inner Shannon.  This change will quite likely impact on the residents, and Mags and the team at the Shannon Dolphin Project will no doubt be monitoring this situation closely.


By Padraig Whooley

IWDG Sightings Officer