Decline in porpoise sightings off protected island
The decline could be due to the impacts of climate change or because they are feeding elsewhere
Bardsey Island , also known as Enlli, is a national nature reserve and a site of special scientific interest, home to choughs, grey seals and puffins.
"I have to emphasise it's a decrease in sightings, the number we see for the number of hours we sit watching, so we can't directly transfer that into population size," he said.
The decline near Bardsey Island, off the Llŷn Peninsula, Gwynedd, could be due to the impacts of climate change or the fact the animals are feeding elsewhere, said Mick Green, manager of Bardsey Marine Mammal Project.
There has been a 97% drop in sightings of porpoises around an island off the north Wales coast, despite the area being protected, a study has found.
Speaking to BBC Radio Wales Breakfast, Mr Green said there had "obviously" been a "large drop in animals using the area around Bardsey Island over the last 20 years".
He said the decline in porpoises had been recorded elsewhere around the Irish Sea, but that "the amount of decline is variable".
Mr Green added that climate change could be a factor, with fish population moving, leading to porpoise following them to catch food, while "they could just be feeding elsewhere".
He also said there is not a huge fishing industry around the Welsh coast.
"But that could be an issue out in the wider Irish Sea and in international waters where large trawlers can operate and we know they do catch porpoises by accident," he said.
"Whether they catch enough to decrease the population we don't know, and that's something that needs looking into."
He added that the organisation was recruiting volunteers and training people to conduct sightings.
He also described the difference between a dolphin and porpoise, with the former being mainly bottlenose dolphins regularly seen in Cardigan Bay and near New Quay.
Porpoises are "a small animal with a very triangular, small fin on their back and you tend to only see them briefly as they come swimming up".
[SRC] https://www.bbc.com/news/articles/ced5pq46zj1o
