150,000 Antarctica penguins die after giant iceberg traps colony

Sydney: Scientists said some 150,000 Adelie penguins living in Antarctica have died after a massive iceberg - the size of a major city - grounded their colony, forcing them to trek long distance for food.

The huge iceberg dubbed 'B09B' measuring about 100 square kilometres (38.6 square miles), became trapped in Commonwealth Bay in East Antarctica in December 2010.

Since then, the penguins have been forced to make a round trip of 120km for food, said researchers from the University of New South Wales' (UNSW) Climate Change Research Centre and New Zealand's West Coast Penguin Trust.

In February 2011, the Adelie penguin population at the bay's Cape Denison was measured to be about 160,000, but by December 2013 it had plunged to an estimated 10,000, researchers said.

Writing in the Antarctic Science journal, researchers said that the growth in Antarctic sea ice is largely driven by changes in wind and local conditions.

"The Cape Denison population could be extirpated within 20 years unless B09B relocates or the now perennial fast ice within the bay breaks out," they wrote.

During their census in December 2013, the researchers said "hundreds of abandoned eggs were noted, and the ground was littered with the freeze-dried carcasses of previous season's chicks".

"It's eerily silent now," UNSW's Chris Turney, who led the 2013 expedition, was quoted as saying to the Sydney Morning Herald on Friday.

"The ones that we saw at Cape Denison were incredibly docile, lethargic, almost unaware of your existence.

"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."

In contrast, penguins living on the eastern fringe of the bay just eight kilometres from the fast ice edge were thriving, the scientists said.

The researchers said the study had "important implications" for the wider East Antarctic if the current trend of increasing sea ice continued.

Sea ice around Antarctica is increasing, in contrast to the Arctic where global warming is causing ice to melt and glaciers to shrink.

Fast ice is sea ice which forms and stays fast along the coast.

(With AFP inputs)