Investigation carried out on Sperm Whale stranded in Sligo: UPDATE

4th Apr 2019

A team from the IWDG consisting of Seán O'Callaghan, Mags Daly and Dr Simon Berrow  travelled to Streedagh Strand, Co Sligo this morning (April 4th) to investigate yesterdays sperm whale stranding and collect samples. Due to the great management skills of local Heritage Officer Sióbhan Ryan, the local authority were able to provide diggers on site to assist in examining the whale carcass. The whale was a female measuring 10.4m in length. There were no obvious signs of ship collision, entanglement nor was the whale emaciated. Examination of the main stomach found no plastic debris, indeed there were no food remains either, apart from a small number of squid eye lenses and no evidence of recent feeding with intestines clean. Some minor parasite burden was noted. 

Samples were taken for genetics and toxicology. Moira Slingerman from the Galway-Mayo Institute of Technology (GMIT) assisted in the examination and took blubber and liver samples to explore legacy and emergent persistent pollutants that may have accumulated in the whale. Cynthia Barile also from GMIT was also present, as Cynthia is carrying out a PhD on sperm and long-finned pilot whales in the Porcupine Bight, funded by a Woodside Scholarship together with lecturer Dr Ian O'Connor. 


As is so often the case with strandings, we know more about what didnt kill the whale, than what did kill it. However, we will continue to explore avenues around acoustic trauma and bacterial infection. We are also  in contact with colleagues in Scotland to see if they are also experiencing higher than ususal sperm whale strandings as they examined a female stranded on Uist in quite an advanced state of decomposition today.

NATOs annual Joint Warrier exercise is currently underway from 30 March to 11 April, west of the Hebrides. A total 35 warships, 5 submarines and 59 aircraft and helicopters from 13 countries are scheduled to take part in this year’s edition of the exercise. However these whales have been dead for 1-2 weeks so this can't explain these strandings unless some active equipment was tested offshore prior to the start of this exercise. 

The IWDG would like to thank Heritage Officer Sióbhan Ryan, Local Authority Vet Conall Calleary, Blane Feeney and Gary McMorrow from Sligo County Council and contractors Eamonn Keegan, Jason Kerrigan and Enda Waters for their fantastic help on the beach today. 

Media reports can be found here:

Podcast on Ocean FM

RTE report on

Today FM

Irish Times



3 April 2019

The IWDG have been informed of another Sperm Whale washed up, this time on Streedagh Strand, Co Sligo. Images supplied by Colin Gillen suggest its an adult female. Generally we tend to observe adult male sperm whales off the Irish coast so this is a little unusual. Having three sperm whales washed up along the westcoast in a short period is now of concern. What could be causing these deaths? A lot of people following media coverage of the sperm whale washed up in the Meditteranean last week will blame plastic pollution. However, without a full necropsy to determine if plastic is present, it cannot definitiively be said that plastic pollution is the cause of death here. IWDG will explore some potential options regarding this increasingly unusual stranding pattern. 


Sperm whale at Sreedagh Strand, Co Sligo. Images courtesy of Colin Gillen 


Media interest in these strandings is high, but dont believe everything you read online (except on


Sperm whale captured by the IWDG drone flown by Seán O'Callaghan, 31st Mar. 2019

Another sperm whale was washed up yesterday, this time at Mace Head, Moyrus, near Carna in Conamara, Co. Galway. It's most likely the same whale reported floating by commercial fishermen fishing out of Ballyconeelly and filmed by Brendan Conneely. Click on the image below to see the video. 

The stranding at Mace Head was reported to the IWDG by Seamus MacDonnacha of Cill Chiaráin, and Rónán Ó Conghaile, this c.40ft whale is in great condition and well worth taking a trip out to Mace Head to see. Three sperm whales washed up this year is a little unusual but nothing sinister, please report any strandings to see if this is the start of something more worrying. 

 Photo by Rónán Ó Conghaile

 Photo by Neasa ní Chualáin 

26th March 2019

Today we received two records of some may say, the largest predator in the world - sperm whales. 

Paul Murphy from the Irish Maritime Squadron sent on images taken by Airman Sean Foley of 105 Sqn, Photo Section.

The floating carcass was taken recorded on Monday 25th March at position 53° 11' N 11°22.720' W and reported to MRCC and NS Op. 


Sperm whale observed offshore. Courtest of Sean Foley, MaritimeSquadron

Sperm whales are widespread and relatively abundant in the deep waters to the west of Ireland. They rarely occur in waters less than 300m deep. A recent study co-ordinated by the Galway-Mayo Institute of Technologhy in which the IWDG were partners (ObSERVE-Acoustic estimated an abundance of 3.2 whales per 1000 km2, which provided an overall estimate across all surveys of 380 individuals in the study area. 

On the same day a sperm whale was washed up at Magheroarty in County Donegal. Donegal IWDG co-ordinator Gareth Doherty visited the stranding today and estimated its length at 43 ft. Samples were taken for genetics and a study of persistent pollutants. 

 Sperm whale stranded at Magheroarty, Co Donegal. Courtesy of Gareth Doherty. 

The IWDG have been receiving images from the Irish Maritime Squadron under the WhaleLog Project since 2007 and they provide a facinating insight into what is occurring offshore. we thank them for their continued support. Please get involved in your IWDG local group and help us record whales, dolphins and porpoise onserved and stranded in Ireland. 


You are welcome to share or use information and articles from this website but please reference the source and acknowledge the IWDG.