At around 1pm yesterday, Sunday 10th July 2016, BDMLR was alerted to a stranded whale on Perranporth beach, Cornwall.
Upon arrival, BDMLR volunteers confirmed that it was a 38ft long sperm whale and an attending veterinary consultant confirmed that it was female. The whale had stranded on a falling tide earlier and died naturally within two hours of being reported, around 3pm.
As a 38 feet (11.5 metres) adult female, this animal would have weighed 14-15 tonnes and there was no way of safely moving her back into the sea at this weight. Females are considerably smaller than males, growing to a maximum of 40 feet (13 metres) and 16 tonnes. Males can grow to 70 feet (20 metres) and 45 tonnes.
It is incredibly rare for a female sperm whale to strand in the UK as females tend to remain with their calves in tropical and sub-tropical waters, with the closest known breeding and nursery area being off the Azores, with what may be females sometimes seen in the southern parts of the Bay of Biscay. Males leave the nursery pod and congregate in sub-polar regions, returning to the warmer waters each winter when the larger males will seek out responsive females for mating.
As this was a lone female it is unlikely that the stranding would have been associated with the mass stranding of male sperm whales in the southern North Sea in January and February of this year.
Tissue samples were taken for later analysis and if the body is still accessible today, a post mortem examination will be undertaken under licence, with results published by the Cetacean Strandings Investigation Programme in due course. BDMLR would ask the public to stay well away from the dead animal for their own safety, as whales can carry zoonotic diseases that transfer to humans and pets and remind people that is illegal to remove or own any part of a dead whale, dolphin or porpoise without an official licence.
Update Thursday 14th July 2016
Here is a brief report from the Cetacean Stranding Investigation Programme who carried out a post mortem examination on Monday. Samples will be sent for specialist analysis and a full report will be published when the results of these investigations are received.
The sperm whale (national reference SW2016/340) which live stranded and died at Perranporth beach on Sunday was examined by the CSIP and by staff and volunteers from the Cornwall Wildlife Trust Marine Strandings Network/Exeter University over the course of Monday afternoon through into Tuesday morning. It was a 10.3m long adult female, which was judged to be in reasonable nutritional condition. The gastrointestinal tract was empty, with bile staining present through much of the intestinal tract, indicating a period of no feeding. Light burdens of nematode parasites and small quantities of squid beaks were also found in the stomachs, but no evidence of marine debris ingestion was noted. No gross evidence of significant disease was found, or any traumatic lesions consistent with ship strike or entanglement.
Globally, segregation exists between male and female sperm whales, including in North Atlantic populations, with the matriarchal pods containing females normally resident in temperate to tropical waters much further south of the UK, whereas males generally travel in more temperate waters. We have historically only ever had juvenile/subadult male sperm whale strandings in the UK and this is the first confirmed female sperm whale to be recorded stranded in the UK, since routine collection of strandings data by the Natural History Museum began in 1913, illustrating the unusual nature of this stranding event. This was also only the sixth sperm whale to be recorded stranded in Cornwall in this same 100+ year period.
The whale died from the pathophysiological effects of live stranding, but there's still a question of whether there was any underlying problem with it, which might explain why it stranded. We collected a large range of samples and specimens, which may help shed light on whether the whale was sick or compromised in some way and will also help further our understanding of a species which can be difficult to study. Samples for bacterial culture have been collected, along with a range of samples for further collaborative studies including histopathology, genetics, toxicology, virology, osteoblast (bone cell) culture, age/diet analysis and life history studies.
BDMLR would like to thank all those who helped in response to this incident and for assistance with the post mortem examination.