Massive lion's mane jellyfish washes up on north Auckland beach

Dozens of jellyfish washed ashore north of Auckland on Monday morning, but there was one in particular that caught beachgoers' eyes.

A lion's mane jellyfish stole the show at Pakiri Beach, north of Warkworth. Locals Adam and Eve Dickinson and their children Lucas and Sofia came across it around 8:30am.

"There was probably 50 to 100 jellyfish," Mr Dickinson told Newshub. "That was the only one like that."

NIWA says the lion's mane, or Cyanea rosea, is the biggest jellyfish species found in New Zealand. It can appear anywhere along the coast, even as far south as Campbell Island - about a quarter the way to Antarctica.

Adam and Eve Dickinson lion's mane beach
A lion's mane on Pakiri Beach. Photo credit: Adam and Eve Dickinson

Mr Dickinson threw caution to the wind and poked it with a stick to see what it would do.

"It was hard to describe - kind of like a muscle contraction kind of thing - It was contracting all the way around, it was pretty cool."

Lion's manes can deliver painful stings, NIWA told Newshub. For minor stings the best cure is rinsing the affected area with seawater - not freshwater - or maybe vinegar.

Any clinging tentacles - the lion's mane has hundreds underneath its picturesque upper half - should be pulled off carefully with tweezers, and definitely not rubbed or scraped off, because this can trigger the release of more venom.

"I picked up a few of the others, the little ones with not many tentacles - I was just showing the kids you don't touch the underneath of the jellyfish - but I didn't want to touch the outside of that one," said Mr Dickinson, who let his kids Lucas and Sofia get close - but not too close.

Lucas and Sofia Dickinson with a lion's mane jellyfish on Pakiri Beach.
Lucas and Sofia Dickinson with a lion's mane jellyfish on Pakiri Beach. Photo credit: Adam and Eve Dickinson

The close encounter hasn't put them off going to the beach - much the opposite, in fact.

"We go to the beach to see cool things like that."

Another lion's mane - this one still in the water - was caught on video by Aucklander Wayne Monastra in Gulf Harbour on Saturday, and shared with Newshub.

Lion's mane in Gulf Harbour.
Lion's mane in Gulf Harbour. Photo credit: Wayne Monastra

About Cyanea rosea - the lion's mane

  • It's the largest jellyfish species found in New Zealand
  • They have a bright pinkish-purplish-brown, saucer-shaped bell with a mop of long tentacles and thick frilly curtains of oral arms underneath
  • It also has a warty bell-like surface, of which the margin is split into 32 scalloped lappets.
  • Under the bell are hundreds of tentacles and four frilly oral arms, used to inject prey or predators with venom
  • They're found around the entire coast of New Zealand as far south as Campbell Island, along the east coast of Australia and in polar, subpolar and temperate seas around the world
  • They sometimes swarm in large numbers in warm summer months when there is an abundance of plankton
  • They can deliver painful stings, even after being stranded, and can cause an allergic reaction.
  • The largest lion's mane ever found measured 2.3m across and had tentacles 37m long - equivalent to the length of three buses.
Lion's mane.
Lion's mane. Photo credit: Adam and Eve Dickinson