A sea slug deadly to dogs and humans, particularly young children, found at Tauranga Bridge Marina has sparked a warning from a local marine expert.

Professor Chris Battershill, the director of the Coastal Marine Field Centre in Tauranga, said due to warmer weather these toxic slugs can sometimes lose their grip from rocks in shallow tidal areas and end up being washed on to the shoreline.

"One of the toxic Grey side-gilled Pleurobranchaea maculata sea slugs which looks like a little grey mouse, but with a sting in its tail, was found at the Bridge Marina last week," he said.

Battershill said the slugs were deadly because their skin contained the toxin Tetrodotoxin (TTX) which was the same toxin as the puffer fish.


"There have been cases where dogs had died after licking them or swallowing them and they can also be deadly to humans, especially young children," he said.

Battershill said sea slugs were common marine animals all across New Zealand, particularly in marine precinct areas but the Grey side-gilled sea slug had been linked to deaths of dogs.

Research was under way to determine the cause of the toxin in these slugs, both by Dr Kaden Leonard and the Cawthron Institute, he said.

Battershill's advice to anyone touching them was to immediately wash their hands thoroughly and alert the marine field centre and seek medical advice.

Symptoms in humans of TTX poisoning include numbness and tingling around the mouth.

Nausea and paralysis can also occur, medical attention should be sought immediately.

Dog owners should ensure they keep their dogs on a leash and parents should keep a close eye on their children playing on the beach, he said.

Some other facts about the Grey side-gilled sea slug:

Scientific name: Pleurobranchea maculata; Translucent grey body, its mantile is covered with minute puckers and folds, with branched papillae on its oral veil; Size ranges up to 100mm in length; Found from low tide to 250m; Commonly in summer and autumn. The largest species can be found in the South Island.


Source: NIWA