Penguin population threatened by melting sea-ice in Antarctica

Verge of extinction

The situation is seemingly critical as the researchers emphasized that some regions experienced a 100 percent loss in sea ice concentration. This could lead to the extinction of more than 90 percent of emperor penguin colonies by the end of the century as global heating is accelerating at an alarming rate.

The BBC reported that up to 10,000 young birds were estimated to have perished due to the melting and breaking sea ice beneath them. This happened before they had the opportunity to develop waterproof feathers needed to swim in the ocean.

They concluded that the birds most likely drowned or met their demise by succumbing to freezing temperatures.

Since the emperor penguins rely on the sea ice for breeding, molting, or foraging, they faced the most profound impact rendered by abrupt reductions in sea ice extent. 

Dr. Peter Fretwell, from the British Antarctic Survey (BAS), told the BBC that the wipeout was a harbinger of things to come.

"Emperors depend on sea-ice for their breeding cycle; it's the stable platform they use to bring up their young. But if that ice is not as extensive as it should be or breaks up faster, these birds are in trouble," he said. "There is hope: we can cut our carbon emissions that are causing the warming. But if we don't we will drive these iconic, beautiful birds to the verge of extinction." 

Breeding ways

Alluding to the penguin’s breeding ways, they first arrive at their preferred spots in late March to April and lay eggs from May to June, the study said. “Eggs hatch after 65 days and chicks fledge during December and January.”

However, for the birds to breed, the land ice must remain stable until the process is completed between the months of April and January.

The research team observed the sea-ice fragmenting in November, which prevented thousands of chicks from fledging their feathers needed for swimming. 

The BBC further reported that four colonies endured breeding failure but the most northerly site – Rothschild Island had some success.

Record-low sea-ice

Despite scientists providing evidence of the reduction of Antarctic sea-ice and its critical consequence on the environment, the situation has not been reprimanded. 

The National Snow and Ice Data Center revealed earlier this year in February that the Antarctic sea ice extent fell to 737,000 square miles (1.91 million square kilometers), setting a new record low, dropping below the previous record of 741,000 square miles (1.92 million square kilometers) set on February 25, 2022. 

Dr. Caroline Holmes, an expert on Antarctic sea-ice alluded to the cause of the current penguin breeding decline and told the BBC that the ocean water becoming warmer around the continent and certain wind patterns played a role in the current circumstance. As seen in the case of the Bellingshausen, the winds pushed ice back towards the coast, making it difficult to spread.

"What we're seeing right now is so far outside what we've observed previously. We expected change but I don't think we expected so much change so rapidly," she said.

"Studies in the Arctic have suggested that if we could reverse climate warming somehow, the sea-ice in the polar north would recover. Whether that might also apply in the Antarctic, we don't know. But there's every reason to think that if it got cold enough, the sea-ice would reform."

Study abstract:

The spring season of 2022 saw record low sea ice extent in Antarctica that persisted throughout the year. At the beginning of December, the Antarctic sea ice extent was tracking with the all-time low set in 2021. The greatest regional negative anomaly of this low extent was in the central and eastern Bellingshausen Sea region, west of the Antarctic Peninsula where, during November, some regions experienced a 100% loss in sea ice concentration. We provide evidence of a regional breeding failure of emperor penguin colonies due to sea ice loss using Sentinel2 satellite imagery. Of the five breeding sites in the region all but one experienced total breeding failure after sea ice break-up before the start of the fledging period of the 2022 breeding season. This is the first recorded incident of a widespread breeding failure of emperor penguins that is clearly linked with large-scale contractions in sea ice extent.