Jellyfish measuring up to 3.2ft in diameter are washing up on Britain’s shores.
As many as ten barrel jellyfish have appeared on beaches around the south coast in recent weeks.
This one was spotted in the sand in Portland, Dorset, by wildlife photographer Steve Trewhella.
Steve Trewhella with one of the barrel jellyfish on a Dorset beach
Experts believe that we could see more of the large marine animals over the next few months because of the predicted warm weather.
Richard Harrington, from the Marine Conservation Society, said: "This predicted hot weather to come could mean even more jellyfish are likely to wash up or be in the seas.
"Although this species is harmless their numbers are likely to grow fairly quickly as sea temperatures rise.
"This is an Atlantic species and are sometimes found washed up but we still advise the public not to touch them."
The sting of the barrel jellyfish is thankfully harmless to humans
Trewhella, 49, from Wareham, said: "It's not that unusual to see jellyfish, they aren't particularly common in Dorset but we do see them every once in a while.
"Jellyfish are a form of plankton, and the warm weather means we might see an increase in the levels of plankton.
"This is something that occurs around this time every year and it is known as the plankton boom.
"However, it is not the warm weather that causes jellyfish to wash up, instead it's the wind and tides that leave them stranded on beaches.
"I think we will see more strandings because of the on-shore winds and the tides, however people should be careful not to touch them."
Barrel jellyfish - Rhizostoma pulmo in Latin - are often known as dustbin-lid jellyfish because of their enormous size.
They are commonly found in the north east Atlantic, Adriatic, and Mediterranean sea and are prey to leatherback turtles.