Emperor penguins have suffered their first “widespread breeding failure” due to record low Antarctic sea ice, reinforcing projections the species will be virtually extinct by 2100, scientists have said.
Last year the cover of sea ice around Antarctica – ice floating on the sea surface, on which emperor penguins rely to hatch and rear their chicks – dropped to its lowest ever cover.
The ice is usually stable between about April until the end of December, with chicks fledging around mid to late December.
But when it breaks up early, thought to be due to warmer seas, chicks likely drown or freeze to death because they have not yet grown their waterproof feathers or are not ready to fledge.
Emperor penguins only live in Antarctica, which is completely dark during winter, with temperatures plummeting as low as -50C.
In the Bellingshausen Sea, all sea ice had gone by November last year, well before the chicks would have developed waterproof feathers, meaning they would have drowned or frozen to death.
In four out of five colonies in that region, it is likely no chicks survived, according to a paper published on Thursday in the journal Communications Earth & Environment.
Lead author of the study, Dr Peter Fretwell, from British Antarctic Survey, called it “catastrophic”.
“We have never seen emperor penguins fail to breed, at this scale, in a single season,” he said.
His team tracked the colonies with satellite imagery, which picked up the stains of penguin faeces on the bright white ice surface.
He called the largest of the penguin species a “window” into Antarctica, whose white surface cools the world by reflecting the sun’s heat, and whose currents influence weather patterns elsewhere.
Pic: Christopher Walton/BAS
Pic: Richard Burt/BAS
“By reducing the sea ice, we will change the world’s weather in many places, and we’re not sure what the consequences [will be],” he told Sky News.
Emperor penguins ‘heading towards extinction’
But the authors believe many more colonies failed to breed last year.
After they submitted their paper, they found nine further colonies elsewhere in Antarctica whose chicks had likely all died, and more where only some would have survived.
In total they think 19 of Antarctica’s 62 colonies, totalling 30%, lost all or many chicks last year because the sea ice disappeared.
Dr Fretwell told Sky News 2021 was a bad year, 2022 was worse, and “it looks like 2023 is going to be even worse”.
Pic: Peter Fretwell/BAS
Pic: Peter Fretwell/BAS
“We’re waiting until the sun comes up in September for Antarctica, and we’re watching with some trepidation to see what the consequences of this sea ice year is,” he said.
The scientists said it is difficult to link specific extreme seasons to climate change, but they expect a longer-term drop in sea ice cover as the climate warms.
Their study adds to a growing body of work that projects that around 90% of emperor penguin colonies will be quasi-extinct by the end of the century.
Though the species will still exist, their numbers will have fallen below a critical threshold needed to survive, including because they need large numbers to huddle together for warmth.
Rod Downie, chief adviser on polar regions at wildlife charity WWF, said: “Emperor penguins are heading towards extinction unless we act now.”
This year Antarctica has lost a “shocking one million square miles of sea ice” compared with the average, he said.
He added he has “not witnessed anything like this before” in 16 years of working in the region.
Urgent action to limit average global temperature rise and protection for Antarctic waters is vital, he said.
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