This article was originally published in Herald Live and was awarded second place in the written content section of the Climate Media Awards, which were hosted by Scrolla.

The number of yellow-bellied sea snakes stranding on SA’s eastern shore has risen 620% since the previous highest number, and the culprit is likely climate change.

Bayworld herpetologist Dr Werner Conradie, who collected the latest arrival from Hobie Beach on Wednesday, said the upswing in stranding numbers was remarkable.

“This one today [Wednesday] is the 36th this year.

“Our previous annual high was five, which we had in 1992 and 2020.

“Since April this year, they have been coming ashore everywhere from KwaZulu-Natal to Cape Town, but the hotspot is here in the eastern and southern Cape.

“We have had 31 stranding between East London and Nature’s Valley.

“In the Nelson Mandela Bay area alone, we have had eight.

“Most have been dead but about 20% have been alive and we’ve been able to rehabilitate and release them.”

The Hobie Beach specimen, a 60cm-long male, is alive.

The snake was hydrating in a bucket of freshwater at Bayworld.

Conradie said the species occurred in the Pacific and Indian oceans, living its whole life in the deep sea.

It was especially plentiful in calm “slicks”, where it preyed on small fish and sipped freshwater that accumulated on floating vegetation and other debris, using sensory hairs in growths beneath its skin to detect changing salinity levels.

“They live in the warm water near the surface and my theory is that as climate change progresses and this warm surface water spreads further, the snakes are moving into areas where they didn’t previously occur.

“But climate change has also been bringing more severe weather, which separates this warm water into pockets, which sometimes then drift into colder water.

“The snakes are stunned by the cold and become lethargic and weak.

“They’re weakened further as they’re bashed by the waves and rocks close to shore, and then as they lie in the sun on the beach.”

Though the species is not a strong swimmer, it has a flattened tail which serves it well as it moves around the slicks, and its other party trick is it can swim backwards.

On land, it is like a “fish out of water” because its compressed shape makes it roll onto its side, and it can barely make any progress.

Conradie said people who came upon a yellow-bellied sea snake should not attempt to pick it up because, though there were no records of fatal bites, it was a member of the cobra family, and there was no antivenin available.

“If it is alive, throwing it back in the water will also not be a good idea because it will not be able to manage the waves, and it will likely just be thrown ashore again.

“The best is to call the stranding hotline and we will try collect it if possible.

“Please also keep your dogs away.”

He said he did not believe it would be dangerous to swimmers.

“In our waters it will likely be suffering from cold shock and, besides that, like most snakes, it is shy.

“It will not likely strike unless you try grab it and it feels threatened.”

He said he had done several postmortems on dead yellow-bellied sea snakes and their guts had on most occasions been empty.

“So this upswing in strandings could also relate to hunger and a decline in prey fish, a factor which we know is affecting the African penguin.

“But I think climate change and the warm water spread and cut-off phenomenon is the main reason.”

He said once the Hobie Beach specimen had defecated he would be examining the faeces under a microscope.

“I have discovered microplastics in the faeces of previous specimens so they obviously ingest this pollution as they feed.

“But how badly the species is affected by this issue is not yet clear.”

The Bayworld Stranding Hotline number is 071-724-2122.

Pictured above: Dr Werner Conradie with the yellow-bellied sea snake which stranded at Hobie Beach on Wednesday.

Source: Guy Rogers