Health authorities have lifted their warning on people going to beaches in the Hauraki Gulf.
The Auckland Regional Public Health Service (ARPHS) lifted the warning today but recommended people take extra care.
The warning was put in place last month after marine life and dogs were found dead at Narrowneckand Cheltenham beaches.
Approximately 15 dogs from a wide geographic area within the Hauraki Gulf became unwell with symptoms consistent with tetrodotoxin (ttx) poisoning. Five of the dogs died.
Although the warning was lifted, children and pets should be supervised at beaches at all times and should not be allowed to eat anything found at them, ARPHS clinical director Julia Peters said.
Parents needed to be aware of where their children were swimming or playing and what they were handling.
Anyone going to the beach should take care not to touch any sea life, dead or alive, found on the beach.
Sea slugs on any beach must be avoided, and shellfish should not be collected from beaches because of the potential for contamination.
Medical attention should be sought immediately if anyone became seriously unwell after going to the beach.
The toxin was known to be a potent poison found in tropical puffer fish but not previously found in sea slugs. It was extremely toxic to humans and even a very small dose could be fatal.
"There is still a lot of uncertainty and the origin of the ttx in the sea slugs is unknown. We also do not know whether sea slugs can clear ttx from their systems, or if this is a one off or a recurrent, localised or generalised event," Dr Peters said.
"While no humans have been affected to date, people have taken care to treat our warnings seriously and many have been staying away from the beaches."
ARPHS would continue to update its public health advice as new information became available.
