On my local beach at Shoeburyness, Southend on sea in Essex there are lots of what appear to be dead Jellyfish. Some are mauve and some White. There appears to be no movement internally or externally. The last time we had such a large number was about 7 or 8 years ago (I am not sure how long ago) and then they seemed to disappear or reduce in numbers until now. In patches there are probably about 5 to 10 per square yard and other areas are clear.