Fin Whale Strands in Portstewart

8th Oct 2015

At around 11:30am on Monday 5th October I received an email saying that a dead whale had washed up on Portstewart strand. I had never seen a stranded whale before and curiosity got the better of me so I headed up to the coast after lunch to see what was happening. It was easy to tell where the whale was along the beach as a large crowd had gathered, along with the coastguard, national trust and the BBC!

The whale’s tongue was swollen and it had a large cut on its underside, it really was a sad sight to see.  There was a lot of speculation as to the species of this whale when it first washed up, some said Minke or Sei and others said a Fin whale. There were no obvious white bands on the pectoral fins so a Minke whale could be ruled out. The lower right jaw was not visible when the whale was on the beach so the species could not be confirmed. A white lower right jaw is a diagnostic feature of a fin whale.  The whale was removed from the strand at around 10pm at night and taken to a local landfill site. The plan was to collect some samples from the whale and possibly carry out a post-mortem.

Tuesday was a busy day! Lots of phone calls were made to ensure we had permission to take samples and perform a post-mortem. With all our gear loaded in the van we headed up to where the whale was kept. We were working alongside colleagues from the veterinary science division who had experience in cetacean post-mortems. The whale was in a much poorer condition than it was the previous day.  The skin was badly damaged from transportation and the tongue had deflated. There was quite a strong smell, especially downwind of the whale. The whale was turned over so the right lower jaw was visible and it was white! We had confirmed the ID as a fin whale.

The whale was further identified as a juvenile female. It was a very sad situation, the young whale had a very thin layer of blubber and the stomach was empty. Despite this, she still weighed in at 13.5 tonnes! Various measurements were recorded including length from tip of upper jaw to tail notch (12.9m). Samples of blubber, skin and the stomach contents were collected. We also collected samples of the baleen to preserve. The samples have been sent away for genetic testing and for the presence of pollutants and disease.


Fin whales are the 2nd largest mammal in the world, coming in just after the blue whale. Adult females can reach 24m (80ft) in length and adult males can reach 22m (72ft). Fin whales are usually seen in small groups of around 3 or 4 individuals. They generally prefer deeper waters beyond the shelf edge but there have also been a number of inshore sightings of these whales, generally around the south coast of Ireland (IWDG). Fin whale sightings around the north-west coast of Ireland are quite rare, but they have been recorded in our waters (IWDG offshore atlas). There are also a few records of strandings of fin whales in NI, but still a relatively rare event!

Even though this was a tragic event, it was a great opportunity for us to find out more about these amazing creatures!

Cathy Hinds

IWDG would like to thank AFBI for their speedy response and for carrying out a post-mortem examination. IWDG are very pleased to be working alongside colleagues from the Agri-Food and Biosciences Institute veterinary science division

Photo credits: AFBI

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