A yellow-bellied sea snake has washed up alive on Ōhope Beach in the Bay of Plenty and DOC is warning beachgoers to keep their distance

A live yellow-bellied sea snake washed up on Ōhope Beach in the Bay of Plenty over the weekend, prompting the Department of Conservation to remind beachgoers to keep well clear of any sea snake they find on a New Zealand shore, dead or alive.

The animal was spotted on the sand by a member of the public on the morning of 4 May. DOC ranger and biodiversity project lead Pearson Tukua and his team identified the snake, removed it carefully from the beach and took it into care. Despite that intervention, the animal later died, according to reporting in the Bay of Plenty Times.

Yellow-bellied sea snakes are tropical and subtropical animals built for life in warm open ocean. They spend their entire lives at sea, and unlike land snakes they cannot crawl effectively on dry sand. Finding one stranded is almost always a sign that something has gone seriously wrong.

DOC marine senior science advisor Karen Middlemiss said the species was an occasional visitor to New Zealand. Sea snakes “were known to occasionally drift into New Zealand waters during weather events,” she said, and the cold conditions of New Zealand’s coastal waters were probably what proved fatal in this case. Yellow-bellied sea snakes that wash up here are often suspected of suffering from hypothermia, since the animal’s tropical biology is not built to cope with the temperatures around our coast.

She added that the species was not as dangerous to people as its reputation might suggest. Although the snakes are highly venomous, Middlemiss said they “only posed a risk if provoked,” and noted that New Zealand had “no recorded cases of anyone being bitten by a sea snake.”

That does not mean a beach encounter is harmless. A snake that looks lifeless can still bite reflexively, and even sluggish individuals will defend themselves if grabbed or stepped on. DOC’s standard advice is to keep well clear, keep dogs and children away, and ring the 0800 DOC HOT hotline so a ranger can respond. 1News reported the snake was found alive on Sunday morning before being collected.

The yellow-bellied sea snake, Hydrophis platurus, is the most widespread sea snake in the world, with a range stretching from the east coast of Africa across the Indian and Pacific oceans to the western coast of Central and South America. It spends almost all of its time drifting on warm-water currents, hunting small fish at the surface. It rarely chooses to come close to land in its natural range, and it does not lay eggs, giving birth to live young at sea instead.

In New Zealand waters these animals are vagrants rather than residents, swept south on warm currents and unable to thermoregulate once the water cools. Sightings tend to cluster on the west coast of the upper North Island and around the Bay of Plenty after periods of warm easterly or northerly weather. Auckland War Memorial Museum records show occasional confirmed sightings going back decades, but the species has never established a foothold on this side of the Tasman.

All sea snakes and kraits are protected in New Zealand under the Wildlife Act 1953. It is illegal to kill, harass, capture or possess any sea snake without a permit, even one that has already died of natural causes. DOC asks that any reports include the location, the time, and a photo if it can be taken safely.

Cold-stressed sea snakes rarely recover even with veterinary support, and the Ōhope carcass is now likely to be examined as part of DOC’s ongoing biodiversity monitoring. The data feeds into a longer record of marine wildlife strandings around the country, which over time can show whether species ranges are shifting, whether storms are pushing more tropical animals south, and whether warm-water visitors are turning up more often.

For people walking the beach this autumn, the practical takeaway is straightforward. If you see a striped, eel-shaped reptile with a flattened, paddle-like tail and a distinctive black-and-yellow body, do not pick it up, do not let your dog investigate it, and do not assume that a still-looking snake is dead. Step back, note the location, and call 0800 DOC HOT.

For now, the Ōhope find is being treated as a one-off reminder that even our cooler southern beaches occasionally serve up surprises from a long way north, and that the right response to a venomous visitor is to admire it from a safe distance and let the experts handle it.

Have you spotted unusual marine wildlife on a New Zealand beach? Share your encounter in the comments below.