East coast bottlenose dolphins on tour

16th Jun 2009 The IWDG cetacean sighting scheme has successfully tracked the movement of a pod of bottlenose dolphins as they travelled southwards along the Irish east coast.


The 1st sighting of c6 dolphins came from Joe Devlin at Greencastle, Co. Down at the mouth of Carlingford Lough at 11:00am on Sun 14th June. Joe's images confirmed them to be bottlenose dolphins Tursiops truncatus. Liam Lawless of the aptly named Blue Dolphin Powerboat School then reported them shortly afterwords at 11:30am between the lighthouse and Green Island in Carlingford Lough on the Down/Louth border. The last known fix of these dolphins in the area was at 17:00 when Pat Mc Adam observed them from his yacht, still half way up the Lough around the #25 channel mark.

At 08:15am Mon. 15th June, commercial fisherman Alan Fanning reported a similar sized pod of upwards of 8 bottlenose dolphins off Loughshinney, North Co. Dublin travelling south. Another report at 08:30am from Hugh Doyle has them off the south beach in Rush. The distance between Carlingford Lough and Rush is 34 miles travelled in 21 hours or an average speed of 2.2 MPH.

An anecdotal report then puts them off Portmarnock at around 10:00am.

IWDG member Justin Ivory and his family then picked up the trail later that evening with a sighting of 6-8 bottlenose dolphins within 25m of the shore by the railway crossing at Kilcoole, Co. Wicklow at 19:10. Justin confirms that the group comprised at least one very pale calf. This was their 4th county border crossing, not to mention their international border crossing from the North into the Republic. There is little question other than these were the same dolphins and yes, they were still heading south. They were seen to stop for some feeding which drew the attention of the little tern colony at Kilcoole.

A tip off to Faith Wilson had herself and Christian Osthoff head south to Wicklow head waiting for them to show up, which they did, but not before Tom Byrne (the 6th recorder) observed them from his wee boat just 150m out, between Wicklow Bay hostel and the Monkey pole at Wicklow town at 20:00. Faith and Christian then picked up the story at 21:00 and stayed with them till 22:30 as they rounded Wicklow Head, heading south in failing light. This is a distance of 38 miles travelled in 12 hours or an average speed of 3.16 MPH during the day, and just 18 miles south of the Wexford border line.

Alas, the odds were on these dolphins continuing south and making the Wexford border in jig time, an amazing five counties in 2 days, but this is in the realm of speculation. They could also have simply turned left, taking the 80 mile transect across the Irish sea ending up in Wales. Perhaps they are Welsh dolphins from the resident Cardigan bay population. Only continued Photo-Id effort will tell.



The facts are that this pod of c8 bottlenose dolphins have from their 1st sighting at 54.024N 6.104W in Co. Down, to their last known position of 52.961N 5.989W in Co. Wicklow travelled a minimum distance of 84 miles in 26 hours, which is an average speed of 3.2 MPH. In so doing they crossed one international border and passed through 4 counties along the Irish east coast. Justin's & Faith's observations suggest they were showing no signs of slowing down, as they maintained a steady pace, stopping only for bouts of feeding on the hoof and classic bottlenose aerial displays.

This sequence of events shows the impressive distances covered by these highly mobile marine mammals, which supports IWDG photo-identification research, that shows a lack of site fidelity among bottlenose living outside the Shannon Estuary. It also illustr