Here is the strandings report for October! We have had a total of 34 strandings, with 11 cetaceans, 21 seals and two basking sharks. Six cetaceans and two seals were subjected to necropsy.
There were ten grey seals (two on the Western Isles, two on Orkney (photo), five on the East coast, and one from the West coast), four common seals (three from the West coast and one from the East coast), and seven seals that could not be identified to a species level due to advanced decomposition of the carcase or insufficient data. Both seals that went for necropsy were juvenile common seals (photo). They were both in a thin condition and exhibited moderate to high verminous pneumonia which likely resulted in compromised feeding and health. Further histopathological and bacteriological examination is currently underway and will hopefully provide more information on the ultimate cause of the morbidity.
The two basking sharks, one of which stranded in Sutherland; the other on the Isle of Arran, were in an advanced state of decomposition and could not be further examined. Nevertheless many thanks to Kate Sampson for going out and measuring and sampling the animal on Arran for us!
Four baleen whales (Mysticetes) were reported to us this month; two minke whales and two mysticetes that could not be identified further due to advanced decomposition or incomplete carcases. One Minke whale was subjected to necropsy and was found to have a severe parasite burden in the intestines; the full story can be found below on this page. After that the harbour porpoise was the most commonly reported cetacean in October though with only three cases; one from the Western Isles, and two from Ayrshire (photo). These latter two were collected by- and are currently stored at Hessilhead wildlife rescue centre awaiting necropsy; thanks to all at Hessilhead who were involved in the collection of these animals! Furthermore there was one white-beaked dolphin reported from Orkney which was sampled by one of our trained stranding volunteers (photo), and two pilot whales, one on Lewis and one at Dunvegan on Skye. The individual from Lewis was collected and used as a demonstration case for this year’s students of the MSc Marine Mammal Science of the University of St Andrews (see photo), the animal from Dunvegan was necropsied in situ. Both were very interesting cases (full stories can be found below on this page) and we have received a great deal of help with the recovery, collection, and necropsy of both these animals; so very many thanks to all involved!
Lastly, a juvenile male striped dolphin stranded alive in the last week of October. The animal was refloated by members of the public, but stranded dead three days later. The carcase was recovered by our trained volunteer Ross Flett, and sent to Inverness for necropsy (see photo). The animal was in a moderate to poor condition and exhibited pathology consistent with the live stranding event. There was moderate dilation of the right ventricle of the brain as well as an inflamed appearance to the choroid plexus (which act as a filtration system and thereby has a role in helping to maintain the delicate environment required by the brain to function optimally); and these lesions indicate there may have been a potential neurological cause to the original stranding. The case is currently awaiting further bacteriological and histopathological examination which will hopefully shed some light on the matter.
Thanks again to all who reported and assisted with strandings this month! It will likely turn dark and stormy soon; nevertheless we hope there will still be lots of you walking beaches regardless of the wintery weather! Keep the reports coming!