25/07/2021
Please note, some may find the following content upsetting.
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Why are headless seals washing up on our beaches?
by Johnny Woodlock - The Irish Seal Sanctuary
Common and Grey seals are protected in Ireland Under the Irish Wildlife Act, 1976 and The EU's Marine Mammal Protection Act, 1972. Ireland also has two species of seals, the Common Seal (or Harbour Seal) and the Grey Seal. Whilst both species haul out on land for key stages of their life history, the majority of their time is spent in the marine environment.
They are considered a species of special concern in Ireland as their numbers have been slowly declining, with only approximately 3,000 – 4,000 remaining.
Since 2012, The Irish Seal Sanctuary (ISS) have been keeping a database of sightings of dead seals washed ashore on Irish beaches.
It became apparent lots of these dead seals had no heads, indeed many appeared to have had their heads cut off. Even though we sometimes see what looks like a bullet wound, we cannot say it is unless a necropsy is performed. Necropsies, the equivalent of human autopsies, are performed by veterinarians and specialised veterinary pathologists to determine an animal’s cause of death. While these cases are reported to authorises, they are often under pressure to conduct a necropsy to confirm if a seal has been shot, and without witnesses, no prosecution can be pursued.
The ISS have amassed a database of photographs and can say with some certainty that some seals have been shot given the destruction of the skull as it becomes exposed. The head is usually all that is seen of a seal at sea. A large calibre bullet will destroy the skull, to do this without a licence it is illegal.
See photograph below.
Lungworm: Often when a member of the public sees blood around the head of a dead seal, they conclude it must have been shot. However, we know this is not always the case. Seals, indeed, all marine mammals carry a very large natural parasite load- especially lungworm. As Founding members of The Irish Whale and Dolphin Group, we attended a demonstration of a necropsy on a harbour Porpoise which had drowned in a net – while the cause of death was known, the investigation showed it’s lungs and airways were almost blocked by masses of lungworms. Most post-mortems we have organised on dead seals and porpoises returned that they too had died of lungworm infestation. We recently investigated a dead common seal with blood around its mouth- closer inspection showed this to be pink frothy blood which is an indicator of lung blood indicating the dead seal died of natural causes. See Lungworm photograph below.
Carcasses such as the one shown below are often reported as a shot seal. It was established early on that the neck is a weak point in seals that have died. I witnessed a gull tear the neck of a dead seal pup to the extent that it looked like the dead seal had a ligature cut its neck. See photograph below.
As can be seen, the neck is nearly cut through- often the case when a young seal is entangled in an item such as a monofilament net as in the photographs below.
In both these cases, the carcass was found shortly after it washed in before the head separated from the body. Often there are dead seals we cannot explain how or why they died so we have learnt not to guess at first sight.
The ISS rely on the public to report the dead seals they see/find and to forward a photograph when/if possible. Over the years, we have had several incidents reported of people feeling intimidated by strangers asking why they were taking the photos of dead seals.
This poses the question, why would anyone be concerned about this?
Thanks to all who have and continue to contribute to our dead seal database.
If you come across a dead seal, please report it with a photograph to: [email protected]
The reports are on our website at www.irishsealsanctuary.org https://irishsealsanctuary.org/seals-in-ireland/dead-seal-database/
We share all the knowledge we obtain- while everyone might not agree with our conclusions, its always good for everyone to discuss, collaborate, and share learnings as the welfare of the seals are the most important thing.
Thank you,
Johnny.
