Two regular Assynt visitors were walking along Stoer beach on Saturday 16th June 2017 when they came across this dead, very young, stranded Common Dolphin and through a third party they made contact with me.
I have been trained and certificated by the Scottish Marine Animal Stranding Scheme (SMASS) in Inverness to take samples of blubber, etc. from dead stranded cetaceans but SMASS must be contacted first to allow them to issue a case number. Later that day I emailed SMASS to let them know of the stranding and sent several photos for their information.
I very soon received a response from SMASS to say that as this was a unique stranding and the animal was fairly fresh they would collect it for a full necropsy. The dolphin was collected the following day and a necropsy was performed on Wednesday 21st June.
As promised SMASS have now provided the very detailed report on the findings of the necropsy but these are the summary observations/comments from it –
“This male neonate common dolphin was in moderate nutritional state. Foetal folds were still evident and vibrissae present on the rostrum. The teeth had not erupted. The right eye was missing assumed to be due to scavengers. The tongue was missing and there was damage to the right lower jaw again assumed to be due to scavengers. There was a small hole in through the umbilicus into the peritoneal cavity through which most of the abdominal organs had been removed. There was damage to the diaphragm and only a small fragment of liver present. The immature testes were present as was the bladder and the distal part of the intestine. All other organs were missing, assumed by avian scavengers. The heart appeared normal. Both lungs were very congested and oozed fluid on cut surfaces. The brain appeared normal, however there was some haemorrhage noted around the brain stem. No parasites were noted in any system examined. Bacteriology on the brain and lung was unrewarding. This is most likely a case of neonatal starvation and maternal separation but the absence of much of the viscera makes it difficult to confirm this.”
Two further interesting facts gleaned from the report were that the animal’s incomplete carcass weighed 7.45kg and it measured 97cm from the tip of the upper jaw to its tail notch. For comparison an adult male Common Dolphin can weigh 150kg and reach 2.7m in length.
I must stress the report makes no suggestion of what I am about to say. The waters around Assynt are frequented by many cetacean species, Common Dolphin being one which is almost only ever recorded from late spring to early autumn. The pods of this dolphin species off our coast always contain young animals such as the one described here.
One possible reason for maternal separation is disturbance by boat activity; this normally takes the form of small fast craft harassing pods by chasing them or driving through them so those on board can ‘get a better look’. This frequently causes mothers and calves to get separated with possible fatal consequences.
So please don’t chase or drive a boat directly towards cetaceans or encircle them and always allow pods to remain together; if they approach you or chose to bow-ride maintain a steady course and speed.
Finally, while it is very sad to find a dead cetacean please always report them as they can help us gain a better understanding of what is happening to our marine mammals. Thank you.
SMASS can be contacted on 01463 243030/ 07979 245893 or email email@example.com.
I am very grateful to Nick Davison and Mariel ten Doeschate of the Scottish Marine Animal Stranding Scheme for allowing me to reproduce the above extract from their report and for the use of their photograph.