It was on New Year’s Day that a dog walker discovered the washed up body of a 4.25-metre long male thresher shark on the sandy shores of Par beach, in Cornwall.

Volunteers from Cornwall Wildlife Trust’s Marine Strandings Network received the call and swiftly attended the scene to recover the shark. The post-mortem that followed revealed that this individual thresher shark had suffered “significant trauma”.

With damage to the mouth and signs of haemorrhaging, conclusions followed that the shark had fallen victim to sports fishing. The injuries it bore, it was deduced, were most likely suffered before the animal died.

Marine Conservation Officer at Cornwall Wildlife Trust, Matt Slater, said: “While it’s difficult to say for certain, early findings suggest the animal’s death may have been the result of line caught sport fishing.”

Thresher sharks – Alopias vulpinus – are rarely seen in UK waters and are highly regarded for their “incredible” predatory abilities, using their elongated tail fin to stun and immobilise their prey. They have often been seen leaping out of the water. 

They are also currently listed as ‘Vulnerable’ by the International Union for Conservation of Nature (IUCN), and, while they are usually found in deeper waters, they occasionally venture into British coastal waters in the summer. Despite their IUCN status, however, they are still susceptible to commercial and sport fishing. 

In fact, commercial fishers are currently allowed to land thresher sharks, although they are not actively targeted by fishers. Recreational anglers also target sharks, though most now practice catch and release fishing.

“Bycatch, the accidental entanglement of marine animals in fishing gear, poses a major risk to sharks and other ocean wildlife,” continued Slater. “Cornwall Wildlife Trust urges anyone carrying out commercial or recreational fishing to follow guidance to ensure the safe handling and release of animals accidentally caught.” 

Cornwall Wildlife Trust has said that a team of “amazing” volunteers and local community members helped move the dead thresher shark from Par beach, as Marine Strandings Network volunteers recorded the stranding and collected key data. Following this, the shark was sent for a post-mortem by the Cornwall Marine Pathology Team; the full results, said Slater, will be released in due course.

Writing for Forbes, the science communicator, author, and marine scientist, Melissa Cristina Márquez, said: “This tragedy is not just about one shark – or even one species. It encapsulates the larger story of how human activities are altering marine environments, often with devastating consequences.

“Maybe 2025 will be the year we all unanimously agree on this fact, as there is growing frustration with policies that fail to address the broader, systemic issues affecting marine ecosystems. 

“While no one ever wants to see such a majestic animal suffer, there is hope these incidents will lead to meaningful actions, ensuring a species like the thresher shark have a fighting chance in our increasingly pressured oceans.”