In picturesque Lemon Bay in the New Caledonia capital of Noumea, a group of retirees has helped marine biologists uncover a whole new understanding of the area’s sea snake population. The group of women, in their 60s and 70s, meet every morning and swim up to 1.8 miles (3 km), cameras in hand, to help identify and record sea snakes. We joined them for a snorkel on a recent dive trip to New Caledonia, and interviewed the marine biologist leading the research project, Dr. Clair Goiran.
Goiran, a marine biologist at the University of New Caledonia, initially a coral specialist, switched her studies to sea snakes after meeting Rick Shine from Sydney University, who came to New Caledonia to study sea snakes in 2002.
“Lemon Bay is a very good place for studying sea snakes because there are lots here and it helps us understand how they react to the urbanization of the reef,” she says. “You see, it’s in town, so it’s a reef that is transformed by human influence, by pollution, by every action we take. So, it’s interesting for us to understand how the snakes have responded to the changing environment.”
Is there a particularly interesting species?
“There are eight different species of sea snakes in this bay, but we study only two,” says Goiran. “The first one is the turtle-headed sea snake, which is a little black one you would see while diving here. This one is not venomous, and we have been studying it for 15 years. This is the longest study of any sea snake population because it’s very convenient, very easy to access.
“And then, we started studying another, much larger venomous species, Hydrophis major or ‘greater sea snake.’ Initially thought to live here in very small numbers, the study’s first objective was to determine the population size. These snakes have unique markings on the side of the body, so we take photos of each one for photo identification. For this we need lots of information, lots of people in the water taking photos.”
New Caledonia grannies offer help
And this is where the grannies come in — many hands make lighter work of the project. With their help, Goiran has discovered that there are a lot more snakes in this small bay than researchers originally thought.
The team quickly learned how to identify each of Noumea’s 14 species and can also identify (and have named) individual snakes, using the unique markings on the sides of their bodies just behind the head.
“When I was shooting the turtle-headed sea snake on my own, I used to see one greater sea snake a month,” says Goiran. “Now with the grannies’ help, we’ve identified 257 different individuals, so the population was completely underestimated. The snakes are very discreet — you can swim by them and if they are maybe 10 feet (3 m) away you won’t notice they are there. It’s wonderful to have volunteers help us and to now know that the population of snakes is doing so well.”
So, how did this group of ‘Fantastic Grannies’ get together? The group grew organically, with little to no recruitment, just a shared love of the local marine environment.
The first to join the project, a friend of Goiran’s, was snorkeling and taking photos for the sheer love of it. She knew her friend was interested in sea snakes, so started emailing her photos whenever she spotted one.
Another volunteer was swimming on her own and she saw this group of ladies having fun so asked if she could join the group. Not all of them knew each other before but have become friends while working on this project.
The team started surveying sea snakes in 2017 and plans to keep going as long as they are useful. At first, the volunteers were afraid of the sea snakes, but have come to understand that they are not dangerous and eager to let others know this.