Communications Earth & Environment, 24 August 2023
Researchers have confirmed that an extremely early Antarctic sea ice breakup led to the catastrophic die-off of emperor penguin chicks in the last breeding season, in November 2022. The event, which killed up to 10,000 young birds, is the highest rate of emperor penguin breeding failure ever recorded. The sea ice underneath the chicks broke apart before they could develop the waterproof feathers needed to swim, causing them to drown or freeze to death. Since 2016, Antarctic sea ice extent has undergone a significant decline: the years 2021/22 and 2022/23 have experienced the lowest sea ice extents observed since observations began 45 years ago. Currently, an area of sea ice the size of Greenland is missing from this periphery of the Antarctic Ice Sheet. In the Bellingshausen Sea of West Antarctica where the penguin study focussed, many regions have experienced a 100% loss in sea ice cover. With more than 90% of emperor penguin colonies predicted to be extinct by the end of the century because of current fossil fuel warming, only rapid emissions cuts can safeguard this iconic species.