The Aldabra banded snail Rhachistia aldabrae declined through the late twentieth century, leading to its extinction in the late 1990s, before this sudden reappearance. |
A snail once thought to
have been among the first species to go extinct because of climate change has
reappeared in the wild, AP reports.
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 reemergence.
"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 Aldabra coral atoll — a UNESCO World
Heritage Site
|
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.
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