About 150,000 Adélie penguins, native to Cape Denison in Commonwealth Bay, Antarctica, have perished after their access to the sea — their source of food — was blocked by a giant iceberg which has inched up the bay for more than 20 years.
The mammoth iceberg got stuck in the bay after it ran into a glacier, according to Australian researchers at the University of New South Wales’ Climate Change Research Center in an article published in Antarctic Science.
Experts estimate that about 150,000 penguins of a colony of about 160,000 have died of starvation since the giant iceberg, named B09B, became lodged in the bay in December 2010, and trapped the birds on land permanently.
The colony of breeding penguins, living close to the sea in the Cape Denison region of the Antarctica, has been known to explorers for at least a century. They have lived in the area with easy access to the sea until 2010 when the massive iceberg, about 2900 square kilometers (1,100 square miles) — approximately the size of the city of Rome — entered the bay and got stuck in it as part of the adverse effects of ongoing climate change.
The iceberg blocked access to the sea and left the colony of penguins stranded, unable to gain access to the sea where they hunt for fish.
With iceberg B09B stuck in the Commonwealth Bay in East Antarctica, the only alternative access to the sea for the penguin colony involves a 60-kilometer trek. The arduous 60-kilometer journey to the sea — an ordeal for penguins that waddle clumsily on their feet — has had a disastrous impact on the colony.
More than 150,000, or about 93 percent, of the original population of 160,000 have perished, according to researchers.
Scientists predict that the colony would cease to exist in the next two decades if the giant iceberg remains lodged in the bay or fast ice within the bay fails to break up.
According to the researchers in the article published in Antarctic Science, “The arrival of iceberg B09B in Commonwealth Bay, East Antarctica, and subsequent fast ice expansion has dramatically increased the distance Adélie penguins breeding at Cape Denison must travel in search of food.”
“The Cape Denison population could be extirpated within 20 years unless B09B relocates or the now perennial fast ice within the bay breaks out,” the researchers added.
The researchers were able to confirm that the dwindling of the colony was due to the giant iceberg in the bay when they observed that another colony of Adelie penguins living only about eight kilometers away from the bay was thriving.
Chris Turney, a climate change expert with the Australasian Antarctic Expedition, who has been studying the penguin colony, told the Sydney Morning Herald that the colony is dying out because the penguins are trapped on land and unable to migrate.
“It’s eerily silent [there] now. The ones that we saw at Cape Denison were incredibly docile, lethargic, almost unaware of your existence,” Turney said. “The ones that are surviving are clearly struggling. They can barely survive themselves, let alone hatch the next generation. We saw lots of dead birds on the ground… it’s just heartbreaking to see.”
Adélie penguins (Pygoscelis adeliae), named after the wife of a French explorer who discovered the penguins in 1840, are a species found mostly along the Antarctic coast. Along with the emperor penguins, snow petrels, Wilson’s Storm petrels, and Antarctic petrels, they are among the most southerly distributed seabirds.
They are mid-sized for penguins, about 46 to 71 centimeters (18 to 28 inches) in height, and weigh about 3.6 to six kilograms (7.9 to 13.2 pounds).
They breed during the months of October to February, with both parents taking turns to incubate eggs for 32 to 34 days. Young chicks are raised on land and go out to sea after they are about 50 to 60 days old.
They feed on fish, mainly Antarctic krill, ice krill, sea krill, and Antarctic silverfish. They are in turn preyed upon by leopard seals, skua, and orcas.
[Image via Jason Auch/Wikimedia Commons]