Global warming is melting sea ice so fast that more than half of Antarctica's population of emperor penguins are set to be wiped out by the end of the century, according to alarming new research saying they should be listed as an endangered species.
Not a single one of Antarctica's 45 known colonies of emperor penguins will be immune to melting sea ice, with at least two-thirds likely to see their populations decline by more than half, the report warns.
"If sea ice declines at rates projected by the climate models and continues to influence emperor penguins as it did in the second half of the 20th century in Terre Adelie, none of the colonies, even the southern-most locations in the Ross Sea, will provide a viable refuge by the end of the 21st Century," warned lead author Dr Stephanie Jenouvrier.
She called for the emperor to be given "endangered species" status to help reduce the damage climate change is inflicting upon them.
The report acknowledges that such a classification would do nothing to save the sea-ice habitat of the species. However, it could prompt other actions that will help reduce the speed and magnitude of the population loss, the report argues.
These include identifying potential refuges - particularly in the Ross Sea, which is situated just below the South Pole and will be the last place impacted by climate change - and improving fishing practices to reduce the number accidentally caught in nets.
Emperor penguins routinely trek between 50 and 130 kilometres over the ice to catch and deliver krill, small crustaceans, and fish that are critical for their diet.
Photo / Thinkstock
"Too little ice reduces the habitat for krill," said Dr Jenouvrier, a biologist with the Woods Hole Oceanographic Institution (WHOI) in the US. "Too much ice requires longer trips for penguin parents to travel to the ocean to hunt and bring back food for their chicks," she said. Though she conceded that some colonies may actually benefit from the melting sea ice, Dr Jenouvrier said "this growth will be short-lived".
The report stems from a 50-year study of the Emperor penguin colony in Terre Adelie, in eastern Antartica, which has seen researchers returning every year to collect biological measurements of the penguins.
The latest study expands on that work by applying its findings to the 45 known colonies, some of which number thousands of penguins.
"Listing the emperor penguin as an endangered species would reflect the scientific assessment of the threats facing an important part of the Antarctic ecostystem under climate change," said Hal Caswell, a scientist emeritus at WHOI and professor at the University of Amsterdam. "When a species is at risk due to one factor - in this case, climate change - it can be helped, sometimes greatly, by amelioration of other factors. That's why the Endangered Species Act is written to protect an endangered species in a number of ways - exploitation, habitat, disturbance - even if those are not the cause of its current predicament," he added.
WHOI worked on the report with the Centre d'Etudes Bilologiques de Chiz? in France, the National Center for Atmospheric Research in the US, the University of Amsterdam and the Cooperative Institute for Research in Environmental Sciences in the US.
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- UK Independent