16 Nov 2022

Highly venomous sea snake found in Auckland's Viaduct Harbour

5:36 am on 16 November 2022
A banded sea snake raises to the sea surface.

A banded sea snake raises to the sea surface. Photo: AFP

A lost and highly venomous sea snake was found in Auckland's Viaduct Harbour yesterday afternoon after it was swept away from the Pacific.

The banded sea snake is a rare sight in Aotearoa, but is still considered a native species as it naturally arrives in our waters via ocean currents.

Department of Conservation spokesperson Clinton Duffy said snakes showed up on New Zealand's shores once or twice a year, but this case was particularly unusual.

"Banded sea snakes aren't oceanic species, they generally live close to shore," he said. "This one's obviously been swept away by ocean currents."

The department's policy was to let it be. "They're a protected species," he said. "You're not allowed to harm them or harass them, and they're highly venomous, so the best course of action is to just leave them alone."

Duffy said the snake was especially venomous, perfect for hunting fish. "They have a very, very powerful neurotoxin," he said. "They are extremely venomous, more venomous than a cobra, so you don't want to be bitten by one."

But the likelihood of being bitten was extremely low, due to the species' unique biology and chilled-out attitude.

"Their fangs are tiny and mounted in the back of their jaw," he said. "You'd actually have to work very hard to get bitten by one, they really have to work for it."

Although he had never seen one in New Zealand, Duffy said he had encountered them before. "I've dived with them in the tropics," he said. "They're not aggressive at all."

As rare as sea snakes were, Duffy said they could become a regular visitor. "We might start to see snakes [in the water] more frequently," he said. "It's possible that as the water warms up and they're able to survive better on it, we may see less washing up on the beach."

But it'll be a long time before snakes can thrive in New Zealand. Duffy said the banded snake seen yesterday was unlikely to survive.

"It's been swept away from its normal habitat, there's very little chance it'll be able to make it back there alive," he said. "It may survive the summer but as water temperatures drop it'll probably die."

He said holidaymakers were very unlikely to encounter a snake, but reiterated one bit of advice if they did: "leave them alone".

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