A five-foot blue shark was spotted swimming in shallows on the Cornish coast, sparking concerns for its welfare.
The creature, which typically lives in deep water, was spotted swimming in Carrick Roads - an estuary near Falmouth - on Wednesday morning.
Marine animal experts and rescuers from charity British Divers Marine Life Rescue were called to the stranding.
The shark was seen twisting around in shallow water, appearing to rub against the sandy sea floor.
Sharing a video of its unusual movements and appealing to shark experts for help, marine biologist Christy Judd wrote on Twitter: “As you can see this shark looks fairly healthy, so this behaviour is very strange! Anyone have any theories?”
As you can see this shark looks fairly healthy, so this behaviour is very strange! Anyone have any theories? pic.twitter.com/1IUkGr0dlN
— Christy T. Judd (She/Her) (@BadBiologist) August 17, 2022
She added that it is unusual for blue sharks to come so far inshore.
“That’s why we’re so concerned about its health - definitely strange behaviour,” she wrote. “We theorised that it could have chased a shoal of fish and then became disoriented.”
Some speculated the shark could have been disoriented by sonar used in military training.
Others suggested the creature - which typically inhabits water saltier than the brackish estuary - could have been “confused” by its surroundings.
The shark was observed for about seven hours, before leaving the area of its own accord.
Blue sharks typically live in deep water. They are known to migrate long distances and visit UK seas in summer months, where they are typically sighted at least 10 miles offshore.
The largest blue shark caught in UK waters measured more than 9ft in length.
