Thousands of young emperor penguin chicks drowned in the Weddell Sea in 2016 when the sea ice on which they were being raised was destroyed during stormy weather. Since then, the colony - which was located at the edge of the Brunt Ice Shelf - has shown no sign of reestablishing itself.
The tragic loss of the Halley Bay colony was reported by a team from the British Antarctic Survey (BAS), who noticed the disappearance using satellite pictures.
Thousands of chicks drowned in the Weddell Sea in 2016. Credit: PA
Dr Peter Fretwell and Dr Phil Trathan said the colony - which for decades was comprised of between 14,000 and 25,000 breeding pairs - appeared to disappear overnight. It is thought that the chicks had not yet developed the right feathers to swim following the breaking of the sea ice.
Speaking to the BBC, Dr Fretwell said: "The sea ice that's formed since 2016 hasn't been as strong. Storm events that occur in October and November will now blow it out early. So there's been some sort of regime change. Sea ice that was previously stable and reliable is now just untenable."
The BAS team believe that since the catastrophic loss of life in 2016, adults have either moved to new areas or packed in breeding all together.
It's not clear why the sea ice on the edge of the Brunt Ice Shelf hasn't properly reformed since 2016, but Dr Trathan said it could be an 'important signal' of what's to come.
The sea ice hasn't properly reformed since the storm in 2016. Credit: PA
Speaking to the BBC, he said: "What's interesting for me is not that colonies move or that we can have major breeding failures - we know that. It's that we are talking here about the deep embayment of the Weddell Sea, which is potentially one of the climate change refugia for those cold-adapted species like emperor penguins.
"And so if we see major disturbances in these refugia - where we haven't previously seen changes in 60 years - that's an important signal."
However, it is possible that the colony would have been doomed to perish anyway, as the Brunt Ice Shelf is gradually being split apart by a huge crack, which could shatter the sea ice in the area.
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Featured Image Credit: PA