A dog walker’s shock at the sight of a giant 4m monster fish washing up on the UK coast

The fish has since been identified as Atlantic bluefin tuna — an endangered species and the largest of its kind

A giant fish has been spotted after an unsuspecting dog walker stumbled across the endangered creature.

The fish, about four meters long, was spotted in Oxwich Bay in Wales on June 10 reported by WalesOnline.

The handler said they noticed a sizable object in the distance and walked over with their pooch, Sasha, to get a closer look. The handler quickly realized it was an unusually large sea creature and described it as “the biggest fish we’ve ever seen.”

The fish has since been identified as Atlantic bluefin tuna — an endangered species and the largest of its kind, according to the World Wife Fund for Nature (WWF).

Ecologist Thomas Faulkner, who works closely with the Wildlife Trust of South & West Wales, recognized the fish and offered his thoughts on why it may have washed up on the Welsh coast.

He said that bluefin tuna are “recolonizing the southwestern littoral… having previously become extinct.”

Mr Faulkner added that this particular species was “typically rare visitors to the UK and even rarer to Wales”.

“They can grow up to four meters long, so you can tell this one by its size alone,” he said, adding, “The south or west winds could have washed it up from Cornwall or the Celtic Deep.”