Yorkshire coast mass wildlife stranding: Why did it happen and what happens next?

Millions of dead sea creatures have been left strewn across the beaches of Holderness after a 'once-in-a-decade' freak weather event.
A dead ray on the beach at FraisthorpeA dead ray on the beach at Fraisthorpe
A dead ray on the beach at Fraisthorpe

The whole of the North Sea coast has been affected, and in Yorkshire Fraisthorpe Beach, near Bridlington, seems to be the epicentre of the mass stranding.