News that doesn't receive the necessary attention.

Tuesday, September 9, 2014

Unsettled science. Snail once thought extinct due to man caused global warming is rediscovered by scientists at UNESCO World Heritage site-AP

9/8/14, "Seychelles snail, thought extinct due to climate change, still alive," AP via Detroit News, 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."...
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." via Rush Limbaugh


3/30/14, "UN climate body backtracks on risk of species extinction," Toronto Star, by Raveena Aulakh

"Scientists with the Intergovernmental Panel on Climate Change seem to have quietly backpedalled on the risk of species extinction. 

In its last assessment report in 2007, the IPCC said humans had shrunk the habitats of many life forms and it predicted that 20 to 30 per cent of all animal and plant species faced a high risk for extinction if average global temperatures rose by 2 to 3 degrees Celsius. 

The UN climate body now says it is no longer as certain. 
In the new report, scientists say “forecasts of very high extinction rates due entirely to climate change may be overestimated.”

While scientists agree that the risk of species extinction will increase due to climate change,there is low agreement concerning the fraction of species at increased risk, the regional and taxonomic distribution of such extinctions and the time frame over which extinctions could occur.”

Hence, this new assessment does not include concrete figures about the percentage of species that could become extinct due to global warming."... 


Global cooling caused mass extinctions in the past:

"99.9 percent of all species that have existed on Earth are extinct."

"Many species vanished in five cataclysmic mass extinctions and today, 99.9 percent of all species that have existed on Earth are extinct.

The Ordovician-Silurian extinction occurred about 439 million years ago due to a drop in sea levels as glaciers formed followed by rising sea levels as glaciers melted. During this extinction 25 percent of marine families and 60 percent of marine genera (the classification above species) were lost.

The Late Devonian extinction took place somewhere around 364 million years ago. To this day its cause is unknown. However, evidence supporting the Devonian mass extinction suggesting that warm water marine species were the most severely affected in this extinction event, has lead many paleontologists to believe that an episode of global cooling, similar to the event which that may have resulted in the Ordovician-Silurian mass extinction, may have lead to the Devonian extinction. Thus this theory suggests that the extinction of the Devonian was triggered by another glaciation event on Gondwana, which is evidenced by glacial deposits of this age in northern Brazil.

Similarly to the late Ordovician crisis, agents such as global cooling and widespread lowering of sea-level may have triggered the late Devonian crisis. Scientists have also suggested that meteorite impacts may have been possible agents for the Devonian mass extinction, but the data in support of a possible extra-terrestrial impact remains inconclusive, and the mechanisms responsible for the Devonian mass extinction are still under debate. What is known, however, is that this mass extinction killed 22 percent of marine families and 57 percent of marine genera."...



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