THERE was disgust and shock at a sight on one of Arran’s beaches recently as a dead harbour porpoise was found with a knot tied around its tail fin and wire just below its head.

Sandra Butler, from Whiting Bay, found the porpoise last week at the south end of the bay.

The Scottish Marine Animal Stranding Scheme (SMASS) are funded by the Scottish Government to investigate mortalities and ascertain whether they are the result of human interference or natural causes.

Dr Andrew Brownlow, of SMASS, said that one possible explanation was that the cetacean could have become caught in fishing nets out at sea and drowned, an example of what is called bycatch, when an unintended marine species is caught whilst fishing for something else.

He says that fishermen could have tied the knot around its tail and attached weights in an effort to sink the carcass.

“What I expect has happened in this case, is that this is a bycaught animal, it’s been accidentally caught up in some fishing nets, brought up onto a fishing vessel and the fisherman have attempted to sink it. What they do quite commonly is wrap some rope around the tail, throw it overboard with a weight attached to it so that it sinks.”

Though he was strongly of the opinion that that is what has happened with this animal, he did not rule out other explanations.

“There are other options, which I don’t think are applicable in this case, but they could be, that the volunteers or members of the public have spotted an animal that has died and washed up on the beach and they’ve wrapped a rope around the tail to secure it.

“The reason I don’t think that’s the case in this particular instance is that according to our records, we don’t seem to have any animal that’s been reported that would tie up with that description in that location.

“It’s possible they did that and just didn’t tell us, but in most cases we are aware and we would have asked the volunteer or the member of the public to secure the animal for us. And also, just looking at the kind of rope that’s been used that would be very consistent with the type of rope that’s available on a fishing vessel.

Whilst acknowledging that the fate of this harbour porpoise was a shame, he was keen to play down fears of similar happening on a large scale around Arran.

“It’s unfortunate. Bycatch is a major issue with cetaceans globally and Scotland is no different, but I don’t think that this is indicative of a major problem, but it [the amount of attention the picture has garnered on social media] shows that people are interested.”