Climate change could cause more than 90% of emperor penguin colonies to disappear from Antarctica

Sudden reductions in volume Sea ice It can have profound effects on Ecosystems And the species that depend on it for reproduction, molting, or feeding. One of these is emperor penguinAptenodet Foresteri)Which depend on these vast frozen areas at all stages of their life cycle.

Almost all emperor penguin colonies depend on stable, stable sea ice, which they use for breeding and molting, while also using the marginal ice zone as foraging habitat. They arrive at their preferred breeding grounds between late March and April and lay eggs from May to June, until they hatch 65 days later and the chicks fledge between December and January.

So, The ground ice on which the entire process depends must remain stable between April and January to ensure successful reproduction.

Now, a study published in Earth and Environment Communications Emperor penguin colonies have experienced unprecedented reproductive failure in a region of Antarctica, where complete loss of sea ice has occurred in 2022, warns. The discovery supports predictions that More than 90% of emperor penguin colonies will be nearly extinct by the end of the century, according to current global statistics.

British researchers in the Antarctic Survey The researchers analyzed the high probability that no chicks would survive in four of five emperor penguin colonies Known in the central and eastern Bellingshausen Sea. They examined satellite images showing the loss of sea ice at breeding sites, long before the chicks developed waterproof feathers.

By early December 2022, the extent of Antarctic sea ice had equaled the previous record low set in 2021. The maximum loss was observed in the central and eastern Bellingshausen Sea, west of the Antarctic Peninsula. There was a 100% loss in November 2022.

Emperor penguins have never been known to fail to reproduce on this scale in a single season.. The loss of sea ice in this region during the Antarctic summer made it unlikely that displaced chicks would survive. We know that emperor penguins are very vulnerable in warm climates, and current scientific evidence suggests so Extreme sea ice loss events like these will become more frequent and widespread.

Since 2016, Antarctica has had the four years with the lowest extent of sea ice in the 45-year satellite record, with the two lowest seasons in 2021/22 and 2022/23. Between 2018 and 2022, 30% of Antarctica’s 62 known emperor penguin colonies will be affected by partial or complete loss of sea ice. Although it is difficult to immediately link specific extreme seasons to climate change, A long-term decline in sea ice extent is expected from the current generation of climate models.

Emperor penguins have previously responded to incidents of sea ice loss by moving to more stable locations the following year. However, this strategy will not work if the sea ice habitat of the entire region is affected.

These groups have never experienced widespread hunting, habitat loss, poaching, or other local human interactions in modern times. Unusually for these types of vertebrates, climate change is the cause The only important factor affecting long-term population change.

Recent efforts to forecast emperor penguin population trends through sea ice loss projections have painted a bleak picture, suggesting that if current rates of warming continue, More than 90% of colonies will be on the verge of extinction by the end of this century.

The five penguin colonies studied in the past 14 years have been discovered using satellite images: Rothschild Island, Verde Inlet, Smiley Island, Bryan Peninsula and Frogner Point. All five colonies have been shown to return to the same site each year to reproduce, with only one previous case of reproductive failure on the Bryan Peninsula in 2010.

Scientists now routinely use satellite images to detect and monitor the colonies, where the brown spots in the guano stand out clearly against the pure white of ice and snow. The team used images from the European Commission’s Copernicus Sentinel-2 satellite mission, which has been monitoring the Antarctic region continuously since 2018.

*Peter Fretwell, lead author of the study, is an award-winning cartographer and senior scientist at the British Antarctic Survey. He pioneered the use of satellite imagery to find and monitor Arctic wildlife, a project that led him to discover nearly half of the world’s emperor penguin colonies. He is a Fellow of the Royal Geographical Society and has completed four field seasons in Antarctica.