Marine researchers have appealed to people to report any sightings of lion's mane jellyfish off the Irish coast, after a number of people had to be treated in hospital for stings in recent weeks.

Scientists at the Ryan Institute at NUI Galway have reiterated their view that the most effective treatment for these stings is to rinse them with vinegar, before immersing the affected area in hot water for 40 minutes.

They have also stressed that existing guidelines state sea water and an ice pack should be used to treat stings.

Lion's mane jellyfish, which can be up to one metre in diameter, have thousands of long tentacles.

While they are one of the least abundant types of jellyfish found in Ireland, there have been a number of sightings off both the east, south and west coasts in recent weeks.

While the stings are not considered fatal, they can cause a lot of discomfort.

This initially begins with localised pain and can progress to cause back pain, nausea and cramp.

Sea swimmers and coastal visitors are being asked to report any sightings to the National Biodiversity Data Centre website.

Scientists believe the jellyfish found in recent weeks may have "over-wintered" in Irish waters and are now on their second season.

Last week, Dún Laoghaire Rathdown County Council said there had been several jellyfish sightings around the well-known Forty Foot bathing area.

It urged people swimming in the area and surrounding areas along the east coast to report any sightings.