Tens of thousands of Antarctic penguin chicks could starve because an iceberg is blocking their parents' access to coastal feeding grounds, officials say.
Some penguin colonies face sharp decline, scientists warn
Adelie penguins on Cape Royds face a 180-km (112-mile) round trip in the coming weeks to bring food to chicks, New Zealand government scientists say.
This means that most of the chicks will probably die, though the colony will almost certainly survive, they add.
The scientists say the iceberg is the biggest floating object in the world.
The 3,000 sq-km (1,200 sq-mile) giant, known as B-15A, could also block sea access to three science stations in the area, according to Antarctica New Zealand agency head Lou Sanson.
He said about 3,000 breeding pairs of Adelie penguins were now facing a long and arduous round journey to bring food to chicks at their nesting grounds at Cape Royds.
"So by the time a penguin comes in from the ice edge on a return... walk, they've used all the food," Mr Sanson told the Associated Press news agency.
"Penguin researchers are predicting that the annual hatching is pretty certain to fail," he added.
The scientists also fear that another penguin colony - at nearby Cape Bird - could be affected by the B-15A.
They said the iceberg had already locked up the ice flows from McMurdo Sound, as it was moving at a speed of 2km a day (1.2 miles).