A carpet of the marine animals were washed up on Punta Umbria beach in Huelva on Monday in what conservationists believe was a direct result of Storm Emma.
A video uploaded by Juana Salas on Facebook showing the extent of the stranding has been viewed over half a million times:
Such mass strandings happen from time to time but the extreme weather conditions of the last week combined to have a devastating effect on the starfish population.
“The sea bottom was churned up at the same time as there being spring tides and add to that a tornado,” explained José Antonino Cuesta, a marine biologist at the Marine Scientific Institute of Andalusia (CSIC).
“Starfish may be at particular risk of strandings after storms because of a behaviour ‘known as “starballing', “ explains Coleen Suckling, a lecturer in Marine Biology at Bangor University, in an article for The Conversation.
“By curling each of their multiple arms to create a large spherical balloon shape with their body, they can essentially roll over the seabed in fast-moving water and cover much greater distances. But during a storm they could be rolled out of control and left stranded on the beach," said Suckling.
Mass starfish strandings aren't completely unheard of, she writes. Several million were found on the coast of Worcester County, Maryland, USA in 1960. Up to 10,000 were found along the strandline on the Isle of Man in the British Isles in 1999. And 50,000 were stranded on the Irish coastline in 2009.
The Beast of the East also caused mass starfish stranding on the British coastline last week, specifically in Ramsgate, Kent.