Marine mammals island strandings

An Orca whale discovered dead on a beach at Baleshare, North Uist, recently is not believed to be from the local ‘West Coast’ pod seen around Lewis and Harris.

And post-mortem of a juvenile Common dolphin which stranded and died on South Beach, Stornoway, is still to be undertaken,

The carcass of the six metre sub-adult Orca was discovered on Monday, July 28th – and both British Divers Marine Life Rescue (BDMLR) Outer Hebrides and the Scottish Marine Animal Strandings Scheme (SMASS) have thanked local residents for their assistance.

A post-mortem has been completed by SMASS, but they are awaiting test results before a cause of death can be announced. However, asymmetric tooth wear in the animal suggests it was a ‘type-1’ animal which follows mackerel and herring boats, feeding’ from the long fishing lines.

“Investigations are ongoing with the Orca, but the problems with its teeth lead us to believe that it’s not from the West Coast population,” said SMASS Strandings Co-ordinator Nick Davison.

“It was a debilitated male animal that hadn’t fed recently. We did find marine debris in the stomach [hooks, lines, straps] but that seems incidental and not the cause of death.”

Nick added: “Even if we can’t find a cause of death, the opportunity to post-mortem Orca is good for research as, because they are apex predators, any pollutants in the marine environment end up accumulating in the blubber so looking at that gives a good indication of not only the health status of the individual and its population, but also its surrounding marine environment.”

The post-mortem of the Common dolphin which stranded itself on July 30th will be next week.

Sandy MacDonald, BDMLR Outer Hebrides, said the 1.5m female dolphin was underweight and swimming strangely: “As it came in to the shore to beach itself, it looked like it may have been having convulsions; it was dying as it came in.”