Endangered Species: Iceberg Threatens Emperor Penguin Colony's Survival

An iceberg's unfortunate placement has severely impacted a colony of emperor penguins, leading to a drastic reduction in breeding success. Researchers observed that the number of chicks in the Coulman Island colony plummeted by approximately 69% by the end of 2025 compared to the previous year. This decline is significantly lower than the average observed between 2017 and 2024.

The crisis unfolded when a nearly 14-kilometer-long iceberg grounded itself on the seabed just north of the colony in late July. This timing was particularly detrimental, coinciding with the hatching of penguin chicks. Emperor penguins rely on stable sea ice for raising their young and require easy access to the open sea for foraging. The grounded iceberg obstructed this vital route, forcing adult penguins to travel an estimated 15 kilometers round trip instead of the usual 9 kilometers to reach open water and find food.

Scientists from the Korean Polar Research Institute suspect that the increased travel distance consumed vital energy and time for the parent penguins. This likely resulted in delayed food delivery to the chicks, many of whom did not survive. The presence of several dead young penguins at the site further supports this theory. While previous research focused on large-scale sea ice changes, this study highlights how even a single iceberg can disrupt breeding success, even when broader sea ice conditions appear favorable.

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While the sea ice conditions as a whole appear favorable, individual icebergs can also affect a colony's breeding success.