Antarctic emperor penguin colony loses 70% of chicks due to iceberg

Researchers reported that a giant iceberg about 14 km long became grounded near the Coulman Island emperor penguin colony in Antarctica. The obstruction forced adult penguins to travel a longer route—up to roughly 15 km instead of the usual 9 km—to reach open water for feeding during the June‑January breeding season.

The extended journey reduced feeding efficiency and led to a dramatic decline in chick survival. In the 2025 breeding season the colony recorded only about 6,658 chicks, roughly a two‑thirds (≈70 %) drop compared with the previous year and 69 % fewer than the long‑term average.

The findings were published by a South‑Korean research team led by Jeong‑Hoon Kim of the Korean Polar Research Institute in the journal Communications Earth & Environment, highlighting how iceberg positioning can directly impact penguin reproductive success.