Sperm whale stranding
On the 29th October 2019 a Sperm whale live stranded and died at Hell’s Mouth on the Llŷn Peninsula in North Wales. The following day a necropsy examination of the animal was carried out by experts from the Cetacean Strandings Investigation Programme (CSIP), who are responsible for the coordination of the investigation of all cetaceans, marine turtles and basking sharks that strand around the UK coastline.
Sperm whales are the largest toothed whales in the world, they possess the largest brain in the animal kingdom and spend much of their lives diving to great depths to hunt for their favourite prey, squid. Their iconic head shape is what makes them unique in comparison to other whale species, with their heads comprising of a third of the body length. If you are lucky enough to spot a single blow deviating to the left whilst at sea, you’ll know you’ve spotted a sperm whale!
Did you know sperm whales only have teeth in their lower jaws?
Interestingly young sperm whales spend time in groups known as bachelor pods until they are around 30 years old, around the UK these can be found in the cooler waters to the north. Whilst females tend to spend more time together and join to form nursery or matriarch pods to look after their young, found in temperate or tropical waters to the south of the UK.
Sperm whale populations have been decimated by centuries of whaling. Historically they provided good quality oil in high quantities from the spermaceti organ in their heads and as a source of ambergris, a waxy substance found in their lower intestines formed around squid beaks, which was used as a fixative in the perfume industry.
Sperm whales communicate using morse code like patterns of echolocation clicks called codas and use their highly developed echolocation ability to locate food and to navigate.
Members of our Living Seas Wales team were fortunate to have the opportunity to visit the site at Hell’s Mouth where the whale stranded and to attend the examination of the whale. Although deeply saddening to see, interestingly it is the first recorded stranding of a Sperm whale in Wales since routine recordings of strandings began in 1913 and only the second calf to be recorded stranded in the UK. The examination of the whale found that it was a 6.7m juvenile male that was in moderate-poor nutritional condition. Squid beaks were found in the stomach contents although there was no evidence of recent feeding, indicating that the animal had been weaned and been feeding on “typical” prey. During the removal and examination of the animal’s brain, the CSIP team found evidence of potential nervous system disease, further tests may provide further information on this.
Sperm whales, like cows, have four stomach chambers full of digestive enzymes, during the examination a large piece of blue plastic sheeting was found in the upper part of the stomach and a large mass of ropes, fragments of monofilament line and other plastic fragments were found in the base of the upper part of the stomach.
A wide range of samples were collected during the examination of the whale and further information on the animal, as it becomes available, will be posted on the CSIP social media.
Welsh stranding and examination information credit: Cetacean Strandings Investigation Programme (CSIP), Marine Environmental Monitoring (MEM)
Photos credit: © Sarah Perry
Note: At the end of November another Sperm whale around the UK, this time on the Isle of Harris in the Hebrides, Scotland. This whale also live stranded and died on the beach. It was a subadult male and upon examination approximately 100kg of marine debris including plastic, sections of fishing net, bundles of rope as well as plastic cups, bags and gloves were found in its stomach. Again whilst it is not thought this was the direct cause of death of the animal it is still nonetheless horrific to think of these animals, having to live and potentially suffer due to the impact us humans have on our planet.
Scottish stranding and examination information credit: Scottish Marine Animal Stranding Scheme (SMASS), also part of CSIP.