Scientists estimate about 150,000 Adelie penguins have died on Antarctica’s Cape Denison in the five years since a vast iceberg changed the landscape of their home, removing their main access to food.

The journal Antarctic Science recently published a study stating that the B09B iceberg crashed with the Mertz Glacier Tongue, causing it to remain in Commonwealth Bay. This area normally has minimal sea ice, creating an ideal habitat for Adelie penguin colonies.

The iceberg is roughly 1,120 square miles in size, blocking access to the Adelie penguins’ natural feeding areas since the beginning of December 2010. The iceberg forced the penguins to walk more than 37 miles to search for food and a new breeding ground, reducing the population to a mere few thousand by 2013.

Adelie penguins are found throughout Antarctica and are well known for their tiny, “tuxedoed” appearance. They are highly sociable, often gathering in groups. Every October, the Adelie penguins build their nests of rocks on land near the open water.

It is estimated that only about 5,500 breeding pairs remain in the area, indicating a significant decline in their population based on estimates from a census and satellite images obtained in 1997. The report stated that “in December 2013, the impact of B09B on the penguins was considerably more dire than the census numbers alone would suggest. Hundreds of abandoned eggs were noted, and the ground was littered with the freeze-dried carcasses of previous season’s chicks.” The study was conducted in 2013-14 by scientists at the Climate Change Research Center at the University of New South Wales in Australia along with New Zealand’s West Coast Penguin Trust.

The direct impact from the iceberg on the Adelie penguin colony gives scientists insight into the negative effects of sea ice on the population. With the long-term environmental changes from climate change, this will have a direct impact on the habitats and food sources for the Adelie penguins. While changes in the population occur, scientists say it is important to keep perspective on the penguins’ population over a larger time frame.

Scientists are unclear how long it will take the Adelie penguins to recolonize the Commonwealth Bay area. They fear that without their natural breeding cycle or new members, the colony could die off completely in 20 years.

However, there is still hope for the Adelie penguin population — scientists have found a thriving colony just 5 miles from the Commonwealth Bay area.