These 7 sea-loving grandmothers are helping research an elusive venomous snake population.

For more than a decade, a pair of scientists had been researching the small and harmless turtle-headed sea snake (Emydocephalus annulatus) in the southwest Pacific's New Caledonia. Over the first eight years of the research, the had six sightings of another species, a five-foot long venomous creature known as the greater sea snake (Hydrophis major).

In 2013, the scientists – Dr Claire Goiran from the University of New Caledonia and Professor Rick Shine from Australia's Macquarie University – decided to take a closer look at the larger and lethal snake. But even when setting their sights on it, they only managed just 10 glimpses a year over the nest 36 months.

What to do? Call in the grandmas.

The inspiring group of citizen scientists is a group of seven snorkeling nonnas – all in their 60s and 70s, and all gorgeous – who call themselves the "the fantastic grandmothers." As recreational snorkelers in this popular swimming spot called Baie des citrons, they offered their assistance and the scientists took them up. Now, their photographs have added a wealth of information on the sea snake.

"The results have been astonishing," says Dr Goiran. "As soon as the grandmothers set to work, we realised that we had massively underestimated the abundance of greater sea snakes in the bay."

© Claire Goiran/UNC

In a paper published in the journal Ecosphere the scientists reveal that thanks to the fantastic seven, they were able to conclude that there are more than 249 of the snakes in the bay. A surprising number given the popularity of the spot.

"Remarkably," says Professor Shine, "they 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."

The scientists gleaned important new information about the snakes' breeding patterns and young; the body of research now comprises more knowledge than for any other related species on the planet, says Goiran.

© Claire Goiran/UNC

"I have been studying sea snakes in the Baie des Citrons for 20 years, and thought I understood them very well – but the Fantastic Grandmothers have shown me just how wrong I was," Goiran says.

"The incredible energy of the Grandmothers, and their intimate familiarity with 'my' study area, have transformed our understanding of the abundance and ecology of marine snakes in this system," she adds. "It's a great pleasure and privilege to work with them."

Revealing the world of lethal sea snakes, one fantastic grandmother at a time.

The study, "Grandmothers and deadly snakes: an unusual project in “citizen science,'" can be read here.