The Auckland Regional Public Health Service is encouraging residents to be extra cautious on beaches as potentially fatal sea slugs return to shores.
The slugs are a common sight along North Shore beaches about this time of year, but the first confirmed sightings have been near the ferry terminal at Waiheke Island.
A number of dogs have been killed in previous years from the slugs, while many more have been made seriously ill due to poisoning.
Medical officer of Health Simon Baker says the slugs also pose a huge risk to young children.
Dr Baker says people should call the Auckland Council as soon as they see slugs on beaches.