Seychelles snail, thought extinct due to climate change, still alive

Associated Press

Nairobi, Kenya — A snail once thought to have been among the first species to go extinct because of climate change has reappeared in the wild.

The Aldabra banded snail, declared extinct seven years ago, was rediscovered on Aug. 23 in the Indian Ocean island nation of Seychelles. The mollusk, which is endemic to the Aldabra coral atoll — a UNESCO World Heritage Site — had not been seen on the islands since 1997, said the Seychelles Islands Foundation.

Conservationists are celebrating the banded snail’s re-emergence.

“Could we live without this little snail? Almost certainly,” said Stuart Pimm, a conservation ecology professor at Duke University. “But we simply do not know what species are going to do for us in an economic sense. Probably from the time that somebody baked the first loaf of bread, a housewife said, ‘I hate bread mold and I wish it would disappear forever.’ And of course we know the scientific name of bread mold is penicillin.”

A research team from the Seychelles Islands Foundation found seven of the purple-and-pink striped snails on Aldabra atoll’s Malabar Island last week. Shane Brice, a junior skipper on the voyage, made the initial discovery.

“I was so surprised; no one (on the expedition) had ever seen the snail before,” Brice said. “It’s quite amazing.”

Catherina Onezia, a senior ranger and assistant training officer for the foundation, said the team was “going crazy” with excitement over the finding.

“It shows that Aldabra has a lot of secrets still, and hopefully (we) will continue to find interesting things,” Onezia said.

Mollusk experts Vincent Florens and Pat Matyot confirmed the discovery after analyzing the discovery team’s photos. Florens, an associate professor of ecology at the University of Mauritius, told The Associated Press the Aldabra banded snail was “the only possible identification,” citing the snail’s distinctive shell pattern and locality.

The snail faces many pressures in Aldabra atoll. The coral islands grew atop an extinct volcano in the Indian Ocean. The isolated atoll, which also is home to the largest population of giant tortoises in the world, provides opportunities to study evolution and biodiversity. Conservationists are unsure how a terrestrial snail like the Aldabra banded snail initially reached these hot, dry islands surrounded by saltwater without drying out.

Onezia said her team will increase expedition efforts on Malabar Island to study the snails.

The snail’s apparent demise was linked to declining rainfall on Aldabra, and was widely considered to be among the first species whose extinction could be directly tied to global warming, said biologist Justin Gerlach, a scientific coordinator for the Nature Protection Trust of Seychelles.

The once-plentiful snail’s population declined exponentially between 1970 and 1990, and the last juvenile snail was found in 1976. The Seychelles Islands Foundation said the discovery of some juvenile snails is encouraging, as they are believed to be particularly vulnerable to desiccation because of reduced rainfall.

“Only time will tell if they can survive the threats of climate change and sea level rise,” Gerlach said.