Scientists are baffled by the increase of jellyfish around the coasts of Wales.
Barrel jellyfish are harmless to humans
Thousands of barrel jellyfish have been found stranded in Carmarthen Bay, and a large number of moon jellyfish have been startling tourists off Anglesey.
Although experts stress that these two species are harmless they are keen to know the reasons for their apparent increase.
The fish are not the only recent arrivals - giant rare leatherback turtles, which feed on the jellyfish, have also been spotted.
Dr John Houghton, a researcher at the University of Wales in Swansea, said it was important to study the creatures.
"What we are trying to do at the moment is work out why these animals - which we really associate with the tropics and much warmer places - are appearing in the Irish Sea in such large numbers," he said.
"It is apparent they have been turning up for quite a long time, although we used to think of them as occasional visitors to these kinds of waters.
Moon jellyfish are often seen floating in "rafts"
"But the numbers we are talking about suggest they have a much closer association."
Dr Houghton revealed it was hard to say whether the increase in jellyfish was caused by global warming.
"There hasn't really been an awful lot of research done on them because they are very hard to study in the water - you catch them in a net and they just turn into nothing.
"What we are trying to do is have a little look at them washing up on the beaches."
Dr Houghton added that leatherback turtles had a history of visiting the area.
"The leatherbacks are fantastic animals - Wales has got quite a close association with them.
"In 1998-9, the largest one ever in the world washed up in Harlech - it was just under 10ft long and about 916 kilos."
Dr Houghton is asking anyone interested in helping the research to contact him at the university, where he is compiling a local survey on ecology of the Welsh and Irish coasts.