sea snake carried to NZ on warm ocean currents
- Size
- Length: 80–120 cm
- Lifespan
- 5–10 years
- Diet
- Carnivorous. Feeds on small fish and eels. Sit-and-wait hunter drifting among mats of floating seaweed in open ocean environments.
- Habitat
- Open ocean and coastal waters of tropical and subtropical regions. Pelagic, rarely coming to land. Occasionally washed up on beaches after storms.
- Range
- Worldwide. Found in tropical and subtropical waters of Indian and Pacific Oceans. Occasionally visits New Zealand waters, particularly in north.
- Endemism
- Native
- Main Threats
- None significant in New Zealand waters. Rare visitor. Global threats include bycatch in fisheries, marine pollution, and climate change.
- Population
- Not Threatened. Venomous marine snake occasionally visiting New Zealand waters from Pacific. Not established. Individuals are rare visitors.
- Conservation Status
- Not Threatened
- Human Risk
- venomous
- Handling Note
- highly venomous sea snake, rarely seen in NZ waters do not touch if found
- Conservation Note
- Native marine reptile; not assessed by NZTCS as marine reptiles are outside the scope of current threat classifications.
- Te Ao Māori
- The Tuatete is a creature of the deep blue horizon. Rarely seen by those who stay on land. In Māori tradition, sea snakes were often grouped with other serpentine beings of ocean. Sometimes viewed as minor taniwha or messengers from distant tropical homelands of Hawaiki. Because they only appear on our shores after massive storms or unusual current shifts, their arrival was often seen as sign of upheaval. A stranger from north bringing word of distant weather. Today, they are a source of great excitement on coastal community Facebook pages.
It is the ultimate uninvited guest of the New Zealand summer. Hydrophis platurus is strikingly beautiful. With a jet-black back and a vibrant lemon-yellow underside. Separated by a sharp, clean line. Their tail is flattened into a paddle. Shaped exactly like an oar. Making them incredibly efficient swimmers in the open ocean. But leaving them almost entirely helpless and floppy if they wash up on the sand. If you find one on a beach in Northland or the Bay of Plenty, it is not there for a holiday. It is likely hypothermic, exhausted, and wondering why the warm current it was following suddenly turned into a fridge.
Biologically, these are highly specialised predators of the blue water. They spend their entire lives at sea. Never needing to touch land to breed or drink. They have evolved a salt gland under their tongue to excrete excess salt from the seawater. And they give birth to live young while floating in the open ocean. They are sit-and-wait hunters. Often found drifting among mats of floating seaweed. Where they wait for small fish to seek shelter beneath them. When a fish gets close, the snake strikes with lightning speed. While they are technically highly venomous. Possessing a potent neurotoxin designed to paralyse fish. They are generally very docile towards humans. Most bites only occur when a well-meaning person tries to pick one up to save it.
In New Zealand, the Yellow-Bellied Sea Snake is a victim of its own curiosity. As our ocean temperatures rise due to climate change, we are seeing more of these tropical drifters reaching our shores. However, they cannot survive a New Zealand winter. Once the water drops below 18°C, their metabolism slows to a crawl. And they eventually perish. If you find one, the official advice is: Do not touch. Not because they are aggressive. But because they are legally protected, highly venomous, and likely in a state of extreme stress. Call the Department of Conservation. Let the professionals handle the tourist who took a very wrong turn at Fiji.