Thousands of Emperor Penguin Chicks Die Due to Antarctic Ice Loss

Rapid global heating due to humans’ use of fossil fuels has contributed to an array of damaging environmental effects on the planet, including extreme weather, unprecedented ocean temperatures and a rapid decline in sea ice.

Sea ice is the habitat of several animal species, including polar bears, Arctic fox, caribou and emperor penguins, who live and breed entirely on frozen Antarctic sea ice.

According to a new study, thousands of emperor penguin chicks from four colonies in Antarctica are thought to have died due to record-low sea ice levels that caused a “catastrophic breeding failure.”

“Abrupt reductions in sea ice extent can have profound effects on ecosystems and the species that depend on the sea ice for breeding, moulting or foraging… Almost all emperor penguin colonies depend upon stable land-fast sea ice, which they use for breeding and moulting, while also using the marginal ice zone as a foraging habitat,” the study said.

The study, “Record low 2022 Antarctic sea ice led to catastrophic breeding failure of emperor penguins,” was published in the journal Communications Earth & Environment.

In the study, the researchers from British Antarctic Survey (BAS) said there was a high probability that none of the emperor penguin chicks from four out of five of the known colonies in the eastern and central parts of the Bellingshausen Sea had survived, a press release from BAS said.

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The scientists looked at satellite images showing sea ice loss at emperor penguin breeding sites long before the chicks would have had time to develop their waterproof feathers.

“They still have their downy plumage. If the ice breaks out before they can safely enter the water, the plumage becomes waterlogged and, basically, the chicks die of exposure,” said Dr. Barbara Wienecke, a senior research scientist at the Australian Antarctic Division who has paid many visits to emperor penguin colonies, as The Guardian reported. “It’s horrendous and I find it extraordinarily distressing to think of this happening.”

For the penguins in their large colonies to breed, the sea ice must be stable and firmly attached to shore from April to January, according to the press release. The penguins lay their eggs during the Antarctic winter of May to June, with eggs hatching after 65 days. Chicks fledge during the summer, from December to January.

Antarctic sea ice extent at the start of December of 2022 equaled the previous record low from 2021. The eastern and central Bellingshausen Sea area experienced the most extreme loss at 100 percent for November of 2022.

“We have never seen emperor penguins fail to breed, at this scale, in a single season. The loss of sea ice in this region during the Antarctic summer made it very unlikely that displaced chicks would survive,” said lead author of the study Dr. Peter Fretwell of BAS in the press release. “We know that emperor penguins are highly vulnerable in a warming climate – and current scientific evidence suggests that extreme sea ice loss events like this will become more frequent and widespread.”

Antarctica has experienced its lowest four years of sea ice extent in its 45-year satellite record since 2016. The two lowest years were 2021 to 2022 and 2022 to 2023. Thirty percent of the identified 62 Antarctic emperor penguin colonies were affected by sea ice loss from 2018 to 2022.

In the past, emperor penguins have responded to the loss of their sea ice habitat by changing to more stable locations the following year. However, according to scientists, that doesn’t work when the whole region is affected; there is simply nowhere for them to go.

Emperor penguins have never had to contend with threats such as large-scale hunting, overfishing or even habitat loss caused by humans. The only major threat considered to affect their long-term population is climate change.

Recent predictions of population trends for emperor penguins based on sea ice loss forecasts have shown that if current rates of warming continue, by the end of the century more than 90 percent of their colonies will become quasi-extinct.

“It’s only by changing our behaviour and the amounts of fossil fuels we use will we reverse the trajectory for these emperor penguins, and many other species,” Fretwell said, as reported by The Guardian.

Satellite images from the European Commission’s satellite mission Copernicus Sentinel-2 were used to discover the five penguin colonies studied in the past 14 years, the press release said. All of the colonies had returned to the same place each year for breeding, and there had only been one prior instance of breeding failure, in 2010 at Bryan Peninsula.

“This paper dramatically reveals the connection between sea ice loss and ecosystem annihilation. Climate change is melting sea ice at an alarming rate. It is likely to be absent from the Arctic in the 2030s – and in the Antarctic, the four lowest sea ice extents recorded have been since 2016,” said Dr. Jeremy Wilkinson, a BAS sea ice physicist, in the press release. “It is another warning sign for humanity that we cannot continue down this path, politicians must act to minimise the impact of climate change. There is no time left.”