Beachgoers at some of Auckland‘s most popular swimming spots have been left covered with itchy red rashes, the result of being “mauled by sea lice”.

Those swimming on the east coast, including at Milford, Ōrewa, Stanmore Bay and Red Beach, have taken to Facebook documenting scores of cases of severe itching and rashes after being stung by the microscopic marine critters.

Auckland mother, Hayley Schelling told the Herald her son was up all night scratching his itchy torso.

“He wears a swim top so they must have got stuck up there ... they do seem quite big,” she said.

“I was panicking ... I thought it was chickenpox,” said another concerned parent after their kids were “absolutely covered” in stings after swimming at a beach on the Hibiscus Coast.

“Our family have been hit hard by sea lice yesterday at Red Beach, the worst case so far,” said another.

“My boy went swimming in Stanmore Bay beach yesterday and got mauled by sea lice.”

Sea lice (or isopods) typically grow up to 1.5mm long and tend to live in warm, shallow sand or rock pools, or near the shoreline.

‘Seabathers eruption’ is an itchy rash of the skin that appears mainly on covered areas soon after swimming in the sea, often caused by stings from sea lice, thimble jellyfish or microscopic sea anemones.

Auckland beachgoers are reporting symptoms similar to chicken pox following an influx of sea lice in the region. Photo / Supplied

“Oh wow my daughter swam at Ōrewa yesterday and she is covered head to toe (literally) in big angry red spots,” said one parent.

Another mum said, “they look like angry chickenpox”.

“My son swam at Ōrewa beach yesterday. He even took his board shorts off straight away after swimming and still just got munched everywhere his shorts had touched him.”

“Red beach too. Hubby is covered in them.”

Beachgoers are asked to be cautious of sea lice and other minuscule ocean critters. Photo / Supplied

Optimal conditions

NIWA crustacean biologist Dr Rachael Peart said this year’s warmer waters made for ideal conditions for sea lice.

“When the ocean is quite warm, which it is at the moment, we can certainly get more reports of them,” she said.

While it might seem like there is an influx in sea lice this year, that was not necessarily the case, Peart said.

“We get heaps of reports around January-February every year, it’s not necessarily an influx.

“It’s a dual effect of more swimmers in the water, plus warm surface temperatures.”

The rash can also be caused by nematocysts (stinging cells) of certain sea anemones and thimble jellyfish.

Peart advised swimmers to rinse off with fresh water if they believe they might have been stung and avoid scratching.

“This can increase the chance of infection,” she said.

She urged people to not let the critters discourage them from enjoying the warmer weather.

“Most of the time it’s just bad luck, wrong place wrong time really. But they’re not sinister.”

“Speaking from Wellington, I say get out there and enjoy the water where you can!”

Advice to swimmers if you get stung

• Make sure you remove your swimwear after taking a dip
• Shower in fresh water straight away
• Do your best to avoid scratching

- NZ Herald