There are two snake species that can be found in New Zealand: the yellow-bellied sea snake and the banded sea krait. These are both water snakes, and both snakes are poisonous.
Because the snakes are small in stature, they are not usually able to actually penetrate human skin in order to spread their poisonous venom. There are no land snakes in nearby Australia.
The snakes are not often seen in the area and there have been fewer than 35 sightings of the yellow-bellied sea snake from 1930 to 2015. The banded sea krait snake is also rarely seen.