Loss of sea ice in Antarctica causes ‘breeding failure’ for emperor penguins
Leading scientists are warning that the world’s changing climate is hitting Antarctica’s wildlife hard – as the region continues to experience a loss of sea ice.
Reports from the British Antarctica Survey highlight how emperor penguins are failing to breed across several colonies due to the decrease. They add that their findings are ‘probably a sign of things to come.’
‘All our predictions of sea ice and emperor populations suggest that this will get a lot worse,’ explains lead author Peter Fretwell who is a researcher at the British Antarctica Survey.
‘How bad depends on whether we can slow or halt our greenhouse gas emission. This was the second year of breeding failure at several of these sites. This year, 2023, is likely to be even worse looking at the current sea ice extent.’
The report authors say its findings show the first major breeding failure for these animals on a regional scale which is being caused by the loss of sea ice.
‘Although emperor penguins are a long lived species, continued breeding failure is like to drive the overall adult population down over time as new recruits to the breeding population fail to show up.’
‘Whether this area remains untenable is unclear, but sea-ice models suggest that over time we will lose ice from many areas of Antarctica, so this is consistent with our models.’
‘This is consistent with our population models which estimate that, due to sea ice loss the overall population of the species will reduce rapidly over the coming decades.’
‘Recent scientific estimates say 90% of emperor colonies will be quasi-extinct by the end of the century.’
Sea ice retreats forces migration
The team explain colonies may continue to try to breed at the same location for several years – but add that if sea ice continues to retreat then the animals will be forced to move away from their normal habitats.
‘Even as a scientist it is very depressing seeing these changes. We have been predicting it for some time, but actually seeing it happening is grim.’
‘I have been to a couple of international conferences over the last month and spoken to several emperor penguin scientists and the feeling about the future for the species is quite bleak.’
The team points to one area of Antarctica which has seen a 100% loss in sea ice concentration.
An adult Emperor Penguin. Image: P Bucktrout and British Antarctic Survey.
The report explains explain that ‘abrupt reductions’ in sea ice can have ‘profound effects on ecosystems and the species that depend on the sea ice for breeding, moulting or foraging.’
They used satellite imagery to pinpoint areas where emperor penguin colonies were facing substantial problems – with the majority of sites experiencing a ‘total breeding failure.’
Experts say that the majority of emperor penguin colonies depend on stable ice areas between April to January to ensure a successful breeding season.
Their location means they have been large safe from the effects of direct human activity, such as hunting or overfishing. Scientists believe climate change is the ‘only major driver of their long-term population change.’
Climate change driving long term population trajectory
‘When sea ice breaks up the consequences for unfledged emperor penguin can be terminal,’ explains Peter. ‘The ice will break up, sometimes disintegrating, sometimes breaking into floes which float away.’
‘For the chicks that go into the water they will drown, if they are immersed but managed to get back out of the water they will most likely freeze to death if they have not got their waterproof feathers.’
‘I saw this happen in 2010 when a freak early rainstorm hit snow hill emperor penguin colony, hundreds of chicks got wet and froze to death as there wet feather could not keep them warm.’
‘Even if they manage to say on the bergs the assumption is that most of them will drift away and starve as the parents will not be able to find them.’
‘The only hope is if the chick have developed enough of their waterproof feathers to swim and keep themselves warm, but this won’t happen until early-to-mid December.’
The scientists explain that climate change is the only factor at the moment which is driving the long term population trajectory for emperor penguin. The team will continue its studies and scientists aim to monitor the region for further developments.