Venomous sea snakes suffering from ‘cold shock’ wash up on SA beaches

In the past year, six venomous yellow-­bellied sea snakes have washed up on beaches in the Eastern Cape and along the Garden Route.

Brett Glasby, the marine wildlife programme management coordinator for the Two Oceans Aquarium Foundation, said seeing these snakes is rare and he has never spotted one himself, except when he was called out to help where one was found.

“It is not a common thing for them to wash up. They like warm water and we find them in the Agulhas current mostly,” Glasby said.

But, he added, strong sea currents and bad weather sometimes push these snakes into cold currents where they sustain “cold shock” and are not able to swim further.

“I only know of a handful that have washed up in the last few years. I was lucky to rescue one. They don’t do well in captivity so I have released it again,” Glasby said. “If you see one you are very lucky. It is a rare event.”

If anybody spots a sea snake on the beach, it should be treated with respect and it is best to notify the nearest aquarium. Glasby said neither humans nor dogs should approach it.

“It would be the worst thing for the snake to put it back in the water. You will sign its death warrant if you put it back in the water,” he added.

When the aquarium gets one of these snakes, the staff have to warm it up very slowly over a few days to treat the cold shock.

“Normally, they will also be very dehydrated. They can’t process salt when they wash up so we bathe them in fresh water,” he added.

Glasby also emphasised that these are venomous snakes and their neurotoxic venom can be lethal. “Keep your distance from it,” he advised.

The yellow-bellied sea snakes grow about 1m long and can get fairly thick as they age.

“It is an open-ocean species. Unlike other sea snakes, it doesn’t live in a coral reef. It lives in the open ocean. They rest just underneath the flotsam and prey on other fish seeking shelter,” he said.

“I have had more people see puffadders and cobras in the sea than sea snakes,” he added. “These are not aggressive snakes.”

Cold shock spike

Glasby said the aquarium has had to treat more than 500 turtle hatchlings for cold shock this year.

Gqeberha-based herpetologist Dr Werner Conradie said there are more snakes than usual washing up on the beach but they are not uncommon.

He said the strong sea currents and storm surges owing to bad weather sometimes wash up these creatures.

Two were found on beaches in Nature’s Valley and Keurboomstrand, one at Kenton-on-Sea, one each at King’s Beach and Maitlands in Gqeberha, and one in Jeffreys Bay.

They are poisonous, Conradie added, but only one fatality caused by this species has been recorded worldwide.

“They have a potent venom that paralyses their prey,” he said.

Steve Meighan, chairperson of the Western Cape Herpetological Association, said these yellow-bellied sea snakes wash up now and again.

“They come in on the warmer currents or if they are sick. It is important not to approach them and to contact an expert to remove them,” he said.

The snake is from the cobra family and so it is important not to touch it or try to help it get back in the water because no antivenin exists for its bite.

“Weather certainly plays a role when they wash up,” Meighan said. DM

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