Nasty surprise waiting on Southland beaches
Visitors to Oreti Beach near Invercargill in recent days will have noticed the bodies of thousands of bluebottle jellyfish washed up on the sand.
Department of Conservation biodiversity programme manager Jessyca Bernard - who said she was "99.9 per cent certain" they were bluebottle jellyfish - warned they were dangerous even when dead.
People who saw them on the beach should not touch them and should keep their pets away from them, she said.
"They may remain potent for hours or even days after the death of the creature or the detachment of the tentacles."
If stung an allergic reaction could follow and those affected should seek medical assistance, she said.
When alive and in the ocean the gas-filled bladders of the jellyfish remained on the water's surface and the remainder of the body including tentacles were submerged, she said.
Because they had no means of propulsion they were moved along by a combination of winds, currents, and tides, often congregating in thousands and sometimes being blown onto beaches.
Ms Bernard said when the jellyfish were blown onto the beach their tentacles invariably detached from the bodies and washed into the sand, leaving only the bladders and jelly of the jellyfish, which varied between 9 centimetres to 30cm in size, visible to the public on the beach.
The Southland Times