Snakes alive – and rather abundant

Looking for unique retirement plans? How does snorkelling with venomous sea snakes sound?

That’s exactly what seven women aged in their 60s and 70s have been doing as part of a unique citizen science project in New Caledonia. 

Scientists Claire Goiran, from the University of New Caledonia, and Rick Shine, from Australia’s Macquarie University, have been documenting the sea snake population in the waters off Noumea for more than 15 years, focusing on a small harmless species known as the turtle‐headed sea snake (Emydocephalus annulatus).

They have also caught occasional glimpses of the larger – and venomous – greater sea snake (Hydrophis major), but had no idea of how many there were until the group dubbed the “Fantastic Grandmothers” got involved.

They volunteered to take cameras with them when they hit the water at the popular swimming spot Baie des Citrons, and the results, says Goiran, have been astonishing. 

“As soon as the grandmothers set to work, we realised that we had massively underestimated the abundance of greater sea snakes in the bay.”

In fact, as they report in a paper published in the journal Ecosphere, they now know there are more than 249 of them in that one bay – and the photographs taken have provided new information about their breeding habits and number of young.

The citizen scientists were not at all fazed by getting close to venomous sea snakes – but that is perhaps not surprising. 

“[T]hey found a large number of lethally toxic sea snakes in a small bay that is occupied every day by hordes of local residents and cruise‐ship passengers, yet no bites by the species have ever been recorded at Baie des Citrons, testifying to their benevolent disposition,” says Shine.