BEACHGOERS are being warned with killer jellyfish thought to be stalking our waters.

Marine experts have warned there is a probability that Portuguese Man Of War jellyfish could wash up on the beaches of Sussex over the next few weeks.

The creatures have a vicious sting that can leave red welts on the skin and, in cases of swimmers getting tangled in their tentacles in warmer climates, repeated stings can prove fatal.

After sightings on beaches in Cornwall and the South West, experts have told residents in Sussex to send in pictures of any jellyfish they see.

Peter Richardson, head of biodiversity and fisheries at the Marine Conservation Society (MCS), told The Argus: "It depends on currents and weather conditions, but if they occur in big enough numbers the probability increases that some make it your way.

"These things are safe if you don’t touch them. So if folks do find one, do not touch it and report it to the MCS."

He said strandings in the past have been in late summer and early autumn, rarely beyond October.

Their appearance could be down to a combination of factors depending on sea surface currents, wind direction and whether or not the animals are present in numbers in the north east Atlantic ocean.

Dr Richardson added: "We also know there are periodic pulses of warm water masses moving northwards from the equator as part of global climatic processes, and when these happen the movements of warm water northwards brings with it warmer water species.

"Recently we have seen reports of tuna and billfish in UK waters, so maybe we are experiencing another warm water pulse coming from further south."

Other jellyfish are already regulars to our shores, though their stings are mild in comparison.

Dr Richardson said: "We had several reports of barrel jellyfish blooms from Sussex in February and March. We also expect to see blooms of moon jellyfish during the summer, in Shoreham Harbour for example, as well as few compass jellyfish too.

"All jellyfish sting – some stings are more powerful than others. Moon jellyfish have a very mild sting, barely noticeable to most, whereas the compass jellyfish sting is much like a nettle sting. You may also get blue jellyfish, which also have a nettle like sting."

For more information and to report jellyfish visit mcsuk.org.