A recent study reveals that deaths of emperor penguin chicks surged in four West Antarctic colonies due to record-low sea ice. This alarming trend aligns with forecasts of 98% of colonies becoming 'quasi-extinct' by 2100, imperiling viable populations. Lead author Peter Fretwell notes unprecedented breeding failure due to reduced sea ice, posing dire survival prospects for displaced chicks.
Sea Ice Loss Led to Mass Die-Off of Penguin Chicks for the First Time
Emperor penguins (Aptenodytes forsteri) rely on stable, frozen sea ice along the shore for survival and breeding. Mating in Antarctic winter, chicks hatch after 65 days, covered in down until November when they grow waterproof feathers, depending on balanced sea ice conditions and parental care.
Stéphanie Jenouvrier, a seabird ecologist and associate scientist at the Woods Hole Oceanographic Institution in Massachusetts, pointed out that excessive sea ice results in lengthy and challenging foraging trips for parents, potentially leading to chick starvation. Conversely, insufficient sea ice increases the risk of chick drowning.
Scientists track emperor penguins by observing their excrement, or guano, which creates brown marks on the icy terrain visible from outer space. Satellite pictures spanning 14 years have uncovered proof of five relatively minor colonies that consistently revisit specific sites in the Bellingshausen Sea area in Western Antarctica for their breeding activities.
In a research article, titled "Record Low 2022 Antarctic Sea Ice Led to Catastrophic Breeding Failure of Emperor Penguins" published
in the journal Communications Earth and Environment, scientists analyzed satellite photographs of this area and concluded that, most likely, four out of these five colonies experienced the loss of all their chicks this year owing to decreasing sea ice.
Recent years have seen the lowest sea ice levels in 45 years of satellite monitoring, with pronounced declines in the central and eastern Bellingshausen Sea, culminating in complete ice disappearance by November 2022. Notably, a record low occurred in June, a period when Antarctic sea ice typically grows, hinting at a potential ongoing decrease.
The study's researchers warned of substantial consequences if this pattern persists, especially for emperor penguins, already deemed threatened on the U.S. endangered species list.
Researchers wrote in their paper that this mass mortality of emperor penguin chicks due to regional sea ice loss marks the first instance of such an event, revealing a significant connection between adverse sea ice conditions and breeding failures, suggesting implications for a warming Antarctica in the future.
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Climate Change Exacerbates Extreme Weather Conditions
El Niño as well as other atmospherix and oceanic variations may have led to the fluctuations in sea ice levels in Antarctica, but the significant decline in recent times might be attributable to climate change.
Persistently low levels of sea ice not only negatively impact Antarctic wildlife but also pose a threat to the region's increasingly fragile glaciers, with potential global repercussions including rising sea levels and disrupted ocean currents that enhance the planet's susceptibility to additional warming.
The research reveals that, in response to specific sea ice reduction, emperor penguins adapt by relocating to more secure breeding areas the subsequent year. However, the scientists caution that this approach will become unfeasible if substantial portions of their icy environment vanish in the upcoming decades.
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