Thousands of poisonous crabs have flocked to Cornwall’s beaches due to rising sea temperatures caused by the climate crisis. The migrating creatures swarm in the shallow waters off St Ives, shedding their shells before returning to depths of up to 300ft.
The crustaceans are instantly recognizable by their long legs and pincers and have a venomous bite that is poisonous to their prey but harmless to humans.
Their presence on Porthgwidden beach was enough to prevent many bathers from entering the sea.
However, Kate Lowe, a marine photographer, captured the event just days after a blue shark bit a diver during an excursion in Penzance.
The crabs were seen gathering in St Ives, Cornwall, to shed their shells before returning to the depths. Photograph: @cornish.coast/BNPS
Kate said: “I go snorkelling most of the time throughout the year but I’ve never seen spider crabs in such numbers. When we got to the beach it looked like there were lots of dark rocks under the surface .
“But it turned out there were thousands of crabs just two or three feet into the water. It was really amazing, they were only up to my knees. I was able to float on top of them and try not to step- the bear.
“Many of the tourists squealed when they saw them. Their shells just floated.”
Experts say that while it is not uncommon to see them in British waters, mass gatherings are becoming more common in the summer due to rising sea temperatures linked to the climate crisis.
Spider crabs – Hyas araneus in Latin – usually congregate in large numbers in shallow water to protect themselves from predators while they wait for their new exoskeletons to thicken and harden.