1000's of Aurelia drying out on salt marsh

1000-1500 moon jellies (Aurelia aurita) drying out on a 0.5 mile stretch of salt marsh and stranded in creek system at the mouth of the Leven Estuary in Morecambe Bay, Cumbria. Some fresher looking dead jellies in pools, but most drying out on grass (had the appearance of a snail trail).