Toxic sea slug warning for Auckland beachgoers

Keep an eye on children and pets this summer

Publish Date : 12 Nov 2020
Toxic sea slug warning for Auckland beachgoers
There are several species of sea slugs and only the species Pleurobranchia maculata is known to be highly poisonous.

While the occurrence of toxic sea slugs on Tāmaki Makaurau beaches has been sporadic over the years, Auckland Council’s Alcohol and Environmental Health Manager Mervyn Chetty says people should remain vigilant.

Native to New Zealand, toxic grey side-gilled sea slugs (Pleurobranchaea maculata) were linked to the deaths of dogs on Auckland beaches in 2009.

The dogs had ingested the sea slugs which contained the toxic substance tetrodotoxin (TTX).

“There has been some social media activity around dogs becoming unwell after visits to Orewa and Takapuna beaches,” Mervyn said.

“While it hasn’t been confirmed that this is due to the dogs being poisoned by eating toxic sea slugs, it is a timely reminder for people to be vigilant and remain cautious at all times.”

Mervyn said people should not touch sea slugs and report sightings to Auckland Council.

“It’s a normal occurrence for sea slugs to be washed ashore, but if there’s unusually high numbers council will investigate.”

Phone the Auckland Council on 09 301 0101 to report your sighting or email

“People can also take a photo and send it to us so our staff can help with identification.”

Auckland Council advises the following:

  • Sea slugs may be present on any beach and if found should be avoided
  • Only the grey side-gilled sea slugs (Pleurobranchaea maculata) are known to contain tetrodotoxin (TTX) and can be highly poisonous
  • Do not touch any sea life (dead or alive) found on the beach as it may contain harmful levels of bacteria or be poisonous
  • Do not eat anything washed ashore
  • Children and pets should be kept under supervision at all times and kept away from any sea life as it may contain harmful levels of bacteria or be poisonous.

If you believe someone has come into contact with a sea slug and they start to feel unwell call 111 for emergency assistance immediately.

If you believe a dog has licked or ingested a sea slug contact your vet immediately.

Back to News