It's a common misconception that New Zealand has no snakes, but it's not the truth. Marine snakes, or sea snakes, are seen regularly in the waters around northern New Zealand when warm subtropical currents carry them south from out of the tropics.
Far from home
In their natural, tropical habitats these snakes are supremely adapted to a life hunting small fish and other vertebrates in tropical seas where they can dive to 60 metres. However New Zealand's colder waters are not an ideal sea snake habitat and most will perish as a result of their journey south.
Of approximately 62 species known worldwide, four species of sea snake have been observed in our waters thought two occur as only single observations. Most commonly observed are the yellow-bellied sea snake - Pelamis platurus, and the rarer yellow-lipped sea krait - Laticauda colubrina, sometimes known as the banded sea krait.
Yellow-bellied sea snake
The yellow-bellied sea-snake is widely distributed across the tropical Pacific and Indian Oceans, where it lives a fully aquatic existence. They drink sea water and even give birth to live young at sea. The yellow-bellied sea-snakes grow up to 90 cm long and are distinctly bi-coloured with black above and yellow or brown on below.
There are at least 62 records of the species in New Zealand, all during the warmer summer season. The first yellow-bellied sea snake was recorded in 1837 and it has been found widely around the North Island.
Yellow-lipped sea krait
Unlike the yellow-bellied sea snake, the yellow-lipped, or banded, sea krait (Māori name Neke) is an inshore feeder. It spends substantial time ashore, making use of the cover of mangroves, leaf litter, and holes in trees and the ground for moulting and laying its eggs (up to 20!).
The species grows up to 1.5 m long, has a dark and pale-ringed body with 40 dark rings and yellow snout and lips. There are only six known records of this species in New Zealand, first recorded in 1880 and later found at Castlepoint, Whangaruru Harobur, Ohope Beach, Northland and the Bay of Plenty.
A beautiful, protected and dangerous species
Sea snakes cannot breed in New Zealand's cool waters and most of these beautiful creatures that reach Aotearoa will unfortunately die from cold shock. However sea snakes are considered a native species under the Wildlife Act 1953 and it is illegal to kill or harass a sea snake, or possess one or any part of one without a permit.
Most importantly, although they are peaceful creatures, the types of sea snake that reach New Zealand represent some of the most venomous snakes in the world. Their venom contains a neurotoxin that can cause death by respiratory and cardiovascular collapse. Good enough reason to never pick up a live specimen. Admire from a distance and contact someone from the Department of Conservation instead!
Auckland War Memorial Museum. NZ Marine Field Guide. [Mobile application software]. Retrieved from https://www.aucklandmuseum.com/collections-research/collections/remix-play-share/nz-marine-life-app
Gill, B. and Whitaker, T. (1996). New Zealand Frogs and Reptiles. David Bateman, Auckland.
Jewell, T. (2008). A Photographic Guide to Reptiles and Amphibians of New Zealand. New Holland Publishers, Auckland.
Cite this article
Rayner, Matt and Dix, Kelly.
Sea snakes and kraits in New Zealand. Auckland War Memorial Museum - Tāmaki Paenga Hira. First published: 24 November 2015. Updated: 12 November 2019.