The obstacle meant the penguins faced a 37-mile walk just to get in the water.
An estimated 150,000 Adelie penguins have died in Antarctica after a giant iceberg blocked their main access to food, according to research.
Penguins in Cape Denison have been affected over a five-year period since the iceberg effectively acted as a blockade to the ocean.
The iceberg has forced the penguins to walk more than 37 miles in search of food, gradually reducing the population to just a few thousand.
The iceberg is about 60 miles wide and crashed in Commonwealth Bay in December 2010, blocking access to their natural feeding areas from then on.
The survey was conducted in 2013-14 by scientists at The Climate Change Research Centre at the University of New South Wales in Australia and New Zealand’s West Coast Penguin Trust.
The research was recently published in the journal Antarctic Science.